[SK_BUFF]: Introduce skb_transport_header(skb)

For the places where we need a pointer to the transport header, it is
still legal to touch skb->h.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>

10 files changed, 40 insertions, 37 deletions

diff --git a/net/ipv6/ah6.c b/net/ipv6/ah6.c
index e5ee981..d2af4fe 100644
--- a/net/ipv6/ah6.c
+++ b/net/ipv6/ah6.c
@@ -268,7 +268,7 @@ static int ah6_output(struct xfrm_state *x, struct sk_buff *skb)
 			goto error_free_iph;
 	}
 
-	ah = (struct ip_auth_hdr *)skb->h.raw;
+	ah = (struct ip_auth_hdr *)skb_transport_header(skb);
 	ah->nexthdr = nexthdr;
 
 	top_iph->priority    = 0;
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index ad522b7..436eb9e 100644
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -87,7 +87,7 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
 	pskb_put(skb, trailer, clen - skb->len);
 
 	top_iph = (struct ipv6hdr *)__skb_push(skb, hdr_len);
-	esph = (struct ipv6_esp_hdr *)skb->h.raw;
+	esph = (struct ipv6_esp_hdr *)skb_transport_header(skb);
 	top_iph->payload_len = htons(skb->len + alen - sizeof(*top_iph));
 	*(u8 *)(trailer->tail - 1) = *skb_network_header(skb);
 	*skb_network_header(skb) = IPPROTO_ESP;
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index 1bda029..f25ee77 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -144,7 +144,7 @@ static int ip6_parse_tlv(struct tlvtype_proc *procs, struct sk_buff **skbp)
 	struct tlvtype_proc *curr;
 	const unsigned char *nh = skb_network_header(skb);
 	int off = skb->h.raw - skb->nh.raw;
-	int len = ((skb->h.raw[1]+1)<<3);
+	int len = (skb_transport_header(skb)[1] + 1) << 3;
 
 	if (skb_transport_offset(skb) + len > skb_headlen(skb))
 		goto bad;
@@ -290,15 +290,14 @@ static int ipv6_destopt_rcv(struct sk_buff **skbp)
 
 	if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
 	    !pskb_may_pull(skb, (skb_transport_offset(skb) +
-				 ((skb->h.raw[1] + 1) << 3)))) {
+				 ((skb_transport_header(skb)[1] + 1) << 3)))) {
 		IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
 				 IPSTATS_MIB_INHDRERRORS);
 		kfree_skb(skb);
 		return -1;
 	}
 
-	opt->lastopt = skb->h.raw - skb->nh.raw;
-	opt->dst1 = skb->h.raw - skb->nh.raw;
+	opt->lastopt = opt->dst1 = skb->h.raw - skb->nh.raw;
 #ifdef CONFIG_IPV6_MIP6
 	dstbuf = opt->dst1;
 #endif
@@ -307,7 +306,7 @@ static int ipv6_destopt_rcv(struct sk_buff **skbp)
 	if (ip6_parse_tlv(tlvprocdestopt_lst, skbp)) {
 		dst_release(dst);
 		skb = *skbp;
-		skb->h.raw += ((skb->h.raw[1]+1)<<3);
+		skb->h.raw += (skb_transport_header(skb)[1] + 1) << 3;
 		opt = IP6CB(skb);
 #ifdef CONFIG_IPV6_MIP6
 		opt->nhoff = dstbuf;
@@ -390,14 +389,14 @@ static int ipv6_rthdr_rcv(struct sk_buff **skbp)
 
 	if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
 	    !pskb_may_pull(skb, (skb_transport_offset(skb) +
-				 ((skb->h.raw[1] + 1) << 3)))) {
+				 ((skb_transport_header(skb)[1] + 1) << 3)))) {
 		IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
 				 IPSTATS_MIB_INHDRERRORS);
 		kfree_skb(skb);
 		return -1;
 	}
 
-	hdr = (struct ipv6_rt_hdr *) skb->h.raw;
+	hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
 
 	switch (hdr->type) {
 #ifdef CONFIG_IPV6_MIP6
@@ -444,8 +443,7 @@ looped_back:
 			break;
 		}
 
