[mirror_ubuntu-artful-kernel.git] / lib / kobject_uevent.c

/*
 * kernel userspace event delivery
 *
 * Copyright (C) 2004 Red Hat, Inc.  All rights reserved.
 * Copyright (C) 2004 Novell, Inc.  All rights reserved.
 * Copyright (C) 2004 IBM, Inc. All rights reserved.
 *
 * Licensed under the GNU GPL v2.
 *
 * Authors:
 *	Robert Love		<rml@novell.com>
 *	Kay Sievers		<kay.sievers@vrfy.org>
 *	Arjan van de Ven	<arjanv@redhat.com>
 *	Greg Kroah-Hartman	<greg@kroah.com>
 */

#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/kobject.h>
#include <linux/export.h>
#include <linux/kmod.h>
#include <linux/slab.h>
#include <linux/user_namespace.h>
#include <linux/socket.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
#include <net/sock.h>
#include <net/net_namespace.h>


u64 uevent_seqnum;
char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH;
#ifdef CONFIG_NET
struct uevent_sock {
	struct list_head list;
	struct sock *sk;
};
static LIST_HEAD(uevent_sock_list);
#endif

/* This lock protects uevent_seqnum and uevent_sock_list */
static DEFINE_MUTEX(uevent_sock_mutex);

/* the strings here must match the enum in include/linux/kobject.h */
static const char *kobject_actions[] = {
	[KOBJ_ADD] =		"add",
	[KOBJ_REMOVE] =		"remove",
	[KOBJ_CHANGE] =		"change",
	[KOBJ_MOVE] =		"move",
	[KOBJ_ONLINE] =		"online",
	[KOBJ_OFFLINE] =	"offline",
};

/**
 * kobject_action_type - translate action string to numeric type
 *
 * @buf: buffer containing the action string, newline is ignored
 * @len: length of buffer
 * @type: pointer to the location to store the action type
 *
 * Returns 0 if the action string was recognized.
 */
int kobject_action_type(const char *buf, size_t count,
			enum kobject_action *type)
{
	enum kobject_action action;
	int ret = -EINVAL;

	if (count && (buf[count-1] == '\n' || buf[count-1] == '\0'))
		count--;

	if (!count)
		goto out;

	for (action = 0; action < ARRAY_SIZE(kobject_actions); action++) {
		if (strncmp(kobject_actions[action], buf, count) != 0)
			continue;
		if (kobject_actions[action][count] != '\0')
			continue;
		*type = action;
		ret = 0;
		break;
	}
out:
	return ret;
}

#ifdef CONFIG_NET
static int kobj_bcast_filter(struct sock *dsk, struct sk_buff *skb, void *data)
{
	struct kobject *kobj = data, *ksobj;
	const struct kobj_ns_type_operations *ops;

	ops = kobj_ns_ops(kobj);
	if (!ops && kobj->kset) {
		ksobj = &kobj->kset->kobj;
		if (ksobj->parent != NULL)
			ops = kobj_ns_ops(ksobj->parent);
	}

	if (ops && ops->netlink_ns && kobj->ktype->namespace) {
		const void *sock_ns, *ns;
		ns = kobj->ktype->namespace(kobj);
		sock_ns = ops->netlink_ns(dsk);
		return sock_ns != ns;
	}

	return 0;
}
#endif

static int kobj_usermode_filter(struct kobject *kobj)
{
	const struct kobj_ns_type_operations *ops;

	ops = kobj_ns_ops(kobj);
	if (ops) {
		const void *init_ns, *ns;
		ns = kobj->ktype->namespace(kobj);
		init_ns = ops->initial_ns();
		return ns != init_ns;
	}

	return 0;
}

/**
 * kobject_uevent_env - send an uevent with environmental data
 *
 * @action: action that is happening
 * @kobj: struct kobject that the action is happening to
 * @envp_ext: pointer to environmental data
 *
 * Returns 0 if kobject_uevent_env() is completed with success or the
 * corresponding error when it fails.
 */
int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
		       char *envp_ext[])
{
	struct kobj_uevent_env *env;
	const char *action_string = kobject_actions[action];
	const char *devpath = NULL;
	const char *subsystem;
	struct kobject *top_kobj;
	struct kset *kset;
	const struct kset_uevent_ops *uevent_ops;
	int i = 0;
	int retval = 0;
#ifdef CONFIG_NET
	struct uevent_sock *ue_sk;
#endif

	pr_debug("kobject: '%s' (%p): %s\n",
		 kobject_name(kobj), kobj, __func__);

