busybox/miscutils/devfsd.c

/*
	devfsd implementation for busybox

	Copyright (C) 2003 by Tito Ragusa <farmatito@tiscali.it>

	Busybox version is based on some previous work and ideas
	Copyright (C) [2003] by [Matteo Croce] <3297627799@wind.it>

	devfsd.c

	Main file for  devfsd  (devfs daemon for Linux).

    Copyright (C) 1998-2002  Richard Gooch

	devfsd.h

    Header file for  devfsd  (devfs daemon for Linux).

    Copyright (C) 1998-2000  Richard Gooch

	compat_name.c

    Compatibility name file for  devfsd  (build compatibility names).

    Copyright (C) 1998-2002  Richard Gooch

	expression.c

    This code provides Borne Shell-like expression expansion.

    Copyright (C) 1997-1999  Richard Gooch

	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, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

    Richard Gooch may be reached by email at  rgooch@atnf.csiro.au
    The postal address is:
      Richard Gooch, c/o ATNF, P. O. Box 76, Epping, N.S.W., 2121, Australia.
*/

#include "libbb.h"
#include "busybox.h"
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <ctype.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <dirent.h>
#include <fcntl.h>
#include <syslog.h>
#include <signal.h>
#include <regex.h>
#include <errno.h>
#include <sys/sysmacros.h>


/* Various defines taken from linux/major.h */
#define IDE0_MAJOR	3
#define IDE1_MAJOR	22
#define IDE2_MAJOR	33
#define IDE3_MAJOR	34
#define IDE4_MAJOR	56
#define IDE5_MAJOR	57
#define IDE6_MAJOR	88
#define IDE7_MAJOR	89
#define IDE8_MAJOR	90
#define IDE9_MAJOR	91


/* Various defines taken from linux/devfs_fs.h */
#define DEVFSD_PROTOCOL_REVISION_KERNEL  5
#define	DEVFSD_IOCTL_BASE	'd'
/*  These are the various ioctls  */
#define DEVFSDIOC_GET_PROTO_REV         _IOR(DEVFSD_IOCTL_BASE, 0, int)
#define DEVFSDIOC_SET_EVENT_MASK        _IOW(DEVFSD_IOCTL_BASE, 2, int)
#define DEVFSDIOC_RELEASE_EVENT_QUEUE   _IOW(DEVFSD_IOCTL_BASE, 3, int)
#define DEVFSDIOC_SET_CONFIG_DEBUG_MASK _IOW(DEVFSD_IOCTL_BASE, 4, int)
#define DEVFSD_NOTIFY_REGISTERED    0
#define DEVFSD_NOTIFY_UNREGISTERED  1
#define DEVFSD_NOTIFY_ASYNC_OPEN    2
#define DEVFSD_NOTIFY_CLOSE         3
#define DEVFSD_NOTIFY_LOOKUP        4
#define DEVFSD_NOTIFY_CHANGE        5
#define DEVFSD_NOTIFY_CREATE        6
#define DEVFSD_NOTIFY_DELETE        7
#define DEVFS_PATHLEN               1024
/*  Never change this otherwise the binary interface will change   */

struct devfsd_notify_struct
{   /*  Use native C types to ensure same types in kernel and user space     */
    unsigned int type;           /*  DEVFSD_NOTIFY_* value                   */
    unsigned int mode;           /*  Mode of the inode or device entry       */
    unsigned int major;          /*  Major number of device entry            */
    unsigned int minor;          /*  Minor number of device entry            */
    unsigned int uid;            /*  Uid of process, inode or device entry   */
    unsigned int gid;            /*  Gid of process, inode or device entry   */
    unsigned int overrun_count;  /*  Number of lost events                   */
    unsigned int namelen;        /*  Number of characters not including '\0' */
    /*  The device name MUST come last                                       */
    char devname[DEVFS_PATHLEN]; /*  This will be '\0' terminated            */
};

#define BUFFER_SIZE 16384
#define DEVFSD_VERSION "1.3.25"
#define CONFIG_FILE  "/etc/devfsd.conf"
#define MODPROBE 		"/sbin/modprobe"
#define MODPROBE_SWITCH_1 "-k"
#define MODPROBE_SWITCH_2 "-C"
#define CONFIG_MODULES_DEVFS "/etc/modules.devfs"
#define MAX_ARGS     (6 + 1)
#define MAX_SUBEXPR  10
#define STRING_LENGTH 255

/* for get_uid_gid() */
#define UID			0
#define GID			1

/* 	for msg_logger(), do_ioctl(),
	fork_and_execute() */
# define DIE			1
# define NO_DIE			0

/* for dir_operation() */
#define RESTORE		0
#define SERVICE		1
#define READ_CONFIG 2

/*  Update only after changing code to reflect new protocol  */
#define DEVFSD_PROTOCOL_REVISION_DAEMON  5

/*  Compile-time check  */
#if DEVFSD_PROTOCOL_REVISION_KERNEL != DEVFSD_PROTOCOL_REVISION_DAEMON
#error protocol version mismatch. Update your kernel headers
#endif

#define AC_PERMISSIONS				0
#define AC_MODLOAD					1
#define AC_EXECUTE					2
#define AC_MFUNCTION				3	/* not supported by busybox */
#define AC_CFUNCTION				4	/* not supported by busybox */
#define AC_COPY						5
#define AC_IGNORE					6
#define AC_MKOLDCOMPAT				7
#define AC_MKNEWCOMPAT				8
#define AC_RMOLDCOMPAT				9
#define AC_RMNEWCOMPAT				10
#define AC_RESTORE					11


struct permissions_type
{
    mode_t mode;
    uid_t uid;
    gid_t gid;
};

struct execute_type
{
    char *argv[MAX_ARGS + 1];  /*  argv[0] must always be the programme  */
};

struct copy_type
{
    const char *source;
    const char *destination;
};

struct action_type
{
    unsigned int what;
    unsigned int when;
};

struct config_entry_struct
{
    struct action_type action;
    regex_t preg;
    union
    {
	struct permissions_type permissions;
	struct execute_type execute;
	struct copy_type copy;
    }
    u;
    struct config_entry_struct *next;
};

struct get_variable_info
{
    const struct devfsd_notify_struct *info;
    const char *devname;
    char devpath[STRING_LENGTH];
};

static void dir_operation(int , const char * , int,  unsigned long* );
static void service(struct stat statbuf, char *path);
static int st_expr_expand(char *, unsigned, const char *, const char *(*) (const char *, void *), void *);
static const char *get_old_name(const char *, unsigned, char *, unsigned, unsigned);
static int mksymlink (const char *oldpath, const char *newpath);
static void read_config_file (char *path, int optional, unsigned long *event_mask);
static void process_config_line (const char *, unsigned long *);
static int  do_servicing (int, unsigned long);
static void service_name (const struct devfsd_notify_struct *);
static void action_permissions (const struct devfsd_notify_struct *, const struct config_entry_struct *);
static void action_execute (const struct devfsd_notify_struct *, const struct config_entry_struct *,
							const regmatch_t *, unsigned);
#ifdef CONFIG_DEVFSD_MODLOAD
static void action_modload (const struct devfsd_notify_struct *info, const struct config_entry_struct *entry);
#endif
static void action_copy (const struct devfsd_notify_struct *, const struct config_entry_struct *,
						 const regmatch_t *, unsigned);
static void action_compat (const struct devfsd_notify_struct *, unsigned);
static void free_config (void);
static void restore(char *spath, struct stat source_stat, int rootlen);
static int copy_inode (const char *, const struct stat *, mode_t, const char *, const struct stat *);
static mode_t get_mode (const char *);
static void signal_handler (int);
static const char *get_variable (const char *, void *);
static int make_dir_tree (const char *);
static int expand_expression(char *, unsigned, const char *, const char *(*)(const char *, void *), void *,
							 const char *, const regmatch_t *, unsigned );
static void expand_regexp (char *, size_t, const char *, const char *, const regmatch_t *, unsigned );
static const char *expand_variable(	char *, unsigned, unsigned *, const char *,
									const char *(*) (const char *, void *), void * );
static const char *get_variable_v2(const char *, const char *(*) (const char *, void *), void *);
static char get_old_ide_name (unsigned , unsigned);
static char *write_old_sd_name (char *, unsigned, unsigned, char *);

/* busybox functions */
#ifdef CONFIG_DEVFSD_VERBOSE
static void msg_logger(int die, int pri, const char * fmt, ... );
#endif
static void do_ioctl(int die, int fd, int request, unsigned long event_mask_flag);
static void fork_and_execute(int die, char *arg0, char **arg );
static int get_uid_gid ( int, const char *);
static void safe_memcpy( char * dest, const char * src, int len);
static unsigned int scan_dev_name_common(const char *d, unsigned int n, int addendum, char *ptr);
static unsigned int scan_dev_name(const char *d, unsigned int n, char *ptr);

