[linux-2.6-block.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/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>
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;
86d56134	31	#ifdef CONFIG_UEVENT_HELPER
6a8d8abb	32	char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH;
86d56134	33	#endif
07e98962 EB	34	#ifdef CONFIG_NET
	35	struct uevent_sock {
	36	struct list_head list;
	37	struct sock *sk;
	38	};
	39	static LIST_HEAD(uevent_sock_list);
cd030c4c CH	40	#endif
cd030c4c CH	41
7b60a18d AV	42	/* This lock protects uevent_seqnum and uevent_sock_list */
	43	static DEFINE_MUTEX(uevent_sock_mutex);
	44
5c5daf65 KS	45	/* the strings here must match the enum in include/linux/kobject.h */
	46	static const char *kobject_actions[] = {
	47	[KOBJ_ADD] = "add",
	48	[KOBJ_REMOVE] = "remove",
	49	[KOBJ_CHANGE] = "change",
	50	[KOBJ_MOVE] = "move",
	51	[KOBJ_ONLINE] = "online",
	52	[KOBJ_OFFLINE] = "offline",
	53	};
	54
	55	/**
	56	* kobject_action_type - translate action string to numeric type
	57	*
	58	* @buf: buffer containing the action string, newline is ignored
	59	* @len: length of buffer
	60	* @type: pointer to the location to store the action type
	61	*
	62	* Returns 0 if the action string was recognized.
	63	*/
	64	int kobject_action_type(const char *buf, size_t count,
	65	enum kobject_action *type)
	66	{
	67	enum kobject_action action;
	68	int ret = -EINVAL;
	69
a9edadbf	70	if (count && (buf[count-1] == '\n' \|\| buf[count-1] == '\0'))
5c5daf65 KS	71	count--;
	72
	73	if (!count)
	74	goto out;
	75
	76	for (action = 0; action < ARRAY_SIZE(kobject_actions); action++) {
	77	if (strncmp(kobject_actions[action], buf, count) != 0)
	78	continue;
	79	if (kobject_actions[action][count] != '\0')
	80	continue;
	81	*type = action;
	82	ret = 0;
	83	break;
	84	}
	85	out:
	86	return ret;
	87	}
	88
c8421286	89	#ifdef CONFIG_NET
5f71a296 EB	90	static int kobj_bcast_filter(struct sock dsk, struct sk_buff skb, void *data)
5f71a296 EB	91	{
82ef3d5d	92	struct kobject kobj = data, ksobj;
5f71a296 EB	93	const struct kobj_ns_type_operations *ops;
	94
	95	ops = kobj_ns_ops(kobj);
82ef3d5d WC	96	if (!ops && kobj->kset) {
	97	ksobj = &kobj->kset->kobj;
	98	if (ksobj->parent != NULL)
	99	ops = kobj_ns_ops(ksobj->parent);
	100	}
	101
	102	if (ops && ops->netlink_ns && kobj->ktype->namespace) {
5f71a296 EB	103	const void sock_ns, ns;
	104	ns = kobj->ktype->namespace(kobj);
	105	sock_ns = ops->netlink_ns(dsk);
	106	return sock_ns != ns;
	107	}
	108
	109	return 0;
	110	}
c8421286	111	#endif
5f71a296	112
86d56134	113	#ifdef CONFIG_UEVENT_HELPER
417daa1e EB	114	static int kobj_usermode_filter(struct kobject *kobj)
	115	{
	116	const struct kobj_ns_type_operations *ops;
	117
	118	ops = kobj_ns_ops(kobj);
	119	if (ops) {
	120	const void init_ns, ns;
	121	ns = kobj->ktype->namespace(kobj);
	122	init_ns = ops->initial_ns();
	123	return ns != init_ns;
	124	}
	125
	126	return 0;
	127	}
	128
bcccff93 VD	129	static int init_uevent_argv(struct kobj_uevent_env env, const char subsystem)
