ipv4: FIB Local/MAIN table collapse

[deliverable/linux.git] / net / ipv4 / fib_frontend.c

diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index e067770235bfb2c58cd88c10ba1eca1ce666b200..7cda3b0521d8366489de3cfb5027a13d44bfbd57 100644 (file)
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -52,14 +52,14 @@ static int __net_init fib4_rules_init(struct net *net)
 {
        struct fib_table *local_table, *main_table;
 
-       local_table = fib_trie_table(RT_TABLE_LOCAL);
-       if (local_table == NULL)
-               return -ENOMEM;
-
-       main_table  = fib_trie_table(RT_TABLE_MAIN);
+       main_table  = fib_trie_table(RT_TABLE_MAIN, NULL);
        if (main_table == NULL)
                goto fail;
 
+       local_table = fib_trie_table(RT_TABLE_LOCAL, main_table);
+       if (local_table == NULL)
+               return -ENOMEM;
+
        hlist_add_head_rcu(&local_table->tb_hlist,
                                &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
        hlist_add_head_rcu(&main_table->tb_hlist,
@@ -74,7 +74,7 @@ fail:
 
 struct fib_table *fib_new_table(struct net *net, u32 id)
 {
-       struct fib_table *tb;
+       struct fib_table *tb, *alias = NULL;
        unsigned int h;
 
        if (id == 0)
@@ -83,7 +83,10 @@ struct fib_table *fib_new_table(struct net *net, u32 id)
        if (tb)
                return tb;
 
-       tb = fib_trie_table(id);
+       if (id == RT_TABLE_LOCAL)
+               alias = fib_new_table(net, RT_TABLE_MAIN);
+
+       tb = fib_trie_table(id, alias);
        if (!tb)
                return NULL;
 
@@ -126,6 +129,48 @@ struct fib_table *fib_get_table(struct net *net, u32 id)
 }
 #endif /* CONFIG_IP_MULTIPLE_TABLES */
 
+static void fib_replace_table(struct net *net, struct fib_table *old,
+                             struct fib_table *new)
+{
+#ifdef CONFIG_IP_MULTIPLE_TABLES
+       switch (new->tb_id) {
+       case RT_TABLE_LOCAL:
+               rcu_assign_pointer(net->ipv4.fib_local, new);
+               break;
+       case RT_TABLE_MAIN:
+               rcu_assign_pointer(net->ipv4.fib_main, new);
+               break;
+       case RT_TABLE_DEFAULT:
+               rcu_assign_pointer(net->ipv4.fib_default, new);
+               break;
+       default:
+               break;
+       }
+
+#endif
+       /* replace the old table in the hlist */
+       hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist);
+}
+
+int fib_unmerge(struct net *net)
+{
+       struct fib_table *old, *new;
+
+       old = fib_get_table(net, RT_TABLE_LOCAL);
+       new = fib_trie_unmerge(old);
+
+       if (!new)
+               return -ENOMEM;
+
+       /* replace merged table with clean table */
+       if (new != old) {
+               fib_replace_table(net, old, new);
+               fib_free_table(old);
+       }
+
+       return 0;
+}
+
 static void fib_flush(struct net *net)
 {
        int flushed = 0;