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Message-Id: <1393569170-25722-9-git-send-email-alex.aring@gmail.com>
Date: Fri, 28 Feb 2014 07:32:50 +0100
From: Alexander Aring <alex.aring@...il.com>
To: alex.bluesman.smirnov@...il.com
Cc: dbaryshkov@...il.com, davem@...emloft.net,
linux-zigbee-devel@...ts.sourceforge.net, netdev@...r.kernel.org,
martin.townsend@...lon.com, Alexander Aring <alex.aring@...il.com>
Subject: [PATCH net-next v6 8/8] 6lowpan: handling 6lowpan fragmentation via inet_frag api
This patch drops the current way of 6lowpan fragmentation on receiving
side and replace it with a implementation which use the inet_frag api.
The old fragmentation handling has some race conditions and isn't
rfc4944 compatible. Also adding support to match fragments on
destination address, source address, tag value and datagram_size
which is missing in the current implementation.
Signed-off-by: Alexander Aring <alex.aring@...il.com>
---
include/net/netns/ieee802154_6lowpan.h | 9 +
net/ieee802154/6lowpan_rtnl.c | 256 +++------------
net/ieee802154/Makefile | 2 +-
net/ieee802154/reassembly.c | 564 +++++++++++++++++++++++++++++++++
net/ieee802154/reassembly.h | 66 ++++
5 files changed, 689 insertions(+), 208 deletions(-)
create mode 100644 net/ieee802154/reassembly.c
create mode 100644 net/ieee802154/reassembly.h
diff --git a/include/net/netns/ieee802154_6lowpan.h b/include/net/netns/ieee802154_6lowpan.h
index 88110b7..079030c 100644
--- a/include/net/netns/ieee802154_6lowpan.h
+++ b/include/net/netns/ieee802154_6lowpan.h
@@ -7,7 +7,16 @@
#ifndef __NETNS_IEEE802154_6LOWPAN_H__
#define __NETNS_IEEE802154_6LOWPAN_H__
+struct netns_sysctl_lowpan {
+#ifdef CONFIG_SYSCTL
+ struct ctl_table_header *frags_hdr;
+#endif
+};
+
struct netns_ieee802154_lowpan {
+ struct netns_sysctl_lowpan sysctl;
+ struct netns_frags frags;
+ u16 max_dsize;
};
#endif
diff --git a/net/ieee802154/6lowpan_rtnl.c b/net/ieee802154/6lowpan_rtnl.c
index f9c9548..c7bd8b5 100644
--- a/net/ieee802154/6lowpan_rtnl.c
+++ b/net/ieee802154/6lowpan_rtnl.c
@@ -54,6 +54,7 @@
#include <net/ieee802154_netdev.h>
#include <net/ipv6.h>
+#include "reassembly.h"
#include "6lowpan.h"
static LIST_HEAD(lowpan_devices);
@@ -70,18 +71,6 @@ struct lowpan_dev_record {
struct list_head list;
};
-struct lowpan_fragment {
- struct sk_buff *skb; /* skb to be assembled */
- u16 length; /* length to be assemled */
- u32 bytes_rcv; /* bytes received */
- u16 tag; /* current fragment tag */
- struct timer_list timer; /* assembling timer */
- struct list_head list; /* fragments list */
-};
-
-static LIST_HEAD(lowpan_fragments);
-static DEFINE_SPINLOCK(flist_lock);
-
static inline struct
lowpan_dev_info *lowpan_dev_info(const struct net_device *dev)
{
@@ -179,69 +168,6 @@ static int lowpan_give_skb_to_devices(struct sk_buff *skb,
return stat;
}
-static void lowpan_fragment_timer_expired(unsigned long entry_addr)
-{
- struct lowpan_fragment *entry = (struct lowpan_fragment *)entry_addr;
-
