[mirror_ubuntu-bionic-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/module.h>
#include <linux/slab.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;
}

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;
}

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