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Commit | Line | Data |
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d9d16e16 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * kernel userspace event delivery | |
4 | * | |
5 | * Copyright (C) 2004 Red Hat, Inc. All rights reserved. | |
6 | * Copyright (C) 2004 Novell, Inc. All rights reserved. | |
7 | * Copyright (C) 2004 IBM, Inc. All rights reserved. | |
8 | * | |
1da177e4 LT |
9 | * Authors: |
10 | * Robert Love <rml@novell.com> | |
11 | * Kay Sievers <kay.sievers@vrfy.org> | |
12 | * Arjan van de Ven <arjanv@redhat.com> | |
13 | * Greg Kroah-Hartman <greg@kroah.com> | |
14 | */ | |
15 | ||
16 | #include <linux/spinlock.h> | |
2d38f9a4 DL |
17 | #include <linux/string.h> |
18 | #include <linux/kobject.h> | |
8bc3bcc9 PG |
19 | #include <linux/export.h> |
20 | #include <linux/kmod.h> | |
5a0e3ad6 | 21 | #include <linux/slab.h> |
1da177e4 LT |
22 | #include <linux/socket.h> |
23 | #include <linux/skbuff.h> | |
24 | #include <linux/netlink.h> | |
f36776fa PR |
25 | #include <linux/uuid.h> |
26 | #include <linux/ctype.h> | |
1da177e4 | 27 | #include <net/sock.h> |
692ec06d | 28 | #include <net/netlink.h> |
07e98962 | 29 | #include <net/net_namespace.h> |
1da177e4 | 30 | |
1da177e4 | 31 | |
cd030c4c | 32 | u64 uevent_seqnum; |
86d56134 | 33 | #ifdef CONFIG_UEVENT_HELPER |
6a8d8abb | 34 | char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH; |
86d56134 | 35 | #endif |
94e5e308 | 36 | |
07e98962 EB |
37 | struct uevent_sock { |
38 | struct list_head list; | |
39 | struct sock *sk; | |
40 | }; | |
94e5e308 CB |
41 | |
42 | #ifdef CONFIG_NET | |
07e98962 | 43 | static LIST_HEAD(uevent_sock_list); |
cd030c4c CH |
44 | #endif |
45 | ||
7b60a18d AV |
46 | /* This lock protects uevent_seqnum and uevent_sock_list */ |
47 | static DEFINE_MUTEX(uevent_sock_mutex); | |
48 | ||
5c5daf65 KS |
49 | /* the strings here must match the enum in include/linux/kobject.h */ |
50 | static const char *kobject_actions[] = { | |
51 | [KOBJ_ADD] = "add", | |
52 | [KOBJ_REMOVE] = "remove", | |
53 | [KOBJ_CHANGE] = "change", | |
54 | [KOBJ_MOVE] = "move", | |
55 | [KOBJ_ONLINE] = "online", | |
56 | [KOBJ_OFFLINE] = "offline", | |
1455cf8d DT |
57 | [KOBJ_BIND] = "bind", |
58 | [KOBJ_UNBIND] = "unbind", | |
5c5daf65 KS |
59 | }; |
60 | ||
f36776fa PR |
61 | static int kobject_action_type(const char *buf, size_t count, |
62 | enum kobject_action *type, | |
63 | const char **args) | |
5c5daf65 KS |
64 | { |
65 | enum kobject_action action; | |
f36776fa PR |
66 | size_t count_first; |
67 | const char *args_start; | |
5c5daf65 KS |
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 | ||
f36776fa PR |
76 | args_start = strnchr(buf, count, ' '); |
77 | if (args_start) { | |
78 | count_first = args_start - buf; | |
79 | args_start = args_start + 1; | |
80 | } else | |
81 | count_first = count; | |
82 | ||
5c5daf65 | 83 | for (action = 0; action < ARRAY_SIZE(kobject_actions); action++) { |
f36776fa | 84 | if (strncmp(kobject_actions[action], buf, count_first) != 0) |
5c5daf65 | 85 | continue; |
f36776fa | 86 | if (kobject_actions[action][count_first] != '\0') |
5c5daf65 | 87 | continue; |
f36776fa PR |
88 | if (args) |
