scenario.py 31 KB
Newer Older
1
from abc import ABC
2
import binascii
3
import calendar
4
from datetime import datetime
5
import logging
Tomas Krizek's avatar
Tomas Krizek committed
6
import os  # requires posix
7
import random
8 9
import socket
import struct
Marek Vavruša's avatar
Marek Vavruša committed
10
import time
11
from typing import Optional
12 13 14

import dns.dnssec
import dns.message
15
import dns.name
16 17 18
import dns.rcode
import dns.rrset
import dns.tsigkeyring
Marek Vavruša's avatar
Marek Vavruša committed
19

20
import pydnstest.augwrap
21
import pydnstest.matchpart
22
import pydnstest.mock_client
23

24

25 26 27 28 29
def str2bool(v):
    """ Return conversion of JSON-ish string value to boolean. """
    return v.lower() in ('yes', 'true', 'on', '1')


30 31 32 33
# Global statistics
g_rtt = 0.0
g_nqueries = 0

34

35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55
class DNSBlob(ABC):
    def to_wire(self) -> bytes:
        raise NotImplementedError

    def __str__(self) -> str:
        return '<DNSBlob>'


class DNSMessage(DNSBlob):
    def __init__(self, message: dns.message.Message) -> None:
        assert message is not None
        self.message = message

    def to_wire(self) -> bytes:
        return self.message.to_wire(max_size=65535)

    def __str__(self) -> str:
        return str(self.message)


class DNSReply(DNSMessage):
56 57
    def __init__(
                self,
58 59 60 61
                message: dns.message.Message,
                query: Optional[dns.message.Message] = None,
                copy_id: bool = False,
                copy_query: bool = False
62
            ) -> None:
63 64 65 66 67
        super().__init__(message)
        if copy_id or copy_query:
            if query is None:
                raise ValueError("query must be provided to adjust copy_id/copy_query")
            self.adjust_reply(query, copy_id, copy_query)
68

69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84
    def adjust_reply(
                self,
                query: dns.message.Message,
                copy_id: bool = True,
                copy_query: bool = True
            ) -> None:
        answer = dns.message.from_wire(self.message.to_wire(),
                                       xfr=self.message.xfr,
                                       one_rr_per_rrset=True)
        answer.use_edns(query.edns, query.ednsflags, options=self.message.options)
        if copy_id:
            answer.id = query.id
        if copy_query:
            answer.question = query.question
        # Re-set, as the EDNS might have reset the ext-rcode
        answer.set_rcode(self.message.rcode())
85

86 87 88 89 90
        # sanity check: adjusted answer should be almost the same
        assert len(answer.answer) == len(self.message.answer)
        assert len(answer.authority) == len(self.message.authority)
        assert len(answer.additional) == len(self.message.additional)
        self.message = answer
91

92 93 94 95 96 97 98 99 100 101 102

class DNSReplyRaw(DNSBlob):
    def __init__(
                self,
                wire: bytes,
                query: Optional[dns.message.Message] = None,
                copy_id: bool = False
            ) -> None:
        assert wire is not None
        self.wire = wire
        if copy_id:
103 104
            if query is None:
                raise ValueError("query must be provided to adjust copy_id")
105 106 107 108 109
            self.adjust_reply(query, copy_id)

    def adjust_reply(
                self,
                query: dns.message.Message,
110
                raw_id: bool = True
111
            ) -> None:
112
        if raw_id:
113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131
            if len(self.wire) < 2:
                raise ValueError(
                    'wire data must contain at least 2 bytes to adjust query id')
            raw_answer = bytearray(self.wire)
            struct.pack_into('!H', raw_answer, 0, query.id)
            self.wire = bytes(raw_answer)

    def to_wire(self) -> bytes:
        return self.wire

    def __str__(self) -> str:
        return '<DNSReplyRaw>'


class DNSReplyServfail(DNSMessage):
    def __init__(self, query: dns.message.Message) -> None:
        message = dns.message.make_response(query)
        message.set_rcode(dns.rcode.SERVFAIL)
        super().__init__(message)
132 133


Marek Vavruša's avatar
Marek Vavruša committed
134 135
class Entry:
    """
136 137
    Data entry represents scripted message and extra metadata,
    notably match criteria and reply adjustments.
Marek Vavruša's avatar
Marek Vavruša committed
138 139 140 141 142 143 144
    """

