/
cstp.c
1155 lines (1010 loc) · 33.6 KB
/
cstp.c
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
/*
* OpenConnect (SSL + DTLS) VPN client
*
* Copyright © 2008-2015 Intel Corporation.
* Copyright © 2008 Nick Andrew <nick@nick-andrew.net>
*
* Author: David Woodhouse <dwmw2@infradead.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* version 2.1, as published by the Free Software Foundation.
*
* This program 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. See the GNU
* Lesser General Public License for more details.
*/
#include <config.h>
#include <unistd.h>
#include <fcntl.h>
#include <time.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <stdarg.h>
#ifdef HAVE_LZ4
#include <lz4.h>
#endif
#include "openconnect-internal.h"
/*
* Data packets are encapsulated in the SSL stream as follows:
*
* 0000: Magic "STF\x1"
* 0004: Big-endian 16-bit length (not including 8-byte header)
* 0006: Byte packet type (see openconnect-internal.h)
* 0008: data payload
*/
static const char data_hdr[8] = {
'S', 'T', 'F', 1,
0, 0, /* Length */
AC_PKT_DATA, /* Type */
0 /* Unknown */
};
/* Strange initialisers here to work around GCC PR#10676 (which was
* fixed in GCC 4.6 but it takes a while for some systems to catch
* up. */
static const struct pkt keepalive_pkt = {
.next = NULL,
{ .cstp.hdr = { 'S', 'T', 'F', 1, 0, 0, AC_PKT_KEEPALIVE, 0 } }
};
static const struct pkt dpd_pkt = {
.next = NULL,
{ .cstp.hdr = { 'S', 'T', 'F', 1, 0, 0, AC_PKT_DPD_OUT, 0 } }
};
static const struct pkt dpd_resp_pkt = {
.next = NULL,
{ .cstp.hdr = { 'S', 'T', 'F', 1, 0, 0, AC_PKT_DPD_RESP, 0 } }
};
/* Calculate MTU to request. Old servers simply use the X-CSTP-MTU: header,
* which represents the tunnel MTU, while new servers do calculations on the
* X-CSTP-Base-MTU: header which represents the cleartext MTU between client
* and server.
*
* If possible, the legacy MTU value should be the TCP MSS less 5 bytes of
* TLS and 8 bytes of CSTP overhead. We can get the MSS from either the
* TCP_INFO or TCP_MAXSEG sockopts.
*
* The base MTU comes from the TCP_INFO sockopt under Linux, but I don't know
* how to work it out on other systems. So leave it blank and do things the
* legacy way there. Contributions welcome...
*
* If we don't even have TCP_MAXSEG, then default to sending a legacy MTU of
* 1406 which is what we always used to do.
*/
static void calculate_mtu(struct openconnect_info *vpninfo, int *base_mtu, int *mtu)
{
*mtu = vpninfo->reqmtu;
*base_mtu = vpninfo->basemtu;
#if defined(__linux__) && defined(TCP_INFO)
if (!*mtu || !*base_mtu) {
struct tcp_info ti;
socklen_t ti_size = sizeof(ti);
if (!getsockopt(vpninfo->ssl_fd, IPPROTO_TCP, TCP_INFO,
&ti, &ti_size)) {
vpn_progress(vpninfo, PRG_DEBUG,
_("TCP_INFO rcv mss %d, snd mss %d, adv mss %d, pmtu %d\n"),
ti.tcpi_rcv_mss, ti.tcpi_snd_mss, ti.tcpi_advmss, ti.tcpi_pmtu);
if (!*base_mtu)
*base_mtu = ti.tcpi_pmtu;
if (!*mtu) {
if (ti.tcpi_rcv_mss < ti.tcpi_snd_mss)
*mtu = ti.tcpi_rcv_mss - 13;
else
*mtu = ti.tcpi_snd_mss - 13;
}
}
}
#endif
#ifdef TCP_MAXSEG
if (!*mtu) {
int mss;
socklen_t mss_size = sizeof(mss);
if (!getsockopt(vpninfo->ssl_fd, IPPROTO_TCP, TCP_MAXSEG,
&mss, &mss_size)) {
vpn_progress(vpninfo, PRG_DEBUG, _("TCP_MAXSEG %d\n"), mss);
*mtu = mss - 13;
}
}
#endif
if (!*mtu) {
/* Default */
*mtu = 1406;
}
if (*mtu < 1280)
*mtu = 1280;
}
/* For OpenSSL the configure script detects DTLS 1.2 support.
