Commit a9b28c2b authored Aug 01, 2017 by Yossi Kuperman Committed by Steffen Klassert Aug 02, 2017

esp6: Fix RX checksum after header pull



Both ip6_input_finish (non-GRO) and esp6_gro_receive (GRO) strip
the IPv6 header without adjusting skb->csum accordingly. As a
result CHECKSUM_COMPLETE breaks and "hw csum failure" is written
to the kernel log by netdev_rx_csum_fault (dev.c).

Fix skb->csum by substracting the checksum value of the pulled IPv6
header using a call to skb_postpull_rcsum.

This affects both transport and tunnel modes.

Note that the fix occurs far from the place that the header was
pulled. This is based on existing code, see:
ipv6_srh_rcv() in exthdrs.c and rawv6_rcv() in raw.c

Signed-off-by: Yossi Kuperman <yossiku@mellanox.com>
Signed-off-by: Ilan Tayari <ilant@mellanox.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

parent e9cba694

net/ipv6/esp6.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -495,6 +495,8 @@ int esp6_input_done2(struct sk_buff *skb, int err)

		trimlen = alen + padlen + 2;
		if (skb->ip_summed == CHECKSUM_COMPLETE) {
		skb_postpull_rcsum(skb, skb_network_header(skb),
		skb_network_header_len(skb));
		csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0);
		skb->csum = csum_block_sub(skb->csum, csumdiff,
		skb->len - trimlen);

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