]>
git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - lib/kobject_uevent.c
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 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
29 static DEFINE_SPINLOCK(sequence_lock
);
30 static struct sock
*uevent_sock
;
32 static char *action_to_string(enum kobject_action action
)
55 * kobject_uevent - notify userspace by ending an uevent
57 * @action: action that is happening (usually KOBJ_ADD and KOBJ_REMOVE)
58 * @kobj: struct kobject that the action is happening to
60 void kobject_uevent(struct kobject
*kobj
, enum kobject_action action
)
65 const char *action_string
;
66 const char *devpath
= NULL
;
67 const char *subsystem
;
68 struct kobject
*top_kobj
;
70 struct kset_uevent_ops
*uevent_ops
;
76 pr_debug("%s\n", __FUNCTION__
);
78 action_string
= action_to_string(action
);
82 /* search the kset we belong to */
84 if (!top_kobj
->kset
&& top_kobj
->parent
) {
86 top_kobj
= top_kobj
->parent
;
87 } while (!top_kobj
->kset
&& top_kobj
->parent
);
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
))
100 /* environment index */
101 envp
= kzalloc(NUM_ENVP
* sizeof (char *), GFP_KERNEL
);
105 /* environment values */
106 buffer
= kmalloc(BUFFER_SIZE
, GFP_KERNEL
);
110 /* complete object path */
111 devpath
= kobject_get_path(kobj
, GFP_KERNEL
);
115 /* originating subsystem */
116 if (uevent_ops
&& uevent_ops
->name
)
117 subsystem
= uevent_ops
->name(kset
, kobj
);
119 subsystem
= kobject_name(&kset
->kobj
);
121 /* event environemnt for helper process only */
122 envp
[i
++] = "HOME=/";
123 envp
[i
++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
127 envp
[i
++] = scratch
;
128 scratch
+= sprintf(scratch
, "ACTION=%s", action_string
) + 1;
129 envp
[i
++] = scratch
;
130 scratch
+= sprintf (scratch
, "DEVPATH=%s", devpath
) + 1;
131 envp
[i
++] = scratch
;
132 scratch
+= sprintf(scratch
, "SUBSYSTEM=%s", subsystem
) + 1;
134 /* just reserve the space, overwrite it after kset call has returned */
135 envp
[i
++] = seq_buff
= scratch
;
136 scratch
+= strlen("SEQNUM=18446744073709551616") + 1;
138 /* let the kset specific function add its stuff */
139 if (uevent_ops
&& uevent_ops
->uevent
) {
140 retval
= uevent_ops
->uevent(kset
, kobj
,
141 &envp
[i
], NUM_ENVP
- i
, scratch
,
142 BUFFER_SIZE
- (scratch
- buffer
));
144 pr_debug ("%s - uevent() returned %d\n",
145 __FUNCTION__
, retval
);
150 /* we will send an event, request a new sequence number */
151 spin_lock(&sequence_lock
);
152 seq
= ++uevent_seqnum
;
153 spin_unlock(&sequence_lock
);
154 sprintf(seq_buff
, "SEQNUM=%llu", (unsigned long long)seq
);
156 /* send netlink message */
161 /* allocate message with the maximum possible size */
162 len
= strlen(action_string
) + strlen(devpath
) + 2;
163 skb
= alloc_skb(len
+ BUFFER_SIZE
, GFP_KERNEL
);
166 scratch
= skb_put(skb
, len
);
167 sprintf(scratch
, "%s@%s", action_string
, devpath
);
169 /* copy keys to our continuous event payload buffer */
170 for (i
= 2; envp
[i
]; i
++) {
171 len
= strlen(envp
[i
]) + 1;
172 scratch
= skb_put(skb
, len
);
173 strcpy(scratch
, envp
[i
]);
176 NETLINK_CB(skb
).dst_group
= 1;
177 netlink_broadcast(uevent_sock
, skb
, 0, 1, GFP_KERNEL
);
181 /* call uevent_helper, usually only enabled during early boot */
182 if (uevent_helper
[0]) {
185 argv
[0] = uevent_helper
;
186 argv
[1] = (char *)subsystem
;
188 call_usermodehelper (argv
[0], argv
, envp
, 0);
197 EXPORT_SYMBOL_GPL(kobject_uevent
);
200 * add_uevent_var - helper for creating event variables
201 * @envp: Pointer to table of environment variables, as passed into
203 * @num_envp: Number of environment variable slots available, as
204 * passed into uevent() method.
205 * @cur_index: Pointer to current index into @envp. It should be
206 * initialized to 0 before the first call to add_uevent_var(),
207 * and will be incremented on success.
208 * @buffer: Pointer to buffer for environment variables, as passed
209 * into uevent() method.
210 * @buffer_size: Length of @buffer, as passed into uevent() method.
211 * @cur_len: Pointer to current length of space used in @buffer.
212 * Should be initialized to 0 before the first call to
213 * add_uevent_var(), and will be incremented on success.
214 * @format: Format for creating environment variable (of the form
215 * "XXX=%x") for snprintf().
217 * Returns 0 if environment variable was added successfully or -ENOMEM
218 * if no space was available.
220 int add_uevent_var(char **envp
, int num_envp
, int *cur_index
,
221 char *buffer
, int buffer_size
, int *cur_len
,
222 const char *format
, ...)
227 * We check against num_envp - 1 to make sure there is at
228 * least one slot left after we return, since kobject_uevent()
229 * needs to set the last slot to NULL.
231 if (*cur_index
>= num_envp
- 1)
234 envp
[*cur_index
] = buffer
+ *cur_len
;
236 va_start(args
, format
);
237 *cur_len
+= vsnprintf(envp
[*cur_index
],
238 max(buffer_size
- *cur_len
, 0),
242 if (*cur_len
> buffer_size
)
248 EXPORT_SYMBOL_GPL(add_uevent_var
);
250 static int __init
kobject_uevent_init(void)
252 uevent_sock
= netlink_kernel_create(NETLINK_KOBJECT_UEVENT
, 1, NULL
,
257 "kobject_uevent: unable to create netlink socket!\n");
264 postcore_initcall(kobject_uevent_init
);
266 #endif /* CONFIG_HOTPLUG */