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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 | ||
f743ca5e | 28 | #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET) |
51107301 JN |
29 | u64 uevent_seqnum; |
30 | char uevent_helper[UEVENT_HELPER_PATH_LEN] = "/sbin/hotplug"; | |
0296b228 | 31 | static DEFINE_SPINLOCK(sequence_lock); |
5f123fbd | 32 | static struct sock *uevent_sock; |
0296b228 | 33 | |
1da177e4 LT |
34 | static char *action_to_string(enum kobject_action action) |
35 | { | |
36 | switch (action) { | |
37 | case KOBJ_ADD: | |
38 | return "add"; | |
39 | case KOBJ_REMOVE: | |
40 | return "remove"; | |
41 | case KOBJ_CHANGE: | |
42 | return "change"; | |
fa675765 GKH |
43 | case KOBJ_MOUNT: |
44 | return "mount"; | |
45 | case KOBJ_UMOUNT: | |
46 | return "umount"; | |
1da177e4 LT |
47 | case KOBJ_OFFLINE: |
48 | return "offline"; | |
49 | case KOBJ_ONLINE: | |
50 | return "online"; | |
51 | default: | |
52 | return NULL; | |
53 | } | |
54 | } | |
1da177e4 | 55 | |
1da177e4 | 56 | /** |
312c004d | 57 | * kobject_uevent - notify userspace by ending an uevent |
1da177e4 | 58 | * |
312c004d | 59 | * @action: action that is happening (usually KOBJ_ADD and KOBJ_REMOVE) |
1da177e4 LT |
60 | * @kobj: struct kobject that the action is happening to |
61 | */ | |
312c004d | 62 | void kobject_uevent(struct kobject *kobj, enum kobject_action action) |
1da177e4 | 63 | { |
5f123fbd KS |
64 | char **envp; |
65 | char *buffer; | |
1da177e4 | 66 | char *scratch; |
5f123fbd KS |
67 | const char *action_string; |
68 | const char *devpath = NULL; | |
69 | const char *subsystem; | |
70 | struct kobject *top_kobj; | |
71 | struct kset *kset; | |
312c004d | 72 | struct kset_uevent_ops *uevent_ops; |
5f123fbd KS |
73 | u64 seq; |
74 | char *seq_buff; | |
1da177e4 LT |
75 | int i = 0; |
76 | int retval; | |
1da177e4 | 77 | |
5f123fbd KS |
78 | pr_debug("%s\n", __FUNCTION__); |
79 | ||
80 | action_string = action_to_string(action); | |
81 | if (!action_string) | |
82 | return; | |
83 | ||
84 | /* search the kset we belong to */ | |
85 | top_kobj = kobj; | |
1da177e4 LT |
86 | if (!top_kobj->kset && top_kobj->parent) { |
87 | do { | |
88 | top_kobj = top_kobj->parent; | |
89 | } while (!top_kobj->kset && top_kobj->parent); | |
90 | } | |
5f123fbd | 91 | if (!top_kobj->kset) |
1da177e4 LT |
92 | return; |
93 | ||
5f123fbd | 94 | kset = top_kobj->kset; |
312c004d | 95 | uevent_ops = kset->uevent_ops; |
1da177e4 | 96 | |
5f123fbd | 97 | /* skip the event, if the filter returns zero. */ |
312c004d KS |
98 | if (uevent_ops && uevent_ops->filter) |
99 | if (!uevent_ops->filter(kset, kobj)) | |
1da177e4 | 100 | return; |
1da177e4 | 101 | |
5f123fbd KS |
102 | /* environment index */ |
103 | envp = kzalloc(NUM_ENVP * sizeof (char *), GFP_KERNEL); | |
1da177e4 LT |
104 | if (!envp) |
105 | return; | |
1da177e4 | 106 | |
5f123fbd | 107 | /* environment values */ |
1da177e4 LT |
108 | buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL); |
109 | if (!buffer) | |
110 | goto exit; | |
111 | ||
5f123fbd KS |
112 | /* complete object path */ |
