Commit | Line | Data |
---|---|---|
1da177e4 LT |
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 | */ | |
16 | ||
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> | |
1da177e4 LT |
22 | #include <linux/kobject.h> |
23 | #include <net/sock.h> | |
24 | ||
25 | #define BUFFER_SIZE 1024 /* buffer for the hotplug env */ | |
26 | #define NUM_ENVP 32 /* number of env pointers */ | |
27 | ||
0296b228 KS |
28 | #if defined(CONFIG_HOTPLUG) |
29 | char hotplug_path[HOTPLUG_PATH_LEN] = "/sbin/hotplug"; | |
30 | u64 hotplug_seqnum; | |
31 | static DEFINE_SPINLOCK(sequence_lock); | |
32 | ||
1da177e4 LT |
33 | static char *action_to_string(enum kobject_action action) |
34 | { | |
35 | switch (action) { | |
36 | case KOBJ_ADD: | |
37 | return "add"; | |
38 | case KOBJ_REMOVE: | |
39 | return "remove"; | |
40 | case KOBJ_CHANGE: | |
41 | return "change"; | |
1da177e4 LT |
42 | case KOBJ_OFFLINE: |
43 | return "offline"; | |
44 | case KOBJ_ONLINE: | |
45 | return "online"; | |
46 | default: | |
47 | return NULL; | |
48 | } | |
49 | } | |
1da177e4 | 50 | |
1da177e4 LT |
51 | static struct sock *uevent_sock; |
52 | ||
53 | /** | |
4ed17dcc | 54 | * send_uevent - notify userspace by sending event through netlink socket |
1da177e4 LT |
55 | * |
56 | * @signal: signal name | |
57 | * @obj: object path (kobject) | |
58 | * @envp: possible hotplug environment to pass with the message | |
59 | * @gfp_mask: | |
60 | */ | |
61 | static int send_uevent(const char *signal, const char *obj, | |
fd4f2df2 | 62 | char **envp, gfp_t gfp_mask) |
1da177e4 LT |
63 | { |
64 | struct sk_buff *skb; | |
65 | char *pos; | |
66 | int len; | |
67 | ||
68 | if (!uevent_sock) | |
69 | return -EIO; | |
70 | ||
71 | len = strlen(signal) + 1; | |
72 | len += strlen(obj) + 1; | |
73 | ||
74 | /* allocate buffer with the maximum possible message size */ | |
75 | skb = alloc_skb(len + BUFFER_SIZE, gfp_mask); | |
76 | if (!skb) | |
77 | return -ENOMEM; | |
78 | ||
79 | pos = skb_put(skb, len); | |
80 | sprintf(pos, "%s@%s", signal, obj); | |
81 | ||
82 | /* copy the environment key by key to our continuous buffer */ | |
83 | if (envp) { | |
84 | int i; | |
85 | ||
86 | for (i = 2; envp[i]; i++) { | |
87 | len = strlen(envp[i]) + 1; | |
88 | pos = skb_put(skb, len); | |
89 | strcpy(pos, envp[i]); | |
90 | } | |
91 | } | |
92 | ||
ac6d439d | 93 | NETLINK_CB(skb).dst_group = 1; |
1da177e4 LT |
94 | return netlink_broadcast(uevent_sock, skb, 0, 1, gfp_mask); |
95 | } | |
96 | ||
97 | static int do_kobject_uevent(struct kobject *kobj, enum kobject_action action, | |
fd4f2df2 | 98 | struct attribute *attr, gfp_t gfp_mask) |
1da177e4 LT |
99 | { |
100 | char *path; | |
101 | char *attrpath; | |
102 | char *signal; | |
103 | int len; | |
104 | int rc = -ENOMEM; | |
105 | ||
106 | path = kobject_get_path(kobj, gfp_mask); | |
107 | if (!path) | |
108 | return -ENOMEM; | |
109 | ||
110 | signal = action_to_string(action); | |
111 | if (!signal) | |
112 | return -EINVAL; | |
113 | ||
114 | if (attr) { | |
115 | len = strlen(path); | |
116 | len += strlen(attr->name) + 2; | |
117 | attrpath = kmalloc(len, gfp_mask); | |
118 | if (!attrpath) | |
119 | goto exit; | |
120 | sprintf(attrpath, "%s/%s", path, attr->name); | |
121 | rc = send_uevent(signal, attrpath, NULL, gfp_mask); | |
122 | kfree(attrpath); | |
123 | } else | |
124 | rc = send_uevent(signal, path, NULL, gfp_mask); | |
125 | ||
126 | exit: | |
127 | kfree(path); | |
128 | return rc; | |
129 | } | |
130 | ||
131 | /** | |
132 | * kobject_uevent - notify userspace by sending event through netlink socket | |
133 | * | |
134 | * @signal: signal name | |
135 | * @kobj: struct kobject that the event is happening to | |
136 | * @attr: optional struct attribute the event belongs to | |
137 | */ | |
138 | int kobject_uevent(struct kobject *kobj, enum kobject_action action, | |
