[linux-2.6-block.git] / lib / kobject_uevent.c

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

#include <linux/spinlock.h>
#include <linux/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	1024	/* buffer for the hotplug env */
#define NUM_ENVP	32	/* number of env pointers */

#if defined(CONFIG_HOTPLUG)
char hotplug_path[HOTPLUG_PATH_LEN] = "/sbin/hotplug";
u64 hotplug_seqnum;
static DEFINE_SPINLOCK(sequence_lock);

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_OFFLINE:
		return "offline";
	case KOBJ_ONLINE:
		return "online";
	default:
		return NULL;
	}
}

static struct sock *uevent_sock;

/**
 * send_uevent - notify userspace by sending event through netlink socket
 *
 * @signal: signal name
 * @obj: object path (kobject)
 * @envp: possible hotplug environment to pass with the message
 * @gfp_mask:
 */
static int send_uevent(const char *signal, const char *obj,
		       char **envp, gfp_t gfp_mask)
{
	struct sk_buff *skb;
	char *pos;
	int len;

	if (!uevent_sock)
		return -EIO;

	len = strlen(signal) + 1;
	len += strlen(obj) + 1;

	/* allocate buffer with the maximum possible message size */
	skb = alloc_skb(len + BUFFER_SIZE, gfp_mask);
	if (!skb)
		return -ENOMEM;

	pos = skb_put(skb, len);
	sprintf(pos, "%s@%s", signal, obj);

	/* copy the environment key by key to our continuous buffer */
	if (envp) {
		int i;

		for (i = 2; envp[i]; i++) {
			len = strlen(envp[i]) + 1;
			pos = skb_put(skb, len);
			strcpy(pos, envp[i]);
		}
	}

	NETLINK_CB(skb).dst_group = 1;
	return netlink_broadcast(uevent_sock, skb, 0, 1, gfp_mask);
}

static int do_kobject_uevent(struct kobject *kobj, enum kobject_action action, 
			     struct attribute *attr, gfp_t gfp_mask)
{
	char *path;
	char *attrpath;
	char *signal;
	int len;
	int rc = -ENOMEM;

	path = kobject_get_path(kobj, gfp_mask);
	if (!path)
		return -ENOMEM;

	signal = action_to_string(action);
	if (!signal)
		return -EINVAL;

	if (attr) {
		len = strlen(path);
		len += strlen(attr->name) + 2;
		attrpath = kmalloc(len, gfp_mask);
		if (!attrpath)
			goto exit;
		sprintf(attrpath, "%s/%s", path, attr->name);
		rc = send_uevent(signal, attrpath, NULL, gfp_mask);
		kfree(attrpath);
	} else
		rc = send_uevent(signal, path, NULL, gfp_mask);

exit:
	kfree(path);
	return rc;
}

/**
 * kobject_uevent - notify userspace by sending event through netlink socket
 * 
 * @signal: signal name
 * @kobj: struct kobject that the event is happening to
 * @attr: optional struct attribute the event belongs to
 */
int kobject_uevent(struct kobject *kobj, enum kobject_action action,
		   struct attribute *attr)
{
	return do_kobject_uevent(kobj, action, attr, GFP_KERNEL);
}
EXPORT_SYMBOL_GPL(kobject_uevent);

int kobject_uevent_atomic(struct kobject *kobj, enum kobject_action action,
			  struct attribute *attr)
{
	return do_kobject_uevent(kobj, action, attr, GFP_ATOMIC);
}
EXPORT_SYMBOL_GPL(kobject_uevent_atomic);

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);

/**
 * kobject_hotplug - notify userspace by executing /sbin/hotplug
 *
 * @action: action that is happening (usually "ADD" or "REMOVE")
 * @kobj: struct kobject that the action is happening to
 */
void kobject_hotplug(struct kobject *kobj, enum kobject_action action)
{
	char *argv [3];
	char **envp = NULL;
	char *buffer = NULL;
	char *seq_buff;
	char *scratch;
	int i = 0;
	int retval;
	char *kobj_path = NULL;
	const char *name = NULL;
	char *action_string;
	u64 seq;
	struct kobject *top_kobj = kobj;
	struct kset *kset;
	static struct kset_hotplug_ops null_hotplug_ops;
	struct kset_hotplug_ops *hotplug_ops = &null_hotplug_ops;

