1#!/usr/bin/env python3 2# 3# SPDX-License-Identifier: BSD-2-Clause 4# 5# Copyright (c) 2017 Kristof Provost <kp@FreeBSD.org> 6# Copyright (c) 2023 Kajetan Staszkiewicz <vegeta@tuxpowered.net> 7# 8# Redistribution and use in source and binary forms, with or without 9# modification, are permitted provided that the following conditions 10# are met: 11# 1. Redistributions of source code must retain the above copyright 12# notice, this list of conditions and the following disclaimer. 13# 2. Redistributions in binary form must reproduce the above copyright 14# notice, this list of conditions and the following disclaimer in the 15# documentation and/or other materials provided with the distribution. 16# 17# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27# SUCH DAMAGE. 28# 29 30import argparse 31import logging 32logging.getLogger("scapy").setLevel(logging.CRITICAL) 33import math 34import scapy.all as sp 35import sys 36 37from copy import copy 38from sniffer import Sniffer 39 40logging.basicConfig(format='%(message)s') 41LOGGER = logging.getLogger(__name__) 42 43PAYLOAD_MAGIC = bytes.fromhex('42c0ffee') 44 45def build_payload(l): 46 pl = len(PAYLOAD_MAGIC) 47 ret = PAYLOAD_MAGIC * math.floor(l/pl) 48 ret += PAYLOAD_MAGIC[0:(l % pl)] 49 return ret 50 51 52def prepare_ipv6(dst_address, send_params): 53 src_address = send_params.get('src_address') 54 hlim = send_params.get('hlim') 55 tc = send_params.get('tc') 56 ip6 = sp.IPv6(dst=dst_address) 57 if src_address: 58 ip6.src = src_address 59 if hlim: 60 ip6.hlim = hlim 61 if tc: 62 ip6.tc = tc 63 return ip6 64 65 66def prepare_ipv4(dst_address, send_params): 67 src_address = send_params.get('src_address') 68 flags = send_params.get('flags') 69 tos = send_params.get('tc') 70 ttl = send_params.get('hlim') 71 ip = sp.IP(dst=dst_address) 72 if src_address: 73 ip.src = src_address 74 if flags: 75 ip.flags = flags 76 if tos: 77 ip.tos = tos 78 if ttl: 79 ip.ttl = ttl 80 return ip 81 82 83def send_icmp_ping(dst_address, sendif, send_params): 84 send_length = send_params['length'] 85 ether = sp.Ether() 86 if ':' in dst_address: 87 ip6 = prepare_ipv6(dst_address, send_params) 88 icmp = sp.ICMPv6EchoRequest(data=sp.raw(build_payload(send_length))) 89 req = ether / ip6 / icmp 90 else: 91 ip = prepare_ipv4(dst_address, send_params) 92 icmp = sp.ICMP(type='echo-request') 93 raw = sp.raw(build_payload(send_length)) 94 req = ether / ip / icmp / raw 95 sp.sendp(req, sendif, verbose=False) 96 97 98def send_tcp_syn(dst_address, sendif, send_params): 99 tcpopt_unaligned = send_params.get('tcpopt_unaligned') 100 seq = send_params.get('seq') 101 mss = send_params.get('mss') 102 ether = sp.Ether() 103 opts=[('Timestamp', (1, 1)), ('MSS', mss if mss else 1280)] 104 if tcpopt_unaligned: 105 opts = [('NOP', 0 )] + opts 106 if ':' in dst_address: 107 ip = prepare_ipv6(dst_address, send_params) 108 else: 109 ip = prepare_ipv4(dst_address, send_params) 110 tcp = sp.TCP(dport=666, flags='S', options=opts, seq=seq) 111 req = ether / ip / tcp 112 sp.sendp(req, iface=sendif, verbose=False) 113 114 115def send_ping(dst_address, sendif, ping_type, send_params): 116 if ping_type == 'icmp': 117 send_icmp_ping(dst_address, sendif, send_params) 118 elif ping_type == 'tcpsyn': 119 send_tcp_syn(dst_address, sendif, send_params) 120 else: 121 raise Exception('Unspported ping type') 122 123 124def check_ipv4(expect_params, packet): 125 src_address = expect_params.get('src_address') 126 dst_address = expect_params.get('dst_address') 127 flags = expect_params.get('flags') 128 tos = expect_params.get('tc') 129 ttl = expect_params.get('hlim') 130 ip = packet.getlayer(sp.IP) 131 if not ip: 132 LOGGER.debug('Packet is not IPv4!') 