libbridge/libbridge_devif.c - manifest_repos/bridge-utils - Git at Google

 /*
  * Copyright (C) 2000 Lennert Buytenhek
  *
  * 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.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */


 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <errno.h>
 #include <string.h>
 #include <dirent.h>
 #include <fcntl.h>

 #include "libbridge.h"
 #include "libbridge_private.h"

 static FILE *fpopen(const char *dir, const char *name)
 {
 	char path[SYSFS_PATH_MAX];

 	snprintf(path, SYSFS_PATH_MAX, "%s/%s", dir, name);
 	return fopen(path, "r");
 }

 static void fetch_id(const char *dev, const char *name, struct bridge_id *id)
 {
 	FILE *f = fpopen(dev, name);

 	if (!f)
 		fprintf(stderr, "%s: %s\n", dev, strerror(errno));
 	else {
 		fscanf(f, "%2hhx%2hhx.%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx",
 		       &id->prio[0], &id->prio[1],
 		       &id->addr[0], &id->addr[1], &id->addr[2],
 		       &id->addr[3], &id->addr[4], &id->addr[5]);
 		fclose(f);
 	}
 }

 /* Fetch an integer attribute out of sysfs. */
 static int fetch_int(const char *dev, const char *name)
 {
 	FILE *f = fpopen(dev, name);
 	int value = -1;

 	if (!f)
 		return 0;

 	fscanf(f, "%i", &value);
 	fclose(f);
 	return value;
 }

 /* Get a time value out of sysfs */
 static void fetch_tv(const char *dev, const char *name,
 		    struct timeval *tv)
 {
 	__jiffies_to_tv(tv, fetch_int(dev, name));
 }

 /*
  * Convert device name to an index in the list of ports in bridge.
  *
  * Old API does bridge operations as if ports were an array
  * inside bridge structure.
  */
 static int get_portno(const char *brname, const char *ifname)
 {
 	int i;
 	int ifindex = if_nametoindex(ifname);
 	int ifindices[MAX_PORTS];
 	unsigned long args[4] = { BRCTL_GET_PORT_LIST,
 				  (unsigned long)ifindices, MAX_PORTS, 0 };
 	struct ifreq ifr;

 	if (ifindex <= 0)
 		goto error;

 	memset(ifindices, 0, sizeof(ifindices));
 	strncpy(ifr.ifr_name, brname, IFNAMSIZ);
 	ifr.ifr_data = (char *) &args;

 	if (ioctl(br_socket_fd, SIOCDEVPRIVATE, &ifr) < 0) {
 		dprintf("get_portno: get ports of %s failed: %s\n",
 			brname, strerror(errno));
 		goto error;
 	}

 	for (i = 0; i < MAX_PORTS; i++) {
 		if (ifindices[i] == ifindex)
 			return i;
 	}

 	dprintf("%s is not a in bridge %s\n", ifname, brname);
  error:
 	return -1;
 }

 /* get information via ioctl */
 static int old_get_bridge_info(const char *bridge, struct bridge_info *info)
 {
 	struct ifreq ifr;
 	struct __bridge_info i;
 	unsigned long args[4] = { BRCTL_GET_BRIDGE_INFO,
 				  (unsigned long) &i, 0, 0 };

 	memset(info, 0, sizeof(*info));
 	strncpy(ifr.ifr_name, bridge, IFNAMSIZ);
 	ifr.ifr_data = (char *) &args;

 	if (ioctl(br_socket_fd, SIOCDEVPRIVATE, &ifr) < 0) {
 		dprintf("%s: can't get info %s\n",
 			bridge, strerror(errno));
 		return errno;
 	}

