-
Notifications
You must be signed in to change notification settings - Fork 1
/
portfwd.c
1174 lines (1025 loc) · 35.7 KB
/
portfwd.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
/*
* SSH port forwarding.
*/
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include "putty.h"
#include "ssh.h"
#include "sshchan.h"
/*
* Enumeration of values that live in the 'socks_state' field of
* struct PortForwarding.
*/
typedef enum {
SOCKS_NONE, /* direct connection (no SOCKS, or SOCKS already done) */
SOCKS_INITIAL, /* don't know if we're SOCKS 4 or 5 yet */
SOCKS_4, /* expect a SOCKS 4 (or 4A) connection message */
SOCKS_5_INITIAL, /* expect a SOCKS 5 preliminary message */
SOCKS_5_CONNECT /* expect a SOCKS 5 connection message */
} SocksState;
typedef struct PortForwarding {
SshChannel *c; /* channel structure held by SSH connection layer */
ConnectionLayer *cl; /* the connection layer itself */
/* Note that ssh need not be filled in if c is non-NULL */
Socket *s;
bool input_wanted;
bool ready;
SocksState socks_state;
/*
* `hostname' and `port' are the real hostname and port, once
* we know what we're connecting to.
*/
char *hostname;
int port;
/*
* `socksbuf' is the buffer we use to accumulate the initial SOCKS
* segment of the incoming data, plus anything after that that we
* receive before we're ready to send data to the SSH server.
*/
strbuf *socksbuf;
size_t socksbuf_consumed;
Plug plug;
Channel chan;
} PortForwarding;
struct PortListener {
ConnectionLayer *cl;
Socket *s;
bool is_dynamic;
/*
* `hostname' and `port' are the real hostname and port, for
* ordinary forwardings.
*/
char *hostname;
int port;
Plug plug;
};
static struct PortForwarding *new_portfwd_state(void)
{
struct PortForwarding *pf = snew(struct PortForwarding);
pf->hostname = NULL;
pf->socksbuf = NULL;
return pf;
}
static void free_portfwd_state(struct PortForwarding *pf)
{
if (!pf)
return;
sfree(pf->hostname);
if (pf->socksbuf)
strbuf_free(pf->socksbuf);
sfree(pf);
}
static struct PortListener *new_portlistener_state(void)
{
struct PortListener *pl = snew(struct PortListener);
pl->hostname = NULL;
return pl;
}
static void free_portlistener_state(struct PortListener *pl)
{
if (!pl)
return;
sfree(pl->hostname);
sfree(pl);
}
static void pfd_log(Plug *plug, PlugLogType type, SockAddr *addr, int port,
const char *error_msg, int error_code)
{
/* we have to dump these since we have no interface to logging.c */
}
static void pfl_log(Plug *plug, PlugLogType type, SockAddr *addr, int port,
const char *error_msg, int error_code)
{
/* we have to dump these since we have no interface to logging.c */
}
static void pfd_close(struct PortForwarding *pf);
static void pfd_closing(Plug *plug, const char *error_msg, int error_code,
bool calling_back)
{
struct PortForwarding *pf =
container_of(plug, struct PortForwarding, plug);
if (error_msg) {
/*
* Socket error. Slam the connection instantly shut.
*/
if (pf->c) {
sshfwd_initiate_close(pf->c, error_msg);
} else {
/*
* We might not have an SSH channel, if a socket error
* occurred during SOCKS negotiation. If not, we must
* clean ourself up without sshfwd_initiate_close's call
* back to pfd_close.
*/
pfd_close(pf);
}
} else {
/*
* Ordinary EOF received on socket. Send an EOF on the SSH
* channel.