- pr_debug("timer expired for frame with tag %d\n", entry->tag);
-
- list_del(&entry->list);
- dev_kfree_skb(entry->skb);
- kfree(entry);
-}
-
-static struct lowpan_fragment *
-lowpan_alloc_new_frame(struct sk_buff *skb, u16 len, u16 tag)
-{
- struct lowpan_fragment *frame;
-
- frame = kzalloc(sizeof(struct lowpan_fragment),
- GFP_ATOMIC);
- if (!frame)
- goto frame_err;
-
- INIT_LIST_HEAD(&frame->list);
-
- frame->length = len;
- frame->tag = tag;
-
- /* allocate buffer for frame assembling */
- frame->skb = netdev_alloc_skb_ip_align(skb->dev, frame->length +
- sizeof(struct ipv6hdr));
-
- if (!frame->skb)
- goto skb_err;
-
- frame->skb->priority = skb->priority;
-
- /* reserve headroom for uncompressed ipv6 header */
- skb_reserve(frame->skb, sizeof(struct ipv6hdr));
- skb_put(frame->skb, frame->length);
-
- /* copy the first control block to keep a
- * trace of the link-layer addresses in case
- * of a link-local compressed address
- */
- memcpy(frame->skb->cb, skb->cb, sizeof(skb->cb));
-
- init_timer(&frame->timer);
- /* time out is the same as for ipv6 - 60 sec */
- frame->timer.expires = jiffies + LOWPAN_FRAG_TIMEOUT;
- frame->timer.data = (unsigned long)frame;
- frame->timer.function = lowpan_fragment_timer_expired;
-
- add_timer(&frame->timer);
-
- list_add_tail(&frame->list, &lowpan_fragments);
-
- return frame;
-
-skb_err:
- kfree(frame);
-frame_err:
- return NULL;
-}
-
static int process_data(struct sk_buff *skb)
{
u8 iphc0, iphc1;
@@ -255,94 +181,6 @@ static int process_data(struct sk_buff *skb)
if (lowpan_fetch_skb_u8(skb, &iphc0))
goto drop;
- /* fragments assembling */
- switch (iphc0 & LOWPAN_DISPATCH_MASK) {
- case LOWPAN_DISPATCH_FRAG1:
- case LOWPAN_DISPATCH_FRAGN:
- {
- struct lowpan_fragment *frame;
- /* slen stores the rightmost 8 bits of the 11 bits length */
- u8 slen, offset = 0;
- u16 len, tag;
- bool found = false;
-
- if (lowpan_fetch_skb_u8(skb, &slen) || /* frame length */
- lowpan_fetch_skb_u16(skb, &tag)) /* fragment tag */
- goto drop;
-
- /* adds the 3 MSB to the 8 LSB to retrieve the 11 bits length */
- len = ((iphc0 & 7) << 8) | slen;
-
- if ((iphc0 & LOWPAN_DISPATCH_MASK) == LOWPAN_DISPATCH_FRAG1) {
- pr_debug("%s received a FRAG1 packet (tag: %d, "
- "size of the entire IP packet: %d)",
- __func__, tag, len);
- } else { /* FRAGN */
- if (lowpan_fetch_skb_u8(skb, &offset))
- goto unlock_and_drop;
- pr_debug("%s received a FRAGN packet (tag: %d, "
- "size of the entire IP packet: %d, "
- "offset: %d)", __func__, tag, len, offset * 8);
- }
-
- /*
- * check if frame assembling with the same tag is
- * already in progress
- */
- spin_lock_bh(&flist_lock);
-
- list_for_each_entry(frame, &lowpan_fragments, list)
- if (frame->tag == tag) {
- found = true;
- break;
- }
-
- /* alloc new frame structure */
- if (!found) {
- pr_debug("%s first fragment received for tag %d, "
- "begin packet reassembly", __func__, tag);
- frame = lowpan_alloc_new_frame(skb, len, tag);
- if (!frame)
