-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathscan_engine_raw.cc
2163 lines (1952 loc) · 82.3 KB
/
scan_engine_raw.cc
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
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
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
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
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
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
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/***************************************************************************
* scan_engine_raw.cc -- includes helper functions for scan_engine.cc that *
* are related to port scanning using raw (IP, Ethernet) packets. *
* *
***********************IMPORTANT NMAP LICENSE TERMS************************
*
* The Nmap Security Scanner is (C) 1996-2024 Nmap Software LLC ("The Nmap
* Project"). Nmap is also a registered trademark of the Nmap Project.
*
* This program is distributed under the terms of the Nmap Public Source
* License (NPSL). The exact license text applying to a particular Nmap
* release or source code control revision is contained in the LICENSE
* file distributed with that version of Nmap or source code control
* revision. More Nmap copyright/legal information is available from
* https://nmap.org/book/man-legal.html, and further information on the
* NPSL license itself can be found at https://nmap.org/npsl/ . This
* header summarizes some key points from the Nmap license, but is no
* substitute for the actual license text.
*
* Nmap is generally free for end users to download and use themselves,
* including commercial use. It is available from https://nmap.org.
*
* The Nmap license generally prohibits companies from using and
* redistributing Nmap in commercial products, but we sell a special Nmap
* OEM Edition with a more permissive license and special features for
* this purpose. See https://nmap.org/oem/
*
* If you have received a written Nmap license agreement or contract
* stating terms other than these (such as an Nmap OEM license), you may
* choose to use and redistribute Nmap under those terms instead.
*
* The official Nmap Windows builds include the Npcap software
* (https://npcap.com) for packet capture and transmission. It is under
* separate license terms which forbid redistribution without special
* permission. So the official Nmap Windows builds may not be redistributed
* without special permission (such as an Nmap OEM license).
*
* Source is provided to this software because we believe users have a
* right to know exactly what a program is going to do before they run it.
* This also allows you to audit the software for security holes.
*
* Source code also allows you to port Nmap to new platforms, fix bugs, and
* add new features. You are highly encouraged to submit your changes as a
* Github PR or by email to the [email protected] mailing list for possible
* incorporation into the main distribution. Unless you specify otherwise, it
* is understood that you are offering us very broad rights to use your
* submissions as described in the Nmap Public Source License Contributor
* Agreement. This is important because we fund the project by selling licenses
* with various terms, and also because the inability to relicense code has
* caused devastating problems for other Free Software projects (such as KDE
* and NASM).
*
* The free version of Nmap is distributed in the hope that it will be
* useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. Warranties,
* indemnification and commercial support are all available through the
* Npcap OEM program--see https://nmap.org/oem/
*
***************************************************************************/
/* $Id$ */
#include "nmap_error.h"
#include "NmapOps.h"
#include "Target.h"
#include "payload.h"
#include "scan_engine.h"
#include "scan_engine_raw.h"
#include "struct_ip.h"
#include "tcpip.h"
#include "utils.h"
#include <string>
#ifndef IPPROTO_SCTP
#include "libnetutil/netutil.h"
#endif
extern NmapOps o;
u16 UltraProbe::sport() const {
switch (mypspec.proto) {
case IPPROTO_TCP:
return probes.IP.pd.tcp.sport;
case IPPROTO_UDP:
return probes.IP.pd.udp.sport;
case IPPROTO_SCTP:
return probes.IP.pd.sctp.sport;
default:
return 0;
}
/* not reached */
}
u16 UltraProbe::dport() const {
switch (mypspec.proto) {
case IPPROTO_TCP:
return mypspec.pd.tcp.dport;
case IPPROTO_UDP:
return mypspec.pd.udp.dport;
case IPPROTO_SCTP:
return mypspec.pd.sctp.dport;
default:
/* dport() can get called for other protos if we
* get ICMP responses during IP proto scans. */
return 0;
}
