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libudev: enumerate - scan /sys/block/ if needed
[thirdparty/systemd.git] / udev / lib / libudev-enumerate.c
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1/*
2 * libudev - interface to udev device information
3 *
4 * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
5 *
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19
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20#include <stdio.h>
21#include <stdlib.h>
22#include <stddef.h>
23#include <unistd.h>
24#include <errno.h>
25#include <string.h>
26#include <dirent.h>
27#include <sys/stat.h>
28
29#include "libudev.h"
30#include "libudev-private.h"
eb1f0e66 31
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32struct udev_enumerate {
33 struct udev *udev;
34 int refcount;
e345e267 35 struct list_node devices_list;
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36};
37
38struct udev_enumerate *udev_enumerate_ref(struct udev_enumerate *udev_enumerate)
39{
40 if (udev_enumerate == NULL)
41 return NULL;
42 udev_enumerate->refcount++;
43 return udev_enumerate;
44}
45
46void udev_enumerate_unref(struct udev_enumerate *udev_enumerate)
47{
48 if (udev_enumerate == NULL)
49 return;
50 udev_enumerate->refcount--;
51 if (udev_enumerate->refcount > 0)
52 return;
53 list_cleanup(udev_enumerate->udev, &udev_enumerate->devices_list);
54 free(udev_enumerate);
55}
56
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57struct udev *udev_enumerate_get_udev(struct udev_enumerate *udev_enumerate)
58{
59 if (udev_enumerate == NULL)
60 return NULL;
61 return udev_enumerate->udev;
62}
63
0de33a61 64struct udev_list_entry *udev_enumerate_get_list_entry(struct udev_enumerate *udev_enumerate)
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65{
66 if (udev_enumerate == NULL)
67 return NULL;
68 return list_get_entry(&udev_enumerate->devices_list);
69}
70
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71static int devices_scan_subsystem(struct udev *udev,
72 const char *basedir, const char *subsystem, const char *subdir,
bc8184ed 73 struct list_node *devices_list)
eb1f0e66 74{
3eb46ec6 75 char path[UTIL_PATH_SIZE];
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76 DIR *dir;
77 struct dirent *dent;
eb1f0e66 78
8753fadf 79 util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
3eb46ec6 80 util_strlcat(path, basedir, sizeof(path));
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81 if (subsystem != NULL) {
82 util_strlcat(path, "/", sizeof(path));
83 util_strlcat(path, subsystem, sizeof(path));
84 }
eb1f0e66 85 if (subdir != NULL)
3eb46ec6 86 util_strlcat(path, subdir, sizeof(path));
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87 dir = opendir(path);
88 if (dir == NULL)
89 return -1;
90 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
8753fadf 91 char syspath[UTIL_PATH_SIZE];
b03e89cf 92 char filename[UTIL_PATH_SIZE];
6f67f1df 93 struct stat statbuf;
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94
95 if (dent->d_name[0] == '.')
96 continue;
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97 util_strlcpy(syspath, path, sizeof(syspath));
98 util_strlcat(syspath, "/", sizeof(syspath));
99 util_strlcat(syspath, dent->d_name, sizeof(syspath));
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100 util_strlcpy(filename, syspath, sizeof(filename));
101 util_strlcat(filename, "/uevent", sizeof(filename));
102 if (stat(filename, &statbuf) != 0)
6f67f1df 103 continue;
8753fadf 104 util_resolve_sys_link(udev, syspath, sizeof(syspath));
bc8184ed 105 list_entry_add(udev, devices_list, syspath, NULL, 1, 1);
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106 }
107 closedir(dir);
108 return 0;
109}
110
111static int devices_scan_subsystems(struct udev *udev,
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112 const char *basedir, const char *subdir,
113 struct udev_list_entry *subsystem_include_list,
114 struct udev_list_entry *subsystem_exclude_list,
115 struct list_node *devices_list)
eb1f0e66 116{
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117 if (subsystem_include_list != NULL) {
118 struct udev_list_entry *list_entry;
eb1f0e66 119
bc8184ed 120 /* if list of subsystems to scan is given, just use this list */
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121 udev_list_entry_foreach(list_entry, subsystem_include_list) {
122 if (udev_list_entry_get_by_name(subsystem_exclude_list, udev_list_entry_get_name(list_entry)) != NULL)
123 continue;
bc8184ed 124 devices_scan_subsystem(udev, basedir, udev_list_entry_get_name(list_entry), subdir, devices_list);
b03e89cf 125 }
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126 } else {
127 char path[UTIL_PATH_SIZE];
128 DIR *dir;
129 struct dirent *dent;
130
131 /* if no list of subsystems to scan is given, scan all, and possible exclude some subsystems */
132 util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
133 util_strlcat(path, basedir, sizeof(path));
134 dir = opendir(path);
135 if (dir == NULL)
136 return -1;
137 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
138 if (dent->d_name[0] == '.')
