X-Git-Url: https://git.artsoft.org/?p=rocksndiamonds.git;a=blobdiff_plain;f=src%2Fnetserv.c;h=636fbf236c484edfee5c5a86f8eb83216d7e4679;hp=6f5a9a4ce1c0e2ec99b09ec610e1ae922de7405e;hb=HEAD;hpb=19e168a132d1c0543a13cbf9495f579c137dea94

diff --git a/src/netserv.c b/src/netserv.c
index 6f5a9a4c..636fbf23 100644
--- a/src/netserv.c
+++ b/src/netserv.c
@@ -1,666 +1,1010 @@
-/***********************************************************
-*  Rocks'n'Diamonds -- McDuffin Strikes Back!              *
-*----------------------------------------------------------*
-*  (c) 1995-98 Artsoft Entertainment                       *
-*              Holger Schemel                              *
-*              Oststrasse 11a                              *
-*              33604 Bielefeld                             *
-*              phone: ++49 +521 290471                     *
-*              email: aeglos@valinor.owl.de                *
-*----------------------------------------------------------*
-*  network.c                                               *
-***********************************************************/
-
-#include <unistd.h>
+// ============================================================================
+// Rocks'n'Diamonds - McDuffin Strikes Back!
+// ----------------------------------------------------------------------------
+// (c) 1995-2014 by Artsoft Entertainment
+//     		    Holger Schemel
+//		    info@artsoft.org
+//		    https://www.artsoft.org/
+// ----------------------------------------------------------------------------
+// netserv.c
+// ============================================================================
+
 #include <fcntl.h>
 #include <sys/time.h>
 #include <signal.h>
-#include <sys/socket.h>
 #include <errno.h>
-#include <string.h>
-#include <netinet/in.h>
-#include <netinet/tcp.h>
-#include <arpa/inet.h>
-#include <netdb.h>
+
+#include "libgame/libgame.h"
 
 #include "netserv.h"
-#include "misc.h"
+#include "main.h"
+
 
-static int clients = 0;
-static int onceonly = 0;
-static int is_daemon = 0;
+static int num_clients = 0;
+static boolean run_server_only_once = FALSE;
 
 struct NetworkServerPlayerInfo
 {
-  int fd;
-  unsigned char player_name[16];
-  unsigned char number;
-  struct NetworkServerPlayerInfo *next;
-  char active;
-  char introduced;
-  unsigned char readbuf[MAX_BUFFER_SIZE];
-  unsigned char writbuf[MAX_BUFFER_SIZE];
-  int nread, nwrite;
+  TCPsocket fd;
+  char player_name[MAX_PLAYER_NAME_LEN + 1];
+  int number;
+  boolean active;
+  boolean introduced;
   byte action;
   boolean action_received;
+
+  struct NetworkServerPlayerInfo *next;
 };
 
-static struct NetworkServerPlayerInfo *user0 = NULL;
+static struct NetworkServerPlayerInfo *first_player = NULL;
+
+#define NEXT(player) ((player)->next ? (player)->next : first_player)
+
+// TODO: peer address
+static TCPsocket lfd;		// listening TCP socket
+static UDPsocket udp;		// listening UDP socket
+static SDLNet_SocketSet fds;	// socket set
+
+static struct NetworkBuffer *read_buffer = NULL;
+static struct NetworkBuffer *write_buffer = NULL;
+
+static unsigned int ServerFrameCounter = 0;
 
-#define NEXT(u) ((u)->next ? (u)->next : user0)
 
-static struct sockaddr_in saddr;
-static int lfd;
-static unsigned char realbuf[512], *buf = realbuf + 4;
+int getNetwork8BitInteger(byte *ptr)
+{
+  return ptr[0];
+}
+
+int putNetwork8BitInteger(byte *ptr, int value)
+{
+  ptr[0] = value;
+
+  return 1;
+}
 
-static int interrupt;
-static int tcp = -1;
+int getNetwork16BitInteger(byte *ptr)
+{
+  return ((ptr[0] << 8) |
+	  (ptr[1] << 0));
+}
 
-static unsigned long ServerFrameCounter = 0;
+int putNetwork16BitInteger(byte *ptr, int value)
+{
+  ptr[0] = (value >> 8) & 0xff;
+  ptr[1] = (value >> 0) & 0xff;
 
-static fd_set fds;
+  return 2;
+}
 
-static void syserr(char *s)
+int getNetwork32BitInteger(byte *ptr)
 {
-  if (!is_daemon)
-    fprintf(stderr, "fatal: %s failed.\n", s);
-  exit(1);
+  return ((ptr[0] << 24) |
+	  (ptr[1] << 16) |
+	  (ptr[2] <<  8) |
+	  (ptr[3] <<  0));
 }
 
