143 lines
4.1 KiB
Python
143 lines
4.1 KiB
Python
#
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# This file is part of LiteEth.
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#
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# Copyright (c) 2015-2017 Florent Kermarrec <florent@enjoy-digital.fr>
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# SPDX-License-Identifier: BSD-2-Clause
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import math
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import binascii
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from litex.soc.interconnect.stream_sim import *
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from liteeth.common import *
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# Helpers ------------------------------------------------------------------------------------------
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def print_mac(s):
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print_with_prefix(s, "[MAC]")
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preamble = split_bytes(eth_preamble, 8, "little")
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def crc32(l):
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crc = []
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crc_bytes = split_bytes(binascii.crc32(bytes(l)), 4, "little")
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for byte in crc_bytes:
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crc.append(int(byte))
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return crc
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# MAC Packet ---------------------------------------------------------------------------------------
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class MACPacket(Packet):
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def __init__(self, init=[]):
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Packet.__init__(self, init)
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self.preamble_error = False
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self.crc_error = False
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def check_remove_preamble(self):
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if comp(self[0:8], preamble):
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for i in range(8):
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self.pop(0)
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return False
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else:
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return True
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def check_remove_crc(self):
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if comp(self[-4:], crc32(self[:-4])):
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for i in range(4):
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self.pop()
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return False
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else:
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return True
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def decode_remove_header(self):
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header = []
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for byte in self[:mac_header.length]:
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header.append(self.pop(0))
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for k, v in sorted(mac_header.fields.items()):
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setattr(self, k, get_field_data(v, header))
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def decode(self):
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self.preamble_error = self.check_remove_preamble()
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self.crc_error = self.check_remove_crc()
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if self.crc_error or self.preamble_error:
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raise ValueError # XXX handle this properly
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else:
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self.decode_remove_header()
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def encode_header(self):
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header = 0
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for k, v in sorted(mac_header.fields.items()):
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value = merge_bytes(split_bytes(getattr(self, k),
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math.ceil(v.width/8)),
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"little")
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header += (value << v.offset+(v.byte*8))
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for d in split_bytes(header, mac_header.length):
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self.insert(0, d)
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def insert_crc(self):
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for d in crc32(self):
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self.append(d)
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def insert_preamble(self):
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for d in reversed(preamble):
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self.insert(0, d)
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def encode(self):
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self.encode_header()
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self.insert_crc()
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self.insert_preamble()
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def __repr__(self):
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r = "--------\n"
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for k in sorted(mac_header.fields.keys()):
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r += k + " : 0x{:0x}\n".format(getattr(self, k))
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r += "payload: "
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for d in self:
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r += "{:02x}".format(d)
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return r
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# MAC ----------------------------------------------------------------------------------------------
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class MAC(Module):
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def __init__(self, phy, debug=False, loopback=False):
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self.phy = phy
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self.debug = debug
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self.loopback = loopback
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self.rx_packet = MACPacket()
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self.ip_callback = None
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self.arp_callback = None
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phy.set_mac_callback(self.callback)
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def set_ip_callback(self, callback):
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self.ip_callback = callback
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def set_arp_callback(self, callback):
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self.arp_callback = callback
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def send(self, packet):
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if self.debug:
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print_mac(">>>>>>>>")
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print_mac(packet)
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packet.encode()
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self.phy.send(packet)
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def callback(self, datas):
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packet = MACPacket(datas)
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packet.decode()
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if self.debug:
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print_mac("<<<<<<<<")
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print_mac(packet)
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if self.loopback:
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self.send(packet)
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else:
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if packet.ethernet_type == ethernet_type_ip:
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if self.ip_callback is not None:
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self.ip_callback(packet)
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elif packet.ethernet_type == ethernet_type_arp:
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if self.arp_callback is not None:
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self.arp_callback(packet)
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else:
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raise ValueError # XXX handle this properly
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