[deliverable/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		<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;
#ifdef CONFIG_UEVENT_HELPER
char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH;
#endif
#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

#ifdef CONFIG_UEVENT_HELPER
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;
}

static int init_uevent_argv(struct kobj_uevent_env *env, const char *subsystem)
{
	int len;

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

	env->argv[0] = uevent_helper;
	env->argv[1] = &env->buf[env->buflen];
	env->argv[2] = NULL;

	env->buflen += len + 1;
	return 0;
}

static void cleanup_uevent_env(struct subprocess_info *info)
{
	kfree(info->data);
}
#endif

/**
 * 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);

#ifdef CONFIG_UEVENT_HELPER
	/* call uevent_helper, usually only enabled during early boot */
	if (uevent_helper[0] && !kobj_usermode_filter(kobj)) {
		struct subprocess_info *info;

		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 = init_uevent_argv(env, subsystem);
		if (retval)
			goto exit;

		retval = -ENOMEM;
		info = call_usermodehelper_setup(env->argv[0], env->argv,
						 env->envp, GFP_KERNEL,
						 NULL, cleanup_uevent_env, env);
		if (info) {
			retval = call_usermodehelper_exec(info, UMH_NO_WAIT);
			env = NULL;	/* freed by cleanup_uevent_env */
		}
	}
#endif