    # Globals
    default_ttl = 3600
    default_cls = 'IN'
    default_rc = 'NOERROR'

145
    def __init__(self, node):
Marek Vavruša's avatar
Marek Vavruša committed
146
        """ Initialize data entry. """
147
        self.node = node
Marek Vavruša's avatar
Marek Vavruša committed
148 149
        self.origin = '.'
        self.message = dns.message.Message()
150 151
        self.message.use_edns(edns=0, payload=4096)
        self.fired = 0
Marek Vavruša's avatar
Marek Vavruša committed
152

153
        # RAW
154
        self.raw_data = self.process_raw()
155

156
        # MATCH
157
        self.match_fields = self.process_match()
158

159
        # FLAGS
160
        self.process_reply_line()
161

162
        # ADJUST
163
        self.adjust_fields = {m.value for m in node.match("/adjust")}
164

165
        # MANDATORY
166
        try:
167
            self.mandatory = list(node.match("/mandatory"))[0]
168
        except (KeyError, IndexError):
169
            self.mandatory = None
170

171
        # TSIG
172 173 174 175 176 177 178
        self.process_tsig()

        # SECTIONS & RECORDS
        self.sections = self.process_sections()

    def process_raw(self):
        try:
179
            return binascii.unhexlify(self.node["/raw"].value)
180
        except KeyError:
181
            return None
182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215

    def process_match(self):
        try:
            self.node["/match_present"]
        except KeyError:
            return None

        fields = set(m.value for m in self.node.match("/match"))

        if 'all' in fields:
            fields.remove("all")
            fields |= set(["opcode", "qtype", "qname", "flags",
                           "rcode", "answer", "authority", "additional"])

        if 'question' in fields:
            fields.remove("question")
            fields |= set(["qtype", "qname"])

        return fields

    def process_reply_line(self):
        """Extracts flags, rcode and opcode from given node and adjust dns message accordingly"""
        self.fields = [f.value for f in self.node.match("/reply")]
        if 'DO' in self.fields:
            self.message.want_dnssec(True)
        opcode = self.get_opcode(fields=self.fields)
        rcode = self.get_rcode(fields=self.fields)
        self.message.flags = self.get_flags(fields=self.fields)
        if rcode is not None:
            self.message.set_rcode(rcode)
        if opcode is not None:
            self.message.set_opcode(opcode)

    def process_tsig(self):
216
        try:
217
            tsig = list(self.node.match("/tsig"))[0]
218 219 220 221 222 223 224
            tsig_keyname = tsig["/keyname"].value
            tsig_secret = tsig["/secret"].value
            keyring = dns.tsigkeyring.from_text({tsig_keyname: tsig_secret})
            self.message.use_tsig(keyring=keyring, keyname=tsig_keyname)
        except (KeyError, IndexError):
            pass

225 226 227
    def process_sections(self):
        sections = set()
        for section in self.node.match("/section/*"):
Tomas Krizek's avatar
Tomas Krizek committed
228
            section_name = os.path.basename(section.path)
229
            sections.add(section_name)
230 231 232
            for record in section.match("/record"):
                owner = record['/domain'].value
                if not owner.endswith("."):
233
                    owner += self.origin
234 235 236 237 238 239 240
                try:
                    ttl = dns.ttl.from_text(record['/ttl'].value)
                except KeyError:
                    ttl = self.default_ttl
                try:
                    rdclass = dns.rdataclass.from_text(record['/class'].value)
                except KeyError:
241
                    rdclass = dns.rdataclass.from_text(self.default_cls)
242 243 244 245
                rdtype = dns.rdatatype.from_text(record['/type'].value)
                rr = dns.rrset.from_text(owner, ttl, rdclass, rdtype)
                if section_name != "question":
                    rd = record['/data'].value.split()
246
                    if rd:
247 248 249 250 251 252 253 254
                        if rdtype == dns.rdatatype.DS:
                            rd[1] = str(dns.dnssec.algorithm_from_text(rd[1]))
                        rd = dns.rdata.from_text(rr.rdclass, rr.rdtype, ' '.join(
                            rd), origin=dns.name.from_text(self.origin), relativize=False)
                    rr.add(rd)
                if section_name == 'question':
                    if rr.rdtype == dns.rdatatype.AXFR:
                        self.message.xfr = True
255
                    self.message.question.append(rr)
256
                elif section_name == 'answer':
257
                    self.message.answer.append(rr)
258
                elif section_name == 'authority':
259
                    self.message.authority.append(rr)
260
                elif section_name == 'additional':
261
                    self.message.additional.append(rr)
262
        return sections
263 264 265