/* not reached */
}
bool UltraProbe::check_proto_port(u8 proto, u16 sport_or_icmpid, u16 dport) const {
if (proto != mypspec.proto)
return false;
switch (proto) {
case IPPROTO_ICMP:
case IPPROTO_ICMPV6:
return sport_or_icmpid == probes.IP.pd.icmp.ident;
break;
case IPPROTO_TCP:
return sport_or_icmpid == probes.IP.pd.tcp.sport &&
dport == mypspec.pd.tcp.dport;
break;
case IPPROTO_UDP:
return sport_or_icmpid == probes.IP.pd.udp.sport &&
dport == mypspec.pd.udp.dport;
break;
case IPPROTO_SCTP:
return sport_or_icmpid == probes.IP.pd.sctp.sport &&
dport == mypspec.pd.sctp.dport;
break;
default:
break;
}
return false;
}
/* Pass an arp packet, including ethernet header. Must be 42bytes */
void UltraProbe::setARP(const u8 *arppkt, u32 arplen) {
type = UP_ARP;
mypspec.type = PS_ARP;
return;
}
void UltraProbe::setND(const u8 *ndpkt, u32 ndlen) {
type = UP_ND;
mypspec.type = PS_ND;
return;
}
/* Sets this UltraProbe as type UP_IP and creates & initializes the
internal IPProbe. The relevant probespec is necessary for setIP
because pspec.type is ambiguous with just the ippacket (e.g. a
tcp packet could be PS_PROTO or PS_TCP). */
void UltraProbe::setIP(const u8 *ippacket, u32 len, const probespec *pspec) {
const struct ip *ip = (const struct ip *) ippacket;
const struct tcp_hdr *tcp = NULL;
const struct udp_hdr *udp = NULL;
const struct sctp_hdr *sctp = NULL;
const struct ppkt *icmp = NULL;
const void *data;
u8 hdr;
type = UP_IP;
if (ip->ip_v == 4) {
data = ipv4_get_data(ip, &len);
assert(data != NULL);
assert(len + ip->ip_hl * 4 == (u32) ntohs(ip->ip_len));
probes.IP.ipid = ntohs(ip->ip_id);
hdr = ip->ip_p;
} else if (ip->ip_v == 6) {
const struct ip6_hdr *ip6 = (const struct ip6_hdr *) ippacket;
data = ipv6_get_data_any(ip6, &len, &hdr);
assert(data != NULL);
assert(len == (u32) ntohs(ip6->ip6_plen));
probes.IP.ipid = ntohl(ip6->ip6_flow & IP6_FLOWLABEL_MASK);
hdr = ip6->ip6_nxt;
} else {
fatal("Bogus packet passed to %s -- only IP packets allowed", __func__);
}
if (hdr == IPPROTO_TCP) {
assert(len >= sizeof(struct tcp_hdr));
tcp = (const struct tcp_hdr *) data;
probes.IP.pd.tcp.sport = ntohs(tcp->th_sport);
probes.IP.pd.tcp.seq = ntohl(tcp->th_seq);
} else if (hdr == IPPROTO_UDP) {
assert(len >= sizeof(struct udp_hdr));
udp = (const struct udp_hdr *) data;
probes.IP.pd.udp.sport = ntohs(udp->uh_sport);
} else if (hdr == IPPROTO_SCTP) {
assert(len >= sizeof(struct sctp_hdr));
sctp = (const struct sctp_hdr *) data;
probes.IP.pd.sctp.sport = ntohs(sctp->sh_sport);
probes.IP.pd.sctp.vtag = ntohl(sctp->sh_vtag);
} else if ((ip->ip_v == 4 && hdr == IPPROTO_ICMP) || (ip->ip_v == 6 && hdr == IPPROTO_ICMPV6)) {
assert(len >= sizeof(struct ppkt));
icmp = (const struct ppkt *) data;
probes.IP.pd.icmp.ident = ntohs(icmp->id);
}
mypspec = *pspec;
return;
}
u16 UltraProbe::icmpid() const {
assert(mypspec.proto == IPPROTO_ICMP || mypspec.proto == IPPROTO_ICMPV6);
return probes.IP.pd.icmp.ident;
}
u32 UltraProbe::tcpseq() const {
if (mypspec.proto == IPPROTO_TCP)
return probes.IP.pd.tcp.seq;
else
fatal("Bogus seq number request to %s -- type is %s", __func__,
pspectype2ascii(mypspec.type));
return 0; // Unreached
}
u32 UltraProbe::sctpvtag() const {
assert(mypspec.proto == IPPROTO_SCTP);
return probes.IP.pd.sctp.vtag;
}
/* The try number can be encoded into a TCP SEQ or ACK
field. This returns a 32-bit number which encodes this value along
with a simple checksum. Decoding is done by seq32_decode. */
static u32 seq32_encode(UltraScanInfo *USI, tryno_t trynum) {
u32 seq;
u8 nfo;
/* tryno is 8 bits */
nfo = trynum.opaque;
/* Mirror the data to ensure it is reconstructed correctly. */
seq = (nfo << 16) + nfo;
/* Obfuscate it a little */
seq = seq ^ USI->seqmask;
return seq;
}
/* Undoes seq32_encode. This extracts a try number and a port number from a
32-bit value. Returns true if the checksum is correct, false otherwise. */
static bool seq32_decode(const UltraScanInfo *USI, u32 seq,
tryno_t *trynum) {
if (trynum)
trynum->opaque = 0;
/* Undo the mask xor. */
seq = seq ^ USI->seqmask;
/* Check that both sides are the same. */
if ((seq >> 16) != (seq & 0xFFFF))
return false;
if (trynum)
trynum->opaque = seq & 0xFF;
return true;
}
/* The try number can be encoded in the source port number. This returns a new
port number that contains a try number encoded into the given port number.
Decoding is done by sport_decode. */
static u16 sport_encode(u16 base_portno, tryno_t trynum) {
return base_portno + trynum.opaque;
}
/* We don't actually decode the port number, since we already compare the
* destination port number of the response with the source port of the probe.