139 | struct attribute *attr) | |
140 | { | |
141 | return do_kobject_uevent(kobj, action, attr, GFP_KERNEL); | |
142 | } | |
143 | EXPORT_SYMBOL_GPL(kobject_uevent); | |
144 | ||
145 | int kobject_uevent_atomic(struct kobject *kobj, enum kobject_action action, | |
146 | struct attribute *attr) | |
147 | { | |
148 | return do_kobject_uevent(kobj, action, attr, GFP_ATOMIC); | |
149 | } | |
150 | EXPORT_SYMBOL_GPL(kobject_uevent_atomic); | |
151 | ||
152 | static int __init kobject_uevent_init(void) | |
153 | { | |
06628607 | 154 | uevent_sock = netlink_kernel_create(NETLINK_KOBJECT_UEVENT, 1, NULL, |
4fdb3bb7 | 155 | THIS_MODULE); |
1da177e4 LT |
156 | |
157 | if (!uevent_sock) { | |
158 | printk(KERN_ERR | |
159 | "kobject_uevent: unable to create netlink socket!\n"); | |
160 | return -ENODEV; | |
161 | } | |
162 | ||
163 | return 0; | |
164 | } | |
165 | ||
166 | postcore_initcall(kobject_uevent_init); | |
167 | ||
1da177e4 LT |
168 | /** |
169 | * kobject_hotplug - notify userspace by executing /sbin/hotplug | |
170 | * | |
171 | * @action: action that is happening (usually "ADD" or "REMOVE") | |
172 | * @kobj: struct kobject that the action is happening to | |
173 | */ | |
174 | void kobject_hotplug(struct kobject *kobj, enum kobject_action action) | |
175 | { | |
176 | char *argv [3]; | |
177 | char **envp = NULL; | |
178 | char *buffer = NULL; | |
179 | char *seq_buff; | |
180 | char *scratch; | |
181 | int i = 0; | |
182 | int retval; | |
183 | char *kobj_path = NULL; | |
f3b4f3c6 | 184 | const char *name = NULL; |
1da177e4 LT |
185 | char *action_string; |
186 | u64 seq; | |
187 | struct kobject *top_kobj = kobj; | |
188 | struct kset *kset; | |
189 | static struct kset_hotplug_ops null_hotplug_ops; | |
190 | struct kset_hotplug_ops *hotplug_ops = &null_hotplug_ops; | |
191 | ||
192 | /* If this kobj does not belong to a kset, | |
193 | try to find a parent that does. */ | |
194 | if (!top_kobj->kset && top_kobj->parent) { | |
195 | do { | |
196 | top_kobj = top_kobj->parent; | |
197 | } while (!top_kobj->kset && top_kobj->parent); | |
198 | } | |
199 | ||
200 | if (top_kobj->kset) | |
201 | kset = top_kobj->kset; | |
202 | else | |
203 | return; | |
204 | ||
205 | if (kset->hotplug_ops) | |
206 | hotplug_ops = kset->hotplug_ops; | |
207 | ||
208 | /* If the kset has a filter operation, call it. | |
209 | Skip the event, if the filter returns zero. */ | |
210 | if (hotplug_ops->filter) { | |
211 | if (!hotplug_ops->filter(kset, kobj)) | |
212 | return; | |
213 | } | |
214 | ||
215 | pr_debug ("%s\n", __FUNCTION__); | |
216 | ||
217 | action_string = action_to_string(action); | |
218 | if (!action_string) | |
219 | return; | |
220 | ||
221 | envp = kmalloc(NUM_ENVP * sizeof (char *), GFP_KERNEL); | |
222 | if (!envp) | |
223 | return; | |
224 | memset (envp, 0x00, NUM_ENVP * sizeof (char *)); | |
225 | ||
226 | buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL); | |
227 | if (!buffer) | |
228 | goto exit; | |
229 | ||
230 | if (hotplug_ops->name) | |
231 | name = hotplug_ops->name(kset, kobj); | |
232 | if (name == NULL) | |
eb11d8ff | 233 | name = kobject_name(&kset->kobj); |
1da177e4 LT |
234 | |
235 | argv [0] = hotplug_path; | |
f3b4f3c6 | 236 | argv [1] = (char *)name; /* won't be changed but 'const' has to go */ |
1da177e4 LT |
237 | argv [2] = NULL; |
238 | ||
239 | /* minimal command environment */ | |
240 | envp [i++] = "HOME=/"; | |
241 | envp [i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin"; | |
242 | ||
243 | scratch = buffer; | |
244 | ||
245 | envp [i++] = scratch; | |
246 | scratch += sprintf(scratch, "ACTION=%s", action_string) + 1; | |
247 | ||
248 | kobj_path = kobject_get_path(kobj, GFP_KERNEL); | |
249 | if (!kobj_path) | |
250 | goto exit; | |
251 | ||
252 | envp [i++] = scratch; | |
