Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752943AbdHRN3S (ORCPT ); Fri, 18 Aug 2017 09:29:18 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:55590 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752848AbdHRNPv (ORCPT ); Fri, 18 Aug 2017 09:15:51 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Craig Gallek" , "Craig Gallek" , "David S. Miller" Date: Fri, 18 Aug 2017 14:13:20 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 099/134] ip6_tunnel: Fix missing tunnel encapsulation limit option In-Reply-To: X-SA-Exim-Connect-IP: 82.70.136.246 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2141 Lines: 55 3.16.47-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Craig Gallek commit 89a23c8b528bd2c89f3981573d6cd7d23840c8a6 upstream. The IPv6 tunneling code tries to insert IPV6_TLV_TNL_ENCAP_LIMIT and IPV6_TLV_PADN options when an encapsulation limit is defined (the default is a limit of 4). An MTU adjustment is done to account for these options as well. However, the options are never present in the generated packets. The issue appears to be a subtlety between IPV6_DSTOPTS and IPV6_RTHDRDSTOPTS defined in RFC 3542. When the IPIP tunnel driver was written, the encap limit options were included as IPV6_RTHDRDSTOPTS in dst0opt of struct ipv6_txoptions. Later, ipv6_push_nfrags_opts was (correctly) updated to require IPV6_RTHDR options when IPV6_RTHDRDSTOPTS are to be used. This caused the options to no longer be included in v6 encapsulated packets. The fix is to use IPV6_DSTOPTS (in dst1opt of struct ipv6_txoptions) instead. IPV6_DSTOPTS do not have the additional IPV6_RTHDR requirement. Fixes: 1df64a8569c7: ("[IPV6]: Add ip6ip6 tunnel driver.") Fixes: 333fad5364d6: ("[IPV6]: Support several new sockopt / ancillary data in Advanced API (RFC3542)") Signed-off-by: Craig Gallek Signed-off-by: David S. Miller [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- net/ipv6/ip6_tunnel.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -883,7 +883,7 @@ static void init_tel_txopt(struct ipv6_t opt->dst_opt[5] = IPV6_TLV_PADN; opt->dst_opt[6] = 1; - opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt; + opt->ops.dst1opt = (struct ipv6_opt_hdr *) opt->dst_opt; opt->ops.opt_nflen = 8; } @@ -1051,7 +1051,7 @@ static int ip6_tnl_xmit2(struct sk_buff proto = fl6->flowi6_proto; if (encap_limit >= 0) { init_tel_txopt(&opt, encap_limit); - ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL); + ipv6_push_frag_opts(skb, &opt.ops, &proto); } if (likely(!skb->encapsulation)) {