summaryrefslogtreecommitdiff
path: root/net/ieee802154/reassembly.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2014-04-02 20:53:45 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-04-02 20:53:45 -0700
commitcd6362befe4cc7bf589a5236d2a780af2d47bcc9 (patch)
tree3bd4e13ec3f92a00dc4f6c3d65e820b54dbfe46e /net/ieee802154/reassembly.c
parent0f1b1e6d73cb989ce2c071edc57deade3b084dfe (diff)
parentb1586f099ba897542ece36e8a23c1a62907261ef (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller: "Here is my initial pull request for the networking subsystem during this merge window: 1) Support for ESN in AH (RFC 4302) from Fan Du. 2) Add full kernel doc for ethtool command structures, from Ben Hutchings. 3) Add BCM7xxx PHY driver, from Florian Fainelli. 4) Export computed TCP rate information in netlink socket dumps, from Eric Dumazet. 5) Allow IPSEC SA to be dumped partially using a filter, from Nicolas Dichtel. 6) Convert many drivers to pci_enable_msix_range(), from Alexander Gordeev. 7) Record SKB timestamps more efficiently, from Eric Dumazet. 8) Switch to microsecond resolution for TCP round trip times, also from Eric Dumazet. 9) Clean up and fix 6lowpan fragmentation handling by making use of the existing inet_frag api for it's implementation. 10) Add TX grant mapping to xen-netback driver, from Zoltan Kiss. 11) Auto size SKB lengths when composing netlink messages based upon past message sizes used, from Eric Dumazet. 12) qdisc dumps can take a long time, add a cond_resched(), From Eric Dumazet. 13) Sanitize netpoll core and drivers wrt. SKB handling semantics. Get rid of never-used-in-tree netpoll RX handling. From Eric W Biederman. 14) Support inter-address-family and namespace changing in VTI tunnel driver(s). From Steffen Klassert. 15) Add Altera TSE driver, from Vince Bridgers. 16) Optimizing csum_replace2() so that it doesn't adjust the checksum by checksumming the entire header, from Eric Dumazet. 17) Expand BPF internal implementation for faster interpreting, more direct translations into JIT'd code, and much cleaner uses of BPF filtering in non-socket ocntexts. From Daniel Borkmann and Alexei Starovoitov" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1976 commits) netpoll: Use skb_irq_freeable to make zap_completion_queue safe. net: Add a test to see if a skb is freeable in irq context qlcnic: Fix build failure due to undefined reference to `vxlan_get_rx_port' net: ptp: move PTP classifier in its own file net: sxgbe: make "core_ops" static net: sxgbe: fix logical vs bitwise operation net: sxgbe: sxgbe_mdio_register() frees the bus Call efx_set_channels() before efx->type->dimension_resources() xen-netback: disable rogue vif in kthread context net/mlx4: Set proper build dependancy with vxlan be2net: fix build dependency on VxLAN mac802154: make csma/cca parameters per-wpan mac802154: allow only one WPAN to be up at any given time net: filter: minor: fix kdoc in __sk_run_filter netlink: don't compare the nul-termination in nla_strcmp can: c_can: Avoid led toggling for every packet. can: c_can: Simplify TX interrupt cleanup can: c_can: Store dlc private can: c_can: Reduce register access can: c_can: Make the code readable ...
