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 | ||
1da177e4 | 127 | /** |
8a82472f | 128 | * kobject_uevent_env - send an uevent with environmental data |
1da177e4 | 129 | * |
ccd490a3 | 130 | * @action: action that is happening |
1da177e4 | 131 | * @kobj: struct kobject that the action is happening to |
8a82472f | 132 | * @envp_ext: pointer to environmental data |
542cfce6 | 133 | * |
f6e6e779 | 134 | * Returns 0 if kobject_uevent_env() is completed with success or the |
542cfce6 | 135 | * corresponding error when it fails. |
1da177e4 | 136 | */ |
542cfce6 | 137 | int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, |
7eff2e7a | 138 | char *envp_ext[]) |
1da177e4 | 139 | { |
7eff2e7a KS |
140 | struct kobj_uevent_env *env; |
141 | const char *action_string = kobject_actions[action]; | |
5f123fbd KS |
142 | const char *devpath = NULL; |
143 | const char *subsystem; | |
144 | struct kobject *top_kobj; | |
145 | struct kset *kset; | |
9cd43611 | 146 | const struct kset_uevent_ops *uevent_ops; |
1da177e4 | 147 | int i = 0; |
542cfce6 | 148 | int retval = 0; |
07e98962 EB |
149 | #ifdef CONFIG_NET |
150 | struct uevent_sock *ue_sk; | |
151 | #endif | |
1da177e4 | 152 | |
9f66fa2a | 153 | pr_debug("kobject: '%s' (%p): %s\n", |
810304db | 154 | kobject_name(kobj), kobj, __func__); |
5f123fbd | 155 | |
5f123fbd KS |
156 | /* search the kset we belong to */ |
157 | top_kobj = kobj; | |
ccd490a3 | 158 | while (!top_kobj->kset && top_kobj->parent) |
14193fb9 | 159 | top_kobj = top_kobj->parent; |
ccd490a3 | 160 | |
542cfce6 | 161 | if (!top_kobj->kset) { |
9f66fa2a GKH |
162 | pr_debug("kobject: '%s' (%p): %s: attempted to send uevent " |
163 | "without kset!\n", kobject_name(kobj), kobj, | |
810304db | 164 | __func__); |
542cfce6 AK |
165 | return -EINVAL; |
166 | } | |
1da177e4 | 167 | |
5f123fbd | 168 | kset = top_kobj->kset; |
312c004d | 169 | uevent_ops = kset->uevent_ops; |
1da177e4 | 170 | |
f67f129e ML |
171 | /* skip the event, if uevent_suppress is set*/ |
172 | if (kobj->uevent_suppress) { | |
173 | pr_debug("kobject: '%s' (%p): %s: uevent_suppress " | |
174 | "caused the event to drop!\n", | |
175 | kobject_name(kobj), kobj, __func__); | |
176 | return 0; | |
177 | } | |
7eff2e7a | 178 | /* skip the event, if the filter returns zero. */ |
312c004d | 179 | if (uevent_ops && uevent_ops->filter) |
542cfce6 | 180 | if (!uevent_ops->filter(kset, kobj)) { |
9f66fa2a GKH |
181 | pr_debug("kobject: '%s' (%p): %s: filter function " |
182 | "caused the event to drop!\n", | |
810304db | 183 | kobject_name(kobj), kobj, __func__); |
542cfce6 AK |
184 | return 0; |
185 | } | |
1da177e4 | 186 | |
86406245 KS |
187 | /* originating subsystem */ |
188 | if (uevent_ops && uevent_ops->name) | |
189 | subsystem = uevent_ops->name(kset, kobj); | |
190 | else | |
191 | subsystem = kobject_name(&kset->kobj); | |
192 | if (!subsystem) { | |
9f66fa2a GKH |
193 | pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the " |
194 | "event to drop!\n", kobject_name(kobj), kobj, | |
810304db | 195 | __func__); |