*/
#if 0
/* Undoes sport_encode. This extracts a try number and ping sequence number from
a port number given a "base" port number (the one given to
sport_encode). Returns true if the decoded values seem reasonable, false
otherwise. */
static bool sport_decode(u16 base_portno, u16 portno,
tryno_t *trynum) {
unsigned int t;
t = portno - base_portno;
if (t > 0xff) {
return false;
} else {
if (trynum)
trynum->opaque = t;
}
return true;
}
#endif
static bool icmp_probe_match(const UltraScanInfo *USI, const UltraProbe *probe,
const struct ppkt *ping,
const struct sockaddr_storage *src,
const struct sockaddr_storage *dst,
u8 proto,
u32 ipid) {
/* Check if it is ICMP or ICMPV6. */
if (!probe->check_proto_port(proto, ntohs(ping->id), 0))
return false;
/* Don't match a timestamp request with an echo reply, for example. */
if (proto == IPPROTO_ICMP &&
((ping->type == 0 && probe->pspec()->pd.icmp.type != 8) ||
(ping->type == 14 && probe->pspec()->pd.icmp.type != 13) ||
(ping->type == 18 && probe->pspec()->pd.icmp.type != 17)))
return false;
if (proto == IPPROTO_ICMPV6 &&
(ping->type == 129 && probe->pspec()->pd.icmpv6.type != 128))
return false;
/* Sometimes we get false results when scanning localhost with
-p- because we scan localhost with src port = dst port and
see our outgoing packet and think it is a response. */
if (probe->dport() == probe->sport() &&
sockaddr_storage_cmp(src, dst) == 0 &&
probe->ipid() == ipid)
return false; /* We saw the packet we ourselves sent */
return true;
}
static bool tcp_probe_match(const UltraScanInfo *USI, const UltraProbe *probe,
const struct tcp_hdr *tcp,
const struct sockaddr_storage *src, const struct sockaddr_storage *dst,
u32 ipid) {
const struct probespec_tcpdata *probedata;
tryno_t tryno = {0};
bool goodseq;
// If magic port is *not* set, then tryno is in the source port, and we
// already checked that it matches.
if (o.magic_port_set) {
/* We are looking to recover the tryno of the probe, which are
encoded in the ACK field for probes with the ACK flag set and in the SEQ
field for all other probes. According to RFC 793, section 3.9, under
"SEGMENT ARRIVES", it's supposed to work like this: If our probe had ACK
set, our ACK number is reflected in the response's SEQ field. If our
probe had SYN or FIN set (and not ACK), then our SEQ is one less than the
returned ACK value because SYN and FIN consume a sequence number (section
3.3). Otherwise, our SEQ is the returned ACK.
However, nmap-os-db shows that these assumptions can't be relied on, so
we try all three possibilities for each probe. */
goodseq = seq32_decode(USI, ntohl(tcp->th_ack) - 1, &tryno)
|| seq32_decode(USI, ntohl(tcp->th_ack), &tryno)
|| seq32_decode(USI, ntohl(tcp->th_seq), &tryno);
if (!goodseq) {
/* Connection info matches, but there was a nonsensical tryno. */
if (o.debugging)
log_write(LOG_PLAIN, "Bad Sequence number from host %s.\n", inet_ntop_ez(src, sizeof(*src)));
return false;
}
/* Make sure that tryno matches the values in the probe. */
if (!probe->check_tryno(tryno.opaque))
return false;
}
/* Make sure we are matching up the right kind of probe, otherwise just the
ports, address, and tryno can be ambiguous, between a SYN and an
ACK probe during a -PS80 -PA80 scan for example. A SYN/ACK can only be
matched to a SYN probe. */
probedata = &probe->pspec()->pd.tcp;
if ((tcp->th_flags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)
&& !(probedata->flags & TH_SYN)) {
return false;
}
/* Sometimes we get false results when scanning localhost with -p- because we
scan localhost with src port = dst port and see our outgoing packet and
think it is a response. */
if (probe->dport() == probe->sport()
&& sockaddr_storage_cmp(src, dst) == 0
&& probe->ipid() == ipid)
return false;
return true;
}
/* Tries to get one *good* (finishes a probe) pcap response to a host discovery
(ping) probe by the (absolute) time given in stime. Even if stime is now,
try an ultra-quick pcap read just in case. Returns true if a "good" result
was found, false if it timed out instead. */
int get_ping_pcap_result(UltraScanInfo *USI, struct timeval *stime) {
bool goodone = false;
bool timedout = false;
bool adjust_timing = true;
struct timeval rcvdtime;
struct link_header linkhdr;
const struct ip *ip_tmp;
unsigned int bytes;
const struct ppkt *ping;
long to_usec;
HostScanStats *hss = NULL;
std::list<UltraProbe *>::iterator probeI;
UltraProbe *probe = NULL;
int newstate = HOST_UNKNOWN;
unsigned int probenum;
unsigned int listsz;
reason_t current_reason = ER_NORESPONSE;
const void *data = NULL;
unsigned int datalen;
struct abstract_ip_hdr hdr;
do {
to_usec = TIMEVAL_SUBTRACT(*stime, USI->now);
if (to_usec < 2000)
to_usec = 2000;
ip_tmp = (struct ip *) readip_pcap(USI->pd, &bytes, to_usec, &rcvdtime,
&linkhdr, true);
gettimeofday(&USI->now, NULL);
if (!ip_tmp) {
if (TIMEVAL_BEFORE(*stime, USI->now)) {
timedout = true;
break;
} else {
continue;
}
}
if (TIMEVAL_SUBTRACT(USI->now, *stime) > 200000) {
/* While packets are still being received, I'll be generous and give
an extra 1/5 sec. But we have to draw the line somewhere */
timedout = true;
}
/* OK, we got a packet. Most packet validity tests are taken care
* of in readip_pcap, so this is simple
*/
datalen = bytes;
data = ip_get_data(ip_tmp, &datalen, &hdr);
if (data == NULL)
continue;
// If it's not sent to us, we don't care.
