/* $Id: netserver.c,v 3.109 1995/06/09 18:03:26 bert Exp $
 *
 * XPilot, a multiplayer gravity war game.  Copyright (C) 1991-95 by
 *
 *      Bjørn Stabell        (bjoerns@staff.cs.uit.no)
 *      Ken Ronny Schouten   (kenrsc@stud.cs.uit.no)
 *      Bert Gÿsbers         (bert@mc.bio.uva.nl)
 *
 * 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.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 * This is the server side of the network connnection stuff.
 *
 * We try very hard to not let the game be disturbed by
 * players logging in.  Therefore a new connection
 * passes through several states before it is actively
 * playing.
 * First we make a new connection structure available
 * with a new socket to listen on.  This socket port
 * number is told to the client via the pack mechanism.
 * In this state the client has to send a packet to this
 * newly created socket with its name and playing parameters.
 * If this succeeds the connection advances to its second state.
 * In this second state the essential server configuration
 * like the map and so on is transmitted to the client.
 * If the client has acknowledged all this data then it
 * advances to the third state, which is the
 * ready-but-not-playing-yet state.  In this state the client
 * has some time to do its final initializations, like mapping
 * its user interface windows and so on.
 * When the client is ready to accept frame updates and process
 * keyboard events then it sends the start-play packet.
 * This play packet advances the connection state into the
 * actively-playing state.  A player structure is allocated and
 * initialized and the other human players are told about this new player.
 * The newly started client is told about the already playing players and
 * play has begun.
 * Apart from these four states there are also two intermediate states.
 * These intermediate states are entered when the previous state
 * has filled the reliable data buffer and the client has not
 * acknowledged all the data yet that is in this reliable data buffer.
 * They are so called output drain states.  Not doing anything else
 * then waiting until the buffer is empty.
 * The difference between these two intermediate states is tricky.
 * The second intermediate state is entered after the
 * ready-but-not-playing-yet state and before the actively-playing state.
 * The difference being that in this second intermediate state the client
 * is already considered an active player by the rest of the server
 * but should not get frame updates yet until it has acknowledged its last
 * reliable data.
 *
 * Communication between the server and the clients is only done
 * using UDP datagrams.  The first client/serverized version of XPilot
 * was using TCP only, but this was too unplayable across the Internet,
 * because TCP is a data stream always sending the next byte.
 * If a packet gets lost then the server has to wait for a
 * timeout before a retransmission can occur.  This is too slow
 * for a real-time program like this game, which is more interested
 * in recent events than in sequenced/reliable events.
 * Therefore UDP is now used which gives more network control to the
 * program.
 * Because some data is considered crucial, like the names of
 * new players and so on, there also had to be a mechanism which
 * enabled reliable data transmission.  Here this is done by creating
 * a data stream which is piggybacked on top of the unreliable data
 * packets.  The client acknowledges this reliable data by sending
 * its byte position in the reliable data stream.  So if the client gets
 * a new reliable data packet and it has not had this data before and
 * there is also no data packet missing inbetween, then it advances
 * its byte position and acknowledges this new position to the server.
 * Otherwise it discards the packet and sends its old byte position
 * to the server meaning that it detected a packet loss.
 * The server maintains an acknowledgement timeout timer for each
 * connection so that it can retransmit a reliable data packet
 * if the acknowledgement timer expires.
 */

#include "types.h"
#ifdef VMS
#include <unixio.h>
#include <unixlib.h>
#else
#include <unistd.h>
#endif
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#ifndef  VMS
#include <sys/param.h>
#endif
#if defined(__hpux) || defined(VMS)
#include <time.h>
#else
#if defined(_AIX)
#if !defined(_BSD_INCLUDES)
#define _BSD_INCLUDES
#endif
#include <time.h>
#endif
#ifdef sco
#include <time.h>
#endif
#include <sys/time.h>
#endif
#ifdef VMS
#include <socket.h>
#include <in.h>
#else
#include <sys/socket.h>
#include <netinet/in.h>
#endif
#include <netdb.h>
#include <ctype.h>

#define SERVER
#include "version.h"
#include "config.h"
#include "const.h"
#include "global.h"
#include "proto.h"
#include "map.h"
#include "pack.h"
#include "bit.h"
#include "socklib.h"
#include "net.h"
#define NETSERVER_C
#include "netserver.h"
#include "packet.h"
#include "setup.h"
#undef NETSERVER_C
#include "saudio.h"
#ifdef sco
#undef select		/* Xos.h defines select as XSelect */
#endif

char netserver_version[] = VERSION;

#define MAX_SELECT_FD			(sizeof(int) * 8 - 1)
#define MAX_MOTD_CHUNK			512
#define MAX_RELIABLE_DATA_PACKET_SIZE	1024

static connection_t	*Conn = NULL;
static int		max_connections = 0;
static setup_t		*Setup = NULL;
static int		contact_socket,
			(*playing_receive[256])(int ind),
			(*login_receive[256])(int ind),
			(*drain_receive[256])(int ind);
static FILE		*motd_fp;
int			compress_maps = 1;
int			login_in_progress;


/*
 * Compress the map data using a simple Run Length Encoding algorithm.
 * If there is more than one consecutive byte with the same type
 * then we set the high bit of the byte and then the next byte
 * gives the number of repetitions.
 * This works well for most maps which have lots of series of the
 * same map object and is simple enough to got implemented quickly.
 */
static int Compress_map(unsigned char *map, int size)
{
    int			i, j, k;

    for (i = j = 0; i < size; i++, j++) {
	if (i + 1 < size
	    && map[i] == map[i + 1]) {
	    for (k = 2; i + k < size; k++) {
		if (map[i] != map[i + k]) {
		    break;
		}
		if (k == 255) {
		    break;
		}
	    }
	    map[j] = (map[i] | SETUP_COMPRESSED);
	    map[++j] = k;
	    i += k - 1;
	} else {
	    map[j] = map[i];
	}
    }
    return j;
}

/*
 * Initialize the structure that gives the client information
 * about our setup.  Like the map and playing rules.
 * We only setup this structure once to save time when new
 * players log in during play.
 */
static int Init_setup(void)
{
    int			i, x, y, team, type, size,
			wormhole = 0,
			treasure = 0,
			target = 0,
			base = 0,
			cannon = 0;
    unsigned char	*mapdata, *mapptr;

    if ((mapdata = (unsigned char *) malloc(World.x * World.y)) == NULL) {
	error("No memory for mapdata");
	return -1;
    }
    memset(mapdata, SETUP_SPACE, World.x * World.y);
    mapptr = mapdata;
    errno = 0;
    for (x = 0; x < World.x; x++) {
	for (y = 0; y < World.y; y++, mapptr++) {
	    type = World.block[x][y];
	    switch (type) {
	    case SPACE:		*mapptr = SETUP_SPACE; break;
	    case FILLED:	*mapptr = SETUP_FILLED; break;
	    case REC_RU:	*mapptr = SETUP_REC_RU; break;
	    case REC_RD:	*mapptr = SETUP_REC_RD; break;
	    case REC_LU:	*mapptr = SETUP_REC_LU; break;
	    case REC_LD:	*mapptr = SETUP_REC_LD; break;
	    case FUEL:		*mapptr = SETUP_FUEL; break;
	    case ACWISE_GRAV:	*mapptr = SETUP_ACWISE_GRAV; break;
	    case CWISE_GRAV:	*mapptr = SETUP_CWISE_GRAV; break;
	    case POS_GRAV:	*mapptr = SETUP_POS_GRAV; break;
	    case NEG_GRAV:	*mapptr = SETUP_NEG_GRAV; break;
	    case ITEM_CONCENTRATOR:	*mapptr = SETUP_ITEM_CONCENTRATOR; break;
	    case DECOR_FILLED:	*mapptr = SETUP_DECOR_FILLED; break;
	    case DECOR_RU:	*mapptr = SETUP_DECOR_RU; break;
	    case DECOR_RD:	*mapptr = SETUP_DECOR_RD; break;
	    case DECOR_LU:	*mapptr = SETUP_DECOR_LU; break;
	    case DECOR_LD:	*mapptr = SETUP_DECOR_LD; break;
	    case WORMHOLE:
		switch (World.wormHoles[wormhole++].type) {
		case WORM_NORMAL: *mapptr = SETUP_WORM_NORMAL; break;
		case WORM_IN:     *mapptr = SETUP_WORM_IN; break;
		case WORM_OUT:    *mapptr = SETUP_WORM_OUT; break;
		default:
		    error("Bad wormhole (%d,%d).", x, y);
		    free(mapdata);
		    return -1;
		}
		break;
	    case TREASURE:
		*mapptr = SETUP_TREASURE + World.treasures[treasure++].team;
		break;
	    case TARGET:
		*mapptr = SETUP_TARGET + World.targets[target++].team;
		break;
	    case BASE:
		if (World.base[base].team == TEAM_NOT_SET) {
		    team = 0;
		} else {
		    team = World.base[base].team;
		}
		switch (World.base[base++].dir) {
		case DIR_UP:    *mapptr = SETUP_BASE_UP + team; break;
		case DIR_RIGHT: *mapptr = SETUP_BASE_RIGHT + team; break;
		case DIR_DOWN:  *mapptr = SETUP_BASE_DOWN + team; break;
		case DIR_LEFT:  *mapptr = SETUP_BASE_LEFT + team; break;
		default:
		    error("Bad base at (%d,%d).", x, y);
		    free(mapdata);
		    return -1;
		}
		break;
	    case CANNON:
		switch (World.cannon[cannon++].dir) {
		case DIR_UP:	*mapptr = SETUP_CANNON_UP; break;
		case DIR_RIGHT:	*mapptr = SETUP_CANNON_RIGHT; break;
		case DIR_DOWN:	*mapptr = SETUP_CANNON_DOWN; break;
		case DIR_LEFT:	*mapptr = SETUP_CANNON_LEFT; break;
		default:
		    error("Bad cannon at (%d,%d).", x, y);
		    free(mapdata);
		    return -1;
		}
		break;
	    case CHECK:
		for (i = 0; i < World.NumChecks; i++) {
		    if (x != World.check[i].x
			|| y != World.check[i].y) {
			continue;
		    }
		    *mapptr = SETUP_CHECK + i;
		    break;
		}
		if (i >= World.NumChecks) {
		    error("Bad checkpoint at (%d,%d).", x, y);
		    free(mapdata);
		    return -1;
		}
		break;
	    default:
		error("Unknown map type (%d) at (%d,%d).", type, x, y);
		*mapptr = SETUP_SPACE;
		break;
	    }
	}
    }
    if (compress_maps == 0) {
	type = SETUP_MAP_UNCOMPRESSED;
	size = World.x * World.y;
    } else {
	type = SETUP_MAP_ORDER_XY;
	size = Compress_map(mapdata, World.x * World.y);
	if (size <= 0 || size > World.x * World.y) {
	    errno = 0;
	    error("Map compression error (%d)", size);
	    free(mapdata);
	    return -1;
	}
	if ((mapdata = (unsigned char *)realloc(mapdata, size)) == NULL) {
	    error("Cannot reallocate mapdata");
	    return -1;
	}
    }

