C++ ENET_NET_TO_HOST_16函数代码示例

int
enet_socket_get_address (ENetSocket socket, ENetAddress * address)
{
    struct sockaddr_in sin;
    socklen_t sinLength = sizeof (struct sockaddr_in);

    if (getsockname (socket, (struct sockaddr *) & sin, & sinLength) == -1)
      return -1;

    address -> host = (enet_uint32) sin.sin_addr.s_addr;
    address -> port = ENET_NET_TO_HOST_16 (sin.sin_port);

    return 0;
}

int
enet_address_set_host (ENetAddress * address, const char * name)
{
    struct addrinfo * result_box;
    int error_code;

    error_code = getaddrinfo(name, NULL, &hints, &result_box);
    if (error_code != 0) return error_code;
    if (result_box == NULL) return -1;

    memcopy(&address, result_box -> ai_addr, result_box -> ai_addrlen);
    address -> port = ENET_NET_TO_HOST_16 (address -> port);
    return error_code;
}

ENetSocket
enet_socket_accept (ENetSocket socket, ENetAddress * address)
{
    SOCKET result;
    // only call enet_address_get_size if ptr is valid
    int length = address != NULL ? enet_address_get_size (address) : 0;

    result = accept (socket,
                     address != NULL ? (struct sockaddr *) address : NULL,
                     address != NULL ? & length : NULL);
    if (result == INVALID_SOCKET)
      return ENET_SOCKET_NULL;

    if (address != NULL)
        address -> port = ENET_NET_TO_HOST_16 (address -> port);

    return result;
}

int
enet_socket_receive (ENetSocket socket,
                     ENetAddress * address,
                     ENetBuffer * buffers,
                     size_t bufferCount)
{
    struct msghdr msgHdr;
    struct sockaddr_in sin;
    int recvLength;

    memset (& msgHdr, 0, sizeof (struct msghdr));

    if (address != NULL)
    {
        msgHdr.msg_name = & sin;
        msgHdr.msg_namelen = sizeof (struct sockaddr_in);
    }

    msgHdr.msg_iov = (struct iovec *) buffers;
    msgHdr.msg_iovlen = bufferCount;

    recvLength = recvmsg (socket, & msgHdr, MSG_NOSIGNAL);

    if (recvLength == -1)
    {
       if (errno == EWOULDBLOCK)
         return 0;

       return -1;
    }

#ifdef HAS_MSGHDR_FLAGS
    if (msgHdr.msg_flags & MSG_TRUNC)
      return -1;
#endif

    if (address != NULL)
    {
        address -> host = (enet_uint32) sin.sin_addr.s_addr;
        address -> port = ENET_NET_TO_HOST_16 (sin.sin_port);
    }

    return recvLength;
}

int
enet_socket_receive (ENetSocket socket,
                     ENetAddress * address,
                     ENetBuffer * buffers,
                     size_t bufferCount)
{
    INT sinLength = sizeof (struct sockaddr_in);
    DWORD flags = 0,
          recvLength;
    struct sockaddr_in sin;
	memset(&sin, 0, sizeof sin);

    if (WSARecvFrom (socket,
                     (LPWSABUF) buffers,
                     (DWORD) bufferCount,
                     & recvLength,
                     & flags,
                     address != NULL ? (struct sockaddr *) & sin : NULL,
                     address != NULL ? & sinLength : NULL,
                     NULL,
                     NULL) == SOCKET_ERROR)
    {
       switch (WSAGetLastError ())
       {
       case WSAEWOULDBLOCK:
       case WSAECONNRESET:
          return 0;
       }

       return -1;
    }

    if (flags & MSG_PARTIAL)
      return -1;

    if (address != NULL)
    {
        address -> host = (enet_uint32) sin.sin_addr.s_addr;
        address -> port = ENET_NET_TO_HOST_16 (sin.sin_port);
    }

    return (int) recvLength;
}

ENetSocket
enet_socket_accept (ENetSocket socket, ENetAddress * address)
{
    int result;
    // only call enet_address_get_size if ptr is valid
    socklen_t length = sizeof (struct sockaddr_in6);

