diff options
Diffstat (limited to 'src/core/ipv4')
| -rw-r--r-- | src/core/ipv4/acd.c | 557 | ||||
| -rw-r--r-- | src/core/ipv4/autoip.c | 379 | ||||
| -rw-r--r-- | src/core/ipv4/dhcp.c | 1999 | ||||
| -rw-r--r-- | src/core/ipv4/etharp.c | 1251 | ||||
| -rw-r--r-- | src/core/ipv4/icmp.c | 407 | ||||
| -rw-r--r-- | src/core/ipv4/igmp.c | 801 | ||||
| -rw-r--r-- | src/core/ipv4/ip4.c | 1166 | ||||
| -rw-r--r-- | src/core/ipv4/ip4_addr.c | 323 | ||||
| -rw-r--r-- | src/core/ipv4/ip4_frag.c | 894 |
9 files changed, 7777 insertions, 0 deletions
diff --git a/src/core/ipv4/acd.c b/src/core/ipv4/acd.c new file mode 100644 index 00000000000..2c7d867caf3 --- /dev/null +++ b/src/core/ipv4/acd.c @@ -0,0 +1,557 @@ +/** + * @file + * + * ACD IPv4 Address Conflict Detection + * + * This is an IPv4 address conflict detection implementation for the lwIP TCP/IP + * stack. It aims to be conform to RFC5227. + * + * @defgroup acd ACD + * @ingroup ip4 + * ACD related functions + * USAGE: + * + * define @ref LWIP_ACD 1 in your lwipopts.h + * Options: + * ACD_TMR_INTERVAL msecs, + * I recommend a value of 100. The value must divide 1000 with a remainder almost 0. + * Possible values are 1000, 500, 333, 250, 200, 166, 142, 125, 111, 100 .... + * + * For fixed IP: + * - call acd_start after selecting an IP address. The caller will be informed + * on conflict status via the callback function. + * + * With AUTOIP: + * - will be called from the autoip module. No extra's needed. + * + * With DHCP: + * - enable LWIP_DHCP_DOES_ACD_CHECK. Then it will be called from the dhcp module. + * No extra's needed. + */ + +/* + * + * Copyright (c) 2007 Dominik Spies <kontakt@dspies.de> + * Copyright (c) 2018 Jasper Verschueren <jasper.verschueren@apart-audio.com> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT + * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * Author: Jasper Verschueren <jasper.verschueren@apart-audio.com> + * Author: Dominik Spies <kontakt@dspies.de> + */ + +#include "lwip/opt.h" + +/* don't build if not configured for use in lwipopts.h */ +#if LWIP_IPV4 && LWIP_ACD + +#include <string.h> + +#include "lwip/acd.h" +#include "lwip/prot/acd.h" + +#define ACD_FOREACH(acd, acd_list) for ((acd) = acd_list; (acd) != NULL; (acd) = (acd)->next) + +#define ACD_TICKS_PER_SECOND (1000 / ACD_TMR_INTERVAL) + +/* Define good random function (LWIP_RAND) in lwipopts.h */ +#ifdef LWIP_RAND +#define LWIP_ACD_RAND(netif, acd) LWIP_RAND() +#else /* LWIP_RAND */ +#ifdef LWIP_AUTOIP_RAND +#include "lwip/autoip.h" +#define LWIP_ACD_RAND(netif, acd) LWIP_AUTOIP_RAND(netif) /* for backwards compatibility */ +#else +#define LWIP_ACD_RAND(netif, acd) ((((u32_t)((netif->hwaddr[5]) & 0xff) << 24) | \ + ((u32_t)((netif->hwaddr[3]) & 0xff) << 16) | \ + ((u32_t)((netif->hwaddr[2]) & 0xff) << 8) | \ + ((u32_t)((netif->hwaddr[4]) & 0xff))) + \ + (acd->sent_num)) +#endif /* LWIP_AUTOIP_RAND */ +#endif /* LWIP_RAND */ + + +#define ACD_RANDOM_PROBE_WAIT(netif, acd) (LWIP_ACD_RAND(netif, acd) % \ + (PROBE_WAIT * ACD_TICKS_PER_SECOND)) + +#define ACD_RANDOM_PROBE_INTERVAL(netif, acd) ((LWIP_ACD_RAND(netif, acd) % \ + ((PROBE_MAX - PROBE_MIN) * ACD_TICKS_PER_SECOND)) + \ + (PROBE_MIN * ACD_TICKS_PER_SECOND )) + +/* Function definitions */ +static void acd_restart(struct netif *netif, struct acd *acd); +static void acd_handle_arp_conflict(struct netif *netif, struct acd *acd); +static void acd_put_in_passive_mode(struct netif *netif, struct acd *acd); + +/** + * @ingroup acd + * Add ACD client to the client list and initialize callback function + * + * @param netif network interface on which to start the acd + * client + * @param acd acd module to be added to the list + * @param acd_conflict_callback callback to be called when conflict information + * is available + */ +err_t +acd_add(struct netif *netif, struct acd *acd, + acd_conflict_callback_t acd_conflict_callback) +{ + struct acd *acd2; + + /* Set callback */ + LWIP_ASSERT_CORE_LOCKED(); + LWIP_ASSERT("acd_conflict_callback != NULL", acd_conflict_callback != NULL); + acd->acd_conflict_callback = acd_conflict_callback; + + /* Check if the acd struct is already added */ + for (acd2 = netif->acd_list; acd2 != NULL; acd2 = acd2->next) { + if (acd2 == acd) { + LWIP_DEBUGF(ACD_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, + ("acd_add(): acd already added to list\n")); + return ERR_OK; + } + } + + /* add acd struct to the list */ + acd->next = netif->acd_list; + netif->acd_list = acd; + + return ERR_OK; +} + +/** + * @ingroup acd + * Remvoe ACD client from the client list + * + * @param netif network interface from which to remove the acd client + * @param acd acd module to be removed from the list + */ +void +acd_remove(struct netif *netif, struct acd *acd) +{ + struct acd *acd2, *prev = NULL; + + LWIP_ASSERT_CORE_LOCKED(); + + for (acd2 = netif->acd_list; acd2 != NULL; acd2 = acd2->next) { + if (acd2 == acd) { + if (prev) { + prev->next = acd->next; + } else { + netif->acd_list = acd->next; + } + return; + } + prev = acd2; + } + LWIP_ASSERT(("acd_remove(): acd not on list\n"), 0); +} + + +/** + * @ingroup acd + * Start ACD client + * + * @param netif network interface on which to start the acd client + * @param acd acd module to start + * @param ipaddr ip address to perform acd on + */ +err_t +acd_start(struct netif *netif, struct acd *acd, ip4_addr_t ipaddr) +{ + err_t result = ERR_OK; + + LWIP_UNUSED_ARG(netif); + LWIP_DEBUGF(ACD_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, + ("acd_start(netif=%p) %c%c%"U16_F"\n", + (void *)netif, netif->name[0], + netif->name[1], (u16_t)netif->num)); + + /* init probing state */ + acd->sent_num = 0; + acd->lastconflict = 0; + ip4_addr_copy(acd->ipaddr, ipaddr); + acd->state = ACD_STATE_PROBE_WAIT; + + acd->ttw = (u16_t)(ACD_RANDOM_PROBE_WAIT(netif, acd)); + + return result; +} + +/** + * @ingroup acd + * Stop ACD client + * + * @param acd acd module to stop + */ +err_t +acd_stop(struct acd *acd) +{ + LWIP_DEBUGF(ACD_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("acd_stop\n")); + + if (acd != NULL) { + acd->state = ACD_STATE_OFF; + } + return ERR_OK; +} + +/** + * @ingroup acd + * Inform the ACD modules when the link goes down + * + * @param netif network interface on which to inform the ACD clients + */ +void +acd_network_changed_link_down(struct netif *netif) +{ + struct acd *acd; + /* loop over the acd's*/ + ACD_FOREACH(acd, netif->acd_list) { + acd_stop(acd); + } +} + +/** + * Has to be called in loop every ACD_TMR_INTERVAL milliseconds + */ +void +acd_tmr(void) +{ + struct netif *netif; + struct acd *acd; + /* loop through netif's */ + NETIF_FOREACH(netif) { + ACD_FOREACH(acd, netif->acd_list) { + if (acd->lastconflict > 0) { + acd->lastconflict--; + } + + LWIP_DEBUGF(ACD_DEBUG | LWIP_DBG_TRACE, + ("acd_tmr() ACD-State: %"U16_F", ttw=%"U16_F"\n", + (u16_t)(acd->state), acd->ttw)); + + if (acd->ttw > 0) { + acd->ttw--; + } + + switch (acd->state) { + case ACD_STATE_PROBE_WAIT: + case ACD_STATE_PROBING: + if (acd->ttw == 0) { + acd->state = ACD_STATE_PROBING; + etharp_acd_probe(netif, &acd->ipaddr); + LWIP_DEBUGF(ACD_DEBUG | LWIP_DBG_TRACE, + ("acd_tmr() PROBING Sent Probe\n")); + acd->sent_num++; + if (acd->sent_num >= PROBE_NUM) { + /* Switch to ANNOUNCE_WAIT: last probe is sent*/ + acd->state = ACD_STATE_ANNOUNCE_WAIT; + + acd->sent_num = 0; + + /* calculate time to wait before announcing */ + acd->ttw = (u16_t)(ANNOUNCE_WAIT * ACD_TICKS_PER_SECOND); + } else { + /* calculate time to wait to next probe */ + acd->ttw = (u16_t)(ACD_RANDOM_PROBE_INTERVAL(netif, acd)); + } + } + break; + + case ACD_STATE_ANNOUNCE_WAIT: + case ACD_STATE_ANNOUNCING: + if (acd->ttw == 0) { + if (acd->sent_num == 0) { + acd->state = ACD_STATE_ANNOUNCING; + + /* reset conflict count to ensure fast re-probing after announcing */ + acd->num_conflicts = 0; + + LWIP_DEBUGF(ACD_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, + ("acd_tmr(): changing state to ANNOUNCING: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n", + ip4_addr1_16(&acd->ipaddr), ip4_addr2_16(&acd->ipaddr), + ip4_addr3_16(&acd->ipaddr), ip4_addr4_16(&acd->ipaddr))); + } + + etharp_acd_announce(netif, &acd->ipaddr); + LWIP_DEBUGF(ACD_DEBUG | LWIP_DBG_TRACE, + ("acd_tmr() ANNOUNCING Sent Announce\n")); + acd->ttw = ANNOUNCE_INTERVAL * ACD_TICKS_PER_SECOND; + acd->sent_num++; + + if (acd->sent_num >= ANNOUNCE_NUM) { + acd->state = ACD_STATE_ONGOING; + acd->sent_num = 0; + acd->ttw = 0; + LWIP_DEBUGF(ACD_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, + ("acd_tmr(): changing state to ONGOING: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n", + ip4_addr1_16(&acd->ipaddr), ip4_addr2_16(&acd->ipaddr), + ip4_addr3_16(&acd->ipaddr), ip4_addr4_16(&acd->ipaddr))); + + /* finally, let acd user know that the address is good and can be used */ + acd->acd_conflict_callback(netif, ACD_IP_OK); + } + } + break; + + case ACD_STATE_RATE_LIMIT: + if (acd->ttw == 0) { + /* acd should be stopped because ipaddr isn't valid any more */ + acd_stop(acd); + /* let the acd user (after rate limit interval) know that their is + * a conflict detected. So it can restart the address acquiring + * process.*/ + acd->acd_conflict_callback(netif, ACD_RESTART_CLIENT); + } + break; + + default: + /* nothing to do in other states */ + break; + } + } + } +} + +/** + * Restarts the acd module + * + * The number of conflicts is increased and the upper layer is informed. + */ +static void +acd_restart(struct netif *netif, struct acd *acd) +{ + /* increase conflict counter. */ + acd->num_conflicts++; + + /* Decline the address */ + acd->acd_conflict_callback(netif, ACD_DECLINE); + + /* if we tried more then MAX_CONFLICTS we must limit our rate for + * acquiring and probing addresses. compliant to RFC 5227 Section 2.1.1 */ + if (acd->num_conflicts >= MAX_CONFLICTS) { + acd->state = ACD_STATE_RATE_LIMIT; + acd->ttw = (u16_t)(RATE_LIMIT_INTERVAL * ACD_TICKS_PER_SECOND); + LWIP_DEBUGF(ACD_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING, + ("acd_restart(): rate limiting initiated. too many conflicts\n")); + } + else { + /* acd should be stopped because ipaddr isn't valid any more */ + acd_stop(acd); + /* let the acd user know right away that their is a conflict detected. + * So it can restart the address acquiring process. */ + acd->acd_conflict_callback(netif, ACD_RESTART_CLIENT); + } +} + +/** + * Handles every incoming ARP Packet, called by etharp_input(). + * + * @param netif network interface to use for acd processing + * @param hdr Incoming ARP packet + */ +void +acd_arp_reply(struct netif *netif, struct etharp_hdr *hdr) +{ + struct acd *acd; + ip4_addr_t sipaddr, dipaddr; + struct eth_addr netifaddr; + SMEMCPY(netifaddr.addr, netif->hwaddr, ETH_HWADDR_LEN); + + /* Copy struct ip4_addr_wordaligned to aligned ip4_addr, to support + * compilers without structure packing (not using structure copy which + * breaks strict-aliasing rules). + */ + IPADDR_WORDALIGNED_COPY_TO_IP4_ADDR_T(&sipaddr, &hdr->sipaddr); + IPADDR_WORDALIGNED_COPY_TO_IP4_ADDR_T(&dipaddr, &hdr->dipaddr); + + LWIP_DEBUGF(ACD_DEBUG | LWIP_DBG_TRACE, ("acd_arp_reply()\n")); + + /* loop over the acd's*/ + ACD_FOREACH(acd, netif->acd_list) { + switch(acd->state) { + case ACD_STATE_OFF: + case ACD_STATE_RATE_LIMIT: + default: + /* do nothing */ + break; + + case ACD_STATE_PROBE_WAIT: + case ACD_STATE_PROBING: + case ACD_STATE_ANNOUNCE_WAIT: + /* RFC 5227 Section 2.1.1: + * from beginning to after ANNOUNCE_WAIT seconds we have a conflict if + * ip.src == ipaddr (someone is already using the address) + * OR + * ip.dst == ipaddr && hw.src != own hwaddr (someone else is probing it) + */ + if ((ip4_addr_eq(&sipaddr, &acd->ipaddr)) || + (ip4_addr_isany_val(sipaddr) && + ip4_addr_eq(&dipaddr, &acd->ipaddr) && + !eth_addr_eq(&netifaddr, &hdr->shwaddr))) { + LWIP_DEBUGF(ACD_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING, + ("acd_arp_reply(): Probe Conflict detected\n")); + acd_restart(netif, acd); + } + break; + + case ACD_STATE_ANNOUNCING: + case ACD_STATE_ONGOING: + case ACD_STATE_PASSIVE_ONGOING: + /* RFC 5227 Section 2.4: + * in any state we have a conflict if + * ip.src == ipaddr && hw.src != own hwaddr (someone is using our address) + */ + if (ip4_addr_eq(&sipaddr, &acd->ipaddr) && + !eth_addr_eq(&netifaddr, &hdr->shwaddr)) { + LWIP_DEBUGF(ACD_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING, + ("acd_arp_reply(): Conflicting ARP-Packet detected\n")); + acd_handle_arp_conflict(netif, acd); + } + break; + } + } +} + +/** + * Handle a IP address conflict after an ARP conflict detection + */ +static void +acd_handle_arp_conflict(struct netif *netif, struct acd *acd) +{ + /* RFC5227, 2.4 "Ongoing Address Conflict Detection and Address Defense" + allows three options where: + a) means retreat on the first conflict, + b) allows to keep an already configured address when having only one + conflict in DEFEND_INTERVAL seconds and + c) the host will not give up it's address and defend it indefinitely + + We use option b) when the acd module represents the netif address, since it + helps to improve the chance that one of the two conflicting hosts may be + able to retain its address. while we are flexible enough to help network + performance + + We use option a) when the acd module does not represent the netif address, + since we cannot have the acd module announcing or restarting. This + situation occurs for the LL acd module when a routable address is used on + the netif but the LL address is still open in the background. */ + + if (acd->state == ACD_STATE_PASSIVE_ONGOING) { + /* Immediately back off on a conflict. */ + LWIP_DEBUGF(ACD_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, + ("acd_handle_arp_conflict(): conflict when we are in passive mode -> back off\n")); + acd_stop(acd); + acd->acd_conflict_callback(netif, ACD_DECLINE); + } + else { + if (acd->lastconflict > 0) { + /* retreat, there was a conflicting ARP in the last DEFEND_INTERVAL seconds */ + LWIP_DEBUGF(ACD_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, + ("acd_handle_arp_conflict(): conflict within DEFEND_INTERVAL -> retreating\n")); + + /* Active TCP sessions are aborted when removing the ip address but a bad + * connection was inevitable anyway with conflicting hosts */ + acd_restart(netif, acd); + } else { + LWIP_DEBUGF(ACD_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, + ("acd_handle_arp_conflict(): we are defending, send ARP Announce\n")); + etharp_acd_announce(netif, &acd->ipaddr); + acd->lastconflict = DEFEND_INTERVAL * ACD_TICKS_PER_SECOND; + } + } +} + +/** + * Put the acd module in passive ongoing conflict detection. + */ +static void +acd_put_in_passive_mode(struct netif *netif, struct acd *acd) +{ + switch(acd->state) { + case ACD_STATE_OFF: + case ACD_STATE_PASSIVE_ONGOING: + default: + /* do nothing */ + break; + + case ACD_STATE_PROBE_WAIT: + case ACD_STATE_PROBING: + case ACD_STATE_ANNOUNCE_WAIT: + case ACD_STATE_RATE_LIMIT: + acd_stop(acd); + acd->acd_conflict_callback(netif, ACD_DECLINE); + break; + + case ACD_STATE_ANNOUNCING: + case ACD_STATE_ONGOING: + acd->state = ACD_STATE_PASSIVE_ONGOING; + LWIP_DEBUGF(ACD_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, + ("acd_put_in_passive_mode()\n")); + break; + } +} + +/** + * @ingroup acd + * Inform the ACD modules of address changes + * + * @param netif network interface on which the address is changing + * @param old_addr old ip address + * @param new_addr new ip address + */ +void +acd_netif_ip_addr_changed(struct netif *netif, const ip_addr_t *old_addr, + const ip_addr_t *new_addr) +{ + struct acd *acd; + + LWIP_DEBUGF(ACD_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, + ("acd_netif_ip_addr_changed(): Address changed\n")); + + LWIP_DEBUGF(ACD_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, + ("acd_netif_ip_addr_changed(): old address = %s\n", ipaddr_ntoa(old_addr))); + LWIP_DEBUGF(ACD_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, + ("acd_netif_ip_addr_changed(): new address = %s\n", ipaddr_ntoa(new_addr))); + + /* If we change from ANY to an IP or from an IP to ANY we do nothing */ + if (ip_addr_isany(old_addr) || ip_addr_isany(new_addr)) { + return; + } + + ACD_FOREACH(acd, netif->acd_list) { + /* Find ACD module of old address */ + if(ip4_addr_eq(&acd->ipaddr, ip_2_ip4(old_addr))) { + /* Did we change from a LL address to a routable address? */ + if (ip_addr_islinklocal(old_addr) && !ip_addr_islinklocal(new_addr)) { + LWIP_DEBUGF(ACD_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, + ("acd_netif_ip_addr_changed(): changed from LL to routable address\n")); + /* Put the module in passive conflict detection mode */ + acd_put_in_passive_mode(netif, acd); + } + } + } +} + +#endif /* LWIP_IPV4 && LWIP_ACD */ diff --git a/src/core/ipv4/autoip.c b/src/core/ipv4/autoip.c new file mode 100644 index 00000000000..461a005338f --- /dev/null +++ b/src/core/ipv4/autoip.c @@ -0,0 +1,379 @@ +/** + * @file + * AutoIP Automatic LinkLocal IP Configuration + * + * This is a AutoIP implementation for the lwIP TCP/IP stack. It aims to conform + * with RFC 3927. It uses IPv4 address conflict detection to evaluate the chosen + * address. The ACD module aims to be conform to RFC 5227. + * RFC 5227 is extracted out of RFC 3927 so the acd module fits nicely in autoip. + * + * @defgroup autoip AUTOIP + * @ingroup ip4 + * AUTOIP related functions + * USAGE: + * + * define @ref LWIP_AUTOIP 1 in your lwipopts.h + * + * Without DHCP: + * - Call autoip_start() after netif_add(). + * + * With DHCP: + * - define @ref LWIP_DHCP_AUTOIP_COOP 1 in your lwipopts.h. + * - Configure your DHCP Client. + * + * @see netifapi_autoip + */ + +/* + * + * Copyright (c) 2007 Dominik Spies <kontakt@dspies.de> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT + * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * Author: Dominik Spies <kontakt@dspies.de> + */ + +#include "lwip/opt.h" + +#if LWIP_IPV4 && LWIP_AUTOIP /* don't build if not configured for use in lwipopts.h */ + +#include "lwip/mem.h" +/* #include "lwip/udp.h" */ +#include "lwip/ip_addr.h" +#include "lwip/netif.h" +#include "lwip/autoip.h" +#include "lwip/acd.h" +#include "lwip/etharp.h" +#include "lwip/prot/autoip.h" + +#include <string.h> + +/** + * Macro that generates the initial IP address to be tried by AUTOIP. + * If you want to override this, define it to something else in lwipopts.h. + */ +#ifndef LWIP_AUTOIP_CREATE_SEED_ADDR +#define LWIP_AUTOIP_CREATE_SEED_ADDR(netif) \ + lwip_htonl(AUTOIP_RANGE_START + ((u32_t)(((u8_t)(netif->hwaddr[4])) | \ + ((u32_t)((u8_t)(netif->hwaddr[5]))) << 8))) +#endif /* LWIP_AUTOIP_CREATE_SEED_ADDR */ + +/* Function definitions */ +static void autoip_restart(struct netif *netif); +static void autoip_create_addr(struct netif *netif, ip4_addr_t *ipaddr); +static err_t autoip_bind(struct netif *netif); +static void autoip_conflict_callback(struct netif *netif, + acd_callback_enum_t state); + +/** + * @ingroup autoip + * Set a statically allocated struct autoip to work with. + * Using this prevents autoip_start to allocate it using mem_malloc. + * + * @param netif the netif for which to set the struct autoip + * @param autoip (uninitialised) autoip struct allocated by the application + */ +void +autoip_set_struct(struct netif *netif, struct autoip *autoip) +{ + LWIP_ASSERT_CORE_LOCKED(); + LWIP_ASSERT("netif != NULL", netif != NULL); + LWIP_ASSERT("autoip != NULL", autoip != NULL); + LWIP_ASSERT("netif already has a struct autoip set", + netif_autoip_data(netif) == NULL); + + /* clear data structure */ + memset(autoip, 0, sizeof(struct autoip)); + /* autoip->state = AUTOIP_STATE_OFF; */ + netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_AUTOIP, autoip); +} + +/** + * @ingroup autoip + * Remove a struct autoip previously set to the netif using autoip_set_struct() + * + * @param netif the netif for which to set the struct autoip + */ +void +autoip_remove_struct(struct netif *netif) +{ + LWIP_ASSERT_CORE_LOCKED(); + LWIP_ASSERT("netif != NULL", netif != NULL); + LWIP_ASSERT("netif has no struct autoip set", + netif_autoip_data(netif) != NULL); + + netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_AUTOIP, NULL); +} + +/** Restart AutoIP client and check the next address (conflict detected) + * + * @param netif The netif under AutoIP control + */ +static void +autoip_restart(struct netif *netif) +{ + struct autoip *autoip = netif_autoip_data(netif); + autoip->tried_llipaddr++; + autoip_start(netif); +} + + +/** + * Create an IP-Address out of range 169.254.1.0 to 169.254.254.255 + * + * @param netif network interface on which create the IP-Address + * @param ipaddr ip address to initialize + */ +static void +autoip_create_addr(struct netif *netif, ip4_addr_t *ipaddr) +{ + struct autoip *autoip = netif_autoip_data(netif); + + /* Here we create an IP-Address out of range 169.254.1.0 to 169.254.254.255 + * compliant to RFC 3927 Section 2.1 + * We have 254 * 256 possibilities */ + + u32_t addr = lwip_ntohl(LWIP_AUTOIP_CREATE_SEED_ADDR(netif)); + addr += autoip->tried_llipaddr; + addr = AUTOIP_NET | (addr & 0xffff); + /* Now, 169.254.0.0 <= addr <= 169.254.255.255 */ + + if (addr < AUTOIP_RANGE_START) { + addr += AUTOIP_RANGE_END - AUTOIP_RANGE_START + 1; + } + if (addr > AUTOIP_RANGE_END) { + addr -= AUTOIP_RANGE_END - AUTOIP_RANGE_START + 1; + } + LWIP_ASSERT("AUTOIP address not in range", (addr >= AUTOIP_RANGE_START) && + (addr <= AUTOIP_RANGE_END)); + ip4_addr_set_u32(ipaddr, lwip_htonl(addr)); + + LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, + ("autoip_create_addr(): tried_llipaddr=%"U16_F", %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n", + (u16_t)(autoip->tried_llipaddr), ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), + ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr))); +} + + +/** + * Configure interface for use with current LL IP-Address + * + * @param netif network interface to configure with current LL IP-Address + */ +static err_t +autoip_bind(struct netif *netif) +{ + struct autoip *autoip = netif_autoip_data(netif); + ip4_addr_t sn_mask, gw_addr; + + autoip->state = AUTOIP_STATE_BOUND; + + LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, + ("autoip_bind(netif=%p) %c%c%"U16_F" %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n", + (void *)netif, netif->name[0], netif->name[1], (u16_t)netif->num, + ip4_addr1_16(&autoip->llipaddr), ip4_addr2_16(&autoip->llipaddr), + ip4_addr3_16(&autoip->llipaddr), ip4_addr4_16(&autoip->llipaddr))); + + IP4_ADDR(&sn_mask, 255, 255, 0, 0); + IP4_ADDR(&gw_addr, 0, 0, 0, 0); + + netif_set_addr(netif, &autoip->llipaddr, &sn_mask, &gw_addr); + /* interface is used by routing now that an address is set */ + + return ERR_OK; +} + +/** +* Handle conflict information from ACD module +* +* @param netif network interface to handle conflict information on +* @param state acd_callback_enum_t + */ +static void +autoip_conflict_callback(struct netif *netif, acd_callback_enum_t state) +{ + struct autoip *autoip = netif_autoip_data(netif); + + switch (state) { + case ACD_IP_OK: + autoip_bind(netif); + break; + case ACD_RESTART_CLIENT: + autoip_restart(netif); + break; + case ACD_DECLINE: + /* "delete" conflicting address so a new one will be selected in + * autoip_start() */ + ip4_addr_set_any(&autoip->llipaddr); + autoip_stop(netif); + break; + default: + break; + } +} + +/** + * @ingroup autoip + * Start AutoIP client + * + * @param netif network interface on which start the AutoIP client + */ +err_t +autoip_start(struct netif *netif) +{ + struct autoip *autoip = netif_autoip_data(netif); + err_t result = ERR_OK; + + LWIP_ASSERT_CORE_LOCKED(); + LWIP_ERROR("netif is not up, old style port?", netif_is_up(netif), return ERR_ARG;); + + if (autoip == NULL) { + /* no AutoIP client attached yet? */ + LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, + ("autoip_start(): starting new AUTOIP client\n")); + autoip = (struct autoip *)mem_calloc(1, sizeof(struct autoip)); + if (autoip == NULL) { + LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, + ("autoip_start(): could not allocate autoip\n")); + return ERR_MEM; + } + /* store this AutoIP client in the netif */ + netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_AUTOIP, autoip); + LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_start(): allocated autoip\n")); + } + + if (autoip->state == AUTOIP_STATE_OFF) { + LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, + ("autoip_start(netif=%p) %c%c%"U16_F"\n", (void *)netif, netif->name[0], + netif->name[1], (u16_t)netif->num)); + + /* add acd struct to list*/ + acd_add(netif, &autoip->acd, autoip_conflict_callback); + + /* In accordance to RFC3927 section 2.1: + * Keep using the same link local address as much as possible. + * Only when there is none or when there was a conflict, select a new one. + */ + if (!ip4_addr_islinklocal(&autoip->llipaddr)) { + autoip_create_addr(netif, &(autoip->llipaddr)); + } + autoip->state = AUTOIP_STATE_CHECKING; + acd_start(netif, &autoip->acd, autoip->llipaddr); + } else { + LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, + ("autoip_start(): already started on netif=%p %c%c%"U16_F"\n", + (void *)netif, netif->name[0], + netif->name[1], (u16_t)netif->num)); + } + + return result; +} + + +/** + * Handle a possible change in the network configuration: link up + * + * If there is an AutoIP address configured and AutoIP is not in cooperation + * with DHCP, start probing for previous address. + */ +void +autoip_network_changed_link_up(struct netif *netif) +{ + struct autoip *autoip = netif_autoip_data(netif); + + if (autoip && (autoip->state != AUTOIP_STATE_OFF) && !LWIP_DHCP_AUTOIP_COOP) { + LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, + ("autoip_network_changed_link_up(): start acd\n")); + autoip->state = AUTOIP_STATE_CHECKING; + /* Start acd check again for the last used address */ + acd_start(netif, &autoip->acd, autoip->llipaddr); + } +} + +/** + * Handle a possible change in the network configuration: link down + * + * If there is an AutoIP address configured and AutoIP is in cooperation + * with DHCP, then stop the autoip module. When the link goes up, we do not want + * the autoip module to start again. DHCP will initiate autoip when needed. + */ +void +autoip_network_changed_link_down(struct netif *netif) +{ + struct autoip *autoip = netif_autoip_data(netif); + + if (autoip && (autoip->state != AUTOIP_STATE_OFF) && LWIP_DHCP_AUTOIP_COOP) { + LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, + ("autoip_network_changed_link_down(): stop autoip\n")); + autoip_stop(netif); + } +} + +/** + * @ingroup autoip + * Stop AutoIP client + * + * @param netif network interface on which stop the AutoIP client + */ +err_t +autoip_stop(struct netif *netif) +{ + struct autoip *autoip = netif_autoip_data(netif); + + LWIP_ASSERT_CORE_LOCKED(); + if (autoip != NULL) { + autoip->state = AUTOIP_STATE_OFF; + if (ip4_addr_islinklocal(netif_ip4_addr(netif))) { + netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4); + } + LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,("autoip_stop()\n")); + } + return ERR_OK; +} + +/** check if AutoIP supplied netif->ip_addr + * + * @param netif the netif to check + * @return 1 if AutoIP supplied netif->ip_addr (state BOUND), + * 0 otherwise + */ +u8_t +autoip_supplied_address(struct netif *netif) +{ + struct autoip *autoip = netif_autoip_data(netif); + return (autoip != NULL) + && (ip4_addr_eq(netif_ip4_addr(netif), &(autoip->llipaddr))) + && (autoip->state == AUTOIP_STATE_BOUND); +} + +u8_t +autoip_accept_packet(struct netif *netif, const ip4_addr_t *addr) +{ + struct autoip *autoip = netif_autoip_data(netif); + return (autoip != NULL) + && (ip4_addr_eq(addr, &(autoip->llipaddr))) + && (autoip->state == AUTOIP_STATE_BOUND); +} + +#endif /* LWIP_IPV4 && LWIP_AUTOIP */ diff --git a/src/core/ipv4/dhcp.c b/src/core/ipv4/dhcp.c new file mode 100644 index 00000000000..d9ed8b0f37a --- /dev/null +++ b/src/core/ipv4/dhcp.c @@ -0,0 +1,1999 @@ +/** + * @file + * Dynamic Host Configuration Protocol client + * + * @defgroup dhcp4 DHCPv4 + * @ingroup ip4 + * DHCP (IPv4) related functions + * This is a DHCP client for the lwIP TCP/IP stack. It aims to conform + * with RFC 2131 and RFC 2132. + * + * @todo: + * - Support for interfaces other than Ethernet (SLIP, PPP, ...) + * + * Options: + * @ref DHCP_COARSE_TIMER_SECS (recommended 60 which is a minute) + * @ref DHCP_FINE_TIMER_MSECS (recommended 500 which equals TCP coarse timer) + * + * dhcp_start() starts a DHCP client instance which + * configures the interface by obtaining an IP address lease and maintaining it. + * + * Use dhcp_release() to end the lease and use dhcp_stop() + * to remove the DHCP client. + * + * @see LWIP_HOOK_DHCP_APPEND_OPTIONS + * @see LWIP_HOOK_DHCP_PARSE_OPTION + * + * @see netifapi_dhcp4 + */ + +/* + * Copyright (c) 2001-2004 Leon Woestenberg <leon.woestenberg@gmx.net> + * Copyright (c) 2001-2004 Axon Digital Design B.V., The Netherlands. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT + * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * This file is part of the lwIP TCP/IP stack. + * The Swedish Institute of Computer Science and Adam Dunkels + * are specifically granted permission to redistribute this + * source code. + * + * Author: Leon Woestenberg <leon.woestenberg@gmx.net> + * + */ + +#include "lwip/opt.h" + +#if LWIP_IPV4 && LWIP_DHCP /* don't build if not configured for use in lwipopts.h */ + +#include "lwip/stats.h" +#include "lwip/mem.h" +#include "lwip/udp.h" +#include "lwip/ip_addr.h" +#include "lwip/netif.h" +#include "lwip/def.h" +#include "lwip/dhcp.h" +#include "lwip/autoip.h" +#include "lwip/acd.h" +#include "lwip/dns.h" +#include "lwip/etharp.h" +#include "lwip/prot/dhcp.h" +#include "lwip/prot/iana.h" + +#include <string.h> + +#ifdef LWIP_HOOK_FILENAME +#include LWIP_HOOK_FILENAME +#endif +#ifndef LWIP_HOOK_DHCP_APPEND_OPTIONS +#define LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, state, msg, msg_type, options_len_ptr) +#endif +#ifndef LWIP_HOOK_DHCP_PARSE_OPTION +#define LWIP_HOOK_DHCP_PARSE_OPTION(netif, dhcp, state, msg, msg_type, option, len, pbuf, offset) do { LWIP_UNUSED_ARG(msg); } while(0) +#endif + +/** DHCP_ADD_EXTRA_REQUEST_OPTIONS: Additional options added to the list of options + * that the client requests from the servers (opt 55: DHCP_OPTION_PARAMETER_REQUEST_LIST) + * If additional options are requested, define this macro as a comma separated list, with leading comma. + * This macro is useful for example when requested vendor specific ids (VCI/VSI options), here is an example + * of requesting the VSI option (option 43) (yes, the notation is a bit strange, but it works :) + * (NOTE: the space between # and define is required because of doxygen...) + * # define DHCP_ADD_EXTRA_REQUEST_OPTIONS ,43 + */ +#ifndef DHCP_ADD_EXTRA_REQUEST_OPTIONS +#define DHCP_ADD_EXTRA_REQUEST_OPTIONS +#endif + +/** DHCP_DEFINE_CUSTOM_TIMEOUTS: if this is defined then you can customize various DHCP timeouts using these macros: + - DHCP_SET_TIMEOUT_FROM_OFFERED_T0_LEASE() to adjust the t0 lease timeout from the offered value + - DHCP_SET_TIMEOUT_FROM_OFFERED_T1_RENEW() same for t1 renew + - DHCP_SET_TIMEOUT_FROM_OFFERED_T2_REBIND() same for t2 rebind + - DHCP_NEXT_TIMEOUT_THRESHOLD to adjust the period of the next timeout + - DHCP_REQUEST_BACKOFF_SEQUENCE to adjust back-off times based on DHCP request attempts + */ +#ifndef DHCP_DEFINE_CUSTOM_TIMEOUTS +#define SET_TIMEOUT_FROM_OFFERED(result, offered, min, max) do { \ + u32_t timeout = (offered + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS; \ + if (timeout > max) { \ + timeout = max; \ + } \ + if (timeout == min) { \ + timeout = 1; \ + } \ + result = (dhcp_timeout_t)timeout; \ +} while(0) + +#define DHCP_SET_TIMEOUT_FROM_OFFERED_T0_LEASE(res, dhcp) SET_TIMEOUT_FROM_OFFERED(res, (dhcp)->offered_t0_lease, 0, 0xffff) +#define DHCP_SET_TIMEOUT_FROM_OFFERED_T1_RENEW(res, dhcp) SET_TIMEOUT_FROM_OFFERED(res, (dhcp)->offered_t1_renew, 0, 0xffff) +#define DHCP_SET_TIMEOUT_FROM_OFFERED_T2_REBIND(res, dhcp) SET_TIMEOUT_FROM_OFFERED(res, (dhcp)->offered_t2_rebind, 0, 0xffff) + +#define DHCP_NEXT_TIMEOUT_THRESHOLD ((60 + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS) +#define DHCP_REQUEST_BACKOFF_SEQUENCE(tries) (u16_t)(( (tries) < 6 ? 