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> |
19 | #include <linux/kobject.h> | |
8bc3bcc9 PG |
20 | #include <linux/export.h> |
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> | |
1da177e4 | 26 | #include <net/sock.h> |
07e98962 | 27 | #include <net/net_namespace.h> |
1da177e4 | 28 | |
1da177e4 | 29 | |
cd030c4c | 30 | u64 uevent_seqnum; |
86d56134 | 31 | #ifdef CONFIG_UEVENT_HELPER |
6a8d8abb | 32 | char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH; |
86d56134 | 33 | #endif |
07e98962 EB |
34 | #ifdef CONFIG_NET |
35 | struct uevent_sock { | |
36 | struct list_head list; | |
37 | struct sock *sk; | |
38 | }; | |
39 | static LIST_HEAD(uevent_sock_list); | |
cd030c4c CH |
40 | #endif |
41 | ||
7b60a18d AV |
42 | /* This lock protects uevent_seqnum and uevent_sock_list */ |
43 | static DEFINE_MUTEX(uevent_sock_mutex); | |
44 | ||
5c5daf65 KS |
45 | /* the strings here must match the enum in include/linux/kobject.h */ |
46 | static const char *kobject_actions[] = { | |
47 | [KOBJ_ADD] = "add", | |
48 | [KOBJ_REMOVE] = "remove", | |
49 | [KOBJ_CHANGE] = "change", | |
50 | [KOBJ_MOVE] = "move", | |
51 | [KOBJ_ONLINE] = "online", | |
52 | [KOBJ_OFFLINE] = "offline", | |
53 | }; | |
54 | ||
55 | /** | |
56 | * kobject_action_type - translate action string to numeric type | |
57 | * | |
58 | * @buf: buffer containing the action string, newline is ignored | |
59 | * @len: length of buffer | |
60 | * @type: pointer to the location to store the action type | |
61 | * | |
62 | * Returns 0 if the action string was recognized. | |
63 | */ | |
64 | int kobject_action_type(const char *buf, size_t count, | |
65 | enum kobject_action *type) | |
66 | { | |
67 | enum kobject_action action; | |
68 | int ret = -EINVAL; | |
69 | ||
a9edadbf | 70 | if (count && (buf[count-1] == '\n' || buf[count-1] == '\0')) |
5c5daf65 KS |
71 | count--; |
72 | ||
73 | if (!count) | |
74 | goto out; | |
75 | ||
76 | for (action = 0; action < ARRAY_SIZE(kobject_actions); action++) { | |
77 | if (strncmp(kobject_actions[action], buf, count) != 0) | |
78 | continue; | |
79 | if (kobject_actions[action][count] != '\0') | |
80 | continue; | |
81 | *type = action; | |
82 | ret = 0; | |
83 | break; | |
84 | } | |
85 | out: | |
86 | return ret; | |
87 | } | |
88 | ||
c8421286 | 89 | #ifdef CONFIG_NET |
5f71a296 EB |
90 | static int kobj_bcast_filter(struct sock *dsk, struct sk_buff *skb, void *data) |
91 | { | |
82ef3d5d | 92 | struct kobject *kobj = data, *ksobj; |
5f71a296 EB |
93 | const struct kobj_ns_type_operations *ops; |
94 | ||
95 | ops = kobj_ns_ops(kobj); | |
82ef3d5d WC |
96 | if (!ops && kobj->kset) { |
97 | ksobj = &kobj->kset->kobj; | |
98 | if (ksobj->parent != NULL) | |
99 | ops = kobj_ns_ops(ksobj->parent); | |
100 | } | |
101 | ||
102 | if (ops && ops->netlink_ns && kobj->ktype->namespace) { | |
5f71a296 EB |
103 | const void *sock_ns, *ns; |
104 | ns = kobj->ktype->namespace(kobj); | |
105 | sock_ns = ops->netlink_ns(dsk); | |
106 | return sock_ns != ns; | |
107 | } | |
108 | ||
109 | return 0; | |
110 | } | |
c8421286 | 111 | #endif |
5f71a296 | 112 | |
86d56134 | 113 | #ifdef CONFIG_UEVENT_HELPER |
417daa1e EB |
114 | static int kobj_usermode_filter(struct kobject *kobj) |
115 | { | |
116 | const struct kobj_ns_type_operations *ops; | |
117 | ||
118 | ops = kobj_ns_ops(kobj); | |
119 | if (ops) { | |
