From d55a2e374a94fa34a3048c6a2be535266e506d97 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Maciej=20=C5=BBenczykowski?= Date: Mon, 2 Sep 2019 09:23:36 -0700 Subject: [PATCH] net-ipv6: fix excessive RTF_ADDRCONF flag on ::1/128 local route (and others) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit There is a subtle change in behaviour introduced by: commit c7a1ce397adacaf5d4bb2eab0a738b5f80dc3e43 'ipv6: Change addrconf_f6i_alloc to use ip6_route_info_create' Before that patch /proc/net/ipv6_route includes: 00000000000000000000000000000001 80 00000000000000000000000000000000 00 00000000000000000000000000000000 00000000 00000003 00000000 80200001 lo Afterwards /proc/net/ipv6_route includes: 00000000000000000000000000000001 80 00000000000000000000000000000000 00 00000000000000000000000000000000 00000000 00000002 00000000 80240001 lo ie. the above commit causes the ::1/128 local (automatic) route to be flagged with RTF_ADDRCONF (0x040000). AFAICT, this is incorrect since these routes are *not* coming from RA's. As such, this patch restores the old behaviour. Fixes: c7a1ce397ada ("ipv6: Change addrconf_f6i_alloc to use ip6_route_info_create") Cc: David Ahern Cc: Lorenzo Colitti Signed-off-by: Maciej Żenczykowski Reviewed-by: David Ahern Signed-off-by: David S. Miller --- net/ipv6/route.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index fd059e08785a..2927e72e511a 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -4388,13 +4388,14 @@ struct fib6_info *addrconf_f6i_alloc(struct net *net, struct fib6_config cfg = { .fc_table = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL, .fc_ifindex = idev->dev->ifindex, - .fc_flags = RTF_UP | RTF_ADDRCONF | RTF_NONEXTHOP, + .fc_flags = RTF_UP | RTF_NONEXTHOP, .fc_dst = *addr, .fc_dst_len = 128, .fc_protocol = RTPROT_KERNEL, .fc_nlinfo.nl_net = net, .fc_ignore_dev_down = true, }; + struct fib6_info *f6i; if (anycast) { cfg.fc_type = RTN_ANYCAST; @@ -4404,7 +4405,10 @@ struct fib6_info *addrconf_f6i_alloc(struct net *net, cfg.fc_flags |= RTF_LOCAL; } - return ip6_route_info_create(&cfg, gfp_flags, NULL); + f6i = ip6_route_info_create(&cfg, gfp_flags, NULL); + if (f6i) + f6i->dst_nocount = true; + return f6i; } /* remove deleted ip from prefsrc entries */