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> | |
20 | #include <linux/module.h> | |
5a0e3ad6 | 21 | #include <linux/slab.h> |
417daa1e | 22 | #include <linux/user_namespace.h> |
1da177e4 LT |
23 | #include <linux/socket.h> |
24 | #include <linux/skbuff.h> | |
25 | #include <linux/netlink.h> | |
1da177e4 | 26 | #include <net/sock.h> |
07e98962 | 27 | #include <net/net_namespace.h> |
1da177e4 | 28 | |
1da177e4 | 29 | |
cd030c4c | 30 | u64 uevent_seqnum; |
6a8d8abb | 31 | char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH; |
cd030c4c | 32 | static DEFINE_SPINLOCK(sequence_lock); |
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); | |
39 | static DEFINE_MUTEX(uevent_sock_mutex); | |
cd030c4c CH |
40 | #endif |
41 | ||
5c5daf65 KS |
42 | /* the strings here must match the enum in include/linux/kobject.h */ |
43 | static const char *kobject_actions[] = { | |
44 | [KOBJ_ADD] = "add", | |
45 | [KOBJ_REMOVE] = "remove", | |
46 | [KOBJ_CHANGE] = "change", | |
47 | [KOBJ_MOVE] = "move", | |
48 | [KOBJ_ONLINE] = "online", | |
49 | [KOBJ_OFFLINE] = "offline", | |
50 | }; | |
51 | ||
52 | /** | |
53 | * kobject_action_type - translate action string to numeric type | |
54 | * | |
55 | * @buf: buffer containing the action string, newline is ignored | |
56 | * @len: length of buffer | |
57 | * @type: pointer to the location to store the action type | |
58 | * | |
59 | * Returns 0 if the action string was recognized. | |
60 | */ | |
61 | int kobject_action_type(const char *buf, size_t count, | |
62 | enum kobject_action *type) | |
63 | { | |
64 | enum kobject_action action; | |
65 | int ret = -EINVAL; | |
66 | ||
a9edadbf | 67 | if (count && (buf[count-1] == '\n' || buf[count-1] == '\0')) |
5c5daf65 KS |
68 | count--; |
69 | ||
70 | if (!count) | |
71 | goto out; | |
72 | ||
73 | for (action = 0; action < ARRAY_SIZE(kobject_actions); action++) { | |
74 | if (strncmp(kobject_actions[action], buf, count) != 0) | |
75 | continue; | |
76 | if (kobject_actions[action][count] != '\0') | |
77 | continue; | |
78 | *type = action; | |
79 | ret = 0; | |
80 | break; | |
81 | } | |
82 | out: | |
83 | return ret; | |
84 | } | |
85 | ||
5f71a296 EB |
86 | static int kobj_bcast_filter(struct sock *dsk, struct sk_buff *skb, void *data) |
87 | { | |
88 | struct kobject *kobj = data; | |
89 | const struct kobj_ns_type_operations *ops; | |
90 | ||
91 | ops = kobj_ns_ops(kobj); | |
92 | if (ops) { | |
93 | const void *sock_ns, *ns; | |
94 | ns = kobj->ktype->namespace(kobj); | |
95 | sock_ns = ops->netlink_ns(dsk); | |
96 | return sock_ns != ns; | |
97 | } | |
98 | ||
99 | return 0; | |
100 | } | |
101 | ||
417daa1e EB |
102 | static int kobj_usermode_filter(struct kobject *kobj) |
103 | { | |
104 | const struct kobj_ns_type_operations *ops; | |
105 | ||
106 | ops = kobj_ns_ops(kobj); | |
107 | if (ops) { | |
108 | const void *init_ns, *ns; | |
109 | ns = kobj->ktype->namespace(kobj); | |
110 | init_ns = ops->initial_ns(); | |
111 | return ns != init_ns; | |
