2 * libudev - interface to udev device information
4 * Copyright (C) 2004-2009 Kay Sievers <kay.sievers@vrfy.org>
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
25 #include "libudev-private.h"
27 int util_create_path(struct udev *udev, const char *path)
29 char p[UTIL_PATH_SIZE];
34 util_strscpy(p, sizeof(p), path);
35 pos = strrchr(p, '/');
36 if (pos == p || pos == NULL)
39 while (pos[-1] == '/')
43 dbg(udev, "stat '%s'\n", p);
44 if (stat(p, &stats) == 0 && (stats.st_mode & S_IFMT) == S_IFDIR)
47 if (util_create_path(udev, p) != 0)
50 dbg(udev, "mkdir '%s'\n", p);
51 udev_selinux_setfscreatecon(udev, p, S_IFDIR|0755);
53 udev_selinux_resetfscreatecon(udev);
58 if (stat(p, &stats) == 0 && (stats.st_mode & S_IFMT) == S_IFDIR)
63 int util_delete_path(struct udev *udev, const char *path)
65 char p[UTIL_PATH_SIZE];
70 pos = strrchr(p, '/');
71 if (pos == p || pos == NULL)
76 pos = strrchr(p, '/');
78 /* don't remove the last one */
79 if ((pos == p) || (pos == NULL))
87 if (errno == ENOTEMPTY)
89 err(udev, "rmdir(%s) failed: %m\n", p);
92 dbg(udev, "removed '%s'\n", p);
97 /* Reset permissions on the device node, before unlinking it to make sure,
98 * that permisions of possible hard links will be removed too.
100 int util_unlink_secure(struct udev *udev, const char *filename)
104 retval = chown(filename, 0, 0);
106 err(udev, "chown(%s, 0, 0) failed: %m\n", filename);
108 retval = chmod(filename, 0000);
110 err(udev, "chmod(%s, 0000) failed: %m\n", filename);
112 retval = unlink(filename);
117 err(udev, "unlink(%s) failed: %m\n", filename);
122 uid_t util_lookup_user(struct udev *udev, const char *user)
125 int buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
131 if (strcmp(user, "root") == 0)
133 uid = strtoul(user, &endptr, 10);
134 if (endptr[0] == '\0')
138 getpwnam_r(user, &pwbuf, buf, buflen, &pw);
141 if (errno == 0 || errno == ENOENT || errno == ESRCH)
142 err(udev, "specified user '%s' unknown\n", user);
144 err(udev, "error resolving user '%s': %m\n", user);
148 gid_t util_lookup_group(struct udev *udev, const char *group)
151 int buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
157 if (strcmp(group, "root") == 0)
159 gid = strtoul(group, &endptr, 10);
160 if (endptr[0] == '\0')
164 getgrnam_r(group, &grbuf, buf, buflen, &gr);
167 if (errno == 0 || errno == ENOENT || errno == ESRCH)
168 err(udev, "specified group '%s' unknown\n", group);
170 err(udev, "error resolving group '%s': %m\n", group);
174 /* handle "[<SUBSYSTEM>/<KERNEL>]<attribute>" format */
175 int util_resolve_subsys_kernel(struct udev *udev, const char *string,
176 char *result, size_t maxsize, int read_value)
178 char temp[UTIL_PATH_SIZE];
181 struct udev_device *dev;
184 if (string[0] != '[')
187 util_strscpy(temp, sizeof(temp), string);
191 sysname = strchr(subsys, '/');
195 sysname = &sysname[1];
197 attr = strchr(sysname, ']');
207 if (read_value && attr == NULL)
210 dev = udev_device_new_from_subsystem_sysname(udev, subsys, sysname);
217 val = udev_device_get_sysattr_value(dev, attr);
219 util_strscpy(result, maxsize, val);
222 info(udev, "value '[%s/%s]%s' is '%s'\n", subsys, sysname, attr, result);
228 l = util_strpcpyl(&s, maxsize, udev_device_get_syspath(dev), NULL);
230 util_strpcpyl(&s, l, "/", attr, NULL);
231 info(udev, "path '[%s/%s]%s' is '%s'\n", subsys, sysname, attr, result);
233 udev_device_unref(dev);
237 int util_run_program(struct udev *udev, const char *command, char **envp,
238 char *result, size_t ressize, size_t *reslen)
241 int outpipe[2] = {-1, -1};
242 int errpipe[2] = {-1, -1};
244 char arg[UTIL_PATH_SIZE];
245 char program[UTIL_PATH_SIZE];
246 char *argv[(sizeof(arg) / 2) + 1];
251 /* build argv from command */
252 util_strscpy(arg, sizeof(arg), command);