133 return False 134 if src_address and ip.src != src_address: 135 LOGGER.debug('Source IPv4 address does not match!') 136 return False 137 if dst_address and ip.dst != dst_address: 138 LOGGER.debug('Destination IPv4 address does not match!') 139 return False 140 if flags and ip.flags != flags: 141 LOGGER.debug(f'Wrong IP flags value {ip.flags}, expected {flags}') 142 return False 143 if tos and ip.tos != tos: 144 LOGGER.debug(f'Wrong ToS value {ip.tos}, expected {tos}') 145 return False 146 if ttl and ip.ttl != ttl: 147 LOGGER.debug(f'Wrong TTL value {ip.ttl}, expected {ttl}') 148 return False 149 return True 150 151 152def check_ipv6(expect_params, packet): 153 src_address = expect_params.get('src_address') 154 dst_address = expect_params.get('dst_address') 155 flags = expect_params.get('flags') 156 hlim = expect_params.get('hlim') 157 tc = expect_params.get('tc') 158 ip6 = packet.getlayer(sp.IPv6) 159 if not ip6: 160 LOGGER.debug('Packet is not IPv6!') 161 return False 162 if src_address and ip6.src != src_address: 163 LOGGER.debug('Source IPv6 address does not match!') 164 return False 165 if dst_address and ip6.dst != dst_address: 166 LOGGER.debug('Destination IPv6 address does not match!') 167 return False 168 # IPv6 has no IP-level checksum. 169 if flags: 170 raise Exception("There's no fragmentation flags in IPv6") 171 if hlim and ip6.hlim != hlim: 172 LOGGER.debug(f'Wrong Hop Limit value {ip6.hlim}, expected {hlim}') 173 return False 174 if tc and ip6.tc != tc: 175 LOGGER.debug(f'Wrong TC value {ip6.tc}, expected {tc}') 176 return False 177 return True 178 179def check_ping_4(expect_params, packet): 180 expect_length = expect_params['length'] 181 if not check_ipv4(expect_params, packet): 182 return False 183 icmp = packet.getlayer(sp.ICMP) 184 if not icmp: 185 LOGGER.debug('Packet is not IPv4 ICMP!') 186 return False 187 raw = packet.getlayer(sp.Raw) 188 if not raw: 189 LOGGER.debug('Packet contains no payload!') 190 return False 191 if raw.load != build_payload(expect_length): 192 LOGGER.debug('Payload magic does not match!') 193 return False 194 return True 195 196def check_ping_request_4(expect_params, packet): 197 if not check_ping_4(expect_params, packet): 198 return False 199 icmp = packet.getlayer(sp.ICMP) 200 if sp.icmptypes[icmp.type] != 'echo-request': 201 LOGGER.debug('Packet is not IPv4 ICMP Echo Request!') 202 return False 203 return True 204 205 206def check_ping_reply_4(expect_params, packet): 207 if not check_ping_4(expect_params, packet): 208 return False 209 icmp = packet.getlayer(sp.ICMP) 210 if sp.icmptypes[icmp.type] != 'echo-reply': 211 LOGGER.debug('Packet is not IPv4 ICMP Echo Reply!') 212 return False 213 return True 214 215 216def check_ping_request_6(expect_params, packet): 217 expect_length = expect_params['length'] 218 if not check_ipv6(expect_params, packet): 219 return False 220 icmp = packet.getlayer(sp.ICMPv6EchoRequest) 221 if not icmp: 222 LOGGER.debug('Packet is not IPv6 ICMP Echo Request!') 223 return False 224 if icmp.data != build_payload(expect_length): 225 LOGGER.debug('Payload magic does not match!') 226 return False 227 return True 228 229 230def check_ping_reply_6(expect_params, packet): 231 expect_length = expect_params['length'] 232 if not check_ipv6(expect_params, packet): 233 return False 234 icmp = packet.getlayer(sp.ICMPv6EchoReply) 235 if not icmp: 236 LOGGER.debug('Packet is not IPv6 ICMP Echo Reply!') 