112 | } | |
113 | ||
114 | return 0; | |
115 | } | |
116 | ||
1da177e4 | 117 | /** |
8a82472f | 118 | * kobject_uevent_env - send an uevent with environmental data |
1da177e4 | 119 | * |
ccd490a3 | 120 | * @action: action that is happening |
1da177e4 | 121 | * @kobj: struct kobject that the action is happening to |
8a82472f | 122 | * @envp_ext: pointer to environmental data |
542cfce6 AK |
123 | * |
124 | * Returns 0 if kobject_uevent() is completed with success or the | |
125 | * corresponding error when it fails. | |
1da177e4 | 126 | */ |
542cfce6 | 127 | int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, |
7eff2e7a | 128 | char *envp_ext[]) |
1da177e4 | 129 | { |
7eff2e7a KS |
130 | struct kobj_uevent_env *env; |
131 | const char *action_string = kobject_actions[action]; | |
5f123fbd KS |
132 | const char *devpath = NULL; |
133 | const char *subsystem; | |
134 | struct kobject *top_kobj; | |
135 | struct kset *kset; | |
9cd43611 | 136 | const struct kset_uevent_ops *uevent_ops; |
5f123fbd | 137 | u64 seq; |
1da177e4 | 138 | int i = 0; |
542cfce6 | 139 | int retval = 0; |
07e98962 EB |
140 | #ifdef CONFIG_NET |
141 | struct uevent_sock *ue_sk; | |
142 | #endif | |
1da177e4 | 143 | |
9f66fa2a | 144 | pr_debug("kobject: '%s' (%p): %s\n", |
810304db | 145 | kobject_name(kobj), kobj, __func__); |
5f123fbd | 146 | |
5f123fbd KS |
147 | /* search the kset we belong to */ |
148 | top_kobj = kobj; | |
ccd490a3 | 149 | while (!top_kobj->kset && top_kobj->parent) |
14193fb9 | 150 | top_kobj = top_kobj->parent; |
ccd490a3 | 151 | |
542cfce6 | 152 | if (!top_kobj->kset) { |
9f66fa2a GKH |
153 | pr_debug("kobject: '%s' (%p): %s: attempted to send uevent " |
154 | "without kset!\n", kobject_name(kobj), kobj, | |
810304db | 155 | __func__); |
542cfce6 AK |
156 | return -EINVAL; |
157 | } | |
1da177e4 | 158 | |
5f123fbd | 159 | kset = top_kobj->kset; |
312c004d | 160 | uevent_ops = kset->uevent_ops; |
1da177e4 | 161 | |
f67f129e ML |
162 | /* skip the event, if uevent_suppress is set*/ |
163 | if (kobj->uevent_suppress) { | |
164 | pr_debug("kobject: '%s' (%p): %s: uevent_suppress " | |
165 | "caused the event to drop!\n", | |
166 | kobject_name(kobj), kobj, __func__); | |
167 | return 0; | |
168 | } | |
7eff2e7a | 169 | /* skip the event, if the filter returns zero. */ |
312c004d | 170 | if (uevent_ops && uevent_ops->filter) |
542cfce6 | 171 | if (!uevent_ops->filter(kset, kobj)) { |
9f66fa2a GKH |
172 | pr_debug("kobject: '%s' (%p): %s: filter function " |
173 | "caused the event to drop!\n", | |
810304db | 174 | kobject_name(kobj), kobj, __func__); |
542cfce6 AK |
175 | return 0; |
176 | } | |
1da177e4 | 177 | |
86406245 KS |
178 | /* originating subsystem */ |
179 | if (uevent_ops && uevent_ops->name) | |
180 | subsystem = uevent_ops->name(kset, kobj); | |
181 | else | |
182 | subsystem = kobject_name(&kset->kobj); | |
183 | if (!subsystem) { | |
9f66fa2a GKH |
184 | pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the " |
