Connection protocol. Joinable servers!

src/client.bat

@@ -1,2 +1,3 @@
+color 0a
 D:/dev/love/love.exe "./client/"
 pause

src/client/connecting.lua

@@ -36,10 +36,28 @@ function connecting.draw()
   return false
 end
 
+function connecting.svChimo( msg )
+  return server.answerChallenge( msg.nonce )
+end
+
+function connecting.connected( msg )
+  server.setToken( msg.token )
+  return scene.game()
+end
+
 function connecting.keypressed(key, code, isrepeat)
   if code == "escape" then return scene.browser() end
 end
 
+function connecting.read( msg )
+  if not msg then return false end
+  local msgs, types = server.deserialise( msg )
+  for i = 1, #msgs do
+    ( connecting[ types[i] ] or print )( msgs[i], ip, port )
+  end
+  return connecting.read( server.receive() )
+end
+
 function connecting.update(dt)
   time = time + dt
   
@@ -49,12 +67,14 @@ function connecting.update(dt)
     server.connect( ip, port )
     --return scene.loadScene( scene.game )
   end
-  return false
+
+  return connecting.read( server.receive() )
 end
 
 function connecting:onLoad( params )
   lg.setCanvas()
   time = 0
+  attempts = 1
   params = params or { ip = "8.8.8.8", port = 8 }
   ip, port = params.ip, params.port
   return server.isValid( ip, port ) and server.connect( ip, port )

src/client/udp.lua

@@ -4,7 +4,9 @@ local config = assert( require 'config' )
 
 local udp = {}
 local packet = assert( require 'shared.packet' )
+local hash = assert( require 'shared.hash' )
 
+local token
 local cxn = assert( socket.udp() )
 local mscxn = assert( socket.udp() )
 cxn:settimeout( 0 )
@@ -15,6 +17,8 @@ function udp.receive()
   return cxn:receive()
 end
 
+udp.deserialise = packet.deserialise
+
 function udp.receiveMeta()
   return mscxn:receive()
 end
@@ -27,6 +31,17 @@ function udp.requestServerList()
   return mscxn:send( packet.get() )
 end
 
+function udp.setToken( token )
+  token = token
+end
+
+function udp.answerChallenge( svNonce )
+  local clNonce = hash.rand()
+  packet.get()
+  packet.clChimo{ nonce = clNonce, hash = hash.hash( clNonce, svNonce ) }
+  return cxn:send( packet.get() )
+end
+
 function udp.isValid( ip, port )
   local s, e = socket.udp()
   if s then s, e = s:setpeername( ip, port ) end
@@ -40,7 +55,9 @@ function udp.connect( ip, port )
 end
 
 function udp.disconnect( )
-  
+  udp.send( packet.get( packet.disconnect{ reason = 0 }))
+  cxn = assert( socket.udp() )
+  cxn:settimeout( 0 )
 end
 
 function udp.send( s )

src/server.bat

@@ -1,2 +1,3 @@
+color 04
 D:/dev/love/love.exe "./server/"
 pause

src/server/main.lua

@@ -20,44 +20,52 @@ local svInfo = packet.serverInfo{ version = 13,
 
 local clients = {}
 local connecting = {}
+local server = { tick = 0, }
 
-local server = { 
-  tick = 0,
+local handlers = setmetatable({
 
-  clientInfo = function( clientInfo, ip, port )
-    local key = ip..port 
-    connecting[key] = connecting[key] or {}
-    local client = connecting[key]
-    local nonce = shared.hash.rand()
-    client.nonce = nonce
-    print( "Received connection request from:", ip, port )
-    print( "Sending authentication nonce:", nonce )
-    packet.svChimo{ nonce = nonce }
-    return udp:sendto( packet.get(), ip, port )
-  end,
+    clChimo = function( clChimo, ip, port )
+      if not connecting[ ip..port ] then
+        return print( "Old connection attempt from:", ip, port )
+      end
+      local remoteHash = clChimo.hash
+      local clNonce = clChimo.nonce
+      local svNonce = connecting[ip..port].nonce
+      local localHash = shared.hash.hash( clNonce, svNonce )
+      if localHash ~= remoteHash then
+        return print( "Hashes differ:", shared.hash.hex( clNonce ), shared.hash.hex( svNonce ) )
+      end
+      print( "Client connected:", ip, port, localHash )
+      clients[ localHash ] = { ip = ip, port = port }
+      packet.connected{ token = localHash }
+      return udp:sendto( packet.get(), ip, port )
+    end,
 
