/*
 * ngIRCd -- The Next Generation IRC Daemon
 * Copyright (c)2001,2002 by Alexander Barton (alex@barton.de)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * Please read the file COPYING, README and AUTHORS for more information.
 *
 * Login and logout
 */


#include "portab.h"

static char UNUSED id[] = "$Id: irc-login.c,v 1.34 2003/03/31 15:54:21 alex Exp $";

#include "imp.h"
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "ngircd.h"
#include "resolve.h"
#include "conn-func.h"
#include "conf.h"
#include "client.h"
#include "channel.h"
#include "log.h"
#include "messages.h"
#include "parse.h"
#include "irc.h"
#include "irc-info.h"
#include "irc-write.h"

#include "exp.h"
#include "irc-login.h"


LOCAL BOOLEAN Hello_User PARAMS(( CLIENT *Client ));
LOCAL VOID Kill_Nick PARAMS(( CHAR *Nick, CHAR *Reason ));


GLOBAL BOOLEAN
IRC_PASS( CLIENT *Client, REQUEST *Req )
{
	assert( Client != NULL );
	assert( Req != NULL );

	/* Fehler liefern, wenn kein lokaler Client */
	if( Client_Conn( Client ) <= NONE ) return IRC_WriteStrClient( Client, ERR_UNKNOWNCOMMAND_MSG, Client_ID( Client ), Req->command );
	
	if(( Client_Type( Client ) == CLIENT_UNKNOWN ) && ( Req->argc == 1))
	{
		/* noch nicht registrierte unbekannte Verbindung */
		Log( LOG_DEBUG, "Connection %d: got PASS command ...", Client_Conn( Client ));

		/* Passwort speichern */
		Client_SetPassword( Client, Req->argv[0] );

		Client_SetType( Client, CLIENT_GOTPASS );
		return CONNECTED;
	}
	else if((( Client_Type( Client ) == CLIENT_UNKNOWN ) || ( Client_Type( Client ) == CLIENT_UNKNOWNSERVER )) && (( Req->argc == 3 ) || ( Req->argc == 4 )))
	{
		CHAR c2, c4, *type, *impl, *serverver, *flags, *ptr, *ircflags;
		INT protohigh, protolow;

		/* noch nicht registrierte Server-Verbindung */
		Log( LOG_DEBUG, "Connection %d: got PASS command (new server link) ...", Client_Conn( Client ));

		/* Passwort speichern */
		Client_SetPassword( Client, Req->argv[0] );

		/* Protokollversion ermitteln */
		if( strlen( Req->argv[1] ) >= 4 )
		{
			c2 = Req->argv[1][2];
			c4 = Req->argv[1][4];

			Req->argv[1][4] = '\0';
			protolow = atoi( &Req->argv[1][2] );
			Req->argv[1][2] = '\0';
			protohigh = atoi( Req->argv[1] );
			
			Req->argv[1][2] = c2;
			Req->argv[1][4] = c4;
		}			
		else protohigh = protolow = 0;

		/* Protokoll-Typ */
		if( strlen( Req->argv[1] ) > 4 ) type = &Req->argv[1][4];
		else type = NULL;

		/* IRC-Flags (nach RFC 2813) */
		if( Req->argc >= 4 ) ircflags = Req->argv[3];
		else ircflags = "";

		/* Implementation, Version und ngIRCd-Flags */
		impl = Req->argv[2];
		ptr = strchr( impl, '|' );
		if( ptr ) *ptr = '\0';

		if( type && ( strcmp( type, PROTOIRCPLUS ) == 0 ))
		{
			/* auf der anderen Seite laeuft ein Server, der
			 * ebenfalls das IRC+-Protokoll versteht */
			serverver = ptr + 1;
			flags = strchr( serverver, ':' );
			if( flags )
			{
				*flags = '\0';
				flags++;
			}
			else flags = "";
			Log( LOG_INFO, "Peer announces itself as %s-%s using protocol %d.%d/IRC+ (flags: \"%s\").", impl, serverver, protohigh, protolow, flags );
		}
		else
		{
			/* auf der anderen Seite laeuft ein Server, der
			 * nur das Originalprotokoll unterstuetzt */
			serverver = "";
			if( strchr( ircflags, 'Z' )) flags = "Z";
			else flags = "";
			Log( LOG_INFO, "Peer announces itself as \"%s\" using protocol %d.%d (flags: \"%s\").", impl, protohigh, protolow, flags );
		}