185 | "event to drop!\n", kobject_name(kobj), kobj, | |
810304db | 186 | __func__); |
86406245 KS |
187 | return 0; |
188 | } | |
189 | ||
7eff2e7a KS |
190 | /* environment buffer */ |
191 | env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL); | |
192 | if (!env) | |
542cfce6 | 193 | return -ENOMEM; |
1da177e4 | 194 | |
5f123fbd KS |
195 | /* complete object path */ |
196 | devpath = kobject_get_path(kobj, GFP_KERNEL); | |
542cfce6 AK |
197 | if (!devpath) { |
198 | retval = -ENOENT; | |
5f123fbd | 199 | goto exit; |
542cfce6 | 200 | } |
1da177e4 | 201 | |
5f123fbd | 202 | /* default keys */ |
7eff2e7a KS |
203 | retval = add_uevent_var(env, "ACTION=%s", action_string); |
204 | if (retval) | |
205 | goto exit; | |
206 | retval = add_uevent_var(env, "DEVPATH=%s", devpath); | |
207 | if (retval) | |
208 | goto exit; | |
209 | retval = add_uevent_var(env, "SUBSYSTEM=%s", subsystem); | |
210 | if (retval) | |
211 | goto exit; | |
212 | ||
213 | /* keys passed in from the caller */ | |
214 | if (envp_ext) { | |
215 | for (i = 0; envp_ext[i]; i++) { | |
c65b9145 | 216 | retval = add_uevent_var(env, "%s", envp_ext[i]); |
7eff2e7a KS |
217 | if (retval) |
218 | goto exit; | |
219 | } | |
220 | } | |
1da177e4 | 221 | |
5f123fbd | 222 | /* let the kset specific function add its stuff */ |
312c004d | 223 | if (uevent_ops && uevent_ops->uevent) { |
7eff2e7a | 224 | retval = uevent_ops->uevent(kset, kobj, env); |
1da177e4 | 225 | if (retval) { |
9f66fa2a GKH |
226 | pr_debug("kobject: '%s' (%p): %s: uevent() returned " |
227 | "%d\n", kobject_name(kobj), kobj, | |
810304db | 228 | __func__, retval); |
1da177e4 LT |
229 | goto exit; |
230 | } | |
231 | } | |
232 | ||
0f4dafc0 KS |
233 | /* |
234 | * Mark "add" and "remove" events in the object to ensure proper | |
235 | * events to userspace during automatic cleanup. If the object did | |
236 | * send an "add" event, "remove" will automatically generated by | |
237 | * the core, if not already done by the caller. | |
238 | */ | |
239 | if (action == KOBJ_ADD) | |
240 | kobj->state_add_uevent_sent = 1; | |
241 | else if (action == KOBJ_REMOVE) | |
242 | kobj->state_remove_uevent_sent = 1; | |
243 | ||
7eff2e7a | 244 | /* we will send an event, so request a new sequence number */ |
1da177e4 | 245 | spin_lock(&sequence_lock); |
312c004d | 246 | seq = ++uevent_seqnum; |
1da177e4 | 247 | spin_unlock(&sequence_lock); |
7eff2e7a KS |
248 | retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)seq); |
249 | if (retval) | |
250 | goto exit; | |
1da177e4 | 251 | |
4d17ffda | 252 | #if defined(CONFIG_NET) |
5f123fbd | 253 | /* send netlink message */ |
07e98962 EB |
254 | mutex_lock(&uevent_sock_mutex); |
255 | list_for_each_entry(ue_sk, &uevent_sock_list, list) { | |
256 | struct sock *uevent_sock = ue_sk->sk; | |
5f123fbd KS |
257 | struct sk_buff *skb; |
258 | size_t len; | |
259 | ||
260 | /* allocate message with the maximum possible size */ | |
261 | len = strlen(action_string) + strlen(devpath) + 2; | |