-static void addtobuffer(struct NetworkServerPlayerInfo *u,
-			unsigned char *b, int len)
+int putNetwork32BitInteger(byte *ptr, int value)
 {
-  if (u->nwrite + len >= MAX_BUFFER_SIZE)
-    Error(ERR_EXIT, "internal error: network send buffer overflow");
+  ptr[0] = (value >> 24) & 0xff;
+  ptr[1] = (value >> 16) & 0xff;
+  ptr[2] = (value >>  8) & 0xff;
+  ptr[3] = (value >>  0) & 0xff;
+
+  return 4;
+}
+
+char *getNetworkString(byte *ptr)
+{
+  return (char *)ptr;
+}
+
+int putNetworkString(byte *ptr, char *s)
+{
+  strcpy((char *)ptr, s);
+
+  return strlen(s) + 1;
+}
+
+struct NetworkBuffer *newNetworkBuffer(void)
+{
+  struct NetworkBuffer *new = checked_calloc(sizeof(struct NetworkBuffer));
+
+  new->max_size = MAX_BUFFER_SIZE;
+  new->size = 0;
+  new->pos = 0;
+
+  new->buffer = checked_calloc(new->max_size);
+
+  return new;
+}
+
+static void resetNetworkBufferForReading(struct NetworkBuffer *nb)
+{
+  nb->pos = 0;
+}
+
+static void resetNetworkBufferForWriting(struct NetworkBuffer *nb)
+{
+  nb->size = 0;
+  nb->pos = 0;
+}
+
+void initNetworkBufferForReceiving(struct NetworkBuffer *nb)
+{
+  resetNetworkBufferForWriting(nb);
+}
+
+void initNetworkBufferForReading(struct NetworkBuffer *nb)
+{
+  resetNetworkBufferForReading(nb);
+
+  // skip message length header
+  getNetworkBuffer32BitInteger(nb);
+}
+
+void initNetworkBufferForWriting(struct NetworkBuffer *nb, int message_type,
+				 int player_nr)
+{
+  resetNetworkBufferForWriting(nb);
+
+  // will be replaced with message length before sending
+  putNetworkBuffer32BitInteger(nb, 0);
+
+  putNetworkBuffer8BitInteger(nb, message_type);
+  putNetworkBuffer8BitInteger(nb, player_nr);
+}
+
+static void copyNetworkBufferForWriting(struct NetworkBuffer *nb_from,
+					struct NetworkBuffer *nb_to,
+					int player_nr)
+{
+  initNetworkBufferForReading(nb_from);
+
+  int message_type = getNetworkBuffer8BitInteger(nb_from);
+
+  // skip player number
+  getNetworkBuffer8BitInteger(nb_from);
+
+  initNetworkBufferForWriting(nb_to, message_type, player_nr);
+
+  while (nb_from->pos < nb_from->size)
+  {
+    int b = getNetworkBuffer8BitInteger(nb_from);
+
+    putNetworkBuffer8BitInteger(nb_to, b);
+  }
+}
+
+static void increaseNetworkBuffer(struct NetworkBuffer *nb, int additional_size)
+{
+  // add some more buffer size than is really required this time
+  nb->max_size += additional_size + MAX_BUFFER_SIZE;
+  nb->buffer = checked_realloc(nb->buffer, nb->max_size);
+}
+
+int receiveNetworkBufferBytes(struct NetworkBuffer *nb, TCPsocket socket,
+			     int num_bytes)
+{
+  if (num_bytes > MAX_PACKET_SIZE)
+  {
+    Debug("network:server", "protocol error: invalid packet size %d",
+	  num_bytes);
+
+    return -1;
+  }
+
+  if (nb->pos + num_bytes > nb->max_size)
+    increaseNetworkBuffer(nb, num_bytes);
+
+  int result = SDLNet_TCP_Recv(socket, &nb->buffer[nb->pos], num_bytes);
+
+  if (result != num_bytes)
+    return result;
+
+  nb->pos += num_bytes;
+  nb->size = nb->pos;
+
+  return num_bytes;
+}
+
+int receiveNetworkBufferPacket(struct NetworkBuffer *nb, TCPsocket socket)
+{
+  int num_bytes, num_bytes_head, num_bytes_body;
+
+  num_bytes_head = 4;
+  num_bytes = receiveNetworkBufferBytes(nb, socket, num_bytes_head);
+
+  if (num_bytes != num_bytes_head)
+    return num_bytes;
+
+  num_bytes_body = getNetwork32BitInteger(nb->buffer);
+  num_bytes = receiveNetworkBufferBytes(nb, socket, num_bytes_body);
+
+  return num_bytes;
+}
+
+int getNetworkBuffer8BitInteger(struct NetworkBuffer *nb)
+{
+  int num_bytes = 1;
+
+  if (nb->pos + num_bytes > nb->size)
+    return 0;
+
+  int value = getNetwork8BitInteger(&nb->buffer[nb->pos]);
+
+  nb->pos += num_bytes;
+
+  return value;
+}
+
+void putNetworkBuffer8BitInteger(struct NetworkBuffer *nb, int value)
+{
+  int num_bytes = 1;
+
+  if (nb->pos + num_bytes > nb->max_size)
+    increaseNetworkBuffer(nb, num_bytes);
+
+  nb->pos += putNetwork8BitInteger(&nb->buffer[nb->pos], value);
+  nb->size = nb->pos;
+}
+
+int getNetworkBuffer16BitInteger(struct NetworkBuffer *nb)
+{
+  int num_bytes = 2;
+
+  if (nb->pos + num_bytes > nb->size)
+    return 0;
+
+  int value = getNetwork16BitInteger(&nb->buffer[nb->pos]);
+
+  nb->pos += num_bytes;
+
+  return value;
+}
+
+void putNetworkBuffer16BitInteger(struct NetworkBuffer *nb, int value)
+{
+  int num_bytes = 2;
+
+  if (nb->pos + num_bytes > nb->max_size)
+    increaseNetworkBuffer(nb, num_bytes);
+
+  nb->pos += putNetwork16BitInteger(&nb->buffer[nb->pos], value);
+  nb->size = nb->pos;
+}
+
+int getNetworkBuffer32BitInteger(struct NetworkBuffer *nb)
+{
+  int num_bytes = 4;
+
+  if (nb->pos + num_bytes > nb->size)
+    return 0;
+
+  int value = getNetwork32BitInteger(&nb->buffer[nb->pos]);
+
+  nb->pos += num_bytes;
+
+  return value;
+}
+
+void putNetworkBuffer32BitInteger(struct NetworkBuffer *nb, int value)
+{
+  int num_bytes = 4;
+
+  if (nb->pos + num_bytes > nb->max_size)
+    increaseNetworkBuffer(nb, num_bytes);
+
+  nb->pos += putNetwork32BitInteger(&nb->buffer[nb->pos], value);
+  nb->size = nb->pos;
+}
+
+char *getNetworkBufferString(struct NetworkBuffer *nb)
+{
+  char *s = getNetworkString(&nb->buffer[nb->pos]);
+
+  nb->pos += strlen(s) + 1;
+
+  return s;
+}
+
+void putNetworkBufferString(struct NetworkBuffer *nb, char *s)
+{
+  int num_bytes = strlen(s) + 1;
+
+  if (nb->pos + num_bytes > nb->max_size)
+    increaseNetworkBuffer(nb, num_bytes);
+
+  nb->pos += putNetworkString(&nb->buffer[nb->pos], s);
+  nb->size = nb->pos;
+}
+
+int getNetworkBufferFile(struct NetworkBuffer *nb, char *filename)
+{
+  FILE *file;
+  int num_bytes = getNetworkBuffer32BitInteger(nb);
+  int i;
+
+  if (!(file = fopen(filename, MODE_WRITE)))
+  {
+    Warn("cannot write file '%s' from network buffer", filename);
+
+    return 0;
+  }
+
+  for (i = 0; i < num_bytes; i++)
+  {
+    int b = getNetworkBuffer8BitInteger(nb);
+
+    putFile8Bit(file, b);
+  }
+
+  fclose(file);
+
+  return num_bytes;
+}
+
+int putNetworkBufferFile(struct NetworkBuffer *nb, char *filename)
+{
+  File *file;
+  int filesize_pos = nb->pos;
+  int num_bytes = 0;
+
+  // will be replaced with file size
+  putNetworkBuffer32BitInteger(nb, 0);
+
+  if (!(file = openFile(filename, MODE_READ)))
+  {
+    Warn("cannot read file '%s' to network buffer", filename);
+
+    return 0;
+  }
+
+  while (1)
+  {
+    int b = getFile8Bit(file);
 