#ifndef SILENT
    if (type != SETUP_MAP_UNCOMPRESSED) {
	printf("Map compression ratio is %-4.2f%%\n",
	    100.0 * size / (World.x * World.y));
    }
#endif
    if ((Setup = (setup_t *) malloc(sizeof(setup_t) + size)) == NULL) {
	error("No memory to hold setup");
	free(mapdata);
	return -1;
    }
    memset(Setup, 0, sizeof(setup_t) + size);
    memcpy(Setup->map_data, mapdata, size);
    free(mapdata);
    Setup->setup_size = ((char *) &Setup->map_data[0] - (char *) Setup) + size;
    Setup->map_data_len = size;
    Setup->map_order = type;
    Setup->frames_per_second = FPS;
    Setup->lives = World.rules->lives;
    Setup->mode = World.rules->mode;
    Setup->x = World.x;
    Setup->y = World.y;
    strncpy(Setup->name, World.name, sizeof(Setup->name) - 1);
    Setup->name[sizeof(Setup->name) - 1] = '\0';
    strncpy(Setup->author, World.author, sizeof(Setup->author) - 1);
    Setup->author[sizeof(Setup->author) - 1] = '\0';

    return 0;
}

/*
 * Initialize the function dispatch tables for the various client
 * connection states.  Some states use the same table.
 */
void Init_receive(void)
{
    int			i;

    for (i = 0; i < 256; i++) {
	login_receive[i] = Receive_undefined;
	playing_receive[i] = Receive_undefined;
	drain_receive[i] = Receive_undefined;
    }

    drain_receive[PKT_QUIT]			= Receive_quit;
    drain_receive[PKT_ACK]			= Receive_ack;
    drain_receive[PKT_VERIFY]			= Receive_discard;
    drain_receive[PKT_PLAY]			= Receive_discard;
    drain_receive[PKT_SHAPE]			= Receive_discard;

    login_receive[PKT_PLAY]			= Receive_play;
    login_receive[PKT_QUIT]			= Receive_quit;
    login_receive[PKT_ACK]			= Receive_ack;
    login_receive[PKT_VERIFY]			= Receive_discard;
    login_receive[PKT_POWER]			= Receive_power;
    login_receive[PKT_POWER_S]			= Receive_power;
    login_receive[PKT_TURNSPEED]		= Receive_power;
    login_receive[PKT_TURNSPEED_S]		= Receive_power;
    login_receive[PKT_TURNRESISTANCE]		= Receive_power;
    login_receive[PKT_TURNRESISTANCE_S]		= Receive_power;
    login_receive[PKT_DISPLAY]			= Receive_display;
    login_receive[PKT_MODIFIERBANK]		= Receive_modifier_bank;
    login_receive[PKT_MOTD]			= Receive_motd;
    login_receive[PKT_SHAPE]			= Receive_shape;
    login_receive[PKT_REQUEST_AUDIO]		= Receive_audio_request;
    login_receive[PKT_ASYNC_FPS]		= Receive_fps_request;

    playing_receive[PKT_ACK]			= Receive_ack;
    playing_receive[PKT_VERIFY]			= Receive_discard;
    playing_receive[PKT_PLAY]			= Receive_play;
    playing_receive[PKT_QUIT]			= Receive_quit;
    playing_receive[PKT_KEYBOARD]		= Receive_keyboard;
    playing_receive[PKT_POWER]			= Receive_power;
    playing_receive[PKT_POWER_S]		= Receive_power;
    playing_receive[PKT_TURNSPEED]		= Receive_power;
    playing_receive[PKT_TURNSPEED_S]		= Receive_power;
    playing_receive[PKT_TURNRESISTANCE]		= Receive_power;
    playing_receive[PKT_TURNRESISTANCE_S]	= Receive_power;
    playing_receive[PKT_ACK_CANNON]		= Receive_ack_cannon;
    playing_receive[PKT_ACK_FUEL]		= Receive_ack_fuel;
    playing_receive[PKT_ACK_TARGET]		= Receive_ack_target;
    playing_receive[PKT_TALK]			= Receive_talk;
    playing_receive[PKT_DISPLAY]		= Receive_display;
    playing_receive[PKT_MODIFIERBANK]		= Receive_modifier_bank;
    playing_receive[PKT_MOTD]			= Receive_motd;
    playing_receive[PKT_SHAPE]			= Receive_shape;
    playing_receive[PKT_POINTER_MOVE]		= Receive_pointer_move;
    playing_receive[PKT_REQUEST_AUDIO]		= Receive_audio_request;
    playing_receive[PKT_ASYNC_FPS]		= Receive_fps_request;
}

/*
 * Initialize the connection structures.
 */
int Setup_net_server(int maxconn, int contsock)
{
    size_t	size;

    contact_socket = contsock;

    Init_receive();

    if (Init_setup() == -1) {
	return -1;
    }
    /*
     * The number of connections is limited by the number of bases
     * and the max number of possible file descriptors to use in
     * the select(2) call minus those for stdin, stdout, stderr,
     * the contact socket, and the socket for the resolver library routines.
     */
    max_connections = MIN(MAX_SELECT_FD - 5, maxconn);
    size = max_connections * sizeof(*Conn);
    if ((Conn = (connection_t *) malloc(size)) == NULL) {
	error("Cannot allocate memory for connections");
	return -1;
    }
    memset(Conn, 0, size);

    return 0;
}

/*
 * Cleanup a connection.  The client may not know yet that
 * it is thrown out of the game so we send it a quit packet.
 * We send it twice because of UDP it could get lost.
 * Since 3.0.6 the client receives a short message
 * explaining why the connection was terminated.
 */
void Destroy_connection(int ind, char *reason)
{
    connection_t	*connp = &Conn[ind];
    int			id,
			len,
			sock;
    char		pkt[MAX_CHARS];

    if (connp->state == CONN_FREE) {
	errno = 0;
	error("Cannot destroy empty connection (\"%s\")", reason);
	return;
    }
    sock = connp->w.sock;
    strncpy(&pkt[1], reason, sizeof(pkt) - 2);
    pkt[sizeof(pkt) - 1] = '\0';
    pkt[0] = PKT_QUIT;
    len = strlen(pkt) + 1;
    if (DgramWrite(sock, pkt, len) != len) {
	GetSocketError(sock);
	DgramWrite(sock, pkt, len);
    }
#ifndef SILENT
    printf("Goodbye %s=%s@%s|%s (\"%s\")\n",
	    connp->nick ? connp->nick : "",
	    connp->real ? connp->real : "",
	    connp->host ? connp->host : "",
	    connp->dpy ? connp->dpy : "",
	    reason);
#endif
    connp->state = CONN_FREE;
    if (connp->id != -1) {
	id = connp->id;
	connp->id = -1;
	Players[GetInd[id]]->conn = NOT_CONNECTED;
	Delete_player(GetInd[id]);
    }
    if (connp->real != NULL) {
	free(connp->real);
    }
    if (connp->nick != NULL) {
	free(connp->nick);
    }
    if (connp->dpy != NULL) {
	free(connp->dpy);
    }
    if (connp->addr != NULL) {
	free(connp->addr);
    }
    if (connp->host != NULL) {
	free(connp->host);
    }
    Sockbuf_cleanup(&connp->w);
    Sockbuf_cleanup(&connp->r);
    Sockbuf_cleanup(&connp->c);
    memset(connp, 0, sizeof(*connp));

    /* Tell the meta server */
    Send_meta_server(1);

    if (DgramWrite(sock, pkt, len) != len) {
	GetSocketError(sock);
	DgramWrite(sock, pkt, len);
    }
    DgramClose(sock);
}

/*
 * A client has requested a playing connection with this server.
 * See if we have room for one more player and if his name is not
 * already in use by some other player.  Because the confirmation
 * may get lost we are willing to send it another time if the
 * client connection is still in the CONN_LISTENING state.
 */
int Setup_connection(char *real, char *nick, char *dpy,
		     int team, char *addr, char *host, unsigned version)
{
    int			i,
			free_conn_index = max_connections,
			my_port,
			sock;
    connection_t	*connp;

    for (i = 0; i < max_connections; i++) {
	connp = &Conn[i];
	if (connp->state == CONN_FREE) {
	    if (free_conn_index == max_connections) {
		free_conn_index = i;
	    }
	    continue;
	}
	if (strcasecmp(connp->nick, nick) == 0) {
	    if (connp->state == CONN_LISTENING
		&& team == connp->team
		&& strcmp(real, connp->real) == 0
		&& strcmp(dpy, connp->dpy) == 0
		&& version == connp->version) {
		/*
		 * May happen for multi-homed hosts
		 * and if previous packet got lost.
		 */
		login_in_progress = 1;
		return connp->my_port;
	    } else {
		/*
		 * Nick already in use.
		 */
		return -1;
	    }
	}
    }

    if (free_conn_index >= max_connections) {
#ifndef SILENT
	printf("Full house for %s(%s)@%s(%s)\n", real, nick, host, dpy);
#endif
	return -1;
    }
    connp = &Conn[free_conn_index];

    if ((sock = CreateDgramSocket(0)) == -1) {
	error("Cannot create datagram socket (%d)", sl_errno);
	return -1;
    }
    if (sock >= MAX_SELECT_FD) {
	/* Not handled with our current oldfashioned use of select(2). */
	errno = 0;
	error("Socket filedescriptor too big");
	DgramClose(sock);
	return -1;
    }
    if ((my_port = GetPortNum(sock)) == 0) {
	error("Cannot get port from socket");
	DgramClose(sock);
	return -1;
    }
    if (SetSocketNonBlocking(sock, 1) == -1) {
	error("Cannot make client socket non-blocking");
	DgramClose(sock);
	return -1;
    }
    if (SetSocketReceiveBufferSize(sock, SERVER_RECV_SIZE + 256) == -1) {
	error("Cannot set receive buffer size to %d", SERVER_RECV_SIZE + 256);
    }
    if (SetSocketSendBufferSize(sock, SERVER_SEND_SIZE + 256) == -1) {
	error("Cannot set send buffer size to %d", SERVER_SEND_SIZE + 256);
    }

    Sockbuf_init(&connp->w, sock, SERVER_SEND_SIZE,
		 SOCKBUF_WRITE | SOCKBUF_DGRAM);