	130	{
	131	int len;
	132
	133	len = strlcpy(&env->buf[env->buflen], subsystem,
	134	sizeof(env->buf) - env->buflen);
	135	if (len >= (sizeof(env->buf) - env->buflen)) {
	136	WARN(1, KERN_ERR "init_uevent_argv: buffer size too small\n");
	137	return -ENOMEM;
	138	}
	139
	140	env->argv[0] = uevent_helper;
	141	env->argv[1] = &env->buf[env->buflen];
	142	env->argv[2] = NULL;
	143
	144	env->buflen += len + 1;
	145	return 0;
	146	}
	147
	148	static void cleanup_uevent_env(struct subprocess_info *info)
	149	{
	150	kfree(info->data);
	151	}
86d56134	152	#endif
bcccff93	153
1da177e4	154	/**
8a82472f	155	* kobject_uevent_env - send an uevent with environmental data
1da177e4	156	*
ccd490a3	157	* @action: action that is happening
1da177e4	158	* @kobj: struct kobject that the action is happening to
8a82472f	159	* @envp_ext: pointer to environmental data
542cfce6	160	*
f6e6e779	161	* Returns 0 if kobject_uevent_env() is completed with success or the
542cfce6	162	* corresponding error when it fails.
1da177e4	163	*/
542cfce6	164	int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
7eff2e7a	165	char *envp_ext[])
1da177e4	166	{
7eff2e7a KS	167	struct kobj_uevent_env *env;
7eff2e7a KS	168	const char *action_string = kobject_actions[action];
5f123fbd KS	169	const char *devpath = NULL;
	170	const char *subsystem;
	171	struct kobject *top_kobj;
	172	struct kset *kset;
9cd43611	173	const struct kset_uevent_ops *uevent_ops;
1da177e4	174	int i = 0;
542cfce6	175	int retval = 0;
07e98962 EB	176	#ifdef CONFIG_NET
	177	struct uevent_sock *ue_sk;
	178	#endif
1da177e4	179
9f66fa2a	180	pr_debug("kobject: '%s' (%p): %s\n",
810304db	181	kobject_name(kobj), kobj, __func__);
5f123fbd	182
5f123fbd KS	183	/* search the kset we belong to */
5f123fbd KS	184	top_kobj = kobj;
ccd490a3	185	while (!top_kobj->kset && top_kobj->parent)
14193fb9	186	top_kobj = top_kobj->parent;
ccd490a3	187
542cfce6	188	if (!top_kobj->kset) {
9f66fa2a GKH	189	pr_debug("kobject: '%s' (%p): %s: attempted to send uevent "
9f66fa2a GKH	190	"without kset!\n", kobject_name(kobj), kobj,
810304db	191	__func__);
542cfce6 AK	192	return -EINVAL;
542cfce6 AK	193	}
1da177e4	194
5f123fbd	195	kset = top_kobj->kset;
312c004d	196	uevent_ops = kset->uevent_ops;
1da177e4	197
f67f129e ML	198	/* skip the event, if uevent_suppress is set*/
	199	if (kobj->uevent_suppress) {
	200	pr_debug("kobject: '%s' (%p): %s: uevent_suppress "
	201	"caused the event to drop!\n",
	202	kobject_name(kobj), kobj, __func__);
	203	return 0;
	204	}
7eff2e7a	205	/* skip the event, if the filter returns zero. */
312c004d	206	if (uevent_ops && uevent_ops->filter)
542cfce6	207	if (!uevent_ops->filter(kset, kobj)) {
9f66fa2a GKH	208	pr_debug("kobject: '%s' (%p): %s: filter function "
9f66fa2a GKH	209	"caused the event to drop!\n",
810304db	210	kobject_name(kobj), kobj, __func__);
542cfce6 AK	211	return 0;
542cfce6 AK	212	}
1da177e4	213
86406245 KS	214	/* originating subsystem */
	215	if (uevent_ops && uevent_ops->name)