    result = accept (socket,
                     address != NULL ? (struct sockaddr *) & address : NULL,
                     address != NULL ? & length : NULL);

    if (result == -1)
        return ENET_SOCKET_NULL;

    if (address != NULL)
        address -> port = ENET_NET_TO_HOST_16 (address -> port);

    return result;
}

ENetSocket
enet_socket_accept (ENetSocket socket, ENetAddress * address)
{
    SOCKET result;
    struct sockaddr_in sin;
    int sinLength = sizeof (struct sockaddr_in);

    result = accept (socket, 
                     address != NULL ? (struct sockaddr *) & sin : NULL, 
                     address != NULL ? & sinLength : NULL);

    if (result == INVALID_SOCKET)
      return ENET_SOCKET_NULL;

    if (address != NULL)
    {
        address -> host = (enet_uint32) sin.sin_addr.s_addr;
        address -> port = ENET_NET_TO_HOST_16 (sin.sin_port);
    }

    return result;
}

int
enet_address_set_host (ENetAddress * address, const char * name)
{
    struct addrinfo * resultList;
    int error_code;

    error_code = getaddrinfo(name, NULL, &hints, &resultList);
    if (error_code != 0)
    {
      if (resultList != NULL)
        freeaddrinfo (resultList);
      return error_code;
    }
    if (resultList == NULL) return -1;

	// We simply grab the first information (IPv6 is sorted first so we get IPv6 information when IPv6 is enabled!
	memcpy(address, resultList->ai_addr, resultList->ai_addrlen);
    address -> port = ENET_NET_TO_HOST_16 (address -> port);

    freeaddrinfo (resultList);
    return error_code;
}

int
enet_socket_receive (ENetSocket socket,
                     ENetAddress * address,
                     ENetBuffer * buffers,
                     size_t bufferCount)
{
    INT length = sizeof (struct sockaddr_in6);
    DWORD flags = 0,
          recvLength;

    if (WSARecvFrom (socket,
                     (LPWSABUF) buffers,
                     (DWORD) bufferCount,
                     & recvLength,
                     & flags,
                     address != NULL ? (struct sockaddr *) address : NULL,
                     address != NULL ? & length : NULL,
                     NULL,
                     NULL) == SOCKET_ERROR)
    {
       switch (WSAGetLastError ())
       {
       case WSAEWOULDBLOCK:
       case WSAECONNRESET:
          return 0;
       }

       return -1;
    }

    if (flags & MSG_PARTIAL)
      return -1;

    if (address != NULL)
        address -> port = ENET_NET_TO_HOST_16 (address -> port);

    return (int) recvLength;
}

ENetIncomingCommand *
enet_peer_queue_incoming_command (ENetPeer * peer, const ENetProtocol * command, ENetPacket * packet, enet_uint32 fragmentCount)
{
    static ENetIncomingCommand dummyCommand;

    ENetChannel * channel = & peer -> channels [command -> header.channelID];
    enet_uint32 unreliableSequenceNumber = 0, reliableSequenceNumber;
    enet_uint16 reliableWindow, currentWindow;
    ENetIncomingCommand * incomingCommand;
    ENetListIterator currentCommand;

    if (peer -> state == ENET_PEER_STATE_DISCONNECT_LATER)
      goto freePacket;

    if ((command -> header.command & ENET_PROTOCOL_COMMAND_MASK) != ENET_PROTOCOL_COMMAND_SEND_UNSEQUENCED)
    {
        reliableSequenceNumber = command -> header.reliableSequenceNumber;
        reliableWindow = reliableSequenceNumber / ENET_PEER_RELIABLE_WINDOW_SIZE;
        currentWindow = channel -> incomingReliableSequenceNumber / ENET_PEER_RELIABLE_WINDOW_SIZE;

        if (reliableSequenceNumber < channel -> incomingReliableSequenceNumber)
           reliableWindow += ENET_PEER_RELIABLE_WINDOWS;

        if (reliableWindow < currentWindow || reliableWindow >= currentWindow + ENET_PEER_FREE_RELIABLE_WINDOWS - 1)
          goto freePacket;
    }
                    
