ia64/linux-2.6.18-xen.hg

view lib/kobject_uevent.c @ 647:a5bb490065f6

Fix the build after public header sync.
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Wed Aug 13 14:01:49 2008 +0100 (2008-08-13)
parents 831230e53067
children
line source
1 /*
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 */
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>
23 #include <net/sock.h>
25 #define BUFFER_SIZE 2048 /* buffer for the variables */
26 #define NUM_ENVP 32 /* number of env pointers */
28 #if defined(CONFIG_HOTPLUG)
29 u64 uevent_seqnum;
30 char uevent_helper[UEVENT_HELPER_PATH_LEN] = "/sbin/hotplug";
31 static DEFINE_SPINLOCK(sequence_lock);
32 #if defined(CONFIG_NET)
33 static struct sock *uevent_sock;
34 #endif
36 static char *action_to_string(enum kobject_action action)
37 {
38 switch (action) {
39 case KOBJ_ADD:
40 return "add";
41 case KOBJ_REMOVE:
42 return "remove";
43 case KOBJ_CHANGE:
44 return "change";
45 case KOBJ_MOUNT:
46 return "mount";
47 case KOBJ_UMOUNT:
48 return "umount";
49 case KOBJ_OFFLINE:
50 return "offline";
51 case KOBJ_ONLINE:
52 return "online";
53 default:
54 return NULL;
55 }
56 }
58 /**
59 * kobject_uevent - notify userspace by ending an uevent
60 *
61 * @action: action that is happening (usually KOBJ_ADD and KOBJ_REMOVE)
62 * @kobj: struct kobject that the action is happening to
63 */
64 void kobject_uevent(struct kobject *kobj, enum kobject_action action)
65 {
66 char **envp;
67 char *buffer;
68 char *scratch;
69 const char *action_string;
70 const char *devpath = NULL;
71 const char *subsystem;
72 struct kobject *top_kobj;
73 struct kset *kset;
74 struct kset_uevent_ops *uevent_ops;
75 u64 seq;
76 char *seq_buff;
77 int i = 0;
78 int retval;
80 pr_debug("%s\n", __FUNCTION__);
82 action_string = action_to_string(action);
83 if (!action_string)
84 return;
86 /* search the kset we belong to */
87 top_kobj = kobj;
88 if (!top_kobj->kset && top_kobj->parent) {
89 do {
90 top_kobj = top_kobj->parent;
91 } while (!top_kobj->kset && top_kobj->parent);
92 }
93 if (!top_kobj->kset)
94 return;
96 kset = top_kobj->kset;
97 uevent_ops = kset->uevent_ops;
99 /* skip the event, if the filter returns zero. */
100 if (uevent_ops && uevent_ops->filter)
101 if (!uevent_ops->filter(kset, kobj))
102 return;
104 /* environment index */
105 envp = kzalloc(NUM_ENVP * sizeof (char *), GFP_KERNEL);
106 if (!envp)
107 return;
109 /* environment values */
110 buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL);
111 if (!buffer)
112 goto exit;
114 /* complete object path */
115 devpath = kobject_get_path(kobj, GFP_KERNEL);
116 if (!devpath)
117 goto exit;
119 /* originating subsystem */
120 if (uevent_ops && uevent_ops->name)
121 subsystem = uevent_ops->name(kset, kobj);
122 else
123 subsystem = kobject_name(&kset->kobj);
125 /* event environemnt for helper process only */
126 envp[i++] = "HOME=/";
127 envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
129 /* default keys */
130 scratch = buffer;
131 envp [i++] = scratch;
132 scratch += sprintf(scratch, "ACTION=%s", action_string) + 1;
133 envp [i++] = scratch;
134 scratch += sprintf (scratch, "DEVPATH=%s", devpath) + 1;
135 envp [i++] = scratch;
136 scratch += sprintf(scratch, "SUBSYSTEM=%s", subsystem) + 1;
138 /* just reserve the space, overwrite it after kset call has returned */
139 envp[i++] = seq_buff = scratch;
140 scratch += strlen("SEQNUM=18446744073709551616") + 1;
142 /* let the kset specific function add its stuff */
143 if (uevent_ops && uevent_ops->uevent) {
144 retval = uevent_ops->uevent(kset, kobj,
145 &envp[i], NUM_ENVP - i, scratch,
