Merge pull request #5 from payonel/develop

Modem component implementation.

src/component/modem.lua

@@ -1,6 +1,343 @@
 local address, _, wireless = ...
+print(address, _, wireless);
 compCheckArg(1,wireless,"boolean")
 
+local socket = require("socket")
+local ser = require("loot.OpenOS.lib.serialization")
+
+-- yes, global
+modem_host = {}
+
+-- modem component
+local obj = {}
+
+-- Modem cards communicate on a real backend port
+modem_host.comms_port = 61234
+modem_host.comms_ip = "127.0.0.10"
+modem_host.connected = false
+modem_host.messages = {}
+modem_host.socket = nil
+
+modem_host.hosting = false
+modem_host.clients = {}
+
+-- [port_number] = true when open
+modem_host.open_ports = {}
+
+function modem_host.createPacketArray(t, address, port, ...)
+	compCheckArg(1,t,type(""))
+	compCheckArg(2,address,type(""),type(0))
+	compCheckArg(3,port,type(0))
+
+	local packed =
+	{
+		t,
+		address,
+		modem_host.id,
+		port,
+		0, -- distance
+		...
+	}
+
+	return packed
+end
+
+function modem_host.packetArrayToPacket(packed)
+	compCheckArg(1,packed,type({}))
+	assert(#packed >= 5)
+
+	local packet = {}
+	packet.type = packed[1]
+	packet.target = packed[2]
+	packet.source = packed[3]
+	packet.port = packed[4]
+	packet.distance = packed[5]
+	packet.payload = {}
+
+	for i=6,#packed do
+		table.insert(packet.payload, packed[i])
+	end
+
+	return packet
+end
+
+function modem_host.packetArrayToDatagram(packed)
+	compCheckArg(1,packed,type({}))
+
+	local datagram = ser.serialize(packed)
+	return datagram .. '\n'
+end
+
+function modem_host.packetToPacketArray(packet)
+	return
+	{
+		packet.type,
+		packet.target,
+		packet.source,
+		packet.port,
+		packet.distance,
+		table.unpack(packet.payload or {})
+	}
+end
+
+function modem_host.datagramToPacketArray(datagram)
+	compCheckArg(1,datagram,type(""))
+	local packed = ser.unserialize(datagram)
+	return packed
+end
+
+function modem_host.datagramToPacket(datagram)
+	local packed = modem_host.datagramToPacketArray(datagram)
+	local packet = modem_host.packedToPacket(packed)
+	return packet
+end
+
+function modem_host.packetToDatagram(packet)
+	local packed = modem_host.packetToPacketArray(packet)
+	local datagram = modem_host.packetArrayToDatagram(packed)
+	return datagram
+end
+
+function modem_host.readDatagram(client) -- client:receive()
+	local raw, err = client:receive()
+	if raw then cprint("received: " .. raw) end
+	return raw, err
+end
+
+function modem_host.readPacketArray(client) -- client:receive()
+	local datagram, err = modem_host.readDatagram(client)
+	if not datagram then return nil, err end
+	return modem_host.datagramToPacketArray(datagram)
+end
+
+function modem_host.readPacket(client) -- client:receive()
+	local packed, err = modem_host.readPacketArray(client)
+	if not packed then return nil, err end
+	return modem_host.packetArrayToPacket(packed)
+end
+
+function modem_host.sendDatagram(client, datagram)
+	cprint("sending: " .. datagram)
+	return client:send(datagram)
+end
+
+function modem_host.sendPacketArray(client, packed)
+	local datagram = modem_host.packetArrayToDatagram(packed)
+	return modem_host.sendDatagram(client, datagram)
+end
+
+function modem_host.sendPacket(client, packet)
+	local datagram = modem_host.packetToDatagram(packet)
+	return modem_host.sendDatagram(client, datagram)
+end
+
+function modem_host.broadcast(packet)
+	-- only host broadcasts
+	-- this method will be hit for all broadcasted messages
+	-- but nonhosting clients will simply not repeat the broadcast
+	if modem_host.hosting then
+		local datagram = modem_host.packetToDatagram(packet)
+		for addr,client in pairs(modem_host.clients) do
+			modem_host.sendDatagram(client, datagram)
+		end
+	end
+end
+
+function modem_host.validTarget(target)
+	if target ==  0 then
+		return true
+	end
+
+	if target == modem_host.id then
+		return true
+	end
+
+	if not modem_host.hosting then
+		return false
+	end
+
+	for address,client in pairs(modem_host.clients) do
+		if address == target then
+			return true
+		end
+	end
+
+	return false
+end
+
+-- backend private methods, these are not pushed to user machine environments
+function modem_host.pushMessage(packet)
+	if not modem_host.validTarget(packet.target) then
+		return false, "invalid target, no such client listening" --ignored
+	end
+
+	table.insert(modem_host.messages, packet)
+
+	return true
+end
+
