Handle hash collision in handshake; properly prune old servers from browser.

src/client/game.lua

@@ -58,8 +58,8 @@ function game.update( dt )
   if t > 0.1 then
     t = 0
     tick = tick + 1
-    server.newPacket()
+    server.newPacket( tick )
-    assert( server.send( packet.get() ) )
+    assert( server.send() )
   end
 end
 
@@ -69,10 +69,7 @@ function game.newGame( )
 end
 
 function game.disconnect( )
-  server.newPacket()
+  return scene.mainmenu( server.disconnect( tick ) )
-  server.disconnect()
-  server.send( packet.get() )
-  return scene.mainmenu( server.disconnect() )
 end
 
 function game.onLoad( params )

src/client/udp.lua

@@ -6,7 +6,6 @@ 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 )
@@ -32,19 +31,20 @@ function udp.requestServerList()
 end
 
 function udp.newPacket( tick )
-  packet.get()
+  if udp.token then packet.connected{ token = udp.token, tick = tick or 0 } end
-  if token then packet.connected{ token = token, tick = tick or 0 } end
 end
 
 function udp.setToken( token )
-  token = token
+  print( "Setting server token:", token )
+  udp.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() )
+  print( "Received authentication nonce. Reply:", clNonce, svNonce )
+  return udp.send()
 end
 
 function udp.isValid( ip, port )
@@ -57,17 +57,22 @@ end
 function udp.connect( ip, port )
   assert( cxn:setpeername( ip, port ) )
   print( "Connection request to:", ip, port )
-  return udp.send( packet.get( packet.clientInfo{ username = config.plName } ) )
+  return udp.send( packet.clientInfo{ username = config.plName })
 end
 
-function udp.disconnect( )
+function udp.disconnect( tick )
-  udp.send( packet.get( packet.disconnect{ reason = 0 }))
+  for i = 1, 10 do 
+    udp.newPacket( tick )
+    packet.disconnect()
+    udp.send()
+  end
+  udp.setToken()
   cxn = assert( socket.udp() )
   cxn:settimeout( 0 )
 end
 
-function udp.send( s )
+function udp.send()
-  return cxn:send( s )
+  return cxn:send( packet.get() )
 end
 
 return udp

src/client/ui/browser.lua

@@ -144,7 +144,7 @@ end
 local metaServerHandlers = setmetatable(
   {  
     default = function() end,
-    heartbeat = serverList.clear,
+    connected = serverList.clear,
     serverInfo = serverList.add,
   }, 
   {__index = function( t ) return t.default end })

src/metaserver/main.lua

@@ -56,6 +56,8 @@ local handlers = setmetatable({
       
       local t = socket.gettime()
       clients[ip].time = t
+      
+      packet.connected{ token = 5, tick = tick }
 
       for svIP, server in pairs( servers ) do
         print( "", svIP, packet.getString( server.info.svname ))

src/server/main.lua

@@ -9,6 +9,8 @@ assert( mscxn:setpeername( shared.metaserver.ip, shared.metaserver.port ), "Coul
 local udp
 local io = assert( io )
 
+local CLIENTTIMEOUT = 10
+
 local svInfo = packet.serverInfo{ version = 13,
   players = 0,
   capacity = 255,
@@ -41,6 +43,7 @@ local handlers = setmetatable({
       end
 
       client.tick = msg.tick
+      client.time = socket.gettime()
       server.currentClient = client
     end,
     
@@ -58,11 +61,17 @@ local handlers = setmetatable({
 
     --Client responds to handshake challenge.
     clChimo = function( clChimo, ip, port )
+      
+      print( "Received handshake response." )
+      
+      --No active challenge, don't send anything.
       local key = ip..":"..port
       if not connecting[ key ] then
         print( "Old connection attempt from:", key )
         return true
       end
+      
+      --Compute session token.
       local remoteHash = clChimo.hash
       local clNonce = clChimo.nonce
       local svNonce = connecting[key].nonce
@@ -72,10 +81,14 @@ local handlers = setmetatable({
         return true
       end
       
+      --Hash collision.
+      while clients[token] do token = token + 1 end
+      
       --Successful handshake.
-      print( "Client connected:", ip, port, token )
+      print( "Client connected:", token, port, ip )
       clients[ token ] = connecting[ key ]
-      clients[ token ].token = token
+      clients[ token ].id = token
+      clients[ token ].time = socket.gettime()
       packet.connected{ token = token, tick = server.tick }
       return udp:sendto( packet.get(), ip, port )
     end,
@@ -126,11 +139,9 @@ end
 --Incoming packet.
 function server.Parse( msg, ip, port )
   if (not msg) or (#msg < 1) then return end
-  print( "Parsing:", ip, port, #msg, msg )
   local msgs, types = packet.deserialise( msg )
   if msgs then
     for i = 1, #msgs do
-      print( "Received: ", types[i], ip, port )
       if handlers[ types[i] ]( msgs[i], ip, port ) then break end
     end
     server.currentClient = false
@@ -164,14 +175,14 @@ end
 
 function server.Advance()
   server.tick = server.tick + 1
+  server.time = socket.gettime()
   if server.tick % 100 == 0 then
     for id, client in pairs( clients ) do
       packet.get()
-      print( "updating client:", id )
       packet.connected{ token = id, tick = server.tick }
       udp:sendto( packet.get(), client.ip, client.port )
       
-      if server.tick - client.tick > 1000 then
+      if server.time - client.time > CLIENTTIMEOUT then
         print( "dropping client:", id )
         clients[id] = nil
       end

src/shared/hash.lua

@@ -1,6 +1,6 @@
 local math = math
 local bit = assert( require 'bit' )
-local max = math.huge
+local max = 65536
 math.randomseed( 4 )
 --hash of a pair of 32-bit numbers
 return { 

src/shared/packet.lua

@@ -109,6 +109,11 @@ newStruct{
   "char       reason",
 }
 
+newStruct{
+  name = "debugLatency",
+  "uint32_t lastTick",
+}
+
 local readBuffer = buffer.new( 1024 )
 function packet.deserialise( str )
   readBuffer:set( str )