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linux/net/ipv4/fib_hash.c
Stephen Hemminger 16c6cf8bb4 ipv4: fib table algorithm performance improvement 
The FIB algorithim for IPV4 is set at compile time, but kernel goes through
the overhead of function call indirection at runtime. Save some
cycles by turning the indirect calls to direct calls to either
hash or trie code.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-05 00:21:56 -07:00

1070 lines
23 KiB
C
Raw Blame History

/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* IPv4 FIB: lookup engine and maintenance routines.
*
* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <asm/uaccess.h>
#include <asm/system.h>
#include <linux/bitops.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/errno.h>
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/inetdevice.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/proc_fs.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
#include <linux/init.h>
#include <net/net_namespace.h>
#include <net/ip.h>
#include <net/protocol.h>
#include <net/route.h>
#include <net/tcp.h>
#include <net/sock.h>
#include <net/ip_fib.h>
#include "fib_lookup.h"
static struct kmem_cache *fn_hash_kmem __read_mostly;
static struct kmem_cache *fn_alias_kmem __read_mostly;
struct fib_node {
struct hlist_node fn_hash;
struct list_head fn_alias;
__be32 fn_key;
struct fib_alias fn_embedded_alias;
};
struct fn_zone {
struct fn_zone *fz_next; /* Next not empty zone */
struct hlist_head *fz_hash; /* Hash table pointer */
int fz_nent; /* Number of entries */
int fz_divisor; /* Hash divisor */
u32 fz_hashmask; /* (fz_divisor - 1) */
#define FZ_HASHMASK(fz) ((fz)->fz_hashmask)
int fz_order; /* Zone order */
__be32 fz_mask;
#define FZ_MASK(fz) ((fz)->fz_mask)
};
/* NOTE. On fast computers evaluation of fz_hashmask and fz_mask
* can be cheaper than memory lookup, so that FZ_* macros are used.
*/
struct fn_hash {
struct fn_zone *fn_zones[33];
struct fn_zone *fn_zone_list;
};
static inline u32 fn_hash(__be32 key, struct fn_zone *fz)
{
u32 h = ntohl(key)>>(32 - fz->fz_order);
h ^= (h>>20);
h ^= (h>>10);
h ^= (h>>5);
h &= FZ_HASHMASK(fz);
return h;
}
static inline __be32 fz_key(__be32 dst, struct fn_zone *fz)
{
return dst & FZ_MASK(fz);
}
static DEFINE_RWLOCK(fib_hash_lock);
static unsigned int fib_hash_genid;
#define FZ_MAX_DIVISOR ((PAGE_SIZE<<MAX_ORDER) / sizeof(struct hlist_head))
static struct hlist_head *fz_hash_alloc(int divisor)
{
unsigned long size = divisor * sizeof(struct hlist_head);
if (size <= PAGE_SIZE) {
return kzalloc(size, GFP_KERNEL);
} else {
return (struct hlist_head *)
__get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(size));
}
}
/* The fib hash lock must be held when this is called. */
static inline void fn_rebuild_zone(struct fn_zone *fz,
struct hlist_head *old_ht,
int old_divisor)
{
int i;
for (i = 0; i < old_divisor; i++) {
struct hlist_node *node, *n;
struct fib_node *f;
hlist_for_each_entry_safe(f, node, n, &old_ht[i], fn_hash) {
struct hlist_head *new_head;
hlist_del(&f->fn_hash);