Diffstat (limited to 'net/ieee802154/reassembly.c')
-rw-r--r--net/ieee802154/reassembly.c571
1 files changed, 571 insertions, 0 deletions
diff --git a/net/ieee802154/reassembly.c b/net/ieee802154/reassembly.c
new file mode 100644
index 000000000000..ef2d54372b13
--- /dev/null
+++ b/net/ieee802154/reassembly.c
@@ -0,0 +1,571 @@
+/* 6LoWPAN fragment reassembly
+ *
+ *
+ * Authors:
+ * Alexander Aring <aar@pengutronix.de>
+ *
+ * Based on: net/ipv6/reassembly.c
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt) "6LoWPAN: " fmt
+
+#include <linux/net.h>
+#include <linux/list.h>
+#include <linux/netdevice.h>
+#include <linux/random.h>
+#include <linux/jhash.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+
+#include <net/ieee802154_netdev.h>
+#include <net/6lowpan.h>
+#include <net/ipv6.h>
+#include <net/inet_frag.h>
+
+#include "reassembly.h"
+
+struct lowpan_frag_info {
+ __be16 d_tag;
+ u16 d_size;
+ u8 d_offset;
+};
+
+struct lowpan_frag_info *lowpan_cb(struct sk_buff *skb)
+{
+ return (struct lowpan_frag_info *)skb->cb;
+}
+
+static struct inet_frags lowpan_frags;
+
+static int lowpan_frag_reasm(struct lowpan_frag_queue *fq,
+ struct sk_buff *prev, struct net_device *dev);
+
+static unsigned int lowpan_hash_frag(__be16 tag, u16 d_size,
+ const struct ieee802154_addr *saddr,
+ const struct ieee802154_addr *daddr)
+{
+ u32 c;
+
+ net_get_random_once(&lowpan_frags.rnd, sizeof(lowpan_frags.rnd));
+ c = jhash_3words(ieee802154_addr_hash(saddr),
+ ieee802154_addr_hash(daddr),
+ (__force u32)(tag + (d_size << 16)),
+ lowpan_frags.rnd);
+
+ return c & (INETFRAGS_HASHSZ - 1);
+}
+
+static unsigned int lowpan_hashfn(struct inet_frag_queue *q)
+{
+ struct lowpan_frag_queue *fq;
+
+ fq = container_of(q, struct lowpan_frag_queue, q);
+ return lowpan_hash_frag(fq->tag, fq->d_size, &fq->saddr, &fq->daddr);
+}
+
+static bool lowpan_frag_match(struct inet_frag_queue *q, void *a)
+{
+ struct lowpan_frag_queue *fq;
+ struct lowpan_create_arg *arg = a;
+
+ fq = container_of(q, struct lowpan_frag_queue, q);
+ return fq->tag == arg->tag && fq->d_size == arg->d_size &&
+ ieee802154_addr_equal(&fq->saddr, arg->src) &&
+ ieee802154_addr_equal(&fq->daddr, arg->dst);
+}
+
+static void lowpan_frag_init(struct inet_frag_queue *q, void *a)
+{
+ struct lowpan_frag_queue *fq;
+ struct lowpan_create_arg *arg = a;
+
+ fq = container_of(q, struct lowpan_frag_queue, q);
+
+ fq->tag = arg->tag;
+ fq->d_size = arg->d_size;
+ fq->saddr = *arg->src;
+ fq->daddr = *arg->dst;
+}
+
+static void lowpan_frag_expire(unsigned long data)
+{
+ struct frag_queue *fq;
+ struct net *net;
+
+ fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q);
+ net = container_of(fq->q.net, struct net, ieee802154_lowpan.frags);
+
+ spin_lock(&fq->q.lock);
+
+ if (fq->q.last_in & INET_FRAG_COMPLETE)
+ goto out;
+
+ inet_frag_kill(&fq->q, &lowpan_frags);
+out:
+ spin_unlock(&fq->q.lock);
+ inet_frag_put(&fq->q, &lowpan_frags);
+}
+
+static inline struct lowpan_frag_queue *
+fq_find(struct net *net, const struct lowpan_frag_info *frag_info,
+ const struct ieee802154_addr *src,
+ const struct ieee802154_addr *dst)
+{
+ struct inet_frag_queue *q;
+ struct lowpan_create_arg arg;
+ unsigned int hash;
+
+ arg.tag = frag_info->d_tag;
+ arg.d_size = frag_info->d_size;
+ arg.src = src;
+ arg.dst = dst;
+
+ read_lock(&lowpan_frags.lock);
+ hash = lowpan_hash_frag(frag_info->d_tag, frag_info->d_size, src, dst);
+
+ q = inet_frag_find(&net->ieee802154_lowpan.frags,
+ &lowpan_frags, &arg, hash);
+ if (IS_ERR_OR_NULL(q)) {
+ inet_frag_maybe_warn_overflow(q, pr_fmt());
+ return NULL;
+ }
+ return container_of(q, struct lowpan_frag_queue, q);
+}
+
+static int lowpan_frag_queue(struct lowpan_frag_queue *fq,
+ struct sk_buff *skb, const u8 frag_type)
+{
+ struct sk_buff *prev, *next;
+ struct net_device *dev;
+ int end, offset;
+
+ if (fq->q.last_in & INET_FRAG_COMPLETE)
+ goto err;
+
+ offset = lowpan_cb(skb)->d_offset << 3;
+ end = lowpan_cb(skb)->d_size;
+
+ /* Is this the final fragment? */
+ if (offset + skb->len == end) {
+ /* If we already have some bits beyond end
+ * or have different end, the segment is corrupted.
