2 * libudev - interface to udev device information
4 * Copyright (C) 2003-2009 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.
23 #include <sys/param.h>
26 #include "libudev-private.h"
28 int util_create_path(struct udev *udev, const char *path)
30 char p[UTIL_PATH_SIZE];
35 util_strscpy(p, sizeof(p), path);
36 pos = strrchr(p, '/');
39 while (pos != p && pos[-1] == '/')
45 dbg(udev, "stat '%s'\n", p);
46 if (stat(p, &stats) == 0) {
47 if ((stats.st_mode & S_IFMT) == S_IFDIR)
53 err = util_create_path(udev, p);
57 dbg(udev, "mkdir '%s'\n", p);
58 udev_selinux_setfscreatecon(udev, p, S_IFDIR|0755);
62 if (err == -EEXIST && stat(p, &stats) == 0) {
63 if ((stats.st_mode & S_IFMT) == S_IFDIR)
69 udev_selinux_resetfscreatecon(udev);
73 int util_delete_path(struct udev *udev, const char *path)
75 char p[UTIL_PATH_SIZE];
82 util_strscpy(p, sizeof(p), path);
83 pos = strrchr(p, '/');
84 if (pos == p || pos == NULL)
89 pos = strrchr(p, '/');
91 /* don't remove the last one */
92 if ((pos == p) || (pos == NULL))
105 /* Reset permissions on the device node, before unlinking it to make sure,
106 * that permissions of possible hard links will be removed too.
108 int util_unlink_secure(struct udev *udev, const char *filename)
112 chown(filename, 0, 0);
113 chmod(filename, 0000);
114 err = unlink(filename);
118 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')
137 errno = getpwnam_r(user, &pwbuf, buf, buflen, &pw);
140 if (errno == 0 || errno == ENOENT || errno == ESRCH)
141 err(udev, "specified user '%s' unknown\n", user);
143 err(udev, "error resolving user '%s': %m\n", user);
147 gid_t util_lookup_group(struct udev *udev, const char *group)
150 int buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
156 if (strcmp(group, "root") == 0)
158 gid = strtoul(group, &endptr, 10);
159 if (endptr[0] == '\0')
166 newbuf = realloc(buf, buflen);
170 errno = getgrnam_r(group, &grbuf, buf, buflen, &gr);
173 } else if (errno == ERANGE) {
176 } else if (errno == 0 || errno == ENOENT || errno == ESRCH) {
177 err(udev, "specified group '%s' unknown\n", group);
179 err(udev, "error resolving group '%s': %m\n", group);
187 /* handle "[<SUBSYSTEM>/<KERNEL>]<attribute>" format */
188 int util_resolve_subsys_kernel(struct udev *udev, const char *string,
189 char *result, size_t maxsize, int read_value)
191 char temp[UTIL_PATH_SIZE];
194 struct udev_device *dev;
197 if (string[0] != '[')
200 util_strscpy(temp, sizeof(temp), string);
204 sysname = strchr(subsys, '/');
208 sysname = &sysname[1];
210 attr = strchr(sysname, ']');
220 if (read_value && attr == NULL)
223 dev = udev_device_new_from_subsystem_sysname(udev, subsys, sysname);
230 val = udev_device_get_sysattr_value(dev, attr);
232 util_strscpy(result, maxsize, val);
235 info(udev, "value '[%s/%s]%s' is '%s'\n", subsys, sysname, attr, result);
241 l = util_strpcpyl(&s, maxsize, udev_device_get_syspath(dev), NULL);
243 util_strpcpyl(&s, l, "/", attr, NULL);
244 info(udev, "path '[%s/%s]%s' is '%s'\n", subsys, sysname, attr, result);
246 udev_device_unref(dev);
250 int util_run_program(struct udev *udev, const char *command, char **envp,
251 char *result, size_t ressize, size_t *reslen,
252 const sigset_t *sigmask, bool reset_prio)
255 int outpipe[2] = {-1, -1};
256 int errpipe[2] = {-1, -1};
258 char arg[UTIL_PATH_SIZE];
259 char program[UTIL_PATH_SIZE];
260 char *argv[((sizeof(arg) + 1) / 2) + 1];
265 info(udev, "'%s' started\n", command);
267 /* build argv from command */
268 util_strscpy(arg, sizeof(arg), command);
270 if (strchr(arg, ' ') != NULL) {
273 while (pos != NULL && pos[0] != '\0') {
274 if (pos[0] == '\'') {
275 /* do not separate quotes */
277 argv[i] = strsep(&pos, "\'");
