[mirror_ubuntu-zesty-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/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;
static DEFINE_SPINLOCK(sequence_lock);
#ifdef CONFIG_NET
struct uevent_sock {
	struct list_head list;
	struct sock *sk;
};
static LIST_HEAD(uevent_sock_list);
static DEFINE_MUTEX(uevent_sock_mutex);
#endif

/* the strings here must match the enum in include/linux/kobject.h */
static const char *kobject_actions[] = {
	[KOBJ_ADD] =		"add",
	[KOBJ_REMOVE] =		"remove",
	[KOBJ_CHANGE] =		"change",
	[KOBJ_MOVE] =		"move",
	[KOBJ_ONLINE] =		"online",
	[KOBJ_OFFLINE] =	"offline",
};

/**
 * kobject_action_type - translate action string to numeric type
 *
 * @buf: buffer containing the action string, newline is ignored
 * @len: length of buffer
 * @type: pointer to the location to store the action type
 *
 * Returns 0 if the action string was recognized.
 */
int kobject_action_type(const char *buf, size_t count,
			enum kobject_action *type)
{
	enum kobject_action action;
	int ret = -EINVAL;

	if (count && (buf[count-1] == '\n' || buf[count-1] == '\0'))
		count--;

	if (!count)
		goto out;

	for (action = 0; action < ARRAY_SIZE(kobject_actions); action++) {
		if (strncmp(kobject_actions[action], buf, count) != 0)
			continue;
		if (kobject_actions[action][count] != '\0')
			continue;
		*type = action;
		ret = 0;
		break;
	}
out:
	return ret;
}

#ifdef CONFIG_NET
static int kobj_bcast_filter(struct sock *dsk, struct sk_buff *skb, void *data)
{
	struct kobject *kobj = data;
	const struct kobj_ns_type_operations *ops;

	ops = kobj_ns_ops(kobj);
	if (ops) {
		const void *sock_ns, *ns;
		ns = kobj->ktype->namespace(kobj);
		sock_ns = ops->netlink_ns(dsk);
		return sock_ns != ns;
	}

	return 0;
}
#endif

static int kobj_usermode_filter(struct kobject *kobj)
{
	const struct kobj_ns_type_operations *ops;

	ops = kobj_ns_ops(kobj);
	if (ops) {
		const void *init_ns, *ns;
		ns = kobj->ktype->namespace(kobj);
		init_ns = ops->initial_ns();
		return ns != init_ns;
	}

	return 0;
}

/**
 * kobject_uevent_env - send an uevent with environmental data
 *
 * @action: action that is happening
 * @kobj: struct kobject that the action is happening to
 * @envp_ext: pointer to environmental data
 *
 * Returns 0 if kobject_uevent_env() is completed with success or the
 * corresponding error when it fails.
 */
int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
		       char *envp_ext[])
{
	struct kobj_uevent_env *env;
	const char *action_string = kobject_actions[action];
	const char *devpath = NULL;
	const char *subsystem;
	struct kobject *top_kobj;
	struct kset *kset;
	const struct kset_uevent_ops *uevent_ops;
	u64 seq;
	int i = 0;
	int retval = 0;
#ifdef CONFIG_NET
	struct uevent_sock *ue_sk;
#endif

	pr_debug("kobject: '%s' (%p): %s\n",
		 kobject_name(kobj), kobj, __func__);

	/* search the kset we belong to */
	top_kobj = kobj;
	while (!top_kobj->kset && top_kobj->parent)
		top_kobj = top_kobj->parent;

	if (!top_kobj->kset) {
		pr_debug("kobject: '%s' (%p): %s: attempted to send uevent "
			 "without kset!\n", kobject_name(kobj), kobj,
			 __func__);
		return -EINVAL;
	}

	kset = top_kobj->kset;
	uevent_ops = kset->uevent_ops;