+ */
+ if (end < fq->q.len ||
+ ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len))
+ goto err;
+ fq->q.last_in |= INET_FRAG_LAST_IN;
+ fq->q.len = end;
+ } else {
+ if (end > fq->q.len) {
+ /* Some bits beyond end -> corruption. */
+ if (fq->q.last_in & INET_FRAG_LAST_IN)
+ goto err;
+ fq->q.len = end;
+ }
+ }
+
+ /* Find out which fragments are in front and at the back of us
+ * in the chain of fragments so far. We must know where to put
+ * this fragment, right?
+ */
+ prev = fq->q.fragments_tail;
+ if (!prev || lowpan_cb(prev)->d_offset < lowpan_cb(skb)->d_offset) {
+ next = NULL;
+ goto found;
+ }
+ prev = NULL;
+ for (next = fq->q.fragments; next != NULL; next = next->next) {
+ if (lowpan_cb(next)->d_offset >= lowpan_cb(skb)->d_offset)
+ break; /* bingo! */
+ prev = next;
+ }
+
+found:
+ /* Insert this fragment in the chain of fragments. */
+ skb->next = next;
+ if (!next)
+ fq->q.fragments_tail = skb;
+ if (prev)
+ prev->next = skb;
+ else
+ fq->q.fragments = skb;
+
+ dev = skb->dev;
+ if (dev)
+ skb->dev = NULL;
+
+ fq->q.stamp = skb->tstamp;
+ if (frag_type == LOWPAN_DISPATCH_FRAG1) {
+ /* Calculate uncomp. 6lowpan header to estimate full size */
+ fq->q.meat += lowpan_uncompress_size(skb, NULL);
+ fq->q.last_in |= INET_FRAG_FIRST_IN;
+ } else {
+ fq->q.meat += skb->len;
+ }
+ add_frag_mem_limit(&fq->q, skb->truesize);
+
+ if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
+ fq->q.meat == fq->q.len) {
+ int res;
+ unsigned long orefdst = skb->_skb_refdst;
+
+ skb->_skb_refdst = 0UL;
+ res = lowpan_frag_reasm(fq, prev, dev);
+ skb->_skb_refdst = orefdst;
+ return res;
+ }
+
+ inet_frag_lru_move(&fq->q);
+ return -1;
+err:
+ kfree_skb(skb);
+ return -1;
+}
+
+/* Check if this packet is complete.
+ * Returns NULL on failure by any reason, and pointer
+ * to current nexthdr field in reassembled frame.
+ *
+ * It is called with locked fq, and caller must check that
+ * queue is eligible for reassembly i.e. it is not COMPLETE,
+ * the last and the first frames arrived and all the bits are here.
+ */
+static int lowpan_frag_reasm(struct lowpan_frag_queue *fq, struct sk_buff *prev,
+ struct net_device *dev)
+{
+ struct sk_buff *fp, *head = fq->q.fragments;
+ int sum_truesize;
+
+ inet_frag_kill(&fq->q, &lowpan_frags);
+
+ /* Make the one we just received the head. */
+ if (prev) {
+ head = prev->next;
+ fp = skb_clone(head, GFP_ATOMIC);
+
+ if (!fp)
+ goto out_oom;
+
+ fp->next = head->next;
+ if (!fp->next)
+ fq->q.fragments_tail = fp;
+ prev->next = fp;
+
+ skb_morph(head, fq->q.fragments);
+ head->next = fq->q.fragments->next;
+
+ consume_skb(fq->q.fragments);
+ fq->q.fragments = head;
+ }
+
+ /* Head of list must not be cloned. */
+ if (skb_unclone(head, GFP_ATOMIC))
+ goto out_oom;
+
+ /* If the first fragment is fragmented itself, we split
+ * it to two chunks: the first with data and paged part
+ * and the second, holding only fragments.
