Blame view

lib/kobject_uevent.c 8.39 KB
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
  /*
   * 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>
2d38f9a4f   Denis V. Lunev   [NETNS]: Do no in...
18
19
20
  #include <linux/string.h>
  #include <linux/kobject.h>
  #include <linux/module.h>
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
21
22
23
  #include <linux/socket.h>
  #include <linux/skbuff.h>
  #include <linux/netlink.h>
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
24
  #include <net/sock.h>
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
25

cd030c4cb   Cornelia Huck   kobject: fix link...
26
  u64 uevent_seqnum;
6a8d8abb6   Kay Sievers   Driver core: add ...
27
  char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH;
cd030c4cb   Cornelia Huck   kobject: fix link...
28
29
30
31
  static DEFINE_SPINLOCK(sequence_lock);
  #if defined(CONFIG_NET)
  static struct sock *uevent_sock;
  #endif
5c5daf657   Kay Sievers   Driver core: excl...
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
  /* 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;
a9edadbf7   Mark Lord   fix uevent action...
56
57
  	if (count && (buf[count-1] == '
  ' || buf[count-1] == '\0'))
5c5daf657   Kay Sievers   Driver core: excl...
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
  		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;
  }
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
75
  /**
8a82472f8   Cornelia Huck   driver core: Intr...
76
   * kobject_uevent_env - send an uevent with environmental data
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
77
   *
ccd490a3c   Kay Sievers   Driver core: kern...
78
   * @action: action that is happening
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
79
   * @kobj: struct kobject that the action is happening to
8a82472f8   Cornelia Huck   driver core: Intr...
80
   * @envp_ext: pointer to environmental data
542cfce6f   Aneesh Kumar K.V   kobject: kobject_...
81
82
83
   *
   * Returns 0 if kobject_uevent() is completed with success or the
   * corresponding error when it fails.
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
84
   */
542cfce6f   Aneesh Kumar K.V   kobject: kobject_...
85
  int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
7eff2e7a8   Kay Sievers   Driver core: chan...
86
  		       char *envp_ext[])
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
87
  {
7eff2e7a8   Kay Sievers   Driver core: chan...
88
89
  	struct kobj_uevent_env *env;
  	const char *action_string = kobject_actions[action];
5f123fbd8   Kay Sievers   [PATCH] merge kob...
90
91
92
93
  	const char *devpath = NULL;
  	const char *subsystem;
  	struct kobject *top_kobj;
  	struct kset *kset;
312c004d3   Kay Sievers   [PATCH] driver co...
94
  	struct kset_uevent_ops *uevent_ops;
5f123fbd8   Kay Sievers   [PATCH] merge kob...
95
  	u64 seq;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
96
  	int i = 0;
542cfce6f   Aneesh Kumar K.V   kobject: kobject_...
97
  	int retval = 0;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
98

9f66fa2a4   Greg Kroah-Hartman   kobject: clean up...
99
100
  	pr_debug("kobject: '%s' (%p): %s
  ",
810304db7   Harvey Harrison   lib: replace rema...
101
  		 kobject_name(kobj), kobj, __func__);
5f123fbd8   Kay Sievers   [PATCH] merge kob...
102

5f123fbd8   Kay Sievers   [PATCH] merge kob...
103
104
  	/* search the kset we belong to */
  	top_kobj = kobj;
ccd490a3c   Kay Sievers   Driver core: kern...
105
  	while (!top_kobj->kset && top_kobj->parent)
14193fb91   John Anthony Kazos Jr   Kobject: kobject_...
106
  		top_kobj = top_kobj->parent;
ccd490a3c   Kay Sievers   Driver core: kern...
107

542cfce6f   Aneesh Kumar K.V   kobject: kobject_...
108
  	if (!top_kobj->kset) {
9f66fa2a4   Greg Kroah-Hartman   kobject: clean up...
109
110
111
  		pr_debug("kobject: '%s' (%p): %s: attempted to send uevent "
  			 "without kset!
  ", kobject_name(kobj), kobj,
810304db7   Harvey Harrison   lib: replace rema...
112
  			 __func__);
542cfce6f   Aneesh Kumar K.V   kobject: kobject_...
113
114
  		return -EINVAL;
  	}
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
115