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;
86d56134	32	#ifdef CONFIG_UEVENT_HELPER
6a8d8abb	33	char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH;
86d56134	34	#endif
07e98962 EB	35	#ifdef CONFIG_NET
	36	struct uevent_sock {
	37	struct list_head list;
	38	struct sock *sk;
	39	};
	40	static LIST_HEAD(uevent_sock_list);
cd030c4c CH	41	#endif
cd030c4c CH	42
7b60a18d AV	43	/* This lock protects uevent_seqnum and uevent_sock_list */
	44	static DEFINE_MUTEX(uevent_sock_mutex);
	45
5c5daf65 KS	46	/* the strings here must match the enum in include/linux/kobject.h */
	47	static const char *kobject_actions[] = {
	48	[KOBJ_ADD] = "add",
	49	[KOBJ_REMOVE] = "remove",
	50	[KOBJ_CHANGE] = "change",
	51	[KOBJ_MOVE] = "move",
	52	[KOBJ_ONLINE] = "online",
	53	[KOBJ_OFFLINE] = "offline",
	54	};
	55
	56	/**
	57	* kobject_action_type - translate action string to numeric type
	58	*
	59	* @buf: buffer containing the action string, newline is ignored
	60	* @len: length of buffer
	61	* @type: pointer to the location to store the action type
	62	*
	63	* Returns 0 if the action string was recognized.
	64	*/
	65	int kobject_action_type(const char *buf, size_t count,
	66	enum kobject_action *type)
	67	{
	68	enum kobject_action action;
	69	int ret = -EINVAL;
	70
a9edadbf	71	if (count && (buf[count-1] == '\n' \|\| buf[count-1] == '\0'))
5c5daf65 KS	72	count--;
	73
	74	if (!count)
	75	goto out;
	76
	77	for (action = 0; action < ARRAY_SIZE(kobject_actions); action++) {
	78	if (strncmp(kobject_actions[action], buf, count) != 0)
	79	continue;
	80	if (kobject_actions[action][count] != '\0')
	81	continue;
	82	*type = action;
	83	ret = 0;
	84	break;
	85	}
	86	out:
	87	return ret;
	88	}
	89
c8421286	90	#ifdef CONFIG_NET
5f71a296 EB	91	static int kobj_bcast_filter(struct sock dsk, struct sk_buff skb, void *data)
5f71a296 EB	92	{
82ef3d5d	93	struct kobject kobj = data, ksobj;
5f71a296 EB	94	const struct kobj_ns_type_operations *ops;
	95
	96	ops = kobj_ns_ops(kobj);
82ef3d5d WC	97	if (!ops && kobj->kset) {
	98	ksobj = &kobj->kset->kobj;
	99	if (ksobj->parent != NULL)
	100	ops = kobj_ns_ops(ksobj->parent);
	101	}
	102
	103	if (ops && ops->netlink_ns && kobj->ktype->namespace) {
5f71a296 EB	104	const void sock_ns, ns;
	105	ns = kobj->ktype->namespace(kobj);
	106	sock_ns = ops->netlink_ns(dsk);
	107	return sock_ns != ns;
	108	}
	109
	110	return 0;
	111	}
c8421286	112	#endif
5f71a296	113
86d56134	114	#ifdef CONFIG_UEVENT_HELPER
417daa1e EB	115	static int kobj_usermode_filter(struct kobject *kobj)
	116	{
	117	const struct kobj_ns_type_operations *ops;
	118
	119	ops = kobj_ns_ops(kobj);
	120	if (ops) {
	121	const void init_ns, ns;
	122	ns = kobj->ktype->namespace(kobj);
	123	init_ns = ops->initial_ns();
	124	return ns != init_ns;
	125	}
	126
	127	return 0;
	128	}
	129
bcccff93 VD	130	static int init_uevent_argv(struct kobj_uevent_env env, const char subsystem)
	131	{
	132	int len;
	133
	134	len = strlcpy(&env->buf[env->buflen], subsystem,
	135	sizeof(env->buf) - env->buflen);
	136	if (len >= (sizeof(env->buf) - env->buflen)) {
	137	WARN(1, KERN_ERR "init_uevent_argv: buffer size too small\n");
	138	return -ENOMEM;
	139	}
	140
	141	env->argv[0] = uevent_helper;
	142	env->argv[1] = &env->buf[env->buflen];
	143	env->argv[2] = NULL;
	144
	145	env->buflen += len + 1;
	146	return 0;
	147	}
	148
	149	static void cleanup_uevent_env(struct subprocess_info *info)
	150	{
	151	kfree(info->data);
	152	}
86d56134	153	#endif
bcccff93	154
1da177e4	155	/**
8a82472f	156	* kobject_uevent_env - send an uevent with environmental data
1da177e4	157	*
ccd490a3	158	* @action: action that is happening
