From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ashwanth Goli Subject: [PATCH] [PATCH net v3] ipv6: remove min MTU check for ipsec tunnels Date: Thu, 10 May 2018 23:15:44 +0530 Message-ID: <1525974344-2112-1-git-send-email-ashwanth@codeaurora.org> Cc: pabeni@redhat.com, dsahern@gmail.com, eric.dumazet@gmail.com To: netdev@vger.kernel.org, davem@davemloft.net Return-path: Received: from smtp.codeaurora.org ([198.145.29.96]:58852 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966662AbeEJRpt (ORCPT ); Thu, 10 May 2018 13:45:49 -0400 Sender: netdev-owner@vger.kernel.org List-ID: With 749439bfac "fix udpv6 sendmsg crash caused by too small MTU" ipsec tunnels that report a MTU less than IPV6_MIN_MTU are broken even for packets that are smaller than IPV6_MIN_MTU. According to rfc2473#section-7.1 if the original IPv6 packet is equal or smaller than the IPv6 minimum link MTU, the tunnel entry-point node encapsulates the original packet, and subsequently fragments the resulting IPv6 tunnel packet into IPv6 fragments that do not exceed the Path MTU to the tunnel exit-point. Dropping the MTU check for ipsec tunnel destinations. Signed-off-by: Ashwanth Goli --- net/ipv6/ip6_output.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 2e891d2..ea1ef1b 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -1235,7 +1235,7 @@ static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork, if (np->frag_size) mtu = np->frag_size; } - if (mtu < IPV6_MIN_MTU) + if (mtu < IPV6_MIN_MTU && !(rt->dst.flags & DST_XFRM_TUNNEL)) return -EINVAL; cork->base.fragsize = mtu; if (dst_allfrag(xfrm_dst_path(&rt->dst))) -- 1.9.1