+function modem_host.dispatchPacket(packet)
+	if packet.target == modem_host.id then
+			if obj.isOpen(packet.port) then
+				table.insert(machine.signals, modem_host.packetToPacketArray(packet))
+			end
+	elseif modem_host.hosting then -- if hosting we will route
+		for source,client in pairs(modem_host.clients) do
+			if source == packet.target then
+				modem_host.sendPacket(client, packet)
+				break
+			end
+		end
+	else -- not hosting, send to host
+		modem_host.sendPacket(modem_host.socket, packet)
+	end
+end
+
+function modem_host.processPendingMessages()
+	-- computer address seems to be applied late
+	if not modem_host.id then
+		modem_host.id = component.list("computer",true)()
+		assert(modem_host.id)
+	end
+
+	modem_host.recvPendingMessages()
+
+	for _,packet in pairs(modem_host.messages) do
+
+		if packet.type == 'modem_message' then
+			-- broadcast if no target
+			if packet.target == 0 then
+				modem_host.broadcast(packet) -- ignored by clients
+
+				-- clean up for broadcasting to self
+				packet.target = modem_host.id
+			end
+
+			modem_host.dispatchPacket(packet)
+		end
+	end
+
+	modem_host.messages = {}
+end
+
+function modem_host.recvPendingMessages()
+	if modem_host.hosting then
+		while true do
+			local client = modem_host.socket:accept()
+			if not client then
+				break;
+			end
+
+			local handshake, err = modem_host.readPacket(client) -- client:receive()
+			if not handshake then
+				client:close()
+			else
+
+				local connectionResponse
+				local accepted = false
+				if handshake.type ~= "handshake" then
+					connectionResponse = modem_host.createPacketArray("handshake", modem_host.id, -1, 
+						false, "unsupported message type");
+				elseif modem_host.validTarget(handshake.source) then -- repeated client
+					connectionResponse = modem_host.createPacketArray("handshake", modem_host.id, -1, 
+						false, "computer address conflict detected, ignoring connection");
+				else
+					client:settimeout(0, 't')
+					modem_host.clients[handshake.source] = client
+					accepted = true
+
+					connectionResponse = modem_host.createPacketArray("handshake", modem_host.id, -1, true);
+				end
+
+				modem_host.sendPacketArray(client, connectionResponse)
+
+				if not accepted then
+					client:close()
+				end
+			end
+		end
+
+		-- recv all pending packets
+		for source, client in pairs(modem_host.clients) do
+			local packet, err = modem_host.readPacket(client)
+			if packet then
+				modem_host.pushMessage(packet)
+			elseif err ~= "timeout" then
+				client:close()
+				modem_host.clients[source] = nil
+			end
+		end
+	elseif modem_host.socket then
+		while true do
+			local packet, err = modem_host.readPacket(modem_host.socket)
+			if packet then
+				modem_host.pushMessage(packet)
+			else
+				break
+			end
+		end
+	end
+end
+
+function modem_host.createNewMessageBoard()
+	local why
+	modem_host.socket, why = socket.bind(modem_host.comms_ip, modem_host.comms_port)
+	if modem_host.socket then
+		modem_host.hosting = true
+	end
+	return modem_host.socket, why
+end
+
+function modem_host.joinExistingMessageBoard()
+	local why
+	modem_host.socket, why = socket.connect(modem_host.comms_ip, modem_host.comms_port)
+	if modem_host.socket then
+		modem_host.hosting = nil
+
+		-- send handshake data
+		local packed = modem_host.createPacketArray("handshake", 0, -1)
+		local sendResult = modem_host.sendPacketArray(modem_host.socket, packed)
+
+		local response, why = modem_host.readPacket(modem_host.socket)
+		assert(response)
+		assert(response.payload)
+
+		if not response.payload[1] then
+			modem_host.socket:close()
+			modem_host.socket = nil
+			return false, response.payload[2], true
+		end
+	end
+	return modem_host.socket, why
+end
+
+function modem_host.connectMessageBoard()
+	if modem_host.connected then
+		return true
+	end
+
+	local ok, info, critical = modem_host.joinExistingMessageBoard()
+
+	if not ok and critical then
+		return nil, info
+	end
+
+	if not ok then
+		ok, info = modem_host.createNewMessageBoard()
+	end
+
+	if not ok then
+		return nil, info
+	end
+
+	modem_host.socket:settimeout(0, 't') -- accept calls must be already pending
+	modem_host.connected = true
+	modem_host.clients = {}
+	modem_host.messages = {}
+
+	return true
+end
+
 local wakeMessage
 local strength
 if wireless then
@@ -14,78 +351,104 @@ local function checkPort(port)
 	return math.floor(port)
 end
 