	/* search the kset we belong to */
	top_kobj = kobj;
	while (!top_kobj->kset && top_kobj->parent)
		top_kobj = top_kobj->parent;

	if (!top_kobj->kset) {
		pr_debug("kobject: '%s' (%p): %s: attempted to send uevent "
			 "without kset!\n", kobject_name(kobj), kobj,
			 __func__);
		return -EINVAL;
	}

	kset = top_kobj->kset;
	uevent_ops = kset->uevent_ops;

	/* skip the event, if uevent_suppress is set*/
	if (kobj->uevent_suppress) {
		pr_debug("kobject: '%s' (%p): %s: uevent_suppress "
				 "caused the event to drop!\n",
				 kobject_name(kobj), kobj, __func__);
		return 0;
	}
	/* skip the event, if the filter returns zero. */
	if (uevent_ops && uevent_ops->filter)
		if (!uevent_ops->filter(kset, kobj)) {
			pr_debug("kobject: '%s' (%p): %s: filter function "
				 "caused the event to drop!\n",
				 kobject_name(kobj), kobj, __func__);
			return 0;
		}

	/* originating subsystem */
	if (uevent_ops && uevent_ops->name)
		subsystem = uevent_ops->name(kset, kobj);
	else
		subsystem = kobject_name(&kset->kobj);
	if (!subsystem) {
		pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the "
			 "event to drop!\n", kobject_name(kobj), kobj,
			 __func__);
		return 0;
	}

	/* environment buffer */
	env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
	if (!env)
		return -ENOMEM;

	/* complete object path */
	devpath = kobject_get_path(kobj, GFP_KERNEL);
	if (!devpath) {
		retval = -ENOENT;
		goto exit;
	}

	/* default keys */
	retval = add_uevent_var(env, "ACTION=%s", action_string);
	if (retval)
		goto exit;
	retval = add_uevent_var(env, "DEVPATH=%s", devpath);
	if (retval)
		goto exit;
	retval = add_uevent_var(env, "SUBSYSTEM=%s", subsystem);
	if (retval)
		goto exit;

	/* keys passed in from the caller */
	if (envp_ext) {
		for (i = 0; envp_ext[i]; i++) {
			retval = add_uevent_var(env, "%s", envp_ext[i]);
			if (retval)
				goto exit;
		}
	}

	/* let the kset specific function add its stuff */
	if (uevent_ops && uevent_ops->uevent) {
		retval = uevent_ops->uevent(kset, kobj, env);
		if (retval) {
			pr_debug("kobject: '%s' (%p): %s: uevent() returned "
				 "%d\n", kobject_name(kobj), kobj,
				 __func__, retval);
			goto exit;
		}
	}

	/*
	 * Mark "add" and "remove" events in the object to ensure proper
	 * events to userspace during automatic cleanup. If the object did
	 * send an "add" event, "remove" will automatically generated by
	 * the core, if not already done by the caller.
	 */
	if (action == KOBJ_ADD)
		kobj->state_add_uevent_sent = 1;
	else if (action == KOBJ_REMOVE)
		kobj->state_remove_uevent_sent = 1;

	mutex_lock(&uevent_sock_mutex);
	/* we will send an event, so request a new sequence number */
	retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)++uevent_seqnum);
	if (retval) {
		mutex_unlock(&uevent_sock_mutex);
		goto exit;
	}

#if defined(CONFIG_NET)
	/* send netlink message */
	list_for_each_entry(ue_sk, &uevent_sock_list, list) {
		struct sock *uevent_sock = ue_sk->sk;
		struct sk_buff *skb;
		size_t len;

		if (!netlink_has_listeners(uevent_sock, 1))
			continue;

