From 89a23c8b528bd2c89f3981573d6cd7d23840c8a6 Mon Sep 17 00:00:00 2001 From: Craig Gallek Date: Wed, 26 Apr 2017 14:37:45 -0400 Subject: [PATCH] ip6_tunnel: Fix missing tunnel encapsulation limit option 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 --- 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 @@ -966,7 +966,7 @@ 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; } @@ -1208,7 +1208,7 @@ route_lookup: 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); } skb_push(skb, sizeof(struct ipv6hdr));