	/* If this kobj does not belong to a kset,
	   try to find a parent that does. */
	if (!top_kobj->kset && top_kobj->parent) {
		do {
			top_kobj = top_kobj->parent;
		} while (!top_kobj->kset && top_kobj->parent);
	}

	if (top_kobj->kset)
		kset = top_kobj->kset;
	else
		return;

	if (kset->hotplug_ops)
		hotplug_ops = kset->hotplug_ops;

	/* If the kset has a filter operation, call it.
	   Skip the event, if the filter returns zero. */
	if (hotplug_ops->filter) {
		if (!hotplug_ops->filter(kset, kobj))
			return;
	}

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

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

	envp = kmalloc(NUM_ENVP * sizeof (char *), GFP_KERNEL);
	if (!envp)
		return;
	memset (envp, 0x00, NUM_ENVP * sizeof (char *));

	buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL);
	if (!buffer)
		goto exit;

	if (hotplug_ops->name)
		name = hotplug_ops->name(kset, kobj);
	if (name == NULL)
		name = kobject_name(&kset->kobj);

	argv [0] = hotplug_path;
	argv [1] = (char *)name; /* won't be changed but 'const' has to go */
	argv [2] = NULL;

	/* minimal command environment */
	envp [i++] = "HOME=/";
	envp [i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";

	scratch = buffer;

	envp [i++] = scratch;
	scratch += sprintf(scratch, "ACTION=%s", action_string) + 1;

	kobj_path = kobject_get_path(kobj, GFP_KERNEL);
	if (!kobj_path)
		goto exit;

	envp [i++] = scratch;
	scratch += sprintf (scratch, "DEVPATH=%s", kobj_path) + 1;

	envp [i++] = scratch;
	scratch += sprintf(scratch, "SUBSYSTEM=%s", name) + 1;

	/* reserve space for the sequence,
	 * put the real one in after the hotplug call */
	envp[i++] = seq_buff = scratch;
	scratch += strlen("SEQNUM=18446744073709551616") + 1;

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

	spin_lock(&sequence_lock);
	seq = ++hotplug_seqnum;
	spin_unlock(&sequence_lock);
	sprintf(seq_buff, "SEQNUM=%llu", (unsigned long long)seq);

	pr_debug ("%s: %s %s seq=%llu %s %s %s %s %s\n",
		  __FUNCTION__, argv[0], argv[1], (unsigned long long)seq,
		  envp[0], envp[1], envp[2], envp[3], envp[4]);

	send_uevent(action_string, kobj_path, envp, GFP_KERNEL);

	if (!hotplug_path[0])
		goto exit;

	retval = call_usermodehelper (argv[0], argv, envp, 0);
	if (retval)
		pr_debug ("%s - call_usermodehelper returned %d\n",
			  __FUNCTION__, retval);

exit:
	kfree(kobj_path);
	kfree(buffer);
	kfree(envp);
	return;
}
EXPORT_SYMBOL(kobject_hotplug);

/**
 * add_hotplug_env_var - helper for creating hotplug environment variables
 * @envp: Pointer to table of environment variables, as passed into
 * hotplug() method.
 * @num_envp: Number of environment variable slots available, as
 * passed into hotplug() method.
 * @cur_index: Pointer to current index into @envp.  It should be
 * initialized to 0 before the first call to add_hotplug_env_var(),
 * and will be incremented on success.
 * @buffer: Pointer to buffer for environment variables, as passed
 * into hotplug() method.
 * @buffer_size: Length of @buffer, as passed into hotplug() method.
 * @cur_len: Pointer to current length of space used in @buffer.
 * Should be initialized to 0 before the first call to
 * add_hotplug_env_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_hotplug_env_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 the hotplug
	 * method 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(add_hotplug_env_var);

