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Commit | Line | Data |
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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 | ||
60a96a59 KS |
28 | /* the strings here must match the enum in include/linux/kobject.h */ |
29 | const char *kobject_actions[] = { | |
30 | "add", | |
31 | "remove", | |
32 | "change", | |
33 | "move", | |
34 | "online", | |
35 | "offline", | |
36 | }; | |
1da177e4 | 37 | |
cd030c4c CH |
38 | #if defined(CONFIG_HOTPLUG) |
39 | u64 uevent_seqnum; | |
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; | |
44 | #endif | |
45 | ||
1da177e4 | 46 | /** |
8a82472f | 47 | * kobject_uevent_env - send an uevent with environmental data |
1da177e4 | 48 | * |
8a82472f | 49 | * @action: action that is happening (usually KOBJ_MOVE) |
1da177e4 | 50 | * @kobj: struct kobject that the action is happening to |
8a82472f | 51 | * @envp_ext: pointer to environmental data |
542cfce6 AK |
52 | * |
53 | * Returns 0 if kobject_uevent() is completed with success or the | |
54 | * corresponding error when it fails. | |
1da177e4 | 55 | */ |
542cfce6 | 56 | int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, |
8a82472f | 57 | char *envp_ext[]) |
1da177e4 | 58 | { |
5f123fbd KS |
59 | char **envp; |
60 | char *buffer; | |
1da177e4 | 61 | char *scratch; |
5f123fbd KS |
62 | const char *action_string; |
63 | const char *devpath = NULL; | |
64 | const char *subsystem; | |
65 | struct kobject *top_kobj; | |
66 | struct kset *kset; | |
312c004d | 67 | struct kset_uevent_ops *uevent_ops; |
5f123fbd KS |
68 | u64 seq; |
69 | char *seq_buff; | |
1da177e4 | 70 | int i = 0; |
542cfce6 | 71 | int retval = 0; |
8a82472f | 72 | int j; |
1da177e4 | 73 | |
5f123fbd KS |
74 | pr_debug("%s\n", __FUNCTION__); |
75 | ||
60a96a59 | 76 | action_string = kobject_actions[action]; |
542cfce6 AK |
77 | if (!action_string) { |
78 | pr_debug("kobject attempted to send uevent without action_string!\n"); | |
79 | return -EINVAL; | |
80 | } | |
5f123fbd KS |
81 | |
82 | /* search the kset we belong to */ | |
83 | top_kobj = kobj; | |
14193fb9 JAKJ |
84 | while (!top_kobj->kset && top_kobj->parent) { |
85 | top_kobj = top_kobj->parent; | |
1da177e4 | 86 | } |
542cfce6 AK |
87 | if (!top_kobj->kset) { |
88 | pr_debug("kobject attempted to send uevent without kset!\n"); | |
89 | return -EINVAL; | |
90 | } | |
1da177e4 | 91 | |
5f123fbd | 92 | kset = top_kobj->kset; |
312c004d | 93 | uevent_ops = kset->uevent_ops; |
1da177e4 | 94 | |
5f123fbd | 95 | /* skip the event, if the filter returns zero. */ |
312c004d | 96 | if (uevent_ops && uevent_ops->filter) |
542cfce6 AK |
97 | if (!uevent_ops->filter(kset, kobj)) { |
98 | pr_debug("kobject filter function caused the event to drop!\n"); | |
99 | return 0; | |
100 | } | |
1da177e4 | 101 | |
86406245 KS |
102 | /* originating subsystem */ |
103 | if (uevent_ops && uevent_ops->name) | |
104 | subsystem = uevent_ops->name(kset, kobj); | |
105 | else | |
106 | subsystem = kobject_name(&kset->kobj); | |
107 | if (!subsystem) { | |
108 | pr_debug("unset subsytem caused the event to drop!\n"); | |
109 | return 0; | |
110 | } | |
111 | ||
5f123fbd KS |
112 | /* environment index */ |
113 | envp = kzalloc(NUM_ENVP * sizeof (char *), GFP_KERNEL); | |
1da177e4 | 114 | if (!envp) |
542cfce6 | 115 | return -ENOMEM; |
1da177e4 | 116 | |
5f123fbd | 117 | /* environment values */ |
1da177e4 | 118 | buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL); |