89 | *args = args_start; | |
5c5daf65 KS |
90 | *type = action; |
91 | ret = 0; | |
92 | break; | |
93 | } | |
94 | out: | |
95 | return ret; | |
96 | } | |
97 | ||
f36776fa PR |
98 | static const char *action_arg_word_end(const char *buf, const char *buf_end, |
99 | char delim) | |
100 | { | |
101 | const char *next = buf; | |
102 | ||
103 | while (next <= buf_end && *next != delim) | |
104 | if (!isalnum(*next++)) | |
105 | return NULL; | |
106 | ||
107 | if (next == buf) | |
108 | return NULL; | |
109 | ||
110 | return next; | |
111 | } | |
112 | ||
113 | static int kobject_action_args(const char *buf, size_t count, | |
114 | struct kobj_uevent_env **ret_env) | |
115 | { | |
116 | struct kobj_uevent_env *env = NULL; | |
117 | const char *next, *buf_end, *key; | |
118 | int key_len; | |
119 | int r = -EINVAL; | |
120 | ||
121 | if (count && (buf[count - 1] == '\n' || buf[count - 1] == '\0')) | |
122 | count--; | |
123 | ||
124 | if (!count) | |
125 | return -EINVAL; | |
126 | ||
127 | env = kzalloc(sizeof(*env), GFP_KERNEL); | |
128 | if (!env) | |
129 | return -ENOMEM; | |
130 | ||
131 | /* first arg is UUID */ | |
132 | if (count < UUID_STRING_LEN || !uuid_is_valid(buf) || | |
133 | add_uevent_var(env, "SYNTH_UUID=%.*s", UUID_STRING_LEN, buf)) | |
134 | goto out; | |
135 | ||
136 | /* | |
137 | * the rest are custom environment variables in KEY=VALUE | |
138 | * format with ' ' delimiter between each KEY=VALUE pair | |
139 | */ | |
140 | next = buf + UUID_STRING_LEN; | |
141 | buf_end = buf + count - 1; | |
142 | ||
143 | while (next <= buf_end) { | |
144 | if (*next != ' ') | |
145 | goto out; | |
146 | ||
147 | /* skip the ' ', key must follow */ | |
148 | key = ++next; | |
149 | if (key > buf_end) | |
150 | goto out; | |
151 | ||
152 | buf = next; | |
153 | next = action_arg_word_end(buf, buf_end, '='); | |
154 | if (!next || next > buf_end || *next != '=') | |
155 | goto out; | |
156 | key_len = next - buf; | |
157 | ||
158 | /* skip the '=', value must follow */ | |
159 | if (++next > buf_end) | |
160 | goto out; | |
161 | ||
162 | buf = next; | |
163 | next = action_arg_word_end(buf, buf_end, ' '); | |
164 | if (!next) | |
165 | goto out; | |
166 | ||
167 | if (add_uevent_var(env, "SYNTH_ARG_%.*s=%.*s", | |
168 | key_len, key, (int) (next - buf), buf)) | |
169 | goto out; | |
170 | } | |
171 | ||
172 | r = 0; | |
173 | out: | |
174 | if (r) | |
175 | kfree(env); | |
176 | else | |
177 | *ret_env = env; | |
178 | return r; | |
179 | } | |
180 | ||
181 | /** | |
182 | * kobject_synth_uevent - send synthetic uevent with arguments | |
183 | * | |
184 | * @kobj: struct kobject for which synthetic uevent is to be generated | |
185 | * @buf: buffer containing action type and action args, newline is ignored | |
186 | * @count: length of buffer | |
187 | * | |
188 | * Returns 0 if kobject_synthetic_uevent() is completed with success or the | |
189 | * corresponding error when it fails. | |
190 | */ | |
191 | int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count) | |
192 | { | |
193 | char *no_uuid_envp[] = { "SYNTH_UUID=0", NULL }; | |
194 | enum kobject_action action; | |
195 | const char *action_args; | |
196 | struct kobj_uevent_env *env; | |
