1 """Utility for playing generated BGP data to ODL.
3 It needs to be run with sudo-able user when you want to use ports below 1024
4 as --myip. This utility is used to avoid excessive waiting times which EXABGP
5 exhibits when used with huge router tables and also avoid the memory cost of
6 EXABGP in this type of scenario."""
8 # Copyright (c) 2015 Cisco Systems, Inc. and others. All rights reserved.
10 # This program and the accompanying materials are made available under the
11 # terms of the Eclipse Public License v1.0 which accompanies this distribution,
12 # and is available at http://www.eclipse.org/legal/epl-v10.html
14 __author__ = "Vratko Polak"
15 __copyright__ = "Copyright(c) 2015, Cisco Systems, Inc."
16 __license__ = "Eclipse Public License v1.0"
17 __email__ = "vrpolak@cisco.com"
29 def parse_arguments():
30 """Use argparse to get arguments,
35 parser = argparse.ArgumentParser()
36 # TODO: Should we use --argument-names-with-spaces?
37 str_help = "Autonomous System number use in the stream."
38 parser.add_argument("--asnumber", default=64496, type=int, help=str_help)
39 # FIXME: We are acting as iBGP peer,
40 # we should mirror AS number from peer's open message.
41 str_help = "Amount of IP prefixes to generate. (negative means ""infinite"")."
42 parser.add_argument("--amount", default="1", type=int, help=str_help)
43 str_help = "Maximum number of IP prefixes to be announced in one iteration"
44 parser.add_argument("--insert", default="1", type=int, help=str_help)
45 str_help = "Maximum number of IP prefixes to be withdrawn in one iteration"
46 parser.add_argument("--withdraw", default="0", type=int, help=str_help)
47 str_help = "The number of prefixes to process without withdrawals"
48 parser.add_argument("--prefill", default="0", type=int, help=str_help)
49 str_help = "Single or two separate UPDATEs for NLRI and WITHDRAWN lists sent"
50 parser.add_argument("--updates", choices=["single", "mixed"],
51 default=["mixed"], help=str_help)
52 str_help = "Base prefix IP address for prefix generation"
53 parser.add_argument("--firstprefix", default="8.0.1.0",
54 type=ipaddr.IPv4Address, help=str_help)
55 str_help = "The prefix length."
56 parser.add_argument("--prefixlen", default=28, type=int, help=str_help)
57 str_help = "Listen for connection, instead of initiating it."
58 parser.add_argument("--listen", action="store_true", help=str_help)
59 str_help = ("Numeric IP Address to bind to and derive BGP ID from." +
60 "Default value only suitable for listening.")
61 parser.add_argument("--myip", default="0.0.0.0",
62 type=ipaddr.IPv4Address, help=str_help)
63 str_help = ("TCP port to bind to when listening or initiating connection." +
64 "Default only suitable for initiating.")
65 parser.add_argument("--myport", default="0", type=int, help=str_help)
66 str_help = "The IP of the next hop to be placed into the update messages."
67 parser.add_argument("--nexthop", default="192.0.2.1",
68 type=ipaddr.IPv4Address, dest="nexthop", help=str_help)
69 str_help = ("Numeric IP Address to try to connect to." +
70 "Currently no effect in listening mode.")
71 parser.add_argument("--peerip", default="127.0.0.2",
72 type=ipaddr.IPv4Address, help=str_help)
73 str_help = "TCP port to try to connect to. No effect in listening mode."
74 parser.add_argument("--peerport", default="179", type=int, help=str_help)
75 str_help = "Local hold time."
76 parser.add_argument("--holdtime", default="180", type=int, help=str_help)
77 str_help = "Log level (--error, --warning, --info, --debug)"
78 parser.add_argument("--error", dest="loglevel", action="store_const",
79 const=logging.ERROR, default=logging.ERROR,
81 parser.add_argument("--warning", dest="loglevel", action="store_const",
82 const=logging.WARNING, default=logging.ERROR,
84 parser.add_argument("--info", dest="loglevel", action="store_const",
85 const=logging.INFO, default=logging.ERROR,
87 parser.add_argument("--debug", dest="loglevel", action="store_const",
88 const=logging.DEBUG, default=logging.ERROR,
90 str_help = "Trailing part of the csv result files for plotting purposes"
91 parser.add_argument("--results", default="bgp.csv", type=str, help=str_help)
92 str_help = "Minimum number of updates to reach to include result into csv."
93 parser.add_argument("--threshold", default="1000", type=int, help=str_help)
94 arguments = parser.parse_args()
95 # TODO: Are sanity checks (such as asnumber>=0) required?
99 def establish_connection(arguments):
100 """Establish connection to BGP peer.
103 :arguments: following command-line argumets are used
104 - arguments.myip: local IP address
105 - arguments.myport: local port
106 - arguments.peerip: remote IP address
107 - arguments.peerport: remote port
112 logging.info("Connecting in the listening mode.")
113 logging.debug("Local IP address: " + str(arguments.myip))
114 logging.debug("Local port: " + str(arguments.myport))
115 listening_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
116 listening_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
117 # bind need single tuple as argument
118 listening_socket.bind((str(arguments.myip), arguments.myport))
119 listening_socket.listen(1)
120 bgp_socket, _ = listening_socket.accept()
121 # TODO: Verify client IP is cotroller IP.
122 listening_socket.close()
124 logging.info("Connecting in the talking mode.")
125 logging.debug("Local IP address: " + str(arguments.myip))
126 logging.debug("Local port: " + str(arguments.myport))
127 logging.debug("Remote IP address: " + str(arguments.peerip))
128 logging.debug("Remote port: " + str(arguments.peerport))
129 talking_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
130 talking_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
131 # bind to force specified address and port
132 talking_socket.bind((str(arguments.myip), arguments.myport))
133 # socket does not spead ipaddr, hence str()
134 talking_socket.connect((str(arguments.peerip), arguments.peerport))
135 bgp_socket = talking_socket
136 logging.info("Connected to ODL.")
140 def get_short_int_from_message(message, offset=16):
141 """Extract 2-bytes number from provided message.
