2 * kernel userspace event delivery
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.
8 * Licensed under the GNU GPL v2.
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>
17 #include <linux/spinlock.h>
18 #include <linux/string.h>
19 #include <linux/kobject.h>
20 #include <linux/module.h>
21 #include <linux/slab.h>
23 #include <linux/socket.h>
24 #include <linux/skbuff.h>
25 #include <linux/netlink.h>
27 #include <net/net_namespace.h>
31 char uevent_helper
[UEVENT_HELPER_PATH_LEN
] = CONFIG_UEVENT_HELPER_PATH
;
32 static DEFINE_SPINLOCK(sequence_lock
);
35 struct list_head list
;
38 static LIST_HEAD(uevent_sock_list
);
39 static DEFINE_MUTEX(uevent_sock_mutex
);
42 /* the strings here must match the enum in include/linux/kobject.h */
43 static const char *kobject_actions
[] = {
45 [KOBJ_REMOVE
] = "remove",
46 [KOBJ_CHANGE
] = "change",
48 [KOBJ_ONLINE
] = "online",
49 [KOBJ_OFFLINE
] = "offline",
53 * kobject_action_type - translate action string to numeric type
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
59 * Returns 0 if the action string was recognized.
61 int kobject_action_type(const char *buf
, size_t count
,
62 enum kobject_action
*type
)
64 enum kobject_action action
;
67 if (count
&& (buf
[count
-1] == '\n' || buf
[count
-1] == '\0'))
73 for (action
= 0; action
< ARRAY_SIZE(kobject_actions
); action
++) {
74 if (strncmp(kobject_actions
[action
], buf
, count
) != 0)
76 if (kobject_actions
[action
][count
] != '\0')
86 static int kobj_bcast_filter(struct sock
*dsk
, struct sk_buff
*skb
, void *data
)
88 struct kobject
*kobj
= data
;
89 const struct kobj_ns_type_operations
*ops
;
91 ops
= kobj_ns_ops(kobj
);
93 const void *sock_ns
, *ns
;
94 ns
= kobj
->ktype
->namespace(kobj
);
95 sock_ns
= ops
->netlink_ns(dsk
);
103 * kobject_uevent_env - send an uevent with environmental data
105 * @action: action that is happening
106 * @kobj: struct kobject that the action is happening to
107 * @envp_ext: pointer to environmental data
109 * Returns 0 if kobject_uevent() is completed with success or the
110 * corresponding error when it fails.
112 int kobject_uevent_env(struct kobject
*kobj
, enum kobject_action action
,
115 struct kobj_uevent_env
*env
;
116 const char *action_string
= kobject_actions
[action
];
117 const char *devpath
= NULL
;
118 const char *subsystem
;
119 struct kobject
*top_kobj
;
121 const struct kset_uevent_ops
*uevent_ops
;
126 struct uevent_sock
*ue_sk
;
129 pr_debug("kobject: '%s' (%p): %s\n",
130 kobject_name(kobj
), kobj
, __func__
);
132 /* search the kset we belong to */
134 while (!top_kobj
->kset
&& top_kobj
->parent
)
135 top_kobj
= top_kobj
->parent
;
137 if (!top_kobj
->kset
) {
138 pr_debug("kobject: '%s' (%p): %s: attempted to send uevent "
139 "without kset!\n", kobject_name(kobj
), kobj
,
144 kset
= top_kobj
->kset
;
145 uevent_ops
= kset
->uevent_ops
;
147 /* skip the event, if uevent_suppress is set*/
148 if (kobj
->uevent_suppress
) {
149 pr_debug("kobject: '%s' (%p): %s: uevent_suppress "
150 "caused the event to drop!\n",
151 kobject_name(kobj
), kobj
, __func__
);
154 /* skip the event, if the filter returns zero. */
155 if (uevent_ops
&& uevent_ops
->filter
)
156 if (!uevent_ops
->filter(kset
, kobj
)) {
157 pr_debug("kobject: '%s' (%p): %s: filter function "
158 "caused the event to drop!\n",
159 kobject_name(kobj
), kobj
, __func__
);
163 /* originating subsystem */
164 if (uevent_ops
&& uevent_ops
->name
)
165 subsystem
= uevent_ops
->name(kset
, kobj
);
167 subsystem
= kobject_name(&kset
->kobj
);
169 pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the "
170 "event to drop!\n", kobject_name(kobj
), kobj
,
175 /* environment buffer */
176 env
= kzalloc(sizeof(struct kobj_uevent_env
), GFP_KERNEL
);
180 /* complete object path */
181 devpath
= kobject_get_path(kobj
, GFP_KERNEL
);
188 retval
= add_uevent_var(env
, "ACTION=%s", action_string
);
191 retval
= add_uevent_var(env
, "DEVPATH=%s", devpath
);
194 retval
= add_uevent_var(env
, "SUBSYSTEM=%s", subsystem
);
198 /* keys passed in from the caller */
200 for (i
= 0; envp_ext
[i
]; i
++) {
201 retval
= add_uevent_var(env
, "%s", envp_ext
[i
]);
207 /* let the kset specific function add its stuff */
208 if (uevent_ops
&& uevent_ops
->uevent
) {
209 retval
= uevent_ops
->uevent(kset
, kobj
, env
);
211 pr_debug("kobject: '%s' (%p): %s: uevent() returned "
212 "%d\n", kobject_name(kobj
), kobj
,
219 * Mark "add" and "remove" events in the object to ensure proper
220 * events to userspace during automatic cleanup. If the object did
221 * send an "add" event, "remove" will automatically generated by
222 * the core, if not already done by the caller.
