[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/socket.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
#include <linux/string.h>
#include <linux/kobject.h>
#include <net/sock.h>

#define BUFFER_SIZE	2048	/* buffer for the variables */
#define NUM_ENVP	32	/* number of env pointers */

#if defined(CONFIG_HOTPLUG)
u64 uevent_seqnum;
char uevent_helper[UEVENT_HELPER_PATH_LEN] = "/sbin/hotplug";
static DEFINE_SPINLOCK(sequence_lock);
#if defined(CONFIG_NET)
static struct sock *uevent_sock;
#endif

static char *action_to_string(enum kobject_action action)
{
	switch (action) {
	case KOBJ_ADD:
		return "add";
	case KOBJ_REMOVE:
		return "remove";
	case KOBJ_CHANGE:
		return "change";
	case KOBJ_MOUNT:
		return "mount";
	case KOBJ_UMOUNT:
		return "umount";
	case KOBJ_OFFLINE:
		return "offline";
	case KOBJ_ONLINE:
		return "online";
	case KOBJ_MOVE:
		return "move";
	default:
		return NULL;
	}
}

/**
 * kobject_uevent_env - send an uevent with environmental data
 *
 * @action: action that is happening (usually KOBJ_MOVE)
 * @kobj: struct kobject that the action is happening to
 * @envp_ext: pointer to environmental data
 *
 * Returns 0 if kobject_uevent() 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[])
{
	char **envp;
	char *buffer;
	char *scratch;
	const char *action_string;
	const char *devpath = NULL;
	const char *subsystem;
	struct kobject *top_kobj;
	struct kset *kset;
	struct kset_uevent_ops *uevent_ops;
	u64 seq;
	char *seq_buff;
	int i = 0;
	int retval = 0;
	int j;

	pr_debug("%s\n", __FUNCTION__);

	action_string = action_to_string(action);
	if (!action_string) {
		pr_debug("kobject attempted to send uevent without action_string!\n");
		return -EINVAL;
	}

	/* search the kset we belong to */
	top_kobj = kobj;
	if (!top_kobj->kset && top_kobj->parent) {
		do {
			top_kobj = top_kobj->parent;
		} while (!top_kobj->kset && top_kobj->parent);
	}
	if (!top_kobj->kset) {
		pr_debug("kobject attempted to send uevent without kset!\n");
		return -EINVAL;
	}

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

	/*  skip the event, if the filter returns zero. */
	if (uevent_ops && uevent_ops->filter)
		if (!uevent_ops->filter(kset, kobj)) {
			pr_debug("kobject filter function caused the event to drop!\n");
			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("unset subsytem caused the event to drop!\n");
		return 0;
	}

	/* environment index */
	envp = kzalloc(NUM_ENVP * sizeof (char *), GFP_KERNEL);
	if (!envp)
		return -ENOMEM;

	/* environment values */
	buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL);
	if (!buffer) {
		retval = -ENOMEM;
		goto exit;
	}

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

	/* event environemnt for helper process only */
	envp[i++] = "HOME=/";
	envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";

	/* default keys */
	scratch = buffer;
	envp [i++] = scratch;
	scratch += sprintf(scratch, "ACTION=%s", action_string) + 1;
	envp [i++] = scratch;
	scratch += sprintf (scratch, "DEVPATH=%s", devpath) + 1;
	envp [i++] = scratch;
	scratch += sprintf(scratch, "SUBSYSTEM=%s", subsystem) + 1;
	for (j = 0; envp_ext && envp_ext[j]; j++)
		envp[i++] = envp_ext[j];
	/* just reserve the space, overwrite it after kset call has returned */
	envp[i++] = seq_buff = scratch;
	scratch += strlen("SEQNUM=18446744073709551616") + 1;

	/* let the kset specific function add its stuff */
	if (uevent_ops && uevent_ops->uevent) {
		retval = uevent_ops->uevent(kset, kobj,
				  &envp[i], NUM_ENVP - i, scratch,
				  BUFFER_SIZE - (scratch - buffer));
		if (retval) {
			pr_debug ("%s - uevent() returned %d\n",
				  __FUNCTION__, retval);
			goto exit;
		}
	}