		/* allocate message with the maximum possible size */
		len = strlen(action_string) + strlen(devpath) + 2;
		skb = alloc_skb(len + env->buflen, GFP_KERNEL);
		if (skb) {
			char *scratch;

			/* add header */
			scratch = skb_put(skb, len);
			sprintf(scratch, "%s@%s", action_string, devpath);

			/* copy keys to our continuous event payload buffer */
			for (i = 0; i < env->envp_idx; i++) {
				len = strlen(env->envp[i]) + 1;
				scratch = skb_put(skb, len);
				strcpy(scratch, env->envp[i]);
			}

			NETLINK_CB(skb).dst_group = 1;
			retval = netlink_broadcast_filtered(uevent_sock, skb,
							    0, 1, GFP_KERNEL,
							    kobj_bcast_filter,
							    kobj);
			/* ENOBUFS should be handled in userspace */
			if (retval == -ENOBUFS || retval == -ESRCH)
				retval = 0;
		} else
			retval = -ENOMEM;
	}
#endif
	mutex_unlock(&uevent_sock_mutex);

	/* call uevent_helper, usually only enabled during early boot */
	if (uevent_helper[0] && !kobj_usermode_filter(kobj)) {
		char *argv [3];

		argv [0] = uevent_helper;
		argv [1] = (char *)subsystem;
		argv [2] = NULL;
		retval = add_uevent_var(env, "HOME=/");
		if (retval)
			goto exit;
		retval = add_uevent_var(env,
					"PATH=/sbin:/bin:/usr/sbin:/usr/bin");
		if (retval)
			goto exit;

		retval = call_usermodehelper(argv[0], argv,
					     env->envp, UMH_WAIT_EXEC);
	}

exit:
	kfree(devpath);
	kfree(env);
	return retval;
}
EXPORT_SYMBOL_GPL(kobject_uevent_env);

/**
 * kobject_uevent - notify userspace by sending an uevent
 *
 * @action: action that is happening
 * @kobj: struct kobject that the action is happening to
 *
 * Returns 0 if kobject_uevent() is completed with success or the
 * corresponding error when it fails.
 */
int kobject_uevent(struct kobject *kobj, enum kobject_action action)
{
	return kobject_uevent_env(kobj, action, NULL);
}
EXPORT_SYMBOL_GPL(kobject_uevent);

/**
 * add_uevent_var - add key value string to the environment buffer
 * @env: environment buffer structure
 * @format: printf format for the key=value pair
 *
 * Returns 0 if environment variable was added successfully or -ENOMEM
 * if no space was available.
 */
int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
{
	va_list args;
	int len;

	if (env->envp_idx >= ARRAY_SIZE(env->envp)) {
		WARN(1, KERN_ERR "add_uevent_var: too many keys\n");
		return -ENOMEM;
	}

	va_start(args, format);
	len = vsnprintf(&env->buf[env->buflen],
			sizeof(env->buf) - env->buflen,
			format, args);
	va_end(args);

	if (len >= (sizeof(env->buf) - env->buflen)) {
		WARN(1, KERN_ERR "add_uevent_var: buffer size too small\n");
		return -ENOMEM;
	}

	env->envp[env->envp_idx++] = &env->buf[env->buflen];
	env->buflen += len + 1;
	return 0;
}
EXPORT_SYMBOL_GPL(add_uevent_var);

#if defined(CONFIG_NET)
static int uevent_net_init(struct net *net)
{
	struct uevent_sock *ue_sk;
	struct netlink_kernel_cfg cfg = {
		.groups	= 1,
		.flags	= NL_CFG_F_NONROOT_RECV,
	};

	ue_sk = kzalloc(sizeof(*ue_sk), GFP_KERNEL);
	if (!ue_sk)
		return -ENOMEM;

	ue_sk->sk = netlink_kernel_create(net, NETLINK_KOBJECT_UEVENT, &cfg);
	if (!ue_sk->sk) {
		printk(KERN_ERR
		       "kobject_uevent: unable to create netlink socket!\n");
		kfree(ue_sk);
		return -ENODEV;
	}
	mutex_lock(&uevent_sock_mutex);
	list_add_tail(&ue_sk->list, &uevent_sock_list);
	mutex_unlock(&uevent_sock_mutex);
	return 0;
}