		Client_SetType( Client, CLIENT_GOTPASSSERVER );
		Client_SetFlags( Client, flags );

		return CONNECTED;
	}
	else if(( Client_Type( Client ) == CLIENT_UNKNOWN  ) || ( Client_Type( Client ) == CLIENT_UNKNOWNSERVER ))
	{
		/* Falsche Anzahl Parameter? */
		return IRC_WriteStrClient( Client, ERR_NEEDMOREPARAMS_MSG, Client_ID( Client ), Req->command );
	}
	else return IRC_WriteStrClient( Client, ERR_ALREADYREGISTRED_MSG, Client_ID( Client ));
} /* IRC_PASS */


GLOBAL BOOLEAN
IRC_NICK( CLIENT *Client, REQUEST *Req )
{
	CLIENT *intr_c, *target, *c;
	CHAR *modes;

	assert( Client != NULL );
	assert( Req != NULL );

	/* Zumindest BitchX sendet NICK-USER in der falschen Reihenfolge. */
#ifndef STRICT_RFC
	if( Client_Type( Client ) == CLIENT_UNKNOWN || Client_Type( Client ) == CLIENT_GOTPASS || Client_Type( Client ) == CLIENT_GOTNICK || Client_Type( Client ) == CLIENT_GOTUSER || Client_Type( Client ) == CLIENT_USER || ( Client_Type( Client ) == CLIENT_SERVER && Req->argc == 1 ))
#else
	if( Client_Type( Client ) == CLIENT_UNKNOWN || Client_Type( Client ) == CLIENT_GOTPASS || Client_Type( Client ) == CLIENT_GOTNICK || Client_Type( Client ) == CLIENT_USER || ( Client_Type( Client ) == CLIENT_SERVER && Req->argc == 1 ))
#endif
	{
		/* User-Registrierung bzw. Nick-Aenderung */

		/* Falsche Anzahl Parameter? */
		if( Req->argc != 1 ) return IRC_WriteStrClient( Client, ERR_NEEDMOREPARAMS_MSG, Client_ID( Client ), Req->command );

		/* "Ziel-Client" ermitteln */
		if( Client_Type( Client ) == CLIENT_SERVER )
		{
			target = Client_Search( Req->prefix );
			if( ! target ) return IRC_WriteStrClient( Client, ERR_NOSUCHNICK_MSG, Client_ID( Client ), Req->argv[0] );
		}
		else
		{
			/* Ist der Client "restricted"? */
			if( Client_HasMode( Client, 'r' )) return IRC_WriteStrClient( Client, ERR_RESTRICTED_MSG, Client_ID( Client ));
			target = Client;
		}

#ifndef STRICT_RFC
		/* Wenn der Client zu seinem eigenen Nick wechseln will, so machen
		 * wir nichts. So macht es das Original und mind. Snak hat probleme,
		 * wenn wir es nicht so machen. Ob es so okay ist? Hm ... */
		if( strcmp( Client_ID( target ), Req->argv[0] ) == 0 ) return CONNECTED;
#endif

		/* pruefen, ob Nick bereits vergeben. Speziallfall: der Client
		 * will nur die Gross- und Kleinschreibung aendern. Das darf
		 * er natuerlich machen :-) */
		if( strcasecmp( Client_ID( target ), Req->argv[0] ) != 0 )
		{
			if( ! Client_CheckNick( target, Req->argv[0] )) return CONNECTED;
		}

		if(( Client_Type( target ) != CLIENT_USER ) && ( Client_Type( target ) != CLIENT_SERVER ))
		{
			/* Neuer Client */
			Log( LOG_DEBUG, "Connection %d: got valid NICK command ...", Client_Conn( Client ));

			/* Client-Nick registrieren */
			Client_SetID( target, Req->argv[0] );

			/* schon ein USER da? Dann registrieren! */
			if( Client_Type( Client ) == CLIENT_GOTUSER ) return Hello_User( Client );
			else Client_SetType( Client, CLIENT_GOTNICK );
		}
		else
		{
			/* Nick-Aenderung */
			if( Client_Conn( target ) > NONE )
			{
				/* lokaler Client */
				Log( LOG_INFO, "User \"%s\" changed nick (connection %d): \"%s\" -> \"%s\".", Client_Mask( target ), Client_Conn( target ), Client_ID( target ), Req->argv[0] );
			}
			else
			{
				/* Remote-Client */
				Log( LOG_DEBUG, "User \"%s\" changed nick: \"%s\" -> \"%s\".", Client_Mask( target ), Client_ID( target ), Req->argv[0] );
			}

