/*
   *	Sysfs attributes of bridge ports
   *	Linux ethernet bridge
   *
   *	Authors:
   *	Stephen Hemminger		<shemminger@osdl.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/capability.h>

  #include <linux/kernel.h>
  #include <linux/netdevice.h>
  #include <linux/if_bridge.h>
  #include <linux/rtnetlink.h>
  #include <linux/spinlock.h>
  
  #include "br_private.h"
  
  struct brport_attribute {
  	struct attribute	attr;
  	ssize_t (*show)(struct net_bridge_port *, char *);

  	int (*store)(struct net_bridge_port *, unsigned long);

  };
  
  #define BRPORT_ATTR(_name,_mode,_show,_store)		        \
  struct brport_attribute brport_attr_##_name = { 	        \
  	.attr = {.name = __stringify(_name), 			\

  		 .mode = _mode },				\

  	.show	= _show,					\
  	.store	= _store,					\
  };
  
  static ssize_t show_path_cost(struct net_bridge_port *p, char *buf)
  {
  	return sprintf(buf, "%d
  ", p->path_cost);
  }

  static BRPORT_ATTR(path_cost, S_IRUGO | S_IWUSR,

  		   show_path_cost, br_stp_set_path_cost);

  
  static ssize_t show_priority(struct net_bridge_port *p, char *buf)
  {
  	return sprintf(buf, "%d
  ", p->priority);
  }

  static BRPORT_ATTR(priority, S_IRUGO | S_IWUSR,

  			 show_priority, br_stp_set_port_priority);

  
  static ssize_t show_designated_root(struct net_bridge_port *p, char *buf)
  {
  	return br_show_bridge_id(buf, &p->designated_root);
  }
  static BRPORT_ATTR(designated_root, S_IRUGO, show_designated_root, NULL);
  
  static ssize_t show_designated_bridge(struct net_bridge_port *p, char *buf)
  {
  	return br_show_bridge_id(buf, &p->designated_bridge);
  }
  static BRPORT_ATTR(designated_bridge, S_IRUGO, show_designated_bridge, NULL);
  
  static ssize_t show_designated_port(struct net_bridge_port *p, char *buf)
  {
  	return sprintf(buf, "%d
  ", p->designated_port);
  }
  static BRPORT_ATTR(designated_port, S_IRUGO, show_designated_port, NULL);
  
  static ssize_t show_designated_cost(struct net_bridge_port *p, char *buf)
  {
  	return sprintf(buf, "%d
  ", p->designated_cost);
  }
  static BRPORT_ATTR(designated_cost, S_IRUGO, show_designated_cost, NULL);
  
  static ssize_t show_port_id(struct net_bridge_port *p, char *buf)
  {
  	return sprintf(buf, "0x%x
  ", p->port_id);
  }
  static BRPORT_ATTR(port_id, S_IRUGO, show_port_id, NULL);
  
  static ssize_t show_port_no(struct net_bridge_port *p, char *buf)
  {
  	return sprintf(buf, "0x%x
  ", p->port_no);
  }
  
  static BRPORT_ATTR(port_no, S_IRUGO, show_port_no, NULL);
  
  static ssize_t show_change_ack(struct net_bridge_port *p, char *buf)
  {
  	return sprintf(buf, "%d
  ", p->topology_change_ack);
  }
  static BRPORT_ATTR(change_ack, S_IRUGO, show_change_ack, NULL);
  
  static ssize_t show_config_pending(struct net_bridge_port *p, char *buf)
  {
  	return sprintf(buf, "%d
  ", p->config_pending);
  }
  static BRPORT_ATTR(config_pending, S_IRUGO, show_config_pending, NULL);
  
  static ssize_t show_port_state(struct net_bridge_port *p, char *buf)
  {
  	return sprintf(buf, "%d
  ", p->state);
  }
  static BRPORT_ATTR(state, S_IRUGO, show_port_state, NULL);
  
  static ssize_t show_message_age_timer(struct net_bridge_port *p,
  					    char *buf)
  {
  	return sprintf(buf, "%ld
  ", br_timer_value(&p->message_age_timer));
  }
  static BRPORT_ATTR(message_age_timer, S_IRUGO, show_message_age_timer, NULL);
  
  static ssize_t show_forward_delay_timer(struct net_bridge_port *p,
  					    char *buf)
  {
  	return sprintf(buf, "%ld
  ", br_timer_value(&p->forward_delay_timer));
  }
  static BRPORT_ATTR(forward_delay_timer, S_IRUGO, show_forward_delay_timer, NULL);
  
  static ssize_t show_hold_timer(struct net_bridge_port *p,
  					    char *buf)
  {
  	return sprintf(buf, "%ld
  ", br_timer_value(&p->hold_timer));
  }
  static BRPORT_ATTR(hold_timer, S_IRUGO, show_hold_timer, NULL);

  static int store_flush(struct net_bridge_port *p, unsigned long v)