static void uevent_net_exit(struct net *net)
{
	struct uevent_sock *ue_sk;

	mutex_lock(&uevent_sock_mutex);
	list_for_each_entry(ue_sk, &uevent_sock_list, list) {
		if (sock_net(ue_sk->sk) == net)
			goto found;
	}
	mutex_unlock(&uevent_sock_mutex);
	return;

found:
	list_del(&ue_sk->list);
	mutex_unlock(&uevent_sock_mutex);

	netlink_kernel_release(ue_sk->sk);
	kfree(ue_sk);
}

static struct pernet_operations uevent_net_ops = {
	.init	= uevent_net_init,
	.exit	= uevent_net_exit,
};

static int __init kobject_uevent_init(void)
{
	return register_pernet_subsys(&uevent_net_ops);
}


postcore_initcall(kobject_uevent_init);
#endif
Commit	Line	Data
1da177e4 LT	1	/*
	2	* kernel userspace event delivery
	3	*
	4	* Copyright (C) 2004 Red Hat, Inc. All rights reserved.
	5	* Copyright (C) 2004 Novell, Inc. All rights reserved.
	6	* Copyright (C) 2004 IBM, Inc. All rights reserved.
	7	*
	8	* Licensed under the GNU GPL v2.
	9	*
	10	* Authors:
	11	* Robert Love <rml@novell.com>
	12	* Kay Sievers <kay.sievers@vrfy.org>
	13	* Arjan van de Ven <arjanv@redhat.com>
	14	* Greg Kroah-Hartman <greg@kroah.com>
	15	*/
	16
	17	#include <linux/spinlock.h>
2d38f9a4 DL	18	#include <linux/string.h>
2d38f9a4 DL	19	#include <linux/kobject.h>
8bc3bcc9 PG	20	#include <linux/export.h>
8bc3bcc9 PG	21	#include <linux/kmod.h>
5a0e3ad6	22	#include <linux/slab.h>
417daa1e	23	#include <linux/user_namespace.h>
1da177e4 LT	24	#include <linux/socket.h>
	25	#include <linux/skbuff.h>
	26	#include <linux/netlink.h>
1da177e4	27	#include <net/sock.h>
07e98962	28	#include <net/net_namespace.h>
1da177e4	29
1da177e4	30
cd030c4c	31	u64 uevent_seqnum;
6a8d8abb	32	char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH;
07e98962 EB	33	#ifdef CONFIG_NET
	34	struct uevent_sock {
	35	struct list_head list;
	36	struct sock *sk;
	37	};
	38	static LIST_HEAD(uevent_sock_list);
cd030c4c CH	39	#endif
cd030c4c CH	40
7b60a18d AV	41	/* This lock protects uevent_seqnum and uevent_sock_list */
	42	static DEFINE_MUTEX(uevent_sock_mutex);
	43
5c5daf65 KS	44	/* the strings here must match the enum in include/linux/kobject.h */
	45	static const char *kobject_actions[] = {
	46	[KOBJ_ADD] = "add",
	47	[KOBJ_REMOVE] = "remove",
	48	[KOBJ_CHANGE] = "change",
	49	[KOBJ_MOVE] = "move",
	50	[KOBJ_ONLINE] = "online",
	51	[KOBJ_OFFLINE] = "offline",
	52	};
	53
	54	/**
	55	* kobject_action_type - translate action string to numeric type
	56	*
	57	* @buf: buffer containing the action string, newline is ignored
	58	* @len: length of buffer
	59	* @type: pointer to the location to store the action type
	60	*
	61	* Returns 0 if the action string was recognized.
	62	*/
	63	int kobject_action_type(const char *buf, size_t count,
	64	enum kobject_action *type)
	65	{
	66	enum kobject_action action;
	67	int ret = -EINVAL;
	68
a9edadbf	69	if (count && (buf[count-1] == '\n' \|\| buf[count-1] == '\0'))
5c5daf65 KS	70	count--;
	71
	72	if (!count)
	73	goto out;
	74
	75	for (action = 0; action < ARRAY_SIZE(kobject_actions); action++) {
