linux/net/bridge/br_stp_if.c

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/*
* 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/kmod.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
#include <net/switchdev.h>
#include "br_private.h"
#include "br_private_stp.h"
/* Port id is composed of priority and port number.
* NB: some 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));
}
#define BR_MAX_PORT_PRIORITY ((u16)~0 >> BR_PORT_BITS)
/* called under bridge lock */
void br_init_port(struct net_bridge_port *p)
{
struct switchdev_attr attr = {
.orig_dev = p->dev,
.id = SWITCHDEV_ATTR_ID_BRIDGE_AGEING_TIME,
.flags = SWITCHDEV_F_SKIP_EOPNOTSUPP | SWITCHDEV_F_DEFER,
.u.ageing_time = jiffies_to_clock_t(p->br->ageing_time),
};
int err;
p->port_id = br_make_port_id(p->priority, p->port_no);
br_become_designated_port(p);
br_set_state(p, BR_STATE_BLOCKING);
p->topology_change_ack = 0;
p->config_pending = 0;
err = switchdev_port_attr_set(p->dev, &attr);
if (err && err != -EOPNOTSUPP)
netdev_err(p->dev, "failed to set HW ageing time\n");
}
/* called under bridge lock */
void br_stp_enable_bridge(struct net_bridge *br)
{
struct net_bridge_port *p;
spin_lock_bh(&br->lock);
if (br->stp_enabled == BR_KERNEL_STP)
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 (netif_running(p->dev) && netif_oper_up(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);
br_ifinfo_notify(RTM_NEWLINK, p);
}
/* called under bridge lock */
void br_stp_disable_port(struct net_bridge_port *p)
{
struct net_bridge *br = p->br;
int wasroot;
wasroot = br_is_root_bridge(br);
br_become_designated_port(p);
br_set_state(p, BR_STATE_DISABLED);
p->topology_change_ack = 0;
p->config_pending = 0;
br_ifinfo_notify(RTM_NEWLINK, p);
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, 0);
br_multicast_disable_port(p);
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 };
struct net_bridge_port *p;
if (net_eq(dev_net(br->dev), &init_net))
r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
else
r = -ENOENT;
spin_lock_bh(&br->lock);
if (br->bridge_forward_delay < BR_MIN_FORWARD_DELAY)
__br_set_forward_delay(br, BR_MIN_FORWARD_DELAY);
else if (br->bridge_forward_delay > BR_MAX_FORWARD_DELAY)
__br_set_forward_delay(br, BR_MAX_FORWARD_DELAY);
if (r == 0) {
br->stp_enabled = BR_USER_STP;
br_debug(br, "userspace STP started\n");
/* Stop hello and hold timers */
del_timer(&br->hello_timer);
list_for_each_entry(p, &br->port_list, list)
del_timer(&p->hold_timer);
} else {
br->stp_enabled = BR_KERNEL_STP;
br_debug(br, "using kernel STP\n");
/* To start timers on any ports left in blocking */
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 };
struct net_bridge_port *p;
if (br->stp_enabled == BR_USER_STP) {
r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
br_info(br, "userspace STP stopped, return code %d\n", r);
/* To start timers on any ports left in blocking */
mod_timer(&br->hello_timer, jiffies + br->hello_time);
list_for_each_entry(p, &br->port_list, list)
mod_timer(&p->hold_timer,
round_jiffies(jiffies + BR_HOLD_TIME));
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 ether_addr_equal() */
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);
bridge: Change local fdb entries whenever mac address of bridge device changes Vlan code may need fdb change when changing mac address of bridge device even if it is caused by the mac address changing of a bridge port. Example configuration: ip link set eth0 address 12:34:56:78:90:ab ip link set eth1 address aa:bb:cc:dd:ee:ff brctl addif br0 eth0 brctl addif br0 eth1 # br0 will have mac address 12:34:56:78:90:ab bridge vlan add dev br0 vid 10 self bridge vlan add dev eth0 vid 10 We will have fdb entry such that f->dst == NULL, f->vlan_id == 10 and f->addr == 12:34:56:78:90:ab at this time. Next, change the mac address of eth0 to greater value. ip link set eth0 address ee:ff:12:34:56:78 Then, mac address of br0 will be recalculated and set to aa:bb:cc:dd:ee:ff. However, an entry aa:bb:cc:dd:ee:ff will not be created and we will be not able to communicate using br0 on vlan 10. Address this issue by deleting and adding local entries whenever changing the mac address of the bridge device. If there already exists an entry that has the same address, for example, in case that br_fdb_changeaddr() has already inserted it, br_fdb_change_mac_address() will simply fail to insert it and no duplicated entry will be made, as it was. This approach also needs br_add_if() to call br_fdb_insert() before br_stp_recalculate_bridge_id() so that we don't create an entry whose dst == NULL in this function to preserve previous behavior. Note that this is a slight change in behavior where the bridge device can receive the traffic to the new address before calling br_stp_recalculate_bridge_id() in br_add_if(). However, it is not a problem because we have already the address on the new port and such a way to insert new one before recalculating bridge id is taken in br_device_event() as well. Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Acked-by: Vlad Yasevich <vyasevic@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-07 07:48:21 +00:00
br_fdb_change_mac_address(br, addr);
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 (ether_addr_equal(p->designated_bridge.addr, oldaddr))
memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
if (ether_addr_equal(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 ether_addr_equal() */
static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
/* called under bridge lock */
bool 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->dev->addr_assign_type == NET_ADDR_SET)
return false;
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 (ether_addr_equal(br->bridge_id.addr, addr))
return false; /* no change */
br_stp_change_bridge_id(br, addr);
return true;
}
/* Acquires and releases bridge lock */
void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
{
struct net_bridge_port *p;
int wasroot;
spin_lock_bh(&br->lock);
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);
spin_unlock_bh(&br->lock);
}
/* called under bridge lock */
int br_stp_set_port_priority(struct net_bridge_port *p, unsigned long newprio)
{
port_id new_port_id;
if (newprio > BR_MAX_PORT_PRIORITY)
return -ERANGE;
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);
}
return 0;
}
/* called under bridge lock */
int br_stp_set_path_cost(struct net_bridge_port *p, unsigned long path_cost)
{
if (path_cost < BR_MIN_PATH_COST ||
path_cost > BR_MAX_PATH_COST)
return -ERANGE;
p->flags |= BR_ADMIN_COST;
p->path_cost = path_cost;
br_configuration_update(p->br);
br_port_state_selection(p->br);
return 0;
}
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]);
}