diff options
Diffstat (limited to 'net/ipv4/udp.c')
| -rw-r--r-- | net/ipv4/udp.c | 1575 |
1 files changed, 1575 insertions, 0 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c new file mode 100644 index 000000000000..6baddfbedca3 --- /dev/null +++ b/net/ipv4/udp.c @@ -0,0 +1,1575 @@ +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * The User Datagram Protocol (UDP). + * + * Version: $Id: udp.c,v 1.102 2002/02/01 22:01:04 davem Exp $ + * + * Authors: Ross Biro, <bir7@leland.Stanford.Edu> + * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> + * Arnt Gulbrandsen, <agulbra@nvg.unit.no> + * Alan Cox, <Alan.Cox@linux.org> + * Hirokazu Takahashi, <taka@valinux.co.jp> + * + * Fixes: + * Alan Cox : verify_area() calls + * Alan Cox : stopped close while in use off icmp + * messages. Not a fix but a botch that + * for udp at least is 'valid'. + * Alan Cox : Fixed icmp handling properly + * Alan Cox : Correct error for oversized datagrams + * Alan Cox : Tidied select() semantics. + * Alan Cox : udp_err() fixed properly, also now + * select and read wake correctly on errors + * Alan Cox : udp_send verify_area moved to avoid mem leak + * Alan Cox : UDP can count its memory + * Alan Cox : send to an unknown connection causes + * an ECONNREFUSED off the icmp, but + * does NOT close. + * Alan Cox : Switched to new sk_buff handlers. No more backlog! + * Alan Cox : Using generic datagram code. Even smaller and the PEEK + * bug no longer crashes it. + * Fred Van Kempen : Net2e support for sk->broadcast. + * Alan Cox : Uses skb_free_datagram + * Alan Cox : Added get/set sockopt support. + * Alan Cox : Broadcasting without option set returns EACCES. + * Alan Cox : No wakeup calls. Instead we now use the callbacks. + * Alan Cox : Use ip_tos and ip_ttl + * Alan Cox : SNMP Mibs + * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support. + * Matt Dillon : UDP length checks. + * Alan Cox : Smarter af_inet used properly. + * Alan Cox : Use new kernel side addressing. + * Alan Cox : Incorrect return on truncated datagram receive. + * Arnt Gulbrandsen : New udp_send and stuff + * Alan Cox : Cache last socket + * Alan Cox : Route cache + * Jon Peatfield : Minor efficiency fix to sendto(). + * Mike Shaver : RFC1122 checks. + * Alan Cox : Nonblocking error fix. + * Willy Konynenberg : Transparent proxying support. + * Mike McLagan : Routing by source + * David S. Miller : New socket lookup architecture. + * Last socket cache retained as it + * does have a high hit rate. + * Olaf Kirch : Don't linearise iovec on sendmsg. + * Andi Kleen : Some cleanups, cache destination entry + * for connect. + * Vitaly E. Lavrov : Transparent proxy revived after year coma. + * Melvin Smith : Check msg_name not msg_namelen in sendto(), + * return ENOTCONN for unconnected sockets (POSIX) + * Janos Farkas : don't deliver multi/broadcasts to a different + * bound-to-device socket + * Hirokazu Takahashi : HW checksumming for outgoing UDP + * datagrams. + * Hirokazu Takahashi : sendfile() on UDP works now. + * Arnaldo C. Melo : convert /proc/net/udp to seq_file + * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which + * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind + * a single port at the same time. + * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support + * + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <asm/system.h> +#include <asm/uaccess.h> +#include <asm/ioctls.h> +#include <linux/types.h> +#include <linux/fcntl.h> +#include <linux/module.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/in.h> +#include <linux/errno.h> +#include <linux/timer.h> +#include <linux/mm.h> +#include <linux/config.h> +#include <linux/inet.h> +#include <linux/ipv6.h> +#include <linux/netdevice.h> +#include <net/snmp.h> +#include <net/tcp.h> +#include <net/protocol.h> +#include <linux/skbuff.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <net/sock.h> +#include <net/udp.h> +#include <net/icmp.h> +#include <net/route.h> +#include <net/inet_common.h> +#include <net/checksum.h> +#include <net/xfrm.h> + +/* + * Snmp MIB for the UDP layer + */ + +DEFINE_SNMP_STAT(struct udp_mib, udp_statistics); + +struct hlist_head udp_hash[UDP_HTABLE_SIZE]; +DEFINE_RWLOCK(udp_hash_lock); + +/* Shared by v4/v6 udp. */ +int udp_port_rover; + +static int udp_v4_get_port(struct sock *sk, unsigned short snum) +{ + struct hlist_node *node; + struct sock *sk2; + struct inet_sock *inet = inet_sk(sk); + + write_lock_bh(&udp_hash_lock); + if (snum == 0) { + int best_size_so_far, best, result, i; + + if (udp_port_rover > sysctl_local_port_range[1] || + udp_port_rover < sysctl_local_port_range[0]) + udp_port_rover = sysctl_local_port_range[0]; + best_size_so_far = 32767; + best = result = udp_port_rover; + for (i = 0; i < UDP_HTABLE_SIZE; i++, result++) { + struct