text: /*
   *	Userspace interface
   *	Linux ethernet bridge
   *
   *	Authors:
   *	Lennert Buytenhek		<buytenh@gnu.org>
   *
   *	$Id: br_if.c,v 1.1.1.1 2001/02/22 14:59:02 serg 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/if_arp.h>
  #include <linux/if_bridge.h>
  #include <linux/inetdevice.h>
  #include <linux/rtnetlink.h>
  #include <asm/uaccess.h>
  #include "br_private.h"
  
  static struct net_bridge *bridge_list;
  
  static int br_initial_port_cost(struct net_device *dev)
  {
  	if (!strncmp(dev->name, "lec", 3))
  		return 7;
  
  	if (!strncmp(dev->name, "eth", 3))
  		return 100;			/* FIXME handle 100Mbps */
  
  	if (!strncmp(dev->name, "plip", 4))
  		return 2500;
  
  	return 100;
  }
  
  /* called under bridge lock */
  static int __br_del_if(struct net_bridge *br, struct net_device *dev)
  {
  	struct net_bridge_port *p;
  	struct net_bridge_port **pptr;
  
  	if ((p = dev->br_port) == NULL)
  		return -EINVAL;
  
  	br_stp_disable_port(p);
  
  	dev_set_promiscuity(dev, -1);
  	dev->br_port = NULL;
  
  	pptr = &br->port_list;
  	while (*pptr != NULL) {
  		if (*pptr == p) {
  			*pptr = p->next;
  			break;
  		}
  
  		pptr = &((*pptr)->next);
  	}
  
  	br_fdb_delete_by_port(br, p);
  	kfree(p);
  	dev_put(dev);
  
  	return 0;
  }
  
  static struct net_bridge **__find_br(char *name)
  {
  	struct net_bridge **b;
  	struct net_bridge *br;
  
  	b = &bridge_list;
  	while ((br = *b) != NULL) {
  		if (!strncmp(br->dev.name, name, IFNAMSIZ))
  			return b;
  
  		b = &(br->next);
  	}
  
  	return NULL;
  }
  
  static void del_ifs(struct net_bridge *br)
  {
  	write_lock_bh(&br->lock);
  	while (br->port_list != NULL)
  		__br_del_if(br, br->port_list->dev);
  	write_unlock_bh(&br->lock);
  }
  
  static struct net_bridge *new_nb(char *name)
  {
  	struct net_bridge *br;
  	struct net_device *dev;
  
  	if ((br = kmalloc(sizeof(*br), GFP_KERNEL)) == NULL)
  		return NULL;
  
  	memset(br, 0, sizeof(*br));
  	dev = &br->dev;
  
  	strncpy(dev->name, name, IFNAMSIZ);
  	dev->priv = br;
  	ether_setup(dev);
  	br_dev_setup(dev);
  
  	br->lock = RW_LOCK_UNLOCKED;
  	br->hash_lock = RW_LOCK_UNLOCKED;
  
  	br->bridge_id.prio[0] = 0x80;
  	br->bridge_id.prio[1] = 0x00;
  	memset(br->bridge_id.addr, 0, ETH_ALEN);
  
  	br->stp_enabled = 1;
  	br->designated_root = br->bridge_id;
  	br->root_path_cost = 0;
  	br->root_port = 0;
  	br->bridge_max_age = br->max_age = 20 * HZ;
  	br->bridge_hello_time = br->hello_time = 2 * HZ;
  	br->bridge_forward_delay = br->forward_delay = 15 * HZ;
  	br->topology_change = 0;
  	br->topology_change_detected = 0;
  	br_timer_clear(&br->hello_timer);
  	br_timer_clear(&br->tcn_timer);
  	br_timer_clear(&br->topology_change_timer);
  
  	br->ageing_time = 300 * HZ;
  	br->gc_interval = 4 * HZ;
  