139 continue;
140 if (udev_list_entry_get_by_name(subsystem_exclude_list, dent->d_name) != NULL)
141 continue;
142 devices_scan_subsystem(udev, basedir, dent->d_name, subdir, devices_list);
143 }
144 closedir(dir);
eb1f0e66 145 }
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146 return 0;
147}
148
8753fadf 149static int devices_delay(struct udev *udev, const char *syspath)
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150{
151 static const char *delay_device_list[] = {
152 "/block/md",
153 "/block/dm-",
154 NULL
155 };
8753fadf 156 size_t len;
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157 int i;
158
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159 len = strlen(udev_get_sys_path(udev));
160
eb1f0e66 161 for (i = 0; delay_device_list[i] != NULL; i++) {
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162 if (strstr(&syspath[len], delay_device_list[i]) != NULL) {
163 info(udev, "delaying: %s\n", syspath);
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164 return 1;
165 }
166 }
167 return 0;
168}
169
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170static struct udev_enumerate *enumerate_new(struct udev *udev)
171{
172 struct udev_enumerate *udev_enumerate;
173
174 udev_enumerate = malloc(sizeof(struct udev_enumerate));
175 if (udev_enumerate == NULL)
176 return NULL;
177 memset(udev_enumerate, 0x00, (sizeof(struct udev_enumerate)));
178 udev_enumerate->refcount = 1;
179 udev_enumerate->udev = udev;
180 list_init(&udev_enumerate->devices_list);
181 return udev_enumerate;
182}
183
eb1f0e66 184/**
bc8184ed 185 * udev_enumerate_new_from_devices:
a076080b 186 * @udev: udev library context
bc8184ed 187 * @subsystem: the list of names of subsystems to look for devices
eb1f0e66 188 *
bf7ad0ea 189 * Returns: an enumeration context
eb1f0e66 190 **/
bc8184ed 191struct udev_enumerate *udev_enumerate_new_from_devices(struct udev *udev, const char *subsystem, ...)
eb1f0e66 192{
bf7ad0ea 193 struct udev_enumerate *udev_enumerate;
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194 va_list vargs;
195 const char *arg;
3eb46ec6 196 char base[UTIL_PATH_SIZE];
eb1f0e66 197 struct stat statbuf;
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198 struct list_node subsystem_include_list;
199 struct list_node subsystem_exclude_list;
0de33a61 200 struct udev_list_entry *list_entry;
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201
202 if (udev == NULL)
203 return NULL;
eb1f0e66 204
6f67f1df 205 udev_enumerate = enumerate_new(udev);
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206 if (udev_enumerate == NULL)
207 return NULL;
eb1f0e66 208
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209 va_start(vargs, subsystem);
210 list_init(&subsystem_include_list);
211 list_init(&subsystem_exclude_list);
212 for (arg = subsystem; arg != NULL; arg = va_arg(vargs, const char *)) {
213 if (arg[0] != '!')
