[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/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;
	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;
	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 <[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>
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)
	90	{
	91	struct kobject *kobj = data;
	92	const struct kobj_ns_type_operations *ops;
	93
	94	ops = kobj_ns_ops(kobj);
	95	if (ops) {
	96	const void sock_ns, ns;
	97	ns = kobj->ktype->namespace(kobj);
	98	sock_ns = ops->netlink_ns(dsk);
	99	return sock_ns != ns;
	100	}
	101
	102	return 0;
	103	}
c8421286	104	#endif
5f71a296	105
417daa1e EB	106	static int kobj_usermode_filter(struct kobject *kobj)
	107	{
	108	const struct kobj_ns_type_operations *ops;
	109
	110	ops = kobj_ns_ops(kobj);
	111	if (ops) {
	112	const void init_ns, ns;
	113	ns = kobj->ktype->namespace(kobj);
	114	init_ns = ops->initial_ns();
	115	return ns != init_ns;
	116	}
	117
	118	return 0;
	119	}
	120
1da177e4	121	/**
8a82472f	122	* kobject_uevent_env - send an uevent with environmental data
1da177e4	123	*
ccd490a3	124	* @action: action that is happening
1da177e4	125	* @kobj: struct kobject that the action is happening to
8a82472f	126	* @envp_ext: pointer to environmental data
542cfce6	127	*
f6e6e779	128	* Returns 0 if kobject_uevent_env() is completed with success or the
542cfce6	129	* corresponding error when it fails.
1da177e4	130	*/
542cfce6	131	int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
7eff2e7a	132	char *envp_ext[])
1da177e4	133	{
7eff2e7a KS	134	struct kobj_uevent_env *env;
7eff2e7a KS	135	const char *action_string = kobject_actions[action];
5f123fbd KS	136	const char *devpath = NULL;
	137	const char *subsystem;
	138	struct kobject *top_kobj;
	139	struct kset *kset;
9cd43611	140	const struct kset_uevent_ops *uevent_ops;
1da177e4	141	int i = 0;
542cfce6	142	int retval = 0;
07e98962 EB	143	#ifdef CONFIG_NET
	144	struct uevent_sock *ue_sk;
	145	#endif
1da177e4	146
9f66fa2a	147	pr_debug("kobject: '%s' (%p): %s\n",
810304db	148	kobject_name(kobj), kobj, __func__);
5f123fbd	149
5f123fbd KS	150	/* search the kset we belong to */
5f123fbd KS	151	top_kobj = kobj;
ccd490a3	152	while (!top_kobj->kset && top_kobj->parent)
14193fb9	153	top_kobj = top_kobj->parent;
ccd490a3	154
542cfce6	155	if (!top_kobj->kset) {
9f66fa2a GKH	156	pr_debug("kobject: '%s' (%p): %s: attempted to send uevent "
9f66fa2a GKH	157	"without kset!\n", kobject_name(kobj), kobj,
810304db	158	__func__);
542cfce6 AK	159	return -EINVAL;
542cfce6 AK	160	}
1da177e4	161
5f123fbd	162	kset = top_kobj->kset;
312c004d	163	uevent_ops = kset->uevent_ops;
1da177e4	164
f67f129e ML	165	/* skip the event, if uevent_suppress is set*/
	166	if (kobj->uevent_suppress) {
	167	pr_debug("kobject: '%s' (%p): %s: uevent_suppress "
	168	"caused the event to drop!\n",
	169	kobject_name(kobj), kobj, __func__);
	170	return 0;
	171	}
7eff2e7a	172	/* skip the event, if the filter returns zero. */
312c004d	173	if (uevent_ops && uevent_ops->filter)
