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> |
417daa1e | 23 | #include <linux/user_namespace.h> |
1da177e4 LT |
24 | #include <linux/socket.h> |
25 | #include <linux/skbuff.h> | |
26 | #include <linux/netlink.h> | |
1da177e4 | 27 | #include <net/sock.h> |
07e98962 | 28 | #include <net/net_namespace.h> |
1da177e4 | 29 | |
1da177e4 | 30 | |
cd030c4c | 31 | u64 uevent_seqnum; |
6a8d8abb | 32 | char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH; |
07e98962 EB |
33 | #ifdef CONFIG_NET |
34 | struct uevent_sock { | |
35 | struct list_head list; | |
36 | struct sock *sk; | |
37 | }; | |
38 | static LIST_HEAD(uevent_sock_list); | |
cd030c4c CH |
39 | #endif |
40 | ||
7b60a18d AV |
41 | /* This lock protects uevent_seqnum and uevent_sock_list */ |
42 | static DEFINE_MUTEX(uevent_sock_mutex); | |
43 | ||
5c5daf65 KS |
44 | /* the strings here must match the enum in include/linux/kobject.h */ |
45 | static const char *kobject_actions[] = { | |
46 | [KOBJ_ADD] = "add", | |
47 | [KOBJ_REMOVE] = "remove", | |
48 | [KOBJ_CHANGE] = "change", | |
49 | [KOBJ_MOVE] = "move", | |
50 | [KOBJ_ONLINE] = "online", | |
51 | [KOBJ_OFFLINE] = "offline", | |
52 | }; | |
53 | ||
54 | /** | |
55 | * kobject_action_type - translate action string to numeric type | |
56 | * | |
57 | * @buf: buffer containing the action string, newline is ignored | |
58 | * @len: length of buffer | |
59 | * @type: pointer to the location to store the action type | |
60 | * | |
61 | * Returns 0 if the action string was recognized. | |
62 | */ | |
63 | int kobject_action_type(const char *buf, size_t count, | |
64 | enum kobject_action *type) | |
65 | { | |
66 | enum kobject_action action; | |
67 | int ret = -EINVAL; | |
68 | ||
a9edadbf | 69 | if (count && (buf[count-1] == '\n' || buf[count-1] == '\0')) |
5c5daf65 KS |
70 | count--; |
71 | ||
72 | if (!count) | |
73 | goto out; | |
74 | ||
75 | for (action = 0; action < ARRAY_SIZE(kobject_actions); action++) { | |
76 | if (strncmp(kobject_actions[action], buf, count) != 0) | |
77 | continue; | |
78 | if (kobject_actions[action][count] != '\0') | |
79 | continue; | |
80 | *type = action; | |
81 | ret = 0; | |
82 | break; | |
83 | } | |
84 | out: | |
85 | return ret; | |
86 | } | |
87 | ||
c8421286 | 88 | #ifdef CONFIG_NET |
5f71a296 EB |
89 | static int kobj_bcast_filter(struct sock *dsk, struct sk_buff *skb, void *data) |
90 | { | |
82ef3d5d | 91 | struct kobject *kobj = data, *ksobj; |
5f71a296 EB |
92 | const struct kobj_ns_type_operations *ops; |
93 | ||
94 | ops = kobj_ns_ops(kobj); | |
82ef3d5d WC |
95 | if (!ops && kobj->kset) { |
96 | ksobj = &kobj->kset->kobj; | |
97 | if (ksobj->parent != NULL) | |
98 | ops = kobj_ns_ops(ksobj->parent); | |
99 | } | |
100 | ||
101 | if (ops && ops->netlink_ns && kobj->ktype->namespace) { | |
5f71a296 EB |
102 | const void *sock_ns, *ns; |
103 | ns = kobj->ktype->namespace(kobj); | |
104 | sock_ns = ops->netlink_ns(dsk); | |
105 | return sock_ns != ns; | |
106 | } | |
107 | ||
108 | return 0; | |
109 | } | |
c8421286 | 110 | #endif |
5f71a296 | 111 | |
417daa1e EB |
112 | static int kobj_usermode_filter(struct kobject *kobj) |
113 | { | |
114 | const struct kobj_ns_type_operations *ops; | |
115 | ||
116 | ops = kobj_ns_ops(kobj); | |
117 | if (ops) { | |
118 | const void *init_ns, *ns; | |
