[deliverable/linux.git] / lib / kobject_uevent.c

/*
 * kernel userspace event delivery
 *
 * Copyright (C) 2004 Red Hat, Inc.  All rights reserved.
 * Copyright (C) 2004 Novell, Inc.  All rights reserved.
 * Copyright (C) 2004 IBM, Inc. All rights reserved.
 *
 * Licensed under the GNU GPL v2.
 *
 * Authors:
 *	Robert Love		<rml@novell.com>
 *	Kay Sievers		<kay.sievers@vrfy.org>
 *	Arjan van de Ven	<arjanv@redhat.com>
 *	Greg Kroah-Hartman	<greg@kroah.com>
 */

#include <linux/spinlock.h>
#include <linux/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_DOCK:
		return "dock";
	case KOBJ_UNDOCK:
		return "undock";
	default:
		return NULL;
	}
}

/**
 * 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
 */
void kobject_uevent(struct kobject *kobj, enum kobject_action action)
{
	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;

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

	action_string = action_to_string(action);
	if (!action_string)
		return;

	/* 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)
		return;

	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))
			return;

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

	/* environment values */
	buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL);
	if (!buffer)
		goto exit;

	/* complete object path */
	devpath = kobject_get_path(kobj, GFP_KERNEL);
	if (!devpath)
		goto exit;

	/* originating subsystem */
	if (uevent_ops && uevent_ops->name)
		subsystem = uevent_ops->name(kset, kobj);
	else
		subsystem = kobject_name(&kset->kobj);

	/* 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;

