[thirdparty/systemd.git] / udev / udev-util.c

/*
 * Copyright (C) 2004-2008 Kay Sievers <kay.sievers@vrfy.org>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdlib.h>
#include <stdio.h>
#include <stddef.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <ctype.h>
#include <pwd.h>
#include <grp.h>
#include <sys/wait.h>

#include "udev.h"

int util_create_path(struct udev *udev, const char *path)
{
	char p[UTIL_PATH_SIZE];
	char *pos;
	struct stat stats;
	int ret;

	util_strlcpy(p, path, sizeof(p));
	pos = strrchr(p, '/');
	if (pos == p || pos == NULL)
		return 0;

	while (pos[-1] == '/')
		pos--;
	pos[0] = '\0';

	dbg(udev, "stat '%s'\n", p);
	if (stat(p, &stats) == 0 && (stats.st_mode & S_IFMT) == S_IFDIR)
		return 0;

	if (util_create_path(udev, p) != 0)
		return -1;

	dbg(udev, "mkdir '%s'\n", p);
	udev_selinux_setfscreatecon(udev, p, S_IFDIR|0755);
	ret = mkdir(p, 0755);
	udev_selinux_resetfscreatecon(udev);
	if (ret == 0)
		return 0;

	if (errno == EEXIST)
		if (stat(p, &stats) == 0 && (stats.st_mode & S_IFMT) == S_IFDIR)
			return 0;
	return -1;
}

int util_delete_path(struct udev *udev, const char *path)
{
	char p[UTIL_PATH_SIZE];
	char *pos;
	int retval;

	strcpy (p, path);
	pos = strrchr(p, '/');
	if (pos == p || pos == NULL)
		return 0;

	while (1) {
		*pos = '\0';
		pos = strrchr(p, '/');

		/* don't remove the last one */
		if ((pos == p) || (pos == NULL))
			break;

		/* remove if empty */
		retval = rmdir(p);
		if (errno == ENOENT)
			retval = 0;
		if (retval) {
			if (errno == ENOTEMPTY)
				return 0;
			err(udev, "rmdir(%s) failed: %m\n", p);
			break;
		}
		dbg(udev, "removed '%s'\n", p);
	}
	return 0;
}

/* Reset permissions on the device node, before unlinking it to make sure,
 * that permisions of possible hard links will be removed too.
 */
int util_unlink_secure(struct udev *udev, const char *filename)
{
	int retval;

	retval = chown(filename, 0, 0);
	if (retval)
		err(udev, "chown(%s, 0, 0) failed: %m\n", filename);

	retval = chmod(filename, 0000);
	if (retval)
		err(udev, "chmod(%s, 0000) failed: %m\n", filename);

	retval = unlink(filename);
	if (errno == ENOENT)
		retval = 0;

	if (retval)
		err(udev, "unlink(%s) failed: %m\n", filename);

	return retval;
}

uid_t util_lookup_user(struct udev *udev, const char *user)
{
	char *endptr;
	int buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
	char buf[buflen];
	struct passwd pwbuf;
	struct passwd *pw;
	uid_t uid;

	if (strcmp(user, "root") == 0)
		return 0;
	uid = strtoul(user, &endptr, 10);
	if (endptr[0] == '\0')
		return uid;

	errno = 0;
	getpwnam_r(user, &pwbuf, buf, buflen, &pw);
	if (pw != NULL)
		return pw->pw_uid;
	if (errno == 0 || errno == ENOENT || errno == ESRCH)
		err(udev, "specified user '%s' unknown\n", user);
	else
		err(udev, "error resolving user '%s': %m\n", user);
	return 0;
}

extern gid_t util_lookup_group(struct udev *udev, const char *group)
{
	char *endptr;
	int buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
	char buf[buflen];
	struct group grbuf;
	struct group *gr;
	gid_t gid = 0;

	if (strcmp(group, "root") == 0)
		return 0;
	gid = strtoul(group, &endptr, 10);
	if (endptr[0] == '\0')
		return gid;

	errno = 0;
	getgrnam_r(group, &grbuf, buf, buflen, &gr);
	if (gr != NULL)
		return gr->gr_gid;
	if (errno == 0 || errno == ENOENT || errno == ESRCH)
		err(udev, "specified group '%s' unknown\n", group);
	else
		err(udev, "error resolving group '%s': %m\n", group);
	return 0;
}

