Restructuring and packet format

FPE/Packet.py

@@ -1,30 +1,91 @@
 import struct
-from Transport import *
+import FPE
 
 class Packet:
+	# Constants
+	MESSAGE      = 0x00;
+	RESOURCE     = 0x01;
+	LINKREQUEST  = 0x02;
+	PROOF        = 0x03;
+	types        = [MESSAGE, RESOURCE, LINKREQUEST, PROOF]
 
-	def __init__(self, destination, data):
-		self.destination = destination
-		self.data   = data
-		self.flags  = 0x00
-		self.header = 0x00
-		self.raw	= None
-		self.sent   = False
-		self.mtu    = 0
+	HEADER_1     = 0x00;	# Normal header format
+	HEADER_2     = 0x01;	# Header format used for link packets in transport
+	HEADER_3     = 0x02;	# Reserved
+	HEADER_4     = 0x03;	# Reserved
+	header_types = [HEADER_1, HEADER_2, HEADER_3, HEADER_4]
+
+	def __init__(self, destination, data, packet_type = MESSAGE, transport_type = None, header_type = HEADER_1, transport_id = None):
+		if destination != None:
+			if transport_type == None:
+				transport_type = FPE.Transport.BROADCAST
+
+			self.header_type    = header_type
+			self.packet_type    = packet_type
+			self.transport_type = transport_type
+
+			self.hops		    = 0;
+			self.destination    = destination
+			self.transport_id   = transport_id
+			self.data 		    = data
+			self.flags	 	    = self.getPackedFlags()
+
+			self.raw    		= None
+			self.packed 		= False
+			self.sent   		= False
+			self.MTU    		= self.destination.MTU
+		else:
+			self.raw    = data
+			self.packed = True
+
+	def getPackedFlags(self):
+		packed_flags = (self.header_type << 6) | (self.transport_type << 4) | (self.destination.type << 2) | self.packet_type
+		return packed_flags
+
+	def pack(self):
+		self.header = ""
+		self.header += struct.pack("!B", self.flags)
+		self.header += struct.pack("!B", self.hops)
+		if self.header_type == Packet.HEADER_2:
+			if t_destination != None:
+				self.header += self.t_destination
+			else:
+				raise IOError("Packet with header type 2 must have a transport ID")
+
+		self.header += self.destination.hash
+		self.ciphertext = self.destination.encrypt(self.data)
+		self.raw = self.header + self.ciphertext
+
+		if len(self.raw) > self.MTU:
+			raise IOError("Packet size of "+str(len(self.raw))+" exceeds MTU of "+str(self.MTU)+" bytes")
+
+		self.packed = True
+
+	def unpack(self):
+		self.flags = ord(self.raw[0])
+		self.hops  = ord(self.raw[1])
+
+		self.header_type      = (self.flags & 0b11000000) >> 6
+		self.transport_type   = (self.flags & 0b00110000) >> 4
+		self.destination_type = (self.flags & 0b00001100) >> 2
+		self.packet_type      = (self.flags & 0b00000011)
+
+		if self.header_type == Packet.HEADER_2:
+			self.transport_id = self.raw[2:12]
+			self.destination_hash = self.raw[12:22]
+			self.data = self.raw[22:]
+		else:
+			self.transport_id = None
+			self.destination_hash = self.raw[2:12]
+			self.data = self.raw[12:]
+
+		self.packed = False
 
 	def send(self):
 		if not self.sent:
-			self.MTU = self.destination.MTU
-			self.header =  struct.pack("!B", self.header ^ self.destination.type ^ self.flags)
-			self.header += self.destination.hash
-			self.ciphertext = self.destination.encrypt(self.data)
-			self.raw = self.header + self.ciphertext
-
-			if len(self.raw) > self.MTU:
-				raise IOError("Packet size of "+str(len(self.raw))+" exceeds MTU of "+str(self.MTU)+" bytes")
-
-			print("Size: "+str(len(self.raw)))
-			Transport.outbound(self.raw)
+			self.pack()
+			FPE.log("Size: "+str(len(self.raw))+" header is "+str(len(self.header))+" payload is "+str(len(self.ciphertext)), FPE.LOG_DEBUG)
+			FPE.Transport.outbound(self.raw)
 			self.sent = True
 		else:
 			raise IOError("Packet was already sent")