linux-stable/net/bridge/br_stp_if.c
Stephen Hemminger 92c0574f11 bridge: make bridge address settings sticky
Normally, the bridge just chooses the smallest mac address as the
bridge id and mac address of bridge device. But if the administrator
has explictly set the interface address then don't change it.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-17 16:10:06 -07:00

288 lines
7.2 KiB
C

/*
* Spanning tree protocol; interface code
* Linux ethernet bridge
*
* Authors:
* Lennert Buytenhek <buytenh@gnu.org>
*
* 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/etherdevice.h>
#include <linux/rtnetlink.h>
#include "br_private.h"
#include "br_private_stp.h"
/* Port id is composed of priority and port number.
* NB: least significant bits of priority are dropped to
* make room for more ports.
*/
static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
{
return ((u16)priority << BR_PORT_BITS)
| (port_no & ((1<<BR_PORT_BITS)-1));
}
/* called under bridge lock */
void br_init_port(struct net_bridge_port *p)
{
p->port_id = br_make_port_id(p->priority, p->port_no);
br_become_designated_port(p);
p->state = BR_STATE_BLOCKING;
p->topology_change_ack = 0;
p->config_pending = 0;
}
/* called under bridge lock */
void br_stp_enable_bridge(struct net_bridge *br)
{
struct net_bridge_port *p;
spin_lock_bh(&br->lock);
mod_timer(&br->hello_timer, jiffies + br->hello_time);
mod_timer(&br->gc_timer, jiffies + HZ/10);
br_config_bpdu_generation(br);
list_for_each_entry(p, &br->port_list, list) {
if ((p->dev->flags & IFF_UP) && netif_carrier_ok(p->dev))
br_stp_enable_port(p);
}
spin_unlock_bh(&br->lock);
}
/* NO locks held */
void br_stp_disable_bridge(struct net_bridge *br)
{
struct net_bridge_port *p;
spin_lock_bh(&br->lock);
list_for_each_entry(p, &br->port_list, list) {
if (p->state != BR_STATE_DISABLED)
br_stp_disable_port(p);
}
br->topology_change = 0;
br->topology_change_detected = 0;
spin_unlock_bh(&br->lock);
del_timer_sync(&br->hello_timer);
del_timer_sync(&br->topology_change_timer);
del_timer_sync(&br->tcn_timer);
del_timer_sync(&br->gc_timer);
}
/* called under bridge lock */
void br_stp_enable_port(struct net_bridge_port *p)
{
br_init_port(p);
br_port_state_selection(p->br);
}
/* called under bridge lock */
void br_stp_disable_port(struct net_bridge_port *p)
{
struct net_bridge *br;
int wasroot;
br = p->br;
printk(KERN_INFO "%s: port %i(%s) entering %s state\n",
br->dev->name, p->port_no, p->dev->name, "disabled");
wasroot = br_is_root_bridge(br);
br_become_designated_port(p);
p->state = BR_STATE_DISABLED;
p->topology_change_ack = 0;
p->config_pending = 0;
del_timer(&p->message_age_timer);
del_timer(&p->forward_delay_timer);
del_timer(&p->hold_timer);
br_fdb_delete_by_port(br, p, 0);
br_configuration_update(br);
br_port_state_selection(br);
if (br_is_root_bridge(br) && !wasroot)
br_become_root_bridge(br);
}
static void br_stp_start(struct net_bridge *br)
{
int r;
char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL };
char *envp[] = { NULL };
r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
if (r == 0) {
br->stp_enabled = BR_USER_STP;
printk(KERN_INFO "%s: userspace STP started\n", br->dev->name);
} else {
br->stp_enabled = BR_KERNEL_STP;
printk(KERN_INFO "%s: starting userspace STP failed, "
"starting kernel STP\n", br->dev->name);
/* To start timers on any ports left in blocking */
spin_lock_bh(&br->lock);
br_port_state_selection(br);
spin_unlock_bh(&br->lock);
}
}
static void br_stp_stop(struct net_bridge *br)
{
int r;
char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
char *envp[] = { NULL };
