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> | |
26045a7b | 25 | #include <linux/uidgid.h> |
f36776fa PR |
26 | #include <linux/uuid.h> |
27 | #include <linux/ctype.h> | |
1da177e4 | 28 | #include <net/sock.h> |
692ec06d | 29 | #include <net/netlink.h> |
07e98962 | 30 | #include <net/net_namespace.h> |
1da177e4 | 31 | |
1da177e4 | 32 | |
cd030c4c | 33 | u64 uevent_seqnum; |
86d56134 | 34 | #ifdef CONFIG_UEVENT_HELPER |
6a8d8abb | 35 | char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH; |
86d56134 | 36 | #endif |
94e5e308 | 37 | |
07e98962 EB |
38 | struct uevent_sock { |
39 | struct list_head list; | |
40 | struct sock *sk; | |
41 | }; | |
94e5e308 CB |
42 | |
43 | #ifdef CONFIG_NET | |
07e98962 | 44 | static LIST_HEAD(uevent_sock_list); |
cd030c4c CH |
45 | #endif |
46 | ||
7b60a18d AV |
47 | /* This lock protects uevent_seqnum and uevent_sock_list */ |
48 | static DEFINE_MUTEX(uevent_sock_mutex); | |
49 | ||
5c5daf65 KS |
50 | /* the strings here must match the enum in include/linux/kobject.h */ |
51 | static const char *kobject_actions[] = { | |
52 | [KOBJ_ADD] = "add", | |
53 | [KOBJ_REMOVE] = "remove", | |
54 | [KOBJ_CHANGE] = "change", | |
55 | [KOBJ_MOVE] = "move", | |
56 | [KOBJ_ONLINE] = "online", | |
57 | [KOBJ_OFFLINE] = "offline", | |
1455cf8d DT |
58 | [KOBJ_BIND] = "bind", |
59 | [KOBJ_UNBIND] = "unbind", | |
5c5daf65 KS |
60 | }; |
61 | ||
f36776fa PR |
62 | static int kobject_action_type(const char *buf, size_t count, |
63 | enum kobject_action *type, | |
64 | const char **args) | |
5c5daf65 KS |
65 | { |
66 | enum kobject_action action; | |
f36776fa PR |
67 | size_t count_first; |
68 | const char *args_start; | |
5c5daf65 KS |
69 | int ret = -EINVAL; |
70 | ||
a9edadbf | 71 | if (count && (buf[count-1] == '\n' || buf[count-1] == '\0')) |
5c5daf65 KS |
72 | count--; |
73 | ||
74 | if (!count) | |
75 | goto out; | |
76 | ||
f36776fa PR |
77 | args_start = strnchr(buf, count, ' '); |
78 | if (args_start) { | |
79 | count_first = args_start - buf; | |
80 | args_start = args_start + 1; | |
81 | } else | |
82 | count_first = count; | |
83 | ||
5c5daf65 | 84 | for (action = 0; action < ARRAY_SIZE(kobject_actions); action++) { |
f36776fa | 85 | if (strncmp(kobject_actions[action], buf, count_first) != 0) |
5c5daf65 | 86 | continue; |
f36776fa | 87 | if (kobject_actions[action][count_first] != '\0') |
5c5daf65 | 88 | continue; |
f36776fa PR |
89 | if (args) |
90 | *args = args_start; | |
5c5daf65 KS |
91 | *type = action; |
92 | ret = 0; | |
93 | break; | |
94 | } | |
95 | out: | |
96 | return ret; | |
97 | } | |
98 | ||
f36776fa PR |
99 | static const char *action_arg_word_end(const char *buf, const char *buf_end, |
100 | char delim) | |
101 | { | |
102 | const char *next = buf; | |
103 | ||
104 | while (next <= buf_end && *next != delim) | |
105 | if (!isalnum(*next++)) | |
106 | return NULL; | |
107 | ||
108 | if (next == buf) | |
109 | return NULL; | |
110 | ||
111 | return next; | |
112 | } | |
113 | ||
114 | static int kobject_action_args(const char *buf, size_t count, | |
115 | struct kobj_uevent_env **ret_env) | |
116 | { | |
117 | struct kobj_uevent_env *env = NULL; | |
118 | const char *next, *buf_end, *key; | |
119 | int key_len; | |
120 | int r = -EINVAL; | |
121 | ||
122 | if (count && (buf[count - 1] == '\n' || buf[count - 1] == '\0')) | |
123 | count--; | |
124 | ||
125 | if (!count) | |
126 | return -EINVAL; | |
127 | ||
128 | env = kzalloc(sizeof(*env), GFP_KERNEL); | |
