[mirror_ubuntu-jammy-kernel.git] / net / phonet / pn_dev.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * File: pn_dev.c
 *
 * Phonet network device
 *
 * Copyright (C) 2008 Nokia Corporation.
 *
 * Authors: Sakari Ailus <sakari.ailus@nokia.com>
 *          Rémi Denis-Courmont
 */

#include <linux/kernel.h>
#include <linux/net.h>
#include <linux/slab.h>
#include <linux/netdevice.h>
#include <linux/phonet.h>
#include <linux/proc_fs.h>
#include <linux/if_arp.h>
#include <net/sock.h>
#include <net/netns/generic.h>
#include <net/phonet/pn_dev.h>

struct phonet_routes {
	struct mutex		lock;
	struct net_device __rcu	*table[64];
};

struct phonet_net {
	struct phonet_device_list pndevs;
	struct phonet_routes routes;
};

static unsigned int phonet_net_id __read_mostly;

static struct phonet_net *phonet_pernet(struct net *net)
{
	return net_generic(net, phonet_net_id);
}

struct phonet_device_list *phonet_device_list(struct net *net)
{
	struct phonet_net *pnn = phonet_pernet(net);
	return &pnn->pndevs;
}

/* Allocate new Phonet device. */
static struct phonet_device *__phonet_device_alloc(struct net_device *dev)
{
	struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
	struct phonet_device *pnd = kmalloc(sizeof(*pnd), GFP_ATOMIC);
	if (pnd == NULL)
		return NULL;
	pnd->netdev = dev;
	bitmap_zero(pnd->addrs, 64);

	BUG_ON(!mutex_is_locked(&pndevs->lock));
	list_add_rcu(&pnd->list, &pndevs->list);
	return pnd;
}

static struct phonet_device *__phonet_get(struct net_device *dev)
{
	struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
	struct phonet_device *pnd;

	BUG_ON(!mutex_is_locked(&pndevs->lock));
	list_for_each_entry(pnd, &pndevs->list, list) {
		if (pnd->netdev == dev)
			return pnd;
	}
	return NULL;
}

static struct phonet_device *__phonet_get_rcu(struct net_device *dev)
{
	struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
	struct phonet_device *pnd;

	list_for_each_entry_rcu(pnd, &pndevs->list, list) {
		if (pnd->netdev == dev)
			return pnd;
	}
	return NULL;
}

static void phonet_device_destroy(struct net_device *dev)
{
	struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
	struct phonet_device *pnd;

	ASSERT_RTNL();

	mutex_lock(&pndevs->lock);
	pnd = __phonet_get(dev);
	if (pnd)
		list_del_rcu(&pnd->list);
	mutex_unlock(&pndevs->lock);

	if (pnd) {
		u8 addr;

		for_each_set_bit(addr, pnd->addrs, 64)
			phonet_address_notify(RTM_DELADDR, dev, addr);
		kfree(pnd);
	}
}

struct net_device *phonet_device_get(struct net *net)
{
	struct phonet_device_list *pndevs = phonet_device_list(net);
	struct phonet_device *pnd;
	struct net_device *dev = NULL;

	rcu_read_lock();
	list_for_each_entry_rcu(pnd, &pndevs->list, list) {
		dev = pnd->netdev;
		BUG_ON(!dev);

		if ((dev->reg_state == NETREG_REGISTERED) &&
			((pnd->netdev->flags & IFF_UP)) == IFF_UP)
			break;
		dev = NULL;
	}
	if (dev)
		dev_hold(dev);
	rcu_read_unlock();
	return dev;
}

int phonet_address_add(struct net_device *dev, u8 addr)
{
	struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
	struct phonet_device *pnd;
	int err = 0;

