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authorLinus Torvalds <torvalds@linux-foundation.org>2015-02-10 20:01:30 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-02-10 20:01:30 -0800
commitc5ce28df0e7c01a1de23c36ebdefcd803f2b6cbb (patch)
tree9830baf38832769e1cf621708889111bbe3c93df /net/ieee802154/6lowpan/reassembly.c
parent29afc4e9a408f2304e09c6dd0dbcfbd2356d0faa (diff)
parent9399f0c51489ae8c16d6559b82a452fdc1895e91 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller: 1) More iov_iter conversion work from Al Viro. [ The "crypto: switch af_alg_make_sg() to iov_iter" commit was wrong, and this pull actually adds an extra commit on top of the branch I'm pulling to fix that up, so that the pre-merge state is ok. - Linus ] 2) Various optimizations to the ipv4 forwarding information base trie lookup implementation. From Alexander Duyck. 3) Remove sock_iocb altogether, from CHristoph Hellwig. 4) Allow congestion control algorithm selection via routing metrics. From Daniel Borkmann. 5) Make ipv4 uncached route list per-cpu, from Eric Dumazet. 6) Handle rfs hash collisions more gracefully, also from Eric Dumazet. 7) Add xmit_more support to r8169, e1000, and e1000e drivers. From Florian Westphal. 8) Transparent Ethernet Bridging support for GRO, from Jesse Gross. 9) Add BPF packet actions to packet scheduler, from Jiri Pirko. 10) Add support for uniqu flow IDs to openvswitch, from Joe Stringer. 11) New NetCP ethernet driver, from Muralidharan Karicheri and Wingman Kwok. 12) More sanely handle out-of-window dupacks, which can result in serious ACK storms. From Neal Cardwell. 13) Various rhashtable bug fixes and enhancements, from Herbert Xu, Patrick McHardy, and Thomas Graf. 14) Support xmit_more in be2net, from Sathya Perla. 15) Group Policy extensions for vxlan, from Thomas Graf. 16) Remove Checksum Offload support for vxlan, from Tom Herbert. 17) Like ipv4, support lockless transmit over ipv6 UDP sockets. From Vlad Yasevich. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1494+1 commits) crypto: fix af_alg_make_sg() conversion to iov_iter ipv4: Namespecify TCP PMTU mechanism i40e: Fix for stats init function call in Rx setup tcp: don't include Fast Open option in SYN-ACK on pure SYN-data openvswitch: Only set TUNNEL_VXLAN_OPT if VXLAN-GBP metadata is set ipv6: Make __ipv6_select_ident static ipv6: Fix fragment id assignment on LE arches. bridge: Fix inability to add non-vlan fdb entry net: Mellanox: Delete unnecessary checks before the function call "vunmap" cxgb4: Add support in cxgb4 to get expansion rom version via ethtool ethtool: rename reserved1 memeber in ethtool_drvinfo for expansion ROM version net: dsa: Remove redundant phy_attach() IB/mlx4: Reset flow support for IB kernel ULPs IB/mlx4: Always use the correct port for mirrored multicast attachments net/bonding: Fix potential bad memory access during bonding events tipc: remove tipc_snprintf tipc: nl compat add noop and remove legacy nl framework tipc: convert legacy nl stats show to nl compat tipc: convert legacy nl net id get to nl compat tipc: convert legacy nl net id set to nl compat ...