1da177e4	159	* @kobj: struct kobject that the action is happening to
8a82472f	160	* @envp_ext: pointer to environmental data
542cfce6	161	*
f6e6e779	162	* Returns 0 if kobject_uevent_env() is completed with success or the
542cfce6	163	* corresponding error when it fails.
1da177e4	164	*/
542cfce6	165	int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
7eff2e7a	166	char *envp_ext[])
1da177e4	167	{
7eff2e7a KS	168	struct kobj_uevent_env *env;
7eff2e7a KS	169	const char *action_string = kobject_actions[action];
5f123fbd KS	170	const char *devpath = NULL;
	171	const char *subsystem;
	172	struct kobject *top_kobj;
	173	struct kset *kset;
9cd43611	174	const struct kset_uevent_ops *uevent_ops;
1da177e4	175	int i = 0;
542cfce6	176	int retval = 0;
07e98962 EB	177	#ifdef CONFIG_NET
	178	struct uevent_sock *ue_sk;
	179	#endif
1da177e4	180
9f66fa2a	181	pr_debug("kobject: '%s' (%p): %s\n",
810304db	182	kobject_name(kobj), kobj, __func__);
5f123fbd	183
5f123fbd KS	184	/* search the kset we belong to */
5f123fbd KS	185	top_kobj = kobj;
ccd490a3	186	while (!top_kobj->kset && top_kobj->parent)
14193fb9	187	top_kobj = top_kobj->parent;
ccd490a3	188
542cfce6	189	if (!top_kobj->kset) {
9f66fa2a GKH	190	pr_debug("kobject: '%s' (%p): %s: attempted to send uevent "
9f66fa2a GKH	191	"without kset!\n", kobject_name(kobj), kobj,
810304db	192	__func__);
542cfce6 AK	193	return -EINVAL;
542cfce6 AK	194	}
1da177e4	195
5f123fbd	196	kset = top_kobj->kset;
312c004d	197	uevent_ops = kset->uevent_ops;
1da177e4	198
f67f129e ML	199	/* skip the event, if uevent_suppress is set*/
	200	if (kobj->uevent_suppress) {
	201	pr_debug("kobject: '%s' (%p): %s: uevent_suppress "
	202	"caused the event to drop!\n",
	203	kobject_name(kobj), kobj, __func__);
	204	return 0;
	205	}
7eff2e7a	206	/* skip the event, if the filter returns zero. */
312c004d	207	if (uevent_ops && uevent_ops->filter)
542cfce6	208	if (!uevent_ops->filter(kset, kobj)) {
9f66fa2a GKH	209	pr_debug("kobject: '%s' (%p): %s: filter function "
9f66fa2a GKH	210	"caused the event to drop!\n",
810304db	211	kobject_name(kobj), kobj, __func__);
542cfce6 AK	212	return 0;
542cfce6 AK	213	}
1da177e4	214
86406245 KS	215	/* originating subsystem */
	216	if (uevent_ops && uevent_ops->name)
	217	subsystem = uevent_ops->name(kset, kobj);
	218	else
	219	subsystem = kobject_name(&kset->kobj);
	220	if (!subsystem) {
9f66fa2a GKH	221	pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the "
9f66fa2a GKH	222	"event to drop!\n", kobject_name(kobj), kobj,
810304db	223	__func__);
86406245 KS	224	return 0;
	225	}
	226
7eff2e7a KS	227	/* environment buffer */
	228	env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
	229	if (!env)
542cfce6	230	return -ENOMEM;
1da177e4	231
5f123fbd KS	232	/* complete object path */
5f123fbd KS	233	devpath = kobject_get_path(kobj, GFP_KERNEL);
542cfce6 AK	234	if (!devpath) {
542cfce6 AK	235	retval = -ENOENT;
5f123fbd	236	goto exit;
542cfce6	237	}
1da177e4	238
5f123fbd	239	/* default keys */
7eff2e7a KS	240	retval = add_uevent_var(env, "ACTION=%s", action_string);
	241	if (retval)
	242	goto exit;
	243	retval = add_uevent_var(env, "DEVPATH=%s", devpath);
	244	if (retval)
	245	goto exit;
	246	retval = add_uevent_var(env, "SUBSYSTEM=%s", subsystem);
	247	if (retval)
	248	goto exit;
	249
	250	/* keys passed in from the caller */
	251	if (envp_ext) {
	252	for (i = 0; envp_ext[i]; i++) {
c65b9145	253	retval = add_uevent_var(env, "%s", envp_ext[i]);
7eff2e7a KS	254	if (retval)
	255	goto exit;
	256	}
	257	}
1da177e4	258
5f123fbd	259	/* let the kset specific function add its stuff */
312c004d	260	if (uevent_ops && uevent_ops->uevent) {