144 :message: given message
145 :offset: offset of the short_int inside the message
147 :return: required short_inf value.
149 default offset value is the BGP message size offset.
151 high_byte_int = ord(message[offset])
152 low_byte_int = ord(message[offset + 1])
153 short_int = high_byte_int * 256 + low_byte_int
157 class MessageError(ValueError):
158 """Value error with logging optimized for hexlified messages."""
160 def __init__(self, text, message, *args):
163 Store and call super init for textual comment,
164 store raw message which caused it.
168 super(MessageError, self).__init__(text, message, *args)
171 """Generate human readable error message.
174 :return: human readable message as string
176 Use a placeholder string if the message is to be empty.
178 message = binascii.hexlify(self.msg)
180 message = "(empty message)"
181 return self.text + ": " + message
184 def read_open_message(bgp_socket):
185 """Receive peer's OPEN message
188 :bgp_socket: the socket to be read
190 :return: received OPEN message.
192 Performs just basic incomming message checks
194 msg_in = bgp_socket.recv(65535) # TODO: Is smaller buffer size safe?
195 # TODO: Can the incoming open message be split in more than one packet?
198 # 37 is minimal length of open message with 4-byte AS number.
199 logging.error("Got something else than open with 4-byte AS number: " +
200 binascii.hexlify(msg_in))
201 raise MessageError("Got something else than open with 4-byte AS number",
203 # TODO: We could check BGP marker, but it is defined only later;
205 reported_length = get_short_int_from_message(msg_in)
206 if len(msg_in) != reported_length:
207 logging.error("Message length is not " + str(reported_length) +
208 " as stated in " + binascii.hexlify(msg_in))
209 raise MessageError("Message length is not " + reported_length +
210 " as stated in ", msg_in)
211 logging.info("Open message received.")
215 class MessageGenerator(object):
216 """Class which generates messages, holds states and configuration values."""
218 # TODO: Define bgp marker as a class (constant) variable.
219 def __init__(self, args):
220 """Initialisation according to command-line args.
223 :args: argsparser's Namespace object which contains command-line
224 options for MesageGenerator initialisation
226 Calculates and stores default values used later on for
229 self.total_prefix_amount = args.amount
230 # Number of update messages left to be sent.
231 self.remaining_prefixes = self.total_prefix_amount
233 # New parameters initialisation
235 self.prefix_base_default = args.firstprefix
236 self.prefix_length_default = args.prefixlen
237 self.wr_prefixes_default = []
238 self.nlri_prefixes_default = []
239 self.version_default = 4
240 self.my_autonomous_system_default = args.asnumber
241 self.hold_time_default = args.holdtime # Local hold time.
242 self.bgp_identifier_default = int(args.myip)
243 self.next_hop_default = args.nexthop
244 self.single_update_default = args.updates == "single"
245 self.randomize_updates_default = args.updates == "random"
246 self.prefix_count_to_add_default = args.insert
247 self.prefix_count_to_del_default = args.withdraw
248 if self.prefix_count_to_del_default < 0:
249 self.prefix_count_to_del_default = 0
250 if self.prefix_count_to_add_default <= self.prefix_count_to_del_default:
251 # total number of prefixes must grow to avoid infinite test loop
252 self.prefix_count_to_add_default = self.prefix_count_to_del_default + 1
253 self.slot_size_default = self.prefix_count_to_add_default
254 self.remaining_prefixes_threshold = self.total_prefix_amount - args.prefill
255 self.results_file_name_default = args.results
256 self.performance_threshold_default = args.threshold
257 # Default values used for randomized part
258 s1_slots = ((self.total_prefix_amount -
259 self.remaining_prefixes_threshold - 1) /
260 self.prefix_count_to_add_default + 1)
261 s2_slots = ((self.remaining_prefixes_threshold - 1) /
262 (self.prefix_count_to_add_default -
263 self.prefix_count_to_del_default) + 1)
265 # S1_Last_Index = s1_slots * self.prefix_count_to_add_default - 1
266 s2_first_index = s1_slots * self.prefix_count_to_add_default
267 s2_last_index = (s2_first_index +
268 s2_slots * (self.prefix_count_to_add_default -
269 self.prefix_count_to_del_default) - 1)
270 self.slot_gap_default = ((self.total_prefix_amount -
271 self.remaining_prefixes_threshold - 1) /
272 self.prefix_count_to_add_default + 1)
273 self.randomize_lowest_default = s2_first_index
274 self.randomize_highest_default = s2_last_index
276 # Initialising counters
277 self.phase1_start_time = 0
278 self.phase1_stop_time = 0
279 self.phase2_start_time = 0
280 self.phase2_stop_time = 0
281 self.phase1_updates_sent = 0
282 self.phase2_updates_sent = 0
283 self.updates_sent = 0
285 self.log_info = args.loglevel <= logging.INFO
286 self.log_debug = args.loglevel <= logging.DEBUG
288 Flags needed for the MessageGenerator performance optimization.
289 Calling logger methods each iteration even with proper log level set
290 slows down significantly the MessageGenerator performance.
291 Measured total generation time (1M updates, dry run, error log level):
292 - logging based on basic logger features: 36,2s
293 - logging based on advanced logger features (lazy logging): 21,2s
294 - conditional calling of logger methods enclosed inside condition: 8,6s
297 logging.info("Generator initialisation")
298 logging.info(" Target total number of prefixes to be introduced: " +
299 str(self.total_prefix_amount))
300 logging.info(" Prefix base: " + str(self.prefix_base_default) + "/" +
301 str(self.prefix_length_default))
302 logging.info(" My Autonomous System number: " +
303 str(self.my_autonomous_system_default))
304 logging.info(" My Hold Time: " + str(self.hold_time_default))
305 logging.info(" My BGP Identifier: " + str(self.bgp_identifier_default))
306 logging.info(" Next Hop: " + str(self.next_hop_default))
307 logging.info(" Prefix count to be inserted at once: " +
308 str(self.prefix_count_to_add_default))
309 logging.info(" Prefix count to be withdrawn at once: " +
310 str(self.prefix_count_to_del_default))
311 logging.info(" Fast pre-fill up to " +
312 str(self.total_prefix_amount -
313 self.remaining_prefixes_threshold) + " prefixes")
314 logging.info(" Remaining number of prefixes to be processed " +
315 "in parallel with withdrawals: " +
316 str(self.remaining_prefixes_threshold))
317 logging.debug(" Prefix index range used after pre-fill procedure [" +
318 str(self.randomize_lowest_default) + ", " +
319 str(self.randomize_highest_default) + "]")
320 if self.single_update_default:
321 logging.info(" Common single UPDATE will be generated " +
322 "for both NLRI & WITHDRAWN lists")
324 logging.info(" Two separate UPDATEs will be generated " +
325 "for each NLRI & WITHDRAWN lists")
326 if self.randomize_updates_default:
327 logging.info(" Generation of UPDATE messages will be randomized")
328 logging.info(" Let\"s go ...\n")
330 # TODO: Notification for hold timer expiration can be handy.