	216	subsystem = uevent_ops->name(kset, kobj);
	217	else
	218	subsystem = kobject_name(&kset->kobj);
	219	if (!subsystem) {
9f66fa2a GKH	220	pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the "
9f66fa2a GKH	221	"event to drop!\n", kobject_name(kobj), kobj,
810304db	222	__func__);
86406245 KS	223	return 0;
	224	}
	225
7eff2e7a KS	226	/* environment buffer */
	227	env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
	228	if (!env)
542cfce6	229	return -ENOMEM;
1da177e4	230
5f123fbd KS	231	/* complete object path */
5f123fbd KS	232	devpath = kobject_get_path(kobj, GFP_KERNEL);
542cfce6 AK	233	if (!devpath) {
542cfce6 AK	234	retval = -ENOENT;
5f123fbd	235	goto exit;
542cfce6	236	}
1da177e4	237
5f123fbd	238	/* default keys */
7eff2e7a KS	239	retval = add_uevent_var(env, "ACTION=%s", action_string);
	240	if (retval)
	241	goto exit;
	242	retval = add_uevent_var(env, "DEVPATH=%s", devpath);
	243	if (retval)
	244	goto exit;
	245	retval = add_uevent_var(env, "SUBSYSTEM=%s", subsystem);
	246	if (retval)
	247	goto exit;
	248
	249	/* keys passed in from the caller */
	250	if (envp_ext) {
	251	for (i = 0; envp_ext[i]; i++) {
c65b9145	252	retval = add_uevent_var(env, "%s", envp_ext[i]);
7eff2e7a KS	253	if (retval)
	254	goto exit;
	255	}
	256	}
1da177e4	257
5f123fbd	258	/* let the kset specific function add its stuff */
312c004d	259	if (uevent_ops && uevent_ops->uevent) {
7eff2e7a	260	retval = uevent_ops->uevent(kset, kobj, env);
1da177e4	261	if (retval) {
9f66fa2a GKH	262	pr_debug("kobject: '%s' (%p): %s: uevent() returned "
9f66fa2a GKH	263	"%d\n", kobject_name(kobj), kobj,
810304db	264	__func__, retval);
1da177e4 LT	265	goto exit;
	266	}
	267	}
	268
0f4dafc0 KS	269	/*
	270	* Mark "add" and "remove" events in the object to ensure proper
	271	* events to userspace during automatic cleanup. If the object did
	272	* send an "add" event, "remove" will automatically generated by
	273	* the core, if not already done by the caller.
	274	*/
	275	if (action == KOBJ_ADD)
	276	kobj->state_add_uevent_sent = 1;
	277	else if (action == KOBJ_REMOVE)
	278	kobj->state_remove_uevent_sent = 1;
	279
7b60a18d	280	mutex_lock(&uevent_sock_mutex);
7eff2e7a	281	/* we will send an event, so request a new sequence number */
7b60a18d AV	282	retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)++uevent_seqnum);
	283	if (retval) {
	284	mutex_unlock(&uevent_sock_mutex);
7eff2e7a	285	goto exit;
7b60a18d	286	}
1da177e4	287
4d17ffda	288	#if defined(CONFIG_NET)
5f123fbd	289	/* send netlink message */
07e98962 EB	290	list_for_each_entry(ue_sk, &uevent_sock_list, list) {
07e98962 EB	291	struct sock *uevent_sock = ue_sk->sk;
5f123fbd KS	292	struct sk_buff *skb;
	293	size_t len;
	294
74099b18 KS	295	if (!netlink_has_listeners(uevent_sock, 1))
	296	continue;
	297
5f123fbd KS	298	/* allocate message with the maximum possible size */
5f123fbd KS	299	len = strlen(action_string) + strlen(devpath) + 2;
7eff2e7a	300	skb = alloc_skb(len + env->buflen, GFP_KERNEL);