 	memcpy(&info->designated_root, &i.designated_root, 8);
 	memcpy(&info->bridge_id, &i.bridge_id, 8);
 	info->root_path_cost = i.root_path_cost;
 	info->root_port = i.root_port;
 	info->topology_change = i.topology_change;
 	info->topology_change_detected = i.topology_change_detected;
 	info->stp_enabled = i.stp_enabled;
 	__jiffies_to_tv(&info->max_age, i.max_age);
 	__jiffies_to_tv(&info->hello_time, i.hello_time);
 	__jiffies_to_tv(&info->forward_delay, i.forward_delay);
 	__jiffies_to_tv(&info->bridge_max_age, i.bridge_max_age);
 	__jiffies_to_tv(&info->bridge_hello_time, i.bridge_hello_time);
 	__jiffies_to_tv(&info->bridge_forward_delay, i.bridge_forward_delay);
 	__jiffies_to_tv(&info->ageing_time, i.ageing_time);
 	__jiffies_to_tv(&info->hello_timer_value, i.hello_timer_value);
 	__jiffies_to_tv(&info->tcn_timer_value, i.tcn_timer_value);
 	__jiffies_to_tv(&info->topology_change_timer_value,
 			i.topology_change_timer_value);
 	__jiffies_to_tv(&info->gc_timer_value, i.gc_timer_value);

 	return 0;
 }

 /*
  * Get bridge parameters using either sysfs or old
  * ioctl.
  */
 int br_get_bridge_info(const char *bridge, struct bridge_info *info)
 {
 	DIR *dir;
 	char path[SYSFS_PATH_MAX];

 	snprintf(path, SYSFS_PATH_MAX, SYSFS_CLASS_NET "%s/bridge", bridge);
 	dir = opendir(path);
 	if (dir == NULL) {
 		dprintf("path '%s' is not a directory\n", path);
 		goto fallback;
 	}

 	memset(info, 0, sizeof(*info));
 	fetch_id(path, "root_id", &info->designated_root);
 	fetch_id(path, "bridge_id", &info->bridge_id);
 	info->root_path_cost = fetch_int(path, "root_path_cost");
 	fetch_tv(path, "max_age", &info->max_age);
 	fetch_tv(path, "hello_time", &info->hello_time);
 	fetch_tv(path, "forward_delay", &info->forward_delay);
 	fetch_tv(path, "max_age", &info->bridge_max_age);
 	fetch_tv(path, "hello_time", &info->bridge_hello_time);
 	fetch_tv(path, "forward_delay", &info->bridge_forward_delay);
 	fetch_tv(path, "ageing_time", &info->ageing_time);
 	fetch_tv(path, "hello_timer", &info->hello_timer_value);
 	fetch_tv(path, "tcn_timer", &info->tcn_timer_value);
 	fetch_tv(path, "topology_change_timer",
 		 &info->topology_change_timer_value);;
 	fetch_tv(path, "gc_timer", &info->gc_timer_value);

 	info->root_port = fetch_int(path, "root_port");
 	info->stp_enabled = fetch_int(path, "stp_state");
 	info->topology_change = fetch_int(path, "topology_change");
 	info->topology_change_detected = fetch_int(path, "topology_change_detected");

 	closedir(dir);
 	return 0;

 fallback:
 	return old_get_bridge_info(bridge, info);
 }

 static int old_get_port_info(const char *brname, const char *port,
 			     struct port_info *info)
 {
 	struct __port_info i;
 	int index;

 	memset(info, 0, sizeof(*info));

 	index = get_portno(brname, port);
 	if (index < 0)
 		return errno;

 	else {
 		struct ifreq ifr;
 		unsigned long args[4] = { BRCTL_GET_PORT_INFO,
 					   (unsigned long) &i, index, 0 };

 		strncpy(ifr.ifr_name, brname, IFNAMSIZ);
 		ifr.ifr_data = (char *) &args;

 		if (ioctl(br_socket_fd, SIOCDEVPRIVATE, &ifr) < 0) {
 			dprintf("old can't get port %s(%d) info %s\n",
 				brname, index, strerror(errno));
 			return errno;
 		}
 	}

