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 | ||
d87499ed | 25 | #define BUFFER_SIZE 2048 /* buffer for the variables */ |
1da177e4 LT |
26 | #define NUM_ENVP 32 /* number of env pointers */ |
27 | ||
4d17ffda | 28 | #if defined(CONFIG_HOTPLUG) |
51107301 JN |
29 | u64 uevent_seqnum; |
30 | char uevent_helper[UEVENT_HELPER_PATH_LEN] = "/sbin/hotplug"; | |
0296b228 | 31 | static DEFINE_SPINLOCK(sequence_lock); |
4d17ffda | 32 | #if defined(CONFIG_NET) |
5f123fbd | 33 | static struct sock *uevent_sock; |
4d17ffda | 34 | #endif |
0296b228 | 35 | |
1da177e4 LT |
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"; | |
fa675765 GKH |
45 | case KOBJ_MOUNT: |
46 | return "mount"; | |
47 | case KOBJ_UMOUNT: | |
48 | return "umount"; | |
1da177e4 LT |
49 | case KOBJ_OFFLINE: |
50 | return "offline"; | |
51 | case KOBJ_ONLINE: | |
52 | return "online"; | |
8a82472f CH |
53 | case KOBJ_MOVE: |
54 | return "move"; | |
1da177e4 LT |
55 | default: |
56 | return NULL; | |
57 | } | |
58 | } | |
1da177e4 | 59 | |
1da177e4 | 60 | /** |
8a82472f | 61 | * kobject_uevent_env - send an uevent with environmental data |
1da177e4 | 62 | * |
8a82472f | 63 | * @action: action that is happening (usually KOBJ_MOVE) |
1da177e4 | 64 | * @kobj: struct kobject that the action is happening to |
8a82472f | 65 | * @envp_ext: pointer to environmental data |
1da177e4 | 66 | */ |
8a82472f CH |
67 | void kobject_uevent_env(struct kobject *kobj, enum kobject_action action, |
68 | char *envp_ext[]) | |
1da177e4 | 69 | { |
5f123fbd KS |
70 | char **envp; |
71 | char *buffer; | |
1da177e4 | 72 | char *scratch; |
5f123fbd KS |
73 | const char *action_string; |
74 | const char *devpath = NULL; | |
75 | const char *subsystem; | |
76 | struct kobject *top_kobj; | |
77 | struct kset *kset; | |
312c004d | 78 | struct kset_uevent_ops *uevent_ops; |
5f123fbd KS |
79 | u64 seq; |
80 | char *seq_buff; | |
1da177e4 LT |
81 | int i = 0; |
82 | int retval; | |
8a82472f | 83 | int j; |
1da177e4 | 84 | |
5f123fbd KS |
85 | pr_debug("%s\n", __FUNCTION__); |
86 | ||
87 | action_string = action_to_string(action); | |
88 | if (!action_string) | |
89 | return; | |
90 | ||
91 | /* search the kset we belong to */ | |
92 | top_kobj = kobj; | |
1da177e4 LT |
93 | if (!top_kobj->kset && top_kobj->parent) { |
94 | do { | |
95 | top_kobj = top_kobj->parent; | |
96 | } while (!top_kobj->kset && top_kobj->parent); | |
97 | } | |
5f123fbd | 98 | if (!top_kobj->kset) |
1da177e4 LT |
99 | return; |
100 | ||
5f123fbd | 101 | kset = top_kobj->kset; |
312c004d | 102 | uevent_ops = kset->uevent_ops; |
1da177e4 | 103 | |
5f123fbd | 104 | /* skip the event, if the filter returns zero. */ |
312c004d KS |
105 | if (uevent_ops && uevent_ops->filter) |
106 | if (!uevent_ops->filter(kset, kobj)) | |
1da177e4 | 107 | return; |
1da177e4 | 108 | |
5f123fbd KS |
109 | /* environment index */ |
110 | envp = kzalloc(NUM_ENVP * sizeof (char *), GFP_KERNEL); | |
1da177e4 LT |
111 | if (!envp) |
112 | return; | |
1da177e4 | 113 | |
5f123fbd | 114 | /* environment values */ |
1da177e4 LT |
115 | buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL); |
116 | if (!buffer) | |
117 | goto exit; | |
118 | ||
5f123fbd KS |
119 | /* complete object path */ |
120 | devpath = kobject_get_path(kobj, GFP_KERNEL); | |
121 | if (!devpath) | |
122 | goto exit; | |
1da177e4 | 123 | |
5f123fbd | 124 | /* originating subsystem */ |