    switch (command -> header.command & ENET_PROTOCOL_COMMAND_MASK)
    {
    case ENET_PROTOCOL_COMMAND_SEND_FRAGMENT:
    case ENET_PROTOCOL_COMMAND_SEND_RELIABLE:
       if (reliableSequenceNumber == channel -> incomingReliableSequenceNumber)
           goto freePacket;
       
       for (currentCommand = enet_list_previous (enet_list_end (& channel -> incomingReliableCommands));
            currentCommand != enet_list_end (& channel -> incomingReliableCommands);
            currentCommand = enet_list_previous (currentCommand))
       {
          incomingCommand = (ENetIncomingCommand *) currentCommand;

          if (reliableSequenceNumber >= channel -> incomingReliableSequenceNumber)
          {
             if (incomingCommand -> reliableSequenceNumber < channel -> incomingReliableSequenceNumber)
               continue;
          }
          else
          if (incomingCommand -> reliableSequenceNumber >= channel -> incomingReliableSequenceNumber)
            break;

          if (incomingCommand -> reliableSequenceNumber <= reliableSequenceNumber)
          {
             if (incomingCommand -> reliableSequenceNumber < reliableSequenceNumber)
               break;

             goto freePacket;
          }
       }
       break;

    case ENET_PROTOCOL_COMMAND_SEND_UNRELIABLE:
       unreliableSequenceNumber = ENET_NET_TO_HOST_16 (command -> sendUnreliable.unreliableSequenceNumber);

       if (reliableSequenceNumber == channel -> incomingReliableSequenceNumber &&
           unreliableSequenceNumber <= channel -> incomingUnreliableSequenceNumber)
           goto freePacket;

       for (currentCommand = enet_list_previous (enet_list_end (& channel -> incomingUnreliableCommands));
            currentCommand != enet_list_end (& channel -> incomingUnreliableCommands);
            currentCommand = enet_list_previous (currentCommand))
       {
          incomingCommand = (ENetIncomingCommand *) currentCommand;

          if ((incomingCommand -> command.header.command & ENET_PROTOCOL_COMMAND_MASK) != ENET_PROTOCOL_COMMAND_SEND_UNRELIABLE)
            continue;

          if (reliableSequenceNumber >= channel -> incomingReliableSequenceNumber)
          {
             if (incomingCommand -> reliableSequenceNumber < channel -> incomingReliableSequenceNumber)
               continue;
          }
          else
          if (incomingCommand -> reliableSequenceNumber >= channel -> incomingReliableSequenceNumber)
            break;

          if (incomingCommand -> reliableSequenceNumber < reliableSequenceNumber)
            break;

          if (incomingCommand -> reliableSequenceNumber > reliableSequenceNumber)
            continue;

          if (incomingCommand -> unreliableSequenceNumber <= unreliableSequenceNumber)
          {
             if (incomingCommand -> unreliableSequenceNumber < unreliableSequenceNumber)
               break;

             goto freePacket;
          }
       }
       break;

//.........这里部分代码省略.........

static int
enet_protocol_handle_incoming_commands (ENetHost * host, ENetEvent * event)
{
    ENetProtocolHeader * header;
    ENetProtocol * command;
    ENetPeer * peer;
    enet_uint8 * currentData;
    size_t commandCount;

    if (host -> receivedDataLength < sizeof (ENetProtocolHeader))
      return 0;

    header = (ENetProtocolHeader *) host -> receivedData;

    header -> peerID = ENET_NET_TO_HOST_16 (header -> peerID);
    header -> sentTime = ENET_NET_TO_HOST_32 (header -> sentTime);

    if (header -> peerID == 0xFFFF)
      peer = NULL;
    else
    if (header -> peerID >= host -> peerCount)
      return 0;
    else
    {
       peer = & host -> peers [header -> peerID];

       if (peer -> state == ENET_PEER_STATE_DISCONNECTED ||
           peer -> state == ENET_PEER_STATE_ZOMBIE ||
           host -> receivedAddress.host != peer -> address.host ||
           header -> challenge != peer -> challenge)
         return 0;
       else
         peer -> address.port = host -> receivedAddress.port;
    }

