fixed bug with comparing wrong viewport variables
[rocksndiamonds.git] / src / network.c
index 6f06d610392aa6d6d3b36c11b2af5315254b6381..6c1f4c6de4d1bd5d91674188fed45a725eb845cb 100644 (file)
@@ -22,6 +22,7 @@
 #include "files.h"
 #include "tools.h"
 #include "screens.h"
+#include "init.h"
 
 struct NetworkClientPlayerInfo
 {
@@ -37,17 +38,20 @@ static struct NetworkClientPlayerInfo first_player =
   NULL
 };
 
-/* server stuff */
+// server stuff
 
-static TCPsocket sfd;          /* TCP server socket */
-static UDPsocket udp;          /* UDP server socket */
-static SDLNet_SocketSet rfds;  /* socket set */
+static TCPsocket sfd;          // TCP server socket
+static UDPsocket udp;          // UDP server socket
+static SDLNet_SocketSet rfds;  // socket set
+
+static struct NetworkBuffer *read_buffer = NULL;
+static struct NetworkBuffer *write_buffer = NULL;
 
-static byte realbuffer[512];
-static byte readbuffer[MAX_BUFFER_SIZE], writbuffer[MAX_BUFFER_SIZE];
-static byte *buffer = realbuffer + 4;
-static int nread = 0, nwrite = 0;
 static boolean stop_network_game = FALSE;
+static boolean stop_network_client = FALSE;
+static char stop_network_client_message[MAX_OUTPUT_LINESIZE + 1];
+
+static struct NetworkLevelInfo network_level;
 
 static void DrawNetworkTextExt(char *message, int font_nr, boolean initialize)
 {
@@ -78,7 +82,7 @@ static void DrawNetworkTextExt(char *message, int font_nr, boolean initialize)
 
       DrawTextSCentered(ypos_1, font_nr, message);
 
-      /* calculate offset to x position caused by rounding */
+      // calculate offset to x position caused by rounding
       int max_chars_per_line = max_line_width / font_width;
       int xoffset = (max_line_width - max_chars_per_line * font_width) / 2;
 
@@ -126,27 +130,19 @@ static void DrawNetworkText_Title(char *message)
   DrawNetworkTextExt(message, FC_GREEN, TRUE);
 }
 
-static void SendBufferToServer(int size)
+static void SendNetworkBufferToServer(struct NetworkBuffer *nb)
 {
   if (!network.enabled)
     return;
 
-  realbuffer[0] = realbuffer[1] = realbuffer[2] = 0;
-  realbuffer[3] = (byte)size;
-  buffer[0] = 0;
-
-  if (nwrite + 4 + size >= MAX_BUFFER_SIZE)
-    Error(ERR_EXIT, "internal error: network send buffer overflow");
+  // set message length header
+  putNetwork32BitInteger(nb->buffer, nb->size - 4);
 
-  memcpy(writbuffer + nwrite, realbuffer, 4 + size);
-  nwrite += 4 + size;
-
-  /* directly send the buffer to the network server */
-  SDLNet_TCP_Send(sfd, writbuffer, nwrite);
-  nwrite = 0;
+  // directly send the buffer to the network server
+  SDLNet_TCP_Send(sfd, nb->buffer, nb->size);
 }
 
-struct NetworkClientPlayerInfo *getNetworkPlayer(int player_nr)
+static struct NetworkClientPlayerInfo *getNetworkPlayer(int player_nr)
 {
   struct NetworkClientPlayerInfo *player = NULL;
 
@@ -154,7 +150,7 @@ struct NetworkClientPlayerInfo *getNetworkPlayer(int player_nr)
     if (player->nr == player_nr)
       break;
 
-  if (player == NULL)  /* should not happen */
+  if (player == NULL)  // should not happen
     Error(ERR_EXIT, "protocol error: reference to non-existing player %d",
          player_nr);
 
@@ -177,17 +173,24 @@ char *getNetworkPlayerName(int player_nr)
   return(EMPTY_PLAYER_NAME);
 }
 
+boolean hasStartedNetworkGame(void)
+{
+  return !network_level.use_network_level_files;
+}
+
+static boolean hasPathSeparator(char *s)
+{
+  return (strchr(s, '/') != NULL);
+}
+
 static void StartNetworkServer(int port)
 {
   static int p;
 
   p = port;
-#if defined(TARGET_SDL2)
+
   server_thread = SDL_CreateThread(NetworkServerThread,
                                   "NetworkServerThread", &p);
-#else
-  server_thread = SDL_CreateThread(NetworkServerThread, &p);
-#endif
   network_server = TRUE;
 }
 
@@ -197,6 +200,12 @@ boolean ConnectToServer(char *hostname, int port)
   int server_host = 0;
   int i;
 
+  if (read_buffer == NULL)
+    read_buffer = newNetworkBuffer();
+
+  if (write_buffer == NULL)
+    write_buffer = newNetworkBuffer();
+
   DrawNetworkText_Title("Initializing Network");
 
   if (port == 0)
@@ -223,7 +232,7 @@ boolean ConnectToServer(char *hostname, int port)
     int data_len = strlen(data_ptr) + 1;
     IPaddress ip_address;
 
-    SDLNet_Write32(0xffffffff, &ip_address.host);      /* 255.255.255.255 */
+    SDLNet_Write32(0xffffffff, &ip_address.host);      // 255.255.255.255
     SDLNet_Write16(port,       &ip_address.port);
 
