Network troubleshooting.

src/client/connecting.lua

@@ -5,7 +5,7 @@ local button = assert( require 'ui.button' )
 local strings = assert( require 'strings' )
 local connecting = {}
 
-local time, ip, port, attempts = 0, 0, 0, 0
+local time, ip, port, attempts = 0, 0, 0, 1
 
 local cancelButton = button{ 
   x = lg.getWidth() / 4,
@@ -43,7 +43,10 @@ end
 function connecting.update(dt)
   time = time + dt
   
-  if time > 5 then 
+  if time > 2 then
+    time = 0
+    attempts = attempts + 1
+    server.connect( ip, port )
     --return scene.loadScene( scene.game )
   end
   return false

src/client/udp.lua

@@ -1,5 +1,6 @@
 local socket = assert( require 'socket' )
 local ms = assert( require 'shared.metaserver' )
+local config = assert( require 'config' )
 
 local udp = {}
 local packet = assert( require 'shared.packet' )
@@ -35,7 +36,7 @@ end
 
 function udp.connect( ip, port )
   assert( cxn:setpeername( ip, port ) )
-  return udp.send( packet.get( packet.heartbeat{ tick = 0, hash = 1234 } ) )
+  return udp.send( packet.get( packet.clientInfo{ username = config.plName } ) )
 end
 
 function udp.disconnect( )

src/metaserver/getip.lua

@@ -1 +1 @@
-assert( assert( require 'socket.http' ).request 'https://api.ipify.org' ) == '142.162.167.92'
+assert( assert( require 'socket.http' ).request 'https://api.ipify.org' == '142.162.167.92')

src/metaserver/main.lua

@@ -1,3 +1,4 @@
+--Note, this won't work unless you set up port forwarding!
 local SERVERTIMEOUT = 30
 local CLIENTTIMEOUT = 1
 
@@ -5,8 +6,11 @@ local shared = assert( require '../shared.shared' )
 local socket = assert( require 'socket' )
 local packet = assert( shared.packet )
 local udp = assert( socket.udp() )
+local msip = assert( require 'getip' )
 udp:settimeout(0)
-assert( udp:setsockname( socket.dns.toip(socket.dns.gethostname()), shared.metaserver.port ))
+local localIP = socket.dns.toip(socket.dns.gethostname())
+print( "Metaserver local IP:", localIP )
+assert( udp:setsockname( localIP, shared.metaserver.port ))
 
 --Servers broadcast their information here.
 --The metaserver builds a list of available servers. ( available meaning, "broadcasted in last ten heartbeats" )

src/server/main.lua

@@ -18,20 +18,46 @@ local svInfo = packet.serverInfo{ version = 13,
   map = "Test Map"
 }
 
+local clients = {}
+local connecting = {}
+
 local server = { 
   tick = 0,
   
-  advertised = function()
-    print( "Advertised." )
+  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,
+
+  advertised = function( ack, ip, port )
+    print( "Advertised via:", ip, port )
   end,
 }
 
-local clients = {}
-
---Developer convenience function: start the local client program.
-function server.StartLocalClient()
-  os.execute( "start vision.bat" )
-end
 
 function server.Advertise()
   print( "Advertise." )
@@ -69,10 +95,9 @@ function server.SetIP( ipString, port )
   svInfo.ip = shared.ip.fromString( ipString )
   svInfo.port = port
   if udp:setsockname( ipString, port ) then
-    print( ipString, port )
     --Find another port.
   elseif port < 65536 then
-    print( "Trying IP:", ipString, port )
+    print( "Trying port:", port )
     return server.SetIP( ipString, port + 1 )
   else
     print( "Could not use IP: "..ipString )

src/shared/hash.lua

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

src/shared/metaserver.lua

@@ -1 +1,3 @@
-return { ip = '192.168.2.15', port = 42069 }
+local ms = { ip = '192.168.2.15', port = 42069 }
+print( "Metaserver public address:", ms.ip, ms.port )
+return ms

src/shared/packet.lua

@@ -4,22 +4,25 @@ local ipString = assert( require 'shared.ipstring' )
 local packet = {}
 local mt = { __index = { new = function( self ) return ffi.new( self.ct ) end } }
 
+local headerByte = 0x41 --Ensure printable characters at start of packets.
+
 local function newStruct( t )
-  assert( not( packet[ t.name ] or packet[ t.netname ] ))
+  assert( not( packet[ t.name ] ))
   packet[ t.name ] = t
-  packet[ t.netname ] = t
+  t.netname = headerByte
+  packet[ headerByte ] = t
+  headerByte = headerByte + 1
   ffi.cdef(("typedef struct {uint8_t netname;\n%s;\n} %s;"):format( table.concat( t, ";\n" ), t.name ))
   t.ct = ffi.typeof( ffi.new( t.name ) )
   t.size = ffi.sizeof( t.ct )
   assert( t.size < 500, t.name )
   setmetatable( t, mt )
 
-  --print( "Packet:", t.name, "Members:", #t + 1, "Size:", t.size, "Alignment:", ffi.alignof( t.ct ) )
+  print( "Packet:", t.name, "Members:", #t + 1, "Size:", t.size, "Alignment:", ffi.alignof( t.ct ) )
 end
 
 newStruct{ 
   name = "serverInfo",
-  netname =        42,
   "uint8_t   players",
   "uint8_t  capacity",
   "ipAddress      ip",
@@ -31,26 +34,38 @@ newStruct{
 
 newStruct{
   name = "clientInfo",
-  netname =        22,
   "char username[31]",
 }
 
+newStruct{
+  name =    "svChimo",
+  "uint32_t    nonce",
+}
+
+newStruct{
+  name =    "clChimo",
+  "uint32_t    nonce",
+  "uint32_t     hash",
+}
+
+newStruct{
+  name = "connected",
+   "uint32_t  token",
+}
+
 newStruct{
   name = "metaServer",
-  netname =       123,
   "char   padding[300]" --Just a bunch of padding to mitigate amplification. 
 }
 
 newStruct{
   name =  "heartbeat",
-  netname =        69,
   "uint32_t     tick",
   "uint32_t     hash",
 }
 
 newStruct{
   name =  "insect",
-  netname =     81,
   "uint8_t     id",
   "bool      dead",
   "int8_t      hp",
@@ -63,7 +78,6 @@ newStruct{
 
 newStruct{
   name = "soleil",
-  netname =     27,
   "uint16_t  azimuth",
   "uint16_t altitude",
   "int8_t       vazi",
@@ -72,7 +86,6 @@ newStruct{
 
 newStruct{
   name = "playerChange",
-  netname =      72,
   "uint8_t          id",
   "uint8_t        role",
   "char   username[31]",
@@ -80,19 +93,16 @@ newStruct{
 
 newStruct{
   name = "chatMessage",
-  netname =         54,
   "char     cmsg[127]",
 }
 
 newStruct{
   name = "command",
-  netname =      32,
   "char   command",
 }
 
 newStruct{
   name =  "advertised",
-  netname =        144,
   "uint32_t      time",
 }
 

src/shared/shared.lua

@@ -8,6 +8,7 @@ local shared = {}
     return rq( ... )
   end
 end]]
+shared.hash = assert( require 'shared.hash' )
 shared.ip = assert( require 'shared.ipstring' )
 shared.packet = assert( require 'shared.packet' )
 shared.print = assert( require 'shared.print' )