/*	$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>
#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;
}