197 | const char *msg = NULL, *devpath; | |
198 | int r; | |
199 | ||
200 | r = kobject_action_type(buf, count, &action, &action_args); | |
201 | if (r) { | |
202 | msg = "unknown uevent action string\n"; | |
203 | goto out; | |
204 | } | |
205 | ||
206 | if (!action_args) { | |
207 | r = kobject_uevent_env(kobj, action, no_uuid_envp); | |
208 | goto out; | |
209 | } | |
210 | ||
211 | r = kobject_action_args(action_args, | |
212 | count - (action_args - buf), &env); | |
213 | if (r == -EINVAL) { | |
214 | msg = "incorrect uevent action arguments\n"; | |
215 | goto out; | |
216 | } | |
217 | ||
218 | if (r) | |
219 | goto out; | |
220 | ||
221 | r = kobject_uevent_env(kobj, action, env->envp); | |
222 | kfree(env); | |
223 | out: | |
224 | if (r) { | |
225 | devpath = kobject_get_path(kobj, GFP_KERNEL); | |
226 | printk(KERN_WARNING "synth uevent: %s: %s", | |
227 | devpath ?: "unknown device", | |
228 | msg ?: "failed to send uevent"); | |
229 | kfree(devpath); | |
230 | } | |
231 | return r; | |
232 | } | |
233 | ||
c8421286 | 234 | #ifdef CONFIG_NET |
5f71a296 EB |
235 | static int kobj_bcast_filter(struct sock *dsk, struct sk_buff *skb, void *data) |
236 | { | |
82ef3d5d | 237 | struct kobject *kobj = data, *ksobj; |
5f71a296 EB |
238 | const struct kobj_ns_type_operations *ops; |
239 | ||
240 | ops = kobj_ns_ops(kobj); | |
82ef3d5d WC |
241 | if (!ops && kobj->kset) { |
242 | ksobj = &kobj->kset->kobj; | |
243 | if (ksobj->parent != NULL) | |
244 | ops = kobj_ns_ops(ksobj->parent); | |
245 | } | |
246 | ||
247 | if (ops && ops->netlink_ns && kobj->ktype->namespace) { | |
5f71a296 EB |
248 | const void *sock_ns, *ns; |
249 | ns = kobj->ktype->namespace(kobj); | |
250 | sock_ns = ops->netlink_ns(dsk); | |
251 | return sock_ns != ns; | |
252 | } | |
253 | ||
254 | return 0; | |
255 | } | |
c8421286 | 256 | #endif |
5f71a296 | 257 | |
86d56134 | 258 | #ifdef CONFIG_UEVENT_HELPER |
417daa1e EB |
259 | static int kobj_usermode_filter(struct kobject *kobj) |
260 | { | |
261 | const struct kobj_ns_type_operations *ops; | |
262 | ||
263 | ops = kobj_ns_ops(kobj); | |
264 | if (ops) { | |
265 | const void *init_ns, *ns; | |
266 | ns = kobj->ktype->namespace(kobj); | |
267 | init_ns = ops->initial_ns(); | |
268 | return ns != init_ns; | |
269 | } | |
270 | ||
271 | return 0; | |
272 | } | |
273 | ||
bcccff93 VD |
274 | static int init_uevent_argv(struct kobj_uevent_env *env, const char *subsystem) |
275 | { | |
276 | int len; | |
277 | ||
278 | len = strlcpy(&env->buf[env->buflen], subsystem, | |
279 | sizeof(env->buf) - env->buflen); | |
280 | if (len >= (sizeof(env->buf) - env->buflen)) { | |
281 | WARN(1, KERN_ERR "init_uevent_argv: buffer size too small\n"); | |
282 | return -ENOMEM; | |
283 | } | |
284 | ||
285 | env->argv[0] = uevent_helper; | |
286 | env->argv[1] = &env->buf[env->buflen]; | |
287 | env->argv[2] = NULL; | |
288 | ||
289 | env->buflen += len + 1; | |
290 | return 0; | |
291 | } | |
292 | ||
293 | static void cleanup_uevent_env(struct subprocess_info *info) | |
294 | { | |
295 | kfree(info->data); | |
296 | } | |
86d56134 | 297 | #endif |
bcccff93 | 298 | |
16dff336 ED |
299 | static int kobject_uevent_net_broadcast(struct kobject *kobj, |
