/*
* Userspace interface
* Linux ethernet bridge
*
* Authors:
* Lennert Buytenhek <buytenh@gnu.org>
*
* $Id: br_if.c,v 1.7 2001/12/24 00:59:55 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/netdevice.h>
#include <linux/ethtool.h>
#include <linux/if_arp.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/rtnetlink.h>
#include <net/sock.h>
#include "br_private.h"
/*
* Determine initial path cost based on speed.
* using recommendations from 802.1d standard
*
* Need to simulate user ioctl because not all device's that support
* ethtool, use ethtool_ops. Also, since driver might sleep need to
* not be holding any locks.
*/
static int br_initial_port_cost(struct net_device *dev)
{
struct ethtool_cmd ecmd = { ETHTOOL_GSET };
struct ifreq ifr;
mm_segment_t old_fs;
int err;
strncpy(ifr.ifr_name, dev->name, IFNAMSIZ);
ifr.ifr_data = (void __user *) &ecmd;
old_fs = get_fs();
set_fs(KERNEL_DS);
err = dev_ethtool(&ifr);
set_fs(old_fs);
if (!err) {
switch(ecmd.speed) {
case SPEED_100:
return 19;
case SPEED_1000:
return 4;
case SPEED_10000:
return 2;
case SPEED_10:
return 100;
default:
pr_info("bridge: can't decode speed from %s: %d\n",
dev->name, ecmd.speed);
return 100;
}
}
/* Old silly heuristics based on name */
if (!strncmp(dev->name, "lec", 3))
return 7;
if (!strncmp(dev->name, "plip", 4))
return 2500;
return 100; /* assume old 10Mbps */
}
static void destroy_nbp(struct net_bridge_port *p)
{
struct net_device *dev = p->dev;
dev->br_port = NULL;
p->br = NULL;
p->dev = NULL;
dev_put(dev);
br_sysfs_freeif(p);
}
static void destroy_nbp_rcu(struct rcu_head *head)
{
struct net_bridge_port *p =
container_of(head, struct net_bridge_port, rcu);
destroy_nbp(p);
}
/* called with RTNL */
static void del_nbp(struct net_bridge_port *p)
{
struct net_bridge *br = p->br;
struct net_device *dev = p->dev;
dev_set_promiscuity(dev, -1);
spin_lock_bh(&br->lock);
br_stp_disable_port(p);
spin_unlock_bh(&br->lock);
br_fdb_delete_by_port(br, p);
list_del_rcu(&p->list);
del_timer_sync(&p->message_age_timer);
del_timer_sync(&p->forward_delay_timer);
del_timer_sync(&p->hold_timer);
call_rcu(&p->rcu, destroy_nbp_rcu);
}
/* called with RTNL */
static void del_br(struct net_bridge *br)
{
struct net_bridge_port *p, *n;
list_for_each_entry_safe(p, n, &br->port_list, list) {
br_sysfs_removeif(p);
del_nbp(p);
}
del_timer_sync(&br->gc_timer);
br_sysfs_delbr(br->dev);
unregister_netdevice(br->dev);
}
static struct net_device *new_bridge_dev(const char *name)
{
struct net_bridge *br;
struct net_device *dev;
dev = alloc_netdev(sizeof(struct net_bridge), name,
br_dev_setup);
if (!dev)
return NULL;
br = netdev_priv(dev);
br->dev = dev;
spin_lock_init(&br->lock);
INIT_LIST_HEAD(&br->port_list);
spin_lock_init(&br->hash_lock);
br->bridge_id.prio[0] = 0x80;
br->bridge_id.prio[1] = 0x00;
memset(br->bridge_id.addr, 0, ETH_ALEN);
br->stp_enabled = 0;
br->designated_root = br->bridge_id;
br->root_path_cost = 0;
br->root_port = 0;
br->bridge_max_age = br->max_age = 20 * HZ;
br->bridge_hello_time = br->hello_time = 2 * HZ;
br->bridge_forward_delay = br->forward_delay = 15 * HZ;
br->topology_change = 0;
br->topology_change_detected = 0;
br->ageing_time = 300 * HZ;
INIT_LIST_HEAD(&br->age_list);
br_stp_timer_init(br);
return dev;
}
/* find an available port number */
static int find_portno(struct net_bridge *br)
{
int index;
struct net_bridge_port *p;
unsigned long *inuse;
inuse = kmalloc(BITS_TO_LONGS(BR_MAX_PORTS)*sizeof(unsigned long),
GFP_KERNEL);
if (!inuse)
return -ENOMEM;
memset(inuse, 0, BITS_TO_LONGS(BR_MAX_PORTS)*sizeof(unsigned long));
set_bit(0, inuse); /* zero is reserved */
list_for_each_entry(p, &br->port_list, list) {
set_bit(p->port_no, inuse);
}
index = find_first_zero_bit(inuse, BR_MAX_PORTS);
kfree(inuse);
return (index >= BR_MAX_PORTS) ? -EXFULL : index;
}
/* called with RTNL */
static struct net_bridge_port *new_nbp(struct net_bridge *br,
struct net_device *dev,
unsigned long cost)
{
int index;
struct net_bridge_port *p;
index = find_portno(br);
if (index < 0)
return ERR_PTR(index);
p = kmalloc(sizeof(*p), GFP_KERNEL);
if (p == NULL)
return ERR_PTR(-ENOMEM);
memset(p, 0, sizeof(*p));
p->br = br;
dev_hold(dev);
p->dev = dev;
p->path_cost = cost;
p->priority = 0x8000 >> BR_PORT_BITS;
dev->br_port = p;
p->port_no = index;
br_init_port(p);
p->state = BR_STATE_DISABLED;
kobject_init(&p->kobj);
return p;
}
int br_add_bridge(const char *name)
{
struct net_device *dev;
int ret;
dev = new_bridge_dev(name);
if (!dev)
return -ENOMEM;
rtnl_lock();
if (strchr(dev->name, '%')) {
ret = dev_alloc_name(dev, dev->name);
if (ret < 0)
goto err1;
}
ret = register_netdevice(dev);
if (ret)
goto err2;
/* network device kobject is not setup until
* after rtnl_unlock does it's hotplug magic.