	/* skip the event, if uevent_suppress is set*/
	if (kobj->uevent_suppress) {
		pr_debug("kobject: '%s' (%p): %s: uevent_suppress "
				 "caused the event to drop!\n",
				 kobject_name(kobj), kobj, __func__);
		return 0;
	}
	/* skip the event, if the filter returns zero. */
	if (uevent_ops && uevent_ops->filter)
		if (!uevent_ops->filter(kset, kobj)) {
			pr_debug("kobject: '%s' (%p): %s: filter function "
				 "caused the event to drop!\n",
				 kobject_name(kobj), kobj, __func__);
			return 0;
		}

	/* originating subsystem */
	if (uevent_ops && uevent_ops->name)
		subsystem = uevent_ops->name(kset, kobj);
	else
		subsystem = kobject_name(&kset->kobj);
	if (!subsystem) {
		pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the "
			 "event to drop!\n", kobject_name(kobj), kobj,
			 __func__);
		return 0;
	}

	/* environment buffer */
	env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
	if (!env)
		return -ENOMEM;

	/* complete object path */
	devpath = kobject_get_path(kobj, GFP_KERNEL);
	if (!devpath) {
		retval = -ENOENT;
		goto exit;
	}

	/* default keys */
	retval = add_uevent_var(env, "ACTION=%s", action_string);
	if (retval)
		goto exit;
	retval = add_uevent_var(env, "DEVPATH=%s", devpath);
	if (retval)
		goto exit;
	retval = add_uevent_var(env, "SUBSYSTEM=%s", subsystem);
	if (retval)
		goto exit;

	/* keys passed in from the caller */
	if (envp_ext) {
		for (i = 0; envp_ext[i]; i++) {
			retval = add_uevent_var(env, "%s", envp_ext[i]);
			if (retval)
				goto exit;
		}
	}

	/* let the kset specific function add its stuff */
	if (uevent_ops && uevent_ops->uevent) {
		retval = uevent_ops->uevent(kset, kobj, env);
		if (retval) {
			pr_debug("kobject: '%s' (%p): %s: uevent() returned "
				 "%d\n", kobject_name(kobj), kobj,
				 __func__, retval);
			goto exit;
		}
	}

	/*
	 * Mark "add" and "remove" events in the object to ensure proper
	 * events to userspace during automatic cleanup. If the object did
	 * send an "add" event, "remove" will automatically generated by
	 * the core, if not already done by the caller.
	 */
	if (action == KOBJ_ADD)
		kobj->state_add_uevent_sent = 1;
	else if (action == KOBJ_REMOVE)
		kobj->state_remove_uevent_sent = 1;

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

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

		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;
	}
	mutex_unlock(&uevent_sock_mutex);
#endif

	/* call uevent_helper, usually only enabled during early boot */
	if (uevent_helper[0] && !kobj_usermode_filter(kobj)) {
		char *argv [3];

		argv [0] = uevent_helper;
		argv [1] = (char *)subsystem;
		argv [2] = NULL;
		retval = add_uevent_var(env, "HOME=/");
		if (retval)
			goto exit;
		retval = add_uevent_var(env,
					"PATH=/sbin:/bin:/usr/sbin:/usr/bin");
		if (retval)
			goto exit;

		retval = call_usermodehelper(argv[0], argv,
					     env->envp, UMH_WAIT_EXEC);
	}

exit:
	kfree(devpath);
	kfree(env);
	return retval;
}
EXPORT_SYMBOL_GPL(kobject_uevent_env);

/**
 * kobject_uevent - notify userspace by sending an uevent
 *
 * @action: action that is happening
 * @kobj: struct kobject that the action is happening to
 *
 * Returns 0 if kobject_uevent() is completed with success or the
 * corresponding error when it fails.
 */
int kobject_uevent(struct kobject *kobj, enum kobject_action action)
{
	return kobject_uevent_env(kobj, action, NULL);
}
EXPORT_SYMBOL_GPL(kobject_uevent);