-  memcpy(u->writbuf + u->nwrite, b, len);
-  u->nwrite += len;
+    if (checkEndOfFile(file))
+      break;
+
+    putNetworkBuffer8BitInteger(nb, b);
+
+    num_bytes++;
+  }
+
+  closeFile(file);
+
+  // set file size
+  putNetwork32BitInteger(&nb->buffer[filesize_pos], num_bytes);
+
+  return num_bytes;
 }
 
-static void flushuser(struct NetworkServerPlayerInfo *u)
+void dumpNetworkBuffer(struct NetworkBuffer *nb)
 {
-  if (u->nwrite)
+  int i;
+
+  Debug("network:buffer", "network buffer maximum size: %d\n", nb->max_size);
+  Debug("network:buffer", "network buffer size:         %d\n", nb->size);
+  Debug("network:buffer", "network buffer position    : %d\n", nb->pos);
+
+  for (i = 0; i < nb->size; i++)
   {
-    write(u->fd, u->writbuf, u->nwrite);
-    u->nwrite = 0;
+    if ((i % 16) == 0)
+      DebugContinued("network:buffer", "\n");
+
+    DebugContinued("", "%02x ", nb->buffer[i]);
   }
+
+  DebugContinued("network:buffer", "\n");
 }
 
-static void broadcast(struct NetworkServerPlayerInfo *except,
-		      int len, int activeonly)
+static void SendNetworkBufferToAllButOne(struct NetworkBuffer *nb,
+					 struct NetworkServerPlayerInfo *except)
 {
-  struct NetworkServerPlayerInfo *u;
+  struct NetworkServerPlayerInfo *player;
+
+  // set message length header
+  putNetwork32BitInteger(nb->buffer, nb->size - 4);
 
-  realbuf[0] = realbuf[1] = realbuf[2] = 0;
-  realbuf[3] = (unsigned char)len;
-  for (u=user0; u; u=u->next)
-    if (u != except && (u->active || !activeonly) && u->introduced)
-      addtobuffer(u, realbuf, 4 + len);
+  for (player = first_player; player != NULL; player = player->next)
+  {
+    if (player != except && player->introduced)
+    {
+      // directly send the buffer to the network client
+      SDLNet_TCP_Send(player->fd, nb->buffer, nb->size);
+    }
+  }
 }
 
-static void sendtoone(struct NetworkServerPlayerInfo *to, int len)
+static void SendNetworkBufferToAll(struct NetworkBuffer *nb)
 {
-  realbuf[0] = realbuf[1] = realbuf[2] = 0;
-  realbuf[3] = (unsigned char)len;
-  addtobuffer(to, realbuf, 4 + len);
+  SendNetworkBufferToAllButOne(nb, NULL);
 }
 
-static void dropuser(struct NetworkServerPlayerInfo *u)
+static void SendNetworkBufferToClient(struct NetworkBuffer *nb,
+				      struct NetworkServerPlayerInfo *player)
 {
-  struct NetworkServerPlayerInfo *v;
-  
-  if (options.verbose)
-    Error(ERR_NETWORK_SERVER, "dropping client %d (%s)",
-	  u->number, u->player_name);
+  // set message length header
+  putNetwork32BitInteger(nb->buffer, nb->size - 4);
 
-  if (u == user0)
-    user0 = u->next;
+  // directly send the buffer to the network client
+  SDLNet_TCP_Send(player->fd, nb->buffer, nb->size);
+}
+
+static void RemovePlayer(struct NetworkServerPlayerInfo *player)
+{
+  Debug("network:server", "dropping client %d (%s)",
+	player->number, player->player_name);
+
+  SDLNet_TCP_DelSocket(fds, player->fd);
+  SDLNet_TCP_Close(player->fd);
+
+  if (player == first_player)
+  {
+    first_player = player->next;
+  }
   else
   {
-    for (v=user0; v; v=v->next)
+    struct NetworkServerPlayerInfo *p;
+
+    for (p = first_player; p != NULL; p = p->next)
     {
-      if (v->next && v->next == u)
+      if (p->next && p->next == player)
       {
-	v->next = u->next;
+	p->next = player->next;
+
 	break;
       }
     }
   }
-  close(u->fd);
 
-  if (u->introduced)
+  if (player->introduced)
   {
-    buf[0] = u->number;
-    buf[1] = OP_PLAYER_DISCONNECTED;
-    broadcast(u, 2, 0);
+    initNetworkBufferForWriting(write_buffer, OP_PLAYER_DISCONNECTED,
+				player->number);
+
+    SendNetworkBufferToAllButOne(write_buffer, player);
   }
 
-  free(u);
-  clients--;
+  free(player);
+  num_clients--;
 
-  if (onceonly && clients == 0)
+#if 0	// do not terminate network server if last player disconnected
+  if (run_server_only_once && num_clients == 0)
   {
-    if (options.verbose)
-    {
-      Error(ERR_NETWORK_SERVER, "no clients left");
-      Error(ERR_NETWORK_SERVER, "aborting");
-    }
+    Debug("network:server", "no clients left");
+    Debug("network:server", "aborting");
+
     exit(0);
   }
+#endif
 }
 
-static void new_connect(int fd)
+static void AddPlayer(TCPsocket fd)
 {
-  struct NetworkServerPlayerInfo *u, *v;
-  unsigned char nxn;
+  struct NetworkServerPlayerInfo *player, *p;
+  int number = 1;
+  boolean again = TRUE;
 