113 | devpath = kobject_get_path(kobj, GFP_KERNEL); | |
114 | if (!devpath) | |
115 | goto exit; | |
1da177e4 | 116 | |
5f123fbd | 117 | /* originating subsystem */ |
312c004d KS |
118 | if (uevent_ops && uevent_ops->name) |
119 | subsystem = uevent_ops->name(kset, kobj); | |
5f123fbd KS |
120 | else |
121 | subsystem = kobject_name(&kset->kobj); | |
1da177e4 | 122 | |
5f123fbd KS |
123 | /* event environemnt for helper process only */ |
124 | envp[i++] = "HOME=/"; | |
125 | envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin"; | |
1da177e4 | 126 | |
5f123fbd | 127 | /* default keys */ |
1da177e4 | 128 | scratch = buffer; |
1da177e4 LT |
129 | envp [i++] = scratch; |
130 | scratch += sprintf(scratch, "ACTION=%s", action_string) + 1; | |
1da177e4 | 131 | envp [i++] = scratch; |
5f123fbd | 132 | scratch += sprintf (scratch, "DEVPATH=%s", devpath) + 1; |
1da177e4 | 133 | envp [i++] = scratch; |
5f123fbd | 134 | scratch += sprintf(scratch, "SUBSYSTEM=%s", subsystem) + 1; |
1da177e4 | 135 | |
5f123fbd | 136 | /* just reserve the space, overwrite it after kset call has returned */ |
1da177e4 LT |
137 | envp[i++] = seq_buff = scratch; |
138 | scratch += strlen("SEQNUM=18446744073709551616") + 1; | |
139 | ||
5f123fbd | 140 | /* let the kset specific function add its stuff */ |
312c004d KS |
141 | if (uevent_ops && uevent_ops->uevent) { |
142 | retval = uevent_ops->uevent(kset, kobj, | |
1da177e4 LT |
143 | &envp[i], NUM_ENVP - i, scratch, |
144 | BUFFER_SIZE - (scratch - buffer)); | |
145 | if (retval) { | |
312c004d | 146 | pr_debug ("%s - uevent() returned %d\n", |
1da177e4 LT |
147 | __FUNCTION__, retval); |
148 | goto exit; | |
149 | } | |
150 | } | |
151 | ||
5f123fbd | 152 | /* we will send an event, request a new sequence number */ |
1da177e4 | 153 | spin_lock(&sequence_lock); |
312c004d | 154 | seq = ++uevent_seqnum; |
1da177e4 LT |
155 | spin_unlock(&sequence_lock); |
156 | sprintf(seq_buff, "SEQNUM=%llu", (unsigned long long)seq); | |
157 | ||
5f123fbd KS |
158 | /* send netlink message */ |
159 | if (uevent_sock) { | |
160 | struct sk_buff *skb; | |
161 | size_t len; | |
162 | ||
163 | /* allocate message with the maximum possible size */ | |
164 | len = strlen(action_string) + strlen(devpath) + 2; | |
165 | skb = alloc_skb(len + BUFFER_SIZE, GFP_KERNEL); | |
166 | if (skb) { | |
167 | /* add header */ | |
168 | scratch = skb_put(skb, len); | |
169 | sprintf(scratch, "%s@%s", action_string, devpath); | |
170 | ||
171 | /* copy keys to our continuous event payload buffer */ | |
172 | for (i = 2; envp[i]; i++) { | |
173 | len = strlen(envp[i]) + 1; | |
174 | scratch = skb_put(skb, len); | |
175 | strcpy(scratch, envp[i]); | |
176 | } | |
177 | ||
178 | NETLINK_CB(skb).dst_group = 1; | |
179 | netlink_broadcast(uevent_sock, skb, 0, 1, GFP_KERNEL); | |
180 | } | |
181 | } | |
1da177e4 | 182 | |
5f123fbd | 183 | /* call uevent_helper, usually only enabled during early boot */ |
312c004d | 184 | if (uevent_helper[0]) { |
5f123fbd | 185 | char *argv [3]; |
1da177e4 | 186 | |
312c004d | 187 | argv [0] = uevent_helper; |
5f123fbd KS |
188 | argv [1] = (char *)subsystem; |