119 | ns = kobj->ktype->namespace(kobj); | |
120 | init_ns = ops->initial_ns(); | |
121 | return ns != init_ns; | |
122 | } | |
123 | ||
124 | return 0; | |
125 | } | |
126 | ||
bcccff93 VD |
127 | static int init_uevent_argv(struct kobj_uevent_env *env, const char *subsystem) |
128 | { | |
129 | int len; | |
130 | ||
131 | len = strlcpy(&env->buf[env->buflen], subsystem, | |
132 | sizeof(env->buf) - env->buflen); | |
133 | if (len >= (sizeof(env->buf) - env->buflen)) { | |
134 | WARN(1, KERN_ERR "init_uevent_argv: buffer size too small\n"); | |
135 | return -ENOMEM; | |
136 | } | |
137 | ||
138 | env->argv[0] = uevent_helper; | |
139 | env->argv[1] = &env->buf[env->buflen]; | |
140 | env->argv[2] = NULL; | |
141 | ||
142 | env->buflen += len + 1; | |
143 | return 0; | |
144 | } | |
145 | ||
146 | static void cleanup_uevent_env(struct subprocess_info *info) | |
147 | { | |
148 | kfree(info->data); | |
149 | } | |
150 | ||
1da177e4 | 151 | /** |
8a82472f | 152 | * kobject_uevent_env - send an uevent with environmental data |
1da177e4 | 153 | * |
ccd490a3 | 154 | * @action: action that is happening |
1da177e4 | 155 | * @kobj: struct kobject that the action is happening to |
8a82472f | 156 | * @envp_ext: pointer to environmental data |
542cfce6 | 157 | * |
f6e6e779 | 158 | * Returns 0 if kobject_uevent_env() is completed with success or the |
542cfce6 | 159 | * corresponding error when it fails. |
1da177e4 | 160 | */ |
542cfce6 | 161 | int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, |
7eff2e7a | 162 | char *envp_ext[]) |
1da177e4 | 163 | { |
7eff2e7a KS |
164 | struct kobj_uevent_env *env; |
165 | const char *action_string = kobject_actions[action]; | |
5f123fbd KS |
166 | const char *devpath = NULL; |
167 | const char *subsystem; | |
168 | struct kobject *top_kobj; | |
169 | struct kset *kset; | |
9cd43611 | 170 | const struct kset_uevent_ops *uevent_ops; |
1da177e4 | 171 | int i = 0; |
542cfce6 | 172 | int retval = 0; |
07e98962 EB |
173 | #ifdef CONFIG_NET |
174 | struct uevent_sock *ue_sk; | |
175 | #endif | |
1da177e4 | 176 | |
9f66fa2a | 177 | pr_debug("kobject: '%s' (%p): %s\n", |
810304db | 178 | kobject_name(kobj), kobj, __func__); |
5f123fbd | 179 | |
5f123fbd KS |
180 | /* search the kset we belong to */ |
181 | top_kobj = kobj; | |
ccd490a3 | 182 | while (!top_kobj->kset && top_kobj->parent) |
14193fb9 | 183 | top_kobj = top_kobj->parent; |
ccd490a3 | 184 | |
542cfce6 | 185 | if (!top_kobj->kset) { |
9f66fa2a GKH |
186 | pr_debug("kobject: '%s' (%p): %s: attempted to send uevent " |
187 | "without kset!\n", kobject_name(kobj), kobj, | |
810304db | 188 | __func__); |
542cfce6 AK |
189 | return -EINVAL; |
190 | } | |
1da177e4 | 191 | |
5f123fbd | 192 | kset = top_kobj->kset; |
312c004d | 193 | uevent_ops = kset->uevent_ops; |
1da177e4 | 194 | |
f67f129e ML |
195 | /* skip the event, if uevent_suppress is set*/ |
196 | if (kobj->uevent_suppress) { | |
197 | pr_debug("kobject: '%s' (%p): %s: uevent_suppress " | |
198 | "caused the event to drop!\n", | |
199 | kobject_name(kobj), kobj, __func__); | |
200 | return 0; | |
201 | } | |
7eff2e7a | 202 | /* skip the event, if the filter returns zero. */ |
312c004d | 203 | if (uevent_ops && uevent_ops->filter) |
542cfce6 | 204 | if (!uevent_ops->filter(kset, kobj)) { |
9f66fa2a GKH |
