summaryrefslogtreecommitdiffstats
path: root/daemon/session.c
blob: 8f97b6818706221f6df8e624f0ddd32df31f61b7 (plain)
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
/*  Copyright (C) 2018-2020 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
 *  SPDX-License-Identifier: GPL-3.0-or-later
 */

#include <assert.h>

#include <libknot/packet/pkt.h>

#include "lib/defines.h"
#include "daemon/session.h"
#include "daemon/engine.h"
#include "daemon/tls.h"
#include "daemon/http.h"
#include "daemon/worker.h"
#include "daemon/io.h"
#include "lib/generic/queue.h"

#define TLS_CHUNK_SIZE (16 * 1024)

/* Initial max frame size: https://tools.ietf.org/html/rfc7540#section-6.5.2 */
#define HTTP_MAX_FRAME_SIZE 16384

/* Per-socket (TCP or UDP) persistent structure.
 *
 * In particular note that for UDP clients it's just one session (per socket)
 * shared for all clients.  For TCP/TLS it's also for the connection-specific socket,
 * i.e one session per connection.
 *
 * LATER(optim.): the memory here is used a bit wastefully.
 */
struct session {
	struct session_flags sflags;  /**< miscellaneous flags. */
	union inaddr peer;            /**< address of peer; not for UDP clients (downstream) */
	union inaddr sockname;        /**< our local address; for UDP it may be a wildcard */
	uv_handle_t *handle;          /**< libuv handle for IO operations. */
	uv_timer_t timeout;           /**< libuv handle for timer. */

	struct tls_ctx *tls_ctx;      /**< server side tls-related data. */
	struct tls_client_ctx *tls_client_ctx;  /**< client side tls-related data. */

#if ENABLE_DOH2
	struct http_ctx *http_ctx;  /**< server side http-related data. */
#endif

	trie_t *tasks;                /**< list of tasks assotiated with given session. */
	queue_t(struct qr_task *) waiting;  /**< list of tasks waiting for sending to upstream. */

	uint8_t *wire_buf;            /**< Buffer for DNS message, except for XDP. */
	ssize_t wire_buf_size;        /**< Buffer size. */
	ssize_t wire_buf_start_idx;   /**< Data start offset in wire_buf. */
	ssize_t wire_buf_end_idx;     /**< Data end offset in wire_buf. */
	uint64_t last_activity;       /**< Time of last IO activity (if any occurs).
				       *   Otherwise session creation time. */
};

static void on_session_close(uv_handle_t *handle)
{
	struct session *session = handle->data;
	assert(session->handle == handle); (void)session;
	io_free(handle);
}

static void on_session_timer_close(uv_handle_t *timer)
{
	struct session *session = timer->data;
	uv_handle_t *handle = session->handle;
	assert(handle && handle->data == session);
	assert (session->sflags.outgoing || handle->type == UV_TCP);
	if (!uv_is_closing(handle)) {
		uv_close(handle, on_session_close);
	}
}

void session_free(struct session *session)
{
	if (session) {
		assert(session_is_empty(session));
		session_clear(session);
		free(session);
	}
}

void session_clear(struct session *session)
{
	assert(session_is_empty(session));
	if (session->handle && session->handle->type == UV_TCP) {
		free(session->wire_buf);
	}
	trie_clear(session->tasks);
	trie_free(session->tasks);
	queue_deinit(session->waiting);
	tls_free(session->tls_ctx);
	tls_client_ctx_free(session->tls_client_ctx);
#if ENABLE_DOH2
	http_free(session->http_ctx);
#endif
	memset(session, 0, sizeof(*session));
}

void session_close(struct session *session)
{
	assert(session_is_empty(session));
	if (session->sflags.closing) {
		return;
	}

	uv_handle_t *handle = session->handle;
	io_stop_read(handle);
	session->sflags.closing = true;

	if (!uv_is_closing((uv_handle_t *)&session->timeout)) {
		uv_timer_stop(&session->timeout);
		if (session->tls_client_ctx) {
			tls_close(&session->tls_client_ctx->c);
		}
		if (session->tls_ctx) {
			tls_close(&session->tls_ctx->c);
		}

		session->timeout.data = session;
		uv_close((uv_handle_t *)&session->timeout, on_session_timer_close);
	}
}

int session_start_read(struct session *session)
{
	return io_start_read(session->handle);
}

int session_stop_read(struct session *session)
{
	return io_stop_read(session->handle);
}