189 | argv [2] = NULL; | |
190 | call_usermodehelper (argv[0], argv, envp, 0); | |
191 | } | |
1da177e4 LT |
192 | |
193 | exit: | |
5f123fbd | 194 | kfree(devpath); |
1da177e4 LT |
195 | kfree(buffer); |
196 | kfree(envp); | |
197 | return; | |
198 | } | |
312c004d | 199 | EXPORT_SYMBOL_GPL(kobject_uevent); |
1da177e4 LT |
200 | |
201 | /** | |
312c004d | 202 | * add_uevent_var - helper for creating event variables |
1da177e4 | 203 | * @envp: Pointer to table of environment variables, as passed into |
312c004d | 204 | * uevent() method. |
1da177e4 | 205 | * @num_envp: Number of environment variable slots available, as |
312c004d | 206 | * passed into uevent() method. |
1da177e4 | 207 | * @cur_index: Pointer to current index into @envp. It should be |
312c004d | 208 | * initialized to 0 before the first call to add_uevent_var(), |
1da177e4 LT |
209 | * and will be incremented on success. |
210 | * @buffer: Pointer to buffer for environment variables, as passed | |
312c004d KS |
211 | * into uevent() method. |
212 | * @buffer_size: Length of @buffer, as passed into uevent() method. | |
1da177e4 LT |
213 | * @cur_len: Pointer to current length of space used in @buffer. |
214 | * Should be initialized to 0 before the first call to | |
312c004d | 215 | * add_uevent_var(), and will be incremented on success. |
1da177e4 LT |
216 | * @format: Format for creating environment variable (of the form |
217 | * "XXX=%x") for snprintf(). | |
218 | * | |
219 | * Returns 0 if environment variable was added successfully or -ENOMEM | |
220 | * if no space was available. | |
221 | */ | |
312c004d KS |
222 | int add_uevent_var(char **envp, int num_envp, int *cur_index, |
223 | char *buffer, int buffer_size, int *cur_len, | |
224 | const char *format, ...) | |
1da177e4 LT |
225 | { |
226 | va_list args; | |
227 | ||
228 | /* | |
229 | * We check against num_envp - 1 to make sure there is at | |
312c004d KS |
230 | * least one slot left after we return, since kobject_uevent() |
231 | * needs to set the last slot to NULL. | |
1da177e4 LT |
232 | */ |
233 | if (*cur_index >= num_envp - 1) | |
234 | return -ENOMEM; | |
235 | ||
236 | envp[*cur_index] = buffer + *cur_len; | |
237 | ||
238 | va_start(args, format); | |
239 | *cur_len += vsnprintf(envp[*cur_index], | |
240 | max(buffer_size - *cur_len, 0), | |
241 | format, args) + 1; | |
242 | va_end(args); | |
243 | ||
244 | if (*cur_len > buffer_size) | |
245 | return -ENOMEM; | |
246 | ||
247 | (*cur_index)++; | |
248 | return 0; | |
249 | } | |
312c004d | 250 | EXPORT_SYMBOL_GPL(add_uevent_var); |
1da177e4 | 251 | |
5f123fbd KS |
252 | static int __init kobject_uevent_init(void) |
253 | { | |
254 | uevent_sock = netlink_kernel_create(NETLINK_KOBJECT_UEVENT, 1, NULL, | |
255 | THIS_MODULE); | |
256 | ||
257 | if (!uevent_sock) { | |
258 | printk(KERN_ERR | |
259 | "kobject_uevent: unable to create netlink socket!\n"); | |
260 | return -ENODEV; | |
261 | } | |
262 | ||
263 | return 0; | |
264 | } | |
265 | ||
266 | postcore_initcall(kobject_uevent_init); | |
267 | ||
1da177e4 | 268 | #endif /* CONFIG_HOTPLUG */ |