-		opt->lastopt = skb->h.raw - skb->nh.raw;
-		opt->srcrt = skb->h.raw - skb->nh.raw;
+		opt->lastopt = opt->srcrt = skb->h.raw - skb->nh.raw;
 		skb->h.raw += (hdr->hdrlen + 1) << 3;
 		opt->dst0 = opt->dst1;
 		opt->dst1 = 0;
@@ -745,7 +743,8 @@ int ipv6_parse_hopopts(struct sk_buff **skbp)
 	 * hop-by-hop options.
 	 */
 	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) ||
-	    !pskb_may_pull(skb, sizeof(struct ipv6hdr) + ((skb->h.raw[1] + 1) << 3))) {
+	    !pskb_may_pull(skb, (sizeof(struct ipv6hdr) +
+				 ((skb_transport_header(skb)[1] + 1) << 3)))) {
 		kfree_skb(skb);
 		return -1;
 	}
@@ -753,7 +752,7 @@ int ipv6_parse_hopopts(struct sk_buff **skbp)
 	opt->hop = sizeof(struct ipv6hdr);
 	if (ip6_parse_tlv(tlvprochopopt_lst, skbp)) {
 		skb = *skbp;
-		skb->h.raw += (skb->h.raw[1]+1)<<3;
+		skb->h.raw += (skb_transport_header(skb)[1] + 1) << 3;
 		opt = IP6CB(skb);
 		opt->nhoff = sizeof(struct ipv6hdr);
 		return 1;
diff --git a/net/ipv6/ipcomp6.c b/net/ipv6/ipcomp6.c
index 4a65016..5555c98 100644
--- a/net/ipv6/ipcomp6.c
+++ b/net/ipv6/ipcomp6.c
@@ -143,7 +143,7 @@ static int ipcomp6_output(struct xfrm_state *x, struct sk_buff *skb)
 	/* compression */
 	plen = skb->len - hdr_len;
 	dlen = IPCOMP_SCRATCH_SIZE;
-	start = skb->h.raw;
+	start = skb_transport_header(skb);
 
 	cpu = get_cpu();
 	scratch = *per_cpu_ptr(ipcomp6_scratches, cpu);
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 1f2a3be..c6436f5e 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -1212,7 +1212,7 @@ int igmp6_event_query(struct sk_buff *skb)
 			in6_dev_put(idev);
 			return -EINVAL;
 		}
-		mlh2 = (struct mld2_query *) skb->h.raw;
+		mlh2 = (struct mld2_query *)skb_transport_header(skb);
 		max_delay = (MLDV2_MRC(ntohs(mlh2->mrc))*HZ)/1000;
 		if (!max_delay)
 			max_delay = 1;
@@ -1235,7 +1235,7 @@ int igmp6_event_query(struct sk_buff *skb)
 				in6_dev_put(idev);
 				return -EINVAL;
 			}
-			mlh2 = (struct mld2_query *) skb->h.raw;
+			mlh2 = (struct mld2_query *)skb_transport_header(skb);
 			mark = 1;
 		}
 	} else {
@@ -1460,18 +1460,20 @@ static inline int mld_dev_queue_xmit(struct sk_buff *skb)
 static void mld_sendpack(struct sk_buff *skb)
 {
 	struct ipv6hdr *pip6 = ipv6_hdr(skb);
-	struct mld2_report *pmr = (struct mld2_report *)skb->h.raw;
+	struct mld2_report *pmr =
+			      (struct mld2_report *)skb_transport_header(skb);
 	int payload_len, mldlen;
 	struct inet6_dev *idev = in6_dev_get(skb->dev);
 	int err;
 