     UDPpacket packet =
@@ -238,9 +247,9 @@ boolean ConnectToServer(char *hostname, int port)
 
     SDLNet_UDP_Send(udp, -1, &packet);
 
-    DrawNetworkText("Looking for local network server ...");
+    DrawNetworkText("Looking for nearby network server ...");
 
-    /* wait for any local network server to answer UDP broadcast */
+    // wait for any nearby network server to answer UDP broadcast
     for (i = 0; i < 5; i++)
     {
       if (SDLNet_CheckSockets(udp_socket_set, 0) == 1)
@@ -249,9 +258,17 @@ boolean ConnectToServer(char *hostname, int port)
 
        if (num_packets == 1)
        {
-         DrawNetworkText_Success("Network server found!");
+         char message[100];
 
          server_host = SDLNet_Read32(&packet.address.host);
+
+         sprintf(message, "Network server found at %d.%d.%d.%d!",
+                 (server_host >> 24) & 0xff,
+                 (server_host >> 16) & 0xff,
+                 (server_host >>  8) & 0xff,
+                 (server_host >>  0) & 0xff);
+
+         DrawNetworkText_Success(message);
        }
        else
        {
@@ -267,33 +284,52 @@ boolean ConnectToServer(char *hostname, int port)
     }
 
     if (server_host == 0)
-      DrawNetworkText_Failed("No network server found!");
+      DrawNetworkText_Failed("No nearby network server found!");
   }
 
   rfds = SDLNet_AllocSocketSet(1);
 
   if (hostname)
   {
+    char message[100];
+
     SDLNet_ResolveHost(&ip, hostname, port);
 
     if (ip.host == INADDR_NONE)
-      Error(ERR_EXIT, "cannot locate host '%s'", hostname);
+    {
+      sprintf(message, "Failed to resolve network server hostname '%s'!",
+             hostname);
+
+      DrawNetworkText_Failed(message);
+
+      return FALSE;
+    }
     else
+    {
       server_host = SDLNet_Read32(&ip.host);
+    }
 
-    DrawNetworkText("Connecting to remote host ...");
+    sprintf(message, "Connecting to network server host %s ...", hostname);
+
+    DrawNetworkText(message);
   }
   else
   {
     // if no hostname was given and no network server was auto-detected in the
     // local network, try to connect to a network server at the local host
     if (server_host == 0)
-      server_host = 0x7f000001;                        /* 127.0.0.1 */
+    {
+      server_host = 0x7f000001;                        // 127.0.0.1
+
+      DrawNetworkText("Looking for local network server ...");
+    }
+    else
+    {
+      DrawNetworkText("Connecting to network server ...");
+    }
 
     SDLNet_Write32(server_host, &ip.host);
     SDLNet_Write16(port,        &ip.port);
-
-    DrawNetworkText("Connecting to local host ...");
   }
 
   Error(ERR_DEBUG, "trying to connect to network server at %d.%d.%d.%d ...",
@@ -314,140 +350,193 @@ boolean ConnectToServer(char *hostname, int port)
   }
   else
   {
-    DrawNetworkText_Failed("Failed to connect to network server!");
+    if (hostname)
+      DrawNetworkText_Failed("Failed to connect to network server!");
+    else
+      DrawNetworkText_Failed("No local network server found!");
 
     printf("SDLNet_TCP_Open(): %s\n", SDLNet_GetError());
   }
 
-  if (hostname)                        /* connect to specified server failed */
+  if (hostname)                        // connect to specified server failed
     return FALSE;
 
   DrawNetworkText("Starting new local network server ...");
 
   StartNetworkServer(port);
 
-  /* wait for server to start up and try connecting several times */
+  // wait for server to start up and try connecting several times
   for (i = 0; i < 30; i++)
   {
-    if ((sfd = SDLNet_TCP_Open(&ip)))          /* connected */
+    if ((sfd = SDLNet_TCP_Open(&ip)))          // connected
     {
-      DrawNetworkText_Success("Successfully connected!");
+      DrawNetworkText_Success("Successfully connected to newly started network server!");
 
       SDLNet_TCP_AddSocket(rfds, sfd);
+
       return TRUE;
     }
 
     Delay_WithScreenUpdates(100);
   }
 
-  DrawNetworkText_Failed("Failed to connect to network server!");
+  DrawNetworkText_Failed("Failed to connect to newly started network server!");
 
-  /* when reaching this point, connect to newly started server has failed */
+  // when reaching this point, connect to newly started server has failed
   return FALSE;
 }
 
 void SendToServer_PlayerName(char *player_name)
 {
-  int len_player_name = strlen(player_name);
+  initNetworkBufferForWriting(write_buffer, OP_PLAYER_NAME, 0);
+
+  putNetworkBufferString(write_buffer, player_name);
+
+  SendNetworkBufferToServer(write_buffer);
 
-  buffer[1] = OP_PLAYER_NAME;
-  memcpy(&buffer[2], player_name, len_player_name);
-  SendBufferToServer(2 + len_player_name);
   Error(ERR_NETWORK_CLIENT, "you set your player name to \"%s\"", player_name);
 }
 
-void SendToServer_ProtocolVersion()
+void SendToServer_ProtocolVersion(void)
 {
-  buffer[1] = OP_PROTOCOL_VERSION;
-  buffer[2] = PROTOCOL_VERSION_1;
-  buffer[3] = PROTOCOL_VERSION_2;
-  buffer[4] = PROTOCOL_VERSION_3;
+  initNetworkBufferForWriting(write_buffer, OP_PROTOCOL_VERSION, 0);
 
