net/bridge/br_stp_if.c - linux - Git at Google

 /*
  *	Spanning tree protocol; interface code
  *	Linux ethernet bridge
  *
  *	Authors:
  *	Lennert Buytenhek		<buytenh@gnu.org>
  *
  *	$Id: br_stp_if.c,v 1.4 2001/04/14 21:14:39 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/smp_lock.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_ifinfo_notify(RTM_NEWLINK, 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");

 	br_ifinfo_notify(RTM_DELLINK, p);

 	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, 1);
 	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, "
 				"staring 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;

 	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]);
 }
	/*
	* Spanning tree protocol; interface code
	* Linux ethernet bridge
	*
	* Authors:
	* Lennert Buytenhek <buytenh@gnu.org>
	*
	* $Id: br_stp_if.c,v 1.4 2001/04/14 21:14:39 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/smp_lock.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_ifinfo_notify(RTM_NEWLINK, 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");

	br_ifinfo_notify(RTM_DELLINK, p);

	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, 1);
	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, "
	"staring 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;

	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]);
	}