129 | if (!env) | |
130 | return -ENOMEM; | |
131 | ||
132 | /* first arg is UUID */ | |
133 | if (count < UUID_STRING_LEN || !uuid_is_valid(buf) || | |
134 | add_uevent_var(env, "SYNTH_UUID=%.*s", UUID_STRING_LEN, buf)) | |
135 | goto out; | |
136 | ||
137 | /* | |
138 | * the rest are custom environment variables in KEY=VALUE | |
139 | * format with ' ' delimiter between each KEY=VALUE pair | |
140 | */ | |
141 | next = buf + UUID_STRING_LEN; | |
142 | buf_end = buf + count - 1; | |
143 | ||
144 | while (next <= buf_end) { | |
145 | if (*next != ' ') | |
146 | goto out; | |
147 | ||
148 | /* skip the ' ', key must follow */ | |
149 | key = ++next; | |
150 | if (key > buf_end) | |
151 | goto out; | |
152 | ||
153 | buf = next; | |
154 | next = action_arg_word_end(buf, buf_end, '='); | |
155 | if (!next || next > buf_end || *next != '=') | |
156 | goto out; | |
157 | key_len = next - buf; | |
158 | ||
159 | /* skip the '=', value must follow */ | |
160 | if (++next > buf_end) | |
161 | goto out; | |
162 | ||
163 | buf = next; | |
164 | next = action_arg_word_end(buf, buf_end, ' '); | |
165 | if (!next) | |
166 | goto out; | |
167 | ||
168 | if (add_uevent_var(env, "SYNTH_ARG_%.*s=%.*s", | |
169 | key_len, key, (int) (next - buf), buf)) | |
170 | goto out; | |
171 | } | |
172 | ||
173 | r = 0; | |
174 | out: | |
175 | if (r) | |
176 | kfree(env); | |
177 | else | |
178 | *ret_env = env; | |
179 | return r; | |
180 | } | |
181 | ||
182 | /** | |
183 | * kobject_synth_uevent - send synthetic uevent with arguments | |
184 | * | |
185 | * @kobj: struct kobject for which synthetic uevent is to be generated | |
186 | * @buf: buffer containing action type and action args, newline is ignored | |
187 | * @count: length of buffer | |
188 | * | |
189 | * Returns 0 if kobject_synthetic_uevent() is completed with success or the | |
190 | * corresponding error when it fails. | |
191 | */ | |
192 | int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count) | |
193 | { | |
194 | char *no_uuid_envp[] = { "SYNTH_UUID=0", NULL }; | |
195 | enum kobject_action action; | |
196 | const char *action_args; | |
197 | struct kobj_uevent_env *env; | |
198 | const char *msg = NULL, *devpath; | |
199 | int r; | |
200 | ||
201 | r = kobject_action_type(buf, count, &action, &action_args); | |
202 | if (r) { | |
549ad243 | 203 | msg = "unknown uevent action string"; |
f36776fa PR |
204 | goto out; |
205 | } | |
206 | ||
207 | if (!action_args) { | |
208 | r = kobject_uevent_env(kobj, action, no_uuid_envp); | |
209 | goto out; | |
210 | } | |
211 | ||
212 | r = kobject_action_args(action_args, | |
213 | count - (action_args - buf), &env); | |
214 | if (r == -EINVAL) { | |
549ad243 | 215 | msg = "incorrect uevent action arguments"; |
f36776fa PR |
216 | goto out; |
217 | } | |
218 | ||
219 | if (r) | |
220 | goto out; | |
221 | ||
222 | r = kobject_uevent_env(kobj, action, env->envp); | |
223 | kfree(env); | |
224 | out: | |
225 | if (r) { | |
226 | devpath = kobject_get_path(kobj, GFP_KERNEL); | |
549ad243 | 227 | pr_warn("synth uevent: %s: %s\n", |
f36776fa PR |
228 | devpath ?: "unknown device", |
229 | msg ?: "failed to send uevent"); | |
230 | kfree(devpath); | |
231 | } | |
232 | return r; | |
233 | } | |
234 | ||
86d56134 | 235 | #ifdef CONFIG_UEVENT_HELPER |
417daa1e EB |
236 | static int kobj_usermode_filter(struct kobject *kobj) |
237 | { | |
238 | const struct kobj_ns_type_operations *ops; | |
239 | ||
