diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index fd3cb1b247df8d7df21008ed000dfb966391b340..7ebdf158a79531304ee29fb4fc7539ae5fd2288d 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -676,13 +676,16 @@ struct sk_buff {
* UDP receive path is one user.
*/
unsigned long dev_scratch;
- int ip_defrag_offset;
};
};
- struct rb_node rbnode; /* used in netem & tcp stack */
+ struct rb_node rbnode; /* used in netem, ip4 defrag, and tcp stack */
struct list_head list;
};
- struct sock *sk;
+
+ union {
+ struct sock *sk;
+ int ip_defrag_offset;
+ };
union {
ktime_t tstamp;
@@ -2585,7 +2588,7 @@ static inline void __skb_queue_purge(struct sk_buff_head *list)
kfree_skb(skb);
}
-void skb_rbtree_purge(struct rb_root *root);
+unsigned int skb_rbtree_purge(struct rb_root *root);
void *netdev_alloc_frag(unsigned int fragsz);
diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h
index f4272a29dc445ec9745b943578f8288bf92a2e8e..b86d1452818818d21e02fbbbf884989e7a21a8b1 100644
--- a/include/net/inet_frag.h
+++ b/include/net/inet_frag.h
@@ -75,7 +75,8 @@ struct inet_frag_queue {
struct timer_list timer;
spinlock_t lock;
refcount_t refcnt;
- struct sk_buff *fragments;
+ struct sk_buff *fragments; /* Used in IPv6. */
+ struct rb_root rb_fragments; /* Used in IPv4. */
struct sk_buff *fragments_tail;
ktime_t stamp;
int len;
diff --git a/include/uapi/linux/snmp.h b/include/uapi/linux/snmp.h
index e5ebc83827abbcaaf82e1f46011540fc273c65f2..f80135e5feaa886000009db6dff75b2bc2d637b2 100644
--- a/include/uapi/linux/snmp.h
+++ b/include/uapi/linux/snmp.h
@@ -56,6 +56,7 @@ enum
IPSTATS_MIB_ECT1PKTS, /* InECT1Pkts */
IPSTATS_MIB_ECT0PKTS, /* InECT0Pkts */
IPSTATS_MIB_CEPKTS, /* InCEPkts */
+ IPSTATS_MIB_REASM_OVERLAPS, /* ReasmOverlaps */
__IPSTATS_MIB_MAX
};
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 51b0a9126e121c3cf092a6baaa6fe58d749213a2..8d574a88125d2772ee37fe717b6503e1f0e8884e 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2858,23 +2858,27 @@ EXPORT_SYMBOL(skb_queue_purge);
/**
* skb_rbtree_purge - empty a skb rbtree
* @root: root of the rbtree to empty
+ * Return value: the sum of truesizes of all purged skbs.
*
* Delete all buffers on an &sk_buff rbtree. Each buffer is removed from
* the list and one reference dropped. This function does not take
* any lock. Synchronization should be handled by the caller (e.g., TCP
* out-of-order queue is protected by the socket lock).
*/
-void skb_rbtree_purge(struct rb_root *root)
+unsigned int skb_rbtree_purge(struct rb_root *root)
{
struct rb_node *p = rb_first(root);
+ unsigned int sum = 0;
while (p) {
struct sk_buff *skb = rb_entry(p, struct sk_buff, rbnode);
p = rb_next(p);
rb_erase(&skb->rbnode, root);
+ sum += skb->truesize;
kfree_skb(skb);
}
+ return sum;
}
/**
diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c
index ccd140e4082dd7de0823e9408e352725a8b4404c..6d258a5669e7926186270bc97aaee7e0fc4a4174 100644
--- a/net/ipv4/inet_fragment.c
+++ b/net/ipv4/inet_fragment.c
@@ -137,12 +137,16 @@ void inet_frag_destroy(struct inet_frag_queue *q)
fp = q->fragments;
nf = q->net;
f = nf->f;
- while (fp) {
- struct sk_buff *xp = fp->next;
-
- sum_truesize += fp->truesize;
- kfree_skb(fp);
- fp = xp;
+ if (fp) {
+ do {
+ struct sk_buff *xp = fp->next;
+
+ sum_truesize += fp->truesize;
+ kfree_skb(fp);
+ fp = xp;
+ } while (fp);
+ } else {
+ sum_truesize = skb_rbtree_purge(&q->rb_fragments);
}
sum = sum_truesize + f->qsize;
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index d14d741fb05e571d6d0b03248da77fd993debdee..0e8f8de77e710ce4faa964734fb6ccaef90f9bff 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -136,7 +136,7 @@ static void ip_expire(struct timer_list *t)
{
struct inet_frag_queue *frag = from_timer(frag, t, timer);
const struct iphdr *iph;
- struct sk_buff *head;
+ struct sk_buff *head = NULL;
struct net *net;
struct ipq *qp;
int err;
@@ -152,14 +152,31 @@ static void ip_expire(struct timer_list *t)
ipq_kill(qp);
__IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
-
- head = qp->q.fragments;
-
__IP_INC_STATS(net, IPSTATS_MIB_REASMTIMEOUT);
- if (!(qp->q.flags & INET_FRAG_FIRST_IN) || !head)
+ if (!qp->q.flags & INET_FRAG_FIRST_IN)
goto out;
+ /* sk_buff::dev and sk_buff::rbnode are unionized. So we
+ * pull the head out of the tree in order to be able to
+ * deal with head->dev.
