From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Ahern Subject: [PATCH net] net/ipv6: onlink nexthop checks should default to main table Date: Tue, 6 Feb 2018 13:17:06 -0800 Message-ID: <20180206211706.20315-1-dsahern@gmail.com> Cc: davem@davemloft.net, David Ahern To: netdev@vger.kernel.org Return-path: Received: from mail-pl0-f68.google.com ([209.85.160.68]:37488 "EHLO mail-pl0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751632AbeBFVRM (ORCPT ); Tue, 6 Feb 2018 16:17:12 -0500 Received: by mail-pl0-f68.google.com with SMTP id ay8so2052987plb.4 for ; Tue, 06 Feb 2018 13:17:12 -0800 (PST) Sender: netdev-owner@vger.kernel.org List-ID: Because of differences in how ipv4 and ipv6 handle fib lookups, verification of nexthops with onlink flag need to default to the main table rather than the local table used by IPv4. As it stands an address within a connected route on device 1 can be used with onlink on device 2. Updating the table properly rejects the route due to the egress device mismatch. Update the extack message as well to show it could be a device mismatch for the nexthop spec. Fixes: fc1e64e1092f ("net/ipv6: Add support for onlink flag") Signed-off-by: David Ahern --- net/ipv6/route.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 69c43d289c69..9dcfadddd800 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -2479,7 +2479,7 @@ static int ip6_route_check_nh_onlink(struct net *net, struct net_device *dev, struct netlink_ext_ack *extack) { - u32 tbid = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL; + u32 tbid = l3mdev_fib_table(dev) ? : RT_TABLE_MAIN; const struct in6_addr *gw_addr = &cfg->fc_gateway; u32 flags = RTF_LOCAL | RTF_ANYCAST | RTF_REJECT; struct rt6_info *grt; @@ -2490,7 +2490,8 @@ static int ip6_route_check_nh_onlink(struct net *net, if (grt) { if (!grt->dst.error && (grt->rt6i_flags & flags || dev != grt->dst.dev)) { - NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway"); + NL_SET_ERR_MSG(extack, + "Nexthop has invalid gateway or device mismatch"); err = -EINVAL; } -- 2.11.0