[mirror_ubuntu-artful-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/socket.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
#include <linux/uuid.h>
#include <linux/ctype.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",
};

static int kobject_action_type(const char *buf, size_t count,
			       enum kobject_action *type,
			       const char **args)
{
	enum kobject_action action;
	size_t count_first;
	const char *args_start;
	int ret = -EINVAL;

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

	if (!count)
		goto out;

	args_start = strnchr(buf, count, ' ');
	if (args_start) {
		count_first = args_start - buf;
		args_start = args_start + 1;
	} else
		count_first = count;

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

static const char *action_arg_word_end(const char *buf, const char *buf_end,
				       char delim)
{
	const char *next = buf;

	while (next <= buf_end && *next != delim)
		if (!isalnum(*next++))
			return NULL;

	if (next == buf)
		return NULL;

	return next;
}

static int kobject_action_args(const char *buf, size_t count,
			       struct kobj_uevent_env **ret_env)
{
	struct kobj_uevent_env *env = NULL;
	const char *next, *buf_end, *key;
	int key_len;
	int r = -EINVAL;

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

	if (!count)
		return -EINVAL;

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

	/* first arg is UUID */
	if (count < UUID_STRING_LEN || !uuid_is_valid(buf) ||
	    add_uevent_var(env, "SYNTH_UUID=%.*s", UUID_STRING_LEN, buf))
		goto out;

	/*
	 * the rest are custom environment variables in KEY=VALUE
	 * format with ' ' delimiter between each KEY=VALUE pair
	 */
	next = buf + UUID_STRING_LEN;
	buf_end = buf + count - 1;

	while (next <= buf_end) {
		if (*next != ' ')
			goto out;

		/* skip the ' ', key must follow */
		key = ++next;
		if (key > buf_end)
			goto out;

		buf = next;
		next = action_arg_word_end(buf, buf_end, '=');
		if (!next || next > buf_end || *next != '=')
			goto out;
		key_len = next - buf;

		/* skip the '=', value must follow */
		if (++next > buf_end)
			goto out;

		buf = next;
		next = action_arg_word_end(buf, buf_end, ' ');
		if (!next)
			goto out;

		if (add_uevent_var(env, "SYNTH_ARG_%.*s=%.*s",
				   key_len, key, (int) (next - buf), buf))
			goto out;
	}

	r = 0;
out:
	if (r)
		kfree(env);
	else
		*ret_env = env;
	return r;
}

/**
 * kobject_synth_uevent - send synthetic uevent with arguments
 *
 * @kobj: struct kobject for which synthetic uevent is to be generated
 * @buf: buffer containing action type and action args, newline is ignored
 * @count: length of buffer
 *
 * Returns 0 if kobject_synthetic_uevent() is completed with success or the
 * corresponding error when it fails.
 */
int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count)
{
	char *no_uuid_envp[] = { "SYNTH_UUID=0", NULL };
	enum kobject_action action;
	const char *action_args;
	struct kobj_uevent_env *env;
	const char *msg = NULL, *devpath;
	int r;

	r = kobject_action_type(buf, count, &action, &action_args);
	if (r) {
		msg = "unknown uevent action string\n";
		goto out;
	}

	if (!action_args) {
		r = kobject_uevent_env(kobj, action, no_uuid_envp);
		goto out;
	}

	r = kobject_action_args(action_args,
				count - (action_args - buf), &env);
	if (r == -EINVAL) {
		msg = "incorrect uevent action arguments\n";
		goto out;
	}

	if (r)
		goto out;

	r = kobject_uevent_env(kobj, action, env->envp);
	kfree(env);
out:
	if (r) {
		devpath = kobject_get_path(kobj, GFP_KERNEL);
		printk(KERN_WARNING "synth uevent: %s: %s",
		       devpath ?: "unknown device",
		       msg ?: "failed to send uevent");
		kfree(devpath);
	}
	return r;
}