7eff2e7a | 262 | skb = alloc_skb(len + env->buflen, GFP_KERNEL); |
5f123fbd | 263 | if (skb) { |
7eff2e7a KS |
264 | char *scratch; |
265 | ||
5f123fbd KS |
266 | /* add header */ |
267 | scratch = skb_put(skb, len); | |
268 | sprintf(scratch, "%s@%s", action_string, devpath); | |
269 | ||
270 | /* copy keys to our continuous event payload buffer */ | |
7eff2e7a KS |
271 | for (i = 0; i < env->envp_idx; i++) { |
272 | len = strlen(env->envp[i]) + 1; | |
5f123fbd | 273 | scratch = skb_put(skb, len); |
7eff2e7a | 274 | strcpy(scratch, env->envp[i]); |
5f123fbd KS |
275 | } |
276 | ||
277 | NETLINK_CB(skb).dst_group = 1; | |
5f71a296 EB |
278 | retval = netlink_broadcast_filtered(uevent_sock, skb, |
279 | 0, 1, GFP_KERNEL, | |
280 | kobj_bcast_filter, | |
281 | kobj); | |
ff491a73 PNA |
282 | /* ENOBUFS should be handled in userspace */ |
283 | if (retval == -ENOBUFS) | |
284 | retval = 0; | |
e0d7bf5d ML |
285 | } else |
286 | retval = -ENOMEM; | |
5f123fbd | 287 | } |
07e98962 | 288 | mutex_unlock(&uevent_sock_mutex); |
4d17ffda | 289 | #endif |
1da177e4 | 290 | |
5f123fbd | 291 | /* call uevent_helper, usually only enabled during early boot */ |
417daa1e | 292 | if (uevent_helper[0] && !kobj_usermode_filter(kobj)) { |
5f123fbd | 293 | char *argv [3]; |
1da177e4 | 294 | |
312c004d | 295 | argv [0] = uevent_helper; |
5f123fbd KS |
296 | argv [1] = (char *)subsystem; |
297 | argv [2] = NULL; | |
7eff2e7a KS |
298 | retval = add_uevent_var(env, "HOME=/"); |
299 | if (retval) | |
300 | goto exit; | |
e374a2bf GKH |
301 | retval = add_uevent_var(env, |
302 | "PATH=/sbin:/bin:/usr/sbin:/usr/bin"); | |
7eff2e7a KS |
303 | if (retval) |
304 | goto exit; | |
305 | ||
0ad1d6f3 | 306 | retval = call_usermodehelper(argv[0], argv, |
05f54c13 | 307 | env->envp, UMH_WAIT_EXEC); |
5f123fbd | 308 | } |
1da177e4 LT |
309 | |
310 | exit: | |
5f123fbd | 311 | kfree(devpath); |
7eff2e7a | 312 | kfree(env); |
542cfce6 | 313 | return retval; |
1da177e4 | 314 | } |
8a82472f CH |
315 | EXPORT_SYMBOL_GPL(kobject_uevent_env); |
316 | ||
317 | /** | |
318 | * kobject_uevent - notify userspace by ending an uevent | |
319 | * | |
ccd490a3 | 320 | * @action: action that is happening |
8a82472f | 321 | * @kobj: struct kobject that the action is happening to |
542cfce6 AK |
322 | * |
323 | * Returns 0 if kobject_uevent() is completed with success or the | |
324 | * corresponding error when it fails. | |
8a82472f | 325 | */ |
542cfce6 | 326 | int kobject_uevent(struct kobject *kobj, enum kobject_action action) |
8a82472f | 327 | { |
542cfce6 | 328 | return kobject_uevent_env(kobj, action, NULL); |
8a82472f | 329 | } |
312c004d | 330 | EXPORT_SYMBOL_GPL(kobject_uevent); |
1da177e4 LT |
331 | |
332 | /** | |
7eff2e7a KS |
333 | * add_uevent_var - add key value string to the environment buffer |
334 | * @env: environment buffer structure | |
335 | * @format: printf format for the key=value pair | |
1da177e4 LT |
336 | * |
