/*      $NetBSD: getpwent.c,v 1.12 2011/01/12 23:34:00 joerg Exp $      */

/*
 * Copyright (c) 1987, 1988, 1989, 1993, 1994, 1995
 *      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.
 */

/*
 * Copied from:  lib/libc/gen/getpwent.c
 *      NetBSD: getpwent.c,v 1.48 2000/10/03 03:22:26 enami Exp
 * and then gutted, leaving only /etc/master.passwd support.
 */

#include <sys/cdefs.h>

#ifdef __weak_alias
#define endpwent                _endpwent
#define getpwent                _getpwent
#define getpwent_r              _getpwent_r
#define getpwuid                _getpwuid
#define getpwnam                _getpwnam
#define setpwent                _setpwent
#define setpassent              _setpassent
#define getpwuid_r              _getpwuid_r
#define getpwnam_r              _getpwnam_r

__weak_alias(endpwent,_endpwent)
__weak_alias(setpwent,_setpwent)
__weak_alias(setpassent,_setpassent)

__weak_alias(getpwent,__getpwent50)
__weak_alias(getpwent_r,__getpwent_r50)
__weak_alias(getpwuid,__getpwuid50)
__weak_alias(getpwnam,__getpwnam50)
__weak_alias(getpwuid_r,__getpwuid_r50)
__weak_alias(getpwnam_r,__getpwnam_r50)
#endif

#include <sys/param.h>

#include <limits.h>
#include <pwd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

static  int             pwstart(void);
static  int             pwscan(int, uid_t, const char *, struct passwd *,
    char *, size_t);
static  int             pwmatchline(int, uid_t, const char *, struct passwd *,
    char *);

static  FILE            *_pw_fp;
static  struct passwd   _pw_passwd;     /* password structure */
static  int             _pw_stayopen;   /* keep fd's open */
static  int             _pw_filesdone;

#define MAXLINELENGTH   1024

static  char            pwline[MAXLINELENGTH];

struct passwd *
getpwent(void)
{

        if ((!_pw_fp && !pwstart()) ||
            !pwscan(0, 0, NULL, &_pw_passwd, pwline, sizeof(pwline)))
                return (NULL);
        return (&_pw_passwd);
}

int
getpwent_r(struct passwd *pwres, char *buf, size_t bufsiz,
    struct passwd **pwd)
{
        int rval;

        if (!_pw_fp && !pwstart())
                return 1;
        rval = !pwscan(0, 0, NULL, pwres, buf, bufsiz);
        if (rval)
                *pwd = NULL;
        else
                *pwd = pwres;
        return rval;
}

struct passwd *
getpwnam(const char *name)
{
        struct passwd *pwd;
        return getpwnam_r(name, &_pw_passwd, pwline, sizeof(pwline),
            &pwd) == 0 ? pwd : NULL;
}

int
getpwnam_r(const char *name, struct passwd *pwres, char *buf, size_t bufsiz,
    struct passwd **pwd)
{
        int rval;

        if (!pwstart())
                return 1;
        rval = !pwscan(1, 0, name, pwres, buf, bufsiz);
        if (!_pw_stayopen)
                endpwent();
        if (rval)
                *pwd = NULL;
        else
                *pwd = pwres;
        return rval;
}

struct passwd *
getpwuid(uid_t uid)
{
        struct passwd *pwd;
        return getpwuid_r(uid, &_pw_passwd, pwline, sizeof(pwline),
            &pwd) == 0 ? pwd : NULL;
}

int
getpwuid_r(uid_t uid, struct passwd *pwres, char *buf, size_t bufsiz,
    struct passwd **pwd)
{
        int rval;

        if (!pwstart())
                return 1;
        rval = !pwscan(1, uid, NULL, pwres, buf, bufsiz);
        if (!_pw_stayopen)
                endpwent();
        if (rval)
                *pwd = NULL;
        else
                *pwd = pwres;
        return rval;
}

void
setpwent(void)
{

        (void) setpassent(0);
}

int
setpassent(int stayopen)
{

        if (!pwstart())
                return 0;
        _pw_stayopen = stayopen;
        return 1;
}

void
endpwent(void)
{

        _pw_filesdone = 0;
        if (_pw_fp) {
                (void)fclose(_pw_fp);
                _pw_fp = NULL;
        }
}

static int
pwstart(void)
{

        _pw_filesdone = 0;
        if (_pw_fp) {
                rewind(_pw_fp);
                return 1;
        }
        return (_pw_fp = fopen(_PATH_MASTERPASSWD, "r")) ? 1 : 0;
}


static int
pwscan(int search, uid_t uid, const char *name, struct passwd *pwd, char *buf,
    size_t bufsiz)
{

        if (_pw_filesdone)
                return 0;
        for (;;) {
                if (!fgets(buf, bufsiz, _pw_fp)) {
                        if (!search)
                                _pw_filesdone = 1;
                        return 0;
                }
                /* skip lines that are too big */
                if (!strchr(buf, '\n')) {
                        int ch;

                        while ((ch = getc(_pw_fp)) != '\n' && ch != EOF)
                                ;
                        continue;
                }
                if (pwmatchline(search, uid, name, pwd, buf))
                        return 1;
        }
        /* NOTREACHED */
}

static int
pwmatchline(int search, uid_t uid, const char *name, struct passwd *pwd,
    char *buf)
{
        unsigned long   id;
        char            *cp, *bp, *ep;

        /* name may be NULL if search is nonzero */

        bp = buf;
        memset(pwd, 0, sizeof(*pwd));
        pwd->pw_name = strsep(&bp, ":\n");              /* name */
        if (search && name && strcmp(pwd->pw_name, name))
                return 0;

        pwd->pw_passwd = strsep(&bp, ":\n");            /* passwd */

        if (!(cp = strsep(&bp, ":\n")))                         /* uid */
                return 0;
        id = strtoul(cp, &ep, 10);
        if (id > UID_MAX || *ep != '\0')
                return 0;
        pwd->pw_uid = (uid_t)id;
        if (search && name == NULL && pwd->pw_uid != uid)
                return 0;

        if (!(cp = strsep(&bp, ":\n")))                         /* gid */
                return 0;
        id = strtoul(cp, &ep, 10);
        if (id > GID_MAX || *ep != '\0')
                return 0;
        pwd->pw_gid = (gid_t)id;

        if (!(pwd->pw_class = strsep(&bp, ":")))                /* class */
                return 0;
        if (!(ep = strsep(&bp, ":")))                           /* change */
                return 0;
        if (!(ep = strsep(&bp, ":")))                           /* expire */
                return 0;

        if (!(pwd->pw_gecos = strsep(&bp, ":\n")))              /* gecos */
                return 0;
        if (!(pwd->pw_dir = strsep(&bp, ":\n")))                /* directory */
                return 0;
        if (!(pwd->pw_shell = strsep(&bp, ":\n")))              /* shell */
                return 0;

        if (strchr(bp, ':') != NULL)
                return 0;

        return 1;
}