7eff2e7a	261	retval = uevent_ops->uevent(kset, kobj, env);
1da177e4	262	if (retval) {
9f66fa2a GKH	263	pr_debug("kobject: '%s' (%p): %s: uevent() returned "
9f66fa2a GKH	264	"%d\n", kobject_name(kobj), kobj,
810304db	265	__func__, retval);
1da177e4 LT	266	goto exit;
	267	}
	268	}
	269
0f4dafc0 KS	270	/*
	271	* Mark "add" and "remove" events in the object to ensure proper
	272	* events to userspace during automatic cleanup. If the object did
	273	* send an "add" event, "remove" will automatically generated by
	274	* the core, if not already done by the caller.
	275	*/
	276	if (action == KOBJ_ADD)
	277	kobj->state_add_uevent_sent = 1;
	278	else if (action == KOBJ_REMOVE)
	279	kobj->state_remove_uevent_sent = 1;
	280
7b60a18d	281	mutex_lock(&uevent_sock_mutex);
7eff2e7a	282	/* we will send an event, so request a new sequence number */
7b60a18d AV	283	retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)++uevent_seqnum);
	284	if (retval) {
	285	mutex_unlock(&uevent_sock_mutex);
7eff2e7a	286	goto exit;
7b60a18d	287	}
1da177e4	288
4d17ffda	289	#if defined(CONFIG_NET)
5f123fbd	290	/* send netlink message */
07e98962 EB	291	list_for_each_entry(ue_sk, &uevent_sock_list, list) {
07e98962 EB	292	struct sock *uevent_sock = ue_sk->sk;
5f123fbd KS	293	struct sk_buff *skb;
	294	size_t len;
	295
74099b18 KS	296	if (!netlink_has_listeners(uevent_sock, 1))
	297	continue;
	298
5f123fbd KS	299	/* allocate message with the maximum possible size */
5f123fbd KS	300	len = strlen(action_string) + strlen(devpath) + 2;
7eff2e7a	301	skb = alloc_skb(len + env->buflen, GFP_KERNEL);
5f123fbd	302	if (skb) {
7eff2e7a KS	303	char *scratch;
7eff2e7a KS	304
5f123fbd KS	305	/* add header */
	306	scratch = skb_put(skb, len);
	307	sprintf(scratch, "%s@%s", action_string, devpath);
	308
	309	/* copy keys to our continuous event payload buffer */
7eff2e7a KS	310	for (i = 0; i < env->envp_idx; i++) {
7eff2e7a KS	311	len = strlen(env->envp[i]) + 1;
5f123fbd	312	scratch = skb_put(skb, len);
7eff2e7a	313	strcpy(scratch, env->envp[i]);
5f123fbd KS	314	}
	315
	316	NETLINK_CB(skb).dst_group = 1;
5f71a296 EB	317	retval = netlink_broadcast_filtered(uevent_sock, skb,
	318	0, 1, GFP_KERNEL,
	319	kobj_bcast_filter,
	320	kobj);
ff491a73	321	/* ENOBUFS should be handled in userspace */
ebf4127c	322	if (retval == -ENOBUFS \|\| retval == -ESRCH)
ff491a73	323	retval = 0;
e0d7bf5d ML	324	} else
e0d7bf5d ML	325	retval = -ENOMEM;
5f123fbd	326	}
4d17ffda	327	#endif
7b60a18d	328	mutex_unlock(&uevent_sock_mutex);
1da177e4	329
86d56134	330	#ifdef CONFIG_UEVENT_HELPER
5f123fbd	331	/* call uevent_helper, usually only enabled during early boot */
417daa1e	332	if (uevent_helper[0] && !kobj_usermode_filter(kobj)) {
bcccff93	333	struct subprocess_info *info;
1da177e4	334
7eff2e7a KS	335	retval = add_uevent_var(env, "HOME=/");
	336	if (retval)
	337	goto exit;
e374a2bf GKH	338	retval = add_uevent_var(env,
e374a2bf GKH	339	"PATH=/sbin:/bin:/usr/sbin:/usr/bin");
7eff2e7a KS	340	if (retval)
7eff2e7a KS	341	goto exit;
bcccff93 VD	342	retval = init_uevent_argv(env, subsystem);
	343	if (retval)
	344	goto exit;
7eff2e7a	345
bcccff93 VD	346	retval = -ENOMEM;
	347	info = call_usermodehelper_setup(env->argv[0], env->argv,
	348	env->envp, GFP_KERNEL,
	349	NULL, cleanup_uevent_env, env);
	350	if (info) {
	351	retval = call_usermodehelper_exec(info, UMH_NO_WAIT);
	352	env = NULL; /* freed by cleanup_uevent_env */
	353	}
5f123fbd	354	}
86d56134	355	#endif
1da177e4 LT	356
1da177e4 LT	357	exit:
5f123fbd	358	kfree(devpath);
7eff2e7a	359	kfree(env);
542cfce6	360	return retval;
1da177e4	361	}
