init/util.c - platform/system/core - Gitiles

 /*
  * Copyright (C) 2008 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include <stdarg.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
 #include <fcntl.h>
 #include <ctype.h>
 #include <errno.h>
 #include <time.h>

 #ifdef HAVE_SELINUX
 #include <selinux/label.h>
 #endif

 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/un.h>

 /* for ANDROID_SOCKET_* */
 #include <cutils/sockets.h>

 #include <private/android_filesystem_config.h>

 #include "init.h"
 #include "log.h"
 #include "util.h"

 /*
  * android_name_to_id - returns the integer uid/gid associated with the given
  * name, or -1U on error.
  */
 static unsigned int android_name_to_id(const char *name)
 {
     const struct android_id_info *info = android_ids;
     unsigned int n;

     for (n = 0; n < android_id_count; n++) {
         if (!strcmp(info[n].name, name))
             return info[n].aid;
     }

     return -1U;
 }

 /*
  * decode_uid - decodes and returns the given string, which can be either the
  * numeric or name representation, into the integer uid or gid. Returns -1U on
  * error.
  */
 unsigned int decode_uid(const char *s)
 {
     unsigned int v;

     if (!s || *s == '\0')
         return -1U;
     if (isalpha(s[0]))
         return android_name_to_id(s);

     errno = 0;
     v = (unsigned int) strtoul(s, 0, 0);
     if (errno)
         return -1U;
     return v;
 }

 /*
  * create_socket - creates a Unix domain socket in ANDROID_SOCKET_DIR
  * ("/dev/socket") as dictated in init.rc. This socket is inherited by the
  * daemon. We communicate the file descriptor's value via the environment
  * variable ANDROID_SOCKET_ENV_PREFIX<name> ("ANDROID_SOCKET_foo").
  */
 int create_socket(const char *name, int type, mode_t perm, uid_t uid, gid_t gid)
 {
     struct sockaddr_un addr;
     int fd, ret;
 #ifdef HAVE_SELINUX
     char *secon;
 #endif

     fd = socket(PF_UNIX, type, 0);
     if (fd < 0) {
         ERROR("Failed to open socket '%s': %s\n", name, strerror(errno));
         return -1;
     }

     memset(&addr, 0 , sizeof(addr));
     addr.sun_family = AF_UNIX;
     snprintf(addr.sun_path, sizeof(addr.sun_path), ANDROID_SOCKET_DIR"/%s",
              name);

     ret = unlink(addr.sun_path);
     if (ret != 0 && errno != ENOENT) {
         ERROR("Failed to unlink old socket '%s': %s\n", name, strerror(errno));
         goto out_close;
     }

 #ifdef HAVE_SELINUX
     secon = NULL;
     if (sehandle) {
         ret = selabel_lookup(sehandle, &secon, addr.sun_path, S_IFSOCK);
         if (ret == 0)
             setfscreatecon(secon);
     }
 #endif

     ret = bind(fd, (struct sockaddr *) &addr, sizeof (addr));
     if (ret) {
         ERROR("Failed to bind socket '%s': %s\n", name, strerror(errno));
         goto out_unlink;
     }

 #ifdef HAVE_SELINUX
     setfscreatecon(NULL);
     freecon(secon);
 #endif

     chown(addr.sun_path, uid, gid);
     chmod(addr.sun_path, perm);

     INFO("Created socket '%s' with mode '%o', user '%d', group '%d'\n",
          addr.sun_path, perm, uid, gid);

     return fd;

 out_unlink:
     unlink(addr.sun_path);
 out_close:
     close(fd);
     return -1;
 }

 /* reads a file, making sure it is terminated with \n \0 */
 void *read_file(const char *fn, unsigned *_sz)
 {
     char *data;
     int sz;
     int fd;
     struct stat sb;

     data = 0;
     fd = open(fn, O_RDONLY);
     if(fd < 0) return 0;

