Commit 3789caba authored Aug 06, 2018 by Shmulik Ladkani Committed by David S. Miller Aug 07, 2018

ip6_tunnel: collect_md xmit: Use ip_tunnel_key's provided src address



When using an ip6tnl device in collect_md mode, the xmit methods ignore
the ipv6.src field present in skb_tunnel_info's key, both for route
calculation purposes (flowi6 construction) and for assigning the
packet's final ipv6h->saddr.

This makes it impossible specifying a desired ipv6 local address in the
encapsulating header (for example, when using tc action tunnel_key).

This is also not aligned with behavior of ipip (ipv4) in collect_md
mode, where the key->u.ipv4.src gets used.

Fix, by assigning fl6.saddr with given key->u.ipv6.src.
In case ipv6.src is not specified, ip6_tnl_xmit uses existing saddr
selection code.

Fixes: 8d79266b ("ip6_tunnel: add collect_md mode to IPv6 tunnels")
Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Reviewed-by: Eyal Birger <eyal.birger@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 9ca61630

net/ipv6/ip6_tunnel.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -1113,7 +1113,7 @@ route_lookup:
		dst = NULL;
		goto tx_err_link_failure;
		}
		if (t->parms.collect_md &&
		if (t->parms.collect_md && ipv6_addr_any(&fl6->saddr) &&
		ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
		&fl6->daddr, 0, &fl6->saddr))
		goto tx_err_link_failure;
		@@ -1255,6 +1255,7 @@ ip4ip6_tnl_xmit(struct sk_buff skb, struct net_device dev)
		key = &tun_info->key;
		memset(&fl6, 0, sizeof(fl6));
		fl6.flowi6_proto = IPPROTO_IPIP;
		fl6.saddr = key->u.ipv6.src;
		fl6.daddr = key->u.ipv6.dst;
		fl6.flowlabel = key->label;
		dsfield = key->tos;
		@@ -1326,6 +1327,7 @@ ip6ip6_tnl_xmit(struct sk_buff skb, struct net_device dev)
		key = &tun_info->key;
		memset(&fl6, 0, sizeof(fl6));
		fl6.flowi6_proto = IPPROTO_IPV6;
		fl6.saddr = key->u.ipv6.src;
		fl6.daddr = key->u.ipv6.dst;
		fl6.flowlabel = key->label;
		dsfield = key->tos;

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