-  SendBufferToServer(5);
+  putNetworkBuffer8BitInteger(write_buffer, PROTOCOL_VERSION_MAJOR);
+  putNetworkBuffer8BitInteger(write_buffer, PROTOCOL_VERSION_MINOR);
+  putNetworkBuffer8BitInteger(write_buffer, PROTOCOL_VERSION_PATCH);
+
+  SendNetworkBufferToServer(write_buffer);
 }
 
 void SendToServer_NrWanted(int nr_wanted)
 {
-  buffer[1] = OP_NUMBER_WANTED;
-  buffer[2] = nr_wanted;
+  initNetworkBufferForWriting(write_buffer, OP_NUMBER_WANTED, 0);
+
+  putNetworkBuffer8BitInteger(write_buffer, nr_wanted);
 
-  SendBufferToServer(3);
+  SendNetworkBufferToServer(write_buffer);
 }
 
-void SendToServer_StartPlaying()
+void SendToServer_LevelFile(void)
 {
-  unsigned int new_random_seed = InitRND(level.random_seed);
+  initNetworkBufferForWriting(write_buffer, OP_LEVEL_FILE, 0);
+
+  putNetworkBufferString(      write_buffer, leveldir_current->identifier);
+  putNetworkBuffer16BitInteger(write_buffer, level.file_info.nr);
+  putNetworkBuffer8BitInteger( write_buffer, level.file_info.type);
+  putNetworkBuffer8BitInteger( write_buffer, level.file_info.packed);
+  putNetworkBufferString(      write_buffer, level.file_info.basename);
+  putNetworkBufferFile(        write_buffer, level.file_info.filename);
+  putNetworkBuffer8BitInteger( write_buffer, level.use_custom_template);
+
+  if (level.use_custom_template)
+  {
+    putNetworkBufferString(write_buffer, level_template.file_info.basename);
+    putNetworkBufferFile(  write_buffer, level_template.file_info.filename);
+  }
 
-  int dummy = 0;               /* !!! HAS NO MEANING ANYMORE !!! */
-                               /* the name of the level must be enough */
+  SendNetworkBufferToServer(write_buffer);
 
-  buffer[1] = OP_START_PLAYING;
-  buffer[2] = (byte)(level_nr >> 8);
-  buffer[3] = (byte)(level_nr & 0xff);
-  buffer[4] = (byte)(dummy >> 8);
-  buffer[5] = (byte)(dummy & 0xff);
+  setString(&network_level.leveldir_identifier, leveldir_current->identifier);
 
-  buffer[6] = (unsigned char)((new_random_seed >> 24) & 0xff);
-  buffer[7] = (unsigned char)((new_random_seed >> 16) & 0xff);
-  buffer[8] = (unsigned char)((new_random_seed >>  8) & 0xff);
-  buffer[9] = (unsigned char)((new_random_seed >>  0) & 0xff);
+  // the sending client does not use network level files (but the real ones)
+  network_level.use_network_level_files = FALSE;
 
-  strcpy((char *)&buffer[10], leveldir_current->identifier);
+#if 0
+  printf("::: '%s'\n", leveldir_current->identifier);
+  printf("::: '%d'\n", level.file_info.nr);
+  printf("::: '%d'\n", level.file_info.type);
+  printf("::: '%d'\n", level.file_info.packed);
+  printf("::: '%s'\n", level.file_info.basename);
+  printf("::: '%s'\n", level.file_info.filename);
 
-  SendBufferToServer(10 + strlen(leveldir_current->identifier) + 1);
+  if (level.use_custom_template)
+    printf("::: '%s'\n", level_template.file_info.filename);
+#endif
 }
 
-void SendToServer_PausePlaying()
+void SendToServer_StartPlaying(void)
 {
-  buffer[1] = OP_PAUSE_PLAYING;
+  unsigned int new_random_seed = InitRND(level.random_seed);
+
+  initNetworkBufferForWriting(write_buffer, OP_START_PLAYING, 0);
 
-  SendBufferToServer(2);
+  putNetworkBufferString(      write_buffer, leveldir_current->identifier);
+  putNetworkBuffer16BitInteger(write_buffer, level_nr);
+  putNetworkBuffer32BitInteger(write_buffer, new_random_seed);
+
+  SendNetworkBufferToServer(write_buffer);
 }
 
-void SendToServer_ContinuePlaying()
+void SendToServer_PausePlaying(void)
 {
-  buffer[1] = OP_CONTINUE_PLAYING;
+  initNetworkBufferForWriting(write_buffer, OP_PAUSE_PLAYING, 0);
 
-  SendBufferToServer(2);
+  SendNetworkBufferToServer(write_buffer);
+}
+
+void SendToServer_ContinuePlaying(void)
+{
+  initNetworkBufferForWriting(write_buffer, OP_CONTINUE_PLAYING, 0);
+
+  SendNetworkBufferToServer(write_buffer);
 }
 
 void SendToServer_StopPlaying(int cause_for_stopping)
 {
-  buffer[1] = OP_STOP_PLAYING;
-  buffer[2] = cause_for_stopping;
+  initNetworkBufferForWriting(write_buffer, OP_STOP_PLAYING, 0);
 
