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; |
cd030c4c | 33 | static DEFINE_SPINLOCK(sequence_lock); |
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); | |
40 | static DEFINE_MUTEX(uevent_sock_mutex); | |
cd030c4c CH |
41 | #endif |
42 | ||
5c5daf65 KS |
43 | /* the strings here must match the enum in include/linux/kobject.h */ |
44 | static const char *kobject_actions[] = { | |
45 | [KOBJ_ADD] = "add", | |
46 | [KOBJ_REMOVE] = "remove", | |
47 | [KOBJ_CHANGE] = "change", | |
48 | [KOBJ_MOVE] = "move", | |
49 | [KOBJ_ONLINE] = "online", | |
50 | [KOBJ_OFFLINE] = "offline", | |
51 | }; | |
52 | ||
53 | /** | |
54 | * kobject_action_type - translate action string to numeric type | |
55 | * | |
56 | * @buf: buffer containing the action string, newline is ignored | |
57 | * @len: length of buffer | |
58 | * @type: pointer to the location to store the action type | |
59 | * | |
60 | * Returns 0 if the action string was recognized. | |
61 | */ | |
62 | int kobject_action_type(const char *buf, size_t count, | |
63 | enum kobject_action *type) | |
64 | { | |
65 | enum kobject_action action; | |
66 | int ret = -EINVAL; | |
67 | ||
a9edadbf | 68 | if (count && (buf[count-1] == '\n' || buf[count-1] == '\0')) |
5c5daf65 KS |
69 | count--; |
70 | ||
71 | if (!count) | |
72 | goto out; | |
73 | ||
74 | for (action = 0; action < ARRAY_SIZE(kobject_actions); action++) { | |
75 | if (strncmp(kobject_actions[action], buf, count) != 0) | |
76 | continue; | |
77 | if (kobject_actions[action][count] != '\0') | |
78 | continue; | |
79 | *type = action; | |
80 | ret = 0; | |
81 | break; | |
82 | } | |
83 | out: | |
84 | return ret; | |
85 | } | |
86 | ||
c8421286 | 87 | #ifdef CONFIG_NET |
5f71a296 EB |
88 | static int kobj_bcast_filter(struct sock *dsk, struct sk_buff *skb, void *data) |
89 | { | |
90 | struct kobject *kobj = data; | |
91 | const struct kobj_ns_type_operations *ops; | |
92 | ||
93 | ops = kobj_ns_ops(kobj); | |
94 | if (ops) { | |
95 | const void *sock_ns, *ns; | |
96 | ns = kobj->ktype->namespace(kobj); | |
97 | sock_ns = ops->netlink_ns(dsk); | |
98 | return sock_ns != ns; | |
99 | } | |
100 | ||
101 | return 0; | |
102 | } | |
c8421286 | 103 | #endif |
5f71a296 | 104 | |
417daa1e EB |
105 | static int kobj_usermode_filter(struct kobject *kobj) |
106 | { | |
107 | const struct kobj_ns_type_operations *ops; | |
108 | ||
109 | ops = kobj_ns_ops(kobj); | |
110 | if (ops) { | |
111 | const void *init_ns, *ns; | |
112 | ns = kobj->ktype->namespace(kobj); | |
113 | init_ns = ops->initial_ns(); | |
114 | return ns != init_ns; | |
115 | } | |
116 | ||
117 | return 0; | |
118 | } | |
119 | ||
1da177e4 | 120 | /** |
8a82472f | 121 | * kobject_uevent_env - send an uevent with environmental data |
1da177e4 | 122 | * |
ccd490a3 | 123 | * @action: action that is happening |
1da177e4 | 124 | * @kobj: struct kobject that the action is happening to |
8a82472f | 125 | * @envp_ext: pointer to environmental data |