hlist_head *list; + int size; + + list = &udp_hash[result & (UDP_HTABLE_SIZE - 1)]; + if (hlist_empty(list)) { + if (result > sysctl_local_port_range[1]) + result = sysctl_local_port_range[0] + + ((result - sysctl_local_port_range[0]) & + (UDP_HTABLE_SIZE - 1)); + goto gotit; + } + size = 0; + sk_for_each(sk2, node, list) + if (++size >= best_size_so_far) + goto next; + best_size_so_far = size; + best = result; + next:; + } + result = best; + for(i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++, result += UDP_HTABLE_SIZE) { + if (result > sysctl_local_port_range[1]) + result = sysctl_local_port_range[0] + + ((result - sysctl_local_port_range[0]) & + (UDP_HTABLE_SIZE - 1)); + if (!udp_lport_inuse(result)) + break; + } + if (i >= (1 << 16) / UDP_HTABLE_SIZE) + goto fail; +gotit: + udp_port_rover = snum = result; + } else { + sk_for_each(sk2, node, + &udp_hash[snum & (UDP_HTABLE_SIZE - 1)]) { + struct inet_sock *inet2 = inet_sk(sk2); + + if (inet2->num == snum && + sk2 != sk && + !ipv6_only_sock(sk2) && + (!sk2->sk_bound_dev_if || + !sk->sk_bound_dev_if || + sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && + (!inet2->rcv_saddr || + !inet->rcv_saddr || + inet2->rcv_saddr == inet->rcv_saddr) && + (!sk2->sk_reuse || !sk->sk_reuse)) + goto fail; + } + } + inet->num = snum; + if (sk_unhashed(sk)) { + struct hlist_head *h = &udp_hash[snum & (UDP_HTABLE_SIZE - 1)]; + + sk_add_node(sk, h); + sock_prot_inc_use(sk->sk_prot); + } + write_unlock_bh(&udp_hash_lock); + return 0; + +fail: + write_unlock_bh(&udp_hash_lock); + return 1; +} + +static void udp_v4_hash(struct sock *sk) +{ + BUG(); +} + +static void udp_v4_unhash(struct sock *sk) +{ + write_lock_bh(&udp_hash_lock); + if (sk_del_node_init(sk)) { + inet_sk(sk)->num = 0; + sock_prot_dec_use(sk->sk_prot); + } + write_unlock_bh(&udp_hash_lock); +} + +/* UDP is nearly always wildcards out the wazoo, it makes no sense to try + * harder than this. -DaveM + */ +static struct sock *udp_v4_lookup_longway(u32 saddr, u16 sport, + u32 daddr, u16 dport, int dif) +{ + struct sock *sk, *result = NULL; + struct hlist_node *node; + unsigned short hnum = ntohs(dport); + int badness = -1; + + sk_for_each(sk, node, &udp_hash[hnum & (UDP_HTABLE_SIZE - 1)]) { + struct inet_sock *inet = inet_sk(sk); + + if (inet->num == hnum && !ipv6_only_sock(sk)) { + int score = (sk->sk_family == PF_INET ? 1 : 0); + if (inet->rcv_saddr) { + if (inet->rcv_saddr != daddr) + continue; + score+=2; + } + if (inet->daddr) { + if (inet->daddr != saddr) + continue; + score+=2; + } + if (inet->dport) { + if (inet->dport != sport) + continue; + score+=2; + } + if (sk->sk_bound_dev_if) { + if (sk->sk_bound_dev_if != dif) + continue; + score+=2; + } + if(score == 9) { + result = sk; + break; + } else if(score > badness) { + result = sk; + badness = score; + } + } + } + return result; +} + +static __inline__ struct sock *udp_v4_lookup(u32 saddr, u16 sport, + u32 daddr, u16 dport, int dif) +{ + struct sock *sk; + + read_lock(&udp_hash_lock); + sk = udp_v4_lookup_longway(saddr, sport, daddr, dport, dif); + if (sk) + sock_hold(sk); + read_unlock(&udp_hash_lock); + return sk; +} + +static inline struct sock *udp_v4_mcast_next(struct sock *sk, + u16 loc_port, u32 loc_addr, + u16 rmt_port, u32 rmt_addr, + int dif) +{ + struct hlist_node *node; + struct sock *s = sk; + unsigned short hnum = ntohs(loc_port); + + sk_for_each_from(s, node) { + struct inet_sock *inet = inet_sk(s); + + if (inet->num != hnum || + (inet->daddr && inet->daddr != rmt_addr) || + (inet->dport != rmt_port && inet->dport) || + (inet->rcv_saddr && inet->rcv_saddr != loc_addr) || + ipv6_only_sock(s) || + (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)) + continue; + if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif)) + continue; + goto found; + } + s = NULL; +found: + return s; +} + +/* + * This routine is called by the ICMP module when it gets some + * sort of error condition. If err < 0 then the socket should + * be closed and the error returned to the user. If err > 0 + * it's just the icmp type << 8 | icmp code. + * Header points to the ip header of the error packet. We move + * on past this. Then (as it used to claim before adjustment) + * header points to the first 8 bytes of the udp header. We need + * to find the appropriate port. + */ + +void udp_err(struct sk_buff *skb, u32 info) +{ + struct inet_sock *inet; + struct iphdr *iph = (struct iphdr*)skb->data; + struct udphdr *uh = (struct udphdr*)(skb->data+(iph->ihl<<2)); + int type = skb->h.icmph->type; + int code = skb->h.icmph->code; + struct sock *sk; + int harderr; + int err; + + sk = udp_v4_lookup(iph->daddr, uh->dest, iph->saddr, uh->source, skb->dev->ifindex); + if (sk == NULL) { + ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); + return; /* No