			/* alle betroffenen User und Server ueber Nick-Aenderung informieren */
			if( Client_Type( Client ) == CLIENT_USER ) IRC_WriteStrClientPrefix( Client, Client, "NICK :%s", Req->argv[0] );
			IRC_WriteStrServersPrefix( Client, target, "NICK :%s", Req->argv[0] );
			IRC_WriteStrRelatedPrefix( target, target, FALSE, "NICK :%s", Req->argv[0] );
			
			/* neuen Client-Nick speichern */
			Client_SetID( target, Req->argv[0] );
		}

		return CONNECTED;
	}
	else if( Client_Type( Client ) == CLIENT_SERVER )
	{
		/* Server fuehrt neuen Client ein */

		/* Falsche Anzahl Parameter? */
		if( Req->argc != 7 ) return IRC_WriteStrClient( Client, ERR_NEEDMOREPARAMS_MSG, Client_ID( Client ), Req->command );

		/* Nick ueberpruefen */
		c = Client_Search( Req->argv[0] );
		if( c )
		{
			/* Der neue Nick ist auf diesem Server bereits registriert:
			 * sowohl der neue, als auch der alte Client muessen nun
			 * disconnectiert werden. */
			Log( LOG_ERR, "Server %s introduces already registered nick \"%s\"!", Client_ID( Client ), Req->argv[0] );
			Kill_Nick( Req->argv[0], "Nick collision" );
			return CONNECTED;
		}

		/* Server, zu dem der Client connectiert ist, suchen */
		intr_c = Client_GetFromToken( Client, atoi( Req->argv[4] ));
		if( ! intr_c )
		{
			Log( LOG_ERR, "Server %s introduces nick \"%s\" on unknown server!?", Client_ID( Client ), Req->argv[0] );
			Kill_Nick( Req->argv[0], "Unknown server" );
			return CONNECTED;
		}

		/* Neue Client-Struktur anlegen */
		c = Client_NewRemoteUser( intr_c, Req->argv[0], atoi( Req->argv[1] ), Req->argv[2], Req->argv[3], atoi( Req->argv[4] ), Req->argv[5] + 1, Req->argv[6], TRUE );
		if( ! c )
		{
			/* Eine neue Client-Struktur konnte nicht angelegt werden.
			 * Der Client muss disconnectiert werden, damit der Netz-
			 * status konsistent bleibt. */
			Log( LOG_ALERT, "Can't create client structure! (on connection %d)", Client_Conn( Client ));
			Kill_Nick( Req->argv[0], "Server error" );
			return CONNECTED;
		}

		modes = Client_Modes( c );
		if( *modes ) Log( LOG_DEBUG, "User \"%s\" (+%s) registered (via %s, on %s, %d hop%s).", Client_Mask( c ), modes, Client_ID( Client ), Client_ID( intr_c ), Client_Hops( c ), Client_Hops( c ) > 1 ? "s": "" );
		else Log( LOG_DEBUG, "User \"%s\" registered (via %s, on %s, %d hop%s).", Client_Mask( c ), Client_ID( Client ), Client_ID( intr_c ), Client_Hops( c ), Client_Hops( c ) > 1 ? "s": "" );

		/* Andere Server, ausser dem Introducer, informieren */
		IRC_WriteStrServersPrefix( Client, Client, "NICK %s %d %s %s %d %s :%s", Req->argv[0], atoi( Req->argv[1] ) + 1, Req->argv[2], Req->argv[3], Client_MyToken( intr_c ), Req->argv[5], Req->argv[6] );

		return CONNECTED;
	}
	else return IRC_WriteStrClient( Client, ERR_ALREADYREGISTRED_MSG, Client_ID( Client ));
} /* IRC_NICK */


GLOBAL BOOLEAN
IRC_USER( CLIENT *Client, REQUEST *Req )
{
	assert( Client != NULL );
	assert( Req != NULL );

#ifndef STRICT_RFC
	if( Client_Type( Client ) == CLIENT_GOTNICK || Client_Type( Client ) == CLIENT_GOTPASS || Client_Type( Client ) == CLIENT_UNKNOWN )
#else
	if( Client_Type( Client ) == CLIENT_GOTNICK || Client_Type( Client ) == CLIENT_GOTPASS )
#endif
	{
		/* Falsche Anzahl Parameter? */
		if( Req->argc != 4 ) return IRC_WriteStrClient( Client, ERR_NEEDMOREPARAMS_MSG, Client_ID( Client ), Req->command );

		Client_SetUser( Client, Req->argv[0], FALSE );
		Client_SetInfo( Client, Req->argv[3] );