332 def store_results(self, file_name=None, threshold=None):
333 """ Stores specified results into files based on file_name value.
336 :param file_name: Trailing (common) part of result file names
337 :param threshold: Minimum number of sent updates needed for each
338 result to be included into result csv file
339 (mainly needed because of the result accuracy)
343 # default values handling
344 if file_name is None:
345 file_name = self.results_file_name_default
346 if threshold is None:
347 threshold = self.performance_threshold_default
348 # performance calculation
349 if self.phase1_updates_sent >= threshold:
350 totals1 = self.phase1_updates_sent
351 performance1 = int(self.phase1_updates_sent /
352 (self.phase1_stop_time - self.phase1_start_time))
356 if self.phase2_updates_sent >= threshold:
357 totals2 = self.phase2_updates_sent
358 performance2 = int(self.phase2_updates_sent /
359 (self.phase2_stop_time - self.phase2_start_time))
364 logging.info("#" * 10 + " Final results " + "#" * 10)
365 logging.info("Number of iterations: " + str(self.iteration))
366 logging.info("Number of UPDATE messages sent in the pre-fill phase: " +
367 str(self.phase1_updates_sent))
368 logging.info("The pre-fill phase duration: " +
369 str(self.phase1_stop_time - self.phase1_start_time) + "s")
370 logging.info("Number of UPDATE messages sent in the 2nd test phase: " +
371 str(self.phase2_updates_sent))
372 logging.info("The 2nd test phase duration: " +
373 str(self.phase2_stop_time - self.phase2_start_time) + "s")
374 logging.info("Threshold for performance reporting: " + str(threshold))
377 phase1_label = ("pre-fill " + str(self.prefix_count_to_add_default) +
378 " route(s) per UPDATE")
379 if self.single_update_default:
380 phase2_label = "+" + (str(self.prefix_count_to_add_default) +
381 "/-" + str(self.prefix_count_to_del_default) +
382 " routes per UPDATE")
384 phase2_label = "+" + (str(self.prefix_count_to_add_default) +
385 "/-" + str(self.prefix_count_to_del_default) +
386 " routes in two UPDATEs")
387 # collecting capacity and performance results
390 if totals1 is not None:
391 totals[phase1_label] = totals1
392 performance[phase1_label] = performance1
393 if totals2 is not None:
394 totals[phase2_label] = totals2
395 performance[phase2_label] = performance2
396 self.write_results_to_file(totals, "totals-" + file_name)
397 self.write_results_to_file(performance, "performance-" + file_name)
399 def write_results_to_file(self, results, file_name):
400 """Writes results to the csv plot file consumable by Jenkins.
403 :param file_name: Name of the (csv) file to be created
409 f = open(file_name, "wt")
411 for key in sorted(results):
412 first_line += key + ", "
413 second_line += str(results[key]) + ", "
414 first_line = first_line[:-2]
415 second_line = second_line[:-2]
416 f.write(first_line + "\n")
417 f.write(second_line + "\n")
418 logging.info("Performance results of message generator stored in " +
420 logging.info(" " + first_line)
421 logging.info(" " + second_line)
425 # Return pseudo-randomized (reproducible) index for selected range
426 def randomize_index(self, index, lowest=None, highest=None):
427 """Calculates pseudo-randomized index from selected range.
430 :param index: input index
431 :param lowest: the lowes index from the randomized area
432 :param highest: the highest index from the randomized area
434 :return: the (pseudo)randomized index
436 Created just as a fame for future generator enhancement.
438 # default values handling
440 lowest = self.randomize_lowest_default
442 highest = self.randomize_highest_default
444 if (index >= lowest) and (index <= highest):
445 # we are in the randomized range -> shuffle it inside
446 # the range (now just reverse the order)
447 new_index = highest - (index - lowest)
449 # we are out of the randomized range -> nothing to do
453 # Get list of prefixes
454 def get_prefix_list(self, slot_index, slot_size=None, prefix_base=None,
455 prefix_len=None, prefix_count=None, randomize=None):
456 """Generates list of IP address prefixes.
459 :param slot_index: index of group of prefix addresses
460 :param slot_size: size of group of prefix addresses
461 in [number of included prefixes]
462 :param prefix_base: IP address of the first prefix
463 (slot_index = 0, prefix_index = 0)
464 :param prefix_len: length of the prefix in bites
465 (the same as size of netmask)
466 :param prefix_count: number of prefixes to be returned
467 from the specified slot
469 :return: list of generated IP address prefixes
471 # default values handling
472 if slot_size is None:
473 slot_size = self.slot_size_default
474 if prefix_base is None:
475 prefix_base = self.prefix_base_default
476 if prefix_len is None:
477 prefix_len = self.prefix_length_default
478 if prefix_count is None:
479 prefix_count = slot_size
480 if randomize is None:
481 randomize = self.randomize_updates_default
482 # generating list of prefixes
485 prefix_gap = 2 ** (32 - prefix_len)
486 for i in range(prefix_count):
487 prefix_index = slot_index * slot_size + i
489 prefix_index = self.randomize_index(prefix_index)
490 indexes.append(prefix_index)
491 prefixes.append(prefix_base + prefix_index * prefix_gap)
493 logging.debug(" Prefix slot index: " + str(slot_index))
494 logging.debug(" Prefix slot size: " + str(slot_size))
495 logging.debug(" Prefix count: " + str(prefix_count))
496 logging.debug(" Prefix indexes: " + str(indexes))
497 logging.debug(" Prefix list: " + str(prefixes))
500 def compose_update_message(self, prefix_count_to_add=None,
501 prefix_count_to_del=None):
502 """Composes an UPDATE message
505 :param prefix_count_to_add: # of prefixes to put into NLRI list
506 :param prefix_count_to_del: # of prefixes to put into WITHDRAWN list
508 :return: encoded UPDATE message in HEX
510 Optionally generates separate UPDATEs for NLRI and WITHDRAWN
511 lists or common message wich includes both prefix lists.
