[IPV6]: Make ipv6_frag_rcv return the same packet
This patch implements the same change taht was done to ip_defrag. It
makes ipv6_frag_rcv return the last packet received of a train of fragments
rather than the head of that sequence.
This allows us to get rid of the sk_buff ** argument later.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index 31601c9..fa1055b 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -42,6 +42,7 @@
#include <linux/icmpv6.h>
#include <linux/random.h>
#include <linux/jhash.h>
+#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/snmp.h>
@@ -107,6 +108,9 @@
static LIST_HEAD(ip6_frag_lru_list);
int ip6_frag_nqueues = 0;
+static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
+ struct net_device *dev);
+
static __inline__ void __fq_unlink(struct frag_queue *fq)
{
hlist_del(&fq->list);
@@ -420,10 +424,11 @@
}
-static void ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
+static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
struct frag_hdr *fhdr, int nhoff)
{
struct sk_buff *prev, *next;
+ struct net_device *dev;
int offset, end;
if (fq->last_in & COMPLETE)
@@ -439,7 +444,7 @@
icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
((u8 *)&fhdr->frag_off -
skb_network_header(skb)));
- return;
+ return -1;
}
if (skb->ip_summed == CHECKSUM_COMPLETE) {
@@ -471,7 +476,7 @@
IPSTATS_MIB_INHDRERRORS);
icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
offsetof(struct ipv6hdr, payload_len));
- return;
+ return -1;
}
if (end > fq->len) {
/* Some bits beyond end -> corruption. */
@@ -564,9 +569,11 @@
else
fq->fragments = skb;
- if (skb->dev)
- fq->iif = skb->dev->ifindex;
- skb->dev = NULL;
+ dev = skb->dev;
+ if (dev) {
+ fq->iif = dev->ifindex;
+ skb->dev = NULL;
+ }
fq->stamp = skb->tstamp;
fq->meat += skb->len;
atomic_add(skb->truesize, &ip6_frag_mem);
@@ -578,14 +585,19 @@
fq->nhoffset = nhoff;
fq->last_in |= FIRST_IN;
}
+
+ if (fq->last_in == (FIRST_IN | LAST_IN) && fq->meat == fq->len)
+ return ip6_frag_reasm(fq, prev, dev);
+
write_lock(&ip6_frag_lock);
list_move_tail(&fq->lru_list, &ip6_frag_lru_list);
write_unlock(&ip6_frag_lock);
- return;
+ return -1;
err:
IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMFAILS);
kfree_skb(skb);
+ return -1;
}
/*
@@ -597,7 +609,7 @@
* 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 ip6_frag_reasm(struct frag_queue *fq, struct sk_buff **skb_in,
+static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
struct net_device *dev)
{
struct sk_buff *fp, *head = fq->fragments;
@@ -606,6 +618,24 @@
fq_kill(fq);
+ /* 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;
+ prev->next = fp;
+
+ skb_morph(head, fq->fragments);
+ head->next = fq->fragments->next;
+
+ kfree_skb(fq->fragments);
+ fq->fragments = head;
+ }
+
BUG_TRAP(head != NULL);
BUG_TRAP(FRAG6_CB(head)->offset == 0);
@@ -674,8 +704,6 @@
ipv6_hdr(head)->payload_len = htons(payload_len);
IP6CB(head)->nhoff = nhoff;
- *skb_in = head;
-
/* Yes, and fold redundant checksum back. 8) */
if (head->ip_summed == CHECKSUM_COMPLETE)
head->csum = csum_partial(skb_network_header(head),
@@ -705,7 +733,6 @@
static int ipv6_frag_rcv(struct sk_buff **skbp)
{
struct sk_buff *skb = *skbp;
- struct net_device *dev = skb->dev;
struct frag_hdr *fhdr;
struct frag_queue *fq;
struct ipv6hdr *hdr = ipv6_hdr(skb);
@@ -744,15 +771,11 @@
if ((fq = fq_find(fhdr->identification, &hdr->saddr, &hdr->daddr,
ip6_dst_idev(skb->dst))) != NULL) {
- int ret = -1;
+ int ret;
spin_lock(&fq->lock);
- ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff);
-
- if (fq->last_in == (FIRST_IN|LAST_IN) &&
- fq->meat == fq->len)
- ret = ip6_frag_reasm(fq, skbp, dev);
+ ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff);
spin_unlock(&fq->lock);
fq_put(fq, NULL);