  {
  	br_fdb_delete_by_port(p->br, p, 0); // Don't delete local entry
  	return 0;
  }
  static BRPORT_ATTR(flush, S_IWUSR, NULL, store_flush);

  static ssize_t show_hairpin_mode(struct net_bridge_port *p, char *buf)
  {
  	int hairpin_mode = (p->flags & BR_HAIRPIN_MODE) ? 1 : 0;
  	return sprintf(buf, "%d
  ", hairpin_mode);
  }

  static int store_hairpin_mode(struct net_bridge_port *p, unsigned long v)

  {
  	if (v)
  		p->flags |= BR_HAIRPIN_MODE;
  	else
  		p->flags &= ~BR_HAIRPIN_MODE;
  	return 0;
  }
  static BRPORT_ATTR(hairpin_mode, S_IRUGO | S_IWUSR,
  		   show_hairpin_mode, store_hairpin_mode);

  #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
  static ssize_t show_multicast_router(struct net_bridge_port *p, char *buf)
  {
  	return sprintf(buf, "%d
  ", p->multicast_router);
  }

  static int store_multicast_router(struct net_bridge_port *p,

  				      unsigned long v)
  {
  	return br_multicast_set_port_router(p, v);
  }
  static BRPORT_ATTR(multicast_router, S_IRUGO | S_IWUSR, show_multicast_router,
  		   store_multicast_router);
  #endif

  static struct brport_attribute *brport_attrs[] = {
  	&brport_attr_path_cost,
  	&brport_attr_priority,
  	&brport_attr_port_id,
  	&brport_attr_port_no,
  	&brport_attr_designated_root,
  	&brport_attr_designated_bridge,
  	&brport_attr_designated_port,
  	&brport_attr_designated_cost,
  	&brport_attr_state,
  	&brport_attr_change_ack,
  	&brport_attr_config_pending,
  	&brport_attr_message_age_timer,
  	&brport_attr_forward_delay_timer,
  	&brport_attr_hold_timer,

  	&brport_attr_flush,

  	&brport_attr_hairpin_mode,

  #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
  	&brport_attr_multicast_router,
  #endif

  	NULL
  };
  
  #define to_brport_attr(_at) container_of(_at, struct brport_attribute, attr)
  #define to_brport(obj)	container_of(obj, struct net_bridge_port, kobj)
  
  static ssize_t brport_show(struct kobject * kobj,
  			   struct attribute * attr, char * buf)
  {
  	struct brport_attribute * brport_attr = to_brport_attr(attr);
  	struct net_bridge_port * p = to_brport(kobj);
  
  	return brport_attr->show(p, buf);
  }
  
  static ssize_t brport_store(struct kobject * kobj,
  			    struct attribute * attr,
  			    const char * buf, size_t count)
  {
  	struct brport_attribute * brport_attr = to_brport_attr(attr);
  	struct net_bridge_port * p = to_brport(kobj);
  	ssize_t ret = -EINVAL;
  	char *endp;
  	unsigned long val;
  
  	if (!capable(CAP_NET_ADMIN))
  		return -EPERM;
  
  	val = simple_strtoul(buf, &endp, 0);
  	if (endp != buf) {

  		if (!rtnl_trylock())
  			return restart_syscall();

  		if (p->dev && p->br && brport_attr->store) {
  			spin_lock_bh(&p->br->lock);
  			ret = brport_attr->store(p, val);
  			spin_unlock_bh(&p->br->lock);
  			if (ret == 0)
  				ret = count;
  		}
  		rtnl_unlock();
  	}
  	return ret;
  }

  const struct sysfs_ops brport_sysfs_ops = {

  	.show = brport_show,
  	.store = brport_store,
  };

  /*
   * Add sysfs entries to ethernet device added to a bridge.
   * Creates a brport subdirectory with bridge attributes.

   * Puts symlink in bridge's brif subdirectory

   */
  int br_sysfs_addif(struct net_bridge_port *p)
  {
  	struct net_bridge *br = p->br;
  	struct brport_attribute **a;
  	int err;

  	err = sysfs_create_link(&p->kobj, &br->dev->dev.kobj,

  				SYSFS_BRIDGE_PORT_LINK);
  	if (err)

  		return err;

  
  	for (a = brport_attrs; *a; ++a) {
  		err = sysfs_create_file(&p->kobj, &((*a)->attr));
  		if (err)

  			return err;

  	}

  	strlcpy(p->sysfs_name, p->dev->name, IFNAMSIZ);
  	return sysfs_create_link(br->ifobj, &p->kobj, p->sysfs_name);
  }
  
  /* Rename bridge's brif symlink */
  int br_sysfs_renameif(struct net_bridge_port *p)
  {
  	struct net_bridge *br = p->br;
  	int err;
  
  	/* If a rename fails, the rollback will cause another
  	 * rename call with the existing name.
  	 */
  	if (!strncmp(p->sysfs_name, p->dev->name, IFNAMSIZ))
  		return 0;
  
  	err = sysfs_rename_link(br->ifobj, &p->kobj,
  				p->sysfs_name, p->dev->name);
  	if (err)
  		netdev_notice(br->dev, "unable to rename link %s to %s",
  			      p->sysfs_name, p->dev->name);
  	else
  		strlcpy(p->sysfs_name, p->dev->name, IFNAMSIZ);

  	return err;
  }