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