542cfce6 AK |
119 | if (!buffer) { |
120 | retval = -ENOMEM; | |
1da177e4 | 121 | goto exit; |
542cfce6 | 122 | } |
1da177e4 | 123 | |
5f123fbd KS |
124 | /* complete object path */ |
125 | devpath = kobject_get_path(kobj, GFP_KERNEL); | |
542cfce6 AK |
126 | if (!devpath) { |
127 | retval = -ENOENT; | |
5f123fbd | 128 | goto exit; |
542cfce6 | 129 | } |
1da177e4 | 130 | |
5f123fbd KS |
131 | /* event environemnt for helper process only */ |
132 | envp[i++] = "HOME=/"; | |
133 | envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin"; | |
1da177e4 | 134 | |
5f123fbd | 135 | /* default keys */ |
1da177e4 | 136 | scratch = buffer; |
1da177e4 LT |
137 | envp [i++] = scratch; |
138 | scratch += sprintf(scratch, "ACTION=%s", action_string) + 1; | |
1da177e4 | 139 | envp [i++] = scratch; |
5f123fbd | 140 | scratch += sprintf (scratch, "DEVPATH=%s", devpath) + 1; |
1da177e4 | 141 | envp [i++] = scratch; |
5f123fbd | 142 | scratch += sprintf(scratch, "SUBSYSTEM=%s", subsystem) + 1; |
8a82472f CH |
143 | for (j = 0; envp_ext && envp_ext[j]; j++) |
144 | envp[i++] = envp_ext[j]; | |
5f123fbd | 145 | /* just reserve the space, overwrite it after kset call has returned */ |
1da177e4 LT |
146 | envp[i++] = seq_buff = scratch; |
147 | scratch += strlen("SEQNUM=18446744073709551616") + 1; | |
148 | ||
5f123fbd | 149 | /* let the kset specific function add its stuff */ |
312c004d KS |
150 | if (uevent_ops && uevent_ops->uevent) { |
151 | retval = uevent_ops->uevent(kset, kobj, | |
1da177e4 LT |
152 | &envp[i], NUM_ENVP - i, scratch, |
153 | BUFFER_SIZE - (scratch - buffer)); | |
154 | if (retval) { | |
312c004d | 155 | pr_debug ("%s - uevent() returned %d\n", |
1da177e4 LT |
156 | __FUNCTION__, retval); |
157 | goto exit; | |
158 | } | |
159 | } | |
160 | ||
5f123fbd | 161 | /* we will send an event, request a new sequence number */ |
1da177e4 | 162 | spin_lock(&sequence_lock); |
312c004d | 163 | seq = ++uevent_seqnum; |
1da177e4 LT |
164 | spin_unlock(&sequence_lock); |
165 | sprintf(seq_buff, "SEQNUM=%llu", (unsigned long long)seq); | |
166 | ||
4d17ffda | 167 | #if defined(CONFIG_NET) |
5f123fbd KS |
168 | /* send netlink message */ |
169 | if (uevent_sock) { | |
170 | struct sk_buff *skb; | |
171 | size_t len; | |
172 | ||
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); | |
176 | if (skb) { | |
177 | /* add header */ | |
178 | scratch = skb_put(skb, len); | |
179 | sprintf(scratch, "%s@%s", action_string, devpath); | |
180 | ||
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]); | |
186 | } | |
187 | ||
188 | NETLINK_CB(skb).dst_group = 1; | |
189 | netlink_broadcast(uevent_sock, skb, 0, 1, GFP_KERNEL); | |
190 | } | |
191 | } | |
4d17ffda | 192 | #endif |
1da177e4 | 193 | |
5f123fbd | 194 | /* call uevent_helper, usually only enabled during early boot */ |
312c004d | 195 | if (uevent_helper[0]) { |
5f123fbd | 196 | char *argv [3]; |
1da177e4 | 197 | |
312c004d | 198 | argv [0] = uevent_helper; |
5f123fbd KS |
199 | argv [1] = (char *)subsystem; |
200 | argv [2] = NULL; | |
86313c48 | 201 | call_usermodehelper (argv[0], argv, envp, UMH_WAIT_EXEC); |
5f123fbd | 202 | } |
1da177e4 LT |
203 | |
204 | exit: | |
5f123fbd | 205 | kfree(devpath); |
1da177e4 LT |
206 | kfree(buffer); |
207 | kfree(envp); | |
542cfce6 | 208 | return retval; |
1da177e4 | 209 | } |
8a82472f CH |
210 | |
211 | EXPORT_SYMBOL_GPL(kobject_uevent_env); | |
212 | ||
213 | /** | |
