[linux.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		<[email protected]>
 *	Kay Sievers		<[email protected]>
 *	Arjan van de Ven	<[email protected]>
 *	Greg Kroah-Hartman	<[email protected]>
 */

#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/kobject.h>
#include <linux/module.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;
static DEFINE_SPINLOCK(sequence_lock);
#ifdef CONFIG_NET
struct uevent_sock {
	struct list_head list;
	struct sock *sk;
};
static LIST_HEAD(uevent_sock_list);
static DEFINE_MUTEX(uevent_sock_mutex);
#endif

/* 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;
	const struct kobj_ns_type_operations *ops;

	ops = kobj_ns_ops(kobj);
	if (ops) {
		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;
	u64 seq;
	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;

	/* we will send an event, so request a new sequence number */
	spin_lock(&sequence_lock);
	seq = ++uevent_seqnum;
	spin_unlock(&sequence_lock);
	retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)seq);
	if (retval)
		goto exit;

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

		/* 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 = 0;
		} else
			retval = -ENOMEM;
	}
	mutex_unlock(&uevent_sock_mutex);
#endif

	/* 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;

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

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