542cfce6 | 126 | * |
f6e6e779 | 127 | * Returns 0 if kobject_uevent_env() is completed with success or the |
542cfce6 | 128 | * corresponding error when it fails. |
1da177e4 | 129 | */ |
542cfce6 | 130 | int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, |
7eff2e7a | 131 | char *envp_ext[]) |
1da177e4 | 132 | { |
7eff2e7a KS |
133 | struct kobj_uevent_env *env; |
134 | const char *action_string = kobject_actions[action]; | |
5f123fbd KS |
135 | const char *devpath = NULL; |
136 | const char *subsystem; | |
137 | struct kobject *top_kobj; | |
138 | struct kset *kset; | |
9cd43611 | 139 | const struct kset_uevent_ops *uevent_ops; |
5f123fbd | 140 | u64 seq; |
1da177e4 | 141 | int i = 0; |
542cfce6 | 142 | int retval = 0; |
07e98962 EB |
143 | #ifdef CONFIG_NET |
144 | struct uevent_sock *ue_sk; | |
145 | #endif | |
1da177e4 | 146 | |
9f66fa2a | 147 | pr_debug("kobject: '%s' (%p): %s\n", |
810304db | 148 | kobject_name(kobj), kobj, __func__); |
5f123fbd | 149 | |
5f123fbd KS |
150 | /* search the kset we belong to */ |
151 | top_kobj = kobj; | |
ccd490a3 | 152 | while (!top_kobj->kset && top_kobj->parent) |
14193fb9 | 153 | top_kobj = top_kobj->parent; |
ccd490a3 | 154 | |
542cfce6 | 155 | if (!top_kobj->kset) { |
9f66fa2a GKH |
156 | pr_debug("kobject: '%s' (%p): %s: attempted to send uevent " |
157 | "without kset!\n", kobject_name(kobj), kobj, | |
810304db | 158 | __func__); |
542cfce6 AK |
159 | return -EINVAL; |
160 | } | |
1da177e4 | 161 | |
5f123fbd | 162 | kset = top_kobj->kset; |
312c004d | 163 | uevent_ops = kset->uevent_ops; |
1da177e4 | 164 | |
f67f129e ML |
165 | /* skip the event, if uevent_suppress is set*/ |
166 | if (kobj->uevent_suppress) { | |
167 | pr_debug("kobject: '%s' (%p): %s: uevent_suppress " | |
168 | "caused the event to drop!\n", | |
169 | kobject_name(kobj), kobj, __func__); | |
170 | return 0; | |
171 | } | |
7eff2e7a | 172 | /* skip the event, if the filter returns zero. */ |
312c004d | 173 | if (uevent_ops && uevent_ops->filter) |
542cfce6 | 174 | if (!uevent_ops->filter(kset, kobj)) { |
9f66fa2a GKH |
175 | pr_debug("kobject: '%s' (%p): %s: filter function " |
176 | "caused the event to drop!\n", | |
810304db | 177 | kobject_name(kobj), kobj, __func__); |
542cfce6 AK |
178 | return 0; |
179 | } | |
1da177e4 | 180 | |
86406245 KS |
181 | /* originating subsystem */ |
182 | if (uevent_ops && uevent_ops->name) | |
183 | subsystem = uevent_ops->name(kset, kobj); | |
184 | else | |
185 | subsystem = kobject_name(&kset->kobj); | |
186 | if (!subsystem) { | |
9f66fa2a GKH |
187 | pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the " |
188 | "event to drop!\n", kobject_name(kobj), kobj, | |
810304db | 189 | __func__); |
86406245 KS |
190 | return 0; |
191 | } | |
192 | ||
7eff2e7a KS |
193 | /* environment buffer */ |
194 | env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL); | |
195 | if (!env) | |
542cfce6 | 196 | return -ENOMEM; |