/**
 * add_uevent_var - add key value string to the environment buffer
 * @env: environment buffer structure
 * @format: printf format for the key=value pair
 *
 * Returns 0 if environment variable was added successfully or -ENOMEM
 * if no space was available.
 */
int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
{
	va_list args;
	int len;

	if (env->envp_idx >= ARRAY_SIZE(env->envp)) {
		WARN(1, KERN_ERR "add_uevent_var: too many keys\n");
		return -ENOMEM;
	}

	va_start(args, format);
	len = vsnprintf(&env->buf[env->buflen],
			sizeof(env->buf) - env->buflen,
			format, args);
	va_end(args);

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

	env->envp[env->envp_idx++] = &env->buf[env->buflen];
	env->buflen += len + 1;
	return 0;
}
EXPORT_SYMBOL_GPL(add_uevent_var);

#if defined(CONFIG_NET)
static int uevent_net_init(struct net *net)
{
	struct uevent_sock *ue_sk;

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

	ue_sk->sk = netlink_kernel_create(net, NETLINK_KOBJECT_UEVENT,
					  1, NULL, NULL, THIS_MODULE);
	if (!ue_sk->sk) {
		printk(KERN_ERR
		       "kobject_uevent: unable to create netlink socket!\n");
		kfree(ue_sk);
		return -ENODEV;
	}
	mutex_lock(&uevent_sock_mutex);
	list_add_tail(&ue_sk->list, &uevent_sock_list);
	mutex_unlock(&uevent_sock_mutex);
	return 0;
}

static void uevent_net_exit(struct net *net)
{
	struct uevent_sock *ue_sk;

	mutex_lock(&uevent_sock_mutex);
	list_for_each_entry(ue_sk, &uevent_sock_list, list) {
		if (sock_net(ue_sk->sk) == net)
			goto found;
	}
	mutex_unlock(&uevent_sock_mutex);
	return;

found:
	list_del(&ue_sk->list);
	mutex_unlock(&uevent_sock_mutex);

	netlink_kernel_release(ue_sk->sk);
	kfree(ue_sk);
}

static struct pernet_operations uevent_net_ops = {
	.init	= uevent_net_init,
	.exit	= uevent_net_exit,
};

static int __init kobject_uevent_init(void)
{
	netlink_set_nonroot(NETLINK_KOBJECT_UEVENT, NL_NONROOT_RECV);
	return register_pernet_subsys(&uevent_net_ops);
}