/* Structs and vars */
static struct config_entry_struct *first_config = NULL;
static struct config_entry_struct *last_config = NULL;
static const char *mount_point = NULL;
static volatile int caught_signal = FALSE;
static volatile int caught_sighup = FALSE;
static struct initial_symlink_struct
{
    char *dest;
    char *name;
} initial_symlinks[] =
{
    {"/proc/self/fd", "fd"},
    {"fd/0", "stdin"},
    {"fd/1", "stdout"},
    {"fd/2", "stderr"},
    {NULL, NULL},
};

static struct event_type
{
    unsigned int type;        /*  The DEVFSD_NOTIFY_* value                  */
    const char *config_name;  /*  The name used in the config file           */
} event_types[] =
{
    {DEVFSD_NOTIFY_REGISTERED,   "REGISTER"},
    {DEVFSD_NOTIFY_UNREGISTERED, "UNREGISTER"},
    {DEVFSD_NOTIFY_ASYNC_OPEN,   "ASYNC_OPEN"},
    {DEVFSD_NOTIFY_CLOSE,        "CLOSE"},
    {DEVFSD_NOTIFY_LOOKUP,       "LOOKUP"},
    {DEVFSD_NOTIFY_CHANGE,       "CHANGE"},
    {DEVFSD_NOTIFY_CREATE,       "CREATE"},
    {DEVFSD_NOTIFY_DELETE,       "DELETE"},
    {0xffffffff,                 NULL}
};

/* busybox functions and messages */

extern void xregcomp(regex_t * preg, const char *regex, int cflags);

const char * const bb_msg_proto_rev			= "protocol revision";
#ifdef CONFIG_DEVFSD_VERBOSE
const char * const bb_msg_bad_config   		= "bad %s config file: %s\n";
const char * const bb_msg_small_buffer		= "buffer too small\n";
const char * const bb_msg_variable_not_found = "variable: %s not found\n";
#endif

#ifdef CONFIG_DEVFSD_VERBOSE
static void msg_logger(int die, int pri, const char * fmt, ... )
{
	va_list ap;

	va_start(ap, fmt);
	if (access ("/dev/log", F_OK) == 0)
	{
		openlog(bb_applet_name, 0, LOG_DAEMON);
		vsyslog( pri , fmt , ap);
		closelog();
 	}
#ifndef CONFIG_DEBUG
	else
#endif
		bb_verror_msg(fmt, ap);
	va_end(ap);
	if(die==DIE)
		exit(EXIT_FAILURE);
}
#endif

static void do_ioctl(int die, int fd, int request, unsigned long event_mask_flag)
{
#ifdef CONFIG_DEVFSD_VERBOSE
	if (ioctl (fd, request, event_mask_flag) == -1)
		msg_logger(die, LOG_ERR, "ioctl(): %m\n");
#else
	if (ioctl (fd, request, event_mask_flag) == -1)
		exit(EXIT_FAILURE);
#endif
}

static void fork_and_execute(int die, char *arg0, char **arg )
{
	switch ( fork () )
	{
	case 0:
		/*  Child  */
		break;
	case -1:
		/*  Parent: Error  : die or return */
#ifdef CONFIG_DEVFSD_VERBOSE
		msg_logger(die, LOG_ERR,(char *) bb_msg_memory_exhausted);
#else
		if(die == DIE)
			exit(EXIT_FAILURE);
#endif
		return;
	default:
		/*  Parent : ok : return or exit  */
		if(arg0 != NULL)
		{
			wait (NULL);
			return;
		}
		exit (EXIT_SUCCESS);
	}
	 /* Child : if arg0 != NULL do execvp */
	if(arg0 != NULL )
	{
		execvp (arg0, arg);
#ifdef CONFIG_DEVFSD_VERBOSE
		msg_logger(DIE, LOG_ERR, "execvp(): %s: %m\n", arg0);
#else
		exit(EXIT_FAILURE);
#endif
	}
}

static void safe_memcpy( char *dest, const char *src, int len)
{
	memcpy (dest , src , len );
	dest[len] = '\0';
}

static unsigned int scan_dev_name_common(const char *d, unsigned int n, int addendum, char *ptr)
{
	if( d[n - 4]=='d' && d[n - 3]=='i' && d[n - 2]=='s' && d[n - 1]=='c')
		return (2 + addendum);
	else if( d[n - 2]=='c' && d[n - 1]=='d')
		return (3 + addendum);
	else if(ptr[0]=='p' && ptr[1]=='a' && ptr[2]=='r' && ptr[3]=='t')
		return (4 + addendum);
	else if( ptr[n - 2]=='m' && ptr[n - 1]=='t')
		return (5 + addendum);
	else
		return 0;
}

static unsigned int scan_dev_name(const char *d, unsigned int n, char *ptr)
{
	if(d[0]=='s' && d[1]=='c' && d[2]=='s' && d[3]=='i' && d[4]=='/')
	{
		if( d[n - 7]=='g' && d[n - 6]=='e' && d[n - 5]=='n' &&
			d[n - 4]=='e' && d[n - 3]=='r' && d[n - 2]=='i' &&
			d[n - 1]=='c' )
			return 1;
		return scan_dev_name_common(d, n, 0, ptr);
	}
	else if(d[0]=='i' && d[1]=='d' && d[2]=='e' && d[3]=='/' &&
			d[4]=='h' && d[5]=='o' && d[6]=='s' && d[7]=='t')
	{
		return scan_dev_name_common(d, n, 4, ptr);
	}
	else if(d[0]=='s' && d[1]=='b' && d[2]=='p' && d[3]=='/')
	{
		return 10;
	}
	else if(d[0]=='v' && d[1]=='c' && d[2]=='c' && d[3]=='/')
	{
		return 11;
	}
	else if(d[0]=='p' && d[1]=='t' && d[2]=='y' && d[3]=='/')
	{
		return 12;
	}
	return 0;
}

/*  Public functions follow  */

int devfsd_main (int argc, char **argv)
{
	int print_version = FALSE;
#ifdef CONFIG_DEVFSD_FG_NP
	int do_daemon = TRUE;
	int no_polling = FALSE;
#endif
	int do_scan;
	int fd, proto_rev, count;
	unsigned long event_mask = 0;
	struct sigaction new_action;
	struct initial_symlink_struct *curr;

	if (argc < 2)
		bb_show_usage();

	for (count = 2; count < argc; ++count)
	{
		if(argv[count][0] == '-')
		{
			if(argv[count][1]=='v' && !argv[count][2]) /* -v */
					print_version = TRUE;
#ifdef CONFIG_DEVFSD_FG_NP
			else if(argv[count][1]=='f' && argv[count][2]=='g' && !argv[count][3]) /* -fg */
					do_daemon = FALSE;
			else if(argv[count][1]=='n' && argv[count][2]=='p' && !argv[count][3]) /* -np */
					no_polling = TRUE;
#endif
			else
				bb_show_usage();
		}
	}

	/* strip last / from mount point, so we don't need to check for it later */
	while( argv[1][1]!='\0' && argv[1][strlen(argv[1])-1] == '/' )
		argv[1][strlen(argv[1]) -1] = '\0';

	mount_point = argv[1];

	if (chdir (mount_point) != 0)
#ifdef CONFIG_DEVFSD_VERBOSE
		bb_error_msg_and_die( " %s: %m", mount_point);
#else
		exit(EXIT_FAILURE);
#endif

	fd = bb_xopen (".devfsd", O_RDONLY);

	if (fcntl (fd, F_SETFD, FD_CLOEXEC) != 0)
#ifdef CONFIG_DEVFSD_VERBOSE
		bb_error_msg( "FD_CLOEXEC");
#else
		exit(EXIT_FAILURE);
#endif

	do_ioctl(DIE, fd, DEVFSDIOC_GET_PROTO_REV,(int )&proto_rev);

	/*setup initial entries */
    for (curr = initial_symlinks; curr->dest != NULL; ++curr)
		symlink (curr->dest, curr->name);

	/* NB: The check for CONFIG_FILE is done in read_config_file() */

	if ( print_version  || (DEVFSD_PROTOCOL_REVISION_DAEMON != proto_rev) )
	{
		bb_printf( "%s v%s\nDaemon %s:\t%d\nKernel-side %s:\t%d\n",
					 bb_applet_name,DEVFSD_VERSION,bb_msg_proto_rev,
					 DEVFSD_PROTOCOL_REVISION_DAEMON,bb_msg_proto_rev, proto_rev);
		if (DEVFSD_PROTOCOL_REVISION_DAEMON != proto_rev)
			bb_error_msg_and_die( "%s mismatch!",bb_msg_proto_rev);
		exit(EXIT_SUCCESS); /* -v */
	}
	/*  Tell kernel we are special (i.e. we get to see hidden entries)  */
	do_ioctl(DIE, fd, DEVFSDIOC_SET_EVENT_MASK, 0);

	sigemptyset (&new_action.sa_mask);
	new_action.sa_flags = 0;

	/*  Set up SIGHUP and SIGUSR1 handlers  */
	new_action.sa_handler = signal_handler;
	if (sigaction (SIGHUP, &new_action, NULL) != 0 || sigaction (SIGUSR1, &new_action, NULL) != 0 )
#ifdef CONFIG_DEVFSD_VERBOSE
		bb_error_msg_and_die( "sigaction()");
#else
		exit(EXIT_FAILURE);
#endif

	bb_printf("%s v%s  started for %s\n",bb_applet_name, DEVFSD_VERSION, mount_point);