240 | ops = kobj_ns_ops(kobj); | |
241 | if (ops) { | |
242 | const void *init_ns, *ns; | |
6be244dc | 243 | |
417daa1e EB |
244 | ns = kobj->ktype->namespace(kobj); |
245 | init_ns = ops->initial_ns(); | |
246 | return ns != init_ns; | |
247 | } | |
248 | ||
249 | return 0; | |
250 | } | |
251 | ||
bcccff93 VD |
252 | static int init_uevent_argv(struct kobj_uevent_env *env, const char *subsystem) |
253 | { | |
b4104180 | 254 | int buffer_size = sizeof(env->buf) - env->buflen; |
bcccff93 VD |
255 | int len; |
256 | ||
b4104180 GKH |
257 | len = strlcpy(&env->buf[env->buflen], subsystem, buffer_size); |
258 | if (len >= buffer_size) { | |
259 | pr_warn("init_uevent_argv: buffer size of %d too small, needed %d\n", | |
260 | buffer_size, len); | |
bcccff93 VD |
261 | return -ENOMEM; |
262 | } | |
263 | ||
264 | env->argv[0] = uevent_helper; | |
265 | env->argv[1] = &env->buf[env->buflen]; | |
266 | env->argv[2] = NULL; | |
267 | ||
268 | env->buflen += len + 1; | |
269 | return 0; | |
270 | } | |
271 | ||
272 | static void cleanup_uevent_env(struct subprocess_info *info) | |
273 | { | |
274 | kfree(info->data); | |
275 | } | |
86d56134 | 276 | #endif |
bcccff93 | 277 | |
26045a7b CB |
278 | #ifdef CONFIG_NET |
279 | static struct sk_buff *alloc_uevent_skb(struct kobj_uevent_env *env, | |
280 | const char *action_string, | |
281 | const char *devpath) | |
282 | { | |
283 | struct netlink_skb_parms *parms; | |
284 | struct sk_buff *skb = NULL; | |
285 | char *scratch; | |
286 | size_t len; | |
287 | ||
288 | /* allocate message with maximum possible size */ | |
289 | len = strlen(action_string) + strlen(devpath) + 2; | |
290 | skb = alloc_skb(len + env->buflen, GFP_KERNEL); | |
291 | if (!skb) | |
292 | return NULL; | |
293 | ||
294 | /* add header */ | |
295 | scratch = skb_put(skb, len); | |
296 | sprintf(scratch, "%s@%s", action_string, devpath); | |
297 | ||
298 | skb_put_data(skb, env->buf, env->buflen); | |
299 | ||
300 | parms = &NETLINK_CB(skb); | |
301 | parms->creds.uid = GLOBAL_ROOT_UID; | |
302 | parms->creds.gid = GLOBAL_ROOT_GID; | |
303 | parms->dst_group = 1; | |
304 | parms->portid = 0; | |
305 | ||
306 | return skb; | |
307 | } | |
26045a7b | 308 | |
a3498436 CB |
309 | static int uevent_net_broadcast_untagged(struct kobj_uevent_env *env, |
310 | const char *action_string, | |
311 | const char *devpath) | |
16dff336 | 312 | { |
d464e84e | 313 | struct sk_buff *skb = NULL; |
16dff336 | 314 | struct uevent_sock *ue_sk; |
a3498436 | 315 | int retval = 0; |
16dff336 ED |
316 | |
317 | /* send netlink message */ | |
318 | list_for_each_entry(ue_sk, &uevent_sock_list, list) { | |
319 | struct sock *uevent_sock = ue_sk->sk; | |
16dff336 ED |
320 | |
321 | if (!netlink_has_listeners(uevent_sock, 1)) | |
322 | continue; | |
323 | ||
d464e84e | 324 | if (!skb) { |
d464e84e | 325 | retval = -ENOMEM; |
26045a7b | 326 | skb = alloc_uevent_skb(env, action_string, devpath); |
d464e84e ED |
327 | if (!skb) |
328 | continue; | |
d464e84e ED |
329 | } |
330 | ||
a3498436 CB |
331 | retval = netlink_broadcast(uevent_sock, skb_get(skb), 0, 1, |
332 | GFP_KERNEL); | |
d464e84e ED |
333 | /* ENOBUFS should be handled in userspace */ |
334 | if (retval == -ENOBUFS || retval == -ESRCH) | |
335 | retval = 0; | |
16dff336 | 336 | } |
d464e84e | 337 | consume_skb(skb); |
a3498436 | 338 | |
16dff336 ED |
339 | return retval; |
340 | } | |
341 | ||
a3498436 CB |
342 | static int uevent_net_broadcast_tagged(struct sock *usk, |