* For GnuTLS just check for v3.2.0+ */
#if defined(DTLS_GNUTLS) && GNUTLS_VERSION_NUMBER >= 0x030200
#define HAVE_DTLS12 1
#endif
#ifdef HAVE_DTLS12
# define DEFAULT_CIPHER_LIST "OC-DTLS1_2-AES256-GCM:OC-DTLS1_2-AES128-GCM:AES256-SHA:AES128-SHA:DES-CBC3-SHA:DES-CBC-SHA"
#else
# define DEFAULT_CIPHER_LIST "AES256-SHA:AES128-SHA:DES-CBC3-SHA:DES-CBC-SHA"
#endif
static void append_compr_types(struct oc_text_buf *buf, const char *proto, int avail)
{
if (avail) {
char sep = ' ';
buf_append(buf, "X-%s-Accept-Encoding:", proto);
if (avail & COMPR_LZ4) {
buf_append(buf, "%coc-lz4", sep);
sep = ',';
}
if (avail & COMPR_LZS) {
buf_append(buf, "%clzs", sep);
sep = ',';
}
if (avail & COMPR_DEFLATE) {
buf_append(buf, "%cdeflate", sep);
sep = ',';
}
buf_append(buf, "\r\n");
}
}
static void append_mobile_headers(struct openconnect_info *vpninfo, struct oc_text_buf *buf)
{
if (vpninfo->mobile_platform_version) {
buf_append(buf, "X-AnyConnect-Identifier-ClientVersion: %s\r\n",
openconnect_version_str);
buf_append(buf, "X-AnyConnect-Identifier-Platform: %s\r\n",
vpninfo->platname);
buf_append(buf, "X-AnyConnect-Identifier-PlatformVersion: %s\r\n",
vpninfo->mobile_platform_version);
buf_append(buf, "X-AnyConnect-Identifier-DeviceType: %s\r\n",
vpninfo->mobile_device_type);
buf_append(buf, "X-AnyConnect-Identifier-Device-UniqueID: %s\r\n",
vpninfo->mobile_device_uniqueid);
}
}
static int start_cstp_connection(struct openconnect_info *vpninfo)
{
struct oc_text_buf *reqbuf;
char buf[65536];
int i;
int dtls_secret_set = 0;
int retried = 0, sessid_found = 0;
struct oc_vpn_option **next_dtls_option = &vpninfo->dtls_options;
struct oc_vpn_option **next_cstp_option = &vpninfo->cstp_options;
struct oc_vpn_option *old_cstp_opts = vpninfo->cstp_options;
struct oc_vpn_option *old_dtls_opts = vpninfo->dtls_options;
const char *old_addr = vpninfo->ip_info.addr;
const char *old_netmask = vpninfo->ip_info.netmask;
const char *old_addr6 = vpninfo->ip_info.addr6;
const char *old_netmask6 = vpninfo->ip_info.netmask6;
int base_mtu, mtu;
/* Clear old options which will be overwritten */
vpninfo->ip_info.addr = vpninfo->ip_info.netmask = NULL;
vpninfo->ip_info.addr6 = vpninfo->ip_info.netmask6 = NULL;
vpninfo->cstp_options = vpninfo->dtls_options = NULL;
vpninfo->ip_info.domain = vpninfo->ip_info.proxy_pac = NULL;
vpninfo->banner = NULL;
for (i = 0; i < 3; i++)
vpninfo->ip_info.dns[i] = vpninfo->ip_info.nbns[i] = NULL;
free_split_routes(vpninfo);
retry:
calculate_mtu(vpninfo, &base_mtu, &mtu);
reqbuf = buf_alloc();
buf_append(reqbuf, "CONNECT /CSCOSSLC/tunnel HTTP/1.1\r\n");
buf_append(reqbuf, "Host: %s\r\n", vpninfo->hostname);
buf_append(reqbuf, "User-Agent: %s\r\n", vpninfo->useragent);
buf_append(reqbuf, "Cookie: webvpn=%s\r\n", vpninfo->cookie);
buf_append(reqbuf, "X-CSTP-Version: 1\r\n");
buf_append(reqbuf, "X-CSTP-Hostname: %s\r\n", vpninfo->localname);
append_mobile_headers(vpninfo, reqbuf);
append_compr_types(reqbuf, "CSTP", vpninfo->req_compr);
if (base_mtu)
buf_append(reqbuf, "X-CSTP-Base-MTU: %d\r\n", base_mtu);
buf_append(reqbuf, "X-CSTP-MTU: %d\r\n", mtu);
buf_append(reqbuf, "X-CSTP-Address-Type: %s\r\n",
vpninfo->disable_ipv6 ? "IPv4" : "IPv6,IPv4");
if (!vpninfo->disable_ipv6)
buf_append(reqbuf, "X-CSTP-Full-IPv6-Capability: true\r\n");
if (vpninfo->dtls_state != DTLS_DISABLED) {
buf_append(reqbuf, "X-DTLS-Master-Secret: ");
for (i = 0; i < sizeof(vpninfo->dtls_secret); i++) {
buf_append(reqbuf, "%02X", vpninfo->dtls_secret[i]);