237 return False 238 if icmp.data != build_payload(expect_length): 239 LOGGER.debug('Payload magic does not match!') 240 return False 241 return True 242 243 244def check_ping_request(expect_params, packet): 245 src_address = expect_params.get('src_address') 246 dst_address = expect_params.get('dst_address') 247 if not (src_address or dst_address): 248 raise Exception('Source or destination address must be given to match the ping request!') 249 if ( 250 (src_address and ':' in src_address) or 251 (dst_address and ':' in dst_address) 252 ): 253 return check_ping_request_6(expect_params, packet) 254 else: 255 return check_ping_request_4(expect_params, packet) 256 257def check_ping_reply(expect_params, packet): 258 src_address = expect_params.get('src_address') 259 dst_address = expect_params.get('dst_address') 260 if not (src_address or dst_address): 261 raise Exception('Source or destination address must be given to match the ping reply!') 262 if ( 263 (src_address and ':' in src_address) or 264 (dst_address and ':' in dst_address) 265 ): 266 return check_ping_reply_6(expect_params, packet) 267 else: 268 return check_ping_reply_4(expect_params, packet) 269 270def check_tcp(expect_params, packet): 271 tcp_flags = expect_params.get('tcp_flags') 272 mss = expect_params.get('mss') 273 seq = expect_params.get('seq') 274 tcp = packet.getlayer(sp.TCP) 275 if not tcp: 276 LOGGER.debug('Packet is not TCP!') 277 return False 278 chksum = tcp.chksum 279 tcp.chksum = None 280 newpacket = sp.Ether(sp.raw(packet[sp.Ether])) 281 new_chksum = newpacket[sp.TCP].chksum 282 if chksum != new_chksum: 283 LOGGER.debug(f'Wrong TCP checksum {chksum}, expected {new_chksum}!') 284 return False 285 if tcp_flags and tcp.flags != tcp_flags: 286 LOGGER.debug(f'Wrong TCP flags {tcp.flags}, expected {tcp_flags}!') 287 return False 288 if seq: 289 if tcp_flags == 'S': 290 tcp_seq = tcp.seq 291 elif tcp_flags == 'SA': 292 tcp_seq = tcp.ack - 1 293 if seq != tcp_seq: 294 LOGGER.debug(f'Wrong TCP Sequence Number {tcp_seq}, expected {seq}') 295 return False 296 if mss: 297 for option in tcp.options: 298 if option[0] == 'MSS': 299 if option[1] != mss: 300 LOGGER.debug(f'Wrong TCP MSS {option[1]}, expected {mss}') 301 return False 302 return True 303 304 305def check_tcp_syn_request_4(expect_params, packet): 306 if not check_ipv4(expect_params, packet): 307 return False 308 if not check_tcp(expect_params | {'tcp_flags': 'S'}, packet): 309 return False 310 return True 311 312 313def check_tcp_syn_reply_4(expect_params, packet): 314 if not check_ipv4(expect_params, packet): 315 return False 316 if not check_tcp(expect_params | {'tcp_flags': 'SA'}, packet): 317 return False 318 return True 319 320 321def check_tcp_syn_request_6(expect_params, packet): 322 if not check_ipv6(expect_params, packet): 323 return False 324 if not check_tcp(expect_params | {'tcp_flags': 'S'}, packet): 325 return False 326 return True 327 328 329def check_tcp_syn_reply_6(expect_params, packet): 330 if not check_ipv6(expect_params, packet): 331 return False 332 if not check_tcp(expect_params | {'tcp_flags': 'SA'}, packet): 333 return False 334 return True 335 336 337def check_tcp_syn_request(expect_params, packet): 338 src_address = expect_params.get('src_address') 339 dst_address = expect_params.get('dst_address') 340 if not (src_address or dst_address): 341 raise Exception('Source or destination address must be given to match the tcp syn request!') 