120 | const void *init_ns, *ns; | |
121 | ns = kobj->ktype->namespace(kobj); | |
122 | init_ns = ops->initial_ns(); | |
123 | return ns != init_ns; | |
124 | } | |
125 | ||
126 | return 0; | |
127 | } | |
128 | ||
bcccff93 VD |
129 | static int init_uevent_argv(struct kobj_uevent_env *env, const char *subsystem) |
130 | { | |
131 | int len; | |
132 | ||
133 | len = strlcpy(&env->buf[env->buflen], subsystem, | |
134 | sizeof(env->buf) - env->buflen); | |
135 | if (len >= (sizeof(env->buf) - env->buflen)) { | |
136 | WARN(1, KERN_ERR "init_uevent_argv: buffer size too small\n"); | |
137 | return -ENOMEM; | |
138 | } | |
139 | ||
140 | env->argv[0] = uevent_helper; | |
141 | env->argv[1] = &env->buf[env->buflen]; | |
142 | env->argv[2] = NULL; | |
143 | ||
144 | env->buflen += len + 1; | |
145 | return 0; | |
146 | } | |
147 | ||
148 | static void cleanup_uevent_env(struct subprocess_info *info) | |
149 | { | |
150 | kfree(info->data); | |
151 | } | |
86d56134 | 152 | #endif |
bcccff93 | 153 | |
1da177e4 | 154 | /** |
8a82472f | 155 | * kobject_uevent_env - send an uevent with environmental data |
1da177e4 | 156 | * |
ccd490a3 | 157 | * @action: action that is happening |
1da177e4 | 158 | * @kobj: struct kobject that the action is happening to |
8a82472f | 159 | * @envp_ext: pointer to environmental data |
542cfce6 | 160 | * |
f6e6e779 | 161 | * Returns 0 if kobject_uevent_env() is completed with success or the |
542cfce6 | 162 | * corresponding error when it fails. |
1da177e4 | 163 | */ |
542cfce6 | 164 | int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, |
7eff2e7a | 165 | char *envp_ext[]) |
1da177e4 | 166 | { |
7eff2e7a KS |
167 | struct kobj_uevent_env *env; |
168 | const char *action_string = kobject_actions[action]; | |
5f123fbd KS |
169 | const char *devpath = NULL; |
170 | const char *subsystem; | |
171 | struct kobject *top_kobj; | |
172 | struct kset *kset; | |
9cd43611 | 173 | const struct kset_uevent_ops *uevent_ops; |
1da177e4 | 174 | int i = 0; |
542cfce6 | 175 | int retval = 0; |
07e98962 EB |
176 | #ifdef CONFIG_NET |
177 | struct uevent_sock *ue_sk; | |
178 | #endif | |
1da177e4 | 179 | |
9f66fa2a | 180 | pr_debug("kobject: '%s' (%p): %s\n", |
810304db | 181 | kobject_name(kobj), kobj, __func__); |
5f123fbd | 182 | |
5f123fbd KS |
183 | /* search the kset we belong to */ |
184 | top_kobj = kobj; | |
ccd490a3 | 185 | while (!top_kobj->kset && top_kobj->parent) |
14193fb9 | 186 | top_kobj = top_kobj->parent; |
ccd490a3 | 187 | |
542cfce6 | 188 | if (!top_kobj->kset) { |
9f66fa2a GKH |
189 | pr_debug("kobject: '%s' (%p): %s: attempted to send uevent " |
190 | "without kset!\n", kobject_name(kobj), kobj, | |
810304db | 191 | __func__); |
542cfce6 AK |
192 | return -EINVAL; |
193 | } | |
1da177e4 | 194 | |
5f123fbd | 195 | kset = top_kobj->kset; |
312c004d | 196 | uevent_ops = kset->uevent_ops; |
1da177e4 | 197 | |
f67f129e ML |
198 | /* skip the event, if uevent_suppress is set*/ |
199 | if (kobj->uevent_suppress) { | |
200 | pr_debug("kobject: '%s' (%p): %s: uevent_suppress " | |
201 | "caused the event to drop!\n", | |
202 | kobject_name(kobj), kobj, __func__); | |
203 | return 0; | |
204 | } | |
7eff2e7a | 205 | /* skip the event, if the filter returns zero. */ |
312c004d | 206 | if (uevent_ops && uevent_ops->filter) |
542cfce6 | 207 | if (!uevent_ops->filter(kset, kobj)) { |