    def __str__(self):
        txt = 'ENTRY_BEGIN\n'
266
        if self.raw_data is None:
267 268 269 270 271 272 273 274 275 276 277 278 279 280 281
            txt += 'MATCH {0}\n'.format(' '.join(self.match_fields))
        txt += 'ADJUST {0}\n'.format(' '.join(self.adjust_fields))
        txt += 'REPLY {rcode} {flags}\n'.format(
            rcode=dns.rcode.to_text(self.message.rcode()),
            flags=' '.join([dns.flags.to_text(self.message.flags),
                            dns.flags.edns_to_text(self.message.ednsflags)])
        )
        for sect_name in ['question', 'answer', 'authority', 'additional']:
            sect = getattr(self.message, sect_name)
            if not sect:
                continue
            txt += 'SECTION {n}\n'.format(n=sect_name.upper())
            for rr in sect:
                txt += str(rr)
                txt += '\n'
282
        if self.raw_data is not None:
283 284 285 286 287 288 289 290 291
            txt += 'RAW\n'
            if self.raw_data:
                txt += binascii.hexlify(self.raw_data)
            else:
                txt += 'NULL'
            txt += '\n'
        txt += 'ENTRY_END\n'
        return txt

292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317
    @classmethod
    def get_flags(cls, fields):
        """From `fields` extracts and returns flags"""
        flags = []
        for code in fields:
            try:
                dns.flags.from_text(code)  # throws KeyError on failure
                flags.append(code)
            except KeyError:
                pass
        return dns.flags.from_text(' '.join(flags))

    @classmethod
    def get_rcode(cls, fields):
        """
        From `fields` extracts and returns rcode.
        Throws `ValueError` if there are more then one rcodes
        """
        rcodes = []
        for code in fields:
            try:
                rcodes.append(dns.rcode.from_text(code))
            except dns.rcode.UnknownRcode:
                pass
        if len(rcodes) > 1:
            raise ValueError("Parse failed, too many rcode values.", rcodes)
318
        if not rcodes:
319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335
            return None
        return rcodes[0]

    @classmethod
    def get_opcode(cls, fields):
        """
        From `fields` extracts and returns opcode.
        Throws `ValueError` if there are more then one opcodes
        """
        opcodes = []
        for code in fields:
            try:
                opcodes.append(dns.opcode.from_text(code))
            except dns.opcode.UnknownOpcode:
                pass
        if len(opcodes) > 1:
            raise ValueError("Parse failed, too many opcode values.")
336
        if not opcodes:
337 338 339
            return None
        return opcodes[0]

Marek Vavruša's avatar
Marek Vavruša committed
340 341
    def match(self, msg):
        """ Compare scripted reply to given message based on match criteria. """
342
        for code in self.match_fields:
Marek Vavruša's avatar
Marek Vavruša committed
343
            try:
344 345
                pydnstest.matchpart.match_part(self.message, msg, code)
            except pydnstest.matchpart.DataMismatch as ex:
346
                errstr = '%s in the response:\n%s' % (str(ex), msg.to_text())
347 348
                # TODO: cisla radku
                raise ValueError("%s, \"%s\": %s" % (self.node.span, code, errstr))
Marek Vavruša's avatar
Marek Vavruša committed
349 350

    def cmp_raw(self, raw_value):
351
        assert self.raw_data is not None
Marek Vavruša's avatar
Marek Vavruša committed
352 353 354 355 356 357 358
        expected = None
        if self.raw_data is not None:
            expected = binascii.hexlify(self.raw_data)
        got = None
        if raw_value is not None:
            got = binascii.hexlify(raw_value)
        if expected != got:
359
            raise ValueError("raw message comparsion failed: expected %s got %s" % (expected, got))
Marek Vavruša's avatar
Marek Vavruša committed
360

361
    def reply(self, query) -> Optional[DNSBlob]:
362 363
        if 'do_not_answer' in self.adjust_fields:
            return None
364
        if self.raw_data is not None:
365
            raw_id = 'raw_id' in self.adjust_fields
366
            assert self.raw_data is not None
367
            return DNSReplyRaw(self.raw_data, query, raw_id)
368 369 370
        copy_id = 'copy_id' in self.adjust_fields
        copy_query = 'copy_query' in self.adjust_fields
        return DNSReply(self.message, query, copy_id, copy_query)
371