342 if ( 343 (src_address and ':' in src_address) or 344 (dst_address and ':' in dst_address) 345 ): 346 return check_tcp_syn_request_6(expect_params, packet) 347 else: 348 return check_tcp_syn_request_4(expect_params, packet) 349 350 351def check_tcp_syn_reply(expect_params, packet): 352 src_address = expect_params.get('src_address') 353 dst_address = expect_params.get('dst_address') 354 if not (src_address or dst_address): 355 raise Exception('Source or destination address must be given to match the tcp syn reply!') 356 if ( 357 (src_address and ':' in src_address) or 358 (dst_address and ':' in dst_address) 359 ): 360 return check_tcp_syn_reply_6(expect_params, packet) 361 else: 362 return check_tcp_syn_reply_4(expect_params, packet) 363 364 365def setup_sniffer(recvif, ping_type, sniff_type, expect_params): 366 if ping_type == 'icmp' and sniff_type == 'request': 367 checkfn = check_ping_request 368 elif ping_type == 'icmp' and sniff_type == 'reply': 369 checkfn = check_ping_reply 370 elif ping_type == 'tcpsyn' and sniff_type == 'request': 371 checkfn = check_tcp_syn_request 372 elif ping_type == 'tcpsyn' and sniff_type == 'reply': 373 checkfn = check_tcp_syn_reply 374 else: 375 raise Exception('Unspported ping or sniff type') 376 377 return Sniffer(expect_params, checkfn, recvif) 378 379 380def parse_args(): 381 parser = argparse.ArgumentParser("pft_ping.py", 382 description="Ping test tool") 383 384 # Parameters of sent ping request 385 parser.add_argument('--sendif', nargs=1, 386 required=True, 387 help='The interface through which the packet(s) will be sent') 388 parser.add_argument('--to', nargs=1, 389 required=True, 390 help='The destination IP address for the ping request') 391 parser.add_argument('--ping-type', 392 choices=('icmp', 'tcpsyn'), 393 help='Type of ping: ICMP (default) or TCP SYN', 394 default='icmp') 395 parser.add_argument('--fromaddr', nargs=1, 396 help='The source IP address for the ping request') 397 398 # Where to look for packets to analyze. 399 # The '+' format is ugly as it mixes positional with optional syntax. 400 # But we have no positional parameters so I guess it's fine to use it. 401 parser.add_argument('--recvif', nargs='+', 402 help='The interfaces on which to expect the ping request') 403 parser.add_argument('--replyif', nargs='+', 404 help='The interfaces which to expect the ping response') 405 406 # Packet settings 407 parser_send = parser.add_argument_group('Values set in transmitted packets') 408 parser_send.add_argument('--send-flags', nargs=1, type=str, 409 help='IPv4 fragmentation flags') 410 parser_send.add_argument('--send-hlim', nargs=1, type=int, 411 help='IPv6 Hop Limit or IPv4 Time To Live') 412 parser_send.add_argument('--send-mss', nargs=1, type=int, 413 help='TCP Maximum Segment Size') 414 parser_send.add_argument('--send-seq', nargs=1, type=int, 415 help='TCP sequence number') 416 parser_send.add_argument('--send-length', nargs=1, type=int, 417 default=[len(PAYLOAD_MAGIC)], help='ICMP Echo Request payload size') 418 parser_send.add_argument('--send-tc', nargs=1, type=int, 419 help='IPv6 Traffic Class or IPv4 DiffServ / ToS') 420 parser_send.add_argument('--send-tcpopt-unaligned', action='store_true', 421 help='Include unaligned TCP options') 422 423 # Expectations 424 parser_expect = parser.add_argument_group('Values expected in sniffed packets') 425 