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 static int create_path(struct udev *udev, const char *path, bool selinux)
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);
59 udev_selinux_setfscreatecon(udev, p, S_IFDIR|0755);
63 if (err == -EEXIST && stat(p, &stats) == 0) {
64 if ((stats.st_mode & S_IFMT) == S_IFDIR)
71 udev_selinux_resetfscreatecon(udev);
75 int util_create_path(struct udev *udev, const char *path)
77 return create_path(udev, path, false);
80 int util_create_path_selinux(struct udev *udev, const char *path)
82 return create_path(udev, path, true);
85 int util_delete_path(struct udev *udev, const char *path)
87 char p[UTIL_PATH_SIZE];
94 util_strscpy(p, sizeof(p), path);
95 pos = strrchr(p, '/');
96 if (pos == p || pos == NULL)
101 pos = strrchr(p, '/');
103 /* don't remove the last one */
104 if ((pos == p) || (pos == NULL))
117 /* Reset permissions on the device node, before unlinking it to make sure,
118 * that permissions of possible hard links will be removed too.
120 int util_unlink_secure(struct udev *udev, const char *filename)
124 chown(filename, 0, 0);
125 chmod(filename, 0000);
126 err = unlink(filename);
130 err(udev, "unlink(%s) failed: %m\n", filename);
134 uid_t util_lookup_user(struct udev *udev, const char *user)
137 int buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
143 if (strcmp(user, "root") == 0)
145 uid = strtoul(user, &endptr, 10);
146 if (endptr[0] == '\0')
149 errno = getpwnam_r(user, &pwbuf, buf, buflen, &pw);
152 if (errno == 0 || errno == ENOENT || errno == ESRCH)
153 err(udev, "specified user '%s' unknown\n", user);
155 err(udev, "error resolving user '%s': %m\n", user);
159 gid_t util_lookup_group(struct udev *udev, const char *group)
162 int buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
168 if (strcmp(group, "root") == 0)
170 gid = strtoul(group, &endptr, 10);
171 if (endptr[0] == '\0')
178 newbuf = realloc(buf, buflen);
182 errno = getgrnam_r(group, &grbuf, buf, buflen, &gr);
185 } else if (errno == ERANGE) {
188 } else if (errno == 0 || errno == ENOENT || errno == ESRCH) {
189 err(udev, "specified group '%s' unknown\n", group);
191 err(udev, "error resolving group '%s': %m\n", group);
199 /* handle "[<SUBSYSTEM>/<KERNEL>]<attribute>" format */
200 int util_resolve_subsys_kernel(struct udev *udev, const char *string,
201 char *result, size_t maxsize, int read_value)
203 char temp[UTIL_PATH_SIZE];
206 struct udev_device *dev;
209 if (string[0] != '[')
212 util_strscpy(temp, sizeof(temp), string);
216 sysname = strchr(subsys, '/');
220 sysname = &sysname[1];
222 attr = strchr(sysname, ']');
232 if (read_value && attr == NULL)
235 dev = udev_device_new_from_subsystem_sysname(udev, subsys, sysname);
242 val = udev_device_get_sysattr_value(dev, attr);
244 util_strscpy(result, maxsize, val);
247 info(udev, "value '[%s/%s]%s' is '%s'\n", subsys, sysname, attr, result);
253 l = util_strpcpyl(&s, maxsize, udev_device_get_syspath(dev), NULL);
255 util_strpcpyl(&s, l, "/", attr, NULL);
256 info(udev, "path '[%s/%s]%s' is '%s'\n", subsys, sysname, attr, result);
258 udev_device_unref(dev);
262 int util_run_program(struct udev *udev, const char *command, char **envp,
263 char *result, size_t ressize, size_t *reslen,
264 const sigset_t *sigmask, bool reset_prio)
267 int outpipe[2] = {-1, -1};
268 int errpipe[2] = {-1, -1};
270 char arg[UTIL_PATH_SIZE];
271 char program[UTIL_PATH_SIZE];
272 char *argv[((sizeof(arg) + 1) / 2) + 1];
277 info(udev, "'%s' started\n", command);
279 /* build argv from command */
280 util_strscpy(arg, sizeof(arg), command);
282 if (strchr(arg, ' ') != NULL) {
285 while (pos != NULL && pos[0] != '\0') {
286 if (pos[0] == '\'') {
287 /* do not separate quotes */
