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Commit 11dc1f36 authored by Stephen Hemminger's avatar Stephen Hemminger Committed by David S. Miller
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[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: default avatarStephen Hemminger <shemminger@osdl.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c0909713

net/bridge/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -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

net/bridge/br.c

+2 −0
Original line number Diff line number Diff line
@@ -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);

net/bridge/br_netlink.c

0 → 100644
+199 −0
Original line number Diff line number Diff line 
/*

 *	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;

}

net/bridge/br_notify.c

+2 −0
Original line number Diff line number Diff line
@@ -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;

net/bridge/br_private.h

+6 −1
Original line number Diff line number Diff line
@@ -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;