5f123fbd8   Kay Sievers   [PATCH] merge kob...
116
  	kset = top_kobj->kset;
312c004d3   Kay Sievers   [PATCH] driver co...
117
  	uevent_ops = kset->uevent_ops;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
118

f67f129e5   Ming Lei   Driver core: impl...
119
120
121
122
123
124
125
126
  	/* 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!
  ",
  				 kobject_name(kobj), kobj, __func__);
  		return 0;
  	}
7eff2e7a8   Kay Sievers   Driver core: chan...
127
  	/* skip the event, if the filter returns zero. */
312c004d3   Kay Sievers   [PATCH] driver co...
128
  	if (uevent_ops && uevent_ops->filter)
542cfce6f   Aneesh Kumar K.V   kobject: kobject_...
129
  		if (!uevent_ops->filter(kset, kobj)) {
9f66fa2a4   Greg Kroah-Hartman   kobject: clean up...
130
131
132
  			pr_debug("kobject: '%s' (%p): %s: filter function "
  				 "caused the event to drop!
  ",
810304db7   Harvey Harrison   lib: replace rema...
133
  				 kobject_name(kobj), kobj, __func__);
542cfce6f   Aneesh Kumar K.V   kobject: kobject_...
134
135
  			return 0;
  		}
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
136

864062457   Kay Sievers   driver core: fix ...
137
138
139
140
141
142
  	/* originating subsystem */
  	if (uevent_ops && uevent_ops->name)
  		subsystem = uevent_ops->name(kset, kobj);
  	else
  		subsystem = kobject_name(&kset->kobj);
  	if (!subsystem) {
9f66fa2a4   Greg Kroah-Hartman   kobject: clean up...
143
144
145
  		pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the "
  			 "event to drop!
  ", kobject_name(kobj), kobj,
810304db7   Harvey Harrison   lib: replace rema...
146
  			 __func__);
864062457   Kay Sievers   driver core: fix ...
147
148
  		return 0;
  	}
7eff2e7a8   Kay Sievers   Driver core: chan...
149
150
151
  	/* environment buffer */
  	env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
  	if (!env)
542cfce6f   Aneesh Kumar K.V   kobject: kobject_...
152
  		return -ENOMEM;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
153

5f123fbd8   Kay Sievers   [PATCH] merge kob...
154
155
  	/* complete object path */
  	devpath = kobject_get_path(kobj, GFP_KERNEL);
542cfce6f   Aneesh Kumar K.V   kobject: kobject_...
156
157
  	if (!devpath) {
  		retval = -ENOENT;
5f123fbd8   Kay Sievers   [PATCH] merge kob...
158
  		goto exit;
542cfce6f   Aneesh Kumar K.V   kobject: kobject_...
159
  	}
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
160

5f123fbd8   Kay Sievers   [PATCH] merge kob...
161
  	/* default keys */
7eff2e7a8   Kay Sievers   Driver core: chan...
162
163
164
165
166
167
168
169
170
171
172
173
174
  	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++) {
c65b9145f   Tejun Heo   uevent: don't pas...
175
  			retval = add_uevent_var(env, "%s", envp_ext[i]);
7eff2e7a8   Kay Sievers   Driver core: chan...
176
177
178
179
  			if (retval)
  				goto exit;
  		}
  	}
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
180

5f123fbd8   Kay Sievers   [PATCH] merge kob...
181
  	/* let the kset specific function add its stuff */
312c004d3   Kay Sievers   [PATCH] driver co...
182
  	if (uevent_ops && uevent_ops->uevent) {
7eff2e7a8   Kay Sievers   Driver core: chan...
183
  		retval = uevent_ops->uevent(kset, kobj, env);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
184
  		if (retval) {
9f66fa2a4   Greg Kroah-Hartman   kobject: clean up...
185
186
187
  			pr_debug("kobject: '%s' (%p): %s: uevent() returned "
  				 "%d
  ", kobject_name(kobj), kobj,
810304db7   Harvey Harrison   lib: replace rema...
188
  				 __func__, retval);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
189
190
191
  			goto exit;
  		}
  	}
0f4dafc05   Kay Sievers   Kobject: auto-cle...
192
193
194
195
196
197
198
199
200
201
  	/*
  	 * 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;
7eff2e7a8   Kay Sievers   Driver core: chan...
202
  	/* we will send an event, so request a new sequence number */
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
203
  	spin_lock(&sequence_lock);
312c004d3   Kay Sievers   [PATCH] driver co...
204
  	seq = ++uevent_seqnum;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
205
  	spin_unlock(&sequence_lock);
7eff2e7a8   Kay Sievers   Driver core: chan...
206
207
208
  	retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)seq);
  	if (retval)
  		goto exit;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
209

