ipv6: reallocate addrconf router for ipv6 address when lo device up

Gao feng · davem330 · commit 33d99113b110 · 2014-01-24T15:59:38.000-08:00
commit 25fb6ca "net IPv6 : Fix broken IPv6 routing table after loopback down-up" allocates addrconf router for ipv6 address when lo device up. but commit a881ae1 "ipv6:don't call addrconf_dst_alloc again when enable lo" breaks this behavior. Since the addrconf router is moved to the garbage list when lo device down, we should release this router and rellocate a new one for ipv6 address when lo device up. This patch solves bug 67951 on bugzilla https://bugzilla.kernel.org/show_bug.cgi?id=67951 change from v1: use ip6_rt_put to repleace ip6_del_rt, thanks Hannes! change code style, suggested by Sergei. CC: Sabrina Dubroca <sd@queasysnail.net> CC: Hannes Frederic Sowa <hannes@stressinduktion.org> Reported-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
@@ -2657,8 +2657,18 @@ static void init_loopback(struct net_device *dev)
 			if (sp_ifa->flags & (IFA_F_DADFAILED | IFA_F_TENTATIVE))
 				continue;
 
-			if (sp_ifa->rt)
-				continue;
+			if (sp_ifa->rt) {
+				/* This dst has been added to garbage list when
+				 * lo device down, release this obsolete dst and
+				 * reallocate a new router for ifa.
+				 */
+				if (sp_ifa->rt->dst.obsolete > 0) {
+					ip6_rt_put(sp_ifa->rt);
+					sp_ifa->rt = NULL;
+				} else {
+					continue;
+				}
+			}
 
 			sp_rt = addrconf_dst_alloc(idev, &sp_ifa->addr, false);
 