337 | * Returns 0 if environment variable was added successfully or -ENOMEM | |
338 | * if no space was available. | |
339 | */ | |
7eff2e7a | 340 | int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...) |
1da177e4 LT |
341 | { |
342 | va_list args; | |
7eff2e7a | 343 | int len; |
1da177e4 | 344 | |
7eff2e7a | 345 | if (env->envp_idx >= ARRAY_SIZE(env->envp)) { |
5cd2b459 | 346 | WARN(1, KERN_ERR "add_uevent_var: too many keys\n"); |
1da177e4 | 347 | return -ENOMEM; |
7eff2e7a | 348 | } |
1da177e4 LT |
349 | |
350 | va_start(args, format); | |
7eff2e7a KS |
351 | len = vsnprintf(&env->buf[env->buflen], |
352 | sizeof(env->buf) - env->buflen, | |
353 | format, args); | |
1da177e4 LT |
354 | va_end(args); |
355 | ||
7eff2e7a | 356 | if (len >= (sizeof(env->buf) - env->buflen)) { |
5cd2b459 | 357 | WARN(1, KERN_ERR "add_uevent_var: buffer size too small\n"); |
1da177e4 | 358 | return -ENOMEM; |
7eff2e7a | 359 | } |
1da177e4 | 360 | |
7eff2e7a KS |
361 | env->envp[env->envp_idx++] = &env->buf[env->buflen]; |
362 | env->buflen += len + 1; | |
1da177e4 LT |
363 | return 0; |
364 | } | |
312c004d | 365 | EXPORT_SYMBOL_GPL(add_uevent_var); |
1da177e4 | 366 | |
4d17ffda | 367 | #if defined(CONFIG_NET) |
07e98962 | 368 | static int uevent_net_init(struct net *net) |
5f123fbd | 369 | { |
07e98962 EB |
370 | struct uevent_sock *ue_sk; |
371 | ||
372 | ue_sk = kzalloc(sizeof(*ue_sk), GFP_KERNEL); | |
373 | if (!ue_sk) | |
374 | return -ENOMEM; | |
375 | ||
376 | ue_sk->sk = netlink_kernel_create(net, NETLINK_KOBJECT_UEVENT, | |
377 | 1, NULL, NULL, THIS_MODULE); | |
378 | if (!ue_sk->sk) { | |
5f123fbd KS |
379 | printk(KERN_ERR |
380 | "kobject_uevent: unable to create netlink socket!\n"); | |
381 | return -ENODEV; | |
382 | } | |
07e98962 EB |
383 | mutex_lock(&uevent_sock_mutex); |
384 | list_add_tail(&ue_sk->list, &uevent_sock_list); | |
385 | mutex_unlock(&uevent_sock_mutex); | |
5f123fbd KS |
386 | return 0; |
387 | } | |
388 | ||
07e98962 EB |
389 | static void uevent_net_exit(struct net *net) |
390 | { | |
391 | struct uevent_sock *ue_sk; | |
392 | ||
393 | mutex_lock(&uevent_sock_mutex); | |
394 | list_for_each_entry(ue_sk, &uevent_sock_list, list) { | |
395 | if (sock_net(ue_sk->sk) == net) | |
396 | goto found; | |
397 | } | |
398 | mutex_unlock(&uevent_sock_mutex); | |
399 | return; | |
400 | ||
401 | found: | |
402 | list_del(&ue_sk->list); | |
403 | mutex_unlock(&uevent_sock_mutex); | |
404 | ||
405 | netlink_kernel_release(ue_sk->sk); | |
406 | kfree(ue_sk); | |
407 | } | |
408 | ||
409 | static struct pernet_operations uevent_net_ops = { | |
410 | .init = uevent_net_init, | |
411 | .exit = uevent_net_exit, | |
412 | }; | |
413 | ||
414 | static int __init kobject_uevent_init(void) | |
415 | { | |
416 | netlink_set_nonroot(NETLINK_KOBJECT_UEVENT, NL_NONROOT_RECV); | |
417 | return register_pernet_subsys(&uevent_net_ops); | |
418 | } | |
419 | ||
420 | ||
5f123fbd | 421 | postcore_initcall(kobject_uevent_init); |
4d17ffda | 422 | #endif |