214 list_entry_add(udev, &subsystem_include_list, arg, NULL, 1, 0);
215 else
216 list_entry_add(udev, &subsystem_exclude_list, &arg[1], NULL, 1, 0);
217 }
218 va_end(vargs);
219
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220 util_strlcpy(base, udev_get_sys_path(udev), sizeof(base));
221 util_strlcat(base, "/subsystem", sizeof(base));
eb1f0e66 222 if (stat(base, &statbuf) == 0) {
b03e89cf 223 /* we have /subsystem/, forget all the old stuff */
6f67f1df 224 info(udev, "searching '/subsystem/*/devices/*' dir\n");
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225 devices_scan_subsystems(udev, "/subsystem", "/devices",
226 list_get_entry(&subsystem_include_list),
227 list_get_entry(&subsystem_exclude_list),
228 &udev_enumerate->devices_list);
eb1f0e66 229 } else {
6f67f1df 230 info(udev, "searching '/bus/*/devices/*' dir\n");
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231 devices_scan_subsystems(udev, "/bus", "/devices",
232 list_get_entry(&subsystem_include_list),
233 list_get_entry(&subsystem_exclude_list),
234 &udev_enumerate->devices_list);
6f67f1df 235 info(udev, "searching '/class/*' dir\n");
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236 devices_scan_subsystems(udev, "/class", NULL,
237 list_get_entry(&subsystem_include_list),
238 list_get_entry(&subsystem_exclude_list),
239 &udev_enumerate->devices_list);
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240 /* if block isn't a class, scan /block/ */
241 util_strlcpy(base, udev_get_sys_path(udev), sizeof(base));
242 util_strlcat(base, "/class/block", sizeof(base));
243 if (stat(base, &statbuf) != 0) {
244 struct udev_list_entry *include_list = list_get_entry(&subsystem_include_list);
245 struct udev_list_entry *exclude_list = list_get_entry(&subsystem_exclude_list);
246 int include_block = (include_list == NULL || udev_list_entry_get_by_name(include_list, "block") != NULL);
247 int exclude_block = (udev_list_entry_get_by_name(exclude_list, "block") != NULL);
248
249 if (include_block && !exclude_block) {
250 info(udev, "searching '/block/*/*' dir\n");
251 /* scan disks */
252 devices_scan_subsystem(udev, "/block", NULL, NULL, &udev_enumerate->devices_list);
253 /* scan partitions */
254 devices_scan_subsystems(udev, "/block", NULL,
255 NULL, NULL,
256 &udev_enumerate->devices_list);
257 }
258 }
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259 }
260
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261 list_cleanup(udev, &subsystem_include_list);
262 list_cleanup(udev, &subsystem_exclude_list);
263
bf7ad0ea 264 /* sort delayed devices to the end of the list */
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265 udev_list_entry_foreach(list_entry, list_get_entry(&udev_enumerate->devices_list)) {
266 if (devices_delay(udev, udev_list_entry_get_name(list_entry)))
267 list_entry_move_to_end(list_entry);
eb1f0e66 268 }
bf7ad0ea 269 return udev_enumerate;
eb1f0e66 270}
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271
272struct udev_enumerate *udev_enumerate_new_from_subsystems(struct udev *udev)
273{
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274 struct udev_enumerate *udev_enumerate;
275 char base[UTIL_PATH_SIZE];
276 struct stat statbuf;
277 const char *subsysdir;
278
279 if (udev == NULL)
280 return NULL;
281
282 udev_enumerate = enumerate_new(udev);
283 if (udev_enumerate == NULL)
284 return NULL;
285
286 util_strlcpy(base, udev_get_sys_path(udev), sizeof(base));
287 util_strlcat(base, "/subsystem", sizeof(base));
288 if (stat(base, &statbuf) == 0)
289 subsysdir = "/subsystem";
290 else
291 subsysdir = "/bus";
292 info(udev, "searching '%s/*' dir\n", subsysdir);
293 devices_scan_subsystem(udev, subsysdir, NULL, NULL, &udev_enumerate->devices_list);
294 info(udev, "searching '%s/*/drivers/*' dir\n", subsysdir);
295 devices_scan_subsystems(udev, subsysdir, "/drivers",
296 NULL, NULL,
297 &udev_enumerate->devices_list);
298 return udev_enumerate;
bc8184ed 299}