	76	if (strncmp(kobject_actions[action], buf, count) != 0)
	77	continue;
	78	if (kobject_actions[action][count] != '\0')
	79	continue;
	80	*type = action;
	81	ret = 0;
	82	break;
	83	}
	84	out:
	85	return ret;
	86	}
	87
c8421286	88	#ifdef CONFIG_NET
5f71a296 EB	89	static int kobj_bcast_filter(struct sock dsk, struct sk_buff skb, void *data)
5f71a296 EB	90	{
82ef3d5d	91	struct kobject kobj = data, ksobj;
5f71a296 EB	92	const struct kobj_ns_type_operations *ops;
	93
	94	ops = kobj_ns_ops(kobj);
82ef3d5d WC	95	if (!ops && kobj->kset) {
	96	ksobj = &kobj->kset->kobj;
	97	if (ksobj->parent != NULL)
	98	ops = kobj_ns_ops(ksobj->parent);
	99	}
	100
	101	if (ops && ops->netlink_ns && kobj->ktype->namespace) {
5f71a296 EB	102	const void sock_ns, ns;
	103	ns = kobj->ktype->namespace(kobj);
	104	sock_ns = ops->netlink_ns(dsk);
	105	return sock_ns != ns;
	106	}
	107
	108	return 0;
	109	}
c8421286	110	#endif
5f71a296	111
417daa1e EB	112	static int kobj_usermode_filter(struct kobject *kobj)
	113	{
	114	const struct kobj_ns_type_operations *ops;
	115
	116	ops = kobj_ns_ops(kobj);
	117	if (ops) {
	118	const void init_ns, ns;
	119	ns = kobj->ktype->namespace(kobj);
	120	init_ns = ops->initial_ns();
	121	return ns != init_ns;
	122	}
	123
	124	return 0;
	125	}
	126
1da177e4	127	/**
8a82472f	128	* kobject_uevent_env - send an uevent with environmental data
1da177e4	129	*
ccd490a3	130	* @action: action that is happening
1da177e4	131	* @kobj: struct kobject that the action is happening to
8a82472f	132	* @envp_ext: pointer to environmental data
542cfce6	133	*
f6e6e779	134	* Returns 0 if kobject_uevent_env() is completed with success or the
542cfce6	135	* corresponding error when it fails.
1da177e4	136	*/
542cfce6	137	int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
7eff2e7a	138	char *envp_ext[])
1da177e4	139	{
7eff2e7a KS	140	struct kobj_uevent_env *env;
7eff2e7a KS	141	const char *action_string = kobject_actions[action];
5f123fbd KS	142	const char *devpath = NULL;
	143	const char *subsystem;
	144	struct kobject *top_kobj;
	145	struct kset *kset;
9cd43611	146	const struct kset_uevent_ops *uevent_ops;
1da177e4	147	int i = 0;
542cfce6	148	int retval = 0;
07e98962 EB	149	#ifdef CONFIG_NET
	150	struct uevent_sock *ue_sk;
	151	#endif
1da177e4	152
9f66fa2a	153	pr_debug("kobject: '%s' (%p): %s\n",
810304db	154	kobject_name(kobj), kobj, __func__);
5f123fbd	155
5f123fbd KS	156	/* search the kset we belong to */
5f123fbd KS	157	top_kobj = kobj;
ccd490a3	158	while (!top_kobj->kset && top_kobj->parent)
14193fb9	159	top_kobj = top_kobj->parent;
ccd490a3	160
542cfce6	161	if (!top_kobj->kset) {
9f66fa2a GKH	162	pr_debug("kobject: '%s' (%p): %s: attempted to send uevent "
9f66fa2a GKH	163	"without kset!\n", kobject_name(kobj), kobj,
810304db	164	__func__);
542cfce6 AK	165	return -EINVAL;
542cfce6 AK	166	}
1da177e4	167
5f123fbd	168	kset = top_kobj->kset;
312c004d	169	uevent_ops = kset->uevent_ops;
1da177e4	170
f67f129e ML	171	/* skip the event, if uevent_suppress is set*/