224 if (action
== KOBJ_ADD
)
225 kobj
->state_add_uevent_sent
= 1;
226 else if (action
== KOBJ_REMOVE
)
227 kobj
->state_remove_uevent_sent
= 1;
229 /* we will send an event, so request a new sequence number */
230 spin_lock(&sequence_lock
);
231 seq
= ++uevent_seqnum
;
232 spin_unlock(&sequence_lock
);
233 retval
= add_uevent_var(env
, "SEQNUM=%llu", (unsigned long long)seq
);
237 #if defined(CONFIG_NET)
238 /* send netlink message */
239 mutex_lock(&uevent_sock_mutex
);
240 list_for_each_entry(ue_sk
, &uevent_sock_list
, list
) {
241 struct sock
*uevent_sock
= ue_sk
->sk
;
245 /* allocate message with the maximum possible size */
246 len
= strlen(action_string
) + strlen(devpath
) + 2;
247 skb
= alloc_skb(len
+ env
->buflen
, GFP_KERNEL
);
252 scratch
= skb_put(skb
, len
);
253 sprintf(scratch
, "%s@%s", action_string
, devpath
);
255 /* copy keys to our continuous event payload buffer */
256 for (i
= 0; i
< env
->envp_idx
; i
++) {
257 len
= strlen(env
->envp
[i
]) + 1;
258 scratch
= skb_put(skb
, len
);
259 strcpy(scratch
, env
->envp
[i
]);
262 NETLINK_CB(skb
).dst_group
= 1;
263 retval
= netlink_broadcast_filtered(uevent_sock
, skb
,
267 /* ENOBUFS should be handled in userspace */
268 if (retval
== -ENOBUFS
)
273 mutex_unlock(&uevent_sock_mutex
);
276 /* call uevent_helper, usually only enabled during early boot */
277 if (uevent_helper
[0]) {
280 argv
[0] = uevent_helper
;
281 argv
[1] = (char *)subsystem
;
283 retval
= add_uevent_var(env
, "HOME=/");
286 retval
= add_uevent_var(env
,
287 "PATH=/sbin:/bin:/usr/sbin:/usr/bin");
291 retval
= call_usermodehelper(argv
[0], argv
,
292 env
->envp
, UMH_WAIT_EXEC
);
300 EXPORT_SYMBOL_GPL(kobject_uevent_env
);
303 * kobject_uevent - notify userspace by ending an uevent
305 * @action: action that is happening
306 * @kobj: struct kobject that the action is happening to
308 * Returns 0 if kobject_uevent() is completed with success or the
309 * corresponding error when it fails.
311 int kobject_uevent(struct kobject
*kobj
, enum kobject_action action
)
313 return kobject_uevent_env(kobj
, action
, NULL
);
315 EXPORT_SYMBOL_GPL(kobject_uevent
);
318 * add_uevent_var - add key value string to the environment buffer
319 * @env: environment buffer structure
320 * @format: printf format for the key=value pair
322 * Returns 0 if environment variable was added successfully or -ENOMEM
323 * if no space was available.
325 int add_uevent_var(struct kobj_uevent_env
*env
, const char *format
, ...)
330 if (env
->envp_idx
>= ARRAY_SIZE(env
->envp
)) {
331 WARN(1, KERN_ERR
"add_uevent_var: too many keys\n");
335 va_start(args
, format
);
336 len
= vsnprintf(&env
->buf
[env
->buflen
],
337 sizeof(env
->buf
) - env
->buflen
,
341 if (len
>= (sizeof(env
->buf
) - env
->buflen
)) {
342 WARN(1, KERN_ERR
"add_uevent_var: buffer size too small\n");
346 env
->envp
[env
->envp_idx
++] = &env
->buf
[env
->buflen
];
347 env
->buflen
+= len
+ 1;
350 EXPORT_SYMBOL_GPL(add_uevent_var
);
352 #if defined(CONFIG_NET)
353 static int uevent_net_init(struct net
*net
)
355 struct uevent_sock
*ue_sk
;
357 ue_sk
= kzalloc(sizeof(*ue_sk
), GFP_KERNEL
);
361 ue_sk
->sk
= netlink_kernel_create(net
, NETLINK_KOBJECT_UEVENT
,
362 1, NULL
, NULL
, THIS_MODULE
);
365 "kobject_uevent: unable to create netlink socket!\n");
368 mutex_lock(&uevent_sock_mutex
);
369 list_add_tail(&ue_sk
->list
, &uevent_sock_list
);
370 mutex_unlock(&uevent_sock_mutex
);
374 static void uevent_net_exit(struct net
*net
)
376 struct uevent_sock
*ue_sk
;
378 mutex_lock(&uevent_sock_mutex
);
379 list_for_each_entry(ue_sk
, &uevent_sock_list
, list
) {
380 if (sock_net(ue_sk
->sk
) == net
)
383 mutex_unlock(&uevent_sock_mutex
);
387 list_del(&ue_sk
->list
);
388 mutex_unlock(&uevent_sock_mutex
);
390 netlink_kernel_release(ue_sk
->sk
);
394 static struct pernet_operations uevent_net_ops
= {
395 .init
= uevent_net_init
,
396 .exit
= uevent_net_exit
,
399 static int __init
kobject_uevent_init(void)
401 netlink_set_nonroot(NETLINK_KOBJECT_UEVENT
, NL_NONROOT_RECV
);
402 return register_pernet_subsys(&uevent_net_ops
);
406 postcore_initcall(kobject_uevent_init
);