 	IP6_INC_STATS(idev, IPSTATS_MIB_OUTREQUESTS);
 	payload_len = skb->tail - skb_network_header(skb) - sizeof(*pip6);
-	mldlen = skb->tail - skb->h.raw;
+	mldlen = skb->tail - skb_transport_header(skb);
 	pip6->payload_len = htons(payload_len);
 
 	pmr->csum = csum_ipv6_magic(&pip6->saddr, &pip6->daddr, mldlen,
-		IPPROTO_ICMPV6, csum_partial(skb->h.raw, mldlen, 0));
+		IPPROTO_ICMPV6, csum_partial(skb_transport_header(skb),
+					     mldlen, 0));
 	err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, skb->dev,
 		mld_dev_queue_xmit);
 	if (!err) {
@@ -1505,7 +1507,7 @@ static struct sk_buff *add_grhead(struct sk_buff *skb, struct ifmcaddr6 *pmc,
 	pgr->grec_auxwords = 0;
 	pgr->grec_nsrcs = 0;
 	pgr->grec_mca = pmc->mca_addr;	/* structure copy */
-	pmr = (struct mld2_report *)skb->h.raw;
+	pmr = (struct mld2_report *)skb_transport_header(skb);
 	pmr->ngrec = htons(ntohs(pmr->ngrec)+1);
 	*ppgr = pgr;
 	return skb;
@@ -1538,7 +1540,7 @@ static struct sk_buff *add_grec(struct sk_buff *skb, struct ifmcaddr6 *pmc,
 	if (!*psf_list)
 		goto empty_source;
 
-	pmr = skb ? (struct mld2_report *)skb->h.raw : NULL;
+	pmr = skb ? (struct mld2_report *)skb_transport_header(skb) : NULL;
 
 	/* EX and TO_EX get a fresh packet, if needed */
 	if (truncate) {
diff --git a/net/ipv6/mip6.c b/net/ipv6/mip6.c
index 8520289..f0288e9 100644
--- a/net/ipv6/mip6.c
+++ b/net/ipv6/mip6.c
@@ -92,10 +92,10 @@ int mip6_mh_filter(struct sock *sk, struct sk_buff *skb)
 
 	if (!pskb_may_pull(skb, (skb_transport_offset(skb)) + 8) ||
 	    !pskb_may_pull(skb, (skb_transport_offset(skb) +
-				 ((skb->h.raw[1] + 1) << 3))))
+				 ((skb_transport_header(skb)[1] + 1) << 3))))
 		return -1;
 
-	mh = (struct ip6_mh *)skb->h.raw;
+	mh = (struct ip6_mh *)skb_transport_header(skb);
 
 	if (mh->ip6mh_hdrlen < mip6_mh_len(mh->ip6mh_type)) {
 		LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH message too short: %d vs >=%d\n",
@@ -158,7 +158,7 @@ static int mip6_destopt_output(struct xfrm_state *x, struct sk_buff *skb)
 	nexthdr = *skb_network_header(skb);
 	*skb_network_header(skb) = IPPROTO_DSTOPTS;
 
-	dstopt = (struct ipv6_destopt_hdr *)skb->h.raw;
+	dstopt = (struct ipv6_destopt_hdr *)skb_transport_header(skb);
 	dstopt->nexthdr = nexthdr;
 
 	hao = mip6_padn((char *)(dstopt + 1),
@@ -370,7 +370,7 @@ static int mip6_rthdr_output(struct xfrm_state *x, struct sk_buff *skb)
 	nexthdr = *skb_network_header(skb);
 	*skb_network_header(skb) = IPPROTO_ROUTING;
 
-	rt2 = (struct rt2_hdr *)skb->h.raw;
+	rt2 = (struct rt2_hdr *)skb_transport_header(skb);
 	rt2->rt_hdr.nexthdr = nexthdr;
 	rt2->rt_hdr.hdrlen = (x->props.header_len >> 3) - 1;
 	rt2->rt_hdr.type = IPV6_SRCRT_TYPE_2;
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 8b946f5..f9a85ab 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -760,7 +760,7 @@ static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
 
 static void ndisc_recv_ns(struct sk_buff *skb)
 {
-	struct nd_msg *msg = (struct nd_msg *)skb->h.raw;
+	struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
 	struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 	struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 	u8 *lladdr = NULL;
@@ -938,7 +938,7 @@ out:
 
 static void ndisc_recv_na(struct sk_buff *skb)
 {
-	struct nd_msg *msg = (struct nd_msg *)skb->h.raw;
+	struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
 	struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 	struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 	u8 *lladdr = NULL;
@@ -1040,7 +1040,7 @@ out:
 