86406245 KS |
196 | return 0; |
197 | } | |
198 | ||
7eff2e7a KS |
199 | /* environment buffer */ |
200 | env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL); | |
201 | if (!env) | |
542cfce6 | 202 | return -ENOMEM; |
1da177e4 | 203 | |
5f123fbd KS |
204 | /* complete object path */ |
205 | devpath = kobject_get_path(kobj, GFP_KERNEL); | |
542cfce6 AK |
206 | if (!devpath) { |
207 | retval = -ENOENT; | |
5f123fbd | 208 | goto exit; |
542cfce6 | 209 | } |
1da177e4 | 210 | |
5f123fbd | 211 | /* default keys */ |
7eff2e7a KS |
212 | retval = add_uevent_var(env, "ACTION=%s", action_string); |
213 | if (retval) | |
214 | goto exit; | |
215 | retval = add_uevent_var(env, "DEVPATH=%s", devpath); | |
216 | if (retval) | |
217 | goto exit; | |
218 | retval = add_uevent_var(env, "SUBSYSTEM=%s", subsystem); | |
219 | if (retval) | |
220 | goto exit; | |
221 | ||
222 | /* keys passed in from the caller */ | |
223 | if (envp_ext) { | |
224 | for (i = 0; envp_ext[i]; i++) { | |
c65b9145 | 225 | retval = add_uevent_var(env, "%s", envp_ext[i]); |
7eff2e7a KS |
226 | if (retval) |
227 | goto exit; | |
228 | } | |
229 | } | |
1da177e4 | 230 | |
5f123fbd | 231 | /* let the kset specific function add its stuff */ |
312c004d | 232 | if (uevent_ops && uevent_ops->uevent) { |
7eff2e7a | 233 | retval = uevent_ops->uevent(kset, kobj, env); |
1da177e4 | 234 | if (retval) { |
9f66fa2a GKH |
235 | pr_debug("kobject: '%s' (%p): %s: uevent() returned " |
236 | "%d\n", kobject_name(kobj), kobj, | |
810304db | 237 | __func__, retval); |
1da177e4 LT |
238 | goto exit; |
239 | } | |
240 | } | |
241 | ||
0f4dafc0 KS |
242 | /* |
243 | * Mark "add" and "remove" events in the object to ensure proper | |
244 | * events to userspace during automatic cleanup. If the object did | |
245 | * send an "add" event, "remove" will automatically generated by | |
246 | * the core, if not already done by the caller. | |
247 | */ | |
248 | if (action == KOBJ_ADD) | |
249 | kobj->state_add_uevent_sent = 1; | |
250 | else if (action == KOBJ_REMOVE) | |
251 | kobj->state_remove_uevent_sent = 1; | |
252 | ||
7b60a18d | 253 | mutex_lock(&uevent_sock_mutex); |
7eff2e7a | 254 | /* we will send an event, so request a new sequence number */ |
7b60a18d AV |
255 | retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)++uevent_seqnum); |
256 | if (retval) { | |
257 | mutex_unlock(&uevent_sock_mutex); | |
7eff2e7a | 258 | goto exit; |
7b60a18d | 259 | } |
1da177e4 | 260 | |
4d17ffda | 261 | #if defined(CONFIG_NET) |
5f123fbd | 262 | /* send netlink message */ |
07e98962 EB |
263 | list_for_each_entry(ue_sk, &uevent_sock_list, list) { |
264 | struct sock *uevent_sock = ue_sk->sk; | |
5f123fbd KS |
265 | struct sk_buff *skb; |
266 | size_t len; | |
267 | ||
74099b18 KS |
268 | if (!netlink_has_listeners(uevent_sock, 1)) |
269 | continue; | |
270 | ||
5f123fbd KS |
271 | /* allocate message with the maximum possible size */ |
272 | len = strlen(action_string) + strlen(devpath) + 2; | |
7eff2e7a | 273 | skb = alloc_skb(len + env->buflen, GFP_KERNEL); |
