]> git.karo-electronics.de Git - karo-tx-linux.git/blobdiff - include/net/sctp/checksum.h
Merge branch 'for-linus' of git://git.kernel.dk/linux-block
[karo-tx-linux.git] / include / net / sctp / checksum.h
index 259924d63ba6a6f0ab71f52ed0f9e7a62c6bfe1b..6bd44fe94c26382e1130b9b989d1ed6efb68b349 100644 (file)
 #include <linux/types.h>
 #include <net/sctp/sctp.h>
 #include <linux/crc32c.h>
+#include <linux/crc32.h>
 
-static inline __u32 sctp_crc32c(__u32 crc, u8 *buffer, u16 length)
+static inline __wsum sctp_csum_update(const void *buff, int len, __wsum sum)
 {
-       return crc32c(crc, buffer, length);
-}
-
-static inline __u32 sctp_start_cksum(__u8 *buffer, __u16 length)
-{
-       __u32 crc = ~(__u32)0;
-       __u8  zero[sizeof(__u32)] = {0};
-
-       /* Optimize this routine to be SCTP specific, knowing how
-        * to skip the checksum field of the SCTP header.
+       /* This uses the crypto implementation of crc32c, which is either
+        * implemented w/ hardware support or resolves to __crc32c_le().
         */
-
-       /* Calculate CRC up to the checksum. */
-       crc = sctp_crc32c(crc, buffer, sizeof(struct sctphdr) - sizeof(__u32));
-
-       /* Skip checksum field of the header. */
-       crc = sctp_crc32c(crc, zero, sizeof(__u32));
-
-       /* Calculate the rest of the CRC. */
-       crc = sctp_crc32c(crc, &buffer[sizeof(struct sctphdr)],
-                           length - sizeof(struct sctphdr));
-       return crc;
-}
-
-static inline __u32 sctp_update_cksum(__u8 *buffer, __u16 length, __u32 crc32)
-{
-       return sctp_crc32c(crc32, buffer, length);
+       return crc32c(sum, buff, len);
 }
 
-static inline __le32 sctp_end_cksum(__u32 crc32)
+static inline __wsum sctp_csum_combine(__wsum csum, __wsum csum2,
+                                      int offset, int len)
 {
-       return cpu_to_le32(~crc32);
+       return __crc32c_le_combine(csum, csum2, len);
 }
 
-/* Calculate the CRC32C checksum of an SCTP packet.  */
 static inline __le32 sctp_compute_cksum(const struct sk_buff *skb,
                                        unsigned int offset)
 {
-       const struct sk_buff *iter;
+       struct sctphdr *sh = sctp_hdr(skb);
+        __le32 ret, old = sh->checksum;
+       const struct skb_checksum_ops ops = {
+               .update  = sctp_csum_update,
+               .combine = sctp_csum_combine,
+       };
 
-       __u32 crc32 = sctp_start_cksum(skb->data + offset,
-                                      skb_headlen(skb) - offset);
-       skb_walk_frags(skb, iter)
-               crc32 = sctp_update_cksum((__u8 *) iter->data,
-                                         skb_headlen(iter), crc32);
+       sh->checksum = 0;
+       ret = cpu_to_le32(~__skb_checksum(skb, offset, skb->len - offset,
+                                         ~(__u32)0, &ops));
+       sh->checksum = old;
 
-       return sctp_end_cksum(crc32);
+       return ret;
 }
 
 #endif /* __sctp_checksum_h__ */