205 | pr_debug("kobject: '%s' (%p): %s: filter function " |
206 | "caused the event to drop!\n", | |
810304db | 207 | kobject_name(kobj), kobj, __func__); |
542cfce6 AK |
208 | return 0; |
209 | } | |
1da177e4 | 210 | |
86406245 KS |
211 | /* originating subsystem */ |
212 | if (uevent_ops && uevent_ops->name) | |
213 | subsystem = uevent_ops->name(kset, kobj); | |
214 | else | |
215 | subsystem = kobject_name(&kset->kobj); | |
216 | if (!subsystem) { | |
9f66fa2a GKH |
217 | pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the " |
218 | "event to drop!\n", kobject_name(kobj), kobj, | |
810304db | 219 | __func__); |
86406245 KS |
220 | return 0; |
221 | } | |
222 | ||
7eff2e7a KS |
223 | /* environment buffer */ |
224 | env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL); | |
225 | if (!env) | |
542cfce6 | 226 | return -ENOMEM; |
1da177e4 | 227 | |
5f123fbd KS |
228 | /* complete object path */ |
229 | devpath = kobject_get_path(kobj, GFP_KERNEL); | |
542cfce6 AK |
230 | if (!devpath) { |
231 | retval = -ENOENT; | |
5f123fbd | 232 | goto exit; |
542cfce6 | 233 | } |
1da177e4 | 234 | |
5f123fbd | 235 | /* default keys */ |
7eff2e7a KS |
236 | retval = add_uevent_var(env, "ACTION=%s", action_string); |
237 | if (retval) | |
238 | goto exit; | |
239 | retval = add_uevent_var(env, "DEVPATH=%s", devpath); | |
240 | if (retval) | |
241 | goto exit; | |
242 | retval = add_uevent_var(env, "SUBSYSTEM=%s", subsystem); | |
243 | if (retval) | |
244 | goto exit; | |
245 | ||
246 | /* keys passed in from the caller */ | |
247 | if (envp_ext) { | |
248 | for (i = 0; envp_ext[i]; i++) { | |
c65b9145 | 249 | retval = add_uevent_var(env, "%s", envp_ext[i]); |
7eff2e7a KS |
250 | if (retval) |
251 | goto exit; | |
252 | } | |
253 | } | |
1da177e4 | 254 | |
5f123fbd | 255 | /* let the kset specific function add its stuff */ |
312c004d | 256 | if (uevent_ops && uevent_ops->uevent) { |
7eff2e7a | 257 | retval = uevent_ops->uevent(kset, kobj, env); |
1da177e4 | 258 | if (retval) { |
9f66fa2a GKH |
259 | pr_debug("kobject: '%s' (%p): %s: uevent() returned " |
260 | "%d\n", kobject_name(kobj), kobj, | |
810304db | 261 | __func__, retval); |
1da177e4 LT |
262 | goto exit; |
263 | } | |
264 | } | |
265 | ||
0f4dafc0 KS |
266 | /* |
267 | * Mark "add" and "remove" events in the object to ensure proper | |
268 | * events to userspace during automatic cleanup. If the object did | |
269 | * send an "add" event, "remove" will automatically generated by | |
270 | * the core, if not already done by the caller. | |
271 | */ | |
272 | if (action == KOBJ_ADD) | |
273 | kobj->state_add_uevent_sent = 1; | |
274 | else if (action == KOBJ_REMOVE) | |
275 | kobj->state_remove_uevent_sent = 1; | |
276 | ||
7b60a18d | 277 | mutex_lock(&uevent_sock_mutex); |
7eff2e7a | 278 | /* we will send an event, so request a new sequence number */ |
7b60a18d AV |
279 | retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)++uevent_seqnum); |
280 | if (retval) { | |
281 | mutex_unlock(&uevent_sock_mutex); | |
7eff2e7a | 282 | goto exit; |
7b60a18d | 283 | } |
1da177e4 | 284 | |
4d17ffda | 285 | #if defined(CONFIG_NET) |
5f123fbd | 286 | /* send netlink message */ |
07e98962 EB |
287 | list_for_each_entry(ue_sk, &uevent_sock_list, list) { |
288 | struct sock *uevent_sock = ue_sk->sk; | |
5f123fbd KS |
289 | struct sk_buff *skb; |