	172	if (kobj->uevent_suppress) {
	173	pr_debug("kobject: '%s' (%p): %s: uevent_suppress "
	174	"caused the event to drop!\n",
	175	kobject_name(kobj), kobj, __func__);
	176	return 0;
	177	}
7eff2e7a	178	/* skip the event, if the filter returns zero. */
312c004d	179	if (uevent_ops && uevent_ops->filter)
542cfce6	180	if (!uevent_ops->filter(kset, kobj)) {
9f66fa2a GKH	181	pr_debug("kobject: '%s' (%p): %s: filter function "
9f66fa2a GKH	182	"caused the event to drop!\n",
810304db	183	kobject_name(kobj), kobj, __func__);
542cfce6 AK	184	return 0;
542cfce6 AK	185	}
1da177e4	186
86406245 KS	187	/* originating subsystem */
	188	if (uevent_ops && uevent_ops->name)
	189	subsystem = uevent_ops->name(kset, kobj);
	190	else
	191	subsystem = kobject_name(&kset->kobj);
	192	if (!subsystem) {
9f66fa2a GKH	193	pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the "
9f66fa2a GKH	194	"event to drop!\n", kobject_name(kobj), kobj,
810304db	195	__func__);
86406245 KS	196	return 0;
	197	}
	198
7eff2e7a KS	199	/* environment buffer */
	200	env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
	201	if (!env)
542cfce6	202	return -ENOMEM;
1da177e4	203
5f123fbd KS	204	/* complete object path */
5f123fbd KS	205	devpath = kobject_get_path(kobj, GFP_KERNEL);
542cfce6 AK	206	if (!devpath) {
542cfce6 AK	207	retval = -ENOENT;
5f123fbd	208	goto exit;
542cfce6	209	}
1da177e4	210
5f123fbd	211	/* default keys */
7eff2e7a KS	212	retval = add_uevent_var(env, "ACTION=%s", action_string);
	213	if (retval)
	214	goto exit;
	215	retval = add_uevent_var(env, "DEVPATH=%s", devpath);
	216	if (retval)
	217	goto exit;
	218	retval = add_uevent_var(env, "SUBSYSTEM=%s", subsystem);
	219	if (retval)
	220	goto exit;
	221
	222	/* keys passed in from the caller */
	223	if (envp_ext) {
	224	for (i = 0; envp_ext[i]; i++) {
c65b9145	225	retval = add_uevent_var(env, "%s", envp_ext[i]);
7eff2e7a KS	226	if (retval)
	227	goto exit;
	228	}
	229	}
1da177e4	230
5f123fbd	231	/* let the kset specific function add its stuff */
312c004d	232	if (uevent_ops && uevent_ops->uevent) {
7eff2e7a	233	retval = uevent_ops->uevent(kset, kobj, env);
1da177e4	234	if (retval) {
9f66fa2a GKH	235	pr_debug("kobject: '%s' (%p): %s: uevent() returned "
9f66fa2a GKH	236	"%d\n", kobject_name(kobj), kobj,
810304db	237	__func__, retval);
1da177e4 LT	238	goto exit;
	239	}
	240	}
	241
0f4dafc0 KS	242	/*
	243	* Mark "add" and "remove" events in the object to ensure proper
	244	* events to userspace during automatic cleanup. If the object did
	245	* send an "add" event, "remove" will automatically generated by
	246	* the core, if not already done by the caller.
	247	*/
	248	if (action == KOBJ_ADD)
	249	kobj->state_add_uevent_sent = 1;
	250	else if (action == KOBJ_REMOVE)
	251	kobj->state_remove_uevent_sent = 1;
	252
7b60a18d	253	mutex_lock(&uevent_sock_mutex);
7eff2e7a	254	/* we will send an event, so request a new sequence number */
7b60a18d AV	255	retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)++uevent_seqnum);
