[IPV6]: Move nextheader offset to the IP6CB

Move nextheader offset to the IP6CB to make it possible to pass a
packet to ip6_input_finish multiple times and have it skip already
parsed headers. As a nice side effect this gets rid of the manual
hopopts skipping in ip6_input_finish.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index 113374d..2a1e7e4 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -152,7 +152,7 @@
 	{-1,			NULL}
 };
 
-static int ipv6_destopt_rcv(struct sk_buff **skbp, unsigned int *nhoffp)
+static int ipv6_destopt_rcv(struct sk_buff **skbp)
 {
 	struct sk_buff *skb = *skbp;
 	struct inet6_skb_parm *opt = IP6CB(skb);
@@ -169,7 +169,7 @@
 
 	if (ip6_parse_tlv(tlvprocdestopt_lst, skb)) {
 		skb->h.raw += ((skb->h.raw[1]+1)<<3);
-		*nhoffp = opt->dst1;
+		opt->nhoff = opt->dst1;
 		return 1;
 	}
 
@@ -192,7 +192,7 @@
   NONE header. No data in packet.
  ********************************/
 
-static int ipv6_nodata_rcv(struct sk_buff **skbp, unsigned int *nhoffp)
+static int ipv6_nodata_rcv(struct sk_buff **skbp)
 {
 	struct sk_buff *skb = *skbp;
 
@@ -215,7 +215,7 @@
   Routing header.
  ********************************/
 
-static int ipv6_rthdr_rcv(struct sk_buff **skbp, unsigned int *nhoffp)
+static int ipv6_rthdr_rcv(struct sk_buff **skbp)
 {
 	struct sk_buff *skb = *skbp;
 	struct inet6_skb_parm *opt = IP6CB(skb);
@@ -249,7 +249,7 @@
 		skb->h.raw += (hdr->hdrlen + 1) << 3;
 		opt->dst0 = opt->dst1;
 		opt->dst1 = 0;
-		*nhoffp = (&hdr->nexthdr) - skb->nh.raw;
+		opt->nhoff = (&hdr->nexthdr) - skb->nh.raw;
 		return 1;
 	}
 
@@ -487,9 +487,14 @@
 
 int ipv6_parse_hopopts(struct sk_buff *skb, int nhoff)
 {
-	IP6CB(skb)->hop = sizeof(struct ipv6hdr);
-	if (ip6_parse_tlv(tlvprochopopt_lst, skb))
+	struct inet6_skb_parm *opt = IP6CB(skb);
+
+	opt->hop = sizeof(struct ipv6hdr);
+	if (ip6_parse_tlv(tlvprochopopt_lst, skb)) {
+		skb->h.raw += (skb->h.raw[1]+1)<<3;
+		opt->nhoff = sizeof(struct ipv6hdr);
 		return sizeof(struct ipv6hdr);
+	}
 	return -1;
 }