[PATCH 3.5 55/64] sctp: Use software crc32 checksum when xfrm transform will happen.

From: Luis Henriques
Date: Mon Oct 28 2013 - 10:52:48 EST -stable review patch. If anyone has any objections, please let me know.


From: Fan Du <fan.du@xxxxxxxxxxxxx>

commit 27127a82561a2a3ed955ce207048e1b066a80a2a upstream.

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@xxxxxxxxxxxxx>
Cc: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Signed-off-by: Fan Du <fan.du@xxxxxxxxxxxxx>
Signed-off-by: Vlad Yasevich <vyasevich@xxxxxxxxx>
Acked-by: Neil Horman <nhorman@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
net/sctp/output.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/sctp/output.c b/net/sctp/output.c
index 83dddb9..a80b310 100644
--- a/net/sctp/output.c
+++ b/net/sctp/output.c
@@ -523,7 +523,8 @@ 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

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