4d17ffda3   Kay Sievers   [PATCH] Kobject: ...
210
  #if defined(CONFIG_NET)
5f123fbd8   Kay Sievers   [PATCH] merge kob...
211
212
213
214
215
216
217
  	/* 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;
7eff2e7a8   Kay Sievers   Driver core: chan...
218
  		skb = alloc_skb(len + env->buflen, GFP_KERNEL);
5f123fbd8   Kay Sievers   [PATCH] merge kob...
219
  		if (skb) {
7eff2e7a8   Kay Sievers   Driver core: chan...
220
  			char *scratch;
5f123fbd8   Kay Sievers   [PATCH] merge kob...
221
222
223
224
225
  			/* add header */
  			scratch = skb_put(skb, len);
  			sprintf(scratch, "%s@%s", action_string, devpath);
  
  			/* copy keys to our continuous event payload buffer */
7eff2e7a8   Kay Sievers   Driver core: chan...
226
227
  			for (i = 0; i < env->envp_idx; i++) {
  				len = strlen(env->envp[i]) + 1;
5f123fbd8   Kay Sievers   [PATCH] merge kob...
228
  				scratch = skb_put(skb, len);
7eff2e7a8   Kay Sievers   Driver core: chan...
229
  				strcpy(scratch, env->envp[i]);
5f123fbd8   Kay Sievers   [PATCH] merge kob...
230
231
232
  			}
  
  			NETLINK_CB(skb).dst_group = 1;
e0d7bf5d5   Ming Lei   kobject: return t...
233
234
  			retval = netlink_broadcast(uevent_sock, skb, 0, 1,
  						   GFP_KERNEL);
ff491a733   Pablo Neira Ayuso   netlink: change r...
235
236
237
  			/* ENOBUFS should be handled in userspace */
  			if (retval == -ENOBUFS)
  				retval = 0;
e0d7bf5d5   Ming Lei   kobject: return t...
238
239
  		} else
  			retval = -ENOMEM;
5f123fbd8   Kay Sievers   [PATCH] merge kob...
240
  	}
4d17ffda3   Kay Sievers   [PATCH] Kobject: ...
241
  #endif
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
242

5f123fbd8   Kay Sievers   [PATCH] merge kob...
243
  	/* call uevent_helper, usually only enabled during early boot */
312c004d3   Kay Sievers   [PATCH] driver co...
244
  	if (uevent_helper[0]) {
5f123fbd8   Kay Sievers   [PATCH] merge kob...
245
  		char *argv [3];
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
246

312c004d3   Kay Sievers   [PATCH] driver co...
247
  		argv [0] = uevent_helper;
5f123fbd8   Kay Sievers   [PATCH] merge kob...
248
249
  		argv [1] = (char *)subsystem;
  		argv [2] = NULL;
7eff2e7a8   Kay Sievers   Driver core: chan...
250
251
252
  		retval = add_uevent_var(env, "HOME=/");
  		if (retval)
  			goto exit;
e374a2bfe   Greg Kroah-Hartman   Kobject: fix codi...
253
254
  		retval = add_uevent_var(env,
  					"PATH=/sbin:/bin:/usr/sbin:/usr/bin");
7eff2e7a8   Kay Sievers   Driver core: chan...
255
256
  		if (retval)
  			goto exit;
0ad1d6f37   Wang Chen   kobject: Transmit...
257
  		retval = call_usermodehelper(argv[0], argv,
05f54c13c   Hugh Dickins   Revert "kobject: ...
258
  					     env->envp, UMH_WAIT_EXEC);
5f123fbd8   Kay Sievers   [PATCH] merge kob...
259
  	}
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
260
261
  
  exit:
5f123fbd8   Kay Sievers   [PATCH] merge kob...
262
  	kfree(devpath);
7eff2e7a8   Kay Sievers   Driver core: chan...
263
  	kfree(env);
542cfce6f   Aneesh Kumar K.V   kobject: kobject_...
264
  	return retval;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
265
  }
8a82472f8   Cornelia Huck   driver core: Intr...
266
267
268
269
270
  EXPORT_SYMBOL_GPL(kobject_uevent_env);
  
