[IPV4]: Increase number of possible routing tables to 2^32
Increase the number of possible routing tables to 2^32 by replacing the
fixed sized array of pointers by a hash table and replacing iterations
over all possible table IDs by hash table walking.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 2696ede..ad4c14f 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -37,6 +37,7 @@
#include <linux/skbuff.h>
#include <linux/netlink.h>
#include <linux/init.h>
+#include <linux/list.h>
#include <net/ip.h>
#include <net/protocol.h>
@@ -51,48 +52,67 @@
#ifndef CONFIG_IP_MULTIPLE_TABLES
-#define RT_TABLE_MIN RT_TABLE_MAIN
-
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];
+
#else
-#define RT_TABLE_MIN 1
+#define FIB_TABLE_HASHSZ 256
+static struct hlist_head fib_table_hash[FIB_TABLE_HASHSZ];
-struct fib_table *fib_tables[RT_TABLE_MAX+1];
-
-struct fib_table *__fib_new_table(u32 id)
+struct fib_table *fib_new_table(u32 id)
{
struct fib_table *tb;
+ unsigned int h;
+ if (id == 0)
+ id = RT_TABLE_MAIN;
+ tb = fib_get_table(id);
+ if (tb)
+ return tb;
tb = fib_hash_init(id);
if (!tb)
return NULL;
- fib_tables[id] = tb;
+ h = id & (FIB_TABLE_HASHSZ - 1);
+ hlist_add_head_rcu(&tb->tb_hlist, &fib_table_hash[h]);
return tb;
}
+struct fib_table *fib_get_table(u32 id)
+{
+ struct fib_table *tb;
+ struct hlist_node *node;
+ unsigned int h;
+ if (id == 0)
+ id = RT_TABLE_MAIN;
+ h = id & (FIB_TABLE_HASHSZ - 1);
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(tb, node, &fib_table_hash[h], tb_hlist) {
+ if (tb->tb_id == id) {
+ rcu_read_unlock();
+ return tb;
+ }
+ }
+ rcu_read_unlock();
+ return NULL;
+}
#endif /* CONFIG_IP_MULTIPLE_TABLES */
-
static void fib_flush(void)
{
int flushed = 0;
-#ifdef CONFIG_IP_MULTIPLE_TABLES
struct fib_table *tb;
- u32 id;
+ struct hlist_node *node;
+ unsigned int h;
- for (id = RT_TABLE_MAX; id>0; id--) {
- if ((tb = fib_get_table(id))==NULL)
- continue;
- flushed += tb->tb_flush(tb);
+ for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
+ hlist_for_each_entry(tb, node, &fib_table_hash[h], tb_hlist)
+ flushed += tb->tb_flush(tb);
}
-#else /* CONFIG_IP_MULTIPLE_TABLES */
- flushed += ip_fib_main_table->tb_flush(ip_fib_main_table);
- flushed += ip_fib_local_table->tb_flush(ip_fib_local_table);
-#endif /* CONFIG_IP_MULTIPLE_TABLES */
if (flushed)
rt_cache_flush(-1);
@@ -334,29 +354,37 @@
int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
{
- u32 t;
- u32 s_t;
+ unsigned int h, s_h;
+ unsigned int e = 0, s_e;
struct fib_table *tb;
+ struct hlist_node *node;
+ int dumped = 0;
if (NLMSG_PAYLOAD(cb->nlh, 0) >= sizeof(struct rtmsg) &&
((struct rtmsg*)NLMSG_DATA(cb->nlh))->rtm_flags&RTM_F_CLONED)
return ip_rt_dump(skb, cb);
- s_t = cb->args[0];
- if (s_t == 0)
- s_t = cb->args[0] = RT_TABLE_MIN;
+ s_h = cb->args[0];
+ s_e = cb->args[1];
- for (t=s_t; t<=RT_TABLE_MAX; t++) {
- if (t < s_t) continue;
- if (t > s_t)
- memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
- if ((tb = fib_get_table(t))==NULL)
- continue;
- if (tb->tb_dump(tb, skb, cb) < 0)
- break;
+ for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
+ e = 0;
+ hlist_for_each_entry(tb, node, &fib_table_hash[h], tb_hlist) {
+ if (e < s_e)
+ goto next;
+ if (dumped)
+ memset(&cb->args[2], 0, sizeof(cb->args) -
+ 2 * sizeof(cb->args[0]));
+ if (tb->tb_dump(tb, skb, cb) < 0)
+ goto out;
+ dumped = 1;
+next:
+ e++;
+ }
}
-
- cb->args[0] = t;
+out:
+ cb->args[1] = e;
+ cb->args[0] = h;
return skb->len;
}
@@ -654,9 +682,15 @@
void __init ip_fib_init(void)
{
+ unsigned int i;
+
+ for (i = 0; i < FIB_TABLE_HASHSZ; i++)
+ INIT_HLIST_HEAD(&fib_table_hash[i]);
#ifndef CONFIG_IP_MULTIPLE_TABLES
ip_fib_local_table = fib_hash_init(RT_TABLE_LOCAL);
+ hlist_add_head_rcu(&ip_fib_local_table->tb_hlist, &fib_table_hash[0]);
ip_fib_main_table = fib_hash_init(RT_TABLE_MAIN);
+ hlist_add_head_rcu(&ip_fib_main_table->tb_hlist, &fib_table_hash[0]);
#else
fib4_rules_init();
#endif