-  SendBufferToServer(3);
+  putNetworkBuffer8BitInteger(write_buffer, cause_for_stopping);
+
+  SendNetworkBufferToServer(write_buffer);
 }
 
 void SendToServer_MovePlayer(byte player_action)
 {
-  buffer[1] = OP_MOVE_PLAYER;
-  buffer[2] = player_action;
+  initNetworkBufferForWriting(write_buffer, OP_MOVE_PLAYER, 0);
+
+  putNetworkBuffer8BitInteger(write_buffer, player_action);
 
-  SendBufferToServer(3);
+  SendNetworkBufferToServer(write_buffer);
 }
 
-static void Handle_OP_BAD_PROTOCOL_VERSION()
+static void Handle_OP_BAD_PROTOCOL_VERSION(void)
 {
+  int protocol_version_major = getNetworkBuffer8BitInteger(read_buffer);
+  int protocol_version_minor = getNetworkBuffer8BitInteger(read_buffer);
+
   Error(ERR_WARN, "protocol version mismatch");
-  Error(ERR_EXIT, "server expects %d.%d.x instead of %d.%d.%d",
-       buffer[2], buffer[3],
-       PROTOCOL_VERSION_1, PROTOCOL_VERSION_2, PROTOCOL_VERSION_3);
+  Error(ERR_WARN, "server expects %d.%d.x instead of %d.%d.%d",
+       protocol_version_major,
+       protocol_version_minor,
+       PROTOCOL_VERSION_MAJOR,
+       PROTOCOL_VERSION_MINOR,
+       PROTOCOL_VERSION_PATCH);
+
+  sprintf(stop_network_client_message, "Network protocol version mismatch! Server expects version %d.%d.x instead of %d.%d.%d!",
+         protocol_version_major,
+         protocol_version_minor,
+         PROTOCOL_VERSION_MAJOR,
+         PROTOCOL_VERSION_MINOR,
+         PROTOCOL_VERSION_PATCH);
+
+  stop_network_client = TRUE;
 }
 
-static void Handle_OP_YOUR_NUMBER()
+static void Handle_OP_YOUR_NUMBER(void)
 {
-  int new_client_nr = buffer[2];
+  int old_client_nr = getNetworkBuffer8BitInteger(read_buffer);
+  int new_client_nr = getNetworkBuffer8BitInteger(read_buffer);
   int new_index_nr = new_client_nr - 1;
   struct PlayerInfo *old_local_player = local_player;
   struct PlayerInfo *new_local_player = &stored_player[new_index_nr];
 
-  printf("OP_YOUR_NUMBER: %d\n", buffer[0]);
+  printf("OP_YOUR_NUMBER: %d\n", old_client_nr);
   first_player.nr = new_client_nr;
 
   if (old_local_player != new_local_player)
   {
-    /* set relevant player settings and change to new player */
+    // set relevant player settings and change to new player
 
     local_player = new_local_player;
 
@@ -462,34 +551,36 @@ static void Handle_OP_YOUR_NUMBER()
     Error(ERR_EXIT, "sorry, more than %d players not allowed", MAX_PLAYERS);
 
   Error(ERR_NETWORK_CLIENT, "you get client # %d", new_client_nr);
+
+  stored_player[new_index_nr].connected_network = TRUE;
 }
 
-static void Handle_OP_NUMBER_WANTED()
+static void Handle_OP_NUMBER_WANTED(void)
 {
-  int client_nr_wanted = buffer[2];
-  int old_client_nr = buffer[0];
-  int new_client_nr = buffer[3];
+  int old_client_nr    = getNetworkBuffer8BitInteger(read_buffer);
+  int client_nr_wanted = getNetworkBuffer8BitInteger(read_buffer);
+  int new_client_nr    = getNetworkBuffer8BitInteger(read_buffer);
   int old_index_nr = old_client_nr - 1;
   int new_index_nr = new_client_nr - 1;
   int index_nr_wanted = client_nr_wanted - 1;
   struct PlayerInfo *old_player = &stored_player[old_index_nr];
   struct PlayerInfo *new_player = &stored_player[new_index_nr];
 
-  printf("OP_NUMBER_WANTED: %d\n", buffer[0]);
+  printf("OP_NUMBER_WANTED: %d\n", old_client_nr);
 
-  if (new_client_nr == client_nr_wanted)       /* switching succeeded */
+  if (new_client_nr == client_nr_wanted)       // switching succeeded
   {
     struct NetworkClientPlayerInfo *player;
 
-    if (old_client_nr != client_nr_wanted)     /* client's nr has changed */
+    if (old_client_nr != client_nr_wanted)     // client's nr has changed
       Error(ERR_NETWORK_CLIENT, "client %d switches to # %d",
            old_client_nr, new_client_nr);
-    else if (old_client_nr == first_player.nr) /* local player keeps his nr */
+    else if (old_client_nr == first_player.nr) // local player keeps his nr
       Error(ERR_NETWORK_CLIENT, "keeping client # %d", new_client_nr);
 
     if (old_client_nr != new_client_nr)
     {
-      /* set relevant player settings and change to new player */
+      // set relevant player settings and change to new player
 
       old_player->connected_network = FALSE;
       new_player->connected_network = TRUE;
@@ -498,7 +589,7 @@ static void Handle_OP_NUMBER_WANTED()
     player = getNetworkPlayer(old_client_nr);
     player->nr = new_client_nr;
 
-    if (old_player == local_player)            /* local player switched */
+    if (old_player == local_player)            // local player switched
     {
       local_player = new_player;
 