if (sockaddr_storage_cmp(USI->SourceSockAddr(), &hdr.dst) != 0)
continue;
/* First check if it is ICMP, TCP, or UDP */
if (hdr.proto == IPPROTO_ICMP || hdr.proto == IPPROTO_ICMPV6) {
/* if it is our response */
ping = (struct ppkt *) data;
if (bytes < 8U) {
if (!ip_tmp->ip_off)
error("Supposed ping packet is only %d bytes long!", bytes);
continue;
}
current_reason = icmp_to_reason(hdr.proto, ping->type, ping->code);
/* Echo reply, Timestamp reply, or Address Mask Reply. RFCs 792 and 950. */
/* ICMPv6 Echo reply */
if (USI->ptech.rawicmpscan
&& ((hdr.proto == IPPROTO_ICMP && (ping->type == 0 || ping->type == 14 || ping->type == 18))
|| (hdr.proto == IPPROTO_ICMPV6 && ping->type == 129))) {
hss = USI->findHost(&hdr.src);
if (!hss)
continue; // Not from a host that interests us
setTargetMACIfAvailable(hss->target, &linkhdr, &hdr.src, 0);
probeI = hss->probes_outstanding.end();
listsz = hss->num_probes_outstanding();
/* A check for weird_responses is needed here. This is not currently
possible because we don't have a good way to look up the original
target of an ICMP probe based on the response. (massping encoded an
array index in the ICMP sequence, which won't work here.) Once we've
found the host that sent the probe that elicited the response, the
test for weird_responses is
if (sending_host->v4host().s_addr != ip->ip_src.s_addr)
hss->target->weird_responses++;
(That is, the target that sent the probe is not the same one that
sent the response.)
*/
goodone = false;
/* Find the probe that provoked this response. */
for (probenum = 0; probenum < listsz && !goodone; probenum++) {
probeI--;
probe = *probeI;
if (!icmp_probe_match(USI, probe, ping, &hdr.src, &hdr.dst, hdr.proto, hdr.ipid))
continue;
goodone = true;
newstate = HOST_UP;
if (o.debugging)
log_write(LOG_STDOUT, "We got a ping packet back from %s: id = %d seq = %d checksum = %d\n", inet_ntop_ez(&hdr.src, sizeof(hdr.src)), ping->id, ping->seq, ping->checksum);
}
}
// For ICMP, the reply of TCP/UDP/ICMP packets can be Destination unreachable, source quench, or time exceeded
/* For ICMPv6, the reply of TCP/UDP/ICMPV6 packets can be Destination Unreachable,
* Packet Too Big, Time Exceeded and Parameter Problem.*/
else if ((hdr.proto == IPPROTO_ICMP && (ping->type == 3 || ping->type
== 4 || ping->type == 11))
|| (hdr.proto == IPPROTO_ICMPV6 && (ping->type == 1 || ping->type == 2
|| ping->type == 3 || ping->type == 4))) {
const void *encaps_data;
unsigned int encaps_len;
struct abstract_ip_hdr encaps_hdr;
if (datalen < 8)
continue;
encaps_len = datalen - 8;
encaps_data = ip_get_data((char *) data + 8, &encaps_len, &encaps_hdr);
if (encaps_data == NULL ||
/* UDP hdr, or TCP hdr up to seq #, or SCTP hdr up to vtag */
((USI->tcp_scan || USI->udp_scan || USI->sctp_scan) && encaps_len < 8)
/* prot scan has no headers coming back, so we don't reserve the
8 extra bytes */
) {
if (o.debugging)
error("Received short ICMP or ICMPv6 packet (%u bytes)", datalen);
continue;
}
/* Bail out early if possible. */
if (!USI->ptech.rawprotoscan) {
if (encaps_hdr.proto == IPPROTO_ICMP && !USI->ptech.rawicmpscan)
continue;
if (encaps_hdr.proto == IPPROTO_ICMPV6 && !USI->ptech.rawicmpscan)
continue;
if (encaps_hdr.proto == IPPROTO_TCP && !USI->ptech.rawtcpscan)
continue;
if (encaps_hdr.proto == IPPROTO_UDP && !USI->ptech.rawudpscan)
continue;
if (encaps_hdr.proto == IPPROTO_SCTP && !USI->ptech.rawsctpscan)
continue;
}
// If it didn't come from us, we don't care.