 	info->port_no = index;
 	memcpy(&info->designated_root, &i.designated_root, 8);
 	memcpy(&info->designated_bridge, &i.designated_bridge, 8);
 	info->port_id = i.port_id;
 	info->designated_port = i.designated_port;
 	info->path_cost = i.path_cost;
 	info->designated_cost = i.designated_cost;
 	info->state = i.state;
 	info->top_change_ack = i.top_change_ack;
 	info->config_pending = i.config_pending;
 	__jiffies_to_tv(&info->message_age_timer_value,
 			i.message_age_timer_value);
 	__jiffies_to_tv(&info->forward_delay_timer_value,
 			i.forward_delay_timer_value);
 	__jiffies_to_tv(&info->hold_timer_value, i.hold_timer_value);
 	info->hairpin_mode = 0;
 	return 0;
 }

 /*
  * Get information about port on bridge.
  */
 int br_get_port_info(const char *brname, const char *port,
 		     struct port_info *info)
 {
 	DIR *d;
 	char path[SYSFS_PATH_MAX];

 	snprintf(path, SYSFS_PATH_MAX, SYSFS_CLASS_NET "%s/brport", port);
 	d = opendir(path);
 	if (!d)
 		goto fallback;

 	memset(info, 0, sizeof(*info));

 	fetch_id(path, "designated_root", &info->designated_root);
 	fetch_id(path, "designated_bridge", &info->designated_bridge);
 	info->port_no = fetch_int(path, "port_no");
 	info->port_id = fetch_int(path, "port_id");
 	info->designated_port = fetch_int(path, "designated_port");
 	info->path_cost = fetch_int(path, "path_cost");
 	info->designated_cost = fetch_int(path, "designated_cost");
 	info->state = fetch_int(path, "state");
 	info->top_change_ack = fetch_int(path, "change_ack");
 	info->config_pending = fetch_int(path, "config_pending");
 	fetch_tv(path, "message_age_timer", &info->message_age_timer_value);
 	fetch_tv(path, "forward_delay_timer", &info->forward_delay_timer_value);
 	fetch_tv(path, "hold_timer", &info->hold_timer_value);
 	info->hairpin_mode = fetch_int(path, "hairpin_mode");

 	closedir(d);

 	return 0;
 fallback:
 	return old_get_port_info(brname, port, info);
 }

 static int set_sysfs(const char *path, unsigned long value)
 {
 	int fd, ret = 0, cc;
 	char buf[32];

 	fd = open(path, O_WRONLY);
 	if (fd < 0)
 		return -1;

 	cc = snprintf(buf, sizeof(buf), "%lu\n", value);
 	if (write(fd, buf, cc) < 0)
 		ret = -1;
 	close(fd);

 	return ret;
 }


 static int br_set(const char *bridge, const char *name,
 		  unsigned long value, unsigned long oldcode)
 {
 	int ret;
 	char path[SYSFS_PATH_MAX];

 	snprintf(path, SYSFS_PATH_MAX, SYSFS_CLASS_NET "%s/bridge/%s",
 		 bridge, name);

 	if ((ret = set_sysfs(path, value)) < 0) {
 		/* fallback to old ioctl */
 		struct ifreq ifr;
 		unsigned long args[4] = { oldcode, value, 0, 0 };

 		strncpy(ifr.ifr_name, bridge, IFNAMSIZ);
 		ifr.ifr_data = (char *) &args;
 		ret = ioctl(br_socket_fd, SIOCDEVPRIVATE, &ifr);
 	}

 	return ret < 0 ? errno : 0;
 }

 int br_set_bridge_forward_delay(const char *br, struct timeval *tv)
 {
 	return br_set(br, "forward_delay", __tv_to_jiffies(tv),
 		      BRCTL_SET_BRIDGE_FORWARD_DELAY);
 }

 int br_set_bridge_hello_time(const char *br, struct timeval *tv)
 {
 	return br_set(br, "hello_time", __tv_to_jiffies(tv),
 		      BRCTL_SET_BRIDGE_HELLO_TIME);
 }

