[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 e5ee981d3e10..d2af4fe3725b 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 ad522b7b5771..436eb9e6a6cf 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 1bda0299890e..f25ee773f52e 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 4a6501695e98..5555c98dea03 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 1f2a3be9308a..c6436f5e3e9f 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 85202891644e..f0288e92fb52 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 8b946f56287a..f9a85ab594db 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 bb049f1c2679..116257d59a36 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 ef29a7bb97ce..31d4271ea540 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 0134d74ef087..d526f4e9c65e 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 -