#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
 *
 * @kobj: struct kobject that the action is happening to
 * @action: action that is happening
 * @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
 *
 * @kobj: struct kobject that the action is happening to
 * @action: action that is happening
 *
 * 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>
f36776fa PR	26	#include <linux/uuid.h>
f36776fa PR	27	#include <linux/ctype.h>
1da177e4	28	#include <net/sock.h>
07e98962	29	#include <net/net_namespace.h>
1da177e4	30
1da177e4	31
cd030c4c	32	u64 uevent_seqnum;
86d56134	33	#ifdef CONFIG_UEVENT_HELPER
6a8d8abb	34	char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH;
86d56134	35	#endif
07e98962 EB	36	#ifdef CONFIG_NET
	37	struct uevent_sock {
	38	struct list_head list;
	39	struct sock *sk;
	40	};
	41	static LIST_HEAD(uevent_sock_list);
cd030c4c CH	42	#endif
cd030c4c CH	43
7b60a18d AV	44	/* This lock protects uevent_seqnum and uevent_sock_list */
	45	static DEFINE_MUTEX(uevent_sock_mutex);
	46
5c5daf65 KS	47	/* the strings here must match the enum in include/linux/kobject.h */
	48	static const char *kobject_actions[] = {
	49	[KOBJ_ADD] = "add",
	50	[KOBJ_REMOVE] = "remove",
	51	[KOBJ_CHANGE] = "change",
	52	[KOBJ_MOVE] = "move",
	53	[KOBJ_ONLINE] = "online",
	54	[KOBJ_OFFLINE] = "offline",
	55	};
	56
f36776fa PR	57	static int kobject_action_type(const char *buf, size_t count,
	58	enum kobject_action *type,
	59	const char **args)
5c5daf65 KS	60	{
5c5daf65 KS	61	enum kobject_action action;
f36776fa PR	62	size_t count_first;
f36776fa PR	63	const char *args_start;
5c5daf65 KS	64	int ret = -EINVAL;
5c5daf65 KS	65
a9edadbf	66	if (count && (buf[count-1] == '\n' \|\| buf[count-1] == '\0'))
5c5daf65 KS	67	count--;
	68
	69	if (!count)
	70	goto out;
	71
f36776fa PR	72	args_start = strnchr(buf, count, ' ');
	73	if (args_start) {
	74	count_first = args_start - buf;
	75	args_start = args_start + 1;
	76	} else
	77	count_first = count;
	78
5c5daf65	79	for (action = 0; action < ARRAY_SIZE(kobject_actions); action++) {
f36776fa	80	if (strncmp(kobject_actions[action], buf, count_first) != 0)
5c5daf65	81	continue;
f36776fa	82	if (kobject_actions[action][count_first] != '\0')
5c5daf65	83	continue;
f36776fa PR	84	if (args)
f36776fa PR	85	*args = args_start;
5c5daf65 KS	86	*type = action;
	87	ret = 0;
	88	break;
	89	}
	90	out:
	91	return ret;
	92	}
	93
f36776fa PR	94	static const char action_arg_word_end(const char buf, const char *buf_end,
	95	char delim)
	96	{
	97	const char *next = buf;
	98
	99	while (next <= buf_end && *next != delim)
	100	if (!isalnum(*next++))
	101	return NULL;
	102
	103	if (next == buf)
	104	return NULL;
	105
	106	return next;
	107	}
	108
	109	static int kobject_action_args(const char *buf, size_t count,
	110	struct kobj_uevent_env **ret_env)
	111	{
	112	struct kobj_uevent_env *env = NULL;
	113	const char next, buf_end, *key;
	114	int key_len;
	115	int r = -EINVAL;
	116
	117	if (count && (buf[count - 1] == '\n' \|\| buf[count - 1] == '\0'))
	118	count--;
	119
	120	if (!count)
	121	return -EINVAL;
	122