	/*  Set umask so that mknod(2), open(2) and mkdir(2) have complete control 	over permissions  */
	umask (0);
	read_config_file (CONFIG_FILE, FALSE, &event_mask);
	/*  Do the scan before forking, so that boot scripts see the finished product  */
	dir_operation(SERVICE,mount_point,0,NULL);
#ifdef CONFIG_DEVFSD_FG_NP
	if (no_polling)
		exit (0);
	if (do_daemon)
	{
#endif
		/*  Release so that the child can grab it  */
		do_ioctl(DIE, fd, DEVFSDIOC_RELEASE_EVENT_QUEUE, 0);
		fork_and_execute(DIE, NULL, NULL);
		setsid ();        /*  Prevent hangups and become pgrp leader         */
#ifdef CONFIG_DEVFSD_FG_NP
	}
	else
		setpgid (0, 0);  /*  Become process group leader                    */
#endif

	while (TRUE)
	{
		do_scan = do_servicing (fd, event_mask);

		free_config ();
		read_config_file (CONFIG_FILE, FALSE, &event_mask);
		if (do_scan)
			dir_operation(SERVICE,mount_point,0,NULL);
	}
}   /*  End Function main  */


/*  Private functions follow  */

static void read_config_file (char *path, int optional, unsigned long *event_mask)
/*  [SUMMARY] Read a configuration database.
    <path> The path to read the database from. If this is a directory, all
    entries in that directory will be read (except hidden entries).
    <optional> If TRUE, the routine will silently ignore a missing config file.
    <event_mask> The event mask is written here. This is not initialised.
    [RETURNS] Nothing.
*/
{
	struct stat statbuf;
	FILE *fp;
	char buf[STRING_LENGTH];
	char *line=NULL;

#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "read_config_file(): %s\n", path);
#endif
	if (stat (path, &statbuf) != 0 || statbuf.st_size == 0 )
		goto read_config_file_err;

	if ( S_ISDIR (statbuf.st_mode) )
	{
		/* strip last / from dirname so we don't need to check for it later */
		while( path  && path[1]!='\0' && path[strlen(path)-1] == '/')
			path[strlen(path) -1] = '\0';

		dir_operation(READ_CONFIG, path, 0, event_mask);
		return;
	}

	if ( ( fp = fopen (path, "r") ) != NULL )
	{
		while (fgets (buf, STRING_LENGTH, fp) != NULL)
		{
			/*  GETS(3)       Linux Programmer's Manual
			fgets() reads in at most one less than size characters from stream  and
			stores  them  into  the buffer pointed to by s.  Reading stops after an
			EOF or a newline.  If a newline is read, it is stored into the  buffer.
			A '\0' is stored after the last character in the buffer.
			*/
			/*buf[strlen (buf) - 1] = '\0';*/
			/*  Skip whitespace  */
			for (line = buf; isspace (*line); ++line)
				/*VOID*/;
			if (line[0] == '\0' || line[0] == '#' )
				continue;
			process_config_line (line, event_mask);
		}
		fclose (fp);
		errno=0;
	}
read_config_file_err:
#ifdef CONFIG_DEVFSD_VERBOSE
	msg_logger(((optional ==  0 ) && (errno == ENOENT))? DIE : NO_DIE, LOG_ERR, "read config file: %s: %m\n", path);
#else
	if(optional ==  0  && errno == ENOENT)
		exit(EXIT_FAILURE);
#endif
	return;
}   /*  End Function read_config_file   */

static void process_config_line (const char *line, unsigned long *event_mask)
/*  [SUMMARY] Process a line from a configuration file.
    <line> The configuration line.
    <event_mask> The event mask is written here. This is not initialised.
    [RETURNS] Nothing.
*/
{
	int  num_args, count;
	struct config_entry_struct *new;
	char p[MAX_ARGS][STRING_LENGTH];
	char when[STRING_LENGTH], what[STRING_LENGTH];
	char name[STRING_LENGTH];
	char * msg="";
	char *ptr;

	/* !!!! Only Uppercase Keywords in devsfd.conf */
	const char *options[] = {	"CLEAR_CONFIG", "INCLUDE", "OPTIONAL_INCLUDE", "RESTORE",
								"PERMISSIONS", "MODLOAD", "EXECUTE", "COPY", "IGNORE",
								"MKOLDCOMPAT", "MKNEWCOMPAT","RMOLDCOMPAT", "RMNEWCOMPAT", 0 };

	short int i;

#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "process_config_line()\n");
#endif

	for (count = 0; count < MAX_ARGS; ++count) p[count][0] = '\0';
	num_args = sscanf (line, "%s %s %s %s %s %s %s %s %s %s",
			when, name, what,
			p[0], p[1], p[2], p[3], p[4], p[5], p[6]);

	i = compare_string_array(options, when );

	/*"CLEAR_CONFIG"*/
	if( i == 0)
	{
		free_config ();
		*event_mask = 0;
		return;
	}

	if ( num_args < 2)
		goto process_config_line_err;

	/* "INCLUDE" & "OPTIONAL_INCLUDE" */
	if( i == 1 || i == 2 )
	{
		st_expr_expand (name, STRING_LENGTH, name, get_variable, NULL );
#ifdef CONFIG_DEBUG
		msg_logger( NO_DIE, LOG_INFO, "%sinclude: %s\n",(toupper (when[0]) == 'I') ? "": "optional_", name);
#endif
		read_config_file (name, (toupper (when[0]) == 'I') ? FALSE : TRUE, event_mask);
		return;
	}
	/* "RESTORE" */
	if( i == 3)
	{
		dir_operation(RESTORE,name, strlen (name),NULL);
		return;
	}
	if (num_args < 3)
		goto process_config_line_err;

	new = xmalloc (sizeof *new);
	memset (new, 0, sizeof *new);

	for (count = 0; event_types[count].config_name != NULL; ++count)
	{
		if (strcasecmp (when, event_types[count].config_name) != 0)
			continue;
		new->action.when = event_types[count].type;
		break;
	}
	if (event_types[count].config_name == NULL)
	{
		msg="WHEN in";
		goto process_config_line_err;
	}

	i = compare_string_array(options, what );

	switch(i)
	{
		case 4:	/* "PERMISSIONS" */
			new->action.what = AC_PERMISSIONS;
			/*  Get user and group  */
			if ( ( ptr = strchr (p[0], '.') ) == NULL )
			{
				msg="UID.GID";
				goto process_config_line_err; /*"missing '.' in UID.GID */
			}

			*ptr++ = '\0';
			new->u.permissions.uid = get_uid_gid (UID, p[0]);
			new->u.permissions.gid = get_uid_gid (GID, ptr);
			/*  Get mode  */
			new->u.permissions.mode = get_mode (p[1]);
			break;
#ifdef CONFIG_DEVFSD_MODLOAD
		case 5:	/*  MODLOAD */
			/*This  action will pass "/dev/$devname" (i.e. "/dev/" prefixed to
			the device name) to the module loading  facility.  In  addition,
			the /etc/modules.devfs configuration file is used.*/
			 new->action.what = AC_MODLOAD;
			 break;
#endif
		case 6: /* EXECUTE */
			new->action.what = AC_EXECUTE;
			num_args -= 3;

			for (count = 0; count < num_args; ++count)
				new->u.execute.argv[count] = bb_xstrdup (p[count]);

			new->u.execute.argv[num_args] = NULL;
			break;
		case 7: /* COPY */
			new->action.what = AC_COPY;
			num_args -= 3;
			if (num_args != 2)
				goto process_config_line_err; /* missing path and function in line */

			new->u.copy.source = bb_xstrdup (p[0]);
			new->u.copy.destination = bb_xstrdup (p[1]);
			break;
		case 8: /* IGNORE */
		/* FALLTROUGH */
		case 9: /* MKOLDCOMPAT */
		/* FALLTROUGH */
		case 10: /* MKNEWCOMPAT */
		/* FALLTROUGH */
		case 11:/* RMOLDCOMPAT */
		/* FALLTROUGH */
		case 12: /* RMNEWCOMPAT */
		/*	AC_IGNORE					6
			AC_MKOLDCOMPAT				7
			AC_MKNEWCOMPAT				8
			AC_RMOLDCOMPAT				9
			AC_RMNEWCOMPAT				10*/
			new->action.what = i - 2;
			break;
		default:
			msg ="WHAT in";
			goto process_config_line_err;
		/*esac*/
	} /* switch (i) */

	xregcomp( &new->preg, name, REG_EXTENDED);

	*event_mask |= 1 << new->action.when;
	new->next = NULL;
	if (first_config == NULL)
		first_config = new;
	else
		last_config->next = new;
	last_config = new;
	return;
process_config_line_err:
#ifdef CONFIG_DEVFSD_VERBOSE
	msg_logger( DIE, LOG_ERR, bb_msg_bad_config, msg , line);
#else
	exit(EXIT_FAILURE);
#endif
}  /*  End Function process_config_line   */

static int do_servicing (int fd, unsigned long event_mask)
/*  [SUMMARY] Service devfs changes until a signal is received.
    <fd> The open control file.
    <event_mask> The event mask.
    [RETURNS] TRUE if SIGHUP was caught, else FALSE.
*/
{
	ssize_t bytes;
	struct devfsd_notify_struct info;
	unsigned long tmp_event_mask;