1da177e4 | 197 | |
5f123fbd KS |
198 | /* complete object path */ |
199 | devpath = kobject_get_path(kobj, GFP_KERNEL); | |
542cfce6 AK |
200 | if (!devpath) { |
201 | retval = -ENOENT; | |
5f123fbd | 202 | goto exit; |
542cfce6 | 203 | } |
1da177e4 | 204 | |
5f123fbd | 205 | /* default keys */ |
7eff2e7a KS |
206 | retval = add_uevent_var(env, "ACTION=%s", action_string); |
207 | if (retval) | |
208 | goto exit; | |
209 | retval = add_uevent_var(env, "DEVPATH=%s", devpath); | |
210 | if (retval) | |
211 | goto exit; | |
212 | retval = add_uevent_var(env, "SUBSYSTEM=%s", subsystem); | |
213 | if (retval) | |
214 | goto exit; | |
215 | ||
216 | /* keys passed in from the caller */ | |
217 | if (envp_ext) { | |
218 | for (i = 0; envp_ext[i]; i++) { | |
c65b9145 | 219 | retval = add_uevent_var(env, "%s", envp_ext[i]); |
7eff2e7a KS |
220 | if (retval) |
221 | goto exit; | |
222 | } | |
223 | } | |
1da177e4 | 224 | |
5f123fbd | 225 | /* let the kset specific function add its stuff */ |
312c004d | 226 | if (uevent_ops && uevent_ops->uevent) { |
7eff2e7a | 227 | retval = uevent_ops->uevent(kset, kobj, env); |
1da177e4 | 228 | if (retval) { |
9f66fa2a GKH |
229 | pr_debug("kobject: '%s' (%p): %s: uevent() returned " |
230 | "%d\n", kobject_name(kobj), kobj, | |
810304db | 231 | __func__, retval); |
1da177e4 LT |
232 | goto exit; |
233 | } | |
234 | } | |
235 | ||
0f4dafc0 KS |
236 | /* |
237 | * Mark "add" and "remove" events in the object to ensure proper | |
238 | * events to userspace during automatic cleanup. If the object did | |
239 | * send an "add" event, "remove" will automatically generated by | |
240 | * the core, if not already done by the caller. | |
241 | */ | |
242 | if (action == KOBJ_ADD) | |
243 | kobj->state_add_uevent_sent = 1; | |
244 | else if (action == KOBJ_REMOVE) | |
245 | kobj->state_remove_uevent_sent = 1; | |
246 | ||
7eff2e7a | 247 | /* we will send an event, so request a new sequence number */ |
1da177e4 | 248 | spin_lock(&sequence_lock); |
312c004d | 249 | seq = ++uevent_seqnum; |
1da177e4 | 250 | spin_unlock(&sequence_lock); |
7eff2e7a KS |
251 | retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)seq); |
252 | if (retval) | |
253 | goto exit; | |
1da177e4 | 254 | |
4d17ffda | 255 | #if defined(CONFIG_NET) |
5f123fbd | 256 | /* send netlink message */ |
07e98962 EB |
257 | mutex_lock(&uevent_sock_mutex); |
258 | list_for_each_entry(ue_sk, &uevent_sock_list, list) { | |
259 | struct sock *uevent_sock = ue_sk->sk; | |
5f123fbd KS |
260 | struct sk_buff *skb; |
261 | size_t len; | |
262 | ||
74099b18 KS |
263 | if (!netlink_has_listeners(uevent_sock, 1)) |
264 | continue; | |
265 | ||
5f123fbd KS |
266 | /* allocate message with the maximum possible size */ |
267 | len = strlen(action_string) + strlen(devpath) + 2; | |
7eff2e7a | 268 | skb = alloc_skb(len + env->buflen, GFP_KERNEL); |
5f123fbd | 269 | if (skb) { |
7eff2e7a KS |
270 | char *scratch; |
271 | ||