@@ -506,7 +597,7 @@ static void Handle_OP_NUMBER_WANTED()
       new_player->connected_locally = TRUE;
     }
   }
-  else if (old_client_nr == first_player.nr)   /* failed -- local player? */
+  else if (old_client_nr == first_player.nr)   // failed -- local player?
   {
     char request[100];
 
@@ -523,23 +614,25 @@ static void Handle_OP_NUMBER_WANTED()
     DrawNetworkPlayers();
 }
 
-static void Handle_OP_PLAYER_NAME(unsigned int len)
+static void Handle_OP_PLAYER_NAME(void)
 {
-  struct NetworkClientPlayerInfo *player;
-  int player_nr = (int)buffer[0];
+  int player_nr = getNetworkBuffer8BitInteger(read_buffer);
+  char *player_name = getNetworkBufferString(read_buffer);
+  struct NetworkClientPlayerInfo *player = getNetworkPlayer(player_nr);
 
   printf("OP_PLAYER_NAME: %d\n", player_nr);
-  player = getNetworkPlayer(player_nr);
-  buffer[len] = 0;
+
+  strncpy(player->name, player_name, MAX_PLAYER_NAME_LEN);
+  player->name[MAX_PLAYER_NAME_LEN] = '\0';
+
   Error(ERR_NETWORK_CLIENT, "client %d calls itself \"%s\"",
-       buffer[0], &buffer[2]);
-  strncpy(player->name, (char *)&buffer[2], MAX_PLAYER_NAME_LEN);
+       player_nr, player->name);
 }
 
-static void Handle_OP_PLAYER_CONNECTED()
+static void Handle_OP_PLAYER_CONNECTED(void)
 {
   struct NetworkClientPlayerInfo *player, *last_player = NULL;
-  int new_client_nr = (int)buffer[0];
+  int new_client_nr = getNetworkBuffer8BitInteger(read_buffer);
   int new_index_nr = new_client_nr - 1;
 
   printf("OP_PLAYER_CONNECTED: %d\n", new_client_nr);
@@ -562,16 +655,16 @@ static void Handle_OP_PLAYER_CONNECTED()
   stored_player[new_index_nr].connected_network = TRUE;
 }
 
-static void Handle_OP_PLAYER_DISCONNECTED()
+static void Handle_OP_PLAYER_DISCONNECTED(void)
 {
   struct NetworkClientPlayerInfo *player, *player_disconnected;
-  int player_nr = (int)buffer[0];
+  int player_nr = getNetworkBuffer8BitInteger(read_buffer);
   int index_nr = player_nr - 1;
 
   printf("OP_PLAYER_DISCONNECTED: %d\n", player_nr);
   player_disconnected = getNetworkPlayer(player_nr);
   Error(ERR_NETWORK_CLIENT, "client %d (%s) disconnected",
-       player_nr, getNetworkPlayerName(buffer[0]));
+       player_nr, getNetworkPlayerName(player_nr));
 
   for (player = &first_player; player; player = player->next)
     if (player->next == player_disconnected)
@@ -600,81 +693,102 @@ static void Handle_OP_PLAYER_DISCONNECTED()
   }
 }
 
-static void Handle_OP_START_PLAYING()
+static void Handle_OP_START_PLAYING(void)
 {
-  LevelDirTree *new_leveldir;
-  int new_level_nr;
-  unsigned int new_random_seed;
-  char *new_leveldir_identifier;
-
-  new_level_nr = (buffer[2] << 8) + buffer[3];
-  new_random_seed =
-    (buffer[6] << 24) | (buffer[7] << 16) | (buffer[8] << 8) | (buffer[9]);
-  new_leveldir_identifier = (char *)&buffer[10];
+  int player_nr = getNetworkBuffer8BitInteger(read_buffer);
+  char *new_leveldir_identifier = getNetworkBufferString(read_buffer);
+  int new_level_nr = getNetworkBuffer16BitInteger(read_buffer);
+  unsigned int new_random_seed = getNetworkBuffer32BitInteger(read_buffer);
 
-  new_leveldir = getTreeInfoFromIdentifier(leveldir_first,
-                                          new_leveldir_identifier);
-  if (new_leveldir == NULL)
+  if (!strEqual(new_leveldir_identifier, network_level.leveldir_identifier))
   {
     Error(ERR_WARN, "no such level identifier: '%s'", new_leveldir_identifier);
 
-    new_leveldir = leveldir_first;
-    Error(ERR_WARN, "using default level set: '%s'", new_leveldir->identifier);
+    stop_network_game = TRUE;
+
+    return;
   }
 
-  printf("OP_START_PLAYING: %d\n", buffer[0]);
+  printf("OP_START_PLAYING: %d\n", player_nr);
   Error(ERR_NETWORK_CLIENT,
        "client %d starts game [level %d from level identifier '%s']\n",
-       buffer[0], new_level_nr, new_leveldir->identifier);
+       player_nr, new_level_nr, new_leveldir_identifier);
+
+  LevelDirTree *new_leveldir =
+    getTreeInfoFromIdentifier(leveldir_first, new_leveldir_identifier);
+
+  if (new_leveldir != NULL)
+  {
+    leveldir_current = new_leveldir;
+    level_nr = new_level_nr;
+  }
 
-  leveldir_current = new_leveldir;
-  level_nr = new_level_nr;
+  // needed if level set of network game changed graphics, sounds or music
+  ReloadCustomArtwork(0);
 
   TapeErase();
-  LoadTape(level_nr);
-  LoadLevel(level_nr);
+
+  if (network_level.use_network_level_files)
+    LoadNetworkLevel(&network_level);
+  else
+    LoadLevel(level_nr);
 