146 BUFFER_SIZE - (scratch - buffer));
147 if (retval) {
148 pr_debug ("%s - uevent() returned %d\n",
149 __FUNCTION__, retval);
150 goto exit;
151 }
152 }
154 /* we will send an event, request a new sequence number */
155 spin_lock(&sequence_lock);
156 seq = ++uevent_seqnum;
157 spin_unlock(&sequence_lock);
158 sprintf(seq_buff, "SEQNUM=%llu", (unsigned long long)seq);
160 #if defined(CONFIG_NET)
161 /* send netlink message */
162 if (uevent_sock) {
163 struct sk_buff *skb;
164 size_t len;
166 /* allocate message with the maximum possible size */
167 len = strlen(action_string) + strlen(devpath) + 2;
168 skb = alloc_skb(len + BUFFER_SIZE, GFP_KERNEL);
169 if (skb) {
170 /* add header */
171 scratch = skb_put(skb, len);
172 sprintf(scratch, "%s@%s", action_string, devpath);
174 /* copy keys to our continuous event payload buffer */
175 for (i = 2; envp[i]; i++) {
176 len = strlen(envp[i]) + 1;
177 scratch = skb_put(skb, len);
178 strcpy(scratch, envp[i]);
179 }
181 NETLINK_CB(skb).dst_group = 1;
182 netlink_broadcast(uevent_sock, skb, 0, 1, GFP_KERNEL);
183 }
184 }
185 #endif
187 /* call uevent_helper, usually only enabled during early boot */
188 if (uevent_helper[0]) {
189 char *argv [3];
191 argv [0] = uevent_helper;
192 argv [1] = (char *)subsystem;
193 argv [2] = NULL;
194 call_usermodehelper (argv[0], argv, envp, 0);
195 }
197 exit:
198 kfree(devpath);
199 kfree(buffer);
200 kfree(envp);
201 return;
202 }
203 EXPORT_SYMBOL_GPL(kobject_uevent);
205 /**
206 * add_uevent_var - helper for creating event variables
207 * @envp: Pointer to table of environment variables, as passed into
208 * uevent() method.
209 * @num_envp: Number of environment variable slots available, as
210 * passed into uevent() method.
211 * @cur_index: Pointer to current index into @envp. It should be
212 * initialized to 0 before the first call to add_uevent_var(),
213 * and will be incremented on success.
214 * @buffer: Pointer to buffer for environment variables, as passed
215 * into uevent() method.
216 * @buffer_size: Length of @buffer, as passed into uevent() method.
217 * @cur_len: Pointer to current length of space used in @buffer.
218 * Should be initialized to 0 before the first call to
219 * add_uevent_var(), and will be incremented on success.
220 * @format: Format for creating environment variable (of the form
221 * "XXX=%x") for snprintf().
222 *
223 * Returns 0 if environment variable was added successfully or -ENOMEM
224 * if no space was available.
225 */
226 int add_uevent_var(char **envp, int num_envp, int *cur_index,
227 char *buffer, int buffer_size, int *cur_len,
228 const char *format, ...)
229 {
230 va_list args;
232 /*
233 * We check against num_envp - 1 to make sure there is at
234 * least one slot left after we return, since kobject_uevent()
235 * needs to set the last slot to NULL.
236 */
237 if (*cur_index >= num_envp - 1)
238 return -ENOMEM;
240 envp[*cur_index] = buffer + *cur_len;
242 va_start(args, format);
243 *cur_len += vsnprintf(envp[*cur_index],
244 max(buffer_size - *cur_len, 0),
245 format, args) + 1;
246 va_end(args);
248 if (*cur_len > buffer_size)
249 return -ENOMEM;
251 (*cur_index)++;
252 return 0;
253 }
254 EXPORT_SYMBOL_GPL(add_uevent_var);
256 #if defined(CONFIG_NET)
257 static int __init kobject_uevent_init(void)
258 {
259 uevent_sock = netlink_kernel_create(NETLINK_KOBJECT_UEVENT, 1, NULL,
260 THIS_MODULE);
262 if (!uevent_sock) {
263 printk(KERN_ERR
264 "kobject_uevent: unable to create netlink socket!\n");
265 return -ENODEV;
266 }
268 return 0;
269 }
271 postcore_initcall(kobject_uevent_init);
272 #endif
274 #endif /* CONFIG_HOTPLUG */