#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "do_servicing()\n");
#endif
	/*  Tell devfs what events we care about  */
	tmp_event_mask = event_mask;
	do_ioctl(DIE, fd, DEVFSDIOC_SET_EVENT_MASK, tmp_event_mask);
	while (!caught_signal)
	{
		errno = 0;
		bytes = read (fd, (char *) &info, sizeof info);
		if (caught_signal)
			break;      /*  Must test for this first     */
		if (errno == EINTR)
			continue;  /*  Yes, the order is important  */
		if (bytes < 1)
			break;
		service_name (&info);
	}
	if (caught_signal)
	{
		int c_sighup = caught_sighup;

		caught_signal = FALSE;
		caught_sighup = FALSE;
		return (c_sighup);
	}
#ifdef CONFIG_DEVFSD_VERBOSE
	msg_logger( NO_DIE, LOG_ERR, "read error on control file: %m\n");
#endif
	/* This is to shut up a compiler warning */
	exit(EXIT_FAILURE);
}   /*  End Function do_servicing  */

static void service_name (const struct devfsd_notify_struct *info)
/*  [SUMMARY] Service a single devfs change.
    <info> The devfs change.
    [RETURNS] Nothing.
*/
{
	unsigned int n;
	regmatch_t mbuf[MAX_SUBEXPR];
	struct config_entry_struct *entry;

#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "service_name()\n");
	if (info->overrun_count > 0)
		msg_logger( NO_DIE, LOG_ERR, "lost %u events\n", info->overrun_count);
#endif

	/*  Discard lookups on "/dev/log" and "/dev/initctl"  */
	if(   info->type == DEVFSD_NOTIFY_LOOKUP &&
		((info->devname[0]=='l' && info->devname[1]=='o' &&
		  info->devname[2]=='g' && !info->devname[3]) &&
		( info->devname[0]=='i' && info->devname[1]=='n' &&
		  info->devname[2]=='i' && info->devname[3]=='c' &&
		  info->devname[4]=='t' && info->devname[5]=='l' && !info->devname[6])))
			return;
	for (entry = first_config; entry != NULL; entry = entry->next)
	{
		/*  First check if action matches the type, then check if name matches */
		if (info->type != entry->action.when || regexec (&entry->preg, info->devname, MAX_SUBEXPR, mbuf, 0) != 0 )
			continue;
		for (n = 0; (n < MAX_SUBEXPR) && (mbuf[n].rm_so != -1); ++n)
			/* VOID */;
#ifdef CONFIG_DEBUG
		msg_logger( NO_DIE, LOG_INFO, "service_name(): action.what %d\n", entry->action.what);
#endif
		switch (entry->action.what)
		{
			case AC_PERMISSIONS:
				action_permissions (info, entry);
				break;
#ifdef CONFIG_DEVFSD_MODLOAD
			case AC_MODLOAD:
				action_modload (info, entry);
				break;
#endif
			case AC_EXECUTE:
				action_execute (info, entry, mbuf, n);
				break;
			case AC_COPY:
				action_copy (info, entry, mbuf, n);
				break;
			case AC_IGNORE:
				return;
				/*break;*/
			case AC_MKOLDCOMPAT:
			case AC_MKNEWCOMPAT:
			case AC_RMOLDCOMPAT:
			case AC_RMNEWCOMPAT:
				action_compat (info, entry->action.what);
				break;
			default:
#ifdef CONFIG_DEVFSD_VERBOSE
				msg_logger( DIE, LOG_ERR, "Unknown action\n");
#else
				exit(EXIT_FAILURE);
#endif
				/*break;*/
		}
	}
}   /*  End Function service_name  */

static void action_permissions (const struct devfsd_notify_struct *info,
				const struct config_entry_struct *entry)
/*  [SUMMARY] Update permissions for a device entry.
    <info> The devfs change.
    <entry> The config file entry.
    [RETURNS] Nothing.
*/
{
	struct stat statbuf;

#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "action_permission()\n");
#endif

	if ( stat (info->devname, &statbuf) != 0	||
		 chmod (info->devname,(statbuf.st_mode & S_IFMT) | (entry->u.permissions.mode & ~S_IFMT)) != 0 ||
		 chown (info->devname, entry->u.permissions.uid, entry->u.permissions.gid) != 0)
	{
#ifdef CONFIG_DEVFSD_VERBOSE
			msg_logger( NO_DIE, LOG_ERR, "chmod() or chown(): %s: %m\n",info->devname);
#endif
		return;
	}

}   /*  End Function action_permissions  */

#ifdef CONFIG_DEVFSD_MODLOAD
static void action_modload (const struct devfsd_notify_struct *info,
			    const struct config_entry_struct *entry)
/*  [SUMMARY] Load a module.
    <info> The devfs change.
    <entry> The config file entry.
    [RETURNS] Nothing.
*/
{
	char *argv[6];
	char device[STRING_LENGTH];

	argv[0] = MODPROBE;
	argv[1] = MODPROBE_SWITCH_1; /* "-k" */
	argv[2] = MODPROBE_SWITCH_2; /* "-C" */
	argv[3] = CONFIG_MODULES_DEVFS;
	argv[4] = device;
	argv[5] = NULL;

	snprintf (device, sizeof (device), "/dev/%s", info->devname);
	#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "action_modload():%s %s %s %s %s\n",argv[0],argv[1],argv[2],argv[3],argv[4]);
	#endif
	fork_and_execute(DIE, argv[0], argv);
}  /*  End Function action_modload  */
#endif

static void action_execute (const struct devfsd_notify_struct *info,
			    const struct config_entry_struct *entry,
			    const regmatch_t *regexpr, unsigned int numexpr)
/*  [SUMMARY] Execute a programme.
    <info> The devfs change.
    <entry> The config file entry.
    <regexpr> The number of subexpression (start, end) offsets within the
    device name.
    <numexpr> The number of elements within <<regexpr>>.
    [RETURNS] Nothing.
*/
{
	unsigned int count;
	struct get_variable_info gv_info;
	char *argv[MAX_ARGS + 1];
	char largv[MAX_ARGS + 1][STRING_LENGTH];

#ifdef CONFIG_DEBUG
	int i;
	char buff[512];
#endif

	gv_info.info = info;
	gv_info.devname = info->devname;
	snprintf (gv_info.devpath, sizeof (gv_info.devpath), "%s/%s", mount_point, info->devname);
	for (count = 0; entry->u.execute.argv[count] != NULL; ++count)
	{
		expand_expression (largv[count], STRING_LENGTH,
				entry->u.execute.argv[count],
				get_variable, &gv_info,
				gv_info.devname, regexpr, numexpr );
		argv[count] = largv[count];
	}
	argv[count] = NULL;

#ifdef CONFIG_DEBUG
	buff[0]='\0';
	for(i=0;argv[i]!=NULL;i++) /* argv[i] < MAX_ARGS + 1 */
	{
		strcat(buff," ");
		if( (strlen(buff)+ 1 + strlen(argv[i])) >= 512)
			break;
		strcat(buff,argv[i]);
	}
	strcat(buff,"\n");
	msg_logger( NO_DIE, LOG_INFO, "action_execute(): %s",buff);
#endif

	fork_and_execute(NO_DIE, argv[0], argv);
}   /*  End Function action_execute  */


static void action_copy (const struct devfsd_notify_struct *info,
			 const struct config_entry_struct *entry,
                         const regmatch_t *regexpr, unsigned int numexpr)
/*  [SUMMARY] Copy permissions.
    <info> The devfs change.
    <entry> The config file entry.
    <regexpr> This list of subexpression (start, end) offsets within the
    device name.
    <numexpr> The number of elements in <<regexpr>>.
    [RETURNS] Nothing.
*/
{
	mode_t new_mode;
	struct get_variable_info gv_info;
	struct stat source_stat, dest_stat;
	char source[STRING_LENGTH], destination[STRING_LENGTH];
	dest_stat.st_mode = 0;

#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "action_copy()\n");
#endif

	if ( (info->type == DEVFSD_NOTIFY_CHANGE) && S_ISLNK (info->mode) )
		return;
	gv_info.info = info;
	gv_info.devname = info->devname;

	snprintf (gv_info.devpath, sizeof (gv_info.devpath), "%s/%s", mount_point, info->devname);
	expand_expression (source, STRING_LENGTH, entry->u.copy.source,
				get_variable, &gv_info, gv_info.devname,
				regexpr, numexpr);

	expand_expression (destination, STRING_LENGTH, entry->u.copy.destination,
				get_variable, &gv_info, gv_info.devname,
				regexpr, numexpr);

	if ( !make_dir_tree (destination) || lstat (source, &source_stat) != 0)
			return;
	lstat (destination, &dest_stat);
	new_mode = source_stat.st_mode & ~S_ISVTX;
	if (info->type == DEVFSD_NOTIFY_CREATE)
		new_mode |= S_ISVTX;
	else if ( (info->type == DEVFSD_NOTIFY_CHANGE) && (dest_stat.st_mode & S_ISVTX) )
		new_mode |= S_ISVTX;
#ifdef CONFIG_DEBUG
	if ( !copy_inode (destination, &dest_stat, new_mode, source, &source_stat) && (errno != EEXIST))
		msg_logger( NO_DIE, LOG_ERR, "copy_inode(): %s to %s: %m\n", source, destination);
#else
	copy_inode (destination, &dest_stat, new_mode, source, &source_stat);
#endif
	return;
}   /*  End Function action_copy  */

static void action_compat (const struct devfsd_notify_struct *info, unsigned int action)
/*  [SUMMARY] Process a compatibility request.
    <info> The devfs change.
    <action> The action to take.
    [RETURNS] Nothing.
*/
{
	const char *compat_name = NULL;
	const char *dest_name = info->devname;
	char *ptr=NULL;
	char compat_buf[STRING_LENGTH], dest_buf[STRING_LENGTH];
	int mode, host, bus, target, lun;
	unsigned int i;
	char rewind_;
	/* 1 to 5  "scsi/" , 6 to 9 "ide/host" */
	const char *fmt[] = {	NULL ,
							"sg/c%db%dt%du%d",			/* scsi/generic */
							"sd/c%db%dt%du%d",			/* scsi/disc */
							"sr/c%db%dt%du%d",			/* scsi/cd */
							"sd/c%db%dt%du%dp%d",		/* scsi/part */
							"st/c%db%dt%du%dm%d%c",		/* scsi/mt */
							"ide/hd/c%db%dt%du%d",		/* ide/host/disc */
							"ide/cd/c%db%dt%du%d",		/* ide/host/cd */
							"ide/hd/c%db%dt%du%dp%d",	/* ide/host/part */
							"ide/mt/c%db%dt%du%d%s",	/* ide/host/mt */
							NULL };

