net/bridge/br.c - linux - Git at Google

 /*
  *	Generic parts
  *	Linux ethernet bridge
  *
  *	Authors:
  *	Lennert Buytenhek		<buytenh@gnu.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/module.h>
 #include <linux/kernel.h>
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
 #include <linux/init.h>
 #include <linux/llc.h>
 #include <net/llc.h>
 #include <net/stp.h>
 #include <net/switchdev.h>

 #include "br_private.h"

 /*
  * Handle changes in state of network devices enslaved to a bridge.
  *
  * Note: don't care about up/down if bridge itself is down, because
  *     port state is checked when bridge is brought up.
  */
 static int br_device_event(struct notifier_block *unused, unsigned long event, void *ptr)
 {
 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 	struct net_bridge_port *p;
 	struct net_bridge *br;
 	bool notified = false;
 	bool changed_addr;
 	int err;

 	/* register of bridge completed, add sysfs entries */
 	if ((dev->priv_flags & IFF_EBRIDGE) && event == NETDEV_REGISTER) {
 		br_sysfs_addbr(dev);
 		return NOTIFY_DONE;
 	}

 	/* not a port of a bridge */
 	p = br_port_get_rtnl(dev);
 	if (!p)
 		return NOTIFY_DONE;

 	br = p->br;

 	switch (event) {
 	case NETDEV_CHANGEMTU:
 		br_mtu_auto_adjust(br);
 		break;

 	case NETDEV_CHANGEADDR:
 		spin_lock_bh(&br->lock);
 		br_fdb_changeaddr(p, dev->dev_addr);
 		changed_addr = br_stp_recalculate_bridge_id(br);
 		spin_unlock_bh(&br->lock);

 		if (changed_addr)
 			call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);

 		break;

 	case NETDEV_CHANGE:
 		br_port_carrier_check(p, &notified);
 		break;

 	case NETDEV_FEAT_CHANGE:
 		netdev_update_features(br->dev);
 		break;

 	case NETDEV_DOWN:
 		spin_lock_bh(&br->lock);
 		if (br->dev->flags & IFF_UP) {
 			br_stp_disable_port(p);
 			notified = true;
 		}
 		spin_unlock_bh(&br->lock);
 		break;

 	case NETDEV_UP:
 		if (netif_running(br->dev) && netif_oper_up(dev)) {
 			spin_lock_bh(&br->lock);
 			br_stp_enable_port(p);
 			notified = true;
 			spin_unlock_bh(&br->lock);
 		}
 		break;

 	case NETDEV_UNREGISTER:
 		br_del_if(br, dev);
 		break;

 	case NETDEV_CHANGENAME:
 		err = br_sysfs_renameif(p);
 		if (err)
 			return notifier_from_errno(err);
 		break;

 	case NETDEV_PRE_TYPE_CHANGE:
 		/* Forbid underlaying device to change its type. */
 		return NOTIFY_BAD;

 	case NETDEV_RESEND_IGMP:
 		/* Propagate to master device */
 		call_netdevice_notifiers(event, br->dev);
 		break;
 	}

 	/* Events that may cause spanning tree to refresh */
 	if (!notified && (event == NETDEV_CHANGEADDR || event == NETDEV_UP ||
 			  event == NETDEV_CHANGE || event == NETDEV_DOWN))
 		br_ifinfo_notify(RTM_NEWLINK, NULL, p);

 	return NOTIFY_DONE;
 }

 static struct notifier_block br_device_notifier = {
 	.notifier_call = br_device_event
 };

 /* called with RTNL or RCU */
 static int br_switchdev_event(struct notifier_block *unused,
 			      unsigned long event, void *ptr)
 {
 	struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
 	struct net_bridge_port *p;
 	struct net_bridge *br;
 	struct switchdev_notifier_fdb_info *fdb_info;
 	int err = NOTIFY_DONE;

 	p = br_port_get_rtnl_rcu(dev);
 	if (!p)
 		goto out;

 	br = p->br;

