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))
100 if (errno == ENOTEMPTY)
102 err(udev, "rmdir(%s) failed: %m\n", p);
105 dbg(udev, "removed '%s'\n", p);
110 /* Reset permissions on the device node, before unlinking it to make sure,
111 * that permissions of possible hard links will be removed too.
113 int util_unlink_secure(struct udev *udev, const char *filename)
117 chown(filename, 0, 0);
118 chmod(filename, 0000);
119 err = unlink(filename);
123 err(udev, "unlink(%s) failed: %m\n", filename);
127 uid_t util_lookup_user(struct udev *udev, const char *user)
130 int buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
136 if (strcmp(user, "root") == 0)
138 uid = strtoul(user, &endptr, 10);
139 if (endptr[0] == '\0')
142 errno = getpwnam_r(user, &pwbuf, buf, buflen, &pw);
145 if (errno == 0 || errno == ENOENT || errno == ESRCH)
146 err(udev, "specified user '%s' unknown\n", user);
148 err(udev, "error resolving user '%s': %m\n", user);
152 gid_t util_lookup_group(struct udev *udev, const char *group)
155 int buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
161 if (strcmp(group, "root") == 0)
163 gid = strtoul(group, &endptr, 10);
164 if (endptr[0] == '\0')
171 newbuf = realloc(buf, buflen);
175 errno = getgrnam_r(group, &grbuf, buf, buflen, &gr);
178 } else if (errno == ERANGE) {
181 } else if (errno == 0 || errno == ENOENT || errno == ESRCH) {
182 err(udev, "specified group '%s' unknown\n", group);
184 err(udev, "error resolving group '%s': %m\n", group);
192 /* handle "[<SUBSYSTEM>/<KERNEL>]<attribute>" format */
193 int util_resolve_subsys_kernel(struct udev *udev, const char *string,
194 char *result, size_t maxsize, int read_value)
196 char temp[UTIL_PATH_SIZE];
199 struct udev_device *dev;
202 if (string[0] != '[')
205 util_strscpy(temp, sizeof(temp), string);
209 sysname = strchr(subsys, '/');
213 sysname = &sysname[1];
215 attr = strchr(sysname, ']');
225 if (read_value && attr == NULL)
228 dev = udev_device_new_from_subsystem_sysname(udev, subsys, sysname);
235 val = udev_device_get_sysattr_value(dev, attr);
237 util_strscpy(result, maxsize, val);
240 info(udev, "value '[%s/%s]%s' is '%s'\n", subsys, sysname, attr, result);
246 l = util_strpcpyl(&s, maxsize, udev_device_get_syspath(dev), NULL);
248 util_strpcpyl(&s, l, "/", attr, NULL);
249 info(udev, "path '[%s/%s]%s' is '%s'\n", subsys, sysname, attr, result);
251 udev_device_unref(dev);
255 int util_run_program(struct udev *udev, const char *command, char **envp,
256 char *result, size_t ressize, size_t *reslen,
257 const sigset_t *sigmask)
260 int outpipe[2] = {-1, -1};
261 int errpipe[2] = {-1, -1};
263 char arg[UTIL_PATH_SIZE];
264 char program[UTIL_PATH_SIZE];
265 char *argv[((sizeof(arg) + 1) / 2) + 1];
270 info(udev, "'%s' started\n", command);
272 /* build argv from command */
273 util_strscpy(arg, sizeof(arg), command);
275 if (strchr(arg, ' ') != NULL) {
278 while (pos != NULL && pos[0] != '\0') {
279 if (pos[0] == '\'') {
280 /* do not separate quotes */
282 argv[i] = strsep(&pos, "\'");
284 while (pos[0] == ' ')
287 argv[i] = strsep(&pos, " ");
289 while (pos[0] == ' ')
292 dbg(udev, "arg[%i] '%s'\n", i, argv[i]);
301 /* prepare pipes from child to parent */
302 if (result != NULL || udev_get_log_priority(udev) >= LOG_INFO) {
303 if (pipe(outpipe) != 0) {
304 err(udev, "pipe failed: %m\n");