	/* we will send an event, request a new sequence number */
	spin_lock(&sequence_lock);
	seq = ++uevent_seqnum;
	spin_unlock(&sequence_lock);
	sprintf(seq_buff, "SEQNUM=%llu", (unsigned long long)seq);

#if defined(CONFIG_NET)
	/* send netlink message */
	if (uevent_sock) {
		struct sk_buff *skb;
		size_t len;

		/* allocate message with the maximum possible size */
		len = strlen(action_string) + strlen(devpath) + 2;
		skb = alloc_skb(len + BUFFER_SIZE, GFP_KERNEL);
		if (skb) {
			/* add header */
			scratch = skb_put(skb, len);
			sprintf(scratch, "%s@%s", action_string, devpath);

			/* copy keys to our continuous event payload buffer */
			for (i = 2; envp[i]; i++) {
				len = strlen(envp[i]) + 1;
				scratch = skb_put(skb, len);
				strcpy(scratch, envp[i]);
			}

			NETLINK_CB(skb).dst_group = 1;
			netlink_broadcast(uevent_sock, skb, 0, 1, GFP_KERNEL);
		}
	}
#endif

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

		argv [0] = uevent_helper;
		argv [1] = (char *)subsystem;
		argv [2] = NULL;
		call_usermodehelper (argv[0], argv, envp, 0);
	}

exit:
	kfree(devpath);
	kfree(buffer);
	kfree(envp);
	return retval;
}

EXPORT_SYMBOL_GPL(kobject_uevent_env);

/**
 * kobject_uevent - notify userspace by ending an uevent
 *
 * @action: action that is happening (usually KOBJ_ADD and KOBJ_REMOVE)
 * @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 - helper for creating event variables
 * @envp: Pointer to table of environment variables, as passed into
 * uevent() method.
 * @num_envp: Number of environment variable slots available, as
 * passed into uevent() method.
 * @cur_index: Pointer to current index into @envp.  It should be
 * initialized to 0 before the first call to add_uevent_var(),
 * and will be incremented on success.
 * @buffer: Pointer to buffer for environment variables, as passed
 * into uevent() method.
 * @buffer_size: Length of @buffer, as passed into uevent() method.
 * @cur_len: Pointer to current length of space used in @buffer.
 * Should be initialized to 0 before the first call to
 * add_uevent_var(), and will be incremented on success.
 * @format: Format for creating environment variable (of the form
 * "XXX=%x") for snprintf().
 *
 * Returns 0 if environment variable was added successfully or -ENOMEM
 * if no space was available.
 */
int add_uevent_var(char **envp, int num_envp, int *cur_index,
		   char *buffer, int buffer_size, int *cur_len,
		   const char *format, ...)
{
	va_list args;

	/*
	 * We check against num_envp - 1 to make sure there is at
	 * least one slot left after we return, since kobject_uevent()
	 * needs to set the last slot to NULL.
	 */
	if (*cur_index >= num_envp - 1)
		return -ENOMEM;

	envp[*cur_index] = buffer + *cur_len;

	va_start(args, format);
	*cur_len += vsnprintf(envp[*cur_index],
			      max(buffer_size - *cur_len, 0),
			      format, args) + 1;
	va_end(args);

	if (*cur_len > buffer_size)
		return -ENOMEM;

	(*cur_index)++;
	return 0;
}
EXPORT_SYMBOL_GPL(add_uevent_var);

#if defined(CONFIG_NET)
static int __init kobject_uevent_init(void)
{
	uevent_sock = netlink_kernel_create(NETLINK_KOBJECT_UEVENT, 1, NULL,
					    NULL, THIS_MODULE);

	if (!uevent_sock) {
		printk(KERN_ERR
		       "kobject_uevent: unable to create netlink socket!\n");
		return -ENODEV;
	}

