sctp: Clean up sctp checksumming code

The sctp crc32c checksum is always generated in little endian.
So, we clean up the code to treat it as little endian and remove
all the __force casts.

Suggested by Herbert Xu.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 12 insertions, 13 deletions

diff --git a/net/sctp/input.c b/net/sctp/input.c
index 693fd0804810..d2e98803ffe3 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -83,14 +83,15 @@ static inline int sctp_rcv_checksum(struct sk_buff *skb)
 {
         struct sk_buff *list = skb_shinfo(skb)->frag_list;
         struct sctphdr *sh = sctp_hdr(skb);
-        __be32 cmp = sh->checksum;
-        __be32 val = sctp_start_cksum((__u8 *)sh, skb_headlen(skb));
+        __le32 cmp = sh->checksum;
+        __le32 val;
+        __u32 tmp = sctp_start_cksum((__u8 *)sh, skb_headlen(skb));
 
         for (; list; list = list->next)
-                val = sctp_update_cksum((__u8 *)list->data, skb_headlen(list),
-                                        val);
+                tmp = sctp_update_cksum((__u8 *)list->data, skb_headlen(list),
+                                        tmp);
 
-        val = sctp_end_cksum(val);
+        val = sctp_end_cksum(tmp);
 
         if (val != cmp) {
                 /* CRC failure, dump it. */
diff --git a/net/sctp/output.c b/net/sctp/output.c
index 2d65b7a7330b..07d58903a746 100644
--- a/net/sctp/output.c
+++ b/net/sctp/output.c
@@ -367,7 +367,6 @@ int sctp_packet_transmit(struct sctp_packet *packet)
         struct sctp_transport *tp = packet->transport;
         struct sctp_association *asoc = tp->asoc;
         struct sctphdr *sh;
-        __be32 crc32 = cpu_to_be32(0);
         struct sk_buff *nskb;
         struct sctp_chunk *chunk, *tmp;
         struct sock *sk;
@@ -532,16 +531,15 @@ int sctp_packet_transmit(struct sctp_packet *packet)
          * by CRC32-C as described in <draft-ietf-tsvwg-sctpcsum-02.txt>.
          */
         if (!sctp_checksum_disable && !(dst->dev->features & NETIF_F_NO_CSUM)) {
-                crc32 = sctp_start_cksum((__u8 *)sh, cksum_buf_len);
-                crc32 = sctp_end_cksum(crc32);
+                __u32 crc32 = sctp_start_cksum((__u8 *)sh, cksum_buf_len);
+
+                /* 3) Put the resultant value into the checksum field in the
+                 *    common header, and leave the rest of the bits unchanged.
+                 */
+                sh->checksum = sctp_end_cksum(crc32);
         } else
                 nskb->ip_summed = CHECKSUM_UNNECESSARY;
 
-        /* 3) Put the resultant value into the checksum field in the
-         *    common header, and leave the rest of the bits unchanged.
-         */
-        sh->checksum = crc32;
-
         /* IP layer ECN support
          * From RFC 2481
          *  "The ECN-Capable Transport (ECT) bit would be set by the