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/*
* Forwarding database
* Linux ethernet bridge
*
* Authors:
* Lennert Buytenhek <buytenh@gnu.org>
*
* $Id: br_fdb.c,v 1.5.2.1 2002/01/17 00:59:01 davem Exp $
*
* 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 <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/if_bridge.h>
#include <asm/atomic.h>
#include <asm/uaccess.h>
#include "br_private.h"
static __inline__ unsigned long __timeout(struct net_bridge *br)
{
unsigned long timeout;
timeout = jiffies - br->ageing_time;
if (br->topology_change)
timeout = jiffies - br->forward_delay;
return timeout;
}
static __inline__ int has_expired(struct net_bridge *br,
struct net_bridge_fdb_entry *fdb)
{
if (!fdb->is_static &&
time_before_eq(fdb->ageing_timer, __timeout(br)))
return 1;
return 0;
}
static __inline__ void copy_fdb(struct __fdb_entry *ent, struct net_bridge_fdb_entry *f)
{
memset(ent, 0, sizeof(struct __fdb_entry));
memcpy(ent->mac_addr, f->addr.addr, ETH_ALEN);
ent->port_no = f->dst?f->dst->port_no:0;
ent->is_local = f->is_local;
ent->ageing_timer_value = 0;
if (!f->is_static)
ent->ageing_timer_value = jiffies - f->ageing_timer;
}
static __inline__ int br_mac_hash(unsigned char *mac)
{
unsigned long x;
x = mac[0];
x = (x << 2) ^ mac[1];
x = (x << 2) ^ mac[2];
x = (x << 2) ^ mac[3];
x = (x << 2) ^ mac[4];
x = (x << 2) ^ mac[5];
x ^= x >> 8;
return x & (BR_HASH_SIZE - 1);
}
static __inline__ void __hash_link(struct net_bridge *br,
struct net_bridge_fdb_entry *ent,
int hash)
{
ent->next_hash = br->hash[hash];
if (ent->next_hash != NULL)
ent->next_hash->pprev_hash = &ent->next_hash;
br->hash[hash] = ent;
ent->pprev_hash = &br->hash[hash];
}
static __inline__ void __hash_unlink(struct net_bridge_fdb_entry *ent)
{
*(ent->pprev_hash) = ent->next_hash;
if (ent->next_hash != NULL)
ent->next_hash->pprev_hash = ent->pprev_hash;
ent->next_hash = NULL;
ent->pprev_hash = NULL;
}
void br_fdb_changeaddr(struct net_bridge_port *p, unsigned char *newaddr)
{
struct net_bridge *br;
int i;
br = p->br;
write_lock_bh(&br->hash_lock);
for (i=0;i<BR_HASH_SIZE;i++) {
struct net_bridge_fdb_entry *f;
f = br->hash[i];
while (f != NULL) {
if (f->dst == p && f->is_local) {
__hash_unlink(f);
memcpy(f->addr.addr, newaddr, ETH_ALEN);
__hash_link(br, f, br_mac_hash(newaddr));
write_unlock_bh(&br->hash_lock);
return;
}
f = f->next_hash;
}
}
write_unlock_bh(&br->hash_lock);
}
void br_fdb_cleanup(struct net_bridge *br)
{
int i;
unsigned long timeout;
timeout = __timeout(br);
write_lock_bh(&br->hash_lock);
for (i=0;i<BR_HASH_SIZE;i++) {
struct net_bridge_fdb_entry *f;
f = br->hash[i];
while (f != NULL) {
struct net_bridge_fdb_entry *g;
g = f->next_hash;
if (!f->is_static &&
time_before_eq(f->ageing_timer, timeout)) {
__hash_unlink(f);
br_fdb_put(f);
}
f = g;
}
}
write_unlock_bh(&br->hash_lock);
}
void br_fdb_delete_by_port(struct net_bridge *br, struct net_bridge_port *p)
{
int i;
write_lock_bh(&br->hash_lock);
