-
Notifications
You must be signed in to change notification settings - Fork 560
/
bufferevent_openssl.c
1521 lines (1334 loc) · 38.7 KB
/
bufferevent_openssl.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
/*
* Copyright (c) 2009-2012 Niels Provos and Nick Mathewson
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
// Get rid of OSX 10.7 and greater deprecation warnings.
#if defined(__APPLE__) && defined(__clang__)
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
#endif
#include "event2/event-config.h"
#include "evconfig-private.h"
#include <sys/types.h>
#ifdef EVENT__HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef EVENT__HAVE_STDARG_H
#include <stdarg.h>
#endif
#ifdef EVENT__HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef _WIN32
#include <winsock2.h>
#endif
#include "event2/bufferevent.h"
#include "event2/bufferevent_struct.h"
#include "event2/bufferevent_ssl.h"
#include "event2/buffer.h"
#include "event2/event.h"
#include "mm-internal.h"
#include "bufferevent-internal.h"
#include "log-internal.h"
#include <openssl/ssl.h>
#include <openssl/err.h>
#include "openssl-compat.h"
/*
* Define an OpenSSL bio that targets a bufferevent.
*/
/* --------------------
A BIO is an OpenSSL abstraction that handles reading and writing data. The
library will happily speak SSL over anything that implements a BIO
interface.
Here we define a BIO implementation that directs its output to a
bufferevent. We'll want to use this only when none of OpenSSL's built-in
IO mechanisms work for us.
-------------------- */
/* every BIO type needs its own integer type value. */
#define BIO_TYPE_LIBEVENT 57
/* ???? Arguably, we should set BIO_TYPE_FILTER or BIO_TYPE_SOURCE_SINK on
* this. */
#if 0
static void
print_err(int val)
{
int err;
printf("Error was %d\n", val);
while ((err = ERR_get_error())) {
const char *msg = (const char*)ERR_reason_error_string(err);
const char *lib = (const char*)ERR_lib_error_string(err);
const char *func = (const char*)ERR_func_error_string(err);
printf("%s in %s %s\n", msg, lib, func);
}
}
#else
#define print_err(v) ((void)0)
#endif
/* Called to initialize a new BIO */
static int
bio_bufferevent_new(BIO *b)
{
BIO_set_init(b, 0);
BIO_set_data(b, NULL); /* We'll be putting the bufferevent in this field.*/
return 1;
}
/* Called to uninitialize the BIO. */
static int
bio_bufferevent_free(BIO *b)
{
if (!b)
return 0;
if (BIO_get_shutdown(b)) {
if (BIO_get_init(b) && BIO_get_data(b))
bufferevent_free(BIO_get_data(b));
BIO_free(b);
}
return 1;
}
/* Called to extract data from the BIO. */
static int
bio_bufferevent_read(BIO *b, char *out, int outlen)
{
int r = 0;
struct evbuffer *input;
BIO_clear_retry_flags(b);
if (!out)
return 0;
if (!BIO_get_data(b))
return -1;
input = bufferevent_get_input(BIO_get_data(b));
if (evbuffer_get_length(input) == 0) {
/* If there's no data to read, say so. */
BIO_set_retry_read(b);
return -1;
} else {
r = evbuffer_remove(input, out, outlen);
}
return r;
}
/* Called to write data into the BIO */
static int
bio_bufferevent_write(BIO *b, const char *in, int inlen)
{
struct bufferevent *bufev = BIO_get_data(b);
struct evbuffer *output;
size_t outlen;
BIO_clear_retry_flags(b);
if (!BIO_get_data(b))
return -1;
output = bufferevent_get_output(bufev);
outlen = evbuffer_get_length(output);
/* Copy only as much data onto the output buffer as can fit under the
* high-water mark. */