+ */
+ if (qp->q.fragments) {
+ head = qp->q.fragments;
+ qp->q.fragments = head->next;
+ } else {
+ head = skb_rb_first(&qp->q.rb_fragments);
+ if (!head)
+ goto out;
+ rb_erase(&head->rbnode, &qp->q.rb_fragments);
+ memset(&head->rbnode, 0, sizeof(head->rbnode));
+ barrier();
+ }
+ if (head == qp->q.fragments_tail)
+ qp->q.fragments_tail = NULL;
+
+ sub_frag_mem_limit(qp->q.net, head->truesize);
+
head->dev = dev_get_by_index_rcu(net, qp->iif);
if (!head->dev)
goto out;
@@ -179,16 +196,16 @@ static void ip_expire(struct timer_list *t)
(skb_rtable(head)->rt_type != RTN_LOCAL))
goto out;
- skb_get(head);
spin_unlock(&qp->q.lock);
icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0);
- kfree_skb(head);
goto out_rcu_unlock;
out:
spin_unlock(&qp->q.lock);
out_rcu_unlock:
rcu_read_unlock();
+ if (head)
+ kfree_skb(head);
ipq_put(qp);
}
@@ -231,7 +248,7 @@ static int ip_frag_too_far(struct ipq *qp)
end = atomic_inc_return(&peer->rid);
qp->rid = end;
- rc = qp->q.fragments && (end - start) > max;
+ rc = qp->q.fragments_tail && (end - start) > max;
if (rc) {
struct net *net;
@@ -245,7 +262,6 @@ static int ip_frag_too_far(struct ipq *qp)
static int ip_frag_reinit(struct ipq *qp)
{
- struct sk_buff *fp;
unsigned int sum_truesize = 0;
if (!mod_timer(&qp->q.timer, jiffies + qp->q.net->timeout)) {
@@ -253,20 +269,14 @@ static int ip_frag_reinit(struct ipq *qp)
return -ETIMEDOUT;
}
- fp = qp->q.fragments;
- do {
- struct sk_buff *xp = fp->next;
-
- sum_truesize += fp->truesize;
- kfree_skb(fp);
- fp = xp;
- } while (fp);
+ sum_truesize = skb_rbtree_purge(&qp->q.rb_fragments);
sub_frag_mem_limit(qp->q.net, sum_truesize);
qp->q.flags = 0;
qp->q.len = 0;
qp->q.meat = 0;
qp->q.fragments = NULL;
+ qp->q.rb_fragments = RB_ROOT;
qp->q.fragments_tail = NULL;
qp->iif = 0;
qp->ecn = 0;
@@ -277,7 +287,9 @@ static int ip_frag_reinit(struct ipq *qp)
/* Add new segment to existing queue. */
static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
{
- struct sk_buff *prev, *next;
+ struct net *net = container_of(qp->q.net, struct net, ipv4.frags);
+ struct rb_node **rbn, *parent;
+ struct sk_buff *skb1;
struct net_device *dev;
unsigned int fragsize;
int flags, offset;
@@ -340,100 +352,58 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
if (err)
goto err;
- /* 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 = qp->q.fragments_tail;
- if (!prev || prev->ip_defrag_offset < offset) {
- next = NULL;
- goto found;
- }
- prev = NULL;
- for (next = qp->q.fragments; next != NULL; next = next->next) {
- if (next->ip_defrag_offset >= offset)
- break; /* bingo! */
- prev = next;
- }
+ /* Note : skb->rbnode and skb->dev share the same location. */
+ dev = skb->dev;
+ /* Makes sure compiler wont do silly aliasing games */
+ barrier();
-found:
- /* We found where to put this one. Check for overlap with
- * preceding fragment, and, if needed, align things so that
- * any overlaps are eliminated.
+ /* RFC5722, Section 4, amended by Errata ID : 3089
+ * When reassembling an IPv6 datagram, if
+ * one or more its constituent fragments is determined to be an
+ * overlapping fragment, the entire datagram (and any constituent
+ * fragments) MUST be silently discarded.
+ *
+ * We do the same here for IPv4 (and increment an snmp counter).
