linux/net/bridge/br_stp_if.c
Nikolay Aleksandrov 76b91c32dd bridge: stp: when using userspace stp stop kernel hello and hold timers
These should be handled only by the respective STP which is in control.
They become problematic for devices with limited resources with many
ports because the hold_timer is per port and fires each second and the
hello timer fires each 2 seconds even though it's global. While in
user-space STP mode these timers are completely unnecessary so it's better
to keep them off.
Also ensure that when the bridge is up these timers are started only when
running with kernel STP.

Signed-off-by: Satish Ashok <sashok@cumulusnetworks.com>
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-28 23:33:20 -07:00

328 lines
8.2 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/kmod.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: 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)
{
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;
}
/* 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_log_state(p);
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_log_state(p);
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;
r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
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);
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]);
}