-  u = checked_malloc(sizeof (struct NetworkServerPlayerInfo));
+  SDLNet_TCP_AddSocket(fds, fd);
 
-  u->fd = fd;
-  u->player_name[0] = 0;
-  u->next = user0;
-  u->active = 0;
-  u->nread = 0;
-  u->nwrite = 0;
-  u->introduced = 0;
-  u->action = 0;
-  u->action_received = FALSE;
+  player = checked_calloc(sizeof(struct NetworkServerPlayerInfo));
 
-  user0 = u;
+  player->fd = fd;
+  player->player_name[0] = 0;
+  player->active = FALSE;
+  player->introduced = FALSE;
+  player->action = 0;
+  player->action_received = FALSE;
+  player->next = first_player;
 
-  nxn = 1;
+  first_player = player;
 
- again:
-  v = u->next;
-  while(v)
+  while (again)
   {
-    if (v->number == nxn)
+    again = FALSE;
+    p = player->next;
+
+    while (p)
     {
-      nxn++;
-      goto again;
+      if (p->number == number)
+      {
+	number++;
+
+	again = TRUE;
+
+	break;
+      }
+
+      p = p->next;
     }
-    v = v->next;
   }
 
-  u->number = nxn;
-  if (options.verbose)
-    Error(ERR_NETWORK_SERVER, "client %d connecting from %s",
-	  nxn, inet_ntoa(saddr.sin_addr));
-  clients++;
+  player->number = number;
+  num_clients++;
+
+  initNetworkBufferForWriting(write_buffer, OP_YOUR_NUMBER, 0);
 
-  buf[0] = 0;
-  buf[1] = OP_YOUR_NUMBER;
-  buf[2] = u->number;
-  sendtoone(u, 3);
+  putNetworkBuffer8BitInteger(write_buffer, player->number);
+
+  SendNetworkBufferToClient(write_buffer, player);
 }
 
-static void Handle_OP_PROTOCOL_VERSION(struct NetworkServerPlayerInfo *u,
-				       unsigned int len)
+static void Handle_OP_PROTOCOL_VERSION(struct NetworkServerPlayerInfo *player)
 {
-  if (len != 5 || buf[2] != PROTOCOL_VERSION_1 || buf[3] != PROTOCOL_VERSION_2)
+  int protocol_version_major = getNetworkBuffer8BitInteger(read_buffer);
+  int protocol_version_minor = getNetworkBuffer8BitInteger(read_buffer);
+  int protocol_version_patch = getNetworkBuffer8BitInteger(read_buffer);
+
+  if (protocol_version_major != PROTOCOL_VERSION_MAJOR ||
+      protocol_version_minor != PROTOCOL_VERSION_MINOR)
   {
-    if (options.verbose)
-      Error(ERR_NETWORK_SERVER,
-	    "client %d (%s) has wrong protocol version %d.%d.%d",
-	    u->number, u->player_name, buf[2], buf[3], buf[4]);
-
-    buf[0] = 0;
-    buf[1] = OP_BAD_PROTOCOL_VERSION;
-    buf[2] = PROTOCOL_VERSION_1;
-    buf[3] = PROTOCOL_VERSION_2;
-    buf[4] = PROTOCOL_VERSION_3;
-    sendtoone(u, 5);
-    flushuser(u);
-
-    dropuser(u);
-    interrupt = 1;
+    Debug("network:server",
+	  "client %d (%s) has wrong protocol version %d.%d.%d",
+	  player->number, player->player_name,
+	  protocol_version_major,
+	  protocol_version_minor,
+	  protocol_version_patch);
+
+    initNetworkBufferForWriting(write_buffer, OP_BAD_PROTOCOL_VERSION, 0);
+
+    putNetworkBuffer8BitInteger(write_buffer, PROTOCOL_VERSION_MAJOR);
+    putNetworkBuffer8BitInteger(write_buffer, PROTOCOL_VERSION_MINOR);
+    putNetworkBuffer8BitInteger(write_buffer, PROTOCOL_VERSION_PATCH);
+
+    SendNetworkBufferToClient(write_buffer, player);
+
+    RemovePlayer(player);
   }
   else
   {
-    if (options.verbose)
-      Error(ERR_NETWORK_SERVER,
-	    "client %d (%s) uses protocol version %d.%d.%d",
-	    u->number, u->player_name, buf[2], buf[3], buf[4]);
+    Debug("network:server",
+	  "client %d (%s) uses protocol version %d.%d.%d",
+	  player->number, player->player_name,
+	  protocol_version_major,
+	  protocol_version_minor,
+	  protocol_version_patch);
   }
 }
 
-static void Handle_OP_NUMBER_WANTED(struct NetworkServerPlayerInfo *u)
+static void Handle_OP_NUMBER_WANTED(struct NetworkServerPlayerInfo *player)
 {
-  struct NetworkServerPlayerInfo *v;
-  int client_nr = u->number;
-  int nr_wanted = buf[2];
-  int nr_is_free = 1;
+  int nr_wanted = getNetworkBuffer8BitInteger(read_buffer);
+  int client_nr = player->number;
+  boolean nr_is_free = TRUE;
+  struct NetworkServerPlayerInfo *p;
 
-  if (options.verbose)
-      Error(ERR_NETWORK_SERVER, "client %d (%s) wants to switch to # %d",
-	    u->number, u->player_name, nr_wanted);
+  Debug("network:server", "client %d (%s) wants to switch to # %d",
+	player->number, player->player_name, nr_wanted);
 
-  for (v=user0; v; v=v->next)
+  for (p = first_player; p != NULL; p = p->next)
   {
-    if (v->number == nr_wanted)
+    if (p->number == nr_wanted)
     {
-      nr_is_free = 0;
+      nr_is_free = FALSE;
+
       break;
     }
   }
 