#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
	25	#define BUFFER_SIZE 1024 /* buffer for the hotplug env */
	26	#define NUM_ENVP 32 /* number of env pointers */
	27
0296b228 KS	28	#if defined(CONFIG_HOTPLUG)
	29	char hotplug_path[HOTPLUG_PATH_LEN] = "/sbin/hotplug";
	30	u64 hotplug_seqnum;
	31	static DEFINE_SPINLOCK(sequence_lock);
	32
1da177e4 LT	33	static char *action_to_string(enum kobject_action action)
	34	{
	35	switch (action) {
	36	case KOBJ_ADD:
	37	return "add";
	38	case KOBJ_REMOVE:
	39	return "remove";
	40	case KOBJ_CHANGE:
	41	return "change";
1da177e4 LT	42	case KOBJ_OFFLINE:
	43	return "offline";
	44	case KOBJ_ONLINE:
	45	return "online";
	46	default:
	47	return NULL;
	48	}
	49	}
1da177e4	50
1da177e4 LT	51	static struct sock *uevent_sock;
	52
	53	/**
4ed17dcc	54	* send_uevent - notify userspace by sending event through netlink socket
1da177e4 LT	55	*
	56	* @signal: signal name
	57	* @obj: object path (kobject)
	58	* @envp: possible hotplug environment to pass with the message
	59	* @gfp_mask:
	60	*/
	61	static int send_uevent(const char signal, const char obj,
fd4f2df2	62	char **envp, gfp_t gfp_mask)
1da177e4 LT	63	{
	64	struct sk_buff *skb;
	65	char *pos;
	66	int len;
	67
	68	if (!uevent_sock)
	69	return -EIO;
	70
	71	len = strlen(signal) + 1;
	72	len += strlen(obj) + 1;
	73
	74	/* allocate buffer with the maximum possible message size */
	75	skb = alloc_skb(len + BUFFER_SIZE, gfp_mask);
	76	if (!skb)
	77	return -ENOMEM;
	78
	79	pos = skb_put(skb, len);
	80	sprintf(pos, "%s@%s", signal, obj);
	81
	82	/* copy the environment key by key to our continuous buffer */
	83	if (envp) {
	84	int i;
	85
	86	for (i = 2; envp[i]; i++) {
	87	len = strlen(envp[i]) + 1;
	88	pos = skb_put(skb, len);
	89	strcpy(pos, envp[i]);
	90	}
	91	}
	92
ac6d439d	93	NETLINK_CB(skb).dst_group = 1;
1da177e4 LT	94	return netlink_broadcast(uevent_sock, skb, 0, 1, gfp_mask);
	95	}
	96
	97	static int do_kobject_uevent(struct kobject *kobj, enum kobject_action action,
fd4f2df2	98	struct attribute *attr, gfp_t gfp_mask)
1da177e4 LT	99	{
	100	char *path;
	101	char *attrpath;
	102	char *signal;
	103	int len;
	104	int rc = -ENOMEM;
	105
	106	path = kobject_get_path(kobj, gfp_mask);
	107	if (!path)
	108	return -ENOMEM;
	109
	110	signal = action_to_string(action);
	111	if (!signal)
	112	return -EINVAL;
	113
	114	if (attr) {
	115	len = strlen(path);
	116	len += strlen(attr->name) + 2;
	117	attrpath = kmalloc(len, gfp_mask);
	118	if (!attrpath)
	119	goto exit;
	120	sprintf(attrpath, "%s/%s", path, attr->name);
	121	rc = send_uevent(signal, attrpath, NULL, gfp_mask);
	122	kfree(attrpath);
	123	} else
	124	rc = send_uevent(signal, path, NULL, gfp_mask);
	125
	126	exit:
	127	kfree(path);
	128	return rc;
	129	}
	130
	131	/**
	132	* kobject_uevent - notify userspace by sending event through netlink socket
	133	*
	134	* @signal: signal name
	135	* @kobj: struct kobject that the event is happening to
	136	* @attr: optional struct attribute the event belongs to
	137	*/
	138	int kobject_uevent(struct kobject *kobj, enum kobject_action action,
	139	struct attribute *attr)
	140	{
	141	return do_kobject_uevent(kobj, action, attr, GFP_KERNEL);
	142	}
	143	EXPORT_SYMBOL_GPL(kobject_uevent);