if (bufev->wm_write.high && bufev->wm_write.high <= (outlen+inlen)) {
if (bufev->wm_write.high <= outlen) {
/* If no data can fit, we'll need to retry later. */
BIO_set_retry_write(b);
return -1;
}
inlen = bufev->wm_write.high - outlen;
}
EVUTIL_ASSERT(inlen > 0);
evbuffer_add(output, in, inlen);
return inlen;
}
/* Called to handle various requests */
static long
bio_bufferevent_ctrl(BIO *b, int cmd, long num, void *ptr)
{
struct bufferevent *bufev = BIO_get_data(b);
long ret = 1;
switch (cmd) {
case BIO_CTRL_GET_CLOSE:
ret = BIO_get_shutdown(b);
break;
case BIO_CTRL_SET_CLOSE:
BIO_set_shutdown(b, (int)num);
break;
case BIO_CTRL_PENDING:
ret = evbuffer_get_length(bufferevent_get_input(bufev)) != 0;
break;
case BIO_CTRL_WPENDING:
ret = evbuffer_get_length(bufferevent_get_output(bufev)) != 0;
break;
/* XXXX These two are given a special-case treatment because
* of cargo-cultism. I should come up with a better reason. */
case BIO_CTRL_DUP:
case BIO_CTRL_FLUSH:
ret = 1;
break;
default:
ret = 0;
break;
}
return ret;
}
/* Called to write a string to the BIO */
static int
bio_bufferevent_puts(BIO *b, const char *s)
{
return bio_bufferevent_write(b, s, strlen(s));
}
/* Method table for the bufferevent BIO */
static BIO_METHOD *methods_bufferevent;
/* Return the method table for the bufferevents BIO */
static BIO_METHOD *
BIO_s_bufferevent(void)
{
if (methods_bufferevent == NULL) {
methods_bufferevent = BIO_meth_new(BIO_TYPE_LIBEVENT, "bufferevent");
if (methods_bufferevent == NULL)
return NULL;
BIO_meth_set_write(methods_bufferevent, bio_bufferevent_write);
BIO_meth_set_read(methods_bufferevent, bio_bufferevent_read);
BIO_meth_set_puts(methods_bufferevent, bio_bufferevent_puts);
BIO_meth_set_ctrl(methods_bufferevent, bio_bufferevent_ctrl);
BIO_meth_set_create(methods_bufferevent, bio_bufferevent_new);
BIO_meth_set_destroy(methods_bufferevent, bio_bufferevent_free);
}
return methods_bufferevent;
}
/* Create a new BIO to wrap communication around a bufferevent. If close_flag
* is true, the bufferevent will be freed when the BIO is closed. */
static BIO *
BIO_new_bufferevent(struct bufferevent *bufferevent)
{
BIO *result;
if (!bufferevent)
return NULL;
if (!(result = BIO_new(BIO_s_bufferevent())))
return NULL;
BIO_set_init(result, 1);
BIO_set_data(result, bufferevent);
/* We don't tell the BIO to close the bufferevent; we do it ourselves on
* be_openssl_destruct() */
BIO_set_shutdown(result, 0);
return result;
}
/* --------------------
Now, here's the OpenSSL-based implementation of bufferevent.
The implementation comes in two flavors: one that connects its SSL object
to an underlying bufferevent using a BIO_bufferevent, and one that has the
SSL object connect to a socket directly. The latter should generally be
faster, except on Windows, where your best bet is using a
bufferevent_async.
(OpenSSL supports many other BIO types, too. But we can't use any unless
we have a good way to get notified when they become readable/writable.)
-------------------- */
struct bio_data_counts {
unsigned long n_written;
unsigned long n_read;
};
struct bufferevent_openssl {
/* Shared fields with common bufferevent implementation code.
If we were set up with an underlying bufferevent, we use the
events here as timers only. If we have an SSL, then we use
the events as socket events.
*/
struct bufferevent_private bev;
/* An underlying bufferevent that we're directing our output to.
