linux/net/bridge/br_sysfs_if.c
Simon Arlott e0f43752a9 bridge: update sysfs link names if port device names have changed
Links for each port are created in sysfs using the device
name, but this could be changed after being added to the
bridge.

As well as being unable to remove interfaces after this
occurs (because userspace tools don't recognise the new
name, and the kernel won't recognise the old name), adding
another interface with the old name to the bridge will
cause an error trying to create the sysfs link.

This fixes the problem by listening for NETDEV_CHANGENAME
notifications and renaming the link.

https://bugzilla.kernel.org/show_bug.cgi?id=12743

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-15 23:10:15 -07:00

293 lines
7.9 KiB
C

/*
* 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 *);
ssize_t (*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\n", p->path_cost);
}
static ssize_t store_path_cost(struct net_bridge_port *p, unsigned long v)
{
br_stp_set_path_cost(p, v);
return 0;
}
static BRPORT_ATTR(path_cost, S_IRUGO | S_IWUSR,
show_path_cost, store_path_cost);
static ssize_t show_priority(struct net_bridge_port *p, char *buf)
{
return sprintf(buf, "%d\n", p->priority);
}
static ssize_t store_priority(struct net_bridge_port *p, unsigned long v)
{
if (v >= (1<<(16-BR_PORT_BITS)))
return -ERANGE;
br_stp_set_port_priority(p, v);
return 0;
}
static BRPORT_ATTR(priority, S_IRUGO | S_IWUSR,
show_priority, store_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\n", 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\n", 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\n", 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\n", 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\n", 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\n", 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\n", 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\n", 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\n", 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\n", br_timer_value(&p->hold_timer));
}
static BRPORT_ATTR(hold_timer, S_IRUGO, show_hold_timer, NULL);
static ssize_t 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\n", hairpin_mode);
}
static ssize_t 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\n", p->multicast_router);
}
static ssize_t 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;
}