dtls_secret_set |= vpninfo->dtls_secret[i];
}
if (!dtls_secret_set) {
vpn_progress(vpninfo, PRG_ERR,
_("CRITICAL ERROR: DTLS master secret is uninitialised. Please report this.\n"));
return -EINVAL;
}
buf_append(reqbuf, "\r\nX-DTLS-CipherSuite: %s\r\n",
vpninfo->dtls_ciphers ? : DEFAULT_CIPHER_LIST);
append_compr_types(reqbuf, "DTLS", vpninfo->req_compr & ~COMPR_DEFLATE);
}
buf_append(reqbuf, "\r\n");
if (buf_error(reqbuf)) {
vpn_progress(vpninfo, PRG_ERR,
_("Error creating HTTPS CONNECT request\n"));
return buf_free(reqbuf);
}
if (vpninfo->dump_http_traffic)
dump_buf(vpninfo, '>', reqbuf->data);
vpninfo->ssl_write(vpninfo, reqbuf->data, reqbuf->pos);
buf_free(reqbuf);
/* FIXME: Use process_http_response() instead of reimplementing it. It has
a header callback function, and can cope with CONNECT requests. */
if ((i = vpninfo->ssl_gets(vpninfo, buf, 65536)) < 0) {
if (i == -EINTR)
return i;
vpn_progress(vpninfo, PRG_ERR,
_("Error fetching HTTPS response\n"));
if (!retried) {
retried = 1;
openconnect_close_https(vpninfo, 0);
if (openconnect_open_https(vpninfo)) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to open HTTPS connection to %s\n"),
vpninfo->hostname);
return -EIO;
}
goto retry;
}
return -EINVAL;
}
if (strncmp(buf, "HTTP/1.1 200 ", 13)) {
if (!strncmp(buf, "HTTP/1.1 503 ", 13)) {
/* "Service Unavailable. Why? */
const char *reason = "<unknown>";
while ((i = vpninfo->ssl_gets(vpninfo, buf, sizeof(buf)))) {
if (!strncmp(buf, "X-Reason: ", 10)) {
reason = buf + 10;
break;
}
}
vpn_progress(vpninfo, PRG_ERR,
_("VPN service unavailable; reason: %s\n"),
reason);
return -EINVAL;
}
vpn_progress(vpninfo, PRG_ERR,
_("Got inappropriate HTTP CONNECT response: %s\n"),
buf);
if (!strncmp(buf, "HTTP/1.1 401 ", 13))
return -EPERM;
return -EINVAL;
}
vpn_progress(vpninfo, PRG_INFO, _("Got CONNECT response: %s\n"), buf);
/* We may have advertised it, but we only do it if the server agrees */
vpninfo->cstp_compr = vpninfo->dtls_compr = 0;
mtu = 0;
while ((i = vpninfo->ssl_gets(vpninfo, buf, sizeof(buf)))) {
struct oc_vpn_option *new_option;
char *colon;
if (i < 0)
return i;
colon = strchr(buf, ':');
if (!colon)
continue;
*colon = 0;
colon++;
if (*colon == ' ')
colon++;
if (strncmp(buf, "X-DTLS-", 7) &&
strncmp(buf, "X-CSTP-", 7))
continue;
new_option = malloc(sizeof(*new_option));
if (!new_option) {
vpn_progress(vpninfo, PRG_ERR, _("No memory for options\n"));
return -ENOMEM;
}
new_option->option = strdup(buf);
new_option->value = strdup(colon);
new_option->next = NULL;
if (!new_option->option || !new_option->value) {
vpn_progress(vpninfo, PRG_ERR, _("No memory for options\n"));
free(new_option->option);
free(new_option->value);
free(new_option);
return -ENOMEM;
}
/* This contains the whole document, including the webvpn cookie. */
if (!strcasecmp(buf, "X-CSTP-Post-Auth-XML"))
vpn_progress(vpninfo, PRG_DEBUG, "%s: %s\n", buf, _("<elided>"));
else
vpn_progress(vpninfo, PRG_DEBUG, "%s: %s\n", buf, colon);
if (!strncmp(buf, "X-DTLS-", 7)) {
*next_dtls_option = new_option;
next_dtls_option = &new_option->next;
if (!strcmp(buf + 7, "MTU")) {
int dtlsmtu = atol(colon);
if (dtlsmtu > mtu)
mtu = dtlsmtu;
} else if (!strcmp(buf + 7, "Session-ID")) {
int dtls_sessid_changed = 0;
if (strlen(colon) != 64) {
vpn_progress(vpninfo, PRG_ERR,
_("X-DTLS-Session-ID not 64 characters; is: \"%s\"\n"),
colon);
vpninfo->dtls_attempt_period = 0;
return -EINVAL;
}
for (i = 0; i < 64; i += 2) {
unsigned char c = unhex(colon + i);
