[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>

6 files changed, 14 insertions, 7 deletions

diff --git a/include/linux/if_pppox.h b/include/linux/if_pppox.h
index 7044f8ab30a0..29d6579ff1a0 100644
--- a/include/linux/if_pppox.h
+++ b/include/linux/if_pppox.h
@@ -116,7 +116,7 @@ struct pppoe_hdr {
 
 static inline struct pppoe_hdr *pppoe_hdr(const struct sk_buff *skb)
 {
-	return (struct pppoe_hdr *)skb->nh.raw;
+	return (struct pppoe_hdr *)skb_network_header(skb);
 }
 
 struct pppoe_opt {
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 47cc8b07c2b4..76d30f34b986 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -960,6 +960,11 @@ static inline void skb_reserve(struct sk_buff *skb, int len)
 	skb->tail += len;
 }
 
+static inline unsigned char *skb_network_header(const struct sk_buff *skb)
+{
+	return skb->nh.raw;
+}
+
 static inline void skb_reset_network_header(struct sk_buff *skb)
 {
 	skb->nh.raw = skb->data;
diff --git a/include/net/cipso_ipv4.h b/include/net/cipso_ipv4.h
index 4c9522c5178f..4f90f5554fac 100644
--- a/include/net/cipso_ipv4.h
+++ b/include/net/cipso_ipv4.h
@@ -120,7 +120,7 @@ extern int cipso_v4_rbm_strictvalid;
  */
 
 #define CIPSO_V4_OPTEXIST(x) (IPCB(x)->opt.cipso != 0)
-#define CIPSO_V4_OPTPTR(x) ((x)->nh.raw + IPCB(x)->opt.cipso)
+#define CIPSO_V4_OPTPTR(x) (skb_network_header(x) + IPCB(x)->opt.cipso)
 
 /*
  * DOI List Functions
diff --git a/include/net/inet_ecn.h b/include/net/inet_ecn.h
index 10117c8503e8..b9ed3898e368 100644
--- a/include/net/inet_ecn.h
+++ b/include/net/inet_ecn.h
@@ -114,12 +114,14 @@ static inline int INET_ECN_set_ce(struct sk_buff *skb)
 {
 	switch (skb->protocol) {
 	case __constant_htons(ETH_P_IP):
-		if (skb->nh.raw + sizeof(struct iphdr) <= skb->tail)
+		if (skb_network_header(skb) + sizeof(struct iphdr) <=
+		    skb->tail)
 			return IP_ECN_set_ce(skb->nh.iph);
 		break;
 
 	case __constant_htons(ETH_P_IPV6):
-		if (skb->nh.raw + sizeof(struct ipv6hdr) <= skb->tail)
+		if (skb_network_header(skb) + sizeof(struct ipv6hdr) <=
+		    skb->tail)
 			return IP6_ECN_set_ce(skb->nh.ipv6h);
 		break;
 	}
diff --git a/include/net/llc_pdu.h b/include/net/llc_pdu.h
index 778f75a40b4d..4a8f58b17e43 100644
--- a/include/net/llc_pdu.h
+++ b/include/net/llc_pdu.h
@@ -203,7 +203,7 @@ struct llc_pdu_sn {
 
 static inline struct llc_pdu_sn *llc_pdu_sn_hdr(struct sk_buff *skb)
 {
-	return (struct llc_pdu_sn *)skb->nh.raw;
+	return (struct llc_pdu_sn *)skb_network_header(skb);
 }
 
 /* Un-numbered PDU format (3 bytes in length) */
@@ -215,7 +215,7 @@ struct llc_pdu_un {
 
 static inline struct llc_pdu_un *llc_pdu_un_hdr(struct sk_buff *skb)
 {
-	return (struct llc_pdu_un *)skb->nh.raw;
+	return (struct llc_pdu_un *)skb_network_header(skb);
 }
 
 /**
diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index 02647fe3d74b..8a6b0e7bded5 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -326,7 +326,7 @@ static inline unsigned char * tcf_get_base_ptr(struct sk_buff *skb, int layer)
 		case TCF_LAYER_LINK:
 			return skb->data;
 		case TCF_LAYER_NETWORK:
-			return skb->nh.raw;
+			return skb_network_header(skb);
 		case TCF_LAYER_TRANSPORT:
 			return skb->h.raw;
 	}