int session_waitinglist_push(struct session *session, struct qr_task *task)
{
	queue_push(session->waiting, task);
	worker_task_ref(task);
	return kr_ok();
}

struct qr_task *session_waitinglist_get(const struct session *session)
{
	return (queue_len(session->waiting) > 0) ? (queue_head(session->waiting)) : NULL;
}

struct qr_task *session_waitinglist_pop(struct session *session, bool deref)
{
	struct qr_task *t = session_waitinglist_get(session);
	queue_pop(session->waiting);
	if (deref) {
		worker_task_unref(t);
	}
	return t;
}

int session_tasklist_add(struct session *session, struct qr_task *task)
{
	trie_t *t = session->tasks;
	uint16_t task_msg_id = 0;
	const char *key = NULL;
	size_t key_len = 0;
	if (session->sflags.outgoing) {
		knot_pkt_t *pktbuf = worker_task_get_pktbuf(task);
		task_msg_id = knot_wire_get_id(pktbuf->wire);
		key = (const char *)&task_msg_id;
		key_len = sizeof(task_msg_id);
	} else {
		key = (const char *)&task;
		key_len = sizeof(char *);
	}
	trie_val_t *v = trie_get_ins(t, key, key_len);
	if (unlikely(!v)) {
		assert(false);
		return kr_error(ENOMEM);
	}
	if (*v == NULL) {
		*v = task;
		worker_task_ref(task);
	} else if (*v != task) {
		assert(false);
		return kr_error(EINVAL);
	}
	return kr_ok();
}

int session_tasklist_del(struct session *session, struct qr_task *task)
{
	trie_t *t = session->tasks;
	uint16_t task_msg_id = 0;
	const char *key = NULL;
	size_t key_len = 0;
	trie_val_t val;
	if (session->sflags.outgoing) {
		knot_pkt_t *pktbuf = worker_task_get_pktbuf(task);
		task_msg_id = knot_wire_get_id(pktbuf->wire);
		key = (const char *)&task_msg_id;
		key_len = sizeof(task_msg_id);
	} else {
		key = (const char *)&task;
		key_len = sizeof(char *);
	}
	int ret = trie_del(t, key, key_len, &val);
	if (ret == kr_ok()) {
		assert(val == task);
		worker_task_unref(val);
	}
	return ret;
}

struct qr_task *session_tasklist_get_first(struct session *session)
{
	trie_val_t *val = trie_get_first(session->tasks, NULL, NULL);
	return val ? (struct qr_task *) *val : NULL;
}

struct qr_task *session_tasklist_del_first(struct session *session, bool deref)
{
	trie_val_t val = NULL;
	int res = trie_del_first(session->tasks, NULL, NULL, &val);
	if (res != kr_ok()) {
		val = NULL;
	} else if (deref) {
		worker_task_unref(val);
	}
	return (struct qr_task *)val;
}
struct qr_task* session_tasklist_del_msgid(const struct session *session, uint16_t msg_id)
{
	trie_t *t = session->tasks;
	assert(session->sflags.outgoing);
	struct qr_task *ret = NULL;
	const char *key = (const char *)&msg_id;
	size_t key_len = sizeof(msg_id);
	trie_val_t val;
	int res = trie_del(t, key, key_len, &val);
	if (res == kr_ok()) {
		if (worker_task_numrefs(val) > 1) {
			ret = val;
		}
		worker_task_unref(val);
	}
	return ret;
}

struct qr_task* session_tasklist_find_msgid(const struct session *session, uint16_t msg_id)
{
	trie_t *t = session->tasks;
	assert(session->sflags.outgoing);
	struct qr_task *ret = NULL;
	trie_val_t *val = trie_get_try(t, (char *)&msg_id, sizeof(msg_id));
	if (val) {
		ret = *val;
	}
	return ret;
}

struct session_flags *session_flags(struct session *session)
{
	return &session->sflags;
}

struct sockaddr *session_get_peer(struct session *session)
{
	return &session->peer.ip;
}

struct sockaddr *session_get_sockname(struct session *session)
{
	return &session->sockname.ip;
}

struct tls_ctx *session_tls_get_server_ctx(const struct session *session)
{
	return session->tls_ctx;
}

void session_tls_set_server_ctx(struct session *session, struct tls_ctx *ctx)
{
	session->tls_ctx = ctx;
}

struct tls_client_ctx *session_tls_get_client_ctx(const struct session *session)
{
	return session->tls_client_ctx;
}

void session_tls_set_client_ctx(struct session *session, struct tls_client_ctx *ctx)
{
	session->tls_client_ctx = ctx;
}

struct tls_common_ctx *session_tls_get_common_ctx(const struct session *session)
{
	struct tls_common_ctx *tls_ctx = session->sflags.outgoing ? &session->tls_client_ctx->c :
								    &session->tls_ctx->c;
	return tls_ctx;
}

