[SK_BUFF]: Introduce skb_set_transport_header

For the cases where the transport header is being set to a offset from
skb->data.

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

include/linux/skbuff.h

@@ -962,6 +962,12 @@ static inline void skb_reset_transport_header(struct sk_buff *skb)
 	skb->h.raw = skb->data;
 }
 
+static inline void skb_set_transport_header(struct sk_buff *skb,
+					    const int offset)
+{
+	skb->h.raw = skb->data + offset;
+}
+
 static inline int skb_transport_offset(const struct sk_buff *skb)
 {
 	return skb->h.raw - skb->data;

net/ax25/af_ax25.c

@@ -1425,7 +1425,6 @@ static int ax25_sendmsg(struct kiocb *iocb, struct socket *sock,
 	struct sockaddr_ax25 sax;
 	struct sk_buff *skb;
 	ax25_digi dtmp, *dp;
-	unsigned char *asmptr;
 	ax25_cb *ax25;
 	size_t size;
 	int lv, err, addr_len = msg->msg_namelen;
@@ -1551,10 +1550,8 @@ static int ax25_sendmsg(struct kiocb *iocb, struct socket *sock,
 	skb_reset_network_header(skb);
 
 	/* Add the PID if one is not supplied by the user in the skb */
-	if (!ax25->pidincl) {
-		asmptr  = skb_push(skb, 1);
-		*asmptr = sk->sk_protocol;
-	}
+	if (!ax25->pidincl)
+		*skb_push(skb, 1) = sk->sk_protocol;
 
 	SOCK_DEBUG(sk, "AX.25: Transmitting buffer\n");
 
@@ -1573,25 +1570,24 @@ static int ax25_sendmsg(struct kiocb *iocb, struct socket *sock,
 		goto out;
 	}
 
-	asmptr = skb_push(skb, 1 + ax25_addr_size(dp));
+	skb_push(skb, 1 + ax25_addr_size(dp));
 
 	SOCK_DEBUG(sk, "Building AX.25 Header (dp=%p).\n", dp);
 
 	if (dp != NULL)
 		SOCK_DEBUG(sk, "Num digipeaters=%d\n", dp->ndigi);
 
 	/* Build an AX.25 header */
-	asmptr += (lv = ax25_addr_build(asmptr, &ax25->source_addr,
-					&sax.sax25_call, dp,
-					AX25_COMMAND, AX25_MODULUS));
+	lv = ax25_addr_build(skb->data, &ax25->source_addr, &sax.sax25_call,
+			     dp, AX25_COMMAND, AX25_MODULUS);
 
 	SOCK_DEBUG(sk, "Built header (%d bytes)\n",lv);
 
-	skb->h.raw = asmptr;
+	skb_set_transport_header(skb, lv);
 
-	SOCK_DEBUG(sk, "base=%p pos=%p\n", skb->data, asmptr);
+	SOCK_DEBUG(sk, "base=%p pos=%p\n", skb->data, skb->h.raw);
 
-	*asmptr = AX25_UI;
+	*skb->h.raw = AX25_UI;
 
 	/* Datagram frames go straight out of the door as UI */
 	ax25_queue_xmit(skb, ax25->ax25_dev->dev);

net/ax25/ax25_in.c

@@ -233,7 +233,7 @@ static int ax25_rcv(struct sk_buff *skb, struct net_device *dev,
 
 	/* UI frame - bypass LAPB processing */
 	if ((*skb->data & ~0x10) == AX25_UI && dp.lastrepeat + 1 == dp.ndigi) {
-		skb->h.raw = skb->data + 2;		/* skip control and pid */
+		skb_set_transport_header(skb, 2); /* skip control and pid */
 
 		ax25_send_to_raw(&dest, skb, skb->data[1]);
 

net/ipv4/esp4.c

@@ -261,7 +261,8 @@ static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
 
 	iph->protocol = nexthdr[1];
 	pskb_trim(skb, skb->len - alen - padlen - 2);
-	skb->h.raw = __skb_pull(skb, sizeof(*esph) + esp->conf.ivlen) - ihl;
+	__skb_pull(skb, sizeof(*esph) + esp->conf.ivlen);
+	skb_set_transport_header(skb, -ihl);
 
 	return 0;
 

net/ipv4/ip_output.c

@@ -593,7 +593,7 @@ int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff*))
 		skb_reserve(skb2, ll_rs);
 		skb_put(skb2, len + hlen);
 		skb_reset_network_header(skb2);
-		skb2->h.raw = skb2->data + hlen;
+		skb2->h.raw = skb2->nh.raw + hlen;
 
 		/*
 		 *	Charge the memory for the fragment to any owner
@@ -724,7 +724,7 @@ static inline int ip_ufo_append_data(struct sock *sk,
 		skb_reset_network_header(skb);
 