new_head = &fz->fz_hash[fn_hash(f->fn_key, fz)];
hlist_add_head(&f->fn_hash, new_head);
}
}
}
static void fz_hash_free(struct hlist_head *hash, int divisor)
{
unsigned long size = divisor * sizeof(struct hlist_head);
if (size <= PAGE_SIZE)
kfree(hash);
else
free_pages((unsigned long)hash, get_order(size));
}
static void fn_rehash_zone(struct fn_zone *fz)
{
struct hlist_head *ht, *old_ht;
int old_divisor, new_divisor;
u32 new_hashmask;
old_divisor = fz->fz_divisor;
switch (old_divisor) {
case 16:
new_divisor = 256;
break;
case 256:
new_divisor = 1024;
break;
default:
if ((old_divisor << 1) > FZ_MAX_DIVISOR) {
printk(KERN_CRIT "route.c: bad divisor %d!\n", old_divisor);
return;
}
new_divisor = (old_divisor << 1);
break;
}
new_hashmask = (new_divisor - 1);
#if RT_CACHE_DEBUG >= 2
printk(KERN_DEBUG "fn_rehash_zone: hash for zone %d grows from %d\n",
fz->fz_order, old_divisor);
#endif
ht = fz_hash_alloc(new_divisor);
if (ht) {
write_lock_bh(&fib_hash_lock);
old_ht = fz->fz_hash;
fz->fz_hash = ht;
fz->fz_hashmask = new_hashmask;
fz->fz_divisor = new_divisor;
fn_rebuild_zone(fz, old_ht, old_divisor);
fib_hash_genid++;
write_unlock_bh(&fib_hash_lock);
fz_hash_free(old_ht, old_divisor);
}
}
static inline void fn_free_node(struct fib_node * f)
{
kmem_cache_free(fn_hash_kmem, f);
}
static inline void fn_free_alias(struct fib_alias *fa, struct fib_node *f)
{
fib_release_info(fa->fa_info);
if (fa == &f->fn_embedded_alias)
fa->fa_info = NULL;
else
kmem_cache_free(fn_alias_kmem, fa);
}
static struct fn_zone *
fn_new_zone(struct fn_hash *table, int z)
{
int i;
struct fn_zone *fz = kzalloc(sizeof(struct fn_zone), GFP_KERNEL);
if (!fz)
return NULL;
if (z) {
fz->fz_divisor = 16;
} else {
fz->fz_divisor = 1;
}
fz->fz_hashmask = (fz->fz_divisor - 1);
fz->fz_hash = fz_hash_alloc(fz->fz_divisor);
if (!fz->fz_hash) {
kfree(fz);
return NULL;
}
fz->fz_order = z;
fz->fz_mask = inet_make_mask(z);
/* Find the first not empty zone with more specific mask */
for (i=z+1; i<=32; i++)
if (table->fn_zones[i])
break;
write_lock_bh(&fib_hash_lock);
if (i>32) {
/* No more specific masks, we are the first. */
fz->fz_next = table->fn_zone_list;
table->fn_zone_list = fz;
} else {
fz->fz_next = table->fn_zones[i]->fz_next;
table->fn_zones[i]->fz_next = fz;
}
table->fn_zones[z] = fz;
fib_hash_genid++;
write_unlock_bh(&fib_hash_lock);
return fz;
}
int fib_table_lookup(struct fib_table *tb,
const struct flowi *flp, struct fib_result *res)
{
int err;
struct fn_zone *fz;
struct fn_hash *t = (struct fn_hash *)tb->tb_data;
read_lock(&fib_hash_lock);
for (fz = t->fn_zone_list; fz; fz = fz->fz_next) {
struct hlist_head *head;
struct hlist_node *node;
struct fib_node *f;
__be32 k = fz_key(flp->fl4_dst, fz);
head = &fz->fz_hash[fn_hash(k, fz)];
hlist_for_each_entry(f, node, head, fn_hash) {
if (f->fn_key != k)
continue;
err = fib_semantic_match(&f->fn_alias,
flp, res,
fz->fz_order);
if (err <= 0)
goto out;
}
}
err = 1;
out:
read_unlock(&fib_hash_lock);
return err;
}
void fib_table_select_default(struct fib_table *tb,
const struct flowi *flp, struct fib_result *res)
{