5f123fbd KS |
272 | /* add header */ |
273 | scratch = skb_put(skb, len); | |
274 | sprintf(scratch, "%s@%s", action_string, devpath); | |
275 | ||
276 | /* copy keys to our continuous event payload buffer */ | |
7eff2e7a KS |
277 | for (i = 0; i < env->envp_idx; i++) { |
278 | len = strlen(env->envp[i]) + 1; | |
5f123fbd | 279 | scratch = skb_put(skb, len); |
7eff2e7a | 280 | strcpy(scratch, env->envp[i]); |
5f123fbd KS |
281 | } |
282 | ||
283 | NETLINK_CB(skb).dst_group = 1; | |
5f71a296 EB |
284 | retval = netlink_broadcast_filtered(uevent_sock, skb, |
285 | 0, 1, GFP_KERNEL, | |
286 | kobj_bcast_filter, | |
287 | kobj); | |
ff491a73 | 288 | /* ENOBUFS should be handled in userspace */ |
ebf4127c | 289 | if (retval == -ENOBUFS || retval == -ESRCH) |
ff491a73 | 290 | retval = 0; |
e0d7bf5d ML |
291 | } else |
292 | retval = -ENOMEM; | |
5f123fbd | 293 | } |
07e98962 | 294 | mutex_unlock(&uevent_sock_mutex); |
4d17ffda | 295 | #endif |
1da177e4 | 296 | |
5f123fbd | 297 | /* call uevent_helper, usually only enabled during early boot */ |
417daa1e | 298 | if (uevent_helper[0] && !kobj_usermode_filter(kobj)) { |
5f123fbd | 299 | char *argv [3]; |
1da177e4 | 300 | |
312c004d | 301 | argv [0] = uevent_helper; |
5f123fbd KS |
302 | argv [1] = (char *)subsystem; |
303 | argv [2] = NULL; | |
7eff2e7a KS |
304 | retval = add_uevent_var(env, "HOME=/"); |
305 | if (retval) | |
306 | goto exit; | |
e374a2bf GKH |
307 | retval = add_uevent_var(env, |
308 | "PATH=/sbin:/bin:/usr/sbin:/usr/bin"); | |
7eff2e7a KS |
309 | if (retval) |
310 | goto exit; | |
311 | ||
0ad1d6f3 | 312 | retval = call_usermodehelper(argv[0], argv, |
05f54c13 | 313 | env->envp, UMH_WAIT_EXEC); |
5f123fbd | 314 | } |
1da177e4 LT |
315 | |
316 | exit: | |
5f123fbd | 317 | kfree(devpath); |
7eff2e7a | 318 | kfree(env); |
542cfce6 | 319 | return retval; |
1da177e4 | 320 | } |
8a82472f CH |
321 | EXPORT_SYMBOL_GPL(kobject_uevent_env); |
322 | ||
323 | /** | |
f6e6e779 | 324 | * kobject_uevent - notify userspace by sending an uevent |
8a82472f | 325 | * |
ccd490a3 | 326 | * @action: action that is happening |
8a82472f | 327 | * @kobj: struct kobject that the action is happening to |
542cfce6 AK |
328 | * |
329 | * Returns 0 if kobject_uevent() is completed with success or the | |
330 | * corresponding error when it fails. | |
8a82472f | 331 | */ |
542cfce6 | 332 | int kobject_uevent(struct kobject *kobj, enum kobject_action action) |
8a82472f | 333 | { |
542cfce6 | 334 | return kobject_uevent_env(kobj, action, NULL); |
8a82472f | 335 | } |
312c004d | 336 | EXPORT_SYMBOL_GPL(kobject_uevent); |
1da177e4 LT |
337 | |
338 | /** | |
7eff2e7a KS |
339 | * add_uevent_var - add key value string to the environment buffer |
340 | * @env: environment buffer structure | |
341 | * @format: printf format for the key=value pair | |
1da177e4 LT |
342 | * |
343 | * Returns 0 if environment variable was added successfully or -ENOMEM | |