	mutex_lock(&pndevs->lock);
	/* Find or create Phonet-specific device data */
	pnd = __phonet_get(dev);
	if (pnd == NULL)
		pnd = __phonet_device_alloc(dev);
	if (unlikely(pnd == NULL))
		err = -ENOMEM;
	else if (test_and_set_bit(addr >> 2, pnd->addrs))
		err = -EEXIST;
	mutex_unlock(&pndevs->lock);
	return err;
}

int phonet_address_del(struct net_device *dev, u8 addr)
{
	struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
	struct phonet_device *pnd;
	int err = 0;

	mutex_lock(&pndevs->lock);
	pnd = __phonet_get(dev);
	if (!pnd || !test_and_clear_bit(addr >> 2, pnd->addrs)) {
		err = -EADDRNOTAVAIL;
		pnd = NULL;
	} else if (bitmap_empty(pnd->addrs, 64))
		list_del_rcu(&pnd->list);
	else
		pnd = NULL;
	mutex_unlock(&pndevs->lock);

	if (pnd)
		kfree_rcu(pnd, rcu);

	return err;
}

/* Gets a source address toward a destination, through a interface. */
u8 phonet_address_get(struct net_device *dev, u8 daddr)
{
	struct phonet_device *pnd;
	u8 saddr;

	rcu_read_lock();
	pnd = __phonet_get_rcu(dev);
	if (pnd) {
		BUG_ON(bitmap_empty(pnd->addrs, 64));

		/* Use same source address as destination, if possible */
		if (test_bit(daddr >> 2, pnd->addrs))
			saddr = daddr;
		else
			saddr = find_first_bit(pnd->addrs, 64) << 2;
	} else
		saddr = PN_NO_ADDR;
	rcu_read_unlock();

	if (saddr == PN_NO_ADDR) {
		/* Fallback to another device */
		struct net_device *def_dev;

		def_dev = phonet_device_get(dev_net(dev));
		if (def_dev) {
			if (def_dev != dev)
				saddr = phonet_address_get(def_dev, daddr);
			dev_put(def_dev);
		}
	}
	return saddr;
}

int phonet_address_lookup(struct net *net, u8 addr)
{
	struct phonet_device_list *pndevs = phonet_device_list(net);
	struct phonet_device *pnd;
	int err = -EADDRNOTAVAIL;

	rcu_read_lock();
	list_for_each_entry_rcu(pnd, &pndevs->list, list) {
		/* Don't allow unregistering devices! */
		if ((pnd->netdev->reg_state != NETREG_REGISTERED) ||
				((pnd->netdev->flags & IFF_UP)) != IFF_UP)
			continue;

		if (test_bit(addr >> 2, pnd->addrs)) {
			err = 0;
			goto found;
		}
	}
found:
	rcu_read_unlock();
	return err;
}

/* automatically configure a Phonet device, if supported */
static int phonet_device_autoconf(struct net_device *dev)
{
	struct if_phonet_req req;
	int ret;

	if (!dev->netdev_ops->ndo_do_ioctl)
		return -EOPNOTSUPP;

	ret = dev->netdev_ops->ndo_do_ioctl(dev, (struct ifreq *)&req,
						SIOCPNGAUTOCONF);
	if (ret < 0)
		return ret;

	ASSERT_RTNL();
	ret = phonet_address_add(dev, req.ifr_phonet_autoconf.device);
	if (ret)
		return ret;
	phonet_address_notify(RTM_NEWADDR, dev,
				req.ifr_phonet_autoconf.device);
	return 0;
}

static void phonet_route_autodel(struct net_device *dev)
{
	struct phonet_net *pnn = phonet_pernet(dev_net(dev));
	unsigned int i;
	DECLARE_BITMAP(deleted, 64);

	/* Remove left-over Phonet routes */
	bitmap_zero(deleted, 64);
	mutex_lock(&pnn->routes.lock);
	for (i = 0; i < 64; i++)
		if (rcu_access_pointer(pnn->routes.table[i]) == dev) {
			RCU_INIT_POINTER(pnn->routes.table[i], NULL);
			set_bit(i, deleted);
		}
	mutex_unlock(&pnn->routes.lock);

	if (bitmap_empty(deleted, 64))
		return; /* short-circuit RCU */
	synchronize_rcu();
	for_each_set_bit(i, deleted, 64) {
		rtm_phonet_notify(RTM_DELROUTE, dev, i);
		dev_put(dev);
	}
}

