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/socket.h>
19 #include <linux/skbuff.h>
20 #include <linux/netlink.h>
21 #include <linux/string.h>
22 #include <linux/kobject.h>
26 /* the strings here must match the enum in include/linux/kobject.h */
27 const char *kobject_actions
[] = {
36 #if defined(CONFIG_HOTPLUG)
38 char uevent_helper
[UEVENT_HELPER_PATH_LEN
] = "/sbin/hotplug";
39 static DEFINE_SPINLOCK(sequence_lock
);
40 #if defined(CONFIG_NET)
41 static struct sock
*uevent_sock
;
45 * kobject_uevent_env - send an uevent with environmental data
47 * @action: action that is happening (usually KOBJ_MOVE)
48 * @kobj: struct kobject that the action is happening to
49 * @envp_ext: pointer to environmental data
51 * Returns 0 if kobject_uevent() is completed with success or the
52 * corresponding error when it fails.
54 int kobject_uevent_env(struct kobject
*kobj
, enum kobject_action action
,
57 struct kobj_uevent_env
*env
;
58 const char *action_string
= kobject_actions
[action
];
59 const char *devpath
= NULL
;
60 const char *subsystem
;
61 struct kobject
*top_kobj
;
63 struct kset_uevent_ops
*uevent_ops
;
68 pr_debug("%s\n", __FUNCTION__
);
70 /* search the kset we belong to */
72 while (!top_kobj
->kset
&& top_kobj
->parent
) {
73 top_kobj
= top_kobj
->parent
;
75 if (!top_kobj
->kset
) {
76 pr_debug("kobject attempted to send uevent without kset!\n");
80 kset
= top_kobj
->kset
;
81 uevent_ops
= kset
->uevent_ops
;
83 /* skip the event, if the filter returns zero. */
84 if (uevent_ops
&& uevent_ops
->filter
)
85 if (!uevent_ops
->filter(kset
, kobj
)) {
86 pr_debug("kobject filter function caused the event to drop!\n");
90 /* originating subsystem */
91 if (uevent_ops
&& uevent_ops
->name
)
92 subsystem
= uevent_ops
->name(kset
, kobj
);
94 subsystem
= kobject_name(&kset
->kobj
);
96 pr_debug("unset subsytem caused the event to drop!\n");
100 /* environment buffer */
101 env
= kzalloc(sizeof(struct kobj_uevent_env
), GFP_KERNEL
);
105 /* complete object path */
106 devpath
= kobject_get_path(kobj
, GFP_KERNEL
);
113 retval
= add_uevent_var(env
, "ACTION=%s", action_string
);
116 retval
= add_uevent_var(env
, "DEVPATH=%s", devpath
);
119 retval
= add_uevent_var(env
, "SUBSYSTEM=%s", subsystem
);
123 /* keys passed in from the caller */
125 for (i
= 0; envp_ext
[i
]; i
++) {
126 retval
= add_uevent_var(env
, envp_ext
[i
]);
132 /* let the kset specific function add its stuff */
133 if (uevent_ops
&& uevent_ops
->uevent
) {
134 retval
= uevent_ops
->uevent(kset
, kobj
, env
);
136 pr_debug ("%s - uevent() returned %d\n",
137 __FUNCTION__
, retval
);
142 /* we will send an event, so request a new sequence number */
143 spin_lock(&sequence_lock
);
144 seq
= ++uevent_seqnum
;
145 spin_unlock(&sequence_lock
);
146 retval
= add_uevent_var(env
, "SEQNUM=%llu", (unsigned long long)seq
);
150 #if defined(CONFIG_NET)
151 /* send netlink message */
156 /* allocate message with the maximum possible size */
157 len
= strlen(action_string
) + strlen(devpath
) + 2;
158 skb
= alloc_skb(len
+ env
->buflen
, GFP_KERNEL
);
163 scratch
= skb_put(skb
, len
);
164 sprintf(scratch
, "%s@%s", action_string
, devpath
);
166 /* copy keys to our continuous event payload buffer */
167 for (i
= 0; i
< env
->envp_idx
; i
++) {
168 len
= strlen(env
->envp
[i
]) + 1;
169 scratch
= skb_put(skb
, len
);
170 strcpy(scratch
, env
->envp
[i
]);
173 NETLINK_CB(skb
).dst_group
= 1;
174 netlink_broadcast(uevent_sock
, skb
, 0, 1, GFP_KERNEL
);
179 /* call uevent_helper, usually only enabled during early boot */
180 if (uevent_helper
[0]) {
183 argv
[0] = uevent_helper
;
184 argv
[1] = (char *)subsystem
;
186 retval
= add_uevent_var(env
, "HOME=/");
189 retval
= add_uevent_var(env
, "PATH=/sbin:/bin:/usr/sbin:/usr/bin");
193 call_usermodehelper (argv
[0], argv
, env
->envp
, UMH_WAIT_EXEC
);
202 EXPORT_SYMBOL_GPL(kobject_uevent_env
);
205 * kobject_uevent - notify userspace by ending an uevent
207 * @action: action that is happening (usually KOBJ_ADD and KOBJ_REMOVE)
208 * @kobj: struct kobject that the action is happening to
210 * Returns 0 if kobject_uevent() is completed with success or the
211 * corresponding error when it fails.
213 int kobject_uevent(struct kobject
*kobj
, enum kobject_action action
)
215 return kobject_uevent_env(kobj
, action
, NULL
);
218 EXPORT_SYMBOL_GPL(kobject_uevent
);
221 * add_uevent_var - add key value string to the environment buffer
222 * @env: environment buffer structure
223 * @format: printf format for the key=value pair
225 * Returns 0 if environment variable was added successfully or -ENOMEM
226 * if no space was available.
228 int add_uevent_var(struct kobj_uevent_env
*env
, const char *format
, ...)
233 if (env
->envp_idx
>= ARRAY_SIZE(env
->envp
)) {
234 printk(KERN_ERR
"add_uevent_var: too many keys\n");
239 va_start(args
, format
);
240 len
= vsnprintf(&env
->buf
[env
->buflen
],
241 sizeof(env
->buf
) - env
->buflen
,
245 if (len
>= (sizeof(env
->buf
) - env
->buflen
)) {
246 printk(KERN_ERR
"add_uevent_var: buffer size too small\n");
251 env
->envp
[env
->envp_idx
++] = &env
->buf
[env
->buflen
];
252 env
->buflen
+= len
+ 1;
255 EXPORT_SYMBOL_GPL(add_uevent_var
);
257 #if defined(CONFIG_NET)
258 static int __init
kobject_uevent_init(void)
260 uevent_sock
= netlink_kernel_create(&init_net
, NETLINK_KOBJECT_UEVENT
,
261 1, NULL
, NULL
, THIS_MODULE
);
264 "kobject_uevent: unable to create netlink socket!\n");
271 postcore_initcall(kobject_uevent_init
);
274 #endif /* CONFIG_HOTPLUG */