[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>

drivers/isdn/i4l/isdn_net.c

@@ -872,7 +872,8 @@ typedef struct {
 static void
 isdn_net_log_skb(struct sk_buff * skb, isdn_net_local * lp)
 {
-	u_char *p = skb->nh.raw; /* hopefully, this was set correctly */
+	/* hopefully, this was set correctly */
+	const u_char *p = skb_network_header(skb);
 	unsigned short proto = ntohs(skb->protocol);
 	int data_ofs;
 	ip_ports *ipp;
@@ -880,7 +881,7 @@ isdn_net_log_skb(struct sk_buff * skb, isdn_net_local * lp)
 
 	addinfo[0] = '\0';
 	/* This check stolen from 2.1.72 dev_queue_xmit_nit() */
-	if (skb->nh.raw < skb->data || skb->nh.raw >= skb->tail) {
+	if (p < skb->data || p >= skb->tail) {
 		/* fall back to old isdn_net_log_packet method() */
 		char * buf = skb->data;
 

drivers/net/bonding/bond_alb.c

@@ -106,7 +106,7 @@ struct arp_pkt {
 
 static inline struct arp_pkt *arp_pkt(const struct sk_buff *skb)
 {
-	return (struct arp_pkt *)skb->nh.raw;
+	return (struct arp_pkt *)skb_network_header(skb);
 }
 
 /* Forward declaration */

drivers/net/loopback.c

@@ -76,7 +76,8 @@ static DEFINE_PER_CPU(struct pcpu_lstats, pcpu_lstats);
 static void emulate_large_send_offload(struct sk_buff *skb)
 {
 	struct iphdr *iph = skb->nh.iph;
-	struct tcphdr *th = (struct tcphdr*)(skb->nh.raw + (iph->ihl * 4));
+	struct tcphdr *th = (struct tcphdr *)(skb_network_header(skb) +
+					      (iph->ihl * 4));
 	unsigned int doffset = (iph->ihl + th->doff) * 4;
 	unsigned int mtu = skb_shinfo(skb)->gso_size + doffset;
 	unsigned int offset = 0;
@@ -93,7 +94,7 @@ static void emulate_large_send_offload(struct sk_buff *skb)
 		skb_set_mac_header(nskb, -ETH_HLEN);
 		skb_reset_network_header(nskb);
 		iph = nskb->nh.iph;
-		memcpy(nskb->data, skb->nh.raw, doffset);
+		memcpy(nskb->data, skb_network_header(skb), doffset);
 		if (skb_copy_bits(skb,
 				  doffset + offset,
 				  nskb->data + doffset,
@@ -108,7 +109,7 @@ static void emulate_large_send_offload(struct sk_buff *skb)
 		memcpy(nskb->cb, skb->cb, sizeof(skb->cb));
 		nskb->pkt_type = skb->pkt_type;
 
-		th = (struct tcphdr*)(nskb->nh.raw + iph->ihl*4);
+		th = (struct tcphdr *)(skb_network_header(nskb) + iph->ihl * 4);
 		iph->tot_len = htons(frag_size + doffset);
 		iph->id = htons(id);
 		iph->check = 0;

drivers/net/pasemi_mac.c

@@ -729,16 +729,18 @@ static int pasemi_mac_start_tx(struct sk_buff *skb, struct net_device *dev)
 	dflags = XCT_MACTX_O | XCT_MACTX_ST | XCT_MACTX_SS | XCT_MACTX_CRC_PAD;
 
 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
+		const unsigned char *nh = skb_network_header(skb);
+
 		switch (skb->nh.iph->protocol) {
 		case IPPROTO_TCP:
 			dflags |= XCT_MACTX_CSUM_TCP;
 			dflags |= XCT_MACTX_IPH((skb->h.raw - skb->nh.raw) >> 2);
-			dflags |= XCT_MACTX_IPO(skb->nh.raw - skb->data);
+			dflags |= XCT_MACTX_IPO(nh - skb->data);
 			break;
 		case IPPROTO_UDP:
 			dflags |= XCT_MACTX_CSUM_UDP;
 			dflags |= XCT_MACTX_IPH((skb->h.raw - skb->nh.raw) >> 2);
-			dflags |= XCT_MACTX_IPO(skb->nh.raw - skb->data);
+			dflags |= XCT_MACTX_IPO(nh - skb->data);
 			break;
 		}
 	}

drivers/s390/net/qeth_main.c

@@ -3778,9 +3778,11 @@ qeth_get_cast_type(struct qeth_card *card, struct sk_buff *skb)
 	}
 	/* try something else */
 	if (skb->protocol == ETH_P_IPV6)
-		return (skb->nh.raw[24] == 0xff) ? RTN_MULTICAST : 0;
+		return (skb_network_header(skb)[24] == 0xff) ?
+				RTN_MULTICAST : 0;
 	else if (skb->protocol == ETH_P_IP)
-		return ((skb->nh.raw[16] & 0xf0) == 0xe0) ? RTN_MULTICAST : 0;
+		return ((skb_network_header(skb)[16] & 0xf0) == 0xe0) ?
+				RTN_MULTICAST : 0;
 	/* ... */
 	if (!memcmp(skb->data, skb->dev->broadcast, 6))
 		return RTN_BROADCAST;