   StartGameActions(FALSE, setup.autorecord, new_random_seed);
 }
 
-static void Handle_OP_PAUSE_PLAYING()
+static void Handle_OP_PAUSE_PLAYING(void)
 {
-  printf("OP_PAUSE_PLAYING: %d\n", buffer[0]);
-  Error(ERR_NETWORK_CLIENT, "client %d pauses game", buffer[0]);
+  int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 
-  tape.pausing = TRUE;
-  DrawVideoDisplay(VIDEO_STATE_PAUSE_ON,0);
+  printf("OP_PAUSE_PLAYING: %d\n", player_nr);
+  Error(ERR_NETWORK_CLIENT, "client %d pauses game", player_nr);
+
+  if (game_status == GAME_MODE_PLAYING)
+  {
+    tape.pausing = TRUE;
+    DrawVideoDisplay(VIDEO_STATE_PAUSE_ON, 0);
+  }
 }
 
-static void Handle_OP_CONTINUE_PLAYING()
+static void Handle_OP_CONTINUE_PLAYING(void)
 {
-  printf("OP_CONTINUE_PLAYING: %d\n", buffer[0]);
-  Error(ERR_NETWORK_CLIENT, "client %d continues game", buffer[0]);
+  int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 
-  tape.pausing = FALSE;
-  DrawVideoDisplay(VIDEO_STATE_PAUSE_OFF,0);
+  printf("OP_CONTINUE_PLAYING: %d\n", player_nr);
+  Error(ERR_NETWORK_CLIENT, "client %d continues game", player_nr);
+
+  if (game_status == GAME_MODE_PLAYING)
+  {
+    tape.pausing = FALSE;
+    DrawVideoDisplay(VIDEO_STATE_PAUSE_OFF, 0);
+  }
 }
 
-static void Handle_OP_STOP_PLAYING()
+static void Handle_OP_STOP_PLAYING(void)
 {
-  printf("OP_STOP_PLAYING: %d [%d]\n", buffer[0], buffer[2]);
-  Error(ERR_NETWORK_CLIENT, "client %d stops game [%d]", buffer[0], buffer[2]);
+  int client_nr = getNetworkBuffer8BitInteger(read_buffer);
+  int cause_for_stopping = getNetworkBuffer8BitInteger(read_buffer);
+
+  printf("OP_STOP_PLAYING: %d [%d]\n", client_nr, cause_for_stopping);
+  Error(ERR_NETWORK_CLIENT, "client %d stops game [%d]",
+       client_nr, cause_for_stopping);
 
   if (game_status == GAME_MODE_PLAYING)
   {
-    int client_nr = buffer[0];
     int index_nr = client_nr - 1;
     struct PlayerInfo *client_player = &stored_player[index_nr];
     boolean stopped_by_remote_player = (!client_player->connected_locally);
     char message[100];
 
-    sprintf(message, (buffer[2] == NETWORK_STOP_BY_PLAYER ?
-                     "Network game stopped by player %d!" :
-                     buffer[2] == NETWORK_STOP_BY_ERROR ?
-                     "Network game stopped due to internal error!" :
-                     "Network game stopped!"), client_nr);
+    if (cause_for_stopping == NETWORK_STOP_BY_PLAYER)
+      sprintf(message, "Network game stopped by player %d!", client_nr);
+    else
+      sprintf(message, (cause_for_stopping == NETWORK_STOP_BY_ERROR ?
+                       "Network game stopped due to internal error!" :
+                       "Network game stopped!"));
 
-    if (buffer[2] != NETWORK_STOP_BY_PLAYER || stopped_by_remote_player)
+    if (cause_for_stopping != NETWORK_STOP_BY_PLAYER ||
+       stopped_by_remote_player)
       Request(message, REQ_CONFIRM | REQ_STAY_CLOSED);
 
     SetGameStatus(GAME_MODE_MAIN);
@@ -683,20 +797,19 @@ static void Handle_OP_STOP_PLAYING()
   }
 }
 
-static void Handle_OP_MOVE_PLAYER(unsigned int len)
+static void Handle_OP_MOVE_PLAYER(void)
 {
-  int server_frame_counter;
+  int player_nr = getNetworkBuffer8BitInteger(read_buffer);
+  int server_frame_counter = getNetworkBuffer32BitInteger(read_buffer);
   int i;
 
   if (!network_playing)
     return;
 
-  server_frame_counter =
-    (buffer[2] << 24) | (buffer[3] << 16) | (buffer[4] << 8) | (buffer[5]);
-
   if (server_frame_counter != FrameCounter)
   {
-    Error(ERR_INFO, "client and servers frame counters out of sync");
+    Error(ERR_INFO, "frame counters of client %d and server out of sync",
+         player_nr);
     Error(ERR_INFO, "frame counter of client is %d", FrameCounter);
     Error(ERR_INFO, "frame counter of server is %d", server_frame_counter);
     Error(ERR_INFO, "this should not happen -- please debug");
@@ -706,97 +819,174 @@ static void Handle_OP_MOVE_PLAYER(unsigned int len)
     return;
   }
 
