linux/net/bridge/br_sysfs_if.c
Fischer, Anna 3982d3d28b net/bridge: Add 'hairpin' port forwarding mode
This patch adds a 'hairpin' (also called 'reflective relay') mode
port configuration to the Linux Ethernet bridge kernel module.
A bridge supporting hairpin forwarding mode can send frames back
out through the port the frame was received on.

Hairpin mode is required to support basic VEPA (Virtual
Ethernet Port Aggregator) capabilities.

You can find additional information on VEPA here:
http://tech.groups.yahoo.com/group/evb/
http://www.ieee802.org/1/files/public/docs2009/new-hudson-vepa_seminar-20090514d.pdf
http://www.internet2.edu/presentations/jt2009jul/20090719-congdon.pdf

An additional patch 'bridge-utils: Add 'hairpin' port forwarding mode'
is provided to allow configuring hairpin mode from userspace tools.

Signed-off-by: Paul Congdon <paul.congdon@hp.com>
Signed-off-by: Anna Fischer <anna.fischer@hp.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-13 16:26:11 -07:00

254 lines
6.8 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);
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,
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;
}
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 brport 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)
goto out2;
for (a = brport_attrs; *a; ++a) {
err = sysfs_create_file(&p->kobj, &((*a)->attr));
if (err)
goto out2;
}
err = sysfs_create_link(br->ifobj, &p->kobj, p->dev->name);
out2:
return err;
}