From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Herbert Subject: [PATCH v5 net-next 04/14] ipv6: Change "final" protocol processing for encapsulation Date: Sun, 15 May 2016 16:42:25 -0700 Message-ID: <1463355755-3481375-5-git-send-email-tom@herbertland.com> References: <1463355755-3481375-1-git-send-email-tom@herbertland.com> Mime-Version: 1.0 Content-Type: text/plain Cc: To: , Return-path: Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:63566 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752202AbcEOXmv (ORCPT ); Sun, 15 May 2016 19:42:51 -0400 Received: from pps.filterd (m0044010.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.11/8.16.0.11) with SMTP id u4FNfreS020628 for ; Sun, 15 May 2016 16:42:51 -0700 Received: from mail.thefacebook.com ([199.201.64.23]) by mx0a-00082601.pphosted.com with ESMTP id 22wyb3mw59-1 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT) for ; Sun, 15 May 2016 16:42:51 -0700 Received: from devbig284.prn2.facebook.com (10.35.15.32) by mx-out.facebook.com (10.223.101.97) with ESMTP id bbeb8bd81af611e6a12624be0595f910-d34ebc50 for ; Sun, 15 May 2016 16:42:50 -0700 In-Reply-To: <1463355755-3481375-1-git-send-email-tom@herbertland.com> Sender: netdev-owner@vger.kernel.org List-ID: When performing foo-over-UDP, UDP packets are processed by the encapsulation handler which returns another protocol to process. This may result in processing two (or more) protocols in the loop that are marked as INET6_PROTO_FINAL. The actions taken for hitting a final protocol, in particular the skb_postpull_rcsum can only be performed once. This patch set adds a check of a final protocol has been seen. The rules are: - If the final protocol has not been seen any protocol is processed (final and non-final). In the case of a final protocol, the final actions are taken (like the skb_postpull_rcsum) - If a final protocol has been seen (e.g. an encapsulating UDP header) then no further non-final protocols are allowed (e.g. extension headers). For more final protocols the final actions are not taken (e.g. skb_postpull_rcsum). Signed-off-by: Tom Herbert --- net/ipv6/ip6_input.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c index d35dff2..94611e4 100644 --- a/net/ipv6/ip6_input.c +++ b/net/ipv6/ip6_input.c @@ -223,6 +223,7 @@ static int ip6_input_finish(struct net *net, struct sock *sk, struct sk_buff *sk unsigned int nhoff; int nexthdr; bool raw; + bool have_final = false; /* * Parse extension headers @@ -242,9 +243,21 @@ resubmit_final: if (ipprot) { int ret; - if (ipprot->flags & INET6_PROTO_FINAL) { + if (have_final) { + if (!(ipprot->flags & INET6_PROTO_FINAL)) { + /* Once we've seen a final protocol don't + * allow encapsulation on any non-final + * ones. This allows foo in UDP encapsulation + * to work. + */ + goto discard; + } + } else if (ipprot->flags & INET6_PROTO_FINAL) { const struct ipv6hdr *hdr; + /* Only do this once for first final protocol */ + have_final = true; + /* Free reference early: we don't need it any more, and it may hold ip_conntrack module loaded indefinitely. */ -- 2.8.0.rc2