512 Updates global counters.
514 # default values handling
515 if prefix_count_to_add is None:
516 prefix_count_to_add = self.prefix_count_to_add_default
517 if prefix_count_to_del is None:
518 prefix_count_to_del = self.prefix_count_to_del_default
520 if self.log_info and not (self.iteration % 1000):
521 logging.info("Iteration: " + str(self.iteration) +
522 " - total remaining prefixes: " +
523 str(self.remaining_prefixes))
525 logging.debug("#" * 10 + " Iteration: " +
526 str(self.iteration) + " " + "#" * 10)
527 logging.debug("Remaining prefixes: " +
528 str(self.remaining_prefixes))
529 # scenario type & one-shot counter
530 straightforward_scenario = (self.remaining_prefixes >
531 self.remaining_prefixes_threshold)
532 if straightforward_scenario:
533 prefix_count_to_del = 0
535 logging.debug("--- STARAIGHTFORWARD SCENARIO ---")
536 if not self.phase1_start_time:
537 self.phase1_start_time = time.time()
540 logging.debug("--- COMBINED SCENARIO ---")
541 if not self.phase2_start_time:
542 self.phase2_start_time = time.time()
543 # tailor the number of prefixes if needed
544 prefix_count_to_add = (prefix_count_to_del +
545 min(prefix_count_to_add - prefix_count_to_del,
546 self.remaining_prefixes))
547 # prefix slots selection for insertion and withdrawal
548 slot_index_to_add = self.iteration
549 slot_index_to_del = slot_index_to_add - self.slot_gap_default
550 # getting lists of prefixes for insertion in this iteration
552 logging.debug("Prefixes to be inserted in this iteration:")
553 prefix_list_to_add = self.get_prefix_list(slot_index_to_add,
554 prefix_count=prefix_count_to_add)
555 # getting lists of prefixes for withdrawal in this iteration
557 logging.debug("Prefixes to be withdrawn in this iteration:")
558 prefix_list_to_del = self.get_prefix_list(slot_index_to_del,
559 prefix_count=prefix_count_to_del)
560 # generating the mesage
561 if self.single_update_default:
562 # Send prefixes to be introduced and withdrawn
563 # in one UPDATE message
564 msg_out = self.update_message(wr_prefixes=prefix_list_to_del,
565 nlri_prefixes=prefix_list_to_add)
567 # Send prefixes to be introduced and withdrawn
568 # in separate UPDATE messages (if needed)
569 msg_out = self.update_message(wr_prefixes=[],
570 nlri_prefixes=prefix_list_to_add)
571 if prefix_count_to_del:
572 msg_out += self.update_message(wr_prefixes=prefix_list_to_del,
574 # updating counters - who knows ... maybe I am last time here ;)
575 if straightforward_scenario:
576 self.phase1_stop_time = time.time()
577 self.phase1_updates_sent = self.updates_sent
579 self.phase2_stop_time = time.time()
580 self.phase2_updates_sent = (self.updates_sent -
581 self.phase1_updates_sent)
582 # updating totals for the next iteration
584 self.remaining_prefixes -= (prefix_count_to_add - prefix_count_to_del)
585 # returning the encoded message
588 # Section of message encoders
590 def open_message(self, version=None, my_autonomous_system=None,
591 hold_time=None, bgp_identifier=None):
592 """Generates an OPEN Message (rfc4271#section-4.2)
595 :param version: see the rfc4271#section-4.2
596 :param my_autonomous_system: see the rfc4271#section-4.2
597 :param hold_time: see the rfc4271#section-4.2
598 :param bgp_identifier: see the rfc4271#section-4.2
600 :return: encoded OPEN message in HEX
603 # Default values handling
605 version = self.version_default
606 if my_autonomous_system is None:
607 my_autonomous_system = self.my_autonomous_system_default
608 if hold_time is None:
609 hold_time = self.hold_time_default
610 if bgp_identifier is None:
611 bgp_identifier = self.bgp_identifier_default
614 marker_hex = "\xFF" * 16
618 type_hex = struct.pack("B", type)
621 version_hex = struct.pack("B", version)
623 # my_autonomous_system
624 # AS_TRANS value, 23456 decadic.