9f66fa2a GKH |
208 | pr_debug("kobject: '%s' (%p): %s: filter function " |
209 | "caused the event to drop!\n", | |
810304db | 210 | kobject_name(kobj), kobj, __func__); |
542cfce6 AK |
211 | return 0; |
212 | } | |
1da177e4 | 213 | |
86406245 KS |
214 | /* originating subsystem */ |
215 | if (uevent_ops && uevent_ops->name) | |
216 | subsystem = uevent_ops->name(kset, kobj); | |
217 | else | |
218 | subsystem = kobject_name(&kset->kobj); | |
219 | if (!subsystem) { | |
9f66fa2a GKH |
220 | pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the " |
221 | "event to drop!\n", kobject_name(kobj), kobj, | |
810304db | 222 | __func__); |
86406245 KS |
223 | return 0; |
224 | } | |
225 | ||
7eff2e7a KS |
226 | /* environment buffer */ |
227 | env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL); | |
228 | if (!env) | |
542cfce6 | 229 | return -ENOMEM; |
1da177e4 | 230 | |
5f123fbd KS |
231 | /* complete object path */ |
232 | devpath = kobject_get_path(kobj, GFP_KERNEL); | |
542cfce6 AK |
233 | if (!devpath) { |
234 | retval = -ENOENT; | |
5f123fbd | 235 | goto exit; |
542cfce6 | 236 | } |
1da177e4 | 237 | |
5f123fbd | 238 | /* default keys */ |
7eff2e7a KS |
239 | retval = add_uevent_var(env, "ACTION=%s", action_string); |
240 | if (retval) | |
241 | goto exit; | |
242 | retval = add_uevent_var(env, "DEVPATH=%s", devpath); | |
243 | if (retval) | |
244 | goto exit; | |
245 | retval = add_uevent_var(env, "SUBSYSTEM=%s", subsystem); | |
246 | if (retval) | |
247 | goto exit; | |
248 | ||
249 | /* keys passed in from the caller */ | |
250 | if (envp_ext) { | |
251 | for (i = 0; envp_ext[i]; i++) { | |
c65b9145 | 252 | retval = add_uevent_var(env, "%s", envp_ext[i]); |
7eff2e7a KS |
253 | if (retval) |
254 | goto exit; | |
255 | } | |
256 | } | |
1da177e4 | 257 | |
5f123fbd | 258 | /* let the kset specific function add its stuff */ |
312c004d | 259 | if (uevent_ops && uevent_ops->uevent) { |
7eff2e7a | 260 | retval = uevent_ops->uevent(kset, kobj, env); |
1da177e4 | 261 | if (retval) { |
9f66fa2a GKH |
262 | pr_debug("kobject: '%s' (%p): %s: uevent() returned " |
263 | "%d\n", kobject_name(kobj), kobj, | |
810304db | 264 | __func__, retval); |
1da177e4 LT |
265 | goto exit; |
266 | } | |
267 | } | |
268 | ||
0f4dafc0 KS |
269 | /* |
270 | * Mark "add" and "remove" events in the object to ensure proper | |
271 | * events to userspace during automatic cleanup. If the object did | |
272 | * send an "add" event, "remove" will automatically generated by | |
273 | * the core, if not already done by the caller. | |
274 | */ | |
275 | if (action == KOBJ_ADD) | |
276 | kobj->state_add_uevent_sent = 1; | |
277 | else if (action == KOBJ_REMOVE) | |
278 | kobj->state_remove_uevent_sent = 1; | |
279 | ||
7b60a18d | 280 | mutex_lock(&uevent_sock_mutex); |
7eff2e7a | 281 | /* we will send an event, so request a new sequence number */ |
7b60a18d AV |
282 | retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)++uevent_seqnum); |
283 | if (retval) { | |
284 | mutex_unlock(&uevent_sock_mutex); | |
7eff2e7a | 285 | goto exit; |
7b60a18d | 286 | } |
1da177e4 | 287 | |
4d17ffda | 288 | #if defined(CONFIG_NET) |
5f123fbd | 289 | /* send netlink message */ |
07e98962 EB |
290 | list_for_each_entry(ue_sk, &uevent_sock_list, list) { |
291 | struct sock *uevent_sock = ue_sk->sk; | |
5f123fbd KS |