socket for error */ + } + + err = 0; + harderr = 0; + inet = inet_sk(sk); + + switch (type) { + default: + case ICMP_TIME_EXCEEDED: + err = EHOSTUNREACH; + break; + case ICMP_SOURCE_QUENCH: + goto out; + case ICMP_PARAMETERPROB: + err = EPROTO; + harderr = 1; + break; + case ICMP_DEST_UNREACH: + if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ + if (inet->pmtudisc != IP_PMTUDISC_DONT) { + err = EMSGSIZE; + harderr = 1; + break; + } + goto out; + } + err = EHOSTUNREACH; + if (code <= NR_ICMP_UNREACH) { + harderr = icmp_err_convert[code].fatal; + err = icmp_err_convert[code].errno; + } + break; + } + + /* + * RFC1122: OK. Passes ICMP errors back to application, as per + * 4.1.3.3. + */ + if (!inet->recverr) { + if (!harderr || sk->sk_state != TCP_ESTABLISHED) + goto out; + } else { + ip_icmp_error(sk, skb, err, uh->dest, info, (u8*)(uh+1)); + } + sk->sk_err = err; + sk->sk_error_report(sk); +out: + sock_put(sk); +} + +/* + * Throw away all pending data and cancel the corking. Socket is locked. + */ +static void udp_flush_pending_frames(struct sock *sk) +{ + struct udp_sock *up = udp_sk(sk); + + if (up->pending) { + up->len = 0; + up->pending = 0; + ip_flush_pending_frames(sk); + } +} + +/* + * Push out all pending data as one UDP datagram. Socket is locked. + */ +static int udp_push_pending_frames(struct sock *sk, struct udp_sock *up) +{ + struct inet_sock *inet = inet_sk(sk); + struct flowi *fl = &inet->cork.fl; + struct sk_buff *skb; + struct udphdr *uh; + int err = 0; + + /* Grab the skbuff where UDP header space exists. */ + if ((skb = skb_peek(&sk->sk_write_queue)) == NULL) + goto out; + + /* + * Create a UDP header + */ + uh = skb->h.uh; + uh->source = fl->fl_ip_sport; + uh->dest = fl->fl_ip_dport; + uh->len = htons(up->len); + uh->check = 0; + + if (sk->sk_no_check == UDP_CSUM_NOXMIT) { + skb->ip_summed = CHECKSUM_NONE; + goto send; + } + + if (skb_queue_len(&sk->sk_write_queue) == 1) { + /* + * Only one fragment on the socket. + */ + if (skb->ip_summed == CHECKSUM_HW) { + skb->csum = offsetof(struct udphdr, check); + uh->check = ~csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, + up->len, IPPROTO_UDP, 0); + } else { + skb->csum = csum_partial((char *)uh, + sizeof(struct udphdr), skb->csum); + uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, + up->len, IPPROTO_UDP, skb->csum); + if (uh->check == 0) + uh->check = -1; + } + } else { + unsigned int csum = 0; + /* + * HW-checksum won't work as there are two or more + * fragments on the socket so that all csums of sk_buffs + * should be together. + */ + if (skb->ip_summed == CHECKSUM_HW) { + int offset = (unsigned char *)uh - skb->data; + skb->csum = skb_checksum(skb, offset, skb->len - offset, 0); + + skb->ip_summed = CHECKSUM_NONE; + } else { + skb->csum = csum_partial((char *)uh, + sizeof(struct udphdr), skb->csum); + } + + skb_queue_walk(&sk->sk_write_queue, skb) { + csum = csum_add(csum, skb->csum); + } + uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, + up->len, IPPROTO_UDP, csum); + if (uh->check == 0) + uh->check = -1; + } +send: + err = ip_push_pending_frames(sk); +out: + up->len = 0; + up->pending = 0; + return err; +} + + +static unsigned short udp_check(struct udphdr *uh, int len, unsigned long saddr, unsigned long daddr, unsigned long base) +{ + return(csum_tcpudp_magic(saddr, daddr, len, IPPROTO_UDP, base)); +} + +int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, + size_t len) +{ + struct inet_sock *inet = inet_sk(sk); + struct udp_sock *up = udp_sk(sk); + int ulen = len; + struct ipcm_cookie ipc; + struct rtable *rt = NULL; + int free = 0; + int connected = 0; + u32 daddr, faddr, saddr; + u16 dport; + u8 tos; + int err; + int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; + + if (len > 0xFFFF) + return -EMSGSIZE; + + /* + * Check the flags. + */ + + if (msg->msg_flags&MSG_OOB) /* Mirror BSD error message compatibility */ + return -EOPNOTSUPP; + + ipc.opt = NULL; + + if (up->pending) { + /* + * There are pending frames. + * The socket lock must be held while it's corked. + */ + lock_sock(sk); + if (likely(up->pending)) { + if (unlikely(up->pending != AF_INET)) { + release_sock(sk); + return -EINVAL; + } + goto do_append_data; + } + release_sock(sk); + } + ulen += sizeof(struct udphdr); + + /* + * Get and verify the address. + */ + if (msg->msg_name) { + struct sockaddr_in * usin = (struct sockaddr_in*)msg->msg_name; + if (msg->msg_namelen < sizeof(*usin)) + return -EINVAL; + if (usin->sin_family != AF_INET) { + if (usin->sin_family != AF_UNSPEC) + return -EAFNOSUPPORT; + } + + daddr = usin->sin_addr.s_addr; + dport = usin->sin_port; + if (dport == 0) + return -EINVAL; + } else { + if (sk->sk_state != TCP_ESTABLISHED) + return -EDESTADDRREQ; + daddr = inet->daddr; + dport = inet->dport; + /* Open fast path for connected socket. + Route will not be used, if at least one option is set. + */ + connected = 1; + } + ipc.addr = inet->saddr; + + ipc.oif = sk->sk_bound_dev_if; + if (msg->msg_controllen) { + err = ip_cmsg_send(msg, &ipc); + if (err) + return err; + if (ipc.opt) + free = 1; + connected = 0; + } + if (!ipc.opt) + ipc.opt = inet->opt; + + saddr = ipc.addr; + ipc.addr = faddr = daddr; + + if (ipc.opt && ipc.opt->srr) { + if (!daddr) + return -EINVAL; + faddr = ipc.opt->faddr; + connected = 0; + } + tos = RT_TOS(inet->tos); + if (sock_flag(sk, SOCK_LOCALROUTE) || + (msg->msg_flags & MSG_DONTROUTE) || + (ipc.opt && ipc.opt->is_strictroute)) { + tos |= RTO_ONLINK; + connected = 0; + } + + if (MULTICAST(daddr)) { + if (!ipc.oif) + ipc.oif = inet->mc_index; + if (!saddr) + saddr = inet->mc_addr; + connected = 0; + } + + if (connected) + rt = (struct rtable*)sk_dst_check(sk, 0); + + if (rt == NULL) { + struct flowi fl = { .oif = ipc.oif, + .nl_u = { .ip4_u = + { .daddr = faddr, + .saddr = saddr, + .tos = tos } }, + .proto = IPPROTO_UDP, + .uli_u = { .ports = + { .sport = inet->sport, + .dport = dport } } }; + err = ip_route_output_flow(&rt, &fl, sk, !(msg->msg_flags&MSG_DONTWAIT)); + if (err) + goto out; + + err = -EACCES; + if ((rt->rt_flags & RTCF_BROADCAST) && + !sock_flag(sk, SOCK_BROADCAST)) + goto out; + if (connected) + sk_dst_set(sk, dst_clone(&rt->u.dst)); + } + + if (msg->msg_flags&MSG_CONFIRM) + goto do_confirm; +back_from_confirm: + + saddr = rt->rt_src; + if (!ipc.addr) + daddr = ipc.addr = rt->rt_dst; + + lock_sock(sk); + if (unlikely(up->pending)) { + /* The socket is already corked while preparing it. */ + /* ... which is an evident application bug. --ANK */ + release_sock(sk); + + NETDEBUG(if (net_ratelimit()) printk(KERN_DEBUG "udp cork app bug 2\n")); + err = -EINVAL; + goto out; + } + /* + * Now cork the socket to pend data. + */ + inet->cork.fl.fl4_dst = daddr; + inet->cork.fl.fl_ip_dport = dport; + inet->cork.fl.fl4_src = saddr; + inet->cork.fl.fl_ip_sport = inet->sport; + up->pending = AF_INET; + +do_append_data: + up->len += ulen; + err = ip_append_data(sk, ip_generic_getfrag, msg->msg_iov, ulen, + sizeof(struct udphdr), &ipc, rt, + corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); + if (err) + udp_flush_pending_frames(sk); + else if (!corkreq) + err = udp_push_pending_frames(sk, up); + release_sock(sk); + +out: + ip_rt_put(rt); + if (free) + kfree(ipc.opt); + if (!err) { + UDP_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS); + return len; + } + return err; + +do_confirm: + dst_confirm(&rt->u.dst); + if (!(msg->msg_flags&MSG_PROBE) || len) + goto back_from_confirm; + err = 0; + goto out; +} + +static int udp_sendpage(struct sock *sk, struct page *page, int offset, + size_t size, int flags) +{ + struct udp_sock *up = udp_sk(sk); + int ret; + + if (!up->pending) { + struct msghdr msg = { .msg_flags = flags|MSG_MORE }; + + /* Call udp_sendmsg to specify destination address which + * sendpage interface can't pass. + * This will succeed only when the socket is connected. + */ + ret = udp_sendmsg(NULL, sk, &msg, 0); + if (ret < 0) + return ret; + } + + lock_sock(sk); + + if (unlikely(!up->pending)) { + release_sock(sk); + + NETDEBUG(if (net_ratelimit()) printk(KERN_DEBUG "udp cork app bug 3\n")); + return -EINVAL; + } + + ret = ip_append_page(sk, page, offset, size, flags); + if (ret == -EOPNOTSUPP) { + release_sock(sk); + return sock_no_sendpage(sk->sk_socket, page, offset, + size, flags); + } + if (ret < 0) { + udp_flush_pending_frames(sk); + goto out; + } + + up->len += size; + if (!(up->corkflag || (flags&MSG_MORE))) + ret = udp_push_pending_frames(sk, up); + if (!ret) + ret = size; +out: + release_sock(sk); + return ret; +} + +/* + * IOCTL requests applicable to the UDP protocol + */ + +int udp_ioctl(struct sock *sk, int cmd, unsigned long arg) +{ + switch(cmd) + { + case SIOCOUTQ: + { + int amount = atomic_read(&sk->sk_wmem_alloc); + return put_user(amount, (int __user *)arg); + } + + case SIOCINQ: + { + struct sk_buff *skb; + unsigned long amount; + + amount = 0; + spin_lock_irq(&sk->sk_receive_queue.lock); + skb = skb_peek(&sk->sk_receive_queue); + if (skb != NULL) { + /* + * We will only return the amount + * of this packet since that is all + * that will be read. + */ + amount = skb->len - sizeof(struct udphdr); + } + spin_unlock_irq(&sk->sk_receive_queue.lock); + return put_user(amount, (int __user *)arg); + } + + default: + return -ENOIOCTLCMD; + } + return(0); +} + +static __inline__ int __udp_checksum_complete(struct sk_buff *skb) +{ + return (unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum)); +} + +static __inline__ int udp_checksum_complete(struct sk_buff *skb) +{ + return skb->ip_summed != CHECKSUM_UNNECESSARY && + __udp_checksum_complete(skb); +} + +/* + * This should be easy, if there is something there we + * return it, otherwise we block. + */ + +static int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, + size_t len, int noblock, int flags, int *addr_len) +{ + struct inet_sock *inet = inet_sk(sk); + struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name; + struct sk_buff *skb; + int copied, err; + + /* + * Check any passed addresses + */ + if (addr_len) + *addr_len=sizeof(*sin); + + if (flags & MSG_ERRQUEUE) + return ip_recv_error(sk, msg, len); + +try_again: + skb = skb_recv_datagram(sk, flags, noblock, &err); + if (!skb) + goto out; + + copied = skb->len - sizeof(struct udphdr); + if (copied > len) { + copied = len; + msg->msg_flags |= MSG_TRUNC; + } + + if (skb->ip_summed==CHECKSUM_UNNECESSARY) { + err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov, + copied); + } else if (msg->msg_flags&MSG_TRUNC) { + if (__udp_checksum_complete(skb)) + goto csum_copy_err; + err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov, + copied); + } else { + err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov); + + if (err == -EINVAL) + goto csum_copy_err; + } + + if (err) + goto out_free; + + sock_recv_timestamp(msg, sk, skb); + + /* Copy the address. */ + if (sin) + { + sin->sin_family = AF_INET; + sin->sin_port = skb->h.uh->source; + sin->sin_addr.s_addr = skb->nh.iph->saddr; + memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); + } + if (inet->cmsg_flags) + ip_cmsg_recv(msg, skb); + + err = copied; + if (flags & MSG_TRUNC) + err = skb->len - sizeof(struct udphdr); + +out_free: + skb_free_datagram(sk, skb); +out: + return err; + +csum_copy_err: + UDP_INC_STATS_BH(UDP_MIB_INERRORS); + + /* Clear queue. */ + if (flags&MSG_PEEK) { + int clear = 0; + spin_lock_irq(&sk->sk_receive_queue.lock); + if (skb == skb_peek(&sk->sk_receive_queue)) { + __skb_unlink(skb, &sk->sk_receive_queue); + clear = 1; + } + spin_unlock_irq(&sk->sk_receive_queue.lock); + if (clear) + kfree_skb(skb); + } + + skb_free_datagram(sk, skb); + + if (noblock) + return -EAGAIN; + goto try_again; +} + + +int udp_disconnect(struct sock *sk, int flags) +{ + struct inet_sock *inet = inet_sk(sk); + /* + * 1003.1g - break association. + */ + + sk->sk_state = TCP_CLOSE; + inet->daddr = 0; + inet->dport = 0; + sk->sk_bound_dev_if = 0; + if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) + inet_reset_saddr(sk); + + if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) { + sk->sk_prot->unhash(sk); + inet->sport = 0; + } + sk_dst_reset(sk); + return 0; +} + +static void udp_close(struct sock *sk, long timeout) +{ + sk_common_release(sk); +} + +/* return: + * 1 if the the UDP system should process it + * 0 if we should drop this packet + * -1 if it should get processed by xfrm4_rcv_encap + */ +static int udp_encap_rcv(struct sock * sk, struct sk_buff *skb) +{ +#ifndef CONFIG_XFRM + return 1; +#else + struct udp_sock *up = udp_sk(sk); + struct udphdr *uh = skb->h.uh; + struct iphdr *iph; + int iphlen, len; + + __u8 *udpdata = (__u8 *)uh + sizeof(struct udphdr); + __u32 *udpdata32 = (__u32 *)udpdata; + __u16 encap_type = up->encap_type; + + /* if we're overly short, let UDP handle it */ + if (udpdata > skb->tail) + return 1; + + /* if this is not encapsulated socket, then just return now */ + if (!encap_type) + return 1; + + len = skb->tail - udpdata; + + switch (encap_type) { + default: + case UDP_ENCAP_ESPINUDP: + /* Check if this is a keepalive packet. If so, eat it. */ + if (len == 1 && udpdata[0] == 0xff) { + return 0; + } else if (len > sizeof(struct ip_esp_hdr) && udpdata32[0] != 0 ) { + /* ESP Packet without Non-ESP header */ + len = sizeof(struct udphdr); + } else + /* Must be an IKE packet.. pass it through */ + return 1; + break; + case UDP_ENCAP_ESPINUDP_NON_IKE: + /* Check if this is a keepalive packet. If so, eat it. */ + if (len == 1 && udpdata[0] == 0xff) { + return 0; + } else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) && + udpdata32[0] == 0 && udpdata32[1] == 0) { + + /* ESP Packet with Non-IKE marker */ + len = sizeof(struct udphdr) + 2 * sizeof(u32); + } else + /* Must be an IKE packet.. pass it through */ + return 1; + break; + } + + /* At this point we are sure that this is an ESPinUDP packet, + * so we need to remove 'len' bytes from the packet (the UDP + * header and optional ESP marker bytes) and then modify the + * protocol to ESP, and then call into the transform receiver. + */ + + /* Now we can update and verify the packet length... */ + iph = skb->nh.iph; + iphlen = iph->ihl << 2; + iph->tot_len = htons(ntohs(iph->tot_len) - len); + if (skb->len < iphlen + len) { + /* packet is too small!?! */ + return 0; + } + + /* pull the data buffer up to the ESP header and set the + * transport