--- modem component
-local obj = {}
-
 function obj.send(address, port, ...) -- Sends the specified data to the specified target.
-	--STUB
 	cprint("modem.send",address, port, ...)
 	compCheckArg(1,address,"string")
 	compCheckArg(2,port,"number")
 	port=checkPort(port)
-	return true
+
+	local packed = modem_host.createPacketArray("modem_message", address, port, ...)
+	local packet = modem_host.packetArrayToPacket(packed)
+	return modem_host.dispatchPacket(packet)
 end
+
 function obj.getWakeMessage() -- Get the current wake-up message.
-	--STUB
 	cprint("modem.getWakeMessage")
 	return wakeMessage
 end
+
 function obj.setWakeMessage(message) -- Set the wake-up message.
-	--STUB
 	cprint("modem.setWakeMessage",message)
 	compCheckArg(1,message,"string","nil")
 	wakeMessage = message
 end
+
 function obj.close(port) -- Closes the specified port (default: all ports). Returns true if ports were closed.
-	--STUB
 	cprint("modem.close",port)
 	compCheckArg(1,port,"number","nil")
 	if port ~= nil then
 		port=checkPort(port)
 	end
-	return false
+
+	if not obj.isOpen(port) then
+		return false;
+	end
+
+	modem_host.open_ports[port] = nil
+	return true
 end
+
 function obj.maxPacketSize() -- Gets the maximum packet size (config setting).
 	cprint("modem.maxPacketSize")
 	return settings.maxNetworkPacketSize
 end
+
 if wireless then
 	function obj.getStrength() -- Get the signal strength (range) used when sending messages.
-		--STUB
 		cprint("modem.getStrength")
 		return strength
 	end
 	function obj.setStrength(newstrength) -- Set the signal strength (range) used when sending messages.
-		--STUB
 		cprint("modem.setStrength",newstrength)
 		compCheckArg(1,newstrength,"number")
 		strength = newstrength
 	end
 end
+
 function obj.isOpen(port) -- Whether the specified port is open.
-	--STUB
 	cprint("modem.isOpen",port)
 	compCheckArg(1,port,"number")
-	return false
+	return modem_host.open_ports[port] ~= nil
 end
+
 function obj.open(port) -- Opens the specified port. Returns true if the port was opened.
-	--STUB
 	cprint("modem.open",port)
 	compCheckArg(1,port,"number")
 	port=checkPort(port)
-	return false
+
+	if obj.isOpen(port) then
+		return false, "port already open"
+	end
+
+	-- make sure we are connected to the message board
+	local ok, why = modem_host.connectMessageBoard()
+	
+	if not ok then
+		return false, why
+	end
+
+	modem_host.open_ports[port] = true
+	return true
 end
+
 function obj.isWireless() -- Whether this is a wireless network card.
-	--STUB
 	cprint("modem.isWireless")
 	return wireless
 end
+
 function obj.broadcast(port, ...) -- Broadcasts the specified data on the specified port.
-	--STUB
 	cprint("modem.broadcast",port, ...)
 	compCheckArg(1,port,"number")
 	port=checkPort(port)
-	return true
+
+	-- we cannot broadcast unless we are connected to the message board
+	if not modem_host.connectMessageBoard() then
+		return false
+	end
+
+	local packed = modem_host.createPacketArray("modem_message", 0, port, ...)
+	local packet = modem_host.packetArrayToPacket(packed)
+	return modem_host.dispatchPacket(packet)
 end
 
 local cec = {}

src/main.lua

@@ -49,6 +49,7 @@ if settings.components == nil then
 	-- Read component files for parameter documentation
 	settings.components = {
 		{"gpu",nil,0,160,50,3},
+		{"modem",nil,1,false},
 		{"eeprom",nil,9,"lua/bios.lua"},
 		{"filesystem",nil,7,"loot/OpenOS",true},
 		{"filesystem",nil,nil,"tmpfs",false},
@@ -313,6 +314,9 @@ function elsa.update(dt)
 		table.remove(kbdcodes,1)
 		table.insert(machine.signals,{kbdcode.type,kbdcode.addr,kbdcode.char or 0,kbdcode.code})
 	end
+	if modem_host then
+		modem_host.processPendingMessages()
+	end
 	if #machine.signals > 0 then
 		signal = machine.signals[1]
 		table.remove(machine.signals, 1)