* so hold reference to avoid race.
*/
dev_hold(dev);
rtnl_unlock();
ret = br_sysfs_addbr(dev);
dev_put(dev);
if (ret)
unregister_netdev(dev);
out:
return ret;
err2:
free_netdev(dev);
err1:
rtnl_unlock();
goto out;
}
int br_del_bridge(const char *name)
{
struct net_device *dev;
int ret = 0;
rtnl_lock();
dev = __dev_get_by_name(name);
if (dev == NULL)
ret = -ENXIO; /* Could not find device */
else if (!(dev->priv_flags & IFF_EBRIDGE)) {
/* Attempt to delete non bridge device! */
ret = -EPERM;
}
else if (dev->flags & IFF_UP) {
/* Not shutdown yet. */
ret = -EBUSY;
}
else
del_br(netdev_priv(dev));
rtnl_unlock();
return ret;
}
/* Mtu of the bridge pseudo-device 1500 or the minimum of the ports */
int br_min_mtu(const struct net_bridge *br)
{
const struct net_bridge_port *p;
int mtu = 0;
ASSERT_RTNL();
if (list_empty(&br->port_list))
mtu = 1500;
else {
list_for_each_entry(p, &br->port_list, list) {
if (!mtu || p->dev->mtu < mtu)
mtu = p->dev->mtu;
}
}
return mtu;
}
/*
* Recomputes features using slave's features
*/
void br_features_recompute(struct net_bridge *br)
{
struct net_bridge_port *p;
unsigned long features, checksum;
features = NETIF_F_SG | NETIF_F_FRAGLIST
| NETIF_F_HIGHDMA | NETIF_F_TSO;
checksum = NETIF_F_IP_CSUM; /* least commmon subset */
list_for_each_entry(p, &br->port_list, list) {
if (!(p->dev->features
& (NETIF_F_IP_CSUM|NETIF_F_NO_CSUM|NETIF_F_HW_CSUM)))
checksum = 0;
features &= p->dev->features;
}
br->dev->features = features | checksum | NETIF_F_LLTX;
}
/* called with RTNL */
int br_add_if(struct net_bridge *br, struct net_device *dev)
{
struct net_bridge_port *p;
int err = 0;
if (dev->flags & IFF_LOOPBACK || dev->type != ARPHRD_ETHER)
return -EINVAL;
if (dev->hard_start_xmit == br_dev_xmit)
return -ELOOP;
if (dev->br_port != NULL)
return -EBUSY;
if (IS_ERR(p = new_nbp(br, dev, br_initial_port_cost(dev))))
return PTR_ERR(p);
if ((err = br_fdb_insert(br, p, dev->dev_addr)))
destroy_nbp(p);
else if ((err = br_sysfs_addif(p)))
del_nbp(p);
else {
dev_set_promiscuity(dev, 1);
list_add_rcu(&p->list, &br->port_list);
spin_lock_bh(&br->lock);
br_stp_recalculate_bridge_id(br);
if ((br->dev->flags & IFF_UP)
&& (dev->flags & IFF_UP) && netif_carrier_ok(dev))
br_stp_enable_port(p);
spin_unlock_bh(&br->lock);
dev_set_mtu(br->dev, br_min_mtu(br));
}
return err;
}
/* called with RTNL */
int br_del_if(struct net_bridge *br, struct net_device *dev)
{
struct net_bridge_port *p = dev->br_port;
if (!p || p->br != br)
return -EINVAL;
br_sysfs_removeif(p);
del_nbp(p);
spin_lock_bh(&br->lock);
br_stp_recalculate_bridge_id(br);
br_features_recompute(br);
spin_unlock_bh(&br->lock);
return 0;
}
void __exit br_cleanup_bridges(void)
{
struct net_device *dev, *nxt;
rtnl_lock();
for (dev = dev_base; dev; dev = nxt) {
nxt = dev->next;
if (dev->priv_flags & IFF_EBRIDGE)
del_br(dev->priv);
}
rtnl_unlock();
}