300 | struct kobj_uevent_env *env, | |
301 | const char *action_string, | |
302 | const char *devpath) | |
303 | { | |
304 | int retval = 0; | |
305 | #if defined(CONFIG_NET) | |
d464e84e | 306 | struct sk_buff *skb = NULL; |
16dff336 ED |
307 | struct uevent_sock *ue_sk; |
308 | ||
309 | /* send netlink message */ | |
310 | list_for_each_entry(ue_sk, &uevent_sock_list, list) { | |
311 | struct sock *uevent_sock = ue_sk->sk; | |
16dff336 ED |
312 | |
313 | if (!netlink_has_listeners(uevent_sock, 1)) | |
314 | continue; | |
315 | ||
d464e84e ED |
316 | if (!skb) { |
317 | /* allocate message with the maximum possible size */ | |
318 | size_t len = strlen(action_string) + strlen(devpath) + 2; | |
16dff336 | 319 | char *scratch; |
16dff336 | 320 | |
d464e84e ED |
321 | retval = -ENOMEM; |
322 | skb = alloc_skb(len + env->buflen, GFP_KERNEL); | |
323 | if (!skb) | |
324 | continue; | |
325 | ||
16dff336 ED |
326 | /* add header */ |
327 | scratch = skb_put(skb, len); | |
328 | sprintf(scratch, "%s@%s", action_string, devpath); | |
329 | ||
4a336a23 | 330 | skb_put_data(skb, env->buf, env->buflen); |
16dff336 ED |
331 | |
332 | NETLINK_CB(skb).dst_group = 1; | |
d464e84e ED |
333 | } |
334 | ||
335 | retval = netlink_broadcast_filtered(uevent_sock, skb_get(skb), | |
336 | 0, 1, GFP_KERNEL, | |
337 | kobj_bcast_filter, | |
338 | kobj); | |
339 | /* ENOBUFS should be handled in userspace */ | |
340 | if (retval == -ENOBUFS || retval == -ESRCH) | |
341 | retval = 0; | |
16dff336 | 342 | } |
d464e84e | 343 | consume_skb(skb); |
16dff336 ED |
344 | #endif |
345 | return retval; | |
346 | } | |
347 | ||
6878e7de DT |
348 | static void zap_modalias_env(struct kobj_uevent_env *env) |
349 | { | |
350 | static const char modalias_prefix[] = "MODALIAS="; | |
9b3fa47d DT |
351 | size_t len; |
352 | int i, j; | |
6878e7de DT |
353 | |
354 | for (i = 0; i < env->envp_idx;) { | |
355 | if (strncmp(env->envp[i], modalias_prefix, | |
356 | sizeof(modalias_prefix) - 1)) { | |
357 | i++; | |
358 | continue; | |
359 | } | |
360 | ||
9b3fa47d DT |
361 | len = strlen(env->envp[i]) + 1; |
362 | ||
363 | if (i != env->envp_idx - 1) { | |
364 | memmove(env->envp[i], env->envp[i + 1], | |
365 | env->buflen - len); | |
366 | ||
367 | for (j = i; j < env->envp_idx - 1; j++) | |
368 | env->envp[j] = env->envp[j + 1] - len; | |
369 | } | |
6878e7de DT |
370 | |
371 | env->envp_idx--; | |
9b3fa47d | 372 | env->buflen -= len; |
6878e7de DT |
373 | } |
374 | } | |
375 | ||
1da177e4 | 376 | /** |
8a82472f | 377 | * kobject_uevent_env - send an uevent with environmental data |
1da177e4 | 378 | * |
1da177e4 | 379 | * @kobj: struct kobject that the action is happening to |
edbbf994 | 380 | * @action: action that is happening |
8a82472f | 381 | * @envp_ext: pointer to environmental data |
542cfce6 | 382 | * |
f6e6e779 | 383 | * Returns 0 if kobject_uevent_env() is completed with success or the |
542cfce6 | 384 | * corresponding error when it fails. |
1da177e4 | 385 | */ |
542cfce6 | 386 | int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, |
7eff2e7a | 387 | char *envp_ext[]) |
1da177e4 | 388 | { |
7eff2e7a KS |
389 | struct kobj_uevent_env *env; |
390 | const char *action_string = kobject_actions[action]; | |