    if (peer != NULL)
      peer -> incomingDataTotal += host -> receivedDataLength;

    commandCount = header -> commandCount;
    currentData = host -> receivedData + sizeof (ENetProtocolHeader);

    while (commandCount > 0 &&
           currentData < & host -> receivedData [host -> receivedDataLength])
    {
       command = (ENetProtocol *) currentData;

       if (currentData + sizeof (ENetProtocolCommandHeader) > & host -> receivedData [host -> receivedDataLength])
         return 0;

       command -> header.commandLength = ENET_NET_TO_HOST_32 (command -> header.commandLength);

       if (currentData + command -> header.commandLength > & host -> receivedData [host -> receivedDataLength])
         return 0;

       -- commandCount;
       currentData += command -> header.commandLength;

       if (peer == NULL)
       {
          if (command -> header.command != ENET_PROTOCOL_COMMAND_CONNECT)
            return 0;
       }

       command -> header.reliableSequenceNumber = ENET_NET_TO_HOST_32 (command -> header.reliableSequenceNumber);

       switch (command -> header.command)
       {
       case ENET_PROTOCOL_COMMAND_ACKNOWLEDGE:
          enet_protocol_handle_acknowledge (host, event, peer, command);

          break;

       case ENET_PROTOCOL_COMMAND_CONNECT:
          peer = enet_protocol_handle_connect (host, header, command);

          break;

       case ENET_PROTOCOL_COMMAND_VERIFY_CONNECT:
          enet_protocol_handle_verify_connect (host, event, peer, command);

          break;

       case ENET_PROTOCOL_COMMAND_DISCONNECT:
          enet_protocol_handle_disconnect (host, peer, command);

          break;

       case ENET_PROTOCOL_COMMAND_PING:
          enet_protocol_handle_ping (host, peer, command);

          break;

       case ENET_PROTOCOL_COMMAND_SEND_RELIABLE:
          enet_protocol_handle_send_reliable (host, peer, command);

          break;

       case ENET_PROTOCOL_COMMAND_SEND_UNRELIABLE:
          enet_protocol_handle_send_unreliable (host, peer, command);

//.........这里部分代码省略.........

static ENetPeer *
enet_protocol_handle_connect (ENetHost * host, const ENetProtocolHeader * header, const ENetProtocol * command)
{
    enet_uint16 mtu;
    enet_uint32 windowSize;
    ENetChannel * channel;
    size_t channelCount;
    ENetPeer * currentPeer;
    ENetProtocol verifyCommand;

    if (command -> header.commandLength < sizeof (ENetProtocolConnect))
      return NULL;

    channelCount = ENET_NET_TO_HOST_32 (command -> connect.channelCount);

    if (channelCount < ENET_PROTOCOL_MINIMUM_CHANNEL_COUNT ||
        channelCount > ENET_PROTOCOL_MAXIMUM_CHANNEL_COUNT)
      return NULL;

    for (currentPeer = host -> peers;
         currentPeer < & host -> peers [host -> peerCount];
         ++ currentPeer)
    {
        if (currentPeer -> state != ENET_PEER_STATE_DISCONNECTED &&
            currentPeer -> address.host == host -> receivedAddress.host &&
            currentPeer -> address.port == host -> receivedAddress.port &&
            currentPeer -> challenge == header -> challenge)
          return NULL;
    }

    for (currentPeer = host -> peers;
         currentPeer < & host -> peers [host -> peerCount];
         ++ currentPeer)
    {
        if (currentPeer -> state == ENET_PEER_STATE_DISCONNECTED)
          break;
    }

    if (currentPeer >= & host -> peers [host -> peerCount])
      return NULL;