	/*  First construct compatibility name  */
	switch (action)
	{
		case AC_MKOLDCOMPAT:
		case AC_RMOLDCOMPAT:
			compat_name = get_old_name (info->devname, info->namelen, compat_buf, info->major, info->minor);
			break;
		case AC_MKNEWCOMPAT:
		case AC_RMNEWCOMPAT:
			ptr = strrchr (info->devname, '/') + 1;
			i=scan_dev_name(info->devname, info->namelen, ptr);

#ifdef CONFIG_DEBUG
			msg_logger( NO_DIE, LOG_INFO, "action_compat(): scan_dev_name() returned %d\n", i);
#endif

			/* nothing found */
			if(i==0 || i > 9)
				return;

			sscanf (info->devname +((i<6)?5:4), "host%d/bus%d/target%d/lun%d/", &host, &bus, &target, &lun);
			snprintf (dest_buf, sizeof (dest_buf), "../%s", info->devname + ((i>5)?4:0));
			dest_name = dest_buf;
			compat_name = compat_buf;


			/* 1 == scsi/generic  2 == scsi/disc 3 == scsi/cd 6 == ide/host/disc 7 == ide/host/cd */
			if( i == 1 || i == 2 || i == 3 || i == 6 || i ==7 )
				sprintf ( compat_buf, fmt[i], host, bus, target, lun);

			/* 4 == scsi/part 8 == ide/host/part */
			if( i == 4 || i == 8)
				sprintf ( compat_buf, fmt[i], host, bus, target, lun, atoi (ptr + 4) );

			/* 5 == scsi/mt */
			if( i == 5)
			{
				rewind_ = info->devname[info->namelen - 1];
				if (rewind_ != 'n')
					rewind_ = '\0';
				mode=0;
				if(ptr[2] ==  'l' /*108*/ || ptr[2] == 'm'/*109*/)
					mode = ptr[2] - 107; /* 1 or 2 */
				if(ptr[2] ==  'a')
					mode = 3;
				sprintf (compat_buf, fmt [i], host, bus, target, lun, mode, rewind_);
			}

			/* 9 == ide/host/mt */
			if( i ==  9 )
				snprintf (compat_buf, sizeof (compat_buf), fmt[i], host, bus, target, lun, ptr + 2);
		/* esac */
	} /* switch(action) */

	if(compat_name == NULL )
		return;

#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "action_compat(): %s\n", compat_name);
#endif

	/*  Now decide what to do with it  */
	switch (action)
	{
		case AC_MKOLDCOMPAT:
		case AC_MKNEWCOMPAT:
			mksymlink (dest_name, compat_name);
			break;
		case AC_RMOLDCOMPAT:
		case AC_RMNEWCOMPAT:
#ifdef CONFIG_DEBUG
			if (unlink (compat_name) != 0)
				msg_logger( NO_DIE, LOG_ERR, "unlink(): %s: %m\n", compat_name);
#else
			unlink (compat_name);
#endif
			break;
		/*esac*/
	} /* switch(action) */
}   /*  End Function action_compat  */

static void restore(char *spath, struct stat source_stat, int rootlen)
{
	char dpath[STRING_LENGTH];
	struct stat dest_stat;

#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "restore()\n");
#endif

	dest_stat.st_mode = 0;
	snprintf (dpath, sizeof dpath, "%s%s", mount_point, spath + rootlen);
	lstat (dpath, &dest_stat);

	if ( S_ISLNK (source_stat.st_mode) || (source_stat.st_mode & S_ISVTX) )
		copy_inode (dpath, &dest_stat, (source_stat.st_mode & ~S_ISVTX) , spath, &source_stat);

	if ( S_ISDIR (source_stat.st_mode) )
		dir_operation(RESTORE, spath, rootlen,NULL);
}


static int copy_inode (const char *destpath, const struct stat *dest_stat,
			mode_t new_mode,
			const char *sourcepath, const struct stat *source_stat)
/*  [SUMMARY] Copy an inode.
    <destpath> The destination path. An existing inode may be deleted.
    <dest_stat> The destination stat(2) information.
    <new_mode> The desired new mode for the destination.
    <sourcepath> The source path.
    <source_stat> The source stat(2) information.
    [RETURNS] TRUE on success, else FALSE.
*/
{
	int source_len, dest_len;
	char source_link[STRING_LENGTH], dest_link[STRING_LENGTH];
	int fd, val;
	struct sockaddr_un un_addr;
	char symlink_val[STRING_LENGTH];

#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "copy_inode()\n");
#endif

	if ( (source_stat->st_mode & S_IFMT) == (dest_stat->st_mode & S_IFMT) )
	{
		/*  Same type  */
		if ( S_ISLNK (source_stat->st_mode) )
		{
			if (( source_len = readlink (sourcepath, source_link, STRING_LENGTH - 1) ) < 0 ||
				( dest_len   = readlink (destpath  , dest_link  , STRING_LENGTH - 1) ) < 0 )
				return (FALSE);
			source_link[source_len]	= '\0';
			dest_link[dest_len] 	= '\0';
			if ( (source_len != dest_len) || (strcmp (source_link, dest_link) != 0) )
			{
				unlink (destpath);
				symlink (source_link, destpath);
			}
			return (TRUE);
		}   /*  Else not a symlink  */
		chmod (destpath, new_mode & ~S_IFMT);
		chown (destpath, source_stat->st_uid, source_stat->st_gid);
		return (TRUE);
	}
	/*  Different types: unlink and create  */
	unlink (destpath);
	switch (source_stat->st_mode & S_IFMT)
	{
		case S_IFSOCK:
			if ( ( fd = socket (AF_UNIX, SOCK_STREAM, 0) ) < 0 )
				break;
			un_addr.sun_family = AF_UNIX;
			snprintf (un_addr.sun_path, sizeof (un_addr.sun_path), "%s", destpath);
			val = bind (fd, (struct sockaddr *) &un_addr, (int) sizeof un_addr);
			close (fd);
			if (val != 0 || chmod (destpath, new_mode & ~S_IFMT) != 0)
				break;
			goto do_chown;
		case S_IFLNK:
			if ( ( val = readlink (sourcepath, symlink_val, STRING_LENGTH - 1) ) < 0 )
				break;
			symlink_val[val] = '\0';
			if (symlink (symlink_val, destpath) == 0)
				return (TRUE);
			break;
		case S_IFREG:
			if ( ( fd = open (destpath, O_RDONLY | O_CREAT, new_mode & ~S_IFMT) ) < 0 )
				break;
			close (fd);
			if (chmod (destpath, new_mode & ~S_IFMT) != 0)
				break;
			goto do_chown;
		case S_IFBLK:
		case S_IFCHR:
		case S_IFIFO:
			if (mknod (destpath, new_mode, source_stat->st_rdev) != 0)
				break;
			goto do_chown;
		case S_IFDIR:
			if (mkdir (destpath, new_mode & ~S_IFMT) != 0)
				break;
do_chown:
			if (chown (destpath, source_stat->st_uid, source_stat->st_gid) == 0)
				return (TRUE);
		/*break;*/
	}
	return (FALSE);
}   /*  End Function copy_inode  */

static void free_config ()
/*  [SUMMARY] Free the configuration information.
    [RETURNS] Nothing.
*/
{
	struct config_entry_struct *c_entry;
	void *next;

#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "free_config()\n");
#endif

	for (c_entry = first_config; c_entry != NULL; c_entry = next)
	{
		unsigned int count;

		next = c_entry->next;
		regfree (&c_entry->preg);
		if (c_entry->action.what == AC_EXECUTE)
		{
			for (count = 0; count < MAX_ARGS; ++count)
			{
				if (c_entry->u.execute.argv[count] == NULL)
					break;
				free (c_entry->u.execute.argv[count]);
			}
		}
		free (c_entry);
	}
	first_config = NULL;
	last_config = NULL;
}   /*  End Function free_config  */

static int get_uid_gid (int flag, const char *string)
/*  [SUMMARY] Convert a string to a UID or GID value.
	<flag> "UID" or "GID".
	<string> The string.
    [RETURNS] The UID or GID value.
*/
{
	struct passwd *pw_ent;
	struct group *grp_ent;
#ifdef CONFIG_DEVFSD_VERBOSE
	char * msg="user";
#endif