parser_expect.add_argument('--expect-flags', nargs=1, type=str, 426 help='IPv4 fragmentation flags') 427 parser_expect.add_argument('--expect-hlim', nargs=1, type=int, 428 help='IPv6 Hop Limit or IPv4 Time To Live') 429 parser_expect.add_argument('--expect-mss', nargs=1, type=int, 430 help='TCP Maximum Segment Size') 431 parser_send.add_argument('--expect-seq', nargs=1, type=int, 432 help='TCP sequence number') 433 parser_expect.add_argument('--expect-tc', nargs=1, type=int, 434 help='IPv6 Traffic Class or IPv4 DiffServ / ToS') 435 436 parser.add_argument('-v', '--verbose', action='store_true', 437 help=('Enable verbose logging. Apart of potentially useful information ' 438 'you might see warnings from parsing packets like NDP or other ' 439 'packets not related to the test being run. Use only when ' 440 'developing because real tests expect empty stderr and stdout.')) 441 442 return parser.parse_args() 443 444 445def main(): 446 args = parse_args() 447 448 if args.verbose: 449 LOGGER.setLevel(logging.DEBUG) 450 451 # Dig out real values of program arguments 452 send_if = args.sendif[0] 453 reply_ifs = args.replyif 454 recv_ifs = args.recvif 455 dst_address = args.to[0] 456 457 # Standardize parameters which have nargs=1. 458 send_params = {} 459 expect_params = {} 460 for param_name in ('flags', 'hlim', 'length', 'mss', 'seq', 'tc'): 461 param_arg = vars(args).get(f'send_{param_name}') 462 send_params[param_name] = param_arg[0] if param_arg else None 463 param_arg = vars(args).get(f'expect_{param_name}') 464 expect_params[param_name] = param_arg[0] if param_arg else None 465 466 expect_params['length'] = send_params['length'] 467 send_params['tcpopt_unaligned'] = args.send_tcpopt_unaligned 468 send_params['src_address'] = args.fromaddr[0] if args.fromaddr else None 469 470 # We may not have a default route. Tell scapy where to start looking for routes 471 sp.conf.iface6 = send_if 472 473 # Configuration sanity checking. 474 if not (reply_ifs or recv_ifs): 475 raise Exception('With no reply or recv interface specified no traffic ' 476 'can be sniffed and verified!' 477 ) 478 479 sniffers = [] 480 481 if recv_ifs: 482 sniffer_params = copy(expect_params) 483 sniffer_params['src_address'] = None 484 sniffer_params['dst_address'] = dst_address 485 for iface in recv_ifs: 486 LOGGER.debug(f'Installing receive sniffer on {iface}') 487 sniffers.append( 488 setup_sniffer(iface, args.ping_type, 'request', sniffer_params, 489 )) 490 491 if reply_ifs: 492 sniffer_params = copy(expect_params) 493 sniffer_params['src_address'] = dst_address 494 sniffer_params['dst_address'] = None 495 for iface in reply_ifs: 496 LOGGER.debug(f'Installing reply sniffer on {iface}') 497 sniffers.append( 498 setup_sniffer(iface, args.ping_type, 'reply', sniffer_params, 499 )) 500 501 LOGGER.debug(f'Installed {len(sniffers)} sniffers') 502 503 send_ping(dst_address, send_if, args.ping_type, send_params) 504 505 err = 0 506 sniffer_num = 0 507 for sniffer in sniffers: 508 sniffer.join() 509 if sniffer.correctPackets == 1: 510 LOGGER.debug(f'Expected ping has been sniffed on {sniffer._recvif}.') 511 else: 512 # Set a bit in err for each failed sniffer. 513 err |= 1<<sniffer_num 514 if sniffer.correctPackets > 1: 515 LOGGER.debug(f'Duplicated ping has been sniffed on {sniffer._recvif}!') 516 else: 517 LOGGER.debug(f'Expected ping has not been sniffed on {sniffer._recvif}!') 518 sniffer_num += 1 519 520 return err 521 522 523if __name__ == '__main__': 524 sys.exit(main()) 525