279 while (pos[0] == ' ')
282 argv[i] = strsep(&pos, " ");
284 while (pos[0] == ' ')
287 dbg(udev, "arg[%i] '%s'\n", i, argv[i]);
296 /* prepare pipes from child to parent */
297 if (result != NULL || udev_get_log_priority(udev) >= LOG_INFO) {
298 if (pipe(outpipe) != 0) {
299 err(udev, "pipe failed: %m\n");
303 if (udev_get_log_priority(udev) >= LOG_INFO) {
304 if (pipe(errpipe) != 0) {
305 err(udev, "pipe failed: %m\n");
310 /* allow programs in /lib/udev/ to be called without the path */
311 if (argv[0][0] != '/') {
312 util_strscpyl(program, sizeof(program), LIBEXECDIR "/", argv[0], NULL);
319 /* child closes parent ends of pipes */
320 if (outpipe[READ_END] > 0)
321 close(outpipe[READ_END]);
322 if (errpipe[READ_END] > 0)
323 close(errpipe[READ_END]);
325 /* discard child output or connect to pipe */
326 devnull = open("/dev/null", O_RDWR);
328 dup2(devnull, STDIN_FILENO);
329 if (outpipe[WRITE_END] < 0)
330 dup2(devnull, STDOUT_FILENO);
331 if (errpipe[WRITE_END] < 0)
332 dup2(devnull, STDERR_FILENO);
335 err(udev, "open /dev/null failed: %m\n");
336 if (outpipe[WRITE_END] > 0) {
337 dup2(outpipe[WRITE_END], STDOUT_FILENO);
338 close(outpipe[WRITE_END]);
340 if (errpipe[WRITE_END] > 0) {
341 dup2(errpipe[WRITE_END], STDERR_FILENO);
342 close(errpipe[WRITE_END]);
346 sigprocmask(SIG_SETMASK, sigmask, NULL);
348 setpriority(PRIO_PROCESS, 0, 0);
350 execve(argv[0], argv, envp);
351 if (errno == ENOENT || errno == ENOTDIR) {
352 /* may be on a filesystem which is not mounted right now */
353 info(udev, "program '%s' not found\n", argv[0]);
356 err(udev, "exec of program '%s' failed\n", argv[0]);
360 err(udev, "fork of '%s' failed: %m\n", argv[0]);
363 /* read from child if requested */
364 if (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {
368 /* parent closes child ends of pipes */
369 if (outpipe[WRITE_END] > 0)
370 close(outpipe[WRITE_END]);
371 if (errpipe[WRITE_END] > 0)
372 close(errpipe[WRITE_END]);
374 /* read child output */
375 while (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {
380 if (outpipe[READ_END] > 0)
381 FD_SET(outpipe[READ_END], &readfds);
382 if (errpipe[READ_END] > 0)
383 FD_SET(errpipe[READ_END], &readfds);
384 fdcount = select(MAX(outpipe[READ_END], errpipe[READ_END])+1, &readfds, NULL, NULL, NULL);
393 if (outpipe[READ_END] > 0 && FD_ISSET(outpipe[READ_END], &readfds)) {
398 count = read(outpipe[READ_END], inbuf, sizeof(inbuf)-1);
400 close(outpipe[READ_END]);
401 outpipe[READ_END] = -1;
403 err(udev, "stdin read failed: %m\n");
410 /* store result for rule processing */
412 if (respos + count < ressize) {
413 memcpy(&result[respos], inbuf, count);
416 err(udev, "ressize %ld too short\n", (long)ressize);
421 while ((line = strsep(&pos, "\n")))
422 if (pos || line[0] != '\0')
423 info(udev, "'%s' (stdout) '%s'\n", argv[0], line);
427 if (errpipe[READ_END] > 0 && FD_ISSET(errpipe[READ_END], &readfds)) {
432 count = read(errpipe[READ_END], errbuf, sizeof(errbuf)-1);
434 close(errpipe[READ_END]);
435 errpipe[READ_END] = -1;
437 err(udev, "stderr read failed: %m\n");
440 errbuf[count] = '\0';
442 while ((line = strsep(&pos, "\n")))
443 if (pos || line[0] != '\0')
444 info(udev, "'%s' (stderr) '%s'\n", argv[0], line);
447 if (outpipe[READ_END] > 0)
448 close(outpipe[READ_END]);
449 if (errpipe[READ_END] > 0)
450 close(errpipe[READ_END]);
452 /* return the child's stdout string */
454 result[respos] = '\0';
455 dbg(udev, "result='%s'\n", result);
460 waitpid(pid, &status, 0);
461 if (WIFEXITED(status)) {
462 info(udev, "'%s' returned with exitcode %i\n", command, WEXITSTATUS(status));
463 if (WEXITSTATUS(status) != 0)
466 err(udev, "'%s' unexpected exit with status 0x%04x\n", command, status);