 int br_set_bridge_max_age(const char *br, struct timeval *tv)
 {
 	return br_set(br, "max_age", __tv_to_jiffies(tv),
 		      BRCTL_SET_BRIDGE_MAX_AGE);
 }

 int br_set_ageing_time(const char *br, struct timeval *tv)
 {
 	return br_set(br, "ageing_time", __tv_to_jiffies(tv),
 		      BRCTL_SET_AGEING_TIME);
 }

 int br_set_stp_state(const char *br, int stp_state)
 {
 	return br_set(br, "stp_state", stp_state, BRCTL_SET_BRIDGE_STP_STATE);
 }

 int br_set_bridge_priority(const char *br, int bridge_priority)
 {
 	return br_set(br, "priority", bridge_priority,
 		      BRCTL_SET_BRIDGE_PRIORITY);
 }

 static int port_set(const char *bridge, const char *ifname,
 		    const char *name, unsigned long value,
 		    unsigned long oldcode)
 {
 	int ret;
 	char path[SYSFS_PATH_MAX];

 	snprintf(path, SYSFS_PATH_MAX, SYSFS_CLASS_NET "%s/brport/%s", ifname, name);

 	if ((ret = set_sysfs(path, value)) < 0) {
 		int index = get_portno(bridge, ifname);

 		if (index < 0)
 			ret = index;
 		else {
 			struct ifreq ifr;
 			unsigned long args[4] = { oldcode, index, value, 0 };

 			strncpy(ifr.ifr_name, bridge, IFNAMSIZ);
 			ifr.ifr_data = (char *) &args;
 			ret = ioctl(br_socket_fd, SIOCDEVPRIVATE, &ifr);
 		}
 	}

 	return ret < 0 ? errno : 0;
 }

 int br_set_port_priority(const char *bridge, const char *port, int priority)
 {
 	return port_set(bridge, port, "priority", priority, BRCTL_SET_PORT_PRIORITY);
 }

 int br_set_path_cost(const char *bridge, const char *port, int cost)
 {
 	return port_set(bridge, port, "path_cost", cost, BRCTL_SET_PATH_COST);
 }

 int br_set_hairpin_mode(const char *bridge, const char *port, int hairpin_mode)
 {
 	return port_set(bridge, port, "hairpin_mode", hairpin_mode, 0);
 }

 static inline void __copy_fdb(struct fdb_entry *ent,
 			      const struct __fdb_entry *f)
 {
 	memcpy(ent->mac_addr, f->mac_addr, 6);
 	ent->port_no = f->port_no;
 	ent->is_local = f->is_local;
 	__jiffies_to_tv(&ent->ageing_timer_value, f->ageing_timer_value);
 }

 int br_read_fdb(const char *bridge, struct fdb_entry *fdbs,
 		unsigned long offset, int num)
 {
 	FILE *f;
 	int i, n;
 	struct __fdb_entry fe[num];
 	char path[SYSFS_PATH_MAX];

 	/* open /sys/class/net/brXXX/brforward */
 	snprintf(path, SYSFS_PATH_MAX, SYSFS_CLASS_NET "%s/brforward", bridge);
 	f = fopen(path, "r");
 	if (f) {
 		fseek(f, offset*sizeof(struct __fdb_entry), SEEK_SET);
 		n = fread(fe, sizeof(struct __fdb_entry), num, f);
 		fclose(f);
 	} else {
 		/* old kernel, use ioctl */
 		unsigned long args[4] = { BRCTL_GET_FDB_ENTRIES,
 					  (unsigned long) fe,
 					  num, offset };
 		struct ifreq ifr;
 		int retries = 0;

 		strncpy(ifr.ifr_name, bridge, IFNAMSIZ);
 		ifr.ifr_data = (char *) args;

 	retry:
 		n = ioctl(br_socket_fd, SIOCDEVPRIVATE, &ifr);