	123	env = kzalloc(sizeof(*env), GFP_KERNEL);
	124	if (!env)
	125	return -ENOMEM;
	126
	127	/* first arg is UUID */
	128	if (count < UUID_STRING_LEN \|\| !uuid_is_valid(buf) \|\|
	129	add_uevent_var(env, "SYNTH_UUID=%.*s", UUID_STRING_LEN, buf))
	130	goto out;
	131
	132	/*
	133	* the rest are custom environment variables in KEY=VALUE
	134	* format with ' ' delimiter between each KEY=VALUE pair
	135	*/
	136	next = buf + UUID_STRING_LEN;
	137	buf_end = buf + count - 1;
	138
	139	while (next <= buf_end) {
	140	if (*next != ' ')
	141	goto out;
	142
	143	/* skip the ' ', key must follow */
	144	key = ++next;
	145	if (key > buf_end)
	146	goto out;
	147
	148	buf = next;
	149	next = action_arg_word_end(buf, buf_end, '=');
	150	if (!next \|\| next > buf_end \|\| *next != '=')
	151	goto out;
	152	key_len = next - buf;
	153
	154	/* skip the '=', value must follow */
	155	if (++next > buf_end)
	156	goto out;
	157
158	buf = next;
159	next = action_arg_word_end(buf, buf_end, ' ');
160	if (!next)
161	goto out;
162
163	if (add_uevent_var(env, "SYNTH_ARG_%.s=%.s",
164	key_len, key, (int) (next - buf), buf))
165	goto out;
166	}
167
168	r = 0;
169	out:
170	if (r)
171	kfree(env);
172	else
173	*ret_env = env;
174	return r;
175	}
176
177	/**
178	* kobject_synth_uevent - send synthetic uevent with arguments
179	*
180	* @kobj: struct kobject for which synthetic uevent is to be generated
181	* @buf: buffer containing action type and action args, newline is ignored
182	* @count: length of buffer
183	*
184	* Returns 0 if kobject_synthetic_uevent() is completed with success or the
185	* corresponding error when it fails.
186	*/
187	int kobject_synth_uevent(struct kobject kobj, const char buf, size_t count)
188	{
189	char *no_uuid_envp[] = { "SYNTH_UUID=0", NULL };
190	enum kobject_action action;
191	const char *action_args;
192	struct kobj_uevent_env *env;
193	const char msg = NULL, devpath;
194	int r;
195
196	r = kobject_action_type(buf, count, &action, &action_args);
197	if (r) {
198	msg = "unknown uevent action string\n";
199	goto out;
200	}
201
202	if (!action_args) {
203	r = kobject_uevent_env(kobj, action, no_uuid_envp);
204	goto out;
205	}
206
207	r = kobject_action_args(action_args,
208	count - (action_args - buf), &env);
209	if (r == -EINVAL) {
210	msg = "incorrect uevent action arguments\n";
211	goto out;
212	}
213
214	if (r)
215	goto out;
216
217	r = kobject_uevent_env(kobj, action, env->envp);
218	kfree(env);
219	out:
220	if (r) {
221	devpath = kobject_get_path(kobj, GFP_KERNEL);
222	printk(KERN_WARNING "synth uevent: %s: %s",
223	devpath ?: "unknown device",
224	msg ?: "failed to send uevent");
225	kfree(devpath);
226	}
227	return r;
228	}
229
c8421286	230	#ifdef CONFIG_NET
5f71a296 EB	231	static int kobj_bcast_filter(struct sock dsk, struct sk_buff skb, void *data)
5f71a296 EB	232	{
82ef3d5d	233	struct kobject kobj = data, ksobj;
5f71a296 EB	234	const struct kobj_ns_type_operations *ops;
	235
	236	ops = kobj_ns_ops(kobj);
82ef3d5d WC	237	if (!ops && kobj->kset) {
	238	ksobj = &kobj->kset->kobj;
	239	if (ksobj->parent != NULL)
	240	ops = kobj_ns_ops(ksobj->parent);
