blob: 920a3ca6e2590ddc3d64950a729441758d0a5ce5 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Denis V. Lunev2d38f9a2008-03-27 14:26:30 -070018#include <linux/string.h>
19#include <linux/kobject.h>
20#include <linux/module.h>
21
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <linux/socket.h>
23#include <linux/skbuff.h>
24#include <linux/netlink.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <net/sock.h>
26
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
Cornelia Huckcd030c42007-07-20 13:58:13 +020028u64 uevent_seqnum;
Kay Sievers6a8d8ab2007-08-15 15:38:28 +020029char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH;
Cornelia Huckcd030c42007-07-20 13:58:13 +020030static DEFINE_SPINLOCK(sequence_lock);
31#if defined(CONFIG_NET)
32static struct sock *uevent_sock;
33#endif
34
Kay Sievers5c5daf62007-08-12 20:43:55 +020035/* the strings here must match the enum in include/linux/kobject.h */
36static const char *kobject_actions[] = {
37 [KOBJ_ADD] = "add",
38 [KOBJ_REMOVE] = "remove",
39 [KOBJ_CHANGE] = "change",
40 [KOBJ_MOVE] = "move",
41 [KOBJ_ONLINE] = "online",
42 [KOBJ_OFFLINE] = "offline",
43};
44
45/**
46 * kobject_action_type - translate action string to numeric type
47 *
48 * @buf: buffer containing the action string, newline is ignored
49 * @len: length of buffer
50 * @type: pointer to the location to store the action type
51 *
52 * Returns 0 if the action string was recognized.
53 */
54int kobject_action_type(const char *buf, size_t count,
55 enum kobject_action *type)
56{
57 enum kobject_action action;
58 int ret = -EINVAL;
59
Mark Lorda9edadb2008-03-28 19:05:25 -040060 if (count && (buf[count-1] == '\n' || buf[count-1] == '\0'))
Kay Sievers5c5daf62007-08-12 20:43:55 +020061 count--;
62
63 if (!count)
64 goto out;
65
66 for (action = 0; action < ARRAY_SIZE(kobject_actions); action++) {
67 if (strncmp(kobject_actions[action], buf, count) != 0)
68 continue;
69 if (kobject_actions[action][count] != '\0')
70 continue;
71 *type = action;
72 ret = 0;
73 break;
74 }
75out:
76 return ret;
77}
78
Linus Torvalds1da177e2005-04-16 15:20:36 -070079/**
Cornelia Huck8a824722006-11-20 17:07:51 +010080 * kobject_uevent_env - send an uevent with environmental data
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 *
Kay Sieversccd490a2007-08-12 20:43:55 +020082 * @action: action that is happening
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 * @kobj: struct kobject that the action is happening to
Cornelia Huck8a824722006-11-20 17:07:51 +010084 * @envp_ext: pointer to environmental data
Aneesh Kumar K.V542cfce2006-12-19 13:01:27 -080085 *
86 * Returns 0 if kobject_uevent() is completed with success or the
87 * corresponding error when it fails.
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 */
Aneesh Kumar K.V542cfce2006-12-19 13:01:27 -080089int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
Kay Sievers7eff2e72007-08-14 15:15:12 +020090 char *envp_ext[])
Linus Torvalds1da177e2005-04-16 15:20:36 -070091{
Kay Sievers7eff2e72007-08-14 15:15:12 +020092 struct kobj_uevent_env *env;
93 const char *action_string = kobject_actions[action];
Kay Sievers5f123fb2005-11-11 14:43:07 +010094 const char *devpath = NULL;
95 const char *subsystem;
96 struct kobject *top_kobj;
97 struct kset *kset;
Kay Sievers312c0042005-11-16 09:00:00 +010098 struct kset_uevent_ops *uevent_ops;
Kay Sievers5f123fb2005-11-11 14:43:07 +010099 u64 seq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 int i = 0;
Aneesh Kumar K.V542cfce2006-12-19 13:01:27 -0800101 int retval = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102
Greg Kroah-Hartman9f66fa22007-11-28 23:49:41 -0800103 pr_debug("kobject: '%s' (%p): %s\n",
Harvey Harrison810304d2008-04-30 00:55:08 -0700104 kobject_name(kobj), kobj, __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105
Kay Sievers5f123fb2005-11-11 14:43:07 +0100106 /* search the kset we belong to */
107 top_kobj = kobj;
Kay Sieversccd490a2007-08-12 20:43:55 +0200108 while (!top_kobj->kset && top_kobj->parent)
John Anthony Kazos Jr14193fb2007-04-04 07:39:17 -0400109 top_kobj = top_kobj->parent;
Kay Sieversccd490a2007-08-12 20:43:55 +0200110
Aneesh Kumar K.V542cfce2006-12-19 13:01:27 -0800111 if (!top_kobj->kset) {
