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linux/net/bridge/br_if.c

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/*
* 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 <linux/if_ether.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 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;
}
}
/* 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 */
}
/*
* Check for port carrier transistions.
* Called from work queue to allow for calling functions that
* might sleep (such as speed check), and to debounce.
*/
static void port_carrier_check(struct work_struct *work)
{
struct net_bridge_port *p;
struct net_device *dev;
struct net_bridge *br;
dev = container_of(work, struct net_bridge_port,
carrier_check.work)->dev;
work_release(work);
rtnl_lock();
p = dev->br_port;
if (!p)
goto done;
br = p->br;
if (netif_carrier_ok(dev))
p->path_cost = port_cost(dev);
if (br->dev->flags & IFF_UP) {
spin_lock_bh(&br->lock);
if (netif_carrier_ok(dev)) {
if (p->state == BR_STATE_DISABLED)
br_stp_enable_port(p);
} else {
if (p->state != BR_STATE_DISABLED)
br_stp_disable_port(p);
}
spin_unlock_bh(&br->lock);
}
done:
rtnl_unlock();
}
static void release_nbp(struct kobject *kobj)
{
struct net_bridge_port *p
= container_of(kobj, struct net_bridge_port, kobj);
kfree(p);
}
static struct kobj_type brport_ktype = {
#ifdef CONFIG_SYSFS
.sysfs_ops = &brport_sysfs_ops,
#endif
.release = release_nbp,
};
static void destroy_nbp(struct net_bridge_port *p)
{
struct net_device *dev = p->dev;
p->br = NULL;
p->dev = NULL;
dev_put(dev);
kobject_put(&p->kobj);
}
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);
}
/* Delete port(interface) from bridge is done in two steps.
* via RCU. First step, marks device as down. That deletes
* all the timers and stops new packets from flowing through.
*
* Final cleanup doesn't occur until after all CPU's finished
* processing packets.
*
* Protected from multiple admin operations by RTNL mutex
*/
static void del_nbp(struct net_bridge_port *p)
{
struct net_bridge *br = p->br;
struct net_device *dev = p->dev;
sysfs_remove_link(&br->ifobj, dev->name);
dev_set_promiscuity(dev, -1);
cancel_delayed_work(&p->carrier_check);
spin_lock_bh(&br->lock);
br_stp_disable_port(p);
spin_unlock_bh(&br->lock);
br_fdb_delete_by_port(br, p, 1);
list_del_rcu(&p->list);
rcu_assign_pointer(dev->br_port, NULL);
kobject_uevent(&p->kobj, KOBJ_REMOVE);
kobject_del(&p->kobj);
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) {
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;
memcpy(br->group_addr, br_group_address, ETH_ALEN);
br->feature_mask = dev->features;
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 = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long),
GFP_KERNEL);
if (!inuse)
return -ENOMEM;
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 but without bridge lock */
static struct net_bridge_port *new_nbp(struct net_bridge *br,
struct net_device *dev)
{
int index;
struct net_bridge_port *p;
index = find_portno(br);
if (index < 0)
return ERR_PTR(index);
p = kzalloc(sizeof(*p), GFP_KERNEL);
if (p == NULL)
return ERR_PTR(-ENOMEM);
p->br = br;
dev_hold(dev);
p->dev = dev;
p->path_cost = port_cost(dev);
p->priority = 0x8000 >> BR_PORT_BITS;
p->port_no = index;
br_init_port(p);
p->state = BR_STATE_DISABLED;
INIT_DELAYED_WORK_NAR(&p->carrier_check, port_carrier_check);
br_stp_port_timer_init(p);
kobject_init(&p->kobj);
kobject_set_name(&p->kobj, SYSFS_BRIDGE_PORT_ATTR);
p->kobj.ktype = &brport_ktype;
p->kobj.parent = &(dev->class_dev.kobj);
p->kobj.kset = NULL;
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) {
free_netdev(dev);
goto out;
}
}
ret = register_netdevice(dev);
if (ret)
goto out;
ret = br_sysfs_addbr(dev);
if (ret)
unregister_netdevice(dev);
out:
rtnl_unlock();
return ret;
}
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: ETH_DATA_LEN 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 = ETH_DATA_LEN;
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;
checksum = br->feature_mask & NETIF_F_ALL_CSUM ? NETIF_F_NO_CSUM : 0;
features = br->feature_mask & ~NETIF_F_ALL_CSUM;
list_for_each_entry(p, &br->port_list, list) {
unsigned long feature = p->dev->features;
if (checksum & NETIF_F_NO_CSUM && !(feature & NETIF_F_NO_CSUM))
checksum ^= NETIF_F_NO_CSUM | NETIF_F_HW_CSUM;
if (checksum & NETIF_F_HW_CSUM && !(feature & NETIF_F_HW_CSUM))
checksum ^= NETIF_F_HW_CSUM | NETIF_F_IP_CSUM;
if (!(feature & NETIF_F_IP_CSUM))
checksum = 0;
if (feature & NETIF_F_GSO)
feature |= NETIF_F_GSO_SOFTWARE;
feature |= NETIF_F_GSO;
features &= feature;
}
if (!(checksum & NETIF_F_ALL_CSUM))
features &= ~NETIF_F_SG;
if (!(features & NETIF_F_SG))
features &= ~NETIF_F_GSO_MASK;
br->dev->features = features | checksum | NETIF_F_LLTX |
NETIF_F_GSO_ROBUST;
}
/* 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;
p = new_nbp(br, dev);
if (IS_ERR(p))
return PTR_ERR(p);
err = kobject_add(&p->kobj);
if (err)
goto err0;
err = br_fdb_insert(br, p, dev->dev_addr);
if (err)
goto err1;
err = br_sysfs_addif(p);
if (err)
goto err2;
rcu_assign_pointer(dev->br_port, p);
dev_set_promiscuity(dev, 1);
list_add_rcu(&p->list, &br->port_list);
spin_lock_bh(&br->lock);
br_stp_recalculate_bridge_id(br);
br_features_recompute(br);
schedule_delayed_work(&p->carrier_check, BR_PORT_DEBOUNCE);
spin_unlock_bh(&br->lock);
dev_set_mtu(br->dev, br_min_mtu(br));
kobject_uevent(&p->kobj, KOBJ_ADD);
return 0;
err2:
br_fdb_delete_by_port(br, p, 1);
err1:
kobject_del(&p->kobj);
err0:
kobject_put(&p->kobj);
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;
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();
}
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