if (sockaddr_storage_cmp(USI->SourceSockAddr(), &encaps_hdr.src) != 0)
continue;
hss = USI->findHost(&encaps_hdr.dst);
if (!hss)
continue; // Not referring to a host that interests us
setTargetMACIfAvailable(hss->target, &linkhdr, &encaps_hdr.dst, 0);
probeI = hss->probes_outstanding.end();
listsz = hss->num_probes_outstanding();
/* Find the probe that provoked this response. */
for (probenum = 0; probenum < listsz; probenum++) {
probeI--;
probe = *probeI;
if (probe->protocol() != encaps_hdr.proto)
continue;
if ((encaps_hdr.proto == IPPROTO_ICMP || encaps_hdr.proto == IPPROTO_ICMPV6)
&& USI->ptech.rawicmpscan) {
/* The response was based on a ping packet we sent */
if (probe->icmpid() != ntohs(((struct icmp *) encaps_data)->icmp_id))
continue;
} else if (encaps_hdr.proto == IPPROTO_TCP && USI->ptech.rawtcpscan) {
const struct tcp_hdr *tcp = (struct tcp_hdr *) encaps_data;
if (probe->dport() != ntohs(tcp->th_dport) ||
probe->sport() != ntohs(tcp->th_sport) ||
probe->tcpseq() != ntohl(tcp->th_seq))
continue;
} else if (encaps_hdr.proto == IPPROTO_UDP && USI->ptech.rawudpscan) {
const struct udp_hdr *udp = (struct udp_hdr *) encaps_data;
if (probe->dport() != ntohs(udp->uh_dport) ||
probe->sport() != ntohs(udp->uh_sport))
continue;
} else if (encaps_hdr.proto == IPPROTO_SCTP && USI->ptech.rawsctpscan) {
const struct sctp_hdr *sctp = (struct sctp_hdr *) encaps_data;
if (probe->dport() != ntohs(sctp->sh_dport) ||
probe->sport() != ntohs(sctp->sh_sport) ||
probe->sctpvtag() != ntohl(sctp->sh_vtag))
continue;
} else if (USI->ptech.rawprotoscan) {
/* Success; we already know that the address and protocol match. */
} else {
assert(0);
}
/* If we made it this far, we found it. We don't yet know if it's
going to change a host state (goodone) or not. */
break;
}
/* Did we fail to find a probe? */
if (probenum >= listsz)
continue;
/* Destination unreachable. */
if ((hdr.proto == IPPROTO_ICMP && ping->type == 3)
|| (hdr.proto == IPPROTO_ICMPV6 && ping->type == 1)) {
// If it's Port or Proto unreachable and the address matches, it's up.
if (((hdr.proto == IPPROTO_ICMP && (ping->code == 2 || ping->code == 3))
|| (hdr.proto == IPPROTO_ICMPV6 && ping->code == 4))
&& sockaddr_storage_cmp(hss->target->TargetSockAddr(), &hdr.src) == 0) {
/* The ICMP or ICMPv6 error came directly from the target, so it's up. */
goodone = true;
newstate = HOST_UP;
if (o.debugging) {
log_write(LOG_STDOUT, "Got port/proto unreachable for %s\n", hss->target->targetipstr());
}
}
else {
/* For other codes, see RFC 1122:
* A Destination Unreachable message that is received with code
* 0 (Net), 1 (Host), or 5 (Bad Source Route) may result from a
* routing transient and MUST therefore be interpreted as only
* a hint, not proof, that the specified destination is unreachable
*/
// Still, it's a response so we should destroy the matching probe.