header to point to ESP. Keep UDP on the stack + * for later. + */ + skb->h.raw = skb_pull(skb, len); + + /* modify the protocol (it's ESP!) */ + iph->protocol = IPPROTO_ESP; + + /* and let the caller know to send this into the ESP processor... */ + return -1; +#endif +} + +/* returns: + * -1: error + * 0: success + * >0: "udp encap" protocol resubmission + * + * Note that in the success and error cases, the skb is assumed to + * have either been requeued or freed. + */ +static int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb) +{ + struct udp_sock *up = udp_sk(sk); + + /* + * Charge it to the socket, dropping if the queue is full. + */ + if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) { + kfree_skb(skb); + return -1; + } + + if (up->encap_type) { + /* + * This is an encapsulation socket, so let's see if this is + * an encapsulated packet. + * If it's a keepalive packet, then just eat it. + * If it's an encapsulateed packet, then pass it to the + * IPsec xfrm input and return the response + * appropriately. Otherwise, just fall through and + * pass this up the UDP socket. + */ + int ret; + + ret = udp_encap_rcv(sk, skb); + if (ret == 0) { + /* Eat the packet .. */ + kfree_skb(skb); + return 0; + } + if (ret < 0) { + /* process the ESP packet */ + ret = xfrm4_rcv_encap(skb, up->encap_type); + UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS); + return -ret; + } + /* FALLTHROUGH -- it's a UDP Packet */ + } + + if (sk->sk_filter && skb->ip_summed != CHECKSUM_UNNECESSARY) { + if (__udp_checksum_complete(skb)) { + UDP_INC_STATS_BH(UDP_MIB_INERRORS); + kfree_skb(skb); + return -1; + } + skb->ip_summed = CHECKSUM_UNNECESSARY; + } + + if (sock_queue_rcv_skb(sk,skb)<0) { + UDP_INC_STATS_BH(UDP_MIB_INERRORS); + kfree_skb(skb); + return -1; + } + UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS); + return 0; +} + +/* + * Multicasts and broadcasts go to each listener. + * + * Note: called only from the BH handler context, + * so we don't need to lock the hashes. + */ +static int udp_v4_mcast_deliver(struct sk_buff *skb, struct udphdr *uh, + u32 saddr, u32 daddr) +{ + struct sock *sk; + int dif; + + read_lock(&udp_hash_lock); + sk = sk_head(&udp_hash[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)]); + dif = skb->dev->ifindex; + sk = udp_v4_mcast_next(sk, uh->dest, daddr, uh->source, saddr, dif); + if (sk) { + struct sock *sknext = NULL; + + do { + struct sk_buff *skb1 = skb; + + sknext = udp_v4_mcast_next(sk_next(sk), uh->dest, daddr, + uh->source, saddr, dif); + if(sknext) + skb1 = skb_clone(skb, GFP_ATOMIC); + + if(skb1) { + int ret = udp_queue_rcv_skb(sk, skb1); + if (ret > 0) + /* we should probably re-process instead + * of dropping packets here. */ + kfree_skb(skb1); + } + sk = sknext; + } while(sknext); + } else + kfree_skb(skb); + read_unlock(&udp_hash_lock); + return 0; +} + +/* Initialize UDP checksum. If exited with zero value (success), + * CHECKSUM_UNNECESSARY means, that no more checks are required. + * Otherwise, csum completion requires chacksumming packet body, + * including udp header and folding it to skb->csum. + */ +static int udp_checksum_init(struct sk_buff *skb, struct udphdr *uh, + unsigned short ulen, u32 saddr, u32 daddr) +{ + if (uh->check == 0) { + skb->ip_summed = CHECKSUM_UNNECESSARY; + } else if (skb->ip_summed == CHECKSUM_HW) { + skb->ip_summed = CHECKSUM_UNNECESSARY; + if (!udp_check(uh, ulen, saddr, daddr, skb->csum)) + return 0; + NETDEBUG(if (net_ratelimit()) printk(KERN_DEBUG "udp v4 hw csum failure.\n")); + skb->ip_summed = CHECKSUM_NONE; + } + if (skb->ip_summed != CHECKSUM_UNNECESSARY) + skb->csum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); + /* Probably, we should checksum udp header (it should be in cache + * in any case) and data in tiny packets (< rx copybreak). + */ + return 0; +} + +/* + * All we need to do is get the socket, and then do a checksum. + */ + +int udp_rcv(struct sk_buff *skb) +{ + struct sock *sk; + struct udphdr *uh; + unsigned short ulen; + struct rtable *rt = (struct rtable*)skb->dst; + u32 saddr = skb->nh.iph->saddr; + u32 daddr = skb->nh.iph->daddr; + int len = skb->len; + + /* + * Validate the packet and the UDP length. + */ + if (!pskb_may_pull(skb, sizeof(struct udphdr))) + goto no_header; + + uh = skb->h.uh; + + ulen = ntohs(uh->len); + + if (ulen > len || ulen < sizeof(*uh)) + goto short_packet; + + if (pskb_trim(skb, ulen)) + goto short_packet; + + if (udp_checksum_init(skb, uh, ulen, saddr, daddr) < 0) + goto csum_error; + + if(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST)) + return udp_v4_mcast_deliver(skb, uh, saddr, daddr); + + sk = udp_v4_lookup(saddr, uh->source, daddr, uh->dest, skb->dev->ifindex); + + if (sk != NULL) { + int ret = udp_queue_rcv_skb(sk, skb); + sock_put(sk); + + /* a return value > 0 means to resubmit the input, but + * it it wants the return to be -protocol, or 0 + */ + if (ret > 0) + return -ret; + return 0; + } + + if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) + goto drop; + + /* No socket. Drop packet silently, if checksum is wrong */ + if (udp_checksum_complete(skb)) + goto csum_error; + + UDP_INC_STATS_BH(UDP_MIB_NOPORTS); + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); + + /* + * Hmm. We got an UDP packet to a port to which we + * don't wanna listen. Ignore it. + */ + kfree_skb(skb); + return(0); + +short_packet: + NETDEBUG(if (net_ratelimit()) + printk(KERN_DEBUG "UDP: short packet: From %u.