Merge branch 'fib-tables-fixes'

Alexander Duyck says:

====================
ipv4: Fix memory leaks and reference issues in fib

This series fixes one major issue and one minor issue in the fib tables.

The major issue is that we had lost the functionality that was flushing the
local table entries from main after we had unmerged the two tries.  In
order to regain the functionality I have performed a partial revert and
then moved the functionality for flushing the external entries from main
into fib_unmerge.

The minor issue was a memory leak that could occur in the event that we
weren't able to add an alias to the local trie resulting in the fib alias
being leaked.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index b9314b48e39f32ef22366087673bcc961d196b43..f390c3bb05c5d2189d169d31038fd5cb991bebaa 100644 (file)
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -243,6 +243,7 @@ int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
                   struct netlink_callback *cb);
 int fib_table_flush(struct net *net, struct fib_table *table);
 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
+void fib_table_flush_external(struct fib_table *table);
 void fib_free_table(struct fib_table *tb);
 
 #ifndef CONFIG_IP_MULTIPLE_TABLES

diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index c3b80478226ed4aab6ed8ce1e75ea34c9a921385..161fc0f0d752fb559918c22c5c87e7ef7c84dbe6 100644 (file)
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -151,7 +151,7 @@ static void fib_replace_table(struct net *net, struct fib_table *old,
 
 int fib_unmerge(struct net *net)
 {
-       struct fib_table *old, *new;
+       struct fib_table *old, *new, *main_table;
 
        /* attempt to fetch local table if it has been allocated */
        old = fib_get_table(net, RT_TABLE_LOCAL);
@@ -162,11 +162,21 @@ int fib_unmerge(struct net *net)
        if (!new)
                return -ENOMEM;
 
+       /* table is already unmerged */
+       if (new == old)
+               return 0;
+
        /* replace merged table with clean table */
-       if (new != old) {
-               fib_replace_table(net, old, new);
-               fib_free_table(old);
-       }
+       fib_replace_table(net, old, new);
+       fib_free_table(old);
+
+       /* attempt to fetch main table if it has been allocated */
+       main_table = fib_get_table(net, RT_TABLE_MAIN);
+       if (!main_table)
+               return 0;
+
+       /* flush local entries from main table */
+       fib_table_flush_external(main_table);
 
        return 0;
 }

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 4cff74d4133f124374146a5c997847f27a5f7345..026f309c51e9b6143e74efe2d31c8c5e7a7a3c26 100644 (file)
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1743,8 +1743,10 @@ struct fib_table *fib_trie_unmerge(struct fib_table *oldtb)
                                local_l = fib_find_node(lt, &local_tp, l->key);
 
                        if (fib_insert_alias(lt, local_tp, local_l, new_fa,
-                                            NULL, l->key))
+                                            NULL, l->key)) {
+                               kmem_cache_free(fn_alias_kmem, new_fa);
                                goto out;
+                       }
                }
 
                /* stop loop if key wrapped back to 0 */
@@ -1760,6 +1762,71 @@ out:
        return NULL;
 }
 
+/* Caller must hold RTNL */
+void fib_table_flush_external(struct fib_table *tb)
+{
+       struct trie *t = (struct trie *)tb->tb_data;
+       struct key_vector *pn = t->kv;
+       unsigned long cindex = 1;
+       struct hlist_node *tmp;
+       struct fib_alias *fa;
+
+       /* walk trie in reverse order */
+       for (;;) {
+               unsigned char slen = 0;
+               struct key_vector *n;
+
+               if (!(cindex--)) {
+                       t_key pkey = pn->key;
+
+                       /* cannot resize the trie vector */
+                       if (IS_TRIE(pn))
+                               break;
+
+                       /* resize completed node */
+                       pn = resize(t, pn);
+                       cindex = get_index(pkey, pn);
+
+                       continue;
+               }
+
+               /* grab the next available node */
+               n = get_child(pn, cindex);
+               if (!n)
+                       continue;
+
+               if (IS_TNODE(n)) {
+                       /* record pn and cindex for leaf walking */
+                       pn = n;
+                       cindex = 1ul << n->bits;
+
+                       continue;
+               }
+
+               hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
+                       /* if alias was cloned to local then we just
+                        * need to remove the local copy from main
+                        */
+                       if (tb->tb_id != fa->tb_id) {
+                               hlist_del_rcu(&fa->fa_list);
+                               alias_free_mem_rcu(fa);
+                               continue;
+                       }
+
+                       /* record local slen */
+                       slen = fa->fa_slen;
+               }
+
+               /* update leaf slen */
+               n->slen = slen;
+
+               if (hlist_empty(&n->leaf)) {
+                       put_child_root(pn, n->key, NULL);
+                       node_free(n);
+               }
+       }
+}
+
 /* Caller must hold RTNL. */
 int fib_table_flush(struct net *net, struct fib_table *tb)
 {