372 373 374 375
    def set_edns(self, fields):
        """ Set EDNS version and bufsize. """
        version = 0
        bufsize = 4096
376
        if fields and fields[0].isdigit():
377
            version = int(fields.pop(0))
378
        if fields and fields[0].isdigit():
379
            bufsize = int(fields.pop(0))
380 381 382
        if bufsize == 0:
            self.message.use_edns(False)
            return
383 384
        opts = []
        for v in fields:
Marek Vavrusa's avatar
Marek Vavrusa committed
385
            k, v = tuple(v.split('=')) if '=' in v else (v, True)
386
            if k.lower() == 'nsid':
387
                opts.append(dns.edns.GenericOption(dns.edns.NSID, '' if v is True else v))
388 389 390
            if k.lower() == 'subnet':
                net = v.split('/')
                subnet_addr = net[0]
391 392
                family = socket.AF_INET6 if ':' in subnet_addr else socket.AF_INET
                addr = socket.inet_pton(family, subnet_addr)
393 394 395
                prefix = len(addr) * 8
                if len(net) > 1:
                    prefix = int(net[1])
396 397
                addr = addr[0: (prefix + 7) / 8]
                if prefix % 8 != 0:  # Mask the last byte
398
                    addr = addr[:-1] + chr(ord(addr[-1]) & 0xFF << (8 - prefix % 8))
399 400 401
                opts.append(dns.edns.GenericOption(8, struct.pack(
                    "!HBB", 1 if family == socket.AF_INET else 2, prefix, 0) + addr))
        self.message.use_edns(edns=version, payload=bufsize, options=opts)
402

403

Marek Vavruša's avatar
Marek Vavruša committed
404 405 406 407
class Range:
    """
    Range represents a set of scripted queries valid for given step range.
    """
408
    log = logging.getLogger('pydnstest.scenario.Range')
Marek Vavruša's avatar
Marek Vavruša committed
409

410
    def __init__(self, node):
Marek Vavruša's avatar
Marek Vavruša committed
411
        """ Initialize reply range. """
412
        self.node = node
413 414
        self.a = int(node['/from'].value)
        self.b = int(node['/to'].value)
415
        assert self.a <= self.b
416 417 418

        address = node["/address"].value
        self.addresses = {address} if address is not None else set()
419
        self.addresses |= {a.value for a in node.match("/address/*")}
420
        self.stored = [Entry(n) for n in node.match("/entry")]
421 422 423 424 425
        self.args = {}
        self.received = 0
        self.sent = 0

    def __del__(self):
426 427
        self.log.info('[ RANGE %d-%d ] %s received: %d sent: %d',
                      self.a, self.b, self.addresses, self.received, self.sent)
Marek Vavruša's avatar
Marek Vavruša committed
428

429 430 431 432 433 434 435 436 437 438
    def __str__(self):
        txt = '\nRANGE_BEGIN {a} {b}\n'.format(a=self.a, b=self.b)
        for addr in self.addresses:
            txt += '        ADDRESS {0}\n'.format(addr)

        for entry in self.stored:
            txt += '\n'
            txt += str(entry)
        txt += 'RANGE_END\n\n'
        return txt
Marek Vavruša's avatar
Marek Vavruša committed
439

440
    def eligible(self, ident, address):
Marek Vavruša's avatar
Marek Vavruša committed
441
        """ Return true if this range is eligible for fetching reply. """
442
        if self.a <= ident <= self.b:
443
            return (None is address
444 445
                    or set() == self.addresses
                    or address in self.addresses)
Marek Vavruša's avatar
Marek Vavruša committed
446 447
        return False

448
    def reply(self, query: dns.message.Message) -> Optional[DNSBlob]:
449
        """Get answer for given query (adjusted if needed)."""
450
        self.received += 1
Marek Vavruša's avatar
Marek Vavruša committed
451 452 453
        for candidate in self.stored:
            try:
                candidate.match(query)
454
                resp = candidate.reply(query)
455 456 457
                # Probabilistic loss
                if 'LOSS' in self.args:
                    if random.random() < float(self.args['LOSS']):
458
                        return DNSReplyServfail(query)
459
                self.sent += 1
460
                candidate.fired += 1
461
                return resp
462
            except ValueError:
Marek Vavruša's avatar
Marek Vavruša committed
463
                pass
464
        return DNSReplyServfail(query)
Marek Vavruša's avatar
Marek Vavruša committed
465 466


467
class StepLogger(logging.LoggerAdapter):  # pylint: disable=too-few-public-methods
468 469 470 471 472 473 474
    """
    Prepent Step identification before each log message.
    """
    def process(self, msg, kwargs):
        return '[STEP %s %s] %s' % (self.extra['id'], self.extra['type'], msg), kwargs


