{This program has a major bug which locks up the system
after the first packet is received.  I have no clue as to
what causes this, and I would appreciate any input.}

program receive;
uses IPX;

const receive_socket = $7777;
      send_socket = $6666;
      maxtime = 99999;
      null = ptr(0,0);

var user_network_number:networkNumber;
    user_node:NetworkNode;
    done:boolean;
    timer:word;

    rec_file:text;

    receive_ecb:ecb;
    receive_header:IPXHeader;
    receive_message:string;

    send_ecb:ecb;
    send_header:IPXHeader;
    send_message:string;

    packet_count:integer;

    hr,mn,start,s100:longint;

procedure sti;
begin
 asm
  sti
 end;
end;

procedure abort(error:string);
begin
 writeln;
 writeln(error);
 halt(0);
end;

procedure open_user_sockets_and_file;
 begin
  IPXCloseSocket(receive_socket);
  IPXCloseSocket(send_socket);
  if IPXOpenSocket(receive_socket) <> 0 then abort('Error opening socket')
  else if IPXOpenSocket(send_socket) <> 0 then abort('Error opening socket')
  else
   begin
    assign(rec_file,paramSTR(1));
    rewrite(rec_file);
   end;
 end;

procedure receive_routine;
 interrupt;
 begin
  IPXReceive(receive_ecb,receive_header,receive_socket,@receive_message,
             sizeof(receive_message),@receive_routine);
 asm
  pop bp
  pop es
  pop ds
  pop di
  pop si
  pop dx
  pop cx
  pop bx
  pop ax
  retf
 end;
 end;

procedure establish_connection_to_remote_user;
 var connection:integer;

  procedure add255(var num:NetworkNumber;
                   var node:NetworkNode);
   var x:integer;
   begin
    for x:=0 to 3 do num[x]:=$ff;
    for x:=0 to 5 do node[x]:=$ff;
   end;

  procedure fix_address(var num:NetworkNumber;
                        var node:NetworkNode;
                            Address:IPXHeader);
   var x:integer;
   begin
    for x:=0 to 3 do num[x] := address.source_network_number[x];
    for x:=0 to 5 do node[x] := address.source_network_node[x];
   end;


 begin
  add255(User_network_number,user_node);
 User_network_number[0]:=9;
 User_network_number[1]:=90;
 User_network_number[2]:=0;
 User_network_number[3]:=6;
  receive_message := '';
  IPXReceive(receive_ecb,receive_header,receive_socket,@receive_message,
             sizeof(receive_message),@receive_routine);

  send_message := 'Looking for Greg Millers host';
  repeat
  IPXSend(User_network_number, User_node, receive_socket, @send_message,
          length(send_message)+1,send_ecb,send_header,send_socket,null);
  write(receive_message);
  until (receive_message = 'Greg Millers host hears you');
  fix_address(User_network_number,User_node,receive_header);

{ User_network_number[0]:=9;
 User_network_number[1]:=90;
 User_network_number[2]:=0;
 User_network_number[3]:=3;
 user_Node[0]:=16;
 User_node[1]:=0;
 user_node[2]:=90;
 user_node[3]:=172;
 user_node[4]:=99;
 user_node[5]:=235;

  receive_message := '';
  IPXReceive(receive_ecb,receive_header,receive_socket,@receive_message,
             sizeof(receive_message),null);

  send_message := 'Looking for Greg Millers host';
  repeat
  IPXSend(User_network_number, User_node, receive_socket, @send_message,
          length(send_message)+1,send_ecb,send_header,send_socket,null);
  write(receive_message);
  until receive_message = 'Greg Millers host hears you';
  fix_address(User_network_number,User_node,receive_header);

{  connection := Get1stConnectionNumber(ParamSTR(1));
  if Connection = 0 then abort('User not found')
  else
   If getInternetAddress(connection,
                         user_network_number,
                         user_node) <> 0 then abort('Network error');}
 end;

procedure get_ready_to_begin_file_receive;

 const null = ptr(0,0);

 var receive_ecb:ecb;
     receive_header:IPXHeader;
     receive_Message:string;

     send_ecb:ecb;
     send_header:IPXHeader;
     send_message:string; receive_ecb:ecb;

     receive_header:IPXHeader;

     receive_Message:string;



     send_ecb:ecb;

     send_header:IPXHeader;

     send_message:string;


 begin
  receive_message := '';
  IPXReceive(receive_ecb,receive_header,receive_socket,@receive_message,
             sizeof(receive_message),null);
  send_message := 'GO!';
  repeat
   begin
    IPXSend(User_network_number, User_node, receive_socket, @send_message,
            length(send_message)+1,send_ecb,send_header,send_socket,null);
   end;
  until (receive_ecb.Completion_code <> 0)
        or (receive_ecb.in_use <> 0)
        or (receive_message <> 'GO!')
 end;

procedure send_service_routine;
 interrupt;
 begin

 asm
  pop bp
  pop es
  pop ds
  pop di
  pop si
  pop dx
  pop cx
  pop bx
  pop ax
  retf
 end;
 end;

procedure send_packet;
 begin
  IPXSend(user_network_number,User_node,Receive_socket,@send_message,
          length(send_message)+1,send_ecb,send_header,send_socket,
          @send_service_routine);
 end;


procedure store_packet;
 begin
  inc(packet_count);
  write(receive_message);
  write(rec_file,receive_message);
  send_packet;
 end;

{$F+}
procedure receive_service_routine;{$F-}
{A receive indicates a packet has arrived}
 interrupt;
 begin
  sti;
  if receive_message = 'GO!' then
   begin
    send_message := 'GO!';
    send_packet;
   end
  else
   begin
    store_packet;
    IPXReceive(receive_ecb,receive_header,receive_socket,
               @receive_message,sizeof(receive_message),
               @receive_service_routine);
    send_packet; {Send Acknowledgemnet}
    {getTime(hr,mn,start,s100);}
    start:=0;
   end;
 asm
  pop bp
  pop es
  pop ds
  pop di
  pop si
  pop dx
  pop cx
  pop bx
  pop ax
  retf
 end; {Program locks up here}
 end;

procedure receive_file;

 begin
  IPXReceive(receive_ecb,receive_header,receive_socket,
             @receive_message,sizeof(receive_message),
             @receive_service_routine);
  done:=false;
  while not done do
   begin
    {getTime(hr,mn,timer,s100);}Inc(start);
    if start > maxtime then
     send_packet;
   end;

 end;

begin
 if not IPXInstalled then writeln('IPX Not installed');
 writeln('Opening files');
 open_user_sockets_and_file;
 writeln('Connecting to remote user');
 establish_connection_to_remote_user;
 writeln('Getting ready to receive');
 Get_ready_to_begin_file_receive;
 writeln('Receiving');
 receive_file;
 close(rec_file);
end.
 receive');

 Get_ready_to_begin_file_receive;

 writeln('Receiving');

 receive_file;

 close(rec_file);

end.