343 | struct kobj_uevent_env *env, | |
344 | const char *action_string, | |
345 | const char *devpath) | |
346 | { | |
347 | struct user_namespace *owning_user_ns = sock_net(usk)->user_ns; | |
348 | struct sk_buff *skb = NULL; | |
349 | int ret = 0; | |
350 | ||
351 | skb = alloc_uevent_skb(env, action_string, devpath); | |
352 | if (!skb) | |
353 | return -ENOMEM; | |
354 | ||
355 | /* fix credentials */ | |
356 | if (owning_user_ns != &init_user_ns) { | |
357 | struct netlink_skb_parms *parms = &NETLINK_CB(skb); | |
358 | kuid_t root_uid; | |
359 | kgid_t root_gid; | |
360 | ||
361 | /* fix uid */ | |
362 | root_uid = make_kuid(owning_user_ns, 0); | |
363 | if (uid_valid(root_uid)) | |
364 | parms->creds.uid = root_uid; | |
365 | ||
366 | /* fix gid */ | |
367 | root_gid = make_kgid(owning_user_ns, 0); | |
368 | if (gid_valid(root_gid)) | |
369 | parms->creds.gid = root_gid; | |
370 | } | |
371 | ||
372 | ret = netlink_broadcast(usk, skb, 0, 1, GFP_KERNEL); | |
373 | /* ENOBUFS should be handled in userspace */ | |
374 | if (ret == -ENOBUFS || ret == -ESRCH) | |
375 | ret = 0; | |
376 | ||
377 | return ret; | |
378 | } | |
379 | #endif | |
380 | ||
381 | static int kobject_uevent_net_broadcast(struct kobject *kobj, | |
382 | struct kobj_uevent_env *env, | |
383 | const char *action_string, | |
384 | const char *devpath) | |
385 | { | |
386 | int ret = 0; | |
387 | ||
388 | #ifdef CONFIG_NET | |
389 | const struct kobj_ns_type_operations *ops; | |
390 | const struct net *net = NULL; | |
391 | ||
392 | ops = kobj_ns_ops(kobj); | |
393 | if (!ops && kobj->kset) { | |
394 | struct kobject *ksobj = &kobj->kset->kobj; | |
6be244dc | 395 | |
a3498436 CB |
396 | if (ksobj->parent != NULL) |
397 | ops = kobj_ns_ops(ksobj->parent); | |
398 | } | |
399 | ||
400 | /* kobjects currently only carry network namespace tags and they | |
401 | * are the only tag relevant here since we want to decide which | |
402 | * network namespaces to broadcast the uevent into. | |
403 | */ | |
404 | if (ops && ops->netlink_ns && kobj->ktype->namespace) | |
405 | if (ops->type == KOBJ_NS_TYPE_NET) | |
406 | net = kobj->ktype->namespace(kobj); | |
407 | ||
408 | if (!net) | |
409 | ret = uevent_net_broadcast_untagged(env, action_string, | |
410 | devpath); | |
411 | else | |
412 | ret = uevent_net_broadcast_tagged(net->uevent_sock->sk, env, | |
413 | action_string, devpath); | |
414 | #endif | |
415 | ||
416 | return ret; | |
417 | } | |
418 | ||
6878e7de DT |
419 | static void zap_modalias_env(struct kobj_uevent_env *env) |
420 | { | |
421 | static const char modalias_prefix[] = "MODALIAS="; | |
9b3fa47d DT |
422 | size_t len; |
423 | int i, j; | |
6878e7de DT |
424 | |
425 | for (i = 0; i < env->envp_idx;) { | |
426 | if (strncmp(env->envp[i], modalias_prefix, | |
427 | sizeof(modalias_prefix) - 1)) { | |
428 | i++; | |
429 | continue; | |
430 | } | |
431 | ||
9b3fa47d DT |
432 | len = strlen(env->envp[i]) + 1; |
433 | ||
434 | if (i != env->envp_idx - 1) { | |
435 | memmove(env->envp[i], env->envp[i + 1], | |
436 | env->buflen - len); | |
437 | ||
438 | for (j = i; j < env->envp_idx - 1; j++) | |
439 | env->envp[j] = env->envp[j + 1] - len; | |
440 | } | |
6878e7de DT |
441 | |
442 | env->envp_idx--; | |
9b3fa47d | 443 | env->buflen -= len; |
6878e7de DT |
444 | } |
445 | } | |
446 | ||
1da177e4 | 447 | /** |
8a82472f | 448 | * kobject_uevent_env - send an uevent with environmental data |
1da177e4 | 449 | * |