    currentPeer -> state = ENET_PEER_STATE_ACKNOWLEDGING_CONNECT;
    currentPeer -> challenge = header -> challenge;
    currentPeer -> address = host -> receivedAddress;
    currentPeer -> outgoingPeerID = ENET_NET_TO_HOST_16 (command -> connect.outgoingPeerID);
    currentPeer -> incomingBandwidth = ENET_NET_TO_HOST_32 (command -> connect.incomingBandwidth);
    currentPeer -> outgoingBandwidth = ENET_NET_TO_HOST_32 (command -> connect.outgoingBandwidth);
    currentPeer -> packetThrottleInterval = ENET_NET_TO_HOST_32 (command -> connect.packetThrottleInterval);
    currentPeer -> packetThrottleAcceleration = ENET_NET_TO_HOST_32 (command -> connect.packetThrottleAcceleration);
    currentPeer -> packetThrottleDeceleration = ENET_NET_TO_HOST_32 (command -> connect.packetThrottleDeceleration);
    currentPeer -> channels = (ENetChannel *) enet_malloc (channelCount * sizeof (ENetChannel));
    currentPeer -> channelCount = channelCount;

    for (channel = currentPeer -> channels;
         channel < & currentPeer -> channels [channelCount];
         ++ channel)
    {
        channel -> outgoingReliableSequenceNumber = 0;
        channel -> outgoingUnreliableSequenceNumber = 0;
        channel -> incomingReliableSequenceNumber = 0;
        channel -> incomingUnreliableSequenceNumber = 0;

        enet_list_clear (& channel -> incomingReliableCommands);
        enet_list_clear (& channel -> incomingUnreliableCommands);
    }

    mtu = ENET_NET_TO_HOST_16 (command -> connect.mtu);

    if (mtu < ENET_PROTOCOL_MINIMUM_MTU)
      mtu = ENET_PROTOCOL_MINIMUM_MTU;
    else
    if (mtu > ENET_PROTOCOL_MAXIMUM_MTU)
      mtu = ENET_PROTOCOL_MAXIMUM_MTU;

    currentPeer -> mtu = mtu;

    if (host -> outgoingBandwidth == 0 &&
        currentPeer -> incomingBandwidth == 0)
      currentPeer -> windowSize = ENET_PROTOCOL_MAXIMUM_WINDOW_SIZE;
    else
      currentPeer -> windowSize = (ENET_MIN (host -> outgoingBandwidth, currentPeer -> incomingBandwidth) /
                                    ENET_PEER_WINDOW_SIZE_SCALE) *
                                      ENET_PROTOCOL_MINIMUM_WINDOW_SIZE;

    if (currentPeer -> windowSize < ENET_PROTOCOL_MINIMUM_WINDOW_SIZE)
      currentPeer -> windowSize = ENET_PROTOCOL_MINIMUM_WINDOW_SIZE;
    else
    if (currentPeer -> windowSize > ENET_PROTOCOL_MAXIMUM_WINDOW_SIZE)
      currentPeer -> windowSize = ENET_PROTOCOL_MAXIMUM_WINDOW_SIZE;

    if (host -> incomingBandwidth == 0)
      windowSize = ENET_PROTOCOL_MAXIMUM_WINDOW_SIZE;
    else
      windowSize = (host -> incomingBandwidth / ENET_PEER_WINDOW_SIZE_SCALE) *
                     ENET_PROTOCOL_MINIMUM_WINDOW_SIZE;

    if (windowSize > ENET_NET_TO_HOST_32 (command -> connect.windowSize))
      windowSize = ENET_NET_TO_HOST_32 (command -> connect.windowSize);

    if (windowSize < ENET_PROTOCOL_MINIMUM_WINDOW_SIZE)
//.........这里部分代码省略.........

// server side processing of updates: does very little and most state is tracked
// client only could be extended to move more gameplay to server (at expense of
// lag)
void process(ENetPacket * packet, int sender) { // sender may be -1
  const u16 len = *(u16*) packet->data;
  if (ENET_NET_TO_HOST_16(len)!=packet->dataLength) {
    disconnect_client(sender, "packet length");
    return;
  }

  u8 *end = packet->data+packet->dataLength;
  u8 *p = packet->data+2;
  char text[MAXTRANS];
  int cn = -1, type;

