jail: Add MS_NODEV MS_NOEXEC MS_NOSUID mount options where needed
[project/procd.git] / plug / udevtrigger.c
1 /*
2 * Copyright (C) 2004-2006 Kay Sievers <kay@vrfy.org>
3 * Copyright (C) 2006 Hannes Reinecke <hare@suse.de>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation version 2 of the License.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
17 *
18 */
19
20 #include <stdlib.h>
21 #include <stddef.h>
22 #include <stdarg.h>
23 #include <stdio.h>
24 #include <stdbool.h>
25 #include <unistd.h>
26 #include <getopt.h>
27 #include <errno.h>
28 #include <dirent.h>
29 #include <fcntl.h>
30 #include <syslog.h>
31 #include <sys/stat.h>
32 #include <sys/types.h>
33 #include <string.h>
34
35 #define PATH_SIZE 512
36
37 #ifndef strlcpy
38 #define strlcpy(d,s,l) (strncpy(d,s,l), (d)[(l)-1] = '\0')
39 #endif
40
41 #ifndef strlcat
42 #define strlcat(d,s,l) strncat(d,s,(l)-strlen(d)-1)
43 #endif
44
45 static int verbose;
46 static int dry_run;
47
48 static void log_message(int priority, const char *format, ...)
49 {
50 va_list args;
51
52 va_start(args, format);
53 vsyslog(priority, format, args);
54 va_end(args);
55 }
56
57 #undef err
58 #define err(format, arg...) \
59 do { \
60 log_message(LOG_ERR ,"%s: " format ,__FUNCTION__ ,## arg); \
61 } while (0)
62
63 #undef info
64 #define info(format, arg...) \
65 do { \
66 log_message(LOG_INFO ,"%s: " format ,__FUNCTION__ ,## arg); \
67 } while (0)
68
69 #ifdef DEBUG
70 #undef dbg
71 #define dbg(format, arg...) \
72 do { \
73 log_message(LOG_DEBUG ,"%s: " format ,__FUNCTION__ ,## arg); \
74 } while (0)
75 #else
76 #define dbg(...) do {} while(0)
77 #endif
78
79
80 static void trigger_uevent(const char *devpath)
81 {
82 char filename[PATH_SIZE];
83 int fd;
84
85 strlcpy(filename, "/sys", sizeof(filename));
86 strlcat(filename, devpath, sizeof(filename));
87 strlcat(filename, "/uevent", sizeof(filename));
88
89 if (verbose)
90 printf("%s\n", devpath);
91
92 if (dry_run)
93 return;
94
95 fd = open(filename, O_WRONLY);
96 if (fd < 0) {
97 dbg("error on opening %s: %s\n", filename, strerror(errno));
98 return;
99 }
100
101 if (write(fd, "add", 3) < 0)
102 info("error on triggering %s: %s\n", filename, strerror(errno));
103
104 close(fd);
105 }
106
107 static int sysfs_resolve_link(char *devpath, size_t size)
108 {
109 char link_path[PATH_SIZE];
110 char link_target[PATH_SIZE];
111 int len;
112 int i;
113 int back;
114
115 strlcpy(link_path, "/sys", sizeof(link_path));
116 strlcat(link_path, devpath, sizeof(link_path));
117 len = readlink(link_path, link_target, sizeof(link_target));
118 if (len <= 0)
119 return -1;
120 link_target[len] = '\0';
121 dbg("path link '%s' points to '%s'", devpath, link_target);
122
123 for (back = 0; strncmp(&link_target[back * 3], "../", 3) == 0; back++)
124 ;
125 dbg("base '%s', tail '%s', back %i", devpath, &link_target[back * 3], back);
126 for (i = 0; i <= back; i++) {
127 char *pos = strrchr(devpath, '/');
128
129 if (pos == NULL)
130 return -1;
131 pos[0] = '\0';
132 }
133 dbg("after moving back '%s'", devpath);
134 strlcat(devpath, "/", size);
135 strlcat(devpath, &link_target[back * 3], size);
136 return 0;
137 }
138
139 static bool device_has_attribute(const char *path, const char *attr,
140 mode_t mode)
141 {
142 char filename[PATH_SIZE];
143 struct stat statbuf;
144
145 strlcpy(filename, path, sizeof(filename));
146 strlcat(filename, attr, sizeof(filename));
147
148 if (stat(filename, &statbuf) < 0)
149 return false;
150
151 if (!(statbuf.st_mode & mode))
152 return false;
153
154 return true;
155 }
156
157 static int device_list_insert(const char *path)
158 {
159 char devpath[PATH_SIZE];
160 struct stat statbuf;
161
162 dbg("add '%s'" , path);
163
164 /* we only have a device, if we have a dev and an uevent file */
165 if (!device_has_attribute(path, "/dev", S_IRUSR) ||
166 !device_has_attribute(path, "/uevent", S_IWUSR))
167 return -1;
168
169 strlcpy(devpath, &path[4], sizeof(devpath));
170
171 /* resolve possible link to real target */
172 if (lstat(path, &statbuf) < 0)
173 return -1;
174 if (S_ISLNK(statbuf.st_mode))
175 if (sysfs_resolve_link(devpath, sizeof(devpath)) != 0)
176 return -1;
177
178 trigger_uevent(devpath);
179 return 0;
180 }
181
182 static void scan_subdir(const char *base, const char *subdir,
183 bool insert, int depth)
184 {
185 DIR *dir;
186 struct dirent *dent;
187
188 dir = opendir(base);
189 if (dir == NULL)
190 return;
191
192 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
193 char dirname[PATH_SIZE];
194
195 if (dent->d_name[0] == '.')
196 continue;
197
198 strlcpy(dirname, base, sizeof(dirname));
199 strlcat(dirname, "/", sizeof(dirname));
200 strlcat(dirname, dent->d_name, sizeof(dirname));
201
202 if (insert) {
203 int err;
204
205 err = device_list_insert(dirname);
206 if (err)
207 continue;
208 }
209
210 if (subdir)
211 strlcat(dirname, subdir, sizeof(base));
212
213 if (depth)
214 scan_subdir(dirname, NULL, true, depth - 1);
215 }
216
217 closedir(dir);
218 }
219
220 int main(int argc, char *argv[], char *envp[])
221 {
222 struct stat statbuf;
223 int option;
224
225 openlog("udevtrigger", LOG_PID | LOG_CONS, LOG_DAEMON);
226
227 while (1) {
228 option = getopt(argc, argv, "vnh");
229 if (option == -1)
230 break;
231
232 switch (option) {
233 case 'v':
234 verbose = 1;
235 break;
236 case 'n':
237 dry_run = 1;
238 break;
239 case 'h':
240 printf("Usage: udevtrigger OPTIONS\n"
241 " -v print the list of devices while running\n"
242 " -n do not actually trigger the events\n"
243 " -h print this text\n"
244 "\n");
245 goto exit;
246 default:
247 goto exit;
248 }
249 }
250
251
252 /* if we have /sys/subsystem, forget all the old stuff */
253 scan_subdir("/sys/bus", "/devices", false, 1);
254 scan_subdir("/sys/class", NULL, false, 1);
255
256 /* scan "block" if it isn't a "class" */
257 if (stat("/sys/class/block", &statbuf) != 0)
258 scan_subdir("/sys/block", NULL, true, 1);
259
260 exit:
261
262 closelog();
263 return 0;
264 }