-  clChimo = function( clChimo, ip, port )
-    if not connecting[ ip..port ] then
-      return print( "Old connection attempt from:", ip, port )
-    end
-    local remoteHash = clChimo.hash
-    local clNonce = clChimo.nonce
-    local svNonce = connecting[ip..port].nonce
-    local localHash = shared.hash.hash( clNonce, svNonce )
-    if localHash ~= remoteHash then
-      return print( "Hashes differ:", shared.hash.hex( clNonce ), shared.hash.hex( svNonce ) )
-    end
-    print( "Client connected:", ip, port, localHash )
-    clients[ localHash ] = { ip = ip, port = port }
-    packet.connected{ token = localHash }
-    return udp:sendto( packet.get(), ip, port )
-  end,
+    advertised = function( ack, ip, port )
+      if ip ~= shared.metaserver.ip then return print( "Advertisement acked from rogue address:", ip, port ) end
+      if udp:getsockname() then 
+        assert( udp:getsockname() == tostring( ack.ip ) )
+        return print( "Advertised. Address already set." )
+      end
+      print( "Advertised. Setting address:", ack.ip, ack.port )
+      server.SetIP( tostring( ack.ip ), ack.port )
+    end,
 
-  advertised = function( ack, ip, port )
-    print( "Advertised via:", ip, port )
-  end,
-}
 
+    clientInfo = function( clientInfo, ip, port )
+      local key = ip..port 
+      connecting[key] = connecting[key] or {}
+      local client = connecting[key]
+      local nonce = shared.hash.rand()
+      client.nonce = nonce
+      print( "Received connection request from:", ip, port )
+      print( "Sending authentication nonce:", nonce )
+      packet.svChimo{ nonce = nonce }
+      return udp:sendto( packet.get(), ip, port )
+    end,
+
+
+    }, {__index = function() return print end })
 
 function server.Advertise()
   print( "Advertise." )
@@ -85,8 +93,8 @@ function server.Parse( msg, ip, port )
 
   local msgs, types = packet.deserialise( msg )
   if msgs then for i = 1, #msgs do
-    print( "Received: ", types[i], ip, port );
-    ( server[ types[i] ] or print )( msgs[i], ip, port )
+    print( "Received: ", types[i], ip, port )
+    handlers[ types[i] ]( msgs[i], ip, port )
   end end
   return server.Parse( udp:receivefrom() ) -- Process other packets.
 end
@@ -94,13 +102,16 @@ end
 function server.SetIP( ipString, port )
   svInfo.ip = shared.ip.fromString( ipString )
   svInfo.port = port
-  if udp:setsockname( ipString, port ) then
+  local ok, err = udp:setsockname( ipString, port )
+  if ok then
+    print( "Server IP:", udp:getsockname() )
+    return true
     --Find another port.
   elseif port < 65536 then
-    print( "Trying port:", port )
+    print( "Could not use port:", ipString, port, err )
     return server.SetIP( ipString, port + 1 )
   else
-    print( "Could not use IP: "..ipString )
+    print( "Could not use IP:", ipString, err )
     return error( "Connection failed." )
   end
 end
@@ -109,8 +120,6 @@ end
 function server.Start()
   udp = assert( socket.udp() )
   udp:settimeout(0)
-  server.SetIP( socket.dns.toip(socket.dns.gethostname()), 51312 )
-  print( "Server started:", udp:getsockname() )
 end
 
 function server.Advance()
@@ -135,6 +144,7 @@ function love.update( dt )
   server.Advance()
   if server.tick % 250 == 0 then
     server.Advertise()
+    server.Parse( mscxn:receive(), shared.metaserver.ip, shared.metaserver.port )
   end
 end
 

src/shared/hash.lua

@@ -1,3 +1,11 @@
+local math = math
 local bit = assert( require 'bit' )
+local max = bit.tobit( 0xffffffff )
+math.randomseed( 4 )
 --hash of a pair of 32-bit numbers
-return { hash = bit.bxor, rand = function() return 5 end, hex = bit.tohex }
+return { 
+  hash = bit.bxor,
+  hex = bit.tohex,
+  rand = function() 
+    return math.random( 1, max )
+  end, }

src/shared/packet.lua

@@ -102,8 +102,15 @@ newStruct{
 }
 
 newStruct{
-  name =  "advertised",
-  "uint32_t      time",
+  name = "advertised",
+  "uint32_t     time",
+  "ipAddress      ip",
+  "uint16_t     port",
+}
+
+newStruct{
+  name = "disconnect",
+  "uint32_t   reason",
 }
 
 local readBuffer = buffer.new( 1024 )