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[IPV4]: Increase number of possible routing tables to 2^32
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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>
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Patrick McHardy authored and David S. Miller committed Sep 22, 2006
1 parent 9e762a4 commit 1af5a8c
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Showing 5 changed files with 101 additions and 82 deletions.
25 changes: 5 additions & 20 deletions include/net/ip_fib.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -150,6 +150,7 @@ struct fib_result_nl {
#endif /* CONFIG_IP_ROUTE_MULTIPATH_WRANDOM */

struct fib_table {
struct hlist_node tb_hlist;
u32 tb_id;
unsigned tb_stamp;
int (*tb_lookup)(struct fib_table *tb, const struct flowi *flp, struct fib_result *res);
Expand Down Expand Up @@ -200,29 +201,13 @@ static inline void fib_select_default(const struct flowi *flp, struct fib_result
}

#else /* CONFIG_IP_MULTIPLE_TABLES */
#define ip_fib_local_table (fib_tables[RT_TABLE_LOCAL])
#define ip_fib_main_table (fib_tables[RT_TABLE_MAIN])
#define ip_fib_local_table fib_get_table(RT_TABLE_LOCAL)
#define ip_fib_main_table fib_get_table(RT_TABLE_MAIN)

extern struct fib_table * fib_tables[RT_TABLE_MAX+1];
extern int fib_lookup(struct flowi *flp, struct fib_result *res);
extern struct fib_table *__fib_new_table(u32 id);

static inline struct fib_table *fib_get_table(u32 id)
{
if (id == 0)
id = RT_TABLE_MAIN;

return fib_tables[id];
}

static inline struct fib_table *fib_new_table(u32 id)
{
if (id == 0)
id = RT_TABLE_MAIN;

return fib_tables[id] ? : __fib_new_table(id);
}

extern struct fib_table *fib_new_table(u32 id);
extern struct fib_table *fib_get_table(u32 id);
extern void fib_select_default(const struct flowi *flp, struct fib_result *res);

#endif /* CONFIG_IP_MULTIPLE_TABLES */
Expand Down
102 changes: 68 additions & 34 deletions net/ipv4/fib_frontend.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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>
Expand All @@ -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;

#else
#define FIB_TABLE_HASHSZ 1
static struct hlist_head fib_table_hash[FIB_TABLE_HASHSZ];

#define RT_TABLE_MIN 1
#else

struct fib_table *fib_tables[RT_TABLE_MAX+1];
#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 *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);
Expand Down Expand Up @@ -334,29 +354,37 @@ int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)

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;

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;
s_h = cb->args[0];
s_e = cb->args[1];

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;
}
Expand Down Expand Up @@ -654,9 +682,15 @@ static struct notifier_block fib_netdev_notifier = {

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
Expand Down
26 changes: 13 additions & 13 deletions net/ipv4/fib_hash.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -684,7 +684,7 @@ fn_hash_dump_bucket(struct sk_buff *skb, struct netlink_callback *cb,
struct fib_node *f;
int i, s_i;

s_i = cb->args[3];
s_i = cb->args[4];
i = 0;
hlist_for_each_entry(f, node, head, fn_hash) {
struct fib_alias *fa;
Expand All @@ -704,14 +704,14 @@ fn_hash_dump_bucket(struct sk_buff *skb, struct netlink_callback *cb,
fa->fa_tos,
fa->fa_info,
NLM_F_MULTI) < 0) {
cb->args[3] = i;
cb->args[4] = i;
return -1;
}
next:
i++;
}
}
cb->args[3] = i;
cb->args[4] = i;
return skb->len;
}

Expand All @@ -722,21 +722,21 @@ fn_hash_dump_zone(struct sk_buff *skb, struct netlink_callback *cb,
{
int h, s_h;

s_h = cb->args[2];
s_h = cb->args[3];
for (h=0; h < fz->fz_divisor; h++) {
if (h < s_h) continue;
if (h > s_h)
memset(&cb->args[3], 0,
sizeof(cb->args) - 3*sizeof(cb->args[0]));
memset(&cb->args[4], 0,
sizeof(cb->args) - 4*sizeof(cb->args[0]));
if (fz->fz_hash == NULL ||
hlist_empty(&fz->fz_hash[h]))
continue;
if (fn_hash_dump_bucket(skb, cb, tb, fz, &fz->fz_hash[h])<0) {
cb->args[2] = h;
cb->args[3] = h;
return -1;
}
}
cb->args[2] = h;
cb->args[3] = h;
return skb->len;
}