int order, last_idx;
struct hlist_node *node;
struct fib_node *f;
struct fib_info *fi = NULL;
struct fib_info *last_resort;
struct fn_hash *t = (struct fn_hash *)tb->tb_data;
struct fn_zone *fz = t->fn_zones[0];
if (fz == NULL)
return;
last_idx = -1;
last_resort = NULL;
order = -1;
read_lock(&fib_hash_lock);
hlist_for_each_entry(f, node, &fz->fz_hash[0], fn_hash) {
struct fib_alias *fa;
list_for_each_entry(fa, &f->fn_alias, fa_list) {
struct fib_info *next_fi = fa->fa_info;
if (fa->fa_scope != res->scope ||
fa->fa_type != RTN_UNICAST)
continue;
if (next_fi->fib_priority > res->fi->fib_priority)
break;
if (!next_fi->fib_nh[0].nh_gw ||
next_fi->fib_nh[0].nh_scope != RT_SCOPE_LINK)
continue;
fa->fa_state |= FA_S_ACCESSED;
if (fi == NULL) {
if (next_fi != res->fi)
break;
} else if (!fib_detect_death(fi, order, &last_resort,
&last_idx, tb->tb_default)) {
fib_result_assign(res, fi);
tb->tb_default = order;
goto out;
}
fi = next_fi;
order++;
}
}
if (order <= 0 || fi == NULL) {
tb->tb_default = -1;
goto out;
}
if (!fib_detect_death(fi, order, &last_resort, &last_idx,
tb->tb_default)) {
fib_result_assign(res, fi);
tb->tb_default = order;
goto out;
}
if (last_idx >= 0)
fib_result_assign(res, last_resort);
tb->tb_default = last_idx;
out:
read_unlock(&fib_hash_lock);
}
/* Insert node F to FZ. */
static inline void fib_insert_node(struct fn_zone *fz, struct fib_node *f)
{
struct hlist_head *head = &fz->fz_hash[fn_hash(f->fn_key, fz)];
hlist_add_head(&f->fn_hash, head);
}
/* Return the node in FZ matching KEY. */
static struct fib_node *fib_find_node(struct fn_zone *fz, __be32 key)
{
struct hlist_head *head = &fz->fz_hash[fn_hash(key, fz)];
struct hlist_node *node;
struct fib_node *f;
hlist_for_each_entry(f, node, head, fn_hash) {
if (f->fn_key == key)
return f;
}
return NULL;
}
int fib_table_insert(struct fib_table *tb, struct fib_config *cfg)
{
struct fn_hash *table = (struct fn_hash *) tb->tb_data;
struct fib_node *new_f = NULL;
struct fib_node *f;
struct fib_alias *fa, *new_fa;
struct fn_zone *fz;
struct fib_info *fi;
u8 tos = cfg->fc_tos;
__be32 key;
int err;
if (cfg->fc_dst_len > 32)
return -EINVAL;
fz = table->fn_zones[cfg->fc_dst_len];
if (!fz && !(fz = fn_new_zone(table, cfg->fc_dst_len)))
return -ENOBUFS;
key = 0;
if (cfg->fc_dst) {
if (cfg->fc_dst & ~FZ_MASK(fz))
return -EINVAL;
key = fz_key(cfg->fc_dst, fz);
}
fi = fib_create_info(cfg);
if (IS_ERR(fi))
return PTR_ERR(fi);
if (fz->fz_nent > (fz->fz_divisor<<1) &&
fz->fz_divisor < FZ_MAX_DIVISOR &&
(cfg->fc_dst_len == 32 ||
(1 << cfg->fc_dst_len) > fz->fz_divisor))
fn_rehash_zone(fz);
f = fib_find_node(fz, key);
if (!f)
fa = NULL;
else
fa = fib_find_alias(&f->fn_alias, tos, fi->fib_priority);
/* Now fa, if non-NULL, points to the first fib alias
* with the same keys [prefix,tos,priority], if such key already
* exists or to the node before which we will insert new one.
*
* If fa is NULL, we will need to allocate a new one and
* insert to the head of f.
*
* If f is NULL, no fib node matched the destination key
* and we need to allocate a new one of those as well.