If it's NULL, then we're connected to an fd, not an evbuffer. */
struct bufferevent *underlying;
/* The SSL object doing our encryption. */
SSL *ssl;
/* A callback that's invoked when data arrives on our outbuf so we
know to write data to the SSL. */
struct evbuffer_cb_entry *outbuf_cb;
/* A count of how much data the bios have read/written total. Used
for rate-limiting. */
struct bio_data_counts counts;
/* If this value is greater than 0, then the last SSL_write blocked,
* and we need to try it again with this many bytes. */
ev_ssize_t last_write;
#define NUM_ERRORS 3
ev_uint32_t errors[NUM_ERRORS];
/* When we next get available space, we should say "read" instead of
"write". This can happen if there's a renegotiation during a read
operation. */
unsigned read_blocked_on_write : 1;
/* When we next get data, we should say "write" instead of "read". */
unsigned write_blocked_on_read : 1;
/* Treat TCP close before SSL close on SSL >= v3 as clean EOF. */
unsigned allow_dirty_shutdown : 1;
/* XXX */
unsigned n_errors : 2;
/* Are we currently connecting, accepting, or doing IO? */
unsigned state : 2;
/* If we reset fd, we sould reset state too */
unsigned old_state : 2;
};
static int be_openssl_enable(struct bufferevent *, short);
static int be_openssl_disable(struct bufferevent *, short);
static void be_openssl_unlink(struct bufferevent *);
static void be_openssl_destruct(struct bufferevent *);
static int be_openssl_adj_timeouts(struct bufferevent *);
static int be_openssl_flush(struct bufferevent *bufev,
short iotype, enum bufferevent_flush_mode mode);
static int be_openssl_ctrl(struct bufferevent *, enum bufferevent_ctrl_op, union bufferevent_ctrl_data *);
const struct bufferevent_ops bufferevent_ops_openssl = {
"ssl",
evutil_offsetof(struct bufferevent_openssl, bev.bev),
be_openssl_enable,
be_openssl_disable,
be_openssl_unlink,
be_openssl_destruct,
be_openssl_adj_timeouts,
be_openssl_flush,
be_openssl_ctrl,
};
/* Given a bufferevent, return a pointer to the bufferevent_openssl that
* contains it, if any. */
static inline struct bufferevent_openssl *
upcast(struct bufferevent *bev)
{
struct bufferevent_openssl *bev_o;
if (!BEV_IS_OPENSSL(bev))
return NULL;
bev_o = (void*)( ((char*)bev) -
evutil_offsetof(struct bufferevent_openssl, bev.bev));
EVUTIL_ASSERT(BEV_IS_OPENSSL(&bev_o->bev.bev));
return bev_o;
}
static inline void
put_error(struct bufferevent_openssl *bev_ssl, unsigned long err)
{
if (bev_ssl->n_errors == NUM_ERRORS)
return;
/* The error type according to openssl is "unsigned long", but
openssl never uses more than 32 bits of it. It _can't_ use more
than 32 bits of it, since it needs to report errors on systems
where long is only 32 bits.