	241	}
	242
	243	if (ops && ops->netlink_ns && kobj->ktype->namespace) {
5f71a296 EB	244	const void sock_ns, ns;
	245	ns = kobj->ktype->namespace(kobj);
	246	sock_ns = ops->netlink_ns(dsk);
	247	return sock_ns != ns;
	248	}
	249
	250	return 0;
	251	}
c8421286	252	#endif
5f71a296	253
86d56134	254	#ifdef CONFIG_UEVENT_HELPER
417daa1e EB	255	static int kobj_usermode_filter(struct kobject *kobj)
	256	{
	257	const struct kobj_ns_type_operations *ops;
	258
	259	ops = kobj_ns_ops(kobj);
	260	if (ops) {
	261	const void init_ns, ns;
	262	ns = kobj->ktype->namespace(kobj);
	263	init_ns = ops->initial_ns();
	264	return ns != init_ns;
	265	}
	266
	267	return 0;
	268	}
	269
bcccff93 VD	270	static int init_uevent_argv(struct kobj_uevent_env env, const char subsystem)
	271	{
	272	int len;
	273
	274	len = strlcpy(&env->buf[env->buflen], subsystem,
	275	sizeof(env->buf) - env->buflen);
	276	if (len >= (sizeof(env->buf) - env->buflen)) {
	277	WARN(1, KERN_ERR "init_uevent_argv: buffer size too small\n");
	278	return -ENOMEM;
	279	}
	280
	281	env->argv[0] = uevent_helper;
	282	env->argv[1] = &env->buf[env->buflen];
	283	env->argv[2] = NULL;
	284
	285	env->buflen += len + 1;
	286	return 0;
	287	}
	288
	289	static void cleanup_uevent_env(struct subprocess_info *info)
	290	{
	291	kfree(info->data);
	292	}
86d56134	293	#endif
bcccff93	294
1da177e4	295	/**
8a82472f	296	* kobject_uevent_env - send an uevent with environmental data
1da177e4	297	*
1da177e4	298	* @kobj: struct kobject that the action is happening to
edbbf994	299	* @action: action that is happening
8a82472f	300	* @envp_ext: pointer to environmental data
542cfce6	301	*
f6e6e779	302	* Returns 0 if kobject_uevent_env() is completed with success or the
542cfce6	303	* corresponding error when it fails.
1da177e4	304	*/
542cfce6	305	int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
7eff2e7a	306	char *envp_ext[])
1da177e4	307	{
7eff2e7a KS	308	struct kobj_uevent_env *env;
7eff2e7a KS	309	const char *action_string = kobject_actions[action];
5f123fbd KS	310	const char *devpath = NULL;
	311	const char *subsystem;
	312	struct kobject *top_kobj;
	313	struct kset *kset;
9cd43611	314	const struct kset_uevent_ops *uevent_ops;
1da177e4	315	int i = 0;
542cfce6	316	int retval = 0;
07e98962 EB	317	#ifdef CONFIG_NET
	318	struct uevent_sock *ue_sk;
	319	#endif
1da177e4	320
9f66fa2a	321	pr_debug("kobject: '%s' (%p): %s\n",
810304db	322	kobject_name(kobj), kobj, __func__);
5f123fbd	323
5f123fbd KS	324	/* search the kset we belong to */
5f123fbd KS	325	top_kobj = kobj;
ccd490a3	326	while (!top_kobj->kset && top_kobj->parent)
14193fb9	327	top_kobj = top_kobj->parent;
ccd490a3	328
542cfce6	329	if (!top_kobj->kset) {
9f66fa2a GKH	330	pr_debug("kobject: '%s' (%p): %s: attempted to send uevent "
9f66fa2a GKH	331	"without kset!\n", kobject_name(kobj), kobj,
810304db	332	__func__);
542cfce6 AK	333	return -EINVAL;
542cfce6 AK	334	}
1da177e4	335
5f123fbd	336	kset = top_kobj->kset;
312c004d	337	uevent_ops = kset->uevent_ops;
1da177e4	338
f67f129e ML	339	/* skip the event, if uevent_suppress is set*/