Greg Kroah-Hartman9f66fa22007-11-28 23:49:41 -0800112 pr_debug("kobject: '%s' (%p): %s: attempted to send uevent "
113 "without kset!\n", kobject_name(kobj), kobj,
Harvey Harrison810304d2008-04-30 00:55:08 -0700114 __func__);
Aneesh Kumar K.V542cfce2006-12-19 13:01:27 -0800115 return -EINVAL;
116 }
Kay Sievers5f123fb2005-11-11 14:43:07 +0100117
118 kset = top_kobj->kset;
Kay Sievers312c0042005-11-16 09:00:00 +0100119 uevent_ops = kset->uevent_ops;
Kay Sievers5f123fb2005-11-11 14:43:07 +0100120
Ming Leif67f1292009-03-01 21:10:49 +0800121 /* skip the event, if uevent_suppress is set*/
122 if (kobj->uevent_suppress) {
123 pr_debug("kobject: '%s' (%p): %s: uevent_suppress "
124 "caused the event to drop!\n",
125 kobject_name(kobj), kobj, __func__);
126 return 0;
127 }
Kay Sievers7eff2e72007-08-14 15:15:12 +0200128 /* skip the event, if the filter returns zero. */
Kay Sievers312c0042005-11-16 09:00:00 +0100129 if (uevent_ops && uevent_ops->filter)
Aneesh Kumar K.V542cfce2006-12-19 13:01:27 -0800130 if (!uevent_ops->filter(kset, kobj)) {
Greg Kroah-Hartman9f66fa22007-11-28 23:49:41 -0800131 pr_debug("kobject: '%s' (%p): %s: filter function "
132 "caused the event to drop!\n",
Harvey Harrison810304d2008-04-30 00:55:08 -0700133 kobject_name(kobj), kobj, __func__);
Aneesh Kumar K.V542cfce2006-12-19 13:01:27 -0800134 return 0;
135 }
Kay Sievers5f123fb2005-11-11 14:43:07 +0100136
Kay Sievers86406242007-03-14 03:25:56 +0100137 /* originating subsystem */
138 if (uevent_ops && uevent_ops->name)
139 subsystem = uevent_ops->name(kset, kobj);
140 else
141 subsystem = kobject_name(&kset->kobj);
142 if (!subsystem) {
Greg Kroah-Hartman9f66fa22007-11-28 23:49:41 -0800143 pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the "
144 "event to drop!\n", kobject_name(kobj), kobj,
Harvey Harrison810304d2008-04-30 00:55:08 -0700145 __func__);
Kay Sievers86406242007-03-14 03:25:56 +0100146 return 0;
147 }
148
Kay Sievers7eff2e72007-08-14 15:15:12 +0200149 /* environment buffer */
150 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
151 if (!env)
Aneesh Kumar K.V542cfce2006-12-19 13:01:27 -0800152 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153
Kay Sievers5f123fb2005-11-11 14:43:07 +0100154 /* complete object path */
155 devpath = kobject_get_path(kobj, GFP_KERNEL);
Aneesh Kumar K.V542cfce2006-12-19 13:01:27 -0800156 if (!devpath) {
157 retval = -ENOENT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 goto exit;
Aneesh Kumar K.V542cfce2006-12-19 13:01:27 -0800159 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160
Kay Sievers5f123fb2005-11-11 14:43:07 +0100161 /* default keys */
Kay Sievers7eff2e72007-08-14 15:15:12 +0200162 retval = add_uevent_var(env, "ACTION=%s", action_string);
163 if (retval)
164 goto exit;
165 retval = add_uevent_var(env, "DEVPATH=%s", devpath);
166 if (retval)
167 goto exit;
168 retval = add_uevent_var(env, "SUBSYSTEM=%s", subsystem);
169 if (retval)
170 goto exit;
171
172 /* keys passed in from the caller */
173 if (envp_ext) {
174 for (i = 0; envp_ext[i]; i++) {
Tejun Heoc65b9142008-11-13 13:20:00 +0900175 retval = add_uevent_var(env, "%s", envp_ext[i]);
Kay Sievers7eff2e72007-08-14 15:15:12 +0200176 if (retval)
177 goto exit;
178 }
179 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180
Kay Sievers5f123fb2005-11-11 14:43:07 +0100181 /* let the kset specific function add its stuff */
Kay Sievers312c0042005-11-16 09:00:00 +0100182 if (uevent_ops && uevent_ops->uevent) {
Kay Sievers7eff2e72007-08-14 15:15:12 +0200183 retval = uevent_ops->uevent(kset, kobj, env);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 if (retval) {
Greg Kroah-Hartman9f66fa22007-11-28 23:49:41 -0800185 pr_debug("kobject: '%s' (%p): %s: uevent() returned "
186 "%d\n", kobject_name(kobj), kobj,
Harvey Harrison810304d2008-04-30 00:55:08 -0700187 __func__, retval);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 goto exit;
189 }
190 }
191
Kay Sievers0f4dafc2007-12-19 01:40:42 +0100192 /*
193 * Mark "add" and "remove" events in the object to ensure proper
194 * events to userspace during automatic cleanup. If the object did
195 * send an "add" event, "remove" will automatically generated by
196 * the core, if not already done by the caller.