    Sockbuf_init(&connp->r, sock, SERVER_RECV_SIZE,
		 SOCKBUF_READ | SOCKBUF_DGRAM);

    Sockbuf_init(&connp->c, -1, MAX_SOCKBUF_SIZE,
		 SOCKBUF_WRITE | SOCKBUF_READ | SOCKBUF_LOCK);

    connp->my_port = my_port;
    connp->real = strdup(real);
    connp->nick = strdup(nick);
    connp->dpy = strdup(dpy);
    connp->addr = strdup(addr);
    connp->host = strdup(host);
    connp->ship = NULL;
    connp->team = team;
    connp->version = version;
    connp->state = CONN_LISTENING;
    connp->start = loops;
    connp->magic = rand() + my_port + sock + team + loops;
    connp->id = -1;
    connp->last_key_change = 0;
    connp->reliable_offset = 0;
    connp->reliable_unsent = 0;
    connp->last_send_loops = 0;
    connp->retransmit_at_loop = 0;
    connp->rtt_retransmit = DEFAULT_RETRANSMIT;
    connp->rtt_smoothed = 0;
    connp->rtt_dev = 0;
    connp->rtt_timeouts = 0;
    connp->acks = 0;
    connp->setup = 0;
    connp->motd_offset = -1;
    connp->motd_stop = 0;
    connp->view_width = DEF_VIEW_SIZE;
    connp->view_height = DEF_VIEW_SIZE;
    connp->debris_colors = 0;
    connp->spark_rand = DEF_SPARK_RAND;
    if (connp->w.buf == NULL
	|| connp->r.buf == NULL
	|| connp->c.buf == NULL
	|| connp->real == NULL
	|| connp->nick == NULL
	|| connp->dpy == NULL
	|| connp->addr == NULL
	|| connp->host == NULL
	) {
	error("Not enough memory for connection");
	/* socket is not yet connected, but it doesn't matter much. */
	Destroy_connection(free_conn_index, "no memory");
	return -1;
    }

    login_in_progress++;

    return my_port;
}

/*
 * Handle a connection that is in the listening state.
 */
static int Handle_listening(int ind)
{
    connection_t	*connp = &Conn[ind];
    unsigned char	type;
    int			n;
    char		nick[MAX_NAME_LEN],
			real[MAX_NAME_LEN];

    if (connp->state != CONN_LISTENING) {
	Destroy_connection(ind, "not listening");
	return -1;
    }
    Sockbuf_clear(&connp->r);
    errno = 0;
    n = DgramReceiveAny(connp->r.sock, connp->r.buf, connp->r.size);
    if (n <= 0) {
	if (n == 0
	    || errno == EWOULDBLOCK
	    || errno == EAGAIN) {
	    n = 0;
	}
	else if (n != 0) {
	    Destroy_connection(ind, "read first packet error");
	}
	return n;
    }
    connp->r.len = n;
    connp->his_port = DgramLastport();
    if (DgramConnect(connp->w.sock, connp->addr, connp->his_port) == -1) {
	error("Cannot connect datagram socket (%s,%d)",
	      connp->host, connp->his_port);
	Destroy_connection(ind, "connect error");
	return -1;
    }
#ifndef SILENT
    printf("Welcome %s=%s@%s|%s (%s/%d)", connp->nick, connp->real,
	   connp->host, connp->dpy, connp->addr, connp->his_port);
    if (connp->version != MY_VERSION)
	printf(" (version %04x)", connp->version);
    printf("\n");
#endif
    if (connp->r.ptr[0] != PKT_VERIFY) {
	Send_reply(ind, PKT_VERIFY, PKT_FAILURE);
	Send_reliable(ind);
	Destroy_connection(ind, "not connecting");
	return -1;
    }
    if ((n = Packet_scanf(&connp->r, "%c%s%s",
			  &type, real, nick)) <= 0) {
	Send_reply(ind, PKT_VERIFY, PKT_FAILURE);
	Send_reliable(ind);
	Destroy_connection(ind, "verify incomplete");
	return -1;
    }
    if (strcmp(real, connp->real) != 0
	|| strcmp(nick, connp->nick) != 0) {
#ifndef SILENT
	printf("Client verified incorrectly (%s,%s)(%s,%s)",
	       real, nick, connp->real, connp->nick);
#endif
	Send_reply(ind, PKT_VERIFY, PKT_FAILURE);
	Send_reliable(ind);
	Destroy_connection(ind, "verify incorrect");
	return -1;
    }
    Sockbuf_clear(&connp->w);
    if (Send_reply(ind, PKT_VERIFY, PKT_SUCCESS) == -1
	|| Packet_printf(&connp->c, "%c%u", PKT_MAGIC, connp->magic) <= 0
	|| Send_reliable(ind) <= 0) {
	Destroy_connection(ind, "confirm failed");
	return -1;
    }
    connp->state = CONN_DRAIN;
    connp->drain_state = CONN_SETUP;
    connp->start = loops;

    return 1;	/* success! */
}

/*
 * Handle a connection that is in the transmit-server-configuration-data state.
 */
static int Handle_setup(int ind)
{
    connection_t	*connp = &Conn[ind];
    char		*buf;
    int			n,
			len;

    if (connp->state != CONN_SETUP) {
	Destroy_connection(ind, "not setup");
	return -1;
    }

    if (connp->setup == 0) {
	n = Packet_printf(&connp->c,
			  "%ld" "%ld%hd" "%hd%hd" "%hd%hd" "%s%s",
			  Setup->map_data_len,
			  Setup->mode, Setup->lives,
			  Setup->x, Setup->y,
			  Setup->frames_per_second, Setup->map_order,
			  Setup->name, Setup->author);
	if (n <= 0) {
	    Destroy_connection(ind, "setup 0 write error");
	    return -1;
	}
	connp->setup = (char *) &Setup->map_data[0] - (char *) Setup;
    }
    else if (connp->setup < Setup->setup_size) {
	if (connp->c.len > 0) {
	    /* If there is still unacked reliable data test for acks. */
	    if ((n = Handle_input(ind)) == -1) {
		return -1;
	    }
	}
    }
    if (connp->setup < Setup->setup_size) {
	len = MIN(connp->c.size, 4096) - connp->c.len;
	if (len <= 0) {
	    /* Wait for acknowledgement of previously transmitted data. */
	    return 0;
	}
	if (len > Setup->setup_size - connp->setup) {
	    len = Setup->setup_size - connp->setup;
	}
	buf = (char *) Setup;
	if (Sockbuf_write(&connp->c, &buf[connp->setup], len) != len) {
	    Destroy_connection(ind, "sockbuf write setup error");
	    return -1;
	}
	connp->setup += len;
	if (len >= 512) {
	    connp->start += (len * FPS) / (8 * 512) + 1;
	}
    }
    if (connp->setup >= Setup->setup_size) {
	connp->state = CONN_DRAIN;
	connp->drain_state = CONN_LOGIN;
	connp->start = loops;
    }

    return 0;
}

/*
 * A client has requested to start active play.
 * See if we can allocate a player structure for it
 * and if this succeeds update the player information
 * to all connected players.
 */
static int Handle_login(int ind)
{
    connection_t	*connp = &Conn[ind];
    player		*pl;
    int			i,
			war_on_id,
			conn_bit;
    char		msg[MSG_LEN];

    if (NumPlayers >= World.NumBases) {
	errno = 0;
	error("Not enough bases for players");
	return -1;
    }
    if (Id >= MAX_ID) {
	errno = 0;
	error("Id too big (%d)", Id);
	return -1;
    }
    if (BIT(World.rules->mode, TEAM_PLAY)) {
	if (connp->team < 0 || connp->team >= MAX_TEAMS) {
	    errno = 0;
	    error("Invalid team %d", connp->team);
	    return -1;
	}
	Check_team_members (connp->team);
	if (World.teams[connp->team].NumMembers
	    >= World.teams[connp->team].NumBases) {
	    errno = 0;
	    error("Not enough bases for team %d", connp->team);
	    return -1;
	}
    } else {
	connp->team = TEAM_NOT_SET;
    }
    for (i = 0; i < NumPlayers; i++) {
	if (strcasecmp(Players[i]->name, connp->nick) == 0) {
	    errno = 0;
	    error("Name already in use %s", connp->nick);
	    return -1;
	}
    }
    Init_player(NumPlayers, connp->ship);
    pl = Players[NumPlayers];
    strcpy(pl->name, connp->nick);
    strcpy(pl->realname, connp->real);
    strcpy(pl->hostname, connp->host);
    if (connp->team != TEAM_NOT_SET) {
	pl->team = connp->team;
    }
    pl->version = connp->version;

    Pick_startpos(NumPlayers);
    Go_home(NumPlayers);
    if (pl->team != TEAM_NOT_SET) {
	World.teams[pl->team].NumMembers++;
    }
    NumPlayers++;
    connp->id = Id++;
    pl->conn = ind;
    memset(pl->last_keyv, 0, sizeof(pl->last_keyv));
    memset(pl->prev_keyv, 0, sizeof(pl->prev_keyv));
    pl->key_changed = 0;

    connp->state = CONN_READY;
    connp->drain_state = CONN_PLAYING;
    connp->start = loops;

    if (Send_reply(ind, PKT_PLAY, PKT_SUCCESS) <= 0) {
	error("Cannot send play reply");
	return -1;
    }

#ifndef	SILENT
    printf("%s (%d) starts at startpos %d.\n",
	   pl->name, NumPlayers, pl->home_base);
#endif