  	return br;
  }
  
  /* called under bridge lock */
  static struct net_bridge_port *new_nbp(struct net_bridge *br, struct net_device *dev)
  {
  	int i;
  	struct net_bridge_port *p;
  
  	p = kmalloc(sizeof(*p), GFP_KERNEL);
  	if (p == NULL)
  		return p;
  
  	memset(p, 0, sizeof(*p));
  	p->br = br;
  	p->dev = dev;
  	p->path_cost = br_initial_port_cost(dev);
  	p->priority = 0x80;
  
  	dev->br_port = p;
  
  	for (i=1;i<255;i++)
  		if (br_get_port(br, i) == NULL)
  			break;
  
  	if (i == 255) {
  		kfree(p);
  		return NULL;
  	}
  
  	p->port_no = i;
  	br_init_port(p);
  	p->state = BR_STATE_DISABLED;
  
  	p->next = br->port_list;
  	br->port_list = p;
  
  	return p;
  }
  
  int br_add_bridge(char *name)
  {
  	struct net_bridge *br;
  
  	if ((br = new_nb(name)) == NULL)
  		return -ENOMEM;
  
  	if (__dev_get_by_name(name) != NULL) {
  		kfree(br);
  		return -EEXIST;
  	}
  
  	br->next = bridge_list;
  	bridge_list = br;
  
  	br_inc_use_count();
  	register_netdev(&br->dev);
  
  	return 0;
  }
  
  int br_del_bridge(char *name)
  {
  	struct net_bridge **b;
  	struct net_bridge *br;
  
  	if ((b = __find_br(name)) == NULL)
  		return -ENXIO;
  
  	br = *b;
  
  	if (br->dev.flags & IFF_UP)
  		return -EBUSY;
  
  	del_ifs(br);
  
  	*b = br->next;
  
  	unregister_netdev(&br->dev);
  	kfree(br);
  	br_dec_use_count();
  
  	return 0;
  }
  
  int br_add_if(struct net_bridge *br, struct net_device *dev)
  {
  	struct net_bridge_port *p;
  
  	if (dev->br_port != NULL)
  		return -EBUSY;
  
  	if (dev->flags & IFF_LOOPBACK || dev->type != ARPHRD_ETHER)
  		return -EINVAL;
  
  	dev_hold(dev);
  	write_lock_bh(&br->lock);
  	if ((p = new_nbp(br, dev)) == NULL) {
  		write_unlock_bh(&br->lock);
  		dev_put(dev);
  		return -EXFULL;
  	}
  
  	dev_set_promiscuity(dev, 1);
  
  	br_stp_recalculate_bridge_id(br);
  	br_fdb_insert(br, p, dev->dev_addr, 1);
  	if ((br->dev.flags & IFF_UP) && (dev->flags & IFF_UP))
  		br_stp_enable_port(p);
  	write_unlock_bh(&br->lock);
  
  	return 0;
  }
  
  int br_del_if(struct net_bridge *br, struct net_device *dev)
  {
  	int retval;
  
  	write_lock_bh(&br->lock);
  	retval = __br_del_if(br, dev);
  	br_stp_recalculate_bridge_id(br);
  	write_unlock_bh(&br->lock);
  
  	return retval;
  }
  
  int br_get_bridge_ifindices(int *indices, int num)
  {
  	struct net_bridge *br;
  	int i;
  
  	i = 0;
  
  	br = bridge_list;
  	for (i=0;i<num;i++) {
  		if (br == NULL)
  			break;
  
  		indices[i] = br->dev.ifindex;
  		br = br->next;
  	}
  
  	return i;
  }
  
  /* called under ioctl_lock */
  void br_get_port_ifindices(struct net_bridge *br, int *ifindices)
  {
  	struct net_bridge_port *p;
  
  	p = br->port_list;
  	while (p != NULL) {
  		ifindices[p->port_no] = p->dev->ifindex;
  		p = p->next;
  	}
  }
  