	return 0;
}

postcore_initcall(kobject_uevent_init);
#endif

#endif /* CONFIG_HOTPLUG */
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>
	18	#include <linux/socket.h>
	19	#include <linux/skbuff.h>
	20	#include <linux/netlink.h>
	21	#include <linux/string.h>
1da177e4 LT	22	#include <linux/kobject.h>
	23	#include <net/sock.h>
	24
d87499ed	25	#define BUFFER_SIZE 2048 /* buffer for the variables */
1da177e4 LT	26	#define NUM_ENVP 32 /* number of env pointers */
1da177e4 LT	27
4d17ffda	28	#if defined(CONFIG_HOTPLUG)
51107301 JN	29	u64 uevent_seqnum;
51107301 JN	30	char uevent_helper[UEVENT_HELPER_PATH_LEN] = "/sbin/hotplug";
0296b228	31	static DEFINE_SPINLOCK(sequence_lock);
4d17ffda	32	#if defined(CONFIG_NET)
5f123fbd	33	static struct sock *uevent_sock;
4d17ffda	34	#endif
0296b228	35
1da177e4 LT	36	static char *action_to_string(enum kobject_action action)
	37	{
	38	switch (action) {
	39	case KOBJ_ADD:
	40	return "add";
	41	case KOBJ_REMOVE:
	42	return "remove";
	43	case KOBJ_CHANGE:
	44	return "change";
fa675765 GKH	45	case KOBJ_MOUNT:
	46	return "mount";
	47	case KOBJ_UMOUNT:
	48	return "umount";
1da177e4 LT	49	case KOBJ_OFFLINE:
	50	return "offline";
	51	case KOBJ_ONLINE:
	52	return "online";
8a82472f CH	53	case KOBJ_MOVE:
8a82472f CH	54	return "move";
1da177e4 LT	55	default:
	56	return NULL;
	57	}
	58	}
1da177e4	59
1da177e4	60	/**
8a82472f	61	* kobject_uevent_env - send an uevent with environmental data
1da177e4	62	*
8a82472f	63	* @action: action that is happening (usually KOBJ_MOVE)
1da177e4	64	* @kobj: struct kobject that the action is happening to
8a82472f	65	* @envp_ext: pointer to environmental data
542cfce6 AK	66	*
	67	* Returns 0 if kobject_uevent() is completed with success or the
	68	* corresponding error when it fails.
1da177e4	69	*/
542cfce6	70	int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
8a82472f	71	char *envp_ext[])
1da177e4	72	{
5f123fbd KS	73	char **envp;
5f123fbd KS	74	char *buffer;
1da177e4	75	char *scratch;
5f123fbd KS	76	const char *action_string;
	77	const char *devpath = NULL;
	78	const char *subsystem;
	79	struct kobject *top_kobj;
	80	struct kset *kset;
312c004d	81	struct kset_uevent_ops *uevent_ops;
5f123fbd KS	82	u64 seq;
5f123fbd KS	83	char *seq_buff;
1da177e4	84	int i = 0;
542cfce6	85	int retval = 0;
8a82472f	86	int j;
1da177e4	87
5f123fbd KS	88	pr_debug("%s\n", __FUNCTION__);
	89
	90	action_string = action_to_string(action);
542cfce6 AK	91	if (!action_string) {
	92	pr_debug("kobject attempted to send uevent without action_string!\n");
	93	return -EINVAL;
	94	}
5f123fbd KS	95
	96	/* search the kset we belong to */
	97	top_kobj = kobj;
1da177e4 LT	98	if (!top_kobj->kset && top_kobj->parent) {
	99	do {
	100	top_kobj = top_kobj->parent;
	101	} while (!top_kobj->kset && top_kobj->parent);
	102	}
542cfce6 AK	103	if (!top_kobj->kset) {
	104	pr_debug("kobject attempted to send uevent without kset!\n");
	105	return -EINVAL;
	106	}
1da177e4	107
5f123fbd	108	kset = top_kobj->kset;
312c004d	109	uevent_ops = kset->uevent_ops;
1da177e4	110
5f123fbd	111	/* skip the event, if the filter returns zero. */
312c004d	112	if (uevent_ops && uevent_ops->filter)
542cfce6 AK	113	if (!uevent_ops->filter(kset, kobj)) {
	114	pr_debug("kobject filter function caused the event to drop!\n");
	115	return 0;
	116	}
1da177e4	117
86406245 KS	118	/* originating subsystem */
	119	if (uevent_ops && uevent_ops->name)
	120	subsystem = uevent_ops->name(kset, kobj);