postcore_initcall(kobject_uevent_init);
#endif
Commit	Line	Data
1da177e4 LT	1	/*
	2	* kernel userspace event delivery
	3	*
	4	* Copyright (C) 2004 Red Hat, Inc. All rights reserved.
	5	* Copyright (C) 2004 Novell, Inc. All rights reserved.
	6	* Copyright (C) 2004 IBM, Inc. All rights reserved.
	7	*
	8	* Licensed under the GNU GPL v2.
	9	*
	10	* Authors:
	11	* Robert Love <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;
6a8d8abb	32	char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH;
cd030c4c	33	static DEFINE_SPINLOCK(sequence_lock);
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);
	40	static DEFINE_MUTEX(uevent_sock_mutex);
cd030c4c CH	41	#endif
cd030c4c CH	42
5c5daf65 KS	43	/* the strings here must match the enum in include/linux/kobject.h */
	44	static const char *kobject_actions[] = {
	45	[KOBJ_ADD] = "add",
	46	[KOBJ_REMOVE] = "remove",
	47	[KOBJ_CHANGE] = "change",
	48	[KOBJ_MOVE] = "move",
	49	[KOBJ_ONLINE] = "online",
	50	[KOBJ_OFFLINE] = "offline",
	51	};
	52
	53	/**
	54	* kobject_action_type - translate action string to numeric type
	55	*
	56	* @buf: buffer containing the action string, newline is ignored
	57	* @len: length of buffer
	58	* @type: pointer to the location to store the action type
	59	*
	60	* Returns 0 if the action string was recognized.
	61	*/
	62	int kobject_action_type(const char *buf, size_t count,
	63	enum kobject_action *type)
	64	{
	65	enum kobject_action action;
	66	int ret = -EINVAL;
	67
a9edadbf	68	if (count && (buf[count-1] == '\n' \|\| buf[count-1] == '\0'))
5c5daf65 KS	69	count--;
	70
	71	if (!count)
	72	goto out;
	73
	74	for (action = 0; action < ARRAY_SIZE(kobject_actions); action++) {
	75	if (strncmp(kobject_actions[action], buf, count) != 0)
	76	continue;
	77	if (kobject_actions[action][count] != '\0')
	78	continue;
	79	*type = action;
	80	ret = 0;
	81	break;
	82	}
	83	out:
	84	return ret;
	85	}
	86
c8421286	87	#ifdef CONFIG_NET
5f71a296 EB	88	static int kobj_bcast_filter(struct sock dsk, struct sk_buff skb, void *data)
	89	{
	90	struct kobject *kobj = data;
	91	const struct kobj_ns_type_operations *ops;
	92
	93	ops = kobj_ns_ops(kobj);
	94	if (ops) {
	95	const void sock_ns, ns;
	96	ns = kobj->ktype->namespace(kobj);
	97	sock_ns = ops->netlink_ns(dsk);
	98	return sock_ns != ns;
	99	}
	100
	101	return 0;
	102	}
c8421286	103	#endif
5f71a296	104
417daa1e EB	105	static int kobj_usermode_filter(struct kobject *kobj)
	106	{
	107	const struct kobj_ns_type_operations *ops;
	108
	109	ops = kobj_ns_ops(kobj);
	110	if (ops) {
	111	const void init_ns, ns;
	112	ns = kobj->ktype->namespace(kobj);
	113	init_ns = ops->initial_ns();
	114	return ns != init_ns;
	115	}
	116
	117	return 0;
	118	}
	119
1da177e4	120	/**
8a82472f	121	* kobject_uevent_env - send an uevent with environmental data
1da177e4	122	*
ccd490a3	123	* @action: action that is happening
1da177e4	124	* @kobj: struct kobject that the action is happening to
8a82472f	125	* @envp_ext: pointer to environmental data
542cfce6	126	*
f6e6e779	127	* Returns 0 if kobject_uevent_env() is completed with success or the
542cfce6	128	* corresponding error when it fails.
1da177e4	129	*/
542cfce6	130	int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
7eff2e7a	131	char *envp_ext[])
1da177e4	132	{