1 << (tries) : 60) * 1000) + +#endif /* DHCP_DEFINE_CUSTOM_TIMEOUTS */ + +/** DHCP_CREATE_RAND_XID: if this is set to 1, the xid is created using + * LWIP_RAND() (this overrides DHCP_GLOBAL_XID) + */ +#ifndef DHCP_CREATE_RAND_XID +#define DHCP_CREATE_RAND_XID 1 +#endif + +/** Default for DHCP_GLOBAL_XID is 0xABCD0000 + * This can be changed by defining DHCP_GLOBAL_XID and DHCP_GLOBAL_XID_HEADER, e.g. + * \#define DHCP_GLOBAL_XID_HEADER "stdlib.h" + * \#define DHCP_GLOBAL_XID rand() + */ +#ifdef DHCP_GLOBAL_XID_HEADER +#include DHCP_GLOBAL_XID_HEADER /* include optional starting XID generation prototypes */ +#endif + +/** DHCP_OPTION_MAX_MSG_SIZE is set to the MTU + * MTU is checked to be big enough in dhcp_start */ +#define DHCP_MAX_MSG_LEN(netif) (netif->mtu) +#define DHCP_MAX_MSG_LEN_MIN_REQUIRED 576 +/** Minimum length for reply before packet is parsed */ +#define DHCP_MIN_REPLY_LEN 44 + +#define REBOOT_TRIES 2 + +#if LWIP_DNS && LWIP_DHCP_MAX_DNS_SERVERS +#if DNS_MAX_SERVERS > LWIP_DHCP_MAX_DNS_SERVERS +#define LWIP_DHCP_PROVIDE_DNS_SERVERS LWIP_DHCP_MAX_DNS_SERVERS +#else +#define LWIP_DHCP_PROVIDE_DNS_SERVERS DNS_MAX_SERVERS +#endif +#else +#define LWIP_DHCP_PROVIDE_DNS_SERVERS 0 +#endif + +#ifndef LWIP_DHCP_INPUT_ERROR +#define LWIP_DHCP_INPUT_ERROR(message, expression, handler) do { if (!(expression)) { \ + handler;} } while(0) +#endif + +/** Option handling: options are parsed in dhcp_parse_reply + * and saved in an array where other functions can load them from. + * This might be moved into the struct dhcp (not necessarily since + * lwIP is single-threaded and the array is only used while in recv + * callback). */ +enum dhcp_option_idx { + DHCP_OPTION_IDX_OVERLOAD = 0, + DHCP_OPTION_IDX_MSG_TYPE, + DHCP_OPTION_IDX_SERVER_ID, + DHCP_OPTION_IDX_LEASE_TIME, + DHCP_OPTION_IDX_T1, + DHCP_OPTION_IDX_T2, + DHCP_OPTION_IDX_SUBNET_MASK, + DHCP_OPTION_IDX_ROUTER, +#if LWIP_DHCP_PROVIDE_DNS_SERVERS + DHCP_OPTION_IDX_DNS_SERVER, + DHCP_OPTION_IDX_DNS_SERVER_LAST = DHCP_OPTION_IDX_DNS_SERVER + LWIP_DHCP_PROVIDE_DNS_SERVERS - 1, +#endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */ +#if LWIP_DHCP_GET_NTP_SRV + DHCP_OPTION_IDX_NTP_SERVER, + DHCP_OPTION_IDX_NTP_SERVER_LAST = DHCP_OPTION_IDX_NTP_SERVER + LWIP_DHCP_MAX_NTP_SERVERS - 1, +#endif /* LWIP_DHCP_GET_NTP_SRV */ + DHCP_OPTION_IDX_MAX +}; + +/** Holds the decoded option values, only valid while in dhcp_recv. + @todo: move this into struct dhcp? */ +static u32_t dhcp_rx_options_val[DHCP_OPTION_IDX_MAX]; +/** Holds a flag which option was received and is contained in dhcp_rx_options_val, + only valid while in dhcp_recv. + @todo: move this into struct dhcp? */ +static u8_t dhcp_rx_options_given[DHCP_OPTION_IDX_MAX]; + +static u8_t dhcp_discover_request_options[] = { + DHCP_OPTION_SUBNET_MASK, + DHCP_OPTION_ROUTER, + DHCP_OPTION_BROADCAST +#if LWIP_DHCP_PROVIDE_DNS_SERVERS + , DHCP_OPTION_DNS_SERVER +#endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */ +#if LWIP_DHCP_GET_NTP_SRV + , DHCP_OPTION_NTP +#endif /* LWIP_DHCP_GET_NTP_SRV */ + DHCP_ADD_EXTRA_REQUEST_OPTIONS +}; + +#ifdef DHCP_GLOBAL_XID +static u32_t xid; +static u8_t xid_initialised; +#endif /* DHCP_GLOBAL_XID */ + +#define dhcp_option_given(dhcp, idx) (dhcp_rx_options_given[idx] != 0) +#define dhcp_got_option(dhcp, idx) (dhcp_rx_options_given[idx] = 1) +#define dhcp_clear_option(dhcp, idx) (dhcp_rx_options_given[idx] = 0) +#define dhcp_clear_all_options(dhcp) (memset(dhcp_rx_options_given, 0, sizeof(dhcp_rx_options_given))) +#define dhcp_get_option_value(dhcp, idx) (dhcp_rx_options_val[idx]) +#define dhcp_set_option_value(dhcp, idx, val) (dhcp_rx_options_val[idx] = (val)) + +static struct udp_pcb *dhcp_pcb; +static u8_t dhcp_pcb_refcount; + +/* DHCP client state machine functions */ +static err_t dhcp_discover(struct netif *netif); +static err_t dhcp_select(struct netif *netif); +static void dhcp_bind(struct netif *netif); +#if LWIP_DHCP_DOES_ACD_CHECK +static err_t dhcp_decline(struct netif *netif); +#endif /* LWIP_DHCP_DOES_ACD_CHECK */ +static err_t dhcp_rebind(struct netif *netif); +static err_t dhcp_reboot(struct netif *netif); +static void dhcp_set_state(struct dhcp *dhcp, u8_t new_state); + +/* receive, unfold, parse and free incoming messages */ +static void dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port); + +/* set the DHCP timers */ +static void dhcp_timeout(struct netif *netif); +static void dhcp_t1_timeout(struct netif *netif); +static void dhcp_t2_timeout(struct netif *netif); + +/* build outgoing messages */ +/* create a DHCP message, fill in common headers */ +static struct pbuf *dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type, u16_t *options_out_len); +/* add a DHCP option (type, then length in bytes) */ +static u16_t dhcp_option(u16_t options_out_len, u8_t *options, u8_t option_type, u8_t option_len); +/* add option values */ +static u16_t dhcp_option_byte(u16_t options_out_len, u8_t *options, u8_t value); +static u16_t dhcp_option_short(u16_t options_out_len, u8_t *options, u16_t value); +static u16_t dhcp_option_long(u16_t options_out_len, u8_t *options, u32_t value); +#if LWIP_NETIF_HOSTNAME +static u16_t dhcp_option_hostname(u16_t options_out_len, u8_t *options, struct netif *netif); +#endif /* LWIP_NETIF_HOSTNAME */ +/* always add the DHCP options trailer to end and pad */ +static void dhcp_option_trailer(u16_t options_out_len, u8_t *options, struct pbuf *p_out); + +/** Ensure DHCP PCB is allocated and bound */ +static err_t +dhcp_inc_pcb_refcount(void) +{ + if (dhcp_pcb_refcount == 0) { + LWIP_ASSERT("dhcp_inc_pcb_refcount(): memory leak", dhcp_pcb == NULL); + + /* allocate UDP PCB */ + dhcp_pcb = udp_new(); + + if (dhcp_pcb == NULL) { + return ERR_MEM; + } + + ip_set_option(dhcp_pcb, SOF_BROADCAST); + + /* set up local and remote port for the pcb -> listen on all interfaces on all src/dest IPs */ + udp_bind(dhcp_pcb, IP4_ADDR_ANY, LWIP_IANA_PORT_DHCP_CLIENT); + udp_connect(dhcp_pcb, IP4_ADDR_ANY, LWIP_IANA_PORT_DHCP_SERVER); + udp_recv(dhcp_pcb, dhcp_recv, NULL); + } + + dhcp_pcb_refcount++; + + return ERR_OK; +} + +/** Free DHCP PCB if the last netif stops using it */ +static void +dhcp_dec_pcb_refcount(void) +{ + LWIP_ASSERT("dhcp_pcb_refcount(): refcount error", (dhcp_pcb_refcount > 0)); + dhcp_pcb_refcount--; + + if (dhcp_pcb_refcount == 0) { + udp_remove(dhcp_pcb); + dhcp_pcb = NULL; + } +} + +/** + * Back-off the DHCP client (because of a received NAK response). + * + * Back-off the DHCP client because of a received NAK. Receiving a + * NAK means the client asked for something non-sensible, for + * example when it tries to renew a lease obtained on another network. + * + * We clear any existing set IP address and restart DHCP negotiation + * afresh (as per RFC2131 3.2.3). + * + * @param netif the netif under DHCP control + */ +static void +dhcp_handle_nak(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_handle_nak(netif=%p) %c%c%"U16_F"\n", + (void *)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); + /* Change to a defined state - set this before assigning the address + to ensure the callback can use dhcp_supplied_address() */ + dhcp_set_state(dhcp, DHCP_STATE_BACKING_OFF); + /* remove IP address from interface (must no longer be used, as per RFC2131) */ + netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4); + /* We can immediately restart discovery */ + dhcp_discover(netif); +} + +#if LWIP_DHCP_DOES_ACD_CHECK +/** +* Handle conflict information from ACD module +* +* @param netif network interface to handle conflict information on +* @param state acd_callback_enum_t + */ +static void +dhcp_conflict_callback(struct netif *netif, acd_callback_enum_t state) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + u16_t msecs; + + LWIP_ASSERT("DHCP should be enabled at this point, but it is not!", + (dhcp != NULL) && (dhcp->state != DHCP_STATE_OFF)); + + switch (state) { + case ACD_IP_OK: + dhcp_bind(netif); + break; + case ACD_RESTART_CLIENT: + /* wait 10s before restarting + * According to RFC2131 section 3.1 point 5: + * If the client detects that the address is already in use (e.g., through + * the use of ARP), the client MUST send a DHCPDECLINE message to the + * server and restarts the configuration process. The client SHOULD wait + * a minimum of ten seconds before restarting the configuration process to + * avoid excessive network traffic in case of looping. */ + dhcp_set_state(dhcp, DHCP_STATE_BACKING_OFF); + msecs = 10 * 1000; + dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline(): set request timeout %"U16_F" msecs\n", msecs)); + break; + case ACD_DECLINE: + /* remove IP address from interface + * (prevents routing from selecting this interface) */ + netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4); + /* Let the DHCP server know we will not use the address */ + dhcp_decline(netif); + break; + default: + break; + } +} + +/** + * Checks if the offered IP address is already in use. + * + * It does this according to the address conflict detection method described in + * RFC5227. + * + * @param netif the netif under DHCP control + */ +static void +dhcp_check(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_check(netif=%p) %c%c\n", (void *)netif, (s16_t)netif->name[0], + (s16_t)netif->name[1])); + dhcp_set_state(dhcp, DHCP_STATE_CHECKING); + + /* start ACD module */ + acd_start(netif, &dhcp->acd, dhcp->offered_ip_addr); +} +#endif /* LWIP_DHCP_DOES_ACD_CHECK */ + +/** + * Remember the configuration offered by a DHCP server. + * + * @param netif the netif under DHCP control + */ +static void +dhcp_handle_offer(struct netif *netif, struct dhcp_msg *msg_in) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_handle_offer(netif=%p) %c%c%"U16_F"\n", + (void *)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); + /* obtain the server address */ + if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_SERVER_ID)) { + dhcp->request_timeout = 0; /* stop timer */ + + ip_addr_set_ip4_u32(&dhcp->server_ip_addr, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_SERVER_ID))); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_handle_offer(): server 0x%08"X32_F"\n", + ip4_addr_get_u32(ip_2_ip4(&dhcp->server_ip_addr)))); + /* remember offered address */ + ip4_addr_copy(dhcp->offered_ip_addr, msg_in->yiaddr); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_handle_offer(): offer for 0x%08"X32_F"\n", + ip4_addr_get_u32(&dhcp->offered_ip_addr))); + + dhcp_select(netif); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, + ("dhcp_handle_offer(netif=%p) did not get server ID!\n", (void *)netif)); + } +} + +/** + * Select a DHCP server offer out of all offers. + * + * Simply select the first offer received. + * + * @param netif the netif under DHCP control + * @return lwIP specific error (see error.h) + */ +static err_t +dhcp_select(struct netif *netif) +{ + struct dhcp *dhcp; + err_t result; + u16_t msecs; + u8_t i; + struct pbuf *p_out; + u16_t options_out_len; + + LWIP_ERROR("dhcp_select: netif != NULL", (netif != NULL), return ERR_ARG;); + dhcp = netif_dhcp_data(netif); + LWIP_ERROR("dhcp_select: dhcp != NULL", (dhcp != NULL), return ERR_VAL;); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_select(netif=%p) %c%c%"U16_F"\n", (void *)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); + dhcp_set_state(dhcp, DHCP_STATE_REQUESTING); + + /* create and initialize the DHCP message header */ + p_out = dhcp_create_msg(netif, dhcp, DHCP_REQUEST, &options_out_len); + if (p_out != NULL) { + struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload; + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); + options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif)); + + /* MUST request the offered IP address */ + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_REQUESTED_IP, 4); + options_out_len = dhcp_option_long(options_out_len, msg_out->options, lwip_ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); + + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_SERVER_ID, 4); + options_out_len = dhcp_option_long(options_out_len, msg_out->options, lwip_ntohl(ip4_addr_get_u32(ip_2_ip4(&dhcp->server_ip_addr)))); + + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options)); + for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) { + options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]); + } + +#if LWIP_NETIF_HOSTNAME + options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif); +#endif /* LWIP_NETIF_HOSTNAME */ + + LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_REQUESTING, msg_out, DHCP_REQUEST, &options_out_len); + dhcp_option_trailer(options_out_len, msg_out->options, p_out); + + /* send broadcast to any DHCP server */ + result = udp_sendto_if_src(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif, IP4_ADDR_ANY); + pbuf_free(p_out); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_select: REQUESTING\n")); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("dhcp_select: could not allocate DHCP request\n")); + result = ERR_MEM; + } + if (dhcp->tries < 255) { + dhcp->tries++; + } + msecs = (u16_t)((dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000); + dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_select(): set request timeout %"U16_F" msecs\n", msecs)); + return result; +} + +/** + * The DHCP timer that checks for lease renewal/rebind timeouts. + * Must be called once a minute (see @ref DHCP_COARSE_TIMER_SECS). + */ +void +dhcp_coarse_tmr(void) +{ + struct netif *netif; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_coarse_tmr()\n")); + /* iterate through all network interfaces */ + NETIF_FOREACH(netif) { + /* only act on DHCP configured interfaces */ + struct dhcp *dhcp = netif_dhcp_data(netif); + if ((dhcp != NULL) && (dhcp->state != DHCP_STATE_OFF)) { + /* compare lease time to expire timeout */ + if (dhcp->t0_timeout && (++dhcp->lease_used == dhcp->t0_timeout)) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t0 timeout\n")); + /* this clients' lease time has expired */ + dhcp_release_and_stop(netif); + dhcp_start(netif); + /* timer is active (non zero), and triggers (zeroes) now? */ + } else if (dhcp->t2_rebind_time && (dhcp->t2_rebind_time-- == 1)) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t2 timeout\n")); + /* this clients' rebind timeout triggered */ + dhcp_t2_timeout(netif); + /* timer is active (non zero), and triggers (zeroes) now */ + } else if (dhcp->t1_renew_time && (dhcp->t1_renew_time-- == 1)) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t1 timeout\n")); + /* this clients' renewal timeout triggered */ + dhcp_t1_timeout(netif); + } + } + } +} + +/** + * DHCP transaction timeout handling (this function must be called every 500ms, + * see @ref DHCP_FINE_TIMER_MSECS). + * + * A DHCP server is expected to respond within a short period of time. + * This timer checks whether an outstanding DHCP request is timed out. + */ +void +dhcp_fine_tmr(void) +{ + struct netif *netif; + /* loop through netif's */ + NETIF_FOREACH(netif) { + struct dhcp *dhcp = netif_dhcp_data(netif); + /* only act on DHCP configured interfaces */ + if (dhcp != NULL) { + /* timer is active (non zero), and is about to trigger now */ + if (dhcp->request_timeout > 1) { + dhcp->request_timeout--; + } else if (dhcp->request_timeout == 1) { + dhcp->request_timeout--; + /* { dhcp->request_timeout == 0 } */ + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_fine_tmr(): request timeout\n")); + /* this client's request timeout triggered */ + dhcp_timeout(netif); + } + } + } +} + +/** + * A DHCP negotiation transaction, or ARP request, has timed out. + * + * The timer that was started with the DHCP or ARP request has + * timed out, indicating no response was received in time. + * + * @param netif the netif under DHCP control + */ +static void +dhcp_timeout(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout()\n")); + /* back-off period has passed, or server selection timed out */ + if ((dhcp->state == DHCP_STATE_BACKING_OFF) || (dhcp->state == DHCP_STATE_SELECTING)) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout(): restarting discovery\n")); + dhcp_discover(netif); + /* receiving the requested lease timed out */ + } else if (dhcp->state == DHCP_STATE_REQUESTING) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, DHCP request timed out\n")); + if (dhcp->tries <= 5) { + dhcp_select(netif); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, releasing, restarting\n")); + dhcp_release_and_stop(netif); + dhcp_start(netif); + } + } else if (dhcp->state == DHCP_STATE_REBOOTING) { + if (dhcp->tries < REBOOT_TRIES) { + dhcp_reboot(netif); + } else { + dhcp_discover(netif); + } + } +} + +/** + * The renewal period has timed out. + * + * @param netif the netif under DHCP control + */ +static void +dhcp_t1_timeout(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_t1_timeout()\n")); + if ((dhcp->state == DHCP_STATE_REQUESTING) || (dhcp->state == DHCP_STATE_BOUND) || + (dhcp->state == DHCP_STATE_RENEWING)) { + /* just retry to renew - note that the rebind timer (t2) will + * eventually time-out if renew tries fail. */ + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, + ("dhcp_t1_timeout(): must renew\n")); + /* This slightly different to RFC2131: DHCPREQUEST will be sent from state + DHCP_STATE_RENEWING, not DHCP_STATE_BOUND */ + dhcp_renew(netif); + /* Calculate next timeout */ + if (((dhcp->t2_timeout - dhcp->lease_used) / 2) >= DHCP_NEXT_TIMEOUT_THRESHOLD) { + dhcp->t1_renew_time = (dhcp_timeout_t)((dhcp->t2_timeout - dhcp->lease_used) / 2); + } + } +} + +/** + * The rebind period has timed out. + * + * @param netif the netif under DHCP control + */ +static void +dhcp_t2_timeout(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_t2_timeout()\n")); + if ((dhcp->state == DHCP_STATE_REQUESTING) || (dhcp->state == DHCP_STATE_BOUND) || + (dhcp->state == DHCP_STATE_RENEWING) || (dhcp->state == DHCP_STATE_REBINDING)) { + /* just retry to rebind */ + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, + ("dhcp_t2_timeout(): must rebind\n")); + /* This slightly different to RFC2131: DHCPREQUEST will be sent from state + DHCP_STATE_REBINDING, not DHCP_STATE_BOUND */ + dhcp_rebind(netif); + /* Calculate next timeout */ + if (((dhcp->t0_timeout - dhcp->lease_used) / 2) >= DHCP_NEXT_TIMEOUT_THRESHOLD) { + dhcp->t2_rebind_time = (dhcp_timeout_t)((dhcp->t0_timeout - dhcp->lease_used) / 2); + } + } +} + +/** + * Handle a DHCP ACK packet + * + * @param netif the netif under DHCP control + */ +static void +dhcp_handle_ack(struct netif *netif, struct dhcp_msg *msg_in) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + +#if LWIP_DHCP_PROVIDE_DNS_SERVERS || LWIP_DHCP_GET_NTP_SRV + u8_t n; +#endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS || LWIP_DHCP_GET_NTP_SRV */ +#if LWIP_DHCP_GET_NTP_SRV + ip4_addr_t ntp_server_addrs[LWIP_DHCP_MAX_NTP_SERVERS]; +#endif + + /* clear options we might not get from the ACK */ + ip4_addr_set_zero(&dhcp->offered_sn_mask); + ip4_addr_set_zero(&dhcp->offered_gw_addr); +#if LWIP_DHCP_BOOTP_FILE + ip4_addr_set_zero(&dhcp->offered_si_addr); +#endif /* LWIP_DHCP_BOOTP_FILE */ + + /* lease time given? */ + if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_LEASE_TIME)) { + /* remember offered lease time */ + dhcp->offered_t0_lease = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_LEASE_TIME); + } + /* renewal period given? */ + if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_T1)) { + /* remember given renewal period */ + dhcp->offered_t1_renew = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_T1); + } else { + /* calculate safe periods for renewal */ + dhcp->offered_t1_renew = dhcp->offered_t0_lease / 2; + } + + /* renewal period given? */ + if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_T2)) { + /* remember given rebind period */ + dhcp->offered_t2_rebind = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_T2); + } else { + /* calculate safe periods for rebinding (offered_t0_lease * 0.875 -> 87.5%)*/ + dhcp->offered_t2_rebind = (dhcp->offered_t0_lease * 7U) / 8U; + } + + /* (y)our internet address */ + ip4_addr_copy(dhcp->offered_ip_addr, msg_in->yiaddr); + +#if LWIP_DHCP_BOOTP_FILE + /* copy boot server address, + boot file name copied in dhcp_parse_reply if not overloaded */ + ip4_addr_copy(dhcp->offered_si_addr, msg_in->siaddr); +#endif /* LWIP_DHCP_BOOTP_FILE */ + + /* subnet mask given? */ + if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_SUBNET_MASK)) { + /* remember given subnet mask */ + ip4_addr_set_u32(&dhcp->offered_sn_mask, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_SUBNET_MASK))); + dhcp->flags |= DHCP_FLAG_SUBNET_MASK_GIVEN; + } else { + dhcp->flags &= ~DHCP_FLAG_SUBNET_MASK_GIVEN; + } + + /* gateway router */ + if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_ROUTER)) { + ip4_addr_set_u32(&dhcp->offered_gw_addr, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_ROUTER))); + } + +#if LWIP_DHCP_GET_NTP_SRV + /* NTP servers */ + for (n = 0; (n < LWIP_DHCP_MAX_NTP_SERVERS) && dhcp_option_given(dhcp, DHCP_OPTION_IDX_NTP_SERVER + n); n++) { + ip4_addr_set_u32(&ntp_server_addrs[n], lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_NTP_SERVER + n))); + } + dhcp_set_ntp_servers(n, ntp_server_addrs); +#endif /* LWIP_DHCP_GET_NTP_SRV */ + +#if LWIP_DHCP_PROVIDE_DNS_SERVERS + /* DNS servers */ + for (n = 0; (n < LWIP_DHCP_PROVIDE_DNS_SERVERS) && dhcp_option_given(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n); n++) { + ip_addr_t dns_addr; + ip_addr_set_ip4_u32_val(dns_addr, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n))); + dns_setserver(n, &dns_addr); + } +#endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */ +} + +/** + * @ingroup dhcp4 + * Set a statically allocated struct dhcp to work with. + * Using this prevents dhcp_start to allocate it using mem_malloc. + * + * @param netif the netif for which to set the struct dhcp + * @param dhcp (uninitialised) dhcp struct allocated by the application + */ +void +dhcp_set_struct(struct netif *netif, struct dhcp *dhcp) +{ + LWIP_ASSERT_CORE_LOCKED(); + LWIP_ASSERT("netif != NULL", netif != NULL); + LWIP_ASSERT("dhcp != NULL", dhcp != NULL); + LWIP_ASSERT("netif already has a struct dhcp set", netif_dhcp_data(netif) == NULL); + + /* clear data structure */ + memset(dhcp, 0, sizeof(struct dhcp)); + /* mark this as externally allocated */ + dhcp->flags |= DHCP_FLAG_EXTERNAL_MEM; + /* dhcp_set_state(&dhcp, DHCP_STATE_OFF); */ + netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, dhcp); +} + +/** + * @ingroup dhcp4 + * Removes a struct dhcp from a netif. + * + * ATTENTION: Only use this when not using dhcp_set_struct() to allocate the + * struct dhcp since the memory is passed back to the heap. + * + * @param netif the netif from which to remove the struct dhcp + */ +void dhcp_cleanup(struct netif *netif) +{ + struct dhcp *dhcp; + LWIP_ASSERT_CORE_LOCKED(); + LWIP_ASSERT("netif != NULL", netif != NULL); + + dhcp = netif_dhcp_data(netif); + if (dhcp != NULL) { + if (!(dhcp->flags & DHCP_FLAG_EXTERNAL_MEM)) { + mem_free(dhcp); + } + netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, NULL); + } +} + +/** + * @ingroup dhcp4 + * Start DHCP negotiation for a network interface. + * + * If no DHCP client instance was attached to this interface, + * a new client is created first. If a DHCP client instance + * was already present, it restarts negotiation. + * + * @param netif The lwIP network interface + * @return lwIP error code + * - ERR_OK - No error + * - ERR_MEM - Out of memory + */ +err_t +dhcp_start(struct netif *netif) +{ + struct dhcp *dhcp; + err_t result; + + LWIP_ASSERT_CORE_LOCKED(); + LWIP_ERROR("netif != NULL", (netif != NULL), return ERR_ARG;); + LWIP_ERROR("netif is not up, old style port?", netif_is_up(netif), return ERR_ARG;); + dhcp = netif_dhcp_data(netif); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_start(netif=%p) %c%c%"U16_F"\n", (void *)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); + + /* check MTU of the netif */ + if (netif->mtu < DHCP_MAX_MSG_LEN_MIN_REQUIRED) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): Cannot use this netif with DHCP: MTU is too small\n")); + return ERR_MEM; + } + + /* no DHCP client attached yet? */ + if (dhcp == NULL) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): mallocing new DHCP client\n")); + dhcp = (struct dhcp *)mem_malloc(sizeof(struct dhcp)); + if (dhcp == NULL) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): could not allocate dhcp\n")); + return ERR_MEM; + } + + /* store this dhcp client in the netif */ + netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, dhcp); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): allocated dhcp\n")); + /* already has DHCP client attached */ + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_start(): restarting DHCP configuration\n")); + + if (dhcp->pcb_allocated != 0) { + dhcp_dec_pcb_refcount(); /* free DHCP PCB if not needed any more */ + } + /* dhcp is cleared below, no need to reset flag*/ + } + + /* clear data structure */ + memset(dhcp, 0, sizeof(struct dhcp)); + /* dhcp_set_state(&dhcp, DHCP_STATE_OFF); */ + + +#if LWIP_DHCP_DOES_ACD_CHECK + /* add acd struct to list*/ + acd_add(netif, &dhcp->acd, dhcp_conflict_callback); +#endif /* LWIP_DHCP_DOES_ACD_CHECK */ + + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting DHCP configuration\n")); + + if (dhcp_inc_pcb_refcount() != ERR_OK) { /* ensure DHCP PCB is allocated */ + return ERR_MEM; + } + dhcp->pcb_allocated = 1; + + if (!netif_is_link_up(netif)) { + /* set state INIT and wait for dhcp_network_changed() to call dhcp_discover() */ + dhcp_set_state(dhcp, DHCP_STATE_INIT); + return ERR_OK; + } + + /* (re)start the DHCP negotiation */ + result = dhcp_discover(netif); + if (result != ERR_OK) { + /* free resources allocated above */ + dhcp_release_and_stop(netif); + return ERR_MEM; + } + return result; +} + +/** + * @ingroup dhcp4 + * Inform a DHCP server of our manual configuration. + * + * This informs DHCP servers of our fixed IP address configuration + * by sending an INFORM message. It does not involve DHCP address + * configuration, it is just here to be nice to the network. + * + * @param netif The lwIP network interface + */ +void +dhcp_inform(struct netif *netif) +{ + struct dhcp dhcp; + struct pbuf *p_out; + u16_t options_out_len; + + LWIP_ASSERT_CORE_LOCKED(); + LWIP_ERROR("netif != NULL", (netif != NULL), return;); + + if (dhcp_inc_pcb_refcount() != ERR_OK) { /* ensure DHCP PCB is allocated */ + return; + } + + memset(&dhcp, 0, sizeof(struct dhcp)); + dhcp_set_state(&dhcp, DHCP_STATE_INFORMING); + + /* create and initialize the DHCP message header */ + p_out = dhcp_create_msg(netif, &dhcp, DHCP_INFORM, &options_out_len); + if (p_out != NULL) { + struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload; + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); + options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif)); + + LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, &dhcp, DHCP_STATE_INFORMING, msg_out, DHCP_INFORM, &options_out_len); + dhcp_option_trailer(options_out_len, msg_out->options, p_out); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_inform: INFORMING\n")); + + udp_sendto_if(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif); + + pbuf_free(p_out); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_inform: could not allocate DHCP request\n")); + } + + dhcp_dec_pcb_refcount(); /* delete DHCP PCB if not needed any more */ +} + +/** Handle a possible change in the network configuration. + * + * This enters the REBOOTING state to verify that the currently bound + * address is still valid. + */ +void +dhcp_network_changed_link_up(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + + if (!dhcp) { + return; + } + switch (dhcp->state) { + case DHCP_STATE_REBINDING: + case DHCP_STATE_RENEWING: + case DHCP_STATE_BOUND: + case DHCP_STATE_REBOOTING: + dhcp->tries = 0; + dhcp_reboot(netif); + break; + case DHCP_STATE_OFF: + /* stay off */ + break; + default: + LWIP_ASSERT("invalid dhcp->state", dhcp->state <= DHCP_STATE_BACKING_OFF); + /* INIT/REQUESTING/CHECKING/BACKING_OFF restart with new 'rid' because the + state changes, SELECTING: continue with current 'rid' as we stay in the + same state */ + /* ensure we start with short timeouts, even if already discovering */ + dhcp->tries = 0; + dhcp_discover(netif); + break; + } +} + +#if LWIP_DHCP_DOES_ACD_CHECK +/** + * Decline an offered lease. + * + * Tell the DHCP server we do not accept the offered address. + * One reason to decline the lease is when we find out the address + * is already in use by another host (through ARP). + * + * @param netif the netif under DHCP control + */ +static err_t +dhcp_decline(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + err_t result; + struct pbuf *p_out; + u16_t options_out_len; + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline()\n")); + dhcp_set_state(dhcp, DHCP_STATE_BACKING_OFF); + + /* create and initialize the DHCP message header */ + p_out = dhcp_create_msg(netif, dhcp, DHCP_DECLINE, &options_out_len); + if (p_out != NULL) { + struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload; + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_REQUESTED_IP, 4); + options_out_len = dhcp_option_long(options_out_len, msg_out->options, lwip_ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); + + LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_BACKING_OFF, msg_out, DHCP_DECLINE, &options_out_len); + dhcp_option_trailer(options_out_len, msg_out->options, p_out); + + /* per section 4.4.4, broadcast DECLINE messages */ + result = udp_sendto_if_src(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif, IP4_ADDR_ANY); + pbuf_free(p_out); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_decline: BACKING OFF\n")); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, + ("dhcp_decline: could not allocate DHCP request\n")); + result = ERR_MEM; + } + return result; +} +#endif /* LWIP_DHCP_DOES_ACD_CHECK */ + + +/** + * Start the DHCP process, discover a DHCP server. + * + * @param netif the netif under DHCP control + */ +static err_t +dhcp_discover(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + err_t result = ERR_OK; + u16_t msecs; + u8_t i; + struct pbuf *p_out; + u16_t options_out_len; + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover()\n")); + +#if LWIP_DHCP_AUTOIP_COOP + if (dhcp->tries >= LWIP_DHCP_AUTOIP_COOP_TRIES) { + autoip_start(netif); + } +#endif /* LWIP_DHCP_AUTOIP_COOP */ + + ip4_addr_set_any(&dhcp->offered_ip_addr); + dhcp_set_state(dhcp, DHCP_STATE_SELECTING); + /* create and initialize the DHCP message header */ + p_out = dhcp_create_msg(netif, dhcp, DHCP_DISCOVER, &options_out_len); + if (p_out != NULL) { + struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: making request\n")); + + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); + options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif)); + +#if LWIP_NETIF_HOSTNAME && LWIP_DHCP_DISCOVER_ADD_HOSTNAME + options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif); +#endif /* LWIP NETIF HOSTNAME && LWIP_DHCP_DISCOVER_ADD_HOSTNAME */ + + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options)); + for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) { + options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]); + } + LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_SELECTING, msg_out, DHCP_DISCOVER, &options_out_len); + dhcp_option_trailer(options_out_len, msg_out->options, p_out); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: sendto(DISCOVER, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER)\n")); + udp_sendto_if_src(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif, IP4_ADDR_ANY); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: deleting()\n")); + pbuf_free(p_out); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover: SELECTING\n")); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_discover: could not allocate DHCP request\n")); + } + + if (dhcp->tries < 255) { + dhcp->tries++; + } + msecs = DHCP_REQUEST_BACKOFF_SEQUENCE(dhcp->tries); + dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover(): set request timeout %"U16_F" msecs\n", msecs)); + return result; +} + + +/** + * Bind the interface to the offered IP address. + * + * @param netif network interface to bind to the offered address + */ +static void +dhcp_bind(struct netif *netif) +{ + struct dhcp *dhcp; + ip4_addr_t sn_mask, gw_addr; + LWIP_ERROR("dhcp_bind: netif != NULL", (netif != NULL), return;); + dhcp = netif_dhcp_data(netif); + LWIP_ERROR("dhcp_bind: dhcp != NULL", (dhcp != NULL), return;); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(netif=%p) %c%c%"U16_F"\n", (void *)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); + + /* reset time used of lease */ + dhcp->lease_used = 0; + + if (dhcp->offered_t0_lease != 0xffffffffUL) { + /* set renewal period timer */ + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t0 renewal timer %"U32_F" secs\n", dhcp->offered_t0_lease)); + DHCP_SET_TIMEOUT_FROM_OFFERED_T0_LEASE(dhcp->t0_timeout, dhcp); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t0_lease * 1000)); + } + + /* temporary DHCP lease? */ + if (dhcp->offered_t1_renew != 0xffffffffUL) { + /* set renewal period timer */ + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t1 renewal timer %"U32_F" secs\n", dhcp->offered_t1_renew)); + DHCP_SET_TIMEOUT_FROM_OFFERED_T1_RENEW(dhcp->t1_timeout, dhcp); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t1_renew * 1000)); + dhcp->t1_renew_time = dhcp->t1_timeout; + } + /* set renewal period timer */ + if (dhcp->offered_t2_rebind != 0xffffffffUL) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t2 rebind timer %"U32_F" secs\n", dhcp->offered_t2_rebind)); + DHCP_SET_TIMEOUT_FROM_OFFERED_T2_REBIND(dhcp->t2_timeout, dhcp); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t2_rebind * 1000)); + dhcp->t2_rebind_time = dhcp->t2_timeout; + } + + /* If we have sub 1 minute lease, t2 and t1 will kick in at the same time. */ + if ((dhcp->t1_timeout >= dhcp->t2_timeout) && (dhcp->t2_timeout > 0)) { + dhcp->t1_timeout = 0; + } + + if (dhcp->flags & DHCP_FLAG_SUBNET_MASK_GIVEN) { + /* copy offered network mask */ + ip4_addr_copy(sn_mask, dhcp->offered_sn_mask); + } else { + /* subnet mask not given, choose a safe subnet mask given the network class */ + u8_t first_octet = ip4_addr1(&dhcp->offered_ip_addr); + if (first_octet <= 127) { + ip4_addr_set_u32(&sn_mask, PP_HTONL(0xff000000UL)); + } else if (first_octet >= 192) { + ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffffff00UL)); + } else { + ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffff0000UL)); + } + } + + ip4_addr_copy(gw_addr, dhcp->offered_gw_addr); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): IP: 0x%08"X32_F" SN: 0x%08"X32_F" GW: 0x%08"X32_F"\n", + ip4_addr_get_u32(&dhcp->offered_ip_addr), ip4_addr_get_u32(&sn_mask), ip4_addr_get_u32(&gw_addr))); + /* netif is now bound to DHCP leased address - set this before assigning the address + to ensure the callback can use dhcp_supplied_address() */ + dhcp_set_state(dhcp, DHCP_STATE_BOUND); + + netif_set_addr(netif, &dhcp->offered_ip_addr, &sn_mask, &gw_addr); + /* interface is used by routing now that an address is set */ +} + +/** + * @ingroup dhcp4 + * Renew an existing DHCP lease at the involved DHCP server. + * + * @param netif network interface which must renew its lease + */ +err_t +dhcp_renew(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + err_t result; + u16_t msecs; + u8_t i; + struct pbuf *p_out; + u16_t options_out_len; + + LWIP_ASSERT_CORE_LOCKED(); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_renew()\n")); + dhcp_set_state(dhcp, DHCP_STATE_RENEWING); + + /* create and initialize the DHCP message header */ + p_out = dhcp_create_msg(netif, dhcp, DHCP_REQUEST, &options_out_len); + if (p_out != NULL) { + struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload; + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); + options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif)); + + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options)); + for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) { + options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]); + } + +#if LWIP_NETIF_HOSTNAME + options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif); +#endif /* LWIP_NETIF_HOSTNAME */ + + LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_RENEWING, msg_out, DHCP_REQUEST, &options_out_len); + dhcp_option_trailer(options_out_len, msg_out->options, p_out); + + result = udp_sendto_if(dhcp_pcb, p_out, &dhcp->server_ip_addr, LWIP_IANA_PORT_DHCP_SERVER, netif); + pbuf_free(p_out); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew: RENEWING\n")); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_renew: could not allocate DHCP request\n")); + result = ERR_MEM; + } + if (dhcp->tries < 255) { + dhcp->tries++; + } + /* back-off on retries, but to a maximum of 20 seconds */ + msecs = (u16_t)(dhcp->tries < 10 ? dhcp->tries * 2000 : 20 * 1000); + dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew(): set request timeout %"U16_F" msecs\n", msecs)); + return result; +} + +/** + * Rebind with a DHCP server for an existing DHCP lease. + * + * @param netif network interface which must rebind with a DHCP server + */ +static err_t +dhcp_rebind(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + err_t result; + u16_t msecs; + u8_t i; + struct pbuf *p_out; + u16_t options_out_len; + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind()\n")); + dhcp_set_state(dhcp, DHCP_STATE_REBINDING); + + /* create and initialize the DHCP message header */ + p_out = dhcp_create_msg(netif, dhcp, DHCP_REQUEST, &options_out_len); + if (p_out != NULL) { + struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload; + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); + options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif)); + + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options)); + for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) { + options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]); + } + +#if LWIP_NETIF_HOSTNAME + options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif); +#endif /* LWIP_NETIF_HOSTNAME */ + + LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_REBINDING, msg_out, DHCP_DISCOVER, &options_out_len); + dhcp_option_trailer(options_out_len, msg_out->options, p_out); + + /* broadcast to server */ + result = udp_sendto_if(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif); + pbuf_free(p_out); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind: REBINDING\n")); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_rebind: could not allocate DHCP request\n")); + result = ERR_MEM; + } + if (dhcp->tries < 255) { + dhcp->tries++; + } + msecs = (u16_t)(dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000); + dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind(): set request timeout %"U16_F" msecs\n", msecs)); + return result; +} + +/** + * Enter REBOOTING state to verify an existing lease + * + * @param netif network interface which must reboot + */ +static err_t +dhcp_reboot(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + err_t result; + u16_t msecs; + u8_t i; + struct pbuf *p_out; + u16_t options_out_len; + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot()\n")); + dhcp_set_state(dhcp, DHCP_STATE_REBOOTING); + + /* create and initialize the DHCP message header */ + p_out = dhcp_create_msg(netif, dhcp, DHCP_REQUEST, &options_out_len); + if (p_out != NULL) { + struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload; + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); + options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN_MIN_REQUIRED); + + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_REQUESTED_IP, 4); + options_out_len = dhcp_option_long(options_out_len, msg_out->options, lwip_ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); + + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options)); + for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) { + options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]); + } + +#if LWIP_NETIF_HOSTNAME + options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif); +#endif /* LWIP_NETIF_HOSTNAME */ + + LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_REBOOTING, msg_out, DHCP_REQUEST, &options_out_len); + dhcp_option_trailer(options_out_len, msg_out->options, p_out); + + /* broadcast to server */ + result = udp_sendto_if(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif); + pbuf_free(p_out); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot: REBOOTING\n")); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_reboot: could not allocate DHCP request\n")); + result = ERR_MEM; + } + if (dhcp->tries < 255) { + dhcp->tries++; + } + msecs = (u16_t)(dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000); + dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot(): set request timeout %"U16_F" msecs\n", msecs)); + return result; +} + +/** + * @ingroup dhcp4 + * Release a DHCP lease and stop DHCP statemachine (and AUTOIP if LWIP_DHCP_AUTOIP_COOP). + * + * @param netif network interface + */ +void +dhcp_release_and_stop(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + ip_addr_t server_ip_addr; + + LWIP_ASSERT_CORE_LOCKED(); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_release_and_stop()\n")); + if (dhcp == NULL) { + return; + } + + /* already off? -> nothing to do */ + if (dhcp->state == DHCP_STATE_OFF) { + return; + } + + ip_addr_copy(server_ip_addr, dhcp->server_ip_addr); + + /* clean old DHCP offer */ + ip_addr_set_zero_ip4(&dhcp->server_ip_addr); + ip4_addr_set_zero(&dhcp->offered_ip_addr); + ip4_addr_set_zero(&dhcp->offered_sn_mask); + ip4_addr_set_zero(&dhcp->offered_gw_addr); +#if LWIP_DHCP_BOOTP_FILE + ip4_addr_set_zero(&dhcp->offered_si_addr); +#endif /* LWIP_DHCP_BOOTP_FILE */ + dhcp->offered_t0_lease = dhcp->offered_t1_renew = dhcp->offered_t2_rebind = 0; + dhcp->t1_renew_time = dhcp->t2_rebind_time = dhcp->lease_used = dhcp->t0_timeout = 0; + + /* send release message when current IP was assigned via DHCP */ + if (dhcp_supplied_address(netif)) { + /* create and initialize the DHCP message header */ + struct pbuf *p_out; + u16_t options_out_len; + dhcp_set_state(dhcp, DHCP_STATE_OFF); + p_out = dhcp_create_msg(netif, dhcp, DHCP_RELEASE, &options_out_len); + if (p_out != NULL) { + struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload; + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_SERVER_ID, 4); + options_out_len = dhcp_option_long(options_out_len, msg_out->options, lwip_ntohl(ip4_addr_get_u32(ip_2_ip4(&server_ip_addr)))); + + LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, dhcp->state, msg_out, DHCP_RELEASE, &options_out_len); + dhcp_option_trailer(options_out_len, msg_out->options, p_out); + + udp_sendto_if(dhcp_pcb, p_out, &server_ip_addr, LWIP_IANA_PORT_DHCP_SERVER, netif); + pbuf_free(p_out); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release: RELEASED, DHCP_STATE_OFF\n")); + } else { + /* sending release failed, but that's not a problem since the correct behaviour of dhcp does not rely on release */ + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_release: could not allocate DHCP request\n")); + } + + /* remove IP address from interface (prevents routing from selecting this interface) */ + netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4); + } else { + dhcp_set_state(dhcp, DHCP_STATE_OFF); + } + +#if LWIP_DHCP_DOES_ACD_CHECK + /* stop acd because we may be in checking state and the callback would trigger a bind */ + acd_remove(netif, &dhcp->acd); +#endif + + if (dhcp->pcb_allocated != 0) { + dhcp_dec_pcb_refcount(); /* free DHCP PCB if not needed any more */ + dhcp->pcb_allocated = 0; + } +} + +/** + * @ingroup dhcp4 + * This function calls dhcp_release_and_stop() internally. + * @deprecated Use dhcp_release_and_stop() instead. + */ +err_t +dhcp_release(struct netif *netif) +{ + dhcp_release_and_stop(netif); + return ERR_OK; +} + +/** + * @ingroup dhcp4 + * This function calls dhcp_release_and_stop() internally. + * @deprecated Use dhcp_release_and_stop() instead. + */ +void +dhcp_stop(struct netif *netif) +{ + dhcp_release_and_stop(netif); +} + +/* + * Set the DHCP state of a DHCP client. + * + * If the state changed, reset the number of tries. + */ +static void +dhcp_set_state(struct dhcp *dhcp, u8_t new_state) +{ + if (new_state != dhcp->state) { + dhcp->state = new_state; + dhcp->tries = 0; + dhcp->request_timeout = 0; + } +} + +/* + * Concatenate an option type and length field to the outgoing + * DHCP message. + * + */ +static u16_t +dhcp_option(u16_t options_out_len, u8_t *options, u8_t option_type, u8_t option_len) +{ + LWIP_ASSERT("dhcp_option: options_out_len + 2 + option_len <= DHCP_OPTIONS_LEN", options_out_len + 2U + option_len <= DHCP_OPTIONS_LEN); + options[options_out_len++] = option_type; + options[options_out_len++] = option_len; + return options_out_len; +} +/* + * Concatenate a single byte to the outgoing DHCP message. + * + */ +static u16_t +dhcp_option_byte(u16_t options_out_len, u8_t *options, u8_t value) +{ + LWIP_ASSERT("dhcp_option_byte: options_out_len < DHCP_OPTIONS_LEN", options_out_len < DHCP_OPTIONS_LEN); + options[options_out_len++] = value; + return options_out_len; +} + +static u16_t +dhcp_option_short(u16_t options_out_len, u8_t *options, u16_t value) +{ + LWIP_ASSERT("dhcp_option_short: options_out_len + 2 <= DHCP_OPTIONS_LEN", options_out_len + 2U <= DHCP_OPTIONS_LEN); + options[options_out_len++] = (u8_t)((value & 0xff00U) >> 8); + options[options_out_len++] = (u8_t) (value & 0x00ffU); + return options_out_len; +} + +static u16_t +dhcp_option_long(u16_t options_out_len, u8_t *options, u32_t value) +{ + LWIP_ASSERT("dhcp_option_long: options_out_len + 4 <= DHCP_OPTIONS_LEN", options_out_len + 4U <= DHCP_OPTIONS_LEN); + options[options_out_len++] = (u8_t)((value & 0xff000000UL) >> 24); + options[options_out_len++] = (u8_t)((value & 0x00ff0000UL) >> 16); + options[options_out_len++] = (u8_t)((value & 0x0000ff00UL) >> 8); + options[options_out_len++] = (u8_t)((value & 0x000000ffUL)); + return options_out_len; +} + +#if LWIP_NETIF_HOSTNAME +static u16_t +dhcp_option_hostname(u16_t options_out_len, u8_t *options, struct netif *netif) +{ + if (netif->hostname != NULL) { + size_t namelen = strlen(netif->hostname); + if (namelen > 0) { + size_t len; + const char *p = netif->hostname; + /* Shrink len to available bytes (need 2 bytes for OPTION_HOSTNAME + and 1 byte for trailer) */ + size_t available = DHCP_OPTIONS_LEN - options_out_len - 3; + LWIP_ASSERT("DHCP: hostname is too long!", namelen <= available); + len = LWIP_MIN(namelen, available); + LWIP_ASSERT("DHCP: hostname is too long!", len <= 0xFF); + options_out_len = dhcp_option(options_out_len, options, DHCP_OPTION_HOSTNAME, (u8_t)len); + while (len--) { + options_out_len = dhcp_option_byte(options_out_len, options, *p++); + } + } + } + return options_out_len; +} +#endif /* LWIP_NETIF_HOSTNAME */ + +/** + * Extract the DHCP message and the DHCP options. + * + * Extract the DHCP message and the DHCP options, each into a contiguous + * piece of memory. As a DHCP message is variable sized by its options, + * and also allows overriding some fields for options, the easy approach + * is to first unfold the options into a contiguous piece of memory, and + * use that further on. + * + */ +static err_t +dhcp_parse_reply(struct pbuf *p, struct dhcp *dhcp) +{ + u8_t *options; + u16_t offset; + u16_t offset_max; + u16_t options_offset; + u16_t options_idx; + u16_t options_idx_max; + struct pbuf *q; + int parse_file_as_options = 0; + int parse_sname_as_options = 0; + struct dhcp_msg *msg_in; +#if LWIP_DHCP_BOOTP_FILE + int file_overloaded = 0; +#endif + + LWIP_UNUSED_ARG(dhcp); + + /* clear received options */ + dhcp_clear_all_options(dhcp); + /* check that beginning of dhcp_msg (up to and including chaddr) is in first pbuf */ + if (p->len < DHCP_SNAME_OFS) { + return ERR_BUF; + } + msg_in = (struct dhcp_msg *)p->payload; +#if LWIP_DHCP_BOOTP_FILE + /* clear boot file name */ + dhcp->boot_file_name[0] = 0; +#endif /* LWIP_DHCP_BOOTP_FILE */ + + /* parse options */ + + /* start with options field */ + options_idx = DHCP_OPTIONS_OFS; + /* parse options to the end of the received packet */ + options_idx_max = p->tot_len; +again: + q = p; + options_offset = options_idx; + while ((q != NULL) && (options_idx >= q->len)) { + options_idx = (u16_t)(options_idx - q->len); + options_idx_max = (u16_t)(options_idx_max - q->len); + q = q->next; + } + if (q == NULL) { + return ERR_BUF; + } + offset = options_idx; + offset_max = options_idx_max; + options = (u8_t *)q->payload; + /* at least 1 byte to read and no end marker, then at least 3 bytes to read? */ + while ((q != NULL) && (offset < offset_max) && (options[offset] != DHCP_OPTION_END)) { + u8_t op = options[offset]; + u8_t len; + u8_t decode_len = 0; + int decode_idx = -1; + u16_t val_offset = (u16_t)(offset + 2); + if (val_offset < offset) { + /* overflow */ + return ERR_BUF; + } + /* len byte might be in the next pbuf */ + if ((offset + 1) < q->len) { + len = options[offset + 1]; + } else { + len = (q->next != NULL ? ((u8_t *)q->next->payload)[0] : 0); + } + /* LWIP_DEBUGF(DHCP_DEBUG, ("msg_offset=%"U16_F", q->len=%"U16_F"\n", msg_offset, q->len)); */ + decode_len = len; + switch (op) { + /* case(DHCP_OPTION_END): handled above */ + case (DHCP_OPTION_PAD): + /* special option: no len encoded */ + decode_len = len = 0; + /* will be increased below */ + break; + case (DHCP_OPTION_SUBNET_MASK): + LWIP_DHCP_INPUT_ERROR("len == 4", len == 4, return ERR_VAL;); + decode_idx = DHCP_OPTION_IDX_SUBNET_MASK; + break; + case (DHCP_OPTION_ROUTER): + decode_len = 4; /* only copy the first given router */ + LWIP_DHCP_INPUT_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;); + decode_idx = DHCP_OPTION_IDX_ROUTER; + break; +#if LWIP_DHCP_PROVIDE_DNS_SERVERS + case (DHCP_OPTION_DNS_SERVER): + /* special case: there might be more than one server */ + LWIP_DHCP_INPUT_ERROR("len %% 4 == 0", len % 4 == 0, return ERR_VAL;); + /* limit number of DNS servers */ + decode_len = LWIP_MIN(len, 4 * DNS_MAX_SERVERS); + LWIP_DHCP_INPUT_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;); + decode_idx = DHCP_OPTION_IDX_DNS_SERVER; + break; +#endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */ + case (DHCP_OPTION_LEASE_TIME): + LWIP_DHCP_INPUT_ERROR("len == 4", len == 4, return ERR_VAL;); + decode_idx = DHCP_OPTION_IDX_LEASE_TIME; + break; +#if LWIP_DHCP_GET_NTP_SRV + case (DHCP_OPTION_NTP): + /* special case: there might be more than one server */ + LWIP_DHCP_INPUT_ERROR("len %% 4 == 0", len % 4 == 0, return ERR_VAL;); + /* limit number of NTP servers */ + decode_len = LWIP_MIN(len, 4 * LWIP_DHCP_MAX_NTP_SERVERS); + LWIP_DHCP_INPUT_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;); + decode_idx = DHCP_OPTION_IDX_NTP_SERVER; + break; +#endif /* LWIP_DHCP_GET_NTP_SRV*/ + case (DHCP_OPTION_OVERLOAD): + LWIP_DHCP_INPUT_ERROR("len == 1", len == 1, return ERR_VAL;); + /* decode overload only in options, not in file/sname: invalid packet */ + LWIP_DHCP_INPUT_ERROR("overload in file/sname", options_offset == DHCP_OPTIONS_OFS, return ERR_VAL;); + decode_idx = DHCP_OPTION_IDX_OVERLOAD; + break; + case (DHCP_OPTION_MESSAGE_TYPE): + LWIP_DHCP_INPUT_ERROR("len == 1", len == 1, return ERR_VAL;); + decode_idx = DHCP_OPTION_IDX_MSG_TYPE; + break; + case (DHCP_OPTION_SERVER_ID): + LWIP_DHCP_INPUT_ERROR("len == 4", len == 4, return ERR_VAL;); + decode_idx = DHCP_OPTION_IDX_SERVER_ID; + break; + case (DHCP_OPTION_T1): + LWIP_DHCP_INPUT_ERROR("len == 4", len == 4, return ERR_VAL;); + decode_idx = DHCP_OPTION_IDX_T1; + break; + case (DHCP_OPTION_T2): + LWIP_DHCP_INPUT_ERROR("len == 4", len == 4, return ERR_VAL;); + decode_idx = DHCP_OPTION_IDX_T2; + break; + default: + decode_len = 0; + LWIP_DEBUGF(DHCP_DEBUG, ("skipping option %"U16_F" in options\n", (u16_t)op)); + LWIP_HOOK_DHCP_PARSE_OPTION(ip_current_netif(), dhcp, dhcp->state, msg_in, + dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE) ? (u8_t)dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE) : 0, + op, len, q, val_offset); + break; + } + if (op == DHCP_OPTION_PAD) { + offset++; + } else { + if (offset + len + 2 > 0xFFFF) { + /* overflow */ + return ERR_BUF; + } + offset = (u16_t)(offset + len + 2); + if (decode_len > 0) { + u32_t value = 0; + u16_t copy_len; +decode_next: + LWIP_ASSERT("check decode_idx", decode_idx >= 0 && decode_idx < DHCP_OPTION_IDX_MAX); + if (!dhcp_option_given(dhcp, decode_idx)) { + copy_len = LWIP_MIN(decode_len, 4); + if (pbuf_copy_partial(q, &value, copy_len, val_offset) != copy_len) { + return ERR_BUF; + } + if (decode_len > 4) { + /* decode more than one u32_t */ + u16_t next_val_offset; + LWIP_DHCP_INPUT_ERROR("decode_len %% 4 == 0", decode_len % 4 == 0, return ERR_VAL;); + dhcp_got_option(dhcp, decode_idx); + dhcp_set_option_value(dhcp, decode_idx, lwip_htonl(value)); + decode_len = (u8_t)(decode_len - 4); + next_val_offset = (u16_t)(val_offset + 4); + if (next_val_offset < val_offset) { + /* overflow */ + return ERR_BUF; + } + val_offset = next_val_offset; + decode_idx++; + goto decode_next; + } else if (decode_len == 4) { + value = lwip_ntohl(value); + } else { + LWIP_DHCP_INPUT_ERROR("invalid decode_len", decode_len == 1, return ERR_VAL;); + value = ((u8_t *)&value)[0]; + } + dhcp_got_option(dhcp, decode_idx); + dhcp_set_option_value(dhcp, decode_idx, value); + } + } + } + if (offset >= q->len) { + offset = (u16_t)(offset - q->len); + offset_max = (u16_t)(offset_max - q->len); + if (offset < offset_max) { + q = q->next; + LWIP_DHCP_INPUT_ERROR("next pbuf was null", q != NULL, return ERR_VAL;); + options = (u8_t *)q->payload; + } else { + /* We've run out of bytes, probably no end marker. Don't proceed. */ + return ERR_BUF; + } + } + } + /* is this an overloaded message? */ + if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_OVERLOAD)) { + u32_t overload = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_OVERLOAD); + dhcp_clear_option(dhcp, DHCP_OPTION_IDX_OVERLOAD); + if (overload == DHCP_OVERLOAD_FILE) { + parse_file_as_options = 1; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded file field\n")); + } else if (overload == DHCP_OVERLOAD_SNAME) { + parse_sname_as_options = 1; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname field\n")); + } else if (overload == DHCP_OVERLOAD_SNAME_FILE) { + parse_sname_as_options = 1; + parse_file_as_options = 1; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname and file field\n")); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("invalid overload option: %d\n", (int)overload)); + } + } + if (parse_file_as_options) { + /* if both are overloaded, parse file first and then sname (RFC 2131 ch. 4.1) */ + parse_file_as_options = 0; + options_idx = DHCP_FILE_OFS; + options_idx_max = DHCP_FILE_OFS + DHCP_FILE_LEN; +#if LWIP_DHCP_BOOTP_FILE + file_overloaded = 1; +#endif + goto again; + } else if (parse_sname_as_options) { + parse_sname_as_options = 0; + options_idx = DHCP_SNAME_OFS; + options_idx_max = DHCP_SNAME_OFS + DHCP_SNAME_LEN; + goto again; + } +#if LWIP_DHCP_BOOTP_FILE + if (!file_overloaded) { + /* only do this for ACK messages */ + if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE) && + (dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE) == DHCP_ACK)) + /* copy bootp file name, don't care for sname (server hostname) */ + if (pbuf_copy_partial(p, dhcp->boot_file_name, DHCP_FILE_LEN-1, DHCP_FILE_OFS) != (DHCP_FILE_LEN-1)) { + return ERR_BUF; + } + /* make sure the string is really NULL-terminated */ + dhcp->boot_file_name[DHCP_FILE_LEN-1] = 0; + } +#endif /* LWIP_DHCP_BOOTP_FILE */ + return ERR_OK; +} + +/** + * If an incoming DHCP message is in response to us, then trigger the state machine + */ +static void +dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port) +{ + struct netif *netif = ip_current_input_netif(); + struct dhcp *dhcp = netif_dhcp_data(netif); + struct dhcp_msg *reply_msg = (struct dhcp_msg *)p->payload; + u8_t msg_type; + u8_t i; + struct dhcp_msg *msg_in; + + LWIP_UNUSED_ARG(arg); + + /* Caught DHCP message from netif that does not have DHCP enabled? -> not interested */ + if ((dhcp == NULL) || (dhcp->pcb_allocated == 0)) { + goto free_pbuf_and_return; + } + + LWIP_ASSERT("invalid server address type", IP_IS_V4(addr)); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_recv(pbuf = %p) from DHCP server %"U16_F".%"U16_F".%"U16_F".%"U16_F" port %"U16_F"\n", (void *)p, + ip4_addr1_16(ip_2_ip4(addr)), ip4_addr2_16(ip_2_ip4(addr)), ip4_addr3_16(ip_2_ip4(addr)), ip4_addr4_16(ip_2_ip4(addr)), port)); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->len = %"U16_F"\n", p->len)); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->tot_len = %"U16_F"\n", p->tot_len)); + /* prevent warnings about unused arguments */ + LWIP_UNUSED_ARG(pcb); + LWIP_UNUSED_ARG(addr); + LWIP_UNUSED_ARG(port); + + if (p->len < DHCP_MIN_REPLY_LEN) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP reply message or pbuf too short\n")); + goto free_pbuf_and_return; + } + + if (reply_msg->op != DHCP_BOOTREPLY) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("not a DHCP reply message, but type %"U16_F"\n", (u16_t)reply_msg->op)); + goto free_pbuf_and_return; + } + /* iterate through hardware address and match against DHCP message */ + for (i = 0; i < netif->hwaddr_len && i < LWIP_MIN(DHCP_CHADDR_LEN, NETIF_MAX_HWADDR_LEN); i++) { + if (netif->hwaddr[i] != reply_msg->chaddr[i]) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, + ("netif->hwaddr[%"U16_F"]==%02"X16_F" != reply_msg->chaddr[%"U16_F"]==%02"X16_F"\n", + (u16_t)i, (u16_t)netif->hwaddr[i], (u16_t)i, (u16_t)reply_msg->chaddr[i])); + goto free_pbuf_and_return; + } + } + /* match transaction ID against what we expected */ + if (lwip_ntohl(reply_msg->xid) != dhcp->xid) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, + ("transaction id mismatch reply_msg->xid(%"X32_F")!=dhcp->xid(%"X32_F")\n", lwip_ntohl(reply_msg->xid), dhcp->xid)); + goto free_pbuf_and_return; + } + /* option fields could be unfold? */ + if (dhcp_parse_reply(p, dhcp) != ERR_OK) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, + ("problem unfolding DHCP message - too short on memory?\n")); + goto free_pbuf_and_return; + } + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("searching DHCP_OPTION_MESSAGE_TYPE\n")); + /* obtain pointer to DHCP message type */ + if (!dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE)) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP_OPTION_MESSAGE_TYPE option not found\n")); + goto free_pbuf_and_return; + } + + msg_in = (struct dhcp_msg *)p->payload; + /* read DHCP message type */ + msg_type = (u8_t)dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE); + /* message type is DHCP ACK? */ + if (msg_type == DHCP_ACK) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_ACK received\n")); + /* in requesting state or just reconnected to the network? */ + if ((dhcp->state == DHCP_STATE_REQUESTING) || + (dhcp->state == DHCP_STATE_REBOOTING)) { + dhcp_handle_ack(netif, msg_in); +#if LWIP_DHCP_DOES_ACD_CHECK + if ((netif->flags & NETIF_FLAG_ETHARP) != 0) { + /* check if the acknowledged lease address is already in use */ + dhcp_check(netif); + } else { + /* bind interface to the acknowledged lease address */ + dhcp_bind(netif); + } +#else + /* bind interface to the acknowledged lease address */ + dhcp_bind(netif); +#endif + } + /* already bound to the given lease address and using it? */ + else if ((dhcp->state == DHCP_STATE_REBINDING) || + (dhcp->state == DHCP_STATE_RENEWING)) { + dhcp_handle_ack(netif, msg_in); + dhcp_bind(netif); + } + } + /* received a DHCP_NAK in appropriate state? */ + else if ((msg_type == DHCP_NAK) && + ((dhcp->state == DHCP_STATE_REBOOTING) || (dhcp->state == DHCP_STATE_REQUESTING) || + (dhcp->state == DHCP_STATE_REBINDING) || (dhcp->state == DHCP_STATE_RENEWING ))) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_NAK received\n")); + dhcp_handle_nak(netif); + } + /* received a DHCP_OFFER in DHCP_STATE_SELECTING state? */ + else if ((msg_type == DHCP_OFFER) && (dhcp->state == DHCP_STATE_SELECTING)) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_OFFER received in DHCP_STATE_SELECTING state\n")); + /* remember offered lease */ + dhcp_handle_offer(netif, msg_in); + } + +free_pbuf_and_return: + pbuf_free(p); +} + +/** + * Create a DHCP request, fill in common headers + * + * @param netif the netif under DHCP control + * @param dhcp dhcp control struct + * @param message_type message type of the request + */ +static struct pbuf * +dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type, u16_t *options_out_len) +{ + u16_t i; + struct pbuf *p_out; + struct dhcp_msg *msg_out; + u16_t options_out_len_loc; + +#ifndef DHCP_GLOBAL_XID + /** default global transaction identifier starting value (easy to match + * with a packet analyser). We simply increment for each new request. + * Predefine DHCP_GLOBAL_XID to a better value or a function call to generate one + * at runtime, any supporting function prototypes can be defined in DHCP_GLOBAL_XID_HEADER */ +#if DHCP_CREATE_RAND_XID && defined(LWIP_RAND) + static u32_t xid; +#else /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */ + static u32_t xid = 0xABCD0000; +#endif /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */ +#else + if (!xid_initialised) { + xid = DHCP_GLOBAL_XID; + xid_initialised = !xid_initialised; + } +#endif + LWIP_ERROR("dhcp_create_msg: netif != NULL", (netif != NULL), return NULL;); + LWIP_ERROR("dhcp_create_msg: dhcp != NULL", (dhcp != NULL), return NULL;); + p_out = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct dhcp_msg), PBUF_RAM); + if (p_out == NULL) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, + ("dhcp_create_msg(): could not allocate pbuf\n")); + return NULL; + } + LWIP_ASSERT("dhcp_create_msg: check that first pbuf can hold struct dhcp_msg", + (p_out->len >= sizeof(struct dhcp_msg))); + + /* DHCP_REQUEST should reuse 'xid' from DHCPOFFER */ + if ((message_type != DHCP_REQUEST) || (dhcp->state == DHCP_STATE_REBOOTING)) { + /* reuse transaction identifier in retransmissions */ + if (dhcp->tries == 0) { +#if DHCP_CREATE_RAND_XID && defined(LWIP_RAND) + xid = LWIP_RAND(); +#else /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */ + xid++; +#endif /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */ + } + dhcp->xid = xid; + } + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, + ("transaction id xid(%"X32_F")\n", xid)); + + msg_out = (struct dhcp_msg *)p_out->payload; + memset(msg_out, 0, sizeof(struct dhcp_msg)); + + msg_out->op = DHCP_BOOTREQUEST; + /* @todo: make link layer independent */ + msg_out->htype = LWIP_IANA_HWTYPE_ETHERNET; + msg_out->hlen = netif->hwaddr_len; + msg_out->xid = lwip_htonl(dhcp->xid); + /* we don't need the broadcast flag since we can receive unicast traffic + before being fully configured! */ + /* set ciaddr to netif->ip_addr based on message_type and state */ + if ((message_type == DHCP_INFORM) || (message_type == DHCP_DECLINE) || (message_type == DHCP_RELEASE) || + ((message_type == DHCP_REQUEST) && /* DHCP_STATE_BOUND not used for sending! */ + ((dhcp->state == DHCP_STATE_RENEWING) || dhcp->state == DHCP_STATE_REBINDING))) { + ip4_addr_copy(msg_out->ciaddr, *netif_ip4_addr(netif)); + } + for (i = 0; i < LWIP_MIN(DHCP_CHADDR_LEN, NETIF_MAX_HWADDR_LEN); i++) { + /* copy netif hardware address (padded with zeroes through memset already) */ + msg_out->chaddr[i] = netif->hwaddr[i]; + } + msg_out->cookie = PP_HTONL(DHCP_MAGIC_COOKIE); + /* Add option MESSAGE_TYPE */ + options_out_len_loc = dhcp_option(0, msg_out->options, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN); + options_out_len_loc = dhcp_option_byte(options_out_len_loc, msg_out->options, message_type); + if (options_out_len) { + *options_out_len = options_out_len_loc; + } + return p_out; +} + +/** + * Add a DHCP message trailer + * + * Adds the END option to the DHCP message, and if + * necessary, up to three padding bytes. + */ +static void +dhcp_option_trailer(u16_t options_out_len, u8_t *options, struct pbuf *p_out) +{ + options[options_out_len++] = DHCP_OPTION_END; + /* packet is too small, or not 4 byte aligned? */ + while (((options_out_len < DHCP_MIN_OPTIONS_LEN) || (options_out_len & 3)) && + (options_out_len < DHCP_OPTIONS_LEN)) { + /* add a fill/padding byte */ + options[options_out_len++] = 0; + } + /* shrink the pbuf to the actual content length */ + pbuf_realloc(p_out, (u16_t)(sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + options_out_len)); +} + +/** check if DHCP supplied netif->ip_addr + * + * @param netif the netif to check + * @return 1 if DHCP supplied netif->ip_addr (states BOUND or RENEWING), + * 0 otherwise + */ +u8_t +dhcp_supplied_address(const struct netif *netif) +{ + if ((netif != NULL) && (netif_dhcp_data(netif) != NULL)) { + struct dhcp *dhcp = netif_dhcp_data(netif); + return (dhcp->state == DHCP_STATE_BOUND) || (dhcp->state == DHCP_STATE_RENEWING) || + (dhcp->state == DHCP_STATE_REBINDING); + } + return 0; +} + +#endif /* LWIP_IPV4 && LWIP_DHCP */ diff --git a/src/core/ipv4/etharp.c b/src/core/ipv4/etharp.c new file mode 100644 index 00000000000..3092dc944ab --- /dev/null +++ b/src/core/ipv4/etharp.c @@ -0,0 +1,1251 @@ +/** + * @file + * Address Resolution Protocol module for IP over Ethernet + * + * Functionally, ARP is divided into two parts. The first maps an IP address + * to a physical address when sending a packet, and the second part answers + * requests from other machines for our physical address. + * + * This implementation complies with RFC 826 (Ethernet ARP). It supports + * Gratuitous ARP from RFC3220 (IP Mobility Support for IPv4) section 4.6 + * if an interface calls etharp_gratuitous(our_netif) upon address change. + */ + +/* + * Copyright (c) 2001-2003 Swedish Institute of Computer Science. + * Copyright (c) 2003-2004 Leon Woestenberg <leon.woestenberg@axon.tv> + * Copyright (c) 2003-2004 Axon Digital Design B.V., The Netherlands. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT + * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * This file is part of the lwIP TCP/IP stack. + * + */ + +#include "lwip/opt.h" + +#if LWIP_IPV4 && LWIP_ARP /* don't build if not configured for use in lwipopts.h */ + +#include "lwip/etharp.h" +#include "lwip/stats.h" +#include "lwip/snmp.h" +#include "lwip/dhcp.h" +#include "lwip/autoip.h" +#include "lwip/acd.h" +#include "lwip/prot/iana.h" +#include "netif/ethernet.h" + +#include <string.h> + +#ifdef LWIP_HOOK_FILENAME +#include LWIP_HOOK_FILENAME +#endif + +/** Re-request a used ARP entry 1 minute before it would expire to prevent + * breaking a steadily used connection because the ARP entry timed out. */ +#define ARP_AGE_REREQUEST_USED_UNICAST (ARP_MAXAGE - 30) +#define ARP_AGE_REREQUEST_USED_BROADCAST (ARP_MAXAGE - 15) + +/** the time an ARP entry stays pending after first request, + * for ARP_TMR_INTERVAL = 1000, this is + * 10 seconds. + * + * @internal Keep this number at least 2, otherwise it might + * run out instantly if the timeout occurs directly after a request. + */ +#define ARP_MAXPENDING 5 + +/** ARP states */ +enum etharp_state { + ETHARP_STATE_EMPTY = 0, + ETHARP_STATE_PENDING, + ETHARP_STATE_STABLE, + ETHARP_STATE_STABLE_REREQUESTING_1, + ETHARP_STATE_STABLE_REREQUESTING_2 +#if ETHARP_SUPPORT_STATIC_ENTRIES + , ETHARP_STATE_STATIC +#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */ +}; + +struct etharp_entry { +#if ARP_QUEUEING + /** Pointer to queue of pending outgoing packets on this ARP entry. */ + struct etharp_q_entry *q; +#else /* ARP_QUEUEING */ + /** Pointer to a single pending outgoing packet on this ARP entry. */ + struct pbuf *q; +#endif /* ARP_QUEUEING */ + ip4_addr_t ipaddr; + struct netif *netif; + struct eth_addr ethaddr; + u16_t ctime; + u8_t state; +}; + +static struct etharp_entry arp_table[ARP_TABLE_SIZE]; + +#if !LWIP_NETIF_HWADDRHINT +static netif_addr_idx_t etharp_cached_entry; +#endif /* !LWIP_NETIF_HWADDRHINT */ + +/** Try hard to create a new entry - we want the IP address to appear in + the cache (even if this means removing an active entry or so). */ +#define ETHARP_FLAG_TRY_HARD 1 +#define ETHARP_FLAG_FIND_ONLY 2 +#if ETHARP_SUPPORT_STATIC_ENTRIES +#define ETHARP_FLAG_STATIC_ENTRY 4 +#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */ + +#if LWIP_NETIF_HWADDRHINT +#define ETHARP_SET_ADDRHINT(netif, addrhint) do { if (((netif) != NULL) && ((netif)->hints != NULL)) { \ + (netif)->hints->addr_hint = (addrhint); }} while(0) +#else /* LWIP_NETIF_HWADDRHINT */ +#define ETHARP_SET_ADDRHINT(netif, addrhint) (etharp_cached_entry = (addrhint)) +#endif /* LWIP_NETIF_HWADDRHINT */ + + +/* Check for maximum ARP_TABLE_SIZE */ +#if (ARP_TABLE_SIZE > NETIF_ADDR_IDX_MAX) +#error "ARP_TABLE_SIZE must fit in an s16_t, you have to reduce it in your lwipopts.h" +#endif + + +static err_t etharp_request_dst(struct netif *netif, const ip4_addr_t *ipaddr, const struct eth_addr *hw_dst_addr); +static err_t etharp_raw(struct netif *netif, + const struct eth_addr *ethsrc_addr, const struct eth_addr *ethdst_addr, + const struct eth_addr *hwsrc_addr, const ip4_addr_t *ipsrc_addr, + const struct eth_addr *hwdst_addr, const ip4_addr_t *ipdst_addr, + const u16_t opcode); + +#if ARP_QUEUEING +/** + * Free a complete queue of etharp entries + * + * @param q a queue of etharp_q_entry's to free + */ +static void +free_etharp_q(struct etharp_q_entry *q) +{ + struct etharp_q_entry *r; + LWIP_ASSERT("q != NULL", q != NULL); + while (q) { + r = q; + q = q->next; + LWIP_ASSERT("r->p != NULL", (r->p != NULL)); + pbuf_free(r->p); + memp_free(MEMP_ARP_QUEUE, r); + } +} +#else /* ARP_QUEUEING */ + +/** Compatibility define: free the queued pbuf */ +#define free_etharp_q(q) pbuf_free(q) + +#endif /* ARP_QUEUEING */ + +/** Clean up ARP table entries */ +static void +etharp_free_entry(int i) +{ + /* remove from SNMP ARP index tree */ + mib2_remove_arp_entry(arp_table[i].netif, &arp_table[i].ipaddr); + /* and empty packet queue */ + if (arp_table[i].q != NULL) { + /* remove all queued packets */ + LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_free_entry: freeing entry %"U16_F", packet queue %p.\n", (u16_t)i, (void *)(arp_table[i].q))); + free_etharp_q(arp_table[i].q); + arp_table[i].q = NULL; + } + /* recycle entry for re-use */ + arp_table[i].state = ETHARP_STATE_EMPTY; +#ifdef LWIP_DEBUG + /* for debugging, clean out the complete entry */ + arp_table[i].ctime = 0; + arp_table[i].netif = NULL; + ip4_addr_set_zero(&arp_table[i].ipaddr); + arp_table[i].ethaddr = ethzero; +#endif /* LWIP_DEBUG */ +} + +/** + * Clears expired entries in the ARP table. + * + * This function should be called every ARP_TMR_INTERVAL milliseconds (1 second), + * in order to expire entries in the ARP table. + */ +void +etharp_tmr(void) +{ + int i; + + LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_timer\n")); + /* remove expired entries from the ARP table */ + for (i = 0; i < ARP_TABLE_SIZE; ++i) { + u8_t state = arp_table[i].state; + if (state != ETHARP_STATE_EMPTY +#if ETHARP_SUPPORT_STATIC_ENTRIES + && (state != ETHARP_STATE_STATIC) +#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */ + ) { + arp_table[i].ctime++; + if ((arp_table[i].ctime >= ARP_MAXAGE) || + ((arp_table[i].state == ETHARP_STATE_PENDING) && + (arp_table[i].ctime >= ARP_MAXPENDING))) { + /* pending or stable entry has become old! */ + LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_timer: expired %s entry %d.\n", + arp_table[i].state >= ETHARP_STATE_STABLE ? "stable" : "pending", i)); + /* clean up entries that have just been expired */ + etharp_free_entry(i); + } else if (arp_table[i].state == ETHARP_STATE_STABLE_REREQUESTING_1) { + /* Don't send more than one request every 2 seconds. */ + arp_table[i].state = ETHARP_STATE_STABLE_REREQUESTING_2; + } else if (arp_table[i].state == ETHARP_STATE_STABLE_REREQUESTING_2) { + /* Reset state to stable, so that the next transmitted packet will + re-send an ARP request. */ + arp_table[i].state = ETHARP_STATE_STABLE; + } else if (arp_table[i].state == ETHARP_STATE_PENDING) { + /* still pending, resend an ARP query */ + etharp_request(arp_table[i].netif, &arp_table[i].ipaddr); + } + } + } +} + +/** + * Search the ARP table for a matching or new entry. + * + * If an IP address is given, return a pending or stable ARP entry that matches + * the address. If no match is found, create a new entry with this address set, + * but in state ETHARP_EMPTY. The caller must check and possibly change the + * state of the returned entry. + * + * If ipaddr is NULL, return a initialized new entry in state ETHARP_EMPTY. + * + * In all cases, attempt to create new entries from an empty entry. If no + * empty entries are available and ETHARP_FLAG_TRY_HARD flag is set, recycle + * old entries. Heuristic choose the least important entry for recycling. + * + * @param ipaddr IP address to find in ARP cache, or to add if not found. + * @param flags See @ref etharp_state + * @param netif netif related to this address (used for NETIF_HWADDRHINT) + * + * @return The ARP entry index that matched or is created, ERR_MEM if no + * entry is found or could be recycled. + */ +static s16_t +etharp_find_entry(const ip4_addr_t *ipaddr, u8_t flags, struct netif *netif) +{ + s16_t old_pending = ARP_TABLE_SIZE, old_stable = ARP_TABLE_SIZE; + s16_t empty = ARP_TABLE_SIZE; + s16_t i = 0; + /* oldest entry with packets on queue */ + s16_t old_queue = ARP_TABLE_SIZE; + /* its age */ + u16_t age_queue = 0, age_pending = 0, age_stable = 0; + + LWIP_UNUSED_ARG(netif); + + /** + * a) do a search through the cache, remember candidates + * b) select candidate entry + * c) create new entry + */ + + /* a) in a single search sweep, do all of this + * 1) remember the first empty entry (if any) + * 2) remember the oldest stable entry (if any) + * 3) remember the oldest pending entry without queued packets (if any) + * 4) remember the oldest pending entry with queued packets (if any) + * 5) search for a matching IP entry, either pending or stable + * until 5 matches, or all entries are searched for. + */ + + for (i = 0; i < ARP_TABLE_SIZE; ++i) { + u8_t state = arp_table[i].state; + /* no empty entry found yet and now we do find one? */ + if ((empty == ARP_TABLE_SIZE) && (state == ETHARP_STATE_EMPTY)) { + LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_find_entry: found empty entry %d\n", (int)i)); + /* remember first empty entry */ + empty = i; + } else if (state != ETHARP_STATE_EMPTY) { + LWIP_ASSERT("state == ETHARP_STATE_PENDING || state >= ETHARP_STATE_STABLE", + state == ETHARP_STATE_PENDING || state >= ETHARP_STATE_STABLE); + /* if given, does IP address match IP address in ARP entry? */ + if (ipaddr && ip4_addr_eq(ipaddr, &arp_table[i].ipaddr) +#if ETHARP_TABLE_MATCH_NETIF + && ((netif == NULL) || (netif == arp_table[i].netif)) +#endif /* ETHARP_TABLE_MATCH_NETIF */ + ) { + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: found matching entry %d\n", (int)i)); + /* found exact IP address match, simply bail out */ + return i; + } + /* pending entry? */ + if (state == ETHARP_STATE_PENDING) { + /* pending with queued packets? */ + if (arp_table[i].q != NULL) { + if (arp_table[i].ctime >= age_queue) { + old_queue = i; + age_queue = arp_table[i].ctime; + } + } else + /* pending without queued packets? */ + { + if (arp_table[i].ctime >= age_pending) { + old_pending = i; + age_pending = arp_table[i].ctime; + } + } + /* stable entry? */ + } else if (state >= ETHARP_STATE_STABLE) { +#if ETHARP_SUPPORT_STATIC_ENTRIES + /* don't record old_stable for static entries since they never expire */ + if (state < ETHARP_STATE_STATIC) +#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */ + { + /* remember entry with oldest stable entry in oldest, its age in maxtime */ + if (arp_table[i].ctime >= age_stable) { + old_stable = i; + age_stable = arp_table[i].ctime; + } + } + } + } + } + /* { we have no match } => try to create a new entry */ + + /* don't create new entry, only search? */ + if (((flags & ETHARP_FLAG_FIND_ONLY) != 0) || + /* or no empty entry found and not allowed to recycle? */ + ((empty == ARP_TABLE_SIZE) && ((flags & ETHARP_FLAG_TRY_HARD) == 0))) { + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: no empty entry found and not allowed to recycle\n")); + return (s16_t)ERR_MEM; + } + + /* b) choose the least destructive entry to recycle: + * 1) empty entry + * 2) oldest stable entry + * 3) oldest pending entry without queued packets + * 4) oldest pending entry with queued packets + * + * { ETHARP_FLAG_TRY_HARD is set at this point } + */ + + /* 1) empty entry available? */ + if (empty < ARP_TABLE_SIZE) { + i = empty; + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: selecting empty entry %d\n", (int)i)); + } else { + /* 2) found recyclable stable entry? */ + if (old_stable < ARP_TABLE_SIZE) { + /* recycle oldest stable*/ + i = old_stable; + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: selecting oldest stable entry %d\n", (int)i)); + /* no queued packets should exist on stable entries */ + LWIP_ASSERT("arp_table[i].q == NULL", arp_table[i].q == NULL); + /* 3) found recyclable pending entry without queued packets? */ + } else if (old_pending < ARP_TABLE_SIZE) { + /* recycle oldest pending */ + i = old_pending; + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: selecting oldest pending entry %d (without queue)\n", (int)i)); + /* 4) found recyclable pending entry with queued packets? */ + } else if (old_queue < ARP_TABLE_SIZE) { + /* recycle oldest pending (queued packets are free in etharp_free_entry) */ + i = old_queue; + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: selecting oldest pending entry %d, freeing packet queue %p\n", (int)i, (void *)(arp_table[i].q))); + /* no empty or recyclable entries found */ + } else { + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: no empty or recyclable entries found\n")); + return (s16_t)ERR_MEM; + } + + /* { empty or recyclable entry found } */ + LWIP_ASSERT("i < ARP_TABLE_SIZE", i < ARP_TABLE_SIZE); + etharp_free_entry(i); + } + + LWIP_ASSERT("i < ARP_TABLE_SIZE", i < ARP_TABLE_SIZE); + LWIP_ASSERT("arp_table[i].state == ETHARP_STATE_EMPTY", + arp_table[i].state == ETHARP_STATE_EMPTY); + + /* IP address given? */ + if (ipaddr != NULL) { + /* set IP address */ + ip4_addr_copy(arp_table[i].ipaddr, *ipaddr); + } + arp_table[i].ctime = 0; +#if ETHARP_TABLE_MATCH_NETIF + arp_table[i].netif = netif; +#endif /* ETHARP_TABLE_MATCH_NETIF */ + return (s16_t)i; +} + +/** + * Update (or insert) a IP/MAC address pair in the ARP cache. + * + * If a pending entry is resolved, any queued packets will be sent + * at this point. + * + * @param netif netif related to this entry (used for NETIF_ADDRHINT) + * @param ipaddr IP address of the inserted ARP entry. + * @param ethaddr Ethernet address of the inserted ARP entry. + * @param flags See @ref etharp_state + * + * @return + * - ERR_OK Successfully updated ARP cache. + * - ERR_MEM If we could not add a new ARP entry when ETHARP_FLAG_TRY_HARD was set. + * - ERR_ARG Non-unicast address given, those will not appear in ARP cache. + * + * @see pbuf_free() + */ +static err_t +etharp_update_arp_entry(struct netif *netif, const ip4_addr_t *ipaddr, struct eth_addr *ethaddr, u8_t flags) +{ + s16_t i; + LWIP_ASSERT("netif->hwaddr_len == ETH_HWADDR_LEN", netif->hwaddr_len == ETH_HWADDR_LEN); + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_update_arp_entry: %"U16_F".%"U16_F".%"U16_F".%"U16_F" - %02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F"\n", + ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr), + (u16_t)ethaddr->addr[0], (u16_t)ethaddr->addr[1], (u16_t)ethaddr->addr[2], + (u16_t)ethaddr->addr[3], (u16_t)ethaddr->addr[4], (u16_t)ethaddr->addr[5])); + /* non-unicast address? */ + if (ip4_addr_isany(ipaddr) || + ip4_addr_isbroadcast(ipaddr, netif) || + ip4_addr_ismulticast(ipaddr)) { + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_update_arp_entry: will not add non-unicast IP address to ARP cache\n")); + return ERR_ARG; + } + /* find or create ARP entry */ + i = etharp_find_entry(ipaddr, flags, netif); + /* bail out if no entry could be found */ + if (i < 0) { + return (err_t)i; + } + +#if ETHARP_SUPPORT_STATIC_ENTRIES + if (flags & ETHARP_FLAG_STATIC_ENTRY) { + /* record static type */ + arp_table[i].state = ETHARP_STATE_STATIC; + } else if (arp_table[i].state == ETHARP_STATE_STATIC) { + /* found entry is a static type, don't overwrite it */ + return ERR_VAL; + } else +#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */ + { + /* mark it stable */ + arp_table[i].state = ETHARP_STATE_STABLE; + } + + /* record network interface */ + arp_table[i].netif = netif; + /* insert in SNMP ARP index tree */ + mib2_add_arp_entry(netif, &arp_table[i].ipaddr); + + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_update_arp_entry: updating stable entry %"S16_F"\n", i)); + /* update address */ + SMEMCPY(&arp_table[i].ethaddr, ethaddr, ETH_HWADDR_LEN); + /* reset time stamp */ + arp_table[i].ctime = 0; + /* this is where we will send out queued packets! */ +#if ARP_QUEUEING + while (arp_table[i].q != NULL) { + struct pbuf *p; + /* remember remainder of queue */ + struct etharp_q_entry *q = arp_table[i].q; + /* pop first item off the queue */ + arp_table[i].q = q->next; + /* get the packet pointer */ + p = q->p; + /* now queue entry can be freed */ + memp_free(MEMP_ARP_QUEUE, q); +#else /* ARP_QUEUEING */ + if (arp_table[i].q != NULL) { + struct pbuf *p = arp_table[i].q; + arp_table[i].q = NULL; +#endif /* ARP_QUEUEING */ + /* send the queued IP packet */ + ethernet_output(netif, p, (struct eth_addr *)(netif->hwaddr), ethaddr, ETHTYPE_IP); + /* free the queued IP packet */ + pbuf_free(p); + } + return ERR_OK; +} + +#if ETHARP_SUPPORT_STATIC_ENTRIES +/** Add a new static entry to the ARP table. If an entry exists for the + * specified IP address, this entry is overwritten. + * If packets are queued for the specified IP address, they are sent out. + * + * @param ipaddr IP address for the new static entry + * @param ethaddr ethernet address for the new static entry + * @return See return values of etharp_add_static_entry + */ +err_t +etharp_add_static_entry(const ip4_addr_t *ipaddr, struct eth_addr *ethaddr) +{ + struct netif *netif; + LWIP_ASSERT_CORE_LOCKED(); + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_add_static_entry: %"U16_F".%"U16_F".%"U16_F".%"U16_F" - %02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F"\n", + ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr), + (u16_t)ethaddr->addr[0], (u16_t)ethaddr->addr[1], (u16_t)ethaddr->addr[2], + (u16_t)ethaddr->addr[3], (u16_t)ethaddr->addr[4], (u16_t)ethaddr->addr[5])); + + netif = ip4_route(ipaddr); + if (netif == NULL) { + return ERR_RTE; + } + + return etharp_update_arp_entry(netif, ipaddr, ethaddr, ETHARP_FLAG_TRY_HARD | ETHARP_FLAG_STATIC_ENTRY); +} + +/** Remove a static entry from the ARP table previously added with a call to + * etharp_add_static_entry. + * + * @param ipaddr IP address of the static entry to remove + * @return ERR_OK: entry removed + * ERR_MEM: entry wasn't found + * ERR_ARG: entry wasn't a static entry but a dynamic one + */ +err_t +etharp_remove_static_entry(const ip4_addr_t *ipaddr) +{ + s16_t i; + LWIP_ASSERT_CORE_LOCKED(); + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_remove_static_entry: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n", + ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr))); + + /* find or create ARP entry */ + i = etharp_find_entry(ipaddr, ETHARP_FLAG_FIND_ONLY, NULL); + /* bail out if no entry could be found */ + if (i < 0) { + return (err_t)i; + } + + if (arp_table[i].state != ETHARP_STATE_STATIC) { + /* entry wasn't a static entry, cannot remove it */ + return ERR_ARG; + } + /* entry found, free it */ + etharp_free_entry(i); + return ERR_OK; +} +#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */ + +/** + * Remove all ARP table entries of the specified netif. + * + * @param netif points to a network interface + */ +void +etharp_cleanup_netif(struct netif *netif) +{ + int i; + + for (i = 0; i < ARP_TABLE_SIZE; ++i) { + u8_t state = arp_table[i].state; + if ((state != ETHARP_STATE_EMPTY) && (arp_table[i].netif == netif)) { + etharp_free_entry(i); + } + } +} + +/** + * Finds (stable) ethernet/IP address pair from ARP table + * using interface and IP address index. + * @note the addresses in the ARP table are in network order! + * + * @param netif points to interface index + * @param ipaddr points to the (network order) IP address index + * @param eth_ret points to return pointer + * @param ip_ret points to return pointer + * @return table index if found, -1 otherwise + */ +ssize_t +etharp_find_addr(struct netif *netif, const ip4_addr_t *ipaddr, + struct eth_addr **eth_ret, const ip4_addr_t **ip_ret) +{ + s16_t i; + + LWIP_ASSERT("eth_ret != NULL && ip_ret != NULL", + eth_ret != NULL && ip_ret != NULL); + + LWIP_UNUSED_ARG(netif); + + i = etharp_find_entry(ipaddr, ETHARP_FLAG_FIND_ONLY, netif); + if ((i >= 0) && (arp_table[i].state >= ETHARP_STATE_STABLE)) { + *eth_ret = &arp_table[i].ethaddr; + *ip_ret = &arp_table[i].ipaddr; + return i; + } + return -1; +} + +/** + * Possibility to iterate over stable ARP table entries + * + * @param i entry number, 0 to ARP_TABLE_SIZE + * @param ipaddr return value: IP address + * @param netif return value: points to interface + * @param eth_ret return value: ETH address + * @return 1 on valid index, 0 otherwise + */ +int +etharp_get_entry(size_t i, ip4_addr_t **ipaddr, struct netif **netif, struct eth_addr **eth_ret) +{ + LWIP_ASSERT("ipaddr != NULL", ipaddr != NULL); + LWIP_ASSERT("netif != NULL", netif != NULL); + LWIP_ASSERT("eth_ret != NULL", eth_ret != NULL); + + if ((i < ARP_TABLE_SIZE) && (arp_table[i].state >= ETHARP_STATE_STABLE)) { + *ipaddr = &arp_table[i].ipaddr; + *netif = arp_table[i].netif; + *eth_ret = &arp_table[i].ethaddr; + return 1; + } else { + return 0; + } +} + +/** + * Responds to ARP requests to us. Upon ARP replies to us, add entry to cache + * send out queued IP packets. Updates cache with snooped address pairs. + * + * Should be called for incoming ARP packets. The pbuf in the argument + * is freed by this function. + * + * @param p The ARP packet that arrived on netif. Is freed by this function. + * @param netif The lwIP network interface on which the ARP packet pbuf arrived. + * + * @see pbuf_free() + */ +void +etharp_input(struct pbuf *p, struct netif *netif) +{ + struct etharp_hdr *hdr; + /* these are aligned properly, whereas the ARP header fields might not be */ + ip4_addr_t sipaddr, dipaddr; + u8_t for_us, from_us; + + LWIP_ASSERT_CORE_LOCKED(); + + LWIP_ERROR("netif != NULL", (netif != NULL), return;); + + hdr = (struct etharp_hdr *)p->payload; + + /* RFC 826 "Packet Reception": */ + if ((hdr->hwtype != PP_HTONS(LWIP_IANA_HWTYPE_ETHERNET)) || + (hdr->hwlen != ETH_HWADDR_LEN) || + (hdr->protolen != sizeof(ip4_addr_t)) || + (hdr->proto != PP_HTONS(ETHTYPE_IP))) { + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, + ("etharp_input: packet dropped, wrong hw type, hwlen, proto, protolen or ethernet type (%"U16_F"/%"U16_F"/%"U16_F"/%"U16_F")\n", + hdr->hwtype, (u16_t)hdr->hwlen, hdr->proto, (u16_t)hdr->protolen)); + ETHARP_STATS_INC(etharp.proterr); + ETHARP_STATS_INC(etharp.drop); + pbuf_free(p); + return; + } + ETHARP_STATS_INC(etharp.recv); + +#if LWIP_ACD + /* We have to check if a host already has configured our ip address and + * continuously check if there is a host with this IP-address so we can + * detect collisions. + * acd_arp_reply ensures the detection of conflicts. It will handle possible + * defending or retreating and will make sure a new IP address is selected. + * etharp_input does not need to handle packets that originate "from_us". + */ + acd_arp_reply(netif, hdr); +#endif /* LWIP_ACD */ + + /* Copy struct ip4_addr_wordaligned to aligned ip4_addr, to support compilers without + * structure packing (not using structure copy which breaks strict-aliasing rules). */ + IPADDR_WORDALIGNED_COPY_TO_IP4_ADDR_T(&sipaddr, &hdr->sipaddr); + IPADDR_WORDALIGNED_COPY_TO_IP4_ADDR_T(&dipaddr, &hdr->dipaddr); + + /* this interface is not configured? */ + if (ip4_addr_isany_val(*netif_ip4_addr(netif))) { + for_us = 0; + from_us = 0; + } else { + /* ARP packet directed to us? */ + for_us = (u8_t)ip4_addr_eq(&dipaddr, netif_ip4_addr(netif)); + /* ARP packet from us? */ + from_us = (u8_t)ip4_addr_eq(&sipaddr, netif_ip4_addr(netif)); + } + + /* ARP message directed to us? + -> add IP address in ARP cache; assume requester wants to talk to us, + can result in directly sending the queued packets for this host. + ARP message not directed to us? + -> update the source IP address in the cache, if present */ + etharp_update_arp_entry(netif, &sipaddr, &(hdr->shwaddr), + for_us ? ETHARP_FLAG_TRY_HARD : ETHARP_FLAG_FIND_ONLY); + + /* now act on the message itself */ + switch (hdr->opcode) { + /* ARP request? */ + case PP_HTONS(ARP_REQUEST): + /* ARP request. If it asked for our address, we send out a + * reply. In any case, we time-stamp any existing ARP entry, + * and possibly send out an IP packet that was queued on it. */ + + LWIP_DEBUGF (ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_input: incoming ARP request\n")); + /* ARP request for our address? */ + if (for_us && !from_us) { + /* send ARP response */ + etharp_raw(netif, + (struct eth_addr *)netif->hwaddr, &hdr->shwaddr, + (struct eth_addr *)netif->hwaddr, netif_ip4_addr(netif), + &hdr->shwaddr, &sipaddr, + ARP_REPLY); + /* we are not configured? */ + } else if (ip4_addr_isany_val(*netif_ip4_addr(netif))) { + /* { for_us == 0 and netif->ip_addr.addr == 0 } */ + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_input: we are unconfigured, ARP request ignored.\n")); + /* request was not directed to us */ + } else { + /* { for_us == 0 and netif->ip_addr.addr != 0 } */ + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_input: ARP request was not for us.\n")); + } + break; + case PP_HTONS(ARP_REPLY): + /* ARP reply. We already updated the ARP cache earlier. */ + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_input: incoming ARP reply\n")); + break; + default: + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_input: ARP unknown opcode type %"S16_F"\n", lwip_htons(hdr->opcode))); + ETHARP_STATS_INC(etharp.err); + break; + } + /* free ARP packet */ + pbuf_free(p); +} + +/** Just a small helper function that sends a pbuf to an ethernet address + * in the arp_table specified by the index 'arp_idx'. + */ +static err_t +etharp_output_to_arp_index(struct netif *netif, struct pbuf *q, netif_addr_idx_t arp_idx) +{ + LWIP_ASSERT("arp_table[arp_idx].state >= ETHARP_STATE_STABLE", + arp_table[arp_idx].state >= ETHARP_STATE_STABLE); + /* if arp table entry is about to expire: re-request it, + but only if its state is ETHARP_STATE_STABLE to prevent flooding the + network with ARP requests if this address is used frequently. */ + if (arp_table[arp_idx].state == ETHARP_STATE_STABLE) { + if (arp_table[arp_idx].ctime >= ARP_AGE_REREQUEST_USED_BROADCAST) { + /* issue a standard request using broadcast */ + if (etharp_request(netif, &arp_table[arp_idx].ipaddr) == ERR_OK) { + arp_table[arp_idx].state = ETHARP_STATE_STABLE_REREQUESTING_1; + } + } else if (arp_table[arp_idx].ctime >= ARP_AGE_REREQUEST_USED_UNICAST) { + /* issue a unicast request (for 15 seconds) to prevent unnecessary broadcast */ + if (etharp_request_dst(netif, &arp_table[arp_idx].ipaddr, &arp_table[arp_idx].ethaddr) == ERR_OK) { + arp_table[arp_idx].state = ETHARP_STATE_STABLE_REREQUESTING_1; + } + } + } + + return ethernet_output(netif, q, (struct eth_addr *)(netif->hwaddr), &arp_table[arp_idx].ethaddr, ETHTYPE_IP); +} + +/** + * Resolve and fill-in Ethernet address header for outgoing IP packet. + * + * For IP multicast and broadcast, corresponding Ethernet addresses + * are selected and the packet is transmitted on the link. + * + * For unicast addresses, the packet is submitted to etharp_query(). In + * case the IP address is outside the local network, the IP address of + * the gateway is used. + * + * @param netif The lwIP network interface which the IP packet will be sent on. + * @param q The pbuf(s) containing the IP packet to be sent. + * @param ipaddr The IP address of the packet destination. + * + * @return + * - ERR_RTE No route to destination (no gateway to external networks), + * or the return type of either etharp_query() or ethernet_output(). + */ +err_t +etharp_output(struct netif *netif, struct pbuf *q, const ip4_addr_t *ipaddr) +{ + const struct eth_addr *dest; + struct eth_addr mcastaddr; + const ip4_addr_t *dst_addr = ipaddr; + + LWIP_ASSERT_CORE_LOCKED(); + LWIP_ASSERT("netif != NULL", netif != NULL); + LWIP_ASSERT("q != NULL", q != NULL); + LWIP_ASSERT("ipaddr != NULL", ipaddr != NULL); + + /* Determine on destination hardware address. Broadcasts and multicasts + * are special, other IP addresses are looked up in the ARP table. */ + + /* broadcast destination IP address? */ + if (ip4_addr_isbroadcast(ipaddr, netif)) { + /* broadcast on Ethernet also */ + dest = (const struct eth_addr *)ðbroadcast; + /* multicast destination IP address? */ + } else if (ip4_addr_ismulticast(ipaddr)) { + /* Hash IP multicast address to MAC address.