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>
25 #define BUFFER_SIZE 2048 /* buffer for the variables */
26 #define NUM_ENVP 32 /* number of env pointers */
28 /* the strings here must match the enum in include/linux/kobject.h */
29 const char *kobject_actions
[] = {
38 #if defined(CONFIG_HOTPLUG)
40 char uevent_helper
[UEVENT_HELPER_PATH_LEN
] = "/sbin/hotplug";
41 static DEFINE_SPINLOCK(sequence_lock
);
42 #if defined(CONFIG_NET)
43 static struct sock
*uevent_sock
;
47 * kobject_uevent_env - send an uevent with environmental data
49 * @action: action that is happening (usually KOBJ_MOVE)
50 * @kobj: struct kobject that the action is happening to
51 * @envp_ext: pointer to environmental data
53 * Returns 0 if kobject_uevent() is completed with success or the
54 * corresponding error when it fails.
56 int kobject_uevent_env(struct kobject
*kobj
, enum kobject_action action
,
62 const char *action_string
;
63 const char *devpath
= NULL
;
64 const char *subsystem
;
65 struct kobject
*top_kobj
;
67 struct kset_uevent_ops
*uevent_ops
;
74 pr_debug("%s\n", __FUNCTION__
);
76 action_string
= kobject_actions
[action
];
78 pr_debug("kobject attempted to send uevent without action_string!\n");
82 /* search the kset we belong to */
84 while (!top_kobj
->kset
&& top_kobj
->parent
) {
85 top_kobj
= top_kobj
->parent
;
87 if (!top_kobj
->kset
) {
88 pr_debug("kobject attempted to send uevent without kset!\n");
92 kset
= top_kobj
->kset
;
93 uevent_ops
= kset
->uevent_ops
;
95 /* skip the event, if the filter returns zero. */
96 if (uevent_ops
&& uevent_ops
->filter
)
97 if (!uevent_ops
->filter(kset
, kobj
)) {
98 pr_debug("kobject filter function caused the event to drop!\n");
102 /* originating subsystem */
103 if (uevent_ops
&& uevent_ops
->name
)
104 subsystem
= uevent_ops
->name(kset
, kobj
);
106 subsystem
= kobject_name(&kset
->kobj
);
108 pr_debug("unset subsytem caused the event to drop!\n");
112 /* environment index */
113 envp
= kzalloc(NUM_ENVP
* sizeof (char *), GFP_KERNEL
);
117 /* environment values */
118 buffer
= kmalloc(BUFFER_SIZE
, GFP_KERNEL
);
124 /* complete object path */
125 devpath
= kobject_get_path(kobj
, GFP_KERNEL
);
131 /* event environemnt for helper process only */
132 envp
[i
++] = "HOME=/";
133 envp
[i
++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
137 envp
[i
++] = scratch
;
138 scratch
+= sprintf(scratch
, "ACTION=%s", action_string
) + 1;
139 envp
[i
++] = scratch
;
140 scratch
+= sprintf (scratch
, "DEVPATH=%s", devpath
) + 1;
141 envp
[i
++] = scratch
;
142 scratch
+= sprintf(scratch
, "SUBSYSTEM=%s", subsystem
) + 1;
143 for (j
= 0; envp_ext
&& envp_ext
[j
]; j
++)
144 envp
[i
++] = envp_ext
[j
];
145 /* just reserve the space, overwrite it after kset call has returned */
146 envp
[i
++] = seq_buff
= scratch
;
147 scratch
+= strlen("SEQNUM=18446744073709551616") + 1;
149 /* let the kset specific function add its stuff */
150 if (uevent_ops
&& uevent_ops
->uevent
) {
151 retval
= uevent_ops
->uevent(kset
, kobj
,
152 &envp
[i
], NUM_ENVP
- i
, scratch
,
153 BUFFER_SIZE
- (scratch
- buffer
));
155 pr_debug ("%s - uevent() returned %d\n",
156 __FUNCTION__
, retval
);
161 /* we will send an event, request a new sequence number */
162 spin_lock(&sequence_lock
);
163 seq
= ++uevent_seqnum
;
164 spin_unlock(&sequence_lock
);