625 my_autonomous_system_2_bytes = 23456
626 # AS number is mappable to 2 bytes
627 if my_autonomous_system < 65536:
628 my_autonomous_system_2_bytes = my_autonomous_system
629 my_autonomous_system_hex_2_bytes = struct.pack(">H",
630 my_autonomous_system)
633 hold_time_hex = struct.pack(">H", hold_time)
636 bgp_identifier_hex = struct.pack(">I", bgp_identifier)
638 # Optional Parameters
639 optional_parameters_hex = (
640 "\x02" # Param type ("Capability Ad")
641 "\x06" # Length (6 bytes)
642 "\x01" # Capability type (NLRI Unicast),
643 # see RFC 4760, secton 8
644 "\x04" # Capability value length
645 "\x00\x01" # AFI (Ipv4)
647 "\x01" # SAFI (Unicast)
649 "\x02" # Param type ("Capability Ad")
650 "\x06" # Length (6 bytes)
651 "\x41" # "32 bit AS Numbers Support"
652 # (see RFC 6793, section 3)
653 "\x04" # Capability value length
654 # My AS in 32 bit format
655 + struct.pack(">I", my_autonomous_system)
658 # Optional Parameters Length
659 optional_parameters_length = len(optional_parameters_hex)
660 optional_parameters_length_hex = struct.pack("B",
661 optional_parameters_length)
663 # Length (big-endian)
665 len(marker_hex) + 2 + len(type_hex) + len(version_hex) +
666 len(my_autonomous_system_hex_2_bytes) +
667 len(hold_time_hex) + len(bgp_identifier_hex) +
668 len(optional_parameters_length_hex) +
669 len(optional_parameters_hex)
671 length_hex = struct.pack(">H", length)
679 my_autonomous_system_hex_2_bytes +
682 optional_parameters_length_hex +
683 optional_parameters_hex
687 logging.debug("OPEN Message encoding")
688 logging.debug(" Marker=0x" + binascii.hexlify(marker_hex))
689 logging.debug(" Length=" + str(length) + " (0x" +
690 binascii.hexlify(length_hex) + ")")
691 logging.debug(" Type=" + str(type) + " (0x" +
692 binascii.hexlify(type_hex) + ")")
693 logging.debug(" Version=" + str(version) + " (0x" +
694 binascii.hexlify(version_hex) + ")")
695 logging.debug(" My Autonomous System=" +
696 str(my_autonomous_system_2_bytes) + " (0x" +
697 binascii.hexlify(my_autonomous_system_hex_2_bytes) +
699 logging.debug(" Hold Time=" + str(hold_time) + " (0x" +
700 binascii.hexlify(hold_time_hex) + ")")
701 logging.debug(" BGP Identifier=" + str(bgp_identifier) +
702 " (0x" + binascii.hexlify(bgp_identifier_hex) + ")")
703 logging.debug(" Optional Parameters Length=" +
704 str(optional_parameters_length) + " (0x" +
705 binascii.hexlify(optional_parameters_length_hex) +
707 logging.debug(" Optional Parameters=0x" +
708 binascii.hexlify(optional_parameters_hex))
709 logging.debug(" OPEN Message encoded: 0x" +
710 binascii.b2a_hex(message_hex))
714 def update_message(self, wr_prefixes=None, nlri_prefixes=None,
715 wr_prefix_length=None, nlri_prefix_length=None,
716 my_autonomous_system=None, next_hop=None):
717 """Generates an UPDATE Message (rfc4271#section-4.3)
720 :param wr_prefixes: see the rfc4271#section-4.3
721 :param nlri_prefixes: see the rfc4271#section-4.3
722 :param wr_prefix_length: see the rfc4271#section-4.3
723 :param nlri_prefix_length: see the rfc4271#section-4.3
724 :param my_autonomous_system: see the rfc4271#section-4.3
725 :param next_hop: see the rfc4271#section-4.3
727 :return: encoded UPDATE message in HEX
730 # Default values handling
731 if wr_prefixes is None:
732 wr_prefixes = self.wr_prefixes_default
733 if nlri_prefixes is None:
734 nlri_prefixes = self.nlri_prefixes_default
735 if wr_prefix_length is None:
736 wr_prefix_length = self.prefix_length_default
737 if nlri_prefix_length is None:
738 nlri_prefix_length = self.prefix_length_default
739 if my_autonomous_system is None:
740 my_autonomous_system = self.my_autonomous_system_default
742 next_hop = self.next_hop_default
745 marker_hex = "\xFF" * 16
749 type_hex = struct.pack("B", type)
752 bytes = ((wr_prefix_length - 1) / 8) + 1
753 withdrawn_routes_hex = ""
754 for prefix in wr_prefixes:
755 withdrawn_route_hex = (struct.pack("B", wr_prefix_length) +
756 struct.pack(">I", int(prefix))[:bytes])
757 withdrawn_routes_hex += withdrawn_route_hex
759 # Withdrawn Routes Length
760 withdrawn_routes_length = len(withdrawn_routes_hex)
761 withdrawn_routes_length_hex = struct.pack(">H", withdrawn_routes_length)
763 # TODO: to replace hardcoded string by encoding?
765 if nlri_prefixes != []:
766 path_attributes_hex = (
767 "\x40" # Flags ("Well-Known")
768 "\x01" # Type (ORIGIN)
771 "\x40" # Flags ("Well-Known")
772 "\x02" # Type (AS_PATH)
774 "\x02" # AS segment type (AS_SEQUENCE)
775 "\x01" # AS segment length (1)
776 # AS segment (4 bytes)
777 + struct.pack(">I", my_autonomous_system) +
778 "\x40" # Flags ("Well-Known")
779 "\x03" # Type (NEXT_HOP)
781 # IP address of the next hop (4 bytes)
782 + struct.pack(">I", int(next_hop))
785 path_attributes_hex = ""
787 # Total Path Attributes Length
788 total_path_attributes_length = len(path_attributes_hex)
789 total_path_attributes_length_hex = struct.pack(">H", total_path_attributes_length)
791 # Network Layer Reachability Information
792 bytes = ((nlri_prefix_length - 1) / 8) + 1
794 for prefix in nlri_prefixes:
795 nlri_prefix_hex = (struct.pack("B", nlri_prefix_length) +
796 struct.pack(">I", int(prefix))[:bytes])
797 nlri_hex += nlri_prefix_hex
799 # Length (big-endian)
801 len(marker_hex) + 2 + len(type_hex) +
802 len(withdrawn_routes_length_hex) + len(withdrawn_routes_hex) +
803 len(total_path_attributes_length_hex) + len(path_attributes_hex) +
805 length_hex = struct.pack(">H", length)
812 withdrawn_routes_length_hex +
813 withdrawn_routes_hex +
814 total_path_attributes_length_hex +
815 path_attributes_hex +