*/
bev_ssl->errors[bev_ssl->n_errors++] = (ev_uint32_t) err;
}
/* Have the base communications channel (either the underlying bufferevent or
* ev_read and ev_write) start reading. Take the read-blocked-on-write flag
* into account. */
static int
start_reading(struct bufferevent_openssl *bev_ssl)
{
if (bev_ssl->underlying) {
bufferevent_unsuspend_read_(bev_ssl->underlying,
BEV_SUSPEND_FILT_READ);
return 0;
} else {
struct bufferevent *bev = &bev_ssl->bev.bev;
int r;
r = bufferevent_add_event_(&bev->ev_read, &bev->timeout_read);
if (r == 0 && bev_ssl->read_blocked_on_write)
r = bufferevent_add_event_(&bev->ev_write,
&bev->timeout_write);
return r;
}
}
/* Have the base communications channel (either the underlying bufferevent or
* ev_read and ev_write) start writing. Take the write-blocked-on-read flag
* into account. */
static int
start_writing(struct bufferevent_openssl *bev_ssl)
{
int r = 0;
if (bev_ssl->underlying) {
if (bev_ssl->write_blocked_on_read) {
bufferevent_unsuspend_read_(bev_ssl->underlying,
BEV_SUSPEND_FILT_READ);
}
} else {
struct bufferevent *bev = &bev_ssl->bev.bev;
r = bufferevent_add_event_(&bev->ev_write, &bev->timeout_write);
if (!r && bev_ssl->write_blocked_on_read)
r = bufferevent_add_event_(&bev->ev_read,
&bev->timeout_read);
}
return r;
}
static void
stop_reading(struct bufferevent_openssl *bev_ssl)
{
if (bev_ssl->write_blocked_on_read)
return;
if (bev_ssl->underlying) {
bufferevent_suspend_read_(bev_ssl->underlying,
BEV_SUSPEND_FILT_READ);
} else {
struct bufferevent *bev = &bev_ssl->bev.bev;
event_del(&bev->ev_read);
}
}
static void
stop_writing(struct bufferevent_openssl *bev_ssl)
{
if (bev_ssl->read_blocked_on_write)
return;
if (bev_ssl->underlying) {
bufferevent_unsuspend_read_(bev_ssl->underlying,
BEV_SUSPEND_FILT_READ);
} else {
struct bufferevent *bev = &bev_ssl->bev.bev;
event_del(&bev->ev_write);
}
}
static int
set_rbow(struct bufferevent_openssl *bev_ssl)
{
if (!bev_ssl->underlying)
stop_reading(bev_ssl);
bev_ssl->read_blocked_on_write = 1;
return start_writing(bev_ssl);
}
static int
set_wbor(struct bufferevent_openssl *bev_ssl)
{
if (!bev_ssl->underlying)
stop_writing(bev_ssl);
bev_ssl->write_blocked_on_read = 1;
return start_reading(bev_ssl);
}
static int
clear_rbow(struct bufferevent_openssl *bev_ssl)
{
struct bufferevent *bev = &bev_ssl->bev.bev;
int r = 0;
bev_ssl->read_blocked_on_write = 0;
if (!(bev->enabled & EV_WRITE))
stop_writing(bev_ssl);
if (bev->enabled & EV_READ)
r = start_reading(bev_ssl);
return r;
}
static int
clear_wbor(struct bufferevent_openssl *bev_ssl)
{
struct bufferevent *bev = &bev_ssl->bev.bev;
int r = 0;
bev_ssl->write_blocked_on_read = 0;
if (!(bev->enabled & EV_READ))
stop_reading(bev_ssl);
if (bev->enabled & EV_WRITE)
r = start_writing(bev_ssl);
return r;
}
static void
conn_closed(struct bufferevent_openssl *bev_ssl, int when, int errcode, int ret)
{
int event = BEV_EVENT_ERROR;
int dirty_shutdown = 0;
unsigned long err;
switch (errcode) {
case SSL_ERROR_ZERO_RETURN:
/* Possibly a clean shutdown. */
if (SSL_get_shutdown(bev_ssl->ssl) & SSL_RECEIVED_SHUTDOWN)
event = BEV_EVENT_EOF;
else
dirty_shutdown = 1;
break;