Marek Vavruša's avatar
Marek Vavruša committed
475 476 477 478 479
class Step:
    """
    Step represents one scripted action in a given moment,
    each step has an order identifier, type and optionally data entry.
    """
480
    require_data = ['QUERY', 'CHECK_ANSWER', 'REPLY']
Marek Vavruša's avatar
Marek Vavruša committed
481

482
    def __init__(self, node):
Marek Vavruša's avatar
Marek Vavruša committed
483
        """ Initialize single scenario step. """
484
        self.node = node
485 486
        self.id = int(node.value)
        self.type = node["/type"].value
487
        self.log = StepLogger(logging.getLogger('pydnstest.scenario.Step'),
488
                              {'id': self.id, 'type': self.type})
489 490 491 492 493
        try:
            self.delay = int(node["/timestamp"].value)
        except KeyError:
            pass
        self.data = [Entry(n) for n in node.match("/entry")]
494
        self.queries = []
495
        self.has_data = self.type in Step.require_data
Marek Vavruša's avatar
Marek Vavruša committed
496 497
        self.answer = None
        self.raw_answer = None
498 499 500
        self.repeat_if_fail = 0
        self.pause_if_fail = 0
        self.next_if_fail = -1
Petr Špaček's avatar
Petr Špaček committed
501

502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519
    def __str__(self):
        txt = '\nSTEP {i} {t}'.format(i=self.id, t=self.type)
        if self.repeat_if_fail:
            txt += ' REPEAT {v}'.format(v=self.repeat_if_fail)
        elif self.pause_if_fail:
            txt += ' PAUSE {v}'.format(v=self.pause_if_fail)
        elif self.next_if_fail != -1:
            txt += ' NEXT {v}'.format(v=self.next_if_fail)
        # if self.args:
        #     txt += ' '
        #     txt += ' '.join(self.args)
        txt += '\n'

        for data in self.data:
            # from IPython.core.debugger import Tracer
            # Tracer()()
            txt += str(data)
        return txt
Marek Vavruša's avatar
Marek Vavruša committed
520

521
    def play(self, ctx):
Marek Vavruša's avatar
Marek Vavruša committed
522 523
        """ Play one step from a scenario. """
        if self.type == 'QUERY':
524 525
            self.log.info('')
            self.log.debug(self.data[0].message.to_text())
526
            # Parse QUERY-specific parameters
527 528
            choice, tcp = None, False
            return self.__query(ctx, tcp=tcp, choice=choice)
529
        elif self.type == 'CHECK_OUT_QUERY':  # ignore
530
            self.log.info('')
531
            return None
532
        elif self.type == 'CHECK_ANSWER' or self.type == 'ANSWER':
533
            self.log.info('')
Marek Vavruša's avatar
Marek Vavruša committed
534
            return self.__check_answer(ctx)
535
        elif self.type == 'TIME_PASSES ELAPSE':
536
            self.log.info('')
537
            return self.__time_passes()
538
        elif self.type == 'REPLY' or self.type == 'MOCK':
539
            self.log.info('')
540
            return None
Marek Vavruša's avatar
Marek Vavruša committed
541
        else:
542
            raise NotImplementedError('step %03d type %s unsupported' % (self.id, self.type))
543

Marek Vavruša's avatar
Marek Vavruša committed
544 545
    def __check_answer(self, ctx):
        """ Compare answer from previously resolved query. """
546
        if not self.data:
547
            raise ValueError("response definition required")
Marek Vavruša's avatar
Marek Vavruša committed
548
        expected = self.data[0]
549
        if expected.raw_data is not None:
550
            self.log.debug("raw answer: %s", ctx.last_raw_answer.to_text())
Marek Vavruša's avatar
Marek Vavruša committed
551 552 553
            expected.cmp_raw(ctx.last_raw_answer)
        else:
            if ctx.last_answer is None:
554
                raise ValueError("no answer from preceding query")
555
            self.log.debug("answer: %s", ctx.last_answer.to_text())
Marek Vavruša's avatar
Marek Vavruša committed
556 557
            expected.match(ctx.last_answer)

558
    def __query(self, ctx, tcp=False, choice=None):
559 560 561 562 563
        """
        Send query and wait for an answer (if the query is not RAW).