 static void ndisc_recv_rs(struct sk_buff *skb)
 {
-	struct rs_msg *rs_msg = (struct rs_msg *) skb->h.raw;
+	struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
 	unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
 	struct neighbour *neigh;
 	struct inet6_dev *idev;
@@ -1097,7 +1097,7 @@ out:
 
 static void ndisc_router_discovery(struct sk_buff *skb)
 {
-	struct ra_msg *ra_msg = (struct ra_msg *) skb->h.raw;
+	struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
 	struct neighbour *neigh = NULL;
 	struct inet6_dev *in6_dev;
 	struct rt6_info *rt = NULL;
@@ -1108,7 +1108,8 @@ static void ndisc_router_discovery(struct sk_buff *skb)
 
 	__u8 * opt = (__u8 *)(ra_msg + 1);
 
-	optlen = (skb->tail - skb->h.raw) - sizeof(struct ra_msg);
+	optlen = (skb->tail - skb_transport_header(skb)) -
+		  sizeof(struct ra_msg);
 
 	if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
 		ND_PRINTK2(KERN_WARNING
@@ -1357,7 +1358,7 @@ static void ndisc_redirect_rcv(struct sk_buff *skb)
 		return;
 	}
 
-	optlen = skb->tail - skb->h.raw;
+	optlen = skb->tail - skb_transport_header(skb);
 	optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
 
 	if (optlen < 0) {
@@ -1584,9 +1585,9 @@ int ndisc_rcv(struct sk_buff *skb)
 	if (!pskb_may_pull(skb, skb->len))
 		return 0;
 
-	msg = (struct nd_msg *) skb->h.raw;
+	msg = (struct nd_msg *)skb_transport_header(skb);
 
-	__skb_push(skb, skb->data-skb->h.raw);
+	__skb_push(skb, skb->data - skb_transport_header(skb));
 
 	if (ipv6_hdr(skb)->hop_limit != 255) {
 		ND_PRINTK2(KERN_WARNING
diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index bb049f1..116257d 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -1077,7 +1077,7 @@ static int rawv6_ioctl(struct sock *sk, int cmd, unsigned long arg)
 			spin_lock_bh(&sk->sk_receive_queue.lock);
 			skb = skb_peek(&sk->sk_receive_queue);
 			if (skb != NULL)
-				amount = skb->tail - skb->h.raw;
+				amount = skb->tail - skb_transport_header(skb);
 			spin_unlock_bh(&sk->sk_receive_queue.lock);
 			return put_user(amount, (int __user *)arg);
 		}
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index ef29a7b..31d4271 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -726,7 +726,7 @@ static int ipv6_frag_rcv(struct sk_buff **skbp)
 	}
 
 	hdr = ipv6_hdr(skb);
-	fhdr = (struct frag_hdr *)skb->h.raw;
+	fhdr = (struct frag_hdr *)skb_transport_header(skb);
 
 	if (!(fhdr->frag_off & htons(0xFFF9))) {
 		/* It is not a fragmented frame */
diff --git a/net/ipv6/xfrm6_mode_transport.c b/net/ipv6/xfrm6_mode_transport.c
index 0134d74..d526f4e 100644
--- a/net/ipv6/xfrm6_mode_transport.c
+++ b/net/ipv6/xfrm6_mode_transport.c
@@ -51,10 +51,11 @@ static int xfrm6_transport_output(struct xfrm_state *x, struct sk_buff *skb)
  */
 static int xfrm6_transport_input(struct xfrm_state *x, struct sk_buff *skb)
 {
-	int ihl = skb->data - skb->h.raw;
+	int ihl = skb->data - skb_transport_header(skb);
 
 	if (skb->h.raw != skb->nh.raw) {
-		memmove(skb->h.raw, skb_network_header(skb), ihl);
+		memmove(skb_transport_header(skb),
+			skb_network_header(skb), ihl);
 		skb->nh.raw = skb->h.raw;
 	}
 	ipv6_hdr(skb)->payload_len = htons(skb->len + ihl -