     // for security reasons, disallow world-writable
     // or group-writable files
     if (fstat(fd, &sb) < 0) {
         ERROR("fstat failed for '%s'\n", fn);
         goto oops;
     }
     if ((sb.st_mode & (S_IWGRP | S_IWOTH)) != 0) {
         ERROR("skipping insecure file '%s'\n", fn);
         goto oops;
     }

     sz = lseek(fd, 0, SEEK_END);
     if(sz < 0) goto oops;

     if(lseek(fd, 0, SEEK_SET) != 0) goto oops;

     data = (char*) malloc(sz + 2);
     if(data == 0) goto oops;

     if(read(fd, data, sz) != sz) goto oops;
     close(fd);
     data[sz] = '\n';
     data[sz+1] = 0;
     if(_sz) *_sz = sz;
     return data;

 oops:
     close(fd);
     if(data != 0) free(data);
     return 0;
 }

 #define MAX_MTD_PARTITIONS 16

 static struct {
     char name[16];
     int number;
 } mtd_part_map[MAX_MTD_PARTITIONS];

 static int mtd_part_count = -1;

 static void find_mtd_partitions(void)
 {
     int fd;
     char buf[1024];
     char *pmtdbufp;
     ssize_t pmtdsize;
     int r;

     fd = open("/proc/mtd", O_RDONLY);
     if (fd < 0)
         return;

     buf[sizeof(buf) - 1] = '\0';
     pmtdsize = read(fd, buf, sizeof(buf) - 1);
     pmtdbufp = buf;
     while (pmtdsize > 0) {
         int mtdnum, mtdsize, mtderasesize;
         char mtdname[16];
         mtdname[0] = '\0';
         mtdnum = -1;
         r = sscanf(pmtdbufp, "mtd%d: %x %x %15s",
                    &mtdnum, &mtdsize, &mtderasesize, mtdname);
         if ((r == 4) && (mtdname[0] == '"')) {
             char *x = strchr(mtdname + 1, '"');
             if (x) {
                 *x = 0;
             }
             INFO("mtd partition %d, %s\n", mtdnum, mtdname + 1);
             if (mtd_part_count < MAX_MTD_PARTITIONS) {
                 strcpy(mtd_part_map[mtd_part_count].name, mtdname + 1);
                 mtd_part_map[mtd_part_count].number = mtdnum;
                 mtd_part_count++;
             } else {
                 ERROR("too many mtd partitions\n");
             }
         }
         while (pmtdsize > 0 && *pmtdbufp != '\n') {
             pmtdbufp++;
             pmtdsize--;
         }
         if (pmtdsize > 0) {
             pmtdbufp++;
             pmtdsize--;
         }
     }
     close(fd);
 }

 int mtd_name_to_number(const char *name)
 {
     int n;
     if (mtd_part_count < 0) {
         mtd_part_count = 0;
         find_mtd_partitions();
     }
     for (n = 0; n < mtd_part_count; n++) {
         if (!strcmp(name, mtd_part_map[n].name)) {
             return mtd_part_map[n].number;
         }
     }
     return -1;
 }

 /*
  * gettime() - returns the time in seconds of the system's monotonic clock or
  * zero on error.
  */
 time_t gettime(void)
 {
     struct timespec ts;
     int ret;

     ret = clock_gettime(CLOCK_MONOTONIC, &ts);
     if (ret < 0) {
         ERROR("clock_gettime(CLOCK_MONOTONIC) failed: %s\n", strerror(errno));
         return 0;
     }

     return ts.tv_sec;
 }

 int mkdir_recursive(const char *pathname, mode_t mode)
 {
     char buf[128];
     const char *slash;
     const char *p = pathname;
     int width;
     int ret;
     struct stat info;

     while ((slash = strchr(p, '/')) != NULL) {
         width = slash - pathname;
         p = slash + 1;
         if (width < 0)
             break;
         if (width == 0)
             continue;
         if ((unsigned int)width > sizeof(buf) - 1) {
             ERROR("path too long for mkdir_recursive\n");
             return -1;
         }
         memcpy(buf, pathname, width);
         buf[width] = 0;
         if (stat(buf, &info) != 0) {
             ret = make_dir(buf, mode);
             if (ret && errno != EEXIST)
                 return ret;
         }
     }
     ret = make_dir(pathname, mode);
     if (ret && errno != EEXIST)
         return ret;
     return 0;
 }

 void sanitize(char *s)
 {
     if (!s)
         return;
     while (isalnum(*s))
         s++;
     *s = 0;
 }
 void make_link(const char *oldpath, const char *newpath)
 {
     int ret;
     char buf[256];
     char *slash;
     int width;

     slash = strrchr(newpath, '/');
     if (!slash)
         return;
     width = slash - newpath;
     if (width <= 0 || width > (int)sizeof(buf) - 1)
         return;
     memcpy(buf, newpath, width);
     buf[width] = 0;
     ret = mkdir_recursive(buf, 0755);
     if (ret)
         ERROR("Failed to create directory %s: %s (%d)\n", buf, strerror(errno), errno);

