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OpenCloudOS-Kernel/net/ipv4/fib_hash.c

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/*
* 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 <linux/slab.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;
};
#define EMBEDDED_HASH_SIZE (L1_CACHE_BYTES / sizeof(struct hlist_head))
struct fn_zone {
struct fn_zone __rcu *fz_next; /* Next not empty zone */
struct hlist_head __rcu *fz_hash; /* Hash table pointer */
seqlock_t fz_lock;
u32 fz_hashmask; /* (fz_divisor - 1) */
u8 fz_order; /* Zone order (0..32) */
u8 fz_revorder; /* 32 - fz_order */
__be32 fz_mask; /* inet_make_mask(order) */
#define FZ_MASK(fz) ((fz)->fz_mask)
struct hlist_head fz_embedded_hash[EMBEDDED_HASH_SIZE];
int fz_nent; /* Number of entries */
int fz_divisor; /* Hash size (mask+1) */
};
struct fn_hash {
struct fn_zone *fn_zones[33];
struct fn_zone __rcu *fn_zone_list;
};
static inline u32 fn_hash(__be32 key, struct fn_zone *fz)
{
u32 h = ntohl(key) >> fz->fz_revorder;
h ^= (h>>20);
h ^= (h>>10);
h ^= (h>>5);
h &= fz->fz_hashmask;
return h;
}
static inline __be32 fz_key(__be32 dst, struct fn_zone *fz)
{
return dst & FZ_MASK(fz);
}
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);
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_rcu(&f->fn_hash);
new_head = rcu_dereference_protected(fz->fz_hash, 1) +
fn_hash(f->fn_key, fz);
hlist_add_head_rcu(&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;
new_divisor = old_divisor = fz->fz_divisor;
switch (old_divisor) {
case EMBEDDED_HASH_SIZE:
new_divisor *= EMBEDDED_HASH_SIZE;
break;
case EMBEDDED_HASH_SIZE*EMBEDDED_HASH_SIZE:
new_divisor *= (EMBEDDED_HASH_SIZE/2);
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) {
struct fn_zone nfz;
memcpy(&nfz, fz, sizeof(nfz));
write_seqlock_bh(&fz->fz_lock);
old_ht = rcu_dereference_protected(fz->fz_hash, 1);
RCU_INIT_POINTER(nfz.fz_hash, ht);
nfz.fz_hashmask = new_hashmask;
nfz.fz_divisor = new_divisor;
fn_rebuild_zone(&nfz, old_ht, old_divisor);
fib_hash_genid++;
rcu_assign_pointer(fz->fz_hash, ht);
fz->fz_hashmask = new_hashmask;
fz->fz_divisor = new_divisor;
write_sequnlock_bh(&fz->fz_lock);
if (old_ht != fz->fz_embedded_hash) {
synchronize_rcu();
fz_hash_free(old_ht, old_divisor);
}
}
}
static void fn_free_node_rcu(struct rcu_head *head)
{
struct fib_node *f = container_of(head, struct fib_node, fn_embedded_alias.rcu);
kmem_cache_free(fn_hash_kmem, f);
}
static inline void fn_free_node(struct fib_node *f)
{
call_rcu(&f->fn_embedded_alias.rcu, fn_free_node_rcu);
}
static void fn_free_alias_rcu(struct rcu_head *head)
{
struct fib_alias *fa = container_of(head, struct fib_alias, rcu);
kmem_cache_free(fn_alias_kmem, fa);
}
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
call_rcu(&fa->rcu, fn_free_alias_rcu);
}
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;
seqlock_init(&fz->fz_lock);
fz->fz_divisor = z ? EMBEDDED_HASH_SIZE : 1;
fz->fz_hashmask = fz->fz_divisor - 1;
RCU_INIT_POINTER(fz->fz_hash, fz->fz_embedded_hash);
fz->fz_order = z;
fz->fz_revorder = 32 - 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;
if (i > 32) {
/* No more specific masks, we are the first. */
rcu_assign_pointer(fz->fz_next,
rtnl_dereference(table->fn_zone_list));
rcu_assign_pointer(table->fn_zone_list, fz);
} else {
rcu_assign_pointer(fz->fz_next,
rtnl_dereference(table->fn_zones[i]->fz_next));
rcu_assign_pointer(table->fn_zones[i]->fz_next, fz);
}
table->fn_zones[z] = fz;
fib_hash_genid++;
return fz;
}
int fib_table_lookup(struct fib_table *tb,
const struct flowi *flp, struct fib_result *res,
int fib_flags)
{
int err;
struct fn_zone *fz;
struct fn_hash *t = (struct fn_hash *)tb->tb_data;
rcu_read_lock();
for (fz = rcu_dereference(t->fn_zone_list);
fz != NULL;
fz = rcu_dereference(fz->fz_next)) {
struct hlist_head *head;
struct hlist_node *node;
struct fib_node *f;
__be32 k;
unsigned int seq;
do {
seq = read_seqbegin(&fz->fz_lock);
k = fz_key(flp->fl4_dst, fz);
head = rcu_dereference(fz->fz_hash) + fn_hash(k, fz);
hlist_for_each_entry_rcu(f, node, head, fn_hash) {
if (f->fn_key != k)
continue;
err = fib_semantic_match(&f->fn_alias,
flp, res,
fz->fz_order, fib_flags);
if (err <= 0)
goto out;
}
} while (read_seqretry(&fz->fz_lock, seq));
}
err = 1;
out:
rcu_read_unlock();
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];
struct hlist_head *head;
if (fz == NULL)
return;
last_idx = -1;
last_resort = NULL;
order = -1;
rcu_read_lock();
head = rcu_dereference(fz->fz_hash);