*/
if (fa && fa->fa_tos == tos &&
fa->fa_info->fib_priority == fi->fib_priority) {
struct fib_alias *fa_first, *fa_match;
err = -EEXIST;
if (cfg->fc_nlflags & NLM_F_EXCL)
goto out;
/* We have 2 goals:
* 1. Find exact match for type, scope, fib_info to avoid
* duplicate routes
* 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
*/
fa_match = NULL;
fa_first = fa;
fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
if (fa->fa_tos != tos)
break;
if (fa->fa_info->fib_priority != fi->fib_priority)
break;
if (fa->fa_type == cfg->fc_type &&
fa->fa_scope == cfg->fc_scope &&
fa->fa_info == fi) {
fa_match = fa;
break;
}
}
if (cfg->fc_nlflags & NLM_F_REPLACE) {
struct fib_info *fi_drop;
u8 state;
fa = fa_first;
if (fa_match) {
if (fa == fa_match)
err = 0;
goto out;
}
write_lock_bh(&fib_hash_lock);
fi_drop = fa->fa_info;
fa->fa_info = fi;
fa->fa_type = cfg->fc_type;
fa->fa_scope = cfg->fc_scope;
state = fa->fa_state;
fa->fa_state &= ~FA_S_ACCESSED;
fib_hash_genid++;
write_unlock_bh(&fib_hash_lock);
fib_release_info(fi_drop);
if (state & FA_S_ACCESSED)
rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
rtmsg_fib(RTM_NEWROUTE, key, fa, cfg->fc_dst_len, tb->tb_id,
&cfg->fc_nlinfo, NLM_F_REPLACE);
return 0;
}
/* Error if we find a perfect match which
* uses the same scope, type, and nexthop
* information.
*/
if (fa_match)
goto out;
if (!(cfg->fc_nlflags & NLM_F_APPEND))
fa = fa_first;
}
err = -ENOENT;
if (!(cfg->fc_nlflags & NLM_F_CREATE))
goto out;
err = -ENOBUFS;
if (!f) {
new_f = kmem_cache_zalloc(fn_hash_kmem, GFP_KERNEL);
if (new_f == NULL)
goto out;
INIT_HLIST_NODE(&new_f->fn_hash);
INIT_LIST_HEAD(&new_f->fn_alias);
new_f->fn_key = key;
f = new_f;
}
new_fa = &f->fn_embedded_alias;
if (new_fa->fa_info != NULL) {
new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
if (new_fa == NULL)
goto out;
}
new_fa->fa_info = fi;
new_fa->fa_tos = tos;
new_fa->fa_type = cfg->fc_type;
new_fa->fa_scope = cfg->fc_scope;
new_fa->fa_state = 0;
/*
* Insert new entry to the list.
*/
write_lock_bh(&fib_hash_lock);
if (new_f)
fib_insert_node(fz, new_f);
list_add_tail(&new_fa->fa_list,
(fa ? &fa->fa_list : &f->fn_alias));
fib_hash_genid++;
write_unlock_bh(&fib_hash_lock);
if (new_f)
fz->fz_nent++;
rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
rtmsg_fib(RTM_NEWROUTE, key, new_fa, cfg->fc_dst_len, tb->tb_id,
&cfg->fc_nlinfo, 0);
return 0;
out:
if (new_f)
kmem_cache_free(fn_hash_kmem, new_f);
fib_release_info(fi);
return err;
}
int fib_table_delete(struct fib_table *tb, struct fib_config *cfg)
{
struct fn_hash *table = (struct fn_hash *)tb->tb_data;
struct fib_node *f;
struct fib_alias *fa, *fa_to_delete;
struct fn_zone *fz;
__be32 key;
if (cfg->fc_dst_len > 32)
return -EINVAL;
if ((fz = table->fn_zones[cfg->fc_dst_len]) == NULL)
return -ESRCH;
key = 0;
if (cfg->fc_dst) {
if (cfg->fc_dst & ~FZ_MASK(fz))
return -EINVAL;
key = fz_key(cfg->fc_dst, fz);
}
f = fib_find_node(fz, key);
if (!f)
fa = NULL;
else
fa = fib_find_alias(&f->fn_alias, cfg->fc_tos, 0);
if (!fa)
return -ESRCH;
fa_to_delete = NULL;
fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
struct fib_info *fi = fa->fa_info;
if (fa->fa_tos != cfg->fc_tos)