-  if (options.verbose)
-  {
-    if (nr_is_free)
-      Error(ERR_NETWORK_SERVER, "client %d (%s) switches to # %d",
-	    u->number, u->player_name, nr_wanted);
-    else if (u->number == nr_wanted)
-      Error(ERR_NETWORK_SERVER, "client %d (%s) still has # %d",
-	    u->number, u->player_name, nr_wanted);
-    else
-      Error(ERR_NETWORK_SERVER,
-	    "client %d (%s) cannot switch (client %d still exists)",
-	    u->number, u->player_name, nr_wanted);
-  }
+  if (nr_is_free)
+    Debug("network:server", "client %d (%s) switches to # %d",
+	  player->number, player->player_name, nr_wanted);
+  else if (player->number == nr_wanted)
+    Debug("network:server", "client %d (%s) already has # %d",
+	  player->number, player->player_name, nr_wanted);
+  else
+    Debug("network:server",
+	  "client %d (%s) cannot switch (client %d already exists)",
+	  player->number, player->player_name, nr_wanted);
 
   if (nr_is_free)
-    u->number = nr_wanted;
+    player->number = nr_wanted;
 
-  buf[0] = client_nr;
-  buf[1] = OP_NUMBER_WANTED;
-  buf[2] = nr_wanted;
-  buf[3] = u->number;
+  initNetworkBufferForWriting(write_buffer, OP_NUMBER_WANTED, client_nr);
 
-  /*
-  sendtoone(u, 4);
-  */
+  putNetworkBuffer8BitInteger(write_buffer, nr_wanted);
+  putNetworkBuffer8BitInteger(write_buffer, player->number);
 
-  broadcast(NULL, 4, 0);
+  SendNetworkBufferToAll(write_buffer);
 }
 
-static void Handle_OP_PLAYER_NAME(struct NetworkServerPlayerInfo *u,
-				  unsigned int len)
+static void Handle_OP_PLAYER_NAME(struct NetworkServerPlayerInfo *player)
 {
-  struct NetworkServerPlayerInfo *v;
+  char *player_name = getNetworkBufferString(read_buffer);
   int i;
 
-  if (len>16)
-    len=16;
-  memcpy(u->player_name, &buf[2], len-2);
-  u->player_name[len-2] = 0;
-  for (i=0; i<len-2; i++)
+  strncpy(player->player_name, player_name, MAX_PLAYER_NAME_LEN);
+  player->player_name[MAX_PLAYER_NAME_LEN] = '\0';
+
+  for (i = 0; i < MAX_PLAYER_NAME_LEN; i++)
   {
-    if (u->player_name[i] < ' ' || 
-	(u->player_name[i] > 0x7e && u->player_name[i] <= 0xa0))
+    if (player->player_name[i] < ' ' ||
+	((unsigned char)(player->player_name[i]) > 0x7e &&
+	 (unsigned char)(player->player_name[i]) <= 0xa0))
     {
-      u->player_name[i] = 0;
+      player->player_name[i] = 0;
+
       break;
     }
   }
 
-  if (!u->introduced)
+  if (!player->introduced)
   {
-    buf[0] = u->number;
-    buf[1] = OP_PLAYER_CONNECTED;
-    broadcast(u, 2, 0);
+    initNetworkBufferForWriting(write_buffer, OP_PLAYER_CONNECTED,
+				player->number);
+
+    SendNetworkBufferToAllButOne(write_buffer, player);
   }
 	      
-  if (options.verbose)
-    Error(ERR_NETWORK_SERVER, "client %d calls itself \"%s\"",
-	  u->number, u->player_name);
-  buf[1] = OP_PLAYER_NAME;
-  broadcast(u, len, 0);
+  Debug("network:server", "client %d calls itself \"%s\"",
+	player->number, player->player_name);
+
+  copyNetworkBufferForWriting(read_buffer, write_buffer, player->number);
 
-  if (!u->introduced)
+  SendNetworkBufferToAllButOne(write_buffer, player);
+
+  if (!player->introduced)
   {
-    for (v=user0; v; v=v->next)
+    struct NetworkServerPlayerInfo *p;
+
+    for (p = first_player; p != NULL; p = p->next)
     {
-      if (v != u && v->introduced)
+      if (p != player && p->introduced)
       {
-	buf[0] = v->number;
-	buf[1] = OP_PLAYER_CONNECTED;
-	sendtoone(u, 2);
-	buf[1] = OP_PLAYER_NAME;
-	memcpy(&buf[2], v->player_name, 14);
-	sendtoone(u, 2+strlen(v->player_name));
+	initNetworkBufferForWriting(write_buffer, OP_PLAYER_CONNECTED,
+				    p->number);
+
+	SendNetworkBufferToClient(write_buffer, player);
+
+	initNetworkBufferForWriting(write_buffer, OP_PLAYER_NAME, p->number);
+
+	putNetworkBufferString(write_buffer, p->player_name);
+
+	SendNetworkBufferToClient(write_buffer, player);
       }
     }
   }
 
-  u->introduced = 1;
+  player->introduced = TRUE;
 }
 
-static void Handle_OP_START_PLAYING(struct NetworkServerPlayerInfo *u)
+static void Handle_OP_START_PLAYING(struct NetworkServerPlayerInfo *player)
 {
-  struct NetworkServerPlayerInfo *v, *w;
+  char *new_leveldir_identifier = getNetworkBufferString(read_buffer);
+  int level_nr = getNetworkBuffer16BitInteger(read_buffer);
 
-  if (options.verbose)
-    Error(ERR_NETWORK_SERVER,
-	  "client %d (%s) starts game [level %d from levedir %d (%s)]",
-	  u->number, u->player_name,
-	  (buf[2] << 8) + buf[3],
-	  (buf[4] << 8) + buf[5],
-	  &buf[6]);
+  Debug("network:server",
+	"client %d (%s) starts game [level %d from level set '%s']",
+	player->number, player->player_name, level_nr,
+	new_leveldir_identifier);
 
-  for (w=user0; w; w=w->next)
-    if (w->introduced)
-      w->active = 1;
+  struct NetworkServerPlayerInfo *p;
 
-  /* reset frame counter */
+  // reset frame counter
   ServerFrameCounter = 0;
 
-  /* reset player actions */
-  for (v=user0; v; v=v->next)
+  Debug("network:server", "resetting ServerFrameCounter to 0");
+
+  // reset player actions
+  for (p = first_player; p != NULL; p = p->next)
   {
-    v->action = 0;
-    v->action_received = FALSE;
+    p->action = 0;
+    p->action_received = FALSE;
+
+    if (p->introduced)
+      p->active = TRUE;
   }
 