hlist_for_each_entry_rcu(f, node, head, fn_hash) {
struct fib_alias *fa;
list_for_each_entry_rcu(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;
fib_alias_accessed(fa);
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:
rcu_read_unlock();
}
/* Insert node F to FZ. */
static inline void fib_insert_node(struct fn_zone *fz, struct fib_node *f)
{
struct hlist_head *head = rtnl_dereference(fz->fz_hash) + fn_hash(f->fn_key, fz);
hlist_add_head_rcu(&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 = rtnl_dereference(fz->fz_hash) + fn_hash(key, fz);
struct hlist_node *node;
struct fib_node *f;
hlist_for_each_entry_rcu(f, node, head, fn_hash) {
if (f->fn_key == key)
return f;
}
return NULL;
}
static struct fib_alias *fib_fast_alloc(struct fib_node *f)
{
struct fib_alias *fa = &f->fn_embedded_alias;
if (fa->fa_info != NULL)
fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
return fa;
}
/* Caller must hold RTNL. */
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) {
u8 state;
fa = fa_first;
if (fa_match) {
if (fa == fa_match)
err = 0;
goto out;
}
err = -ENOBUFS;
new_fa = fib_fast_alloc(f);
if (new_fa == NULL)
goto out;
new_fa->fa_tos = fa->fa_tos;
new_fa->fa_info = fi;
new_fa->fa_type = cfg->fc_type;
new_fa->fa_scope = cfg->fc_scope;
state = fa->fa_state;
new_fa->fa_state = state & ~FA_S_ACCESSED;
fib_hash_genid++;
list_replace_rcu(&fa->fa_list, &new_fa->fa_list);
fn_free_alias(fa, f);
if (state & FA_S_ACCESSED)
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, 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 = fib_fast_alloc(f);
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.
*/
if (new_f)
fib_insert_node(fz, new_f);
list_add_tail_rcu(&new_fa->fa_list,
(fa ? &fa->fa_list : &f->fn_alias));
fib_hash_genid++;
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;
list_del_rcu(&fa->fa_list);
if (list_empty(&f->fn_alias)) {
hlist_del_rcu(&f->fn_hash);
kill_fn = 1;
}
fib_hash_genid++;
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 = rtnl_dereference(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)) {
list_del_rcu(&fa->fa_list);
if (list_empty(&f->fn_alias)) {
hlist_del_rcu(&f->fn_hash);
kill_f = 1;
}
fib_hash_genid++;
fn_free_alias(fa, f);
found++;
}
}
if (kill_f) {
fn_free_node(f);
fz->fz_nent--;
}
}
return found;
}
/* caller must hold RTNL. */
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 = rtnl_dereference(table->fn_zone_list);
fz != NULL;
fz = rtnl_dereference(fz->fz_next)) {
int i;
for (i = fz->fz_divisor - 1; i >= 0; i--)
found += fn_flush_list(fz, i);
}
return found;
}
void fib_free_table(struct fib_table *tb)
{
struct fn_hash *table = (struct fn_hash *) tb->tb_data;
struct fn_zone *fz, *next;
next = table->fn_zone_list;
while (next != NULL) {
fz = next;
next = fz->fz_next;
if (fz->fz_hash != fz->fz_embedded_hash)
fz_hash_free(fz->fz_hash, fz->fz_divisor);
kfree(fz);
}
kfree(tb);
}
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_rcu(f, node, head, fn_hash) {
struct fib_alias *fa;
list_for_each_entry_rcu(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;
struct hlist_head *head = rcu_dereference(fz->fz_hash);
if (head == NULL)
return skb->len;
s_h = cb->args[3];
for (h = s_h; h < fz->fz_divisor; h++) {
if (hlist_empty(head + h))
continue;
if (fn_hash_dump_bucket(skb, cb, tb, fz, head + 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 = 0, s_m;
struct fn_zone *fz;
struct fn_hash *table = (struct fn_hash *)tb->tb_data;
s_m = cb->args[2];
rcu_read_lock();
for (fz = rcu_dereference(table->fn_zone_list);
fz != NULL;
fz = rcu_dereference(fz->fz_next), m++) {
if (m < s_m)
continue;
if (fn_hash_dump_zone(skb, cb, tb, fz) < 0) {
cb->args[2] = m;
rcu_read_unlock();
return -1;
}
memset(&cb->args[3], 0,
sizeof(cb->args) - 3*sizeof(cb->args[0]));
}
rcu_read_unlock();
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 = rcu_dereference(table->fn_zone_list);
iter->zone != NULL;
iter->zone = rcu_dereference(iter->zone->fz_next)) {
int maxslot;
if (!iter->zone->fz_nent)
continue;
iter->hash_head = rcu_dereference(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 = rcu_dereference(iter->zone->fz_next);
if (!iter->zone)
goto out;
iter->bucket = 0;
iter->hash_head = rcu_dereference(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(RCU)
{
void *v = NULL;
rcu_read_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(RCU)
{
rcu_read_unlock();
}
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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