*/
if (pf->c)
sshfwd_write_eof(pf->c);
}
}
static void pfl_terminate(struct PortListener *pl);
static void pfl_closing(Plug *plug, const char *error_msg, int error_code,
bool calling_back)
{
struct PortListener *pl = (struct PortListener *) plug;
pfl_terminate(pl);
}
static SshChannel *wrap_lportfwd_open(
ConnectionLayer *cl, const char *hostname, int port,
Socket *s, Channel *chan)
{
SocketPeerInfo *pi;
char *description;
SshChannel *toret;
pi = sk_peer_info(s);
if (pi && pi->log_text) {
description = dupprintf("forwarding from %s", pi->log_text);
} else {
description = dupstr("forwarding");
}
toret = ssh_lportfwd_open(cl, hostname, port, description, pi, chan);
sk_free_peer_info(pi);
sfree(description);
return toret;
}
static char *ipv4_to_string(unsigned ipv4)
{
return dupprintf("%u.%u.%u.%u",
(ipv4 >> 24) & 0xFF, (ipv4 >> 16) & 0xFF,
(ipv4 >> 8) & 0xFF, (ipv4 ) & 0xFF);
}
static char *ipv6_to_string(ptrlen ipv6)
{
const unsigned char *addr = ipv6.ptr;
assert(ipv6.len == 16);
return dupprintf("%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x",
(unsigned)GET_16BIT_MSB_FIRST(addr + 0),
(unsigned)GET_16BIT_MSB_FIRST(addr + 2),
(unsigned)GET_16BIT_MSB_FIRST(addr + 4),
(unsigned)GET_16BIT_MSB_FIRST(addr + 6),
(unsigned)GET_16BIT_MSB_FIRST(addr + 8),
(unsigned)GET_16BIT_MSB_FIRST(addr + 10),
(unsigned)GET_16BIT_MSB_FIRST(addr + 12),
(unsigned)GET_16BIT_MSB_FIRST(addr + 14));
}
static void pfd_receive(Plug *plug, int urgent, const char *data, size_t len)
{
struct PortForwarding *pf =
container_of(plug, struct PortForwarding, plug);
if (len == 0)
return;
if (pf->socks_state != SOCKS_NONE) {
BinarySource src[1];
/*
* Store all the data we've got in socksbuf.
*/
put_data(pf->socksbuf, data, len);
/*
* Check the start of socksbuf to see if it's a valid and
* complete message in the SOCKS exchange.
*/
if (pf->socks_state == SOCKS_INITIAL) {
/* Preliminary: check the first byte of the data (which we
* _must_ have by now) to find out which SOCKS major
* version we're speaking. */
switch (pf->socksbuf->u[0]) {
case 4:
pf->socks_state = SOCKS_4;
break;
case 5:
pf->socks_state = SOCKS_5_INITIAL;
break;
default:
pfd_close(pf); /* unrecognised version */
return;
}
}
BinarySource_BARE_INIT(src, pf->socksbuf->u, pf->socksbuf->len);
get_data(src, pf->socksbuf_consumed);
while (pf->socks_state != SOCKS_NONE) {
unsigned socks_version, message_type, reserved_byte;
unsigned reply_code, port, ipv4, method;
ptrlen methods;
const char *socks4_hostname;
strbuf *output;
switch (pf->socks_state) {
case SOCKS_INITIAL:
case SOCKS_NONE:
unreachable("These case values cannot appear");
case SOCKS_4:
/* SOCKS 4/4A connect message */
socks_version = get_byte(src);
message_type = get_byte(src);
if (get_err(src) == BSE_OUT_OF_DATA)
return;
if (socks_version == 4 && message_type == 1) {
/* CONNECT message */
bool name_based = false;
port = get_uint16(src);
ipv4 = get_uint32(src);
if (ipv4 > 0x00000000 && ipv4 < 0x00000100) {
/*
* Addresses in this range indicate the SOCKS 4A
* extension to specify a hostname, which comes
* after the username.
