From 688f8e0ff7381c3438a4ec55699b01e9030772a2 Mon Sep 17 00:00:00 2001
From: Izaya <redtailedairways@gmail.com>
Date: Sat, 17 Feb 2018 14:56:06 +1100
Subject: [PATCH] implemented the beginning of layer 4 and 4 support

---
 OpenOS/etc/rc.d/minitel.lua |   5 +-
 OpenOS/usr/lib/net.lua      | 110 ++++++++++++++++++++++++++++++++++++
 2 files changed, 113 insertions(+), 2 deletions(-)
 create mode 100644 OpenOS/usr/lib/net.lua

diff --git a/OpenOS/etc/rc.d/minitel.lua b/OpenOS/etc/rc.d/minitel.lua
index 5e12d90..1b00380 100644
--- a/OpenOS/etc/rc.d/minitel.lua
+++ b/OpenOS/etc/rc.d/minitel.lua
@@ -151,8 +151,8 @@ function start()
  event.listen("modem_message",processPacket)
  print("Started packet listening daemon: "..tostring(processPacket))
  
- local function queuePacket(_,ptype,to,vport,data)
-  npID = genPacketID()
+ local function queuePacket(_,ptype,to,vport,data,npID)
+  npID = npID or genPacketID()
   pqueue[npID] = {ptype,to,vport,data,0,0}
   dprint(npID,table.unpack(pqueue[npID]))
  end
@@ -179,6 +179,7 @@ function start()
  timers[#timers+1]=event.timer(0,packetPusher,math.huge)
  print("Started packet pusher: "..tostring(timers[#timers]))
  
+ listeners["net_ack"]=dprint
  event.listen("net_ack",dprint)
 end
 
diff --git a/OpenOS/usr/lib/net.lua b/OpenOS/usr/lib/net.lua
new file mode 100644
index 0000000..8d2f375
--- /dev/null
+++ b/OpenOS/usr/lib/net.lua
@@ -0,0 +1,110 @@
+local computer = require "computer"
+local event = require "event"
+local net = {}
+net.mtu = 4096
+net.streamdelay = 60
+net.minport = 32768
+net.maxport = 65535
+net.openports = {}
+
+function net.genPacketID()
+ local npID = ""
+ for i = 1, 16 do
+  npID = npID .. string.char(math.random(32,126))
+ end
+ return npID
+end
+
+function net.usend(to,port,data,npID)
+ computer.pushSignal("net_send",0,to,port,data,npID)
+end
+
+function net.rsend(to,port,data)
+ local pid = net.genPacketID()
+ computer.pushSignal("net_send",1,to,port,data,pid)
+ repeat
+  _,rpid = event.pull("net_ack")
+ until rpid == pid
+end
+
+-- ordered packet delivery, layer 4?
+
+function net.send(to,port,ldata)
+ local tdata = {}
+ if ldata:len() > net.mtu then
+  for i = 1, ldata:len(), net.mtu do
+   tdata[#tdata+1] = ldata:sub(1,net.mtu)
+   ldata = ldata:sub(net.mtu+1)
+  end
+ else
+  tdata = {ldata}
+ end
+ for k,v in ipairs(tdata) do
+  net.rsend(to,port,v)
+ end
+end
+
+-- socket stuff, layer 5?
+
+local function cwrite(self,data)
+ net.send(self.addr,self.port,data)
+end
+local function cread(self,length)
+ local rdata = ""
+ rdata = self.rbuffer:sub(1,length)
+ self.rbuffer = self.rbuffer:sub(length+1)
+ return rdata
+end
+
+local function socket(addr,port) -- todo, add remote closing of sockets
+ local conn = {}
+ conn.addr,conn.port = addr,tonumber(port)
+ conn.rbuffer = ""
+ conn.write = cwrite
+ conn.read = cread
+ conn.state = "open"
+ local function listener(_,f,p,d)
+  if f == conn.addr and p == conn.port then
+   conn.rbuffer = conn.rbuffer .. d
+  end
+ end
+ event.listen("net_msg",listener)
+ function conn.close(self)
+  event.ignore("net_msg",listener)
+  conn.state = "closed"
+ end
+ return conn
+end
+
+function net.open(to,port)
+ net.rsend(to,port,"openstream")
+ local st = computer.uptime()+net.streamdelay
+ local est = false
+ while true do
+  _,from,rport,data = event.pull("net_msg")
+  if to == from and rport == port then
+   if tonumber(data) then
+    est = true
+   end
+   break
+  end
+  if st < computer.uptime() then
+   return nil, "timed out"
+  end
+ end
+ if not est then
+  return nil, "refused"
+ end
+ return socket(to,data,port)
+end
+
+function net.listen(port)
+ repeat
+  _, from, rport, data = event.pull("net_msg")
+ until rport == port
+ local nport = math.random(net.minport,net.maxport)
+ net.rsend(from,rport,tostring(nport))
+ return socket(from,nport,port)
+end
+
+return net