[BRIDGE]: netlink interface for link management

Add basic netlink support to the Ethernet bridge. Including:
 * dump interfaces in bridges
 * monitor link status changes
 * change state of bridge port

For some demo programs see:
	http://developer.osdl.org/shemminger/prototypes/brnl.tar.gz

These are to allow building a daemon that does alternative
implementations of Spanning Tree Protocol.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Stephen Hemminger 2006-05-25 16:00:12 -07:00 committed by David S. Miller
parent c090971326
commit 11dc1f36a6
6 changed files with 214 additions and 2 deletions

View file

@ -6,7 +6,7 @@ obj-$(CONFIG_BRIDGE) += bridge.o
bridge-y := br.o br_device.o br_fdb.o br_forward.o br_if.o br_input.o \
br_ioctl.o br_notify.o br_stp.o br_stp_bpdu.o \
br_stp_if.o br_stp_timer.o
br_stp_if.o br_stp_timer.o br_netlink.o
bridge-$(CONFIG_SYSFS) += br_sysfs_if.o br_sysfs_br.o

View file

@ -48,6 +48,7 @@ static int __init br_init(void)
if (err)
goto err_out2;
br_netlink_init();
brioctl_set(br_ioctl_deviceless_stub);
br_handle_frame_hook = br_handle_frame;
@ -67,6 +68,7 @@ static void __exit br_deinit(void)
{
rcu_assign_pointer(br_stp_sap->rcv_func, NULL);
br_netlink_fini();
br_netfilter_fini();
unregister_netdevice_notifier(&br_device_notifier);
brioctl_set(NULL);

199
net/bridge/br_netlink.c Normal file
View file

@ -0,0 +1,199 @@
/*
* Bridge netlink control interface
*
* 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/kernel.h>
#include <linux/rtnetlink.h>
#include "br_private.h"
/*
* Create one netlink message for one interface
* Contains port and master info as well as carrier and bridge state.
*/
static int br_fill_ifinfo(struct sk_buff *skb, const struct net_bridge_port *port,
u32 pid, u32 seq, int event, unsigned int flags)
{
const struct net_bridge *br = port->br;
const struct net_device *dev = port->dev;
struct ifinfomsg *r;
struct nlmsghdr *nlh;
unsigned char *b = skb->tail;
u32 mtu = dev->mtu;
u8 operstate = netif_running(dev) ? dev->operstate : IF_OPER_DOWN;
u8 portstate = port->state;
pr_debug("br_fill_info event %d port %s master %s\n",
event, dev->name, br->dev->name);
nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*r), flags);
r = NLMSG_DATA(nlh);
r->ifi_family = AF_BRIDGE;
r->__ifi_pad = 0;
r->ifi_type = dev->type;
r->ifi_index = dev->ifindex;
r->ifi_flags = dev_get_flags(dev);
r->ifi_change = 0;
RTA_PUT(skb, IFLA_IFNAME, strlen(dev->name)+1, dev->name);
RTA_PUT(skb, IFLA_MASTER, sizeof(int), &br->dev->ifindex);
if (dev->addr_len)
RTA_PUT(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr);
RTA_PUT(skb, IFLA_MTU, sizeof(mtu), &mtu);
if (dev->ifindex != dev->iflink)
RTA_PUT(skb, IFLA_LINK, sizeof(int), &dev->iflink);
RTA_PUT(skb, IFLA_OPERSTATE, sizeof(operstate), &operstate);
if (event == RTM_NEWLINK)
RTA_PUT(skb, IFLA_PROTINFO, sizeof(portstate), &portstate);
nlh->nlmsg_len = skb->tail - b;
return skb->len;
nlmsg_failure:
rtattr_failure:
skb_trim(skb, b - skb->data);
return -EINVAL;
}
/*
* Notify listeners of a change in port information
*/
void br_ifinfo_notify(int event, struct net_bridge_port *port)
{
struct sk_buff *skb;
int err = -ENOMEM;
pr_debug("bridge notify event=%d\n", event);
skb = alloc_skb(NLMSG_SPACE(sizeof(struct ifinfomsg) + 128),
GFP_ATOMIC);
if (!skb)
goto err_out;
err = br_fill_ifinfo(skb, port, current->pid, 0, event, 0);
if (err)
goto err_kfree;
NETLINK_CB(skb).dst_group = RTNLGRP_LINK;
netlink_broadcast(rtnl, skb, 0, RTNLGRP_LINK, GFP_ATOMIC);
return;
err_kfree:
kfree_skb(skb);
err_out:
netlink_set_err(rtnl, 0, RTNLGRP_LINK, err);
}
/*
* Dump information about all ports, in response to GETLINK
*/
static int br_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
{
struct net_device *dev;
int idx;
int s_idx = cb->args[0];
int err = 0;
read_lock(&dev_base_lock);
for (dev = dev_base, idx = 0; dev; dev = dev->next) {
struct net_bridge_port *p = dev->br_port;
/* not a bridge port */
if (!p)
continue;
if (idx < s_idx)
continue;
err = br_fill_ifinfo(skb, p, NETLINK_CB(cb->skb).pid,
cb->nlh->nlmsg_seq, RTM_NEWLINK, NLM_F_MULTI);
if (err <= 0)
break;
++idx;
}
read_unlock(&dev_base_lock);
cb->args[0] = idx;
return skb->len;
}
/*
* Change state of port (ie from forwarding to blocking etc)
* Used by spanning tree in user space.
*/
static int br_rtm_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
struct rtattr **rta = arg;
struct ifinfomsg *ifm = NLMSG_DATA(nlh);
struct net_device *dev;
struct net_bridge_port *p;
u8 new_state;
if (ifm->ifi_family != AF_BRIDGE)
return -EPFNOSUPPORT;
/* Must pass valid state as PROTINFO */
if (rta[IFLA_PROTINFO-1]) {
u8 *pstate = RTA_DATA(rta[IFLA_PROTINFO-1]);
new_state = *pstate;
} else
return -EINVAL;
if (new_state > BR_STATE_BLOCKING)
return -EINVAL;
/* Find bridge port */
dev = __dev_get_by_index(ifm->ifi_index);
if (!dev)
return -ENODEV;
p = dev->br_port;
if (!p)
return -EINVAL;
/* if kernel STP is running, don't allow changes */
if (p->br->stp_enabled)
return -EBUSY;
if (!netif_running(dev))
return -ENETDOWN;
if (!netif_carrier_ok(dev) && new_state != BR_STATE_DISABLED)
return -ENETDOWN;
p->state = new_state;
br_log_state(p);
return 0;
}
static struct rtnetlink_link bridge_rtnetlink_table[RTM_NR_MSGTYPES] = {
[RTM_GETLINK - RTM_BASE] = { .dumpit = br_dump_ifinfo, },
[RTM_SETLINK - RTM_BASE] = { .doit = br_rtm_setlink, },
};
void __init br_netlink_init(void)
{
rtnetlink_links[PF_BRIDGE] = bridge_rtnetlink_table;
}
void __exit br_netlink_fini(void)
{
rtnetlink_links[PF_BRIDGE] = NULL;
}