*/
name_based = true;
}
get_asciz(src); /* skip username */
socks4_hostname = name_based ? get_asciz(src) : NULL;
if (get_err(src) == BSE_OUT_OF_DATA)
return;
if (get_err(src))
goto socks4_reject;
pf->port = port;
if (name_based) {
pf->hostname = dupstr(socks4_hostname);
} else {
pf->hostname = ipv4_to_string(ipv4);
}
output = strbuf_new();
put_byte(output, 0); /* reply version */
put_byte(output, 90); /* SOCKS 4 'request granted' */
put_uint16(output, 0); /* null port field */
put_uint32(output, 0); /* null address field */
sk_write(pf->s, output->u, output->len);
strbuf_free(output);
pf->socks_state = SOCKS_NONE;
pf->socksbuf_consumed = src->pos;
break;
}
socks4_reject:
output = strbuf_new();
put_byte(output, 0); /* reply version */
put_byte(output, 91); /* SOCKS 4 'request rejected' */
put_uint16(output, 0); /* null port field */
put_uint32(output, 0); /* null address field */
sk_write(pf->s, output->u, output->len);
strbuf_free(output);
pfd_close(pf);
return;
case SOCKS_5_INITIAL:
/* SOCKS 5 initial method list */
socks_version = get_byte(src);
methods = get_pstring(src);
method = 0xFF; /* means 'no usable method found' */
{
int i;
for (i = 0; i < methods.len; i++) {
if (((const unsigned char *)methods.ptr)[i] == 0 ) {
method = 0; /* no auth */
break;
}
}
}
if (get_err(src) == BSE_OUT_OF_DATA)
return;
if (get_err(src))
method = 0xFF;
output = strbuf_new();
put_byte(output, 5); /* SOCKS version */
put_byte(output, method); /* selected auth method */
sk_write(pf->s, output->u, output->len);
strbuf_free(output);
if (method == 0xFF) {
pfd_close(pf);
return;
}
pf->socks_state = SOCKS_5_CONNECT;
pf->socksbuf_consumed = src->pos;
break;
case SOCKS_5_CONNECT:
/* SOCKS 5 connect message */
socks_version = get_byte(src);
message_type = get_byte(src);
reserved_byte = get_byte(src);
if (socks_version == 5 && message_type == 1 &&
reserved_byte == 0) {
reply_code = 0; /* success */
switch (get_byte(src)) {
case 1: /* IPv4 */
pf->hostname = ipv4_to_string(get_uint32(src));
break;
case 4: /* IPv6 */
pf->hostname = ipv6_to_string(get_data(src, 16));
break;
case 3: /* unresolved domain name */
pf->hostname = mkstr(get_pstring(src));
break;
default:
pf->hostname = NULL;
reply_code = 8; /* address type not supported */
break;
}
pf->port = get_uint16(src);
} else {
reply_code = 7; /* command not supported */
}
if (get_err(src) == BSE_OUT_OF_DATA)
return;
if (get_err(src))
reply_code = 1; /* general server failure */
output = strbuf_new();
put_byte(output, 5); /* SOCKS version */
put_byte(output, reply_code);
put_byte(output, 0); /* reserved */
put_byte(output, 1); /* IPv4 address follows */
put_uint32(output, 0); /* bound IPv4 address (unused) */
put_uint16(output, 0); /* bound port number (unused) */
sk_write(pf->s, output->u, output->len);
strbuf_free(output);
if (reply_code != 0) {
pfd_close(pf);
return;
}
pf->socks_state = SOCKS_NONE;
pf->socksbuf_consumed = src->pos;
break;
}
}
/*
* We come here when we're ready to make an actual
* connection.
*/
/*
* Freeze the socket until the SSH server confirms the
* connection.