break;
if ((!cfg->fc_type ||
fa->fa_type == cfg->fc_type) &&
(cfg->fc_scope == RT_SCOPE_NOWHERE ||
fa->fa_scope == cfg->fc_scope) &&
(!cfg->fc_protocol ||
fi->fib_protocol == cfg->fc_protocol) &&
fib_nh_match(cfg, fi) == 0) {
fa_to_delete = fa;
break;
}
}
if (fa_to_delete) {
int kill_fn;
fa = fa_to_delete;
rtmsg_fib(RTM_DELROUTE, key, fa, cfg->fc_dst_len,
tb->tb_id, &cfg->fc_nlinfo, 0);
kill_fn = 0;
write_lock_bh(&fib_hash_lock);
list_del(&fa->fa_list);
if (list_empty(&f->fn_alias)) {
hlist_del(&f->fn_hash);
kill_fn = 1;
}
fib_hash_genid++;
write_unlock_bh(&fib_hash_lock);
if (fa->fa_state & FA_S_ACCESSED)
rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
fn_free_alias(fa, f);
if (kill_fn) {
fn_free_node(f);
fz->fz_nent--;
}
return 0;
}
return -ESRCH;
}
static int fn_flush_list(struct fn_zone *fz, int idx)
{
struct hlist_head *head = &fz->fz_hash[idx];
struct hlist_node *node, *n;
struct fib_node *f;
int found = 0;
hlist_for_each_entry_safe(f, node, n, head, fn_hash) {
struct fib_alias *fa, *fa_node;
int kill_f;
kill_f = 0;
list_for_each_entry_safe(fa, fa_node, &f->fn_alias, fa_list) {
struct fib_info *fi = fa->fa_info;
if (fi && (fi->fib_flags&RTNH_F_DEAD)) {
write_lock_bh(&fib_hash_lock);
list_del(&fa->fa_list);
if (list_empty(&f->fn_alias)) {
hlist_del(&f->fn_hash);
kill_f = 1;
}
fib_hash_genid++;
write_unlock_bh(&fib_hash_lock);
fn_free_alias(fa, f);
found++;
}
}
if (kill_f) {
fn_free_node(f);
fz->fz_nent--;
}
}
return found;
}
int fib_table_flush(struct fib_table *tb)
{
struct fn_hash *table = (struct fn_hash *) tb->tb_data;
struct fn_zone *fz;
int found = 0;
for (fz = table->fn_zone_list; fz; fz = fz->fz_next) {
int i;
for (i = fz->fz_divisor - 1; i >= 0; i--)
found += fn_flush_list(fz, i);
}
return found;
}
static inline int
fn_hash_dump_bucket(struct sk_buff *skb, struct netlink_callback *cb,
struct fib_table *tb,
struct fn_zone *fz,
struct hlist_head *head)
{
struct hlist_node *node;
struct fib_node *f;
int i, s_i;
s_i = cb->args[4];
i = 0;
hlist_for_each_entry(f, node, head, fn_hash) {
struct fib_alias *fa;
list_for_each_entry(fa, &f->fn_alias, fa_list) {
if (i < s_i)
goto next;
if (fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
cb->nlh->nlmsg_seq,
RTM_NEWROUTE,
tb->tb_id,
fa->fa_type,
fa->fa_scope,
f->fn_key,
fz->fz_order,
fa->fa_tos,
fa->fa_info,
NLM_F_MULTI) < 0) {
cb->args[4] = i;
return -1;
}
next:
i++;
}
}
cb->args[4] = i;
return skb->len;
}
static inline int
fn_hash_dump_zone(struct sk_buff *skb, struct netlink_callback *cb,
struct fib_table *tb,
struct fn_zone *fz)
{
int h, s_h;
if (fz->fz_hash == NULL)
return skb->len;
s_h = cb->args[3];
for (h = s_h; h < fz->fz_divisor; h++) {
if (hlist_empty(&fz->fz_hash[h]))
continue;
if (fn_hash_dump_bucket(skb, cb, tb, fz, &fz->fz_hash[h]) < 0) {
cb->args[3] = h;
return -1;
}
memset(&cb->args[4], 0,
sizeof(cb->args) - 4*sizeof(cb->args[0]));
}
cb->args[3] = h;
return skb->len;
}
int fib_table_dump(struct fib_table *tb, struct sk_buff *skb,
struct netlink_callback *cb)
{
int m, s_m;
struct fn_zone *fz;
struct fn_hash *table = (struct fn_hash *)tb->tb_data;
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 (fn_hash_dump_zone(skb, cb, tb, fz) < 0) {