for (i=0;i<BR_HASH_SIZE;i++) {
struct net_bridge_fdb_entry *f;
f = br->hash[i];
while (f != NULL) {
struct net_bridge_fdb_entry *g;
g = f->next_hash;
if (f->dst == p) {
__hash_unlink(f);
br_fdb_put(f);
}
f = g;
}
}
write_unlock_bh(&br->hash_lock);
}
struct net_bridge_fdb_entry *br_fdb_get(struct net_bridge *br, unsigned char *addr)
{
struct net_bridge_fdb_entry *fdb;
read_lock_bh(&br->hash_lock);
fdb = br->hash[br_mac_hash(addr)];
while (fdb != NULL) {
if (!memcmp(fdb->addr.addr, addr, ETH_ALEN)) {
if (!has_expired(br, fdb)) {
atomic_inc(&fdb->use_count);
read_unlock_bh(&br->hash_lock);
return fdb;
}
read_unlock_bh(&br->hash_lock);
return NULL;
}
fdb = fdb->next_hash;
}
read_unlock_bh(&br->hash_lock);
return NULL;
}
void br_fdb_put(struct net_bridge_fdb_entry *ent)
{
if (atomic_dec_and_test(&ent->use_count))
kfree(ent);
}
int br_fdb_get_entries(struct net_bridge *br,
unsigned char *_buf,
int maxnum,
int offset)
{
int i;
int num;
struct __fdb_entry *walk;
num = 0;
walk = (struct __fdb_entry *)_buf;
read_lock_bh(&br->hash_lock);
for (i=0;i<BR_HASH_SIZE;i++) {
struct net_bridge_fdb_entry *f;
f = br->hash[i];
while (f != NULL && num < maxnum) {
struct __fdb_entry ent;
int err;
struct net_bridge_fdb_entry *g;
struct net_bridge_fdb_entry **pp;
if (has_expired(br, f)) {
f = f->next_hash;
continue;
}
if (offset) {
offset--;
f = f->next_hash;
continue;
}
copy_fdb(&ent, f);
atomic_inc(&f->use_count);
read_unlock_bh(&br->hash_lock);
err = copy_to_user(walk, &ent, sizeof(struct __fdb_entry));
read_lock_bh(&br->hash_lock);
g = f->next_hash;
pp = f->pprev_hash;
br_fdb_put(f);
if (err)
goto out_fault;
if (g == NULL && pp == NULL)
goto out_disappeared;
num++;
walk++;
f = g;
}
}
out:
read_unlock_bh(&br->hash_lock);
return num;
out_disappeared:
num = -EAGAIN;
goto out;
out_fault:
num = -EFAULT;
goto out;
}
static __inline__ void __fdb_possibly_replace(struct net_bridge_fdb_entry *fdb,
struct net_bridge_port *source,
int is_local)
{
if (!fdb->is_static || is_local) {
fdb->dst = source;
fdb->is_local = is_local;
fdb->is_static = is_local;
fdb->ageing_timer = jiffies;
}
}
void br_fdb_insert(struct net_bridge *br,
struct net_bridge_port *source,
unsigned char *addr,
int is_local)
{
struct net_bridge_fdb_entry *fdb;
int hash;
hash = br_mac_hash(addr);
write_lock_bh(&br->hash_lock);
fdb = br->hash[hash];
while (fdb != NULL) {
if (!fdb->is_local &&
!memcmp(fdb->addr.addr, addr, ETH_ALEN)) {
__fdb_possibly_replace(fdb, source, is_local);
write_unlock_bh(&br->hash_lock);
return;
}
fdb = fdb->next_hash;
}
fdb = kmalloc(sizeof(*fdb), GFP_ATOMIC);
if (fdb == NULL) {
write_unlock_bh(&br->hash_lock);
return;
}
memcpy(fdb->addr.addr, addr, ETH_ALEN);
atomic_set(&fdb->use_count, 1);
fdb->dst = source;
fdb->is_local = is_local;
fdb->is_static = is_local;
fdb->ageing_timer = jiffies;
__hash_link(br, fdb, hash);
write_unlock_bh(&br->hash_lock);
}
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