312c004d KS |
125 | if (uevent_ops && uevent_ops->name) |
126 | subsystem = uevent_ops->name(kset, kobj); | |
5f123fbd KS |
127 | else |
128 | subsystem = kobject_name(&kset->kobj); | |
1da177e4 | 129 | |
5f123fbd KS |
130 | /* event environemnt for helper process only */ |
131 | envp[i++] = "HOME=/"; | |
132 | envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin"; | |
1da177e4 | 133 | |
5f123fbd | 134 | /* default keys */ |
1da177e4 | 135 | scratch = buffer; |
1da177e4 LT |
136 | envp [i++] = scratch; |
137 | scratch += sprintf(scratch, "ACTION=%s", action_string) + 1; | |
1da177e4 | 138 | envp [i++] = scratch; |
5f123fbd | 139 | scratch += sprintf (scratch, "DEVPATH=%s", devpath) + 1; |
1da177e4 | 140 | envp [i++] = scratch; |
5f123fbd | 141 | scratch += sprintf(scratch, "SUBSYSTEM=%s", subsystem) + 1; |
8a82472f CH |
142 | for (j = 0; envp_ext && envp_ext[j]; j++) |
143 | envp[i++] = envp_ext[j]; | |
5f123fbd | 144 | /* just reserve the space, overwrite it after kset call has returned */ |
1da177e4 LT |
145 | envp[i++] = seq_buff = scratch; |
146 | scratch += strlen("SEQNUM=18446744073709551616") + 1; | |
147 | ||
5f123fbd | 148 | /* let the kset specific function add its stuff */ |
312c004d KS |
149 | if (uevent_ops && uevent_ops->uevent) { |
150 | retval = uevent_ops->uevent(kset, kobj, | |
1da177e4 LT |
151 | &envp[i], NUM_ENVP - i, scratch, |
152 | BUFFER_SIZE - (scratch - buffer)); | |
153 | if (retval) { | |
312c004d | 154 | pr_debug ("%s - uevent() returned %d\n", |
1da177e4 LT |
155 | __FUNCTION__, retval); |
156 | goto exit; | |
157 | } | |
158 | } | |
159 | ||
5f123fbd | 160 | /* we will send an event, request a new sequence number */ |
1da177e4 | 161 | spin_lock(&sequence_lock); |
312c004d | 162 | seq = ++uevent_seqnum; |
1da177e4 LT |
163 | spin_unlock(&sequence_lock); |
164 | sprintf(seq_buff, "SEQNUM=%llu", (unsigned long long)seq); | |
165 | ||
4d17ffda | 166 | #if defined(CONFIG_NET) |
5f123fbd KS |
167 | /* send netlink message */ |
168 | if (uevent_sock) { | |
169 | struct sk_buff *skb; | |
170 | size_t len; | |
171 | ||
172 | /* allocate message with the maximum possible size */ | |
173 | len = strlen(action_string) + strlen(devpath) + 2; | |
174 | skb = alloc_skb(len + BUFFER_SIZE, GFP_KERNEL); | |
175 | if (skb) { | |
176 | /* add header */ | |
177 | scratch = skb_put(skb, len); | |
178 | sprintf(scratch, "%s@%s", action_string, devpath); | |
179 | ||
180 | /* copy keys to our continuous event payload buffer */ | |
181 | for (i = 2; envp[i]; i++) { | |
182 | len = strlen(envp[i]) + 1; | |
183 | scratch = skb_put(skb, len); | |
184 | strcpy(scratch, envp[i]); | |
185 | } | |
186 | ||
187 | NETLINK_CB(skb).dst_group = 1; | |
188 | netlink_broadcast(uevent_sock, skb, 0, 1, GFP_KERNEL); | |
189 | } | |
190 | } | |
4d17ffda | 191 | #endif |
1da177e4 | 192 | |
5f123fbd | 193 | /* call uevent_helper, usually only enabled during early boot */ |
312c004d | 194 | if (uevent_helper[0]) { |
5f123fbd | 195 | char *argv [3]; |
1da177e4 | 196 | |
312c004d | 197 | argv [0] = uevent_helper; |
5f123fbd KS |
198 | argv [1] = (char *)subsystem; |
199 | argv [2] = NULL; | |
200 | call_usermodehelper (argv[0], argv, envp, 0); | |
201 | } | |
1da177e4 LT |
202 | |
203 | exit: | |
5f123fbd | 204 | kfree(devpath); |
1da177e4 LT |
205 | kfree(buffer); |
206 | kfree(envp); | |
207 | return; | |
208 | } | |
8a82472f CH |