253 | scratch += sprintf (scratch, "DEVPATH=%s", kobj_path) + 1; | |
254 | ||
255 | envp [i++] = scratch; | |
256 | scratch += sprintf(scratch, "SUBSYSTEM=%s", name) + 1; | |
257 | ||
258 | /* reserve space for the sequence, | |
259 | * put the real one in after the hotplug call */ | |
260 | envp[i++] = seq_buff = scratch; | |
261 | scratch += strlen("SEQNUM=18446744073709551616") + 1; | |
262 | ||
263 | if (hotplug_ops->hotplug) { | |
264 | /* have the kset specific function add its stuff */ | |
265 | retval = hotplug_ops->hotplug (kset, kobj, | |
266 | &envp[i], NUM_ENVP - i, scratch, | |
267 | BUFFER_SIZE - (scratch - buffer)); | |
268 | if (retval) { | |
269 | pr_debug ("%s - hotplug() returned %d\n", | |
270 | __FUNCTION__, retval); | |
271 | goto exit; | |
272 | } | |
273 | } | |
274 | ||
275 | spin_lock(&sequence_lock); | |
276 | seq = ++hotplug_seqnum; | |
277 | spin_unlock(&sequence_lock); | |
278 | sprintf(seq_buff, "SEQNUM=%llu", (unsigned long long)seq); | |
279 | ||
280 | pr_debug ("%s: %s %s seq=%llu %s %s %s %s %s\n", | |
281 | __FUNCTION__, argv[0], argv[1], (unsigned long long)seq, | |
282 | envp[0], envp[1], envp[2], envp[3], envp[4]); | |
283 | ||
284 | send_uevent(action_string, kobj_path, envp, GFP_KERNEL); | |
285 | ||
286 | if (!hotplug_path[0]) | |
287 | goto exit; | |
288 | ||
289 | retval = call_usermodehelper (argv[0], argv, envp, 0); | |
290 | if (retval) | |
291 | pr_debug ("%s - call_usermodehelper returned %d\n", | |
292 | __FUNCTION__, retval); | |
293 | ||
294 | exit: | |
295 | kfree(kobj_path); | |
296 | kfree(buffer); | |
297 | kfree(envp); | |
298 | return; | |
299 | } | |
300 | EXPORT_SYMBOL(kobject_hotplug); | |
301 | ||
302 | /** | |
303 | * add_hotplug_env_var - helper for creating hotplug environment variables | |
304 | * @envp: Pointer to table of environment variables, as passed into | |
305 | * hotplug() method. | |
306 | * @num_envp: Number of environment variable slots available, as | |
307 | * passed into hotplug() method. | |
308 | * @cur_index: Pointer to current index into @envp. It should be | |
309 | * initialized to 0 before the first call to add_hotplug_env_var(), | |
310 | * and will be incremented on success. | |
311 | * @buffer: Pointer to buffer for environment variables, as passed | |
312 | * into hotplug() method. | |
313 | * @buffer_size: Length of @buffer, as passed into hotplug() method. | |
314 | * @cur_len: Pointer to current length of space used in @buffer. | |
315 | * Should be initialized to 0 before the first call to | |
316 | * add_hotplug_env_var(), and will be incremented on success. | |
317 | * @format: Format for creating environment variable (of the form | |
318 | * "XXX=%x") for snprintf(). | |
319 | * | |
320 | * Returns 0 if environment variable was added successfully or -ENOMEM | |
321 | * if no space was available. | |
322 | */ | |
323 | int add_hotplug_env_var(char **envp, int num_envp, int *cur_index, | |
324 | char *buffer, int buffer_size, int *cur_len, | |
325 | const char *format, ...) | |
326 | { | |
327 | va_list args; | |
328 | ||
329 | /* | |
330 | * We check against num_envp - 1 to make sure there is at | |
331 | * least one slot left after we return, since the hotplug | |
332 | * method needs to set the last slot to NULL. | |
333 | */ | |
334 | if (*cur_index >= num_envp - 1) | |
335 | return -ENOMEM; | |
336 | ||
337 | envp[*cur_index] = buffer + *cur_len; | |
338 | ||
339 | va_start(args, format); | |
340 | *cur_len += vsnprintf(envp[*cur_index], | |
341 | max(buffer_size - *cur_len, 0), | |
342 | format, args) + 1; | |
343 | va_end(args); | |
344 | ||
345 | if (*cur_len > buffer_size) | |
346 | return -ENOMEM; | |
347 | ||
348 | (*cur_index)++; | |
349 | return 0; | |
350 | } | |
351 | EXPORT_SYMBOL(add_hotplug_env_var); | |
352 | ||
353 | #endif /* CONFIG_HOTPLUG */ |