- goto unlock_and_drop;
- }
-
- /* if payload fits buffer, copy it */
- if (likely((offset * 8 + skb->len) <= frame->length))
- skb_copy_to_linear_data_offset(frame->skb, offset * 8,
- skb->data, skb->len);
- else
- goto unlock_and_drop;
-
- frame->bytes_rcv += skb->len;
-
- /* frame assembling complete */
- if ((frame->bytes_rcv == frame->length) &&
- frame->timer.expires > jiffies) {
- /* if timer haven't expired - first of all delete it */
- del_timer_sync(&frame->timer);
- list_del(&frame->list);
- spin_unlock_bh(&flist_lock);
-
- pr_debug("%s successfully reassembled fragment "
- "(tag %d)", __func__, tag);
-
- dev_kfree_skb(skb);
- skb = frame->skb;
- kfree(frame);
-
- if (lowpan_fetch_skb_u8(skb, &iphc0))
- goto drop;
-
- break;
- }
- spin_unlock_bh(&flist_lock);
-
- return kfree_skb(skb), 0;
- }
- default:
- break;
- }
-
if (lowpan_fetch_skb_u8(skb, &iphc1))
goto drop;
@@ -355,8 +193,6 @@ static int process_data(struct sk_buff *skb)
IEEE802154_ADDR_LEN, iphc0, iphc1,
lowpan_give_skb_to_devices);
-unlock_and_drop:
- spin_unlock_bh(&flist_lock);
drop:
kfree_skb(skb);
return -EINVAL;
@@ -603,44 +439,53 @@ static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
struct sk_buff *local_skb;
+ int ret;
if (!netif_running(dev))
- goto drop;
+ goto drop_skb;
if (dev->type != ARPHRD_IEEE802154)
- goto drop;
+ goto drop_skb;
+
+ local_skb = skb_clone(skb, GFP_ATOMIC);
+ if (!local_skb)
+ goto drop_skb;
+
+ kfree_skb(skb);
/* check that it's our buffer */
if (skb->data[0] == LOWPAN_DISPATCH_IPV6) {
- /* Copy the packet so that the IPv6 header is
- * properly aligned.
- */
- local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
- skb_tailroom(skb), GFP_ATOMIC);
- if (!local_skb)
- goto drop;
-
local_skb->protocol = htons(ETH_P_IPV6);
local_skb->pkt_type = PACKET_HOST;
/* Pull off the 1-byte of 6lowpan header. */
skb_pull(local_skb, 1);
- lowpan_give_skb_to_devices(local_skb, NULL);
-
- kfree_skb(local_skb);
- kfree_skb(skb);
+ ret = lowpan_give_skb_to_devices(local_skb, NULL);
+ if (ret == NET_RX_DROP)
+ goto drop;
} else {
switch (skb->data[0] & 0xe0) {
case LOWPAN_DISPATCH_IPHC: /* ipv6 datagram */
+ ret = process_data(local_skb);
+ if (ret == NET_RX_DROP)
+ goto drop;
+ break;
case LOWPAN_DISPATCH_FRAG1: /* first fragment header */
+ ret = lowpan_frag_rcv(local_skb, LOWPAN_DISPATCH_FRAG1);
+ if (ret == 1) {
+ ret = process_data(local_skb);
+ if (ret == NET_RX_DROP)
+ goto drop;
+ }
+ break;
case LOWPAN_DISPATCH_FRAGN: /* next fragments headers */
- local_skb = skb_clone(skb, GFP_ATOMIC);
- if (!local_skb)
- goto drop;
- process_data(local_skb);
-
- kfree_skb(skb);
+ ret = lowpan_frag_rcv(local_skb, LOWPAN_DISPATCH_FRAGN);
+ if (ret == 1) {
+ ret = process_data(local_skb);
+ if (ret == NET_RX_DROP)
+ goto drop;
+ }
break;
default:
break;
@@ -648,9 +493,9 @@ static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
}
return NET_RX_SUCCESS;
-
-drop:
+drop_skb:
kfree_skb(skb);
+drop:
return NET_RX_DROP;
}
