sctp: Use software crc32 checksum when xfrm transform will happen.

[ Upstream commit 27127a82561a2a3ed955ce207048e1b066a80a2a ]

igb/ixgbe have hardware sctp checksum support, when this feature is enabled
and also IPsec is armed to protect sctp traffic, ugly things happened as
xfrm_output checks CHECKSUM_PARTIAL to do checksum operation(sum every thing
up and pack the 16bits result in the checksum field). The result is fail
establishment of sctp communication.

Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/sctp/output.c b/net/sctp/output.c
index 32ba8d0..d957fe1 100644 (file)
--- a/net/sctp/output.c
+++ b/net/sctp/output.c
@@ -518,7 +518,8 @@ int sctp_packet_transmit(struct sctp_packet *packet)
         * by CRC32-C as described in <draft-ietf-tsvwg-sctpcsum-02.txt>.
         */
        if (!sctp_checksum_disable) {
-               if (!(dst->dev->features & NETIF_F_SCTP_CSUM)) {
+               if (!(dst->dev->features & NETIF_F_SCTP_CSUM) ||
+                   (dst_xfrm(dst) != NULL)) {
                        __u32 crc32 = sctp_start_cksum((__u8 *)sh, cksum_buf_len);
 
                        /* 3) Put the resultant value into the checksum field in the