1 files changed, 55 insertions, 21 deletions

diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index fabb86d..d7fa2bf 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);