From 863b25581ce9e6f27dd9acc210356ca35ffe30a2 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Wed, 26 Aug 2020 19:48:54 +0300 Subject: ipv4: nexthop: Correctly update nexthop group when removing a nexthop Each nexthop group contains an indication if it has IPv4 nexthops ('has_v4'). Its purpose is to prevent IPv6 routes from using groups with IPv4 nexthops. However, the indication is not updated when a nexthop is removed. This results in the kernel wrongly rejecting IPv6 routes from pointing to groups that only contain IPv6 nexthops. Example: # ip nexthop replace id 1 via 192.0.2.2 dev dummy10 # ip nexthop replace id 2 via 2001:db8:1::2 dev dummy10 # ip nexthop replace id 10 group 1/2 # ip nexthop del id 1 # ip route replace 2001:db8:10::/64 nhid 10 Error: IPv6 routes can not use an IPv4 nexthop. Solve this by updating the indication according to the new set of member nexthops. Signed-off-by: Ido Schimmel Reviewed-by: David Ahern Signed-off-by: David S. Miller --- net/ipv4/nexthop.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'net/ipv4/nexthop.c') diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c index 1b736e3e1baa..5199a2815df6 100644 --- a/net/ipv4/nexthop.c +++ b/net/ipv4/nexthop.c @@ -797,7 +797,7 @@ static void remove_nh_grp_entry(struct net *net, struct nh_grp_entry *nhge, return; } - newg->has_v4 = nhg->has_v4; + newg->has_v4 = false; newg->mpath = nhg->mpath; newg->fdb_nh = nhg->fdb_nh; newg->num_nh = nhg->num_nh; @@ -806,12 +806,18 @@ static void remove_nh_grp_entry(struct net *net, struct nh_grp_entry *nhge, nhges = nhg->nh_entries; new_nhges = newg->nh_entries; for (i = 0, j = 0; i < nhg->num_nh; ++i) { + struct nh_info *nhi; + /* current nexthop getting removed */ if (nhg->nh_entries[i].nh == nh) { newg->num_nh--; continue; } + nhi = rtnl_dereference(nhges[i].nh->nh_info); + if (nhi->family == AF_INET) + newg->has_v4 = true; + list_del(&nhges[i].nh_list); new_nhges[j].nh_parent = nhges[i].nh_parent; new_nhges[j].nh = nhges[i].nh; -- cgit v1.2.3