*/
sk_set_frozen(pf->s, true);
pf->c = wrap_lportfwd_open(pf->cl, pf->hostname, pf->port, pf->s,
&pf->chan);
}
if (pf->ready)
sshfwd_write(pf->c, data, len);
}
static void pfd_sent(Plug *plug, size_t bufsize)
{
struct PortForwarding *pf =
container_of(plug, struct PortForwarding, plug);
if (pf->c)
sshfwd_unthrottle(pf->c, bufsize);
}
static const PlugVtable PortForwarding_plugvt = {
.log = pfd_log,
.closing = pfd_closing,
.receive = pfd_receive,
.sent = pfd_sent,
};
static void pfd_chan_free(Channel *chan);
static void pfd_open_confirmation(Channel *chan);
static void pfd_open_failure(Channel *chan, const char *errtext);
static size_t pfd_send(
Channel *chan, bool is_stderr, const void *data, size_t len);
static void pfd_send_eof(Channel *chan);
static void pfd_set_input_wanted(Channel *chan, bool wanted);
static char *pfd_log_close_msg(Channel *chan);
static const ChannelVtable PortForwarding_channelvt = {
.free = pfd_chan_free,
.open_confirmation = pfd_open_confirmation,
.open_failed = pfd_open_failure,
.send = pfd_send,
.send_eof = pfd_send_eof,
.set_input_wanted = pfd_set_input_wanted,
.log_close_msg = pfd_log_close_msg,
.want_close = chan_default_want_close,
.rcvd_exit_status = chan_no_exit_status,
.rcvd_exit_signal = chan_no_exit_signal,
.rcvd_exit_signal_numeric = chan_no_exit_signal_numeric,
.run_shell = chan_no_run_shell,
.run_command = chan_no_run_command,
.run_subsystem = chan_no_run_subsystem,
.enable_x11_forwarding = chan_no_enable_x11_forwarding,
.enable_agent_forwarding = chan_no_enable_agent_forwarding,
.allocate_pty = chan_no_allocate_pty,
.set_env = chan_no_set_env,
.send_break = chan_no_send_break,
.send_signal = chan_no_send_signal,
.change_window_size = chan_no_change_window_size,
.request_response = chan_no_request_response,
};
Channel *portfwd_raw_new(ConnectionLayer *cl, Plug **plug, bool start_ready)
{
struct PortForwarding *pf;
pf = new_portfwd_state();
pf->plug.vt = &PortForwarding_plugvt;
pf->chan.initial_fixed_window_size = 0;
pf->chan.vt = &PortForwarding_channelvt;
pf->input_wanted = true;
pf->c = NULL;
pf->cl = cl;
pf->input_wanted = true;
pf->ready = start_ready;
pf->socks_state = SOCKS_NONE;
pf->hostname = NULL;
pf->port = 0;
*plug = &pf->plug;
return &pf->chan;
}
void portfwd_raw_free(Channel *pfchan)
{
struct PortForwarding *pf;
assert(pfchan->vt == &PortForwarding_channelvt);
pf = container_of(pfchan, struct PortForwarding, chan);
free_portfwd_state(pf);
}
void portfwd_raw_setup(Channel *pfchan, Socket *s, SshChannel *sc)
{
struct PortForwarding *pf;
assert(pfchan->vt == &PortForwarding_channelvt);
pf = container_of(pfchan, struct PortForwarding, chan);
pf->s = s;
pf->c = sc;
}
/*
called when someone connects to the local port
*/
static int pfl_accepting(Plug *p, accept_fn_t constructor, accept_ctx_t ctx)
{
struct PortListener *pl = container_of(p, struct PortListener, plug);
struct PortForwarding *pf;
Channel *chan;
Plug *plug;
Socket *s;
const char *err;
chan = portfwd_raw_new(pl->cl, &plug, false);
s = constructor(ctx, plug);
if ((err = sk_socket_error(s)) != NULL) {
portfwd_raw_free(chan);
return 1;
}
pf = container_of(chan, struct PortForwarding, chan);
if (pl->is_dynamic) {
pf->s = s;
pf->socks_state = SOCKS_INITIAL;
pf->socksbuf = strbuf_new();
pf->socksbuf_consumed = 0;
pf->port = 0; /* "hostname" buffer is so far empty */
sk_set_frozen(s, false); /* we want to receive SOCKS _now_! */
} else {
pf->hostname = dupstr(pl->hostname);
pf->port = pl->port;
portfwd_raw_setup(
chan, s,
wrap_lportfwd_open(pl->cl, pf->hostname, pf->port, s, &pf->chan));
}
return 0;
}
static const PlugVtable PortListener_plugvt = {
.log = pfl_log,
.closing = pfl_closing,
.accepting = pfl_accepting,
};
/*
* Add a new port-forwarding listener from srcaddr:port -> desthost:destport.