/* notify Phonet of device events */
static int phonet_device_notify(struct notifier_block *me, unsigned long what,
				void *ptr)
{
	struct net_device *dev = netdev_notifier_info_to_dev(ptr);

	switch (what) {
	case NETDEV_REGISTER:
		if (dev->type == ARPHRD_PHONET)
			phonet_device_autoconf(dev);
		break;
	case NETDEV_UNREGISTER:
		phonet_device_destroy(dev);
		phonet_route_autodel(dev);
		break;
	}
	return 0;

}

static struct notifier_block phonet_device_notifier = {
	.notifier_call = phonet_device_notify,
	.priority = 0,
};

/* Per-namespace Phonet devices handling */
static int __net_init phonet_init_net(struct net *net)
{
	struct phonet_net *pnn = phonet_pernet(net);

	if (!proc_create_net("phonet", 0, net->proc_net, &pn_sock_seq_ops,
			sizeof(struct seq_net_private)))
		return -ENOMEM;

	INIT_LIST_HEAD(&pnn->pndevs.list);
	mutex_init(&pnn->pndevs.lock);
	mutex_init(&pnn->routes.lock);
	return 0;
}

static void __net_exit phonet_exit_net(struct net *net)
{
	struct phonet_net *pnn = phonet_pernet(net);

	remove_proc_entry("phonet", net->proc_net);
	WARN_ON_ONCE(!list_empty(&pnn->pndevs.list));
}

static struct pernet_operations phonet_net_ops = {
	.init = phonet_init_net,
	.exit = phonet_exit_net,
	.id   = &phonet_net_id,
	.size = sizeof(struct phonet_net),
};

/* Initialize Phonet devices list */
int __init phonet_device_init(void)
{
	int err = register_pernet_subsys(&phonet_net_ops);
	if (err)
		return err;

	proc_create_net("pnresource", 0, init_net.proc_net, &pn_res_seq_ops,
			sizeof(struct seq_net_private));
	register_netdevice_notifier(&phonet_device_notifier);
	err = phonet_netlink_register();
	if (err)
		phonet_device_exit();
	return err;
}

void phonet_device_exit(void)
{
	rtnl_unregister_all(PF_PHONET);
	unregister_netdevice_notifier(&phonet_device_notifier);
	unregister_pernet_subsys(&phonet_net_ops);
	remove_proc_entry("pnresource", init_net.proc_net);
}

int phonet_route_add(struct net_device *dev, u8 daddr)
{
	struct phonet_net *pnn = phonet_pernet(dev_net(dev));
	struct phonet_routes *routes = &pnn->routes;
	int err = -EEXIST;

	daddr = daddr >> 2;
	mutex_lock(&routes->lock);
	if (routes->table[daddr] == NULL) {
		rcu_assign_pointer(routes->table[daddr], dev);
		dev_hold(dev);
		err = 0;
	}
	mutex_unlock(&routes->lock);
	return err;
}

int phonet_route_del(struct net_device *dev, u8 daddr)
{
	struct phonet_net *pnn = phonet_pernet(dev_net(dev));
	struct phonet_routes *routes = &pnn->routes;

	daddr = daddr >> 2;
	mutex_lock(&routes->lock);
	if (rcu_access_pointer(routes->table[daddr]) == dev)
		RCU_INIT_POINTER(routes->table[daddr], NULL);
	else
		dev = NULL;
	mutex_unlock(&routes->lock);