    /*
     * Tell him about himself first.
     */
    Send_player(pl->conn, pl->id);
    Send_score(pl->conn, pl->id, pl->score, pl->life, pl->mychar);
    Send_base(pl->conn, pl->id, pl->home_base);
    /*
     * And tell him about all the others.
     */
    for (i = 0; i < NumPlayers - 1; i++) {
	Send_player(pl->conn, Players[i]->id);
	Send_score(pl->conn, Players[i]->id,
		   Players[i]->score, Players[i]->life, Players[i]->mychar);
	if (!IS_TANK_IND(i)) {
	    Send_base(pl->conn, Players[i]->id, Players[i]->home_base);
	}
    }
    /*
     * And tell all the others about him.
     */
    for (i = 0; i < NumPlayers - 1; i++) {
	if (Players[i]->conn != NOT_CONNECTED) {
	    Send_player(Players[i]->conn, pl->id);
	    Send_score(Players[i]->conn, pl->id, pl->score,
		       pl->life, pl->mychar);
	    Send_base(Players[i]->conn, pl->id, pl->home_base);
	}
	/*
	 * And tell him about the relationships others have with eachother.
	 */
	else if (IS_ROBOT_IND(i)) {
	    if ((war_on_id = Robot_war_on_player(i)) != -1) {
		Send_war(pl->conn, Players[i]->id, war_on_id);
	    }
	}
    }

    if (NumPlayers == 1) {
	sprintf(msg, "Welcome to \"%s\", made by %s.",
		World.name, World.author);
    } else if (BIT(World.rules->mode, TEAM_PLAY)) {
	sprintf(msg, "%s (%s, team %d) has entered \"%s\", made by %s.",
		pl->name, pl->realname, pl->team, World.name, World.author);
    } else {
	sprintf(msg, "%s (%s) has entered \"%s\", made by %s.",
		pl->name, pl->realname, World.name, World.author);
    }
    Set_message(msg);

    conn_bit = (1 << ind);
    for (i = 0; i < World.NumCannons; i++) {
	/*
	 * The client assumes at startup that all cannons are active.
	 */
	if (World.cannon[i].dead_time == 0) {
	    SET_BIT(World.cannon[i].conn_mask, conn_bit);
	} else {
	    CLR_BIT(World.cannon[i].conn_mask, conn_bit);
	}
    }
    for (i = 0; i < World.NumFuels; i++) {
	/*
	 * The client assumes at startup that all fuelstations are filled.
	 */
	if (World.fuel[i].fuel == MAX_STATION_FUEL) {
	    SET_BIT(World.fuel[i].conn_mask, conn_bit);
	} else {
	    CLR_BIT(World.fuel[i].conn_mask, conn_bit);
	}
    }
    for (i = 0; i < World.NumTargets; i++) {
	/*
	 * The client assumes at startup that all targets are not damaged.
	 */
	if (World.targets[i].dead_time == 0
	    && World.targets[i].damage == TARGET_DAMAGE) {
	    SET_BIT(World.targets[i].conn_mask, conn_bit);
	    CLR_BIT(World.targets[i].update_mask, conn_bit);
	} else {
	    CLR_BIT(World.targets[i].conn_mask, conn_bit);
	    SET_BIT(World.targets[i].update_mask, conn_bit);
	}
    }

    sound_player_init(pl);

    sound_play_all(START_SOUND);

    return 0;
}

/*
 * Process a client packet.
 * The client may be in one of several states,
 * therefore we use function dispatch tables for easy processing.
 * Some functions may process requests from clients being
 * in different states.
 */
static int Handle_input(int ind)
{
    connection_t	*connp = &Conn[ind];
    int			type,
			login = 0,
			result,
			(**receive_tbl)(int ind);

    if (connp->state & (CONN_PLAYING | CONN_READY)) {
	receive_tbl = &playing_receive[0];
    }
    else if (connp->state == CONN_LOGIN) {
	receive_tbl = &login_receive[0];
    }
    else if (connp->state & (CONN_DRAIN | CONN_SETUP)) {
	receive_tbl = &drain_receive[0];
    }
    else if (connp->state == CONN_LISTENING) {
	return Handle_listening(ind);
    } else {
	if (connp->state != CONN_FREE) {
	    Destroy_connection(ind, "not input");
	}
	return -1;
    }
    connp->num_keyboard_updates = 0;

    Sockbuf_clear(&connp->r);
    if (Sockbuf_read(&connp->r) == -1) {
	Destroy_connection(ind, "input error");
	return -1;
    }
    if (connp->r.len <= 0) {
	/*
	 * No input.
	 */
	return 0;
    }
    while (connp->r.ptr < connp->r.buf + connp->r.len) {
	type = (connp->r.ptr[0] & 0xFF);
	result = (*receive_tbl[type])(ind);
	if (result == -1) {
	    /*
	     * Unrecoverable error.
	     * Connection has been destroyed.
	     */
	    return -1;
	}
	if (result == 0) {
	    /*
	     * Incomplete client packet.
	     * Drop rest of packet.
	     */
	    Sockbuf_clear(&connp->r);
	    break;
	}
	if (result == 2) {
	    /*
	     * A new player has started playing.
	     */
	    login = 1;
	}
    }
    return 1 + login;
}

int Input(void)
{
    int			i,
			j,
			n,
			r,
			ind,
			max,
			sock,
			state,
			found,
			fdmask,
			count,
			save_mask,
			contact_mask,
			num_input = 0,
			num_logins = 0,
			num_reliable = 0,
			input_fd_bit[MAX_SELECT_FD],
			input_ind[MAX_SELECT_FD],
			input_reliable[MAX_SELECT_FD];
    connection_t	*connp;
    struct timeval	tv;
    char		msg[MSG_LEN];

    login_in_progress = 0;

    contact_mask = (1 << contact_socket);
    max = contact_socket;
    fdmask = contact_mask;

    for (i = 0; i < max_connections; i++) {
	connp = &Conn[i];
	if (connp->state == CONN_FREE) {
	    continue;
	}
	if (loops - connp->start > CONNECTION_TIMEOUT) {
	    /*
	     * Timeout this fellow if we have not heard a single thing
	     * from him for a long time.
	     */
	    if (connp->state & (CONN_PLAYING | CONN_READY)) {
		sprintf(msg, "%s mysteriously disappeared!?", connp->nick);
		Set_message(msg);
	    }
	    Destroy_connection(i, "timeout");
	    continue;
	}
	if (connp->state != CONN_PLAYING) {
	    login_in_progress++;
	    input_reliable[num_reliable++] = i;
	    if (connp->state == CONN_SETUP) {
		Handle_setup(i);
		continue;
	    }
	}
	sock = connp->r.sock;
	SET_BIT(fdmask, 1 << sock);
	input_fd_bit[num_input] = (1 << sock);
	input_ind[num_input] = i;
	num_input++;
	if (sock > max) {
	    max = sock;
	}
    }

    /*
     * Clients should limit the number of packets sent.
     */
    count = 5;

    for (save_mask = fdmask; count-- > 0; fdmask = save_mask) {
	tv.tv_sec = 0;
	tv.tv_usec = 0;
	n = select(max + 1, &fdmask, NULL, NULL, &tv);
	if (n <= 0) {
	    if (n == 0) {
		/* No input */
		break;
	    }
	    if (errno == EINTR) {
		/* Interrupted */
		continue;
	    }
	    /*
	     * One of the connections was destroyed.
	     * See if we can recover from this.
	     * This is a dirty hack, which needs a better fix.
	     */
	    found = 0;
	    for (i = 0; i < num_input; i++) {
		ind = input_ind[i];
		connp = &Conn[ind];
		if (connp->state == CONN_FREE) {
		    found++;
		    /*
		     * Oops indeed.
		     */
		    CLR_BIT(save_mask, input_fd_bit[i]);
		    for (j = 0; j < num_reliable; j++) {
			if (input_reliable[j] == ind) {
			    input_reliable[j--]
				    = input_reliable[--num_reliable];
			}
		    }
		    --num_input;
		    input_ind[i] = input_ind[num_input];
		    input_fd_bit[i] = input_fd_bit[num_input];
		    i--;
		}
	    }
	    if (found > 0) {
		continue;
	    }
	    error("Select Input");
	    End_game();
	}
	for (i = 0; i < num_input; i++) {
	    if (BIT(fdmask, input_fd_bit[i])) {
		ind = input_ind[i];
		connp = &Conn[ind];
		state = connp->state;
		if ((r = Handle_input(ind)) == -1) {
		    CLR_BIT(save_mask, input_fd_bit[i]);
		    if (state != CONN_PLAYING) {
			login_in_progress--;
		    }
		    if (num_input-- <= 1) {
			count = 0;
			break;
		    }
		    if (i < num_input) {
			input_fd_bit[i] = input_fd_bit[num_input];
			input_ind[i] = input_ind[num_input];
			i--;
		    }
		}
		else if (r > 0) {
		    if (connp->state == CONN_PLAYING) {
			connp->start = loops;
		    }
		    else if (r == 2) {
			num_logins++;
		    }
		}
		if (n-- <= 1) {
		    break;
		}
	    }
	}
	if (fdmask & contact_mask) {
	    Contact();
	}
    }

    for (i = 0; i < num_reliable; i++) {
	ind = input_reliable[i];
	connp = &Conn[ind];
	if (connp->state & (CONN_DRAIN | CONN_READY | CONN_SETUP
			    | CONN_LOGIN)) {
	    if (connp->c.len > 0) {
		if (Send_reliable(ind) == -1) {
		    continue;
		}
	    }
	}
    }

    if (num_logins > 0) {
	/* Tell the meta server */
	Send_meta_server(1);
    }

    return num_logins;
}

/*
 * Send a reply to a special client request.
 * Not used consistently everywhere.
 * It could be used to setup some form of reliable
 * communication from the client to the server.
 */
int Send_reply(int ind, int replyto, int result)
{
    connection_t	*connp = &Conn[ind];
    int			n;

    n = Packet_printf(&connp->c, "%c%c%c", PKT_REPLY, replyto, result);
    if (n == -1) {
	Destroy_connection(ind, "write error");
	return -1;
    }
    return n;
}

/*
 * Send all frame data related to the player self and his HUD.
 */
int Send_self(int ind,
	      player *pl,
	      int lock_id,
	      int lock_dist,
	      int lock_dir,
	      int autopilotlight,
	      long status,
	      char *mods)
{
    connection_t	*connp = &Conn[ind];
    int			n;
    u_byte		stat = status;
    int			sbuf_len = connp->w.len;

    n = Packet_printf(&connp->w,
		      "%c"
		      "%hd%hd%hd%hd%c"
		      "%c%c%c"
		      "%hd%hd%c%c"
		      "%c%c%c%c%c"
		      "%c%c%c%c%c"
		      "%c%c%c%c"
		      "%c%hd%hd"
		      "%hd%hd%c"
		      "%c%c"
		      ,
		      PKT_SELF,
		      (int) (pl->pos.x + 0.5), (int) (pl->pos.y + 0.5),
		      (int) pl->vel.x, (int) pl->vel.y,
		      pl->dir,
		      (int) (pl->power + 0.5),
		      (int) (pl->turnspeed + 0.5),
		      (int) (pl->turnresistance * 255.0 + 0.5),
		      lock_id, lock_dist, lock_dir,
		      pl->check,

		      pl->item[ITEM_CLOAK],
		      pl->item[ITEM_SENSOR],
		      pl->item[ITEM_MINE],
		      pl->item[ITEM_MISSILE],
		      pl->item[ITEM_ECM],

		      pl->item[ITEM_TRANSPORTER],
		      pl->item[ITEM_WIDEANGLE],
		      pl->item[ITEM_REARSHOT],
		      pl->item[ITEM_AFTERBURNER],
		      pl->fuel.num_tanks,

		      pl->item[ITEM_LASER],
		      pl->item[ITEM_EMERGENCY_THRUST],
		      pl->item[ITEM_TRACTOR_BEAM],
		      pl->item[ITEM_AUTOPILOT],

		      pl->fuel.current,
		      pl->fuel.sum >> FUEL_SCALE_BITS,
		      pl->fuel.max >> FUEL_SCALE_BITS,

		      connp->view_width, connp->view_height,
		      connp->debris_colors,

		      stat,
		      autopilotlight

		      );
    if (n <= 0) {
	return n;
    }
    if (connp->version >= 0x3200) {
	n = Packet_printf(&connp->w,
			  "%c",
			  pl->item[ITEM_EMERGENCY_SHIELD]);
	if (n <= 0) {
	    connp->w.len = sbuf_len;
	}
    }
    n = Packet_printf(&Conn[ind].w, "%c%s", PKT_MODIFIERS, mods);
    if (n <= 0) {
	connp->w.len = sbuf_len;
    }

    return n;
}

/*
 * Somebody is leaving the game.
 */
int Send_leave(int ind, int id)
{
    connection_t	*connp = &Conn[ind];

    if (!BIT(connp->state, CONN_PLAYING | CONN_READY)) {
	errno = 0;
	error("Connection not ready for leave info (%d,%d)",
	      connp->state, connp->id);
	return 0;
    }
    return Packet_printf(&connp->c, "%c%hd", PKT_LEAVE, id);
}

