/* Copyright (C) 2005 Christoffer Soop <christoffer at soop dot org>
 * 
 * This 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.
 * 
 * This 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.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include <sys/types.h>
#include <sys/syslog.h>
#include <stdio.h>
#include <vauth.h>
#include <vpopmail.h>


#define BUF_SIZE 1024
#define MAX_PARAMS 4
#define TRUE_RESULT 0x01
#define FALSE_RESULT 0x00

int main() {
	
	char buf[BUF_SIZE + 1];  // Allow for string termination
	char c;
	char* param[MAX_PARAMS];
	param[0] = &buf[0]; // this won't change...
	
	short len; 
	int i,j;
	
	int result;	
	
	openlog( "ejabberd", LOG_NDELAY, LOG_AUTH );
	syslog( LOG_INFO, "Starting ejabberd check_vpopmail" );

	while( 1 ) {		
		// read first two bytes from stdin
		// convert bytes to integer len
		i=0;
		while( i<2 ) {
			c = getchar();
			if( c == EOF ) return 0;
			buf[i++] = c;
		}
		len = buf[0]*256 + buf[1];
		
		if( len == 0 ) {
			syslog( LOG_WARNING, "Packet length is zero" );
			// try again 
			continue;
		} else if( len < 0 ) {
			syslog( LOG_ERR, "Negative packet length; exiting" );
			return 1;
		} else if( len > BUF_SIZE ) {
			syslog( LOG_ERR, "Packet length of %d larger than buffer of size %d", len, BUF_SIZE );
			return 1;
		}

		//syslog( LOG_DEBUG, "packet length %d", len );
		
		// read packet of len bytes from stdin to buffer
		// note: packet is on the form [auth|setpass|isuser]:<user>:<domain>:<password>
		// example: 36auth:christoffer:jabberwocky.se:test
		i=0; j=0; 
		while( i<len & j<MAX_PARAMS ) {
			c = getchar();
			if( c == EOF ) return 0;
			
			// split packet on ':'
			if( c == ':' ) {
				// terminate string
				buf[i] = '\0';
				// store index of next string
				// NB if i==BUF_SIZE-1 this will point to the last positon in the array
				// since the length of the array == BUF_SIZE+1 
				param[++j]=&buf[i]+1;
			} else {
				// store character	
				buf[i]=c;
			}
			i++;
		}
		// terminate the last parameter
		buf[i] = '\0';
		// syslog( LOG_INFO, "op: %s, user: %s, domain: %s, pass: %s", \
				param[0], param[1], param[2], param[3] );

		if( strcmp( param[0], "auth" )==0 ) {
			if( j!=3 ) {
				syslog( LOG_ERR, "Expected exactly four parameters, found %d", j+1 );
				return 1;
			}
			result = (vauth_user( param[1], param[2], param[3], NULL ) != NULL);
			syslog( LOG_DEBUG, \
				"Authentication for user '%s@%s' %s", \
				param[1], \
				param[2], \
				result ? "was successfull" : "failed" );
		} else if( strcmp( param[0], "setpass" )==0 ) { 
			// TODO: Test setpass operation
			if( j!=3 ) {
				syslog( LOG_ERR, "Expected exactly four parameters, found %d", j+1 );
				return 1;
			}
			result = vpasswd( param[1], param[2], param[3], 0 );
			syslog( LOG_INFO, "The password for user '%s@%si' %s changed", \
				param[1], param[2], result == 0 ? "was" : "could not be" );
		} else if( strcmp( param[0], "isuser" )==0 ) {
			// TODO: Test isuser operation
			// FIXME: Find out if the password is sent or not, i.e. if we get
			// 		  three or four parameters.
			if( j<2 ) {
				syslog( LOG_ERR, "Expected at least two parameters, found %d", j+1 );
				return 1;
			}
			// The theory is: if we get a passwd struct back, the user exists...
			result = vauth_getpw( param[1], param[2] ) != NULL;
		} else {
			// if we don't know what to do, the result is a failure
			result = 0;  
			// log warning
			syslog( LOG_ERR, "Unknown operation '%s'", param[0] );
		}			
		// write back the result length (2 bytes)		
		//fputs( "\x00\x02", stdout );
		putchar( 0x00 );
		putchar( 0x02 );
		// write back the result
		putchar( 0x00 );
		putchar( result ? TRUE_RESULT : FALSE_RESULT );
		fflush( stdout );
		// syslog( LOG_DEBUG, "Returned result" );
	}	
	return 0;
}