5f123fbd | 274 | if (skb) { |
7eff2e7a KS |
275 | char *scratch; |
276 | ||
5f123fbd KS |
277 | /* add header */ |
278 | scratch = skb_put(skb, len); | |
279 | sprintf(scratch, "%s@%s", action_string, devpath); | |
280 | ||
281 | /* copy keys to our continuous event payload buffer */ | |
7eff2e7a KS |
282 | for (i = 0; i < env->envp_idx; i++) { |
283 | len = strlen(env->envp[i]) + 1; | |
5f123fbd | 284 | scratch = skb_put(skb, len); |
7eff2e7a | 285 | strcpy(scratch, env->envp[i]); |
5f123fbd KS |
286 | } |
287 | ||
288 | NETLINK_CB(skb).dst_group = 1; | |
5f71a296 EB |
289 | retval = netlink_broadcast_filtered(uevent_sock, skb, |
290 | 0, 1, GFP_KERNEL, | |
291 | kobj_bcast_filter, | |
292 | kobj); | |
ff491a73 | 293 | /* ENOBUFS should be handled in userspace */ |
ebf4127c | 294 | if (retval == -ENOBUFS || retval == -ESRCH) |
ff491a73 | 295 | retval = 0; |
e0d7bf5d ML |
296 | } else |
297 | retval = -ENOMEM; | |
5f123fbd | 298 | } |
4d17ffda | 299 | #endif |
7b60a18d | 300 | mutex_unlock(&uevent_sock_mutex); |
1da177e4 | 301 | |
5f123fbd | 302 | /* call uevent_helper, usually only enabled during early boot */ |
417daa1e | 303 | if (uevent_helper[0] && !kobj_usermode_filter(kobj)) { |
5f123fbd | 304 | char *argv [3]; |
1da177e4 | 305 | |
312c004d | 306 | argv [0] = uevent_helper; |
5f123fbd KS |
307 | argv [1] = (char *)subsystem; |
308 | argv [2] = NULL; | |
7eff2e7a KS |
309 | retval = add_uevent_var(env, "HOME=/"); |
310 | if (retval) | |
311 | goto exit; | |
e374a2bf GKH |
312 | retval = add_uevent_var(env, |
313 | "PATH=/sbin:/bin:/usr/sbin:/usr/bin"); | |
7eff2e7a KS |
314 | if (retval) |
315 | goto exit; | |
316 | ||
0ad1d6f3 | 317 | retval = call_usermodehelper(argv[0], argv, |
05f54c13 | 318 | env->envp, UMH_WAIT_EXEC); |
5f123fbd | 319 | } |
1da177e4 LT |
320 | |
321 | exit: | |
5f123fbd | 322 | kfree(devpath); |
7eff2e7a | 323 | kfree(env); |
542cfce6 | 324 | return retval; |
1da177e4 | 325 | } |
8a82472f CH |
326 | EXPORT_SYMBOL_GPL(kobject_uevent_env); |
327 | ||
328 | /** | |
f6e6e779 | 329 | * kobject_uevent - notify userspace by sending an uevent |
8a82472f | 330 | * |
ccd490a3 | 331 | * @action: action that is happening |
8a82472f | 332 | * @kobj: struct kobject that the action is happening to |
542cfce6 AK |
333 | * |
334 | * Returns 0 if kobject_uevent() is completed with success or the | |
335 | * corresponding error when it fails. | |
8a82472f | 336 | */ |
542cfce6 | 337 | int kobject_uevent(struct kobject *kobj, enum kobject_action action) |
8a82472f | 338 | { |
542cfce6 | 339 | return kobject_uevent_env(kobj, action, NULL); |
8a82472f | 340 | } |
312c004d | 341 | EXPORT_SYMBOL_GPL(kobject_uevent); |
1da177e4 LT |
342 | |
343 | /** | |
7eff2e7a KS |
344 | * add_uevent_var - add key value string to the environment buffer |
345 | * @env: environment buffer structure | |
346 | * @format: printf format for the key=value pair | |
1da177e4 LT |
347 | * |
348 | * Returns 0 if environment variable was added successfully or -ENOMEM | |
