udp: add model

liteeth/common.py

@@ -77,6 +77,8 @@ udp_header = {
 	"checksum":					HField( 6,  0, 16)
 }
 
+udp_protocol = 0x11
+
 def reverse_bytes(v):
 	n = math.ceil(flen(v)/8)
 	r = []

liteeth/test/Makefile

@@ -7,6 +7,7 @@ model_tb:
 	$(CMD) ./model/mac.py
 	$(CMD) ./model/arp.py
 	$(CMD) ./model/ip.py
+	$(CMD) ./model/udp.py
 
 mac_core_tb:
 	$(CMD) mac_core_tb.py
@@ -18,4 +19,7 @@ arp_tb:
 	$(CMD) arp_tb.py
 
 ip_tb:
-	$(CMD) ip_tb.py	
+	$(CMD) ip_tb.py
+
+udp_tb:
+	$(CMD) udp_tb.py

liteeth/test/model/dumps.py

@@ -62,5 +62,7 @@ udp_infos = {
 	"destination_mac_address"	:	0xd07ab596cd0a,
 	"protocol"					:	0x11,
 	"source_ip_address"			:	0xc0a80165,
-	"destination_ip_address"	:	0xb27b0d78
+	"destination_ip_address"	:	0xb27b0d78,
+	"source_port"				:	0xa63f,
+	"destination_port"			:	0x690f
 }

liteeth/test/model/ip.py

@@ -8,8 +8,6 @@ from liteeth.test.model import mac
 def print_ip(s):
 	print_with_prefix(s, "[IP]")
 
-preamble = split_bytes(eth_preamble, 8)
-
 def carry_around_add(a, b):
     c = a + b
     return (c & 0xffff) + (c >> 16)
@@ -75,9 +73,13 @@ class IP(Module):
 		self.rx_packet = IPPacket()
 		self.table = {}
 		self.request_pending = False
+		self.udp_callback = None
 
 		self.mac.set_ip_callback(self.callback)
 
+	def set_udp_callback(self, callback):
+		self.udp_callback = callback
+
 	def send(self, packet):
 		packet.encode()
 		packet.insert_checksum()
@@ -104,16 +106,22 @@ class IP(Module):
 		if self.loopback:
 			self.send(packet)
 		else:
+			if packet.version != 0x4:
+				raise ValueError
+			if packet.ihl != 0x5:
+				raise ValueError
 			self.process(packet)
 
 	def process(self, packet):
-		pass
+		if packet.protocol == udp_protocol:
+			if self.udp_callback is not None:
+				self.udp_callback(packet)
 
 if __name__ == "__main__":
 	from liteeth.test.model.dumps import *
 	from liteeth.test.model.mac import *
 	errors = 0
-	# ARP request
+	# UDP packet
 	packet = MACPacket(udp)
 	packet.decode_remove_header()
 	#print(packet)

liteeth/test/model/udp.py

@@ -0,0 +1,109 @@
+import math
+
+from liteeth.common import *
+from liteeth.test.common import *
+
+from liteeth.test.model import ip
+
+def print_udp(s):
+	print_with_prefix(s, "[UDP]")
+
+# UDP model
+class UDPPacket(Packet):
+	def __init__(self, init=[]):
+		Packet.__init__(self, init)
+
+	def decode(self):
+		header = []
+		for byte in self[:udp_header_len]:
+			header.append(self.pop(0))
+		for k, v in sorted(udp_header.items()):
+			setattr(self, k, get_field_data(v, header))
+
+	def encode(self):
+		header = 0
+		for k, v in sorted(udp_header.items()):
+			value = merge_bytes(split_bytes(getattr(self, k), math.ceil(v.width/8)), "little")
+			header += (value << v.offset+(v.byte*8))
+		for d in split_bytes(header, udp_header_len):
+			self.insert(0, d)
+
+	def __repr__(self):
+		r = "--------\n"
+		for k in sorted(udp_header.keys()):
+			r += k + " : 0x%x" %getattr(self,k) + "\n"
+		r += "payload: "
+		for d in self:
+			r += "%02x" %d
+		return r
+
+class UDP(Module):
+	def  __init__(self, ip, ip_address, debug=False, loopback=False):
+		self.ip = ip
+		self.debug = debug
+		self.loopback = loopback
+		self.tx_packets = []
+		self.tx_packet = UDPPacket()
+		self.rx_packet = UDPPacket()
+
+		self.ip.set_udp_callback(self.callback)
+
+	def send(self, packet):
+		packet.encode()
+		if self.debug:
+			print_udp(">>>>>>>>")
+			print_udp(packet)
+		ip_packet = ip.IPPacket(packet)
+		ip_packet.version = 0x4
+		ip_packet.ihl = 0x5
+		ip_packet.dscp = 0x0
+		ip_packet.ecn = 0x0
+		ip_packet.total_length = len(packet) + ip_packet.ihl
+		ip_packet.identification = 0
+		ip_packet.flags = 0
+		ip_packet.fragment_offset = 0
+		ip_packet.time_to_live = 0x80
+		ip_packet.source_ip_address = ip_address,
+		ip_packet.destination_ip_address = 0x12345678 # XXX
+		self.ip.send(ip_packet)
+
+	def callback(self, packet):
+		packet = UDPPacket(packet)
+		packet.decode()
+		if self.debug:
+			print_udp("<<<<<<<<")
+			print_udp(packet)
+		if self.loopback:
+			self.send(packet)
+		else:
+			self.process(packet)
+
+	def process(self, packet):
+		pass
+
+if __name__ == "__main__":
+	from liteeth.test.model.dumps import *
+	from liteeth.test.model.mac import *
+	from liteeth.test.model.ip import *
+	errors = 0
+	# UDP packet
+	packet = MACPacket(udp)
+	packet.decode_remove_header()
+	#print(packet)
+	packet = IPPacket(packet)
+	packet.decode()
+	#print(packet)
+	packet = UDPPacket(packet)
+	packet.decode()
+	#print(packet)
+	if packet.length != (len(packet)+udp_header_len):
+		errors += 1
+	errors += verify_packet(packet, udp_infos)
+	packet.encode()
+	packet.decode()
+	#print(packet)
+	if packet.length != (len(packet)+udp_header_len):
+		errors += 1
+	errors += verify_packet(packet, udp_infos)
+
+	print("udp errors " + str(errors))