Commit d2dbbba7 authored Oct 15, 2013 by Vlad Yasevich Committed by David S. Miller Oct 17, 2013

sctp: Perform software checksum if packet has to be fragmented.



IP/IPv6 fragmentation knows how to compute only TCP/UDP checksum.
This causes problems if SCTP packets has to be fragmented and
ipsummed has been set to PARTIAL due to checksum offload support.
This condition can happen when retransmitting after MTU discover,
or when INIT or other control chunks are larger then MTU.
Check for the rare fragmentation condition in SCTP and use software
checksum calculation in this case.

CC: 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>

parent 27127a82

net/sctp/output.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -537,7 +537,7 @@ int sctp_packet_transmit(struct sctp_packet *packet)
	*/		*/
	if (!sctp_checksum_disable) {		if (!sctp_checksum_disable) {
	if (!(dst->dev->features & NETIF_F_SCTP_CSUM) \|\|		if (!(dst->dev->features & NETIF_F_SCTP_CSUM) \|\|
	(dst_xfrm(dst) != NULL)) {		(dst_xfrm(dst) != NULL) \|\| packet->ipfragok) {
	__u32 crc32 = sctp_start_cksum((__u8 *)sh, cksum_buf_len);		__u32 crc32 = sctp_start_cksum((__u8 *)sh, cksum_buf_len);

	/* 3) Put the resultant value into the checksum field in the		/* 3) Put the resultant value into the checksum field in the