289 argv[i] = strsep(&pos, "\'");
291 while (pos[0] == ' ')
294 argv[i] = strsep(&pos, " ");
296 while (pos[0] == ' ')
299 dbg(udev, "arg[%i] '%s'\n", i, argv[i]);
308 /* prepare pipes from child to parent */
309 if (result != NULL || udev_get_log_priority(udev) >= LOG_INFO) {
310 if (pipe(outpipe) != 0) {
311 err(udev, "pipe failed: %m\n");
315 if (udev_get_log_priority(udev) >= LOG_INFO) {
316 if (pipe(errpipe) != 0) {
317 err(udev, "pipe failed: %m\n");
322 /* allow programs in /lib/udev/ to be called without the path */
323 if (argv[0][0] != '/') {
324 util_strscpyl(program, sizeof(program), LIBEXECDIR "/", argv[0], NULL);
331 /* child closes parent ends of pipes */
332 if (outpipe[READ_END] > 0)
333 close(outpipe[READ_END]);
334 if (errpipe[READ_END] > 0)
335 close(errpipe[READ_END]);
337 /* discard child output or connect to pipe */
338 devnull = open("/dev/null", O_RDWR);
340 dup2(devnull, STDIN_FILENO);
341 if (outpipe[WRITE_END] < 0)
342 dup2(devnull, STDOUT_FILENO);
343 if (errpipe[WRITE_END] < 0)
344 dup2(devnull, STDERR_FILENO);
347 err(udev, "open /dev/null failed: %m\n");
348 if (outpipe[WRITE_END] > 0) {
349 dup2(outpipe[WRITE_END], STDOUT_FILENO);
350 close(outpipe[WRITE_END]);
352 if (errpipe[WRITE_END] > 0) {
353 dup2(errpipe[WRITE_END], STDERR_FILENO);
354 close(errpipe[WRITE_END]);
358 sigprocmask(SIG_SETMASK, sigmask, NULL);
360 setpriority(PRIO_PROCESS, 0, 0);
362 execve(argv[0], argv, envp);
363 if (errno == ENOENT || errno == ENOTDIR) {
364 /* may be on a filesystem which is not mounted right now */
365 info(udev, "program '%s' not found\n", argv[0]);
368 err(udev, "exec of program '%s' failed\n", argv[0]);
372 err(udev, "fork of '%s' failed: %m\n", argv[0]);
375 /* read from child if requested */
376 if (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {
380 /* parent closes child ends of pipes */
381 if (outpipe[WRITE_END] > 0)
382 close(outpipe[WRITE_END]);
383 if (errpipe[WRITE_END] > 0)
384 close(errpipe[WRITE_END]);
386 /* read child output */
387 while (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {
392 if (outpipe[READ_END] > 0)
393 FD_SET(outpipe[READ_END], &readfds);
394 if (errpipe[READ_END] > 0)
395 FD_SET(errpipe[READ_END], &readfds);
396 fdcount = select(MAX(outpipe[READ_END], errpipe[READ_END])+1, &readfds, NULL, NULL, NULL);
405 if (outpipe[READ_END] > 0 && FD_ISSET(outpipe[READ_END], &readfds)) {
410 count = read(outpipe[READ_END], inbuf, sizeof(inbuf)-1);
412 close(outpipe[READ_END]);
413 outpipe[READ_END] = -1;
415 err(udev, "stdin read failed: %m\n");
422 /* store result for rule processing */
424 if (respos + count < ressize) {
425 memcpy(&result[respos], inbuf, count);
428 err(udev, "ressize %ld too short\n", (long)ressize);
433 while ((line = strsep(&pos, "\n")))
434 if (pos || line[0] != '\0')
435 info(udev, "'%s' (stdout) '%s'\n", argv[0], line);
439 if (errpipe[READ_END] > 0 && FD_ISSET(errpipe[READ_END], &readfds)) {
444 count = read(errpipe[READ_END], errbuf, sizeof(errbuf)-1);
446 close(errpipe[READ_END]);
447 errpipe[READ_END] = -1;
449 err(udev, "stderr read failed: %m\n");
452 errbuf[count] = '\0';
454 while ((line = strsep(&pos, "\n")))
455 if (pos || line[0] != '\0')
456 info(udev, "'%s' (stderr) '%s'\n", argv[0], line);
459 if (outpipe[READ_END] > 0)
460 close(outpipe[READ_END]);
461 if (errpipe[READ_END] > 0)
462 close(errpipe[READ_END]);
464 /* return the child's stdout string */
466 result[respos] = '\0';
467 dbg(udev, "result='%s'\n", result);
472 waitpid(pid, &status, 0);
473 if (WIFEXITED(status)) {
474 info(udev, "'%s' returned with exitcode %i\n", command, WEXITSTATUS(status));
475 if (WEXITSTATUS(status) != 0)
478 err(udev, "'%s' unexpected exit with status 0x%04x\n", command, status);