820 logging.debug("UPDATE Message encoding")
821 logging.debug(" Marker=0x" + binascii.hexlify(marker_hex))
822 logging.debug(" Length=" + str(length) + " (0x" +
823 binascii.hexlify(length_hex) + ")")
824 logging.debug(" Type=" + str(type) + " (0x" +
825 binascii.hexlify(type_hex) + ")")
826 logging.debug(" withdrawn_routes_length=" +
827 str(withdrawn_routes_length) + " (0x" +
828 binascii.hexlify(withdrawn_routes_length_hex) + ")")
829 logging.debug(" Withdrawn_Routes=" + str(wr_prefixes) + "/" +
830 str(wr_prefix_length) + " (0x" +
831 binascii.hexlify(withdrawn_routes_hex) + ")")
832 logging.debug(" Total Path Attributes Length=" +
833 str(total_path_attributes_length) + " (0x" +
834 binascii.hexlify(total_path_attributes_length_hex) +
836 logging.debug(" Path Attributes=" + "(0x" +
837 binascii.hexlify(path_attributes_hex) + ")")
838 logging.debug(" Network Layer Reachability Information=" +
839 str(nlri_prefixes) + "/" + str(nlri_prefix_length) +
840 " (0x" + binascii.hexlify(nlri_hex) + ")")
841 logging.debug(" UPDATE Message encoded: 0x" +
842 binascii.b2a_hex(message_hex))
845 self.updates_sent += 1
846 # returning encoded message
849 def notification_message(self, error_code, error_subcode, data_hex=""):
850 """Generates a NOTIFICATION Message (rfc4271#section-4.5)
853 :param error_code: see the rfc4271#section-4.5
854 :param error_subcode: see the rfc4271#section-4.5
855 :param data_hex: see the rfc4271#section-4.5
857 :return: encoded NOTIFICATION message in HEX
861 marker_hex = "\xFF" * 16
865 type_hex = struct.pack("B", type)
868 error_code_hex = struct.pack("B", error_code)
871 error_subcode_hex = struct.pack("B", error_subcode)
873 # Length (big-endian)
874 length = (len(marker_hex) + 2 + len(type_hex) + len(error_code_hex) +
875 len(error_subcode_hex) + len(data_hex))
876 length_hex = struct.pack(">H", length)
878 # NOTIFICATION Message
889 logging.debug("NOTIFICATION Message encoding")
890 logging.debug(" Marker=0x" + binascii.hexlify(marker_hex))
891 logging.debug(" Length=" + str(length) + " (0x" +
892 binascii.hexlify(length_hex) + ")")
893 logging.debug(" Type=" + str(type) + " (0x" +
894 binascii.hexlify(type_hex) + ")")
895 logging.debug(" Error Code=" + str(error_code) + " (0x" +
896 binascii.hexlify(error_code_hex) + ")")
897 logging.debug(" Error Subode=" + str(error_subcode) + " (0x" +
898 binascii.hexlify(error_subcode_hex) + ")")
899 logging.debug(" Data=" + " (0x" + binascii.hexlify(data_hex) + ")")
900 logging.debug(" NOTIFICATION Message encoded: 0x" +
901 binascii.b2a_hex(message_hex))
905 def keepalive_message(self):
906 """Generates a KEEP ALIVE Message (rfc4271#section-4.4)
909 :return: encoded KEEP ALIVE message in HEX
913 marker_hex = "\xFF" * 16
917 type_hex = struct.pack("B", type)
919 # Length (big-endian)
920 length = len(marker_hex) + 2 + len(type_hex)
921 length_hex = struct.pack(">H", length)
931 logging.debug("KEEP ALIVE Message encoding")
932 logging.debug(" Marker=0x" + binascii.hexlify(marker_hex))
933 logging.debug(" Length=" + str(length) + " (0x" +
934 binascii.hexlify(length_hex) + ")")
935 logging.debug(" Type=" + str(type) + " (0x" +
936 binascii.hexlify(type_hex) + ")")
937 logging.debug(" KEEP ALIVE Message encoded: 0x" +
938 binascii.b2a_hex(message_hex))
943 class TimeTracker(object):
944 """Class for tracking timers, both for my keepalives and
948 def __init__(self, msg_in):
949 """Initialisation. based on defaults and OPEN message from peer.
952 msg_in: the OPEN message received from peer.
954 # Note: Relative time is always named timedelta, to stress that
955 # the (non-delta) time is absolute.
956 self.report_timedelta = 1.0 # In seconds. TODO: Configurable?
957 # Upper bound for being stuck in the same state, we should
958 # at least report something before continuing.
959 # Negotiate the hold timer by taking the smaller
960 # of the 2 values (mine and the peer's).
961 hold_timedelta = 180 # Not an attribute of self yet.
962 # TODO: Make the default value configurable,
963 # default value could mirror what peer said.
964 peer_hold_timedelta = get_short_int_from_message(msg_in, offset=22)
965 if hold_timedelta > peer_hold_timedelta:
966 hold_timedelta = peer_hold_timedelta
967 if hold_timedelta != 0 and hold_timedelta < 3:
968 logging.error("Invalid hold timedelta value: " + str(hold_timedelta))
969 raise ValueError("Invalid hold timedelta value: ", hold_timedelta)
970 self.hold_timedelta = hold_timedelta
971 # If we do not hear from peer this long, we assume it has died.
972 self.keepalive_timedelta = int(hold_timedelta / 3.0)
973 # Upper limit for duration between messages, to avoid being
974 # declared to be dead.
975 # The same as calling snapshot(), but also declares a field.
976 self.snapshot_time = time.time()
977 # Sometimes we need to store time. This is where to get
978 # the value from afterwards. Time_keepalive may be too strict.
979 self.peer_hold_time = self.snapshot_time + self.hold_timedelta
980 # At this time point, peer will be declared dead.
981 self.my_keepalive_time = None # to be set later
982 # At this point, we should be sending keepalive message.
985 """Store current time in instance data to use later."""
986 # Read as time before something interesting was called.
987 self.snapshot_time = time.time()
989 def reset_peer_hold_time(self):
990 """Move hold time to future as peer has just proven it still lives."""
991 self.peer_hold_time = time.time() + self.hold_timedelta
993 # Some methods could rely on self.snapshot_time, but it is better
994 # to require user to provide it explicitly.