/*
 * Somebody is declaring war.
 */
int Send_war(int ind, int robot_id, int killer_id)
{
    connection_t	*connp = &Conn[ind];

    if (!BIT(connp->state, CONN_PLAYING | CONN_READY)) {
	errno = 0;
	error("Connection not ready for war declaration (%d,%d,%d)",
	      ind, connp->state, connp->id);
	return 0;
    }
    return Packet_printf(&connp->c, "%c%hd%hd", PKT_WAR,
			 robot_id, killer_id);
}

/*
 * Somebody is programming a robot to seek some player.
 */
int Send_seek(int ind, int programmer_id, int robot_id, int sought_id)
{
    connection_t	*connp = &Conn[ind];

    if (!BIT(connp->state, CONN_PLAYING | CONN_READY)) {
	errno = 0;
	error("Connection not ready for seek declaration (%d,%d,%d)",
	      ind, connp->state, connp->id);
	return 0;
    }
    return Packet_printf(&connp->c, "%c%hd%hd%hd", PKT_SEEK,
			 programmer_id, robot_id, sought_id);
}

/*
 * Somebody is joining the game.
 */
int Send_player(int ind, int id)
{
    connection_t	*connp = &Conn[ind];
    player		*pl = Players[GetInd[id]];
    int			n;
    char		buf[MSG_LEN], ext[MSG_LEN];
    int			sbuf_len = connp->c.len;

    if (!BIT(connp->state, CONN_PLAYING|CONN_READY)) {
	errno = 0;
	error("Connection not ready for player info (%d,%d)",
	      connp->state, connp->id);
	return 0;
    }
    Convert_ship_2_string(pl->ship, buf, ext,
			  (connp->version < 0x3200) ? 0x3100 : 0x3200);
    n = Packet_printf(&connp->c,
		      "%c%hd" "%c%c" "%s%s%s" "%S",
		      PKT_PLAYER, pl->id,
		      pl->team, pl->mychar,
		      pl->name, pl->realname, pl->hostname,
		      buf);
    if (connp->version > 0x3200) {
	if (n > 0) {
	    n = Packet_printf(&connp->c, "%S", ext);
	    if (n <= 0) {
		connp->c.len = sbuf_len;
	    }
	}
    }
    return n;
}

/*
 * Send the new score for some player to a client.
 */
int Send_score(int ind, int id, int score, int life, int mychar)
{
    connection_t	*connp = &Conn[ind];

    if (!BIT(connp->state, CONN_PLAYING | CONN_READY)) {
	errno = 0;
	error("Connection not ready for score(%d,%d)",
	    connp->state, connp->id);
	return 0;
    }
    return Packet_printf(&connp->c, "%c%hd%hd%hd%c", PKT_SCORE,
			 id, score, life, mychar);
}

/*
 * Send the new race info for some player to a client.
 */
int Send_timing(int ind, int id, int check, int round)
{
    connection_t	*connp = &Conn[ind];

    if (connp->version < 0x3261) {
	return 1;
    }
    if (!BIT(connp->state, CONN_PLAYING | CONN_READY)) {
	errno = 0;
	error("Connection not ready for timing(%d,%d)",
	      connp->state, connp->id);
	return 0;
    }
    return Packet_printf(&connp->c, "%c%hd%hu", PKT_TIMING,
			 id, round * MAX_CHECKS + check);
}

/*
 * Send info about a player having which base.
 */
int Send_base(int ind, int id, int num)
{
    connection_t	*connp = &Conn[ind];

    if (!BIT(connp->state, CONN_PLAYING | CONN_READY)) {
	errno = 0;
	error("Connection not ready for base info (%d,%d)",
	    connp->state, connp->id);
	return 0;
    }
    return Packet_printf(&connp->c, "%c%hd%hu", PKT_BASE, id, num);
}

/*
 * Send the amount of fuel in a fuelstation.
 */
int Send_fuel(int ind, int num, int fuel)
{
    return Packet_printf(&Conn[ind].w, "%c%hu%hu", PKT_FUEL,
			 num, fuel >> FUEL_SCALE_BITS);
}

int Send_score_object(int ind, int score, int x, int y, char *string)
{
    connection_t	*connp = &Conn[ind];

    if (!BIT(connp->state, CONN_PLAYING | CONN_READY)) {
	errno = 0;
	error("Connection not ready for base info (%d,%d)",
	    connp->state, connp->id);
	return 0;
    }
    return Packet_printf(&Conn[ind].c, "%c%hd%hu%hu%s",PKT_SCORE_OBJECT,
			 score, x, y, string);
}

int Send_cannon(int ind, int num, int dead_time)
{
    return Packet_printf(&Conn[ind].w, "%c%hu%hu", PKT_CANNON,
	num, dead_time);
}

int Send_destruct(int ind, int count)
{
    return Packet_printf(&Conn[ind].w, "%c%hd", PKT_DESTRUCT, count);
}

int Send_shutdown(int ind, int count, int delay)
{
    return Packet_printf(&Conn[ind].w, "%c%hd%hd", PKT_SHUTDOWN,
	count, delay);
}

int Send_thrusttime(int ind, int count, int max)
{
    return Packet_printf(&Conn[ind].w, "%c%hd%hd", PKT_THRUSTTIME, count, max);
}

int Send_shieldtime(int ind, int count, int max)
{
    if (Conn[ind].version < 0x3200) {
	return 1;
    }
    return Packet_printf(&Conn[ind].w, "%c%hd%hd", PKT_SHIELDTIME, count, max);
}

int Send_debris(int ind, int type, unsigned char *p, int n)
{
    int			avail;
    sockbuf_t		*w = &Conn[ind].w;

    if ((n & 0xFF) != n) {
	errno = 0;
	error("Bad number of debris %d", n);
	return 0;
    }
    avail = w->size - w->len - SOCKBUF_WRITE_SPARE - 2;
    if (n * 2 >= avail) {
	if (avail > 2) {
	    n = (avail - 1) / 2;
	} else {
	    return 0;
	}
    }
    w->buf[w->len++] = PKT_DEBRIS + type;
    w->buf[w->len++] = n;
    memcpy(&w->buf[w->len], p, n * 2);
    w->len += n * 2;

    return n;
}

int Send_fastshot(int ind, int type, unsigned char *p, int n)
{
    int			avail;
    sockbuf_t		*w = &Conn[ind].w;

    if ((n & 0xFF) != n) {
	errno = 0;
	error("Bad number of fastshot %d", n);
	return 0;
    }
    avail = w->size - w->len - SOCKBUF_WRITE_SPARE - 3;
    if (n * 2 >= avail) {
	if (avail > 2) {
	    n = (avail - 1) / 2;
	} else {
	    return 0;
	}
    }
    w->buf[w->len++] = PKT_FASTSHOT;
    w->buf[w->len++] = type;
    w->buf[w->len++] = n;
    memcpy(&w->buf[w->len], p, n * 2);
    w->len += n * 2;

    return n;
}

int Send_missile(int ind, int x, int y, int len, int dir)
{
    return Packet_printf(&Conn[ind].w, "%c%hd%hd%c%c",
			 PKT_MISSILE, x, y, len, dir);
}

int Send_ball(int ind, int x, int y, int id)
{
    return Packet_printf(&Conn[ind].w, "%c%hd%hd%hd", PKT_BALL, x, y, id);
}

int Send_mine(int ind, int x, int y, int teammine, int id)
{
    connection_t	*connp = &Conn[ind];

    return Packet_printf(&connp->w, "%c%hd%hd%c%hd", PKT_MINE, x, y,
			 teammine, id);
}

int Send_target(int ind, int num, int dead_time, int damage)
{
    return Packet_printf(&Conn[ind].w, "%c%hu%hu%hu", PKT_TARGET,
			 num, dead_time, damage);
}

int Send_item(int ind, int x, int y, int type)
{
    if (type >= ITEM_EMERGENCY_SHIELD) {
	if (Conn[ind].version < 0x3200) {
	    return 1;
	}
    }
    return Packet_printf(&Conn[ind].w, "%c%hd%hd%c", PKT_ITEM, x, y, type);
}

int Send_paused(int ind, int x, int y, int count)
{
    return Packet_printf(&Conn[ind].w, "%c%hd%hd%hd", PKT_PAUSED, x, y, count);
}

int Send_ecm(int ind, int x, int y, int size)
{
    return Packet_printf(&Conn[ind].w, "%c%hd%hd%hd", PKT_ECM, x, y, size);
}

int Send_trans(int ind, int x1, int y1, int x2, int y2)
{
    return Packet_printf(&Conn[ind].w,"%c%hd%hd%hd%hd",
			 PKT_TRANS, x1, y1, x2, y2);
}

int Send_ship(int ind, int x, int y, int id, int dir,
	      int shield, int cloak, int emergency_shield)
{
    return Packet_printf(&Conn[ind].w,
			 "%c%hd%hd%hd" "%c" "%c",
			 PKT_SHIP, x, y, id,
			 dir,
			 (shield != 0) | ((cloak != 0) << 1)
			     | ((emergency_shield != 0) << 2)
			);
}

int Send_refuel(int ind, int x0, int y0, int x1, int y1)
{
    return Packet_printf(&Conn[ind].w,
			 "%c%hd%hd%hd%hd",
			 PKT_REFUEL, x0, y0, x1, y1);
}