+ */
+ if (skb_has_frag_list(head)) {
+ struct sk_buff *clone;
+ int i, plen = 0;
+
+ clone = alloc_skb(0, GFP_ATOMIC);
+ if (!clone)
+ goto out_oom;
+ clone->next = head->next;
+ head->next = clone;
+ skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
+ skb_frag_list_init(head);
+ for (i = 0; i < skb_shinfo(head)->nr_frags; i++)
+ plen += skb_frag_size(&skb_shinfo(head)->frags[i]);
+ clone->len = head->data_len - plen;
+ clone->data_len = clone->len;
+ head->data_len -= clone->len;
+ head->len -= clone->len;
+ add_frag_mem_limit(&fq->q, clone->truesize);
+ }
+
+ WARN_ON(head == NULL);
+
+ sum_truesize = head->truesize;
+ for (fp = head->next; fp;) {
+ bool headstolen;
+ int delta;
+ struct sk_buff *next = fp->next;
+
+ sum_truesize += fp->truesize;
+ if (skb_try_coalesce(head, fp, &headstolen, &delta)) {
+ kfree_skb_partial(fp, headstolen);
+ } else {
+ if (!skb_shinfo(head)->frag_list)
+ skb_shinfo(head)->frag_list = fp;
+ head->data_len += fp->len;
+ head->len += fp->len;
+ head->truesize += fp->truesize;
+ }
+ fp = next;
+ }
+ sub_frag_mem_limit(&fq->q, sum_truesize);
+
+ head->next = NULL;
+ head->dev = dev;
+ head->tstamp = fq->q.stamp;
+
+ fq->q.fragments = NULL;
+ fq->q.fragments_tail = NULL;
+
+ return 1;
+out_oom:
+ net_dbg_ratelimited("lowpan_frag_reasm: no memory for reassembly\n");
+ return -1;
+}
+
+static int lowpan_get_frag_info(struct sk_buff *skb, const u8 frag_type,
+ struct lowpan_frag_info *frag_info)
+{
+ bool fail;
+ u8 pattern = 0, low = 0;
+
+ fail = lowpan_fetch_skb(skb, &pattern, 1);
+ fail |= lowpan_fetch_skb(skb, &low, 1);
+ frag_info->d_size = (pattern & 7) << 8 | low;
+ fail |= lowpan_fetch_skb(skb, &frag_info->d_tag, 2);
+
+ if (frag_type == LOWPAN_DISPATCH_FRAGN) {
+ fail |= lowpan_fetch_skb(skb, &frag_info->d_offset, 1);
+ } else {
+ skb_reset_network_header(skb);
+ frag_info->d_offset = 0;
+ }
+
+ if (unlikely(fail))
+ return -EIO;
+
+ return 0;
+}
+
+int lowpan_frag_rcv(struct sk_buff *skb, const u8 frag_type)
+{
+ struct lowpan_frag_queue *fq;
+ struct net *net = dev_net(skb->dev);
+ struct lowpan_frag_info *frag_info = lowpan_cb(skb);
+ struct ieee802154_addr source, dest;
+ int err;
+
+ source = mac_cb(skb)->source;
+ dest = mac_cb(skb)->dest;
+
+ err = lowpan_get_frag_info(skb, frag_type, frag_info);
+ if (err < 0)
+ goto err;
+
+ if (frag_info->d_size > net->ieee802154_lowpan.max_dsize)
+ goto err;
+
+ inet_frag_evictor(&net->ieee802154_lowpan.frags, &lowpan_frags, false);
+
+ fq = fq_find(net, frag_info, &source, &dest);
+ if (fq != NULL) {
+ int ret;
+ spin_lock(&fq->q.lock);
+ ret = lowpan_frag_queue(fq, skb, frag_type);
+ spin_unlock(&fq->q.lock);
+
+ inet_frag_put(&fq->q, &lowpan_frags);
+ return ret;
+ }
+
+err:
+ kfree_skb(skb);
+ return -1;
+}
+EXPORT_SYMBOL(lowpan_frag_rcv);
+
+#ifdef CONFIG_SYSCTL
+static struct ctl_table lowpan_frags_ns_ctl_table[] = {
+ {
+ .procname = "6lowpanfrag_high_thresh",
+ .data = &init_net.ieee802154_lowpan.frags.high_thresh,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec
+ },
+ {
+ .procname = "6lowpanfrag_low_thresh",
+ .data = &init_net.ieee802154_lowpan.frags.low_thresh,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec
+ },
+ {
+ .procname = "6lowpanfrag_time",
+ .data = &init_net.ieee802154_lowpan.frags.timeout,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_jiffies,
+ },
+ {
+ .procname = "6lowpanfrag_max_datagram_size",
+ .data = &init_net.ieee802154_lowpan.max_dsize,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec
+ },
+ { }
+};
+
+static struct ctl_table lowpan_frags_ctl_table[] = {
+ {
+ .procname = "6lowpanfrag_secret_interval",