349 | * if no space was available. | |
350 | */ | |
7eff2e7a | 351 | int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...) |
1da177e4 LT |
352 | { |
353 | va_list args; | |
7eff2e7a | 354 | int len; |
1da177e4 | 355 | |
7eff2e7a | 356 | if (env->envp_idx >= ARRAY_SIZE(env->envp)) { |
5cd2b459 | 357 | WARN(1, KERN_ERR "add_uevent_var: too many keys\n"); |
1da177e4 | 358 | return -ENOMEM; |
7eff2e7a | 359 | } |
1da177e4 LT |
360 | |
361 | va_start(args, format); | |
7eff2e7a KS |
362 | len = vsnprintf(&env->buf[env->buflen], |
363 | sizeof(env->buf) - env->buflen, | |
364 | format, args); | |
1da177e4 LT |
365 | va_end(args); |
366 | ||
7eff2e7a | 367 | if (len >= (sizeof(env->buf) - env->buflen)) { |
5cd2b459 | 368 | WARN(1, KERN_ERR "add_uevent_var: buffer size too small\n"); |
1da177e4 | 369 | return -ENOMEM; |
7eff2e7a | 370 | } |
1da177e4 | 371 | |
7eff2e7a KS |
372 | env->envp[env->envp_idx++] = &env->buf[env->buflen]; |
373 | env->buflen += len + 1; | |
1da177e4 LT |
374 | return 0; |
375 | } | |
312c004d | 376 | EXPORT_SYMBOL_GPL(add_uevent_var); |
1da177e4 | 377 | |
4d17ffda | 378 | #if defined(CONFIG_NET) |
07e98962 | 379 | static int uevent_net_init(struct net *net) |
5f123fbd | 380 | { |
07e98962 | 381 | struct uevent_sock *ue_sk; |
a31f2d17 PNA |
382 | struct netlink_kernel_cfg cfg = { |
383 | .groups = 1, | |
9785e10a | 384 | .flags = NL_CFG_F_NONROOT_RECV, |
a31f2d17 | 385 | }; |
07e98962 EB |
386 | |
387 | ue_sk = kzalloc(sizeof(*ue_sk), GFP_KERNEL); | |
388 | if (!ue_sk) | |
389 | return -ENOMEM; | |
390 | ||
9f00d977 | 391 | ue_sk->sk = netlink_kernel_create(net, NETLINK_KOBJECT_UEVENT, &cfg); |
07e98962 | 392 | if (!ue_sk->sk) { |
5f123fbd KS |
393 | printk(KERN_ERR |
394 | "kobject_uevent: unable to create netlink socket!\n"); | |
743db2d9 | 395 | kfree(ue_sk); |
5f123fbd KS |
396 | return -ENODEV; |
397 | } | |
07e98962 EB |
398 | mutex_lock(&uevent_sock_mutex); |
399 | list_add_tail(&ue_sk->list, &uevent_sock_list); | |
400 | mutex_unlock(&uevent_sock_mutex); | |
5f123fbd KS |
401 | return 0; |
402 | } | |
403 | ||
07e98962 EB |
404 | static void uevent_net_exit(struct net *net) |
405 | { | |
406 | struct uevent_sock *ue_sk; | |
407 | ||
408 | mutex_lock(&uevent_sock_mutex); | |
409 | list_for_each_entry(ue_sk, &uevent_sock_list, list) { | |
410 | if (sock_net(ue_sk->sk) == net) | |
411 | goto found; | |
412 | } | |
413 | mutex_unlock(&uevent_sock_mutex); | |
414 | return; | |
415 | ||
416 | found: | |
417 | list_del(&ue_sk->list); | |
418 | mutex_unlock(&uevent_sock_mutex); | |
419 | ||
420 | netlink_kernel_release(ue_sk->sk); | |
421 | kfree(ue_sk); | |
422 | } | |
423 | ||
424 | static struct pernet_operations uevent_net_ops = { | |
425 | .init = uevent_net_init, | |
426 | .exit = uevent_net_exit, | |
427 | }; | |
428 | ||
429 | static int __init kobject_uevent_init(void) | |
430 | { | |
07e98962 EB |
431 | return register_pernet_subsys(&uevent_net_ops); |
432 | } | |
433 | ||
434 | ||
5f123fbd | 435 | postcore_initcall(kobject_uevent_init); |
4d17ffda | 436 | #endif |