	256	if (retval) {
	257	mutex_unlock(&uevent_sock_mutex);
7eff2e7a	258	goto exit;
7b60a18d	259	}
1da177e4	260
4d17ffda	261	#if defined(CONFIG_NET)
5f123fbd	262	/* send netlink message */
07e98962 EB	263	list_for_each_entry(ue_sk, &uevent_sock_list, list) {
07e98962 EB	264	struct sock *uevent_sock = ue_sk->sk;
5f123fbd KS	265	struct sk_buff *skb;
	266	size_t len;
	267
74099b18 KS	268	if (!netlink_has_listeners(uevent_sock, 1))
	269	continue;
	270
5f123fbd KS	271	/* allocate message with the maximum possible size */
5f123fbd KS	272	len = strlen(action_string) + strlen(devpath) + 2;
7eff2e7a	273	skb = alloc_skb(len + env->buflen, GFP_KERNEL);
5f123fbd	274	if (skb) {
7eff2e7a KS	275	char *scratch;
7eff2e7a KS	276
5f123fbd KS	277	/* add header */
	278	scratch = skb_put(skb, len);
	279	sprintf(scratch, "%s@%s", action_string, devpath);
	280
	281	/* copy keys to our continuous event payload buffer */
7eff2e7a KS	282	for (i = 0; i < env->envp_idx; i++) {
7eff2e7a KS	283	len = strlen(env->envp[i]) + 1;
5f123fbd	284	scratch = skb_put(skb, len);
7eff2e7a	285	strcpy(scratch, env->envp[i]);
5f123fbd KS	286	}
	287
	288	NETLINK_CB(skb).dst_group = 1;
5f71a296 EB	289	retval = netlink_broadcast_filtered(uevent_sock, skb,
	290	0, 1, GFP_KERNEL,
	291	kobj_bcast_filter,
	292	kobj);
ff491a73	293	/* ENOBUFS should be handled in userspace */
ebf4127c	294	if (retval == -ENOBUFS \|\| retval == -ESRCH)
ff491a73	295	retval = 0;
e0d7bf5d ML	296	} else
e0d7bf5d ML	297	retval = -ENOMEM;
5f123fbd	298	}
4d17ffda	299	#endif
7b60a18d	300	mutex_unlock(&uevent_sock_mutex);
1da177e4	301
5f123fbd	302	/* call uevent_helper, usually only enabled during early boot */
417daa1e	303	if (uevent_helper[0] && !kobj_usermode_filter(kobj)) {
5f123fbd	304	char *argv [3];
1da177e4	305
312c004d	306	argv [0] = uevent_helper;
5f123fbd KS	307	argv [1] = (char *)subsystem;
5f123fbd KS	308	argv [2] = NULL;
7eff2e7a KS	309	retval = add_uevent_var(env, "HOME=/");
	310	if (retval)
	311	goto exit;
e374a2bf GKH	312	retval = add_uevent_var(env,
e374a2bf GKH	313	"PATH=/sbin:/bin:/usr/sbin:/usr/bin");
7eff2e7a KS	314	if (retval)
	315	goto exit;
	316
0ad1d6f3	317	retval = call_usermodehelper(argv[0], argv,
05f54c13	318	env->envp, UMH_WAIT_EXEC);
5f123fbd	319	}
1da177e4 LT	320
1da177e4 LT	321	exit:
5f123fbd	322	kfree(devpath);
7eff2e7a	323	kfree(env);
542cfce6	324	return retval;
1da177e4	325	}
8a82472f CH	326	EXPORT_SYMBOL_GPL(kobject_uevent_env);
	327
	328	/**
f6e6e779	329	* kobject_uevent - notify userspace by sending an uevent
8a82472f	330	*
ccd490a3	331	* @action: action that is happening
8a82472f	332	* @kobj: struct kobject that the action is happening to
542cfce6 AK	333	*
	334	* Returns 0 if kobject_uevent() is completed with success or the
	335	* corresponding error when it fails.
8a82472f	336	*/
542cfce6	337	int kobject_uevent(struct kobject *kobj, enum kobject_action action)
8a82472f	338	{
542cfce6	339	return kobject_uevent_env(kobj, action, NULL);
8a82472f	340	}
312c004d	341	EXPORT_SYMBOL_GPL(kobject_uevent);