cb->args[2] = m;
read_unlock(&fib_hash_lock);
return -1;
}
memset(&cb->args[3], 0,
sizeof(cb->args) - 3*sizeof(cb->args[0]));
}
read_unlock(&fib_hash_lock);
cb->args[2] = m;
return skb->len;
}
void __init fib_hash_init(void)
{
fn_hash_kmem = kmem_cache_create("ip_fib_hash", sizeof(struct fib_node),
0, SLAB_PANIC, NULL);
fn_alias_kmem = kmem_cache_create("ip_fib_alias", sizeof(struct fib_alias),
0, SLAB_PANIC, NULL);
}
struct fib_table *fib_hash_table(u32 id)
{
struct fib_table *tb;
tb = kmalloc(sizeof(struct fib_table) + sizeof(struct fn_hash),
GFP_KERNEL);
if (tb == NULL)
return NULL;
tb->tb_id = id;
tb->tb_default = -1;
memset(tb->tb_data, 0, sizeof(struct fn_hash));
return tb;
}
/* ------------------------------------------------------------------------ */
#ifdef CONFIG_PROC_FS
struct fib_iter_state {
struct seq_net_private p;
struct fn_zone *zone;
int bucket;
struct hlist_head *hash_head;
struct fib_node *fn;
struct fib_alias *fa;
loff_t pos;
unsigned int genid;
int valid;
};
static struct fib_alias *fib_get_first(struct seq_file *seq)
{
struct fib_iter_state *iter = seq->private;
struct fib_table *main_table;
struct fn_hash *table;
main_table = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
table = (struct fn_hash *)main_table->tb_data;
iter->bucket = 0;
iter->hash_head = NULL;
iter->fn = NULL;
iter->fa = NULL;
iter->pos = 0;
iter->genid = fib_hash_genid;
iter->valid = 1;
for (iter->zone = table->fn_zone_list; iter->zone;
iter->zone = iter->zone->fz_next) {
int maxslot;
if (!iter->zone->fz_nent)
continue;
iter->hash_head = iter->zone->fz_hash;
maxslot = iter->zone->fz_divisor;
for (iter->bucket = 0; iter->bucket < maxslot;
++iter->bucket, ++iter->hash_head) {
struct hlist_node *node;
struct fib_node *fn;
hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
struct fib_alias *fa;
list_for_each_entry(fa, &fn->fn_alias, fa_list) {
iter->fn = fn;
iter->fa = fa;
goto out;
}
}
}
}
out:
return iter->fa;
}
static struct fib_alias *fib_get_next(struct seq_file *seq)
{
struct fib_iter_state *iter = seq->private;
struct fib_node *fn;
struct fib_alias *fa;
/* Advance FA, if any. */
fn = iter->fn;
fa = iter->fa;
if (fa) {
BUG_ON(!fn);
list_for_each_entry_continue(fa, &fn->fn_alias, fa_list) {
iter->fa = fa;
goto out;
}
}
fa = iter->fa = NULL;
/* Advance FN. */
if (fn) {
struct hlist_node *node = &fn->fn_hash;
hlist_for_each_entry_continue(fn, node, fn_hash) {
iter->fn = fn;
list_for_each_entry(fa, &fn->fn_alias, fa_list) {
iter->fa = fa;
goto out;
}
}
}
fn = iter->fn = NULL;
/* Advance hash chain. */
if (!iter->zone)
goto out;
for (;;) {
struct hlist_node *node;
int maxslot;
maxslot = iter->zone->fz_divisor;
while (++iter->bucket < maxslot) {
iter->hash_head++;
hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
list_for_each_entry(fa, &fn->fn_alias, fa_list) {
iter->fn = fn;
iter->fa = fa;
goto out;
}
}
}
iter->zone = iter->zone->fz_next;
if (!iter->zone)
goto out;
iter->bucket = 0;
iter->hash_head = iter->zone->fz_hash;
hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
list_for_each_entry(fa, &fn->fn_alias, fa_list) {
iter->fn = fn;
iter->fa = fa;