int Send_connector(int ind, int x0, int y0, int x1, int y1, int tractor)
{
    connection_t *connp = &Conn[ind];

    return Packet_printf(&connp->w,
			 "%c%hd%hd%hd%hd%c",
			 PKT_CONNECTOR, x0, y0, x1, y1, tractor);
}

int Send_laser(int ind, int color, int x, int y, int len, int dir)
{
    connection_t *connp = &Conn[ind];

    return Packet_printf(&connp->w, "%c%c%hd%hd%hd%c", PKT_LASER,
			 color, x, y, len, dir);
}

int Send_radar(int ind, int x, int y, int size)
{
    connection_t	*connp = &Conn[ind];

    return Packet_printf(&connp->w, "%c%hd%hd%c", PKT_RADAR, x, y, size);
}

int Send_damaged(int ind, int damaged)
{
    return Packet_printf(&Conn[ind].w, "%c%c", PKT_DAMAGED, damaged);
}

int Send_audio(int ind, int type, int vol)
{
    connection_t *connp = &Conn[ind];

    if (connp->w.size - connp->w.len <= 32) {
	return 0;
    }
    return Packet_printf(&connp->w, "%c%c%c", PKT_AUDIO, type, vol);
}

int Send_time_left(int ind, long sec)
{
    connection_t *connp = &Conn[ind];

    return Packet_printf(&connp->w, "%c%ld", PKT_TIME_LEFT, sec);
}

int Send_eyes(int ind, int id)
{
    connection_t *connp = &Conn[ind];

    return Packet_printf(&connp->w, "%c%hd", PKT_EYES, id);
}

int Send_message(int ind, char *msg)
{
    connection_t	*connp = &Conn[ind];

    if (!BIT(connp->state, CONN_PLAYING | CONN_READY)) {
	errno = 0;
	error("Connection not ready for message (%d,%d)",
	    connp->state, connp->id);
	return 0;
    }
    return Packet_printf(&connp->c, "%c%S", PKT_MESSAGE, msg);
}

int Send_start_of_frame(int ind)
{
    connection_t	*connp = &Conn[ind];

    if (connp->state != CONN_PLAYING) {
	if (connp->state != CONN_READY) {
	    errno = 0;
	    error("Connection not ready for frame (%d,%d)",
		connp->state, connp->id);
	}
	return -1;
    }
    /*
     * We tell the client which frame number this is and
     * which keyboard update we have last received.
     */
    Sockbuf_clear(&connp->w);
    if (Packet_printf(&connp->w,
		      "%c%ld%ld",
		      PKT_START, loops, connp->last_key_change) <= 0) {
	Destroy_connection(ind, "write error");
	return -1;
    }

    /* Return ok */
    return 0;
}

int Send_end_of_frame(int ind)
{
    connection_t	*connp = &Conn[ind];
    int			n;
    extern int		last_packet_of_frame;

    last_packet_of_frame = 1;
    n = Packet_printf(&connp->w, "%c%ld", PKT_END, loops);
    last_packet_of_frame = 0;
    if (n == -1) {
	Destroy_connection(ind, "write error");
	return -1;
    }
    if (n == 0) {
	/*
	 * Frame update size exceeded buffer size.
	 * Drop this packet.
	 */
	Sockbuf_clear(&connp->w);
	return 0;
    }
    while (connp->motd_offset >= 0
	&& connp->c.len + connp->w.len < MAX_RELIABLE_DATA_PACKET_SIZE) {
	Send_motd(ind);
    }
    if (connp->c.len > 0 && connp->w.len < MAX_RELIABLE_DATA_PACKET_SIZE) {
	if (Send_reliable(ind) == -1) {
	    return -1;
	}
	if (connp->w.len == 0) {
	    return 1;
	}
    }
    if (Sockbuf_flush(&connp->w) == -1) {
	Destroy_connection(ind, "flush error");
	return -1;
    }
    Sockbuf_clear(&connp->w);
    return 0;
}

static int Receive_keyboard(int ind)
{
    connection_t	*connp = &Conn[ind];
    player		*pl;
    long		change;
    u_byte		ch;
    const int		size = KEYBOARD_SIZE;

    if (connp->r.ptr - connp->r.buf + size + 1 + 4 > connp->r.len) {
	/*
	 * Incomplete client packet.
	 */
	return 0;
    }
    Packet_scanf(&connp->r, "%c%ld", &ch, &change);
    if (change <= connp->last_key_change) {
	/*
	 * We already have this key.
	 * Nothing to do.
	 */
	connp->r.ptr += size;
    }
    else {
	connp->last_key_change = change;
	pl = Players[GetInd[connp->id]];
	memcpy(pl->last_keyv, connp->r.ptr, size);
	connp->r.ptr += size;
	pl->key_changed = 1;
	Handle_keyboard(GetInd[connp->id]);
    }
    if (connp->num_keyboard_updates++ && (connp->state & CONN_PLAYING)) {
	Destroy_connection(ind, "no macros");
	return -1;
    }

    return 1;
}

static int Receive_quit(int ind)
{
    Destroy_connection(ind, "client quit");

    return -1;
}

static int Receive_play(int ind)
{
    connection_t	*connp = &Conn[ind];
    unsigned char	ch;
    int			n;

    if ((n = Packet_scanf(&connp->r, "%c", &ch)) != 1) {
	errno = 0;
	error("Cannot receive play packet");
	Destroy_connection(ind, "receive error");
	return -1;
    }
    if (ch != PKT_PLAY) {
	errno = 0;
	error("Packet is not of play type");
	Destroy_connection(ind, "not play");
	return -1;
    }
    if (connp->state != CONN_LOGIN) {
	if (connp->state != CONN_PLAYING) {
	    if (connp->state == CONN_READY) {
		connp->r.ptr = connp->r.buf + connp->r.len;
		return 0;
	    }
	    errno = 0;
	    error("Connection not in login state (%02x)", connp->state);
	    Destroy_connection(ind, "not login");
	    return -1;
	}
	if (Send_reliable(ind) == -1) {
	    return -1;
	}
	return 0;
    }
    Sockbuf_clear(&connp->w);
    if (Handle_login(ind) == -1) {
	Destroy_connection(ind, "login failed");
	return -1;
    }

    return 2;
}

static int Receive_power(int ind)
{
    connection_t	*connp = &Conn[ind];
    player		*pl;
    unsigned char	ch;
    short		tmp;
    int			n;
    float		power;

    if ((n = Packet_scanf(&connp->r, "%c%hd", &ch, &tmp)) <= 0) {
	if (n == -1) {
	    Destroy_connection(ind, "read error");
	}
	return n;
    }
    power = (float) tmp / 256.0F;
    pl = Players[GetInd[connp->id]];
    switch (ch) {
    case PKT_POWER:
	pl->power = power;
	break;
    case PKT_POWER_S:
	pl->power_s = power;
	break;
    case PKT_TURNSPEED:
	pl->turnspeed = power;
	break;
    case PKT_TURNSPEED_S:
	pl->turnspeed_s = power;
	break;
    case PKT_TURNRESISTANCE:
	pl->turnresistance = power;
	break;
    case PKT_TURNRESISTANCE_S:
	pl->turnresistance_s = power;
	break;
    default:
	errno = 0;
	error("Not a power packet (%d,%02x)", ch, connp->state);
	Destroy_connection(ind, "not power");
	return -1;
    }
    return 1;
}

/*
 * Send the reliable data.
 * If the client is in the receive-frame-updates state then
 * all reliable data is piggybacked at the end of the
 * frame update packets.  (Except maybe for the MOTD data, which
 * could be transmitted in its own packets since MOTDs can be big.)
 * Otherwise if the client is not actively playing yet then
 * the reliable data is sent in its own packets since there
 * is no other data to combine it with.
 *
 * This thing still is not finished, but it works better than in 3.0.0 I hope.
 */
int Send_reliable(int ind)
{
    connection_t	*connp = &Conn[ind];
    char		*read_buf;
    int			i,
			n,
			len,
			todo,
			max_todo;
    long		rel_off;
    const int		max_packet_size = MAX_RELIABLE_DATA_PACKET_SIZE,
			min_send_size = 1;  /* was 4 in 3.0.7, 1 in 3.1.0 */

    if (connp->c.len <= 0
	|| connp->last_send_loops == loops) {
	connp->last_send_loops = loops;
	return 0;
    }
    read_buf = connp->c.buf;
    max_todo = connp->c.len;
    rel_off = connp->reliable_offset;
    if (connp->w.len > 0) {
	/* We are piggybacking on a frame update. */
	if (connp->w.len >= max_packet_size - min_send_size) {
	    /* Frame already too big */
	    return 0;
	}
	if (max_todo > max_packet_size - connp->w.len) {
	    /* Do not exceed minimum fragment size. */
	    max_todo = max_packet_size - connp->w.len;
	}
    }
    if (connp->retransmit_at_loop > loops) {
	/*
	 * It is no time to retransmit yet.
	 */
	if (max_todo <= connp->reliable_unsent - connp->reliable_offset
			+ min_send_size
	    || connp->w.len == 0) {
	    /*
	     * And we cannot send anything new either
	     * and we do not want to introduce a new packet.
	     */
	    return 0;
	}
    }
    else if (connp->retransmit_at_loop != 0) {
	/*
	 * Timeout.
	 * Either our packet or the acknowledgement got lost,
	 * so retransmit.
	 */
	connp->acks >>= 1;
    }

    todo = max_todo;
    for (i = 0; i <= connp->acks && todo > 0; i++) {
	len = (todo > max_packet_size) ? max_packet_size : todo;
	if (Packet_printf(&connp->w, "%c%hd%ld%ld", PKT_RELIABLE,
			  len, rel_off, loops) <= 0
	    || Sockbuf_write(&connp->w, read_buf, len) != len) {
	    error("Cannot write reliable data");
	    Destroy_connection(ind, "write error");
	    return -1;
	}
	if ((n = Sockbuf_flush(&connp->w)) < len) {
	    if (n == 0
		&& (errno == EWOULDBLOCK
		    || errno == EAGAIN)) {
		connp->acks = 0;
		break;
	    } else {
		error("Cannot flush reliable data (%d)", n);
		Destroy_connection(ind, "flush error");
		return -1;
	    }
	}
	todo -= len;
	rel_off += len;
	read_buf += len;
    }

    /*
     * Drop rest of outgoing data packet if something remains at all.
     */
    Sockbuf_clear(&connp->w);

    connp->last_send_loops = loops;

    if (max_todo - todo <= 0) {
	/*
	 * We have not transmitted anything at all.
	 */
	return 0;
    }