     ret = symlink(oldpath, newpath);
     if (ret && errno != EEXIST)
         ERROR("Failed to symlink %s to %s: %s (%d)\n", oldpath, newpath, strerror(errno), errno);
 }

 void remove_link(const char *oldpath, const char *newpath)
 {
     char path[256];
     ssize_t ret;
     ret = readlink(newpath, path, sizeof(path) - 1);
     if (ret <= 0)
         return;
     path[ret] = 0;
     if (!strcmp(path, oldpath))
         unlink(newpath);
 }

 int wait_for_file(const char *filename, int timeout)
 {
     struct stat info;
     time_t timeout_time = gettime() + timeout;
     int ret = -1;

     while (gettime() < timeout_time && ((ret = stat(filename, &info)) < 0))
         usleep(10000);

     return ret;
 }

 void open_devnull_stdio(void)
 {
     int fd;
     static const char *name = "/dev/__null__";
     if (mknod(name, S_IFCHR | 0600, (1 << 8) | 3) == 0) {
         fd = open(name, O_RDWR);
         unlink(name);
         if (fd >= 0) {
             dup2(fd, 0);
             dup2(fd, 1);
             dup2(fd, 2);
             if (fd > 2) {
                 close(fd);
             }
             return;
         }
     }

     exit(1);
 }

 void get_hardware_name(char *hardware, unsigned int *revision)
 {
     char data[1024];
     int fd, n;
     char *x, *hw, *rev;

     /* Hardware string was provided on kernel command line */
     if (hardware[0])
         return;

     fd = open("/proc/cpuinfo", O_RDONLY);
     if (fd < 0) return;

     n = read(fd, data, 1023);
     close(fd);
     if (n < 0) return;

     data[n] = 0;
     hw = strstr(data, "\nHardware");
     rev = strstr(data, "\nRevision");

     if (hw) {
         x = strstr(hw, ": ");
         if (x) {
             x += 2;
             n = 0;
             while (*x && *x != '\n') {
                 if (!isspace(*x))
                     hardware[n++] = tolower(*x);
                 x++;
                 if (n == 31) break;
             }
             hardware[n] = 0;
         }
     }

     if (rev) {
         x = strstr(rev, ": ");
         if (x) {
             *revision = strtoul(x + 2, 0, 16);
         }
     }
 }

 void import_kernel_cmdline(int in_qemu,
                            void (*import_kernel_nv)(char *name, int in_qemu))
 {
     char cmdline[1024];
     char *ptr;
     int fd;

     fd = open("/proc/cmdline", O_RDONLY);
     if (fd >= 0) {
         int n = read(fd, cmdline, 1023);
         if (n < 0) n = 0;

         /* get rid of trailing newline, it happens */
         if (n > 0 && cmdline[n-1] == '\n') n--;

         cmdline[n] = 0;
         close(fd);
     } else {
         cmdline[0] = 0;
     }

     ptr = cmdline;
     while (ptr && *ptr) {
         char *x = strchr(ptr, ' ');
         if (x != 0) *x++ = 0;
         import_kernel_nv(ptr, in_qemu);
         ptr = x;
     }
 }

 int make_dir(const char *path, mode_t mode)
 {
     int rc;

 #ifdef HAVE_SELINUX
     char *secontext = NULL;

     if (sehandle) {
         selabel_lookup(sehandle, &secontext, path, mode);
         setfscreatecon(secontext);
     }
 #endif

     rc = mkdir(path, mode);

 #ifdef HAVE_SELINUX
     if (secontext) {
         int save_errno = errno;
         freecon(secontext);
         setfscreatecon(NULL);
         errno = save_errno;
     }
 #endif
     return rc;
 }

 int restorecon(const char *pathname)
 {
 #ifdef HAVE_SELINUX
     char *secontext = NULL;
     struct stat sb;
     int i;

     if (is_selinux_enabled() <= 0 || !sehandle)
         return 0;

     if (lstat(pathname, &sb) < 0)
         return -errno;
     if (selabel_lookup(sehandle, &secontext, pathname, sb.st_mode) < 0)
         return -errno;
     if (lsetfilecon(pathname, secontext) < 0) {
         freecon(secontext);
         return -errno;
     }
     freecon(secontext);
 #endif
     return 0;
 }
	/*
	* Copyright (C) 2008 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include <stdarg.h>
	#include <stdlib.h>
	#include <stdio.h>
	#include <string.h>
	#include <fcntl.h>
	#include <ctype.h>
	#include <errno.h>
	#include <time.h>