#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "get_uid_gid()\n");


	if(flag != UID && flag != GID )
		msg_logger( DIE, LOG_ERR,"get_uid_gid(): flag != UID && flag != GID\n");
#endif

	if ( isdigit (string[0]) || ( (string[0] == '-') && isdigit (string[1]) ) )
		return atoi (string);

	if ( flag == UID && ( pw_ent  = getpwnam (string) ) != NULL )
		return (pw_ent->pw_uid);

	if ( flag == GID && ( grp_ent = getgrnam (string) ) != NULL )
		return (grp_ent->gr_gid);
#ifdef CONFIG_DEVFSD_VERBOSE
	else
		msg="group";

	msg_logger( NO_DIE, LOG_ERR,"unknown %s: %s, defaulting to %cID=0\n", msg, string, msg[0] - 32);
#endif
	return (0);
}/*  End Function get_uid_gid  */

static mode_t get_mode (const char *string)
/*  [SUMMARY] Convert a string to a mode value.
    <string> The string.
    [RETURNS] The mode value.
*/
{
	mode_t mode;
	int i;
#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "get_mode()\n");
#endif

	if ( isdigit (string[0]) )
		return strtoul (string, NULL, 8);
	if (strlen (string) != 9)
#ifdef CONFIG_DEVFSD_VERBOSE
		msg_logger( DIE, LOG_ERR, "bad mode: %s\n", string);
#else
		exit(EXIT_FAILURE);
#endif
	mode = 0;
	i= S_IRUSR;
	while(i>0)
	{
		if(string[0]=='r'||string[0]=='w'||string[0]=='x')
			mode+=i;
		i=i/2;
		string++;
	}
	return (mode);
}   /*  End Function get_mode  */

static void signal_handler (int sig)
{
#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "signal_handler()\n");
#endif

	caught_signal = TRUE;
	if (sig == SIGHUP)
		caught_sighup = TRUE;
#ifdef CONFIG_DEVFSD_VERBOSE
	msg_logger( NO_DIE, LOG_INFO, "Caught %s\n",(sig == SIGHUP)?"SIGHUP" : "SIGUSR1");
#endif
}   /*  End Function signal_handler  */

static const char *get_variable (const char *variable, void *info)
{
	struct get_variable_info *gv_info = info;
	static char hostname[STRING_LENGTH], sbuf[STRING_LENGTH];
	const char *field_names[] = { "hostname", "mntpt", "devpath", "devname",
								   "uid", "gid", "mode", hostname, mount_point,
								   gv_info->devpath, gv_info->devname, 0 };
	short int i;
#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "get_variable()\n");
#endif

	if (gethostname (hostname, STRING_LENGTH - 1) != 0)
#ifdef CONFIG_DEVFSD_VERBOSE
		msg_logger( DIE, LOG_ERR, "gethostname(): %m\n");
#else
		exit(EXIT_FAILURE);
#endif
		/* Here on error we should do exit(RV_SYS_ERROR), instead we do exit(EXIT_FAILURE) */
		hostname[STRING_LENGTH - 1] = '\0';

	/* compare_string_array returns i>=0  */
	i=compare_string_array(field_names, variable);

	if ( i > 6 && (i > 1 && gv_info == NULL))
			return (NULL);
	if( i >= 0 || i <= 3)
	{
#ifdef CONFIG_DEBUG
		msg_logger( NO_DIE, LOG_INFO, "get_variable(): i=%d %s\n",i ,field_names[i+7]);
#endif
		return(field_names[i+7]);
	}

	if(i == 4 )
		sprintf (sbuf, "%u", gv_info->info->uid);
	else if(i == 5)
		sprintf (sbuf, "%u", gv_info->info->gid);
	else if(i == 6)
		sprintf (sbuf, "%o", gv_info->info->mode);
#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "get_variable(): %s\n", sbuf);
#endif
	return (sbuf);
}   /*  End Function get_variable  */

static void service(struct stat statbuf, char *path)
{
	struct devfsd_notify_struct info;

#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "service()\n");
#endif

	memset (&info, 0, sizeof info);
	info.type = DEVFSD_NOTIFY_REGISTERED;
	info.mode = statbuf.st_mode;
	info.major = major (statbuf.st_rdev);
	info.minor = minor (statbuf.st_rdev);
	info.uid = statbuf.st_uid;
	info.gid = statbuf.st_gid;
	snprintf (info.devname, sizeof (info.devname), "%s", path + strlen (mount_point) + 1);
	info.namelen = strlen (info.devname);
	service_name (&info);
	if ( S_ISDIR (statbuf.st_mode) )
		dir_operation(SERVICE,path,0,NULL);
}

static void dir_operation(int type, const char * dir_name, int var, unsigned long *event_mask)
/*  [SUMMARY] Scan a directory tree and generate register events on leaf nodes.
	<flag> To choose which function to perform
	<dp> The directory pointer. This is closed upon completion.
    <dir_name> The name of the directory.
	<rootlen> string length parameter.
    [RETURNS] Nothing.
*/
{
	struct stat statbuf;
	DIR *dp;
	struct dirent *de;
	char path[STRING_LENGTH];


#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "dir_operation()\n");
#endif

	if((dp = opendir( dir_name))==NULL)
	{
#ifdef CONFIG_DEBUG
		msg_logger( NO_DIE, LOG_ERR, "opendir(): %s: %m\n", dir_name);
#endif
		return;
	}

	while ( (de = readdir (dp) ) != NULL )
	{

		if(de->d_name && *de->d_name == '.' && (!de->d_name[1] || (de->d_name[1] == '.' && !de->d_name[2])))
			continue;
		snprintf (path, sizeof (path), "%s/%s", dir_name, de->d_name);
#ifdef CONFIG_DEBUG
		msg_logger( NO_DIE, LOG_ERR, "dir_operation(): %s\n", path);
#endif

		if (lstat (path, &statbuf) != 0)
		{
#ifdef CONFIG_DEBUG
			msg_logger( NO_DIE, LOG_ERR, "%s: %m\n", path);
#endif
			continue;
		}
		switch(type)
		{
			case SERVICE:
				service(statbuf,path);
				break;
			case RESTORE:
				restore(path, statbuf, var);
				break;
			case READ_CONFIG:
				read_config_file (path, var, event_mask);
				break;
		}
	}
	closedir (dp);
}   /*  End Function do_scan_and_service  */

static int mksymlink (const char *oldpath, const char *newpath)
/*  [SUMMARY] Create a symlink, creating intervening directories as required.
    <oldpath> The string contained in the symlink.
    <newpath> The name of the new symlink.
    [RETURNS] 0 on success, else -1.
*/
{
#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "mksymlink()\n", newpath);
#endif


	if ( !make_dir_tree (newpath) )
		return (-1);

	if (symlink (oldpath, newpath) != 0)
    {
		if (errno != EEXIST)
		{
#ifdef CONFIG_DEBUG
			msg_logger( NO_DIE, LOG_ERR, "mksymlink(): %s to %s: %m\n", oldpath, newpath);
#endif
			return (-1);
		}
	}
    return (0);
}   /*  End Function mksymlink  */


static int make_dir_tree (const char *path)
/*  [SUMMARY] Creating intervening directories for a path as required.
    <path> The full pathname (including the leaf node).
    [RETURNS] TRUE on success, else FALSE.
*/
{
#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "make_dir_tree()\n");
#endif
	if (bb_make_directory( dirname((char *)path),  S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH ,FILEUTILS_RECUR )==-1)
	{
#ifdef CONFIG_DEBUG
		msg_logger( NO_DIE, LOG_ERR, "make_dir_tree(): %s: %m\n", path);
#endif
		return (FALSE);
	}
	return(TRUE);
} /*  End Function make_dir_tree  */

static int expand_expression(char *output, unsigned int outsize,
			      const char *input,
			      const char *(*get_variable_func)(const char *variable, void *info),
                              void *info,
                              const char *devname,
                              const regmatch_t *ex, unsigned int numexp)
/*  [SUMMARY] Expand enviroment variables and regular subexpressions in string.
    <output> The output expanded expression is written here.
    <length> The size of the output buffer.
    <input> The input expression. This may equal <<output>>.
    <get_variable> A function which will be used to get variable values. If
    this returns NULL, the environment is searched instead. If this is NULL,
    only the environment is searched.
    <info> An arbitrary pointer passed to <<get_variable>>.
    <devname> Device name; specifically, this is the string that contains all
    of the regular subexpressions.
    <ex> Array of start / end offsets into info->devname for each subexpression
    <numexp> Number of regular subexpressions found in <<devname>>.
    [RETURNS] TRUE on success, else FALSE.
*/
{
	char temp[STRING_LENGTH];

#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "expand_expression()\n");
#endif

	if ( !st_expr_expand (temp, STRING_LENGTH, input, get_variable_func, info) )
		return (FALSE);
	expand_regexp (output, outsize, temp, devname, ex, numexp);
	return (TRUE);
}   /*  End Function expand_expression  */

static void expand_regexp (char *output, size_t outsize, const char *input,
			   const char *devname,
			   const regmatch_t *ex, unsigned int numex )
/*  [SUMMARY] Expand all occurrences of the regular subexpressions \0 to \9.
    <output> The output expanded expression is written here.
    <outsize> The size of the output buffer.
    <input> The input expression. This may NOT equal <<output>>, because
    supporting that would require yet another string-copy. However, it's not
    hard to write a simple wrapper function to add this functionality for those
    few cases that need it.
    <devname> Device name; specifically, this is the string that contains all
    of the regular subexpressions.
    <ex> An array of start and end offsets into <<devname>>, one for each
    subexpression
    <numex> Number of subexpressions in the offset-array <<ex>>.
    [RETURNS] Nothing.
*/
{
	const char last_exp = '0' - 1 + numex;
	int c = -1;

