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rtbrick-bngblaster/code/ldpupdate
2024-02-23 21:12:51 +01:00

247 lines
7.9 KiB
Python

#!/usr/bin/env python3
"""
LDP RAW Update Generator
Christian Giese, December 2022
Copyright (C) 2020-2024, RtBrick, Inc.
SPDX-License-Identifier: BSD-3-Clause
"""
from socket import inet_aton
import argparse
import ipaddress
import logging
import struct
import sys
try:
from scapy.all import *
log_runtime.setLevel(logging.ERROR)
from scapy.contrib.ldp import *
log_runtime.setLevel(logging.INFO)
except:
print("Failed to load scapy!")
exit(1)
# ==============================================================
# PATCHES
# ==============================================================
# Monkey patch scapy LDP FecTLVField
def _monkey_i2m_fec(self, pkt, x):
if not x:
return b""
if isinstance(x, bytes):
return x
s = b"\x01\x00"
tmp_len = 0
fec = b""
for o in x:
a = ipaddress.ip_address(o[0])
if a.version == 4:
fec += b"\x02\x00\x01"
# mask length
fec += struct.pack("!B", o[1])
# Prefix
l = o[1]+7>>3
p = ipaddress.v4_int_to_packed(int(a))
fec += p[:l]
tmp_len += 4+l
else:
fec += b"\x02\x00\x02"
# mask length
fec += struct.pack("!B", o[1])
# Prefix
l = o[1]+7>>3
p = ipaddress.v6_int_to_packed(int(a))
fec += p[:l]
tmp_len += 4+l
s += struct.pack("!H", tmp_len)
s += fec
return s
scapy.contrib.ldp.FecTLVField.i2m = _monkey_i2m_fec
def _monkey_i2m_address(self, pkt, x):
if not x:
return b""
if isinstance(x, bytes):
return x
a = ipaddress.ip_address(x[0])
if a.version == 4:
tmp_len = 2 + len(x) * 4
s = b"\x01\x01" + struct.pack("!H", tmp_len) + b"\x00\x01"
for o in x:
s += inet_aton(o)
else:
tmp_len = 2 + len(x) * 16
s = b"\x01\x01" + struct.pack("!H", tmp_len) + b"\x00\x02"
for o in x:
a = ipaddress.ip_address(o)
s += ipaddress.v6_int_to_packed(int(a))
return s
scapy.contrib.ldp.AddressTLVField.i2m = _monkey_i2m_address
# ==============================================================
# DEFINITIONS
# ==============================================================
DESCRIPTION = """
The LDP RAW update generator is a simple
tool to generate LDP RAW update streams
for use with the BNG Blaster.
"""
LOG_LEVELS = {
'warning': logging.WARNING,
'info': logging.INFO,
'debug': logging.DEBUG
}
MPLS_LABEL_MIN = 1
MPLS_LABEL_MAX = 1048575
# ==============================================================
# FUNCTIONS
# ==============================================================
def init_logging(log_level: int) -> logging.Logger:
"""Init logging."""
level = LOG_LEVELS[log_level]
log = logging.getLogger()
log.setLevel(level)
handler = logging.StreamHandler(sys.stdout)
handler.setLevel(level)
formatter = logging.Formatter('[%(asctime)s][%(levelname)-7s] %(message)s')
formatter.datefmt = '%Y-%m-%d %H:%M:%S'
handler.setFormatter(formatter)
log.addHandler(handler)
return log
def label_type(label: int) -> int:
"""Argument parser type for MPLS labels."""
