/*
 * Copyright (c) 1985, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

RCSID("$Id: getusershell.c 21005 2007-06-08 01:54:35Z lha $");

#ifndef HAVE_GETUSERSHELL

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#ifdef HAVE_PATHS_H
#include <paths.h>
#endif
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif

#ifdef HAVE_USERSEC_H
struct aud_rec;
#include <usersec.h>
#endif
#ifdef HAVE_USERCONF_H
#include <userconf.h>
#endif
#include "roken.h"

#ifndef _PATH_SHELLS
#define _PATH_SHELLS "/etc/shells"
#endif

#ifndef _PATH_BSHELL
#define _PATH_BSHELL "/bin/sh"
#endif

#ifndef _PATH_CSHELL
#define _PATH_CSHELL "/bin/csh"
#endif

/*
 * Local shells should NOT be added here.  They should be added in
 * /etc/shells.
 */

static char *okshells[] = { _PATH_BSHELL, _PATH_CSHELL, NULL };
static char **curshell, **shells, *strings;
static char **initshells (void);

/*
 * Get a list of shells from _PATH_SHELLS, if it exists.
 */
char * ROKEN_LIB_FUNCTION
getusershell()
{
    char *ret;

    if (curshell == NULL)
	curshell = initshells();
    ret = *curshell;
    if (ret != NULL)
	curshell++;
    return (ret);
}

void ROKEN_LIB_FUNCTION
endusershell()
{
    if (shells != NULL)
	free(shells);
    shells = NULL;
    if (strings != NULL)
	free(strings);
    strings = NULL;
    curshell = NULL;
}

void ROKEN_LIB_FUNCTION
setusershell()
{
    curshell = initshells();
}

static char **
initshells()
{
    char **sp, *cp;
#ifdef HAVE_GETCONFATTR
    char *tmp;
    int nsh;
#else
    FILE *fp;
#endif
    struct stat statb;

    free(shells);
    shells = NULL;
    free(strings);
    strings = NULL;
#ifdef HAVE_GETCONFATTR
    if(getconfattr(SC_SYS_LOGIN, SC_SHELLS, &tmp, SEC_LIST) != 0)
	return okshells;

    for(cp = tmp, nsh = 0; *cp; cp += strlen(cp) + 1, nsh++);

    shells = calloc(nsh + 1, sizeof(*shells));
    if(shells == NULL)
	return okshells;

    strings = malloc(cp - tmp);
    if(strings == NULL) {
	free(shells);
	shells = NULL;
	return okshells;
    }
    memcpy(strings, tmp, cp - tmp);
    for(sp = shells, cp = strings; *cp; cp += strlen(cp) + 1, sp++)
	*sp = cp;
#else
    if ((fp = fopen(_PATH_SHELLS, "r")) == NULL)
	return (okshells);
    if (fstat(fileno(fp), &statb) == -1) {
	fclose(fp);
	return (okshells);
    }
    if ((strings = malloc((u_int)statb.st_size)) == NULL) {
	fclose(fp);
	return (okshells);
    }
    shells = calloc((unsigned)statb.st_size / 3, sizeof (char *));
    if (shells == NULL) {
	fclose(fp);
	free(strings);
	strings = NULL;
	return (okshells);
    }
    sp = shells;
    cp = strings;
    while (fgets(cp, MaxPathLen + 1, fp) != NULL) {
	while (*cp != '#' && *cp != '/' && *cp != '\0')
	    cp++;
	if (*cp == '#' || *cp == '\0')
	    continue;
	*sp++ = cp;
	while (!isspace((unsigned char)*cp) && *cp != '#' && *cp != '\0')
	    cp++;
	*cp++ = '\0';
    }
    fclose(fp);
#endif
    *sp = NULL;
    return (shells);
}
#endif /* HAVE_GETUSERSHELL */