#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "expand_regexp()\n");
#endif

	/*  Guarantee NULL termination by writing an explicit '\0' character into
	the very last byte  */
	if (outsize)
		output[--outsize] = '\0';
	/*  Copy the input string into the output buffer, replacing '\\' with '\'
	and '\0' .. '\9' with subexpressions 0 .. 9, if they exist. Other \x
	codes are deleted  */
	while ( (c != '\0') && (outsize != 0) )
	{
		c = *input;
		++input;
		if (c == '\\')
		{
			c = *input;
			++input;
			if (c != '\\')
			{
				if ((c >= '0') && (c <= last_exp))
				{
					const regmatch_t *subexp = ex + (c - '0');
					unsigned int sublen = subexp->rm_eo - subexp->rm_so;

					/*  Range checking  */
					if (sublen > outsize)
						sublen = outsize;
					strncpy (output, devname + subexp->rm_so, sublen);
					output += sublen;
					outsize -= sublen;
				}
				continue;
			}
		}
		*output = c;
		++output;
		--outsize;
	} /* while */
}   /*  End Function expand_regexp  */


/* from compat_name.c */

struct translate_struct
{
	char *match;    /*  The string to match to (up to length)                */
	char *format;   /*  Format of output, "%s" takes data past match string,
			NULL is effectively "%s" (just more efficient)       */
};

static struct translate_struct translate_table[] =
{
	{"sound/",     NULL},
	{"printers/",  "lp%s"},
	{"v4l/",       NULL},
	{"parports/",  "parport%s"},
	{"fb/",        "fb%s"},
	{"netlink/",   NULL},
	{"loop/",      "loop%s"},
	{"floppy/",    "fd%s"},
	{"rd/",        "ram%s"},
	{"md/",        "md%s"},         /*  Meta-devices                         */
	{"vc/",        "tty%s"},
	{"misc/",      NULL},
	{"isdn/",      NULL},
	{"pg/",        "pg%s"},         /*  Parallel port generic ATAPI interface*/
	{"i2c/",       "i2c-%s"},
	{"staliomem/", "staliomem%s"},  /*  Stallion serial driver control       */
	{"tts/E",      "ttyE%s"},       /*  Stallion serial driver               */
	{"cua/E",      "cue%s"},        /*  Stallion serial driver callout       */
	{"tts/R",      "ttyR%s"},       /*  Rocketport serial driver             */
	{"cua/R",      "cur%s"},        /*  Rocketport serial driver callout     */
	{"ip2/",       "ip2%s"},        /*  Computone serial driver control      */
	{"tts/F",      "ttyF%s"},       /*  Computone serial driver              */
	{"cua/F",      "cuf%s"},        /*  Computone serial driver callout      */
	{"tts/C",      "ttyC%s"},       /*  Cyclades serial driver               */
	{"cua/C",      "cub%s"},        /*  Cyclades serial driver callout       */
	{"tts/",       "ttyS%s"},       /*  Generic serial: must be after others */
	{"cua/",       "cua%s"},        /*  Generic serial: must be after others */
	{"input/js",   "js%s"},         /*  Joystick driver                      */
	{NULL,         NULL}
};

const char *get_old_name (const char *devname, unsigned int namelen,
			  char *buffer, unsigned int major, unsigned int minor)
/*  [SUMMARY] Translate a kernel-supplied name into an old name.
    <devname> The device name provided by the kernel.
    <namelen> The length of the name.
    <buffer> A buffer that may be used. This should be at least 128 bytes long.
    <major> The major number for the device.
    <minor> The minor number for the device.
    [RETURNS] A pointer to the old name if known, else NULL.
*/
{
	const char *compat_name = NULL;
	char *ptr;
	struct translate_struct *trans;
	unsigned int i;
	char mode;
	int indexx;
	const char *pty1;
	const char *pty2;
	size_t len;
	/* 1 to 5  "scsi/" , 6 to 9 "ide/host", 10 sbp/, 11 vcc/, 12 pty/ */
	const char *fmt[] = {	NULL ,
							"sg%u",			/* scsi/generic */
							NULL,			/* scsi/disc */
							"sr%u",			/* scsi/cd */
							NULL,			/* scsi/part */
							"nst%u%c",		/* scsi/mt */
							"hd%c"	,		/* ide/host/disc */
							"hd%c"	,		/* ide/host/cd */
							"hd%c%s",		/* ide/host/part */
							"%sht%d",		/* ide/host/mt */
							"sbpcd%u",		/* sbp/ */
							"vcs%s",		/* vcc/ */
							"%cty%c%c",		/* pty/ */
							NULL };

#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "get_old_name()\n");
#endif

	for (trans = translate_table; trans->match != NULL; ++trans)
	{
		 len = strlen (trans->match);

		if (strncmp (devname, trans->match, len) == 0)
		{
			if (trans->format == NULL)
				return (devname + len);
			sprintf (buffer, trans->format, devname + len);
			return (buffer);
		}
	}

	ptr = (strrchr (devname, '/') + 1);
	i = scan_dev_name(devname, namelen, ptr);

	if( i > 0 && i < 13)
		compat_name = buffer;
	else
		return NULL;

#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "get_old_name(): scan_dev_name() returned %d\n", i);
#endif

	/* 1 == scsi/generic, 3 == scsi/cd, 10 == sbp/ */
	if( i == 1 || i == 3 || i == 10 )
		sprintf (buffer, fmt[i], minor);

	/* 2 ==scsi/disc, 4 == scsi/part */
	if( i == 2 || i == 4)
		compat_name = write_old_sd_name (buffer, major, minor,((i == 2)?"":(ptr + 4)));

	/* 5 == scsi/mt */
	if( i == 5)
	{
		mode = ptr[2];
		if (mode == 'n')
			mode = '\0';
		sprintf (buffer, fmt[i], minor & 0x1f, mode);
		if (devname[namelen - 1] != 'n')
			++compat_name;
	}
	/* 6 == ide/host/disc, 7 == ide/host/cd, 8 == ide/host/part */
	if( i == 6 || i == 7 || i == 8 )
		sprintf (buffer, fmt[i] , get_old_ide_name (major, minor), ptr + 4);	/* last arg should be ignored for i == 6 or i== 7 */

	/* 9 ==  ide/host/mt */
	if( i == 9 )
		sprintf (buffer, fmt[i], ptr + 2, minor & 0x7f);

	/*  11 == vcc/ */
	if( i == 11 )
	{
		sprintf (buffer, fmt[i], devname + 4);
		if (buffer[3] == '0')
			buffer[3] = '\0';
	}
	/* 12 ==  pty/ */
	if( i == 12 )
	{
		pty1 = "pqrstuvwxyzabcde";
		pty2 = "0123456789abcdef";
		indexx = atoi (devname + 5);
		sprintf (buffer, fmt[i], (devname[4] == 'm') ? 'p' : 't', pty1[indexx >> 4], pty2[indexx & 0x0f]);
	}
#ifdef CONFIG_DEBUG
	if(compat_name!=NULL)
		msg_logger( NO_DIE, LOG_INFO, "get_old_name(): compat_name  %s\n", compat_name);
#endif
	return (compat_name);
}   /*  End Function get_old_name  */

static char get_old_ide_name (unsigned int major, unsigned int minor)
/*  [SUMMARY] Get the old IDE name for a device.
    <major> The major number for the device.
    <minor> The minor number for the device.
    [RETURNS] The drive letter.
*/
{
	char letter='y';	/* 121 */
	char c='a'; 		/*  97 */
	int i=IDE0_MAJOR;

#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "get_old_ide_name()\n");
#endif

	/* I hope it works like the previous code as it saves a few bytes. Tito ;P */
	do {
		if(	i==IDE0_MAJOR || i==IDE1_MAJOR || i==IDE2_MAJOR ||
			i==IDE3_MAJOR || i==IDE4_MAJOR || i==IDE5_MAJOR ||
			i==IDE6_MAJOR || i==IDE7_MAJOR || i==IDE8_MAJOR ||
			i==IDE9_MAJOR )
		{
			if(i==major)
			{
				letter=c;
				break;
			}
			c+=2;
		}
		i++;
	} while(i<=IDE9_MAJOR);

	if (minor > 63)
		++letter;
	return (letter);
}   /*  End Function get_old_ide_name  */

static char *write_old_sd_name (char *buffer,
				unsigned int major, unsigned int minor,
				char *part)
/*  [SUMMARY] Write the old SCSI disc name to a buffer.
    <buffer> The buffer to write to.
    <major> The major number for the device.
    <minor> The minor number for the device.
    <part> The partition string. Must be "" for a whole-disc entry.
    [RETURNS] A pointer to the buffer on success, else NULL.
*/
{
	unsigned int disc_index;

#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "write_old_sd_name()\n");
#endif

	if (major == 8)
	{
		sprintf (buffer, "sd%c%s", 'a' + (minor >> 4), part);
		return (buffer);
	}
	if ( (major > 64) && (major < 72) )
	{
		disc_index = ( (major - 64) << 4 ) + (minor >> 4);
		if (disc_index < 26)
			sprintf (buffer, "sd%c%s", 'a' + disc_index, part);
		else
			sprintf (buffer, "sd%c%c%s", 'a' + (disc_index / 26) - 1, 'a' + disc_index % 26,part);
		return (buffer);
	}
	return (NULL);
}   /*  End Function write_old_sd_name  */