*
* desthost == NULL indicates dynamic SOCKS port forwarding.
*
* On success, returns NULL and fills in *pl_ret. On error, returns a
* dynamically allocated error message string.
*/
static char *pfl_listen(const char *desthost, int destport,
const char *srcaddr, int port,
ConnectionLayer *cl, Conf *conf,
struct PortListener **pl_ret, int address_family)
{
const char *err;
struct PortListener *pl;
/*
* Open socket.
*/
pl = *pl_ret = new_portlistener_state();
pl->plug.vt = &PortListener_plugvt;
if (desthost) {
pl->hostname = dupstr(desthost);
pl->port = destport;
pl->is_dynamic = false;
} else
pl->is_dynamic = true;
pl->cl = cl;
pl->s = new_listener(srcaddr, port, &pl->plug,
!conf_get_bool(conf, CONF_lport_acceptall),
conf, address_family);
if ((err = sk_socket_error(pl->s)) != NULL) {
char *err_ret = dupstr(err);
sk_close(pl->s);
free_portlistener_state(pl);
*pl_ret = NULL;
return err_ret;
}
return NULL;
}
static char *pfd_log_close_msg(Channel *chan)
{
return dupstr("Forwarded port closed");
}
static void pfd_close(struct PortForwarding *pf)
{
if (!pf)
return;
sk_close(pf->s);
free_portfwd_state(pf);
}
/*
* Terminate a listener.
*/
static void pfl_terminate(struct PortListener *pl)
{
if (!pl)
return;
sk_close(pl->s);
free_portlistener_state(pl);
}
static void pfd_set_input_wanted(Channel *chan, bool wanted)
{
assert(chan->vt == &PortForwarding_channelvt);
PortForwarding *pf = container_of(chan, PortForwarding, chan);
pf->input_wanted = wanted;
sk_set_frozen(pf->s, !pf->input_wanted);
}
static void pfd_chan_free(Channel *chan)
{
assert(chan->vt == &PortForwarding_channelvt);
PortForwarding *pf = container_of(chan, PortForwarding, chan);
pfd_close(pf);
}
/*
* Called to send data down the raw connection.
*/
static size_t pfd_send(
Channel *chan, bool is_stderr, const void *data, size_t len)
{
assert(chan->vt == &PortForwarding_channelvt);
PortForwarding *pf = container_of(chan, PortForwarding, chan);
return sk_write(pf->s, data, len);
}
static void pfd_send_eof(Channel *chan)
{
assert(chan->vt == &PortForwarding_channelvt);
PortForwarding *pf = container_of(chan, PortForwarding, chan);
sk_write_eof(pf->s);
}
static void pfd_open_confirmation(Channel *chan)
{
assert(chan->vt == &PortForwarding_channelvt);
PortForwarding *pf = container_of(chan, PortForwarding, chan);
pf->ready = true;
sk_set_frozen(pf->s, false);
sk_write(pf->s, NULL, 0);
if (pf->socksbuf) {
sshfwd_write(pf->c, pf->socksbuf->u + pf->socksbuf_consumed,
pf->socksbuf->len - pf->socksbuf_consumed);
strbuf_free(pf->socksbuf);
pf->socksbuf = NULL;
}
}
static void pfd_open_failure(Channel *chan, const char *errtext)
{
assert(chan->vt == &PortForwarding_channelvt);
PortForwarding *pf = container_of(chan, PortForwarding, chan);
logeventf(pf->cl->logctx,
"Forwarded connection refused by remote%s%s",
errtext ? ": " : "", errtext ? errtext : "");
}
/* ----------------------------------------------------------------------
* Code to manage the complete set of currently active port
* forwardings, and update it from Conf.