	if (!dev)
		return -ENOENT;
	synchronize_rcu();
	dev_put(dev);
	return 0;
}

struct net_device *phonet_route_get_rcu(struct net *net, u8 daddr)
{
	struct phonet_net *pnn = phonet_pernet(net);
	struct phonet_routes *routes = &pnn->routes;
	struct net_device *dev;

	daddr >>= 2;
	dev = rcu_dereference(routes->table[daddr]);
	return dev;
}

struct net_device *phonet_route_output(struct net *net, u8 daddr)
{
	struct phonet_net *pnn = phonet_pernet(net);
	struct phonet_routes *routes = &pnn->routes;
	struct net_device *dev;

	daddr >>= 2;
	rcu_read_lock();
	dev = rcu_dereference(routes->table[daddr]);
	if (dev)
		dev_hold(dev);
	rcu_read_unlock();

	if (!dev)
		dev = phonet_device_get(net); /* Default route */
	return dev;
}
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0-only
	2	/*
	3	* File: pn_dev.c
	4	*
	5	* Phonet network device
	6	*
	7	* Copyright (C) 2008 Nokia Corporation.
	8	*
	9	* Authors: Sakari Ailus <sakari.ailus@nokia.com>
	10	* Rémi Denis-Courmont
	11	*/
	12
	13	#include <linux/kernel.h>
	14	#include <linux/net.h>
	15	#include <linux/slab.h>
	16	#include <linux/netdevice.h>
	17	#include <linux/phonet.h>
	18	#include <linux/proc_fs.h>
	19	#include <linux/if_arp.h>
	20	#include <net/sock.h>
	21	#include <net/netns/generic.h>
	22	#include <net/phonet/pn_dev.h>
	23
	24	struct phonet_routes {
	25	struct mutex lock;
	26	struct net_device __rcu *table[64];
	27	};
	28
	29	struct phonet_net {
	30	struct phonet_device_list pndevs;
	31	struct phonet_routes routes;
	32	};
	33
	34	static unsigned int phonet_net_id __read_mostly;
	35
	36	static struct phonet_net phonet_pernet(struct net net)
	37	{
	38	return net_generic(net, phonet_net_id);
	39	}
	40
	41	struct phonet_device_list phonet_device_list(struct net net)
	42	{
	43	struct phonet_net *pnn = phonet_pernet(net);
	44	return &pnn->pndevs;
	45	}
	46
	47	/* Allocate new Phonet device. */
	48	static struct phonet_device __phonet_device_alloc(struct net_device dev)
	49	{
	50	struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
	51	struct phonet_device pnd = kmalloc(sizeof(pnd), GFP_ATOMIC);
	52	if (pnd == NULL)
	53	return NULL;
	54	pnd->netdev = dev;
	55	bitmap_zero(pnd->addrs, 64);
	56
	57	BUG_ON(!mutex_is_locked(&pndevs->lock));
	58	list_add_rcu(&pnd->list, &pndevs->list);
	59	return pnd;
	60	}
	61
	62	static struct phonet_device __phonet_get(struct net_device dev)
	63	{
	64	struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
	65	struct phonet_device *pnd;
	66
	67	BUG_ON(!mutex_is_locked(&pndevs->lock));
	68	list_for_each_entry(pnd, &pndevs->list, list) {
	69	if (pnd->netdev == dev)
	70	return pnd;
	71	}
	72	return NULL;
	73	}
	74
	75	static struct phonet_device __phonet_get_rcu(struct net_device dev)
	76	{
	77	struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
	78	struct phonet_device *pnd;
	79
	80	list_for_each_entry_rcu(pnd, &pndevs->list, list) {
	81	if (pnd->netdev == dev)
	82	return pnd;
	83	}
	84	return NULL;
	85	}
	86
