ipv6: fix ECMP route replacement

[linux-2.6-block.git] / net / ipv6 / ip6_fib.c

diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 96dbffff5a2400bfca0a7b0bee9072d76ec92e88..bde57b113009794637a07b405173bef1fd3c6fb3 100644 (file)
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -693,6 +693,7 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
 {
        struct rt6_info *iter = NULL;
        struct rt6_info **ins;
+       struct rt6_info **fallback_ins = NULL;
        int replace = (info->nlh &&
                       (info->nlh->nlmsg_flags & NLM_F_REPLACE));
        int add = (!info->nlh ||
@@ -716,8 +717,13 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
                            (info->nlh->nlmsg_flags & NLM_F_EXCL))
                                return -EEXIST;
                        if (replace) {
-                               found++;
-                               break;
+                               if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) {
+                                       found++;
+                                       break;
+                               }
+                               if (rt_can_ecmp)
+                                       fallback_ins = fallback_ins ?: ins;
+                               goto next_iter;
                        }
 
                        if (iter->dst.dev == rt->dst.dev &&
@@ -753,9 +759,17 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
                if (iter->rt6i_metric > rt->rt6i_metric)
                        break;
 
+next_iter:
                ins = &iter->dst.rt6_next;
        }
 
+       if (fallback_ins && !found) {
+               /* No ECMP-able route found, replace first non-ECMP one */
+               ins = fallback_ins;
+               iter = *ins;
+               found++;
+       }
+
        /* Reset round-robin state, if necessary */
        if (ins == &fn->leaf)
                fn->rr_ptr = NULL;
@@ -815,6 +829,8 @@ add:
                }
 
        } else {
+               int nsiblings;
+
                if (!found) {
                        if (add)
                                goto add;
@@ -835,8 +851,27 @@ add:
                        info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
                        fn->fn_flags |= RTN_RTINFO;
                }
+               nsiblings = iter->rt6i_nsiblings;
                fib6_purge_rt(iter, fn, info->nl_net);
                rt6_release(iter);
+
+               if (nsiblings) {
+                       /* Replacing an ECMP route, remove all siblings */
+                       ins = &rt->dst.rt6_next;
+                       iter = *ins;
+                       while (iter) {
+                               if (rt6_qualify_for_ecmp(iter)) {
+                                       *ins = iter->dst.rt6_next;
+                                       fib6_purge_rt(iter, fn, info->nl_net);
+                                       rt6_release(iter);
+                                       nsiblings--;
+                               } else {
+                                       ins = &iter->dst.rt6_next;
+                               }
+                               iter = *ins;
+                       }
+                       WARN_ON(nsiblings != 0);
+               }
        }
 
        return 0;