	340	if (kobj->uevent_suppress) {
	341	pr_debug("kobject: '%s' (%p): %s: uevent_suppress "
	342	"caused the event to drop!\n",
	343	kobject_name(kobj), kobj, __func__);
	344	return 0;
	345	}
7eff2e7a	346	/* skip the event, if the filter returns zero. */
312c004d	347	if (uevent_ops && uevent_ops->filter)
542cfce6	348	if (!uevent_ops->filter(kset, kobj)) {
9f66fa2a GKH	349	pr_debug("kobject: '%s' (%p): %s: filter function "
9f66fa2a GKH	350	"caused the event to drop!\n",
810304db	351	kobject_name(kobj), kobj, __func__);
542cfce6 AK	352	return 0;
542cfce6 AK	353	}
1da177e4	354
86406245 KS	355	/* originating subsystem */
	356	if (uevent_ops && uevent_ops->name)
	357	subsystem = uevent_ops->name(kset, kobj);
	358	else
	359	subsystem = kobject_name(&kset->kobj);
	360	if (!subsystem) {
9f66fa2a GKH	361	pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the "
9f66fa2a GKH	362	"event to drop!\n", kobject_name(kobj), kobj,
810304db	363	__func__);
86406245 KS	364	return 0;
	365	}
	366
7eff2e7a KS	367	/* environment buffer */
	368	env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
	369	if (!env)
542cfce6	370	return -ENOMEM;
1da177e4	371
5f123fbd KS	372	/* complete object path */
5f123fbd KS	373	devpath = kobject_get_path(kobj, GFP_KERNEL);
542cfce6 AK	374	if (!devpath) {
542cfce6 AK	375	retval = -ENOENT;
5f123fbd	376	goto exit;
542cfce6	377	}
1da177e4	378
5f123fbd	379	/* default keys */
7eff2e7a KS	380	retval = add_uevent_var(env, "ACTION=%s", action_string);
	381	if (retval)
	382	goto exit;
	383	retval = add_uevent_var(env, "DEVPATH=%s", devpath);
	384	if (retval)
	385	goto exit;
	386	retval = add_uevent_var(env, "SUBSYSTEM=%s", subsystem);
	387	if (retval)
	388	goto exit;
	389
	390	/* keys passed in from the caller */
	391	if (envp_ext) {
	392	for (i = 0; envp_ext[i]; i++) {
c65b9145	393	retval = add_uevent_var(env, "%s", envp_ext[i]);
7eff2e7a KS	394	if (retval)
	395	goto exit;
	396	}
	397	}
1da177e4	398
5f123fbd	399	/* let the kset specific function add its stuff */
312c004d	400	if (uevent_ops && uevent_ops->uevent) {
7eff2e7a	401	retval = uevent_ops->uevent(kset, kobj, env);
1da177e4	402	if (retval) {
9f66fa2a GKH	403	pr_debug("kobject: '%s' (%p): %s: uevent() returned "
9f66fa2a GKH	404	"%d\n", kobject_name(kobj), kobj,
810304db	405	__func__, retval);
1da177e4 LT	406	goto exit;
	407	}
	408	}
	409
0f4dafc0 KS	410	/*
	411	* Mark "add" and "remove" events in the object to ensure proper
	412	* events to userspace during automatic cleanup. If the object did
	413	* send an "add" event, "remove" will automatically generated by
	414	* the core, if not already done by the caller.
	415	*/
	416	if (action == KOBJ_ADD)
	417	kobj->state_add_uevent_sent = 1;
	418	else if (action == KOBJ_REMOVE)
	419	kobj->state_remove_uevent_sent = 1;
	420
7b60a18d	421	mutex_lock(&uevent_sock_mutex);
7eff2e7a	422	/* we will send an event, so request a new sequence number */
7b60a18d AV	423	retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)++uevent_seqnum);
	424	if (retval) {
	425	mutex_unlock(&uevent_sock_mutex);
7eff2e7a	426	goto exit;
7b60a18d	427	}