*/ + mcastaddr.addr[0] = LL_IP4_MULTICAST_ADDR_0; + mcastaddr.addr[1] = LL_IP4_MULTICAST_ADDR_1; + mcastaddr.addr[2] = LL_IP4_MULTICAST_ADDR_2; + mcastaddr.addr[3] = ip4_addr2(ipaddr) & 0x7f; + mcastaddr.addr[4] = ip4_addr3(ipaddr); + mcastaddr.addr[5] = ip4_addr4(ipaddr); + /* destination Ethernet address is multicast */ + dest = &mcastaddr; + /* unicast destination IP address? */ + } else { + netif_addr_idx_t i; + /* outside local network? if so, this can neither be a global broadcast nor + a subnet broadcast. */ + if (!ip4_addr_net_eq(ipaddr, netif_ip4_addr(netif), netif_ip4_netmask(netif)) && + !ip4_addr_islinklocal(ipaddr)) { +#if LWIP_AUTOIP + struct ip_hdr *iphdr = LWIP_ALIGNMENT_CAST(struct ip_hdr *, q->payload); + /* According to RFC 3297, chapter 2.6.2 (Forwarding Rules), a packet with + a link-local source address must always be "directly to its destination + on the same physical link. The host MUST NOT send the packet to any + router for forwarding". */ + if (!ip4_addr_islinklocal(&iphdr->src)) +#endif /* LWIP_AUTOIP */ + { +#ifdef LWIP_HOOK_ETHARP_GET_GW + /* For advanced routing, a single default gateway might not be enough, so get + the IP address of the gateway to handle the current destination address. */ + dst_addr = LWIP_HOOK_ETHARP_GET_GW(netif, ipaddr); + if (dst_addr == NULL) +#endif /* LWIP_HOOK_ETHARP_GET_GW */ + { + /* interface has default gateway? */ + if (!ip4_addr_isany_val(*netif_ip4_gw(netif))) { + /* send to hardware address of default gateway IP address */ + dst_addr = netif_ip4_gw(netif); + /* no default gateway available */ + } else { + /* no route to destination error (default gateway missing) */ + return ERR_RTE; + } + } + } + } +#if LWIP_NETIF_HWADDRHINT + if (netif->hints != NULL) { + /* per-pcb cached entry was given */ + netif_addr_idx_t etharp_cached_entry = netif->hints->addr_hint; + if (etharp_cached_entry < ARP_TABLE_SIZE) { +#endif /* LWIP_NETIF_HWADDRHINT */ + if ((arp_table[etharp_cached_entry].state >= ETHARP_STATE_STABLE) && +#if ETHARP_TABLE_MATCH_NETIF + (arp_table[etharp_cached_entry].netif == netif) && +#endif + (ip4_addr_eq(dst_addr, &arp_table[etharp_cached_entry].ipaddr))) { + /* the per-pcb-cached entry is stable and the right one! */ + ETHARP_STATS_INC(etharp.cachehit); + return etharp_output_to_arp_index(netif, q, etharp_cached_entry); + } +#if LWIP_NETIF_HWADDRHINT + } + } +#endif /* LWIP_NETIF_HWADDRHINT */ + + /* find stable entry: do this here since this is a critical path for + throughput and etharp_find_entry() is kind of slow */ + for (i = 0; i < ARP_TABLE_SIZE; i++) { + if ((arp_table[i].state >= ETHARP_STATE_STABLE) && +#if ETHARP_TABLE_MATCH_NETIF + (arp_table[i].netif == netif) && +#endif + (ip4_addr_eq(dst_addr, &arp_table[i].ipaddr))) { + /* found an existing, stable entry */ + ETHARP_SET_ADDRHINT(netif, i); + return etharp_output_to_arp_index(netif, q, i); + } + } + /* no stable entry found, use the (slower) query function: + queue on destination Ethernet address belonging to ipaddr */ + return etharp_query(netif, dst_addr, q); + } + + /* continuation for multicast/broadcast destinations */ + /* obtain source Ethernet address of the given interface */ + /* send packet directly on the link */ + return ethernet_output(netif, q, (struct eth_addr *)(netif->hwaddr), dest, ETHTYPE_IP); +} + +/** + * Send an ARP request for the given IP address and/or queue a packet. + * + * If the IP address was not yet in the cache, a pending ARP cache entry + * is added and an ARP request is sent for the given address. The packet + * is queued on this entry. + * + * If the IP address was already pending in the cache, a new ARP request + * is sent for the given address. The packet is queued on this entry. + * + * If the IP address was already stable in the cache, and a packet is + * given, it is directly sent and no ARP request is sent out. + * + * If the IP address was already stable in the cache, and no packet is + * given, an ARP request is sent out. + * + * @param netif The lwIP network interface on which ipaddr + * must be queried for. + * @param ipaddr The IP address to be resolved. + * @param q If non-NULL, a pbuf that must be delivered to the IP address. + * q is not freed by this function. + * + * @note q must only be ONE packet, not a packet queue! + * + * @return + * - ERR_BUF Could not make room for Ethernet header. + * - ERR_MEM Hardware address unknown, and no more ARP entries available + * to query for address or queue the packet. + * - ERR_MEM Could not queue packet due to memory shortage. + * - ERR_RTE No route to destination (no gateway to external networks). + * - ERR_ARG Non-unicast address given, those will not appear in ARP cache. + * + */ +err_t +etharp_query(struct netif *netif, const ip4_addr_t *ipaddr, struct pbuf *q) +{ + struct eth_addr *srcaddr = (struct eth_addr *)netif->hwaddr; + err_t result = ERR_MEM; + int is_new_entry = 0; + s16_t i_err; + netif_addr_idx_t i; + + /* non-unicast address? */ + if (ip4_addr_isbroadcast(ipaddr, netif) || + ip4_addr_ismulticast(ipaddr) || + ip4_addr_isany(ipaddr)) { + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: will not add non-unicast IP address to ARP cache\n")); + return ERR_ARG; + } + + /* find entry in ARP cache, ask to create entry if queueing packet */ + i_err = etharp_find_entry(ipaddr, ETHARP_FLAG_TRY_HARD, netif); + + /* could not find or create entry? */ + if (i_err < 0) { + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: could not create ARP entry\n")); + if (q) { + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: packet dropped\n")); + ETHARP_STATS_INC(etharp.memerr); + } + return (err_t)i_err; + } + LWIP_ASSERT("type overflow", (size_t)i_err < NETIF_ADDR_IDX_MAX); + i = (netif_addr_idx_t)i_err; + + /* mark a fresh entry as pending (we just sent a request) */ + if (arp_table[i].state == ETHARP_STATE_EMPTY) { + is_new_entry = 1; + arp_table[i].state = ETHARP_STATE_PENDING; + /* record network interface for re-sending arp request in etharp_tmr */ + arp_table[i].netif = netif; + } + + /* { i is either a STABLE or (new or existing) PENDING entry } */ + LWIP_ASSERT("arp_table[i].state == PENDING or STABLE", + ((arp_table[i].state == ETHARP_STATE_PENDING) || + (arp_table[i].state >= ETHARP_STATE_STABLE))); + + /* do we have a new entry? or an implicit query request? */ + if (is_new_entry || (q == NULL)) { + /* try to resolve it; send out ARP request */ + result = etharp_request(netif, ipaddr); + if (result != ERR_OK) { + /* ARP request couldn't be sent */ + /* We don't re-send arp request in etharp_tmr, but we still queue packets, + since this failure could be temporary, and the next packet calling + etharp_query again could lead to sending the queued packets. */ + } else { + /* ARP request successfully sent */ + if ((arp_table[i].state == ETHARP_STATE_PENDING) && !is_new_entry) { + /* A new ARP request has been sent for a pending entry. Reset the ctime to + not let it expire too fast. */ + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: reset ctime for entry %"S16_F"\n", (s16_t)i)); + arp_table[i].ctime = 0; + } + } + if (q == NULL) { + return result; + } + } + + /* packet given? */ + LWIP_ASSERT("q != NULL", q != NULL); + /* stable entry? */ + if (arp_table[i].state >= ETHARP_STATE_STABLE) { + /* we have a valid IP->Ethernet address mapping */ + ETHARP_SET_ADDRHINT(netif, i); + /* send the packet */ + result = ethernet_output(netif, q, srcaddr, &(arp_table[i].ethaddr), ETHTYPE_IP); + /* pending entry? (either just created or already pending */ + } else if (arp_table[i].state == ETHARP_STATE_PENDING) { + /* entry is still pending, queue the given packet 'q' */ + struct pbuf *p; + int copy_needed = 0; + /* IF q includes a pbuf that must be copied, copy the whole chain into a + * new PBUF_RAM. See the definition of PBUF_NEEDS_COPY for details. */ + p = q; + while (p) { + LWIP_ASSERT("no packet queues allowed!", (p->len != p->tot_len) || (p->next == NULL)); + if (PBUF_NEEDS_COPY(p)) { + copy_needed = 1; + break; + } + p = p->next; + } + if (copy_needed) { + /* copy the whole packet into new pbufs */ + p = pbuf_clone(PBUF_LINK, PBUF_RAM, q); + } else { + /* referencing the old pbuf is enough */ + p = q; + pbuf_ref(p); + } + /* packet could be taken over? */ + if (p != NULL) { + /* queue packet ... */ +#if ARP_QUEUEING + struct etharp_q_entry *new_entry; + /* allocate a new arp queue entry */ + new_entry = (struct etharp_q_entry *)memp_malloc(MEMP_ARP_QUEUE); + if (new_entry != NULL) { + unsigned int qlen = 0; + new_entry->next = NULL; + new_entry->p = p; + if (arp_table[i].q != NULL) { + /* queue was already existent, append the new entry to the end */ + struct etharp_q_entry *r; + r = arp_table[i].q; + qlen++; + while (r->next != NULL) { + r = r->next; + qlen++; + } + r->next = new_entry; + } else { + /* queue did not exist, first item in queue */ + arp_table[i].q = new_entry; + } +#if ARP_QUEUE_LEN + if (qlen >= ARP_QUEUE_LEN) { + struct etharp_q_entry *old; + old = arp_table[i].q; + arp_table[i].q = arp_table[i].q->next; + pbuf_free(old->p); + memp_free(MEMP_ARP_QUEUE, old); + } +#endif + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: queued packet %p on ARP entry %"U16_F"\n", (void *)q, i)); + result = ERR_OK; + } else { + /* the pool MEMP_ARP_QUEUE is empty */ + pbuf_free(p); + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: could not queue a copy of PBUF_REF packet %p (out of memory)\n", (void *)q)); + result = ERR_MEM; + } +#else /* ARP_QUEUEING */ + /* always queue one packet per ARP request only, freeing a previously queued packet */ + if (arp_table[i].q != NULL) { + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: dropped previously queued packet %p for ARP entry %"U16_F"\n", (void *)q, (u16_t)i)); + pbuf_free(arp_table[i].q); + } + arp_table[i].q = p; + result = ERR_OK; + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: queued packet %p on ARP entry %"U16_F"\n", (void *)q, (u16_t)i)); +#endif /* ARP_QUEUEING */ + } else { + ETHARP_STATS_INC(etharp.memerr); + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: could not queue a copy of PBUF_REF packet %p (out of memory)\n", (void *)q)); + result = ERR_MEM; + } + } + return result; +} + +/** + * Send a raw ARP packet (opcode and all addresses can be modified) + * + * @param netif the lwip network interface on which to send the ARP packet + * @param ethsrc_addr the source MAC address for the ethernet header + * @param ethdst_addr the destination MAC address for the ethernet header + * @param hwsrc_addr the source MAC address for the ARP protocol header + * @param ipsrc_addr the source IP address for the ARP protocol header + * @param hwdst_addr the destination MAC address for the ARP protocol header + * @param ipdst_addr the destination IP address for the ARP protocol header + * @param opcode the type of the ARP packet + * @return ERR_OK if the ARP packet has been sent + * ERR_MEM if the ARP packet couldn't be allocated + * any other err_t on failure + */ +static err_t +etharp_raw(struct netif *netif, const struct eth_addr *ethsrc_addr, + const struct eth_addr *ethdst_addr, + const struct eth_addr *hwsrc_addr, const ip4_addr_t *ipsrc_addr, + const struct eth_addr *hwdst_addr, const ip4_addr_t *ipdst_addr, + const u16_t opcode) +{ + struct pbuf *p; + err_t result = ERR_OK; + struct etharp_hdr *hdr; + + LWIP_ASSERT("netif != NULL", netif != NULL); + + /* allocate a pbuf for the outgoing ARP request packet */ + p = pbuf_alloc(PBUF_LINK, SIZEOF_ETHARP_HDR, PBUF_RAM); + /* could allocate a pbuf for an ARP request? */ + if (p == NULL) { + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, + ("etharp_raw: could not allocate pbuf for ARP request.\n")); + ETHARP_STATS_INC(etharp.memerr); + return ERR_MEM; + } + LWIP_ASSERT("check that first pbuf can hold struct etharp_hdr", + (p->len >= SIZEOF_ETHARP_HDR)); + + hdr = (struct etharp_hdr *)p->payload; + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_raw: sending raw ARP packet.\n")); + hdr->opcode = lwip_htons(opcode); + + LWIP_ASSERT("netif->hwaddr_len must be the same as ETH_HWADDR_LEN for etharp!", + (netif->hwaddr_len == ETH_HWADDR_LEN)); + + /* Write the ARP MAC-Addresses */ + SMEMCPY(&hdr->shwaddr, hwsrc_addr, ETH_HWADDR_LEN); + SMEMCPY(&hdr->dhwaddr, hwdst_addr, ETH_HWADDR_LEN); + /* Copy struct ip4_addr_wordaligned to aligned ip4_addr, to support compilers without + * structure packing. */ + IPADDR_WORDALIGNED_COPY_FROM_IP4_ADDR_T(&hdr->sipaddr, ipsrc_addr); + IPADDR_WORDALIGNED_COPY_FROM_IP4_ADDR_T(&hdr->dipaddr, ipdst_addr); + + hdr->hwtype = PP_HTONS(LWIP_IANA_HWTYPE_ETHERNET); + hdr->proto = PP_HTONS(ETHTYPE_IP); + /* set hwlen and protolen */ + hdr->hwlen = ETH_HWADDR_LEN; + hdr->protolen = sizeof(ip4_addr_t); + + /* send ARP query */ +#if LWIP_AUTOIP + /* If we are using Link-Local, all ARP packets that contain a Link-Local + * 'sender IP address' MUST be sent using link-layer broadcast instead of + * link-layer unicast. (See RFC3927 Section 2.5, last paragraph) */ + if (ip4_addr_islinklocal(ipsrc_addr)) { + ethernet_output(netif, p, ethsrc_addr, ðbroadcast, ETHTYPE_ARP); + } else +#endif /* LWIP_AUTOIP */ + { + ethernet_output(netif, p, ethsrc_addr, ethdst_addr, ETHTYPE_ARP); + } + + ETHARP_STATS_INC(etharp.xmit); + /* free ARP query packet */ + pbuf_free(p); + p = NULL; + /* could not allocate pbuf for ARP request */ + + return result; +} + +/** + * Send an ARP request packet asking for ipaddr to a specific eth address. + * Used to send unicast request to refresh the ARP table just before an entry + * times out + * + * @param netif the lwip network interface on which to send the request + * @param ipaddr the IP address for which to ask + * @param hw_dst_addr the ethernet address to send this packet to + * @return ERR_OK if the request has been sent + * ERR_MEM if the ARP packet couldn't be allocated + * any other err_t on failure + */ +static err_t +etharp_request_dst(struct netif *netif, const ip4_addr_t *ipaddr, const struct eth_addr *hw_dst_addr) +{ + return etharp_raw(netif, (struct eth_addr *)netif->hwaddr, hw_dst_addr, + (struct eth_addr *)netif->hwaddr, netif_ip4_addr(netif), ðzero, + ipaddr, ARP_REQUEST); +} + +/** + * Send an ARP request packet asking for ipaddr. + * + * @param netif the lwip network interface on which to send the request + * @param ipaddr the IP address for which to ask + * @return ERR_OK if the request has been sent + * ERR_MEM if the ARP packet couldn't be allocated + * any other err_t on failure + */ +err_t +etharp_request(struct netif *netif, const ip4_addr_t *ipaddr) +{ + LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_request: sending ARP request.\n")); + return etharp_request_dst(netif, ipaddr, ðbroadcast); +} + +#if LWIP_ACD +/** + * Send an ARP request packet probing for an ipaddr. + * Used to send probe messages for address conflict detection. + * + * @param netif the lwip network interface on which to send the request + * @param ipaddr the IP address to probe + * @return ERR_OK if the request has been sent + * ERR_MEM if the ARP packet couldn't be allocated + * any other err_t on failure + */ +err_t +etharp_acd_probe(struct netif *netif, const ip4_addr_t *ipaddr) +{ + return etharp_raw(netif, (struct eth_addr *)netif->hwaddr, ðbroadcast, + (struct eth_addr *)netif->hwaddr, IP4_ADDR_ANY4, ðzero, + ipaddr, ARP_REQUEST); +} + +/** + * Send an ARP request packet announcing an ipaddr. + * Used to send announce messages for address conflict detection. + * + * @param netif the lwip network interface on which to send the request + * @param ipaddr the IP address to announce + * @return ERR_OK if the request has been sent + * ERR_MEM if the ARP packet couldn't be allocated + * any other err_t on failure + */ +err_t +etharp_acd_announce(struct netif *netif, const ip4_addr_t *ipaddr) +{ + return etharp_raw(netif, (struct eth_addr *)netif->hwaddr, ðbroadcast, + (struct eth_addr *)netif->hwaddr, ipaddr, ðzero, + ipaddr, ARP_REQUEST); +} +#endif /* LWIP_ACD */ + +#endif /* LWIP_IPV4 && LWIP_ARP */ diff --git a/src/core/ipv4/icmp.c b/src/core/ipv4/icmp.c new file mode 100644 index 00000000000..9a82a67aa93 --- /dev/null +++ b/src/core/ipv4/icmp.c @@ -0,0 +1,407 @@ +/** + * @file + * ICMP - Internet Control Message Protocol + * + */ + +/* + * Copyright (c) 2001-2004 Swedish Institute of Computer Science. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT + * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * This file is part of the lwIP TCP/IP stack. + * + * Author: Adam Dunkels <adam@sics.se> + * + */ + +/* Some ICMP messages should be passed to the transport protocols. This + is not implemented. */ + +#include "lwip/opt.h" + +#if LWIP_IPV4 && LWIP_ICMP /* don't build if not configured for use in lwipopts.h */ + +#include "lwip/icmp.h" +#include "lwip/inet_chksum.h" +#include "lwip/ip.h" +#include "lwip/def.h" +#include "lwip/stats.h" + +#include <string.h> + +#ifdef LWIP_HOOK_FILENAME +#include LWIP_HOOK_FILENAME +#endif + +/** Small optimization: set to 0 if incoming PBUF_POOL pbuf always can be + * used to modify and send a response packet (and to 1 if this is not the case, + * e.g. when link header is stripped off when receiving) */ +#ifndef LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN +#define LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN 1 +#endif /* LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN */ + +/* The maximum amount of data from the original packet to return in a dest-unreachable */ +#define ICMP_DEST_UNREACH_DATASIZE 8 + +static void icmp_send_response(struct pbuf *p, u8_t type, u8_t code); + +/** + * Processes ICMP input packets, called from ip_input(). + * + * Currently only processes icmp echo requests and sends + * out the echo response. + * + * @param p the icmp echo request packet, p->payload pointing to the icmp header + * @param inp the netif on which this packet was received + */ +void +icmp_input(struct pbuf *p, struct netif *inp) +{ + u8_t type; +#ifdef LWIP_DEBUG + u8_t code; +#endif /* LWIP_DEBUG */ + struct icmp_echo_hdr *iecho; + const struct ip_hdr *iphdr_in; + u16_t hlen; + const ip4_addr_t *src; + + ICMP_STATS_INC(icmp.recv); + MIB2_STATS_INC(mib2.icmpinmsgs); + + iphdr_in = ip4_current_header(); + hlen = IPH_HL_BYTES(iphdr_in); + if (hlen < IP_HLEN) { + LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: short IP header (%"S16_F" bytes) received\n", hlen)); + goto lenerr; + } + if (p->len < sizeof(u16_t) * 2) { + LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: short ICMP (%"U16_F" bytes) received\n", p->tot_len)); + goto lenerr; + } + + type = *((u8_t *)p->payload); +#ifdef LWIP_DEBUG + code = *(((u8_t *)p->payload) + 1); + /* if debug is enabled but debug statement below is somehow disabled: */ + LWIP_UNUSED_ARG(code); +#endif /* LWIP_DEBUG */ + switch (type) { + case ICMP_ER: + /* This is OK, echo reply might have been parsed by a raw PCB + (as obviously, an echo request has been sent, too). */ + MIB2_STATS_INC(mib2.icmpinechoreps); + break; + case ICMP_ECHO: + MIB2_STATS_INC(mib2.icmpinechos); + src = ip4_current_dest_addr(); + /* multicast destination address? */ + if (ip4_addr_ismulticast(ip4_current_dest_addr())) { +#if LWIP_MULTICAST_PING + /* For multicast, use address of receiving interface as source address */ + src = netif_ip4_addr(inp); +#else /* LWIP_MULTICAST_PING */ + LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: Not echoing to multicast pings\n")); + goto icmperr; +#endif /* LWIP_MULTICAST_PING */ + } + /* broadcast destination address? */ + if (ip4_addr_isbroadcast(ip4_current_dest_addr(), ip_current_netif())) { +#if LWIP_BROADCAST_PING + /* For broadcast, use address of receiving interface as source address */ + src = netif_ip4_addr(inp); +#else /* LWIP_BROADCAST_PING */ + LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: Not echoing to broadcast pings\n")); + goto icmperr; +#endif /* LWIP_BROADCAST_PING */ + } + LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ping\n")); + if (p->tot_len < sizeof(struct icmp_echo_hdr)) { + LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: bad ICMP echo received\n")); + goto lenerr; + } +#if CHECKSUM_CHECK_ICMP + IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_CHECK_ICMP) { + if (inet_chksum_pbuf(p) != 0) { + LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: checksum failed for received ICMP echo\n")); + pbuf_free(p); + ICMP_STATS_INC(icmp.chkerr); + MIB2_STATS_INC(mib2.icmpinerrors); + return; + } + } +#endif +#if LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN + if (pbuf_add_header(p, hlen + PBUF_LINK_HLEN + PBUF_LINK_ENCAPSULATION_HLEN)) { + /* p is not big enough to contain link headers + * allocate a new one and copy p into it + */ + struct pbuf *r; + u16_t alloc_len = (u16_t)(p->tot_len + hlen); + if (alloc_len < p->tot_len) { + LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: allocating new pbuf failed (tot_len overflow)\n")); + goto icmperr; + } + /* allocate new packet buffer with space for link headers */ + r = pbuf_alloc(PBUF_LINK, alloc_len, PBUF_RAM); + if (r == NULL) { + LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: allocating new pbuf failed\n")); + goto icmperr; + } + if (r->len < hlen + sizeof(struct icmp_echo_hdr)) { + LWIP_DEBUGF(ICMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("first pbuf cannot hold the ICMP header\n")); + pbuf_free(r); + goto icmperr; + } + /* copy the ip header */ + MEMCPY(r->payload, iphdr_in, hlen); + /* switch r->payload back to icmp header (cannot fail) */ + if (pbuf_remove_header(r, hlen)) { + LWIP_ASSERT("icmp_input: moving r->payload to icmp header failed", 0); + pbuf_free(r); + goto icmperr; + } + /* copy the rest of the packet without ip header */ + if (pbuf_copy(r, p) != ERR_OK) { + LWIP_DEBUGF(ICMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("icmp_input: copying to new pbuf failed\n")); + pbuf_free(r); + goto icmperr; + } + /* free the original p */ + pbuf_free(p); + /* we now have an identical copy of p that has room for link headers */ + p = r; + } else { + /* restore p->payload to point to icmp header (cannot fail) */ + if (pbuf_remove_header(p, hlen + PBUF_LINK_HLEN + PBUF_LINK_ENCAPSULATION_HLEN)) { + LWIP_ASSERT("icmp_input: restoring original p->payload failed", 0); + goto icmperr; + } + } +#endif /* LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN */ + /* At this point, all checks are OK. */ + /* We generate an answer by switching the dest and src ip addresses, + * setting the icmp type to ECHO_RESPONSE and updating the checksum. */ + iecho = (struct icmp_echo_hdr *)p->payload; + if (pbuf_add_header(p, hlen)) { + LWIP_DEBUGF(ICMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("Can't move over header in packet\n")); + } else { + err_t ret; + struct ip_hdr *iphdr = (struct ip_hdr *)p->payload; + ip4_addr_copy(iphdr->src, *src); + ip4_addr_copy(iphdr->dest, *ip4_current_src_addr()); + ICMPH_TYPE_SET(iecho, ICMP_ER); +#if CHECKSUM_GEN_ICMP + IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_ICMP) { + /* adjust the checksum */ + if (iecho->chksum > PP_HTONS(0xffffU - (ICMP_ECHO << 8))) { + iecho->chksum = (u16_t)(iecho->chksum + PP_HTONS((u16_t)(ICMP_ECHO << 8)) + 1); + } else { + iecho->chksum = (u16_t)(iecho->chksum + PP_HTONS(ICMP_ECHO << 8)); + } + } +#if LWIP_CHECKSUM_CTRL_PER_NETIF + else { + iecho->chksum = 0; + } +#endif /* LWIP_CHECKSUM_CTRL_PER_NETIF */ +#else /* CHECKSUM_GEN_ICMP */ + iecho->chksum = 0; +#endif /* CHECKSUM_GEN_ICMP */ + + /* Set the correct TTL and recalculate the header checksum. */ + IPH_TTL_SET(iphdr, ICMP_TTL); + IPH_CHKSUM_SET(iphdr, 0); +#if CHECKSUM_GEN_IP + IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_IP) { + IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, hlen)); + } +#endif /* CHECKSUM_GEN_IP */ + + ICMP_STATS_INC(icmp.xmit); + /* increase number of messages attempted to send */ + MIB2_STATS_INC(mib2.icmpoutmsgs); + /* increase number of echo replies attempted to send */ + MIB2_STATS_INC(mib2.icmpoutechoreps); + + /* send an ICMP packet */ + ret = ip4_output_if(p, src, LWIP_IP_HDRINCL, + ICMP_TTL, 0, IP_PROTO_ICMP, inp); + if (ret != ERR_OK) { + LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ip_output_if returned an error: %s\n", lwip_strerr(ret))); + } + } + break; + default: + if (type == ICMP_DUR) { + MIB2_STATS_INC(mib2.icmpindestunreachs); + } else if (type == ICMP_TE) { + MIB2_STATS_INC(mib2.icmpintimeexcds); + } else if (type == ICMP_PP) { + MIB2_STATS_INC(mib2.icmpinparmprobs); + } else if (type == ICMP_SQ) { + MIB2_STATS_INC(mib2.icmpinsrcquenchs); + } else if (type == ICMP_RD) { + MIB2_STATS_INC(mib2.icmpinredirects); + } else if (type == ICMP_TS) { + MIB2_STATS_INC(mib2.icmpintimestamps); + } else if (type == ICMP_TSR) { + MIB2_STATS_INC(mib2.icmpintimestampreps); + } else if (type == ICMP_AM) { + MIB2_STATS_INC(mib2.icmpinaddrmasks); + } else if (type == ICMP_AMR) { + MIB2_STATS_INC(mib2.icmpinaddrmaskreps); + } + LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ICMP type %"S16_F" code %"S16_F" not supported.\n", + (s16_t)type, (s16_t)code)); + ICMP_STATS_INC(icmp.proterr); + ICMP_STATS_INC(icmp.drop); + } + pbuf_free(p); + return; +lenerr: + pbuf_free(p); + ICMP_STATS_INC(icmp.lenerr); + MIB2_STATS_INC(mib2.icmpinerrors); + return; +#if LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN || !LWIP_MULTICAST_PING || !LWIP_BROADCAST_PING +icmperr: + pbuf_free(p); + ICMP_STATS_INC(icmp.err); + MIB2_STATS_INC(mib2.icmpinerrors); + return; +#endif /* LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN || !LWIP_MULTICAST_PING || !LWIP_BROADCAST_PING */ +} + +/** + * Send an icmp 'destination unreachable' packet, called from ip_input() if + * the transport layer protocol is unknown and from udp_input() if the local + * port is not bound. + * + * @param p the input packet for which the 'unreachable' should be sent, + * p->payload pointing to the IP header + * @param t type of the 'unreachable' packet + */ +void +icmp_dest_unreach(struct pbuf *p, enum icmp_dur_type t) +{ + MIB2_STATS_INC(mib2.icmpoutdestunreachs); + icmp_send_response(p, ICMP_DUR, t); +} + +#if IP_FORWARD || IP_REASSEMBLY +/** + * Send a 'time exceeded' packet, called from ip_forward() if TTL is 0. + * + * @param p the input packet for which the 'time exceeded' should be sent, + * p->payload pointing to the IP header + * @param t type of the 'time exceeded' packet + */ +void +icmp_time_exceeded(struct pbuf *p, enum icmp_te_type t) +{ + MIB2_STATS_INC(mib2.icmpouttimeexcds); + icmp_send_response(p, ICMP_TE, t); +} + +#endif /* IP_FORWARD || IP_REASSEMBLY */ + +/** + * Send an icmp packet in response to an incoming packet. + * + * @param p the input packet for which the 'unreachable' should be sent, + * p->payload pointing to the IP header + * @param type Type of the ICMP header + * @param code Code of the ICMP header + */ +static void +icmp_send_response(struct pbuf *p, u8_t type, u8_t code) +{ + struct pbuf *q; + struct ip_hdr *iphdr; + struct icmp_hdr *icmphdr; + ip4_addr_t iphdr_src; + struct netif *netif; + u16_t response_pkt_len; + + /* increase number of messages attempted to send */ + MIB2_STATS_INC(mib2.icmpoutmsgs); + + /* Keep IP header + up to 8 bytes */ + response_pkt_len = IP_HLEN + ICMP_DEST_UNREACH_DATASIZE; + if (p->tot_len < response_pkt_len) { + response_pkt_len = p->tot_len; + } + + /* ICMP header + part of original packet */ + q = pbuf_alloc(PBUF_IP, sizeof(struct icmp_hdr) + response_pkt_len, PBUF_RAM); + if (q == NULL) { + LWIP_DEBUGF(ICMP_DEBUG, ("icmp_send_response: failed to allocate pbuf for ICMP packet.\n")); + MIB2_STATS_INC(mib2.icmpouterrors); + return; + } + LWIP_ASSERT("check that first pbuf can hold icmp message", + (q->len >= (sizeof(struct icmp_hdr) + response_pkt_len))); + + iphdr = (struct ip_hdr *)p->payload; + LWIP_DEBUGF(ICMP_DEBUG, ("icmp_send_response: Sending ICMP type %02X for packet from ", type)); + ip4_addr_debug_print_val(ICMP_DEBUG, iphdr->src); + LWIP_DEBUGF(ICMP_DEBUG, (" to ")); + ip4_addr_debug_print_val(ICMP_DEBUG, iphdr->dest); + LWIP_DEBUGF(ICMP_DEBUG, ("\n")); + + icmphdr = (struct icmp_hdr *)q->payload; + icmphdr->type = type; + icmphdr->code = code; + icmphdr->data = 0; + + /* copy fields from original packet */ + pbuf_copy_partial_pbuf(q, p, response_pkt_len, sizeof(struct icmp_hdr)); + + ip4_addr_copy(iphdr_src, iphdr->src); +#ifdef LWIP_HOOK_IP4_ROUTE_SRC + { + ip4_addr_t iphdr_dst; + ip4_addr_copy(iphdr_dst, iphdr->dest); + netif = ip4_route_src(&iphdr_dst, &iphdr_src); + } +#else + netif = ip4_route(&iphdr_src); +#endif + if (netif != NULL) { + /* calculate checksum */ + icmphdr->chksum = 0; +#if CHECKSUM_GEN_ICMP + IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_ICMP) { + icmphdr->chksum = inet_chksum(icmphdr, q->len); + } +#endif + ICMP_STATS_INC(icmp.xmit); + ip4_output_if(q, NULL, &iphdr_src, ICMP_TTL, 0, IP_PROTO_ICMP, netif); + } + pbuf_free(q); +} + +#endif /* LWIP_IPV4 && LWIP_ICMP */ diff --git a/src/core/ipv4/igmp.c b/src/core/ipv4/igmp.c new file mode 100644 index 00000000000..a74df16faf0 --- /dev/null +++ b/src/core/ipv4/igmp.c @@ -0,0 +1,801 @@ +/** + * @file + * IGMP - Internet Group Management Protocol + * + * @defgroup igmp IGMP + * @ingroup ip4 + * To be called from TCPIP thread + */ + +/* + * Copyright (c) 2002 CITEL Technologies Ltd. