[IPV4]: Unify access to the routing tables.

Replace the direct pointers to local and main tables with
calls to fib_get_table() with appropriate argument.

This doesn't introduce additional dereferences, but makes the access to fib
tables uniform in any (CONFIG_IP_MULTIPLE_TABLES) case.

Acked-by: Benjamin Thery <benjamin.thery@bull.net>
Acked-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ip_fib.h

@@ -120,16 +120,22 @@ struct fib_result_nl {
 	int             err;      
 };
 
+extern struct hlist_head fib_table_hash[];
+
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 
 #define FIB_RES_NH(res)		((res).fi->fib_nh[(res).nh_sel])
 #define FIB_RES_RESET(res)	((res).nh_sel = 0)
 
+#define FIB_TABLE_HASHSZ 2
+
 #else /* CONFIG_IP_ROUTE_MULTIPATH */
 
 #define FIB_RES_NH(res)		((res).fi->fib_nh[0])
 #define FIB_RES_RESET(res)
 
+#define FIB_TABLE_HASHSZ 256
+
 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
 
 #define FIB_RES_PREFSRC(res)		((res).fi->fib_prefsrc ? : __fib_res_prefsrc(&res))
@@ -156,14 +162,17 @@ struct fib_table {
 
 #ifndef CONFIG_IP_MULTIPLE_TABLES
 
-extern struct fib_table *ip_fib_local_table;
-extern struct fib_table *ip_fib_main_table;
+#define TABLE_LOCAL_INDEX	0
+#define TABLE_MAIN_INDEX	1
 
 static inline struct fib_table *fib_get_table(u32 id)
 {
-	if (id != RT_TABLE_LOCAL)
-		return ip_fib_main_table;
-	return ip_fib_local_table;
+	struct hlist_head *ptr;
+
+	ptr = id == RT_TABLE_LOCAL ?
+		&fib_table_hash[TABLE_LOCAL_INDEX] :
+		&fib_table_hash[TABLE_MAIN_INDEX];
+	return hlist_entry(ptr->first, struct fib_table, tb_hlist);
 }
 
 static inline struct fib_table *fib_new_table(u32 id)
@@ -173,16 +182,24 @@ static inline struct fib_table *fib_new_table(u32 id)
 
 static inline int fib_lookup(const struct flowi *flp, struct fib_result *res)
 {
-	if (ip_fib_local_table->tb_lookup(ip_fib_local_table, flp, res) &&
-	    ip_fib_main_table->tb_lookup(ip_fib_main_table, flp, res))
-		return -ENETUNREACH;
-	return 0;
+	struct fib_table *table;
+
+	table = fib_get_table(RT_TABLE_LOCAL);
+	if (!table->tb_lookup(table, flp, res))
+		return 0;
+
+	table = fib_get_table(RT_TABLE_MAIN);
+	if (!table->tb_lookup(table, flp, res))
+		return 0;
+	return -ENETUNREACH;
 }
 
-static inline void fib_select_default(const struct flowi *flp, struct fib_result *res)
+static inline void fib_select_default(const struct flowi *flp,
+				      struct fib_result *res)
 {
+	struct fib_table *table = fib_get_table(RT_TABLE_MAIN);
 	if (FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
-		ip_fib_main_table->tb_select_default(ip_fib_main_table, flp, res);
+		table->tb_select_default(table, flp, res);
 }
 
 #else /* CONFIG_IP_MULTIPLE_TABLES */

net/ipv4/fib_frontend.c

@@ -50,39 +50,34 @@
 #define FFprint(a...) printk(KERN_DEBUG a)
 
 static struct sock *fibnl;
+struct hlist_head fib_table_hash[FIB_TABLE_HASHSZ];
 
 #ifndef CONFIG_IP_MULTIPLE_TABLES
 
-struct fib_table *ip_fib_local_table;
-struct fib_table *ip_fib_main_table;
-
-#define FIB_TABLE_HASHSZ 1
-static struct hlist_head fib_table_hash[FIB_TABLE_HASHSZ];
-
 static int __net_init fib4_rules_init(struct net *net)
 {
-	ip_fib_local_table = fib_hash_init(RT_TABLE_LOCAL);
-	if (ip_fib_local_table == NULL)
+	struct fib_table *local_table, *main_table;
+
+	local_table = fib_hash_init(RT_TABLE_LOCAL);
+	if (local_table == NULL)
 		return -ENOMEM;
 
-	ip_fib_main_table  = fib_hash_init(RT_TABLE_MAIN);
-	if (ip_fib_main_table == NULL)
+	main_table  = fib_hash_init(RT_TABLE_MAIN);
+	if (main_table == NULL)
 		goto fail;
 
-	hlist_add_head_rcu(&ip_fib_local_table->tb_hlist, &fib_table_hash[0]);
-	hlist_add_head_rcu(&ip_fib_main_table->tb_hlist, &fib_table_hash[0]);
+	hlist_add_head_rcu(&local_table->tb_hlist,
+				&fib_table_hash[TABLE_LOCAL_INDEX]);
+	hlist_add_head_rcu(&main_table->tb_hlist,
+				&fib_table_hash[TABLE_MAIN_INDEX]);
 	return 0;
 
 fail:
-	kfree(ip_fib_local_table);
-	ip_fib_local_table = NULL;
+	kfree(local_table);
 	return -ENOMEM;
 }
 #else
 
-#define FIB_TABLE_HASHSZ 256
-static struct hlist_head fib_table_hash[FIB_TABLE_HASHSZ];
-
 struct fib_table *fib_new_table(u32 id)
 {
 	struct fib_table *tb;