From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steffen Klassert Subject: [PATCH 3/8] xfrm6: Fix CHECKSUM_COMPLETE after IPv6 header push Date: Mon, 21 Aug 2017 07:49:28 +0200 Message-ID: <1503294573-10206-4-git-send-email-steffen.klassert@secunet.com> References: <1503294573-10206-1-git-send-email-steffen.klassert@secunet.com> Mime-Version: 1.0 Content-Type: text/plain Cc: Herbert Xu , Steffen Klassert , To: David Miller Return-path: Received: from a.mx.secunet.com ([62.96.220.36]:34906 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751081AbdHUFtm (ORCPT ); Mon, 21 Aug 2017 01:49:42 -0400 In-Reply-To: <1503294573-10206-1-git-send-email-steffen.klassert@secunet.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Yossi Kuperman xfrm6_transport_finish rebuilds the IPv6 header based on the original one and pushes it back without fixing skb->csum. Therefore, CHECKSUM_COMPLETE is no longer valid and the packet gets dropped. Fix skb->csum by calling skb_postpush_rcsum. Note: A valid IPv4 header has checksum 0, unlike IPv6. Thus, the change is not needed in the sibling xfrm4_transport_finish function. Signed-off-by: Yossi Kuperman Signed-off-by: Ilan Tayari Signed-off-by: Steffen Klassert --- net/ipv6/xfrm6_input.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/ipv6/xfrm6_input.c b/net/ipv6/xfrm6_input.c index 3ef5d91..f95943a 100644 --- a/net/ipv6/xfrm6_input.c +++ b/net/ipv6/xfrm6_input.c @@ -34,6 +34,7 @@ EXPORT_SYMBOL(xfrm6_rcv_spi); int xfrm6_transport_finish(struct sk_buff *skb, int async) { struct xfrm_offload *xo = xfrm_offload(skb); + int nhlen = skb->data - skb_network_header(skb); skb_network_header(skb)[IP6CB(skb)->nhoff] = XFRM_MODE_SKB_CB(skb)->protocol; @@ -43,8 +44,9 @@ int xfrm6_transport_finish(struct sk_buff *skb, int async) return 1; #endif - __skb_push(skb, skb->data - skb_network_header(skb)); + __skb_push(skb, nhlen); ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); + skb_postpush_rcsum(skb, skb_network_header(skb), nhlen); if (xo && (xo->flags & XFRM_GRO)) { skb_mac_header_rebuild(skb); -- 2.7.4