995 def reset_my_keepalive_time(self, keepalive_time):
996 """Calculate and set the next my KEEP ALIVE timeout time
999 :keepalive_time: the initial value of the KEEP ALIVE timer
1001 self.my_keepalive_time = keepalive_time + self.keepalive_timedelta
1003 def is_time_for_my_keepalive(self):
1004 """Check for my KEEP ALIVE timeout occurence"""
1005 if self.hold_timedelta == 0:
1007 return self.snapshot_time >= self.my_keepalive_time
1009 def get_next_event_time(self):
1010 """Set the time of the next expected or to be sent KEEP ALIVE"""
1011 if self.hold_timedelta == 0:
1012 return self.snapshot_time + 86400
1013 return min(self.my_keepalive_time, self.peer_hold_time)
1015 def check_peer_hold_time(self, snapshot_time):
1016 """Raise error if nothing was read from peer until specified time."""
1017 # Hold time = 0 means keepalive checking off.
1018 if self.hold_timedelta != 0:
1019 # time.time() may be too strict
1020 if snapshot_time > self.peer_hold_time:
1021 logging.error("Peer has overstepped the hold timer.")
1022 raise RuntimeError("Peer has overstepped the hold timer.")
1023 # TODO: Include hold_timedelta?
1024 # TODO: Add notification sending (attempt). That means
1025 # move to write tracker.
1028 class ReadTracker(object):
1029 """Class for tracking read of mesages chunk by chunk and
1033 def __init__(self, bgp_socket, timer):
1034 """The reader initialisation.
1037 bgp_socket: socket to be used for sending
1038 timer: timer to be used for scheduling
1040 # References to outside objects.
1041 self.socket = bgp_socket
1043 # BGP marker length plus length field length.
1044 self.header_length = 18
1045 # TODO: make it class (constant) attribute
1046 # Computation of where next chunk ends depends on whether
1047 # we are beyond length field.
1048 self.reading_header = True
1049 # Countdown towards next size computation.
1050 self.bytes_to_read = self.header_length
1051 # Incremental buffer for message under read.
1054 def read_message_chunk(self):
1055 """Read up to one message
1058 Currently it does not return anything.
1060 # TODO: We could return the whole message, currently not needed.
1061 # We assume the socket is readable.
1062 chunk_message = self.socket.recv(self.bytes_to_read)
1063 self.msg_in += chunk_message
1064 self.bytes_to_read -= len(chunk_message)
1065 # TODO: bytes_to_read < 0 is not possible, right?
1066 if not self.bytes_to_read:
1067 # Finished reading a logical block.
1068 if self.reading_header:
1069 # The logical block was a BGP header.
1070 # Now we know the size of the message.
1071 self.reading_header = False
1072 self.bytes_to_read = get_short_int_from_message(self.msg_in)
1073 else: # We have finished reading the body of the message.
1074 # Peer has just proven it is still alive.
1075 self.timer.reset_peer_hold_time()
1076 # TODO: Do we want to count received messages?
1077 # This version ignores the received message.
1078 # TODO: Should we do validation and exit on anything
1079 # besides update or keepalive?
1080 # Prepare state for reading another message.
1081 logging.debug("Message received: 0x%s", binascii.b2a_hex(self.msg_in))
1083 self.reading_header = True
1084 self.bytes_to_read = self.header_length
1085 # We should not act upon peer_hold_time if we are reading
1086 # something right now.
1089 def wait_for_read(self):
1090 """Read message until timeout (next expected event).
1093 Used when no more updates has to be sent to avoid busy-wait.
1094 Currently it does not return anything.
1096 # Compute time to the first predictable state change
1097 event_time = self.timer.get_next_event_time()
1098 # snapshot_time would be imprecise
1099 wait_timedelta = event_time - time.time()
1100 if wait_timedelta < 0:
1101 # The program got around to waiting to an event in "very near
1102 # future" so late that it became a "past" event, thus tell
1103 # "select" to not wait at all. Passing negative timedelta to
1104 # select() would lead to either waiting forever (for -1) or
1105 # select.error("Invalid parameter") (for everything else).
1107 # And wait for event or something to read.
1108 select.select([self.socket], [], [self.socket], wait_timedelta)
1109 # Not checking anything, that will be done in next iteration.
1113 class WriteTracker(object):
1114 """Class tracking enqueueing messages and sending chunks of them."""
1116 def __init__(self, bgp_socket, generator, timer):
1117 """The writter initialisation.
1120 bgp_socket: socket to be used for sending
1121 generator: generator to be used for message generation
1122 timer: timer to be used for scheduling
1124 # References to outside objects,
1125 self.socket = bgp_socket
1126 self.generator = generator
1128 # Really new fields.
1129 # TODO: Would attribute docstrings add anything substantial?
1130 self.sending_message = False
1131 self.bytes_to_send = 0
1134 def enqueue_message_for_sending(self, message):
1135 """Enqueue message and change state.
1138 message: message to be enqueued into the msg_out buffer
1140 self.msg_out += message
1141 self.bytes_to_send += len(message)
1142 self.sending_message = True
1144 def send_message_chunk_is_whole(self):
1145 """Send enqueued data from msg_out buffer
1148 :return: true if no remaining data to send
1150 # We assume there is a msg_out to send and socket is writable.
1151 # print "going to send", repr(self.msg_out)
1152 self.timer.snapshot()
1153 bytes_sent = self.socket.send(self.msg_out)
1154 # Forget the part of message that was sent.
1155 self.msg_out = self.msg_out[bytes_sent:]
1156 self.bytes_to_send -= bytes_sent
1157 if not self.bytes_to_send:
1158 # TODO: Is it possible to hit negative bytes_to_send?
1159 self.sending_message = False
1160 # We should have reset hold timer on peer side.
1161 self.timer.reset_my_keepalive_time(self.timer.snapshot_time)
1162 # The possible reason for not prioritizing reads is gone.
1167 class StateTracker(object):
1168 """Main loop has state so complex it warrants this separate class."""
1170 def __init__(self, bgp_socket, generator, timer):
1171 """The state tracker initialisation.