goodone = true;
newstate = HOST_UNKNOWN;
adjust_timing = false;
if (o.debugging) {
log_write(LOG_STDOUT, "Got destination unreachable for %s\n", hss->target->targetipstr());
}
}
} else if ((hdr.proto == IPPROTO_ICMP && ping->type == 11)
|| (hdr.proto == IPPROTO_ICMPV6 && ping->type == 3)) {
if (o.debugging)
log_write(LOG_STDOUT, "Got Time Exceeded for %s\n", hss->target->targetipstr());
goodone = 1;
newstate = HOST_DOWN;
/* I don't want anything to do with timing this. */
adjust_timing = false;
} else if (hdr.proto == IPPROTO_ICMP) {
if (ping->type == 4) {
if (o.debugging)
log_write(LOG_STDOUT, "Got ICMP source quench\n");
usleep(50000);
} else {
if (o.debugging) {
log_write(LOG_STDOUT, "Got ICMP message type %d code %d\n",
ping->type, ping->code);
}
}
} else if (hdr.proto == IPPROTO_ICMPV6) {
if (ping->type == 4) {
if (o.debugging)
log_write(LOG_STDOUT, "Got ICMPv6 Parameter Problem\n");
} else {
if (o.debugging)
log_write(LOG_STDOUT, "Got ICMPv6 message type %d code %d\n",
ping->type, ping->code);
}
}
}
} else if (hdr.proto == IPPROTO_TCP && USI->ptech.rawtcpscan) {
const struct tcp_hdr *tcp = (struct tcp_hdr *) data;
/* Check that the packet has useful flags. */
if (o.discovery_ignore_rst
&& (tcp->th_flags & TH_RST))
continue;
else if (!(tcp->th_flags & TH_RST)
&& ((tcp->th_flags & (TH_SYN | TH_ACK)) != (TH_SYN | TH_ACK)))
continue;
/* Now ensure this host is even in the incomplete list */
hss = USI->findHost(&hdr.src);
if (!hss)
continue; // Not from a host that interests us
setTargetMACIfAvailable(hss->target, &linkhdr, &hdr.src, 0);
probeI = hss->probes_outstanding.end();
listsz = hss->num_probes_outstanding();
u16 sport = ntohs(tcp->th_sport);
u16 dport = ntohs(tcp->th_dport);
goodone = false;
/* Find the probe that provoked this response. */
for (probenum = 0; probenum < listsz && !goodone; probenum++) {
probeI--;
probe = *probeI;
if (!probe->check_proto_port(hdr.proto, dport, sport))
continue;
if (!tcp_probe_match(USI, probe, tcp, &hdr.src, &hdr.dst, hdr.ipid))
continue;
goodone = true;
newstate = HOST_UP;
/* Fill out the reason. */
if (o.pingtype & PINGTYPE_TCP_USE_SYN) {
if (tcp->th_flags & TH_RST) {
current_reason = ER_RESETPEER;
} else if ((tcp->th_flags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
current_reason = ER_SYNACK;
}
} else if (o.pingtype & PINGTYPE_TCP_USE_ACK) {
if (tcp->th_flags & TH_RST)
current_reason = ER_RESETPEER;
}
if (o.debugging)
log_write(LOG_STDOUT, "We got a TCP ping packet back from %s port %hu (trynum = %d)\n", inet_ntop_ez(&hdr.src, sizeof(hdr.src)), sport, probe->get_tryno());
}
} else if (hdr.proto == IPPROTO_UDP && USI->ptech.rawudpscan) {
const struct udp_hdr *udp = (struct udp_hdr *) data;
/* Search for this host on the incomplete list */
hss = USI->findHost(&hdr.src);
if (!hss)
continue; // Not from a host that interests us
probeI = hss->probes_outstanding.end();
listsz = hss->num_probes_outstanding();
goodone = false;
u16 sport = ntohs(udp->uh_sport);
u16 dport = ntohs(udp->uh_dport);
for (probenum = 0; probenum < listsz && !goodone; probenum++) {
probeI--;
probe = *probeI;
if (!probe->check_proto_port(hdr.proto, dport, sport))
continue;
/* Sometimes we get false results when scanning localhost with
-p- because we scan localhost with src port = dst port and
see our outgoing packet and think it is a response. */
if (probe->dport() == probe->sport() &&
sockaddr_storage_cmp(&hdr.src, &hdr.dst) == 0 &&
probe->ipid() == hdr.ipid)
continue; /* We saw the packet we ourselves sent */
goodone = true;
newstate = HOST_UP;
current_reason = ER_UDPRESPONSE;
if (o.debugging)
log_write(LOG_STDOUT, "In response to UDP-ping, we got UDP packet back from %s port %hu (trynum = %d)\n", inet_ntop_ez(&hdr.src, sizeof(hdr.src)), sport, probe->get_tryno());
}
} else if (hdr.proto == IPPROTO_SCTP && USI->ptech.rawsctpscan) {
const struct sctp_hdr *sctp = (struct sctp_hdr *) data;
const struct dnet_sctp_chunkhdr *chunk =
(struct dnet_sctp_chunkhdr *) ((u8 *) sctp + 12);
/* Search for this host on the incomplete list */
hss = USI->findHost(&hdr.src);
if (!hss)
continue; // Not from a host that interests us
probeI = hss->probes_outstanding.end();
listsz = hss->num_probes_outstanding();
goodone = false;
u16 sport = ntohs(sctp->sh_sport);
u16 dport = ntohs(sctp->sh_dport);
for (probenum = 0; probenum < listsz && !goodone; probenum++) {
probeI--;
probe = *probeI;
if (!probe->check_proto_port(hdr.proto, dport, sport))
continue;
/* Sometimes we get false results when scanning localhost with
-p- because we scan localhost with src port = dst port and
see our outgoing packet and think it is a response. */
if (probe->dport() == probe->sport() &&
sockaddr_storage_cmp(&hdr.src, &hdr.dst) == 0 &&
probe->ipid() == hdr.ipid)
continue; /* We saw the packet we ourselves sent */
goodone = true;
newstate = HOST_UP;
if (chunk->sch_type == SCTP_INIT_ACK) {