1da177e4	428
4d17ffda	429	#if defined(CONFIG_NET)
5f123fbd	430	/* send netlink message */
07e98962 EB	431	list_for_each_entry(ue_sk, &uevent_sock_list, list) {
07e98962 EB	432	struct sock *uevent_sock = ue_sk->sk;
5f123fbd KS	433	struct sk_buff *skb;
	434	size_t len;
	435
74099b18 KS	436	if (!netlink_has_listeners(uevent_sock, 1))
	437	continue;
	438
5f123fbd KS	439	/* allocate message with the maximum possible size */
5f123fbd KS	440	len = strlen(action_string) + strlen(devpath) + 2;
7eff2e7a	441	skb = alloc_skb(len + env->buflen, GFP_KERNEL);
5f123fbd	442	if (skb) {
7eff2e7a KS	443	char *scratch;
7eff2e7a KS	444
5f123fbd KS	445	/* add header */
	446	scratch = skb_put(skb, len);
	447	sprintf(scratch, "%s@%s", action_string, devpath);
	448
	449	/* copy keys to our continuous event payload buffer */
7eff2e7a KS	450	for (i = 0; i < env->envp_idx; i++) {
7eff2e7a KS	451	len = strlen(env->envp[i]) + 1;
5f123fbd	452	scratch = skb_put(skb, len);
7eff2e7a	453	strcpy(scratch, env->envp[i]);
5f123fbd KS	454	}
	455
	456	NETLINK_CB(skb).dst_group = 1;
5f71a296 EB	457	retval = netlink_broadcast_filtered(uevent_sock, skb,
	458	0, 1, GFP_KERNEL,
	459	kobj_bcast_filter,
	460	kobj);
ff491a73	461	/* ENOBUFS should be handled in userspace */
ebf4127c	462	if (retval == -ENOBUFS \|\| retval == -ESRCH)
ff491a73	463	retval = 0;
e0d7bf5d ML	464	} else
e0d7bf5d ML	465	retval = -ENOMEM;
5f123fbd	466	}
4d17ffda	467	#endif
7b60a18d	468	mutex_unlock(&uevent_sock_mutex);
1da177e4	469
86d56134	470	#ifdef CONFIG_UEVENT_HELPER
5f123fbd	471	/* call uevent_helper, usually only enabled during early boot */
417daa1e	472	if (uevent_helper[0] && !kobj_usermode_filter(kobj)) {
bcccff93	473	struct subprocess_info *info;
1da177e4	474
7eff2e7a KS	475	retval = add_uevent_var(env, "HOME=/");
	476	if (retval)
	477	goto exit;
e374a2bf GKH	478	retval = add_uevent_var(env,
e374a2bf GKH	479	"PATH=/sbin:/bin:/usr/sbin:/usr/bin");
7eff2e7a KS	480	if (retval)
7eff2e7a KS	481	goto exit;
bcccff93 VD	482	retval = init_uevent_argv(env, subsystem);
	483	if (retval)
	484	goto exit;
7eff2e7a	485
bcccff93 VD	486	retval = -ENOMEM;
	487	info = call_usermodehelper_setup(env->argv[0], env->argv,
	488	env->envp, GFP_KERNEL,
	489	NULL, cleanup_uevent_env, env);
	490	if (info) {
	491	retval = call_usermodehelper_exec(info, UMH_NO_WAIT);
	492	env = NULL; /* freed by cleanup_uevent_env */
	493	}
5f123fbd	494	}
86d56134	495	#endif
1da177e4 LT	496
1da177e4 LT	497	exit:
5f123fbd	498	kfree(devpath);
7eff2e7a	499	kfree(env);
542cfce6	500	return retval;
1da177e4	501	}
8a82472f CH	502	EXPORT_SYMBOL_GPL(kobject_uevent_env);
	503
	504	/**
f6e6e779	505	* kobject_uevent - notify userspace by sending an uevent
8a82472f	506	*
8a82472f	507	* @kobj: struct kobject that the action is happening to
edbbf994	508	* @action: action that is happening
542cfce6 AK	509	*
	510	* Returns 0 if kobject_uevent() is completed with success or the
	511	* corresponding error when it fails.
8a82472f	512	*/
542cfce6	513	int kobject_uevent(struct kobject *kobj, enum kobject_action action)
8a82472f	514	{