*/
- if (prev) {
- int i = (prev->ip_defrag_offset + prev->len) - offset;
-
- if (i > 0) {
- offset += i;
- err = -EINVAL;
- if (end <= offset)
- goto err;
- err = -ENOMEM;
- if (!pskb_pull(skb, i))
- goto err;
- if (skb->ip_summed != CHECKSUM_UNNECESSARY)
- skb->ip_summed = CHECKSUM_NONE;
- }
- }
-
- err = -ENOMEM;
- while (next && next->ip_defrag_offset < end) {
- int i = end - next->ip_defrag_offset; /* overlap is 'i' bytes */
-
- if (i < next->len) {
- int delta = -next->truesize;
-
- /* Eat head of the next overlapped fragment
- * and leave the loop. The next ones cannot overlap.
- */
- if (!pskb_pull(next, i))
- goto err;
- delta += next->truesize;
- if (delta)
- add_frag_mem_limit(qp->q.net, delta);
- next->ip_defrag_offset += i;
- qp->q.meat -= i;
- if (next->ip_summed != CHECKSUM_UNNECESSARY)
- next->ip_summed = CHECKSUM_NONE;
- break;
- } else {
- struct sk_buff *free_it = next;
-
- /* Old fragment is completely overridden with
- * new one drop it.
- */
- next = next->next;
-
- if (prev)
- prev->next = next;
- else
- qp->q.fragments = next;
-
- qp->q.meat -= free_it->len;
- sub_frag_mem_limit(qp->q.net, free_it->truesize);
- kfree_skb(free_it);
- }
+ /* Find out where to put this fragment. */
+ skb1 = qp->q.fragments_tail;
+ if (!skb1) {
+ /* This is the first fragment we've received. */
+ rb_link_node(&skb->rbnode, NULL, &qp->q.rb_fragments.rb_node);
+ qp->q.fragments_tail = skb;
+ } else if ((skb1->ip_defrag_offset + skb1->len) < end) {
+ /* This is the common/special case: skb goes to the end. */
+ /* Detect and discard overlaps. */
+ if (offset < (skb1->ip_defrag_offset + skb1->len))
+ goto discard_qp;
+ /* Insert after skb1. */
+ rb_link_node(&skb->rbnode, &skb1->rbnode, &skb1->rbnode.rb_right);
+ qp->q.fragments_tail = skb;
+ } else {
+ /* Binary search. Note that skb can become the first fragment, but
+ * not the last (covered above). */
+ rbn = &qp->q.rb_fragments.rb_node;
+ do {
+ parent = *rbn;
+ skb1 = rb_to_skb(parent);
+ if (end <= skb1->ip_defrag_offset)
+ rbn = &parent->rb_left;
+ else if (offset >= skb1->ip_defrag_offset + skb1->len)
+ rbn = &parent->rb_right;
+ else /* Found an overlap with skb1. */
+ goto discard_qp;
+ } while (*rbn);
+ /* Here we have parent properly set, and rbn pointing to
+ * one of its NULL left/right children. Insert skb. */
+ rb_link_node(&skb->rbnode, parent, rbn);
}
+ rb_insert_color(&skb->rbnode, &qp->q.rb_fragments);
- /* Note : skb->ip_defrag_offset and skb->dev share the same location */
- dev = skb->dev;
if (dev)
qp->iif = dev->ifindex;
- /* Makes sure compiler wont do silly aliasing games */
- barrier();
skb->ip_defrag_offset = offset;
- /* Insert this fragment in the chain of fragments. */
- skb->next = next;
- if (!next)
- qp->q.fragments_tail = skb;
- if (prev)
- prev->next = skb;
- else
- qp->q.fragments = skb;
-
qp->q.stamp = skb->tstamp;
qp->q.meat += skb->len;
qp->ecn |= ecn;
@@ -455,7 +425,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
unsigned long orefdst = skb->_skb_refdst;
skb->_skb_refdst = 0UL;
- err = ip_frag_reasm(qp, prev, dev);
+ err = ip_frag_reasm(qp, skb, dev);
skb->_skb_refdst = orefdst;
return err;
}
@@ -463,20 +433,24 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
skb_dst_drop(skb);
return -EINPROGRESS;
+discard_qp:
+ inet_frag_kill(&qp->q);
+ err = -EINVAL;
+ __IP_INC_STATS(net, IPSTATS_MIB_REASM_OVERLAPS);
err:
kfree_skb(skb);
return err;
}
-
/* Build a new IP datagram from all its fragments. */
-
-static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
+static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
struct net_device *dev)
{
struct net *net = container_of(qp->q.net, struct net, ipv4.frags);
struct iphdr *iph;
- struct sk_buff *fp, *head = qp->q.fragments;
+ struct sk_buff *fp, *head = skb_rb_first(&qp->q.rb_fragments);
+ struct sk_buff **nextp; /* To build frag_list. */
+ struct rb_node *rbn;
