liteeth/test/model/arp.py

159 lines
4.7 KiB
Python

import math
from litex.soc.interconnect.stream_sim import *
from liteeth.common import *
from test.model import mac
def print_arp(s):
print_with_prefix(s, "[ARP]")
preamble = split_bytes(eth_preamble, 8)
# ARP model
class ARPPacket(Packet):
def __init__(self, init=[]):
Packet.__init__(self, init)
def decode(self):
header = []
for byte in self[:arp_header.length]:
header.append(self.pop(0))
for k, v in sorted(arp_header.fields.items()):
setattr(self, k, get_field_data(v, header))
def encode(self):
header = 0
for k, v in sorted(arp_header.fields.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, arp_header.length):
self.insert(0, d)
def __repr__(self):
r = "--------\n"
for k in sorted(arp_header.fields.keys()):
r += k + " : 0x{:0x}\n".format(getattr(self, k))
r += "payload: "
for d in self:
r += "{:02x}".format(d)
return r
class ARP(Module):
def __init__(self, mac, mac_address, ip_address, debug=False):
self.mac = mac
self.mac_address = mac_address
self.ip_address = ip_address
self.debug = debug
self.tx_packets = []
self.tx_packet = ARPPacket()
self.rx_packet = ARPPacket()
self.table = {}
self.request_pending = False
self.mac.set_arp_callback(self.callback)
def send(self, packet):
packet.encode()
if self.debug:
print_arp(">>>>>>>>")
print_arp(packet)
mac_packet = mac.MACPacket(packet)
mac_packet.target_mac = packet.target_mac
mac_packet.sender_mac = packet.sender_mac
mac_packet.ethernet_type = ethernet_type_arp
self.mac.send(mac_packet)
def callback(self, packet):
packet = ARPPacket(packet)
packet.decode()
if self.debug:
print_arp("<<<<<<<<")
print_arp(packet)
self.process(packet)
def process(self, packet):
if len(packet) != eth_min_len-arp_header.length:
raise ValueError
if packet.hwtype != arp_hwtype_ethernet:
raise ValueError
if packet.proto != arp_proto_ip:
raise ValueError
if packet.hwsize != 6:
raise ValueError
if packet.protosize != 4:
raise ValueError
if packet.opcode == arp_opcode_request:
self.process_request(packet)
elif packet.opcode == arp_opcode_reply:
self.process_reply(packet)
def process_request(self, request):
if request.target_ip == self.ip_address:
reply = ARPPacket([0]*(eth_min_len-arp_header.length))
reply.hwtype = arp_hwtype_ethernet
reply.proto = arp_proto_ip
reply.opcode = arp_opcode_reply
reply.hwsize = 6
reply.protosize = 4
reply.sender_mac = self.mac_address
reply.sender_ip = self.ip_address
reply.target_mac = request.sender_mac
reply.target_ip = request.sender_ip
self.send(reply)
def process_reply(self, reply):
self.table[reply.sender_ip] = reply.sender_mac
def request(self, ip_address):
request = ARPPacket([0]*(eth_min_len-arp_header.length))
request.hwtype = arp_hwtype_ethernet
request.proto = arp_proto_ip
request.opcode = arp_opcode_request
request.hwsize = 6
request.protosize = 4
request.sender_mac = self.mac_address
request.sender_ip = self.ip_address
request.target_mac = 0xffffffffffff
request.target_ip = ip_address
if __name__ == "__main__":
from model.dumps import *
from model.mac import *
errors = 0
# ARP request
packet = MACPacket(arp_request)
packet.decode_remove_header()
packet = ARPPacket(packet)
# check decoding
packet.decode()
# print(packet)
errors += verify_packet(packet, arp_request_infos)
# check encoding
packet.encode()
packet.decode()
# print(packet)
errors += verify_packet(packet, arp_request_infos)
# ARP Reply
packet = MACPacket(arp_reply)
packet.decode_remove_header()
packet = ARPPacket(packet)
# check decoding
packet.decode()
# print(packet)
errors += verify_packet(packet, arp_reply_infos)
# check encoding
packet.encode()
packet.decode()
# print(packet)
errors += verify_packet(packet, arp_reply_infos)
print("arp errors " + str(errors))