Add network implemention

libnetwork.lua

@@ -1,9 +1,149 @@
-function socket() -- Allocate a new socket
+--[[ 
+    Local netcard wrapper
+        This require should return a table like:
+        {
+            broadcast=function(port,...):bool
+            send=function(uuid,port,...):bool
+            open=function(port):bool
+            isOpen=function(port):bool
+            close=function(port):bool
+        }
+--]]
+local netcard=require("localNetcard")
 
+-- Check Netcard
+if(netcard.broadcast==nil or 
+    netcard.send==nil or 
+    netcard.open==nil or 
+    netcard.isOpen==nil or 
+    netcard.close==nil) then
+    print("Error: netcard invalid.")
+end
+
+local sker= -- Socket Kernel Table
+    {
+        fdset= -- Store information of sockets
+        {
+            --[[
+            status : string ="Ready" "Connected" "Closed"
+            remote_hwport : int
+            remote_cookie : string
+            --]]
+        }
+    }
+
+local arpker={} -- ARP Kernel Table
+
+
+function _findFirstAvaliableSocket()
+    local i=0 
+    while ( sker.fdset[i] ~= nil ) do i=i+1 end
+    return i
+end
+
+function _doCreateSocket(sfd)
+    if(sker.fdset[sfd]~=nil) then return false,"sfd invalid"
+    else
+        sker.fdset[sfd]=
+            {
+                status="Ready"
+            }
+        return true,"Success"
+    end
+end
+
+function _getSocketStatus(sfd)
+    if(sker.fdset[sfd]==nil) then return nil
+    else
+        return sker.fdset[sfd].status
+    end
+end
+
+function _setSocketStatus(sfd,status,...)
+    if(sker.fdset[sfd]==nil) then return false
+    else
+        sker.fdset[sfd].status=status
+        if(status=="Connected") then
+            sker.fdset[sfd].remote_hwport=arg[1]
+        end
+        return true
+    end
+end
+
+function _isPortValid(port)
+    return port>0 and port<65536
+end
+
+function _doConnect(sfd,remote_uuid,port) -- Connect to a remote device via uuid and port
+    -- Send SYN package (1,1,1)
+    local syn=string.pack("iii",1,1,1)
+    if(not netcard.send(remote_uuid,port,syn)) then 
+        return -1,"Network error"
+    end
+    -- Wait 1.5 seconds for SYN+ACK (1,1,3)
+    local e,remote_hwport=event.pull(1.5,"net_synack")
+    if(e==nil) then 
+        return -2,"Connection timed out"
+    end
+    --- Send ACK package (1,1,2)
+    local ack=string.pack("iii",1,1,2)
+    if(not netcard.send(remote_uuid,port,ack)) then 
+        return -1,"Network error"
+    end
+
+    -- Connection established
+    return 0,"Success",remote_hwport
+end
+
+function _isInArpCache(tag) -- Check ARP Check Table with tag for uuid
+    if(arpker[tag]~=nil) then
+        return true,arpker[tag].uuid
+    else
+        return false
+    end
+end
+
+function _generateARPQuest(tag) -- Generate a ARP quest
+    local s=string.pack("iiii",1,0,1,string.length(tag))
+    s=s..tag
+    return s
+end
+
+function _doArpBroadcastQuery(tag) -- Broadcast ARP quest to hardware port 9 (arp)
+    if(netcard.broadcast(9,tag)) then return true,"Success"
+    else return false,"Netcard error"
+end
+
+function socket() -- Allocate a new socket
+    local idx=_findFirstAvaliableSocket()
+    local ret,emsg=_doCreateSocket(idx)
+    if(not ret) then
+        return -1,emsg
+    else
+        return ret,emsg
+    end
 end
 
 function connect(sfd,remote_tag,port) -- Connect to a remote device
-
+    if(_getSocketStatus(sfd)~="Ready") then
+        return -1,"Socket not ready"
+    elseif(not _isPortValid(port)) then
+        return -2,"Port Invalid"
+    else
+        -- Try to resolve remote_tag to remote_uuid
+        local remote_uuid=do_arp_query(remote_tag)
+        if(remote_uuid == nil) then
+            return -3,"Tag can not be resolved into uuid"
+        else
+            local eret,emsg,remote_hwport=_doConnect(sfd,remote_uuid,port)
+            if(eret==0) then
+                _setSocketStatus(sfd,"Connected",remote_hwport)
+                return 0,"Success"
+            else
+                return eret,emsg
+            end
+        end
+    end
 end
 
 function bind(sfd,port) -- Bind socket at specific port
@@ -46,8 +186,19 @@ function arp_listener() -- ARP: Listen to arp broadcast and record informations.
 
 end
 
-function do_arp_query() -- ARP: Query uuid with tag, will send arp-request
-
+function do_arp_query(tag) -- ARP: Query uuid with tag, might send arp-request
+    local ret,uuid=_isInArpCache(tag)
+    if(ret) then return uuid
+    else
+        local quest=_generateARPQuest(tag)
+        for i=1,3,1 do
+            if(_doArpBroadcastQuery(quest)) then
+                local e,etag,euuid=event.pull(0.5,"net_newarp")
+                if(e~=nil) then return euuid end
+            end
+        end
+        return nil -- Failed to query arp in 3 tries.
+    end
 end
 
 function run_arp() -- Start ARP Services in background
@@ -56,4 +207,8 @@ end
 
 function run_dhcp_client() -- Start DHCP Client in background
 
+end
+
+function run_tcp() -- Start TCP Services in background
+
 end