1da177e4 | 450 | * @kobj: struct kobject that the action is happening to |
edbbf994 | 451 | * @action: action that is happening |
8a82472f | 452 | * @envp_ext: pointer to environmental data |
542cfce6 | 453 | * |
f6e6e779 | 454 | * Returns 0 if kobject_uevent_env() is completed with success or the |
542cfce6 | 455 | * corresponding error when it fails. |
1da177e4 | 456 | */ |
542cfce6 | 457 | int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, |
7eff2e7a | 458 | char *envp_ext[]) |
1da177e4 | 459 | { |
7eff2e7a KS |
460 | struct kobj_uevent_env *env; |
461 | const char *action_string = kobject_actions[action]; | |
5f123fbd KS |
462 | const char *devpath = NULL; |
463 | const char *subsystem; | |
464 | struct kobject *top_kobj; | |
465 | struct kset *kset; | |
9cd43611 | 466 | const struct kset_uevent_ops *uevent_ops; |
1da177e4 | 467 | int i = 0; |
542cfce6 | 468 | int retval = 0; |
1da177e4 | 469 | |
c03a0fd0 TH |
470 | /* |
471 | * Mark "remove" event done regardless of result, for some subsystems | |
472 | * do not want to re-trigger "remove" event via automatic cleanup. | |
473 | */ | |
474 | if (action == KOBJ_REMOVE) | |
475 | kobj->state_remove_uevent_sent = 1; | |
476 | ||
9f66fa2a | 477 | pr_debug("kobject: '%s' (%p): %s\n", |
810304db | 478 | kobject_name(kobj), kobj, __func__); |
5f123fbd | 479 | |
5f123fbd KS |
480 | /* search the kset we belong to */ |
481 | top_kobj = kobj; | |
ccd490a3 | 482 | while (!top_kobj->kset && top_kobj->parent) |
14193fb9 | 483 | top_kobj = top_kobj->parent; |
ccd490a3 | 484 | |
542cfce6 | 485 | if (!top_kobj->kset) { |
9f66fa2a GKH |
486 | pr_debug("kobject: '%s' (%p): %s: attempted to send uevent " |
487 | "without kset!\n", kobject_name(kobj), kobj, | |
810304db | 488 | __func__); |
542cfce6 AK |
489 | return -EINVAL; |
490 | } | |
1da177e4 | 491 | |
5f123fbd | 492 | kset = top_kobj->kset; |
312c004d | 493 | uevent_ops = kset->uevent_ops; |
1da177e4 | 494 | |
f67f129e ML |
495 | /* skip the event, if uevent_suppress is set*/ |
496 | if (kobj->uevent_suppress) { | |
497 | pr_debug("kobject: '%s' (%p): %s: uevent_suppress " | |
498 | "caused the event to drop!\n", | |
499 | kobject_name(kobj), kobj, __func__); | |
500 | return 0; | |
501 | } | |
7eff2e7a | 502 | /* skip the event, if the filter returns zero. */ |
312c004d | 503 | if (uevent_ops && uevent_ops->filter) |
542cfce6 | 504 | if (!uevent_ops->filter(kset, kobj)) { |
9f66fa2a GKH |
505 | pr_debug("kobject: '%s' (%p): %s: filter function " |
506 | "caused the event to drop!\n", | |
810304db | 507 | kobject_name(kobj), kobj, __func__); |
542cfce6 AK |
508 | return 0; |
509 | } | |
1da177e4 | 510 | |
86406245 KS |
511 | /* originating subsystem */ |
512 | if (uevent_ops && uevent_ops->name) | |
513 | subsystem = uevent_ops->name(kset, kobj); | |
514 | else | |
515 | subsystem = kobject_name(&kset->kobj); | |
516 | if (!subsystem) { | |
9f66fa2a GKH |
517 | pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the " |
518 | "event to drop!\n", kobject_name(kobj), kobj, | |
810304db | 519 | __func__); |
86406245 KS |
520 | return 0; |
521 | } | |
522 | ||
7eff2e7a KS |
523 | /* environment buffer */ |
524 | env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL); | |
525 | if (!env) | |
542cfce6 | 526 | return -ENOMEM; |
1da177e4 | 527 | |
5f123fbd KS |
528 | /* complete object path */ |
529 | devpath = kobject_get_path(kobj, GFP_KERNEL); | |
542cfce6 AK |
530 | if (!devpath) { |
531 | retval = -ENOENT; | |