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of CITEL Technologies Ltd nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY CITEL TECHNOLOGIES AND CONTRIBUTORS ``AS IS'' + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL CITEL TECHNOLOGIES OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * This file is a contribution to the lwIP TCP/IP stack. + * The Swedish Institute of Computer Science and Adam Dunkels + * are specifically granted permission to redistribute this + * source code. +*/ + +/*------------------------------------------------------------- +Note 1) +Although the rfc requires V1 AND V2 capability +we will only support v2 since now V1 is very old (August 1989) +V1 can be added if required + +a debug print and statistic have been implemented to +show this up. +------------------------------------------------------------- +------------------------------------------------------------- +Note 2) +A query for a specific group address (as opposed to ALLHOSTS) +has now been implemented as I am unsure if it is required + +a debug print and statistic have been implemented to +show this up. +------------------------------------------------------------- +------------------------------------------------------------- +Note 3) +The router alert rfc 2113 is implemented in outgoing packets +but not checked rigorously incoming +------------------------------------------------------------- +Steve Reynolds +------------------------------------------------------------*/ + +/*----------------------------------------------------------------------------- + * RFC 988 - Host extensions for IP multicasting - V0 + * RFC 1054 - Host extensions for IP multicasting - + * RFC 1112 - Host extensions for IP multicasting - V1 + * RFC 2236 - Internet Group Management Protocol, Version 2 - V2 <- this code is based on this RFC (it's the "de facto" standard) + * RFC 3376 - Internet Group Management Protocol, Version 3 - V3 + * RFC 4604 - Using Internet Group Management Protocol Version 3... - V3+ + * RFC 2113 - IP Router Alert Option - + *----------------------------------------------------------------------------*/ + +/*----------------------------------------------------------------------------- + * Includes + *----------------------------------------------------------------------------*/ + +#include "lwip/opt.h" + +#if LWIP_IPV4 && LWIP_IGMP /* don't build if not configured for use in lwipopts.h */ + +#include "lwip/igmp.h" +#include "lwip/debug.h" +#include "lwip/def.h" +#include "lwip/mem.h" +#include "lwip/ip.h" +#include "lwip/inet_chksum.h" +#include "lwip/netif.h" +#include "lwip/stats.h" +#include "lwip/prot/igmp.h" + +#include <string.h> + +static struct igmp_group *igmp_lookup_group(struct netif *ifp, const ip4_addr_t *addr); +static err_t igmp_remove_group(struct netif *netif, struct igmp_group *group); +static void igmp_timeout(struct netif *netif, struct igmp_group *group); +static void igmp_start_timer(struct igmp_group *group, u8_t max_time); +static void igmp_delaying_member(struct igmp_group *group, u8_t maxresp); +static err_t igmp_ip_output_if(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest, struct netif *netif); +static void igmp_send(struct netif *netif, struct igmp_group *group, u8_t type); + +static ip4_addr_t allsystems; +static ip4_addr_t allrouters; + +/** + * Initialize the IGMP module + */ +void +igmp_init(void) +{ + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_init: initializing\n")); + + IP4_ADDR(&allsystems, 224, 0, 0, 1); + IP4_ADDR(&allrouters, 224, 0, 0, 2); +} + +/** + * Start IGMP processing on interface + * + * @param netif network interface on which start IGMP processing + */ +err_t +igmp_start(struct netif *netif) +{ + struct igmp_group *group; + + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_start: starting IGMP processing on if %p\n", (void *)netif)); + + group = igmp_lookup_group(netif, &allsystems); + + if (group != NULL) { + group->group_state = IGMP_GROUP_IDLE_MEMBER; + group->use++; + + /* Allow the igmp messages at the MAC level */ + if (netif->igmp_mac_filter != NULL) { + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_start: igmp_mac_filter(ADD ")); + ip4_addr_debug_print_val(IGMP_DEBUG, allsystems); + LWIP_DEBUGF(IGMP_DEBUG, (") on if %p\n", (void *)netif)); + netif->igmp_mac_filter(netif, &allsystems, NETIF_ADD_MAC_FILTER); + } + + return ERR_OK; + } + + return ERR_MEM; +} + +/** + * Stop IGMP processing on interface + * + * @param netif network interface on which stop IGMP processing + */ +err_t +igmp_stop(struct netif *netif) +{ + struct igmp_group *group = netif_igmp_data(netif); + + netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_IGMP, NULL); + + while (group != NULL) { + struct igmp_group *next = group->next; /* avoid use-after-free below */ + + /* disable the group at the MAC level */ + if (netif->igmp_mac_filter != NULL) { + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_stop: igmp_mac_filter(DEL ")); + ip4_addr_debug_print_val(IGMP_DEBUG, group->group_address); + LWIP_DEBUGF(IGMP_DEBUG, (") on if %p\n", (void *)netif)); + netif->igmp_mac_filter(netif, &(group->group_address), NETIF_DEL_MAC_FILTER); + } + + /* free group */ + memp_free(MEMP_IGMP_GROUP, group); + + /* move to "next" */ + group = next; + } + return ERR_OK; +} + +/** + * Report IGMP memberships for this interface + * + * @param netif network interface on which report IGMP memberships + */ +void +igmp_report_groups(struct netif *netif) +{ + struct igmp_group *group = netif_igmp_data(netif); + + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_report_groups: sending IGMP reports on if %p\n", (void *)netif)); + + /* Skip the first group in the list, it is always the allsystems group added in igmp_start() */ + if (group != NULL) { + group = group->next; + } + + while (group != NULL) { + igmp_delaying_member(group, IGMP_JOIN_DELAYING_MEMBER_TMR); + group = group->next; + } +} + +/** + * Search for a group in the netif's igmp group list + * + * @param ifp the network interface for which to look + * @param addr the group ip address to search for + * @return a struct igmp_group* if the group has been found, + * NULL if the group wasn't found. + */ +struct igmp_group * +igmp_lookfor_group(struct netif *ifp, const ip4_addr_t *addr) +{ + struct igmp_group *group = netif_igmp_data(ifp); + + while (group != NULL) { + if (ip4_addr_eq(&(group->group_address), addr)) { + return group; + } + group = group->next; + } + + /* to be clearer, we return NULL here instead of + * 'group' (which is also NULL at this point). + */ + return NULL; +} + +/** + * Search for a specific igmp group and create a new one if not found- + * + * @param ifp the network interface for which to look + * @param addr the group ip address to search + * @return a struct igmp_group*, + * NULL on memory error. + */ +static struct igmp_group * +igmp_lookup_group(struct netif *ifp, const ip4_addr_t *addr) +{ + struct igmp_group *group; + struct igmp_group *list_head = netif_igmp_data(ifp); + + /* Search if the group already exists */ + group = igmp_lookfor_group(ifp, addr); + if (group != NULL) { + /* Group already exists. */ + return group; + } + + /* Group doesn't exist yet, create a new one */ + group = (struct igmp_group *)memp_malloc(MEMP_IGMP_GROUP); + if (group != NULL) { + ip4_addr_set(&(group->group_address), addr); + group->timer = 0; /* Not running */ + group->group_state = IGMP_GROUP_NON_MEMBER; + group->last_reporter_flag = 0; + group->use = 0; + + /* Ensure allsystems group is always first in list */ + if (list_head == NULL) { + /* this is the first entry in linked list */ + LWIP_ASSERT("igmp_lookup_group: first group must be allsystems", + (ip4_addr_eq(addr, &allsystems) != 0)); + group->next = NULL; + netif_set_client_data(ifp, LWIP_NETIF_CLIENT_DATA_INDEX_IGMP, group); + } else { + /* append _after_ first entry */ + LWIP_ASSERT("igmp_lookup_group: all except first group must not be allsystems", + (ip4_addr_eq(addr, &allsystems) == 0)); + group->next = list_head->next; + list_head->next = group; + } + } + + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_lookup_group: %sallocated a new group with address ", (group ? "" : "impossible to "))); + ip4_addr_debug_print(IGMP_DEBUG, addr); + LWIP_DEBUGF(IGMP_DEBUG, (" on if %p\n", (void *)ifp)); + + return group; +} + +/** + * Remove a group from netif's igmp group list, but don't free it yet + * + * @param group the group to remove from the netif's igmp group list + * @return ERR_OK if group was removed from the list, an err_t otherwise + */ +static err_t +igmp_remove_group(struct netif *netif, struct igmp_group *group) +{ + err_t err = ERR_OK; + struct igmp_group *tmp_group; + + /* Skip the first group in the list, it is always the allsystems group added in igmp_start() */ + for (tmp_group = netif_igmp_data(netif); tmp_group != NULL; tmp_group = tmp_group->next) { + if (tmp_group->next == group) { + tmp_group->next = group->next; + break; + } + } + /* Group not found in netif's igmp group list */ + if (tmp_group == NULL) { + err = ERR_ARG; + } + + return err; +} + +/** + * Called from ip_input() if a new IGMP packet is received. + * + * @param p received igmp packet, p->payload pointing to the igmp header + * @param inp network interface on which the packet was received + * @param dest destination ip address of the igmp packet + */ +void +igmp_input(struct pbuf *p, struct netif *inp, const ip4_addr_t *dest) +{ + struct igmp_msg *igmp; + struct igmp_group *group; + struct igmp_group *groupref; + + IGMP_STATS_INC(igmp.recv); + + /* Note that the length CAN be greater than 8 but only 8 are used - All are included in the checksum */ + if (p->len < IGMP_MINLEN) { + pbuf_free(p); + IGMP_STATS_INC(igmp.lenerr); + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: length error\n")); + return; + } + + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: message from ")); + ip4_addr_debug_print_val(IGMP_DEBUG, ip4_current_header()->src); + LWIP_DEBUGF(IGMP_DEBUG, (" to address ")); + ip4_addr_debug_print_val(IGMP_DEBUG, ip4_current_header()->dest); + LWIP_DEBUGF(IGMP_DEBUG, (" on if %p\n", (void *)inp)); + + /* Now calculate and check the checksum */ + igmp = (struct igmp_msg *)p->payload; + if (inet_chksum(igmp, p->len)) { + pbuf_free(p); + IGMP_STATS_INC(igmp.chkerr); + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: checksum error\n")); + return; + } + + /* Packet is ok so find an existing group */ + group = igmp_lookfor_group(inp, dest); /* use the destination IP address of incoming packet */ + + /* If group can be found or create... */ + if (!group) { + pbuf_free(p); + IGMP_STATS_INC(igmp.drop); + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: IGMP frame not for us\n")); + return; + } + + /* NOW ACT ON THE INCOMING MESSAGE TYPE... */ + switch (igmp->igmp_msgtype) { + case IGMP_MEMB_QUERY: + /* IGMP_MEMB_QUERY to the "all systems" address ? */ + if ((ip4_addr_eq(dest, &allsystems)) && ip4_addr_isany(&igmp->igmp_group_address)) { + /* THIS IS THE GENERAL QUERY */ + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: General IGMP_MEMB_QUERY on \"ALL SYSTEMS\" address (224.0.0.1) [igmp_maxresp=%i]\n", (int)(igmp->igmp_maxresp))); + + if (igmp->igmp_maxresp == 0) { + IGMP_STATS_INC(igmp.rx_v1); + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: got an all hosts query with time== 0 - this is V1 and not implemented - treat as v2\n")); + igmp->igmp_maxresp = IGMP_V1_DELAYING_MEMBER_TMR; + } else { + IGMP_STATS_INC(igmp.rx_general); + } + + groupref = netif_igmp_data(inp); + + /* Do not send messages on the all systems group address! */ + /* Skip the first group in the list, it is always the allsystems group added in igmp_start() */ + if (groupref != NULL) { + groupref = groupref->next; + } + + while (groupref) { + igmp_delaying_member(groupref, igmp->igmp_maxresp); + groupref = groupref->next; + } + } else { + /* IGMP_MEMB_QUERY to a specific group ? */ + if (!ip4_addr_isany(&igmp->igmp_group_address)) { + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: IGMP_MEMB_QUERY to a specific group ")); + ip4_addr_debug_print_val(IGMP_DEBUG, igmp->igmp_group_address); + if (ip4_addr_eq(dest, &allsystems)) { + ip4_addr_t groupaddr; + LWIP_DEBUGF(IGMP_DEBUG, (" using \"ALL SYSTEMS\" address (224.0.0.1) [igmp_maxresp=%i]\n", (int)(igmp->igmp_maxresp))); + /* we first need to re-look for the group since we used dest last time */ + ip4_addr_copy(groupaddr, igmp->igmp_group_address); + group = igmp_lookfor_group(inp, &groupaddr); + } else { + LWIP_DEBUGF(IGMP_DEBUG, (" with the group address as destination [igmp_maxresp=%i]\n", (int)(igmp->igmp_maxresp))); + } + + if (group != NULL) { + IGMP_STATS_INC(igmp.rx_group); + igmp_delaying_member(group, igmp->igmp_maxresp); + } else { + IGMP_STATS_INC(igmp.drop); + } + } else { + IGMP_STATS_INC(igmp.proterr); + } + } + break; + case IGMP_V2_MEMB_REPORT: + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: IGMP_V2_MEMB_REPORT\n")); + IGMP_STATS_INC(igmp.rx_report); + if (group->group_state == IGMP_GROUP_DELAYING_MEMBER) { + /* This is on a specific group we have already looked up */ + group->timer = 0; /* stopped */ + group->group_state = IGMP_GROUP_IDLE_MEMBER; + group->last_reporter_flag = 0; + } + break; + default: + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: unexpected msg %d in state %d on group %p on if %p\n", + igmp->igmp_msgtype, group->group_state, (void *)&group, (void *)inp)); + IGMP_STATS_INC(igmp.proterr); + break; + } + + pbuf_free(p); + return; +} + +/** + * @ingroup igmp + * Join a group on one network interface. + * + * @param ifaddr ip address of the network interface which should join a new group + * @param groupaddr the ip address of the group which to join + * @return ERR_OK if group was joined on the netif(s), an err_t otherwise + */ +err_t +igmp_joingroup(const ip4_addr_t *ifaddr, const ip4_addr_t *groupaddr) +{ + err_t err = ERR_VAL; /* no matching interface */ + struct netif *netif; + + LWIP_ASSERT_CORE_LOCKED(); + + /* make sure it is multicast address */ + LWIP_ERROR("igmp_joingroup: attempt to join non-multicast address", ip4_addr_ismulticast(groupaddr), return ERR_VAL;); + LWIP_ERROR("igmp_joingroup: attempt to join allsystems address", (!ip4_addr_eq(groupaddr, &allsystems)), return ERR_VAL;); + + /* loop through netif's */ + NETIF_FOREACH(netif) { + /* Should we join this interface ? */ + if ((netif->flags & NETIF_FLAG_IGMP) && ((ip4_addr_isany(ifaddr) || ip4_addr_eq(netif_ip4_addr(netif), ifaddr)))) { + err = igmp_joingroup_netif(netif, groupaddr); + if (err != ERR_OK) { + /* Return an error even if some network interfaces are joined */ + /** @todo undo any other netif already joined */ + return err; + } + } + } + + return err; +} + +/** + * @ingroup igmp + * Join a group on one network interface. + * + * @param netif the network interface which should join a new group + * @param groupaddr the ip address of the group which to join + * @return ERR_OK if group was joined on the netif, an err_t otherwise + */ +err_t +igmp_joingroup_netif(struct netif *netif, const ip4_addr_t *groupaddr) +{ + struct igmp_group *group; + + LWIP_ASSERT_CORE_LOCKED(); + + /* make sure it is multicast address */ + LWIP_ERROR("igmp_joingroup_netif: attempt to join non-multicast address", ip4_addr_ismulticast(groupaddr), return ERR_VAL;); + LWIP_ERROR("igmp_joingroup_netif: attempt to join allsystems address", (!ip4_addr_eq(groupaddr, &allsystems)), return ERR_VAL;); + + /* make sure it is an igmp-enabled netif */ + LWIP_ERROR("igmp_joingroup_netif: attempt to join on non-IGMP netif", netif->flags & NETIF_FLAG_IGMP, return ERR_VAL;); + + /* find group or create a new one if not found */ + group = igmp_lookup_group(netif, groupaddr); + + if (group != NULL) { + /* This should create a new group, check the state to make sure */ + if (group->group_state != IGMP_GROUP_NON_MEMBER) { + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_joingroup_netif: join to group not in state IGMP_GROUP_NON_MEMBER\n")); + } else { + /* OK - it was new group */ + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_joingroup_netif: join to new group: ")); + ip4_addr_debug_print(IGMP_DEBUG, groupaddr); + LWIP_DEBUGF(IGMP_DEBUG, ("\n")); + + /* If first use of the group, allow the group at the MAC level */ + if ((group->use == 0) && (netif->igmp_mac_filter != NULL)) { + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_joingroup_netif: igmp_mac_filter(ADD ")); + ip4_addr_debug_print(IGMP_DEBUG, groupaddr); + LWIP_DEBUGF(IGMP_DEBUG, (") on if %p\n", (void *)netif)); + netif->igmp_mac_filter(netif, groupaddr, NETIF_ADD_MAC_FILTER); + } + + IGMP_STATS_INC(igmp.tx_join); + igmp_send(netif, group, IGMP_V2_MEMB_REPORT); + + igmp_start_timer(group, IGMP_JOIN_DELAYING_MEMBER_TMR); + + /* Need to work out where this timer comes from */ + group->group_state = IGMP_GROUP_DELAYING_MEMBER; + } + /* Increment group use */ + group->use++; + /* Join on this interface */ + return ERR_OK; + } else { + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_joingroup_netif: Not enough memory to join to group\n")); + return ERR_MEM; + } +} + +/** + * @ingroup igmp + * Leave a group on one network interface. + * + * @param ifaddr ip address of the network interface which should leave a group + * @param groupaddr the ip address of the group which to leave + * @return ERR_OK if group was left on the netif(s), an err_t otherwise + */ +err_t +igmp_leavegroup(const ip4_addr_t *ifaddr, const ip4_addr_t *groupaddr) +{ + err_t err = ERR_VAL; /* no matching interface */ + struct netif *netif; + + LWIP_ASSERT_CORE_LOCKED(); + + /* make sure it is multicast address */ + LWIP_ERROR("igmp_leavegroup: attempt to leave non-multicast address", ip4_addr_ismulticast(groupaddr), return ERR_VAL;); + LWIP_ERROR("igmp_leavegroup: attempt to leave allsystems address", (!ip4_addr_eq(groupaddr, &allsystems)), return ERR_VAL;); + + /* loop through netif's */ + NETIF_FOREACH(netif) { + /* Should we leave this interface ? */ + if ((netif->flags & NETIF_FLAG_IGMP) && ((ip4_addr_isany(ifaddr) || ip4_addr_eq(netif_ip4_addr(netif), ifaddr)))) { + err_t res = igmp_leavegroup_netif(netif, groupaddr); + if (err != ERR_OK) { + /* Store this result if we have not yet gotten a success */ + err = res; + } + } + } + + return err; +} + +/** + * @ingroup igmp + * Leave a group on one network interface. + * + * @param netif the network interface which should leave a group + * @param groupaddr the ip address of the group which to leave + * @return ERR_OK if group was left on the netif, an err_t otherwise + */ +err_t +igmp_leavegroup_netif(struct netif *netif, const ip4_addr_t *groupaddr) +{ + struct igmp_group *group; + + LWIP_ASSERT_CORE_LOCKED(); + + /* make sure it is multicast address */ + LWIP_ERROR("igmp_leavegroup_netif: attempt to leave non-multicast address", ip4_addr_ismulticast(groupaddr), return ERR_VAL;); + LWIP_ERROR("igmp_leavegroup_netif: attempt to leave allsystems address", (!ip4_addr_eq(groupaddr, &allsystems)), return ERR_VAL;); + + /* make sure it is an igmp-enabled netif */ + LWIP_ERROR("igmp_leavegroup_netif: attempt to leave on non-IGMP netif", netif->flags & NETIF_FLAG_IGMP, return ERR_VAL;); + + /* find group */ + group = igmp_lookfor_group(netif, groupaddr); + + if (group != NULL) { + /* Only send a leave if the flag is set according to the state diagram */ + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_leavegroup_netif: Leaving group: ")); + ip4_addr_debug_print(IGMP_DEBUG, groupaddr); + LWIP_DEBUGF(IGMP_DEBUG, ("\n")); + + /* If there is no other use of the group */ + if (group->use <= 1) { + /* Remove the group from the list */ + igmp_remove_group(netif, group); + + /* If we are the last reporter for this group */ + if (group->last_reporter_flag) { + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_leavegroup_netif: sending leaving group\n")); + IGMP_STATS_INC(igmp.tx_leave); + igmp_send(netif, group, IGMP_LEAVE_GROUP); + } + + /* Disable the group at the MAC level */ + if (netif->igmp_mac_filter != NULL) { + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_leavegroup_netif: igmp_mac_filter(DEL ")); + ip4_addr_debug_print(IGMP_DEBUG, groupaddr); + LWIP_DEBUGF(IGMP_DEBUG, (") on if %p\n", (void *)netif)); + netif->igmp_mac_filter(netif, groupaddr, NETIF_DEL_MAC_FILTER); + } + + /* Free group struct */ + memp_free(MEMP_IGMP_GROUP, group); + } else { + /* Decrement group use */ + group->use--; + } + return ERR_OK; + } else { + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_leavegroup_netif: not member of group\n")); + return ERR_VAL; + } +} + +/** + * The igmp timer function (both for NO_SYS=1 and =0) + * Should be called every IGMP_TMR_INTERVAL milliseconds (100 ms is default). + */ +void +igmp_tmr(void) +{ + struct netif *netif; + + NETIF_FOREACH(netif) { + struct igmp_group *group = netif_igmp_data(netif); + + while (group != NULL) { + if (group->timer > 0) { + group->timer--; + if (group->timer == 0) { + igmp_timeout(netif, group); + } + } + group = group->next; + } + } +} + +/** + * Called if a timeout for one group is reached. + * Sends a report for this group. + * + * @param group an igmp_group for which a timeout is reached + */ +static void +igmp_timeout(struct netif *netif, struct igmp_group *group) +{ + /* If the state is IGMP_GROUP_DELAYING_MEMBER then we send a report for this group + (unless it is the allsystems group) */ + if ((group->group_state == IGMP_GROUP_DELAYING_MEMBER) && + (!(ip4_addr_eq(&(group->group_address), &allsystems)))) { + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_timeout: report membership for group with address ")); + ip4_addr_debug_print_val(IGMP_DEBUG, group->group_address); + LWIP_DEBUGF(IGMP_DEBUG, (" on if %p\n", (void *)netif)); + + group->group_state = IGMP_GROUP_IDLE_MEMBER; + + IGMP_STATS_INC(igmp.tx_report); + igmp_send(netif, group, IGMP_V2_MEMB_REPORT); + } +} + +/** + * Start a timer for an igmp group + * + * @param group the igmp_group for which to start a timer + * @param max_time the time in multiples of IGMP_TMR_INTERVAL (decrease with + * every call to igmp_tmr()) + */ +static void +igmp_start_timer(struct igmp_group *group, u8_t max_time) +{ +#ifdef LWIP_RAND + group->timer = (u16_t)(max_time > 2 ? (LWIP_RAND() % max_time) : 1); +#else /* LWIP_RAND */ + /* ATTENTION: use this only if absolutely necessary! */ + group->timer = max_time / 2; +#endif /* LWIP_RAND */ + + if (group->timer == 0) { + group->timer = 1; + } +} + +/** + * Delaying membership report for a group if necessary + * + * @param group the igmp_group for which "delaying" membership report + * @param maxresp query delay + */ +static void +igmp_delaying_member(struct igmp_group *group, u8_t maxresp) +{ + if ((group->group_state == IGMP_GROUP_IDLE_MEMBER) || + ((group->group_state == IGMP_GROUP_DELAYING_MEMBER) && + ((group->timer == 0) || (maxresp < group->timer)))) { + igmp_start_timer(group, maxresp); + group->group_state = IGMP_GROUP_DELAYING_MEMBER; + } +} + + +/** + * Sends an IP packet on a network interface. This function constructs the IP header + * and calculates the IP header checksum. If the source IP address is NULL, + * the IP address of the outgoing network interface is filled in as source address. + * + * @param p the packet to send (p->payload points to the data, e.g. next + protocol header; if dest == LWIP_IP_HDRINCL, p already includes an + IP header and p->payload points to that IP header) + * @param src the source IP address to send from (if src == IP4_ADDR_ANY, the + * IP address of the netif used to send is used as source address) + * @param dest the destination IP address to send the packet to + * @param netif the netif on which to send this packet + * @return ERR_OK if the packet was sent OK + * ERR_BUF if p doesn't have enough space for IP/LINK headers + * returns errors returned by netif->output + */ +static err_t +igmp_ip_output_if(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest, struct netif *netif) +{ + /* This is the "router alert" option */ + u16_t ra[2]; + ra[0] = PP_HTONS(ROUTER_ALERT); + ra[1] = 0x0000; /* Router shall examine packet */ + IGMP_STATS_INC(igmp.xmit); + return ip4_output_if_opt(p, src, dest, IGMP_TTL, 0, IP_PROTO_IGMP, netif, ra, ROUTER_ALERTLEN); +} + +/** + * Send an igmp packet to a specific group. + * + * @param group the group to which to send the packet + * @param type the type of igmp packet to send + */ +static void +igmp_send(struct netif *netif, struct igmp_group *group, u8_t type) +{ + struct pbuf *p = NULL; + struct igmp_msg *igmp = NULL; + ip4_addr_t src = *IP4_ADDR_ANY4; + ip4_addr_t *dest = NULL; + + /* IP header + "router alert" option + IGMP header */ + p = pbuf_alloc(PBUF_TRANSPORT, IGMP_MINLEN, PBUF_RAM); + + if (p) { + igmp = (struct igmp_msg *)p->payload; + LWIP_ASSERT("igmp_send: check that first pbuf can hold struct igmp_msg", + (p->len >= sizeof(struct igmp_msg))); + ip4_addr_copy(src, *netif_ip4_addr(netif)); + + if (type == IGMP_V2_MEMB_REPORT) { + dest = &(group->group_address); + ip4_addr_copy(igmp->igmp_group_address, group->group_address); + group->last_reporter_flag = 1; /* Remember we were the last to report */ + } else { + if (type == IGMP_LEAVE_GROUP) { + dest = &allrouters; + ip4_addr_copy(igmp->igmp_group_address, group->group_address); + } + } + + if ((type == IGMP_V2_MEMB_REPORT) || (type == IGMP_LEAVE_GROUP)) { + igmp->igmp_msgtype = type; + igmp->igmp_maxresp = 0; + igmp->igmp_checksum = 0; + igmp->igmp_checksum = inet_chksum(igmp, IGMP_MINLEN); + + igmp_ip_output_if(p, &src, dest, netif); + } + + pbuf_free(p); + } else { + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_send: not enough memory for igmp_send\n")); + IGMP_STATS_INC(igmp.memerr); + } +} + +#endif /* LWIP_IPV4 && LWIP_IGMP */ diff --git a/src/core/ipv4/ip4.c b/src/core/ipv4/ip4.c new file mode 100644 index 00000000000..e044bff2df9 --- /dev/null +++ b/src/core/ipv4/ip4.c @@ -0,0 +1,1166 @@ +/** + * @file + * This is the IPv4 layer implementation for incoming and outgoing IP traffic. + * + * @see ip_frag.c + * + */ + +/* + * Copyright (c) 2001-2004 Swedish Institute of Computer Science. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT + * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * This file is part of the lwIP TCP/IP stack. + * + * Author: Adam Dunkels <adam@sics.se> + * + */ + +#include "lwip/opt.h" + +#if LWIP_IPV4 + +#include "lwip/ip.h" +#include "lwip/def.h" +#include "lwip/mem.h" +#include "lwip/ip4_frag.h" +#include "lwip/inet_chksum.h" +#include "lwip/netif.h" +#include "lwip/icmp.h" +#include "lwip/igmp.h" +#include "lwip/priv/raw_priv.h" +#include "lwip/udp.h" +#include "lwip/priv/tcp_priv.h" +#include "lwip/autoip.h" +#include "lwip/stats.h" +#include "lwip/prot/iana.h" + +#include <string.h> + +#ifdef LWIP_HOOK_FILENAME +#include LWIP_HOOK_FILENAME +#endif + +/** Set this to 0 in the rare case of wanting to call an extra function to + * generate the IP checksum (in contrast to calculating it on-the-fly). */ +#ifndef LWIP_INLINE_IP_CHKSUM +#if LWIP_CHECKSUM_CTRL_PER_NETIF +#define LWIP_INLINE_IP_CHKSUM 0 +#else /* LWIP_CHECKSUM_CTRL_PER_NETIF */ +#define LWIP_INLINE_IP_CHKSUM 1 +#endif /* LWIP_CHECKSUM_CTRL_PER_NETIF */ +#endif + +#if LWIP_INLINE_IP_CHKSUM && CHECKSUM_GEN_IP +#define CHECKSUM_GEN_IP_INLINE 1 +#else +#define CHECKSUM_GEN_IP_INLINE 0 +#endif + +#if LWIP_DHCP || defined(LWIP_IP_ACCEPT_UDP_PORT) +#define IP_ACCEPT_LINK_LAYER_ADDRESSING 1 + +/** Some defines for DHCP to let link-layer-addressed packets through while the + * netif is down. + * To use this in your own application/protocol, define LWIP_IP_ACCEPT_UDP_PORT(port) + * to return 1 if the port is accepted and 0 if the port is not accepted. + */ +#if LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) +/* accept DHCP client port and custom port */ +#define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) (((port) == PP_NTOHS(LWIP_IANA_PORT_DHCP_CLIENT)) \ + || (LWIP_IP_ACCEPT_UDP_PORT(port))) +#elif defined(LWIP_IP_ACCEPT_UDP_PORT) /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */ +/* accept custom port only */ +#define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) (LWIP_IP_ACCEPT_UDP_PORT(port)) +#else /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */ +/* accept DHCP client port only */ +#define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) ((port) == PP_NTOHS(LWIP_IANA_PORT_DHCP_CLIENT)) +#endif /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */ + +#else /* LWIP_DHCP */ +#define IP_ACCEPT_LINK_LAYER_ADDRESSING 0 +#endif /* LWIP_DHCP */ + +/** The IP header ID of the next outgoing IP packet */ +static u16_t ip_id; + +#if LWIP_MULTICAST_TX_OPTIONS +/** The default netif used for multicast */ +static struct netif *ip4_default_multicast_netif; + +/** + * @ingroup ip4 + * Set a default netif for IPv4 multicast. */ +void +ip4_set_default_multicast_netif(struct netif *default_multicast_netif) +{ + ip4_default_multicast_netif = default_multicast_netif; +} +#endif /* LWIP_MULTICAST_TX_OPTIONS */ + +#ifdef LWIP_HOOK_IP4_ROUTE_SRC +/** + * Source based IPv4 routing must be fully implemented in + * LWIP_HOOK_IP4_ROUTE_SRC(). This function only provides the parameters. + */ +struct netif * +ip4_route_src(const ip4_addr_t *src, const ip4_addr_t *dest) +{ + if (src != NULL) { + /* when src==NULL, the hook is called from ip4_route(dest) */ + struct netif *netif = LWIP_HOOK_IP4_ROUTE_SRC(src, dest); + if (netif != NULL) { + return netif; + } + } + return ip4_route(dest); +} +#endif /* LWIP_HOOK_IP4_ROUTE_SRC */ + +/** + * Finds the appropriate network interface for a given IP address. It + * searches the list of network interfaces linearly. A match is found + * if the masked IP address of the network interface equals the masked + * IP address given to the function. + * + * @param dest the destination IP address for which to find the route + * @return the netif on which to send to reach dest + */ +struct netif * +ip4_route(const ip4_addr_t *dest) +{ +#if !LWIP_SINGLE_NETIF + struct netif *netif; + + LWIP_ASSERT_CORE_LOCKED(); + +#if LWIP_MULTICAST_TX_OPTIONS + /* Use administratively selected interface for multicast by default */ + if (ip4_addr_ismulticast(dest) && ip4_default_multicast_netif) { + return ip4_default_multicast_netif; + } +#endif /* LWIP_MULTICAST_TX_OPTIONS */ + + /* bug #54569: in case LWIP_SINGLE_NETIF=1 and LWIP_DEBUGF() disabled, the following loop is optimized away */ + LWIP_UNUSED_ARG(dest); + + /* iterate through netifs */ + NETIF_FOREACH(netif) { + /* is the netif up, does it have a link and a valid address? */ + if (netif_is_up(netif) && netif_is_link_up(netif) && !ip4_addr_isany_val(*netif_ip4_addr(netif))) { + /* network mask matches? */ + if (ip4_addr_net_eq(dest, netif_ip4_addr(netif), netif_ip4_netmask(netif))) { + /* return netif on which to forward IP packet */ + return netif; + } + /* gateway matches on a non broadcast interface? (i.e. peer in a point to point interface) */ + if (((netif->flags & NETIF_FLAG_BROADCAST) == 0) && ip4_addr_eq(dest, netif_ip4_gw(netif))) { + /* return netif on which to forward IP packet */ + return netif; + } + } + } + +#if LWIP_NETIF_LOOPBACK && !LWIP_HAVE_LOOPIF + /* loopif is disabled, loopback traffic is passed through any netif */ + if (ip4_addr_isloopback(dest)) { + /* don't check for link on loopback traffic */ + if ((netif_default != NULL) && netif_is_up(netif_default)) { + return netif_default; + } + /* default netif is not up, just use any netif for loopback traffic */ + NETIF_FOREACH(netif) { + if (netif_is_up(netif)) { + return netif; + } + } + return NULL; + } +#endif /* LWIP_NETIF_LOOPBACK && !LWIP_HAVE_LOOPIF */ + +#ifdef LWIP_HOOK_IP4_ROUTE_SRC + netif = LWIP_HOOK_IP4_ROUTE_SRC(NULL, dest); + if (netif != NULL) { + return netif; + } +#elif defined(LWIP_HOOK_IP4_ROUTE) + netif = LWIP_HOOK_IP4_ROUTE(dest); + if (netif != NULL) { + return netif; + } +#endif +#endif /* !LWIP_SINGLE_NETIF */ + + if ((netif_default == NULL) || !netif_is_up(netif_default) || !netif_is_link_up(netif_default) || + ip4_addr_isany_val(*netif_ip4_addr(netif_default)) || ip4_addr_isloopback(dest)) { + /* No matching netif found and default netif is not usable. + If this is not good enough for you, use LWIP_HOOK_IP4_ROUTE() */ + LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip4_route: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n", + ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest))); + IP_STATS_INC(ip.rterr); + MIB2_STATS_INC(mib2.ipoutnoroutes); + return NULL; + } + + return netif_default; +} + +#if IP_FORWARD +/** + * Determine whether an IP address is in a reserved set of addresses + * that may not be forwarded, or whether datagrams to that destination + * may be forwarded. + * @param p the packet to forward + * @return 1: can forward 0: discard + */ +static int +ip4_canforward(struct pbuf *p) +{ + u32_t addr = lwip_htonl(ip4_addr_get_u32(ip4_current_dest_addr())); + +#ifdef LWIP_HOOK_IP4_CANFORWARD + int ret = LWIP_HOOK_IP4_CANFORWARD(p, addr); + if (ret >= 0) { + return ret; + } +#endif /* LWIP_HOOK_IP4_CANFORWARD */ + + if (p->flags & PBUF_FLAG_LLBCAST) { + /* don't route link-layer broadcasts */ + return 0; + } + if ((p->flags & PBUF_FLAG_LLMCAST) || IP_MULTICAST(addr)) { + /* don't route link-layer multicasts (use LWIP_HOOK_IP4_CANFORWARD instead) */ + return 0; + } + if (IP_EXPERIMENTAL(addr)) { + return 0; + } + if (IP_CLASSA(addr)) { + u32_t net = addr & IP_CLASSA_NET; + if ((net == 0) || (net == ((u32_t)IP_LOOPBACKNET << IP_CLASSA_NSHIFT))) { + /* don't route loopback packets */ + return 0; + } + } + return 1; +} + +/** + * Forwards an IP packet. It finds an appropriate route for the + * packet, decrements the TTL value of the packet, adjusts the + * checksum and outputs the packet on the appropriate interface. + * + * @param p the packet to forward (p->payload points to IP header) + * @param iphdr the IP header of the input packet + * @param inp the netif on which this packet was received + */ +static void +ip4_forward(struct pbuf *p, struct ip_hdr *iphdr, struct netif *inp) +{ + struct netif *netif; + + PERF_START; + LWIP_UNUSED_ARG(inp); + + if (!ip4_canforward(p)) { + goto return_noroute; + } + + /* RFC3927 2.7: do not forward link-local addresses */ + if (ip4_addr_islinklocal(ip4_current_dest_addr())) { + LWIP_DEBUGF(IP_DEBUG, ("ip4_forward: not forwarding LLA %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n", + ip4_addr1_16(ip4_current_dest_addr()), ip4_addr2_16(ip4_current_dest_addr()), + ip4_addr3_16(ip4_current_dest_addr()), ip4_addr4_16(ip4_current_dest_addr()))); + goto return_noroute; + } + + /* Find network interface where to forward this IP packet to. */ + netif = ip4_route_src(ip4_current_src_addr(), ip4_current_dest_addr()); + if (netif == NULL) { + LWIP_DEBUGF(IP_DEBUG, ("ip4_forward: no forwarding route for %"U16_F".%"U16_F".%"U16_F".%"U16_F" found\n", + ip4_addr1_16(ip4_current_dest_addr()), ip4_addr2_16(ip4_current_dest_addr()), + ip4_addr3_16(ip4_current_dest_addr()), ip4_addr4_16(ip4_current_dest_addr()))); + /* @todo: send ICMP_DUR_NET? */ + goto return_noroute; + } +#if !IP_FORWARD_ALLOW_TX_ON_RX_NETIF + /* Do not forward packets onto the same network interface on which + * they arrived. */ + if (netif == inp) { + LWIP_DEBUGF(IP_DEBUG, ("ip4_forward: not bouncing packets back on incoming interface.