292 | struct sk_buff *skb; |
293 | size_t len; | |
294 | ||
74099b18 KS |
295 | if (!netlink_has_listeners(uevent_sock, 1)) |
296 | continue; | |
297 | ||
5f123fbd KS |
298 | /* allocate message with the maximum possible size */ |
299 | len = strlen(action_string) + strlen(devpath) + 2; | |
7eff2e7a | 300 | skb = alloc_skb(len + env->buflen, GFP_KERNEL); |
5f123fbd | 301 | if (skb) { |
7eff2e7a KS |
302 | char *scratch; |
303 | ||
5f123fbd KS |
304 | /* add header */ |
305 | scratch = skb_put(skb, len); | |
306 | sprintf(scratch, "%s@%s", action_string, devpath); | |
307 | ||
308 | /* copy keys to our continuous event payload buffer */ | |
7eff2e7a KS |
309 | for (i = 0; i < env->envp_idx; i++) { |
310 | len = strlen(env->envp[i]) + 1; | |
5f123fbd | 311 | scratch = skb_put(skb, len); |
7eff2e7a | 312 | strcpy(scratch, env->envp[i]); |
5f123fbd KS |
313 | } |
314 | ||
315 | NETLINK_CB(skb).dst_group = 1; | |
5f71a296 EB |
316 | retval = netlink_broadcast_filtered(uevent_sock, skb, |
317 | 0, 1, GFP_KERNEL, | |
318 | kobj_bcast_filter, | |
319 | kobj); | |
ff491a73 | 320 | /* ENOBUFS should be handled in userspace */ |
ebf4127c | 321 | if (retval == -ENOBUFS || retval == -ESRCH) |
ff491a73 | 322 | retval = 0; |
e0d7bf5d ML |
323 | } else |
324 | retval = -ENOMEM; | |
5f123fbd | 325 | } |
4d17ffda | 326 | #endif |
7b60a18d | 327 | mutex_unlock(&uevent_sock_mutex); |
1da177e4 | 328 | |
86d56134 | 329 | #ifdef CONFIG_UEVENT_HELPER |
5f123fbd | 330 | /* call uevent_helper, usually only enabled during early boot */ |
417daa1e | 331 | if (uevent_helper[0] && !kobj_usermode_filter(kobj)) { |
bcccff93 | 332 | struct subprocess_info *info; |
1da177e4 | 333 | |
7eff2e7a KS |
334 | retval = add_uevent_var(env, "HOME=/"); |
335 | if (retval) | |
336 | goto exit; | |
e374a2bf GKH |
337 | retval = add_uevent_var(env, |
338 | "PATH=/sbin:/bin:/usr/sbin:/usr/bin"); | |
7eff2e7a KS |
339 | if (retval) |
340 | goto exit; | |
bcccff93 VD |
341 | retval = init_uevent_argv(env, subsystem); |
342 | if (retval) | |
343 | goto exit; | |
7eff2e7a | 344 | |
bcccff93 VD |
345 | retval = -ENOMEM; |
346 | info = call_usermodehelper_setup(env->argv[0], env->argv, | |
347 | env->envp, GFP_KERNEL, | |
348 | NULL, cleanup_uevent_env, env); | |
349 | if (info) { | |
350 | retval = call_usermodehelper_exec(info, UMH_NO_WAIT); | |
351 | env = NULL; /* freed by cleanup_uevent_env */ | |
352 | } | |
5f123fbd | 353 | } |
86d56134 | 354 | #endif |
1da177e4 LT |
355 | |
356 | exit: | |
5f123fbd | 357 | kfree(devpath); |
7eff2e7a | 358 | kfree(env); |
542cfce6 | 359 | return retval; |
1da177e4 | 360 | } |
8a82472f CH |
361 | EXPORT_SYMBOL_GPL(kobject_uevent_env); |
362 | ||
363 | /** | |
f6e6e779 | 364 | * kobject_uevent - notify userspace by sending an uevent |
8a82472f | 365 | * |
ccd490a3 | 366 | * @action: action that is happening |
8a82472f | 367 | * @kobj: struct kobject that the action is happening to |
542cfce6 AK |
368 | * |
369 | * Returns 0 if kobject_uevent() is completed with success or the | |
370 | * corresponding error when it fails. | |
8a82472f | 371 | */ |
542cfce6 | 372 | int kobject_uevent(struct kobject *kobj, enum kobject_action action) |
8a82472f | 373 | { |
542cfce6 | 374 | return kobject_uevent_env(kobj, action, NULL); |
8a82472f | 375 | } |
312c004d | 376 | EXPORT_SYMBOL_GPL(kobject_uevent); |
1da177e4 LT |
377 | |
378 | /** | |