Expand All @@ -746,21 +746,21 @@ static int fn_hash_dump(struct fib_table *tb, struct sk_buff *skb, struct netlin
struct fn_zone *fz;
struct fn_hash *table = (struct fn_hash*)tb->tb_data;

s_m = cb->args[1];
s_m = cb->args[2];
read_lock(&fib_hash_lock);
for (fz = table->fn_zone_list, m=0; fz; fz = fz->fz_next, m++) {
if (m < s_m) continue;
if (m > s_m)
memset(&cb->args[2], 0,
sizeof(cb->args) - 2*sizeof(cb->args[0]));
memset(&cb->args[3], 0,
sizeof(cb->args) - 3*sizeof(cb->args[0]));
if (fn_hash_dump_zone(skb, cb, tb, fz) < 0) {
cb->args[1] = m;
cb->args[2] = m;
read_unlock(&fib_hash_lock);
return -1;
}
}
read_unlock(&fib_hash_lock);
cb->args[1] = m;
cb->args[2] = m;
return skb->len;
}

Expand Down
4 changes: 2 additions & 2 deletions net/ipv4/fib_rules.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -172,8 +172,8 @@ static struct fib_table *fib_empty_table(void)
u32 id;

for (id = 1; id <= RT_TABLE_MAX; id++)
if (fib_tables[id] == NULL)
return __fib_new_table(id);
if (fib_get_table(id) == NULL)
return fib_new_table(id);
return NULL;
}

Expand Down
26 changes: 13 additions & 13 deletions net/ipv4/fib_trie.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1848,7 +1848,7 @@ static int fn_trie_dump_fa(t_key key, int plen, struct list_head *fah, struct fi

u32 xkey = htonl(key);

s_i = cb->args[3];
s_i = cb->args[4];
i = 0;

/* rcu_read_lock is hold by caller */
Expand All @@ -1870,12 +1870,12 @@ static int fn_trie_dump_fa(t_key key, int plen, struct list_head *fah, struct fi
plen,
fa->fa_tos,
fa->fa_info, 0) < 0) {
cb->args[3] = i;
cb->args[4] = i;
return -1;
}
i++;
}
cb->args[3] = i;
cb->args[4] = i;
return skb->len;
}

Expand All @@ -1886,14 +1886,14 @@ static int fn_trie_dump_plen(struct trie *t, int plen, struct fib_table *tb, str
struct list_head *fa_head;
struct leaf *l = NULL;

s_h = cb->args[2];
s_h = cb->args[3];

for (h = 0; (l = nextleaf(t, l)) != NULL; h++) {
if (h < s_h)
continue;
if (h > s_h)
memset(&cb->args[3], 0,
sizeof(cb->args) - 3*sizeof(cb->args[0]));
memset(&cb->args[4], 0,
sizeof(cb->args) - 4*sizeof(cb->args[0]));

fa_head = get_fa_head(l, plen);

Expand All @@ -1904,11 +1904,11 @@ static int fn_trie_dump_plen(struct trie *t, int plen, struct fib_table *tb, str
continue;

if (fn_trie_dump_fa(l->key, plen, fa_head, tb, skb, cb)<0) {
cb->args[2] = h;
cb->args[3] = h;
return -1;
}
}
cb->args[2] = h;
cb->args[3] = h;
return skb->len;
}

Expand All @@ -1917,23 +1917,23 @@ static int fn_trie_dump(struct fib_table *tb, struct sk_buff *skb, struct netlin
int m, s_m;
struct trie *t = (struct trie *) tb->tb_data;

s_m = cb->args[1];
s_m = cb->args[2];

rcu_read_lock();
for (m = 0; m <= 32; m++) {
if (m < s_m)
continue;
if (m > s_m)
memset(&cb->args[2], 0,
sizeof(cb->args) - 2*sizeof(cb->args[0]));
memset(&cb->args[3], 0,
sizeof(cb->args) - 3*sizeof(cb->args[0]));

if (fn_trie_dump_plen(t, 32-m, tb, skb, cb)<0) {
cb->args[1] = m;
cb->args[2] = m;
goto out;
}
}
rcu_read_unlock();
cb->args[1] = m;
cb->args[2] = m;
return skb->len;
out:
rcu_read_unlock();
Expand Down

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