197 */
198 if (action == KOBJ_ADD)
199 kobj->state_add_uevent_sent = 1;
200 else if (action == KOBJ_REMOVE)
201 kobj->state_remove_uevent_sent = 1;
202
Kay Sievers7eff2e72007-08-14 15:15:12 +0200203 /* we will send an event, so request a new sequence number */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 spin_lock(&sequence_lock);
Kay Sievers312c0042005-11-16 09:00:00 +0100205 seq = ++uevent_seqnum;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 spin_unlock(&sequence_lock);
Kay Sievers7eff2e72007-08-14 15:15:12 +0200207 retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)seq);
208 if (retval)
209 goto exit;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210
Kay Sievers4d17ffd2006-04-25 15:37:26 +0200211#if defined(CONFIG_NET)
Kay Sievers5f123fb2005-11-11 14:43:07 +0100212 /* send netlink message */
213 if (uevent_sock) {
214 struct sk_buff *skb;
215 size_t len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216
Kay Sievers5f123fb2005-11-11 14:43:07 +0100217 /* allocate message with the maximum possible size */
218 len = strlen(action_string) + strlen(devpath) + 2;
Kay Sievers7eff2e72007-08-14 15:15:12 +0200219 skb = alloc_skb(len + env->buflen, GFP_KERNEL);
Kay Sievers5f123fb2005-11-11 14:43:07 +0100220 if (skb) {
Kay Sievers7eff2e72007-08-14 15:15:12 +0200221 char *scratch;
222
Kay Sievers5f123fb2005-11-11 14:43:07 +0100223 /* add header */
224 scratch = skb_put(skb, len);
225 sprintf(scratch, "%s@%s", action_string, devpath);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226
Kay Sievers5f123fb2005-11-11 14:43:07 +0100227 /* copy keys to our continuous event payload buffer */
Kay Sievers7eff2e72007-08-14 15:15:12 +0200228 for (i = 0; i < env->envp_idx; i++) {
229 len = strlen(env->envp[i]) + 1;
Kay Sievers5f123fb2005-11-11 14:43:07 +0100230 scratch = skb_put(skb, len);
Kay Sievers7eff2e72007-08-14 15:15:12 +0200231 strcpy(scratch, env->envp[i]);
Kay Sievers5f123fb2005-11-11 14:43:07 +0100232 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233
Kay Sievers5f123fb2005-11-11 14:43:07 +0100234 NETLINK_CB(skb).dst_group = 1;
Ming Leie0d7bf52008-11-16 18:23:27 +0800235 retval = netlink_broadcast(uevent_sock, skb, 0, 1,
236 GFP_KERNEL);
Pablo Neira Ayusoff491a72009-02-05 23:56:36 -0800237 /* ENOBUFS should be handled in userspace */
238 if (retval == -ENOBUFS)
239 retval = 0;
Ming Leie0d7bf52008-11-16 18:23:27 +0800240 } else
241 retval = -ENOMEM;
Kay Sievers5f123fb2005-11-11 14:43:07 +0100242 }
Kay Sievers4d17ffd2006-04-25 15:37:26 +0200243#endif
Kay Sievers5f123fb2005-11-11 14:43:07 +0100244
245 /* call uevent_helper, usually only enabled during early boot */
Kay Sievers312c0042005-11-16 09:00:00 +0100246 if (uevent_helper[0]) {
Kay Sievers5f123fb2005-11-11 14:43:07 +0100247 char *argv [3];
248
Kay Sievers312c0042005-11-16 09:00:00 +0100249 argv [0] = uevent_helper;
Kay Sievers5f123fb2005-11-11 14:43:07 +0100250 argv [1] = (char *)subsystem;
251 argv [2] = NULL;
Kay Sievers7eff2e72007-08-14 15:15:12 +0200252 retval = add_uevent_var(env, "HOME=/");
253 if (retval)
254 goto exit;
Greg Kroah-Hartmane374a2b2008-01-24 21:59:04 -0800255 retval = add_uevent_var(env,
256 "PATH=/sbin:/bin:/usr/sbin:/usr/bin");
Kay Sievers7eff2e72007-08-14 15:15:12 +0200257 if (retval)
258 goto exit;
259
Wang Chen0ad1d6f2008-06-24 16:59:02 +0800260 retval = call_usermodehelper(argv[0], argv,
Hugh Dickins05f54c12009-04-16 21:55:29 +0100261 env->envp, UMH_WAIT_EXEC);
Kay Sievers5f123fb2005-11-11 14:43:07 +0100262 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263
264exit:
Kay Sievers5f123fb2005-11-11 14:43:07 +0100265 kfree(devpath);
Kay Sievers7eff2e72007-08-14 15:15:12 +0200266 kfree(env);
Aneesh Kumar K.V542cfce2006-12-19 13:01:27 -0800267 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268}
Cornelia Huck8a824722006-11-20 17:07:51 +0100269EXPORT_SYMBOL_GPL(kobject_uevent_env);
270
271/**
272 * kobject_uevent - notify userspace by ending an uevent
273 *
Kay Sieversccd490a2007-08-12 20:43:55 +0200274 * @action: action that is happening
Cornelia Huck8a824722006-11-20 17:07:51 +0100275 * @kobj: struct kobject that the action is happening to
Aneesh Kumar K.V542cfce2006-12-19 13:01:27 -0800276 *
277 * Returns 0 if kobject_uevent() is completed with success or the
278 * corresponding error when it fails.