1da177e4 LT	342
1da177e4 LT	343	/**
7eff2e7a KS	344	* add_uevent_var - add key value string to the environment buffer
	345	* @env: environment buffer structure
	346	* @format: printf format for the key=value pair
1da177e4 LT	347	*
	348	* Returns 0 if environment variable was added successfully or -ENOMEM
	349	* if no space was available.
	350	*/
7eff2e7a	351	int add_uevent_var(struct kobj_uevent_env env, const char format, ...)
1da177e4 LT	352	{
1da177e4 LT	353	va_list args;
7eff2e7a	354	int len;
1da177e4	355
7eff2e7a	356	if (env->envp_idx >= ARRAY_SIZE(env->envp)) {
5cd2b459	357	WARN(1, KERN_ERR "add_uevent_var: too many keys\n");
1da177e4	358	return -ENOMEM;
7eff2e7a	359	}
1da177e4 LT	360
1da177e4 LT	361	va_start(args, format);
7eff2e7a KS	362	len = vsnprintf(&env->buf[env->buflen],
	363	sizeof(env->buf) - env->buflen,
	364	format, args);
1da177e4 LT	365	va_end(args);
1da177e4 LT	366
7eff2e7a	367	if (len >= (sizeof(env->buf) - env->buflen)) {
5cd2b459	368	WARN(1, KERN_ERR "add_uevent_var: buffer size too small\n");
1da177e4	369	return -ENOMEM;
7eff2e7a	370	}
1da177e4	371
7eff2e7a KS	372	env->envp[env->envp_idx++] = &env->buf[env->buflen];
7eff2e7a KS	373	env->buflen += len + 1;
1da177e4 LT	374	return 0;
1da177e4 LT	375	}
312c004d	376	EXPORT_SYMBOL_GPL(add_uevent_var);
1da177e4	377
4d17ffda	378	#if defined(CONFIG_NET)
07e98962	379	static int uevent_net_init(struct net *net)
5f123fbd	380	{
07e98962	381	struct uevent_sock *ue_sk;
a31f2d17 PNA	382	struct netlink_kernel_cfg cfg = {
a31f2d17 PNA	383	.groups = 1,
9785e10a	384	.flags = NL_CFG_F_NONROOT_RECV,
a31f2d17	385	};
07e98962 EB	386
	387	ue_sk = kzalloc(sizeof(*ue_sk), GFP_KERNEL);
	388	if (!ue_sk)
	389	return -ENOMEM;
	390
9f00d977	391	ue_sk->sk = netlink_kernel_create(net, NETLINK_KOBJECT_UEVENT, &cfg);
07e98962	392	if (!ue_sk->sk) {
5f123fbd KS	393	printk(KERN_ERR
5f123fbd KS	394	"kobject_uevent: unable to create netlink socket!\n");
743db2d9	395	kfree(ue_sk);
5f123fbd KS	396	return -ENODEV;
5f123fbd KS	397	}
07e98962 EB	398	mutex_lock(&uevent_sock_mutex);
	399	list_add_tail(&ue_sk->list, &uevent_sock_list);
	400	mutex_unlock(&uevent_sock_mutex);
5f123fbd KS	401	return 0;
	402	}
	403
07e98962 EB	404	static void uevent_net_exit(struct net *net)
	405	{
	406	struct uevent_sock *ue_sk;
	407
	408	mutex_lock(&uevent_sock_mutex);
	409	list_for_each_entry(ue_sk, &uevent_sock_list, list) {
	410	if (sock_net(ue_sk->sk) == net)
	411	goto found;
	412	}
	413	mutex_unlock(&uevent_sock_mutex);
	414	return;
	415
	416	found:
	417	list_del(&ue_sk->list);
	418	mutex_unlock(&uevent_sock_mutex);
	419
	420	netlink_kernel_release(ue_sk->sk);
	421	kfree(ue_sk);
	422	}
	423
	424	static struct pernet_operations uevent_net_ops = {
	425	.init = uevent_net_init,
	426	.exit = uevent_net_exit,
	427	};
	428
	429	static int __init kobject_uevent_init(void)
	430	{
07e98962 EB	431	return register_pernet_subsys(&uevent_net_ops);
	432	}
	433
	434
5f123fbd	435	postcore_initcall(kobject_uevent_init);
4d17ffda	436	#endif