5f123fbd KS |
391 | const char *devpath = NULL; |
392 | const char *subsystem; | |
393 | struct kobject *top_kobj; | |
394 | struct kset *kset; | |
9cd43611 | 395 | const struct kset_uevent_ops *uevent_ops; |
1da177e4 | 396 | int i = 0; |
542cfce6 | 397 | int retval = 0; |
1da177e4 | 398 | |
9f66fa2a | 399 | pr_debug("kobject: '%s' (%p): %s\n", |
810304db | 400 | kobject_name(kobj), kobj, __func__); |
5f123fbd | 401 | |
5f123fbd KS |
402 | /* search the kset we belong to */ |
403 | top_kobj = kobj; | |
ccd490a3 | 404 | while (!top_kobj->kset && top_kobj->parent) |
14193fb9 | 405 | top_kobj = top_kobj->parent; |
ccd490a3 | 406 | |
542cfce6 | 407 | if (!top_kobj->kset) { |
9f66fa2a GKH |
408 | pr_debug("kobject: '%s' (%p): %s: attempted to send uevent " |
409 | "without kset!\n", kobject_name(kobj), kobj, | |
810304db | 410 | __func__); |
542cfce6 AK |
411 | return -EINVAL; |
412 | } | |
1da177e4 | 413 | |
5f123fbd | 414 | kset = top_kobj->kset; |
312c004d | 415 | uevent_ops = kset->uevent_ops; |
1da177e4 | 416 | |
f67f129e ML |
417 | /* skip the event, if uevent_suppress is set*/ |
418 | if (kobj->uevent_suppress) { | |
419 | pr_debug("kobject: '%s' (%p): %s: uevent_suppress " | |
420 | "caused the event to drop!\n", | |
421 | kobject_name(kobj), kobj, __func__); | |
422 | return 0; | |
423 | } | |
7eff2e7a | 424 | /* skip the event, if the filter returns zero. */ |
312c004d | 425 | if (uevent_ops && uevent_ops->filter) |
542cfce6 | 426 | if (!uevent_ops->filter(kset, kobj)) { |
9f66fa2a GKH |
427 | pr_debug("kobject: '%s' (%p): %s: filter function " |
428 | "caused the event to drop!\n", | |
810304db | 429 | kobject_name(kobj), kobj, __func__); |
542cfce6 AK |
430 | return 0; |
431 | } | |
1da177e4 | 432 | |
86406245 KS |
433 | /* originating subsystem */ |
434 | if (uevent_ops && uevent_ops->name) | |
435 | subsystem = uevent_ops->name(kset, kobj); | |
436 | else | |
437 | subsystem = kobject_name(&kset->kobj); | |
438 | if (!subsystem) { | |
9f66fa2a GKH |
439 | pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the " |
440 | "event to drop!\n", kobject_name(kobj), kobj, | |
810304db | 441 | __func__); |
86406245 KS |
442 | return 0; |
443 | } | |
444 | ||
7eff2e7a KS |
445 | /* environment buffer */ |
446 | env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL); | |
447 | if (!env) | |
542cfce6 | 448 | return -ENOMEM; |
1da177e4 | 449 | |
5f123fbd KS |
450 | /* complete object path */ |
451 | devpath = kobject_get_path(kobj, GFP_KERNEL); | |
542cfce6 AK |
452 | if (!devpath) { |
453 | retval = -ENOENT; | |
5f123fbd | 454 | goto exit; |
542cfce6 | 455 | } |
1da177e4 | 456 | |
5f123fbd | 457 | /* default keys */ |
7eff2e7a KS |
458 | retval = add_uevent_var(env, "ACTION=%s", action_string); |
459 | if (retval) | |
460 | goto exit; | |
461 | retval = add_uevent_var(env, "DEVPATH=%s", devpath); | |
462 | if (retval) | |
463 | goto exit; | |
464 | retval = add_uevent_var(env, "SUBSYSTEM=%s", subsystem); | |
465 | if (retval) | |
466 | goto exit; | |
467 | ||
468 | /* keys passed in from the caller */ | |
469 | if (envp_ext) { | |
470 | for (i = 0; envp_ext[i]; i++) { | |
c65b9145 | 471 | retval = add_uevent_var(env, "%s", envp_ext[i]); |
