Message ID | 20170426183745.194717-1-kraigatgoog@gmail.com |
---|---|
State | Accepted, archived |
Delegated to: | David Miller |
Headers | show |
From: Craig Gallek <kraigatgoog@gmail.com> Date: Wed, 26 Apr 2017 14:37:45 -0400 > From: Craig Gallek <cgallek@google.com> > > 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 <kraig@google.com> > --- > > v2: Change tunnel code to use dst1opt rather than making the checks for > dst0opt more permissive. Thanks for the detailed analysis in the commit message, this made reviewing your patch a lot easier. Applied, thank you.
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index ad15d38b41e8..c81f9541f1f7 100644 --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -954,7 +954,7 @@ static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit) 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; } @@ -1176,7 +1176,7 @@ int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield, if (encap_limit >= 0) { init_tel_txopt(&opt, encap_limit); - ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL, NULL); + ipv6_push_frag_opts(skb, &opt.ops, &proto); } /* Calculate max headroom for all the headers and adjust