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Diffstat (limited to 'net/ipv4/ip_fragment.c')
-rw-r--r--net/ipv4/ip_fragment.c76
1 files changed, 55 insertions, 21 deletions
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index fabb86db763b..d7fa2bf3a0c1 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -109,6 +109,9 @@ static u32 ipfrag_hash_rnd;
static LIST_HEAD(ipq_lru_list);
int ip_frag_nqueues = 0;
+static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
+ struct net_device *dev);
+
static __inline__ void __ipq_unlink(struct ipq *qp)
{
hlist_del(&qp->list);
@@ -464,17 +467,20 @@ static int ip_frag_reinit(struct ipq *qp)
}
/* Add new segment to existing queue. */
-static void ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
+static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
{
struct sk_buff *prev, *next;
+ struct net_device *dev;
int flags, offset;
int ihl, end;
+ int err = -ENOENT;
if (qp->last_in & COMPLETE)
goto err;
if (!(IPCB(skb)->flags & IPSKB_FRAG_COMPLETE) &&
- unlikely(ip_frag_too_far(qp)) && unlikely(ip_frag_reinit(qp))) {
+ unlikely(ip_frag_too_far(qp)) &&
+ unlikely(err = ip_frag_reinit(qp))) {
ipq_kill(qp);
goto err;
}
@@ -487,6 +493,7 @@ static void ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
/* Determine the position of this fragment. */
end = offset + skb->len - ihl;
+ err = -EINVAL;
/* Is this the final fragment? */
if ((flags & IP_MF) == 0) {
@@ -514,9 +521,12 @@ static void ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
if (end == offset)
goto err;
+ err = -ENOMEM;
if (pskb_pull(skb, ihl) == NULL)
goto err;
- if (pskb_trim_rcsum(skb, end-offset))
+
+ err = pskb_trim_rcsum(skb, end - offset);
+ if (err)
goto err;
/* Find out which fragments are in front and at the back of us
@@ -539,8 +549,10 @@ static void ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
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)
@@ -548,6 +560,8 @@ static void ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
}
}
+ err = -ENOMEM;
+
while (next && FRAG_CB(next)->offset < end) {
int i = end - FRAG_CB(next)->offset; /* overlap is 'i' bytes */
@@ -589,37 +603,62 @@ static void ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
else
qp->fragments = skb;
- if (skb->dev)
- qp->iif = skb->dev->ifindex;
- skb->dev = NULL;
+ dev = skb->dev;
+ if (dev) {
+ qp->iif = dev->ifindex;
+ skb->dev = NULL;
+ }
qp->stamp = skb->tstamp;
qp->meat += skb->len;
atomic_add(skb->truesize, &ip_frag_mem);
if (offset == 0)
qp->last_in |= FIRST_IN;
+ if (qp->last_in == (FIRST_IN | LAST_IN) && qp->meat == qp->len)
+ return ip_frag_reasm(qp, prev, dev);
+
write_lock(&ipfrag_lock);
list_move_tail(&qp->lru_list, &ipq_lru_list);
write_unlock(&ipfrag_lock);
-
- return;
+ return -EINPROGRESS;
err:
kfree_skb(skb);
+ return err;
}
/* Build a new IP datagram from all its fragments. */
-static struct sk_buff *ip_frag_reasm(struct ipq *qp, struct net_device *dev)
+static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
+ struct net_device *dev)
{
struct iphdr *iph;
struct sk_buff *fp, *head = qp->fragments;
int len;
int ihlen;
+ int err;
ipq_kill(qp);
+ /* Make the one we just received the head. */
+ if (prev) {
+ head = prev->next;
+ fp = skb_clone(head, GFP_ATOMIC);
+
+ if (!fp)
+ goto out_nomem;
+
+ fp->next = head->next;
+ prev->next = fp;
+
+ skb_morph(head, qp->fragments);
+ head->next = qp->fragments->next;
+
+ kfree_skb(qp->fragments);
+ qp->fragments = head;
+ }
+
BUG_TRAP(head != NULL);
BUG_TRAP(FRAG_CB(head)->offset == 0);
@@ -627,10 +666,12 @@ static struct sk_buff *ip_frag_reasm(struct ipq *qp, struct net_device *dev)
ihlen = ip_hdrlen(head);
len = ihlen + qp->len;
+ err = -E2BIG;
if (len > 65535)
goto out_oversize;
/* Head of list must not be cloned. */
+ err = -ENOMEM;
if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
goto out_nomem;
@@ -681,7 +722,7 @@ static struct sk_buff *ip_frag_reasm(struct ipq *qp, struct net_device *dev)
iph->tot_len = htons(len);
IP_INC_STATS_BH(IPSTATS_MIB_REASMOKS);
qp->fragments = NULL;
- return head;
+ return 0;
out_nomem:
LIMIT_NETDEBUG(KERN_ERR "IP: queue_glue: no memory for gluing "
@@ -694,14 +735,13 @@ out_oversize:
NIPQUAD(qp->saddr));
out_fail:
IP_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
- return NULL;
+ return err;
}
/* Process an incoming IP datagram fragment. */
struct sk_buff *ip_defrag(struct sk_buff *skb, u32 user)
{
struct ipq *qp;
- struct net_device *dev;
IP_INC_STATS_BH(IPSTATS_MIB_REASMREQDS);
@@ -709,23 +749,17 @@ struct sk_buff *ip_defrag(struct sk_buff *skb, u32 user)
if (atomic_read(&ip_frag_mem) > sysctl_ipfrag_high_thresh)
ip_evictor();
- dev = skb->dev;
-
/* Lookup (or create) queue header */
if ((qp = ip_find(ip_hdr(skb), user)) != NULL) {
- struct sk_buff *ret = NULL;
+ int ret;
spin_lock(&qp->lock);
- ip_frag_queue(qp, skb);
-
- if (qp->last_in == (FIRST_IN|LAST_IN) &&
- qp->meat == qp->len)
- ret = ip_frag_reasm(qp, dev);
+ ret = ip_frag_queue(qp, skb);
spin_unlock(&qp->lock);
ipq_put(qp, NULL);
- return ret;
+ return ret ? NULL : skb;
}
IP_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);