[SK_BUFF]: Introduce skb_network_header()

For the places where we need a pointer to the network header, it is still legal
to touch skb->nh.raw directly if just adding to, subtracting from or setting it
to another layer header.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 7 deletions

diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index d8a585bd2cb4..cb5a723d4cb4 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -273,14 +273,16 @@ _decode_session6(struct sk_buff *skb, struct flowi *fl)
         u16 offset = skb->h.raw - skb->nh.raw;
         struct ipv6hdr *hdr = skb->nh.ipv6h;
         struct ipv6_opt_hdr *exthdr;
-        u8 nexthdr = skb->nh.raw[IP6CB(skb)->nhoff];
+        const unsigned char *nh = skb_network_header(skb);
+        u8 nexthdr = nh[IP6CB(skb)->nhoff];
 
         memset(fl, 0, sizeof(struct flowi));
         ipv6_addr_copy(&fl->fl6_dst, &hdr->daddr);
         ipv6_addr_copy(&fl->fl6_src, &hdr->saddr);
 
-        while (pskb_may_pull(skb, skb->nh.raw + offset + 1 - skb->data)) {
-                exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset);
+        while (pskb_may_pull(skb, nh + offset + 1 - skb->data)) {
+                nh = skb_network_header(skb);
+                exthdr = (struct ipv6_opt_hdr *)(nh + offset);
 
                 switch (nexthdr) {
                 case NEXTHDR_ROUTING:
@@ -288,7 +290,7 @@ _decode_session6(struct sk_buff *skb, struct flowi *fl)
                 case NEXTHDR_DEST:
                         offset += ipv6_optlen(exthdr);
                         nexthdr = exthdr->nexthdr;
-                        exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset);
+                        exthdr = (struct ipv6_opt_hdr *)(nh + offset);
                         break;
 
                 case IPPROTO_UDP:
@@ -296,7 +298,7 @@ _decode_session6(struct sk_buff *skb, struct flowi *fl)
                 case IPPROTO_TCP:
                 case IPPROTO_SCTP:
                 case IPPROTO_DCCP:
-                        if (pskb_may_pull(skb, skb->nh.raw + offset + 4 - skb->data)) {
+                        if (pskb_may_pull(skb, nh + offset + 4 - skb->data)) {
                                 __be16 *ports = (__be16 *)exthdr;
 
                                 fl->fl_ip_sport = ports[0];
@@ -306,7 +308,7 @@ _decode_session6(struct sk_buff *skb, struct flowi *fl)
                         return;
 
                 case IPPROTO_ICMPV6:
-                        if (pskb_may_pull(skb, skb->nh.raw + offset + 2 - skb->data)) {
+                        if (pskb_may_pull(skb, nh + offset + 2 - skb->data)) {
                                 u8 *icmp = (u8 *)exthdr;
 
                                 fl->fl_icmp_type = icmp[0];
@@ -317,7 +319,7 @@ _decode_session6(struct sk_buff *skb, struct flowi *fl)
 
 #ifdef CONFIG_IPV6_MIP6
                 case IPPROTO_MH:
-                        if (pskb_may_pull(skb, skb->nh.raw + offset + 3 - skb->data)) {
+                        if (pskb_may_pull(skb, nh + offset + 3 - skb->data)) {
                                 struct ip6_mh *mh;
                                 mh = (struct ip6_mh *)exthdr;