        The received answer is stored in self.answer and ctx.last_answer.
        """
564
        if not self.data:
565
            raise ValueError("query definition required")
566
        if self.data[0].raw_data is not None:
Marek Vavruša's avatar
Marek Vavruša committed
567 568 569 570
            data_to_wire = self.data[0].raw_data
        else:
            # Don't use a message copy as the EDNS data portion is not copied.
            data_to_wire = self.data[0].message.to_wire()
571
        if choice is None or not choice:
572
            choice = list(ctx.client.keys())[0]
573
        if choice not in ctx.client:
574
            raise ValueError('step %03d invalid QUERY target: %s' % (self.id, choice))
575

576
        tstart = datetime.now()
577 578

        # Send query and wait for answer
Marek Vavruša's avatar
Marek Vavruša committed
579
        answer = None
580 581 582 583
        sock = pydnstest.mock_client.setup_socket(ctx.client[choice][0],
                                                  ctx.client[choice][1],
                                                  tcp)
        pydnstest.mock_client.send_query(sock, data_to_wire)
584
        if self.data[0].raw_data is None:
585 586
            answer = pydnstest.mock_client.get_answer(sock)

587 588 589 590 591
        # Track RTT
        rtt = (datetime.now() - tstart).total_seconds() * 1000
        global g_rtt, g_nqueries
        g_nqueries += 1
        g_rtt += rtt
592

Marek Vavruša's avatar
Marek Vavruša committed
593 594 595 596
        # Remember last answer for checking later
        self.raw_answer = answer
        ctx.last_raw_answer = answer
        if self.raw_answer is not None:
Petr Špaček's avatar
Petr Špaček committed
597
            self.answer = dns.message.from_wire(self.raw_answer, one_rr_per_rrset=True)
Marek Vavruša's avatar
Marek Vavruša committed
598 599 600 601
        else:
            self.answer = None
        ctx.last_answer = self.answer

602
    def __time_passes(self):
Marek Vavruša's avatar
Marek Vavruša committed
603
        """ Modify system time. """
604 605 606 607
        file_old = os.environ["FAKETIME_TIMESTAMP_FILE"]
        file_next = os.environ["FAKETIME_TIMESTAMP_FILE"] + ".next"
        with open(file_old, 'r') as time_file:
            line = time_file.readline().strip()
608
        t = time.mktime(datetime.strptime(line, '@%Y-%m-%d %H:%M:%S').timetuple())
609
        t += self.delay
610 611 612 613
        with open(file_next, 'w') as time_file:
            time_file.write(datetime.fromtimestamp(t).strftime('@%Y-%m-%d %H:%M:%S') + "\n")
            time_file.flush()
        os.replace(file_next, file_old)
Marek Vavruša's avatar
Marek Vavruša committed
614

615

Marek Vavruša's avatar
Marek Vavruša committed
616
class Scenario:
617
    log = logging.getLogger('pydnstest.scenatio.Scenario')
618

619
    def __init__(self, node, filename):
Marek Vavruša's avatar
Marek Vavruša committed
620
        """ Initialize scenario with description. """
621
        self.node = node
622
        self.info = node.value
623
        self.file = filename
624
        self.ranges = [Range(n) for n in node.match("/range")]
625
        self.current_range = None
626
        self.steps = [Step(n) for n in node.match("/step")]
Marek Vavruša's avatar
Marek Vavruša committed
627
        self.current_step = None
628
        self.client = {}
Marek Vavruša's avatar
Marek Vavruša committed
629

630 631 632 633 634
    def __str__(self):
        txt = 'SCENARIO_BEGIN'
        if self.info:
            txt += ' {0}'.format(self.info)
        txt += '\n'
635 636
        for range_ in self.ranges:
            txt += str(range_)
637 638 639 640 641
        for step in self.steps:
            txt += str(step)
        txt += "\nSCENARIO_END"
        return txt

642
    def reply(self, query: dns.message.Message, address=None) -> Optional[DNSBlob]:
643
        """Generate answer packet for given query."""
644
        current_step_id = self.current_step.id
Marek Vavruša's avatar
Marek Vavruša committed
645 646
        # Unknown address, select any match
        # TODO: workaround until the server supports stub zones
647
        all_addresses = set()  # type: ignore
648 649 650
        for rng in self.ranges:
            all_addresses.update(rng.addresses)
        if address not in all_addresses:
Marek Vavruša's avatar
Marek Vavruša committed
651 652 653
            address = None
        # Find current valid query response range
        for rng in self.ranges:
654
            if rng.eligible(current_step_id, address):
655
                self.current_range = rng
656
                return rng.reply(query)
Marek Vavruša's avatar
Marek Vavruša committed
657 658
        # Find any prescripted one-shot replies
        for step in self.steps:
659
            if step.id < current_step_id or step.type != 'REPLY':
Marek Vavruša's avatar
Marek Vavruša committed
660 661 662
                continue
            try:
                candidate = step.data[0]
663 664 665
                candidate.match(query)
                step.data.remove(candidate)
                return candidate.reply(query)
666
            except (IndexError, ValueError):
Marek Vavruša's avatar
Marek Vavruša committed
667
                pass
668
        return DNSReplyServfail(query)
Marek Vavruša's avatar
Marek Vavruša committed
669