@@ -778,43 +623,40 @@ static int __init lowpan_init_module(void)
{
int err = 0;
- err = lowpan_netlink_init();
+ err = lowpan_net_frag_init();
if (err < 0)
goto out;
+ err = lowpan_netlink_init();
+ if (err < 0)
+ goto out_frag;
+
dev_add_pack(&lowpan_packet_type);
err = register_netdevice_notifier(&lowpan_dev_notifier);
- if (err < 0) {
- dev_remove_pack(&lowpan_packet_type);
- lowpan_netlink_fini();
- }
+ if (err < 0)
+ goto out_pack;
+
+ return 0;
+
+out_pack:
+ dev_remove_pack(&lowpan_packet_type);
+ lowpan_netlink_fini();
+out_frag:
+ lowpan_net_frag_exit();
out:
return err;
}
static void __exit lowpan_cleanup_module(void)
{
- struct lowpan_fragment *frame, *tframe;
-
lowpan_netlink_fini();
dev_remove_pack(&lowpan_packet_type);
- unregister_netdevice_notifier(&lowpan_dev_notifier);
+ lowpan_net_frag_exit();
- /* Now 6lowpan packet_type is removed, so no new fragments are
- * expected on RX, therefore that's the time to clean incomplete
- * fragments.
- */
- spin_lock_bh(&flist_lock);
- list_for_each_entry_safe(frame, tframe, &lowpan_fragments, list) {
- del_timer_sync(&frame->timer);
- list_del(&frame->list);
- dev_kfree_skb(frame->skb);
- kfree(frame);
- }
- spin_unlock_bh(&flist_lock);
+ unregister_netdevice_notifier(&lowpan_dev_notifier);
}
module_init(lowpan_init_module);
diff --git a/net/ieee802154/Makefile b/net/ieee802154/Makefile
index 3d08adf..b113fc4 100644
--- a/net/ieee802154/Makefile
+++ b/net/ieee802154/Makefile
@@ -2,6 +2,6 @@ obj-$(CONFIG_IEEE802154) += ieee802154.o af_802154.o
obj-$(CONFIG_IEEE802154_6LOWPAN) += 6lowpan.o
obj-$(CONFIG_6LOWPAN_IPHC) += 6lowpan_iphc.o
-6lowpan-y := 6lowpan_rtnl.o
+6lowpan-y := 6lowpan_rtnl.o reassembly.o
ieee802154-y := netlink.o nl-mac.o nl-phy.o nl_policy.o wpan-class.o
af_802154-y := af_ieee802154.o raw.o dgram.o
diff --git a/net/ieee802154/reassembly.c b/net/ieee802154/reassembly.c
new file mode 100644
index 0000000..eb5995e
--- /dev/null
+++ b/net/ieee802154/reassembly.c
@@ -0,0 +1,564 @@
+/* 6LoWPAN fragment reassembly
+ *
+ *
+ * Authors:
+ * Alexander Aring <aar@...gutronix.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/ipv6.h>
+#include <net/inet_frag.h>
+
+#include "6lowpan.h"
+#include "reassembly.h"
+
+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, __be16 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);
+}
+
+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_addr_equal(&fq->saddr, arg->src) &&
+ ieee802154_addr_addr_equal(&fq->daddr, arg->dst);
+}
+EXPORT_SYMBOL(lowpan_frag_match);
+
+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;
+}
+EXPORT_SYMBOL(lowpan_frag_init);
+
+void lowpan_expire_frag_queue(struct frag_queue *fq, struct inet_frags *frags)
+{
+ spin_lock(&fq->q.lock);
+
+ if (fq->q.last_in & INET_FRAG_COMPLETE)
+ goto out;
+
+ inet_frag_kill(&fq->q, frags);
+out:
+ spin_unlock(&fq->q.lock);
+ inet_frag_put(&fq->q, frags);
+}
+EXPORT_SYMBOL(lowpan_expire_frag_queue);
+
+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);
+
