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);