if (vpninfo->dtls_session_id[i/2] != c) {
vpninfo->dtls_session_id[i/2] = c;
dtls_sessid_changed = 1;
}
}
sessid_found = 1;
if (dtls_sessid_changed && vpninfo->dtls_state > DTLS_SLEEPING)
vpninfo->dtls_need_reconnect = 1;
} else if (!strcmp(buf + 7, "Content-Encoding")) {
if (!strcmp(colon, "lzs"))
vpninfo->dtls_compr = COMPR_LZS;
else if (!strcmp(colon, "oc-lz4"))
vpninfo->dtls_compr = COMPR_LZ4;
else {
vpn_progress(vpninfo, PRG_ERR,
_("Unknown DTLS-Content-Encoding %s\n"),
colon);
return -EINVAL;
}
}
continue;
}
/* CSTP options... */
*next_cstp_option = new_option;
next_cstp_option = &new_option->next;
if (!strcmp(buf + 7, "Keepalive")) {
vpninfo->ssl_times.keepalive = atol(colon);
} else if (!strcmp(buf + 7, "DPD")) {
int j = atol(colon);
if (j && (!vpninfo->ssl_times.dpd || j < vpninfo->ssl_times.dpd))
vpninfo->ssl_times.dpd = j;
} else if (!strcmp(buf + 7, "Rekey-Time")) {
vpninfo->ssl_times.rekey = atol(colon);
} else if (!strcmp(buf + 7, "Rekey-Method")) {
if (!strcmp(colon, "new-tunnel"))
vpninfo->ssl_times.rekey_method = REKEY_TUNNEL;
else if (!strcmp(colon, "ssl"))
vpninfo->ssl_times.rekey_method = REKEY_SSL;
else
vpninfo->ssl_times.rekey_method = REKEY_NONE;
} else if (!strcmp(buf + 7, "Content-Encoding")) {
if (!strcmp(colon, "deflate"))
vpninfo->cstp_compr = COMPR_DEFLATE;
else if (!strcmp(colon, "lzs"))
vpninfo->cstp_compr = COMPR_LZS;
else if (!strcmp(colon, "oc-lz4"))
vpninfo->cstp_compr = COMPR_LZ4;
else {
vpn_progress(vpninfo, PRG_ERR,
_("Unknown CSTP-Content-Encoding %s\n"),
colon);
return -EINVAL;
}
} else if (!strcmp(buf + 7, "MTU")) {
int cstpmtu = atol(colon);
if (cstpmtu > mtu)
mtu = cstpmtu;
} else if (!strcmp(buf + 7, "DynDNS")) {
if (!strcmp(colon, "true"))
vpninfo->is_dyndns = 1;
} else if (!strcmp(buf + 7, "Address-IP6")) {
vpninfo->ip_info.netmask6 = new_option->value;
} else if (!strcmp(buf + 7, "Address")) {
if (strchr(new_option->value, ':')) {
if (!vpninfo->disable_ipv6)
vpninfo->ip_info.addr6 = new_option->value;
} else
vpninfo->ip_info.addr = new_option->value;
} else if (!strcmp(buf + 7, "Netmask")) {
if (strchr(new_option->value, ':')) {
if (!vpninfo->disable_ipv6)
vpninfo->ip_info.netmask6 = new_option->value;
} else
vpninfo->ip_info.netmask = new_option->value;
} else if (!strcmp(buf + 7, "DNS")) {
int j;
for (j = 0; j < 3; j++) {
if (!vpninfo->ip_info.dns[j]) {
vpninfo->ip_info.dns[j] = new_option->value;
break;
}
}
} else if (!strcmp(buf + 7, "NBNS")) {
int j;
for (j = 0; j < 3; j++) {
if (!vpninfo->ip_info.nbns[j]) {
vpninfo->ip_info.nbns[j] = new_option->value;
break;
}
}
} else if (!strcmp(buf + 7, "Default-Domain")) {
vpninfo->ip_info.domain = new_option->value;
} else if (!strcmp(buf + 7, "MSIE-Proxy-PAC-URL")) {
vpninfo->ip_info.proxy_pac = new_option->value;
} else if (!strcmp(buf + 7, "Banner")) {
vpninfo->banner = new_option->value;
} else if (!strcmp(buf + 7, "Split-DNS")) {
struct oc_split_include *dns = malloc(sizeof(*dns));
if (!dns)
continue;
dns->route = new_option->value;
dns->next = vpninfo->ip_info.split_dns;
vpninfo->ip_info.split_dns = dns;
} else if (!strcmp(buf + 7, "Split-Include") || !strcmp(buf + 7, "Split-Include-IP6")) {
struct oc_split_include *inc = malloc(sizeof(*inc));
if (!inc)
continue;
inc->route = new_option->value;
inc->next = vpninfo->ip_info.split_includes;
vpninfo->ip_info.split_includes = inc;
} else if (!strcmp(buf + 7, "Split-Exclude") || !strcmp(buf + 7, "Split-Exclude-IP6")) {
struct oc_split_include *exc = malloc(sizeof(*exc));