7eff2e7a KS |
472 | if (retval) |
473 | goto exit; | |
474 | } | |
475 | } | |
1da177e4 | 476 | |
5f123fbd | 477 | /* let the kset specific function add its stuff */ |
312c004d | 478 | if (uevent_ops && uevent_ops->uevent) { |
7eff2e7a | 479 | retval = uevent_ops->uevent(kset, kobj, env); |
1da177e4 | 480 | if (retval) { |
9f66fa2a GKH |
481 | pr_debug("kobject: '%s' (%p): %s: uevent() returned " |
482 | "%d\n", kobject_name(kobj), kobj, | |
810304db | 483 | __func__, retval); |
1da177e4 LT |
484 | goto exit; |
485 | } | |
486 | } | |
487 | ||
6878e7de DT |
488 | switch (action) { |
489 | case KOBJ_ADD: | |
490 | /* | |
491 | * Mark "add" event so we can make sure we deliver "remove" | |
492 | * event to userspace during automatic cleanup. If | |
493 | * the object did send an "add" event, "remove" will | |
494 | * automatically generated by the core, if not already done | |
495 | * by the caller. | |
496 | */ | |
0f4dafc0 | 497 | kobj->state_add_uevent_sent = 1; |
6878e7de DT |
498 | break; |
499 | ||
500 | case KOBJ_REMOVE: | |
0f4dafc0 | 501 | kobj->state_remove_uevent_sent = 1; |
6878e7de DT |
502 | break; |
503 | ||
504 | case KOBJ_UNBIND: | |
505 | zap_modalias_env(env); | |
506 | break; | |
507 | ||
508 | default: | |
509 | break; | |
510 | } | |
0f4dafc0 | 511 | |
7b60a18d | 512 | mutex_lock(&uevent_sock_mutex); |
7eff2e7a | 513 | /* we will send an event, so request a new sequence number */ |
7b60a18d AV |
514 | retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)++uevent_seqnum); |
515 | if (retval) { | |
516 | mutex_unlock(&uevent_sock_mutex); | |
7eff2e7a | 517 | goto exit; |
7b60a18d | 518 | } |
16dff336 ED |
519 | retval = kobject_uevent_net_broadcast(kobj, env, action_string, |
520 | devpath); | |
7b60a18d | 521 | mutex_unlock(&uevent_sock_mutex); |
1da177e4 | 522 | |
86d56134 | 523 | #ifdef CONFIG_UEVENT_HELPER |
5f123fbd | 524 | /* call uevent_helper, usually only enabled during early boot */ |
417daa1e | 525 | if (uevent_helper[0] && !kobj_usermode_filter(kobj)) { |
bcccff93 | 526 | struct subprocess_info *info; |
1da177e4 | 527 | |
7eff2e7a KS |
528 | retval = add_uevent_var(env, "HOME=/"); |
529 | if (retval) | |
530 | goto exit; | |
e374a2bf GKH |
531 | retval = add_uevent_var(env, |
532 | "PATH=/sbin:/bin:/usr/sbin:/usr/bin"); | |
7eff2e7a KS |
533 | if (retval) |
534 | goto exit; | |
bcccff93 VD |
535 | retval = init_uevent_argv(env, subsystem); |
536 | if (retval) | |
537 | goto exit; | |
7eff2e7a | 538 | |
bcccff93 VD |
539 | retval = -ENOMEM; |
540 | info = call_usermodehelper_setup(env->argv[0], env->argv, | |
541 | env->envp, GFP_KERNEL, | |
542 | NULL, cleanup_uevent_env, env); | |
543 | if (info) { | |
544 | retval = call_usermodehelper_exec(info, UMH_NO_WAIT); | |
545 | env = NULL; /* freed by cleanup_uevent_env */ | |
546 | } | |
5f123fbd | 547 | } |
86d56134 | 548 | #endif |
1da177e4 LT |
549 | |
550 | exit: | |
5f123fbd | 551 | kfree(devpath); |
7eff2e7a | 552 | kfree(env); |
542cfce6 | 553 | return retval; |
1da177e4 | 554 | } |
8a82472f CH |
555 | EXPORT_SYMBOL_GPL(kobject_uevent_env); |
556 | ||
557 | /** | |
f6e6e779 | 558 | * kobject_uevent - notify userspace by sending an uevent |
8a82472f | 559 | * |