5f123fbd | 532 | goto exit; |
542cfce6 | 533 | } |
1da177e4 | 534 | |
5f123fbd | 535 | /* default keys */ |
7eff2e7a KS |
536 | retval = add_uevent_var(env, "ACTION=%s", action_string); |
537 | if (retval) | |
538 | goto exit; | |
539 | retval = add_uevent_var(env, "DEVPATH=%s", devpath); | |
540 | if (retval) | |
541 | goto exit; | |
542 | retval = add_uevent_var(env, "SUBSYSTEM=%s", subsystem); | |
543 | if (retval) | |
544 | goto exit; | |
545 | ||
546 | /* keys passed in from the caller */ | |
547 | if (envp_ext) { | |
548 | for (i = 0; envp_ext[i]; i++) { | |
c65b9145 | 549 | retval = add_uevent_var(env, "%s", envp_ext[i]); |
7eff2e7a KS |
550 | if (retval) |
551 | goto exit; | |
552 | } | |
553 | } | |
1da177e4 | 554 | |
5f123fbd | 555 | /* let the kset specific function add its stuff */ |
312c004d | 556 | if (uevent_ops && uevent_ops->uevent) { |
7eff2e7a | 557 | retval = uevent_ops->uevent(kset, kobj, env); |
1da177e4 | 558 | if (retval) { |
9f66fa2a GKH |
559 | pr_debug("kobject: '%s' (%p): %s: uevent() returned " |
560 | "%d\n", kobject_name(kobj), kobj, | |
810304db | 561 | __func__, retval); |
1da177e4 LT |
562 | goto exit; |
563 | } | |
564 | } | |
565 | ||
6878e7de DT |
566 | switch (action) { |
567 | case KOBJ_ADD: | |
568 | /* | |
569 | * Mark "add" event so we can make sure we deliver "remove" | |
570 | * event to userspace during automatic cleanup. If | |
571 | * the object did send an "add" event, "remove" will | |
572 | * automatically generated by the core, if not already done | |
573 | * by the caller. | |
574 | */ | |
0f4dafc0 | 575 | kobj->state_add_uevent_sent = 1; |
6878e7de DT |
576 | break; |
577 | ||
6878e7de DT |
578 | case KOBJ_UNBIND: |
579 | zap_modalias_env(env); | |
580 | break; | |
581 | ||
582 | default: | |
583 | break; | |
584 | } | |
0f4dafc0 | 585 | |
7b60a18d | 586 | mutex_lock(&uevent_sock_mutex); |
7eff2e7a | 587 | /* we will send an event, so request a new sequence number */ |
e0d70bcb | 588 | retval = add_uevent_var(env, "SEQNUM=%llu", ++uevent_seqnum); |
7b60a18d AV |
589 | if (retval) { |
590 | mutex_unlock(&uevent_sock_mutex); | |
7eff2e7a | 591 | goto exit; |
7b60a18d | 592 | } |
16dff336 ED |
593 | retval = kobject_uevent_net_broadcast(kobj, env, action_string, |
594 | devpath); | |
7b60a18d | 595 | mutex_unlock(&uevent_sock_mutex); |
1da177e4 | 596 | |
86d56134 | 597 | #ifdef CONFIG_UEVENT_HELPER |
5f123fbd | 598 | /* call uevent_helper, usually only enabled during early boot */ |
417daa1e | 599 | if (uevent_helper[0] && !kobj_usermode_filter(kobj)) { |
bcccff93 | 600 | struct subprocess_info *info; |
1da177e4 | 601 | |
7eff2e7a KS |
602 | retval = add_uevent_var(env, "HOME=/"); |
603 | if (retval) | |
604 | goto exit; | |
e374a2bf GKH |
605 | retval = add_uevent_var(env, |
606 | "PATH=/sbin:/bin:/usr/sbin:/usr/bin"); | |
7eff2e7a KS |
607 | if (retval) |
608 | goto exit; | |
bcccff93 VD |
609 | retval = init_uevent_argv(env, subsystem); |
610 | if (retval) | |
611 | goto exit; | |
7eff2e7a | 612 | |
bcccff93 VD |
613 | retval = -ENOMEM; |
614 | info = call_usermodehelper_setup(env->argv[0], env->argv, | |
615 | env->envp, GFP_KERNEL, | |
616 | NULL, cleanup_uevent_env, env); | |
617 | if (info) { | |
618 | retval = call_usermodehelper_exec(info, UMH_NO_WAIT); | |
619 | env = NULL; /* freed by cleanup_uevent_env */ | |
620 | } | |
5f123fbd | 621 | } |
86d56134 | 622 | #endif |
1da177e4 LT |
623 | |
624 | exit: | |
5f123fbd | 625 | kfree(devpath); |