542cfce6	174	if (!uevent_ops->filter(kset, kobj)) {
9f66fa2a GKH	175	pr_debug("kobject: '%s' (%p): %s: filter function "
9f66fa2a GKH	176	"caused the event to drop!\n",
810304db	177	kobject_name(kobj), kobj, __func__);
542cfce6 AK	178	return 0;
542cfce6 AK	179	}
1da177e4	180
86406245 KS	181	/* originating subsystem */
	182	if (uevent_ops && uevent_ops->name)
	183	subsystem = uevent_ops->name(kset, kobj);
	184	else
	185	subsystem = kobject_name(&kset->kobj);
	186	if (!subsystem) {
9f66fa2a GKH	187	pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the "
9f66fa2a GKH	188	"event to drop!\n", kobject_name(kobj), kobj,
810304db	189	__func__);
86406245 KS	190	return 0;
	191	}
	192
7eff2e7a KS	193	/* environment buffer */
	194	env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
	195	if (!env)
542cfce6	196	return -ENOMEM;
1da177e4	197
5f123fbd KS	198	/* complete object path */
5f123fbd KS	199	devpath = kobject_get_path(kobj, GFP_KERNEL);
542cfce6 AK	200	if (!devpath) {
542cfce6 AK	201	retval = -ENOENT;
5f123fbd	202	goto exit;
542cfce6	203	}
1da177e4	204
5f123fbd	205	/* default keys */
7eff2e7a KS	206	retval = add_uevent_var(env, "ACTION=%s", action_string);
	207	if (retval)
	208	goto exit;
	209	retval = add_uevent_var(env, "DEVPATH=%s", devpath);
	210	if (retval)
	211	goto exit;
	212	retval = add_uevent_var(env, "SUBSYSTEM=%s", subsystem);
	213	if (retval)
	214	goto exit;
	215
	216	/* keys passed in from the caller */
	217	if (envp_ext) {
	218	for (i = 0; envp_ext[i]; i++) {
c65b9145	219	retval = add_uevent_var(env, "%s", envp_ext[i]);
7eff2e7a KS	220	if (retval)
	221	goto exit;
	222	}
	223	}
1da177e4	224
5f123fbd	225	/* let the kset specific function add its stuff */
312c004d	226	if (uevent_ops && uevent_ops->uevent) {
7eff2e7a	227	retval = uevent_ops->uevent(kset, kobj, env);
1da177e4	228	if (retval) {
9f66fa2a GKH	229	pr_debug("kobject: '%s' (%p): %s: uevent() returned "
9f66fa2a GKH	230	"%d\n", kobject_name(kobj), kobj,
810304db	231	__func__, retval);
1da177e4 LT	232	goto exit;
	233	}
	234	}
	235
0f4dafc0 KS	236	/*
	237	* Mark "add" and "remove" events in the object to ensure proper
	238	* events to userspace during automatic cleanup. If the object did
	239	* send an "add" event, "remove" will automatically generated by
	240	* the core, if not already done by the caller.
	241	*/
	242	if (action == KOBJ_ADD)
	243	kobj->state_add_uevent_sent = 1;
	244	else if (action == KOBJ_REMOVE)
	245	kobj->state_remove_uevent_sent = 1;
	246
7b60a18d	247	mutex_lock(&uevent_sock_mutex);
7eff2e7a	248	/* we will send an event, so request a new sequence number */
7b60a18d AV	249	retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)++uevent_seqnum);
	250	if (retval) {
	251	mutex_unlock(&uevent_sock_mutex);
7eff2e7a	252	goto exit;
7b60a18d	253	}
1da177e4	254
4d17ffda	255	#if defined(CONFIG_NET)
5f123fbd	256	/* send netlink message */
07e98962 EB	257	list_for_each_entry(ue_sk, &uevent_sock_list, list) {
07e98962 EB	258	struct sock *uevent_sock = ue_sk->sk;