*/
struct PortFwdRecord {
enum { DESTROY, KEEP, CREATE } status;
int type;
unsigned sport, dport;
char *saddr, *daddr;
char *sserv, *dserv;
struct ssh_rportfwd *remote;
int addressfamily;
struct PortListener *local;
};
static int pfr_cmp(void *av, void *bv)
{
PortFwdRecord *a = (PortFwdRecord *) av;
PortFwdRecord *b = (PortFwdRecord *) bv;
int i;
if (a->type > b->type)
return +1;
if (a->type < b->type)
return -1;
if (a->addressfamily > b->addressfamily)
return +1;
if (a->addressfamily < b->addressfamily)
return -1;
if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
return i < 0 ? -1 : +1;
if (a->sport > b->sport)
return +1;
if (a->sport < b->sport)
return -1;
if (a->type != 'D') {
if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
return i < 0 ? -1 : +1;
if (a->dport > b->dport)
return +1;
if (a->dport < b->dport)
return -1;
}
return 0;
}
static void pfr_free(PortFwdRecord *pfr)
{
/* Dispose of any listening socket. */
if (pfr->local)
pfl_terminate(pfr->local);
sfree(pfr->saddr);
sfree(pfr->daddr);
sfree(pfr->sserv);
sfree(pfr->dserv);
sfree(pfr);
}
struct PortFwdManager {
ConnectionLayer *cl;
Conf *conf;
tree234 *forwardings;
};
PortFwdManager *portfwdmgr_new(ConnectionLayer *cl)
{
PortFwdManager *mgr = snew(PortFwdManager);
mgr->cl = cl;
mgr->conf = NULL;
mgr->forwardings = newtree234(pfr_cmp);
return mgr;
}
void portfwdmgr_close(PortFwdManager *mgr, PortFwdRecord *pfr)
{
PortFwdRecord *realpfr = del234(mgr->forwardings, pfr);
if (realpfr == pfr)
pfr_free(pfr);
}
void portfwdmgr_close_all(PortFwdManager *mgr)
{
PortFwdRecord *pfr;
while ((pfr = delpos234(mgr->forwardings, 0)) != NULL)
pfr_free(pfr);
}
void portfwdmgr_free(PortFwdManager *mgr)
{
portfwdmgr_close_all(mgr);
freetree234(mgr->forwardings);
if (mgr->conf)
conf_free(mgr->conf);
sfree(mgr);
}
void portfwdmgr_config(PortFwdManager *mgr, Conf *conf)
{
PortFwdRecord *pfr;
int i;
char *key, *val;
if (mgr->conf)
conf_free(mgr->conf);
mgr->conf = conf_copy(conf);
/*
* Go through the existing port forwardings and tag them
* with status==DESTROY. Any that we want to keep will be
* re-enabled (status==KEEP) as we go through the
* configuration and find out which bits are the same as
* they were before.
*/
for (i = 0; (pfr = index234(mgr->forwardings, i)) != NULL; i++)
pfr->status = DESTROY;
for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
val != NULL;
val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
char *kp, *kp2, *vp, *vp2;
char address_family, type;
int sport, dport, sserv, dserv;
char *sports, *dports, *saddr, *host;
kp = key;
address_family = 'A';
type = 'L';
if (*kp == 'A' || *kp == '4' || *kp == '6')
address_family = *kp++;
if (*kp == 'L' || *kp == 'R')
type = *kp++;
if ((kp2 = host_strchr(kp, ':')) != NULL) {
/*
* There's a colon in the middle of the source port
* string, which means that the part before it is
* actually a source address.