-  broadcast(NULL, 10 + strlen(&buf[10])+1, 0);
+  copyNetworkBufferForWriting(read_buffer, write_buffer, player->number);
+
+  SendNetworkBufferToAll(write_buffer);
 }
 
-static void Handle_OP_PAUSE_PLAYING(struct NetworkServerPlayerInfo *u)
+static void Handle_OP_PAUSE_PLAYING(struct NetworkServerPlayerInfo *player)
 {
-  if (options.verbose)
-    Error(ERR_NETWORK_SERVER, "client %d (%s) pauses game",
-	  u->number, u->player_name);
-  broadcast(NULL, 2, 0);
+  Debug("network:server", "client %d (%s) pauses game",
+	player->number, player->player_name);
+
+  copyNetworkBufferForWriting(read_buffer, write_buffer, player->number);
+
+  SendNetworkBufferToAll(write_buffer);
 }
 
-static void Handle_OP_CONTINUE_PLAYING(struct NetworkServerPlayerInfo *u)
+static void Handle_OP_CONTINUE_PLAYING(struct NetworkServerPlayerInfo *player)
 {
-  if (options.verbose)
-    Error(ERR_NETWORK_SERVER, "client %d (%s) continues game",
-	  u->number, u->player_name);
-  broadcast(NULL, 2, 0);
+  Debug("network:server", "client %d (%s) continues game",
+	player->number, player->player_name);
+
+  copyNetworkBufferForWriting(read_buffer, write_buffer, player->number);
+
+  SendNetworkBufferToAll(write_buffer);
 }
 
-static void Handle_OP_STOP_PLAYING(struct NetworkServerPlayerInfo *u)
+static void Handle_OP_STOP_PLAYING(struct NetworkServerPlayerInfo *player)
 {
-  if (options.verbose)
-    Error(ERR_NETWORK_SERVER, "client %d (%s) stops game",
-	  u->number, u->player_name);
-  broadcast(NULL, 2, 0);
+  int cause_for_stopping = getNetworkBuffer8BitInteger(read_buffer);
+
+  Debug("network:server", "client %d (%s) stops game [%d]",
+	player->number, player->player_name, cause_for_stopping);
+
+  copyNetworkBufferForWriting(read_buffer, write_buffer, player->number);
+
+  SendNetworkBufferToAll(write_buffer);
 }
 
-static void Handle_OP_MOVE_FIGURE(struct NetworkServerPlayerInfo *u)
+static void Handle_OP_MOVE_PLAYER(struct NetworkServerPlayerInfo *player)
 {
-  struct NetworkServerPlayerInfo *v;
+  int player_action = getNetworkBuffer8BitInteger(read_buffer);
   int last_client_nr = 0;
+  struct NetworkServerPlayerInfo *p;
   int i;
 
-  /* store player action */
-  for (v=user0; v; v=v->next)
+  // store player action
+  for (p = first_player; p != NULL; p = p->next)
   {
-    if (v->number == u->number)
+    if (p->number == player->number)
     {
-      v->action = buf[2];
-      v->action_received = TRUE;
+      p->action = player_action;
+      p->action_received = TRUE;
     }
   }
 
-  /* check if server received action from each player */
-  for (v=user0; v; v=v->next)
+  // check if server received action from each player
+  for (p = first_player; p != NULL; p = p->next)
   {
-    if (!v->action_received)
+    if (!p->action_received)
       return;
 
-    if (v->number > last_client_nr)
-      last_client_nr = v->number;
+    if (p->number > last_client_nr)
+      last_client_nr = p->number;
   }
 
-  /* initialize all player actions to zero */
-  for (i=0; i<last_client_nr; i++)
-    buf[6 + i] = 0;
+  int player_action_all[last_client_nr];
+
+  // initialize all player actions to zero
+  for (i = 0; i < last_client_nr; i++)
+    player_action_all[i] = 0;
 
-  /* broadcast actions of all players to all players */
-  for (v=user0; v; v=v->next)
+  // broadcast actions of all players to all players
+  for (p = first_player; p != NULL; p = p->next)
   {
-    buf[6 + v->number-1] = v->action;
-    v->action = 0;
-    v->action_received = FALSE;
+    player_action_all[p->number - 1] = p->action;
+
+    p->action = 0;
+    p->action_received = FALSE;
   }
 
-  buf[2] = (unsigned char)((ServerFrameCounter >> 24) & 0xff);
-  buf[3] = (unsigned char)((ServerFrameCounter >> 16) & 0xff);
-  buf[4] = (unsigned char)((ServerFrameCounter >>  8) & 0xff);
-  buf[5] = (unsigned char)((ServerFrameCounter >>  0) & 0xff);
+  initNetworkBufferForWriting(write_buffer, OP_MOVE_PLAYER, player->number);
+
+  putNetworkBuffer32BitInteger(write_buffer, ServerFrameCounter);
 
-  broadcast(NULL, 6 + last_client_nr, 0);
+  for (i = 0; i < last_client_nr; i++)
+    putNetworkBuffer8BitInteger(write_buffer, player_action_all[i]);
+
+  SendNetworkBufferToAll(write_buffer);
 
   ServerFrameCounter++;
 }
 
+static void Handle_OP_BROADCAST_MESSAGE(struct NetworkServerPlayerInfo *player)
+{
+  char *message = getNetworkBufferString(read_buffer);
+
+  Debug("network:server", "client %d (%s) sends message: %s",
+	player->number, player->player_name, message);
+
+  copyNetworkBufferForWriting(read_buffer, write_buffer, player->number);
+
+  SendNetworkBufferToAllButOne(write_buffer, player);
+}
+
+static void Handle_OP_LEVEL_FILE(struct NetworkServerPlayerInfo *player)
+{
+  copyNetworkBufferForWriting(read_buffer, write_buffer, player->number);
+
+  SendNetworkBufferToAllButOne(write_buffer, player);
+}
+
+static void ExitNetworkServer(int exit_value)
+{
+  Debug("network:server", "exiting network server");
+
+  exit(exit_value);
+}
+
+// the following is not used for a standalone server;
+// the pointer points to an integer containing the port-number
+int NetworkServerThread(void *ptr)
+{
+  network.is_server_thread = TRUE;
+
+  NetworkServer(*((int *) ptr), 0);
+
+  // should never be reached
+  return 0;
+}
+
 void NetworkServer(int port, int serveronly)
 {
-  int i, sl, on;
-  struct NetworkServerPlayerInfo *u;
-  int mfd;
-  int r; 
-  unsigned int len;
-  struct protoent *tcpproto;
-  struct timeval tv;
-  int is_daemon = 0;
+  struct NetworkServerPlayerInfo *player;
+  IPaddress ip;
 