	#ifdef HAVE_SELINUX
	#include <selinux/label.h>
	#endif

	#include <sys/stat.h>
	#include <sys/types.h>
	#include <sys/socket.h>
	#include <sys/un.h>

	/* for ANDROID_SOCKET_* */
	#include <cutils/sockets.h>

	#include <private/android_filesystem_config.h>

	#include "init.h"
	#include "log.h"
	#include "util.h"

	/*
	* android_name_to_id - returns the integer uid/gid associated with the given
	* name, or -1U on error.
	*/
	static unsigned int android_name_to_id(const char *name)
	{
	const struct android_id_info *info = android_ids;
	unsigned int n;

	for (n = 0; n < android_id_count; n++) {
	if (!strcmp(info[n].name, name))
	return info[n].aid;
	}

	return -1U;
	}

	/*
	* decode_uid - decodes and returns the given string, which can be either the
	* numeric or name representation, into the integer uid or gid. Returns -1U on
	* error.
	*/
	unsigned int decode_uid(const char *s)
	{
	unsigned int v;

	if (!s \|\| *s == '\0')
	return -1U;
	if (isalpha(s[0]))
	return android_name_to_id(s);

	errno = 0;
	v = (unsigned int) strtoul(s, 0, 0);
	if (errno)
	return -1U;
	return v;
	}

	/*
	* create_socket - creates a Unix domain socket in ANDROID_SOCKET_DIR
	* ("/dev/socket") as dictated in init.rc. This socket is inherited by the
	* daemon. We communicate the file descriptor's value via the environment
	* variable ANDROID_SOCKET_ENV_PREFIX<name> ("ANDROID_SOCKET_foo").
	*/
	int create_socket(const char *name, int type, mode_t perm, uid_t uid, gid_t gid)
	{
	struct sockaddr_un addr;
	int fd, ret;
	#ifdef HAVE_SELINUX
	char *secon;
	#endif

	fd = socket(PF_UNIX, type, 0);
	if (fd < 0) {
	ERROR("Failed to open socket '%s': %s\n", name, strerror(errno));
	return -1;
	}

	memset(&addr, 0 , sizeof(addr));
	addr.sun_family = AF_UNIX;
	snprintf(addr.sun_path, sizeof(addr.sun_path), ANDROID_SOCKET_DIR"/%s",
	name);

	ret = unlink(addr.sun_path);
	if (ret != 0 && errno != ENOENT) {
	ERROR("Failed to unlink old socket '%s': %s\n", name, strerror(errno));
	goto out_close;
	}

	#ifdef HAVE_SELINUX
	secon = NULL;
	if (sehandle) {
	ret = selabel_lookup(sehandle, &secon, addr.sun_path, S_IFSOCK);
	if (ret == 0)
	setfscreatecon(secon);
	}
	#endif

	ret = bind(fd, (struct sockaddr *) &addr, sizeof (addr));
	if (ret) {
	ERROR("Failed to bind socket '%s': %s\n", name, strerror(errno));
	goto out_unlink;
	}

	#ifdef HAVE_SELINUX
	setfscreatecon(NULL);
	freecon(secon);
	#endif

	chown(addr.sun_path, uid, gid);
	chmod(addr.sun_path, perm);

	INFO("Created socket '%s' with mode '%o', user '%d', group '%d'\n",
	addr.sun_path, perm, uid, gid);

	return fd;

	out_unlink:
	unlink(addr.sun_path);
	out_close:
	close(fd);
	return -1;
	}

	/* reads a file, making sure it is terminated with \n \0 */
	void read_file(const char fn, unsigned *_sz)
	{
	char *data;
	int sz;
	int fd;
	struct stat sb;

	data = 0;
	fd = open(fn, O_RDONLY);
	if(fd < 0) return 0;