	144
	145	int kobject_uevent_atomic(struct kobject *kobj, enum kobject_action action,
	146	struct attribute *attr)
	147	{
	148	return do_kobject_uevent(kobj, action, attr, GFP_ATOMIC);
	149	}
	150	EXPORT_SYMBOL_GPL(kobject_uevent_atomic);
	151
	152	static int __init kobject_uevent_init(void)
	153	{
06628607	154	uevent_sock = netlink_kernel_create(NETLINK_KOBJECT_UEVENT, 1, NULL,
4fdb3bb7	155	THIS_MODULE);
1da177e4 LT	156
	157	if (!uevent_sock) {
	158	printk(KERN_ERR
	159	"kobject_uevent: unable to create netlink socket!\n");
	160	return -ENODEV;
	161	}
	162
	163	return 0;
	164	}
	165
	166	postcore_initcall(kobject_uevent_init);
	167
1da177e4 LT	168	/**
	169	* kobject_hotplug - notify userspace by executing /sbin/hotplug
	170	*
	171	* @action: action that is happening (usually "ADD" or "REMOVE")
	172	* @kobj: struct kobject that the action is happening to
	173	*/
	174	void kobject_hotplug(struct kobject *kobj, enum kobject_action action)
	175	{
	176	char *argv [3];
	177	char **envp = NULL;
	178	char *buffer = NULL;
	179	char *seq_buff;
	180	char *scratch;
	181	int i = 0;
	182	int retval;
	183	char *kobj_path = NULL;
f3b4f3c6	184	const char *name = NULL;
1da177e4 LT	185	char *action_string;
	186	u64 seq;
	187	struct kobject *top_kobj = kobj;
	188	struct kset *kset;
	189	static struct kset_hotplug_ops null_hotplug_ops;
	190	struct kset_hotplug_ops *hotplug_ops = &null_hotplug_ops;
	191
	192	/* If this kobj does not belong to a kset,
	193	try to find a parent that does. */
	194	if (!top_kobj->kset && top_kobj->parent) {
	195	do {
	196	top_kobj = top_kobj->parent;
	197	} while (!top_kobj->kset && top_kobj->parent);
	198	}
	199
	200	if (top_kobj->kset)
	201	kset = top_kobj->kset;
	202	else
	203	return;
	204
	205	if (kset->hotplug_ops)
	206	hotplug_ops = kset->hotplug_ops;
	207
	208	/* If the kset has a filter operation, call it.
	209	Skip the event, if the filter returns zero. */
	210	if (hotplug_ops->filter) {
	211	if (!hotplug_ops->filter(kset, kobj))
	212	return;
	213	}
	214
	215	pr_debug ("%s\n", __FUNCTION__);
	216
	217	action_string = action_to_string(action);
	218	if (!action_string)
	219	return;
	220
	221	envp = kmalloc(NUM_ENVP * sizeof (char *), GFP_KERNEL);
	222	if (!envp)
	223	return;
	224	memset (envp, 0x00, NUM_ENVP * sizeof (char *));
	225
	226	buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL);
	227	if (!buffer)
	228	goto exit;
	229
	230	if (hotplug_ops->name)
	231	name = hotplug_ops->name(kset, kobj);
	232	if (name == NULL)
eb11d8ff	233	name = kobject_name(&kset->kobj);
1da177e4 LT	234
1da177e4 LT	235	argv [0] = hotplug_path;
f3b4f3c6	236	argv [1] = (char )name; / won't be changed but 'const' has to go */
1da177e4 LT	237	argv [2] = NULL;
	238
	239	/* minimal command environment */
	240	envp [i++] = "HOME=/";
	241	envp [i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
	242
	243	scratch = buffer;
	244
	245	envp [i++] = scratch;
	246	scratch += sprintf(scratch, "ACTION=%s", action_string) + 1;
	247
	248	kobj_path = kobject_get_path(kobj, GFP_KERNEL);
	249	if (!kobj_path)
	250	goto exit;
	251
	252	envp [i++] = scratch;
	253	scratch += sprintf (scratch, "DEVPATH=%s", kobj_path) + 1;
	254
	255	envp [i++] = scratch;