    /*
     * Retransmission timer with exponential backoff.
     */
    if (connp->rtt_retransmit > MAX_RETRANSMIT) {
	connp->rtt_retransmit = MAX_RETRANSMIT;
    }
    if (connp->retransmit_at_loop <= loops) {
	connp->retransmit_at_loop = loops + connp->rtt_retransmit;
	connp->rtt_retransmit <<= 1;
	connp->rtt_timeouts++;
    } else {
	connp->retransmit_at_loop = loops + connp->rtt_retransmit;
    }

    if (rel_off > connp->reliable_unsent) {
	connp->reliable_unsent = rel_off;
    }

    return (max_todo - todo);
}

static int Receive_ack(int ind)
{
    connection_t	*connp = &Conn[ind];
    int			n;
    unsigned char	ch;
    long		rel,
			rtt,	/* RoundTrip Time */
			diff,
			delta,
			rel_loops;

    if ((n = Packet_scanf(&connp->r, "%c%ld%ld",
			  &ch, &rel, &rel_loops)) <= 0) {
	errno = 0;
	error("Cannot read ack packet (%d)", n);
	Destroy_connection(ind, "read error");
	return -1;
    }
    if (ch != PKT_ACK) {
	errno = 0;
	error("Not an ack packet (%d)", ch);
	Destroy_connection(ind, "not ack");
	return -1;
    }
    rtt = loops - rel_loops;
    if (rtt > 0 && rtt <= MAX_RTT) {
	/*
	 * These roundtrip estimation calculations are derived from Comer's
	 * books "Internetworking with TCP/IP" parts I & II.
	 */
	if (connp->rtt_smoothed == 0) {
	    /*
	     * Initialize the rtt estimator by this first measurement.
	     * The estimator is scaled by 3 bits.
	     */
	    connp->rtt_smoothed = rtt << 3;
	}
	/*
	 * Scale the estimator back by 3 bits before calculating the error.
	 */
	delta = rtt - (connp->rtt_smoothed >> 3);
	/*
	 * Add one eigth of the error to the estimator.
	 */
	connp->rtt_smoothed += delta;
	/*
	 * Now we need the absolute value of the error.
	 */
	if (delta < 0) {
	    delta = -delta;
	}
	/*
	 * The rtt deviation is scaled by 2 bits.
	 * Now we add one fourth of the difference between the
	 * error and the previous deviation to the deviation.
	 */
	connp->rtt_dev += delta - (connp->rtt_dev >> 2);
	/*
	 * The calculation of the retransmission timeout is what this is
	 * all about.  We take the smoothed rtt plus twice the deviation
	 * as the next retransmission timeout to use.  Because of the
	 * scaling used we get the following statement:
	 */
	connp->rtt_retransmit = ((connp->rtt_smoothed >> 2)
	    + connp->rtt_dev) >> 1;
	/*
	 * Now keep it within reasonable bounds.
	 */
	if (connp->rtt_retransmit < MIN_RETRANSMIT) {
	    connp->rtt_retransmit = MIN_RETRANSMIT;
	}
    }
    diff = rel - connp->reliable_offset;
    if (diff > connp->c.len) {
	/* Impossible to ack data that has not been send */
	errno = 0;
	error("Bad ack (diff=%ld,cru=%ld,c=%ld,len=%d)",
	    diff, rel, connp->reliable_offset, connp->c.len);
	Destroy_connection(ind, "bad ack");
	return -1;
    }
    else if (diff <= 0) {
	/* Late or duplicate ack of old data.  Discard. */
	return 1;
    }
    Sockbuf_advance(&connp->c, (int) diff);
    connp->reliable_offset += diff;
    if ((n = ((diff + 512 - 1) / 512)) > connp->acks) {
	connp->acks = n;
    }
    else {
	connp->acks++;
    }
    if (connp->reliable_offset >= connp->reliable_unsent) {
	/*
	 * All reliable data has been sent and acked.
	 */
	connp->retransmit_at_loop = 0;
	if (connp->state == CONN_DRAIN) {
	    connp->state = connp->drain_state;
	    connp->start = loops;
	}
    }
    if (connp->state == CONN_READY
	&& (connp->c.len <= 0
	    || (connp->c.buf[0] != PKT_REPLY
		&& connp->c.buf[0] != PKT_PLAY
		&& connp->c.buf[0] != PKT_SUCCESS
		&& connp->c.buf[0] != PKT_FAILURE))) {
	connp->state = connp->drain_state;
	connp->start = loops;
	if (connp->state == CONN_PLAYING) {
	    login_in_progress--;
	}
    }
    connp->rtt_timeouts = 0;

    return 1;
}

static int Receive_discard(int ind)
{
    connection_t	*connp = &Conn[ind];

    errno = 0;
    error("Discarding packet %d while in state %02x",
	  connp->r.ptr[0], connp->state);
    connp->r.ptr = connp->r.buf + connp->r.len;

    return 0;
}

static int Receive_undefined(int ind)
{
    connection_t	*connp = &Conn[ind];

    errno = 0;
    error("Unknown packet type (%d,%02x)", connp->r.ptr[0], connp->state);
    Destroy_connection(ind, "undefined packet");
    return -1;
}

static int Receive_ack_cannon(int ind)
{
    connection_t	*connp = &Conn[ind];
    long		loops_ack;
    unsigned char	ch;
    int			n;
    unsigned short	num;

    if ((n = Packet_scanf(&connp->r, "%c%ld%hu",
			  &ch, &loops_ack, &num)) <= 0) {
	if (n == -1) {
	    Destroy_connection(ind, "read error");
	}
	return n;
    }
    if (num >= World.NumCannons) {
	Destroy_connection(ind, "bad cannon ack");
	return -1;
    }
    if (loops_ack > World.cannon[num].last_change) {
	SET_BIT(World.cannon[num].conn_mask, 1 << ind);
    }
    return 1;
}

static int Receive_ack_fuel(int ind)
{
    connection_t	*connp = &Conn[ind];
    long		loops_ack;
    unsigned char	ch;
    int			n;
    unsigned short	num;

    if ((n = Packet_scanf(&connp->r, "%c%ld%hu",
			  &ch, &loops_ack, &num)) <= 0) {
	if (n == -1) {
	    Destroy_connection(ind, "read error");
	}
	return n;
    }
    if (num >= World.NumFuels) {
	Destroy_connection(ind, "bad fuel ack");
	return -1;
    }
    if (loops_ack > World.fuel[num].last_change) {
	SET_BIT(World.fuel[num].conn_mask, 1 << ind);
    }
    return 1;
}

static int Receive_ack_target(int ind)
{
    connection_t	*connp = &Conn[ind];
    long		loops_ack;
    unsigned char	ch;
    int			n;
    unsigned short	num;

    if ((n = Packet_scanf(&connp->r, "%c%ld%hu",
			  &ch, &loops_ack, &num)) <= 0) {
	if (n == -1) {
	    Destroy_connection(ind, "read error");
	}
	return n;
    }
    if (num >= World.NumTargets) {
	Destroy_connection(ind, "bad target ack");
	return -1;
    }
    /*
     * Because the "loops" value as received by the client as part
     * of a frame update is 1 higher than the actual change to the
     * target in collision.c a valid map object change
     * acknowledgement must be at least 1 higher.
     * That's why we should use the '>' symbol to compare
     * and not the '>=' symbol.
     * The same applies to cannon and fuelstation updates.
     * This fix was discovered for 3.2.7, previously some
     * destroyed targets could have been displayed with
     * a diagonal cross through them.
     */
    if (loops_ack > World.targets[num].last_change) {
	SET_BIT(World.targets[num].conn_mask, 1 << ind);
	CLR_BIT(World.targets[num].update_mask, 1 << ind);
    }
    return 1;
}

/*
 * If a message contains a colon then everything before that colon is
 * either a unique player name prefix, or a team number with players.
 * If the string does not match one team or one player the message is not sent.
 * If no colon, the message is general.
 */
static void Handle_talk(int ind, char *str)
{
    connection_t	*connp = &Conn[ind];
    player		*pl = Players[GetInd[connp->id]];
    int			i, sent, team, len;
    char		*cp,
			msg[MSG_LEN * 2];

    if ((cp = strchr (str, ':')) == NULL
	|| cp == str
	|| strchr("-_~)(/\\}{[]", cp[1])	/* smileys are smileys */
	) {
	sprintf(msg, "%s [%s]", str, pl->name);
	Set_message(msg);
	return;
    }
    *cp++ = '\0';
    len = strlen (str);
    sprintf(msg, "%s [%s]", cp, pl->name);

    if (strspn(str, "0123456789") == len) {		/* Team message */
	team = atoi (str);
	sprintf(msg + strlen(msg), ":[%d]", team);
	for (sent = i = 0; i < NumPlayers; i++) {
	    if (Players[i]->team != TEAM_NOT_SET && Players[i]->team == team) {
		sent++;
		Set_player_message (Players[i], msg);
	    }
	}
	if (sent) {
	    if (pl->team != team)
		Set_player_message (pl, msg);
	} else {
	    sprintf(msg, "Message not sent, nobody in team %d!",
		    team);
	    Set_player_message(pl, msg);
	}
    }
    else if (strcasecmp(str, "god") == 0) {
	FILE *fp = fopen(LOGFILE, "a");
	if (fp) {
	    time_t		now;
	    struct tm		*tmp;
	    static char		month_names[13][4] = {
				    "Jan", "Feb", "Mar", "Apr", "May", "Jun",
				    "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
				    "Bug"
				};

	    time(&now);
	    tmp = localtime(&now);
	    fprintf(fp,
		    "[%s]{%s@%s(%s)|%s}(%02d %s %02d:%02d:%02d):\n"
		    "\t%s\n",
		    pl->name,
		    pl->realname, connp->host, connp->addr, connp->dpy,
		    tmp->tm_mday, month_names[tmp->tm_mon],
		    tmp->tm_hour, tmp->tm_min, tmp->tm_sec,
		    cp);
	    fclose(fp);
	    sprintf(msg + strlen(msg), ":[%s]", "GOD");
	    Set_player_message(pl, msg);
	}
    }
    else {						/* Player message */
	for (sent = -1, i = 0; i < NumPlayers; i++) {
	    if (strncasecmp(Players[i]->name, str, len) == 0
		|| strncasecmp(Players[i]->realname, str, len) == 0)
		sent = (sent == -1) ? i : -2;
	}
	switch (sent) {
	case -2:
	    sprintf(msg, "Message not sent, %s matches more than one player!",
		    str);
	    Set_player_message(pl, msg);
	    break;
	case -1:
	    sprintf(msg, "Message not sent, %s does not match any player!",
		    str);
	    Set_player_message(pl, msg);
	    break;
	default:
	    if (Players[sent] != pl) {
		sprintf(msg + strlen(msg), ":[%s]", Players[sent]->name);
		Set_player_message(Players[sent], msg);
		Set_player_message(pl, msg);
	    }
	    break;
	}
    }
}