if (!exc)
continue;
exc->route = new_option->value;
exc->next = vpninfo->ip_info.split_excludes;
vpninfo->ip_info.split_excludes = exc;
}
}
if (!mtu) {
vpn_progress(vpninfo, PRG_ERR,
_("No MTU received. Aborting\n"));
return -EINVAL;
}
vpninfo->ip_info.mtu = mtu;
if (!vpninfo->ip_info.addr && !vpninfo->ip_info.addr6) {
vpn_progress(vpninfo, PRG_ERR,
_("No IP address received. Aborting\n"));
return -EINVAL;
}
if (mtu < 1280 &&
(vpninfo->ip_info.addr6 || vpninfo->ip_info.netmask6)) {
vpn_progress(vpninfo, PRG_ERR,
_("IPv6 configuration received but MTU %d is too small.\n"),
mtu);
}
if (old_addr) {
if (strcmp(old_addr, vpninfo->ip_info.addr)) {
vpn_progress(vpninfo, PRG_ERR,
_("Reconnect gave different Legacy IP address (%s != %s)\n"),
vpninfo->ip_info.addr, old_addr);
return -EINVAL;
}
}
if (old_netmask) {
if (strcmp(old_netmask, vpninfo->ip_info.netmask)) {
vpn_progress(vpninfo, PRG_ERR,
_("Reconnect gave different Legacy IP netmask (%s != %s)\n"),
vpninfo->ip_info.netmask, old_netmask);
return -EINVAL;
}
}
if (old_addr6) {
if (strcmp(old_addr6, vpninfo->ip_info.addr6)) {
vpn_progress(vpninfo, PRG_ERR,
_("Reconnect gave different IPv6 address (%s != %s)\n"),
vpninfo->ip_info.addr6, old_addr6);
return -EINVAL;
}
}
if (old_netmask6) {
if (strcmp(old_netmask6, vpninfo->ip_info.netmask6)) {
vpn_progress(vpninfo, PRG_ERR,
_("Reconnect gave different IPv6 netmask (%s != %s)\n"),
vpninfo->ip_info.netmask6, old_netmask6);
return -EINVAL;
}
}
while (old_dtls_opts) {
struct oc_vpn_option *tmp = old_dtls_opts;
old_dtls_opts = old_dtls_opts->next;
free(tmp->value);
free(tmp->option);
free(tmp);
}
while (old_cstp_opts) {
struct oc_vpn_option *tmp = old_cstp_opts;
old_cstp_opts = old_cstp_opts->next;
free(tmp->value);
free(tmp->option);
free(tmp);
}
vpn_progress(vpninfo, PRG_INFO, _("CSTP connected. DPD %d, Keepalive %d\n"),
vpninfo->ssl_times.dpd, vpninfo->ssl_times.keepalive);
vpn_progress(vpninfo, PRG_DEBUG, _("CSTP Ciphersuite: %s\n"),
openconnect_get_cstp_cipher(vpninfo));
monitor_fd_new(vpninfo, ssl);
monitor_read_fd(vpninfo, ssl);
monitor_except_fd(vpninfo, ssl);
if (!sessid_found)
vpninfo->dtls_attempt_period = 0;
if (vpninfo->ssl_times.rekey <= 0)
vpninfo->ssl_times.rekey_method = REKEY_NONE;
vpninfo->ssl_times.last_rekey = vpninfo->ssl_times.last_rx =
vpninfo->ssl_times.last_tx = time(NULL);
return 0;
}
int cstp_connect(struct openconnect_info *vpninfo)
{
int ret;
int deflate_bufsize = 0;
int compr_type;
/* This needs to be done before openconnect_setup_dtls() because it's
sent with the CSTP CONNECT handshake. Even if we don't end up doing
DTLS. */
if (vpninfo->dtls_state == DTLS_NOSECRET) {
if (openconnect_random(vpninfo->dtls_secret, sizeof(vpninfo->dtls_secret)))
return -EINVAL;
/* The application will later call openconnect_setup_dtls() */
vpninfo->dtls_state = DTLS_SECRET;
}
ret = openconnect_open_https(vpninfo);
if (ret)
return ret;
ret = start_cstp_connection(vpninfo);
if (ret)
goto out;
/* Allow for the theoretical possibility of having *different*
* compression type for CSTP and DTLS. Although all we've seen
* in practice is that one is enabled and the other isn't. */
compr_type = vpninfo->cstp_compr | vpninfo->dtls_compr;
/* This will definitely be smaller than zlib's */
if (compr_type & (COMPR_LZS|COMPR_LZ4))
deflate_bufsize = vpninfo->ip_info.mtu;
/* If deflate compression is enabled (which is CSTP-only), it needs its
* context to be allocated. */
if (compr_type & COMPR_DEFLATE) {