%u.%u.%u:%u %d/%d to %u.%u.%u.%u:%u\n", + NIPQUAD(saddr), + ntohs(uh->source), + ulen, + len, + NIPQUAD(daddr), + ntohs(uh->dest))); +no_header: + UDP_INC_STATS_BH(UDP_MIB_INERRORS); + kfree_skb(skb); + return(0); + +csum_error: + /* + * RFC1122: OK. Discards the bad packet silently (as far as + * the network is concerned, anyway) as per 4.1.3.4 (MUST). + */ + NETDEBUG(if (net_ratelimit()) + printk(KERN_DEBUG "UDP: bad checksum. From %d.%d.%d.%d:%d to %d.%d.%d.%d:%d ulen %d\n", + NIPQUAD(saddr), + ntohs(uh->source), + NIPQUAD(daddr), + ntohs(uh->dest), + ulen)); +drop: + UDP_INC_STATS_BH(UDP_MIB_INERRORS); + kfree_skb(skb); + return(0); +} + +static int udp_destroy_sock(struct sock *sk) +{ + lock_sock(sk); + udp_flush_pending_frames(sk); + release_sock(sk); + return 0; +} + +/* + * Socket option code for UDP + */ +static int udp_setsockopt(struct sock *sk, int level, int optname, + char __user *optval, int optlen) +{ + struct udp_sock *up = udp_sk(sk); + int val; + int err = 0; + + if (level != SOL_UDP) + return ip_setsockopt(sk, level, optname, optval, optlen); + + if(optlen<sizeof(int)) + return -EINVAL; + + if (get_user(val, (int __user *)optval)) + return -EFAULT; + + switch(optname) { + case UDP_CORK: + if (val != 0) { + up->corkflag = 1; + } else { + up->corkflag = 0; + lock_sock(sk); + udp_push_pending_frames(sk, up); + release_sock(sk); + } + break; + + case UDP_ENCAP: + switch (val) { + case 0: + case UDP_ENCAP_ESPINUDP: + case UDP_ENCAP_ESPINUDP_NON_IKE: + up->encap_type = val; + break; + default: + err = -ENOPROTOOPT; + break; + } + break; + + default: + err = -ENOPROTOOPT; + break; + }; + + return err; +} + +static int udp_getsockopt(struct sock *sk, int level, int optname, + char __user *optval, int __user *optlen) +{ + struct udp_sock *up = udp_sk(sk); + int val, len; + + if (level != SOL_UDP) + return ip_getsockopt(sk, level, optname, optval, optlen); + + if(get_user(len,optlen)) + return -EFAULT; + + len = min_t(unsigned int, len, sizeof(int)); + + if(len < 0) + return -EINVAL; + + switch(optname) { + case UDP_CORK: + val = up->corkflag; + break; + + case UDP_ENCAP: + val = up->encap_type; + break; + + default: + return -ENOPROTOOPT; + }; + + if(put_user(len, optlen)) + return -EFAULT; + if(copy_to_user(optval, &val,len)) + return -EFAULT; + return 0; +} + +/** + * udp_poll - wait for a UDP event. + * @file - file struct + * @sock - socket + * @wait - poll table + * + * This is same as datagram poll, except for the special case of + * blocking sockets. If application is using a blocking fd + * and a packet with checksum error is in the queue; + * then it could get return from select indicating data available + * but then block when reading it. Add special case code + * to work around these arguably broken applications. + */ +unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait) +{ + unsigned int mask = datagram_poll(file, sock, wait); + struct sock *sk = sock->sk; + + /* Check for false positives due to checksum errors */ + if ( (mask & POLLRDNORM) && + !(file->f_flags & O_NONBLOCK) && + !(sk->sk_shutdown & RCV_SHUTDOWN)){ + struct sk_buff_head *rcvq = &sk->sk_receive_queue; + struct sk_buff *skb; + + spin_lock_irq(&rcvq->lock); + while ((skb = skb_peek(rcvq)) != NULL) { + if (udp_checksum_complete(skb)) { + UDP_INC_STATS_BH(UDP_MIB_INERRORS); + __skb_unlink(skb, rcvq); + kfree_skb(skb); + } else { + skb->ip_summed = CHECKSUM_UNNECESSARY; + break; + } + } + spin_unlock_irq(&rcvq->lock); + + /* nothing to see, move along */ + if (skb == NULL) + mask &= ~(POLLIN | POLLRDNORM); + } + + return mask; + +} + +struct proto udp_prot = { + .name = "UDP", + .owner = THIS_MODULE, + .close = udp_close, + .connect = ip4_datagram_connect, + .disconnect = udp_disconnect, + .ioctl = udp_ioctl, + .destroy = udp_destroy_sock, + .setsockopt = udp_setsockopt, + .getsockopt = udp_getsockopt, + .sendmsg = udp_sendmsg, + .recvmsg = udp_recvmsg, + .sendpage = udp_sendpage, + .backlog_rcv = udp_queue_rcv_skb, + .hash = udp_v4_hash, + .unhash = udp_v4_unhash, + .get_port = udp_v4_get_port, + .obj_size = sizeof(struct