	/* 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;
}
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,
					    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";
a6a888b3 KA	53	case KOBJ_DOCK:
	54	return "dock";
	55	case KOBJ_UNDOCK:
	56	return "undock";
1da177e4 LT	57	default:
	58	return NULL;
	59	}
	60	}
1da177e4	61
1da177e4	62	/**
312c004d	63	* kobject_uevent - notify userspace by ending an uevent
1da177e4	64	*
312c004d	65	* @action: action that is happening (usually KOBJ_ADD and KOBJ_REMOVE)
1da177e4 LT	66	* @kobj: struct kobject that the action is happening to
1da177e4 LT	67	*/
312c004d	68	void kobject_uevent(struct kobject *kobj, enum kobject_action action)
1da177e4	69	{
5f123fbd KS	70	char **envp;
5f123fbd KS	71	char *buffer;
1da177e4	72	char *scratch;
5f123fbd KS	73	const char *action_string;
	74	const char *devpath = NULL;
	75	const char *subsystem;
	76	struct kobject *top_kobj;
	77	struct kset *kset;
312c004d	78	struct kset_uevent_ops *uevent_ops;
5f123fbd KS	79	u64 seq;
5f123fbd KS	80	char *seq_buff;
1da177e4 LT	81	int i = 0;
1da177e4 LT	82	int retval;
1da177e4	83
5f123fbd KS	84	pr_debug("%s\n", __FUNCTION__);
	85
	86	action_string = action_to_string(action);
	87	if (!action_string)
	88	return;
	89
	90	/* search the kset we belong to */
	91	top_kobj = kobj;
1da177e4 LT	92	if (!top_kobj->kset && top_kobj->parent) {
	93	do {
	94	top_kobj = top_kobj->parent;
	95	} while (!top_kobj->kset && top_kobj->parent);
	96	}
5f123fbd	97	if (!top_kobj->kset)
1da177e4 LT	98	return;
1da177e4 LT	99
5f123fbd	100	kset = top_kobj->kset;
312c004d	101	uevent_ops = kset->uevent_ops;
1da177e4	102
5f123fbd	103	/* skip the event, if the filter returns zero. */
312c004d KS	104	if (uevent_ops && uevent_ops->filter)
312c004d KS	105	if (!uevent_ops->filter(kset, kobj))
1da177e4	106	return;
1da177e4	107
5f123fbd KS	108	/* environment index */
5f123fbd KS	109	envp = kzalloc(NUM_ENVP * sizeof (char *), GFP_KERNEL);
1da177e4 LT	110	if (!envp)
1da177e4 LT	111	return;
1da177e4	112
5f123fbd	113	/* environment values */
1da177e4 LT	114	buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL);
	115	if (!buffer)
	116	goto exit;
	117
5f123fbd KS	118	/* complete object path */
	119	devpath = kobject_get_path(kobj, GFP_KERNEL);
	120	if (!devpath)
	121	goto exit;
1da177e4	122
5f123fbd	123	/* originating subsystem */
312c004d KS	124	if (uevent_ops && uevent_ops->name)
312c004d KS	125	subsystem = uevent_ops->name(kset, kobj);
5f123fbd KS	126	else
5f123fbd KS	127	subsystem = kobject_name(&kset->kobj);
1da177e4	128
5f123fbd KS	129	/* event environemnt for helper process only */
	130	envp[i++] = "HOME=/";
	131	envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
1da177e4	132
5f123fbd	133	/* default keys */
1da177e4	134	scratch = buffer;
1da177e4 LT	135	envp [i++] = scratch;
1da177e4 LT	136	scratch += sprintf(scratch, "ACTION=%s", action_string) + 1;
1da177e4	137	envp [i++] = scratch;
5f123fbd	138	scratch += sprintf (scratch, "DEVPATH=%s", devpath) + 1;
1da177e4	139	envp [i++] = scratch;
5f123fbd	140	scratch += sprintf(scratch, "SUBSYSTEM=%s", subsystem) + 1;
1da177e4	141
5f123fbd	142	/* just reserve the space, overwrite it after kset call has returned */
1da177e4 LT	143	envp[i++] = seq_buff = scratch;
	144	scratch += strlen("SEQNUM=18446744073709551616") + 1;
	145
5f123fbd	146	/* let the kset specific function add its stuff */
312c004d KS	147	if (uevent_ops && uevent_ops->uevent) {
312c004d KS	148	retval = uevent_ops->uevent(kset, kobj,
1da177e4 LT	149	&envp[i], NUM_ENVP - i, scratch,
	150	BUFFER_SIZE - (scratch - buffer));
	151	if (retval) {
312c004d	152	pr_debug ("%s - uevent() returned %d\n",
1da177e4 LT	153	__FUNCTION__, retval);
	154	goto exit;
	155	}
	156	}
	157
5f123fbd	158	/* we will send an event, request a new sequence number */
1da177e4	159	spin_lock(&sequence_lock);
312c004d	160	seq = ++uevent_seqnum;
1da177e4 LT	161	spin_unlock(&sequence_lock);
	162	sprintf(seq_buff, "SEQNUM=%llu", (unsigned long long)seq);
	163
4d17ffda	164	#if defined(CONFIG_NET)
5f123fbd KS	165	/* send netlink message */
	166	if (uevent_sock) {
	167	struct sk_buff *skb;
	168	size_t len;
	169
	170	/* allocate message with the maximum possible size */
	171	len = strlen(action_string) + strlen(devpath) + 2;
	172	skb = alloc_skb(len + BUFFER_SIZE, GFP_KERNEL);
	173	if (skb) {
	174	/* add header */
	175	scratch = skb_put(skb, len);
	176	sprintf(scratch, "%s@%s", action_string, devpath);
	177
	178	/* copy keys to our continuous event payload buffer */
	179	for (i = 2; envp[i]; i++) {
	180	len = strlen(envp[i]) + 1;
	181	scratch = skb_put(skb, len);
	182	strcpy(scratch, envp[i]);
	183	}
	184
	185	NETLINK_CB(skb).dst_group = 1;
	186	netlink_broadcast(uevent_sock, skb, 0, 1, GFP_KERNEL);
	187	}
	188	}
4d17ffda	189	#endif
1da177e4	190
5f123fbd	191	/* call uevent_helper, usually only enabled during early boot */
312c004d	192	if (uevent_helper[0]) {
5f123fbd	193	char *argv [3];
1da177e4	194
312c004d	195	argv [0] = uevent_helper;
5f123fbd KS	196	argv [1] = (char *)subsystem;
	197	argv [2] = NULL;
	198	call_usermodehelper (argv[0], argv, envp, 0);
	199	}
1da177e4 LT	200
1da177e4 LT	201	exit:
5f123fbd	202	kfree(devpath);
1da177e4 LT	203	kfree(buffer);
	204	kfree(envp);
	205	return;
	206	}
312c004d	207	EXPORT_SYMBOL_GPL(kobject_uevent);
1da177e4 LT	208
1da177e4 LT	209	/**
312c004d	210	* add_uevent_var - helper for creating event variables
1da177e4	211	* @envp: Pointer to table of environment variables, as passed into
312c004d	212	* uevent() method.
1da177e4	213	* @num_envp: Number of environment variable slots available, as
312c004d	214	* passed into uevent() method.
1da177e4	215	* @cur_index: Pointer to current index into @envp. It should be
312c004d	216	* initialized to 0 before the first call to add_uevent_var(),
1da177e4 LT	217	* and will be incremented on success.
1da177e4 LT	218	* @buffer: Pointer to buffer for environment variables, as passed
312c004d KS	219	* into uevent() method.
312c004d KS	220	* @buffer_size: Length of @buffer, as passed into uevent() method.
1da177e4 LT	221	* @cur_len: Pointer to current length of space used in @buffer.
1da177e4 LT	222	* Should be initialized to 0 before the first call to
312c004d	223	* add_uevent_var(), and will be incremented on success.
1da177e4 LT	224	* @format: Format for creating environment variable (of the form
	225	* "XXX=%x") for snprintf().
	226	*
	227	* Returns 0 if environment variable was added successfully or -ENOMEM
	228	* if no space was available.
	229	*/
312c004d KS	230	int add_uevent_var(char *envp, int num_envp, int cur_index,
	231	char buffer, int buffer_size, int cur_len,
	232	const char *format, ...)
1da177e4 LT	233	{
	234	va_list args;
	235
	236	/*
	237	* We check against num_envp - 1 to make sure there is at
312c004d KS	238	* least one slot left after we return, since kobject_uevent()
312c004d KS	239	* needs to set the last slot to NULL.
1da177e4 LT	240	*/
	241	if (*cur_index >= num_envp - 1)
	242	return -ENOMEM;
	243
	244	envp[cur_index] = buffer + cur_len;
	245
	246	va_start(args, format);
	247	cur_len += vsnprintf(envp[cur_index],
	248	max(buffer_size - *cur_len, 0),
	249	format, args) + 1;
	250	va_end(args);
	251
	252	if (*cur_len > buffer_size)
	253	return -ENOMEM;
	254
	255	(*cur_index)++;
	256	return 0;
	257	}
312c004d	258	EXPORT_SYMBOL_GPL(add_uevent_var);
1da177e4	259
4d17ffda	260	#if defined(CONFIG_NET)
5f123fbd KS	261	static int __init kobject_uevent_init(void)
	262	{
	263	uevent_sock = netlink_kernel_create(NETLINK_KOBJECT_UEVENT, 1, NULL,
	264	THIS_MODULE);
	265
	266	if (!uevent_sock) {
	267	printk(KERN_ERR
	268	"kobject_uevent: unable to create netlink socket!\n");
	269	return -ENODEV;
	270	}
	271
	272	return 0;
	273	}
	274
	275	postcore_initcall(kobject_uevent_init);
4d17ffda	276	#endif
5f123fbd	277
1da177e4	278	#endif /* CONFIG_HOTPLUG */