209 | |
210 | EXPORT_SYMBOL_GPL(kobject_uevent_env); | |
211 | ||
212 | /** | |
213 | * kobject_uevent - notify userspace by ending an uevent | |
214 | * | |
215 | * @action: action that is happening (usually KOBJ_ADD and KOBJ_REMOVE) | |
216 | * @kobj: struct kobject that the action is happening to | |
217 | */ | |
218 | void kobject_uevent(struct kobject *kobj, enum kobject_action action) | |
219 | { | |
220 | kobject_uevent_env(kobj, action, NULL); | |
221 | } | |
222 | ||
312c004d | 223 | EXPORT_SYMBOL_GPL(kobject_uevent); |
1da177e4 LT |
224 | |
225 | /** | |
312c004d | 226 | * add_uevent_var - helper for creating event variables |
1da177e4 | 227 | * @envp: Pointer to table of environment variables, as passed into |
312c004d | 228 | * uevent() method. |
1da177e4 | 229 | * @num_envp: Number of environment variable slots available, as |
312c004d | 230 | * passed into uevent() method. |
1da177e4 | 231 | * @cur_index: Pointer to current index into @envp. It should be |
312c004d | 232 | * initialized to 0 before the first call to add_uevent_var(), |
1da177e4 LT |
233 | * and will be incremented on success. |
234 | * @buffer: Pointer to buffer for environment variables, as passed | |
312c004d KS |
235 | * into uevent() method. |
236 | * @buffer_size: Length of @buffer, as passed into uevent() method. | |
1da177e4 LT |
237 | * @cur_len: Pointer to current length of space used in @buffer. |
238 | * Should be initialized to 0 before the first call to | |
312c004d | 239 | * add_uevent_var(), and will be incremented on success. |
1da177e4 LT |
240 | * @format: Format for creating environment variable (of the form |
241 | * "XXX=%x") for snprintf(). | |
242 | * | |
243 | * Returns 0 if environment variable was added successfully or -ENOMEM | |
244 | * if no space was available. | |
245 | */ | |
312c004d KS |
246 | int add_uevent_var(char **envp, int num_envp, int *cur_index, |
247 | char *buffer, int buffer_size, int *cur_len, | |
248 | const char *format, ...) | |
1da177e4 LT |
249 | { |
250 | va_list args; | |
251 | ||
252 | /* | |
253 | * We check against num_envp - 1 to make sure there is at | |
312c004d KS |
254 | * least one slot left after we return, since kobject_uevent() |
255 | * needs to set the last slot to NULL. | |
1da177e4 LT |
256 | */ |
257 | if (*cur_index >= num_envp - 1) | |
258 | return -ENOMEM; | |
259 | ||
260 | envp[*cur_index] = buffer + *cur_len; | |
261 | ||
262 | va_start(args, format); | |
263 | *cur_len += vsnprintf(envp[*cur_index], | |
264 | max(buffer_size - *cur_len, 0), | |
265 | format, args) + 1; | |
266 | va_end(args); | |
267 | ||
268 | if (*cur_len > buffer_size) | |
269 | return -ENOMEM; | |
270 | ||
271 | (*cur_index)++; | |
272 | return 0; | |
273 | } | |
312c004d | 274 | EXPORT_SYMBOL_GPL(add_uevent_var); |
1da177e4 | 275 | |
4d17ffda | 276 | #if defined(CONFIG_NET) |
5f123fbd KS |
277 | static int __init kobject_uevent_init(void) |
278 | { | |
279 | uevent_sock = netlink_kernel_create(NETLINK_KOBJECT_UEVENT, 1, NULL, | |
280 | THIS_MODULE); | |
281 | ||
282 | if (!uevent_sock) { | |
283 | printk(KERN_ERR | |
284 | "kobject_uevent: unable to create netlink socket!\n"); | |
285 | return -ENODEV; | |
286 | } | |
287 | ||
288 | return 0; | |
289 | } | |
290 | ||
291 | postcore_initcall(kobject_uevent_init); | |
4d17ffda | 292 | #endif |
5f123fbd | 293 | |
1da177e4 | 294 | #endif /* CONFIG_HOTPLUG */ |