8a82472f | 560 | * @kobj: struct kobject that the action is happening to |
edbbf994 | 561 | * @action: action that is happening |
542cfce6 AK |
562 | * |
563 | * Returns 0 if kobject_uevent() is completed with success or the | |
564 | * corresponding error when it fails. | |
8a82472f | 565 | */ |
542cfce6 | 566 | int kobject_uevent(struct kobject *kobj, enum kobject_action action) |
8a82472f | 567 | { |
542cfce6 | 568 | return kobject_uevent_env(kobj, action, NULL); |
8a82472f | 569 | } |
312c004d | 570 | EXPORT_SYMBOL_GPL(kobject_uevent); |
1da177e4 LT |
571 | |
572 | /** | |
7eff2e7a KS |
573 | * add_uevent_var - add key value string to the environment buffer |
574 | * @env: environment buffer structure | |
575 | * @format: printf format for the key=value pair | |
1da177e4 LT |
576 | * |
577 | * Returns 0 if environment variable was added successfully or -ENOMEM | |
578 | * if no space was available. | |
579 | */ | |
7eff2e7a | 580 | int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...) |
1da177e4 LT |
581 | { |
582 | va_list args; | |
7eff2e7a | 583 | int len; |
1da177e4 | 584 | |
7eff2e7a | 585 | if (env->envp_idx >= ARRAY_SIZE(env->envp)) { |
5cd2b459 | 586 | WARN(1, KERN_ERR "add_uevent_var: too many keys\n"); |
1da177e4 | 587 | return -ENOMEM; |
7eff2e7a | 588 | } |
1da177e4 LT |
589 | |
590 | va_start(args, format); | |
7eff2e7a KS |
591 | len = vsnprintf(&env->buf[env->buflen], |
592 | sizeof(env->buf) - env->buflen, | |
593 | format, args); | |
1da177e4 LT |
594 | va_end(args); |
595 | ||
7eff2e7a | 596 | if (len >= (sizeof(env->buf) - env->buflen)) { |
5cd2b459 | 597 | WARN(1, KERN_ERR "add_uevent_var: buffer size too small\n"); |
1da177e4 | 598 | return -ENOMEM; |
7eff2e7a | 599 | } |
1da177e4 | 600 | |
7eff2e7a KS |
601 | env->envp[env->envp_idx++] = &env->buf[env->buflen]; |
602 | env->buflen += len + 1; | |
1da177e4 LT |
603 | return 0; |
604 | } | |
312c004d | 605 | EXPORT_SYMBOL_GPL(add_uevent_var); |
1da177e4 | 606 | |
4d17ffda | 607 | #if defined(CONFIG_NET) |
692ec06d CB |
608 | static int uevent_net_broadcast(struct sock *usk, struct sk_buff *skb, |
609 | struct netlink_ext_ack *extack) | |
610 | { | |
611 | /* u64 to chars: 2^64 - 1 = 21 chars */ | |
612 | char buf[sizeof("SEQNUM=") + 21]; | |
613 | struct sk_buff *skbc; | |
614 | int ret; | |
615 | ||
616 | /* bump and prepare sequence number */ | |
617 | ret = snprintf(buf, sizeof(buf), "SEQNUM=%llu", ++uevent_seqnum); | |
618 | if (ret < 0 || (size_t)ret >= sizeof(buf)) | |
619 | return -ENOMEM; | |
620 | ret++; | |
621 | ||
622 | /* verify message does not overflow */ | |
623 | if ((skb->len + ret) > UEVENT_BUFFER_SIZE) { | |
624 | NL_SET_ERR_MSG(extack, "uevent message too big"); | |
625 | return -EINVAL; | |
626 | } | |
627 | ||
628 | /* copy skb and extend to accommodate sequence number */ | |
629 | skbc = skb_copy_expand(skb, 0, ret, GFP_KERNEL); | |
630 | if (!skbc) | |
631 | return -ENOMEM; | |
632 | ||
633 | /* append sequence number */ | |
634 | skb_put_data(skbc, buf, ret); | |
635 | ||
636 | /* remove msg header */ | |
637 | skb_pull(skbc, NLMSG_HDRLEN); | |
638 | ||
639 | /* set portid 0 to inform userspace message comes from kernel */ | |
640 | NETLINK_CB(skbc).portid = 0; | |