165 sprintf(seq_buff
, "SEQNUM=%llu", (unsigned long long)seq
);
167 #if defined(CONFIG_NET)
168 /* send netlink message */
173 /* allocate message with the maximum possible size */
174 len
= strlen(action_string
) + strlen(devpath
) + 2;
175 skb
= alloc_skb(len
+ BUFFER_SIZE
, GFP_KERNEL
);
178 scratch
= skb_put(skb
, len
);
179 sprintf(scratch
, "%s@%s", action_string
, devpath
);
181 /* copy keys to our continuous event payload buffer */
182 for (i
= 2; envp
[i
]; i
++) {
183 len
= strlen(envp
[i
]) + 1;
184 scratch
= skb_put(skb
, len
);
185 strcpy(scratch
, envp
[i
]);
188 NETLINK_CB(skb
).dst_group
= 1;
189 netlink_broadcast(uevent_sock
, skb
, 0, 1, GFP_KERNEL
);
194 /* call uevent_helper, usually only enabled during early boot */
195 if (uevent_helper
[0]) {
198 argv
[0] = uevent_helper
;
199 argv
[1] = (char *)subsystem
;
201 call_usermodehelper (argv
[0], argv
, envp
, UMH_WAIT_EXEC
);
211 EXPORT_SYMBOL_GPL(kobject_uevent_env
);
214 * kobject_uevent - notify userspace by ending an uevent
216 * @action: action that is happening (usually KOBJ_ADD and KOBJ_REMOVE)
217 * @kobj: struct kobject that the action is happening to
219 * Returns 0 if kobject_uevent() is completed with success or the
220 * corresponding error when it fails.
222 int kobject_uevent(struct kobject
*kobj
, enum kobject_action action
)
224 return kobject_uevent_env(kobj
, action
, NULL
);
227 EXPORT_SYMBOL_GPL(kobject_uevent
);
230 * add_uevent_var - helper for creating event variables
231 * @envp: Pointer to table of environment variables, as passed into
233 * @num_envp: Number of environment variable slots available, as
234 * passed into uevent() method.
235 * @cur_index: Pointer to current index into @envp. It should be
236 * initialized to 0 before the first call to add_uevent_var(),
237 * and will be incremented on success.
238 * @buffer: Pointer to buffer for environment variables, as passed
239 * into uevent() method.
240 * @buffer_size: Length of @buffer, as passed into uevent() method.
241 * @cur_len: Pointer to current length of space used in @buffer.
242 * Should be initialized to 0 before the first call to
243 * add_uevent_var(), and will be incremented on success.
244 * @format: Format for creating environment variable (of the form
245 * "XXX=%x") for snprintf().
247 * Returns 0 if environment variable was added successfully or -ENOMEM
248 * if no space was available.
250 int add_uevent_var(char **envp
, int num_envp
, int *cur_index
,
251 char *buffer
, int buffer_size
, int *cur_len
,
252 const char *format
, ...)
257 * We check against num_envp - 1 to make sure there is at
258 * least one slot left after we return, since kobject_uevent()
259 * needs to set the last slot to NULL.
261 if (*cur_index
>= num_envp
- 1)
264 envp
[*cur_index
] = buffer
+ *cur_len
;
266 va_start(args
, format
);
267 *cur_len
+= vsnprintf(envp
[*cur_index
],
268 max(buffer_size
- *cur_len
, 0),
272 if (*cur_len
> buffer_size
)
278 EXPORT_SYMBOL_GPL(add_uevent_var
);
280 #if defined(CONFIG_NET)
281 static int __init
kobject_uevent_init(void)
283 uevent_sock
= netlink_kernel_create(NETLINK_KOBJECT_UEVENT
, 1, NULL
,
288 "kobject_uevent: unable to create netlink socket!\n");
295 postcore_initcall(kobject_uevent_init
);
298 #endif /* CONFIG_HOTPLUG */
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