View file

@ -14,6 +14,7 @@
*/
#include <linux/kernel.h>
#include <linux/rtnetlink.h>
#include "br_private.h"
@ -49,6 +50,7 @@ static int br_device_event(struct notifier_block *unused, unsigned long event, v
case NETDEV_CHANGEADDR:
br_fdb_changeaddr(p, dev->dev_addr);
br_ifinfo_notify(RTM_NEWLINK, p);
br_stp_recalculate_bridge_id(br);
break;

View file

@ -29,7 +29,7 @@
#define BR_PORT_DEBOUNCE (HZ/10)
#define BR_VERSION "2.1"
#define BR_VERSION "2.2"
typedef struct bridge_id bridge_id;
typedef struct mac_addr mac_addr;
@ -237,6 +237,11 @@ extern struct net_bridge_fdb_entry *(*br_fdb_get_hook)(struct net_bridge *br,
extern void (*br_fdb_put_hook)(struct net_bridge_fdb_entry *ent);
/* br_netlink.c */
extern void br_netlink_init(void);
extern void br_netlink_fini(void);
extern void br_ifinfo_notify(int event, struct net_bridge_port *port);
#ifdef CONFIG_SYSFS
/* br_sysfs_if.c */
extern struct sysfs_ops brport_sysfs_ops;

View file

@ -16,6 +16,7 @@
#include <linux/kernel.h>
#include <linux/smp_lock.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
#include "br_private.h"
#include "br_private_stp.h"
@ -86,6 +87,7 @@ void br_stp_disable_bridge(struct net_bridge *br)
void br_stp_enable_port(struct net_bridge_port *p)
{
br_init_port(p);
br_ifinfo_notify(RTM_NEWLINK, p);
br_port_state_selection(p->br);
}
@ -99,6 +101,8 @@ void br_stp_disable_port(struct net_bridge_port *p)
printk(KERN_INFO "%s: port %i(%s) entering %s state\n",
br->dev->name, p->port_no, p->dev->name, "disabled");
br_ifinfo_notify(RTM_DELLINK, p);
wasroot = br_is_root_bridge(br);
br_become_designated_port(p);
p->state = BR_STATE_DISABLED;