8a82472f CH	362	EXPORT_SYMBOL_GPL(kobject_uevent_env);
	363
	364	/**
f6e6e779	365	* kobject_uevent - notify userspace by sending an uevent
8a82472f	366	*
ccd490a3	367	* @action: action that is happening
8a82472f	368	* @kobj: struct kobject that the action is happening to
542cfce6 AK	369	*
	370	* Returns 0 if kobject_uevent() is completed with success or the
	371	* corresponding error when it fails.
8a82472f	372	*/
542cfce6	373	int kobject_uevent(struct kobject *kobj, enum kobject_action action)
8a82472f	374	{
542cfce6	375	return kobject_uevent_env(kobj, action, NULL);
8a82472f	376	}
312c004d	377	EXPORT_SYMBOL_GPL(kobject_uevent);
1da177e4 LT	378
1da177e4 LT	379	/**
7eff2e7a KS	380	* add_uevent_var - add key value string to the environment buffer
	381	* @env: environment buffer structure
	382	* @format: printf format for the key=value pair
1da177e4 LT	383	*
	384	* Returns 0 if environment variable was added successfully or -ENOMEM
	385	* if no space was available.
	386	*/
7eff2e7a	387	int add_uevent_var(struct kobj_uevent_env env, const char format, ...)
1da177e4 LT	388	{
1da177e4 LT	389	va_list args;
7eff2e7a	390	int len;
1da177e4	391
7eff2e7a	392	if (env->envp_idx >= ARRAY_SIZE(env->envp)) {
5cd2b459	393	WARN(1, KERN_ERR "add_uevent_var: too many keys\n");
1da177e4	394	return -ENOMEM;
7eff2e7a	395	}
1da177e4 LT	396
1da177e4 LT	397	va_start(args, format);
7eff2e7a KS	398	len = vsnprintf(&env->buf[env->buflen],
	399	sizeof(env->buf) - env->buflen,
	400	format, args);
1da177e4 LT	401	va_end(args);
1da177e4 LT	402
7eff2e7a	403	if (len >= (sizeof(env->buf) - env->buflen)) {
5cd2b459	404	WARN(1, KERN_ERR "add_uevent_var: buffer size too small\n");
1da177e4	405	return -ENOMEM;
7eff2e7a	406	}
1da177e4	407
7eff2e7a KS	408	env->envp[env->envp_idx++] = &env->buf[env->buflen];
7eff2e7a KS	409	env->buflen += len + 1;
1da177e4 LT	410	return 0;
1da177e4 LT	411	}
312c004d	412	EXPORT_SYMBOL_GPL(add_uevent_var);
1da177e4	413
4d17ffda	414	#if defined(CONFIG_NET)
07e98962	415	static int uevent_net_init(struct net *net)
5f123fbd	416	{
07e98962	417	struct uevent_sock *ue_sk;
a31f2d17 PNA	418	struct netlink_kernel_cfg cfg = {
a31f2d17 PNA	419	.groups = 1,
9785e10a	420	.flags = NL_CFG_F_NONROOT_RECV,
a31f2d17	421	};
07e98962 EB	422
	423	ue_sk = kzalloc(sizeof(*ue_sk), GFP_KERNEL);
	424	if (!ue_sk)
	425	return -ENOMEM;
	426
9f00d977	427	ue_sk->sk = netlink_kernel_create(net, NETLINK_KOBJECT_UEVENT, &cfg);
07e98962	428	if (!ue_sk->sk) {
5f123fbd KS	429	printk(KERN_ERR
5f123fbd KS	430	"kobject_uevent: unable to create netlink socket!\n");
743db2d9	431	kfree(ue_sk);
5f123fbd KS	432	return -ENODEV;
5f123fbd KS	433	}
07e98962 EB	434	mutex_lock(&uevent_sock_mutex);
	435	list_add_tail(&ue_sk->list, &uevent_sock_list);
	436	mutex_unlock(&uevent_sock_mutex);
5f123fbd KS	437	return 0;
	438	}
	439
07e98962 EB	440	static void uevent_net_exit(struct net *net)
	441	{
	442	struct uevent_sock *ue_sk;
	443
	444	mutex_lock(&uevent_sock_mutex);
	445	list_for_each_entry(ue_sk, &uevent_sock_list, list) {
	446	if (sock_net(ue_sk->sk) == net)
	447	goto found;
	448	}
	449	mutex_unlock(&uevent_sock_mutex);
	450	return;
	451
	452	found:
	453	list_del(&ue_sk->list);
	454	mutex_unlock(&uevent_sock_mutex);
	455
	456	netlink_kernel_release(ue_sk->sk);
	457	kfree(ue_sk);
	458	}
	459
	460	static struct pernet_operations uevent_net_ops = {
	461	.init = uevent_net_init,
	462	.exit = uevent_net_exit,
	463	};
	464
	465	static int __init kobject_uevent_init(void)
	466	{
07e98962 EB	467	return register_pernet_subsys(&uevent_net_ops);
	468	}
	469
	470
5f123fbd	471	postcore_initcall(kobject_uevent_init);
4d17ffda	472	#endif