/* handle "[<SUBSYSTEM>/<KERNEL>]<attribute>" format */
int util_resolve_subsys_kernel(struct udev *udev, const char *string,
			       char *result, size_t maxsize, int read_value)
{
	char temp[UTIL_PATH_SIZE];
	char *subsys;
	char *sysname;
	struct udev_device *dev;
	char *attr;

	if (string == NULL)
		string = result;
	if (string[0] != '[')
		return -1;

	util_strlcpy(temp, string, sizeof(temp));

	subsys = &temp[1];

	sysname = strchr(subsys, '/');
	if (sysname == NULL)
		return -1;
	sysname[0] = '\0';
	sysname = &sysname[1];

	attr = strchr(sysname, ']');
	if (attr == NULL)
		return -1;
	attr[0] = '\0';
	attr = &attr[1];
	if (attr[0] == '/')
		attr = &attr[1];
	if (attr[0] == '\0')
		attr = NULL;

	if (read_value && attr == NULL)
		return -1;

	dev = udev_device_new_from_subsystem_sysname(udev, subsys, sysname);
	if (dev == NULL)
		return -1;

	if (read_value) {
		const char *val;

		val = udev_device_get_sysattr_value(dev, attr);
		if (val != NULL)
			util_strlcpy(result, val, maxsize);
		else
			result[0] = '\0';
		info(udev, "value '[%s/%s]%s' is '%s'\n", subsys, sysname, attr, result);
	} else {
		util_strlcpy(result, udev_device_get_syspath(dev), maxsize);
		if (attr != NULL) {
			util_strlcat(result, "/", maxsize);
			util_strlcat(result, attr, maxsize);
		}
		info(udev, "path '[%s/%s]%s' is '%s'\n", subsys, sysname, attr, result);
	}
	udev_device_unref(dev);
	return 0;
}

int util_run_program(struct udev *udev, const char *command, char **envp,
		     char *result, size_t ressize, size_t *reslen)
{
	int status;
	int outpipe[2] = {-1, -1};
	int errpipe[2] = {-1, -1};
	pid_t pid;
	char arg[UTIL_PATH_SIZE];
	char program[UTIL_PATH_SIZE];
	char *argv[(sizeof(arg) / 2) + 1];
	int devnull;
	int i;
	int err = 0;

	/* build argv from command */
	util_strlcpy(arg, command, sizeof(arg));
	i = 0;
	if (strchr(arg, ' ') != NULL) {
		char *pos = arg;

		while (pos != NULL && pos[0] != '\0') {
			if (pos[0] == '\'') {
				/* do not separate quotes */
				pos++;
				argv[i] = strsep(&pos, "\'");
				while (pos != NULL && pos[0] == ' ')
					pos++;
			} else {
				argv[i] = strsep(&pos, " ");
			}
			dbg(udev, "arg[%i] '%s'\n", i, argv[i]);
			i++;
		}
		argv[i] = NULL;
	} else {
		argv[0] = arg;
		argv[1] = NULL;
	}
	info(udev, "'%s'\n", command);

	/* prepare pipes from child to parent */
	if (result != NULL || udev_get_log_priority(udev) >= LOG_INFO) {
		if (pipe(outpipe) != 0) {
			err(udev, "pipe failed: %m\n");
			return -1;
		}
	}
	if (udev_get_log_priority(udev) >= LOG_INFO) {
		if (pipe(errpipe) != 0) {
			err(udev, "pipe failed: %m\n");
			return -1;
		}
	}

	/* allow programs in /lib/udev/ to be called without the path */
	if (strchr(argv[0], '/') == NULL) {
		util_strlcpy(program, UDEV_PREFIX "/lib/udev/", sizeof(program));
		util_strlcat(program, argv[0], sizeof(program));
		argv[0] = program;
	}

	pid = fork();
	switch(pid) {
	case 0:
		/* child closes parent ends of pipes */
		if (outpipe[READ_END] > 0)
			close(outpipe[READ_END]);
		if (errpipe[READ_END] > 0)
			close(errpipe[READ_END]);