#if ENABLE_DOH2
struct http_ctx *session_http_get_server_ctx(const struct session *session)
{
	return session->http_ctx;
}

void session_http_set_server_ctx(struct session *session, struct http_ctx *ctx)
{
	session->http_ctx = ctx;
}
#endif

uv_handle_t *session_get_handle(struct session *session)
{
	return session->handle;
}

struct session *session_get(uv_handle_t *h)
{
	return h->data;
}

struct session *session_new(uv_handle_t *handle, bool has_tls, bool has_http)
{
	if (!handle) {
		return NULL;
	}
	struct session *session = calloc(1, sizeof(struct session));
	if (!session) {
		return NULL;
	}

	queue_init(session->waiting);
	session->tasks = trie_create(NULL);
	if (handle->type == UV_TCP) {
		size_t wire_buffer_size = KNOT_WIRE_MAX_PKTSIZE;
		if (has_tls) {
			/* When decoding large packets,
			 * gnutls gives the application chunks of size 16 kb each. */
			wire_buffer_size += TLS_CHUNK_SIZE;
			session->sflags.has_tls = true;
		}
#if ENABLE_DOH2
		if (has_http) {
			/* When decoding large packets,
			 * HTTP/2 frames can be up to 16 KB by default. */
			wire_buffer_size += HTTP_MAX_FRAME_SIZE;
			session->sflags.has_http = true;
		}
#endif
		uint8_t *wire_buf = malloc(wire_buffer_size);
		if (!wire_buf) {
			free(session);
			return NULL;
		}
		session->wire_buf = wire_buf;
		session->wire_buf_size = wire_buffer_size;
	} else if (handle->type == UV_UDP) {
		/* We use the singleton buffer from worker for all UDP (!)
		 * libuv documentation doesn't really guarantee this is OK,
		 * but the implementation for unix systems does not hold
		 * the buffer (both UDP and TCP) - always makes a NON-blocking
		 * syscall that fills the buffer and immediately calls
		 * the callback, whatever the result of the operation.
		 * We still need to keep in mind to only touch the buffer
		 * in this callback... */
		assert(handle->loop->data);
		session->wire_buf = the_worker->wire_buf;
		session->wire_buf_size = sizeof(the_worker->wire_buf);
	} else {
		assert(handle->type == UV_POLL/*XDP*/);
		/* - wire_buf* are left zeroed, as they make no sense
		 * - timer is unused but OK for simplicity (server-side sessions are few)
		 */
	}

	uv_timer_init(handle->loop, &session->timeout);

	session->handle = handle;
	handle->data = session;
	session->timeout.data = session;
	session_touch(session);

	return session;
}

size_t session_tasklist_get_len(const struct session *session)
{
	return trie_weight(session->tasks);
}

size_t session_waitinglist_get_len(const struct session *session)
{
	return queue_len(session->waiting);
}

bool session_tasklist_is_empty(const struct session *session)
{
	return session_tasklist_get_len(session) == 0;
}

bool session_waitinglist_is_empty(const struct session *session)
{
	return session_waitinglist_get_len(session) == 0;
}

bool session_is_empty(const struct session *session)
{
	return session_tasklist_is_empty(session) &&
	       session_waitinglist_is_empty(session);
}

bool session_has_tls(const struct session *session)
{
	return session->sflags.has_tls;
}

void session_set_has_tls(struct session *session, bool has_tls)
{
	session->sflags.has_tls = has_tls;
}

void session_waitinglist_retry(struct session *session, bool increase_timeout_cnt)
{
	while (!session_waitinglist_is_empty(session)) {
		struct qr_task *task = session_waitinglist_pop(session, false);
		if (increase_timeout_cnt) {
			worker_task_timeout_inc(task);
		}
		worker_task_step(task, &session->peer.ip, NULL);
		worker_task_unref(task);
	}
}

void session_waitinglist_finalize(struct session *session, int status)
{
	while (!session_waitinglist_is_empty(session)) {
		struct qr_task *t = session_waitinglist_pop(session, false);
		worker_task_finalize(t, status);
		worker_task_unref(t);
	}
}