vpninfo->deflate_adler32 = 1;
vpninfo->inflate_adler32 = 1;
if (inflateInit2(&vpninfo->inflate_strm, -12) ||
deflateInit2(&vpninfo->deflate_strm, Z_DEFAULT_COMPRESSION,
Z_DEFLATED, -12, 9, Z_DEFAULT_STRATEGY)) {
vpn_progress(vpninfo, PRG_ERR, _("Compression setup failed\n"));
ret = -ENOMEM;
goto out;
}
/* Add four bytes for the adler32 */
deflate_bufsize = deflateBound(&vpninfo->deflate_strm,
vpninfo->ip_info.mtu) + 4;
}
/* If *any* compression is enabled, we'll need a deflate_pkt to compress into */
if (deflate_bufsize > vpninfo->deflate_pkt_size) {
free(vpninfo->deflate_pkt);
vpninfo->deflate_pkt = malloc(sizeof(struct pkt) + deflate_bufsize);
if (!vpninfo->deflate_pkt) {
vpninfo->deflate_pkt_size = 0;
vpn_progress(vpninfo, PRG_ERR,
_("Allocation of deflate buffer failed\n"));
ret = -ENOMEM;
goto out;
}
vpninfo->deflate_pkt_size = deflate_bufsize;
memset(vpninfo->deflate_pkt, 0, sizeof(struct pkt));
memcpy(vpninfo->deflate_pkt->cstp.hdr, data_hdr, 8);
vpninfo->deflate_pkt->cstp.hdr[6] = AC_PKT_COMPRESSED;
}
out:
if (ret < 0)
openconnect_close_https(vpninfo, 0);
return ret;
}
static int cstp_reconnect(struct openconnect_info *vpninfo)
{
if (vpninfo->cstp_compr == COMPR_DEFLATE) {
/* Requeue the original packet that was deflated */
if (vpninfo->current_ssl_pkt == vpninfo->deflate_pkt) {
vpninfo->current_ssl_pkt = NULL;
queue_packet(&vpninfo->outgoing_queue, vpninfo->pending_deflated_pkt);
vpninfo->pending_deflated_pkt = NULL;
}
inflateEnd(&vpninfo->inflate_strm);
deflateEnd(&vpninfo->deflate_strm);
}
return ssl_reconnect(vpninfo);
}
int decompress_and_queue_packet(struct openconnect_info *vpninfo, int compr_type,
unsigned char *buf, int len)
{
struct pkt *new = malloc(sizeof(struct pkt) + vpninfo->ip_info.mtu);
const char *comprname = "";
if (!new)
return -ENOMEM;
new->next = NULL;
if (compr_type == COMPR_DEFLATE) {
uint32_t pkt_sum;
comprname = "deflate";
vpninfo->inflate_strm.next_in = buf;
vpninfo->inflate_strm.avail_in = len - 4;
vpninfo->inflate_strm.next_out = new->data;
vpninfo->inflate_strm.avail_out = vpninfo->ip_info.mtu;
vpninfo->inflate_strm.total_out = 0;
if (inflate(&vpninfo->inflate_strm, Z_SYNC_FLUSH)) {
vpn_progress(vpninfo, PRG_ERR, _("inflate failed\n"));
free(new);
return -EINVAL;
}
new->len = vpninfo->inflate_strm.total_out;
vpninfo->inflate_adler32 = adler32(vpninfo->inflate_adler32,
new->data, new->len);
pkt_sum = load_be32(buf + len - 4);
if (vpninfo->inflate_adler32 != pkt_sum)
vpninfo->quit_reason = "Compression (inflate) adler32 failure";
} else if (compr_type == COMPR_LZS) {
comprname = "LZS";
new->len = lzs_decompress(new->data, vpninfo->ip_info.mtu, buf, len);
if (new->len < 0) {
len = new->len;
if (len == 0)
len = -EINVAL;
vpn_progress(vpninfo, PRG_ERR, _("LZS decompression failed: %s\n"),
strerror(-len));
free(new);
return len;
}
#ifdef HAVE_LZ4
} else if (compr_type == COMPR_LZ4) {
comprname = "LZ4";
new->len = LZ4_decompress_safe((void *)buf, (void *)new->data, len, vpninfo->ip_info.mtu);
if (new->len <= 0) {
len = new->len;
if (len == 0)
len = -EINVAL;
vpn_progress(vpninfo, PRG_ERR, _("LZ4 decompression failed\n"));
free(new);
return len;
}
#endif
} else {
vpn_progress(vpninfo, PRG_ERR,
_("Unknown compression type %d\n"), compr_type);
return -EINVAL;
}
vpn_progress(vpninfo, PRG_TRACE,
_("Received %s compressed data packet of %d bytes (was %d)\n"),
comprname, new->len, len);
queue_packet(&vpninfo->incoming_queue, new);
return 0;
}