	256	scratch += sprintf(scratch, "SUBSYSTEM=%s", name) + 1;
	257
	258	/* reserve space for the sequence,
	259	* put the real one in after the hotplug call */
	260	envp[i++] = seq_buff = scratch;
	261	scratch += strlen("SEQNUM=18446744073709551616") + 1;
	262
	263	if (hotplug_ops->hotplug) {
	264	/* have the kset specific function add its stuff */
	265	retval = hotplug_ops->hotplug (kset, kobj,
	266	&envp[i], NUM_ENVP - i, scratch,
	267	BUFFER_SIZE - (scratch - buffer));
	268	if (retval) {
	269	pr_debug ("%s - hotplug() returned %d\n",
	270	__FUNCTION__, retval);
	271	goto exit;
	272	}
	273	}
	274
	275	spin_lock(&sequence_lock);
	276	seq = ++hotplug_seqnum;
	277	spin_unlock(&sequence_lock);
	278	sprintf(seq_buff, "SEQNUM=%llu", (unsigned long long)seq);
	279
	280	pr_debug ("%s: %s %s seq=%llu %s %s %s %s %s\n",
	281	__FUNCTION__, argv[0], argv[1], (unsigned long long)seq,
	282	envp[0], envp[1], envp[2], envp[3], envp[4]);
	283
	284	send_uevent(action_string, kobj_path, envp, GFP_KERNEL);
	285
	286	if (!hotplug_path[0])
	287	goto exit;
	288
	289	retval = call_usermodehelper (argv[0], argv, envp, 0);
	290	if (retval)
	291	pr_debug ("%s - call_usermodehelper returned %d\n",
	292	__FUNCTION__, retval);
	293
	294	exit:
	295	kfree(kobj_path);
	296	kfree(buffer);
	297	kfree(envp);
	298	return;
	299	}
	300	EXPORT_SYMBOL(kobject_hotplug);
301
302	/**
303	* add_hotplug_env_var - helper for creating hotplug environment variables
304	* @envp: Pointer to table of environment variables, as passed into
305	* hotplug() method.
306	* @num_envp: Number of environment variable slots available, as
307	* passed into hotplug() method.
308	* @cur_index: Pointer to current index into @envp. It should be
309	* initialized to 0 before the first call to add_hotplug_env_var(),
310	* and will be incremented on success.
311	* @buffer: Pointer to buffer for environment variables, as passed
312	* into hotplug() method.
313	* @buffer_size: Length of @buffer, as passed into hotplug() method.
314	* @cur_len: Pointer to current length of space used in @buffer.
315	* Should be initialized to 0 before the first call to
316	* add_hotplug_env_var(), and will be incremented on success.
317	* @format: Format for creating environment variable (of the form
318	* "XXX=%x") for snprintf().
319	*
320	* Returns 0 if environment variable was added successfully or -ENOMEM
321	* if no space was available.
322	*/
323	int add_hotplug_env_var(char *envp, int num_envp, int cur_index,
324	char buffer, int buffer_size, int cur_len,
325	const char *format, ...)
326	{
327	va_list args;
328
329	/*
330	* We check against num_envp - 1 to make sure there is at
331	* least one slot left after we return, since the hotplug
332	* method needs to set the last slot to NULL.
333	*/
334	if (*cur_index >= num_envp - 1)
335	return -ENOMEM;
336
337	envp[cur_index] = buffer + cur_len;
338
339	va_start(args, format);
340	cur_len += vsnprintf(envp[cur_index],
341	max(buffer_size - *cur_len, 0),
342	format, args) + 1;
343	va_end(args);
344
345	if (*cur_len > buffer_size)
346	return -ENOMEM;
347
348	(*cur_index)++;
349	return 0;
350	}
351	EXPORT_SYMBOL(add_hotplug_env_var);
352
353	#endif /* CONFIG_HOTPLUG */