+ .data = &lowpan_frags.secret_interval,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_jiffies,
+ },
+ { }
+};
+
+static int __net_init lowpan_frags_ns_sysctl_register(struct net *net)
+{
+ struct ctl_table *table;
+ struct ctl_table_header *hdr;
+
+ table = lowpan_frags_ns_ctl_table;
+ if (!net_eq(net, &init_net)) {
+ table = kmemdup(table, sizeof(lowpan_frags_ns_ctl_table),
+ GFP_KERNEL);
+ if (table == NULL)
+ goto err_alloc;
+
+ table[0].data = &net->ieee802154_lowpan.frags.high_thresh;
+ table[1].data = &net->ieee802154_lowpan.frags.low_thresh;
+ table[2].data = &net->ieee802154_lowpan.frags.timeout;
+ table[3].data = &net->ieee802154_lowpan.max_dsize;
+
+ /* Don't export sysctls to unprivileged users */
+ if (net->user_ns != &init_user_ns)
+ table[0].procname = NULL;
+ }
+
+ hdr = register_net_sysctl(net, "net/ieee802154/6lowpan", table);
+ if (hdr == NULL)
+ goto err_reg;
+
+ net->ieee802154_lowpan.sysctl.frags_hdr = hdr;
+ return 0;
+
+err_reg:
+ if (!net_eq(net, &init_net))
+ kfree(table);
+err_alloc:
+ return -ENOMEM;
+}
+
+static void __net_exit lowpan_frags_ns_sysctl_unregister(struct net *net)
+{
+ struct ctl_table *table;
+
+ table = net->ieee802154_lowpan.sysctl.frags_hdr->ctl_table_arg;
+ unregister_net_sysctl_table(net->ieee802154_lowpan.sysctl.frags_hdr);
+ if (!net_eq(net, &init_net))
+ kfree(table);
+}
+
+static struct ctl_table_header *lowpan_ctl_header;
+
+static int lowpan_frags_sysctl_register(void)
+{
+ lowpan_ctl_header = register_net_sysctl(&init_net,
+ "net/ieee802154/6lowpan",
+ lowpan_frags_ctl_table);
+ return lowpan_ctl_header == NULL ? -ENOMEM : 0;
+}
+
+static void lowpan_frags_sysctl_unregister(void)
+{
+ unregister_net_sysctl_table(lowpan_ctl_header);
+}
+#else
+static inline int lowpan_frags_ns_sysctl_register(struct net *net)
+{
+ return 0;
+}
+
+static inline void lowpan_frags_ns_sysctl_unregister(struct net *net)
+{
+}
+
+static inline int lowpan_frags_sysctl_register(void)
+{
+ return 0;
+}
+
+static inline void lowpan_frags_sysctl_unregister(void)
+{
+}
+#endif
+
+static int __net_init lowpan_frags_init_net(struct net *net)
+{
+ net->ieee802154_lowpan.frags.high_thresh = IPV6_FRAG_HIGH_THRESH;
+ net->ieee802154_lowpan.frags.low_thresh = IPV6_FRAG_LOW_THRESH;
+ net->ieee802154_lowpan.frags.timeout = IPV6_FRAG_TIMEOUT;
+ net->ieee802154_lowpan.max_dsize = 0xFFFF;
+
+ inet_frags_init_net(&net->ieee802154_lowpan.frags);
+
+ return lowpan_frags_ns_sysctl_register(net);
+}
+
+static void __net_exit lowpan_frags_exit_net(struct net *net)
+{
+ lowpan_frags_ns_sysctl_unregister(net);
+ inet_frags_exit_net(&net->ieee802154_lowpan.frags, &lowpan_frags);
+}
+
+static struct pernet_operations lowpan_frags_ops = {
+ .init = lowpan_frags_init_net,
+ .exit = lowpan_frags_exit_net,
+};
+
+int __init lowpan_net_frag_init(void)
+{
+ int ret;
+
+ ret = lowpan_frags_sysctl_register();
+ if (ret)
+ return ret;
+
+ ret = register_pernet_subsys(&lowpan_frags_ops);
+ if (ret)
+ goto err_pernet;
+
+ lowpan_frags.hashfn = lowpan_hashfn;
+ lowpan_frags.constructor = lowpan_frag_init;
+ lowpan_frags.destructor = NULL;
+ lowpan_frags.skb_free = NULL;
+ lowpan_frags.qsize = sizeof(struct frag_queue);
+ lowpan_frags.match = lowpan_frag_match;
+ lowpan_frags.frag_expire = lowpan_frag_expire;
+ lowpan_frags.secret_interval = 10 * 60 * HZ;
+ inet_frags_init(&lowpan_frags);
+
+ return ret;
+err_pernet:
+ lowpan_frags_sysctl_unregister();
+ return ret;
+}
+
+void lowpan_net_frag_exit(void)
+{
+ inet_frags_fini(&lowpan_frags);
+ lowpan_frags_sysctl_unregister();
+ unregister_pernet_subsys(&lowpan_frags_ops);
+}