[SCTP]: Introduce sctp_hdr()

For consistency with all the other skb->h.raw accessors.

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

4 files changed, 20 insertions, 17 deletions

diff --git a/include/linux/sctp.h b/include/linux/sctp.h
index d4f86560bfff..d76767dfe59e 100644
--- a/include/linux/sctp.h
+++ b/include/linux/sctp.h
@@ -63,6 +63,15 @@ typedef struct sctphdr {
         __be32 checksum;
 } __attribute__((packed)) sctp_sctphdr_t;
 
+#ifdef __KERNEL__
+#include <linux/skbuff.h>
+
+static inline struct sctphdr *sctp_hdr(const struct sk_buff *skb)
+{
+        return (struct sctphdr *)skb->h.raw;
+}
+#endif
+
 /* Section 3.2.  Chunk Field Descriptions. */
 typedef struct sctp_chunkhdr {
         __u8 type;
diff --git a/net/sctp/input.c b/net/sctp/input.c
index 9311b5ddf5c0..3a322c584c74 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -79,14 +79,10 @@ static void sctp_add_backlog(struct sock *sk, struct sk_buff *skb);
 /* Calculate the SCTP checksum of an SCTP packet.  */
 static inline int sctp_rcv_checksum(struct sk_buff *skb)
 {
-        struct sctphdr *sh;
-        __u32 cmp, val;
         struct sk_buff *list = skb_shinfo(skb)->frag_list;
-
-        sh = (struct sctphdr *) skb->h.raw;
-        cmp = ntohl(sh->checksum);
-
-        val = sctp_start_cksum((__u8 *)sh, skb_headlen(skb));
+        struct sctphdr *sh = sctp_hdr(skb);
+        __u32 cmp = ntohl(sh->checksum);
+        __u32 val = sctp_start_cksum((__u8 *)sh, skb_headlen(skb));
 
         for (; list; list = list->next)
                 val = sctp_update_cksum((__u8 *)list->data, skb_headlen(list),
@@ -138,7 +134,7 @@ int sctp_rcv(struct sk_buff *skb)
         if (skb_linearize(skb))
                 goto discard_it;
 
-        sh = (struct sctphdr *) skb->h.raw;
+        sh = sctp_hdr(skb);
 
         /* Pull up the IP and SCTP headers. */
         __skb_pull(skb, skb_transport_offset(skb));
@@ -905,7 +901,7 @@ static struct sctp_association *__sctp_rcv_init_lookup(struct sk_buff *skb,
         struct sctp_association *asoc;
         union sctp_addr addr;
         union sctp_addr *paddr = &addr;
-        struct sctphdr *sh = (struct sctphdr *) skb->h.raw;
+        struct sctphdr *sh = sctp_hdr(skb);
         sctp_chunkhdr_t *ch;
         union sctp_params params;
         sctp_init_chunk_t *init;
diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
index 001be2de0b3c..0992bc5bb528 100644
--- a/net/sctp/ipv6.c
+++ b/net/sctp/ipv6.c
@@ -390,7 +390,7 @@ static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
         addr->v6.sin6_flowinfo = 0; /* FIXME */
         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 
-        sh = (struct sctphdr *) skb->h.raw;
+        sh = sctp_hdr(skb);
         if (is_saddr) {
                 *port  = sh->source;
                 from = &ipv6_hdr(skb)->saddr;
@@ -765,7 +765,7 @@ static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
         if (msgname) {
                 sctp_inet6_msgname(msgname, addr_len);
                 sin6 = (struct sockaddr_in6 *)msgname;
-                sh = (struct sctphdr *)skb->h.raw;
+                sh = sctp_hdr(skb);
                 sin6->sin6_port = sh->source;
 
                 /* Map ipv4 address into v4-mapped-on-v6 address. */
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 08f92ba4ebd7..7c28c9b959e2 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -235,7 +235,7 @@ static void sctp_v4_from_skb(union sctp_addr *addr, struct sk_buff *skb,
         port = &addr->v4.sin_port;
         addr->v4.sin_family = AF_INET;
 
-        sh = (struct sctphdr *) skb->h.raw;
+        sh = sctp_hdr(skb);
         if (is_saddr) {
                 *port  = sh->source;
                 from = &ip_hdr(skb)->saddr;
@@ -731,13 +731,11 @@ static void sctp_inet_event_msgname(struct sctp_ulpevent *event, char *msgname,
 /* Initialize and copy out a msgname from an inbound skb. */
 static void sctp_inet_skb_msgname(struct sk_buff *skb, char *msgname, int *len)
 {
-        struct sctphdr *sh;
-        struct sockaddr_in *sin;
-
         if (msgname) {
+                struct sctphdr *sh = sctp_hdr(skb);
+                struct sockaddr_in *sin = (struct sockaddr_in *)msgname;
+
                 sctp_inet_msgname(msgname, len);
-                sin = (struct sockaddr_in *)msgname;
-                sh = (struct sctphdr *)skb->h.raw;
                 sin->sin_port = sh->source;
                 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
         }