5 files changed, 20 insertions, 7 deletions

diff --git a/net/ipv6/exthdrs_core.c b/net/ipv6/exthdrs_core.c
index 37f548b7f6dc..72957f4a7c6c 100644
--- a/net/ipv6/exthdrs_core.c
+++ b/net/ipv6/exthdrs_core.c
@@ -57,6 +57,9 @@ int ipv6_ext_hdr(u8 nexthdr)
  *	    it returns NULL.
  *	  - First fragment header is skipped, not-first ones
  *	    are considered as unparsable.
+ *	  - Reports the offset field of the final fragment header so it is
+ *	    possible to tell whether this is a first fragment, later fragment,
+ *	    or not fragmented.
  *	  - ESP is unparsable for now and considered like
  *	    normal payload protocol.
  *	  - Note also special handling of AUTH header. Thanks to IPsec wizards.
@@ -64,10 +67,13 @@ int ipv6_ext_hdr(u8 nexthdr)
  * --ANK (980726)
  */
 
-int ipv6_skip_exthdr(const struct sk_buff *skb, int start, u8 *nexthdrp)
+int ipv6_skip_exthdr(const struct sk_buff *skb, int start, u8 *nexthdrp,
+		     __be16 *frag_offp)
 {
 	u8 nexthdr = *nexthdrp;
 
+	*frag_offp = 0;
+
 	while (ipv6_ext_hdr(nexthdr)) {
 		struct ipv6_opt_hdr _hdr, *hp;
 		int hdrlen;
@@ -87,7 +93,8 @@ int ipv6_skip_exthdr(const struct sk_buff *skb, int start, u8 *nexthdrp)
 			if (fp == NULL)
 				return -1;
 
-			if (ntohs(*fp) & ~0x7)
+			*frag_offp = *fp;
+			if (ntohs(*frag_offp) & ~0x7)
 				break;
 			hdrlen = 8;
 		} else if (nexthdr == NEXTHDR_AUTH)
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index 9e2bdccf9143..01d46bff63c3 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -135,11 +135,12 @@ static int is_ineligible(struct sk_buff *skb)
 	int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
 	int len = skb->len - ptr;
 	__u8 nexthdr = ipv6_hdr(skb)->nexthdr;
+	__be16 frag_off;
 
 	if (len < 0)
 		return 1;
 
-	ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr);
+	ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off);
 	if (ptr < 0)
 		return 0;
 	if (nexthdr == IPPROTO_ICMPV6) {
@@ -596,6 +597,7 @@ static void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
 	int inner_offset;
 	int hash;
 	u8 nexthdr;
+	__be16 frag_off;
 
 	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
 		return;
@@ -603,7 +605,8 @@ static void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
 	nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
 	if (ipv6_ext_hdr(nexthdr)) {
 		/* now skip over extension headers */
-		inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr);
+		inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
+						&nexthdr, &frag_off);
 		if (inner_offset<0)
 			return;
 	} else {
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index a46c64eb0a66..1ca5d45a12e8 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -280,6 +280,7 @@ int ip6_mc_input(struct sk_buff *skb)
 			u8 *ptr = skb_network_header(skb) + opt->ra;
 			struct icmp6hdr *icmp6;
 			u8 nexthdr = hdr->nexthdr;
+			__be16 frag_off;
 			int offset;
 
 			/* Check if the value of Router Alert
@@ -293,7 +294,7 @@ int ip6_mc_input(struct sk_buff *skb)
 					goto out;
 				}
 				offset = ipv6_skip_exthdr(skb, sizeof(*hdr),
-							  &nexthdr);
+							  &nexthdr, &frag_off);
 				if (offset < 0)
 					goto out;
 
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index a24e15557843..3221bc675654 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -329,10 +329,11 @@ static int ip6_forward_proxy_check(struct sk_buff *skb)
 {
 	struct ipv6hdr *hdr = ipv6_hdr(skb);
 	u8 nexthdr = hdr->nexthdr;
+	__be16 frag_off;
 	int offset;
 
 	if (ipv6_ext_hdr(nexthdr)) {
-		offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr);
+		offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr, &frag_off);
 		if (offset < 0)
 			return 0;
 	} else
diff --git a/net/ipv6/netfilter/ip6t_REJECT.c b/net/ipv6/netfilter/ip6t_REJECT.c
index b5a2aa58a03a..aad2fa41cf46 100644
--- a/net/ipv6/netfilter/ip6t_REJECT.c
+++ b/net/ipv6/netfilter/ip6t_REJECT.c
@@ -49,6 +49,7 @@ static void send_reset(struct net *net, struct sk_buff *oldskb)
 	const __u8 tclass = DEFAULT_TOS_VALUE;
 	struct dst_entry *dst = NULL;
 	u8 proto;
+	__be16 frag_off;
 	struct flowi6 fl6;
 
 	if ((!(ipv6_addr_type(&oip6h->saddr) & IPV6_ADDR_UNICAST)) ||
@@ -58,7 +59,7 @@ static void send_reset(struct net *net, struct sk_buff *oldskb)
 	}
 
 	proto = oip6h->nexthdr;
-	tcphoff = ipv6_skip_exthdr(oldskb, ((u8*)(oip6h+1) - oldskb->data), &proto);
+	tcphoff = ipv6_skip_exthdr(oldskb, ((u8*)(oip6h+1) - oldskb->data), &proto, &frag_off);
 
 	if ((tcphoff < 0) || (tcphoff > oldskb->len)) {
 		pr_debug("Cannot get TCP header.\n");