\n")); + goto return_noroute; + } +#endif /* IP_FORWARD_ALLOW_TX_ON_RX_NETIF */ + + /* decrement TTL */ + IPH_TTL_SET(iphdr, IPH_TTL(iphdr) - 1); + /* send ICMP if TTL == 0 */ + if (IPH_TTL(iphdr) == 0) { + MIB2_STATS_INC(mib2.ipinhdrerrors); +#if LWIP_ICMP + /* Don't send ICMP messages in response to ICMP messages */ + if (IPH_PROTO(iphdr) != IP_PROTO_ICMP) { + icmp_time_exceeded(p, ICMP_TE_TTL); + } +#endif /* LWIP_ICMP */ + return; + } + + /* Incrementally update the IP checksum. */ + if (IPH_CHKSUM(iphdr) >= PP_HTONS(0xffffU - 0x100)) { + IPH_CHKSUM_SET(iphdr, (u16_t)(IPH_CHKSUM(iphdr) + PP_HTONS(0x100) + 1)); + } else { + IPH_CHKSUM_SET(iphdr, (u16_t)(IPH_CHKSUM(iphdr) + PP_HTONS(0x100))); + } + + /* Take care of setting checksums to 0 for checksum offload netifs */ + if (CHECKSUM_GEN_IP || NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_IP)) { + IPH_CHKSUM_SET(iphdr, 0); + } + switch (IPH_PROTO(iphdr)) { +#if LWIP_UDP +#if LWIP_UDPLITE + case IP_PROTO_UDPLITE: +#endif + case IP_PROTO_UDP: + if (CHECKSUM_GEN_UDP || NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_UDP)) { + ((struct udp_hdr *)((u8_t *)iphdr + IPH_HL_BYTES(iphdr)))->chksum = 0; + } + break; +#endif +#if LWIP_TCP + case IP_PROTO_TCP: + if (CHECKSUM_GEN_TCP || NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_TCP)) { + ((struct tcp_hdr *)((u8_t *)iphdr + IPH_HL_BYTES(iphdr)))->chksum = 0; + } + break; +#endif +#if LWIP_ICMP + case IP_PROTO_ICMP: + if (CHECKSUM_GEN_ICMP || NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_ICMP)) { + ((struct icmp_hdr *)((u8_t *)iphdr + IPH_HL_BYTES(iphdr)))->chksum = 0; + } + break; +#endif + default: + /* there's really nothing to do here other than satisfying 'switch-default' */ + break; + } + + LWIP_DEBUGF(IP_DEBUG, ("ip4_forward: forwarding packet to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n", + ip4_addr1_16(ip4_current_dest_addr()), ip4_addr2_16(ip4_current_dest_addr()), + ip4_addr3_16(ip4_current_dest_addr()), ip4_addr4_16(ip4_current_dest_addr()))); + + IP_STATS_INC(ip.fw); + MIB2_STATS_INC(mib2.ipforwdatagrams); + IP_STATS_INC(ip.xmit); + + PERF_STOP("ip4_forward"); + /* don't fragment if interface has mtu set to 0 [loopif] */ + if (netif->mtu && (p->tot_len > netif->mtu)) { + if ((IPH_OFFSET(iphdr) & PP_NTOHS(IP_DF)) == 0) { +#if IP_FRAG + ip4_frag(p, netif, ip4_current_dest_addr()); +#else /* IP_FRAG */ + /* @todo: send ICMP Destination Unreachable code 13 "Communication administratively prohibited"? */ +#endif /* IP_FRAG */ + } else { +#if LWIP_ICMP + /* send ICMP Destination Unreachable code 4: "Fragmentation Needed and DF Set" */ + icmp_dest_unreach(p, ICMP_DUR_FRAG); +#endif /* LWIP_ICMP */ + } + return; + } + /* transmit pbuf on chosen interface */ + netif->output(netif, p, ip4_current_dest_addr()); + return; +return_noroute: + MIB2_STATS_INC(mib2.ipoutnoroutes); +} +#endif /* IP_FORWARD */ + +/** Return true if the current input packet should be accepted on this netif */ +static int +ip4_input_accept(struct netif *netif) +{ + LWIP_DEBUGF(IP_DEBUG, ("ip_input: iphdr->dest 0x%"X32_F" netif->ip_addr 0x%"X32_F" (0x%"X32_F", 0x%"X32_F", 0x%"X32_F")\n", + ip4_addr_get_u32(ip4_current_dest_addr()), ip4_addr_get_u32(netif_ip4_addr(netif)), + ip4_addr_get_u32(ip4_current_dest_addr()) & ip4_addr_get_u32(netif_ip4_netmask(netif)), + ip4_addr_get_u32(netif_ip4_addr(netif)) & ip4_addr_get_u32(netif_ip4_netmask(netif)), + ip4_addr_get_u32(ip4_current_dest_addr()) & ~ip4_addr_get_u32(netif_ip4_netmask(netif)))); + + /* interface is up and configured? */ + if ((netif_is_up(netif)) && (!ip4_addr_isany_val(*netif_ip4_addr(netif)))) { + /* unicast to this interface address? */ + if (ip4_addr_eq(ip4_current_dest_addr(), netif_ip4_addr(netif)) || + /* or broadcast on this interface network address? */ + ip4_addr_isbroadcast(ip4_current_dest_addr(), netif) +#if LWIP_NETIF_LOOPBACK && !LWIP_HAVE_LOOPIF + || (ip4_addr_get_u32(ip4_current_dest_addr()) == PP_HTONL(IPADDR_LOOPBACK)) +#endif /* LWIP_NETIF_LOOPBACK && !LWIP_HAVE_LOOPIF */ + ) { + LWIP_DEBUGF(IP_DEBUG, ("ip4_input: packet accepted on interface %c%c\n", + netif->name[0], netif->name[1])); + /* accept on this netif */ + return 1; + } +#if LWIP_AUTOIP + /* connections to link-local addresses must persist after changing + the netif's address (RFC3927 ch. 1.9) */ + if (autoip_accept_packet(netif, ip4_current_dest_addr())) { + LWIP_DEBUGF(IP_DEBUG, ("ip4_input: LLA packet accepted on interface %c%c\n", + netif->name[0], netif->name[1])); + /* accept on this netif */ + return 1; + } +#endif /* LWIP_AUTOIP */ + } + return 0; +} + +/** + * This function is called by the network interface device driver when + * an IP packet is received. The function does the basic checks of the + * IP header such as packet size being at least larger than the header + * size etc. If the packet was not destined for us, the packet is + * forwarded (using ip_forward). The IP checksum is always checked. + * + * Finally, the packet is sent to the upper layer protocol input function. + * + * @param p the received IP packet (p->payload points to IP header) + * @param inp the netif on which this packet was received + * @return ERR_OK if the packet was processed (could return ERR_* if it wasn't + * processed, but currently always returns ERR_OK) + */ +err_t +ip4_input(struct pbuf *p, struct netif *inp) +{ + const struct ip_hdr *iphdr; + struct netif *netif; + u16_t iphdr_hlen; + u16_t iphdr_len; +#if IP_ACCEPT_LINK_LAYER_ADDRESSING || LWIP_IGMP + int check_ip_src = 1; +#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING || LWIP_IGMP */ +#if LWIP_RAW + raw_input_state_t raw_status; +#endif /* LWIP_RAW */ + + LWIP_ASSERT_CORE_LOCKED(); + + IP_STATS_INC(ip.recv); + MIB2_STATS_INC(mib2.ipinreceives); + + /* identify the IP header */ + iphdr = (struct ip_hdr *)p->payload; + if (IPH_V(iphdr) != 4) { + LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_WARNING, ("IP packet dropped due to bad version number %"U16_F"\n", (u16_t)IPH_V(iphdr))); + ip4_debug_print(p); + pbuf_free(p); + IP_STATS_INC(ip.err); + IP_STATS_INC(ip.drop); + MIB2_STATS_INC(mib2.ipinhdrerrors); + return ERR_OK; + } + +#ifdef LWIP_HOOK_IP4_INPUT + if (LWIP_HOOK_IP4_INPUT(p, inp)) { + /* the packet has been eaten */ + return ERR_OK; + } +#endif + + /* obtain IP header length in bytes */ + iphdr_hlen = IPH_HL_BYTES(iphdr); + /* obtain ip length in bytes */ + iphdr_len = lwip_ntohs(IPH_LEN(iphdr)); + + /* Trim pbuf. This is especially required for packets < 60 bytes. */ + if (iphdr_len < p->tot_len) { + pbuf_realloc(p, iphdr_len); + } + + /* header length exceeds first pbuf length, or ip length exceeds total pbuf length? */ + if ((iphdr_hlen > p->len) || (iphdr_len > p->tot_len) || (iphdr_hlen < IP_HLEN)) { + if (iphdr_hlen < IP_HLEN) { + LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, + ("ip4_input: short IP header (%"U16_F" bytes) received, IP packet dropped\n", iphdr_hlen)); + } + if (iphdr_hlen > p->len) { + LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, + ("IP header (len %"U16_F") does not fit in first pbuf (len %"U16_F"), IP packet dropped.\n", + iphdr_hlen, p->len)); + } + if (iphdr_len > p->tot_len) { + LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, + ("IP (len %"U16_F") is longer than pbuf (len %"U16_F"), IP packet dropped.\n", + iphdr_len, p->tot_len)); + } + /* free (drop) packet pbufs */ + pbuf_free(p); + IP_STATS_INC(ip.lenerr); + IP_STATS_INC(ip.drop); + MIB2_STATS_INC(mib2.ipindiscards); + return ERR_OK; + } + + /* verify checksum */ +#if CHECKSUM_CHECK_IP + IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_CHECK_IP) { + if (inet_chksum(iphdr, iphdr_hlen) != 0) { + + LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, + ("Checksum (0x%"X16_F") failed, IP packet dropped.\n", inet_chksum(iphdr, iphdr_hlen))); + ip4_debug_print(p); + pbuf_free(p); + IP_STATS_INC(ip.chkerr); + IP_STATS_INC(ip.drop); + MIB2_STATS_INC(mib2.ipinhdrerrors); + return ERR_OK; + } + } +#endif + + /* copy IP addresses to aligned ip_addr_t */ + ip_addr_copy_from_ip4(ip_data.current_iphdr_dest, iphdr->dest); + ip_addr_copy_from_ip4(ip_data.current_iphdr_src, iphdr->src); + + /* match packet against an interface, i.e. is this packet for us? */ + if (ip4_addr_ismulticast(ip4_current_dest_addr())) { +#if LWIP_IGMP + if ((inp->flags & NETIF_FLAG_IGMP) && (igmp_lookfor_group(inp, ip4_current_dest_addr()))) { + /* IGMP snooping switches need 0.0.0.0 to be allowed as source address (RFC 4541) */ + ip4_addr_t allsystems; + IP4_ADDR(&allsystems, 224, 0, 0, 1); + if (ip4_addr_eq(ip4_current_dest_addr(), &allsystems) && + ip4_addr_isany(ip4_current_src_addr())) { + check_ip_src = 0; + } + netif = inp; + } else { + netif = NULL; + } +#else /* LWIP_IGMP */ + if ((netif_is_up(inp)) && (!ip4_addr_isany_val(*netif_ip4_addr(inp)))) { + netif = inp; + } else { + netif = NULL; + } +#endif /* LWIP_IGMP */ + } else { + /* start trying with inp. if that's not acceptable, start walking the + list of configured netifs. */ + if (ip4_input_accept(inp)) { + netif = inp; + } else { + netif = NULL; +#if !LWIP_NETIF_LOOPBACK || LWIP_HAVE_LOOPIF + /* Packets sent to the loopback address must not be accepted on an + * interface that does not have the loopback address assigned to it, + * unless a non-loopback interface is used for loopback traffic. */ + if (!ip4_addr_isloopback(ip4_current_dest_addr())) +#endif /* !LWIP_NETIF_LOOPBACK || LWIP_HAVE_LOOPIF */ + { +#if !LWIP_SINGLE_NETIF + NETIF_FOREACH(netif) { + if (netif == inp) { + /* we checked that before already */ + continue; + } + if (ip4_input_accept(netif)) { + break; + } + } +#endif /* !LWIP_SINGLE_NETIF */ + } + } + } + +#if IP_ACCEPT_LINK_LAYER_ADDRESSING + /* Pass DHCP messages regardless of destination address. DHCP traffic is addressed + * using link layer addressing (such as Ethernet MAC) so we must not filter on IP. + * According to RFC 1542 section 3.1.1, referred by RFC 2131). + * + * If you want to accept private broadcast communication while a netif is down, + * define LWIP_IP_ACCEPT_UDP_PORT(dst_port), e.g.: + * + * #define LWIP_IP_ACCEPT_UDP_PORT(dst_port) ((dst_port) == PP_NTOHS(12345)) + */ + if (netif == NULL) { + /* remote port is DHCP server? */ + if (IPH_PROTO(iphdr) == IP_PROTO_UDP) { + const struct udp_hdr *udphdr = (const struct udp_hdr *)((const u8_t *)iphdr + iphdr_hlen); + LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip4_input: UDP packet to DHCP client port %"U16_F"\n", + lwip_ntohs(udphdr->dest))); + if (IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(udphdr->dest)) { + LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip4_input: DHCP packet accepted.\n")); + netif = inp; + check_ip_src = 0; + } + } + } +#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */ + + /* broadcast or multicast packet source address? Compliant with RFC 1122: 3.2.1.3 */ +#if LWIP_IGMP || IP_ACCEPT_LINK_LAYER_ADDRESSING + if (check_ip_src +#if IP_ACCEPT_LINK_LAYER_ADDRESSING + /* DHCP servers need 0.0.0.0 to be allowed as source address (RFC 1.1.2.2: 3.2.1.3/a) */ + && !ip4_addr_isany_val(*ip4_current_src_addr()) +#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */ + ) +#endif /* LWIP_IGMP || IP_ACCEPT_LINK_LAYER_ADDRESSING */ + { + if ((ip4_addr_isbroadcast(ip4_current_src_addr(), inp)) || + (ip4_addr_ismulticast(ip4_current_src_addr()))) { + /* packet source is not valid */ + LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("ip4_input: packet source is not valid.\n")); + /* free (drop) packet pbufs */ + pbuf_free(p); + IP_STATS_INC(ip.drop); + MIB2_STATS_INC(mib2.ipinaddrerrors); + MIB2_STATS_INC(mib2.ipindiscards); + return ERR_OK; + } + } + + /* packet not for us? */ + if (netif == NULL) { + /* packet not for us, route or discard */ + LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip4_input: packet not for us.\n")); +#if IP_FORWARD + /* non-broadcast packet? */ + if (!ip4_addr_isbroadcast(ip4_current_dest_addr(), inp)) { + /* try to forward IP packet on (other) interfaces */ + ip4_forward(p, (struct ip_hdr *)p->payload, inp); + } else +#endif /* IP_FORWARD */ + { + IP_STATS_INC(ip.drop); + MIB2_STATS_INC(mib2.ipinaddrerrors); + MIB2_STATS_INC(mib2.ipindiscards); + } + pbuf_free(p); + return ERR_OK; + } + /* packet consists of multiple fragments? */ + if ((IPH_OFFSET(iphdr) & PP_HTONS(IP_OFFMASK | IP_MF)) != 0) { +#if IP_REASSEMBLY /* packet fragment reassembly code present? */ + LWIP_DEBUGF(IP_DEBUG, ("IP packet is a fragment (id=0x%04"X16_F" tot_len=%"U16_F" len=%"U16_F" MF=%"U16_F" offset=%"U16_F"), calling ip4_reass()\n", + lwip_ntohs(IPH_ID(iphdr)), p->tot_len, lwip_ntohs(IPH_LEN(iphdr)), (u16_t)!!(IPH_OFFSET(iphdr) & PP_HTONS(IP_MF)), (u16_t)((lwip_ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK) * 8))); + /* reassemble the packet*/ + p = ip4_reass(p); + /* packet not fully reassembled yet? */ + if (p == NULL) { + return ERR_OK; + } + iphdr = (const struct ip_hdr *)p->payload; +#else /* IP_REASSEMBLY == 0, no packet fragment reassembly code present */ + pbuf_free(p); + LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since it was fragmented (0x%"X16_F") (while IP_REASSEMBLY == 0).\n", + lwip_ntohs(IPH_OFFSET(iphdr)))); + IP_STATS_INC(ip.opterr); + IP_STATS_INC(ip.drop); + /* unsupported protocol feature */ + MIB2_STATS_INC(mib2.ipinunknownprotos); + return ERR_OK; +#endif /* IP_REASSEMBLY */ + } + +#if IP_OPTIONS_ALLOWED == 0 /* no support for IP options in the IP header? */ + +#if LWIP_IGMP + /* there is an extra "router alert" option in IGMP messages which we allow for but do not police */ + if ((iphdr_hlen > IP_HLEN) && (IPH_PROTO(iphdr) != IP_PROTO_IGMP)) { +#else + if (iphdr_hlen > IP_HLEN) { +#endif /* LWIP_IGMP */ + LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since there were IP options (while IP_OPTIONS_ALLOWED == 0).\n")); + pbuf_free(p); + IP_STATS_INC(ip.opterr); + IP_STATS_INC(ip.drop); + /* unsupported protocol feature */ + MIB2_STATS_INC(mib2.ipinunknownprotos); + return ERR_OK; + } +#endif /* IP_OPTIONS_ALLOWED == 0 */ + + /* send to upper layers */ + LWIP_DEBUGF(IP_DEBUG, ("ip4_input: \n")); + ip4_debug_print(p); + LWIP_DEBUGF(IP_DEBUG, ("ip4_input: p->len %"U16_F" p->tot_len %"U16_F"\n", p->len, p->tot_len)); + + ip_data.current_netif = netif; + ip_data.current_input_netif = inp; + ip_data.current_ip4_header = iphdr; + ip_data.current_ip_header_tot_len = IPH_HL_BYTES(iphdr); + +#if LWIP_RAW + /* raw input did not eat the packet? */ + raw_status = raw_input(p, inp); + if (raw_status != RAW_INPUT_EATEN) +#endif /* LWIP_RAW */ + { + pbuf_remove_header(p, iphdr_hlen); /* Move to payload, no check necessary. */ + + switch (IPH_PROTO(iphdr)) { +#if LWIP_UDP + case IP_PROTO_UDP: +#if LWIP_UDPLITE + case IP_PROTO_UDPLITE: +#endif /* LWIP_UDPLITE */ + MIB2_STATS_INC(mib2.ipindelivers); + udp_input(p, inp); + break; +#endif /* LWIP_UDP */ +#if LWIP_TCP + case IP_PROTO_TCP: + MIB2_STATS_INC(mib2.ipindelivers); + tcp_input(p, inp); + break; +#endif /* LWIP_TCP */ +#if LWIP_ICMP + case IP_PROTO_ICMP: + MIB2_STATS_INC(mib2.ipindelivers); + icmp_input(p, inp); + break; +#endif /* LWIP_ICMP */ +#if LWIP_IGMP + case IP_PROTO_IGMP: + igmp_input(p, inp, ip4_current_dest_addr()); + break; +#endif /* LWIP_IGMP */ + default: +#if LWIP_RAW + if (raw_status == RAW_INPUT_DELIVERED) { + MIB2_STATS_INC(mib2.ipindelivers); + } else +#endif /* LWIP_RAW */ + { +#if LWIP_ICMP + /* send ICMP destination protocol unreachable unless is was a broadcast */ + if (!ip4_addr_isbroadcast(ip4_current_dest_addr(), netif) && + !ip4_addr_ismulticast(ip4_current_dest_addr())) { + pbuf_header_force(p, (s16_t)iphdr_hlen); /* Move to ip header, no check necessary. */ + icmp_dest_unreach(p, ICMP_DUR_PROTO); + } +#endif /* LWIP_ICMP */ + + LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("Unsupported transport protocol %"U16_F"\n", (u16_t)IPH_PROTO(iphdr))); + + IP_STATS_INC(ip.proterr); + IP_STATS_INC(ip.drop); + MIB2_STATS_INC(mib2.ipinunknownprotos); + } + pbuf_free(p); + break; + } + } + + /* @todo: this is not really necessary... */ + ip_data.current_netif = NULL; + ip_data.current_input_netif = NULL; + ip_data.current_ip4_header = NULL; + ip_data.current_ip_header_tot_len = 0; + ip4_addr_set_any(ip4_current_src_addr()); + ip4_addr_set_any(ip4_current_dest_addr()); + + return ERR_OK; +} + +/** + * Sends an IP packet on a network interface. This function constructs + * the IP header and calculates the IP header checksum. If the source + * IP address is NULL, the IP address of the outgoing network + * interface is filled in as source address. + * If the destination IP address is LWIP_IP_HDRINCL, p is assumed to already + * include an IP header and p->payload points to it instead of the data. + * + * @param p the packet to send (p->payload points to the data, e.g. next + protocol header; if dest == LWIP_IP_HDRINCL, p already includes an + IP header and p->payload points to that IP header) + * @param src the source IP address to send from (if src == IP4_ADDR_ANY, the + * IP address of the netif used to send is used as source address) + * @param dest the destination IP address to send the packet to + * @param ttl the TTL value to be set in the IP header + * @param tos the TOS value to be set in the IP header + * @param proto the PROTOCOL to be set in the IP header + * @param netif the netif on which to send this packet + * @return ERR_OK if the packet was sent OK + * ERR_BUF if p doesn't have enough space for IP/LINK headers + * returns errors returned by netif->output + * + * @note ip_id: RFC791 "some host may be able to simply use + * unique identifiers independent of destination" + */ +err_t +ip4_output_if(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest, + u8_t ttl, u8_t tos, + u8_t proto, struct netif *netif) +{ +#if IP_OPTIONS_SEND + return ip4_output_if_opt(p, src, dest, ttl, tos, proto, netif, NULL, 0); +} + +/** + * Same as ip_output_if() but with the possibility to include IP options: + * + * @ param ip_options pointer to the IP options, copied into the IP header + * @ param optlen length of ip_options + */ +err_t +ip4_output_if_opt(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest, + u8_t ttl, u8_t tos, u8_t proto, struct netif *netif, void *ip_options, + u16_t optlen) +{ +#endif /* IP_OPTIONS_SEND */ + const ip4_addr_t *src_used = src; + if (dest != LWIP_IP_HDRINCL) { + if (ip4_addr_isany(src)) { + src_used = netif_ip4_addr(netif); + } + } + +#if IP_OPTIONS_SEND + return ip4_output_if_opt_src(p, src_used, dest, ttl, tos, proto, netif, + ip_options, optlen); +#else /* IP_OPTIONS_SEND */ + return ip4_output_if_src(p, src_used, dest, ttl, tos, proto, netif); +#endif /* IP_OPTIONS_SEND */ +} + +/** + * Same as ip_output_if() but 'src' address is not replaced by netif address + * when it is 'any'. + */ +err_t +ip4_output_if_src(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest, + u8_t ttl, u8_t tos, + u8_t proto, struct netif *netif) +{ +#if IP_OPTIONS_SEND + return ip4_output_if_opt_src(p, src, dest, ttl, tos, proto, netif, NULL, 0); +} + +/** + * Same as ip_output_if_opt() but 'src' address is not replaced by netif address + * when it is 'any'. + */ +err_t +ip4_output_if_opt_src(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest, + u8_t ttl, u8_t tos, u8_t proto, struct netif *netif, void *ip_options, + u16_t optlen) +{ +#endif /* IP_OPTIONS_SEND */ + struct ip_hdr *iphdr; + ip4_addr_t dest_addr; +#if CHECKSUM_GEN_IP_INLINE + u32_t chk_sum = 0; +#endif /* CHECKSUM_GEN_IP_INLINE */ + + LWIP_ASSERT_CORE_LOCKED(); + LWIP_IP_CHECK_PBUF_REF_COUNT_FOR_TX(p); + + MIB2_STATS_INC(mib2.ipoutrequests); + + /* Should the IP header be generated or is it already included in p? */ + if (dest != LWIP_IP_HDRINCL) { + u16_t ip_hlen = IP_HLEN; +#if IP_OPTIONS_SEND + u16_t optlen_aligned = 0; + if (optlen != 0) { +#if CHECKSUM_GEN_IP_INLINE + int i; +#endif /* CHECKSUM_GEN_IP_INLINE */ + if (optlen > (IP_HLEN_MAX - IP_HLEN)) { + /* optlen too long */ + LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip4_output_if_opt: optlen too long\n")); + IP_STATS_INC(ip.err); + MIB2_STATS_INC(mib2.ipoutdiscards); + return ERR_VAL; + } + /* round up to a multiple of 4 */ + optlen_aligned = (u16_t)((optlen + 3) & ~3); + ip_hlen = (u16_t)(ip_hlen + optlen_aligned); + /* First write in the IP options */ + if (pbuf_add_header(p, optlen_aligned)) { + LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip4_output_if_opt: not enough room for IP options in pbuf\n")); + IP_STATS_INC(ip.err); + MIB2_STATS_INC(mib2.ipoutdiscards); + return ERR_BUF; + } + MEMCPY(p->payload, ip_options, optlen); + if (optlen < optlen_aligned) { + /* zero the remaining bytes */ + memset(((char *)p->payload) + optlen, 0, (size_t)(optlen_aligned - optlen)); + } +#if CHECKSUM_GEN_IP_INLINE + for (i = 0; i < optlen_aligned / 2; i++) { + chk_sum += ((u16_t *)p->payload)[i]; + } +#endif /* CHECKSUM_GEN_IP_INLINE */ + } +#endif /* IP_OPTIONS_SEND */ + /* generate IP header */ + if (pbuf_add_header(p, IP_HLEN)) { + LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip4_output: not enough room for IP header in pbuf\n")); + + IP_STATS_INC(ip.err); + MIB2_STATS_INC(mib2.ipoutdiscards); + return ERR_BUF; + } + + iphdr = (struct ip_hdr *)p->payload; + LWIP_ASSERT("check that first pbuf can hold struct ip_hdr", + (p->len >= sizeof(struct ip_hdr))); + + IPH_TTL_SET(iphdr, ttl); + IPH_PROTO_SET(iphdr, proto); +#if CHECKSUM_GEN_IP_INLINE + chk_sum += PP_NTOHS(proto | (ttl << 8)); +#endif /* CHECKSUM_GEN_IP_INLINE */ + + /* dest cannot be NULL here */ + ip4_addr_copy(iphdr->dest, *dest); +#if CHECKSUM_GEN_IP_INLINE + chk_sum += ip4_addr_get_u32(&iphdr->dest) & 0xFFFF; + chk_sum += ip4_addr_get_u32(&iphdr->dest) >> 16; +#endif /* CHECKSUM_GEN_IP_INLINE */ + + IPH_VHL_SET(iphdr, 4, ip_hlen / 4); + IPH_TOS_SET(iphdr, tos); +#if CHECKSUM_GEN_IP_INLINE + chk_sum += PP_NTOHS(tos | (iphdr->_v_hl << 8)); +#endif /* CHECKSUM_GEN_IP_INLINE */ + IPH_LEN_SET(iphdr, lwip_htons(p->tot_len)); +#if CHECKSUM_GEN_IP_INLINE + chk_sum += iphdr->_len; +#endif /* CHECKSUM_GEN_IP_INLINE */ + IPH_OFFSET_SET(iphdr, 0); + IPH_ID_SET(iphdr, lwip_htons(ip_id)); +#if CHECKSUM_GEN_IP_INLINE + chk_sum += iphdr->_id; +#endif /* CHECKSUM_GEN_IP_INLINE */ + ++ip_id; + + if (src == NULL) { + ip4_addr_copy(iphdr->src, *IP4_ADDR_ANY4); + } else { + /* src cannot be NULL here */ + ip4_addr_copy(iphdr->src, *src); + } + +#if CHECKSUM_GEN_IP_INLINE + chk_sum += ip4_addr_get_u32(&iphdr->src) & 0xFFFF; + chk_sum += ip4_addr_get_u32(&iphdr->src) >> 16; + chk_sum = (chk_sum >> 16) + (chk_sum & 0xFFFF); + chk_sum = (chk_sum >> 16) + chk_sum; + chk_sum = ~chk_sum; + IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_IP) { + iphdr->_chksum = (u16_t)chk_sum; /* network order */ + } +#if LWIP_CHECKSUM_CTRL_PER_NETIF + else { + IPH_CHKSUM_SET(iphdr, 0); + } +#endif /* LWIP_CHECKSUM_CTRL_PER_NETIF*/ +#else /* CHECKSUM_GEN_IP_INLINE */ + IPH_CHKSUM_SET(iphdr, 0); +#if CHECKSUM_GEN_IP + IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_IP) { + IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, ip_hlen)); + } +#endif /* CHECKSUM_GEN_IP */ +#endif /* CHECKSUM_GEN_IP_INLINE */ + } else { + /* IP header already included in p */ + if (p->len < IP_HLEN) { + LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip4_output: LWIP_IP_HDRINCL but pbuf is too short\n")); + IP_STATS_INC(ip.err); + MIB2_STATS_INC(mib2.ipoutdiscards); + return ERR_BUF; + } + iphdr = (struct ip_hdr *)p->payload; + ip4_addr_copy(dest_addr, iphdr->dest); + dest = &dest_addr; + } + + IP_STATS_INC(ip.xmit); + + LWIP_DEBUGF(IP_DEBUG, ("ip4_output_if: %c%c%"U16_F"\n", netif->name[0], netif->name[1], (u16_t)netif->num)); + ip4_debug_print(p); + +#if ENABLE_LOOPBACK + if (ip4_addr_eq(dest, netif_ip4_addr(netif)) +#if !LWIP_HAVE_LOOPIF + || ip4_addr_isloopback(dest) +#endif /* !LWIP_HAVE_LOOPIF */ + ) { + /* Packet to self, enqueue it for loopback */ + LWIP_DEBUGF(IP_DEBUG, ("netif_loop_output()\n")); + return netif_loop_output(netif, p); + } +#if LWIP_MULTICAST_TX_OPTIONS + if ((p->flags & PBUF_FLAG_MCASTLOOP) != 0) { + netif_loop_output(netif, p); + } +#endif /* LWIP_MULTICAST_TX_OPTIONS */ +#endif /* ENABLE_LOOPBACK */ +#if IP_FRAG + /* don't fragment if interface has mtu set to 0 [loopif] */ + if (netif->mtu && (p->tot_len > netif->mtu)) { + return ip4_frag(p, netif, dest); + } +#endif /* IP_FRAG */ + + LWIP_DEBUGF(IP_DEBUG, ("ip4_output_if: call netif->output()\n")); + return netif->output(netif, p, dest); +} + +/** + * Simple interface to ip_output_if. It finds the outgoing network + * interface and calls upon ip_output_if to do the actual work. + * + * @param p the packet to send (p->payload points to the data, e.g. next + protocol header; if dest == LWIP_IP_HDRINCL, p already includes an + IP header and p->payload points to that IP header) + * @param src the source IP address to send from (if src == IP4_ADDR_ANY, the + * IP address of the netif used to send is used as source address) + * @param dest the destination IP address to send the packet to + * @param ttl the TTL value to be set in the IP header + * @param tos the TOS value to be set in the IP header + * @param proto the PROTOCOL to be set in the IP header + * + * @return ERR_RTE if no route is found + * see ip_output_if() for more return values + */ +err_t +ip4_output(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest, + u8_t ttl, u8_t tos, u8_t proto) +{ + struct netif *netif; + + LWIP_IP_CHECK_PBUF_REF_COUNT_FOR_TX(p); + + if ((netif = ip4_route_src(src, dest)) == NULL) { + LWIP_DEBUGF(IP_DEBUG, ("ip4_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n", + ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest))); + IP_STATS_INC(ip.rterr); + return ERR_RTE; + } + + return ip4_output_if(p, src, dest, ttl, tos, proto, netif); +} + +#if LWIP_NETIF_USE_HINTS +/** Like ip_output, but takes and addr_hint pointer that is passed on to netif->addr_hint + * before calling ip_output_if. + * + * @param p the packet to send (p->payload points to the data, e.g. next + protocol header; if dest == LWIP_IP_HDRINCL, p already includes an + IP header and p->payload points to that IP header) + * @param src the source IP address to send from (if src == IP4_ADDR_ANY, the + * IP address of the netif used to send is used as source address) + * @param dest the destination IP address to send the packet to + * @param ttl the TTL value to be set in the IP header + * @param tos the TOS value to be set in the IP header + * @param proto the PROTOCOL to be set in the IP header + * @param netif_hint netif output hint pointer set to netif->hint before + * calling ip_output_if() + * + * @return ERR_RTE if no route is found + * see ip_output_if() for more return values + */ +err_t +ip4_output_hinted(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest, + u8_t ttl, u8_t tos, u8_t proto, struct netif_hint *netif_hint) +{ + struct netif *netif; + err_t err; + + LWIP_IP_CHECK_PBUF_REF_COUNT_FOR_TX(p); + + if ((netif = ip4_route_src(src, dest)) == NULL) { + LWIP_DEBUGF(IP_DEBUG, ("ip4_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n", + ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest))); + IP_STATS_INC(ip.rterr); + return ERR_RTE; + } + + NETIF_SET_HINTS(netif, netif_hint); + err = ip4_output_if(p, src, dest, ttl, tos, proto, netif); + NETIF_RESET_HINTS(netif); + + return err; +} +#endif /* LWIP_NETIF_USE_HINTS*/ + +#if IP_DEBUG +/* Print an IP header by using LWIP_DEBUGF + * @param p an IP packet, p->payload pointing to the IP header + */ +void +ip4_debug_print(struct pbuf *p) +{ + struct ip_hdr *iphdr = (struct ip_hdr *)p->payload; + + LWIP_DEBUGF(IP_DEBUG, ("IP header:\n")); + LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n")); + LWIP_DEBUGF(IP_DEBUG, ("|%2"S16_F" |%2"S16_F" | 0x%02"X16_F" | %5"U16_F" | (v, hl, tos, len)\n", + (u16_t)IPH_V(iphdr), + (u16_t)IPH_HL(iphdr), + (u16_t)IPH_TOS(iphdr), + lwip_ntohs(IPH_LEN(iphdr)))); + LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n")); + LWIP_DEBUGF(IP_DEBUG, ("| %5"U16_F" |%"U16_F"%"U16_F"%"U16_F"| %4"U16_F" | (id, flags, offset)\n", + lwip_ntohs(IPH_ID(iphdr)), + (u16_t)(lwip_ntohs(IPH_OFFSET(iphdr)) >> 15 & 1), + (u16_t)(lwip_ntohs(IPH_OFFSET(iphdr)) >> 14 & 1), + (u16_t)(lwip_ntohs(IPH_OFFSET(iphdr)) >> 13 & 1), + (u16_t)(lwip_ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK))); + LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n")); + LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | 0x%04"X16_F" | (ttl, proto, chksum)\n", + (u16_t)IPH_TTL(iphdr), + (u16_t)IPH_PROTO(iphdr), + lwip_ntohs(IPH_CHKSUM(iphdr)))); + LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n")); + LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | %3"U16_F" | %3"U16_F" | (src)\n", + ip4_addr1_16_val(iphdr->src), + ip4_addr2_16_val(iphdr->src), + ip4_addr3_16_val(iphdr->src), + ip4_addr4_16_val(iphdr->src))); + LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n")); + LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | %3"U16_F" | %3"U16_F" | (dest)\n", + ip4_addr1_16_val(iphdr->dest), + ip4_addr2_16_val(iphdr->dest), + ip4_addr3_16_val(iphdr->dest), + ip4_addr4_16_val(iphdr->dest))); + LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n")); +} +#endif /* IP_DEBUG */ + +#endif /* LWIP_IPV4 */ diff --git a/src/core/ipv4/ip4_addr.c b/src/core/ipv4/ip4_addr.c new file mode 100644 index 00000000000..79127ac9534 --- /dev/null +++ b/src/core/ipv4/ip4_addr.c @@ -0,0 +1,323 @@ +/** + * @file + * This is the IPv4 address tools implementation. + * + */ + +/* + * Copyright (c) 2001-2004 Swedish Institute of Computer Science. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT + * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * This file is part of the lwIP TCP/IP stack. + * + * Author: Adam Dunkels <adam@sics.se> + * + */ + +#include "lwip/opt.h" + +#if LWIP_IPV4 + +#include "lwip/ip_addr.h" +#include "lwip/netif.h" + +/* used by IP4_ADDR_ANY and IP_ADDR_BROADCAST in ip_addr.h */ +const ip_addr_t ip_addr_any = IPADDR4_INIT(IPADDR_ANY); +const ip_addr_t ip_addr_broadcast = IPADDR4_INIT(IPADDR_BROADCAST); + +/** + * Determine if an address is a broadcast address on a network interface + * + * @param addr address to be checked + * @param netif the network interface against which the address is checked + * @return returns non-zero if the address is a broadcast address + */ +u8_t +ip4_addr_isbroadcast_u32(u32_t addr, const struct netif *netif) +{ + ip4_addr_t ipaddr; + ip4_addr_set_u32(&ipaddr, addr); + + /* all ones (broadcast) or all zeroes (old skool broadcast) */ + if ((~addr == IPADDR_ANY) || + (addr == IPADDR_ANY)) { + return 1; + /* no broadcast support on this network interface? */ + } else if ((netif->flags & NETIF_FLAG_BROADCAST) == 0) { + /* the given address cannot be a broadcast address + * nor can we check against any broadcast addresses */ + return 0; + /* address matches network interface address exactly? => no broadcast */ + } else if (addr == ip4_addr_get_u32(netif_ip4_addr(netif))) { + return 0; + /* on the same (sub) network... */ + } else if (ip4_addr_net_eq(&ipaddr, netif_ip4_addr(netif), netif_ip4_netmask(netif)) + /* ...and host identifier bits are all ones? =>... */ + && ((addr & ~ip4_addr_get_u32(netif_ip4_netmask(netif))) == + (IPADDR_BROADCAST & ~ip4_addr_get_u32(netif_ip4_netmask(netif))))) { + /* => network broadcast address */ + return 1; + } else { + return 0; + } +} + +/** Checks if a netmask is valid (starting with ones, then only zeros) + * + * @param netmask the IPv4 netmask to check (in network byte order!) + * @return 1 if the netmask is valid, 0 if it is not + */ +u8_t +ip4_addr_netmask_valid(u32_t netmask) +{ + u32_t mask; + u32_t nm_hostorder = lwip_htonl(netmask); + + /* first, check for the first zero */ + for (mask = 1UL << 31 ; mask != 0; mask >>= 1) { + if ((nm_hostorder & mask) == 0) { + break; + } + } + /* then check that there is no one */ + for (; mask != 0; mask >>= 1) { + if ((nm_hostorder & mask) != 0) { + /* there is a one after the first zero -> invalid */ + return 0; + } + } + /* no one after the first zero -> valid */ + return 1; +} + +/** + * Ascii internet address interpretation routine. + * The value returned is in network order. + * + * @param cp IP address in ascii representation (e.g. "127.0.0.1") + * @return ip address in network order + */ +u32_t +ipaddr_addr(const char *cp) +{ + ip4_addr_t val; + + if (ip4addr_aton(cp, &val)) { + return ip4_addr_get_u32(&val); + } + return (IPADDR_NONE); +} + +/** + * Check whether "cp" is a valid ascii representation + * of an Internet address and convert to a binary address. + * Returns 1 if the address is valid, 0 if not. + * This replaces inet_addr, the return value from which + * cannot distinguish between failure and a local broadcast address. + * + * @param cp IP address in ascii representation (e.g. "127.0.0.1") + * @param addr pointer to which to save the ip address in network order + * @return 1 if cp could be converted to addr, 0 on failure + */ +int +ip4addr_aton(const char *cp, ip4_addr_t *addr) +{ + u32_t val; + u8_t base; + char c; + u32_t parts[4]; + u32_t *pp = parts; + + c = *cp; + for (;;) { + /* + * Collect number up to ``.''