	87	static void phonet_device_destroy(struct net_device *dev)
	88	{
	89	struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
	90	struct phonet_device *pnd;
	91
	92	ASSERT_RTNL();
	93
	94	mutex_lock(&pndevs->lock);
	95	pnd = __phonet_get(dev);
	96	if (pnd)
	97	list_del_rcu(&pnd->list);
	98	mutex_unlock(&pndevs->lock);
	99
	100	if (pnd) {
	101	u8 addr;
	102
	103	for_each_set_bit(addr, pnd->addrs, 64)
	104	phonet_address_notify(RTM_DELADDR, dev, addr);
	105	kfree(pnd);
	106	}
	107	}
	108
	109	struct net_device phonet_device_get(struct net net)
	110	{
	111	struct phonet_device_list *pndevs = phonet_device_list(net);
	112	struct phonet_device *pnd;
	113	struct net_device *dev = NULL;
	114
	115	rcu_read_lock();
	116	list_for_each_entry_rcu(pnd, &pndevs->list, list) {
	117	dev = pnd->netdev;
	118	BUG_ON(!dev);
	119
	120	if ((dev->reg_state == NETREG_REGISTERED) &&
	121	((pnd->netdev->flags & IFF_UP)) == IFF_UP)
	122	break;
	123	dev = NULL;
	124	}
	125	if (dev)
	126	dev_hold(dev);
	127	rcu_read_unlock();
	128	return dev;
	129	}
	130
	131	int phonet_address_add(struct net_device *dev, u8 addr)
	132	{
	133	struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
	134	struct phonet_device *pnd;
	135	int err = 0;
	136
	137	mutex_lock(&pndevs->lock);
	138	/* Find or create Phonet-specific device data */
	139	pnd = __phonet_get(dev);
	140	if (pnd == NULL)
	141	pnd = __phonet_device_alloc(dev);
	142	if (unlikely(pnd == NULL))
	143	err = -ENOMEM;
	144	else if (test_and_set_bit(addr >> 2, pnd->addrs))
	145	err = -EEXIST;
	146	mutex_unlock(&pndevs->lock);
	147	return err;
	148	}
	149
	150	int phonet_address_del(struct net_device *dev, u8 addr)
	151	{
	152	struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
	153	struct phonet_device *pnd;
	154	int err = 0;
	155
	156	mutex_lock(&pndevs->lock);
	157	pnd = __phonet_get(dev);
	158	if (!pnd \|\| !test_and_clear_bit(addr >> 2, pnd->addrs)) {
	159	err = -EADDRNOTAVAIL;
	160	pnd = NULL;
	161	} else if (bitmap_empty(pnd->addrs, 64))
	162	list_del_rcu(&pnd->list);
	163	else
	164	pnd = NULL;
	165	mutex_unlock(&pndevs->lock);
	166
	167	if (pnd)
	168	kfree_rcu(pnd, rcu);
	169
	170	return err;
	171	}
	172
	173	/* Gets a source address toward a destination, through a interface. */
	174	u8 phonet_address_get(struct net_device *dev, u8 daddr)
	175	{
	176	struct phonet_device *pnd;
	177	u8 saddr;
	178
	179	rcu_read_lock();
	180	pnd = __phonet_get_rcu(dev);
	181	if (pnd) {
	182	BUG_ON(bitmap_empty(pnd->addrs, 64));
	183
	184	/* Use same source address as destination, if possible */
	185	if (test_bit(daddr >> 2, pnd->addrs))
	186	saddr = daddr;
	187	else
	188	saddr = find_first_bit(pnd->addrs, 64) << 2;
	189	} else
	190	saddr = PN_NO_ADDR;
	191	rcu_read_unlock();
	192
	193	if (saddr == PN_NO_ADDR) {
	194	/* Fallback to another device */
	195	struct net_device *def_dev;
	196
	197	def_dev = phonet_device_get(dev_net(dev));
	198	if (def_dev) {
	199	if (def_dev != dev)
	200	saddr = phonet_address_get(def_dev, daddr);
	201	dev_put(def_dev);