	// for security reasons, disallow world-writable
	// or group-writable files
	if (fstat(fd, &sb) < 0) {
	ERROR("fstat failed for '%s'\n", fn);
	goto oops;
	}
	if ((sb.st_mode & (S_IWGRP \| S_IWOTH)) != 0) {
	ERROR("skipping insecure file '%s'\n", fn);
	goto oops;
	}

	sz = lseek(fd, 0, SEEK_END);
	if(sz < 0) goto oops;

	if(lseek(fd, 0, SEEK_SET) != 0) goto oops;

	data = (char*) malloc(sz + 2);
	if(data == 0) goto oops;

	if(read(fd, data, sz) != sz) goto oops;
	close(fd);
	data[sz] = '\n';
	data[sz+1] = 0;
	if(_sz) *_sz = sz;
	return data;

	oops:
	close(fd);
	if(data != 0) free(data);
	return 0;
	}

	#define MAX_MTD_PARTITIONS 16

	static struct {
	char name[16];
	int number;
	} mtd_part_map[MAX_MTD_PARTITIONS];

	static int mtd_part_count = -1;

	static void find_mtd_partitions(void)
	{
	int fd;
	char buf[1024];
	char *pmtdbufp;
	ssize_t pmtdsize;
	int r;

	fd = open("/proc/mtd", O_RDONLY);
	if (fd < 0)
	return;

	buf[sizeof(buf) - 1] = '\0';
	pmtdsize = read(fd, buf, sizeof(buf) - 1);
	pmtdbufp = buf;
	while (pmtdsize > 0) {
	int mtdnum, mtdsize, mtderasesize;
	char mtdname[16];
	mtdname[0] = '\0';
	mtdnum = -1;
	r = sscanf(pmtdbufp, "mtd%d: %x %x %15s",
	&mtdnum, &mtdsize, &mtderasesize, mtdname);
	if ((r == 4) && (mtdname[0] == '"')) {
	char *x = strchr(mtdname + 1, '"');
	if (x) {
	*x = 0;
	}
	INFO("mtd partition %d, %s\n", mtdnum, mtdname + 1);
	if (mtd_part_count < MAX_MTD_PARTITIONS) {
	strcpy(mtd_part_map[mtd_part_count].name, mtdname + 1);
	mtd_part_map[mtd_part_count].number = mtdnum;
	mtd_part_count++;
	} else {
	ERROR("too many mtd partitions\n");
	}
	}
	while (pmtdsize > 0 && *pmtdbufp != '\n') {
	pmtdbufp++;
	pmtdsize--;
	}
	if (pmtdsize > 0) {
	pmtdbufp++;
	pmtdsize--;
	}
	}
	close(fd);
	}

	int mtd_name_to_number(const char *name)
	{
	int n;
	if (mtd_part_count < 0) {
	mtd_part_count = 0;
	find_mtd_partitions();
	}
	for (n = 0; n < mtd_part_count; n++) {
	if (!strcmp(name, mtd_part_map[n].name)) {
	return mtd_part_map[n].number;
	}
	}
	return -1;
	}

	/*
	* gettime() - returns the time in seconds of the system's monotonic clock or
	* zero on error.
	*/
	time_t gettime(void)
	{
	struct timespec ts;
	int ret;

	ret = clock_gettime(CLOCK_MONOTONIC, &ts);
	if (ret < 0) {
	ERROR("clock_gettime(CLOCK_MONOTONIC) failed: %s\n", strerror(errno));
	return 0;
	}

	return ts.tv_sec;
	}

	int mkdir_recursive(const char *pathname, mode_t mode)
	{
	char buf[128];
	const char *slash;
	const char *p = pathname;
	int width;
	int ret;
	struct stat info;

	while ((slash = strchr(p, '/')) != NULL) {
	width = slash - pathname;
	p = slash + 1;
	if (width < 0)
	break;
	if (width == 0)
	continue;
	if ((unsigned int)width > sizeof(buf) - 1) {
	ERROR("path too long for mkdir_recursive\n");
	return -1;
	}
	memcpy(buf, pathname, width);
	buf[width] = 0;
	if (stat(buf, &info) != 0) {
	ret = make_dir(buf, mode);
	if (ret && errno != EEXIST)
	return ret;
	}
	}
	ret = make_dir(pathname, mode);
	if (ret && errno != EEXIST)
	return ret;
	return 0;
	}

	void sanitize(char *s)
	{
	if (!s)
	return;
	while (isalnum(*s))
	s++;
	*s = 0;
	}
	void make_link(const char oldpath, const char newpath)
	{
	int ret;
	char buf[256];
	char *slash;
	int width;

	slash = strrchr(newpath, '/');
	if (!slash)
	return;
	width = slash - newpath;
	if (width <= 0 \|\| width > (int)sizeof(buf) - 1)
	return;
	memcpy(buf, newpath, width);
	buf[width] = 0;
	ret = mkdir_recursive(buf, 0755);
	if (ret)
	ERROR("Failed to create directory %s: %s (%d)\n", buf, strerror(errno), errno);