		/* discard child output or connect to pipe */
		devnull = open("/dev/null", O_RDWR);
		if (devnull > 0) {
			dup2(devnull, STDIN_FILENO);
			if (outpipe[WRITE_END] < 0)
				dup2(devnull, STDOUT_FILENO);
			if (errpipe[WRITE_END] < 0)
				dup2(devnull, STDERR_FILENO);
			close(devnull);
		} else
			err(udev, "open /dev/null failed: %m\n");
		if (outpipe[WRITE_END] > 0) {
			dup2(outpipe[WRITE_END], STDOUT_FILENO);
			close(outpipe[WRITE_END]);
		}
		if (errpipe[WRITE_END] > 0) {
			dup2(errpipe[WRITE_END], STDERR_FILENO);
			close(errpipe[WRITE_END]);
		}
		execve(argv[0], argv, envp);
		if (errno == ENOENT || errno == ENOTDIR) {
			/* may be on a filesytem which is not mounted right now */
			info(udev, "program '%s' not found\n", argv[0]);
		} else {
			/* other problems */
			err(udev, "exec of program '%s' failed\n", argv[0]);
		}
		_exit(1);
	case -1:
		err(udev, "fork of '%s' failed: %m\n", argv[0]);
		return -1;
	default:
		/* read from child if requested */
		if (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {
			ssize_t count;
			size_t respos = 0;

			/* parent closes child ends of pipes */
			if (outpipe[WRITE_END] > 0)
				close(outpipe[WRITE_END]);
			if (errpipe[WRITE_END] > 0)
				close(errpipe[WRITE_END]);

			/* read child output */
			while (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {
				int fdcount;
				fd_set readfds;

				FD_ZERO(&readfds);
				if (outpipe[READ_END] > 0)
					FD_SET(outpipe[READ_END], &readfds);
				if (errpipe[READ_END] > 0)
					FD_SET(errpipe[READ_END], &readfds);
				fdcount = select(UDEV_MAX(outpipe[READ_END], errpipe[READ_END])+1, &readfds, NULL, NULL, NULL);
				if (fdcount < 0) {
					if (errno == EINTR)
						continue;
					err = -1;
					break;
				}

				/* get stdout */
				if (outpipe[READ_END] > 0 && FD_ISSET(outpipe[READ_END], &readfds)) {
					char inbuf[1024];
					char *pos;
					char *line;

					count = read(outpipe[READ_END], inbuf, sizeof(inbuf)-1);
					if (count <= 0) {
						close(outpipe[READ_END]);
						outpipe[READ_END] = -1;
						if (count < 0) {
							err(udev, "stdin read failed: %m\n");
							err = -1;
						}
						continue;
					}
					inbuf[count] = '\0';

					/* store result for rule processing */
					if (result) {
						if (respos + count < ressize) {
							memcpy(&result[respos], inbuf, count);
							respos += count;
						} else {
							err(udev, "ressize %ld too short\n", (long)ressize);
							err = -1;
						}
					}
					pos = inbuf;
					while ((line = strsep(&pos, "\n")))
						if (pos || line[0] != '\0')
							info(udev, "'%s' (stdout) '%s'\n", argv[0], line);
				}

				/* get stderr */
				if (errpipe[READ_END] > 0 && FD_ISSET(errpipe[READ_END], &readfds)) {
					char errbuf[1024];
					char *pos;
					char *line;

					count = read(errpipe[READ_END], errbuf, sizeof(errbuf)-1);
					if (count <= 0) {
						close(errpipe[READ_END]);
						errpipe[READ_END] = -1;
						if (count < 0)
							err(udev, "stderr read failed: %m\n");
						continue;
					}
					errbuf[count] = '\0';
					pos = errbuf;
					while ((line = strsep(&pos, "\n")))
						if (pos || line[0] != '\0')
							info(udev, "'%s' (stderr) '%s'\n", argv[0], line);
				}
			}
			if (outpipe[READ_END] > 0)
				close(outpipe[READ_END]);
			if (errpipe[READ_END] > 0)
				close(errpipe[READ_END]);