 	switch (event) {
 	case SWITCHDEV_FDB_ADD_TO_BRIDGE:
 		fdb_info = ptr;
 		err = br_fdb_external_learn_add(br, p, fdb_info->addr,
 						fdb_info->vid, false);
 		if (err) {
 			err = notifier_from_errno(err);
 			break;
 		}
 		br_fdb_offloaded_set(br, p, fdb_info->addr,
 				     fdb_info->vid);
 		break;
 	case SWITCHDEV_FDB_DEL_TO_BRIDGE:
 		fdb_info = ptr;
 		err = br_fdb_external_learn_del(br, p, fdb_info->addr,
 						fdb_info->vid, false);
 		if (err)
 			err = notifier_from_errno(err);
 		break;
 	case SWITCHDEV_FDB_OFFLOADED:
 		fdb_info = ptr;
 		br_fdb_offloaded_set(br, p, fdb_info->addr,
 				     fdb_info->vid);
 		break;
 	}

 out:
 	return err;
 }

 static struct notifier_block br_switchdev_notifier = {
 	.notifier_call = br_switchdev_event,
 };

 void br_opt_toggle(struct net_bridge *br, enum net_bridge_opts opt, bool on)
 {
 	bool cur = !!br_opt_get(br, opt);

 	br_debug(br, "toggle option: %d state: %d -> %d\n",
 		 opt, cur, on);

 	if (cur == on)
 		return;

 	if (on)
 		set_bit(opt, &br->options);
 	else
 		clear_bit(opt, &br->options);
 }

 static void __net_exit br_net_exit(struct net *net)
 {
 	struct net_device *dev;
 	LIST_HEAD(list);

 	rtnl_lock();
 	for_each_netdev(net, dev)
 		if (dev->priv_flags & IFF_EBRIDGE)
 			br_dev_delete(dev, &list);

 	unregister_netdevice_many(&list);
 	rtnl_unlock();

 }

 static struct pernet_operations br_net_ops = {
 	.exit	= br_net_exit,
 };

 static const struct stp_proto br_stp_proto = {
 	.rcv	= br_stp_rcv,
 };

 static int __init br_init(void)
 {
 	int err;

 	BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > FIELD_SIZEOF(struct sk_buff, cb));

 	err = stp_proto_register(&br_stp_proto);
 	if (err < 0) {
 		pr_err("bridge: can't register sap for STP\n");
 		return err;
 	}

 	err = br_fdb_init();
 	if (err)
 		goto err_out;

 	err = register_pernet_subsys(&br_net_ops);
 	if (err)
 		goto err_out1;

 	err = br_nf_core_init();
 	if (err)
 		goto err_out2;

 	err = register_netdevice_notifier(&br_device_notifier);
 	if (err)
 		goto err_out3;

 	err = register_switchdev_notifier(&br_switchdev_notifier);
 	if (err)
 		goto err_out4;

 	err = br_netlink_init();
 	if (err)
 		goto err_out5;

 	brioctl_set(br_ioctl_deviceless_stub);

 #if IS_ENABLED(CONFIG_ATM_LANE)
 	br_fdb_test_addr_hook = br_fdb_test_addr;
 #endif

 #if IS_MODULE(CONFIG_BRIDGE_NETFILTER)
 	pr_info("bridge: filtering via arp/ip/ip6tables is no longer available "
 		"by default. Update your scripts to load br_netfilter if you "
 		"need this.\n");
 #endif

 	return 0;

 err_out5:
 	unregister_switchdev_notifier(&br_switchdev_notifier);
 err_out4:
 	unregister_netdevice_notifier(&br_device_notifier);
 err_out3:
 	br_nf_core_fini();
 err_out2:
 	unregister_pernet_subsys(&br_net_ops);
 err_out1:
 	br_fdb_fini();
 err_out:
 	stp_proto_unregister(&br_stp_proto);
 	return err;
 }

 static void __exit br_deinit(void)
 {
 	stp_proto_unregister(&br_stp_proto);
 	br_netlink_fini();
 	unregister_switchdev_notifier(&br_switchdev_notifier);
 	unregister_netdevice_notifier(&br_device_notifier);
 	brioctl_set(NULL);
 	unregister_pernet_subsys(&br_net_ops);

 	rcu_barrier(); /* Wait for completion of call_rcu()'s */

 	br_nf_core_fini();
 #if IS_ENABLED(CONFIG_ATM_LANE)
 	br_fdb_test_addr_hook = NULL;
 #endif
 	br_fdb_fini();
 }