5f123fbd KS	259	struct sk_buff *skb;
	260	size_t len;
	261
74099b18 KS	262	if (!netlink_has_listeners(uevent_sock, 1))
	263	continue;
	264
5f123fbd KS	265	/* allocate message with the maximum possible size */
5f123fbd KS	266	len = strlen(action_string) + strlen(devpath) + 2;
7eff2e7a	267	skb = alloc_skb(len + env->buflen, GFP_KERNEL);
5f123fbd	268	if (skb) {
7eff2e7a KS	269	char *scratch;
7eff2e7a KS	270
5f123fbd KS	271	/* add header */
	272	scratch = skb_put(skb, len);
	273	sprintf(scratch, "%s@%s", action_string, devpath);
	274
	275	/* copy keys to our continuous event payload buffer */
7eff2e7a KS	276	for (i = 0; i < env->envp_idx; i++) {
7eff2e7a KS	277	len = strlen(env->envp[i]) + 1;
5f123fbd	278	scratch = skb_put(skb, len);
7eff2e7a	279	strcpy(scratch, env->envp[i]);
5f123fbd KS	280	}
	281
	282	NETLINK_CB(skb).dst_group = 1;
5f71a296 EB	283	retval = netlink_broadcast_filtered(uevent_sock, skb,
	284	0, 1, GFP_KERNEL,
	285	kobj_bcast_filter,
	286	kobj);
ff491a73	287	/* ENOBUFS should be handled in userspace */
ebf4127c	288	if (retval == -ENOBUFS \|\| retval == -ESRCH)
ff491a73	289	retval = 0;
e0d7bf5d ML	290	} else
e0d7bf5d ML	291	retval = -ENOMEM;
5f123fbd	292	}
4d17ffda	293	#endif
7b60a18d	294	mutex_unlock(&uevent_sock_mutex);
1da177e4	295
5f123fbd	296	/* call uevent_helper, usually only enabled during early boot */
417daa1e	297	if (uevent_helper[0] && !kobj_usermode_filter(kobj)) {
5f123fbd	298	char *argv [3];
1da177e4	299
312c004d	300	argv [0] = uevent_helper;
5f123fbd KS	301	argv [1] = (char *)subsystem;
5f123fbd KS	302	argv [2] = NULL;
7eff2e7a KS	303	retval = add_uevent_var(env, "HOME=/");
	304	if (retval)
	305	goto exit;
e374a2bf GKH	306	retval = add_uevent_var(env,
e374a2bf GKH	307	"PATH=/sbin:/bin:/usr/sbin:/usr/bin");
7eff2e7a KS	308	if (retval)
	309	goto exit;
	310
0ad1d6f3	311	retval = call_usermodehelper(argv[0], argv,
05f54c13	312	env->envp, UMH_WAIT_EXEC);
5f123fbd	313	}
1da177e4 LT	314
1da177e4 LT	315	exit:
5f123fbd	316	kfree(devpath);
7eff2e7a	317	kfree(env);
542cfce6	318	return retval;
1da177e4	319	}
8a82472f CH	320	EXPORT_SYMBOL_GPL(kobject_uevent_env);
	321
	322	/**
f6e6e779	323	* kobject_uevent - notify userspace by sending an uevent
8a82472f	324	*
ccd490a3	325	* @action: action that is happening
8a82472f	326	* @kobj: struct kobject that the action is happening to
542cfce6 AK	327	*
	328	* Returns 0 if kobject_uevent() is completed with success or the
	329	* corresponding error when it fails.
8a82472f	330	*/
542cfce6	331	int kobject_uevent(struct kobject *kobj, enum kobject_action action)
8a82472f	332	{
542cfce6	333	return kobject_uevent_env(kobj, action, NULL);
8a82472f	334	}
312c004d	335	EXPORT_SYMBOL_GPL(kobject_uevent);
1da177e4 LT	336
1da177e4 LT	337	/**
7eff2e7a KS	338	* add_uevent_var - add key value string to the environment buffer
	339	* @env: environment buffer structure
	340	* @format: printf format for the key=value pair
1da177e4 LT	341	*
	342	* Returns 0 if environment variable was added successfully or -ENOMEM
	343	* if no space was available.