-#ifndef NeXT
+#if defined(PLATFORM_UNIX) && !defined(PLATFORM_NEXT)
   struct sigaction sact;
 #endif
 
+  if (read_buffer == NULL)
+    read_buffer = newNetworkBuffer();
+
+  if (write_buffer == NULL)
+    write_buffer = newNetworkBuffer();
+
   if (port == 0)
     port = DEFAULT_SERVER_PORT;
 
-  if (!serveronly)
-    onceonly = 1;
+  // if only running the network server, exit on Ctrl-C
+  if (serveronly)
+    signal(SIGINT, ExitNetworkServer);
 
-  if ((tcpproto = getprotobyname("tcp")) != NULL)
-    tcp = tcpproto->p_proto;
+  if (!serveronly)
+    run_server_only_once = TRUE;
 
-#ifdef NeXT
+#if defined(PLATFORM_UNIX)
+#if defined(PLATFORM_NEXT)
   signal(SIGPIPE, SIG_IGN);
 #else
   sact.sa_handler = SIG_IGN;
   sigemptyset(&sact.sa_mask);
   sact.sa_flags = 0;
   sigaction(SIGPIPE, &sact, NULL);
+#endif
 #endif
 
+  if (SDLNet_ResolveHost(&ip, NULL, port) == -1)
+    Fail("SDLNet_ResolveHost() failed: %s", SDLNet_GetError());
 
-  lfd = socket(PF_INET, SOCK_STREAM, 0);
-  saddr.sin_family = AF_INET;
-  saddr.sin_addr.s_addr = htonl(INADDR_ANY);
-  saddr.sin_port = htons(port);
+  if ((fds = SDLNet_AllocSocketSet(MAX_PLAYERS + 1 + 1)) == NULL)
+    Fail("SDLNet_AllocSocketSet() failed: %s"), SDLNet_GetError();
 
-  if (lfd < 0)
-    syserr("socket");
-  on = 1;
+  if ((lfd = SDLNet_TCP_Open(&ip)) == NULL)
+    Fail("SDLNet_TCP_Open() failed: %s"), SDLNet_GetError();
 
-  setsockopt(lfd, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof(int));
-  if (bind(lfd, (struct sockaddr *)&saddr, sizeof(saddr)) < 0)
-    syserr("bind");
+  if (SDLNet_TCP_AddSocket(fds, lfd) == -1)
+    Fail("SDLNet_TCP_AddSocket() failed: %s"), SDLNet_GetError();
 
-  listen(lfd, 5);
+  if ((udp = SDLNet_UDP_Open(port)) == NULL)
+    Fail("SDLNet_UDP_Open() failed: %s", SDLNet_GetError());
 
-  if (is_daemon)
-  {
-    /* become a daemon, breaking all ties with the controlling terminal */
-    options.verbose = 0;
-    for (i=0; i<255; i++)
-    {
-      if (i != lfd)
-	close(i);
-    }
+  if (SDLNet_UDP_AddSocket(fds, udp) == -1)
+    Fail("SDLNet_TCP_AddSocket() failed: %s"), SDLNet_GetError();
 
-    if (fork())
-      exit(0);
-    setsid();
-    if (fork())
-      exit(0);
-    chdir("/");
-
-    /* open a fake stdin, stdout, stderr, just in case */
-    open("/dev/null", O_RDONLY);
-    open("/dev/null", O_WRONLY);
-    open("/dev/null", O_WRONLY);
-  }
+  Debug("network:server", "started up, listening on port %d", port);
+  Debug("network:server", "using protocol version %d.%d.%d",
+	PROTOCOL_VERSION_MAJOR,
+	PROTOCOL_VERSION_MINOR,
+	PROTOCOL_VERSION_PATCH);
 
-  if (options.verbose)
+  while (1)
   {
-    Error(ERR_NETWORK_SERVER, "started up, listening on port %d", port);
-    Error(ERR_NETWORK_SERVER, "using protocol version %d.%d.%d",
-	  PROTOCOL_VERSION_1, PROTOCOL_VERSION_2, PROTOCOL_VERSION_3);
-  }
+    // wait for 100 ms for activity on open network sockets
+    if (SDLNet_CheckSockets(fds, 100) < 1)
+      continue;
 
-  while(1)
-  {
-    interrupt = 0;
+    // accept incoming TCP connections
+    if (SDLNet_SocketReady(lfd))
+    {
+      Debug("network:server", "got TCP packet");
 
-    for (u=user0; u; u=u->next)
-      flushuser(u);
+      TCPsocket newsock;
 
-    FD_ZERO(&fds);
-    mfd = lfd;
-    u = user0;
-    while (u)
+      newsock = SDLNet_TCP_Accept(lfd);
+
+      if (newsock)
+	AddPlayer(newsock);
+    }
+
+    // accept incoming UDP packets
+    if (SDLNet_SocketReady(udp))
     {
-      FD_SET(u->fd, &fds);
-      if (u->fd > mfd)
-	mfd = u->fd;
-      u = u->next;
+      Debug("network:server", "got UDP packet");
+
+      static UDPpacket packet;
+
+      int num_packets = SDLNet_UDP_Recv(udp, &packet);
+
+      if (num_packets == 1)
+      {
+        // bounce packet
+        SDLNet_UDP_Send(udp, -1, &packet);
+      }
     }
-    FD_SET(lfd, &fds);
-    tv.tv_sec = 0;
-    tv.tv_usec = 500000;
-    if ((sl = select(mfd + 1, &fds, NULL, NULL, &tv)) < 0)
+
+    for (player = first_player; player != NULL; player = player->next)
     {
-      if (errno != EINTR)
-	syserr("select");
-      else
+      if (!SDLNet_SocketReady(player->fd))
 	continue;
-    }
 
-    if (sl < 0)
-      continue;
-    
-    if (sl == 0)
-      continue;
+      initNetworkBufferForReceiving(read_buffer);
 