  while (p<end) switch (type = getint(p)) {
    case SV_TEXT:
      sgetstr();
    break;
    case SV_INITC2S:
      sgetstr();
      strcpy_s(clients[cn].name, text);
      sgetstr();
      getint(p);
    break;
    case SV_MAPCHANGE: {
      sgetstr();
      int reqmode = getint(p);
      if (reqmode<0) reqmode = 0;
      if (smapname[0] && !mapreload && !vote(text, reqmode, sender)) return;
      mapreload = false;
      mode = reqmode;
      minremain = mode&1 ? 15 : 10;
      mapend = lastsec+minremain*60;
      interm = 0;
      strcpy_s(smapname, text);
      resetitems();
      sender = -1;
    }
    break;
    case SV_ITEMLIST: {
      int n;
      while ((n = getint(p))!=-1) if (notgotitems) {
        server_entity se = { false, 0 };
        while (sents.size()<=n) sents.push_back(se);
        sents[n].spawned = true;
      }
      notgotitems = false;
    }
    break;
    case SV_ITEMPICKUP: {
      const int n = getint(p);
      pickup(n, getint(p), sender);
    }
    break;
    case SV_PING:
      send2(false, cn, SV_PONG, getint(p));
    break;
    case SV_POS: {
      cn = getint(p);
      if (cn<0 || cn>=clients.size() || clients[cn].type==ST_EMPTY) {
        disconnect_client(sender, "client num");
        return;
      }
      int size = msgsizelookup(type);
      assert(size!=-1);
      loopi(size-2) getint(p);
    }
    break;
    case SV_SENDMAP: {
      sgetstr();
      const auto mapsize = getint(p);
      sendmaps(sender, text, mapsize, p);
    }
    return;
    case SV_RECVMAP:
      send(sender, recvmap(sender));
    return;
    case SV_EXT:   // allows for new features that require no server updates 
      for (int n = getint(p); n; n--) getint(p);
    break;
    default: {
      const int size = msgsizelookup(type);
      if (size==-1) { disconnect_client(sender, "tag type"); return; };
      loopi(size-1) getint(p);
    }
  }

  if (p>end) { disconnect_client(sender, "end of packet"); return; };
  multicast(packet, sender);
}

void localservertoclient(uchar *buf, int len)   // processes any updates from the server
{
	if(ENET_NET_TO_HOST_16(*(ushort *)buf)!=len) neterr("packet length");
	incomingdemodata(buf, len);

	uchar *end = buf+len;
	uchar *p = buf+2;
	char text[MAXTRANS];
	int cn = -1, type;
	dynent *d = NULL;
	bool mapchanged = false;

	while(p<end) switch(type = getint(p))
	{
		case SV_INITS2C:                    // welcome messsage from the server
			{
				cn = getint(p);
				int prot = getint(p);
				if(prot!=PROTOCOL_VERSION)
				{
					conoutf("you are using a different game protocol (you: %d, server: %d)", PROTOCOL_VERSION, prot);
					disconnect();
					return;
				};
				toservermap[0] = 0;
				clientnum = cn;                 // we are now fully connected
				if(!getint(p)) strcpy_s(toservermap, getclientmap());   // we are the first client on this server, set map
				sgetstr();
				if(text[0] && strcmp(text, clientpassword))
				{
					conoutf("you need to set the correct password to join this server!");
					disconnect();
					return;
				};
				if(getint(p)==1)
				{
					conoutf("server is FULL, disconnecting..");
				};
				break;
			};

		case SV_POS:                        // position of another client
			{
				cn = getint(p);
				d = getclient(cn);
				if(!d) return;
				d->o.x   = getint(p)/DMF;
				d->o.y   = getint(p)/DMF;
				d->o.z   = getint(p)/DMF;
				d->yaw   = getint(p)/DAF;
				d->pitch = getint(p)/DAF;
				d->roll  = getint(p)/DAF;
				d->vel.x = getint(p)/DVF;
				d->vel.y = getint(p)/DVF;
				d->vel.z = getint(p)/DVF;
				int f = getint(p);
				d->strafe = (f&3)==3 ? -1 : f&3;
				f >>= 2;
				d->move = (f&3)==3 ? -1 : f&3;
				d->onfloor = (f>>2)&1;
				int state = f>>3;
				if(state==CS_DEAD && d->state!=CS_DEAD) d->lastaction = lastmillis;
				d->state = state;
				if(!demoplayback) updatepos(d);
				break;
			};