670
    def play(self, paddr):
Marek Vavruša's avatar
Marek Vavruša committed
671
        """ Play given scenario. """
672 673
        # Store test subject => address mapping
        self.client = paddr
Marek Vavruša's avatar
Marek Vavruša committed
674

675 676 677 678 679 680 681
        step = None
        i = 0
        while i < len(self.steps):
            step = self.steps[i]
            self.current_step = step
            try:
                step.play(self)
682
            except ValueError as ex:
683
                if step.repeat_if_fail > 0:
684
                    self.log.info("[play] step %d: exception - '%s', retrying step %d (%d left)",
685
                                  step.id, ex, step.next_if_fail, step.repeat_if_fail)
686
                    step.repeat_if_fail -= 1
687
                    if step.pause_if_fail > 0:
688
                        time.sleep(step.pause_if_fail)
689
                    if step.next_if_fail != -1:
690 691
                        next_steps = [j for j in range(len(self.steps)) if self.steps[
                            j].id == step.next_if_fail]
692
                        if not next_steps:
693 694
                            raise ValueError('step %d: wrong NEXT value "%d"' %
                                             (step.id, step.next_if_fail))
695
                        next_step = next_steps[0]
696
                        if next_step < len(self.steps):
697 698
                            i = next_step
                        else:
699 700
                            raise ValueError('step %d: Can''t branch to NEXT value "%d"' %
                                             (step.id, step.next_if_fail))
701 702
                    continue
                else:
703 704
                    raise ValueError('%s step %d %s' % (self.file, step.id, str(ex)))
            i += 1
705

706 707
        for r in self.ranges:
            for e in r.stored:
708
                if e.mandatory and e.fired == 0:
709
                    # TODO: cisla radku
710
                    raise ValueError('Mandatory section at %s not fired' % e.mandatory.span)
711

712

713
def get_next(file_in, skip_empty=True):
714 715 716
    """ Return next token from the input stream. """
    while True:
        line = file_in.readline()
717
        if not line:
718
            return False
719
        quoted, escaped = False, False
720 721
        for i, char in enumerate(line):
            if char == '\\':
722
                escaped = not escaped
723
            if not escaped and char == '"':
724
                quoted = not quoted
725
            if char == ';' and not quoted:
726 727
                line = line[0:i]
                break
728
            if char != '\\':
729
                escaped = False
730
        tokens = ' '.join(line.strip().split()).split()
731
        if not tokens:
732 733 734 735
            if skip_empty:
                continue
            else:
                return '', []
736 737 738
        op = tokens.pop(0)
        return op, tokens

739

740
def parse_config(scn_cfg, qmin, installdir):  # FIXME: pylint: disable=too-many-statements
741 742
    """
    Transform scene config (key, value) pairs into dict filled with defaults.
743 744 745
    Returns tuple:
      context dict: {Jinja2 variable: value}
      trust anchor dict: {domain: [TA lines for particular domain]}
746 747 748 749 750 751
    """
    # defaults
    do_not_query_localhost = True
    harden_glue = True
    sockfamily = 0  # auto-select value for socket.getaddrinfo
    trust_anchor_list = []
752
    trust_anchor_files = {}
753
    negative_ta_list = []
754 755 756 757 758 759 760 761 762 763 764
    stub_addr = None
    override_timestamp = None

    features = {}
    feature_list_delimiter = ';'
    feature_pair_delimiter = '='