goto out;
}
}
}
out:
iter->pos++;
return fa;
}
static struct fib_alias *fib_get_idx(struct seq_file *seq, loff_t pos)
{
struct fib_iter_state *iter = seq->private;
struct fib_alias *fa;
if (iter->valid && pos >= iter->pos && iter->genid == fib_hash_genid) {
fa = iter->fa;
pos -= iter->pos;
} else
fa = fib_get_first(seq);
if (fa)
while (pos && (fa = fib_get_next(seq)))
--pos;
return pos ? NULL : fa;
}
static void *fib_seq_start(struct seq_file *seq, loff_t *pos)
__acquires(fib_hash_lock)
{
void *v = NULL;
read_lock(&fib_hash_lock);
if (fib_get_table(seq_file_net(seq), RT_TABLE_MAIN))
v = *pos ? fib_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
return v;
}
static void *fib_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
++*pos;
return v == SEQ_START_TOKEN ? fib_get_first(seq) : fib_get_next(seq);
}
static void fib_seq_stop(struct seq_file *seq, void *v)
__releases(fib_hash_lock)
{
read_unlock(&fib_hash_lock);
}
static unsigned fib_flag_trans(int type, __be32 mask, struct fib_info *fi)
{
static const unsigned type2flags[RTN_MAX + 1] = {
[7] = RTF_REJECT, [8] = RTF_REJECT,
};
unsigned flags = type2flags[type];
if (fi && fi->fib_nh->nh_gw)
flags |= RTF_GATEWAY;
if (mask == htonl(0xFFFFFFFF))
flags |= RTF_HOST;
flags |= RTF_UP;
return flags;
}
/*
* This outputs /proc/net/route.
*
* It always works in backward compatibility mode.
* The format of the file is not supposed to be changed.
*/
static int fib_seq_show(struct seq_file *seq, void *v)
{
struct fib_iter_state *iter;
int len;
__be32 prefix, mask;
unsigned flags;
struct fib_node *f;
struct fib_alias *fa;
struct fib_info *fi;
if (v == SEQ_START_TOKEN) {
seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
"\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
"\tWindow\tIRTT");
goto out;
}
iter = seq->private;
f = iter->fn;
fa = iter->fa;
fi = fa->fa_info;
prefix = f->fn_key;
mask = FZ_MASK(iter->zone);
flags = fib_flag_trans(fa->fa_type, mask, fi);
if (fi)
seq_printf(seq,
"%s\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u%n",
fi->fib_dev ? fi->fib_dev->name : "*", prefix,
fi->fib_nh->nh_gw, flags, 0, 0, fi->fib_priority,
mask, (fi->fib_advmss ? fi->fib_advmss + 40 : 0),
fi->fib_window,
fi->fib_rtt >> 3, &len);
else
seq_printf(seq,
"*\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u%n",
prefix, 0, flags, 0, 0, 0, mask, 0, 0, 0, &len);
seq_printf(seq, "%*s\n", 127 - len, "");
out:
return 0;
}
static const struct seq_operations fib_seq_ops = {
.start = fib_seq_start,
.next = fib_seq_next,
.stop = fib_seq_stop,
.show = fib_seq_show,
};
static int fib_seq_open(struct inode *inode, struct file *file)
{
return seq_open_net(inode, file, &fib_seq_ops,
sizeof(struct fib_iter_state));
}
static const struct file_operations fib_seq_fops = {
.owner = THIS_MODULE,
.open = fib_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_net,
};
int __net_init fib_proc_init(struct net *net)
{
if (!proc_net_fops_create(net, "route", S_IRUGO, &fib_seq_fops))
return -ENOMEM;
return 0;
}
void __net_exit fib_proc_exit(struct net *net)
{
proc_net_remove(net, "route");
}
#endif /* CONFIG_PROC_FS */
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