7eff2e7a KS |
379 | * add_uevent_var - add key value string to the environment buffer |
380 | * @env: environment buffer structure | |
381 | * @format: printf format for the key=value pair | |
1da177e4 LT |
382 | * |
383 | * Returns 0 if environment variable was added successfully or -ENOMEM | |
384 | * if no space was available. | |
385 | */ | |
7eff2e7a | 386 | int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...) |
1da177e4 LT |
387 | { |
388 | va_list args; | |
7eff2e7a | 389 | int len; |
1da177e4 | 390 | |
7eff2e7a | 391 | if (env->envp_idx >= ARRAY_SIZE(env->envp)) { |
5cd2b459 | 392 | WARN(1, KERN_ERR "add_uevent_var: too many keys\n"); |
1da177e4 | 393 | return -ENOMEM; |
7eff2e7a | 394 | } |
1da177e4 LT |
395 | |
396 | va_start(args, format); | |
7eff2e7a KS |
397 | len = vsnprintf(&env->buf[env->buflen], |
398 | sizeof(env->buf) - env->buflen, | |
399 | format, args); | |
1da177e4 LT |
400 | va_end(args); |
401 | ||
7eff2e7a | 402 | if (len >= (sizeof(env->buf) - env->buflen)) { |
5cd2b459 | 403 | WARN(1, KERN_ERR "add_uevent_var: buffer size too small\n"); |
1da177e4 | 404 | return -ENOMEM; |
7eff2e7a | 405 | } |
1da177e4 | 406 | |
7eff2e7a KS |
407 | env->envp[env->envp_idx++] = &env->buf[env->buflen]; |
408 | env->buflen += len + 1; | |
1da177e4 LT |
409 | return 0; |
410 | } | |
312c004d | 411 | EXPORT_SYMBOL_GPL(add_uevent_var); |
1da177e4 | 412 | |
4d17ffda | 413 | #if defined(CONFIG_NET) |
07e98962 | 414 | static int uevent_net_init(struct net *net) |
5f123fbd | 415 | { |
07e98962 | 416 | struct uevent_sock *ue_sk; |
a31f2d17 PNA |
417 | struct netlink_kernel_cfg cfg = { |
418 | .groups = 1, | |
9785e10a | 419 | .flags = NL_CFG_F_NONROOT_RECV, |
a31f2d17 | 420 | }; |
07e98962 EB |
421 | |
422 | ue_sk = kzalloc(sizeof(*ue_sk), GFP_KERNEL); | |
423 | if (!ue_sk) | |
424 | return -ENOMEM; | |
425 | ||
9f00d977 | 426 | ue_sk->sk = netlink_kernel_create(net, NETLINK_KOBJECT_UEVENT, &cfg); |
07e98962 | 427 | if (!ue_sk->sk) { |
5f123fbd KS |
428 | printk(KERN_ERR |
429 | "kobject_uevent: unable to create netlink socket!\n"); | |
743db2d9 | 430 | kfree(ue_sk); |
5f123fbd KS |
431 | return -ENODEV; |
432 | } | |
07e98962 EB |
433 | mutex_lock(&uevent_sock_mutex); |
434 | list_add_tail(&ue_sk->list, &uevent_sock_list); | |
435 | mutex_unlock(&uevent_sock_mutex); | |
5f123fbd KS |
436 | return 0; |
437 | } | |
438 | ||
07e98962 EB |
439 | static void uevent_net_exit(struct net *net) |
440 | { | |
441 | struct uevent_sock *ue_sk; | |
442 | ||
443 | mutex_lock(&uevent_sock_mutex); | |
444 | list_for_each_entry(ue_sk, &uevent_sock_list, list) { | |
445 | if (sock_net(ue_sk->sk) == net) | |
446 | goto found; | |
447 | } | |
448 | mutex_unlock(&uevent_sock_mutex); | |
449 | return; | |
450 | ||
451 | found: | |
452 | list_del(&ue_sk->list); | |
453 | mutex_unlock(&uevent_sock_mutex); | |
454 | ||
455 | netlink_kernel_release(ue_sk->sk); | |
456 | kfree(ue_sk); | |
457 | } | |
458 | ||
459 | static struct pernet_operations uevent_net_ops = { | |
460 | .init = uevent_net_init, | |
461 | .exit = uevent_net_exit, | |
462 | }; | |
463 | ||
464 | static int __init kobject_uevent_init(void) | |
465 | { | |
07e98962 EB |
466 | return register_pernet_subsys(&uevent_net_ops); |
467 | } | |
468 | ||
469 | ||
5f123fbd | 470 | postcore_initcall(kobject_uevent_init); |
4d17ffda | 471 | #endif |