1174 bgp_socket: socket to be used for sending / receiving
1175 generator: generator to be used for message generation
1176 timer: timer to be used for scheduling
1178 # References to outside objects.
1179 self.socket = bgp_socket
1180 self.generator = generator
1183 self.reader = ReadTracker(bgp_socket, timer)
1184 self.writer = WriteTracker(bgp_socket, generator, timer)
1185 # Prioritization state.
1186 self.prioritize_writing = False
1187 # In general, we prioritize reading over writing. But in order
1188 # not to get blocked by neverending reads, we should
1189 # check whether we are not risking running out of holdtime.
1190 # So in some situations, this field is set to True to attempt
1191 # finishing sending a message, after which this field resets
1193 # TODO: Alternative is to switch fairly between reading and
1194 # writing (called round robin from now on).
1195 # Message counting is done in generator.
1197 def perform_one_loop_iteration(self):
1198 """ The main loop iteration
1201 Calculates priority, resolves all conditions, calls
1202 appropriate method and returns to caller to repeat.
1204 self.timer.snapshot()
1205 if not self.prioritize_writing:
1206 if self.timer.is_time_for_my_keepalive():
1207 if not self.writer.sending_message:
1208 # We need to schedule a keepalive ASAP.
1209 self.writer.enqueue_message_for_sending(self.generator.keepalive_message())
1210 # We are sending a message now, so let's prioritize it.
1211 self.prioritize_writing = True
1212 # Now we know what our priorities are, we have to check
1213 # which actions are available.
1214 # socket.socket() returns three lists,
1215 # we store them to list of lists.
1216 list_list = select.select([self.socket], [self.socket], [self.socket],
1217 self.timer.report_timedelta)
1218 read_list, write_list, except_list = list_list
1219 # Lists are unpacked, each is either [] or [self.socket],
1220 # so we will test them as boolean.
1222 logging.error("Exceptional state on the socket.")
1223 raise RuntimeError("Exceptional state on socket", self.socket)
1224 # We will do either read or write.
1225 if not (self.prioritize_writing and write_list):
1226 # Either we have no reason to rush writes,
1227 # or the socket is not writable.
1228 # We are focusing on reading here.
1229 if read_list: # there is something to read indeed
1230 # In this case we want to read chunk of message
1231 # and repeat the select,
1232 self.reader.read_message_chunk()
1234 # We were focusing on reading, but nothing to read was there.
1235 # Good time to check peer for hold timer.
1236 self.timer.check_peer_hold_time(self.timer.snapshot_time)
1237 # Quiet on the read front, we can have attempt to write.
1239 # Either we really want to reset peer's view of our hold
1240 # timer, or there was nothing to read.
1241 # Were we in the middle of sending a message?
1242 if self.writer.sending_message:
1243 # Was it the end of a message?
1244 whole = self.writer.send_message_chunk_is_whole()
1245 # We were pressed to send something and we did it.
1246 if self.prioritize_writing and whole:
1247 # We prioritize reading again.
1248 self.prioritize_writing = False
1250 # Finally to check if still update messages to be generated.
1251 if self.generator.remaining_prefixes:
1252 msg_out = self.generator.compose_update_message()
1253 if not self.generator.remaining_prefixes:
1254 # We have just finished update generation,
1255 # end-of-rib is due.
1256 logging.info("All update messages generated.")
1257 logging.info("Storing performance results.")
1258 self.generator.store_results()
1259 logging.info("Finally an END-OF-RIB is going to be sent.")
1260 msg_out += self.generator.update_message(wr_prefixes=[],
1262 self.writer.enqueue_message_for_sending(msg_out)
1263 # Attempt for real sending to be done in next iteration.
1265 # Nothing to write anymore, except occasional keepalives.
1266 logging.info("Everything has been done." +
1267 "Now just waiting for possible incomming message.")
1268 # To avoid busy loop, we do idle waiting here.
1269 self.reader.wait_for_read()
1271 # We can neither read nor write.
1272 logging.warning("Input and output both blocked for " +
1273 str(self.timer.report_timedelta) + " seconds.")
1274 # FIXME: Are we sure select has been really waiting
1280 """ One time initialisation and iterations looping.
1283 Establish BGP connection and run iterations.
1285 arguments = parse_arguments()
1286 logging.basicConfig(format="%(asctime)s %(levelname)s: %(message)s",
1287 level=arguments.loglevel)
1288 bgp_socket = establish_connection(arguments)
1289 # Initial handshake phase. TODO: Can it be also moved to StateTracker?
1290 # Receive open message before sending anything.
1291 # FIXME: Add parameter to send default open message first,
1292 # to work with "you first" peers.
1293 msg_in = read_open_message(bgp_socket)
1294 timer = TimeTracker(msg_in)
1295 generator = MessageGenerator(arguments)
1296 msg_out = generator.open_message()
1297 logging.debug("Sending the OPEN message: " + binascii.hexlify(msg_out))
1298 # Send our open message to the peer.
1299 bgp_socket.send(msg_out)
1300 # Wait for confirming keepalive.
1301 # TODO: Surely in just one packet?
1302 # Using exact keepalive length to not to see possible updates.
1303 msg_in = bgp_socket.recv(19)
1304 if msg_in != generator.keepalive_message():
1305 logging.error("Open not confirmed by keepalive, instead got " +
1306 binascii.hexlify(msg_in))
1307 raise MessageError("Open not confirmed by keepalive, instead got",
1309 timer.reset_peer_hold_time()
1310 # Send the keepalive to indicate the connection is accepted.
1311 timer.snapshot() # Remember this time.
1312 msg_out = generator.keepalive_message()
1313 logging.debug("Sending a KEEP ALIVE message: " + binascii.hexlify(msg_out))
1314 bgp_socket.send(msg_out)
1315 # Use the remembered time.
1316 timer.reset_my_keepalive_time(timer.snapshot_time)
1317 # End of initial handshake phase.
1318 state = StateTracker(bgp_socket, generator, timer)
1319 while True: # main reactor loop
1320 state.perform_one_loop_iteration()
1322 if __name__ == "__main__":