  /**
   * kobject_uevent - notify userspace by ending an uevent
   *
ccd490a3c   Kay Sievers   Driver core: kern...
271
   * @action: action that is happening
8a82472f8   Cornelia Huck   driver core: Intr...
272
   * @kobj: struct kobject that the action is happening to
542cfce6f   Aneesh Kumar K.V   kobject: kobject_...
273
274
275
   *
   * Returns 0 if kobject_uevent() is completed with success or the
   * corresponding error when it fails.
8a82472f8   Cornelia Huck   driver core: Intr...
276
   */
542cfce6f   Aneesh Kumar K.V   kobject: kobject_...
277
  int kobject_uevent(struct kobject *kobj, enum kobject_action action)
8a82472f8   Cornelia Huck   driver core: Intr...
278
  {
542cfce6f   Aneesh Kumar K.V   kobject: kobject_...
279
  	return kobject_uevent_env(kobj, action, NULL);
8a82472f8   Cornelia Huck   driver core: Intr...
280
  }
312c004d3   Kay Sievers   [PATCH] driver co...
281
  EXPORT_SYMBOL_GPL(kobject_uevent);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
282
283
  
  /**
7eff2e7a8   Kay Sievers   Driver core: chan...
284
285
286
   * add_uevent_var - add key value string to the environment buffer
   * @env: environment buffer structure
   * @format: printf format for the key=value pair
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
287
288
289
290
   *
   * Returns 0 if environment variable was added successfully or -ENOMEM
   * if no space was available.
   */
7eff2e7a8   Kay Sievers   Driver core: chan...
291
  int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
292
293
  {
  	va_list args;
7eff2e7a8   Kay Sievers   Driver core: chan...
294
  	int len;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
295

7eff2e7a8   Kay Sievers   Driver core: chan...
296
  	if (env->envp_idx >= ARRAY_SIZE(env->envp)) {
5cd2b459d   Arjan van de Ven   Use WARN() in lib/
297
298
  		WARN(1, KERN_ERR "add_uevent_var: too many keys
  ");
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
299
  		return -ENOMEM;
7eff2e7a8   Kay Sievers   Driver core: chan...
300
  	}
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
301
302
  
  	va_start(args, format);
7eff2e7a8   Kay Sievers   Driver core: chan...
303
304
305
  	len = vsnprintf(&env->buf[env->buflen],
  			sizeof(env->buf) - env->buflen,
  			format, args);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
306
  	va_end(args);
7eff2e7a8   Kay Sievers   Driver core: chan...
307
  	if (len >= (sizeof(env->buf) - env->buflen)) {
5cd2b459d   Arjan van de Ven   Use WARN() in lib/
308
309
  		WARN(1, KERN_ERR "add_uevent_var: buffer size too small
  ");
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
310
  		return -ENOMEM;
7eff2e7a8   Kay Sievers   Driver core: chan...
311
  	}
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
312

7eff2e7a8   Kay Sievers   Driver core: chan...
313
314
  	env->envp[env->envp_idx++] = &env->buf[env->buflen];
  	env->buflen += len + 1;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
315
316
  	return 0;
  }
312c004d3   Kay Sievers   [PATCH] driver co...
317
  EXPORT_SYMBOL_GPL(add_uevent_var);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
318

4d17ffda3   Kay Sievers   [PATCH] Kobject: ...
319
  #if defined(CONFIG_NET)
5f123fbd8   Kay Sievers   [PATCH] merge kob...
320
321
  static int __init kobject_uevent_init(void)
  {
b4b510290   Eric W. Biederman   [NET]: Support mu...
322
323
  	uevent_sock = netlink_kernel_create(&init_net, NETLINK_KOBJECT_UEVENT,
  					    1, NULL, NULL, THIS_MODULE);
5f123fbd8   Kay Sievers   [PATCH] merge kob...
324
325
326
327
328
329
  	if (!uevent_sock) {
  		printk(KERN_ERR
  		       "kobject_uevent: unable to create netlink socket!
  ");
  		return -ENODEV;
  	}
d094cbe99   Kay Sievers   driver core: allo...
330
  	netlink_set_nonroot(NETLINK_KOBJECT_UEVENT, NL_NONROOT_RECV);
5f123fbd8   Kay Sievers   [PATCH] merge kob...
331
332
333
334
  	return 0;
  }
  
  postcore_initcall(kobject_uevent_init);
4d17ffda3   Kay Sievers   [PATCH] Kobject: ...
335
  #endif