ipv4: Remember FIB alias list head and table in lookup results.

This will be used later to implement fib_select_default() in a
completely generic manner, instead of the current situation where the
default route is re-looked up in the TRIE/HASH table and then the
available aliases are analyzed.

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

5 files changed, 14 insertions, 8 deletions

diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index 2c0508a6e07c..f5199b08ba53 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -96,12 +96,15 @@ struct fib_info {
 struct fib_rule;
 #endif
 
+struct fib_table;
 struct fib_result {
         unsigned char   prefixlen;
         unsigned char   nh_sel;
         unsigned char   type;
         unsigned char   scope;
         struct fib_info *fi;
+        struct fib_table *table;
+        struct list_head *fa_head;
 #ifdef CONFIG_IP_MULTIPLE_TABLES
         struct fib_rule *r;
 #endif
diff --git a/net/ipv4/fib_hash.c b/net/ipv4/fib_hash.c
index b3acb0417b21..0a88866ad1e5 100644
--- a/net/ipv4/fib_hash.c
+++ b/net/ipv4/fib_hash.c
@@ -288,7 +288,7 @@ int fib_table_lookup(struct fib_table *tb,
                                 if (f->fn_key != k)
                                         continue;
 
-                                err = fib_semantic_match(&f->fn_alias,
+                                err = fib_semantic_match(tb, &f->fn_alias,
                                                  flp, res,
                                                  fz->fz_order, fib_flags);
                                 if (err <= 0)
diff --git a/net/ipv4/fib_lookup.h b/net/ipv4/fib_lookup.h
index c079cc0ec651..d5c40d8f6632 100644
--- a/net/ipv4/fib_lookup.h
+++ b/net/ipv4/fib_lookup.h
@@ -25,7 +25,7 @@ static inline void fib_alias_accessed(struct fib_alias *fa)
 }
 
 /* Exported by fib_semantics.c */
-extern int fib_semantic_match(struct list_head *head,
+extern int fib_semantic_match(struct fib_table *tb, struct list_head *head,
                               const struct flowi *flp,
                               struct fib_result *res, int prefixlen, int fib_flags);
 extern void fib_release_info(struct fib_info *);
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 48e93a560077..1bf6fb906cfc 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -889,8 +889,9 @@ failure:
 }
 
 /* Note! fib_semantic_match intentionally uses  RCU list functions. */
-int fib_semantic_match(struct list_head *head, const struct flowi *flp,
-                       struct fib_result *res, int prefixlen, int fib_flags)
+int fib_semantic_match(struct fib_table *tb, struct list_head *head,
+                       const struct flowi *flp, struct fib_result *res,
+                       int prefixlen, int fib_flags)
 {
         struct fib_alias *fa;
         int nh_sel = 0;
@@ -954,6 +955,8 @@ out_fill_res:
         res->type = fa->fa_type;
         res->scope = fa->fa_scope;
         res->fi = fa->fa_info;
+        res->table = tb;
+        res->fa_head = head;
         if (!(fib_flags & FIB_LOOKUP_NOREF))
                 atomic_inc(&res->fi->fib_clntref);
         return 0;
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 0f280348e0fd..8cee5c8848ed 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1340,7 +1340,7 @@ err:
 }
 
 /* should be called with rcu_read_lock */
-static int check_leaf(struct trie *t, struct leaf *l,
+static int check_leaf(struct fib_table *tb, struct trie *t, struct leaf *l,
                       t_key key,  const struct flowi *flp,
                       struct fib_result *res, int fib_flags)
 {
@@ -1356,7 +1356,7 @@ static int check_leaf(struct trie *t, struct leaf *l,
                 if (l->key != (key & ntohl(mask)))
                         continue;
 
-                err = fib_semantic_match(&li->falh, flp, res, plen, fib_flags);
+                err = fib_semantic_match(tb, &li->falh, flp, res, plen, fib_flags);
 
 #ifdef CONFIG_IP_FIB_TRIE_STATS
                 if (err <= 0)
@@ -1398,7 +1398,7 @@ int fib_table_lookup(struct fib_table *tb, const struct flowi *flp,
 
         /* Just a leaf? */
         if (IS_LEAF(n)) {
-                ret = check_leaf(t, (struct leaf *)n, key, flp, res, fib_flags);
+                ret = check_leaf(tb, t, (struct leaf *)n, key, flp, res, fib_flags);
                 goto found;
         }
 
@@ -1423,7 +1423,7 @@ int fib_table_lookup(struct fib_table *tb, const struct flowi *flp,
                 }
 
                 if (IS_LEAF(n)) {
-                        ret = check_leaf(t, (struct leaf *)n, key, flp, res, fib_flags);
+                        ret = check_leaf(tb, t, (struct leaf *)n, key, flp, res, fib_flags);
                         if (ret > 0)
                                 goto backtrace;
                         goto found;