/*  expression.c */

/*EXPERIMENTAL_FUNCTION*/

int st_expr_expand (char *output, unsigned int length, const char *input,
		     const char *(*get_variable_func) (const char *variable,
						  void *info),
		     void *info)
/*  [SUMMARY] Expand an expression using Borne Shell-like unquoted rules.
    <output> The output expanded expression is written here.
    <length> The size of the output buffer.
    <input> The input expression. This may equal <<output>>.
    <get_variable> A function which will be used to get variable values. If
    this returns NULL, the environment is searched instead. If this is NULL,
    only the environment is searched.
    <info> An arbitrary pointer passed to <<get_variable>>.
    [RETURNS] TRUE on success, else FALSE.
*/
{
	char ch;
	unsigned int len;
	unsigned int out_pos = 0;
	const char *env;
	const char *ptr;
	struct passwd *pwent;
	char buffer[BUFFER_SIZE], tmp[STRING_LENGTH];

#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "st_expr_expand()\n");
#endif

	if (length > BUFFER_SIZE)
		length = BUFFER_SIZE;
	for (; TRUE; ++input)
	{
		switch (ch = *input)
		{
			case '$':
				/*  Variable expansion  */
				input = expand_variable (buffer, length, &out_pos, ++input, get_variable_func, info);
				if (input == NULL)
					return (FALSE);
				break;
			case '~':
				/*  Home directory expansion  */
				ch = input[1];
				if ( isspace (ch) || (ch == '/') || (ch == '\0') )
				{
					/* User's own home directory: leave separator for next time */
					if ( ( env = getenv ("HOME") ) == NULL )
					{
#ifdef CONFIG_DEVFSD_VERBOSE
						msg_logger( NO_DIE, LOG_INFO, bb_msg_variable_not_found, "HOME");
#endif
						return (FALSE);
					}
					len = strlen (env);
					if (len + out_pos >= length)
						goto st_expr_expand_out;
					memcpy (buffer + out_pos, env, len + 1);
					out_pos += len;
					continue;
				}
				/*  Someone else's home directory  */
				for (ptr = ++input; !isspace (ch) && (ch != '/') && (ch != '\0'); ch = *++ptr)
					/* VOID */ ;
				len = ptr - input;
				if (len >= sizeof tmp)
					goto st_expr_expand_out;
				safe_memcpy (tmp, input, len);
				input = ptr - 1;
				if ( ( pwent = getpwnam (tmp) ) == NULL )
				{
#ifdef CONFIG_DEVFSD_VERBOSE
					msg_logger( NO_DIE, LOG_INFO, "no pwent for: %s\n", tmp);
#endif
					return (FALSE);
				}
				len = strlen (pwent->pw_dir);
				if (len + out_pos >= length)
					goto st_expr_expand_out;
				memcpy (buffer + out_pos, pwent->pw_dir, len + 1);
				out_pos += len;
				break;
			case '\0':
			/* Falltrough */
			default:
				if (out_pos >= length)
					goto st_expr_expand_out;
				buffer[out_pos++] = ch;
				if (ch == '\0')
				{
					memcpy (output, buffer, out_pos);
					return (TRUE);
				}
				break;
			/* esac */
		}
	}
	return (FALSE);
st_expr_expand_out:
#ifdef CONFIG_DEVFSD_VERBOSE
	msg_logger( NO_DIE, LOG_INFO, bb_msg_small_buffer);
#endif
	return (FALSE);
}   /*  End Function st_expr_expand  */


/*  Private functions follow  */

static const char *expand_variable (char *buffer, unsigned int length,
				    unsigned int *out_pos, const char *input,
				    const char *(*func) (const char *variable,
							 void *info),
				    void *info)
/*  [SUMMARY] Expand a variable.
    <buffer> The buffer to write to.
    <length> The length of the output buffer.
    <out_pos> The current output position. This is updated.
    <input> A pointer to the input character pointer.
    <func> A function which will be used to get variable values. If this
    returns NULL, the environment is searched instead. If this is NULL, only
    the environment is searched.
    <info> An arbitrary pointer passed to <<func>>.
    <errfp> Diagnostic messages are written here.
    [RETURNS] A pointer to the end of this subexpression on success, else NULL.
*/
{
	char ch;
	int len;
	unsigned int open_braces;
	const char *env, *ptr;
	char tmp[STRING_LENGTH];

#ifdef CONFIG_DEBUG
	msg_logger( NO_DIE, LOG_INFO, "expand_variable()\n");
#endif

	ch = input[0];
	if (ch == '$')
	{
		/*  Special case for "$$": PID  */
		sprintf ( tmp, "%d", (int) getpid () );
		len = strlen (tmp);
		if (len + *out_pos >= length)
			goto expand_variable_out;

		memcpy (buffer + *out_pos, tmp, len + 1);
		out_pos += len;
		return (input);
	}
	/*  Ordinary variable expansion, possibly in braces  */
	if (ch != '{')
	{
		/*  Simple variable expansion  */
		for (ptr = input; isalnum (ch) || (ch == '_') || (ch == ':');ch = *++ptr)
			/* VOID */ ;
		len = ptr - input;
		if (len >= sizeof tmp)
			goto expand_variable_out;

		safe_memcpy (tmp, input, len);
		input = ptr - 1;
		if ( ( env = get_variable_v2 (tmp, func, info) ) == NULL )
		{
#ifdef CONFIG_DEVFSD_VERBOSE
			msg_logger( NO_DIE, LOG_INFO, bb_msg_variable_not_found, tmp);
#endif
			return (NULL);
		}
		len = strlen (env);
		if (len + *out_pos >= length)
			goto expand_variable_out;

		memcpy (buffer + *out_pos, env, len + 1);
		*out_pos += len;
		return (input);
	}
	/*  Variable in braces: check for ':' tricks  */
	ch = *++input;
	for (ptr = input; isalnum (ch) || (ch == '_'); ch = *++ptr)
		/* VOID */;
	if (ch == '}')
	{
		/*  Must be simple variable expansion with "${var}"  */
		len = ptr - input;
		if (len >= sizeof tmp)
			goto expand_variable_out;

		safe_memcpy (tmp, input, len);
		ptr = expand_variable (buffer, length, out_pos, tmp, func, info );
		if (ptr == NULL)
			return (NULL);
		return (input + len);
	}
	if (ch != ':' || ptr[1] != '-' )
	{
#ifdef CONFIG_DEVFSD_VERBOSE
		msg_logger( NO_DIE, LOG_INFO,"illegal char in var name\n");
#endif
		return (NULL);
	}
	/*  It's that handy "${var:-word}" expression. Check if var is defined  */
	len = ptr - input;
	if (len >= sizeof tmp)
		goto expand_variable_out;

	safe_memcpy (tmp, input, len);
	/*  Move input pointer to ':'  */
	input = ptr;
	/*  First skip to closing brace, taking note of nested expressions  */
	ptr += 2;
	ch = ptr[0];
	for (open_braces = 1; open_braces > 0; ch = *++ptr)
	{
		switch (ch)
		{
			case '{':
				++open_braces;
				break;
			case '}':
				--open_braces;
				break;
			case '\0':
#ifdef CONFIG_DEVFSD_VERBOSE
				msg_logger( NO_DIE, LOG_INFO,"\"}\" not found in: %s\n", input);
#endif
				return (NULL);
			default:
				break;
		}
	}
	--ptr;
	/*  At this point ptr should point to closing brace of "${var:-word}"  */
	if ( ( env = get_variable_v2 (tmp, func, info) ) != NULL )
	{
		/*  Found environment variable, so skip the input to the closing brace
			and return the variable  */
		input = ptr;
		len = strlen (env);
		if (len + *out_pos >= length)
			goto expand_variable_out;

		memcpy (buffer + *out_pos, env, len + 1);
		*out_pos += len;
		return (input);
	}
	/*  Environment variable was not found, so process word. Advance input
	pointer to start of word in "${var:-word}"  */
	input += 2;
	len = ptr - input;
	if (len >= sizeof tmp)
		goto expand_variable_out;

	safe_memcpy (tmp, input, len);
	input = ptr;
	if ( !st_expr_expand (tmp, STRING_LENGTH, tmp, func, info ) )
		return (NULL);
	len = strlen (tmp);
	if (len + *out_pos >= length)
		goto expand_variable_out;

	memcpy (buffer + *out_pos, tmp, len + 1);
	*out_pos += len;
	return (input);
expand_variable_out:
#ifdef CONFIG_DEVFSD_VERBOSE
	msg_logger( NO_DIE, LOG_INFO, bb_msg_small_buffer);
#endif
	return (NULL);
}   /*  End Function expand_variable  */


static const char *get_variable_v2 (const char *variable,
				  const char *(*func) (const char *variable, void *info),
				 void *info)
/*  [SUMMARY] Get a variable from the environment or .
    <variable> The variable name.
    <func> A function which will be used to get the variable. If this returns
    NULL, the environment is searched instead. If this is NULL, only the
    environment is searched.
    [RETURNS] The value of the variable on success, else NULL.
*/
{
	const char *value;

#ifdef CONFIG_DEBUG
		msg_logger( NO_DIE, LOG_INFO, "get_variable_v2()\n");
#endif

	if (func != NULL)
	{
		value = (*func) (variable, info);
		if (value != NULL)
			return (value);
	}
	return getenv (variable);
}   /*  End Function get_variable  */

/* END OF CODE */