Commit 8c0aa3f6 authored Feb 26, 2019 by David Ahern Committed by Greg Kroah-Hartman Mar 10, 2019

ipv4: Return error for RTA_VIA attribute



[ Upstream commit b6e9e5df4ecf100f6a10ab2ade8e46d47a4b9779 ]

IPv4 currently does not support nexthops outside of the AF_INET family.
Specifically, it does not handle RTA_VIA attribute. If it is passed
in a route add request, the actual route added only uses the device
which is clearly not what the user intended:

  $ ip ro add 172.16.1.0/24 via inet6 2001:db8:1::1 dev eth0
  $ ip ro ls
  ...
  172.16.1.0/24 dev eth0

Catch this and fail the route add:
  $ ip ro add 172.16.1.0/24 via inet6 2001:db8:1::1 dev eth0
  Error: IPv4 does not support RTA_VIA attribute.

Fixes: 03c05665 ("mpls: Netlink commands to add, remove, and dump routes")
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 125bc1e6

net/ipv4/fib_frontend.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -700,6 +700,10 @@ static int rtm_to_fib_config(struct net net, struct sk_buff skb,
		case RTA_GATEWAY:
		cfg->fc_gw = nla_get_be32(attr);
		break;
		case RTA_VIA:
		NL_SET_ERR_MSG(extack, "IPv4 does not support RTA_VIA attribute");
		err = -EINVAL;
		goto errout;
		case RTA_PRIORITY:
		cfg->fc_priority = nla_get_u32(attr);
		break;