214 | * kobject_uevent - notify userspace by ending an uevent | |
215 | * | |
216 | * @action: action that is happening (usually KOBJ_ADD and KOBJ_REMOVE) | |
217 | * @kobj: struct kobject that the action is happening to | |
542cfce6 AK |
218 | * |
219 | * Returns 0 if kobject_uevent() is completed with success or the | |
220 | * corresponding error when it fails. | |
8a82472f | 221 | */ |
542cfce6 | 222 | int kobject_uevent(struct kobject *kobj, enum kobject_action action) |
8a82472f | 223 | { |
542cfce6 | 224 | return kobject_uevent_env(kobj, action, NULL); |
8a82472f CH |
225 | } |
226 | ||
312c004d | 227 | EXPORT_SYMBOL_GPL(kobject_uevent); |
1da177e4 LT |
228 | |
229 | /** | |
312c004d | 230 | * add_uevent_var - helper for creating event variables |
1da177e4 | 231 | * @envp: Pointer to table of environment variables, as passed into |
312c004d | 232 | * uevent() method. |
1da177e4 | 233 | * @num_envp: Number of environment variable slots available, as |
312c004d | 234 | * passed into uevent() method. |
1da177e4 | 235 | * @cur_index: Pointer to current index into @envp. It should be |
312c004d | 236 | * initialized to 0 before the first call to add_uevent_var(), |
1da177e4 LT |
237 | * and will be incremented on success. |
238 | * @buffer: Pointer to buffer for environment variables, as passed | |
312c004d KS |
239 | * into uevent() method. |
240 | * @buffer_size: Length of @buffer, as passed into uevent() method. | |
1da177e4 LT |
241 | * @cur_len: Pointer to current length of space used in @buffer. |
242 | * Should be initialized to 0 before the first call to | |
312c004d | 243 | * add_uevent_var(), and will be incremented on success. |
1da177e4 LT |
244 | * @format: Format for creating environment variable (of the form |
245 | * "XXX=%x") for snprintf(). | |
246 | * | |
247 | * Returns 0 if environment variable was added successfully or -ENOMEM | |
248 | * if no space was available. | |
249 | */ | |
312c004d KS |
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, ...) | |
1da177e4 LT |
253 | { |
254 | va_list args; | |
255 | ||
256 | /* | |
257 | * We check against num_envp - 1 to make sure there is at | |
312c004d KS |
258 | * least one slot left after we return, since kobject_uevent() |
259 | * needs to set the last slot to NULL. | |
1da177e4 LT |
260 | */ |
261 | if (*cur_index >= num_envp - 1) | |
262 | return -ENOMEM; | |
263 | ||
264 | envp[*cur_index] = buffer + *cur_len; | |
265 | ||
266 | va_start(args, format); | |
267 | *cur_len += vsnprintf(envp[*cur_index], | |
268 | max(buffer_size - *cur_len, 0), | |
269 | format, args) + 1; | |
270 | va_end(args); | |
271 | ||
272 | if (*cur_len > buffer_size) | |
273 | return -ENOMEM; | |
274 | ||
275 | (*cur_index)++; | |
276 | return 0; | |
277 | } | |
312c004d | 278 | EXPORT_SYMBOL_GPL(add_uevent_var); |
1da177e4 | 279 | |
4d17ffda | 280 | #if defined(CONFIG_NET) |
5f123fbd KS |
281 | static int __init kobject_uevent_init(void) |
282 | { | |
b4b51029 EB |
283 | uevent_sock = netlink_kernel_create(&init_net, NETLINK_KOBJECT_UEVENT, |
284 | 1, NULL, NULL, THIS_MODULE); | |
5f123fbd KS |
285 | if (!uevent_sock) { |
286 | printk(KERN_ERR | |
287 | "kobject_uevent: unable to create netlink socket!\n"); | |
288 | return -ENODEV; | |
289 | } | |
290 | ||
291 | return 0; | |
292 | } | |
293 | ||
294 | postcore_initcall(kobject_uevent_init); | |
4d17ffda | 295 | #endif |
5f123fbd | 296 | |
1da177e4 | 297 | #endif /* CONFIG_HOTPLUG */ |