label = int(label)
if label < MPLS_LABEL_MIN or label > MPLS_LABEL_MAX:
raise argparse.ArgumentTypeError("MPLS label out of range %s - %s" % (MPLS_LABEL_MIN, MPLS_LABEL_MAX))
return label
# ==============================================================
# MAIN
# ==============================================================
def main():
# parse arguments
parser = argparse.ArgumentParser(description=DESCRIPTION)
parser.add_argument('-l', '--lsr-id', metavar='ADDRESS', type=ipaddress.ip_address, required=True, help='LSR identifier')
parser.add_argument('-i', '--message-id-base', metavar='N', type=int, default=1000, help='message identifier base')
parser.add_argument('-w', '--withdraw', action="store_true", help='withdraw')
parser.add_argument('-a', '--address-base', metavar='ADDRESS', type=ipaddress.ip_address, help='address message base')
parser.add_argument('-A', '--address-num', metavar='N', type=int, default=0, help='address message count')
parser.add_argument('-p', '--prefix-base', metavar='PREFIX', type=ipaddress.ip_network, help='label mapping base prefix')
parser.add_argument('-P', '--prefix-num', metavar='N', type=int, default=0, help='label mapping prefix count')
parser.add_argument('-m', '--label-base', metavar='LABEL', type=label_type, default=10000, help='label base')
parser.add_argument('-M', '--label-num', metavar='N', type=int, default=1, help='label count')
parser.add_argument('-f', '--file', type=str, default="out.ldp", help='output file')
parser.add_argument('--append', action="store_true", help="append to file if exist")
parser.add_argument('--pcap', metavar='FILE', type=str, help="write LDP updates to PCAP file")
parser.add_argument('--log-level', type=str, default='info', choices=LOG_LEVELS.keys(), help='logging Level')
args = parser.parse_args()
# init logging
log = init_logging(args.log_level)
# Here we will store packets for optional PCAP output
pcap_packets = []
def pcap(message):
if args.pcap:
pcap_packets.append(Ether()/IP()/TCP(sport=len(pcap_packets)+10000, dport=646, seq=1, flags='PA')/message)
addresses = []
if args.address_base and args.address_num > 0:
log.info("init %s addresses" % (args.address_num))
address = args.address_base
for _ in range(args.address_num):
log.debug("add address %s" % (address))
addresses.append(address)
address += 1
prefixes = []
if args.prefix_base and args.prefix_num > 0:
log.info("init %s labeled prefixes" % (args.prefix_num))
prefix = args.prefix_base
label_index = 0
label = args.label_base
for _ in range(args.prefix_num):
log.debug("add prefix %s via label %s" % (prefix, label))
prefixes.append((prefix, label))
label_index += 1
if label_index < args.label_num:
label = args.label_base + label_index
if label > MPLS_LABEL_MAX:
label_index = 0
label = args.label_base
else:
label_index = 0
label = args.label_base
prefix = ipaddress.ip_network("%s/%s" % (prefix.broadcast_address+1, prefix.prefixlen))
if len(addresses) + len(prefixes) == 0:
exit(0)
if args.append:
log.info("open file %s (append)" % args.file)
file_flags = "ab"
else:
log.info("open file %s (replace)" % args.file)
file_flags = "wb"
with open(args.file, file_flags) as f:
mid = args.message_id_base
for address in addresses:
if args.withdraw:
pdu = LDP(id=args.lsr_id)/LDPAddressWM(id=mid, address=[str(address)])
else:
pdu = LDP(id=args.lsr_id)/LDPAddress(id=mid, address=[str(address)])
mid+=1
pdu_bin = bytearray(pdu.build())
pcap(pdu)
f.write(pdu_bin)
for prefix, label in prefixes:
if args.withdraw:
pdu = LDP(id=args.lsr_id)/LDPLabelWM(id=mid, fec=[(str(prefix.network_address),int(prefix.prefixlen))],label=label)
else:
pdu = LDP(id=args.lsr_id)/LDPLabelMM(id=mid, fec=[(str(prefix.network_address),int(prefix.prefixlen))],label=label)
mid+=1
pdu_bin = bytearray(pdu.build())
pcap(pdu)
f.write(pdu_bin)
if args.pcap:
log.info("create PCAP file %s" % args.pcap)
try:
wrpcap(args.pcap, pcap_packets)
except Exception as e:
log.error("failed to create PCAP file")
log.debug(e)
log.info("finished")
if __name__ == "__main__":
main()