static int Receive_talk(int ind)
{
    connection_t	*connp = &Conn[ind];
    unsigned char	ch;
    int			n;
    long		seq;
    char		str[MAX_CHARS];

    if ((n = Packet_scanf(&connp->r, "%c%ld%s", &ch, &seq, str)) <= 0) {
	if (n == -1) {
	    Destroy_connection(ind, "read error");
	}
	return n;
    }
    if (seq > connp->talk_sequence_num) {
	if ((n = Packet_printf(&connp->c, "%c%ld", PKT_TALK_ACK, seq)) <= 0) {
	    if (n == -1) {
		Destroy_connection(ind, "write error");
	    }
	    return n;
	}
	connp->talk_sequence_num = seq;
	Handle_talk (ind, str);
    }
    return 1;
}

static int Receive_display(int ind)
{
    connection_t	*connp = &Conn[ind];
    unsigned char	ch, debris_colors, spark_rand;
    short		width, height;
    int			n;

    if ((n = Packet_scanf(&connp->r, "%c%hd%hd%c%c", &ch, &width, &height,
			  &debris_colors, &spark_rand)) <= 0) {
	if (n == -1) {
	    Destroy_connection(ind, "read error");
	}
	return n;
    }
    LIMIT(width, MIN_VIEW_SIZE, MAX_VIEW_SIZE);
    LIMIT(height, MIN_VIEW_SIZE, MAX_VIEW_SIZE);
    connp->view_width = width;
    connp->view_height = height;
    connp->debris_colors = debris_colors;
    connp->spark_rand = spark_rand;
    return 1;
}

static int str2num (char **strp, int min, int max)
{
    char *str = *strp;
    int num = 0;

    while (isdigit(*str)) {
	num *= 10;
	num += *str++ - '0';
    }
    *strp = str;
    if (num < min || num > max)
	return min;
    return num;
}

static int Receive_modifier_bank(int ind)
{
    connection_t	*connp = &Conn[ind];
    player		*pl;
    unsigned char	bank;
    char		str[MAX_CHARS];
    unsigned char	ch;
    char		*cp;
    modifiers		mods;
    int			n;

    if ((n = Packet_scanf(&connp->r, "%c%c%s", &ch, &bank, str)) <= 0) {
	if (n == -1) {
	    Destroy_connection(ind, "read modbank");
	}
	return n;
    }
    pl = Players[GetInd[connp->id]];
    if (bank < NUM_MODBANKS) {
	CLEAR_MODS(mods);
	if (BIT(World.rules->mode, ALLOW_MODIFIERS)) {
	    for (cp = str; *cp; cp++) {
		switch (*cp) {
		case 'F': case 'f':
		    if (!BIT(World.rules->mode, ALLOW_NUKES))
			break;
		    if (*(cp+1) == 'N' || *(cp+1) == 'n')
			SET_BIT(mods.nuclear, FULLNUCLEAR);
		    break;
		case 'N': case 'n':
		    if (!BIT(World.rules->mode, ALLOW_NUKES))
			break;
		    SET_BIT(mods.nuclear, NUCLEAR);
		    break;
		case 'C': case 'c':
		    if (!BIT(World.rules->mode, ALLOW_CLUSTERS))
			break;
		    SET_BIT(mods.warhead, CLUSTER);
		    break;
		case 'I': case 'i':
		    SET_BIT(mods.warhead, IMPLOSION);
		    break;
		case 'V': case 'v':
		    cp++; mods.velocity = str2num (&cp, 0, MODS_VELOCITY_MAX);
		    cp--;
		    break;
		case 'X': case 'x':
		    cp++; mods.mini = str2num (&cp, 1, MODS_MINI_MAX+1) - 1;
		    cp--;
		    break;
		case 'Z': case 'z':
		    cp++; mods.spread = str2num (&cp, 0, MODS_SPREAD_MAX);
		    cp--;
		    break;
		case 'B': case 'b':
		    cp++; mods.power = str2num (&cp, 0, MODS_POWER_MAX);
		    cp--;
		    break;
		case 'L': case 'l':
		    cp++;
		    if (!BIT(World.rules->mode, ALLOW_LASER_MODIFIERS))
			break;
		    if (*cp == 'S' || *cp == 's')
			SET_BIT(mods.laser, STUN);
		    if (*cp == 'B' || *cp == 'b')
			SET_BIT(mods.laser, BLIND);
		    break;
		}
	    }
	}
	pl->modbank[bank] = mods;
    }
    return 1;
}

void Get_display_parameters(int ind, int *width, int *height,
			    int *debris_colors, int *spark_rand)
{
    connection_t	*connp = &Conn[ind];

    *width = connp->view_width;
    *height = connp->view_height;
    *debris_colors = connp->debris_colors;
    *spark_rand = connp->spark_rand;
}

int Get_player_id(int ind)
{
    connection_t	*connp = &Conn[ind];

    return connp->id;
}

static int Receive_shape(int ind)
{
    connection_t	*connp = &Conn[ind];
    int			n;
    char		ch;
    char		str[2*MSG_LEN];

    if ((n = Packet_scanf(&connp->r, "%c%S", &ch, str)) <= 0) {
	if (n == -1) {
	    Destroy_connection(ind, "read shape");
	}
	return n;
    }
    if (connp->version > 0x3200) {
	if ((n = Packet_scanf(&connp->r, "%S", &str[strlen(str)])) <= 0) {
	    if (n == -1) {
		Destroy_connection(ind, "read shape ext");
	    }
	    return n;
	}
    }
    if (connp->state == CONN_LOGIN && connp->ship == NULL) {
	connp->ship = Parse_shape_str(str);
    }
    return 1;
}

static int Receive_motd(int ind)
{
    connection_t	*connp = &Conn[ind];
    unsigned char	ch;
    long		offset;
    int			n;
    long		bytes;

    if ((n = Packet_scanf(&connp->r,
			  "%c%ld%ld",
			  &ch, &offset, &bytes)) <= 0) {
	if (n == -1) {
	    Destroy_connection(ind, "read error");
	}
	return n;
    }
    connp->motd_offset = offset;
    connp->motd_stop = offset + bytes;

    return 1;
}

/*
 * Send the server MOTD to the client.
 * The last time we send a motd packet it should
 * have datalength zero to mean EOMOTD.
 */
static int Send_motd(int ind)
{
    connection_t	*connp = &Conn[ind];
    int			len = 0;
    long		off = connp->motd_offset,
			size = 0,
			readmax;
    char		buf[MAX_MOTD_CHUNK];

    if (off < 0) {
	errno = 0;
	error("Send_motd bad offset %ld", off);
	Destroy_connection(ind, "motd offset");
	return -1;
    }
    if (connp->c.len >= MAX_RELIABLE_DATA_PACKET_SIZE) {
	return 1;
    }
    if (motd_fp || (motd_fp = fopen(SERVERMOTDFILE, "r"))) {
	if (fseek(motd_fp, 0, SEEK_END) >= 0) {
	    size = ftell(motd_fp);
	    if (size < 0) {
		size = 0;
	    }
	    if (size < connp->motd_stop) {
		connp->motd_stop = size;
	    }
	    else if (size > connp->motd_stop) {
		size = connp->motd_stop;
	    }
	    readmax = connp->motd_stop - connp->motd_offset;
	    if (readmax <= 0) {
		len = 0;
	    }
	    else if (fseek(motd_fp, connp->motd_offset, SEEK_SET) >= 0) {
		len = fread(buf, 1, (int)MIN(readmax, sizeof buf), motd_fp);
	    }
	}
    }
    if (len <= 0) {
	len = 0;
	connp->motd_offset = -1;
	if (motd_fp) {
	    fclose(motd_fp);
	    motd_fp = NULL;
	}
    }
    if (Packet_printf(&connp->c,
		      "%c%ld%hd%ld",
		      PKT_MOTD, off, len, size) <= 0) {
	Destroy_connection(ind, "motd header");
	return -1;
    }
    if (len > 0) {
	connp->motd_offset += len;
	if (Sockbuf_write(&connp->c, buf, len) != len) {
	    Destroy_connection(ind, "motd data");
	    return -1;
	}
    }

    /* Return ok */
    return 0;
}

static int Receive_pointer_move(int ind)
{
    connection_t	*connp = &Conn[ind];
    player		*pl;
    unsigned char	ch;
    short		movement;
    int			n;
    float		turnspeed, turndir;

    if ((n = Packet_scanf(&connp->r, "%c%hd", &ch, &movement)) <= 0) {
	if (n == -1) {
	    Destroy_connection(ind, "read error");
	}
	return n;
    }
    pl = Players[GetInd[connp->id]];
    if (BIT(pl->used, OBJ_AUTOPILOT))
	Autopilot(ind, 0);
    turnspeed = movement * pl->turnspeed / MAX_PLAYER_TURNSPEED;
    if (turnspeed < 0) {
	turndir = -1;
	turnspeed = -turnspeed;
    }
    else {
	turndir = 1;
    }
    LIMIT(turnspeed, MIN_PLAYER_TURNSPEED, MAX_PLAYER_TURNSPEED);
    pl->turnvel -= turndir * turnspeed;

    return 1;
}

static int Receive_fps_request(int ind)
{
    connection_t	*connp = &Conn[ind];
    player		*pl;
    int			n;
    unsigned char	ch;
    unsigned char	fps;

    if ((n = Packet_scanf(&connp->r, "%c%c", &ch, &fps)) <= 0) {
	if (n == -1) {
	    Destroy_connection(ind, "read error");
	}
	return n;
    }
    if (connp->id != -1) {
	pl = Players[GetInd[connp->id]];
	pl->player_fps = fps;
	if (fps > FPS) pl->player_fps = FPS;
	if (fps < (FPS / 2)) pl->player_fps = FPS / 2;
	if (fps == 0) pl->player_fps = FPS;
	n = FPS - fps;
	if (n <= 0) {
	    pl->player_count = 0;
	} else {
	    pl->player_count = FPS / n;
	}
    }

    return 1;
}
static int Receive_audio_request(int ind)
{
    connection_t	*connp = &Conn[ind];
    player		*pl;
    int			n;
    unsigned char	ch;
    unsigned char	onoff;

    if ((n = Packet_scanf(&connp->r, "%c%c", &ch, &onoff)) <= 0) {
	if (n == -1) {
	    Destroy_connection(ind, "read error");
	}
	return n;
    }
    if (connp->id != -1) {
	pl = Players[GetInd[connp->id]];
	sound_player_onoff(pl, onoff);
    }

    return 1;
}

