Patchwork [v2] ipv6: del unreachable route when an addr is deleted on lo

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Submitter Nicolas Dichtel
Date Sept. 26, 2012, 10:04 a.m.
Message ID <1348653895-4027-1-git-send-email-nicolas.dichtel@6wind.com>
Download mbox | patch
Permalink /patch/187033/
State Accepted
Delegated to: David Miller
Headers show

Comments

Nicolas Dichtel - Sept. 26, 2012, 10:04 a.m.
When an address is added on loopback (ip -6 a a 2002::1/128 dev lo), two routes
are added:
 - one in the local table:
    local 2002::1 via :: dev lo  proto none  metric 0
 - one the in main table (for the prefix):
    unreachable 2002::1 dev lo  proto kernel  metric 256  error -101

When the address is deleted, the route inserted in the main table remains
because we use rt6_lookup(), which returns NULL when dst->error is set, which
is the case here! Thus, it is better to use ip6_route_lookup() to avoid this
kind of filter.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
---
v2: rt cannot be NULL, so adjust the test after ip6_route_lookup()

 net/ipv6/addrconf.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)
David Miller - Oct. 1, 2012, 8:49 p.m.
From: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Date: Wed, 26 Sep 2012 12:04:55 +0200

> When an address is added on loopback (ip -6 a a 2002::1/128 dev lo), two routes
> are added:
>  - one in the local table:
>     local 2002::1 via :: dev lo  proto none  metric 0
>  - one the in main table (for the prefix):
>     unreachable 2002::1 dev lo  proto kernel  metric 256  error -101
> 
> When the address is deleted, the route inserted in the main table remains
> because we use rt6_lookup(), which returns NULL when dst->error is set, which
> is the case here! Thus, it is better to use ip6_route_lookup() to avoid this
> kind of filter.
> 
> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
> ---
> v2: rt cannot be NULL, so adjust the test after ip6_route_lookup()

Applied, thanks.
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Patch

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 6bc85f7..ea3e9af 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -788,10 +788,16 @@  static void ipv6_del_addr(struct inet6_ifaddr *ifp)
 		struct in6_addr prefix;
 		struct rt6_info *rt;
 		struct net *net = dev_net(ifp->idev->dev);
+		struct flowi6 fl6 = {};
+
 		ipv6_addr_prefix(&prefix, &ifp->addr, ifp->prefix_len);
-		rt = rt6_lookup(net, &prefix, NULL, ifp->idev->dev->ifindex, 1);
+		fl6.flowi6_oif = ifp->idev->dev->ifindex;
+		fl6.daddr = prefix;
+		rt = (struct rt6_info *)ip6_route_lookup(net, &fl6,
+							 RT6_LOOKUP_F_IFACE);
 
-		if (rt && addrconf_is_prefix_route(rt)) {
+		if (rt != net->ipv6.ip6_null_entry &&
+		    addrconf_is_prefix_route(rt)) {
 			if (onlink == 0) {
 				ip6_del_rt(rt);
 				rt = NULL;