 module_init(br_init)
 module_exit(br_deinit)
 MODULE_LICENSE("GPL");
 MODULE_VERSION(BR_VERSION);
 MODULE_ALIAS_RTNL_LINK("bridge");
	/*
	* Generic parts
	* Linux ethernet bridge
	*
	* Authors:
	* Lennert Buytenhek <buytenh@gnu.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/module.h>
	#include <linux/kernel.h>
	#include <linux/netdevice.h>
	#include <linux/etherdevice.h>
	#include <linux/init.h>
	#include <linux/llc.h>
	#include <net/llc.h>
	#include <net/stp.h>
	#include <net/switchdev.h>

	#include "br_private.h"

	/*
	* Handle changes in state of network devices enslaved to a bridge.
	*
	* Note: don't care about up/down if bridge itself is down, because
	* port state is checked when bridge is brought up.
	*/
	static int br_device_event(struct notifier_block unused, unsigned long event, void ptr)
	{
	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
	struct net_bridge_port *p;
	struct net_bridge *br;
	bool notified = false;
	bool changed_addr;
	int err;

	/* register of bridge completed, add sysfs entries */
	if ((dev->priv_flags & IFF_EBRIDGE) && event == NETDEV_REGISTER) {
	br_sysfs_addbr(dev);
	return NOTIFY_DONE;
	}

	/* not a port of a bridge */
	p = br_port_get_rtnl(dev);
	if (!p)
	return NOTIFY_DONE;

	br = p->br;

	switch (event) {
	case NETDEV_CHANGEMTU:
	br_mtu_auto_adjust(br);
	break;

	case NETDEV_CHANGEADDR:
	spin_lock_bh(&br->lock);
	br_fdb_changeaddr(p, dev->dev_addr);
	changed_addr = br_stp_recalculate_bridge_id(br);
	spin_unlock_bh(&br->lock);

	if (changed_addr)
	call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);

	break;

	case NETDEV_CHANGE:
	br_port_carrier_check(p, &notified);
	break;

	case NETDEV_FEAT_CHANGE:
	netdev_update_features(br->dev);
	break;

	case NETDEV_DOWN:
	spin_lock_bh(&br->lock);
	if (br->dev->flags & IFF_UP) {
	br_stp_disable_port(p);
	notified = true;
	}
	spin_unlock_bh(&br->lock);
	break;

	case NETDEV_UP:
	if (netif_running(br->dev) && netif_oper_up(dev)) {
	spin_lock_bh(&br->lock);
	br_stp_enable_port(p);
	notified = true;
	spin_unlock_bh(&br->lock);
	}
	break;

	case NETDEV_UNREGISTER:
	br_del_if(br, dev);
	break;

	case NETDEV_CHANGENAME:
	err = br_sysfs_renameif(p);
	if (err)
	return notifier_from_errno(err);
	break;

	case NETDEV_PRE_TYPE_CHANGE:
	/* Forbid underlaying device to change its type. */
	return NOTIFY_BAD;

	case NETDEV_RESEND_IGMP:
	/* Propagate to master device */
	call_netdevice_notifiers(event, br->dev);
	break;
	}

	/* Events that may cause spanning tree to refresh */
	if (!notified && (event == NETDEV_CHANGEADDR \|\| event == NETDEV_UP \|\|
	event == NETDEV_CHANGE \|\| event == NETDEV_DOWN))
	br_ifinfo_notify(RTM_NEWLINK, NULL, p);

	return NOTIFY_DONE;
	}

	static struct notifier_block br_device_notifier = {
	.notifier_call = br_device_event
	};

	/* called with RTNL or RCU */
	static int br_switchdev_event(struct notifier_block *unused,
	unsigned long event, void *ptr)
	{
	struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
	struct net_bridge_port *p;
	struct net_bridge *br;
	struct switchdev_notifier_fdb_info *fdb_info;
	int err = NOTIFY_DONE;

	p = br_port_get_rtnl_rcu(dev);
	if (!p)
	goto out;

	br = p->br;