641 | NETLINK_CB(skbc).dst_group = 1; | |
642 | ||
643 | ret = netlink_broadcast(usk, skbc, 0, 1, GFP_KERNEL); | |
644 | /* ENOBUFS should be handled in userspace */ | |
645 | if (ret == -ENOBUFS || ret == -ESRCH) | |
646 | ret = 0; | |
647 | ||
648 | return ret; | |
649 | } | |
650 | ||
651 | static int uevent_net_rcv_skb(struct sk_buff *skb, struct nlmsghdr *nlh, | |
652 | struct netlink_ext_ack *extack) | |
653 | { | |
654 | struct net *net; | |
655 | int ret; | |
656 | ||
657 | if (!nlmsg_data(nlh)) | |
658 | return -EINVAL; | |
659 | ||
660 | /* | |
661 | * Verify that we are allowed to send messages to the target | |
662 | * network namespace. The caller must have CAP_SYS_ADMIN in the | |
663 | * owning user namespace of the target network namespace. | |
664 | */ | |
665 | net = sock_net(NETLINK_CB(skb).sk); | |
666 | if (!netlink_ns_capable(skb, net->user_ns, CAP_SYS_ADMIN)) { | |
667 | NL_SET_ERR_MSG(extack, "missing CAP_SYS_ADMIN capability"); | |
668 | return -EPERM; | |
669 | } | |
670 | ||
671 | mutex_lock(&uevent_sock_mutex); | |
672 | ret = uevent_net_broadcast(net->uevent_sock->sk, skb, extack); | |
673 | mutex_unlock(&uevent_sock_mutex); | |
674 | ||
675 | return ret; | |
676 | } | |
677 | ||
678 | static void uevent_net_rcv(struct sk_buff *skb) | |
679 | { | |
680 | netlink_rcv_skb(skb, &uevent_net_rcv_skb); | |
681 | } | |
682 | ||
07e98962 | 683 | static int uevent_net_init(struct net *net) |
5f123fbd | 684 | { |
07e98962 | 685 | struct uevent_sock *ue_sk; |
a31f2d17 PNA |
686 | struct netlink_kernel_cfg cfg = { |
687 | .groups = 1, | |
692ec06d CB |
688 | .input = uevent_net_rcv, |
689 | .flags = NL_CFG_F_NONROOT_RECV | |
a31f2d17 | 690 | }; |
07e98962 EB |
691 | |
692 | ue_sk = kzalloc(sizeof(*ue_sk), GFP_KERNEL); | |
693 | if (!ue_sk) | |
694 | return -ENOMEM; | |
695 | ||
9f00d977 | 696 | ue_sk->sk = netlink_kernel_create(net, NETLINK_KOBJECT_UEVENT, &cfg); |
07e98962 | 697 | if (!ue_sk->sk) { |
5f123fbd KS |
698 | printk(KERN_ERR |
699 | "kobject_uevent: unable to create netlink socket!\n"); | |
743db2d9 | 700 | kfree(ue_sk); |
5f123fbd KS |
701 | return -ENODEV; |
702 | } | |
94e5e308 CB |
703 | |
704 | net->uevent_sock = ue_sk; | |
705 | ||
07e98962 EB |
706 | mutex_lock(&uevent_sock_mutex); |
707 | list_add_tail(&ue_sk->list, &uevent_sock_list); | |
708 | mutex_unlock(&uevent_sock_mutex); | |
5f123fbd KS |
709 | return 0; |
710 | } | |
711 | ||
07e98962 EB |
712 | static void uevent_net_exit(struct net *net) |
713 | { | |
94e5e308 | 714 | struct uevent_sock *ue_sk = net->uevent_sock; |
07e98962 EB |
715 | |
716 | mutex_lock(&uevent_sock_mutex); | |
07e98962 EB |
717 | list_del(&ue_sk->list); |
718 | mutex_unlock(&uevent_sock_mutex); | |
719 | ||
720 | netlink_kernel_release(ue_sk->sk); | |
721 | kfree(ue_sk); | |
722 | } | |
723 | ||
724 | static struct pernet_operations uevent_net_ops = { | |
725 | .init = uevent_net_init, | |
726 | .exit = uevent_net_exit, | |
727 | }; | |
728 | ||
729 | static int __init kobject_uevent_init(void) | |
730 | { | |
07e98962 EB |
731 | return register_pernet_subsys(&uevent_net_ops); |
732 | } | |
733 | ||
734 | ||
5f123fbd | 735 | postcore_initcall(kobject_uevent_init); |
4d17ffda | 736 | #endif |