chiark / gitweb /
[PATCH] udevstart: simplify "dev" file searching
[elogind.git] / udev_start.c
1 /*
2  * udevstart.c
3  *
4  * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
5  * 
6  * Quick and dirty way to populate a /dev with udev if your system
7  * does not have access to a shell.  Based originally on a patch to udev 
8  * from Harald Hoyer <harald@redhat.com>
9  *
10  *      This program is free software; you can redistribute it and/or modify it
11  *      under the terms of the GNU General Public License as published by the
12  *      Free Software Foundation version 2 of the License.
13  * 
14  *      This program is distributed in the hope that it will be useful, but
15  *      WITHOUT ANY WARRANTY; without even the implied warranty of
16  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  *      General Public License for more details.
18  * 
19  *      You should have received a copy of the GNU General Public License along
20  *      with this program; if not, write to the Free Software Foundation, Inc.,
21  *      675 Mass Ave, Cambridge, MA 02139, USA.
22  *
23  */
24
25 #include <stdlib.h>
26 #include <stddef.h>
27 #include <string.h>
28 #include <stdio.h>
29 #include <errno.h>
30 #include <ctype.h>
31 #include <dirent.h>
32 #include <sys/wait.h>
33 #include <sys/stat.h>
34 #include <sys/types.h>
35 #include <unistd.h>
36
37 #include "libsysfs/sysfs/libsysfs.h"
38 #include "logging.h"
39 #include "udev_utils.h"
40 #include "list.h"
41 #include "udev.h"
42
43
44 #define MAX_PATH_SIZE           512
45
46 struct device {
47         struct list_head list;
48         char path[MAX_PATH_SIZE];
49         char subsys[MAX_PATH_SIZE];
50 };
51
52 /* sort files in lexical order */
53 static int device_list_insert(const char *path, char *subsystem, struct list_head *device_list)
54 {
55         struct device *loop_device;
56         struct device *new_device;
57
58         dbg("insert: '%s'\n", path);
59
60         list_for_each_entry(loop_device, device_list, list) {
61                 if (strcmp(loop_device->path, path) > 0) {
62                         break;
63                 }
64         }
65
66         new_device = malloc(sizeof(struct device));
67         if (new_device == NULL) {
68                 dbg("error malloc");
69                 return -ENOMEM;
70         }
71
72         strfieldcpy(new_device->path, path);
73         strfieldcpy(new_device->subsys, subsystem);
74         list_add_tail(&new_device->list, &loop_device->list);
75         dbg("add '%s' from subsys '%s'", new_device->path, new_device->subsys);
76         return 0;
77 }
78
79 /* list of devices that we should run last due to any one of a number of reasons */
80 static char *last_list[] = {
81         "/block/dm",    /* on here because dm wants to have the block devices around before it */
82         NULL,
83 };
84
85 /* list of devices that we should run first due to any one of a number of reasons */
86 static char *first_list[] = {
87         "/class/mem",   /* people tend to like their memory devices around first... */
88         NULL,
89 };
90
91 static int add_device(const char *path, const char *subsystem)
92 {
93         struct udevice udev;
94         struct sysfs_class_device *class_dev;
95         const char *devpath;
96
97         devpath = &path[strlen(sysfs_path)];
98
99         /* set environment for callouts and dev.d/ */
100         setenv("DEVPATH", devpath, 1);
101         setenv("SUBSYSTEM", subsystem, 1);
102
103         dbg("exec  : '%s' (%s)\n", devpath, path);
104
105         class_dev = sysfs_open_class_device_path(path);
106         if (class_dev == NULL) {
107                 dbg ("sysfs_open_class_device_path failed");
108                 return -ENODEV;
109         }
110
111         udev_init_device(&udev, devpath, subsystem);
112         udev_add_device(&udev, class_dev);
113
114         /* run dev.d/ scripts if we created a node or changed a netif name */
115         if (udev_dev_d && udev.devname[0] != '\0') {
116                 setenv("DEVNAME", udev.devname, 1);
117                 udev_multiplex_directory(&udev, DEVD_DIR, DEVD_SUFFIX);
118         }
119
120         sysfs_close_class_device(class_dev);
121
122         return 0;
123 }
124
125 static void exec_list(struct list_head *device_list)
126 {
127         struct device *loop_device;
128         struct device *tmp_device;
129         int i;
130
131         /* handle the "first" type devices first */
132         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
133                 for (i = 0; first_list[i] != NULL; i++) {
134                         if (strncmp(loop_device->path, first_list[i], strlen(first_list[i])) == 0) {
135                                 add_device(loop_device->path, loop_device->subsys);
136                                 list_del(&loop_device->list);
137                                 free(loop_device);
138                                 break;
139                         }
140                 }
141         }
142
143         /* handle the devices we are allowed to, excluding the "last" type devices */
144         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
145                 int found = 0;
146                 for (i = 0; last_list[i] != NULL; i++) {
147                         if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
148                                 found = 1;
149                                 break;
150                         }