	202	}
	203	}
	204	return saddr;
	205	}
	206
	207	int phonet_address_lookup(struct net *net, u8 addr)
	208	{
	209	struct phonet_device_list *pndevs = phonet_device_list(net);
	210	struct phonet_device *pnd;
	211	int err = -EADDRNOTAVAIL;
	212
	213	rcu_read_lock();
	214	list_for_each_entry_rcu(pnd, &pndevs->list, list) {
	215	/* Don't allow unregistering devices! */
	216	if ((pnd->netdev->reg_state != NETREG_REGISTERED) \|\|
	217	((pnd->netdev->flags & IFF_UP)) != IFF_UP)
	218	continue;
	219
	220	if (test_bit(addr >> 2, pnd->addrs)) {
	221	err = 0;
	222	goto found;
	223	}
	224	}
	225	found:
	226	rcu_read_unlock();
	227	return err;
	228	}
	229
	230	/* automatically configure a Phonet device, if supported */
	231	static int phonet_device_autoconf(struct net_device *dev)
	232	{
	233	struct if_phonet_req req;
	234	int ret;
	235
	236	if (!dev->netdev_ops->ndo_do_ioctl)
	237	return -EOPNOTSUPP;
	238
	239	ret = dev->netdev_ops->ndo_do_ioctl(dev, (struct ifreq *)&req,
	240	SIOCPNGAUTOCONF);
	241	if (ret < 0)
	242	return ret;
	243
	244	ASSERT_RTNL();
	245	ret = phonet_address_add(dev, req.ifr_phonet_autoconf.device);
	246	if (ret)
	247	return ret;
	248	phonet_address_notify(RTM_NEWADDR, dev,
	249	req.ifr_phonet_autoconf.device);
	250	return 0;
	251	}
	252
	253	static void phonet_route_autodel(struct net_device *dev)
	254	{
	255	struct phonet_net *pnn = phonet_pernet(dev_net(dev));
	256	unsigned int i;
	257	DECLARE_BITMAP(deleted, 64);
	258
	259	/* Remove left-over Phonet routes */
	260	bitmap_zero(deleted, 64);
	261	mutex_lock(&pnn->routes.lock);
	262	for (i = 0; i < 64; i++)
	263	if (rcu_access_pointer(pnn->routes.table[i]) == dev) {
	264	RCU_INIT_POINTER(pnn->routes.table[i], NULL);
	265	set_bit(i, deleted);
	266	}
	267	mutex_unlock(&pnn->routes.lock);
	268
	269	if (bitmap_empty(deleted, 64))
	270	return; /* short-circuit RCU */
	271	synchronize_rcu();
	272	for_each_set_bit(i, deleted, 64) {
	273	rtm_phonet_notify(RTM_DELROUTE, dev, i);
	274	dev_put(dev);
	275	}
	276	}
	277
	278	/* notify Phonet of device events */
	279	static int phonet_device_notify(struct notifier_block *me, unsigned long what,
	280	void *ptr)
	281	{
	282	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
	283
	284	switch (what) {
	285	case NETDEV_REGISTER:
	286	if (dev->type == ARPHRD_PHONET)
	287	phonet_device_autoconf(dev);
	288	break;
	289	case NETDEV_UNREGISTER:
	290	phonet_device_destroy(dev);
	291	phonet_route_autodel(dev);
	292	break;
	293	}
	294	return 0;
	295
	296	}
	297
	298	static struct notifier_block phonet_device_notifier = {
	299	.notifier_call = phonet_device_notify,
	300	.priority = 0,
	301	};
	302
	303	/* Per-namespace Phonet devices handling */
	304	static int __net_init phonet_init_net(struct net *net)
	305	{
	306	struct phonet_net *pnn = phonet_pernet(net);
	307
	308	if (!proc_create_net("phonet", 0, net->proc_net, &pn_sock_seq_ops,
	309	sizeof(struct seq_net_private)))
	310	return -ENOMEM;
	311
	312	INIT_LIST_HEAD(&pnn->pndevs.list);