			/* return the childs stdout string */
			if (result) {
				result[respos] = '\0';
				dbg(udev, "result='%s'\n", result);
				if (reslen)
					*reslen = respos;
			}
		}
		waitpid(pid, &status, 0);
		if (WIFEXITED(status)) {
			info(udev, "'%s' returned with status %i\n", argv[0], WEXITSTATUS(status));
			if (WEXITSTATUS(status) != 0)
				err = -1;
		} else {
			err(udev, "'%s' abnormal exit\n", command);
			err = -1;
		}
	}
	return err;
}
Commit	Line	Data
c81b35c0	1	/*
55e9959b	2	* Copyright (C) 2004-2008 Kay Sievers <kay.sievers@vrfy.org>
c81b35c0	3	*
55e9959b KS	4	* This program is free software: you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation, either version 2 of the License, or
	7	* (at your option) any later version.
c81b35c0	8	*
55e9959b KS	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program. If not, see <http://www.gnu.org/licenses/>.
c81b35c0 KS	16	*/
c81b35c0 KS	17
c81b35c0 KS	18	#include <stdlib.h>
c81b35c0 KS	19	#include <stdio.h>
4a539daf	20	#include <stddef.h>
c81b35c0	21	#include <unistd.h>
01618658	22	#include <string.h>
c81b35c0	23	#include <fcntl.h>
4a539daf	24	#include <errno.h>
9f8dfa19	25	#include <ctype.h>
3a020a85 KS	26	#include <pwd.h>
3a020a85 KS	27	#include <grp.h>
d0db192f	28	#include <sys/wait.h>
c81b35c0	29
c81b35c0	30	#include "udev.h"
c81b35c0	31
54808d77	32	int util_create_path(struct udev udev, const char path)
4a539daf	33	{
a390e6f7 KS	34	char p[UTIL_PATH_SIZE];
	35	char *pos;
	36	struct stat stats;
	37	int ret;
	38
	39	util_strlcpy(p, path, sizeof(p));
	40	pos = strrchr(p, '/');
	41	if (pos == p \|\| pos == NULL)
	42	return 0;
	43
	44	while (pos[-1] == '/')
	45	pos--;
	46	pos[0] = '\0';
	47
	48	dbg(udev, "stat '%s'\n", p);
	49	if (stat(p, &stats) == 0 && (stats.st_mode & S_IFMT) == S_IFDIR)
	50	return 0;
	51
54808d77	52	if (util_create_path(udev, p) != 0)
a390e6f7 KS	53	return -1;
	54
	55	dbg(udev, "mkdir '%s'\n", p);
	56	udev_selinux_setfscreatecon(udev, p, S_IFDIR\|0755);
	57	ret = mkdir(p, 0755);
	58	udev_selinux_resetfscreatecon(udev);
	59	if (ret == 0)
	60	return 0;
	61
	62	if (errno == EEXIST)
	63	if (stat(p, &stats) == 0 && (stats.st_mode & S_IFMT) == S_IFDIR)
	64	return 0;
	65	return -1;
	66	}
4a539daf	67
54808d77	68	int util_delete_path(struct udev udev, const char path)
a390e6f7 KS	69	{
	70	char p[UTIL_PATH_SIZE];
	71	char *pos;
	72	int retval;
	73
	74	strcpy (p, path);
	75	pos = strrchr(p, '/');
	76	if (pos == p \|\| pos == NULL)
	77	return 0;
	78
	79	while (1) {
	80	*pos = '\0';
	81	pos = strrchr(p, '/');
	82
	83	/* don't remove the last one */
	84	if ((pos == p) \|\| (pos == NULL))
	85	break;
	86
	87	/* remove if empty */
	88	retval = rmdir(p);
	89	if (errno == ENOENT)
	90	retval = 0;
	91	if (retval) {
	92	if (errno == ENOTEMPTY)
	93	return 0;
	94	err(udev, "rmdir(%s) failed: %m\n", p);
	95	break;
b8476286	96	}
a390e6f7 KS	97	dbg(udev, "removed '%s'\n", p);
	98	}
	99	return 0;
b8476286 KS	100	}
b8476286 KS	101
a390e6f7 KS	102	/* Reset permissions on the device node, before unlinking it to make sure,
	103	* that permisions of possible hard links will be removed too.
	104	*/
54808d77	105	int util_unlink_secure(struct udev udev, const char filename)