151                 }
152                 if (found)
153                         continue;
154
155                 add_device(loop_device->path, loop_device->subsys);
156                 list_del(&loop_device->list);
157                 free(loop_device);
158         }
159
160         /* handle the rest of the devices left over, if any */
161         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
162                 add_device(loop_device->path, loop_device->subsys);
163                 list_del(&loop_device->list);
164                 free(loop_device);
165         }
166 }
167
168 static int has_devt(const char *directory)
169 {
170         char filename[MAX_PATH_SIZE];
171         struct stat statbuf;
172
173         snprintf(filename, MAX_PATH_SIZE, "%s/dev", directory);
174         filename[MAX_PATH_SIZE-1] = '\0';
175
176         if (stat(filename, &statbuf) == 0)
177                 return 1;
178
179         return 0;
180 }
181
182 static void udev_scan_block(void)
183 {
184         char base[MAX_PATH_SIZE];
185         DIR *dir;
186         struct dirent *dent;
187         LIST_HEAD(device_list);
188
189         snprintf(base, MAX_PATH_SIZE, "%s/block", sysfs_path);
190         base[MAX_PATH_SIZE-1] = '\0';
191
192         dir = opendir(base);
193         if (dir != NULL) {
194                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
195                         char dirname[MAX_PATH_SIZE];
196                         DIR *dir2;
197                         struct dirent *dent2;
198
199                         if (dent->d_name[0] == '.')
200                                 continue;
201
202                         snprintf(dirname, MAX_PATH_SIZE, "%s/%s", base, dent->d_name);
203                         dirname[MAX_PATH_SIZE-1] = '\0';
204                         if (has_devt(dirname))
205                                 device_list_insert(dirname, "block", &device_list);
206                         else
207                                 continue;
208
209                         snprintf(dirname, MAX_PATH_SIZE, "%s/%s", base, dent->d_name);
210                         dir2 = opendir(dirname);
211                         if (dir2 != NULL) {
212                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
213                                         char dirname2[MAX_PATH_SIZE];
214
215                                         if (dent2->d_name[0] == '.')
216                                                 continue;
217
218                                         snprintf(dirname2, MAX_PATH_SIZE, "%s/%s", dirname, dent2->d_name);
219                                         dirname2[MAX_PATH_SIZE-1] = '\0';
220
221                                         if (has_devt(dirname2))
222                                                 device_list_insert(dirname2, "block", &device_list);
223                                 }
224                                 closedir(dir2);
225                         }
226                 }
227                 closedir(dir);
228         }
229
230         exec_list(&device_list);
231 }
232
233 static void udev_scan_class(void)
234 {
235         char base[MAX_PATH_SIZE];
236         DIR *dir;
237         struct dirent *dent;
238         LIST_HEAD(device_list);
239
240         snprintf(base, MAX_PATH_SIZE, "%s/class", sysfs_path);
241         base[MAX_PATH_SIZE-1] = '\0';
242
243         dir = opendir(base);
244         if (dir != NULL) {
245                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
246                         char dirname[MAX_PATH_SIZE];
247                         DIR *dir2;
248                         struct dirent *dent2;
249
250                         if (dent->d_name[0] == '.')
251                                 continue;
252
253                         snprintf(dirname, MAX_PATH_SIZE, "%s/%s", base, dent->d_name);
254                         dirname[MAX_PATH_SIZE-1] = '\0';
255                         dir2 = opendir(dirname);
256                         if (dir2 != NULL) {
257                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
258                                         char dirname2[MAX_PATH_SIZE];
259
260                                         if (dent2->d_name[0] == '.')
261                                                 continue;
262
263                                         snprintf(dirname2, MAX_PATH_SIZE, "%s/%s", dirname, dent2->d_name);
264                                         dirname2[MAX_PATH_SIZE-1] = '\0';
265
266                                         /* pass the net class as it is */
267                                         if (strcmp(dent->d_name, "net") == 0)
268                                                 device_list_insert(dirname2, "net", &device_list);
269                                         else if (has_devt(dirname2))
270                                                 device_list_insert(dirname2, dent->d_name, &device_list);
271                                 }
272                                 closedir(dir2);
273                         }
274                 }
275                 closedir(dir);
276         }
277
278         exec_list(&device_list);
279 }
280
281 int udev_start(void)
282 {
283         /* set environment for callouts and dev.d/ */
284         setenv("ACTION", "add", 1);
285         setenv("UDEV_START", "1", 1);
286
287         udev_scan_class();
288         udev_scan_block();
289
290         return 0;
291 }