case SSL_ERROR_SYSCALL:
/* IO error; possibly a dirty shutdown. */
if ((ret == 0 || ret == -1) && ERR_peek_error() == 0)
dirty_shutdown = 1;
break;
case SSL_ERROR_SSL:
/* Protocol error. */
break;
case SSL_ERROR_WANT_X509_LOOKUP:
/* XXXX handle this. */
break;
case SSL_ERROR_NONE:
case SSL_ERROR_WANT_READ:
case SSL_ERROR_WANT_WRITE:
case SSL_ERROR_WANT_CONNECT:
case SSL_ERROR_WANT_ACCEPT:
default:
/* should be impossible; treat as normal error. */
event_warnx("BUG: Unexpected OpenSSL error code %d", errcode);
break;
}
while ((err = ERR_get_error())) {
put_error(bev_ssl, err);
}
if (dirty_shutdown && bev_ssl->allow_dirty_shutdown)
event = BEV_EVENT_EOF;
stop_reading(bev_ssl);
stop_writing(bev_ssl);
/* when is BEV_EVENT_{READING|WRITING} */
event = when | event;
bufferevent_run_eventcb_(&bev_ssl->bev.bev, event, 0);
}
static void
init_bio_counts(struct bufferevent_openssl *bev_ssl)
{
BIO *rbio, *wbio;
wbio = SSL_get_wbio(bev_ssl->ssl);
bev_ssl->counts.n_written = wbio ? BIO_number_written(wbio) : 0;
rbio = SSL_get_rbio(bev_ssl->ssl);
bev_ssl->counts.n_read = rbio ? BIO_number_read(rbio) : 0;
}
static inline void
decrement_buckets(struct bufferevent_openssl *bev_ssl)
{
unsigned long num_w = BIO_number_written(SSL_get_wbio(bev_ssl->ssl));
unsigned long num_r = BIO_number_read(SSL_get_rbio(bev_ssl->ssl));
/* These next two subtractions can wrap around. That's okay. */
unsigned long w = num_w - bev_ssl->counts.n_written;
unsigned long r = num_r - bev_ssl->counts.n_read;
if (w)
bufferevent_decrement_write_buckets_(&bev_ssl->bev, w);
if (r)
bufferevent_decrement_read_buckets_(&bev_ssl->bev, r);
bev_ssl->counts.n_written = num_w;
bev_ssl->counts.n_read = num_r;
}
#define OP_MADE_PROGRESS 1
#define OP_BLOCKED 2
#define OP_ERR 4
/* Return a bitmask of OP_MADE_PROGRESS (if we read anything); OP_BLOCKED (if
we're now blocked); and OP_ERR (if an error occurred). */
static int
do_read(struct bufferevent_openssl *bev_ssl, int n_to_read) {
/* Requires lock */
struct bufferevent *bev = &bev_ssl->bev.bev;
struct evbuffer *input = bev->input;
int r, n, i, n_used = 0, atmost;
struct evbuffer_iovec space[2];
int result = 0;
if (bev_ssl->bev.read_suspended)
return 0;
atmost = bufferevent_get_read_max_(&bev_ssl->bev);
if (n_to_read > atmost)
n_to_read = atmost;
n = evbuffer_reserve_space(input, n_to_read, space, 2);
if (n < 0)
return OP_ERR;
for (i=0; i<n; ++i) {
if (bev_ssl->bev.read_suspended)
break;
ERR_clear_error();
r = SSL_read(bev_ssl->ssl, space[i].iov_base, space[i].iov_len);
if (r>0) {
result |= OP_MADE_PROGRESS;
if (bev_ssl->read_blocked_on_write)
if (clear_rbow(bev_ssl) < 0)
return OP_ERR | result;
++n_used;
space[i].iov_len = r;
decrement_buckets(bev_ssl);
} else {
int err = SSL_get_error(bev_ssl->ssl, r);
print_err(err);
switch (err) {
case SSL_ERROR_WANT_READ:
/* Can't read until underlying has more data. */
if (bev_ssl->read_blocked_on_write)
if (clear_rbow(bev_ssl) < 0)
return OP_ERR | result;
break;
case SSL_ERROR_WANT_WRITE:
/* This read operation requires a write, and the
* underlying is full */
if (!bev_ssl->read_blocked_on_write)
if (set_rbow(bev_ssl) < 0)
return OP_ERR | result;
break;
default:
conn_closed(bev_ssl, BEV_EVENT_READING, err, r);
break;
}
result |= OP_BLOCKED;
break; /* out of the loop */
}
}
if (n_used) {
evbuffer_commit_space(input, space, n_used);
if (bev_ssl->underlying)
BEV_RESET_GENERIC_READ_TIMEOUT(bev);
}
return result;
}
/* Return a bitmask of OP_MADE_PROGRESS (if we wrote anything); OP_BLOCKED (if
we're now blocked); and OP_ERR (if an error occurred). */
static int
do_write(struct bufferevent_openssl *bev_ssl, int atmost)
{
int i, r, n, n_written = 0;
struct bufferevent *bev = &bev_ssl->bev.bev;
struct evbuffer *output = bev->output;
struct evbuffer_iovec space[8];
int result = 0;
if (bev_ssl->last_write > 0)
atmost = bev_ssl->last_write;
else
atmost = bufferevent_get_write_max_(&bev_ssl->bev);
n = evbuffer_peek(output, atmost, NULL, space, 8);
if (n < 0)
return OP_ERR | result;
if (n > 8)
n = 8;
for (i=0; i < n; ++i) {
if (bev_ssl->bev.write_suspended)
break;
/* SSL_write will (reasonably) return 0 if we tell it to
send 0 data. Skip this case so we don't interpret the
result as an error */
if (space[i].iov_len == 0)
continue;
ERR_clear_error();
r = SSL_write(bev_ssl->ssl, space[i].iov_base,
space[i].iov_len);
if (r > 0) {
result |= OP_MADE_PROGRESS;
if (bev_ssl->write_blocked_on_read)
if (clear_wbor(bev_ssl) < 0)
return OP_ERR | result;
n_written += r;
bev_ssl->last_write = -1;
decrement_buckets(bev_ssl);
} else {
int err = SSL_get_error(bev_ssl->ssl, r);
print_err(err);
switch (err) {
case SSL_ERROR_WANT_WRITE:
/* Can't read until underlying has more data. */
if (bev_ssl->write_blocked_on_read)
if (clear_wbor(bev_ssl) < 0)
return OP_ERR | result;
bev_ssl->last_write = space[i].iov_len;
break;
case SSL_ERROR_WANT_READ:
/* This read operation requires a write, and the
* underlying is full */
if (!bev_ssl->write_blocked_on_read)
if (set_wbor(bev_ssl) < 0)
return OP_ERR | result;
bev_ssl->last_write = space[i].iov_len;
break;
default:
conn_closed(bev_ssl, BEV_EVENT_WRITING, err, r);
bev_ssl->last_write = -1;
break;
}
result |= OP_BLOCKED;
break;
}
}
if (n_written) {
evbuffer_drain(output, n_written);
if (bev_ssl->underlying)
BEV_RESET_GENERIC_WRITE_TIMEOUT(bev);
bufferevent_trigger_nolock_(bev, EV_WRITE, BEV_OPT_DEFER_CALLBACKS);
}
return result;
}
#define WRITE_FRAME 15000
#define READ_DEFAULT 4096
/* Try to figure out how many bytes to read; return 0 if we shouldn't be
* reading. */
static int
bytes_to_read(struct bufferevent_openssl *bev)
{
struct evbuffer *input = bev->bev.bev.input;
struct event_watermark *wm = &bev->bev.bev.wm_read;
int result = READ_DEFAULT;
ev_ssize_t limit;
/* XXX 99% of this is generic code that nearly all bufferevents will
* want. */
if (bev->write_blocked_on_read) {
return 0;
}
if (! (bev->bev.bev.enabled & EV_READ)) {
return 0;
}
if (bev->bev.read_suspended) {
return 0;
}
if (wm->high) {
if (evbuffer_get_length(input) >= wm->high) {
return 0;
}
result = wm->high - evbuffer_get_length(input);
} else {
result = READ_DEFAULT;
}
/* Respect the rate limit */
limit = bufferevent_get_read_max_(&bev->bev);
if (result > limit) {
result = limit;
}
return result;
}
/* Things look readable. If write is blocked on read, write till it isn't.