	344	*/
7eff2e7a	345	int add_uevent_var(struct kobj_uevent_env env, const char format, ...)
1da177e4 LT	346	{
1da177e4 LT	347	va_list args;
7eff2e7a	348	int len;
1da177e4	349
7eff2e7a	350	if (env->envp_idx >= ARRAY_SIZE(env->envp)) {
5cd2b459	351	WARN(1, KERN_ERR "add_uevent_var: too many keys\n");
1da177e4	352	return -ENOMEM;
7eff2e7a	353	}
1da177e4 LT	354
1da177e4 LT	355	va_start(args, format);
7eff2e7a KS	356	len = vsnprintf(&env->buf[env->buflen],
	357	sizeof(env->buf) - env->buflen,
	358	format, args);
1da177e4 LT	359	va_end(args);
1da177e4 LT	360
7eff2e7a	361	if (len >= (sizeof(env->buf) - env->buflen)) {
5cd2b459	362	WARN(1, KERN_ERR "add_uevent_var: buffer size too small\n");
1da177e4	363	return -ENOMEM;
7eff2e7a	364	}
1da177e4	365
7eff2e7a KS	366	env->envp[env->envp_idx++] = &env->buf[env->buflen];
7eff2e7a KS	367	env->buflen += len + 1;
1da177e4 LT	368	return 0;
1da177e4 LT	369	}
312c004d	370	EXPORT_SYMBOL_GPL(add_uevent_var);
1da177e4	371
4d17ffda	372	#if defined(CONFIG_NET)
07e98962	373	static int uevent_net_init(struct net *net)
5f123fbd	374	{
07e98962	375	struct uevent_sock *ue_sk;
a31f2d17 PNA	376	struct netlink_kernel_cfg cfg = {
a31f2d17 PNA	377	.groups = 1,
9785e10a	378	.flags = NL_CFG_F_NONROOT_RECV,
a31f2d17	379	};
07e98962 EB	380
	381	ue_sk = kzalloc(sizeof(*ue_sk), GFP_KERNEL);
	382	if (!ue_sk)
	383	return -ENOMEM;
	384
9f00d977	385	ue_sk->sk = netlink_kernel_create(net, NETLINK_KOBJECT_UEVENT, &cfg);
07e98962	386	if (!ue_sk->sk) {
5f123fbd KS	387	printk(KERN_ERR
5f123fbd KS	388	"kobject_uevent: unable to create netlink socket!\n");
743db2d9	389	kfree(ue_sk);
5f123fbd KS	390	return -ENODEV;
5f123fbd KS	391	}
07e98962 EB	392	mutex_lock(&uevent_sock_mutex);
	393	list_add_tail(&ue_sk->list, &uevent_sock_list);
	394	mutex_unlock(&uevent_sock_mutex);
5f123fbd KS	395	return 0;
	396	}
	397
07e98962 EB	398	static void uevent_net_exit(struct net *net)
	399	{
	400	struct uevent_sock *ue_sk;
	401
	402	mutex_lock(&uevent_sock_mutex);
	403	list_for_each_entry(ue_sk, &uevent_sock_list, list) {
	404	if (sock_net(ue_sk->sk) == net)
	405	goto found;
	406	}
	407	mutex_unlock(&uevent_sock_mutex);
	408	return;
	409
	410	found:
	411	list_del(&ue_sk->list);
	412	mutex_unlock(&uevent_sock_mutex);
	413
	414	netlink_kernel_release(ue_sk->sk);
	415	kfree(ue_sk);
	416	}
	417
	418	static struct pernet_operations uevent_net_ops = {
	419	.init = uevent_net_init,
	420	.exit = uevent_net_exit,
	421	};
	422
	423	static int __init kobject_uevent_init(void)
	424	{
07e98962 EB	425	return register_pernet_subsys(&uevent_net_ops);
	426	}
	427
	428
5f123fbd	429	postcore_initcall(kobject_uevent_init);
4d17ffda	430	#endif