5f123fbd	301	if (skb) {
7eff2e7a KS	302	char *scratch;
7eff2e7a KS	303
5f123fbd KS	304	/* add header */
	305	scratch = skb_put(skb, len);
	306	sprintf(scratch, "%s@%s", action_string, devpath);
	307
	308	/* copy keys to our continuous event payload buffer */
7eff2e7a KS	309	for (i = 0; i < env->envp_idx; i++) {
7eff2e7a KS	310	len = strlen(env->envp[i]) + 1;
5f123fbd	311	scratch = skb_put(skb, len);
7eff2e7a	312	strcpy(scratch, env->envp[i]);
5f123fbd KS	313	}
	314
	315	NETLINK_CB(skb).dst_group = 1;
5f71a296 EB	316	retval = netlink_broadcast_filtered(uevent_sock, skb,
	317	0, 1, GFP_KERNEL,
	318	kobj_bcast_filter,
	319	kobj);
ff491a73	320	/* ENOBUFS should be handled in userspace */
ebf4127c	321	if (retval == -ENOBUFS \|\| retval == -ESRCH)
ff491a73	322	retval = 0;
e0d7bf5d ML	323	} else
e0d7bf5d ML	324	retval = -ENOMEM;
5f123fbd	325	}
4d17ffda	326	#endif
7b60a18d	327	mutex_unlock(&uevent_sock_mutex);
1da177e4	328
86d56134	329	#ifdef CONFIG_UEVENT_HELPER
5f123fbd	330	/* call uevent_helper, usually only enabled during early boot */
417daa1e	331	if (uevent_helper[0] && !kobj_usermode_filter(kobj)) {
bcccff93	332	struct subprocess_info *info;
1da177e4	333
7eff2e7a KS	334	retval = add_uevent_var(env, "HOME=/");
	335	if (retval)
	336	goto exit;
e374a2bf GKH	337	retval = add_uevent_var(env,
e374a2bf GKH	338	"PATH=/sbin:/bin:/usr/sbin:/usr/bin");
7eff2e7a KS	339	if (retval)
7eff2e7a KS	340	goto exit;
bcccff93 VD	341	retval = init_uevent_argv(env, subsystem);
	342	if (retval)
	343	goto exit;
7eff2e7a	344
bcccff93 VD	345	retval = -ENOMEM;
	346	info = call_usermodehelper_setup(env->argv[0], env->argv,
	347	env->envp, GFP_KERNEL,
	348	NULL, cleanup_uevent_env, env);
	349	if (info) {
	350	retval = call_usermodehelper_exec(info, UMH_NO_WAIT);
	351	env = NULL; /* freed by cleanup_uevent_env */
	352	}
5f123fbd	353	}
86d56134	354	#endif
1da177e4 LT	355
1da177e4 LT	356	exit:
5f123fbd	357	kfree(devpath);
7eff2e7a	358	kfree(env);
542cfce6	359	return retval;
1da177e4	360	}
8a82472f CH	361	EXPORT_SYMBOL_GPL(kobject_uevent_env);
	362
	363	/**
f6e6e779	364	* kobject_uevent - notify userspace by sending an uevent
8a82472f	365	*
ccd490a3	366	* @action: action that is happening
8a82472f	367	* @kobj: struct kobject that the action is happening to
542cfce6 AK	368	*
	369	* Returns 0 if kobject_uevent() is completed with success or the
	370	* corresponding error when it fails.
8a82472f	371	*/
542cfce6	372	int kobject_uevent(struct kobject *kobj, enum kobject_action action)
8a82472f	373	{
542cfce6	374	return kobject_uevent_env(kobj, action, NULL);
8a82472f	375	}
312c004d	376	EXPORT_SYMBOL_GPL(kobject_uevent);
1da177e4 LT	377
1da177e4 LT	378	/**
7eff2e7a KS	379	* add_uevent_var - add key value string to the environment buffer
	380	* @env: environment buffer structure
	381	* @format: printf format for the key=value pair
1da177e4 LT	382	*
	383	* Returns 0 if environment variable was added successfully or -ENOMEM
	384	* if no space was available.