7eff2e7a | 626 | kfree(env); |
542cfce6 | 627 | return retval; |
1da177e4 | 628 | } |
8a82472f CH |
629 | EXPORT_SYMBOL_GPL(kobject_uevent_env); |
630 | ||
631 | /** | |
f6e6e779 | 632 | * kobject_uevent - notify userspace by sending an uevent |
8a82472f | 633 | * |
8a82472f | 634 | * @kobj: struct kobject that the action is happening to |
edbbf994 | 635 | * @action: action that is happening |
542cfce6 AK |
636 | * |
637 | * Returns 0 if kobject_uevent() is completed with success or the | |
638 | * corresponding error when it fails. | |
8a82472f | 639 | */ |
542cfce6 | 640 | int kobject_uevent(struct kobject *kobj, enum kobject_action action) |
8a82472f | 641 | { |
542cfce6 | 642 | return kobject_uevent_env(kobj, action, NULL); |
8a82472f | 643 | } |
312c004d | 644 | EXPORT_SYMBOL_GPL(kobject_uevent); |
1da177e4 LT |
645 | |
646 | /** | |
7eff2e7a KS |
647 | * add_uevent_var - add key value string to the environment buffer |
648 | * @env: environment buffer structure | |
649 | * @format: printf format for the key=value pair | |
1da177e4 LT |
650 | * |
651 | * Returns 0 if environment variable was added successfully or -ENOMEM | |
652 | * if no space was available. | |
653 | */ | |
7eff2e7a | 654 | int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...) |
1da177e4 LT |
655 | { |
656 | va_list args; | |
7eff2e7a | 657 | int len; |
1da177e4 | 658 | |
7eff2e7a | 659 | if (env->envp_idx >= ARRAY_SIZE(env->envp)) { |
5cd2b459 | 660 | WARN(1, KERN_ERR "add_uevent_var: too many keys\n"); |
1da177e4 | 661 | return -ENOMEM; |
7eff2e7a | 662 | } |
1da177e4 LT |
663 | |
664 | va_start(args, format); | |
7eff2e7a KS |
665 | len = vsnprintf(&env->buf[env->buflen], |
666 | sizeof(env->buf) - env->buflen, | |
667 | format, args); | |
1da177e4 LT |
668 | va_end(args); |
669 | ||
7eff2e7a | 670 | if (len >= (sizeof(env->buf) - env->buflen)) { |
5cd2b459 | 671 | WARN(1, KERN_ERR "add_uevent_var: buffer size too small\n"); |
1da177e4 | 672 | return -ENOMEM; |
7eff2e7a | 673 | } |
1da177e4 | 674 | |
7eff2e7a KS |
675 | env->envp[env->envp_idx++] = &env->buf[env->buflen]; |
676 | env->buflen += len + 1; | |
1da177e4 LT |
677 | return 0; |
678 | } | |
312c004d | 679 | EXPORT_SYMBOL_GPL(add_uevent_var); |
1da177e4 | 680 | |
4d17ffda | 681 | #if defined(CONFIG_NET) |
692ec06d CB |
682 | static int uevent_net_broadcast(struct sock *usk, struct sk_buff *skb, |
683 | struct netlink_ext_ack *extack) | |
684 | { | |
685 | /* u64 to chars: 2^64 - 1 = 21 chars */ | |
686 | char buf[sizeof("SEQNUM=") + 21]; | |
687 | struct sk_buff *skbc; | |
688 | int ret; | |
689 | ||
690 | /* bump and prepare sequence number */ | |
691 | ret = snprintf(buf, sizeof(buf), "SEQNUM=%llu", ++uevent_seqnum); | |
692 | if (ret < 0 || (size_t)ret >= sizeof(buf)) | |
693 | return -ENOMEM; | |
694 | ret++; | |
695 | ||
696 | /* verify message does not overflow */ | |
697 | if ((skb->len + ret) > UEVENT_BUFFER_SIZE) { | |
698 | NL_SET_ERR_MSG(extack, "uevent message too big"); | |
699 | return -EINVAL; | |
700 | } | |
701 | ||
702 | /* copy skb and extend to accommodate sequence number */ | |
703 | skbc = skb_copy_expand(skb, 0, ret, GFP_KERNEL); | |
704 | if (!skbc) | |
705 | return -ENOMEM; | |
706 | ||
707 | /* append sequence number */ | |
708 | skb_put_data(skbc, buf, ret); | |
709 | ||
710 | /* remove msg header */ | |
711 | skb_pull(skbc, NLMSG_HDRLEN); | |
712 | ||
713 | /* set portid 0 to inform userspace message comes from kernel */ | |