b8476286	106	{
a390e6f7	107	int retval;
b8476286	108
a390e6f7 KS	109	retval = chown(filename, 0, 0);
	110	if (retval)
	111	err(udev, "chown(%s, 0, 0) failed: %m\n", filename);
f0308095	112
a390e6f7 KS	113	retval = chmod(filename, 0000);
	114	if (retval)
	115	err(udev, "chmod(%s, 0000) failed: %m\n", filename);
4a539daf	116
a390e6f7 KS	117	retval = unlink(filename);
	118	if (errno == ENOENT)
	119	retval = 0;
db6e59df	120
a390e6f7 KS	121	if (retval)
a390e6f7 KS	122	err(udev, "unlink(%s) failed: %m\n", filename);
fb179207	123
a390e6f7	124	return retval;
fb179207 KS	125	}
fb179207 KS	126
54808d77	127	uid_t util_lookup_user(struct udev udev, const char user)
3a020a85	128	{
a391f49d	129	char *endptr;
aaff3d02 AJ	130	int buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
	131	char buf[buflen];
	132	struct passwd pwbuf;
3a020a85	133	struct passwd *pw;
a391f49d	134	uid_t uid;
3a020a85	135
20254eb0 KS	136	if (strcmp(user, "root") == 0)
20254eb0 KS	137	return 0;
90024521 KS	138	uid = strtoul(user, &endptr, 10);
	139	if (endptr[0] == '\0')
	140	return uid;
	141
	142	errno = 0;
	143	getpwnam_r(user, &pwbuf, buf, buflen, &pw);
	144	if (pw != NULL)
	145	return pw->pw_uid;
	146	if (errno == 0 \|\| errno == ENOENT \|\| errno == ESRCH)
	147	err(udev, "specified user '%s' unknown\n", user);
	148	else
	149	err(udev, "error resolving user '%s': %m\n", user);
	150	return 0;
	151	}
3a020a85	152
90024521 KS	153	extern gid_t util_lookup_group(struct udev udev, const char group)
	154	{
	155	char *endptr;
	156	int buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
	157	char buf[buflen];
	158	struct group grbuf;
	159	struct group *gr;
	160	gid_t gid = 0;
3a020a85	161
90024521	162	if (strcmp(group, "root") == 0)
a391f49d	163	return 0;
90024521 KS	164	gid = strtoul(group, &endptr, 10);
	165	if (endptr[0] == '\0')
	166	return gid;
	167
	168	errno = 0;
	169	getgrnam_r(group, &grbuf, buf, buflen, &gr);
	170	if (gr != NULL)
	171	return gr->gr_gid;
	172	if (errno == 0 \|\| errno == ENOENT \|\| errno == ESRCH)
	173	err(udev, "specified group '%s' unknown\n", group);
	174	else
	175	err(udev, "error resolving group '%s': %m\n", group);
	176	return 0;
	177	}
d0db192f	178
14f40256 KS	179	/* handle "[<SUBSYSTEM>/<KERNEL>]<attribute>" format */
	180	int util_resolve_subsys_kernel(struct udev udev, const char string,
	181	char *result, size_t maxsize, int read_value)
	182	{
	183	char temp[UTIL_PATH_SIZE];
	184	char *subsys;
	185	char *sysname;
	186	struct udev_device *dev;
	187	char *attr;
	188
	189	if (string == NULL)
	190	string = result;
	191	if (string[0] != '[')
	192	return -1;
	193
	194	util_strlcpy(temp, string, sizeof(temp));
	195
	196	subsys = &temp[1];
	197
	198	sysname = strchr(subsys, '/');
	199	if (sysname == NULL)
	200	return -1;
	201	sysname[0] = '\0';
	202	sysname = &sysname[1];
	203
	204	attr = strchr(sysname, ']');
	205	if (attr == NULL)
	206	return -1;
	207	attr[0] = '\0';
	208	attr = &attr[1];
	209	if (attr[0] == '/')
	210	attr = &attr[1];
	211	if (attr[0] == '\0')
	212	attr = NULL;
	213
	214	if (read_value && attr == NULL)
	215	return -1;
	216
	217	dev = udev_device_new_from_subsystem_sysname(udev, subsys, sysname);
	218	if (dev == NULL)