* Read from the underlying buffer until we block or we hit our high-water
* mark.
*/
static void
consider_reading(struct bufferevent_openssl *bev_ssl)
{
int r;
int n_to_read;
int all_result_flags = 0;
while (bev_ssl->write_blocked_on_read) {
r = do_write(bev_ssl, WRITE_FRAME);
if (r & (OP_BLOCKED|OP_ERR))
break;
}
if (bev_ssl->write_blocked_on_read)
return;
n_to_read = bytes_to_read(bev_ssl);
while (n_to_read) {
r = do_read(bev_ssl, n_to_read);
all_result_flags |= r;
if (r & (OP_BLOCKED|OP_ERR))
break;
if (bev_ssl->bev.read_suspended)
break;
/* Read all pending data. This won't hit the network
* again, and will (most importantly) put us in a state
* where we don't need to read anything else until the
* socket is readable again. It'll potentially make us
* overrun our read high-watermark (somewhat
* regrettable). The damage to the rate-limit has
* already been done, since OpenSSL went and read a
* whole SSL record anyway. */
n_to_read = SSL_pending(bev_ssl->ssl);
/* XXX This if statement is actually a bad bug, added to avoid
* XXX a worse bug.
*
* The bad bug: It can potentially cause resource unfairness
* by reading too much data from the underlying bufferevent;
* it can potentially cause read looping if the underlying
* bufferevent is a bufferevent_pair and deferred callbacks
* aren't used.
*
* The worse bug: If we didn't do this, then we would
* potentially not read any more from bev_ssl->underlying
* until more data arrived there, which could lead to us
* waiting forever.
*/
if (!n_to_read && bev_ssl->underlying)
n_to_read = bytes_to_read(bev_ssl);
}
if (all_result_flags & OP_MADE_PROGRESS) {
struct bufferevent *bev = &bev_ssl->bev.bev;
bufferevent_trigger_nolock_(bev, EV_READ, 0);
}
if (!bev_ssl->underlying) {
/* Should be redundant, but let's avoid busy-looping */
if (bev_ssl->bev.read_suspended ||
!(bev_ssl->bev.bev.enabled & EV_READ)) {
event_del(&bev_ssl->bev.bev.ev_read);
}
}
}
static void
consider_writing(struct bufferevent_openssl *bev_ssl)
{
int r;
struct evbuffer *output = bev_ssl->bev.bev.output;
struct evbuffer *target = NULL;
struct event_watermark *wm = NULL;
while (bev_ssl->read_blocked_on_write) {
r = do_read(bev_ssl, 1024); /* XXXX 1024 is a hack */
if (r & OP_MADE_PROGRESS) {
struct bufferevent *bev = &bev_ssl->bev.bev;
bufferevent_trigger_nolock_(bev, EV_READ, 0);
}
if (r & (OP_ERR|OP_BLOCKED))
break;
}
if (bev_ssl->read_blocked_on_write)
return;
if (bev_ssl->underlying) {
target = bev_ssl->underlying->output;
wm = &bev_ssl->underlying->wm_write;
}
while ((bev_ssl->bev.bev.enabled & EV_WRITE) &&
(! bev_ssl->bev.write_suspended) &&
evbuffer_get_length(output) &&
(!target || (! wm->high || evbuffer_get_length(target) < wm->high))) {
int n_to_write;
if (wm && wm->high)
n_to_write = wm->high - evbuffer_get_length(target);
else
n_to_write = WRITE_FRAME;
r = do_write(bev_ssl, n_to_write);
if (r & (OP_BLOCKED|OP_ERR))