 		/* table can change during ioctl processing */
 		if (n < 0 && errno == EAGAIN && ++retries < 10) {
 			sleep(0);
 			goto retry;
 		}
 	}

 	for (i = 0; i < n; i++)
 		__copy_fdb(fdbs+i, fe+i);

 	return n;
 }
	/*
	* Copyright (C) 2000 Lennert Buytenhek
	*
	* 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.
	*
	* This program is distributed in the hope that it will be useful, but
	* WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	*/


	#include <stdio.h>
	#include <stdlib.h>
	#include <unistd.h>
	#include <errno.h>
	#include <string.h>
	#include <dirent.h>
	#include <fcntl.h>

	#include "libbridge.h"
	#include "libbridge_private.h"

	static FILE fpopen(const char dir, const char *name)
	{
	char path[SYSFS_PATH_MAX];

	snprintf(path, SYSFS_PATH_MAX, "%s/%s", dir, name);
	return fopen(path, "r");
	}

	static void fetch_id(const char dev, const char name, struct bridge_id *id)
	{
	FILE *f = fpopen(dev, name);

	if (!f)
	fprintf(stderr, "%s: %s\n", dev, strerror(errno));
	else {
	fscanf(f, "%2hhx%2hhx.%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx",
	&id->prio[0], &id->prio[1],
	&id->addr[0], &id->addr[1], &id->addr[2],
	&id->addr[3], &id->addr[4], &id->addr[5]);
	fclose(f);
	}
	}

	/* Fetch an integer attribute out of sysfs. */
	static int fetch_int(const char dev, const char name)
	{
	FILE *f = fpopen(dev, name);
	int value = -1;

	if (!f)
	return 0;

	fscanf(f, "%i", &value);
	fclose(f);
	return value;
	}

	/* Get a time value out of sysfs */
	static void fetch_tv(const char dev, const char name,
	struct timeval *tv)
	{
	__jiffies_to_tv(tv, fetch_int(dev, name));
	}

	/*
	* Convert device name to an index in the list of ports in bridge.
	*
	* Old API does bridge operations as if ports were an array
	* inside bridge structure.
	*/
	static int get_portno(const char brname, const char ifname)
	{
	int i;
	int ifindex = if_nametoindex(ifname);
	int ifindices[MAX_PORTS];
	unsigned long args[4] = { BRCTL_GET_PORT_LIST,
	(unsigned long)ifindices, MAX_PORTS, 0 };
	struct ifreq ifr;

	if (ifindex <= 0)
	goto error;

	memset(ifindices, 0, sizeof(ifindices));
	strncpy(ifr.ifr_name, brname, IFNAMSIZ);
	ifr.ifr_data = (char *) &args;

	if (ioctl(br_socket_fd, SIOCDEVPRIVATE, &ifr) < 0) {
	dprintf("get_portno: get ports of %s failed: %s\n",
	brname, strerror(errno));
	goto error;
	}

	for (i = 0; i < MAX_PORTS; i++) {
	if (ifindices[i] == ifindex)
	return i;
	}

	dprintf("%s is not a in bridge %s\n", ifname, brname);
	error:
	return -1;
	}

	/* get information via ioctl */
	static int old_get_bridge_info(const char bridge, struct bridge_info info)
	{
	struct ifreq ifr;
	struct __bridge_info i;
	unsigned long args[4] = { BRCTL_GET_BRIDGE_INFO,
	(unsigned long) &i, 0, 0 };

	memset(info, 0, sizeof(*info));
	strncpy(ifr.ifr_name, bridge, IFNAMSIZ);
	ifr.ifr_data = (char *) &args;

	if (ioctl(br_socket_fd, SIOCDEVPRIVATE, &ifr) < 0) {
	dprintf("%s: can't get info %s\n",
	bridge, strerror(errno));
	return errno;
	}