		Log( LOG_DEBUG, "Connection %d: got valid USER command ...", Client_Conn( Client ));
		if( Client_Type( Client ) == CLIENT_GOTNICK ) return Hello_User( Client );
		else Client_SetType( Client, CLIENT_GOTUSER );
		return CONNECTED;
	}
	else if( Client_Type( Client ) == CLIENT_USER || Client_Type( Client ) == CLIENT_SERVER || Client_Type( Client ) == CLIENT_SERVICE )
	{
		return IRC_WriteStrClient( Client, ERR_ALREADYREGISTRED_MSG, Client_ID( Client ));
	}
	else return IRC_WriteStrClient( Client, ERR_NOTREGISTERED_MSG, Client_ID( Client ));
} /* IRC_USER */


GLOBAL BOOLEAN
IRC_QUIT( CLIENT *Client, REQUEST *Req )
{
	CLIENT *target;
	
	assert( Client != NULL );
	assert( Req != NULL );

	if ( Client_Type( Client ) == CLIENT_SERVER )
	{
		/* Server */

		/* Falsche Anzahl Parameter? */
		if( Req->argc > 1 ) return IRC_WriteStrClient( Client, ERR_NEEDMOREPARAMS_MSG, Client_ID( Client ), Req->command );

		target = Client_Search( Req->prefix );
		if( ! target )
		{
			/* Den Client kennen wir nicht (mehr), also nichts zu tun. */
			Log( LOG_WARNING, "Got QUIT from %s for unknown client!?", Client_ID( Client ));
			return CONNECTED;
		}

		if( Req->argc == 0 ) Client_Destroy( target, "Got QUIT command.", NULL, TRUE );
		else Client_Destroy( target, "Got QUIT command.", Req->argv[0], TRUE );

		return CONNECTED;
	}
	else
	{
		/* User, Service, oder noch nicht registriert */
		
		/* Falsche Anzahl Parameter? */
		if( Req->argc > 1 ) return IRC_WriteStrClient( Client, ERR_NEEDMOREPARAMS_MSG, Client_ID( Client ), Req->command );

		if( Req->argc == 0 ) Conn_Close( Client_Conn( Client ), "Got QUIT command.", NULL, TRUE );
		else Conn_Close( Client_Conn( Client ), "Got QUIT command.", Req->argv[0], TRUE );
		
		return DISCONNECTED;
	}
} /* IRC_QUIT */


GLOBAL BOOLEAN
IRC_PING( CLIENT *Client, REQUEST *Req )
{
	CLIENT *target, *from;

	assert( Client != NULL );
	assert( Req != NULL );

	/* Falsche Anzahl Parameter? */
	if( Req->argc < 1 ) return IRC_WriteStrClient( Client, ERR_NOORIGIN_MSG, Client_ID( Client ));
#ifdef STRICT_RFC
	if( Req->argc > 2 ) return IRC_WriteStrClient( Client, ERR_NEEDMOREPARAMS_MSG, Client_ID( Client ), Req->command );
#endif

	if( Req->argc > 1 )
	{
		/* es wurde ein Ziel-Client angegeben */
		target = Client_Search( Req->argv[1] );
		if(( ! target ) || ( Client_Type( target ) != CLIENT_SERVER )) return IRC_WriteStrClient( Client, ERR_NOSUCHSERVER_MSG, Client_ID( Client ), Req->argv[1] );
		if( target != Client_ThisServer( ))
		{
			/* ok, forwarden */
			if( Client_Type( Client ) == CLIENT_SERVER ) from = Client_Search( Req->prefix );
			else from = Client;
			if( ! from ) return IRC_WriteStrClient( Client, ERR_NOSUCHSERVER_MSG, Client_ID( Client ), Req->prefix );
			return IRC_WriteStrClientPrefix( target, from, "PING %s :%s", Client_ID( from ), Req->argv[1] );
		}
	}

	Log( LOG_DEBUG, "Connection %d: got PING, sending PONG ...", Client_Conn( Client ));
	return IRC_WriteStrClient( Client, "PONG %s :%s", Client_ID( Client_ThisServer( )), Client_ID( Client ));
} /* IRC_PING */


GLOBAL BOOLEAN
IRC_PONG( CLIENT *Client, REQUEST *Req )
{
	CLIENT *target, *from;

	assert( Client != NULL );
	assert( Req != NULL );