	121	else
	122	subsystem = kobject_name(&kset->kobj);
	123	if (!subsystem) {
	124	pr_debug("unset subsytem caused the event to drop!\n");
	125	return 0;
	126	}
	127
5f123fbd KS	128	/* environment index */
5f123fbd KS	129	envp = kzalloc(NUM_ENVP * sizeof (char *), GFP_KERNEL);
1da177e4	130	if (!envp)
542cfce6	131	return -ENOMEM;
1da177e4	132
5f123fbd	133	/* environment values */
1da177e4	134	buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL);
542cfce6 AK	135	if (!buffer) {
542cfce6 AK	136	retval = -ENOMEM;
1da177e4	137	goto exit;
542cfce6	138	}
1da177e4	139
5f123fbd KS	140	/* complete object path */
5f123fbd KS	141	devpath = kobject_get_path(kobj, GFP_KERNEL);
542cfce6 AK	142	if (!devpath) {
542cfce6 AK	143	retval = -ENOENT;
5f123fbd	144	goto exit;
542cfce6	145	}
1da177e4	146
5f123fbd KS	147	/* event environemnt for helper process only */
	148	envp[i++] = "HOME=/";
	149	envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
1da177e4	150
5f123fbd	151	/* default keys */
1da177e4	152	scratch = buffer;
1da177e4 LT	153	envp [i++] = scratch;
1da177e4 LT	154	scratch += sprintf(scratch, "ACTION=%s", action_string) + 1;
1da177e4	155	envp [i++] = scratch;
5f123fbd	156	scratch += sprintf (scratch, "DEVPATH=%s", devpath) + 1;
1da177e4	157	envp [i++] = scratch;
5f123fbd	158	scratch += sprintf(scratch, "SUBSYSTEM=%s", subsystem) + 1;
8a82472f CH	159	for (j = 0; envp_ext && envp_ext[j]; j++)
8a82472f CH	160	envp[i++] = envp_ext[j];
5f123fbd	161	/* just reserve the space, overwrite it after kset call has returned */
1da177e4 LT	162	envp[i++] = seq_buff = scratch;
	163	scratch += strlen("SEQNUM=18446744073709551616") + 1;
	164
5f123fbd	165	/* let the kset specific function add its stuff */
312c004d KS	166	if (uevent_ops && uevent_ops->uevent) {
312c004d KS	167	retval = uevent_ops->uevent(kset, kobj,
1da177e4 LT	168	&envp[i], NUM_ENVP - i, scratch,
	169	BUFFER_SIZE - (scratch - buffer));
	170	if (retval) {
312c004d	171	pr_debug ("%s - uevent() returned %d\n",
1da177e4 LT	172	__FUNCTION__, retval);
	173	goto exit;
	174	}
	175	}
	176
5f123fbd	177	/* we will send an event, request a new sequence number */
1da177e4	178	spin_lock(&sequence_lock);
312c004d	179	seq = ++uevent_seqnum;
1da177e4 LT	180	spin_unlock(&sequence_lock);
	181	sprintf(seq_buff, "SEQNUM=%llu", (unsigned long long)seq);
	182
4d17ffda	183	#if defined(CONFIG_NET)
5f123fbd KS	184	/* send netlink message */
	185	if (uevent_sock) {
	186	struct sk_buff *skb;
	187	size_t len;
	188
	189	/* allocate message with the maximum possible size */
	190	len = strlen(action_string) + strlen(devpath) + 2;
	191	skb = alloc_skb(len + BUFFER_SIZE, GFP_KERNEL);
	192	if (skb) {
	193	/* add header */
	194	scratch = skb_put(skb, len);
	195	sprintf(scratch, "%s@%s", action_string, devpath);
	196
	197	/* copy keys to our continuous event payload buffer */
	198	for (i = 2; envp[i]; i++) {
	199	len = strlen(envp[i]) + 1;
	200	scratch = skb_put(skb, len);
	201	strcpy(scratch, envp[i]);
	202	}
	203
	204	NETLINK_CB(skb).dst_group = 1;
	205	netlink_broadcast(uevent_sock, skb, 0, 1, GFP_KERNEL);
	206	}
	207	}
4d17ffda	208	#endif
1da177e4	209
5f123fbd	210	/* call uevent_helper, usually only enabled during early boot */
312c004d	211	if (uevent_helper[0]) {
5f123fbd	212	char *argv [3];
1da177e4	213
312c004d	214	argv [0] = uevent_helper;
5f123fbd KS	215	argv [1] = (char *)subsystem;
	216	argv [2] = NULL;
	217	call_usermodehelper (argv[0], argv, envp, 0);