-  /* copy valid player actions */
+  // copy valid player actions (will be set to 0 for not connected players)
   for (i = 0; i < MAX_PLAYERS; i++)
     stored_player[i].effective_action =
-      (i < len - 6 ? buffer[6 + i] : 0);
+      getNetworkBuffer8BitInteger(read_buffer);
 
   network_player_action_received = TRUE;
 }
 
-static void HandleNetworkingMessages()
+static void Handle_OP_BROADCAST_MESSAGE(void)
+{
+  int player_nr = getNetworkBuffer8BitInteger(read_buffer);
+
+  printf("OP_BROADCAST_MESSAGE: %d\n", player_nr);
+  Error(ERR_NETWORK_CLIENT, "client %d sends message", player_nr);
+}
+
+static void Handle_OP_LEVEL_FILE(void)
 {
-  unsigned int message_length;
+  int player_nr = getNetworkBuffer8BitInteger(read_buffer);
+  char *leveldir_identifier;
+  char *network_level_dir;
+  struct LevelFileInfo *file_info = &network_level.file_info;
+  struct LevelFileInfo *tmpl_info = &network_level.tmpl_info;
+  boolean use_custom_template;
+
+  setString(&network_level.leveldir_identifier, NULL);
+  setString(&network_level.file_info.basename,  NULL);
+  setString(&network_level.file_info.filename,  NULL);
+  setString(&network_level.tmpl_info.basename,  NULL);
+  setString(&network_level.tmpl_info.filename,  NULL);
+
+  printf("OP_LEVEL_FILE: %d\n", player_nr);
+
+  leveldir_identifier = getStringCopy(getNetworkBufferString(read_buffer));
+
+  if (hasPathSeparator(leveldir_identifier))
+    Error(ERR_EXIT, "protocol error: invalid filename from network client");
+
+  InitNetworkLevelDirectory(leveldir_identifier);
+
+  network_level_dir   = getNetworkLevelDir(leveldir_identifier);
+
+  file_info->nr       = getNetworkBuffer16BitInteger(read_buffer);
+  file_info->type     = getNetworkBuffer8BitInteger(read_buffer);
+  file_info->packed   = getNetworkBuffer8BitInteger(read_buffer);
+  file_info->basename = getStringCopy(getNetworkBufferString(read_buffer));
+  file_info->filename = getPath2(network_level_dir, file_info->basename);
+
+  if (hasPathSeparator(file_info->basename))
+    Error(ERR_EXIT, "protocol error: invalid filename from network client");
+
+  getNetworkBufferFile(read_buffer, file_info->filename);
 
+  use_custom_template = getNetworkBuffer8BitInteger(read_buffer);
+  if (use_custom_template)
+  {
+    *tmpl_info = *file_info;
+
+    tmpl_info->basename = getStringCopy(getNetworkBufferString(read_buffer));
+    tmpl_info->filename = getPath2(network_level_dir, tmpl_info->basename);
+
+    if (hasPathSeparator(tmpl_info->basename))
+      Error(ERR_EXIT, "protocol error: invalid filename from network client");
+
+    getNetworkBufferFile(read_buffer, tmpl_info->filename);
+  }
+
+  network_level.leveldir_identifier = leveldir_identifier;
+  network_level.use_custom_template = use_custom_template;
+
+  // the receiving client(s) use(s) the transferred network level files
+  network_level.use_network_level_files = TRUE;
+
+#if 0
+  printf("::: '%s'\n", leveldir_identifier);
+  printf("::: '%d'\n", file_info->nr);
+  printf("::: '%d'\n", file_info->type);
+  printf("::: '%d'\n", file_info->packed);
+  printf("::: '%s'\n", file_info->basename);
+  printf("::: '%s'\n", file_info->filename);
+
+  if (use_custom_template)
+    printf("::: '%s'\n", tmpl_info->filename);
+#endif
+}
+
+static void HandleNetworkingMessage(void)
+{
   stop_network_game = FALSE;
 
-  while (nread >= 4 && nread >= 4 + readbuffer[3])
+  initNetworkBufferForReading(read_buffer);
+
+  int message_type = getNetworkBuffer8BitInteger(read_buffer);
+
+  switch (message_type)
   {
-    message_length = readbuffer[3];
-    if (readbuffer[0] || readbuffer[1] || readbuffer[2])
-      Error(ERR_EXIT, "wrong network server line length");
+    case OP_BAD_PROTOCOL_VERSION:
+      Handle_OP_BAD_PROTOCOL_VERSION();
+      break;
 
-    memcpy(buffer, &readbuffer[4], message_length);
-    nread -= 4 + message_length;
-    memmove(readbuffer, readbuffer + 4 + message_length, nread);
+    case OP_YOUR_NUMBER:
+      Handle_OP_YOUR_NUMBER();
+      break;
 
-    switch (buffer[1])
-    {
-      case OP_BAD_PROTOCOL_VERSION:
-       Handle_OP_BAD_PROTOCOL_VERSION();
-       break;
+    case OP_NUMBER_WANTED:
+      Handle_OP_NUMBER_WANTED();
+      break;
 
-      case OP_YOUR_NUMBER:
-       Handle_OP_YOUR_NUMBER();
-       break;
+    case OP_PLAYER_NAME:
+      Handle_OP_PLAYER_NAME();
+      break;
 
-      case OP_NUMBER_WANTED:
-       Handle_OP_NUMBER_WANTED();
-       break;
+    case OP_PLAYER_CONNECTED:
+      Handle_OP_PLAYER_CONNECTED();
+      break;
 
-      case OP_PLAYER_NAME:
-       Handle_OP_PLAYER_NAME(message_length);
-       break;
+    case OP_PLAYER_DISCONNECTED:
+      Handle_OP_PLAYER_DISCONNECTED();
+      break;
 