current_reason = ER_INITACK;
} else if (chunk->sch_type == SCTP_ABORT) {
current_reason = ER_ABORT;
} else {
current_reason = ER_UNKNOWN;
if (o.debugging)
log_write(LOG_STDOUT, "Received scan response with unexpected SCTP chunks: n/a");
}
}
} else if (!USI->ptech.rawprotoscan) {
if (o.debugging > 2)
error("Received packet with protocol %d; ignoring.", hdr.proto);
}
/* Check for a protocol reply */
if (!goodone && USI->ptech.rawprotoscan) {
hss = USI->findHost(&hdr.src);
if (!hss)
continue;
setTargetMACIfAvailable(hss->target, &linkhdr, &hdr.src, 0);
probeI = hss->probes_outstanding.end();
listsz = hss->num_probes_outstanding();
goodone = false;
for (probenum = 0; probenum < listsz && !goodone; probenum++) {
probeI--;
probe = *probeI;
if (probe->protocol() == hdr.proto) {
/* if this is our probe we sent to localhost, then it doesn't count! */
if (sockaddr_storage_cmp(&hdr.src, &hdr.dst) == 0 &&
probe->ipid() == hdr.ipid)
break;
newstate = HOST_UP;
current_reason = ER_PROTORESPONSE;
goodone = true;
}
}
}
} while (!goodone && !timedout);
if (goodone && newstate != HOST_UNKNOWN) {
if (probe->isPing())
ultrascan_ping_update(USI, hss, probeI, &USI->now, adjust_timing);
else {
ultrascan_host_probe_update(USI, hss, probeI, newstate, &rcvdtime, adjust_timing);
/* If the host is up, we can forget our other probes. */
if (newstate == HOST_UP)
hss->destroyAllOutstandingProbes();
if (newstate == HOST_UP && data)
setTargetMACIfAvailable(hss->target, &linkhdr, &hdr.src, 0);
hss->target->reason.reason_id = current_reason;
hss->target->reason.ttl = hdr.ttl;
if (sockaddr_storage_cmp(&hdr.src, hss->target->TargetSockAddr()) != 0) {
hss->target->reason.set_ip_addr(&hdr.src);
}
}
}
return goodone;
}
/* Initiate libpcap or some other sniffer as appropriate to be able to catch
responses */
void begin_sniffer(UltraScanInfo *USI, std::vector<Target *> &Targets) {
std::string pcap_filter = "";
/* 20 IPv6 addresses is max (45 byte addy + 14 (" or src host ")) * 20 == 1180 */
std::string dst_hosts = "";
unsigned int len = 0;
unsigned int targetno;
bool doIndividual = Targets.size() <= 20; // Don't bother IP limits if scanning huge # of hosts
if (doIndividual) {
for (targetno = 0; targetno < Targets.size(); targetno++) {
dst_hosts += (targetno == 0) ? "" : " or ";
dst_hosts += "src host ";
dst_hosts += Targets[targetno]->targetipstr();
}
}
if ((USI->pd = my_pcap_open_live(Targets[0]->deviceName(), 256, (o.spoofsource) ? 1 : 0, pcap_selectable_fd_valid() ? 200 : 2)) == NULL)
fatal("%s", PCAP_OPEN_ERRMSG);
int datalink = pcap_datalink(USI->pd);
if (datalink < 0) {
error("Warning: unable to determine data link for interface %s", Targets[0]->deviceName());
}
if (USI->ping_scan_arp) {
assert(datalink == DLT_EN10MB);
/* Some OSs including Windows 7 and Solaris 10 have been seen to send their
ARP replies to the broadcast address, not to the (unicast) address that
the request came from, therefore listening for ARP packets directed to
us is not enough. Look inside the ARP reply at the target address field
instead. The filter string will look like
arp and arp[18:4] = 0xAABBCCDD and arp[22:2] = 0xEEFF */
char macstring[2 * ETH_ADDR_LEN + 1];
const u8 *mac = Targets[0]->SrcMACAddress();
assert(mac);
len = Snprintf(macstring, sizeof(macstring), "%02X%02X%02X%02X%02X%02X",
mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
if (len != sizeof(macstring) - 1)
fatal("macstring length is %d, should be %u", len, (unsigned)(sizeof(macstring) - 1));
/* First four bytes of MAC. */
pcap_filter = "arp and arp[18:4] = 0x";
pcap_filter.append(macstring, 0, 4 * 2);
/* Last two bytes. */
pcap_filter += " and arp[22:2] = 0x";
pcap_filter.append(macstring, 4 * 2, 2 * 2);
//its not arp, so lets check if for a protocol scan.
} else if (USI->ping_scan_nd) {
/* Libpcap: IPv6 upper-layer protocol is not supported by proto[x] */
/* Grab the ICMPv6 type using ip6[X:Y] syntax. This works only if there are no
extension headers (top-level nh is IPPROTO_ICMPV6). */
const u8 *srcmac = Targets[0]->SrcMACAddress();
assert(srcmac);
char filterstr[256];
Snprintf(filterstr, 256, "icmp6 and ip6[6:1] = %u and ip6[40:1] = %u",
IPPROTO_ICMPV6, ICMPV6_NEIGHBOR_ADVERTISEMENT);
pcap_filter.append(filterstr);
} else if (USI->prot_scan || (USI->ping_scan && USI->ptech.rawprotoscan)) {
pcap_filter = "dst host ";
pcap_filter += inet_ntop_ez(USI->SourceSockAddr(), sizeof(struct sockaddr_storage));
if (doIndividual) {
pcap_filter += " and (icmp or icmp6 or (";
pcap_filter += dst_hosts;
pcap_filter += "))";
}
} else if (USI->tcp_scan || USI->udp_scan || USI->sctp_scan || USI->ping_scan) {
pcap_filter = "dst host ";
pcap_filter += inet_ntop_ez(USI->SourceSockAddr(), sizeof(struct sockaddr_storage));
pcap_filter += " and (icmp or icmp6 or ";
if (doIndividual) {
pcap_filter += "((";
}
// have to accept all of these because pingprobe could be any, regardless of scan type.