	219	return -1;
	220
	221	if (read_value) {
	222	const char *val;
	223
	224	val = udev_device_get_sysattr_value(dev, attr);
	225	if (val != NULL)
	226	util_strlcpy(result, val, maxsize);
	227	else
	228	result[0] = '\0';
	229	info(udev, "value '[%s/%s]%s' is '%s'\n", subsys, sysname, attr, result);
	230	} else {
	231	util_strlcpy(result, udev_device_get_syspath(dev), maxsize);
	232	if (attr != NULL) {
	233	util_strlcat(result, "/", maxsize);
	234	util_strlcat(result, attr, maxsize);
	235	}
	236	info(udev, "path '[%s/%s]%s' is '%s'\n", subsys, sysname, attr, result);
	237	}
	238	udev_device_unref(dev);
	239	return 0;
	240	}
	241
54808d77 KS	242	int util_run_program(struct udev udev, const char command, char **envp,
54808d77 KS	243	char result, size_t ressize, size_t reslen)
d0db192f KS	244	{
	245	int status;
	246	int outpipe[2] = {-1, -1};
	247	int errpipe[2] = {-1, -1};
	248	pid_t pid;
	249	char arg[UTIL_PATH_SIZE];
	250	char program[UTIL_PATH_SIZE];
	251	char *argv[(sizeof(arg) / 2) + 1];
	252	int devnull;
	253	int i;
	254	int err = 0;
	255
	256	/* build argv from command */
	257	util_strlcpy(arg, command, sizeof(arg));
	258	i = 0;
	259	if (strchr(arg, ' ') != NULL) {
	260	char *pos = arg;
	261
	262	while (pos != NULL && pos[0] != '\0') {
	263	if (pos[0] == '\'') {
	264	/* do not separate quotes */
	265	pos++;
	266	argv[i] = strsep(&pos, "\'");
	267	while (pos != NULL && pos[0] == ' ')
	268	pos++;
	269	} else {
	270	argv[i] = strsep(&pos, " ");
	271	}
	272	dbg(udev, "arg[%i] '%s'\n", i, argv[i]);
	273	i++;
	274	}
	275	argv[i] = NULL;
	276	} else {
	277	argv[0] = arg;
	278	argv[1] = NULL;
	279	}
	280	info(udev, "'%s'\n", command);
	281
	282	/* prepare pipes from child to parent */
	283	if (result != NULL \|\| udev_get_log_priority(udev) >= LOG_INFO) {
	284	if (pipe(outpipe) != 0) {
	285	err(udev, "pipe failed: %m\n");
	286	return -1;
	287	}
	288	}
	289	if (udev_get_log_priority(udev) >= LOG_INFO) {
	290	if (pipe(errpipe) != 0) {
	291	err(udev, "pipe failed: %m\n");
	292	return -1;
	293	}
	294	}
	295
	296	/* allow programs in /lib/udev/ to be called without the path */
	297	if (strchr(argv[0], '/') == NULL) {
	298	util_strlcpy(program, UDEV_PREFIX "/lib/udev/", sizeof(program));
	299	util_strlcat(program, argv[0], sizeof(program));
	300	argv[0] = program;
	301	}
	302
	303	pid = fork();
	304	switch(pid) {
	305	case 0:
	306	/* child closes parent ends of pipes */
	307	if (outpipe[READ_END] > 0)
308	close(outpipe[READ_END]);
309	if (errpipe[READ_END] > 0)
310	close(errpipe[READ_END]);
311
312	/* discard child output or connect to pipe */
313	devnull = open("/dev/null", O_RDWR);
314	if (devnull > 0) {
315	dup2(devnull, STDIN_FILENO);
316	if (outpipe[WRITE_END] < 0)
317	dup2(devnull, STDOUT_FILENO);
318	if (errpipe[WRITE_END] < 0)
319	dup2(devnull, STDERR_FILENO);
320	close(devnull);
321	} else
322	err(udev, "open /dev/null failed: %m\n");
323	if (outpipe[WRITE_END] > 0) {
324	dup2(outpipe[WRITE_END], STDOUT_FILENO);
325	close(outpipe[WRITE_END]);
326	}
327	if (errpipe[WRITE_END] > 0) {
328	dup2(errpipe[WRITE_END], STDERR_FILENO);
329	close(errpipe[WRITE_END]);
330	}
331	execve(argv[0], argv, envp);
332	if (errno == ENOENT \|\| errno == ENOTDIR) {
