/*
    Copyright (C) 2001,2002 Bernhard R. Link <brlink@debian.org>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License version 2 as
    published by the Free Software Foundation.

    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.

    Please tell me, if you find errors or mistakes.

Based on parts of the GNU C Library:

   Common code for file-based database parsers in nss_files module.
   Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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
   Lesser General Public License for more details.
*/

#define _GNU_SOURCE 1

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <nss.h>
#include <pwd.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include <errno.h>
#include <ctype.h>

#include "s_config.h"

enum nss_status _nss_extrausers_getpwuid_r(uid_t,struct passwd *,char *, size_t,int *);
enum nss_status _nss_extrausers_setpwent (void);
enum nss_status _nss_extrausers_endpwent (void);
enum nss_status _nss_extrausers_getpwnam_r(const char *,struct passwd *,char *,size_t,int *);
enum nss_status _nss_extrausers_getpwent_r(struct passwd *, char *, size_t,int *);

static enum nss_status p_search(FILE *f,const char *name,const uid_t uid,struct passwd *pw, int *errnop,char *buffer, size_t buflen);

static inline enum nss_status p_search(FILE *f,const char *name,const uid_t uid,struct passwd *pw, int *errnop,char *buffer, size_t buflen)
{
#define SANEQUIT {funlockfile(stream);if( f==NULL)  fclose(stream);}
#define TOCOLON(p,h) { while( *p && *p != ':' ) \
				p++; \
			h=p; \
			if(!*p) { \
				SANEQUIT \
				*errnop = 0; \
				return NSS_STATUS_UNAVAIL; \
			} \
			p++; \
			*h='\0'; \
			h--; \
			}
	FILE *stream = f;
	char *p,*h;
	uid_t t_uid;
	gid_t t_gid;
	char *t_name,*t_passwd,*t_gecos,*t_shell,*t_dir;

	if( stream == NULL ) {
		stream = fopen(USERSFILE,"r");
		if( stream == NULL ) {
			*errnop = errno;
			return NSS_STATUS_UNAVAIL;
		}
	}
	flockfile(stream);
	while( 1 ) {
		buffer[buflen - 1] = '\xff';
		p = fgets_unlocked(buffer,buflen,stream);
		if( p == NULL ) {
			if( feof_unlocked(stream) ) {
				SANEQUIT
				*errnop = ENOENT;
				return NSS_STATUS_NOTFOUND;
			} else {
				*errnop = errno;
				SANEQUIT
				return NSS_STATUS_UNAVAIL;
			}
		}
		h = index(p,'\n');
		if( buffer[buflen - 1] != '\xff' || h == NULL ) {
			SANEQUIT
			*errnop = ERANGE;
			return NSS_STATUS_TRYAGAIN;
		}
		while( isspace(*h) && h != p ) {
			*h = '\0';
			h--;
		}

		/* extract name */
		while (isspace (*p))
			++p;
		t_name = p;
		TOCOLON(p,h);
		if( name && strcmp(name,t_name)!=0 )
			continue;
		/* passwd (should be "x" or "!!" or something...) */
		while (isspace (*p))
			++p;
		t_passwd = p;
		TOCOLON(p,h);
		/* extract uid */
		t_uid = strtol(p,&h,10);
		if( *h != ':' ) {
			SANEQUIT
			*errnop = 0;
			return NSS_STATUS_UNAVAIL;
		}
		if( t_uid < MINUID ) {
			continue;
		}
		if( uid != 0 && uid != t_uid) {
			continue;
		}
		p = ++h;
		/* extract gid */
		t_gid = strtol(p,&h,10);
		if( *h != ':' ) {
			SANEQUIT
			*errnop = 0;
			return NSS_STATUS_UNAVAIL;
		}
		if( t_gid < MINGID ) {
			continue;
		}
		p = ++h;
		/* extract gecos */
		while (isspace (*p))
			++p;
		t_gecos = p;
		TOCOLON(p,h);
		/* extract dir */
		while (isspace (*p))
			++p;
		t_dir = p;
		TOCOLON(p,h);
		/* extract shell */
		while (isspace (*p))
			++p;
		t_shell = p;
		if( index(p,':') ) {
			SANEQUIT
			*errnop = 0;
			return NSS_STATUS_UNAVAIL;
		}

		SANEQUIT
		*errnop = 0;
		pw->pw_name = t_name;
		pw->pw_uid = t_uid;
		pw->pw_passwd = t_passwd;
		pw->pw_gid = t_gid;
		pw->pw_gecos = t_gecos;
		pw->pw_dir = t_dir;
		pw->pw_shell = t_shell;
		return NSS_STATUS_SUCCESS;
	}
}

enum nss_status _nss_extrausers_getpwuid_r( uid_t uid, struct passwd *result,
	char *buf, size_t buflen, int *errnop)
{
	*errnop = 0;
	if ( result )
		return p_search(NULL,NULL,uid,result,errnop,buf,buflen);
	else
		return NSS_STATUS_UNAVAIL;
}

enum nss_status _nss_extrausers_getpwnam_r(const char *name, struct passwd *result,
		char *buf, size_t buflen, int *errnop)
{
	*errnop = 0;
	if ( result )
		return p_search(NULL,name,0,result,errnop,buf,buflen);
	else
		return NSS_STATUS_UNAVAIL;
}

static FILE *usersfile = NULL;

enum nss_status _nss_extrausers_setpwent (void)
{

	if ( usersfile != NULL )
	{
		fclose(usersfile);
		usersfile = NULL;
	}
	usersfile = fopen(USERSFILE,"r");
	if ( usersfile == NULL )
	{
		return NSS_STATUS_UNAVAIL;
	}

	return NSS_STATUS_SUCCESS;
}

enum nss_status _nss_extrausers_endpwent (void)
{

	if ( usersfile != NULL )
	{
		fclose(usersfile);
		usersfile = NULL;
	}
	return NSS_STATUS_SUCCESS;
}

enum nss_status _nss_extrausers_getpwent_r (struct passwd *pw,
                char * buffer, size_t buflen,int * errnop)
{
	*errnop = -1;

	if ( pw == NULL )
		return NSS_STATUS_UNAVAIL;
	if ( usersfile == NULL )
		return NSS_STATUS_UNAVAIL;

  	return p_search(usersfile,NULL,0,pw,errnop,buffer,buflen);
}