	313	mutex_init(&pnn->pndevs.lock);
	314	mutex_init(&pnn->routes.lock);
	315	return 0;
	316	}
	317
	318	static void __net_exit phonet_exit_net(struct net *net)
	319	{
	320	struct phonet_net *pnn = phonet_pernet(net);
	321
	322	remove_proc_entry("phonet", net->proc_net);
	323	WARN_ON_ONCE(!list_empty(&pnn->pndevs.list));
	324	}
	325
	326	static struct pernet_operations phonet_net_ops = {
	327	.init = phonet_init_net,
	328	.exit = phonet_exit_net,
	329	.id = &phonet_net_id,
	330	.size = sizeof(struct phonet_net),
	331	};
	332
	333	/* Initialize Phonet devices list */
	334	int __init phonet_device_init(void)
	335	{
	336	int err = register_pernet_subsys(&phonet_net_ops);
	337	if (err)
	338	return err;
	339
	340	proc_create_net("pnresource", 0, init_net.proc_net, &pn_res_seq_ops,
	341	sizeof(struct seq_net_private));
	342	register_netdevice_notifier(&phonet_device_notifier);
	343	err = phonet_netlink_register();
	344	if (err)
	345	phonet_device_exit();
	346	return err;
	347	}
	348
	349	void phonet_device_exit(void)
	350	{
	351	rtnl_unregister_all(PF_PHONET);
	352	unregister_netdevice_notifier(&phonet_device_notifier);
	353	unregister_pernet_subsys(&phonet_net_ops);
	354	remove_proc_entry("pnresource", init_net.proc_net);
	355	}
	356
	357	int phonet_route_add(struct net_device *dev, u8 daddr)
	358	{
	359	struct phonet_net *pnn = phonet_pernet(dev_net(dev));
	360	struct phonet_routes *routes = &pnn->routes;
	361	int err = -EEXIST;
	362
	363	daddr = daddr >> 2;
	364	mutex_lock(&routes->lock);
	365	if (routes->table[daddr] == NULL) {
	366	rcu_assign_pointer(routes->table[daddr], dev);
	367	dev_hold(dev);
	368	err = 0;
	369	}
	370	mutex_unlock(&routes->lock);
	371	return err;
	372	}
	373
	374	int phonet_route_del(struct net_device *dev, u8 daddr)
	375	{
	376	struct phonet_net *pnn = phonet_pernet(dev_net(dev));
	377	struct phonet_routes *routes = &pnn->routes;
	378
	379	daddr = daddr >> 2;
	380	mutex_lock(&routes->lock);
	381	if (rcu_access_pointer(routes->table[daddr]) == dev)
	382	RCU_INIT_POINTER(routes->table[daddr], NULL);
	383	else
	384	dev = NULL;
	385	mutex_unlock(&routes->lock);
	386
	387	if (!dev)
	388	return -ENOENT;
	389	synchronize_rcu();
	390	dev_put(dev);
	391	return 0;
	392	}
	393
	394	struct net_device phonet_route_get_rcu(struct net net, u8 daddr)
	395	{
	396	struct phonet_net *pnn = phonet_pernet(net);
	397	struct phonet_routes *routes = &pnn->routes;
	398	struct net_device *dev;
	399
	400	daddr >>= 2;
	401	dev = rcu_dereference(routes->table[daddr]);
	402	return dev;
	403	}
	404
	405	struct net_device phonet_route_output(struct net net, u8 daddr)
	406	{
	407	struct phonet_net *pnn = phonet_pernet(net);
	408	struct phonet_routes *routes = &pnn->routes;
	409	struct net_device *dev;
	410
	411	daddr >>= 2;
	412	rcu_read_lock();
	413	dev = rcu_dereference(routes->table[daddr]);
	414	if (dev)
	415	dev_hold(dev);
	416	rcu_read_unlock();
	417
	418	if (!dev)
	419	dev = phonet_device_get(net); /* Default route */
	420	return dev;
	421	}