break;
}
if (!bev_ssl->underlying) {
if (evbuffer_get_length(output) == 0) {
event_del(&bev_ssl->bev.bev.ev_write);
} else if (bev_ssl->bev.write_suspended ||
!(bev_ssl->bev.bev.enabled & EV_WRITE)) {
/* Should be redundant, but let's avoid busy-looping */
event_del(&bev_ssl->bev.bev.ev_write);
}
}
}
static void
be_openssl_readcb(struct bufferevent *bev_base, void *ctx)
{
struct bufferevent_openssl *bev_ssl = ctx;
consider_reading(bev_ssl);
}
static void
be_openssl_writecb(struct bufferevent *bev_base, void *ctx)
{
struct bufferevent_openssl *bev_ssl = ctx;
consider_writing(bev_ssl);
}
static void
be_openssl_eventcb(struct bufferevent *bev_base, short what, void *ctx)
{
struct bufferevent_openssl *bev_ssl = ctx;
int event = 0;
if (what & BEV_EVENT_EOF) {
if (bev_ssl->allow_dirty_shutdown)
event = BEV_EVENT_EOF;
else
event = BEV_EVENT_ERROR;
} else if (what & BEV_EVENT_TIMEOUT) {
/* We sure didn't set this. Propagate it to the user. */
event = what;
} else if (what & BEV_EVENT_ERROR) {
/* An error occurred on the connection. Propagate it to the user. */
event = what;
} else if (what & BEV_EVENT_CONNECTED) {
/* Ignore it. We're saying SSL_connect() already, which will
eat it. */
}
if (event)
bufferevent_run_eventcb_(&bev_ssl->bev.bev, event, 0);
}
static void
be_openssl_readeventcb(evutil_socket_t fd, short what, void *ptr)
{
struct bufferevent_openssl *bev_ssl = ptr;
bufferevent_incref_and_lock_(&bev_ssl->bev.bev);
if (what == EV_TIMEOUT) {
bufferevent_run_eventcb_(&bev_ssl->bev.bev,
BEV_EVENT_TIMEOUT|BEV_EVENT_READING, 0);
} else {
consider_reading(bev_ssl);
}
bufferevent_decref_and_unlock_(&bev_ssl->bev.bev);
}
static void
be_openssl_writeeventcb(evutil_socket_t fd, short what, void *ptr)
{
struct bufferevent_openssl *bev_ssl = ptr;
bufferevent_incref_and_lock_(&bev_ssl->bev.bev);
if (what == EV_TIMEOUT) {
bufferevent_run_eventcb_(&bev_ssl->bev.bev,
BEV_EVENT_TIMEOUT|BEV_EVENT_WRITING, 0);
} else {
consider_writing(bev_ssl);
}
bufferevent_decref_and_unlock_(&bev_ssl->bev.bev);
}
static int
be_openssl_auto_fd(struct bufferevent_openssl *bev_ssl, int fd)
{
if (!bev_ssl->underlying) {
struct bufferevent *bev = &bev_ssl->bev.bev;
if (event_initialized(&bev->ev_read) && fd < 0) {
fd = event_get_fd(&bev->ev_read);
}
}
return fd;
}
static int
set_open_callbacks(struct bufferevent_openssl *bev_ssl, evutil_socket_t fd)
{
if (bev_ssl->underlying) {
bufferevent_setcb(bev_ssl->underlying,
be_openssl_readcb, be_openssl_writecb, be_openssl_eventcb,
bev_ssl);
return 0;
} else {
struct bufferevent *bev = &bev_ssl->bev.bev;
int rpending=0, wpending=0, r1=0, r2=0;
if (event_initialized(&bev->ev_read)) {
rpending = event_pending(&bev->ev_read, EV_READ, NULL);
wpending = event_pending(&bev->ev_write, EV_WRITE, NULL);
event_del(&bev->ev_read);
event_del(&bev->ev_write);
}
event_assign(&bev->ev_read, bev->ev_base, fd,
EV_READ|EV_PERSIST|EV_FINALIZE,