-    if (FD_ISSET(lfd, &fds))
-    {
-      int newfd, slen;
+      int num_bytes = receiveNetworkBufferPacket(read_buffer, player->fd);
 
-      slen = sizeof(saddr);
-      newfd = accept(lfd, (struct sockaddr *)&saddr, &slen);
-      if (newfd < 0)
+      if (num_bytes <= 0)
       {
-	if (errno != EINTR)
-	  syserr("accept");
+	Debug("network:server", "EOF from client %d (%s)",
+	      player->number, player->player_name);
+
+	RemovePlayer(player);
+
+	break;
       }
-      else
+
+      initNetworkBufferForReading(read_buffer);
+
+      int message_type = getNetworkBuffer8BitInteger(read_buffer);
+
+      // skip player number
+      getNetworkBuffer8BitInteger(read_buffer);
+
+      if (!player->introduced &&
+	  message_type != OP_PLAYER_NAME &&
+	  message_type != OP_PROTOCOL_VERSION)
       {
-	if (tcp != -1)
-	{
-	  on = 1;
-	  setsockopt(newfd, tcp, TCP_NODELAY, (char *)&on, sizeof(int));
-	}
-	new_connect(newfd);
-      }
-      continue;
-    }
+	Debug("network:server", "got opcode %d for client %d which is not introduced yet (expected OP_PLAYER_NAME or OP_PROTOCOL_VERSION)", message_type, player->number);
 
-    u = user0;
+	RemovePlayer(player);
 
-    do
-    {
-      if (FD_ISSET(u->fd, &fds))
+	break;
+      }
+
+      switch (message_type)
       {
-	r = read(u->fd, u->readbuf + u->nread, MAX_BUFFER_SIZE - u->nread);
-	if (r <= 0)
-	{
-	  if (options.verbose)
-	    Error(ERR_NETWORK_SERVER, "EOF from client %d (%s)",
-		  u->number, u->player_name);
-	  dropuser(u);
-	  interrupt = 1;
+	case OP_PROTOCOL_VERSION:
+	  Handle_OP_PROTOCOL_VERSION(player);
 	  break;
-	}
-	u->nread += r;
-	while (u->nread >= 4 && u->nread >= 4 + u->readbuf[3])
-	{
-	  len = u->readbuf[3];
-	  if (u->readbuf[0] || u->readbuf[1] || u->readbuf[2])
-	  {
-	    if (options.verbose)
-	      Error(ERR_NETWORK_SERVER, "crap from client %d (%s)",
-		    u->number, u->player_name);
-	    write(u->fd, "\033]50;kanji24\007\033#8\033(0", 19);
-	    dropuser(u);
-	    interrupt = 1;
-	    break;
-	  }
-	  memcpy(buf, &u->readbuf[4], len);
-	  u->nread -= 4 + len;
-	  memmove(u->readbuf, u->readbuf + 4 + len, u->nread);
-
-	  buf[0] = u->number;
-	  if (!u->introduced && buf[1] != OP_PLAYER_NAME)
-	  {
-	    if (options.verbose)
-	      Error(ERR_NETWORK_SERVER, "!(client %d)->introduced && buf[1]==%d (expected OP_PLAYER_NAME)", buf[0], buf[1]);
-
-	    dropuser(u);
-	    interrupt = 1;
-	    break;
-	  }
-
-	  switch(buf[1])
-	  {
-	    case OP_PLAYER_NAME:
-	      Handle_OP_PLAYER_NAME(u, len);
-	      break;
-
-	    case OP_PROTOCOL_VERSION:
-	      Handle_OP_PROTOCOL_VERSION(u, len);
-	      break;
-
-	    case OP_NUMBER_WANTED:
-	      Handle_OP_NUMBER_WANTED(u);
-	      break;
-
-	    case OP_START_PLAYING:
-	      Handle_OP_START_PLAYING(u);
-	      break;
-
-	    case OP_PAUSE_PLAYING:
-	      Handle_OP_PAUSE_PLAYING(u);
-	      break;
-
-	    case OP_CONTINUE_PLAYING:
-	      Handle_OP_CONTINUE_PLAYING(u);
-	      break;
-
-	    case OP_STOP_PLAYING:
-	      Handle_OP_STOP_PLAYING(u);
-	      break;
-
-	    case OP_MOVE_FIGURE:
-	      Handle_OP_MOVE_FIGURE(u);
-	      break;
-
-	    case OP_BROADCAST_MESSAGE:
-	      buf[len] = '\0';
-	      if (options.verbose)
-		Error(ERR_NETWORK_SERVER, "client %d (%s) sends message: %s",
-		      u->number, u->player_name, &buf[2]);
-	      broadcast(u, len, 0);
-	      break;
-	    
-	    default:
-	      if (options.verbose)
-		Error(ERR_NETWORK_SERVER,
-		      "unknown opcode %d from client %d (%s)",
-		      buf[0], u->number, u->player_name);
-	  }
-	}
-      }
 
-      if (u && !interrupt)
-	u = u->next;
+	case OP_NUMBER_WANTED:
+	  Handle_OP_NUMBER_WANTED(player);
+	  break;
+
+	case OP_PLAYER_NAME:
+	  Handle_OP_PLAYER_NAME(player);
+	  break;
+
+	case OP_START_PLAYING:
+	  Handle_OP_START_PLAYING(player);
+	  break;
+
+	case OP_PAUSE_PLAYING:
+	  Handle_OP_PAUSE_PLAYING(player);
+	  break;
+
+	case OP_CONTINUE_PLAYING:
+	  Handle_OP_CONTINUE_PLAYING(player);
+	  break;
+
+	case OP_STOP_PLAYING:
+	  Handle_OP_STOP_PLAYING(player);
+	  break;
+
+	case OP_MOVE_PLAYER:
+	  Handle_OP_MOVE_PLAYER(player);
+	  break;
+
+	case OP_BROADCAST_MESSAGE:
+	  Handle_OP_BROADCAST_MESSAGE(player);
+	  break;
+
+	case OP_LEVEL_FILE:
+	  Handle_OP_LEVEL_FILE(player);
+	  break;
+
+	default:
+	  Debug("network:server", "unknown opcode %d from client %d (%s)",
+		message_type, player->number, player->player_name);
+      }
     }
-    while (u && !interrupt);
   }
 }