	/* Falsche Anzahl Parameter? */
	if( Req->argc < 1 ) return IRC_WriteStrClient( Client, ERR_NOORIGIN_MSG, Client_ID( Client ));
	if( Req->argc > 2 ) return IRC_WriteStrClient( Client, ERR_NEEDMOREPARAMS_MSG, Client_ID( Client ), Req->command );

	/* forwarden? */
	if( Req->argc == 2 )
	{
		target = Client_Search( Req->argv[1] );
		if(( ! target ) || ( Client_Type( target ) != CLIENT_SERVER )) return IRC_WriteStrClient( Client, ERR_NOSUCHSERVER_MSG, Client_ID( Client ), Req->argv[1] );
		if( target != Client_ThisServer( ))
		{
			/* ok, forwarden */
			if( Client_Type( Client ) == CLIENT_SERVER ) from = Client_Search( Req->prefix );
			else from = Client;
			if( ! from ) return IRC_WriteStrClient( Client, ERR_NOSUCHSERVER_MSG, Client_ID( Client ), Req->prefix );
			return IRC_WriteStrClientPrefix( target, from, "PONG %s :%s", Client_ID( from ), Req->argv[1] );
		}
	}

	/* Der Connection-Timestamp wurde schon beim Lesen aus dem Socket
	 * aktualisiert, daher muss das hier nicht mehr gemacht werden. */

	if( Client_Conn( Client ) > NONE ) Log( LOG_DEBUG, "Connection %d: received PONG. Lag: %ld seconds.", Client_Conn( Client ), time( NULL ) - Conn_LastPing( Client_Conn( Client )));
	else Log( LOG_DEBUG, "Connection %d: received PONG.", Client_Conn( Client ));

	return CONNECTED;
} /* IRC_PONG */


LOCAL BOOLEAN
Hello_User( CLIENT *Client )
{
	assert( Client != NULL );

	/* Passwort ueberpruefen */
	if( strcmp( Client_Password( Client ), Conf_ServerPwd ) != 0 )
	{
		/* Falsches Passwort */
		Log( LOG_ERR, "User \"%s\" rejected (connection %d): Bad password!", Client_Mask( Client ), Client_Conn( Client ));
		Conn_Close( Client_Conn( Client ), NULL, "Bad password", TRUE );
		return DISCONNECTED;
	}

	Log( LOG_NOTICE, "User \"%s\" registered (connection %d).", Client_Mask( Client ), Client_Conn( Client ));

	/* Andere Server informieren */
	IRC_WriteStrServers( NULL, "NICK %s 1 %s %s 1 +%s :%s", Client_ID( Client ), Client_User( Client ), Client_Hostname( Client ), Client_Modes( Client ), Client_Info( Client ));

	if( ! IRC_WriteStrClient( Client, RPL_WELCOME_MSG, Client_ID( Client ), Client_Mask( Client ))) return FALSE;
	if( ! IRC_WriteStrClient( Client, RPL_YOURHOST_MSG, Client_ID( Client ), Client_ID( Client_ThisServer( )), PACKAGE_VERSION, TARGET_CPU, TARGET_VENDOR, TARGET_OS )) return FALSE;
	if( ! IRC_WriteStrClient( Client, RPL_CREATED_MSG, Client_ID( Client ), NGIRCd_StartStr )) return FALSE;
	if( ! IRC_WriteStrClient( Client, RPL_MYINFO_MSG, Client_ID( Client ), Client_ID( Client_ThisServer( )), PACKAGE_VERSION, USERMODES, CHANMODES )) return FALSE;

	/* Features */
	if( ! IRC_WriteStrClient( Client, RPL_ISUPPORT_MSG, Client_ID( Client ), CLIENT_NICK_LEN - 1, CHANNEL_TOPIC_LEN - 1, CLIENT_AWAY_LEN - 1, Conf_MaxJoins )) return DISCONNECTED;

	Client_SetType( Client, CLIENT_USER );

	if( ! IRC_Send_LUSERS( Client )) return DISCONNECTED;
	if( ! IRC_Show_MOTD( Client )) return DISCONNECTED;

	return CONNECTED;
} /* Hello_User */


LOCAL VOID
Kill_Nick( CHAR *Nick, CHAR *Reason )
{
	REQUEST r;

	assert( Nick != NULL );
	assert( Reason != NULL );

	r.prefix = Client_ThisServer( );
	r.argv[0] = Nick;
	r.argv[1] = Reason;
	r.argc = 2;

	Log( LOG_ERR, "User(s) with nick \"%s\" will be disconnected: %s", Nick, Reason );
	IRC_KILL( Client_ThisServer( ), &r );
} /* Kill_Nick */


/* -eof- */