*/
char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
saddr = host_strduptrim(saddr_tmp);
sfree(saddr_tmp);
sports = kp2+1;
} else {
saddr = NULL;
sports = kp;
}
sport = atoi(sports);
sserv = 0;
if (sport == 0) {
sserv = 1;
sport = net_service_lookup(sports);
if (!sport) {
logeventf(mgr->cl->logctx, "Service lookup failed for source"
" port \"%s\"", sports);
}
}
if (type == 'L' && !strcmp(val, "D")) {
/* dynamic forwarding */
host = NULL;
dports = NULL;
dport = -1;
dserv = 0;
type = 'D';
} else {
/* ordinary forwarding */
vp = val;
vp2 = vp + host_strcspn(vp, ":");
host = dupprintf("%.*s", (int)(vp2 - vp), vp);
if (*vp2)
vp2++;
dports = vp2;
dport = atoi(dports);
dserv = 0;
if (dport == 0) {
dserv = 1;
dport = net_service_lookup(dports);
if (!dport) {
logeventf(mgr->cl->logctx,
"Service lookup failed for destination"
" port \"%s\"", dports);
}
}
}
if (sport && dport) {
/* Set up a description of the source port. */
pfr = snew(PortFwdRecord);
pfr->type = type;
pfr->saddr = saddr;
pfr->sserv = sserv ? dupstr(sports) : NULL;
pfr->sport = sport;
pfr->daddr = host;
pfr->dserv = dserv ? dupstr(dports) : NULL;
pfr->dport = dport;
pfr->local = NULL;
pfr->remote = NULL;
pfr->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
address_family == '6' ? ADDRTYPE_IPV6 :
ADDRTYPE_UNSPEC);
PortFwdRecord *existing = add234(mgr->forwardings, pfr);
if (existing != pfr) {
if (existing->status == DESTROY) {
/*
* We already have a port forwarding up and running
* with precisely these parameters. Hence, no need
* to do anything; simply re-tag the existing one
* as KEEP.
*/
existing->status = KEEP;
}
/*
* Anything else indicates that there was a duplicate
* in our input, which we'll silently ignore.
*/
pfr_free(pfr);
} else {
pfr->status = CREATE;
}
} else {
sfree(saddr);
sfree(host);
}
}
/*
* Now go through and destroy any port forwardings which were
* not re-enabled.
*/
for (i = 0; (pfr = index234(mgr->forwardings, i)) != NULL; i++) {
if (pfr->status == DESTROY) {
char *message;
message = dupprintf("%s port forwarding from %s%s%d",
pfr->type == 'L' ? "local" :
pfr->type == 'R' ? "remote" : "dynamic",
pfr->saddr ? pfr->saddr : "",
pfr->saddr ? ":" : "",
pfr->sport);
if (pfr->type != 'D') {
char *msg2 = dupprintf("%s to %s:%d", message,
pfr->daddr, pfr->dport);
sfree(message);
message = msg2;
}
logeventf(mgr->cl->logctx, "Cancelling %s", message);
sfree(message);
/* pfr->remote or pfr->local may be NULL if setting up a
* forwarding failed. */
if (pfr->remote) {
/*
* Cancel the port forwarding at the server
* end.
*
* Actually closing the listening port on the server
* side may fail - because in SSH-1 there's no message
* in the protocol to request it!
*
* Instead, we simply remove the record of the
* forwarding from our local end, so that any
* connections the server tries to make on it are
* rejected.
*/
ssh_rportfwd_remove(mgr->cl, pfr->remote);
pfr->remote = NULL;
} else if (pfr->local) {
pfl_terminate(pfr->local);
pfr->local = NULL;
}
delpos234(mgr->forwardings, i);
pfr_free(pfr);
i--; /* so we don't skip one in the list */
}
}
/*
* And finally, set up any new port forwardings (status==CREATE).
*/
for (i = 0; (pfr = index234(mgr->forwardings, i)) != NULL; i++) {
if (pfr->status == CREATE) {
char *sportdesc, *dportdesc;
sportdesc = dupprintf("%s%s%s%s%d%s",
pfr->saddr ? pfr->saddr : "",
pfr->saddr ? ":" : "",
pfr->sserv ? pfr->sserv : "",
pfr->sserv ? "(" : "",
pfr->sport,
pfr->sserv ? ")" : "");
if (pfr->type == 'D') {
dportdesc = NULL;
} else {
dportdesc = dupprintf("%s:%s%s%d%s",
pfr->daddr,
pfr->dserv ? pfr->dserv : "",
pfr->dserv ? "(" : "",
pfr->dport,
pfr->dserv ? ")" : "");
}
if (pfr->type == 'L') {
char *err = pfl_listen(pfr->daddr, pfr->dport,
pfr->saddr, pfr->sport,
mgr->cl, conf, &pfr->local,
pfr->addressfamily);