	ret = symlink(oldpath, newpath);
	if (ret && errno != EEXIST)
	ERROR("Failed to symlink %s to %s: %s (%d)\n", oldpath, newpath, strerror(errno), errno);
	}

	void remove_link(const char oldpath, const char newpath)
	{
	char path[256];
	ssize_t ret;
	ret = readlink(newpath, path, sizeof(path) - 1);
	if (ret <= 0)
	return;
	path[ret] = 0;
	if (!strcmp(path, oldpath))
	unlink(newpath);
	}

	int wait_for_file(const char *filename, int timeout)
	{
	struct stat info;
	time_t timeout_time = gettime() + timeout;
	int ret = -1;

	while (gettime() < timeout_time && ((ret = stat(filename, &info)) < 0))
	usleep(10000);

	return ret;
	}

	void open_devnull_stdio(void)
	{
	int fd;
	static const char *name = "/dev/__null__";
	if (mknod(name, S_IFCHR \| 0600, (1 << 8) \| 3) == 0) {
	fd = open(name, O_RDWR);
	unlink(name);
	if (fd >= 0) {
	dup2(fd, 0);
	dup2(fd, 1);
	dup2(fd, 2);
	if (fd > 2) {
	close(fd);
	}
	return;
	}
	}

	exit(1);
	}

	void get_hardware_name(char hardware, unsigned int revision)
	{
	char data[1024];
	int fd, n;
	char x, hw, *rev;

	/* Hardware string was provided on kernel command line */
	if (hardware[0])
	return;

	fd = open("/proc/cpuinfo", O_RDONLY);
	if (fd < 0) return;

	n = read(fd, data, 1023);
	close(fd);
	if (n < 0) return;

	data[n] = 0;
	hw = strstr(data, "\nHardware");
	rev = strstr(data, "\nRevision");

	if (hw) {
	x = strstr(hw, ": ");
	if (x) {
	x += 2;
	n = 0;
	while (x && x != '\n') {
	if (!isspace(*x))
	hardware[n++] = tolower(*x);
	x++;
	if (n == 31) break;
	}
	hardware[n] = 0;
	}
	}

	if (rev) {
	x = strstr(rev, ": ");
	if (x) {
	*revision = strtoul(x + 2, 0, 16);
	}
	}
	}

	void import_kernel_cmdline(int in_qemu,
	void (import_kernel_nv)(char name, int in_qemu))
	{
	char cmdline[1024];
	char *ptr;
	int fd;

	fd = open("/proc/cmdline", O_RDONLY);
	if (fd >= 0) {
	int n = read(fd, cmdline, 1023);
	if (n < 0) n = 0;

	/* get rid of trailing newline, it happens */
	if (n > 0 && cmdline[n-1] == '\n') n--;

	cmdline[n] = 0;
	close(fd);
	} else {
	cmdline[0] = 0;
	}

	ptr = cmdline;
	while (ptr && *ptr) {
	char *x = strchr(ptr, ' ');
	if (x != 0) *x++ = 0;
	import_kernel_nv(ptr, in_qemu);
	ptr = x;
	}
	}

	int make_dir(const char *path, mode_t mode)
	{
	int rc;

	#ifdef HAVE_SELINUX
	char *secontext = NULL;

	if (sehandle) {
	selabel_lookup(sehandle, &secontext, path, mode);
	setfscreatecon(secontext);
	}
	#endif

	rc = mkdir(path, mode);

	#ifdef HAVE_SELINUX
	if (secontext) {
	int save_errno = errno;
	freecon(secontext);
	setfscreatecon(NULL);
	errno = save_errno;
	}
	#endif
	return rc;
	}

	int restorecon(const char *pathname)
	{
	#ifdef HAVE_SELINUX
	char *secontext = NULL;
	struct stat sb;
	int i;

	if (is_selinux_enabled() <= 0 \|\| !sehandle)
	return 0;

	if (lstat(pathname, &sb) < 0)
	return -errno;
	if (selabel_lookup(sehandle, &secontext, pathname, sb.st_mode) < 0)
	return -errno;
	if (lsetfilecon(pathname, secontext) < 0) {
	freecon(secontext);
	return -errno;
	}
	freecon(secontext);
	#endif
	return 0;
	}