Diffstat (limited to 'net/ieee802154/6lowpan/reassembly.c')
-rw-r--r--net/ieee802154/6lowpan/reassembly.c585
1 files changed, 585 insertions, 0 deletions
diff --git a/net/ieee802154/6lowpan/reassembly.c b/net/ieee802154/6lowpan/reassembly.c
new file mode 100644
index 00000000000..f46e4d1306f
--- /dev/null
+++ b/net/ieee802154/6lowpan/reassembly.c
@@ -0,0 +1,585 @@
+/* 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 "6lowpan_i.h"
+
+static const char lowpan_frags_cache_name[] = "lowpan-frags";
+
+struct lowpan_frag_info {
+ u16 d_tag;
+ u16 d_size;
+ u8 d_offset;
+};
+
+static 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(u16 tag, u16 d_size,
+ const struct ieee802154_addr *saddr,
+ const struct ieee802154_addr *daddr)
+{
+ net_get_random_once(&lowpan_frags.rnd, sizeof(lowpan_frags.rnd));
+ return jhash_3words(ieee802154_addr_hash(saddr),
+ ieee802154_addr_hash(daddr),
+ (__force u32)(tag + (d_size << 16)),
+ lowpan_frags.rnd);
+}
+
+static unsigned int lowpan_hashfn(const struct inet_frag_queue *q)
+{
+ const 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(const struct inet_frag_queue *q, const void *a)
+{
+ const struct lowpan_frag_queue *fq;
+ const 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, const void *a)
+{
+ const struct lowpan_create_arg *arg = a;
+ struct lowpan_frag_queue *fq;
+
+ 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.flags & 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;
+ struct netns_ieee802154_lowpan *ieee802154_lowpan =
+ net_ieee802154_lowpan(net);
+
+ arg.tag = frag_info->d_tag;
+ arg.d_size = frag_info->d_size;
+ arg.src = src;
+ arg.dst = dst;
+
+ hash = lowpan_hash_frag(frag_info->d_tag, frag_info->d_size, src, dst);
+
+ q = inet_frag_find(&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.flags & 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.flags & INET_FRAG_LAST_IN) && end != fq->q.len))
+ goto err;
+ fq->q.flags |= INET_FRAG_LAST_IN;
+ fq->q.len = end;
+ } else {
+ if (end > fq->q.len) {
+ /* Some bits beyond end -> corruption. */
+ if (fq->q.flags & 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.flags |= INET_FRAG_FIRST_IN;
+ } else {
+ fq->q.meat += skb->len;
+ }
+ add_frag_mem_limit(&fq->q, skb->truesize);
+
+ if (fq->q.flags == (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;
+ }
+
+ 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;
+ __be16 d_tag = 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, &d_tag, 2);
+ frag_info->d_tag = ntohs(d_tag);
+
+ 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 > IPV6_MIN_MTU) {
+ net_warn_ratelimited("lowpan_frag_rcv: datagram size exceeds MTU\n");
+ goto err;
+ }
+
+ 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 int zero;
+
+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_minmax,
+ .extra1 = &init_net.ieee802154_lowpan.frags.low_thresh
+ },
+ {
+ .procname = "6lowpanfrag_low_thresh",
+ .data = &init_net.ieee802154_lowpan.frags.low_thresh,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &init_net.ieee802154_lowpan.frags.high_thresh
+ },
+ {
+ .procname = "6lowpanfrag_time",
+ .data = &init_net.ieee802154_lowpan.frags.timeout,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_jiffies,
+ },
+ { }
+};
+
+/* secret interval has been deprecated */
+static int lowpan_frags_secret_interval_unused;
+static struct ctl_table lowpan_frags_ctl_table[] = {
+ {
+ .procname = "6lowpanfrag_secret_interval",
+ .data = &lowpan_frags_secret_interval_unused,
+ .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;
+ struct netns_ieee802154_lowpan *ieee802154_lowpan =
+ net_ieee802154_lowpan(net);
+
+ 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 = &ieee802154_lowpan->frags.high_thresh;
+ table[0].extra1 = &ieee802154_lowpan->frags.low_thresh;
+ table[0].extra2 = &init_net.ieee802154_lowpan.frags.high_thresh;
+ table[1].data = &ieee802154_lowpan->frags.low_thresh;
+ table[1].extra2 = &ieee802154_lowpan->frags.high_thresh;
+ table[2].data = &ieee802154_lowpan->frags.timeout;
+
+ /* 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;
+
+ 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;
+ struct netns_ieee802154_lowpan *ieee802154_lowpan =
+ net_ieee802154_lowpan(net);
+
+ table = ieee802154_lowpan->sysctl.frags_hdr->ctl_table_arg;
+ unregister_net_sysctl_table(ieee802154_lowpan->sysctl.frags_hdr);
+ if (!net_eq(net, &init_net))
+ kfree(table);
+}
+
+static struct ctl_table_header *lowpan_ctl_header;
+
+static int __init 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 __init 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)
+{
+ struct netns_ieee802154_lowpan *ieee802154_lowpan =
+ net_ieee802154_lowpan(net);
+
+ ieee802154_lowpan->frags.high_thresh = IPV6_FRAG_HIGH_THRESH;
+ ieee802154_lowpan->frags.low_thresh = IPV6_FRAG_LOW_THRESH;
+ ieee802154_lowpan->frags.timeout = IPV6_FRAG_TIMEOUT;
+
+ inet_frags_init_net(&ieee802154_lowpan->frags);
+
+ return lowpan_frags_ns_sysctl_register(net);
+}
+
+static void __net_exit lowpan_frags_exit_net(struct net *net)
+{
+ struct netns_ieee802154_lowpan *ieee802154_lowpan =
+ net_ieee802154_lowpan(net);
+
+ lowpan_frags_ns_sysctl_unregister(net);
+ inet_frags_exit_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.frags_cache_name = lowpan_frags_cache_name;
+ ret = inet_frags_init(&lowpan_frags);
+ if (ret)
+ goto err_pernet;
+
+ 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);
+}