pcap_filter += "tcp or udp or sctp";
if (doIndividual) {
pcap_filter += ") and (";
pcap_filter += dst_hosts;
pcap_filter += "))";
}
pcap_filter += ")";
} else {
assert(0);
}
if (o.debugging)
log_write(LOG_PLAIN, "Packet capture filter (device %s): %s\n", Targets[0]->deviceFullName(), pcap_filter.c_str());
set_pcap_filter(Targets[0]->deviceFullName(), USI->pd, pcap_filter.c_str());
/* pcap_setnonblock(USI->pd, 1, NULL); */
return;
}
/* The probe sent is returned. */
UltraProbe *sendArpScanProbe(UltraScanInfo *USI, HostScanStats *hss,
tryno_t tryno) {
int rc;
UltraProbe *probe = new UltraProbe();
/* 3 cheers for libdnet header files */
u8 frame[ETH_HDR_LEN + ARP_HDR_LEN + ARP_ETHIP_LEN];
eth_pack_hdr(frame, ETH_ADDR_BROADCAST, *hss->target->SrcMACAddress(),
ETH_TYPE_ARP);
arp_pack_hdr_ethip(frame + ETH_HDR_LEN, ARP_OP_REQUEST,
*hss->target->SrcMACAddress(), *hss->target->v4sourceip(),
"\x00\x00\x00\x00\x00\x00", *hss->target->v4hostip());
// RFC 826 says that the ar$tha field need not be set to anything in particular (i.e. its value doesn't matter)
// We use 00:00:00:00:00:00 since that is what IP stacks in currently popular operating systems use
gettimeofday(&USI->now, NULL);
probe->sent = USI->now;
hss->probeSent(sizeof(frame));
if ((rc = eth_send(USI->ethsd, frame, sizeof(frame))) != sizeof(frame)) {
int err = socket_errno();
error("WARNING: eth_send of ARP packet returned %i rather than expected %d (errno=%i: %s)", rc, (int) sizeof(frame), err, strerror(err));
}
PacketTrace::traceArp(PacketTrace::SENT, (u8 *) frame + ETH_HDR_LEN, sizeof(frame) - ETH_HDR_LEN, &USI->now);
probe->tryno = tryno;
/* First build the probe */
probe->setARP(frame, sizeof(frame));
/* Now that the probe has been sent, add it to the Queue for this host */
hss->probes_outstanding.push_back(probe);
USI->gstats->num_probes_active++;
hss->num_probes_active++;
gettimeofday(&USI->now, NULL);
return probe;
}
UltraProbe *sendNDScanProbe(UltraScanInfo *USI, HostScanStats *hss,
tryno_t tryno) {
UltraProbe *probe = new UltraProbe();
struct eth_nfo eth;
struct eth_nfo *ethptr = NULL;
u8 *packet = NULL;
u32 packetlen = 0;
struct in6_addr ns_dst_ip6;
ns_dst_ip6 = *hss->target->v6hostip();
if (USI->ethsd) {
unsigned char ns_dst_mac[6] = {0x33, 0x33, 0xff};
ns_dst_mac[3] = ns_dst_ip6.s6_addr[13];
ns_dst_mac[4] = ns_dst_ip6.s6_addr[14];
ns_dst_mac[5] = ns_dst_ip6.s6_addr[15];
memcpy(eth.srcmac, hss->target->SrcMACAddress(), 6);
memcpy(eth.dstmac, ns_dst_mac, 6);
eth.ethsd = USI->ethsd;
eth.devname[0] = '\0';
ethptr = ð
}
unsigned char multicast_prefix[13] = {0};
multicast_prefix[0] = 0xff;
multicast_prefix[1] = 0x02;
multicast_prefix[11] = 0x1;
multicast_prefix[12] = 0xff;
memcpy(&ns_dst_ip6, multicast_prefix, sizeof(multicast_prefix));
const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) USI->SourceSockAddr();
struct icmpv6_msg_nd ns_msg;
ns_msg.icmpv6_flags = htons(0);
memcpy(&ns_msg.icmpv6_target, hss->target->v6hostip(), IP6_ADDR_LEN);
ns_msg.icmpv6_option_type = 1;
ns_msg.icmpv6_option_length = 1;
memcpy(&ns_msg.icmpv6_mac, hss->target->SrcMACAddress(), ETH_ADDR_LEN);
packet = build_icmpv6_raw(&sin6->sin6_addr, &ns_dst_ip6,