	385	*/
7eff2e7a	386	int add_uevent_var(struct kobj_uevent_env env, const char format, ...)
1da177e4 LT	387	{
1da177e4 LT	388	va_list args;
7eff2e7a	389	int len;
1da177e4	390
7eff2e7a	391	if (env->envp_idx >= ARRAY_SIZE(env->envp)) {
5cd2b459	392	WARN(1, KERN_ERR "add_uevent_var: too many keys\n");
1da177e4	393	return -ENOMEM;
7eff2e7a	394	}
1da177e4 LT	395
1da177e4 LT	396	va_start(args, format);
7eff2e7a KS	397	len = vsnprintf(&env->buf[env->buflen],
	398	sizeof(env->buf) - env->buflen,
	399	format, args);
1da177e4 LT	400	va_end(args);
1da177e4 LT	401
7eff2e7a	402	if (len >= (sizeof(env->buf) - env->buflen)) {
5cd2b459	403	WARN(1, KERN_ERR "add_uevent_var: buffer size too small\n");
1da177e4	404	return -ENOMEM;
7eff2e7a	405	}
1da177e4	406
7eff2e7a KS	407	env->envp[env->envp_idx++] = &env->buf[env->buflen];
7eff2e7a KS	408	env->buflen += len + 1;
1da177e4 LT	409	return 0;
1da177e4 LT	410	}
312c004d	411	EXPORT_SYMBOL_GPL(add_uevent_var);
1da177e4	412
4d17ffda	413	#if defined(CONFIG_NET)
07e98962	414	static int uevent_net_init(struct net *net)
5f123fbd	415	{
07e98962	416	struct uevent_sock *ue_sk;
a31f2d17 PNA	417	struct netlink_kernel_cfg cfg = {
a31f2d17 PNA	418	.groups = 1,
9785e10a	419	.flags = NL_CFG_F_NONROOT_RECV,
a31f2d17	420	};
07e98962 EB	421
	422	ue_sk = kzalloc(sizeof(*ue_sk), GFP_KERNEL);
	423	if (!ue_sk)
	424	return -ENOMEM;
	425
9f00d977	426	ue_sk->sk = netlink_kernel_create(net, NETLINK_KOBJECT_UEVENT, &cfg);
07e98962	427	if (!ue_sk->sk) {
5f123fbd KS	428	printk(KERN_ERR
5f123fbd KS	429	"kobject_uevent: unable to create netlink socket!\n");
743db2d9	430	kfree(ue_sk);
5f123fbd KS	431	return -ENODEV;
5f123fbd KS	432	}
07e98962 EB	433	mutex_lock(&uevent_sock_mutex);
	434	list_add_tail(&ue_sk->list, &uevent_sock_list);
	435	mutex_unlock(&uevent_sock_mutex);
5f123fbd KS	436	return 0;
	437	}
	438
07e98962 EB	439	static void uevent_net_exit(struct net *net)
	440	{
	441	struct uevent_sock *ue_sk;
	442
	443	mutex_lock(&uevent_sock_mutex);
	444	list_for_each_entry(ue_sk, &uevent_sock_list, list) {
	445	if (sock_net(ue_sk->sk) == net)
	446	goto found;
	447	}
	448	mutex_unlock(&uevent_sock_mutex);
	449	return;
	450
	451	found:
	452	list_del(&ue_sk->list);
	453	mutex_unlock(&uevent_sock_mutex);
	454
	455	netlink_kernel_release(ue_sk->sk);
	456	kfree(ue_sk);
	457	}
	458
	459	static struct pernet_operations uevent_net_ops = {
	460	.init = uevent_net_init,
	461	.exit = uevent_net_exit,
	462	};
	463
	464	static int __init kobject_uevent_init(void)
	465	{
07e98962 EB	466	return register_pernet_subsys(&uevent_net_ops);
	467	}
	468
	469
5f123fbd	470	postcore_initcall(kobject_uevent_init);
4d17ffda	471	#endif