 		/* initialize protocol header pointer */
-		skb->h.raw = skb->data + fragheaderlen;
+		skb->h.raw = skb->nh.raw + fragheaderlen;
 
 		skb->ip_summed = CHECKSUM_PARTIAL;
 		skb->csum = 0;
@@ -1099,8 +1099,6 @@ ssize_t	ip_append_page(struct sock *sk, struct page *page,
 		}
 		if (len <= 0) {
 			struct sk_buff *skb_prev;
-			char *data;
-			struct iphdr *iph;
 			int alloclen;
 
 			skb_prev = skb;
@@ -1123,16 +1121,15 @@ ssize_t	ip_append_page(struct sock *sk, struct page *page,
 			/*
 			 *	Find where to start putting bytes.
 			 */
-			data = skb_put(skb, fragheaderlen + fraggap);
+			skb_put(skb, fragheaderlen + fraggap);
 			skb_reset_network_header(skb);
-			iph = ip_hdr(skb);
-			data += fragheaderlen;
-			skb->h.raw = data;
+			skb->h.raw = skb->nh.raw + fragheaderlen;
 
 			if (fraggap) {
-				skb->csum = skb_copy_and_csum_bits(
-					skb_prev, maxfraglen,
-					data, fraggap, 0);
+				skb->csum = skb_copy_and_csum_bits(skb_prev,
+								   maxfraglen,
+								   skb->h.raw,
+								   fraggap, 0);
 				skb_prev->csum = csum_sub(skb_prev->csum,
 							  skb->csum);
 				pskb_trim_unique(skb_prev, maxfraglen);

net/ipv4/tcp_input.c

@@ -3636,7 +3636,7 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list,
 		skb_set_mac_header(nskb, skb_mac_header(skb) - skb->head);
 		skb_set_network_header(nskb,
 				       skb_network_header(skb) - skb->head);
-		nskb->h.raw = nskb->data + (skb->h.raw - skb->head);
+		skb_set_transport_header(nskb, skb->h.raw - skb->head);
 
 		skb_reserve(nskb, header);
 		memcpy(nskb->head, skb->head, header);

net/ipv6/ah6.c

@@ -247,7 +247,7 @@ static int ah6_output(struct xfrm_state *x, struct sk_buff *skb)
 	memcpy(tmp_base, top_iph, sizeof(tmp_base));
 
 	tmp_ext = NULL;
-	extlen = skb->h.raw - (unsigned char *)(top_iph + 1);
+	extlen = skb_transport_offset(skb) + sizeof(struct ipv6hdr);
 	if (extlen) {
 		extlen += sizeof(*tmp_ext);
 		tmp_ext = kmalloc(extlen, GFP_ATOMIC);

net/ipv6/esp6.c

@@ -228,8 +228,8 @@ static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
 		ret = nexthdr[1];
 	}
 
-	skb->h.raw = __skb_pull(skb, sizeof(*esph) + esp->conf.ivlen) - hdr_len;
-
+	__skb_pull(skb, sizeof(*esph) + esp->conf.ivlen);
+	skb_set_transport_header(skb, -hdr_len);
 out:
 	return ret;
 }

net/ipv6/netfilter/nf_conntrack_reasm.c

@@ -785,7 +785,7 @@ struct sk_buff *nf_ct_frag6_gather(struct sk_buff *skb)
 		goto ret_orig;
 	}
 
-	clone->h.raw = clone->data + fhoff;
+	skb_set_transport_header(clone, fhoff);
 	hdr = ipv6_hdr(clone);
 	fhdr = (struct frag_hdr *)clone->h.raw;
 

net/ipv6/xfrm6_mode_beet.c

@@ -42,7 +42,7 @@ static int xfrm6_beet_output(struct xfrm_state *x, struct sk_buff *skb)
 
 	hdr_len = ip6_find_1stfragopt(skb, &prevhdr);
 	skb->nh.raw = prevhdr - x->props.header_len;
-	skb->h.raw = skb->data + hdr_len;
+	skb_set_transport_header(skb, hdr_len);
 	memmove(skb->data, iph, hdr_len);
 
 	skb_reset_network_header(skb);

net/ipv6/xfrm6_mode_ro.c

@@ -54,7 +54,7 @@ static int xfrm6_ro_output(struct xfrm_state *x, struct sk_buff *skb)
 
 	hdr_len = x->type->hdr_offset(x, skb, &prevhdr);
 	skb->nh.raw = prevhdr - x->props.header_len;
-	skb->h.raw = skb->data + hdr_len;
+	skb_set_transport_header(skb, hdr_len);
 	memmove(skb->data, iph, hdr_len);
 	return 0;
 }

net/ipv6/xfrm6_mode_transport.c

@@ -36,7 +36,7 @@ static int xfrm6_transport_output(struct xfrm_state *x, struct sk_buff *skb)
 
 	hdr_len = x->type->hdr_offset(x, skb, &prevhdr);
 	skb->nh.raw = prevhdr - x->props.header_len;
-	skb->h.raw = skb->data + hdr_len;
+	skb_set_transport_header(skb, hdr_len);
 	memmove(skb->data, iph, hdr_len);
 	return 0;
 }