254 if (strchr(arg, ' ') != NULL) {
257 while (pos != NULL && pos[0] != '\0') {
258 if (pos[0] == '\'') {
259 /* do not separate quotes */
261 argv[i] = strsep(&pos, "\'");
262 while (pos != NULL && pos[0] == ' ')
265 argv[i] = strsep(&pos, " ");
267 dbg(udev, "arg[%i] '%s'\n", i, argv[i]);
275 info(udev, "'%s'\n", command);
277 /* prepare pipes from child to parent */
278 if (result != NULL || udev_get_log_priority(udev) >= LOG_INFO) {
279 if (pipe(outpipe) != 0) {
280 err(udev, "pipe failed: %m\n");
284 if (udev_get_log_priority(udev) >= LOG_INFO) {
285 if (pipe(errpipe) != 0) {
286 err(udev, "pipe failed: %m\n");
291 /* allow programs in /lib/udev/ to be called without the path */
292 if (argv[0][0] != '/') {
293 util_strscpyl(program, sizeof(program), LIBEXECDIR "/", argv[0], NULL);
300 /* child closes parent ends of pipes */
301 if (outpipe[READ_END] > 0)
302 close(outpipe[READ_END]);
303 if (errpipe[READ_END] > 0)
304 close(errpipe[READ_END]);
306 /* discard child output or connect to pipe */
307 devnull = open("/dev/null", O_RDWR);
309 dup2(devnull, STDIN_FILENO);
310 if (outpipe[WRITE_END] < 0)
311 dup2(devnull, STDOUT_FILENO);
312 if (errpipe[WRITE_END] < 0)
313 dup2(devnull, STDERR_FILENO);
316 err(udev, "open /dev/null failed: %m\n");
317 if (outpipe[WRITE_END] > 0) {
318 dup2(outpipe[WRITE_END], STDOUT_FILENO);
319 close(outpipe[WRITE_END]);
321 if (errpipe[WRITE_END] > 0) {
322 dup2(errpipe[WRITE_END], STDERR_FILENO);
323 close(errpipe[WRITE_END]);
325 execve(argv[0], argv, envp);
326 if (errno == ENOENT || errno == ENOTDIR) {
327 /* may be on a filesytem which is not mounted right now */
328 info(udev, "program '%s' not found\n", argv[0]);
331 err(udev, "exec of program '%s' failed\n", argv[0]);
335 err(udev, "fork of '%s' failed: %m\n", argv[0]);
338 /* read from child if requested */
339 if (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {
343 /* parent closes child ends of pipes */
344 if (outpipe[WRITE_END] > 0)
345 close(outpipe[WRITE_END]);
346 if (errpipe[WRITE_END] > 0)
347 close(errpipe[WRITE_END]);
349 /* read child output */
350 while (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {
355 if (outpipe[READ_END] > 0)
356 FD_SET(outpipe[READ_END], &readfds);
357 if (errpipe[READ_END] > 0)
358 FD_SET(errpipe[READ_END], &readfds);
359 fdcount = select(UDEV_MAX(outpipe[READ_END], errpipe[READ_END])+1, &readfds, NULL, NULL, NULL);
368 if (outpipe[READ_END] > 0 && FD_ISSET(outpipe[READ_END], &readfds)) {
373 count = read(outpipe[READ_END], inbuf, sizeof(inbuf)-1);
375 close(outpipe[READ_END]);
376 outpipe[READ_END] = -1;
378 err(udev, "stdin read failed: %m\n");
385 /* store result for rule processing */
387 if (respos + count < ressize) {
388 memcpy(&result[respos], inbuf, count);
391 err(udev, "ressize %ld too short\n", (long)ressize);
396 while ((line = strsep(&pos, "\n")))
397 if (pos || line[0] != '\0')
398 info(udev, "'%s' (stdout) '%s'\n", argv[0], line);
402 if (errpipe[READ_END] > 0 && FD_ISSET(errpipe[READ_END], &readfds)) {
407 count = read(errpipe[READ_END], errbuf, sizeof(errbuf)-1);
409 close(errpipe[READ_END]);
410 errpipe[READ_END] = -1;
412 err(udev, "stderr read failed: %m\n");
415 errbuf[count] = '\0';
417 while ((line = strsep(&pos, "\n")))
418 if (pos || line[0] != '\0')
419 info(udev, "'%s' (stderr) '%s'\n", argv[0], line);
422 if (outpipe[READ_END] > 0)
423 close(outpipe[READ_END]);
424 if (errpipe[READ_END] > 0)
425 close(errpipe[READ_END]);
427 /* return the childs stdout string */
429 result[respos] = '\0';
430 dbg(udev, "result='%s'\n", result);
435 waitpid(pid, &status, 0);
436 if (WIFEXITED(status)) {
437 info(udev, "'%s' returned with status %i\n", argv[0], WEXITSTATUS(status));
438 if (WEXITSTATUS(status) != 0)
441 err(udev, "'%s' abnormal exit\n", command);