udp_sock), +}; + +/* ------------------------------------------------------------------------ */ +#ifdef CONFIG_PROC_FS + +static struct sock *udp_get_first(struct seq_file *seq) +{ + struct sock *sk; + struct udp_iter_state *state = seq->private; + + for (state->bucket = 0; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) { + struct hlist_node *node; + sk_for_each(sk, node, &udp_hash[state->bucket]) { + if (sk->sk_family == state->family) + goto found; + } + } + sk = NULL; +found: + return sk; +} + +static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk) +{ + struct udp_iter_state *state = seq->private; + + do { + sk = sk_next(sk); +try_again: + ; + } while (sk && sk->sk_family != state->family); + + if (!sk && ++state->bucket < UDP_HTABLE_SIZE) { + sk = sk_head(&udp_hash[state->bucket]); + goto try_again; + } + return sk; +} + +static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos) +{ + struct sock *sk = udp_get_first(seq); + + if (sk) + while(pos && (sk = udp_get_next(seq, sk)) != NULL) + --pos; + return pos ? NULL : sk; +} + +static void *udp_seq_start(struct seq_file *seq, loff_t *pos) +{ + read_lock(&udp_hash_lock); + return *pos ? udp_get_idx(seq, *pos-1) : (void *)1; +} + +static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + struct sock *sk; + + if (v == (void *)1) + sk = udp_get_idx(seq, 0); + else + sk = udp_get_next(seq, v); + + ++*pos; + return sk; +} + +static void udp_seq_stop(struct seq_file *seq, void *v) +{ + read_unlock(&udp_hash_lock); +} + +static int udp_seq_open(struct inode *inode, struct file *file) +{ + struct udp_seq_afinfo *afinfo = PDE(inode)->data; + struct seq_file *seq; + int rc = -ENOMEM; + struct udp_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL); + + if (!s) + goto out; + memset(s, 0, sizeof(*s)); + s->family = afinfo->family; + s->seq_ops.start = udp_seq_start; + s->seq_ops.next = udp_seq_next; + s->seq_ops.show = afinfo->seq_show; + s->seq_ops.stop = udp_seq_stop; + + rc = seq_open(file, &s->seq_ops); + if (rc) + goto out_kfree; + + seq = file->private_data; + seq->private = s; +out: + return rc; +out_kfree: + kfree(s); + goto out; +} + +/* ------------------------------------------------------------------------ */ +int udp_proc_register(struct udp_seq_afinfo *afinfo) +{ + struct proc_dir_entry *p; + int rc = 0; + + if (!afinfo) + return -EINVAL; + afinfo->seq_fops->owner = afinfo->owner; + afinfo->seq_fops->open = udp_seq_open; + afinfo->seq_fops->read = seq_read; + afinfo->seq_fops->llseek = seq_lseek; + afinfo->seq_fops->release = seq_release_private; + + p = proc_net_fops_create(afinfo->name, S_IRUGO, afinfo->seq_fops); + if (p) + p->data = afinfo; + else + rc = -ENOMEM; + return rc; +} + +void udp_proc_unregister(struct udp_seq_afinfo *afinfo) +{ + if (!afinfo) + return; + proc_net_remove(afinfo->name); + memset(afinfo->seq_fops, 0, sizeof(*afinfo->seq_fops)); +} + +/* ------------------------------------------------------------------------ */ +static void udp4_format_sock(struct sock *sp, char *tmpbuf, int bucket) +{ + struct inet_sock *inet = inet_sk(sp); + unsigned int dest = inet->daddr; + unsigned int src = inet->rcv_saddr; + __u16 destp = ntohs(inet->dport); + __u16 srcp = ntohs(inet->sport); + + sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X" + " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p", + bucket, src, srcp, dest, destp, sp->sk_state, + atomic_read(&sp->sk_wmem_alloc), + atomic_read(&sp->sk_rmem_alloc), + 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp), + atomic_read(&sp->sk_refcnt), sp); +} + +static int udp4_seq_show(struct seq_file *seq, void *v) +{ + if (v == SEQ_START_TOKEN) + seq_printf(seq, "%-127s\n", + " sl local_address rem_address st tx_queue " + "rx_queue tr tm->when retrnsmt uid timeout " + "inode"); + else { + char tmpbuf[129]; + struct udp_iter_state *state = seq->private; + + udp4_format_sock(v, tmpbuf, state->bucket); + seq_printf(seq, "%-127s\n", tmpbuf); + } + return 0; +} + +/* ------------------------------------------------------------------------ */ +static struct file_operations udp4_seq_fops; +static struct udp_seq_afinfo udp4_seq_afinfo = { + .owner = THIS_MODULE, + .name = "udp", + .family = AF_INET, + .seq_show = udp4_seq_show, + .seq_fops = &udp4_seq_fops, +}; + +int __init udp4_proc_init(void) +{ + return udp_proc_register(&udp4_seq_afinfo); +} + +void udp4_proc_exit(void) +{ + udp_proc_unregister(&udp4_seq_afinfo); +} +#endif /* CONFIG_PROC_FS */ + +EXPORT_SYMBOL(udp_disconnect); +EXPORT_SYMBOL(udp_hash); +EXPORT_SYMBOL(udp_hash_lock); +EXPORT_SYMBOL(udp_ioctl); +EXPORT_SYMBOL(udp_port_rover); +EXPORT_SYMBOL(udp_prot); +EXPORT_SYMBOL(udp_sendmsg); +EXPORT_SYMBOL(udp_poll); + +#ifdef CONFIG_PROC_FS +EXPORT_SYMBOL(udp_proc_register); +EXPORT_SYMBOL(udp_proc_unregister); +#endif |