OpenE2K
/
linux
6
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

ip6_tunnel: Fix encapsulation layout 

Commit 058214a4d1 ("ip6_tun: Add infrastructure for doing
encapsulation") added the ip6_tnl_encap() call in ip6_tnl_xmit(), before
the call to ipv6_push_frag_opts() to append the IPv6 Tunnel Encapsulation
Limit option (option 4, RFC 2473, par. 5.1) to the outer IPv6 header.

As long as the option didn't actually end up in generated packets, this
wasn't an issue. Then commit 89a23c8b52 ("ip6_tunnel: Fix missing tunnel
encapsulation limit option") fixed sending of this option, and the
resulting layout, e.g. for FoU, is:

.-------------------.------------.----------.-------------------.----- - -
| Outer IPv6 Header | UDP header | Option 4 | Inner IPv6 Header | Payload
'-------------------'------------'----------'-------------------'----- - -

Needless to say, FoU and GUE (at least) won't work over IPv6. The option
is appended by default, and I couldn't find a way to disable it with the
current iproute2.

Turn this into a more reasonable:

.-------------------.----------.------------.-------------------.----- - -
| Outer IPv6 Header | Option 4 | UDP header | Inner IPv6 Header | Payload
'-------------------'----------'------------'-------------------'----- - -

With this, and with 84dad55951 ("udp6: fix encap return code for
resubmitting"), FoU and GUE work again over IPv6.

Fixes: 058214a4d1 ("ip6_tun: Add infrastructure for doing encapsulation")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Stefano Brivio 2018-10-18 21:25:07 +02:00 committed by David S. Miller
parent b06f9d9f1a
commit d4d576f5ab
1 changed files with 5 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
net/ipv6/ip6_tunnel.c
View File

@ -1184,11 +1184,6 @@ route_lookup:
}
skb_dst_set(skb, dst);
if (encap_limit >= 0) {
init_tel_txopt(&opt, encap_limit);
ipv6_push_frag_opts(skb, &opt.ops, &proto);
}
if (hop_limit == 0) {
if (skb->protocol == htons(ETH_P_IP))
hop_limit = ip_hdr(skb)->ttl;
@ -1210,6 +1205,11 @@ route_lookup:
if (err)
return err;
if (encap_limit >= 0) {
init_tel_txopt(&opt, encap_limit);
ipv6_push_frag_opts(skb, &opt.ops, &proto);
}
skb_push(skb, sizeof(struct ipv6hdr));
skb_reset_network_header(skb);
ipv6h = ipv6_hdr(skb);