    for k, v in scn_cfg:
        # Enable selectively for some tests
        if k == 'do-not-query-localhost':
            do_not_query_localhost = str2bool(v)
765
        elif k == 'domain-insecure':
766
            negative_ta_list.append(v)
767
        elif k == 'harden-glue':
768
            harden_glue = str2bool(v)
769
        elif k == 'query-minimization':
770 771
            qmin = str2bool(v)
        elif k == 'trust-anchor':
772 773 774 775 776 777
            trust_anchor = v.strip('"\'')
            trust_anchor_list.append(trust_anchor)
            domain = dns.name.from_text(trust_anchor.split()[0]).canonicalize()
            if domain not in trust_anchor_files:
                trust_anchor_files[domain] = []
            trust_anchor_files[domain].append(trust_anchor)
778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806
        elif k == 'val-override-timestamp':
            override_timestamp_str = v.strip('"\'')
            override_timestamp = int(override_timestamp_str)
        elif k == 'val-override-date':
            override_date_str = v.strip('"\'')
            ovr_yr = override_date_str[0:4]
            ovr_mnt = override_date_str[4:6]
            ovr_day = override_date_str[6:8]
            ovr_hr = override_date_str[8:10]
            ovr_min = override_date_str[10:12]
            ovr_sec = override_date_str[12:]
            override_date_str_arg = '{0} {1} {2} {3} {4} {5}'.format(
                ovr_yr, ovr_mnt, ovr_day, ovr_hr, ovr_min, ovr_sec)
            override_date = time.strptime(override_date_str_arg, "%Y %m %d %H %M %S")
            override_timestamp = calendar.timegm(override_date)
        elif k == 'stub-addr':
            stub_addr = v.strip('"\'')
        elif k == 'features':
            feature_list = v.split(feature_list_delimiter)
            try:
                for f_item in feature_list:
                    if f_item.find(feature_pair_delimiter) != -1:
                        f_key, f_value = [x.strip()
                                          for x
                                          in f_item.split(feature_pair_delimiter, 1)]
                    else:
                        f_key = f_item.strip()
                        f_value = ""
                    features[f_key] = f_value
807 808
            except KeyError as ex:
                raise KeyError("can't parse features (%s) in config section (%s)" % (v, str(ex)))
809 810 811 812 813 814 815
        elif k == 'feature-list':
            try:
                f_key, f_value = [x.strip() for x in v.split(feature_pair_delimiter, 1)]
                if f_key not in features:
                    features[f_key] = []
                f_value = f_value.replace("{{INSTALL_DIR}}", installdir)
                features[f_key].append(f_value)
816 817 818
            except KeyError as ex:
                raise KeyError("can't parse feature-list (%s) in config section (%s)"
                               % (v, str(ex)))
819 820
        elif k == 'force-ipv6' and v.upper() == 'TRUE':
            sockfamily = socket.AF_INET6
821 822
        else:
            raise NotImplementedError('unsupported CONFIG key "%s"' % k)
823 824 825

    ctx = {
        "DO_NOT_QUERY_LOCALHOST": str(do_not_query_localhost).lower(),
826
        "NEGATIVE_TRUST_ANCHORS": negative_ta_list,
827 828 829 830 831
        "FEATURES": features,
        "HARDEN_GLUE": str(harden_glue).lower(),
        "INSTALL_DIR": installdir,
        "QMIN": str(qmin).lower(),
        "TRUST_ANCHORS": trust_anchor_list,
832
        "TRUST_ANCHOR_FILES": trust_anchor_files.keys()
833 834 835 836 837 838 839 840 841 842 843 844 845
    }
    if stub_addr:
        ctx['ROOT_ADDR'] = stub_addr
        # determine and verify socket family for specified root address
        gai = socket.getaddrinfo(stub_addr, 53, sockfamily, 0,
                                 socket.IPPROTO_UDP, socket.AI_NUMERICHOST)
        assert len(gai) == 1
        sockfamily = gai[0][0]
    if not sockfamily:
        sockfamily = socket.AF_INET  # default to IPv4
    ctx['_SOCKET_FAMILY'] = sockfamily
    if override_timestamp:
        ctx['_OVERRIDE_TIMESTAMP'] = override_timestamp
846
    return (ctx, trust_anchor_files)
847 848


849
def parse_file(path):
850
    """ Parse scenario from a file. """
851

852 853
    aug = pydnstest.augwrap.AugeasWrapper(
        confpath=path, lens='Deckard', loadpath=os.path.dirname(__file__))
854
    node = aug.tree
855 856 857
    config = []
    for line in [c.value for c in node.match("/config/*")]:
        if line:
858 859 860 861 862
            if not line.startswith(';'):
                if '#' in line:
                    line = line[0:line.index('#')]
                # Break to key-value pairs
                # e.g.: ['minimization', 'on']
863
                kv = [x.strip() for x in line.split(':', 1)]
864 865
                if len(kv) >= 2:
                    config.append(kv)
Tomas Krizek's avatar
Tomas Krizek committed
866
    scenario = Scenario(node["/scenario"], os.path.basename(node.path))
867
    return scenario, config