714 | NETLINK_CB(skbc).portid = 0; | |
715 | NETLINK_CB(skbc).dst_group = 1; | |
716 | ||
717 | ret = netlink_broadcast(usk, skbc, 0, 1, GFP_KERNEL); | |
718 | /* ENOBUFS should be handled in userspace */ | |
719 | if (ret == -ENOBUFS || ret == -ESRCH) | |
720 | ret = 0; | |
721 | ||
722 | return ret; | |
723 | } | |
724 | ||
725 | static int uevent_net_rcv_skb(struct sk_buff *skb, struct nlmsghdr *nlh, | |
726 | struct netlink_ext_ack *extack) | |
727 | { | |
728 | struct net *net; | |
729 | int ret; | |
730 | ||
731 | if (!nlmsg_data(nlh)) | |
732 | return -EINVAL; | |
733 | ||
734 | /* | |
735 | * Verify that we are allowed to send messages to the target | |
736 | * network namespace. The caller must have CAP_SYS_ADMIN in the | |
737 | * owning user namespace of the target network namespace. | |
738 | */ | |
739 | net = sock_net(NETLINK_CB(skb).sk); | |
740 | if (!netlink_ns_capable(skb, net->user_ns, CAP_SYS_ADMIN)) { | |
741 | NL_SET_ERR_MSG(extack, "missing CAP_SYS_ADMIN capability"); | |
742 | return -EPERM; | |
743 | } | |
744 | ||
745 | mutex_lock(&uevent_sock_mutex); | |
746 | ret = uevent_net_broadcast(net->uevent_sock->sk, skb, extack); | |
747 | mutex_unlock(&uevent_sock_mutex); | |
748 | ||
749 | return ret; | |
750 | } | |
751 | ||
752 | static void uevent_net_rcv(struct sk_buff *skb) | |
753 | { | |
754 | netlink_rcv_skb(skb, &uevent_net_rcv_skb); | |
755 | } | |
756 | ||
07e98962 | 757 | static int uevent_net_init(struct net *net) |
5f123fbd | 758 | { |
07e98962 | 759 | struct uevent_sock *ue_sk; |
a31f2d17 PNA |
760 | struct netlink_kernel_cfg cfg = { |
761 | .groups = 1, | |
692ec06d CB |
762 | .input = uevent_net_rcv, |
763 | .flags = NL_CFG_F_NONROOT_RECV | |
a31f2d17 | 764 | }; |
07e98962 EB |
765 | |
766 | ue_sk = kzalloc(sizeof(*ue_sk), GFP_KERNEL); | |
767 | if (!ue_sk) | |
768 | return -ENOMEM; | |
769 | ||
9f00d977 | 770 | ue_sk->sk = netlink_kernel_create(net, NETLINK_KOBJECT_UEVENT, &cfg); |
07e98962 | 771 | if (!ue_sk->sk) { |
b3fa29ad | 772 | pr_err("kobject_uevent: unable to create netlink socket!\n"); |
743db2d9 | 773 | kfree(ue_sk); |
5f123fbd KS |
774 | return -ENODEV; |
775 | } | |
94e5e308 CB |
776 | |
777 | net->uevent_sock = ue_sk; | |
778 | ||
a3498436 CB |
779 | /* Restrict uevents to initial user namespace. */ |
780 | if (sock_net(ue_sk->sk)->user_ns == &init_user_ns) { | |
781 | mutex_lock(&uevent_sock_mutex); | |
782 | list_add_tail(&ue_sk->list, &uevent_sock_list); | |
783 | mutex_unlock(&uevent_sock_mutex); | |
784 | } | |
785 | ||
5f123fbd KS |
786 | return 0; |
787 | } | |
788 | ||
07e98962 EB |
789 | static void uevent_net_exit(struct net *net) |
790 | { | |
94e5e308 | 791 | struct uevent_sock *ue_sk = net->uevent_sock; |
07e98962 | 792 | |
a3498436 CB |
793 | if (sock_net(ue_sk->sk)->user_ns == &init_user_ns) { |
794 | mutex_lock(&uevent_sock_mutex); | |
795 | list_del(&ue_sk->list); | |
796 | mutex_unlock(&uevent_sock_mutex); | |
797 | } | |
07e98962 EB |
798 | |
799 | netlink_kernel_release(ue_sk->sk); | |
800 | kfree(ue_sk); | |
801 | } | |
802 | ||
803 | static struct pernet_operations uevent_net_ops = { | |
804 | .init = uevent_net_init, | |
805 | .exit = uevent_net_exit, | |
806 | }; | |
807 | ||
808 | static int __init kobject_uevent_init(void) | |
809 | { | |
07e98962 EB |
810 | return register_pernet_subsys(&uevent_net_ops); |
811 | } | |
812 | ||
813 | ||
5f123fbd | 814 | postcore_initcall(kobject_uevent_init); |
4d17ffda | 815 | #endif |