if (br->stp_enabled == BR_USER_STP) {
r = call_usermodehelper(BR_STP_PROG, argv, envp, 1);
printk(KERN_INFO "%s: userspace STP stopped, return code %d\n",
br->dev->name, r);
/* To start timers on any ports left in blocking */
spin_lock_bh(&br->lock);
br_port_state_selection(br);
spin_unlock_bh(&br->lock);
}
br->stp_enabled = BR_NO_STP;
}
void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
{
ASSERT_RTNL();
if (val) {
if (br->stp_enabled == BR_NO_STP)
br_stp_start(br);
} else {
if (br->stp_enabled != BR_NO_STP)
br_stp_stop(br);
}
}
/* called under bridge lock */
void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr)
{
/* should be aligned on 2 bytes for compare_ether_addr() */
unsigned short oldaddr_aligned[ETH_ALEN >> 1];
unsigned char *oldaddr = (unsigned char *)oldaddr_aligned;
struct net_bridge_port *p;
int wasroot;
wasroot = br_is_root_bridge(br);
memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
memcpy(br->bridge_id.addr, addr, ETH_ALEN);
memcpy(br->dev->dev_addr, addr, ETH_ALEN);
list_for_each_entry(p, &br->port_list, list) {
if (!compare_ether_addr(p->designated_bridge.addr, oldaddr))
memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
if (!compare_ether_addr(p->designated_root.addr, oldaddr))
memcpy(p->designated_root.addr, addr, ETH_ALEN);
}
br_configuration_update(br);
br_port_state_selection(br);
if (br_is_root_bridge(br) && !wasroot)
br_become_root_bridge(br);
}
/* should be aligned on 2 bytes for compare_ether_addr() */
static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
/* called under bridge lock */
void br_stp_recalculate_bridge_id(struct net_bridge *br)
{
const unsigned char *br_mac_zero =
(const unsigned char *)br_mac_zero_aligned;
const unsigned char *addr = br_mac_zero;
struct net_bridge_port *p;
/* user has chosen a value so keep it */
if (br->flags & BR_SET_MAC_ADDR)
return;
list_for_each_entry(p, &br->port_list, list) {
if (addr == br_mac_zero ||
memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
addr = p->dev->dev_addr;
}
if (compare_ether_addr(br->bridge_id.addr, addr))
br_stp_change_bridge_id(br, addr);
}
/* called under bridge lock */
void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
{
struct net_bridge_port *p;
int wasroot;
wasroot = br_is_root_bridge(br);
list_for_each_entry(p, &br->port_list, list) {
if (p->state != BR_STATE_DISABLED &&
br_is_designated_port(p)) {
p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
p->designated_bridge.prio[1] = newprio & 0xFF;
}
}
br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
br->bridge_id.prio[1] = newprio & 0xFF;
br_configuration_update(br);
br_port_state_selection(br);
if (br_is_root_bridge(br) && !wasroot)
br_become_root_bridge(br);
}
/* called under bridge lock */
void br_stp_set_port_priority(struct net_bridge_port *p, u8 newprio)
{
port_id new_port_id = br_make_port_id(newprio, p->port_no);
if (br_is_designated_port(p))
p->designated_port = new_port_id;
p->port_id = new_port_id;
p->priority = newprio;
if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
p->port_id < p->designated_port) {
br_become_designated_port(p);
br_port_state_selection(p->br);
}
}
/* called under bridge lock */
void br_stp_set_path_cost(struct net_bridge_port *p, u32 path_cost)
{
p->path_cost = path_cost;
br_configuration_update(p->br);
br_port_state_selection(p->br);
}
ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id)
{
return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
id->prio[0], id->prio[1],
id->addr[0], id->addr[1], id->addr[2],
id->addr[3], id->addr[4], id->addr[5]);
}