	memcpy(&info->designated_root, &i.designated_root, 8);
	memcpy(&info->bridge_id, &i.bridge_id, 8);
	info->root_path_cost = i.root_path_cost;
	info->root_port = i.root_port;
	info->topology_change = i.topology_change;
	info->topology_change_detected = i.topology_change_detected;
	info->stp_enabled = i.stp_enabled;
	__jiffies_to_tv(&info->max_age, i.max_age);
	__jiffies_to_tv(&info->hello_time, i.hello_time);
	__jiffies_to_tv(&info->forward_delay, i.forward_delay);
	__jiffies_to_tv(&info->bridge_max_age, i.bridge_max_age);
	__jiffies_to_tv(&info->bridge_hello_time, i.bridge_hello_time);
	__jiffies_to_tv(&info->bridge_forward_delay, i.bridge_forward_delay);
	__jiffies_to_tv(&info->ageing_time, i.ageing_time);
	__jiffies_to_tv(&info->hello_timer_value, i.hello_timer_value);
	__jiffies_to_tv(&info->tcn_timer_value, i.tcn_timer_value);
	__jiffies_to_tv(&info->topology_change_timer_value,
	i.topology_change_timer_value);
	__jiffies_to_tv(&info->gc_timer_value, i.gc_timer_value);

	return 0;
	}

	/*
	* Get bridge parameters using either sysfs or old
	* ioctl.
	*/
	int br_get_bridge_info(const char bridge, struct bridge_info info)
	{
	DIR *dir;
	char path[SYSFS_PATH_MAX];

	snprintf(path, SYSFS_PATH_MAX, SYSFS_CLASS_NET "%s/bridge", bridge);
	dir = opendir(path);
	if (dir == NULL) {
	dprintf("path '%s' is not a directory\n", path);
	goto fallback;
	}

	memset(info, 0, sizeof(*info));
	fetch_id(path, "root_id", &info->designated_root);
	fetch_id(path, "bridge_id", &info->bridge_id);
	info->root_path_cost = fetch_int(path, "root_path_cost");
	fetch_tv(path, "max_age", &info->max_age);
	fetch_tv(path, "hello_time", &info->hello_time);
	fetch_tv(path, "forward_delay", &info->forward_delay);
	fetch_tv(path, "max_age", &info->bridge_max_age);
	fetch_tv(path, "hello_time", &info->bridge_hello_time);
	fetch_tv(path, "forward_delay", &info->bridge_forward_delay);
	fetch_tv(path, "ageing_time", &info->ageing_time);
	fetch_tv(path, "hello_timer", &info->hello_timer_value);
	fetch_tv(path, "tcn_timer", &info->tcn_timer_value);
	fetch_tv(path, "topology_change_timer",
	&info->topology_change_timer_value);;
	fetch_tv(path, "gc_timer", &info->gc_timer_value);

	info->root_port = fetch_int(path, "root_port");
	info->stp_enabled = fetch_int(path, "stp_state");
	info->topology_change = fetch_int(path, "topology_change");
	info->topology_change_detected = fetch_int(path, "topology_change_detected");

	closedir(dir);
	return 0;

	fallback:
	return old_get_bridge_info(bridge, info);
	}

	static int old_get_port_info(const char brname, const char port,
	struct port_info *info)
	{
	struct __port_info i;
	int index;

	memset(info, 0, sizeof(*info));

	index = get_portno(brname, port);
	if (index < 0)
	return errno;

	else {
	struct ifreq ifr;
	unsigned long args[4] = { BRCTL_GET_PORT_INFO,
	(unsigned long) &i, index, 0 };

	strncpy(ifr.ifr_name, brname, IFNAMSIZ);
	ifr.ifr_data = (char *) &args;

	if (ioctl(br_socket_fd, SIOCDEVPRIVATE, &ifr) < 0) {
	dprintf("old can't get port %s(%d) info %s\n",
	brname, index, strerror(errno));
	return errno;
	}
	}