542cfce6	515	return kobject_uevent_env(kobj, action, NULL);
8a82472f	516	}
312c004d	517	EXPORT_SYMBOL_GPL(kobject_uevent);
1da177e4 LT	518
1da177e4 LT	519	/**
7eff2e7a KS	520	* add_uevent_var - add key value string to the environment buffer
	521	* @env: environment buffer structure
	522	* @format: printf format for the key=value pair
1da177e4 LT	523	*
	524	* Returns 0 if environment variable was added successfully or -ENOMEM
	525	* if no space was available.
	526	*/
7eff2e7a	527	int add_uevent_var(struct kobj_uevent_env env, const char format, ...)
1da177e4 LT	528	{
1da177e4 LT	529	va_list args;
7eff2e7a	530	int len;
1da177e4	531
7eff2e7a	532	if (env->envp_idx >= ARRAY_SIZE(env->envp)) {
5cd2b459	533	WARN(1, KERN_ERR "add_uevent_var: too many keys\n");
1da177e4	534	return -ENOMEM;
7eff2e7a	535	}
1da177e4 LT	536
1da177e4 LT	537	va_start(args, format);
7eff2e7a KS	538	len = vsnprintf(&env->buf[env->buflen],
	539	sizeof(env->buf) - env->buflen,
	540	format, args);
1da177e4 LT	541	va_end(args);
1da177e4 LT	542
7eff2e7a	543	if (len >= (sizeof(env->buf) - env->buflen)) {
5cd2b459	544	WARN(1, KERN_ERR "add_uevent_var: buffer size too small\n");
1da177e4	545	return -ENOMEM;
7eff2e7a	546	}
1da177e4	547
7eff2e7a KS	548	env->envp[env->envp_idx++] = &env->buf[env->buflen];
7eff2e7a KS	549	env->buflen += len + 1;
1da177e4 LT	550	return 0;
1da177e4 LT	551	}
312c004d	552	EXPORT_SYMBOL_GPL(add_uevent_var);
1da177e4	553
4d17ffda	554	#if defined(CONFIG_NET)
07e98962	555	static int uevent_net_init(struct net *net)
5f123fbd	556	{
07e98962	557	struct uevent_sock *ue_sk;
a31f2d17 PNA	558	struct netlink_kernel_cfg cfg = {
a31f2d17 PNA	559	.groups = 1,
9785e10a	560	.flags = NL_CFG_F_NONROOT_RECV,
a31f2d17	561	};
07e98962 EB	562
	563	ue_sk = kzalloc(sizeof(*ue_sk), GFP_KERNEL);
	564	if (!ue_sk)
	565	return -ENOMEM;
	566
9f00d977	567	ue_sk->sk = netlink_kernel_create(net, NETLINK_KOBJECT_UEVENT, &cfg);
07e98962	568	if (!ue_sk->sk) {
5f123fbd KS	569	printk(KERN_ERR
5f123fbd KS	570	"kobject_uevent: unable to create netlink socket!\n");
743db2d9	571	kfree(ue_sk);
5f123fbd KS	572	return -ENODEV;
5f123fbd KS	573	}
07e98962 EB	574	mutex_lock(&uevent_sock_mutex);
	575	list_add_tail(&ue_sk->list, &uevent_sock_list);
	576	mutex_unlock(&uevent_sock_mutex);
5f123fbd KS	577	return 0;
	578	}
	579
07e98962 EB	580	static void uevent_net_exit(struct net *net)
	581	{
	582	struct uevent_sock *ue_sk;
	583
	584	mutex_lock(&uevent_sock_mutex);
	585	list_for_each_entry(ue_sk, &uevent_sock_list, list) {
	586	if (sock_net(ue_sk->sk) == net)
	587	goto found;
	588	}
	589	mutex_unlock(&uevent_sock_mutex);
	590	return;
	591
	592	found:
	593	list_del(&ue_sk->list);
	594	mutex_unlock(&uevent_sock_mutex);
	595
	596	netlink_kernel_release(ue_sk->sk);
	597	kfree(ue_sk);
	598	}
	599
	600	static struct pernet_operations uevent_net_ops = {
	601	.init = uevent_net_init,
	602	.exit = uevent_net_exit,
	603	};
	604
	605	static int __init kobject_uevent_init(void)
	606	{
07e98962 EB	607	return register_pernet_subsys(&uevent_net_ops);
	608	}
	609
	610
5f123fbd	611	postcore_initcall(kobject_uevent_init);
4d17ffda	612	#endif