333	/* may be on a filesytem which is not mounted right now */
334	info(udev, "program '%s' not found\n", argv[0]);
335	} else {
336	/* other problems */
337	err(udev, "exec of program '%s' failed\n", argv[0]);
338	}
339	_exit(1);
340	case -1:
341	err(udev, "fork of '%s' failed: %m\n", argv[0]);
342	return -1;
343	default:
344	/* read from child if requested */
345	if (outpipe[READ_END] > 0 \|\| errpipe[READ_END] > 0) {
346	ssize_t count;
347	size_t respos = 0;
348
349	/* parent closes child ends of pipes */
350	if (outpipe[WRITE_END] > 0)
351	close(outpipe[WRITE_END]);
352	if (errpipe[WRITE_END] > 0)
353	close(errpipe[WRITE_END]);
354
355	/* read child output */
356	while (outpipe[READ_END] > 0 \|\| errpipe[READ_END] > 0) {
357	int fdcount;
358	fd_set readfds;
359
360	FD_ZERO(&readfds);
361	if (outpipe[READ_END] > 0)
362	FD_SET(outpipe[READ_END], &readfds);
363	if (errpipe[READ_END] > 0)
364	FD_SET(errpipe[READ_END], &readfds);
365	fdcount = select(UDEV_MAX(outpipe[READ_END], errpipe[READ_END])+1, &readfds, NULL, NULL, NULL);
366	if (fdcount < 0) {
367	if (errno == EINTR)
368	continue;
369	err = -1;
370	break;
371	}
372
373	/* get stdout */
374	if (outpipe[READ_END] > 0 && FD_ISSET(outpipe[READ_END], &readfds)) {
375	char inbuf[1024];
376	char *pos;
377	char *line;
378
379	count = read(outpipe[READ_END], inbuf, sizeof(inbuf)-1);
380	if (count <= 0) {
381	close(outpipe[READ_END]);
382	outpipe[READ_END] = -1;
383	if (count < 0) {
384	err(udev, "stdin read failed: %m\n");
385	err = -1;
386	}
387	continue;
388	}
389	inbuf[count] = '\0';
390
391	/* store result for rule processing */
392	if (result) {
393	if (respos + count < ressize) {
394	memcpy(&result[respos], inbuf, count);
395	respos += count;
396	} else {
397	err(udev, "ressize %ld too short\n", (long)ressize);
398	err = -1;
399	}
400	}
401	pos = inbuf;
402	while ((line = strsep(&pos, "\n")))
403	if (pos \|\| line[0] != '\0')
404	info(udev, "'%s' (stdout) '%s'\n", argv[0], line);
405	}
406
407	/* get stderr */
408	if (errpipe[READ_END] > 0 && FD_ISSET(errpipe[READ_END], &readfds)) {
409	char errbuf[1024];
410	char *pos;
411	char *line;
412
413	count = read(errpipe[READ_END], errbuf, sizeof(errbuf)-1);
414	if (count <= 0) {
415	close(errpipe[READ_END]);
416	errpipe[READ_END] = -1;
417	if (count < 0)
418	err(udev, "stderr read failed: %m\n");
419	continue;
420	}
421	errbuf[count] = '\0';
422	pos = errbuf;
423	while ((line = strsep(&pos, "\n")))
424	if (pos \|\| line[0] != '\0')
425	info(udev, "'%s' (stderr) '%s'\n", argv[0], line);
426	}
427	}
428	if (outpipe[READ_END] > 0)
429	close(outpipe[READ_END]);
430	if (errpipe[READ_END] > 0)
431	close(errpipe[READ_END]);
432
433	/* return the childs stdout string */
434	if (result) {
435	result[respos] = '\0';
436	dbg(udev, "result='%s'\n", result);
437	if (reslen)
438	*reslen = respos;
439	}
440	}
441	waitpid(pid, &status, 0);
442	if (WIFEXITED(status)) {
443	info(udev, "'%s' returned with status %i\n", argv[0], WEXITSTATUS(status));
444	if (WEXITSTATUS(status) != 0)
445	err = -1;
446	} else {
c4e63d54	447	err(udev, "'%s' abnormal exit\n", command);
d0db192f KS	448	err = -1;
	449	}
	450	}
	451	return err;
	452	}