290 | size_t len; | |
291 | ||
74099b18 KS |
292 | if (!netlink_has_listeners(uevent_sock, 1)) |
293 | continue; | |
294 | ||
5f123fbd KS |
295 | /* allocate message with the maximum possible size */ |
296 | len = strlen(action_string) + strlen(devpath) + 2; | |
7eff2e7a | 297 | skb = alloc_skb(len + env->buflen, GFP_KERNEL); |
5f123fbd | 298 | if (skb) { |
7eff2e7a KS |
299 | char *scratch; |
300 | ||
5f123fbd KS |
301 | /* add header */ |
302 | scratch = skb_put(skb, len); | |
303 | sprintf(scratch, "%s@%s", action_string, devpath); | |
304 | ||
305 | /* copy keys to our continuous event payload buffer */ | |
7eff2e7a KS |
306 | for (i = 0; i < env->envp_idx; i++) { |
307 | len = strlen(env->envp[i]) + 1; | |
5f123fbd | 308 | scratch = skb_put(skb, len); |
7eff2e7a | 309 | strcpy(scratch, env->envp[i]); |
5f123fbd KS |
310 | } |
311 | ||
312 | NETLINK_CB(skb).dst_group = 1; | |
5f71a296 EB |
313 | retval = netlink_broadcast_filtered(uevent_sock, skb, |
314 | 0, 1, GFP_KERNEL, | |
315 | kobj_bcast_filter, | |
316 | kobj); | |
ff491a73 | 317 | /* ENOBUFS should be handled in userspace */ |
ebf4127c | 318 | if (retval == -ENOBUFS || retval == -ESRCH) |
ff491a73 | 319 | retval = 0; |
e0d7bf5d ML |
320 | } else |
321 | retval = -ENOMEM; | |
5f123fbd | 322 | } |
4d17ffda | 323 | #endif |
7b60a18d | 324 | mutex_unlock(&uevent_sock_mutex); |
1da177e4 | 325 | |
5f123fbd | 326 | /* call uevent_helper, usually only enabled during early boot */ |
417daa1e | 327 | if (uevent_helper[0] && !kobj_usermode_filter(kobj)) { |
bcccff93 | 328 | struct subprocess_info *info; |
1da177e4 | 329 | |
7eff2e7a KS |
330 | retval = add_uevent_var(env, "HOME=/"); |
331 | if (retval) | |
332 | goto exit; | |
e374a2bf GKH |
333 | retval = add_uevent_var(env, |
334 | "PATH=/sbin:/bin:/usr/sbin:/usr/bin"); | |
7eff2e7a KS |
335 | if (retval) |
336 | goto exit; | |
bcccff93 VD |
337 | retval = init_uevent_argv(env, subsystem); |
338 | if (retval) | |
339 | goto exit; | |
7eff2e7a | 340 | |
bcccff93 VD |
341 | retval = -ENOMEM; |
342 | info = call_usermodehelper_setup(env->argv[0], env->argv, | |
343 | env->envp, GFP_KERNEL, | |
344 | NULL, cleanup_uevent_env, env); | |
345 | if (info) { | |
346 | retval = call_usermodehelper_exec(info, UMH_NO_WAIT); | |
347 | env = NULL; /* freed by cleanup_uevent_env */ | |
348 | } | |
5f123fbd | 349 | } |
1da177e4 LT |
350 | |
351 | exit: | |
5f123fbd | 352 | kfree(devpath); |
7eff2e7a | 353 | kfree(env); |
542cfce6 | 354 | return retval; |
1da177e4 | 355 | } |
8a82472f CH |
356 | EXPORT_SYMBOL_GPL(kobject_uevent_env); |
357 | ||
358 | /** | |
f6e6e779 | 359 | * kobject_uevent - notify userspace by sending an uevent |
8a82472f | 360 | * |
ccd490a3 | 361 | * @action: action that is happening |
8a82472f | 362 | * @kobj: struct kobject that the action is happening to |
542cfce6 AK |
363 | * |
364 | * Returns 0 if kobject_uevent() is completed with success or the | |
365 | * corresponding error when it fails. | |
8a82472f | 366 | */ |
542cfce6 | 367 | int kobject_uevent(struct kobject *kobj, enum kobject_action action) |
8a82472f | 368 | { |
542cfce6 | 369 | return kobject_uevent_env(kobj, action, NULL); |
8a82472f | 370 | } |
312c004d | 371 | EXPORT_SYMBOL_GPL(kobject_uevent); |
1da177e4 LT |
372 | |
373 | /** | |
7eff2e7a KS |
