man ip-tunnel ttl section says: 0 is a special value meaning that packets inherit the TTL value.
IPv4 tunnel respect this in ip_tunnel_xmit(), but IPv6 tunnel has not implement it yet. To make IPv6 behave consistently with IP tunnel, add ipv6 tunnel inherit support. Signed-off-by: Hangbin Liu <liuhang...@gmail.com> --- net/ipv6/ip6_tunnel.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index 5df2a58..419960b 100644 --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -1188,7 +1188,15 @@ int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield, init_tel_txopt(&opt, encap_limit); ipv6_push_frag_opts(skb, &opt.ops, &proto); } - hop_limit = hop_limit ? : ip6_dst_hoplimit(dst); + + if (hop_limit == 0) { + if (skb->protocol == htons(ETH_P_IP)) + hop_limit = ip_hdr(skb)->ttl; + else if (skb->protocol == htons(ETH_P_IPV6)) + hop_limit = ipv6_hdr(skb)->hop_limit; + else + hop_limit = ip6_dst_hoplimit(dst); + } /* Calculate max headroom for all the headers and adjust * needed_headroom if necessary. -- 2.5.5