	218	}
1da177e4 LT	219
1da177e4 LT	220	exit:
5f123fbd	221	kfree(devpath);
1da177e4 LT	222	kfree(buffer);
1da177e4 LT	223	kfree(envp);
542cfce6	224	return retval;
1da177e4	225	}
8a82472f CH	226
	227	EXPORT_SYMBOL_GPL(kobject_uevent_env);
	228
	229	/**
	230	* kobject_uevent - notify userspace by ending an uevent
	231	*
	232	* @action: action that is happening (usually KOBJ_ADD and KOBJ_REMOVE)
	233	* @kobj: struct kobject that the action is happening to
542cfce6 AK	234	*
	235	* Returns 0 if kobject_uevent() is completed with success or the
	236	* corresponding error when it fails.
8a82472f	237	*/
542cfce6	238	int kobject_uevent(struct kobject *kobj, enum kobject_action action)
8a82472f	239	{
542cfce6	240	return kobject_uevent_env(kobj, action, NULL);
8a82472f CH	241	}
8a82472f CH	242
312c004d	243	EXPORT_SYMBOL_GPL(kobject_uevent);
1da177e4 LT	244
1da177e4 LT	245	/**
312c004d	246	* add_uevent_var - helper for creating event variables
1da177e4	247	* @envp: Pointer to table of environment variables, as passed into
312c004d	248	* uevent() method.
1da177e4	249	* @num_envp: Number of environment variable slots available, as
312c004d	250	* passed into uevent() method.
1da177e4	251	* @cur_index: Pointer to current index into @envp. It should be
312c004d	252	* initialized to 0 before the first call to add_uevent_var(),
1da177e4 LT	253	* and will be incremented on success.
1da177e4 LT	254	* @buffer: Pointer to buffer for environment variables, as passed
312c004d KS	255	* into uevent() method.
312c004d KS	256	* @buffer_size: Length of @buffer, as passed into uevent() method.
1da177e4 LT	257	* @cur_len: Pointer to current length of space used in @buffer.
1da177e4 LT	258	* Should be initialized to 0 before the first call to
312c004d	259	* add_uevent_var(), and will be incremented on success.
1da177e4 LT	260	* @format: Format for creating environment variable (of the form
	261	* "XXX=%x") for snprintf().
	262	*
	263	* Returns 0 if environment variable was added successfully or -ENOMEM
	264	* if no space was available.
	265	*/
312c004d KS	266	int add_uevent_var(char *envp, int num_envp, int cur_index,
	267	char buffer, int buffer_size, int cur_len,
	268	const char *format, ...)
1da177e4 LT	269	{
	270	va_list args;
	271
	272	/*
	273	* We check against num_envp - 1 to make sure there is at
312c004d KS	274	* least one slot left after we return, since kobject_uevent()
312c004d KS	275	* needs to set the last slot to NULL.
1da177e4 LT	276	*/
	277	if (*cur_index >= num_envp - 1)
	278	return -ENOMEM;
	279
	280	envp[cur_index] = buffer + cur_len;
	281
	282	va_start(args, format);
	283	cur_len += vsnprintf(envp[cur_index],
	284	max(buffer_size - *cur_len, 0),
	285	format, args) + 1;
	286	va_end(args);
	287
	288	if (*cur_len > buffer_size)
	289	return -ENOMEM;
	290
	291	(*cur_index)++;
	292	return 0;
	293	}
312c004d	294	EXPORT_SYMBOL_GPL(add_uevent_var);
1da177e4	295
4d17ffda	296	#if defined(CONFIG_NET)
5f123fbd KS	297	static int __init kobject_uevent_init(void)
	298	{
	299	uevent_sock = netlink_kernel_create(NETLINK_KOBJECT_UEVENT, 1, NULL,
af65bdfc	300	NULL, THIS_MODULE);
5f123fbd KS	301
	302	if (!uevent_sock) {
	303	printk(KERN_ERR
	304	"kobject_uevent: unable to create netlink socket!\n");
	305	return -ENODEV;
	306	}
	307
	308	return 0;
	309	}
	310
	311	postcore_initcall(kobject_uevent_init);
4d17ffda	312	#endif
5f123fbd	313
1da177e4	314	#endif /* CONFIG_HOTPLUG */