Cornelia Huck8a824722006-11-20 17:07:51 +0100279 */
Aneesh Kumar K.V542cfce2006-12-19 13:01:27 -0800280int kobject_uevent(struct kobject *kobj, enum kobject_action action)
Cornelia Huck8a824722006-11-20 17:07:51 +0100281{
Aneesh Kumar K.V542cfce2006-12-19 13:01:27 -0800282 return kobject_uevent_env(kobj, action, NULL);
Cornelia Huck8a824722006-11-20 17:07:51 +0100283}
Kay Sievers312c0042005-11-16 09:00:00 +0100284EXPORT_SYMBOL_GPL(kobject_uevent);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285
286/**
Kay Sievers7eff2e72007-08-14 15:15:12 +0200287 * add_uevent_var - add key value string to the environment buffer
288 * @env: environment buffer structure
289 * @format: printf format for the key=value pair
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 *
291 * Returns 0 if environment variable was added successfully or -ENOMEM
292 * if no space was available.
293 */
Kay Sievers7eff2e72007-08-14 15:15:12 +0200294int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295{
296 va_list args;
Kay Sievers7eff2e72007-08-14 15:15:12 +0200297 int len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298
Kay Sievers7eff2e72007-08-14 15:15:12 +0200299 if (env->envp_idx >= ARRAY_SIZE(env->envp)) {
Arjan van de Ven5cd2b452008-07-25 19:45:39 -0700300 WARN(1, KERN_ERR "add_uevent_var: too many keys\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 return -ENOMEM;
Kay Sievers7eff2e72007-08-14 15:15:12 +0200302 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303
304 va_start(args, format);
Kay Sievers7eff2e72007-08-14 15:15:12 +0200305 len = vsnprintf(&env->buf[env->buflen],
306 sizeof(env->buf) - env->buflen,
307 format, args);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 va_end(args);
309
Kay Sievers7eff2e72007-08-14 15:15:12 +0200310 if (len >= (sizeof(env->buf) - env->buflen)) {
Arjan van de Ven5cd2b452008-07-25 19:45:39 -0700311 WARN(1, KERN_ERR "add_uevent_var: buffer size too small\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312 return -ENOMEM;
Kay Sievers7eff2e72007-08-14 15:15:12 +0200313 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314
Kay Sievers7eff2e72007-08-14 15:15:12 +0200315 env->envp[env->envp_idx++] = &env->buf[env->buflen];
316 env->buflen += len + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 return 0;
318}
Kay Sievers312c0042005-11-16 09:00:00 +0100319EXPORT_SYMBOL_GPL(add_uevent_var);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320
Kay Sievers4d17ffd2006-04-25 15:37:26 +0200321#if defined(CONFIG_NET)
Kay Sievers5f123fb2005-11-11 14:43:07 +0100322static int __init kobject_uevent_init(void)
323{
Eric W. Biedermanb4b51022007-09-12 13:05:38 +0200324 uevent_sock = netlink_kernel_create(&init_net, NETLINK_KOBJECT_UEVENT,
325 1, NULL, NULL, THIS_MODULE);
Kay Sievers5f123fb2005-11-11 14:43:07 +0100326 if (!uevent_sock) {
327 printk(KERN_ERR
328 "kobject_uevent: unable to create netlink socket!\n");
329 return -ENODEV;
330 }
Kay Sieversd094cbe2009-04-03 19:04:15 +0200331 netlink_set_nonroot(NETLINK_KOBJECT_UEVENT, NL_NONROOT_RECV);
Kay Sievers5f123fb2005-11-11 14:43:07 +0100332 return 0;
333}
334
335postcore_initcall(kobject_uevent_init);
Kay Sievers4d17ffd2006-04-25 15:37:26 +0200336#endif