int len;
int ihlen;
int err;
@@ -490,25 +464,20 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
goto out_fail;
}
/* Make the one we just received the head. */
- if (prev) {
- head = prev->next;
- fp = skb_clone(head, GFP_ATOMIC);
+ if (head != skb) {
+ fp = skb_clone(skb, GFP_ATOMIC);
if (!fp)
goto out_nomem;
-
- fp->next = head->next;
- if (!fp->next)
+ rb_replace_node(&skb->rbnode, &fp->rbnode, &qp->q.rb_fragments);
+ if (qp->q.fragments_tail == skb)
qp->q.fragments_tail = fp;
- prev->next = fp;
-
- skb_morph(head, qp->q.fragments);
- head->next = qp->q.fragments->next;
-
- consume_skb(qp->q.fragments);
- qp->q.fragments = head;
+ skb_morph(skb, head);
+ rb_replace_node(&head->rbnode, &skb->rbnode,
+ &qp->q.rb_fragments);
+ consume_skb(head);
+ head = skb;
}
- WARN_ON(!head);
WARN_ON(head->ip_defrag_offset != 0);
/* Allocate a new buffer for the datagram. */
@@ -533,24 +502,35 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
clone = alloc_skb(0, GFP_ATOMIC);
if (!clone)
goto out_nomem;
- 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 = clone->data_len = head->data_len - plen;
- head->data_len -= clone->len;
- head->len -= clone->len;
+ skb->truesize += clone->truesize;
clone->csum = 0;
clone->ip_summed = head->ip_summed;
add_frag_mem_limit(qp->q.net, clone->truesize);
+ skb_shinfo(head)->frag_list = clone;
+ nextp = &clone->next;
+ } else {
+ nextp = &skb_shinfo(head)->frag_list;
}
- skb_shinfo(head)->frag_list = head->next;
skb_push(head, head->data - skb_network_header(head));
- for (fp=head->next; fp; fp = fp->next) {
+ /* Traverse the tree in order, to build frag_list. */
+ rbn = rb_next(&head->rbnode);
+ rb_erase(&head->rbnode, &qp->q.rb_fragments);
+ while (rbn) {
+ struct rb_node *rbnext = rb_next(rbn);
+ fp = rb_to_skb(rbn);
+ rb_erase(rbn, &qp->q.rb_fragments);
+ rbn = rbnext;
+ *nextp = fp;
+ nextp = &fp->next;
+ fp->prev = NULL;
+ memset(&fp->rbnode, 0, sizeof(fp->rbnode));
head->data_len += fp->len;
head->len += fp->len;
if (head->ip_summed != fp->ip_summed)
@@ -561,7 +541,9 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
}
sub_frag_mem_limit(qp->q.net, head->truesize);
+ *nextp = NULL;
head->next = NULL;
+ head->prev = NULL;
head->dev = dev;
head->tstamp = qp->q.stamp;
IPCB(head)->frag_max_size = max(qp->max_df_size, qp->q.max_size);
@@ -589,6 +571,7 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
__IP_INC_STATS(net, IPSTATS_MIB_REASMOKS);
qp->q.fragments = NULL;
+ qp->q.rb_fragments = RB_ROOT;
qp->q.fragments_tail = NULL;
return 0;
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index b46e4cf9a55a1aa58e1fa344443e184053e05ffd..70289682a6701438aed99a00a9705c39fa4394d3 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -119,6 +119,7 @@ static const struct snmp_mib snmp4_ipextstats_list[] = {
SNMP_MIB_ITEM("InECT1Pkts", IPSTATS_MIB_ECT1PKTS),
SNMP_MIB_ITEM("InECT0Pkts", IPSTATS_MIB_ECT0PKTS),
SNMP_MIB_ITEM("InCEPkts", IPSTATS_MIB_CEPKTS),
+ SNMP_MIB_ITEM("ReasmOverlaps", IPSTATS_MIB_REASM_OVERLAPS),
SNMP_MIB_SENTINEL
};
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index 0610bdab721cb9d6d69ac6cd7a5d21367efed23c..38d69ef516d5dd87f4d76889597b48c12e62ed71 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -463,6 +463,7 @@ nf_ct_frag6_reasm(struct frag_queue *fq, struct sk_buff *prev, struct net_devic
head->csum);
fq->q.fragments = NULL;
+ fq->q.rb_fragments = RB_ROOT;
fq->q.fragments_tail = NULL;
return true;
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index 6edd2ac8ae4bd0946b81e787aedc2486be02b990..b4e558ab39fa4b24fe364b67c092c161f949d87f 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -405,6 +405,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
__IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS);
rcu_read_unlock();
fq->q.fragments = NULL;
+ fq->q.rb_fragments = RB_ROOT;
fq->q.fragments_tail = NULL;
return 1;