+ lowpan_expire_frag_queue(fq, &lowpan_frags);
+}
+
+static inline struct lowpan_frag_queue *
+fq_find(struct net *net, const struct ieee802154_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 = mac_cb(skb)->frag_info.d_offset << 3;
+ end = mac_cb(skb)->frag_info.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 || mac_cb(prev)->frag_info.d_offset <
+ mac_cb(skb)->frag_info.d_offset) {
+ next = NULL;
+ goto found;
+ }
+ prev = NULL;
+ for (next = fq->q.fragments; next != NULL; next = next->next) {
+ if (mac_cb(next)->frag_info.d_offset >=
+ mac_cb(skb)->frag_info.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 ieee802154_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 ieee802154_frag_info *frag_info = &mac_cb(skb)->frag_info;
+ int err;
+
+ 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, &mac_cb(skb)->sa, &mac_cb(skb)->da);
+ 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[2].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)
+ goto out;
+
+ 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);
+err_pernet:
+ lowpan_frags_sysctl_unregister();
+out:
+ return ret;
+}
+
+void lowpan_net_frag_exit(void)
+{
+ inet_frags_fini(&lowpan_frags);
+ lowpan_frags_sysctl_unregister();
+ unregister_pernet_subsys(&lowpan_frags_ops);
+}
diff --git a/net/ieee802154/reassembly.h b/net/ieee802154/reassembly.h
new file mode 100644
index 0000000..055518b
--- /dev/null
+++ b/net/ieee802154/reassembly.h
@@ -0,0 +1,66 @@
+#ifndef __IEEE802154_6LOWPAN_REASSEMBLY_H__
+#define __IEEE802154_6LOWPAN_REASSEMBLY_H__
+
+#include <net/inet_frag.h>
+
+struct lowpan_create_arg {
+ __be16 tag;
+ u16 d_size;
+ const struct ieee802154_addr *src;
+ const struct ieee802154_addr *dst;
+};
+
+/* Equivalent of ipv4 struct ip
+ */
+struct lowpan_frag_queue {
+ struct inet_frag_queue q;
+
+ __be16 tag;
+ u16 d_size;
+ struct ieee802154_addr saddr;
+ struct ieee802154_addr daddr;
+};
+
+static inline u32 ieee802154_addr_hash(const struct ieee802154_addr *a)
+{
+ switch (a->addr_type) {
+ case IEEE802154_ADDR_LONG:
+ return (__force u32)((((u32 *)a->hwaddr))[0] ^
+ ((u32 *)(a->hwaddr))[1]);
+ case IEEE802154_ADDR_SHORT:
+ return (__force u32)(a->short_addr);
+ default:
+ return 0;
+ }
+}
+
+static inline bool ieee802154_addr_addr_equal(const struct ieee802154_addr *a1,
+ const struct ieee802154_addr *a2)
+{
+ if (a1->pan_id != a2->pan_id)
+ return false;
+
+ if (a1->addr_type != a2->addr_type)
+ return false;
+
+ switch (a1->addr_type) {
+ case IEEE802154_ADDR_LONG:
+ if (memcmp(a1->hwaddr, a2->hwaddr, IEEE802154_ADDR_LEN))
+ return false;
+ break;
+ case IEEE802154_ADDR_SHORT:
+ if (a1->short_addr != a2->short_addr)
+ return false;
+ break;
+ default:
+ return false;
+ }
+
+ return true;
+}
+
+int lowpan_frag_rcv(struct sk_buff *skb, const u8 frag_type);
+void lowpan_net_frag_exit(void);
+int lowpan_net_frag_init(void);
+
+#endif /* __IEEE802154_6LOWPAN_REASSEMBLY_H__ */
--
1.9.0
--
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