. + * Values are specified as for C: + * 0x=hex, 0=octal, 1-9=decimal. + */ + if (!lwip_isdigit(c)) { + return 0; + } + val = 0; + base = 10; + if (c == '0') { + c = *++cp; + if (c == 'x' || c == 'X') { + base = 16; + c = *++cp; + } else { + base = 8; + } + } + for (;;) { + if (lwip_isdigit(c)) { + if((base == 8) && ((u32_t)(c - '0') >= 8)) + break; + val = (val * base) + (u32_t)(c - '0'); + c = *++cp; + } else if (base == 16 && lwip_isxdigit(c)) { + val = (val << 4) | (u32_t)(c + 10 - (lwip_islower(c) ? 'a' : 'A')); + c = *++cp; + } else { + break; + } + } + if (c == '.') { + /* + * Internet format: + * a.b.c.d + * a.b.c (with c treated as 16 bits) + * a.b (with b treated as 24 bits) + */ + if (pp >= parts + 3) { + return 0; + } + *pp++ = val; + c = *++cp; + } else { + break; + } + } + /* + * Check for trailing characters. + */ + if (c != '\0' && !lwip_isspace(c)) { + return 0; + } + /* + * Concoct the address according to + * the number of parts specified. + */ + switch (pp - parts + 1) { + + case 0: + return 0; /* initial nondigit */ + + case 1: /* a -- 32 bits */ + break; + + case 2: /* a.b -- 8.24 bits */ + if (val > 0xffffffUL) { + return 0; + } + if (parts[0] > 0xff) { + return 0; + } + val |= parts[0] << 24; + break; + + case 3: /* a.b.c -- 8.8.16 bits */ + if (val > 0xffff) { + return 0; + } + if ((parts[0] > 0xff) || (parts[1] > 0xff)) { + return 0; + } + val |= (parts[0] << 24) | (parts[1] << 16); + break; + + case 4: /* a.b.c.d -- 8.8.8.8 bits */ + if (val > 0xff) { + return 0; + } + if ((parts[0] > 0xff) || (parts[1] > 0xff) || (parts[2] > 0xff)) { + return 0; + } + val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8); + break; + default: + LWIP_ASSERT("unhandled", 0); + break; + } + if (addr) { + ip4_addr_set_u32(addr, lwip_htonl(val)); + } + return 1; +} + +/** + * Convert numeric IP address into decimal dotted ASCII representation. + * returns ptr to static buffer; not reentrant! + * + * @param addr ip address in network order to convert + * @return pointer to a global static (!) buffer that holds the ASCII + * representation of addr + */ +char * +ip4addr_ntoa(const ip4_addr_t *addr) +{ + static char str[IP4ADDR_STRLEN_MAX]; + return ip4addr_ntoa_r(addr, str, IP4ADDR_STRLEN_MAX); +} + +/** + * Same as ip4addr_ntoa, but reentrant since a user-supplied buffer is used. + * + * @param addr ip address in network order to convert + * @param buf target buffer where the string is stored + * @param buflen length of buf + * @return either pointer to buf which now holds the ASCII + * representation of addr or NULL if buf was too small + */ +char * +ip4addr_ntoa_r(const ip4_addr_t *addr, char *buf, int buflen) +{ + u32_t s_addr; + char inv[3]; + char *rp; + u8_t *ap; + u8_t rem; + u8_t n; + u8_t i; + int len = 0; + + s_addr = ip4_addr_get_u32(addr); + + rp = buf; + ap = (u8_t *)&s_addr; + for (n = 0; n < 4; n++) { + i = 0; + do { + rem = *ap % (u8_t)10; + *ap /= (u8_t)10; + inv[i++] = (char)('0' + rem); + } while (*ap); + while (i--) { + if (len++ >= buflen) { + return NULL; + } + *rp++ = inv[i]; + } + if (len++ >= buflen) { + return NULL; + } + *rp++ = '.'; + ap++; + } + *--rp = 0; + return buf; +} + +#endif /* LWIP_IPV4 */ diff --git a/src/core/ipv4/ip4_frag.c b/src/core/ipv4/ip4_frag.c new file mode 100644 index 00000000000..530314471f7 --- /dev/null +++ b/src/core/ipv4/ip4_frag.c @@ -0,0 +1,894 @@ +/** + * @file + * This is the IPv4 packet segmentation and reassembly implementation. + * + */ + +/* + * Copyright (c) 2001-2004 Swedish Institute of Computer Science. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT + * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * This file is part of the lwIP TCP/IP stack. + * + * Author: Jani Monoses <jani@iv.ro> + * Simon Goldschmidt + * original reassembly code by Adam Dunkels <adam@sics.se> + * + */ + +#include "lwip/opt.h" + +#if LWIP_IPV4 + +#include "lwip/ip4_frag.h" +#include "lwip/def.h" +#include "lwip/inet_chksum.h" +#include "lwip/netif.h" +#include "lwip/stats.h" +#include "lwip/icmp.h" + +#include <string.h> + +#if IP_REASSEMBLY +/** + * The IP reassembly code currently has the following limitations: + * - IP header options are not supported + * - fragments must not overlap (e.g. due to different routes), + * currently, overlapping or duplicate fragments are thrown away + * if IP_REASS_CHECK_OVERLAP=1 (the default)! + * + * @todo: work with IP header options + */ + +/** Setting this to 0, you can turn off checking the fragments for overlapping + * regions. The code gets a little smaller. Only use this if you know that + * overlapping won't occur on your network! */ +#ifndef IP_REASS_CHECK_OVERLAP +#define IP_REASS_CHECK_OVERLAP 1 +#endif /* IP_REASS_CHECK_OVERLAP */ + +/** Set to 0 to prevent freeing the oldest datagram when the reassembly buffer is + * full (IP_REASS_MAX_PBUFS pbufs are enqueued). The code gets a little smaller. + * Datagrams will be freed by timeout only. Especially useful when MEMP_NUM_REASSDATA + * is set to 1, so one datagram can be reassembled at a time, only. */ +#ifndef IP_REASS_FREE_OLDEST +#define IP_REASS_FREE_OLDEST 1 +#endif /* IP_REASS_FREE_OLDEST */ + +#define IP_REASS_FLAG_LASTFRAG 0x01 + +#define IP_REASS_VALIDATE_TELEGRAM_FINISHED 1 +#define IP_REASS_VALIDATE_PBUF_QUEUED 0 +#define IP_REASS_VALIDATE_PBUF_DROPPED -1 + +/** This is a helper struct which holds the starting + * offset and the ending offset of this fragment to + * easily chain the fragments. + * It has the same packing requirements as the IP header, since it replaces + * the IP header in memory in incoming fragments (after copying it) to keep + * track of the various fragments. (-> If the IP header doesn't need packing, + * this struct doesn't need packing, too.) + */ +#ifdef PACK_STRUCT_USE_INCLUDES +# include "arch/bpstruct.h" +#endif +PACK_STRUCT_BEGIN +struct ip_reass_helper { + PACK_STRUCT_FIELD(struct pbuf *next_pbuf); + PACK_STRUCT_FIELD(u16_t start); + PACK_STRUCT_FIELD(u16_t end); +} PACK_STRUCT_STRUCT; +PACK_STRUCT_END +#ifdef PACK_STRUCT_USE_INCLUDES +# include "arch/epstruct.h" +#endif + +#define IP_ADDRESSES_AND_ID_MATCH(iphdrA, iphdrB) \ + (ip4_addr_eq(&(iphdrA)->src, &(iphdrB)->src) && \ + ip4_addr_eq(&(iphdrA)->dest, &(iphdrB)->dest) && \ + IPH_ID(iphdrA) == IPH_ID(iphdrB)) ? 1 : 0 + +/* global variables */ +static struct ip_reassdata *reassdatagrams; +static u16_t ip_reass_pbufcount; + +/* function prototypes */ +static void ip_reass_dequeue_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev); +static int ip_reass_free_complete_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev); + +/** + * Reassembly timer base function + * for both NO_SYS == 0 and 1 (!). + * + * Should be called every 1000 msec (defined by IP_TMR_INTERVAL). + */ +void +ip_reass_tmr(void) +{ + struct ip_reassdata *r, *prev = NULL; + + r = reassdatagrams; + while (r != NULL) { + /* Decrement the timer. Once it reaches 0, + * clean up the incomplete fragment assembly */ + if (r->timer > 0) { + r->timer--; + LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass_tmr: timer dec %"U16_F"\n", (u16_t)r->timer)); + prev = r; + r = r->next; + } else { + /* reassembly timed out */ + struct ip_reassdata *tmp; + LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass_tmr: timer timed out\n")); + tmp = r; + /* get the next pointer before freeing */ + r = r->next; + /* free the helper struct and all enqueued pbufs */ + ip_reass_free_complete_datagram(tmp, prev); + } + } +} + +/** + * Free a datagram (struct ip_reassdata) and all its pbufs. + * Updates the total count of enqueued pbufs (ip_reass_pbufcount), + * SNMP counters and sends an ICMP time exceeded packet. + * + * @param ipr datagram to free + * @param prev the previous datagram in the linked list + * @return the number of pbufs freed + */ +static int +ip_reass_free_complete_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev) +{ + u16_t pbufs_freed = 0; + u16_t clen; + struct pbuf *p; + struct ip_reass_helper *iprh; + + LWIP_ASSERT("prev != ipr", prev != ipr); + if (prev != NULL) { + LWIP_ASSERT("prev->next == ipr", prev->next == ipr); + } + + MIB2_STATS_INC(mib2.ipreasmfails); +#if LWIP_ICMP + iprh = (struct ip_reass_helper *)ipr->p->payload; + if (iprh->start == 0) { + /* The first fragment was received, send ICMP time exceeded. */ + /* First, de-queue the first pbuf from r->p. */ + p = ipr->p; + ipr->p = iprh->next_pbuf; + /* Then, copy the original header into it. */ + SMEMCPY(p->payload, &ipr->iphdr, IP_HLEN); + icmp_time_exceeded(p, ICMP_TE_FRAG); + clen = pbuf_clen(p); + LWIP_ASSERT("pbufs_freed + clen <= 0xffff", pbufs_freed + clen <= 0xffff); + pbufs_freed = (u16_t)(pbufs_freed + clen); + pbuf_free(p); + } +#endif /* LWIP_ICMP */ + + /* First, free all received pbufs. The individual pbufs need to be released + separately as they have not yet been chained */ + p = ipr->p; + while (p != NULL) { + struct pbuf *pcur; + iprh = (struct ip_reass_helper *)p->payload; + pcur = p; + /* get the next pointer before freeing */ + p = iprh->next_pbuf; + clen = pbuf_clen(pcur); + LWIP_ASSERT("pbufs_freed + clen <= 0xffff", pbufs_freed + clen <= 0xffff); + pbufs_freed = (u16_t)(pbufs_freed + clen); + pbuf_free(pcur); + } + /* Then, unchain the struct ip_reassdata from the list and free it. */ + ip_reass_dequeue_datagram(ipr, prev); + LWIP_ASSERT("ip_reass_pbufcount >= pbufs_freed", ip_reass_pbufcount >= pbufs_freed); + ip_reass_pbufcount = (u16_t)(ip_reass_pbufcount - pbufs_freed); + + return pbufs_freed; +} + +#if IP_REASS_FREE_OLDEST +/** + * Free the oldest datagram to make room for enqueueing new fragments. + * The datagram 'fraghdr' belongs to is not freed! + * + * @param fraghdr IP header of the current fragment + * @param pbufs_needed number of pbufs needed to enqueue + * (used for freeing other datagrams if not enough space) + * @return the number of pbufs freed + */ +static int +ip_reass_remove_oldest_datagram(struct ip_hdr *fraghdr, int pbufs_needed) +{ + /* @todo Can't we simply remove the last datagram in the + * linked list behind reassdatagrams? + */ + struct ip_reassdata *r, *oldest, *prev, *oldest_prev; + int pbufs_freed = 0, pbufs_freed_current; + int other_datagrams; + + /* Free datagrams until being allowed to enqueue 'pbufs_needed' pbufs, + * but don't free the datagram that 'fraghdr' belongs to! */ + do { + oldest = NULL; + prev = NULL; + oldest_prev = NULL; + other_datagrams = 0; + r = reassdatagrams; + while (r != NULL) { + if (!IP_ADDRESSES_AND_ID_MATCH(&r->iphdr, fraghdr)) { + /* Not the same datagram as fraghdr */ + other_datagrams++; + if (oldest == NULL) { + oldest = r; + oldest_prev = prev; + } else if (r->timer <= oldest->timer) { + /* older than the previous oldest */ + oldest = r; + oldest_prev = prev; + } + } + if (r->next != NULL) { + prev = r; + } + r = r->next; + } + if (oldest != NULL) { + pbufs_freed_current = ip_reass_free_complete_datagram(oldest, oldest_prev); + pbufs_freed += pbufs_freed_current; + } + } while ((pbufs_freed < pbufs_needed) && (other_datagrams > 1)); + return pbufs_freed; +} +#endif /* IP_REASS_FREE_OLDEST */ + +/** + * Enqueues a new fragment into the fragment queue + * @param fraghdr points to the new fragments IP hdr + * @param clen number of pbufs needed to enqueue (used for freeing other datagrams if not enough space) + * @return A pointer to the queue location into which the fragment was enqueued + */ +static struct ip_reassdata * +ip_reass_enqueue_new_datagram(struct ip_hdr *fraghdr, int clen) +{ + struct ip_reassdata *ipr; +#if ! IP_REASS_FREE_OLDEST + LWIP_UNUSED_ARG(clen); +#endif + + /* No matching previous fragment found, allocate a new reassdata struct */ + ipr = (struct ip_reassdata *)memp_malloc(MEMP_REASSDATA); + if (ipr == NULL) { +#if IP_REASS_FREE_OLDEST + if (ip_reass_remove_oldest_datagram(fraghdr, clen) >= clen) { + ipr = (struct ip_reassdata *)memp_malloc(MEMP_REASSDATA); + } + if (ipr == NULL) +#endif /* IP_REASS_FREE_OLDEST */ + { + IPFRAG_STATS_INC(ip_frag.memerr); + LWIP_DEBUGF(IP_REASS_DEBUG, ("Failed to alloc reassdata struct\n")); + return NULL; + } + } + memset(ipr, 0, sizeof(struct ip_reassdata)); + ipr->timer = IP_REASS_MAXAGE; + + /* enqueue the new structure to the front of the list */ + ipr->next = reassdatagrams; + reassdatagrams = ipr; + /* copy the ip header for later tests and input */ + /* @todo: no ip options supported? */ + SMEMCPY(&(ipr->iphdr), fraghdr, IP_HLEN); + return ipr; +} + +/** + * Dequeues a datagram from the datagram queue. Doesn't deallocate the pbufs. + * @param ipr points to the queue entry to dequeue + */ +static void +ip_reass_dequeue_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev) +{ + /* dequeue the reass struct */ + if (reassdatagrams == ipr) { + /* it was the first in the list */ + reassdatagrams = ipr->next; + } else { + /* it wasn't the first, so it must have a valid 'prev' */ + LWIP_ASSERT("sanity check linked list", prev != NULL); + prev->next = ipr->next; + } + + /* now we can free the ip_reassdata struct */ + memp_free(MEMP_REASSDATA, ipr); +} + +/** + * Chain a new pbuf into the pbuf list that composes the datagram. The pbuf list + * will grow over time as new pbufs are rx. + * Also checks that the datagram passes basic continuity checks (if the last + * fragment was received at least once). + * @param ipr points to the reassembly state + * @param new_p points to the pbuf for the current fragment + * @param is_last is 1 if this pbuf has MF==0 (ipr->flags not updated yet) + * @return see IP_REASS_VALIDATE_* defines + */ +static int +ip_reass_chain_frag_into_datagram_and_validate(struct ip_reassdata *ipr, struct pbuf *new_p, int is_last) +{ + struct ip_reass_helper *iprh, *iprh_tmp, *iprh_prev = NULL; + struct pbuf *q; + u16_t offset, len; + u8_t hlen; + struct ip_hdr *fraghdr; + int valid = 1; + + /* Extract length and fragment offset from current fragment */ + fraghdr = (struct ip_hdr *)new_p->payload; + len = lwip_ntohs(IPH_LEN(fraghdr)); + hlen = IPH_HL_BYTES(fraghdr); + if (hlen > len) { + /* invalid datagram */ + return IP_REASS_VALIDATE_PBUF_DROPPED; + } + len = (u16_t)(len - hlen); + offset = IPH_OFFSET_BYTES(fraghdr); + + /* overwrite the fragment's ip header from the pbuf with our helper struct, + * and setup the embedded helper structure. */ + /* make sure the struct ip_reass_helper fits into the IP header */ + LWIP_ASSERT("sizeof(struct ip_reass_helper) <= IP_HLEN", + sizeof(struct ip_reass_helper) <= IP_HLEN); + iprh = (struct ip_reass_helper *)new_p->payload; + iprh->next_pbuf = NULL; + iprh->start = offset; + iprh->end = (u16_t)(offset + len); + if (iprh->end < offset) { + /* u16_t overflow, cannot handle this */ + return IP_REASS_VALIDATE_PBUF_DROPPED; + } + + /* Iterate through until we either get to the end of the list (append), + * or we find one with a larger offset (insert). */ + for (q = ipr->p; q != NULL;) { + iprh_tmp = (struct ip_reass_helper *)q->payload; + if (iprh->start < iprh_tmp->start) { + /* the new pbuf should be inserted before this */ + iprh->next_pbuf = q; + if (iprh_prev != NULL) { + /* not the fragment with the lowest offset */ +#if IP_REASS_CHECK_OVERLAP + if ((iprh->start < iprh_prev->end) || (iprh->end > iprh_tmp->start)) { + /* fragment overlaps with previous or following, throw away */ + return IP_REASS_VALIDATE_PBUF_DROPPED; + } +#endif /* IP_REASS_CHECK_OVERLAP */ + iprh_prev->next_pbuf = new_p; + if (iprh_prev->end != iprh->start) { + /* There is a fragment missing between the current + * and the previous fragment */ + valid = 0; + } + } else { +#if IP_REASS_CHECK_OVERLAP + if (iprh->end > iprh_tmp->start) { + /* fragment overlaps with following, throw away */ + return IP_REASS_VALIDATE_PBUF_DROPPED; + } +#endif /* IP_REASS_CHECK_OVERLAP */ + /* fragment with the lowest offset */ + ipr->p = new_p; + } + break; + } else if (iprh->start == iprh_tmp->start) { + /* received the same datagram twice: no need to keep the datagram */ + return IP_REASS_VALIDATE_PBUF_DROPPED; +#if IP_REASS_CHECK_OVERLAP + } else if (iprh->start < iprh_tmp->end) { + /* overlap: no need to keep the new datagram */ + return IP_REASS_VALIDATE_PBUF_DROPPED; +#endif /* IP_REASS_CHECK_OVERLAP */ + } else { + /* Check if the fragments received so far have no holes. */ + if (iprh_prev != NULL) { + if (iprh_prev->end != iprh_tmp->start) { + /* There is a fragment missing between the current + * and the previous fragment */ + valid = 0; + } + } + } + q = iprh_tmp->next_pbuf; + iprh_prev = iprh_tmp; + } + + /* If q is NULL, then we made it to the end of the list. Determine what to do now */ + if (q == NULL) { + if (iprh_prev != NULL) { + /* this is (for now), the fragment with the highest offset: + * chain it to the last fragment */ +#if IP_REASS_CHECK_OVERLAP + LWIP_ASSERT("check fragments don't overlap", iprh_prev->end <= iprh->start); +#endif /* IP_REASS_CHECK_OVERLAP */ + iprh_prev->next_pbuf = new_p; + if (iprh_prev->end != iprh->start) { + valid = 0; + } + } else { +#if IP_REASS_CHECK_OVERLAP + LWIP_ASSERT("no previous fragment, this must be the first fragment!", + ipr->p == NULL); +#endif /* IP_REASS_CHECK_OVERLAP */ + /* this is the first fragment we ever received for this ip datagram */ + ipr->p = new_p; + } + } + + /* At this point, the validation part begins: */ + /* If we already received the last fragment */ + if (is_last || ((ipr->flags & IP_REASS_FLAG_LASTFRAG) != 0)) { + /* and had no holes so far */ + if (valid) { + /* then check if the rest of the fragments is here */ + /* Check if the queue starts with the first datagram */ + if ((ipr->p == NULL) || (((struct ip_reass_helper *)ipr->p->payload)->start != 0)) { + valid = 0; + } else { + /* and check that there are no holes after this datagram */ + iprh_prev = iprh; + q = iprh->next_pbuf; + while (q != NULL) { + iprh = (struct ip_reass_helper *)q->payload; + if (iprh_prev->end != iprh->start) { + valid = 0; + break; + } + iprh_prev = iprh; + q = iprh->next_pbuf; + } + /* if still valid, all fragments are received + * (because to the MF==0 already arrived */ + if (valid) { + LWIP_ASSERT("sanity check", ipr->p != NULL); + LWIP_ASSERT("sanity check", + ((struct ip_reass_helper *)ipr->p->payload) != iprh); + LWIP_ASSERT("validate_datagram:next_pbuf!=NULL", + iprh->next_pbuf == NULL); + } + } + } + /* If valid is 0 here, there are some fragments missing in the middle + * (since MF == 0 has already arrived). Such datagrams simply time out if + * no more fragments are received... */ + return valid ? IP_REASS_VALIDATE_TELEGRAM_FINISHED : IP_REASS_VALIDATE_PBUF_QUEUED; + } + /* If we come here, not all fragments were received, yet! */ + return IP_REASS_VALIDATE_PBUF_QUEUED; /* not yet valid! */ +} + +/** + * Reassembles incoming IP fragments into an IP datagram. + * + * @param p points to a pbuf chain of the fragment + * @return NULL if reassembly is incomplete, ? otherwise + */ +struct pbuf * +ip4_reass(struct pbuf *p) +{ + struct pbuf *r; + struct ip_hdr *fraghdr; + struct ip_reassdata *ipr; + struct ip_reass_helper *iprh; + u16_t offset, len, clen; + u8_t hlen; + int valid; + int is_last; + + IPFRAG_STATS_INC(ip_frag.recv); + MIB2_STATS_INC(mib2.ipreasmreqds); + + fraghdr = (struct ip_hdr *)p->payload; + + if (IPH_HL_BYTES(fraghdr) != IP_HLEN) { + LWIP_DEBUGF(IP_REASS_DEBUG, ("ip4_reass: IP options currently not supported!\n")); + IPFRAG_STATS_INC(ip_frag.err); + goto nullreturn; + } + + offset = IPH_OFFSET_BYTES(fraghdr); + len = lwip_ntohs(IPH_LEN(fraghdr)); + hlen = IPH_HL_BYTES(fraghdr); + if (hlen > len) { + /* invalid datagram */ + goto nullreturn; + } + len = (u16_t)(len - hlen); + + /* Check if we are allowed to enqueue more datagrams. */ + clen = pbuf_clen(p); + if ((ip_reass_pbufcount + clen) > IP_REASS_MAX_PBUFS) { +#if IP_REASS_FREE_OLDEST + if (!ip_reass_remove_oldest_datagram(fraghdr, clen) || + ((ip_reass_pbufcount + clen) > IP_REASS_MAX_PBUFS)) +#endif /* IP_REASS_FREE_OLDEST */ + { + /* No datagram could be freed and still too many pbufs enqueued */ + LWIP_DEBUGF(IP_REASS_DEBUG, ("ip4_reass: Overflow condition: pbufct=%d, clen=%d, MAX=%d\n", + ip_reass_pbufcount, clen, IP_REASS_MAX_PBUFS)); + IPFRAG_STATS_INC(ip_frag.memerr); + /* @todo: send ICMP time exceeded here? */ + /* drop this pbuf */ + goto nullreturn; + } + } + + /* Look for the datagram the fragment belongs to in the current datagram queue, + * remembering the previous in the queue for later dequeueing. */ + for (ipr = reassdatagrams; ipr != NULL; ipr = ipr->next) { + /* Check if the incoming fragment matches the one currently present + in the reassembly buffer. If so, we proceed with copying the + fragment into the buffer. */ + if (IP_ADDRESSES_AND_ID_MATCH(&ipr->iphdr, fraghdr)) { + LWIP_DEBUGF(IP_REASS_DEBUG, ("ip4_reass: matching previous fragment ID=%"X16_F"\n", + lwip_ntohs(IPH_ID(fraghdr)))); + IPFRAG_STATS_INC(ip_frag.cachehit); + break; + } + } + + if (ipr == NULL) { + /* Enqueue a new datagram into the datagram queue */ + ipr = ip_reass_enqueue_new_datagram(fraghdr, clen); + /* Bail if unable to enqueue */ + if (ipr == NULL) { + goto nullreturn; + } + } else { + if (((lwip_ntohs(IPH_OFFSET(fraghdr)) & IP_OFFMASK) == 0) && + ((lwip_ntohs(IPH_OFFSET(&ipr->iphdr)) & IP_OFFMASK) != 0)) { + /* ipr->iphdr is not the header from the first fragment, but fraghdr is + * -> copy fraghdr into ipr->iphdr since we want to have the header + * of the first fragment (for ICMP time exceeded and later, for copying + * all options, if supported)*/ + SMEMCPY(&ipr->iphdr, fraghdr, IP_HLEN); + } + } + + /* At this point, we have either created a new entry or pointing + * to an existing one */ + + /* check for 'no more fragments', and update queue entry*/ + is_last = (IPH_OFFSET(fraghdr) & PP_NTOHS(IP_MF)) == 0; + if (is_last) { + u16_t datagram_len = (u16_t)(offset + len); + if ((datagram_len < offset) || (datagram_len > (0xFFFF - IP_HLEN))) { + /* u16_t overflow, cannot handle this */ + goto nullreturn_ipr; + } + } + /* find the right place to insert this pbuf */ + /* @todo: trim pbufs if fragments are overlapping */ + valid = ip_reass_chain_frag_into_datagram_and_validate(ipr, p, is_last); + if (valid == IP_REASS_VALIDATE_PBUF_DROPPED) { + goto nullreturn_ipr; + } + /* if we come here, the pbuf has been enqueued */ + + /* Track the current number of pbufs current 'in-flight', in order to limit + the number of fragments that may be enqueued at any one time + (overflow checked by testing against IP_REASS_MAX_PBUFS) */ + ip_reass_pbufcount = (u16_t)(ip_reass_pbufcount + clen); + if (is_last) { + u16_t datagram_len = (u16_t)(offset + len); + ipr->datagram_len = datagram_len; + ipr->flags |= IP_REASS_FLAG_LASTFRAG; + LWIP_DEBUGF(IP_REASS_DEBUG, + ("ip4_reass: last fragment seen, total len %"S16_F"\n", + ipr->datagram_len)); + } + + if (valid == IP_REASS_VALIDATE_TELEGRAM_FINISHED) { + struct ip_reassdata *ipr_prev; + /* the totally last fragment (flag more fragments = 0) was received at least + * once AND all fragments are received */ + u16_t datagram_len = (u16_t)(ipr->datagram_len + IP_HLEN); + + /* save the second pbuf before copying the header over the pointer */ + r = ((struct ip_reass_helper *)ipr->p->payload)->next_pbuf; + + /* copy the original ip header back to the first pbuf */ + fraghdr = (struct ip_hdr *)(ipr->p->payload); + SMEMCPY(fraghdr, &ipr->iphdr, IP_HLEN); + IPH_LEN_SET(fraghdr, lwip_htons(datagram_len)); + IPH_OFFSET_SET(fraghdr, 0); + IPH_CHKSUM_SET(fraghdr, 0); + /* @todo: do we need to set/calculate the correct checksum? */ +#if CHECKSUM_GEN_IP + IF__NETIF_CHECKSUM_ENABLED(ip_current_input_netif(), NETIF_CHECKSUM_GEN_IP) { + IPH_CHKSUM_SET(fraghdr, inet_chksum(fraghdr, IP_HLEN)); + } +#endif /* CHECKSUM_GEN_IP */ + + p = ipr->p; + + /* chain together the pbufs contained within the reass_data list. */ + while (r != NULL) { + iprh = (struct ip_reass_helper *)r->payload; + + /* hide the ip header for every succeeding fragment */ + pbuf_remove_header(r, IP_HLEN); + pbuf_cat(p, r); + r = iprh->next_pbuf; + } + + /* find the previous entry in the linked list */ + if (ipr == reassdatagrams) { + ipr_prev = NULL; + } else { + for (ipr_prev = reassdatagrams; ipr_prev != NULL; ipr_prev = ipr_prev->next) { + if (ipr_prev->next == ipr) { + break; + } + } + } + + /* release the sources allocate for the fragment queue entry */ + ip_reass_dequeue_datagram(ipr, ipr_prev); + + /* and adjust the number of pbufs currently queued for reassembly. */ + clen = pbuf_clen(p); + LWIP_ASSERT("ip_reass_pbufcount >= clen", ip_reass_pbufcount >= clen); + ip_reass_pbufcount = (u16_t)(ip_reass_pbufcount - clen); + + MIB2_STATS_INC(mib2.ipreasmoks); + + /* Return the pbuf chain */ + return p; + } + /* the datagram is not (yet?) reassembled completely */ + LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass_pbufcount: %d out\n", ip_reass_pbufcount)); + return NULL; + +nullreturn_ipr: + LWIP_ASSERT("ipr != NULL", ipr != NULL); + if (ipr->p == NULL) { + /* dropped pbuf after creating a new datagram entry: remove the entry, too */ + LWIP_ASSERT("not firstalthough just enqueued", ipr == reassdatagrams); + ip_reass_dequeue_datagram(ipr, NULL); + } + +nullreturn: + LWIP_DEBUGF(IP_REASS_DEBUG, ("ip4_reass: nullreturn\n")); + IPFRAG_STATS_INC(ip_frag.drop); + pbuf_free(p); + return NULL; +} +#endif /* IP_REASSEMBLY */ + +#if IP_FRAG +#if !LWIP_NETIF_TX_SINGLE_PBUF +/** Allocate a new struct pbuf_custom_ref */ +static struct pbuf_custom_ref * +ip_frag_alloc_pbuf_custom_ref(void) +{ + return (struct pbuf_custom_ref *)memp_malloc(MEMP_FRAG_PBUF); +} + +/** Free a struct pbuf_custom_ref */ +static void +ip_frag_free_pbuf_custom_ref(struct pbuf_custom_ref *p) +{ + LWIP_ASSERT("p != NULL", p != NULL); + memp_free(MEMP_FRAG_PBUF, p); +} + +/** Free-callback function to free a 'struct pbuf_custom_ref', called by + * pbuf_free. */ +static void +ipfrag_free_pbuf_custom(struct pbuf *p) +{ + struct pbuf_custom_ref *pcr = (struct pbuf_custom_ref *)p; + LWIP_ASSERT("pcr != NULL", pcr != NULL); + LWIP_ASSERT("pcr == p", (void *)pcr == (void *)p); + if (pcr->original != NULL) { + pbuf_free(pcr->original); + } + ip_frag_free_pbuf_custom_ref(pcr); +} +#endif /* !LWIP_NETIF_TX_SINGLE_PBUF */ + +/** + * Fragment an IP datagram if too large for the netif. + * + * Chop the datagram in MTU sized chunks and send them in order + * by pointing PBUF_REFs into p. + * + * @param p ip packet to send + * @param netif the netif on which to send + * @param dest destination ip address to which to send + * + * @return ERR_OK if sent successfully, err_t otherwise + */ +err_t +ip4_frag(struct pbuf *p, struct netif *netif, const ip4_addr_t *dest) +{ + struct pbuf *rambuf; +#if !LWIP_NETIF_TX_SINGLE_PBUF + struct pbuf *newpbuf; + u16_t newpbuflen = 0; + u16_t left_to_copy; +#endif + struct ip_hdr *original_iphdr; + struct ip_hdr *iphdr; + const u16_t nfb = (u16_t)((netif->mtu - IP_HLEN) / 8); + u16_t left, fragsize; + u16_t ofo; + int last; + u16_t poff = IP_HLEN; + u16_t tmp; + int mf_set; + + original_iphdr = (struct ip_hdr *)p->payload; + iphdr = original_iphdr; + if (IPH_HL_BYTES(iphdr) != IP_HLEN) { + /* ip4_frag() does not support IP options */ + return ERR_VAL; + } + LWIP_ERROR("ip4_frag(): pbuf too short", p->len >= IP_HLEN, return ERR_VAL); + + /* Save original offset */ + tmp = lwip_ntohs(IPH_OFFSET(iphdr)); + ofo = tmp & IP_OFFMASK; + /* already fragmented? if so, the last fragment we create must have MF, too */ + mf_set = tmp & IP_MF; + + left = (u16_t)(p->tot_len - IP_HLEN); + + while (left) { + /* Fill this fragment */ + fragsize = LWIP_MIN(left, (u16_t)(nfb * 8)); + +#if LWIP_NETIF_TX_SINGLE_PBUF + rambuf = pbuf_alloc(PBUF_IP, fragsize, PBUF_RAM); + if (rambuf == NULL) { + goto memerr; + } + LWIP_ASSERT("this needs a pbuf in one piece!", + (rambuf->len == rambuf->tot_len) && (rambuf->next == NULL)); + poff += pbuf_copy_partial(p, rambuf->payload, fragsize, poff); + /* make room for the IP header */ + if (pbuf_add_header(rambuf, IP_HLEN)) { + pbuf_free(rambuf); + goto memerr; + } + /* fill in the IP header */ + SMEMCPY(rambuf->payload, original_iphdr, IP_HLEN); + iphdr = (struct ip_hdr *)rambuf->payload; +#else /* LWIP_NETIF_TX_SINGLE_PBUF */ + /* When not using a static buffer, create a chain of pbufs. + * The first will be a PBUF_RAM holding the link and IP header. + * The rest will be PBUF_REFs mirroring the pbuf chain to be fragged, + * but limited to the size of an mtu. + */ + rambuf = pbuf_alloc(PBUF_LINK, IP_HLEN, PBUF_RAM); + if (rambuf == NULL) { + goto memerr; + } + LWIP_ASSERT("this needs a pbuf in one piece!", + (rambuf->len >= (IP_HLEN))); + SMEMCPY(rambuf->payload, original_iphdr, IP_HLEN); + iphdr = (struct ip_hdr *)rambuf->payload; + + left_to_copy = fragsize; + while (left_to_copy) { + struct pbuf_custom_ref *pcr; + u16_t plen = (u16_t)(p->len - poff); + LWIP_ASSERT("p->len >= poff", p->len >= poff); + newpbuflen = LWIP_MIN(left_to_copy, plen); + /* Is this pbuf already empty? */ + if (!newpbuflen) { + poff = 0; + p = p->next; + continue; + } + pcr = ip_frag_alloc_pbuf_custom_ref(); + if (pcr == NULL) { + pbuf_free(rambuf); + goto memerr; + } + /* Mirror this pbuf, although we might not need all of it. */ + newpbuf = pbuf_alloced_custom(PBUF_RAW, newpbuflen, PBUF_REF, &pcr->pc, + (u8_t *)p->payload + poff, newpbuflen); + if (newpbuf == NULL) { + ip_frag_free_pbuf_custom_ref(pcr); + pbuf_free(rambuf); + goto memerr; + } + pbuf_ref(p); + pcr->original = p; + pcr->pc.custom_free_function = ipfrag_free_pbuf_custom; + + /* Add it to end of rambuf's chain, but using pbuf_cat, not pbuf_chain + * so that it is removed when pbuf_dechain is later called on rambuf. + */ + pbuf_cat(rambuf, newpbuf); + left_to_copy = (u16_t)(left_to_copy - newpbuflen); + if (left_to_copy) { + poff = 0; + p = p->next; + } + } + poff = (u16_t)(poff + newpbuflen); +#endif /* LWIP_NETIF_TX_SINGLE_PBUF */ + + /* Correct header */ + last = (left <= netif->mtu - IP_HLEN); + + /* Set new offset and MF flag */ + tmp = (IP_OFFMASK & (ofo)); + if (!last || mf_set) { + /* the last fragment has MF set if the input frame had it */ + tmp = tmp | IP_MF; + } + IPH_OFFSET_SET(iphdr, lwip_htons(tmp)); + IPH_LEN_SET(iphdr, lwip_htons((u16_t)(fragsize + IP_HLEN))); + IPH_CHKSUM_SET(iphdr, 0); +#if CHECKSUM_GEN_IP + IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_IP) { + IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, IP_HLEN)); + } +#endif /* CHECKSUM_GEN_IP */ + + /* No need for separate header pbuf - we allowed room for it in rambuf + * when allocated. + */ + netif->output(netif, rambuf, dest); + IPFRAG_STATS_INC(ip_frag.xmit); + + /* Unfortunately we can't reuse rambuf - the hardware may still be + * using the buffer. Instead we free it (and the ensuing chain) and + * recreate it next time round the loop. If we're lucky the hardware + * will have already sent the packet, the free will really free, and + * there will be zero memory penalty. + */ + + pbuf_free(rambuf); + left = (u16_t)(left - fragsize); + ofo = (u16_t)(ofo + nfb); + } + MIB2_STATS_INC(mib2.ipfragoks); + return ERR_OK; +memerr: + MIB2_STATS_INC(mib2.ipfragfails); + return ERR_MEM; +} +#endif /* IP_FRAG */ + +#endif /* LWIP_IPV4 */ |