7eff2e7a KS	133	struct kobj_uevent_env *env;
7eff2e7a KS	134	const char *action_string = kobject_actions[action];
5f123fbd KS	135	const char *devpath = NULL;
	136	const char *subsystem;
	137	struct kobject *top_kobj;
	138	struct kset *kset;
9cd43611	139	const struct kset_uevent_ops *uevent_ops;
5f123fbd	140	u64 seq;
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
7eff2e7a	247	/* we will send an event, so request a new sequence number */
1da177e4	248	spin_lock(&sequence_lock);
312c004d	249	seq = ++uevent_seqnum;
1da177e4	250	spin_unlock(&sequence_lock);
7eff2e7a KS	251	retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)seq);
	252	if (retval)
	253	goto exit;
1da177e4	254
4d17ffda	255	#if defined(CONFIG_NET)
5f123fbd	256	/* send netlink message */
07e98962 EB	257	mutex_lock(&uevent_sock_mutex);
	258	list_for_each_entry(ue_sk, &uevent_sock_list, list) {
	259	struct sock *uevent_sock = ue_sk->sk;
5f123fbd KS	260	struct sk_buff *skb;
	261	size_t len;
	262
74099b18 KS	263	if (!netlink_has_listeners(uevent_sock, 1))
	264	continue;
	265
5f123fbd KS	266	/* allocate message with the maximum possible size */
5f123fbd KS	267	len = strlen(action_string) + strlen(devpath) + 2;
7eff2e7a	268	skb = alloc_skb(len + env->buflen, GFP_KERNEL);
5f123fbd	269	if (skb) {
7eff2e7a KS	270	char *scratch;
7eff2e7a KS	271
5f123fbd KS	272	/* add header */
	273	scratch = skb_put(skb, len);
	274	sprintf(scratch, "%s@%s", action_string, devpath);
	275
	276	/* copy keys to our continuous event payload buffer */
7eff2e7a KS	277	for (i = 0; i < env->envp_idx; i++) {
7eff2e7a KS	278	len = strlen(env->envp[i]) + 1;
5f123fbd	279	scratch = skb_put(skb, len);
7eff2e7a	280	strcpy(scratch, env->envp[i]);
5f123fbd KS	281	}
	282
	283	NETLINK_CB(skb).dst_group = 1;
5f71a296 EB	284	retval = netlink_broadcast_filtered(uevent_sock, skb,
	285	0, 1, GFP_KERNEL,
	286	kobj_bcast_filter,
	287	kobj);
ff491a73	288	/* ENOBUFS should be handled in userspace */
ebf4127c	289	if (retval == -ENOBUFS \|\| retval == -ESRCH)
ff491a73	290	retval = 0;
e0d7bf5d ML	291	} else
e0d7bf5d ML	292	retval = -ENOMEM;
5f123fbd	293	}
07e98962	294	mutex_unlock(&uevent_sock_mutex);
4d17ffda	295	#endif
1da177e4	296
5f123fbd	297	/* call uevent_helper, usually only enabled during early boot */
417daa1e	298	if (uevent_helper[0] && !kobj_usermode_filter(kobj)) {
5f123fbd	299	char *argv [3];
1da177e4	300
312c004d	301	argv [0] = uevent_helper;
5f123fbd KS	302	argv [1] = (char *)subsystem;
5f123fbd KS	303	argv [2] = NULL;
7eff2e7a KS	304	retval = add_uevent_var(env, "HOME=/");
	305	if (retval)
	306	goto exit;
e374a2bf GKH	307	retval = add_uevent_var(env,
e374a2bf GKH	308	"PATH=/sbin:/bin:/usr/sbin:/usr/bin");
7eff2e7a KS	309	if (retval)
	310	goto exit;
	311
0ad1d6f3	312	retval = call_usermodehelper(argv[0], argv,
05f54c13	313	env->envp, UMH_WAIT_EXEC);
5f123fbd	314	}
1da177e4 LT	315
1da177e4 LT	316	exit:
5f123fbd	317	kfree(devpath);
7eff2e7a	318	kfree(env);
542cfce6	319	return retval;
1da177e4	320	}
8a82472f CH	321	EXPORT_SYMBOL_GPL(kobject_uevent_env);
	322
	323	/**
f6e6e779	324	* kobject_uevent - notify userspace by sending an uevent
8a82472f	325	*
ccd490a3	326	* @action: action that is happening
8a82472f	327	* @kobj: struct kobject that the action is happening to
542cfce6 AK	328	*