308 if (udev_get_log_priority(udev) >= LOG_INFO) {
309 if (pipe(errpipe) != 0) {
310 err(udev, "pipe failed: %m\n");
315 /* allow programs in /lib/udev/ to be called without the path */
316 if (argv[0][0] != '/') {
317 util_strscpyl(program, sizeof(program), LIBEXECDIR "/", argv[0], NULL);
324 /* child closes parent ends of pipes */
325 if (outpipe[READ_END] > 0)
326 close(outpipe[READ_END]);
327 if (errpipe[READ_END] > 0)
328 close(errpipe[READ_END]);
330 /* discard child output or connect to pipe */
331 devnull = open("/dev/null", O_RDWR);
333 dup2(devnull, STDIN_FILENO);
334 if (outpipe[WRITE_END] < 0)
335 dup2(devnull, STDOUT_FILENO);
336 if (errpipe[WRITE_END] < 0)
337 dup2(devnull, STDERR_FILENO);
340 err(udev, "open /dev/null failed: %m\n");
341 if (outpipe[WRITE_END] > 0) {
342 dup2(outpipe[WRITE_END], STDOUT_FILENO);
343 close(outpipe[WRITE_END]);
345 if (errpipe[WRITE_END] > 0) {
346 dup2(errpipe[WRITE_END], STDERR_FILENO);
347 close(errpipe[WRITE_END]);
351 sigprocmask(SIG_SETMASK, sigmask, NULL);
353 execve(argv[0], argv, envp);
354 if (errno == ENOENT || errno == ENOTDIR) {
355 /* may be on a filesystem which is not mounted right now */
356 info(udev, "program '%s' not found\n", argv[0]);
359 err(udev, "exec of program '%s' failed\n", argv[0]);
363 err(udev, "fork of '%s' failed: %m\n", argv[0]);
366 /* read from child if requested */
367 if (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {
371 /* parent closes child ends of pipes */
372 if (outpipe[WRITE_END] > 0)
373 close(outpipe[WRITE_END]);
374 if (errpipe[WRITE_END] > 0)
375 close(errpipe[WRITE_END]);
377 /* read child output */
378 while (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {
383 if (outpipe[READ_END] > 0)
384 FD_SET(outpipe[READ_END], &readfds);
385 if (errpipe[READ_END] > 0)
386 FD_SET(errpipe[READ_END], &readfds);
387 fdcount = select(MAX(outpipe[READ_END], errpipe[READ_END])+1, &readfds, NULL, NULL, NULL);
396 if (outpipe[READ_END] > 0 && FD_ISSET(outpipe[READ_END], &readfds)) {
401 count = read(outpipe[READ_END], inbuf, sizeof(inbuf)-1);
403 close(outpipe[READ_END]);
404 outpipe[READ_END] = -1;
406 err(udev, "stdin read failed: %m\n");
413 /* store result for rule processing */
415 if (respos + count < ressize) {
416 memcpy(&result[respos], inbuf, count);
419 err(udev, "ressize %ld too short\n", (long)ressize);
424 while ((line = strsep(&pos, "\n")))
425 if (pos || line[0] != '\0')
426 info(udev, "'%s' (stdout) '%s'\n", argv[0], line);
430 if (errpipe[READ_END] > 0 && FD_ISSET(errpipe[READ_END], &readfds)) {
435 count = read(errpipe[READ_END], errbuf, sizeof(errbuf)-1);
437 close(errpipe[READ_END]);
438 errpipe[READ_END] = -1;
440 err(udev, "stderr read failed: %m\n");
443 errbuf[count] = '\0';
445 while ((line = strsep(&pos, "\n")))
446 if (pos || line[0] != '\0')
447 info(udev, "'%s' (stderr) '%s'\n", argv[0], line);
450 if (outpipe[READ_END] > 0)
451 close(outpipe[READ_END]);
452 if (errpipe[READ_END] > 0)
453 close(errpipe[READ_END]);
455 /* return the childs stdout string */
457 result[respos] = '\0';
458 dbg(udev, "result='%s'\n", result);
463 waitpid(pid, &status, 0);
464 if (WIFEXITED(status)) {
465 info(udev, "'%s' returned with exitcode %i\n", command, WEXITSTATUS(status));
466 if (WEXITSTATUS(status) != 0)
469 err(udev, "'%s' unexpected exit with status 0x%04x\n", command, status);