344 | * if no space was available. | |
345 | */ | |
7eff2e7a | 346 | int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...) |
1da177e4 LT |
347 | { |
348 | va_list args; | |
7eff2e7a | 349 | int len; |
1da177e4 | 350 | |
7eff2e7a | 351 | if (env->envp_idx >= ARRAY_SIZE(env->envp)) { |
5cd2b459 | 352 | WARN(1, KERN_ERR "add_uevent_var: too many keys\n"); |
1da177e4 | 353 | return -ENOMEM; |
7eff2e7a | 354 | } |
1da177e4 LT |
355 | |
356 | va_start(args, format); | |
7eff2e7a KS |
357 | len = vsnprintf(&env->buf[env->buflen], |
358 | sizeof(env->buf) - env->buflen, | |
359 | format, args); | |
1da177e4 LT |
360 | va_end(args); |
361 | ||
7eff2e7a | 362 | if (len >= (sizeof(env->buf) - env->buflen)) { |
5cd2b459 | 363 | WARN(1, KERN_ERR "add_uevent_var: buffer size too small\n"); |
1da177e4 | 364 | return -ENOMEM; |
7eff2e7a | 365 | } |
1da177e4 | 366 | |
7eff2e7a KS |
367 | env->envp[env->envp_idx++] = &env->buf[env->buflen]; |
368 | env->buflen += len + 1; | |
1da177e4 LT |
369 | return 0; |
370 | } | |
312c004d | 371 | EXPORT_SYMBOL_GPL(add_uevent_var); |
1da177e4 | 372 | |
4d17ffda | 373 | #if defined(CONFIG_NET) |
07e98962 | 374 | static int uevent_net_init(struct net *net) |
5f123fbd | 375 | { |
07e98962 EB |
376 | struct uevent_sock *ue_sk; |
377 | ||
378 | ue_sk = kzalloc(sizeof(*ue_sk), GFP_KERNEL); | |
379 | if (!ue_sk) | |
380 | return -ENOMEM; | |
381 | ||
382 | ue_sk->sk = netlink_kernel_create(net, NETLINK_KOBJECT_UEVENT, | |
383 | 1, NULL, NULL, THIS_MODULE); | |
384 | if (!ue_sk->sk) { | |
5f123fbd KS |
385 | printk(KERN_ERR |
386 | "kobject_uevent: unable to create netlink socket!\n"); | |
743db2d9 | 387 | kfree(ue_sk); |
5f123fbd KS |
388 | return -ENODEV; |
389 | } | |
07e98962 EB |
390 | mutex_lock(&uevent_sock_mutex); |
391 | list_add_tail(&ue_sk->list, &uevent_sock_list); | |
392 | mutex_unlock(&uevent_sock_mutex); | |
5f123fbd KS |
393 | return 0; |
394 | } | |
395 | ||
07e98962 EB |
396 | static void uevent_net_exit(struct net *net) |
397 | { | |
398 | struct uevent_sock *ue_sk; | |
399 | ||
400 | mutex_lock(&uevent_sock_mutex); | |
401 | list_for_each_entry(ue_sk, &uevent_sock_list, list) { | |
402 | if (sock_net(ue_sk->sk) == net) | |
403 | goto found; | |
404 | } | |
405 | mutex_unlock(&uevent_sock_mutex); | |
406 | return; | |
407 | ||
408 | found: | |
409 | list_del(&ue_sk->list); | |
410 | mutex_unlock(&uevent_sock_mutex); | |
411 | ||
412 | netlink_kernel_release(ue_sk->sk); | |
413 | kfree(ue_sk); | |
414 | } | |
415 | ||
416 | static struct pernet_operations uevent_net_ops = { | |
417 | .init = uevent_net_init, | |
418 | .exit = uevent_net_exit, | |
419 | }; | |
420 | ||
421 | static int __init kobject_uevent_init(void) | |
422 | { | |
423 | netlink_set_nonroot(NETLINK_KOBJECT_UEVENT, NL_NONROOT_RECV); | |
424 | return register_pernet_subsys(&uevent_net_ops); | |
425 | } | |
426 | ||
427 | ||
5f123fbd | 428 | postcore_initcall(kobject_uevent_init); |
4d17ffda | 429 | #endif |