	switch (event) {
	case SWITCHDEV_FDB_ADD_TO_BRIDGE:
	fdb_info = ptr;
	err = br_fdb_external_learn_add(br, p, fdb_info->addr,
	fdb_info->vid, false);
	if (err) {
	err = notifier_from_errno(err);
	break;
	}
	br_fdb_offloaded_set(br, p, fdb_info->addr,
	fdb_info->vid);
	break;
	case SWITCHDEV_FDB_DEL_TO_BRIDGE:
	fdb_info = ptr;
	err = br_fdb_external_learn_del(br, p, fdb_info->addr,
	fdb_info->vid, false);
	if (err)
	err = notifier_from_errno(err);
	break;
	case SWITCHDEV_FDB_OFFLOADED:
	fdb_info = ptr;
	br_fdb_offloaded_set(br, p, fdb_info->addr,
	fdb_info->vid);
	break;
	}

	out:
	return err;
	}

	static struct notifier_block br_switchdev_notifier = {
	.notifier_call = br_switchdev_event,
	};

	void br_opt_toggle(struct net_bridge *br, enum net_bridge_opts opt, bool on)
	{
	bool cur = !!br_opt_get(br, opt);

	br_debug(br, "toggle option: %d state: %d -> %d\n",
	opt, cur, on);

	if (cur == on)
	return;

	if (on)
	set_bit(opt, &br->options);
	else
	clear_bit(opt, &br->options);
	}

	static void __net_exit br_net_exit(struct net *net)
	{
	struct net_device *dev;
	LIST_HEAD(list);

	rtnl_lock();
	for_each_netdev(net, dev)
	if (dev->priv_flags & IFF_EBRIDGE)
	br_dev_delete(dev, &list);

	unregister_netdevice_many(&list);
	rtnl_unlock();

	}

	static struct pernet_operations br_net_ops = {
	.exit = br_net_exit,
	};

	static const struct stp_proto br_stp_proto = {
	.rcv = br_stp_rcv,
	};

	static int __init br_init(void)
	{
	int err;

	BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > FIELD_SIZEOF(struct sk_buff, cb));

	err = stp_proto_register(&br_stp_proto);
	if (err < 0) {
	pr_err("bridge: can't register sap for STP\n");
	return err;
	}

	err = br_fdb_init();
	if (err)
	goto err_out;

	err = register_pernet_subsys(&br_net_ops);
	if (err)
	goto err_out1;

	err = br_nf_core_init();
	if (err)
	goto err_out2;

	err = register_netdevice_notifier(&br_device_notifier);
	if (err)
	goto err_out3;

	err = register_switchdev_notifier(&br_switchdev_notifier);
	if (err)
	goto err_out4;

	err = br_netlink_init();
	if (err)
	goto err_out5;

	brioctl_set(br_ioctl_deviceless_stub);

	#if IS_ENABLED(CONFIG_ATM_LANE)
	br_fdb_test_addr_hook = br_fdb_test_addr;
	#endif

	#if IS_MODULE(CONFIG_BRIDGE_NETFILTER)
	pr_info("bridge: filtering via arp/ip/ip6tables is no longer available "
	"by default. Update your scripts to load br_netfilter if you "
	"need this.\n");
	#endif

	return 0;

	err_out5:
	unregister_switchdev_notifier(&br_switchdev_notifier);
	err_out4:
	unregister_netdevice_notifier(&br_device_notifier);
	err_out3:
	br_nf_core_fini();
	err_out2:
	unregister_pernet_subsys(&br_net_ops);
	err_out1:
	br_fdb_fini();
	err_out:
	stp_proto_unregister(&br_stp_proto);
	return err;
	}

	static void __exit br_deinit(void)
	{
	stp_proto_unregister(&br_stp_proto);
	br_netlink_fini();
	unregister_switchdev_notifier(&br_switchdev_notifier);
	unregister_netdevice_notifier(&br_device_notifier);
	brioctl_set(NULL);
	unregister_pernet_subsys(&br_net_ops);

	rcu_barrier(); /* Wait for completion of call_rcu()'s */

	br_nf_core_fini();
	#if IS_ENABLED(CONFIG_ATM_LANE)
	br_fdb_test_addr_hook = NULL;
	#endif
	br_fdb_fini();
	}

	module_init(br_init)
	module_exit(br_deinit)
	MODULE_LICENSE("GPL");
	MODULE_VERSION(BR_VERSION);
	MODULE_ALIAS_RTNL_LINK("bridge");