	info->port_no = index;
	memcpy(&info->designated_root, &i.designated_root, 8);
	memcpy(&info->designated_bridge, &i.designated_bridge, 8);
	info->port_id = i.port_id;
	info->designated_port = i.designated_port;
	info->path_cost = i.path_cost;
	info->designated_cost = i.designated_cost;
	info->state = i.state;
	info->top_change_ack = i.top_change_ack;
	info->config_pending = i.config_pending;
	__jiffies_to_tv(&info->message_age_timer_value,
	i.message_age_timer_value);
	__jiffies_to_tv(&info->forward_delay_timer_value,
	i.forward_delay_timer_value);
	__jiffies_to_tv(&info->hold_timer_value, i.hold_timer_value);
	info->hairpin_mode = 0;
	return 0;
	}

	/*
	* Get information about port on bridge.
	*/
	int br_get_port_info(const char brname, const char port,
	struct port_info *info)
	{
	DIR *d;
	char path[SYSFS_PATH_MAX];

	snprintf(path, SYSFS_PATH_MAX, SYSFS_CLASS_NET "%s/brport", port);
	d = opendir(path);
	if (!d)
	goto fallback;

	memset(info, 0, sizeof(*info));

	fetch_id(path, "designated_root", &info->designated_root);
	fetch_id(path, "designated_bridge", &info->designated_bridge);
	info->port_no = fetch_int(path, "port_no");
	info->port_id = fetch_int(path, "port_id");
	info->designated_port = fetch_int(path, "designated_port");
	info->path_cost = fetch_int(path, "path_cost");
	info->designated_cost = fetch_int(path, "designated_cost");
	info->state = fetch_int(path, "state");
	info->top_change_ack = fetch_int(path, "change_ack");
	info->config_pending = fetch_int(path, "config_pending");
	fetch_tv(path, "message_age_timer", &info->message_age_timer_value);
	fetch_tv(path, "forward_delay_timer", &info->forward_delay_timer_value);
	fetch_tv(path, "hold_timer", &info->hold_timer_value);
	info->hairpin_mode = fetch_int(path, "hairpin_mode");

	closedir(d);

	return 0;
	fallback:
	return old_get_port_info(brname, port, info);
	}

	static int set_sysfs(const char *path, unsigned long value)
	{
	int fd, ret = 0, cc;
	char buf[32];

	fd = open(path, O_WRONLY);
	if (fd < 0)
	return -1;

	cc = snprintf(buf, sizeof(buf), "%lu\n", value);
	if (write(fd, buf, cc) < 0)
	ret = -1;
	close(fd);

	return ret;
	}


	static int br_set(const char bridge, const char name,
	unsigned long value, unsigned long oldcode)
	{
	int ret;
	char path[SYSFS_PATH_MAX];

	snprintf(path, SYSFS_PATH_MAX, SYSFS_CLASS_NET "%s/bridge/%s",
	bridge, name);

	if ((ret = set_sysfs(path, value)) < 0) {
	/* fallback to old ioctl */
	struct ifreq ifr;
	unsigned long args[4] = { oldcode, value, 0, 0 };

	strncpy(ifr.ifr_name, bridge, IFNAMSIZ);
	ifr.ifr_data = (char *) &args;
	ret = ioctl(br_socket_fd, SIOCDEVPRIVATE, &ifr);
	}

	return ret < 0 ? errno : 0;
	}

	int br_set_bridge_forward_delay(const char br, struct timeval tv)
	{
	return br_set(br, "forward_delay", __tv_to_jiffies(tv),
	BRCTL_SET_BRIDGE_FORWARD_DELAY);
	}

	int br_set_bridge_hello_time(const char br, struct timeval tv)
	{
	return br_set(br, "hello_time", __tv_to_jiffies(tv),
	BRCTL_SET_BRIDGE_HELLO_TIME);
	}