	329	* Returns 0 if kobject_uevent() is completed with success or the
	330	* corresponding error when it fails.
8a82472f	331	*/
542cfce6	332	int kobject_uevent(struct kobject *kobj, enum kobject_action action)
8a82472f	333	{
542cfce6	334	return kobject_uevent_env(kobj, action, NULL);
8a82472f	335	}
312c004d	336	EXPORT_SYMBOL_GPL(kobject_uevent);
1da177e4 LT	337
1da177e4 LT	338	/**
7eff2e7a KS	339	* add_uevent_var - add key value string to the environment buffer
	340	* @env: environment buffer structure
	341	* @format: printf format for the key=value pair
1da177e4 LT	342	*
	343	* Returns 0 if environment variable was added successfully or -ENOMEM
	344	* if no space was available.
	345	*/
7eff2e7a	346	int add_uevent_var(struct kobj_uevent_env env, const char format, ...)
1da177e4 LT	347	{
1da177e4 LT	348	va_list args;
7eff2e7a	349	int len;
1da177e4	350
7eff2e7a	351	if (env->envp_idx >= ARRAY_SIZE(env->envp)) {
5cd2b459	352	WARN(1, KERN_ERR "add_uevent_var: too many keys\n");
1da177e4	353	return -ENOMEM;
7eff2e7a	354	}
1da177e4 LT	355
1da177e4 LT	356	va_start(args, format);
7eff2e7a KS	357	len = vsnprintf(&env->buf[env->buflen],
	358	sizeof(env->buf) - env->buflen,
	359	format, args);
1da177e4 LT	360	va_end(args);
1da177e4 LT	361
7eff2e7a	362	if (len >= (sizeof(env->buf) - env->buflen)) {
5cd2b459	363	WARN(1, KERN_ERR "add_uevent_var: buffer size too small\n");
1da177e4	364	return -ENOMEM;
7eff2e7a	365	}
1da177e4	366
7eff2e7a KS	367	env->envp[env->envp_idx++] = &env->buf[env->buflen];
7eff2e7a KS	368	env->buflen += len + 1;
1da177e4 LT	369	return 0;
1da177e4 LT	370	}
312c004d	371	EXPORT_SYMBOL_GPL(add_uevent_var);
1da177e4	372
4d17ffda	373	#if defined(CONFIG_NET)
07e98962	374	static int uevent_net_init(struct net *net)
5f123fbd	375	{
07e98962 EB	376	struct uevent_sock *ue_sk;
	377
	378	ue_sk = kzalloc(sizeof(*ue_sk), GFP_KERNEL);
	379	if (!ue_sk)
	380	return -ENOMEM;
	381
	382	ue_sk->sk = netlink_kernel_create(net, NETLINK_KOBJECT_UEVENT,
	383	1, NULL, NULL, THIS_MODULE);
	384	if (!ue_sk->sk) {
5f123fbd KS	385	printk(KERN_ERR
5f123fbd KS	386	"kobject_uevent: unable to create netlink socket!\n");
743db2d9	387	kfree(ue_sk);
5f123fbd KS	388	return -ENODEV;
5f123fbd KS	389	}
07e98962 EB	390	mutex_lock(&uevent_sock_mutex);
	391	list_add_tail(&ue_sk->list, &uevent_sock_list);
	392	mutex_unlock(&uevent_sock_mutex);
5f123fbd KS	393	return 0;
	394	}
	395
07e98962 EB	396	static void uevent_net_exit(struct net *net)
	397	{
	398	struct uevent_sock *ue_sk;
	399
	400	mutex_lock(&uevent_sock_mutex);
	401	list_for_each_entry(ue_sk, &uevent_sock_list, list) {
	402	if (sock_net(ue_sk->sk) == net)
	403	goto found;
	404	}
	405	mutex_unlock(&uevent_sock_mutex);
	406	return;
	407
	408	found:
	409	list_del(&ue_sk->list);
	410	mutex_unlock(&uevent_sock_mutex);
	411
	412	netlink_kernel_release(ue_sk->sk);
	413	kfree(ue_sk);
	414	}
	415
	416	static struct pernet_operations uevent_net_ops = {
	417	.init = uevent_net_init,
	418	.exit = uevent_net_exit,
	419	};
	420
	421	static int __init kobject_uevent_init(void)
	422	{
	423	netlink_set_nonroot(NETLINK_KOBJECT_UEVENT, NL_NONROOT_RECV);
	424	return register_pernet_subsys(&uevent_net_ops);
	425	}
	426
	427
5f123fbd	428	postcore_initcall(kobject_uevent_init);
4d17ffda	429	#endif