374 | * add_uevent_var - add key value string to the environment buffer |
375 | * @env: environment buffer structure | |
376 | * @format: printf format for the key=value pair | |
1da177e4 LT |
377 | * |
378 | * Returns 0 if environment variable was added successfully or -ENOMEM | |
379 | * if no space was available. | |
380 | */ | |
7eff2e7a | 381 | int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...) |
1da177e4 LT |
382 | { |
383 | va_list args; | |
7eff2e7a | 384 | int len; |
1da177e4 | 385 | |
7eff2e7a | 386 | if (env->envp_idx >= ARRAY_SIZE(env->envp)) { |
5cd2b459 | 387 | WARN(1, KERN_ERR "add_uevent_var: too many keys\n"); |
1da177e4 | 388 | return -ENOMEM; |
7eff2e7a | 389 | } |
1da177e4 LT |
390 | |
391 | va_start(args, format); | |
7eff2e7a KS |
392 | len = vsnprintf(&env->buf[env->buflen], |
393 | sizeof(env->buf) - env->buflen, | |
394 | format, args); | |
1da177e4 LT |
395 | va_end(args); |
396 | ||
7eff2e7a | 397 | if (len >= (sizeof(env->buf) - env->buflen)) { |
5cd2b459 | 398 | WARN(1, KERN_ERR "add_uevent_var: buffer size too small\n"); |
1da177e4 | 399 | return -ENOMEM; |
7eff2e7a | 400 | } |
1da177e4 | 401 | |
7eff2e7a KS |
402 | env->envp[env->envp_idx++] = &env->buf[env->buflen]; |
403 | env->buflen += len + 1; | |
1da177e4 LT |
404 | return 0; |
405 | } | |
312c004d | 406 | EXPORT_SYMBOL_GPL(add_uevent_var); |
1da177e4 | 407 | |
4d17ffda | 408 | #if defined(CONFIG_NET) |
07e98962 | 409 | static int uevent_net_init(struct net *net) |
5f123fbd | 410 | { |
07e98962 | 411 | struct uevent_sock *ue_sk; |
a31f2d17 PNA |
412 | struct netlink_kernel_cfg cfg = { |
413 | .groups = 1, | |
9785e10a | 414 | .flags = NL_CFG_F_NONROOT_RECV, |
a31f2d17 | 415 | }; |
07e98962 EB |
416 | |
417 | ue_sk = kzalloc(sizeof(*ue_sk), GFP_KERNEL); | |
418 | if (!ue_sk) | |
419 | return -ENOMEM; | |
420 | ||
9f00d977 | 421 | ue_sk->sk = netlink_kernel_create(net, NETLINK_KOBJECT_UEVENT, &cfg); |
07e98962 | 422 | if (!ue_sk->sk) { |
5f123fbd KS |
423 | printk(KERN_ERR |
424 | "kobject_uevent: unable to create netlink socket!\n"); | |
743db2d9 | 425 | kfree(ue_sk); |
5f123fbd KS |
426 | return -ENODEV; |
427 | } | |
07e98962 EB |
428 | mutex_lock(&uevent_sock_mutex); |
429 | list_add_tail(&ue_sk->list, &uevent_sock_list); | |
430 | mutex_unlock(&uevent_sock_mutex); | |
5f123fbd KS |
431 | return 0; |
432 | } | |
433 | ||
07e98962 EB |
434 | static void uevent_net_exit(struct net *net) |
435 | { | |
436 | struct uevent_sock *ue_sk; | |
437 | ||
438 | mutex_lock(&uevent_sock_mutex); | |
439 | list_for_each_entry(ue_sk, &uevent_sock_list, list) { | |
440 | if (sock_net(ue_sk->sk) == net) | |
441 | goto found; | |
442 | } | |
443 | mutex_unlock(&uevent_sock_mutex); | |
444 | return; | |
445 | ||
446 | found: | |
447 | list_del(&ue_sk->list); | |
448 | mutex_unlock(&uevent_sock_mutex); | |
449 | ||
450 | netlink_kernel_release(ue_sk->sk); | |
451 | kfree(ue_sk); | |
452 | } | |
453 | ||
454 | static struct pernet_operations uevent_net_ops = { | |
455 | .init = uevent_net_init, | |
456 | .exit = uevent_net_exit, | |
457 | }; | |
458 | ||
459 | static int __init kobject_uevent_init(void) | |
460 | { | |
07e98962 EB |
461 | return register_pernet_subsys(&uevent_net_ops); |
462 | } | |
463 | ||
464 | ||
5f123fbd | 465 | postcore_initcall(kobject_uevent_init); |
4d17ffda | 466 | #endif |