int compress_packet(struct openconnect_info *vpninfo, int compr_type, struct pkt *this)
{
int ret;
if (compr_type == COMPR_DEFLATE) {
vpninfo->deflate_strm.next_in = this->data;
vpninfo->deflate_strm.avail_in = this->len;
vpninfo->deflate_strm.next_out = (void *)vpninfo->deflate_pkt->data;
vpninfo->deflate_strm.avail_out = vpninfo->deflate_pkt_size - 4;
vpninfo->deflate_strm.total_out = 0;
ret = deflate(&vpninfo->deflate_strm, Z_SYNC_FLUSH);
if (ret) {
vpn_progress(vpninfo, PRG_ERR, _("deflate failed %d\n"), ret);
/* Things are going to go horribly wrong if we try to do any
more compression. Give up entirely. */
vpninfo->cstp_compr = 0;
return -EIO;
}
/* Add ongoing adler32 to tail of compressed packet */
vpninfo->deflate_adler32 = adler32(vpninfo->deflate_adler32,
this->data, this->len);
store_be32(&vpninfo->deflate_pkt->data[vpninfo->deflate_strm.total_out],
vpninfo->deflate_adler32);
vpninfo->deflate_pkt->len = vpninfo->deflate_strm.total_out + 4;
return 0;
} else if (compr_type == COMPR_LZS) {
if (this->len < 40)
return -EFBIG;
ret = lzs_compress(vpninfo->deflate_pkt->data, this->len,
this->data, this->len);
if (ret < 0)
return ret;
vpninfo->deflate_pkt->len = ret;
return 0;
#ifdef HAVE_LZ4
} else if (compr_type == COMPR_LZ4) {
if (this->len < 40)
return -EFBIG;
ret = LZ4_compress_limitedOutput((void*)this->data, (void*)vpninfo->deflate_pkt->data, this->len,
this->len);
if (ret <= 0) {
if (ret == 0)
ret = -EFBIG;
return ret;
}
vpninfo->deflate_pkt->len = ret;
return 0;
#endif
} else
return -EINVAL;
return 0;
}
int cstp_mainloop(struct openconnect_info *vpninfo, int *timeout)
{
int ret;
int work_done = 0;
if (vpninfo->ssl_fd == -1)
goto do_reconnect;
/* FIXME: The poll() handling here is fairly simplistic. Actually,
if the SSL connection stalls it could return a WANT_WRITE error
on _either_ of the SSL_read() or SSL_write() calls. In that case,
we should probably remove POLLIN from the events we're looking for,
and add POLLOUT. As it is, though, it'll just chew CPU time in that
fairly unlikely situation, until the write backlog clears. */
while (1) {
int len = vpninfo->deflate_pkt_size ? : vpninfo->ip_info.mtu;
int payload_len;
if (!vpninfo->cstp_pkt) {
vpninfo->cstp_pkt = malloc(sizeof(struct pkt) + len);
if (!vpninfo->cstp_pkt) {
vpn_progress(vpninfo, PRG_ERR, _("Allocation failed\n"));
break;
}
}
len = ssl_nonblock_read(vpninfo, vpninfo->cstp_pkt->cstp.hdr, len + 8);
if (!len)
break;
if (len < 0)
goto do_reconnect;
if (len < 8) {
vpn_progress(vpninfo, PRG_ERR, _("Short packet received (%d bytes)\n"), len);
vpninfo->quit_reason = "Short packet received";
return 1;
}
if (vpninfo->cstp_pkt->cstp.hdr[0] != 'S' || vpninfo->cstp_pkt->cstp.hdr[1] != 'T' ||
vpninfo->cstp_pkt->cstp.hdr[2] != 'F' || vpninfo->cstp_pkt->cstp.hdr[3] != 1 ||
vpninfo->cstp_pkt->cstp.hdr[7])
goto unknown_pkt;
payload_len = load_be16(vpninfo->cstp_pkt->cstp.hdr + 4);
if (len != 8 + payload_len) {
vpn_progress(vpninfo, PRG_ERR,
_("Unexpected packet length. SSL_read returned %d but packet is\n"),
len);
vpn_progress(vpninfo, PRG_ERR,
"%02x %02x %02x %02x %02x %02x %02x %02x\n",
vpninfo->cstp_pkt->cstp.hdr[0], vpninfo->cstp_pkt->cstp.hdr[1],
vpninfo->cstp_pkt->cstp.hdr[2], vpninfo->cstp_pkt->cstp.hdr[3],
vpninfo->cstp_pkt->cstp.hdr[4], vpninfo->cstp_pkt->cstp.hdr[5],
vpninfo->cstp_pkt->cstp.hdr[6], vpninfo->cstp_pkt->cstp.hdr[7]);
continue;
}
vpninfo->ssl_times.last_rx = time(NULL);
switch (vpninfo->cstp_pkt->cstp.hdr[6]) {
case AC_PKT_DPD_OUT:
vpn_progress(vpninfo, PRG_DEBUG,
_("Got CSTP DPD request\n"));
vpninfo->owe_ssl_dpd_response = 1;
continue;
case AC_PKT_DPD_RESP:
vpn_progress(vpninfo, PRG_DEBUG,
_("Got CSTP DPD response\n"));
continue;
case AC_PKT_KEEPALIVE:
vpn_progress(vpninfo, PRG_DEBUG,
_("Got CSTP Keepalive\n"));
continue;
case AC_PKT_DATA:
vpn_progress(vpninfo, PRG_TRACE,
_("Received uncompressed data packet of %d bytes\n"),
payload_len);
vpninfo->cstp_pkt->len = payload_len;
queue_packet(&vpninfo->incoming_queue, vpninfo->cstp_pkt);
vpninfo->cstp_pkt = NULL;
work_done = 1;
continue;
case AC_PKT_DISCONN: {
int i;
if (payload_len >= 2) {
for (i = 1; i < payload_len; i++) {
if (!isprint(vpninfo->cstp_pkt->data[i]))
vpninfo->cstp_pkt->data[i] = '.';
}
vpninfo->cstp_pkt->data[payload_len] = 0;
vpn_progress(vpninfo, PRG_ERR,
_("Received server disconnect: %02x '%s'\n"),
vpninfo->cstp_pkt->data[0], vpninfo->cstp_pkt->data + 1);
} else {
vpn_progress(vpninfo, PRG_ERR, _("Received server disconnect\n"));
}
vpninfo->quit_reason = "Server request";
return -EPIPE;
}
case AC_PKT_COMPRESSED:
if (!vpninfo->cstp_compr) {
vpn_progress(vpninfo, PRG_ERR,
_("Compressed packet received in !deflate mode\n"));
goto unknown_pkt;
}
decompress_and_queue_packet(vpninfo, vpninfo->cstp_compr,
vpninfo->cstp_pkt->data, payload_len);
work_done = 1;
continue;
case AC_PKT_TERM_SERVER:
vpn_progress(vpninfo, PRG_ERR, _("received server terminate packet\n"));
vpninfo->quit_reason = "Server request";
return -EPIPE;
}
unknown_pkt:
vpn_progress(vpninfo, PRG_ERR,
_("Unknown packet %02x %02x %02x %02x %02x %02x %02x %02x\n"),
vpninfo->cstp_pkt->cstp.hdr[0], vpninfo->cstp_pkt->cstp.hdr[1],
vpninfo->cstp_pkt->cstp.hdr[2], vpninfo->cstp_pkt->cstp.hdr[3],
vpninfo->cstp_pkt->cstp.hdr[4], vpninfo->cstp_pkt->cstp.hdr[5],
vpninfo->cstp_pkt->cstp.hdr[6], vpninfo->cstp_pkt->cstp.hdr[7]);
vpninfo->quit_reason = "Unknown packet received";
return 1;
}
/* If SSL_write() fails we are expected to try again. With exactly
the same data, at exactly the same location. So we keep the
packet we had before.... */
if (vpninfo->current_ssl_pkt) {
handle_outgoing:
vpninfo->ssl_times.last_tx = time(NULL);
unmonitor_write_fd(vpninfo, ssl);
ret = ssl_nonblock_write(vpninfo,
vpninfo->current_ssl_pkt->cstp.hdr,
vpninfo->current_ssl_pkt->len + 8);
if (ret < 0)
goto do_reconnect;
else if (!ret) {
/* -EAGAIN: ssl_nonblock_write() will have added the SSL
fd to ->select_wfds if appropriate, so we can just
return and wait. Unless it's been stalled for so long
that DPD kicks in and we kill the connection. */
switch (ka_stalled_action(&vpninfo->ssl_times, timeout)) {
case KA_DPD_DEAD:
goto peer_dead;
case KA_REKEY:
goto do_rekey;
case KA_NONE:
return work_done;
default:
/* This should never happen */
;
}
}
if (ret != vpninfo->current_ssl_pkt->len + 8) {
vpn_progress(vpninfo, PRG_ERR,
_("SSL wrote too few bytes! Asked for %d, sent %d\n"),
vpninfo->current_ssl_pkt->len + 8, ret);
vpninfo->quit_reason = "Internal error";
return 1;
}
/* Don't free the 'special' packets */
if (vpninfo->current_ssl_pkt == vpninfo->deflate_pkt)
free(vpninfo->pending_deflated_pkt);
else if (vpninfo->current_ssl_pkt != &dpd_pkt &&
vpninfo->current_ssl_pkt != &dpd_resp_pkt &&
vpninfo->current_ssl_pkt != &keepalive_pkt)
free(vpninfo->current_ssl_pkt);
vpninfo->current_ssl_pkt = NULL;
}
if (vpninfo->owe_ssl_dpd_response) {
vpninfo->owe_ssl_dpd_response = 0;
vpninfo->current_ssl_pkt = (struct pkt *)&dpd_resp_pkt;
goto handle_outgoing;
}