		case SV_SOUND:
			playsound(getint(p), &d->o);
			break;

		case SV_TEXT:
			sgetstr();
			conoutf("%s:\f %s", d->name, text);
			break;

		case SV_MAPCHANGE:
			sgetstr();
			changemapserv(text, getint(p));
			mapchanged = true;
			break;

		case SV_ITEMLIST:
			{
				int n;
				if(mapchanged) { senditemstoserver = false; resetspawns(); };
				while((n = getint(p))!=-1) if(mapchanged) setspawn(n, true);
				break;
			};

		case SV_MAPRELOAD:          // server requests next map
			{
				getint(p);
				sprintf_sd(nextmapalias)("nextmap_%s", getclientmap());
				char *map = getalias(nextmapalias);     // look up map in the cycle
				changemap(map ? map : getclientmap());
				break;
			};

		case SV_INITC2S:            // another client either connected or changed name/team
//.........这里部分代码省略.........

void localservertoclient(uchar *buf, int len) // processes any updates from the server
{
	if (ENET_NET_TO_HOST_16(*(ushort *)buf) != len)
		neterr("packet length");
	incomingdemodata(buf, len);

	uchar *end = buf + len;
	uchar *p = buf + 2;
	char text[MAXTRANS];
	int cn = -1, type;
	Sprite *spr = NULL;
	bool mapchanged = false;

	while (p < end)
		switch (type = getint(p)) {
		case SV_INITS2C:                    // welcome messsage from the server
		{
			cn = getint(p);
			int prot = getint(p);
			if (prot != PROTOCOL_VERSION) {
				conoutf( "you are using a different game protocol (you: %d, server: %d)", PROTOCOL_VERSION, prot);
				disconnect();
				return;
			};
			toservermap = "";
			clientnum = cn;                 // we are now fully connected
			if (!getint(p)) {
				toservermap = getclientmap(); // we are the first client on this server, set map
			}
			sgetstr();

			if (text[0] && strcmp(text, clientpassword)) {
				conoutf( "you need to set the correct password to join this server!");
				disconnect();
				return;
			};
			if (getint(p) == 1) {
				conoutf("server is FULL, disconnecting..");
			};
			break;
		}
		case SV_POS:                        // position of another client
		{
			cn = getint(p);
			spr = getclient(cn);
			if (!spr)
				return;
			spr->o.x = getint(p) / DMF;
			spr->o.y = getint(p) / DMF;
			spr->o.z = getint(p) / DMF;
			spr->yaw = getint(p) / DAF;
			spr->pitch = getint(p) / DAF;
			spr->roll = getint(p) / DAF;
			spr->vel.x = getint(p) / DVF;
			spr->vel.y = getint(p) / DVF;
			spr->vel.z = getint(p) / DVF;
			int f = getint(p);
			spr->strafe = (f & 3) == 3 ? -1 : f & 3;
			f >>= 2;
			spr->move = (f & 3) == 3 ? -1 : f & 3;
			spr->onfloor = (f >> 2) & 1;
			int state = f >> 3;
			if (state == CS_DEAD && spr->state != CS_DEAD)
				spr->lastaction = lastmillis;
			spr->state = state;
			if (!demoplayback)
				updatepos(spr);
			break;
		}
		case SV_SOUND:
			playsound(getint(p), &spr->o);
			break;
		case SV_TEXT:
			sgetstr();
			conoutf("%s:\f %s", spr->name, text);
			break;
		case SV_MAPCHANGE:
			sgetstr();
			changemapserv(text, getint(p));
			mapchanged = true;
			break;
		case SV_ITEMLIST: {
			int n;
			if (mapchanged) {
				senditemstoserver = false;
				resetspawns();
			};
			while ((n = getint(p)) != -1) {
				if (mapchanged)
					setspawn(n, true);
			}
			break;
		}

		case SV_MAPRELOAD:          // server requests next map
		{
			getint(p);
			std::string nextmapalias = std::string("nextmap_") + getclientmap();
			std::string map = getalias(nextmapalias);     // look up map in the cycle
			changemap(map.empty() ? getclientmap() : map);
//.........这里部分代码省略.........