-      case OP_PLAYER_CONNECTED:
-       Handle_OP_PLAYER_CONNECTED();
-       break;
-      
-      case OP_PLAYER_DISCONNECTED:
-       Handle_OP_PLAYER_DISCONNECTED();
-       break;
+    case OP_START_PLAYING:
+      Handle_OP_START_PLAYING();
+      break;
 
-      case OP_START_PLAYING:
-       Handle_OP_START_PLAYING();
-       break;
+    case OP_PAUSE_PLAYING:
+      Handle_OP_PAUSE_PLAYING();
+      break;
 
-      case OP_PAUSE_PLAYING:
-       Handle_OP_PAUSE_PLAYING();
-       break;
+    case OP_CONTINUE_PLAYING:
+      Handle_OP_CONTINUE_PLAYING();
+      break;
 
-      case OP_CONTINUE_PLAYING:
-       Handle_OP_CONTINUE_PLAYING();
-       break;
+    case OP_STOP_PLAYING:
+      Handle_OP_STOP_PLAYING();
+      break;
 
-      case OP_STOP_PLAYING:
-       Handle_OP_STOP_PLAYING();
-       break;
+    case OP_MOVE_PLAYER:
+      Handle_OP_MOVE_PLAYER();
+      break;
 
-      case OP_MOVE_PLAYER:
-       Handle_OP_MOVE_PLAYER(message_length);
-       break;
+    case OP_BROADCAST_MESSAGE:
+      Handle_OP_BROADCAST_MESSAGE();
+      break;
 
-      case OP_BROADCAST_MESSAGE:
-       printf("OP_BROADCAST_MESSAGE: %d\n", buffer[0]);
-       Error(ERR_NETWORK_CLIENT, "client %d sends message", buffer[0]);
-       break;
-    }
+    case OP_LEVEL_FILE:
+      Handle_OP_LEVEL_FILE();
+      break;
+
+    default:
+      if (options.verbose)
+       Error(ERR_NETWORK_CLIENT,
+             "unknown opcode %d from server", message_type);
   }
 
   fflush(stdout);
 
-  /* in case of internal error, stop network game */
+  // in case of internal error, stop network game
   if (stop_network_game)
     SendToServer_StopPlaying(NETWORK_STOP_BY_ERROR);
 }
 
-static char *HandleNetworkingPackets()
+static char *HandleNetworkingPackets(void)
 {
   while (1)
   {
-    /* ---------- check network server for activity ---------- */
+    // ---------- check network server for activity ----------
 
-    int num_active_sockets = SDLNet_CheckSockets(rfds, 1);
+    int num_active_sockets = SDLNet_CheckSockets(rfds, 0);
 
     if (num_active_sockets < 0)
       return "Error checking network sockets!";
@@ -804,9 +994,11 @@ static char *HandleNetworkingPackets()
     if (num_active_sockets == 0)
       break;   // no active sockets, stop here
 
-    /* ---------- read packets from network server ---------- */
+    // ---------- read packets from network server ----------
 
-    int num_bytes = SDLNet_TCP_Recv(sfd, readbuffer + nread, 1);
+    initNetworkBufferForReceiving(read_buffer);
+
+    int num_bytes = receiveNetworkBufferPacket(read_buffer, sfd);
 
     if (num_bytes < 0)
       return "Error reading from network server!";
@@ -814,15 +1006,27 @@ static char *HandleNetworkingPackets()
     if (num_bytes == 0)
       return "Connection to network server lost!";
 
-    nread += num_bytes;
+    HandleNetworkingMessage();
 
-    HandleNetworkingMessages();
+    if (stop_network_client)
+      return stop_network_client_message;
   }
 
   return NULL;
 }
 
-static void HandleNetworkingDisconnect()
+static void FreeNetworkClientPlayerInfo(struct NetworkClientPlayerInfo *player)
+{
+  if (player == NULL)
+    return;
+
+  if (player->next)
+    FreeNetworkClientPlayerInfo(player->next);
+
+  checked_free(player);
+}
+
+static void HandleNetworkingDisconnect(void)
 {
   int i;
 
@@ -838,10 +1042,19 @@ static void HandleNetworkingDisconnect()
 
   for (i = 0; i < MAX_PLAYERS; i++)
     stored_player[i].connected_network = FALSE;
+
+  FreeNetworkClientPlayerInfo(first_player.next);
+
+  first_player.nr = 0;
+  first_player.next = NULL;
 }
 
-void HandleNetworking()
+void HandleNetworking(void)
 {
+  // do not handle any networking packets if request dialog is active
+  if (game.request_active)
+    return;
+
   char *error_message = HandleNetworkingPackets();
 
   if (error_message != NULL)
@@ -859,11 +1072,14 @@ void HandleNetworking()
     else
     {
       Request(error_message, REQ_CONFIRM);
+
+      if (game_status == GAME_MODE_MAIN)
+       ClearNetworkPlayers();
     }
   }
 }
 
-void DisconnectFromNetworkServer()
+void DisconnectFromNetworkServer(void)
 {
   DrawNetworkText_Title("Terminating Network");
   DrawNetworkText("Disconnecting from network server ...");
@@ -871,7 +1087,4 @@ void DisconnectFromNetworkServer()
   HandleNetworkingDisconnect();
 
   DrawNetworkText_Success("Successfully disconnected!");
-
-  /* short time to recognize result of network initialization */
-  Delay_WithScreenUpdates(1000);
 }