	int br_set_bridge_max_age(const char br, struct timeval tv)
	{
	return br_set(br, "max_age", __tv_to_jiffies(tv),
	BRCTL_SET_BRIDGE_MAX_AGE);
	}

	int br_set_ageing_time(const char br, struct timeval tv)
	{
	return br_set(br, "ageing_time", __tv_to_jiffies(tv),
	BRCTL_SET_AGEING_TIME);
	}

	int br_set_stp_state(const char *br, int stp_state)
	{
	return br_set(br, "stp_state", stp_state, BRCTL_SET_BRIDGE_STP_STATE);
	}

	int br_set_bridge_priority(const char *br, int bridge_priority)
	{
	return br_set(br, "priority", bridge_priority,
	BRCTL_SET_BRIDGE_PRIORITY);
	}

	static int port_set(const char bridge, const char ifname,
	const char *name, unsigned long value,
	unsigned long oldcode)
	{
	int ret;
	char path[SYSFS_PATH_MAX];

	snprintf(path, SYSFS_PATH_MAX, SYSFS_CLASS_NET "%s/brport/%s", ifname, name);

	if ((ret = set_sysfs(path, value)) < 0) {
	int index = get_portno(bridge, ifname);

	if (index < 0)
	ret = index;
	else {
	struct ifreq ifr;
	unsigned long args[4] = { oldcode, index, value, 0 };

	strncpy(ifr.ifr_name, bridge, IFNAMSIZ);
	ifr.ifr_data = (char *) &args;
	ret = ioctl(br_socket_fd, SIOCDEVPRIVATE, &ifr);
	}
	}

	return ret < 0 ? errno : 0;
	}

	int br_set_port_priority(const char bridge, const char port, int priority)
	{
	return port_set(bridge, port, "priority", priority, BRCTL_SET_PORT_PRIORITY);
	}

	int br_set_path_cost(const char bridge, const char port, int cost)
	{
	return port_set(bridge, port, "path_cost", cost, BRCTL_SET_PATH_COST);
	}

	int br_set_hairpin_mode(const char bridge, const char port, int hairpin_mode)
	{
	return port_set(bridge, port, "hairpin_mode", hairpin_mode, 0);
	}

	static inline void __copy_fdb(struct fdb_entry *ent,
	const struct __fdb_entry *f)
	{
	memcpy(ent->mac_addr, f->mac_addr, 6);
	ent->port_no = f->port_no;
	ent->is_local = f->is_local;
	__jiffies_to_tv(&ent->ageing_timer_value, f->ageing_timer_value);
	}

	int br_read_fdb(const char bridge, struct fdb_entry fdbs,
	unsigned long offset, int num)
	{
	FILE *f;
	int i, n;
	struct __fdb_entry fe[num];
	char path[SYSFS_PATH_MAX];

	/* open /sys/class/net/brXXX/brforward */
	snprintf(path, SYSFS_PATH_MAX, SYSFS_CLASS_NET "%s/brforward", bridge);
	f = fopen(path, "r");
	if (f) {
	fseek(f, offset*sizeof(struct __fdb_entry), SEEK_SET);
	n = fread(fe, sizeof(struct __fdb_entry), num, f);
	fclose(f);
	} else {
	/* old kernel, use ioctl */
	unsigned long args[4] = { BRCTL_GET_FDB_ENTRIES,
	(unsigned long) fe,
	num, offset };
	struct ifreq ifr;
	int retries = 0;

	strncpy(ifr.ifr_name, bridge, IFNAMSIZ);
	ifr.ifr_data = (char *) args;

	retry:
	n = ioctl(br_socket_fd, SIOCDEVPRIVATE, &ifr);

	/* table can change during ioctl processing */
	if (n < 0 && errno == EAGAIN && ++retries < 10) {
	sleep(0);
	goto retry;
	}
	}

	for (i = 0; i < n; i++)
	__copy_fdb(fdbs+i, fe+i);

	return n;
	}