void session_tasklist_finalize(struct session *session, int status)
{
	while (session_tasklist_get_len(session) > 0) {
		struct qr_task *t = session_tasklist_del_first(session, false);
		assert(worker_task_numrefs(t) > 0);
		worker_task_finalize(t, status);
		worker_task_unref(t);
	}
}

int session_tasklist_finalize_expired(struct session *session)
{
	int ret = 0;
	queue_t(struct qr_task *) q;
	uint64_t now = kr_now();
	trie_t *t = session->tasks;
	trie_it_t *it;
	queue_init(q);
	for (it = trie_it_begin(t); !trie_it_finished(it); trie_it_next(it)) {
		trie_val_t *v = trie_it_val(it);
		struct qr_task *task = (struct qr_task *)*v;
		if ((now - worker_task_creation_time(task)) >= KR_RESOLVE_TIME_LIMIT) {
			queue_push(q, task);
			worker_task_ref(task);
		}
	}
	trie_it_free(it);

	struct qr_task *task = NULL;
	uint16_t msg_id = 0;
	char *key = (char *)&task;
	int32_t keylen = sizeof(struct qr_task *);
	if (session->sflags.outgoing) {
		key = (char *)&msg_id;
		keylen = sizeof(msg_id);
	}
	while (queue_len(q) > 0) {
		task = queue_head(q);
		if (session->sflags.outgoing) {
			knot_pkt_t *pktbuf = worker_task_get_pktbuf(task);
			msg_id = knot_wire_get_id(pktbuf->wire);
		}
		int res = trie_del(t, key, keylen, NULL);
		if (!worker_task_finished(task)) {
			/* task->pending_count must be zero,
			 * but there are can be followers,
			 * so run worker_task_subreq_finalize() to ensure retrying
			 * for all the followers. */
			worker_task_subreq_finalize(task);
			worker_task_finalize(task, KR_STATE_FAIL);
		}
		if (res == KNOT_EOK) {
			worker_task_unref(task);
		}
		queue_pop(q);
		worker_task_unref(task);
		++ret;
	}

	queue_deinit(q);
	return ret;
}

int session_timer_start(struct session *session, uv_timer_cb cb,
			uint64_t timeout, uint64_t repeat)
{
	uv_timer_t *timer = &session->timeout;
	assert(timer->data == session);
	int ret = uv_timer_start(timer, cb, timeout, repeat);
	if (ret != 0) {
		uv_timer_stop(timer);
		return kr_error(ENOMEM);
	}
	return 0;
}

int session_timer_restart(struct session *session)
{
	return uv_timer_again(&session->timeout);
}

int session_timer_stop(struct session *session)
{
	return uv_timer_stop(&session->timeout);
}

ssize_t session_wirebuf_consume(struct session *session, const uint8_t *data, ssize_t len)
{
	if (data != &session->wire_buf[session->wire_buf_end_idx]) {
		/* shouldn't happen */
		return kr_error(EINVAL);
	}

	if (len < 0) {
		/* shouldn't happen */
		return kr_error(EINVAL);
	}

	if (session->wire_buf_end_idx + len > session->wire_buf_size) {
		/* shouldn't happen */
		return kr_error(EINVAL);
	}

	session->wire_buf_end_idx += len;
	return len;
}

knot_pkt_t *session_produce_packet(struct session *session, knot_mm_t *mm)
{
	session->sflags.wirebuf_error = false;
	if (session->wire_buf_end_idx == 0) {
		return NULL;
	}

	if (session->wire_buf_start_idx == session->wire_buf_end_idx) {
		session->wire_buf_start_idx = 0;
		session->wire_buf_end_idx = 0;
		return NULL;
	}

	if (session->wire_buf_start_idx > session->wire_buf_end_idx) {
		session->sflags.wirebuf_error = true;
		session->wire_buf_start_idx = 0;
		session->wire_buf_end_idx = 0;
		return NULL;
	}

	const uv_handle_t *handle = session->handle;
	uint8_t *msg_start = &session->wire_buf[session->wire_buf_start_idx];
	ssize_t wirebuf_msg_data_size = session->wire_buf_end_idx - session->wire_buf_start_idx;
	uint16_t msg_size = 0;

	if (!handle) {
		session->sflags.wirebuf_error = true;
		return NULL;
	} else if (handle->type == UV_TCP) {
		if (wirebuf_msg_data_size < 2) {
			return NULL;
		}
		msg_size = knot_wire_read_u16(msg_start);
		if (msg_size >= session->wire_buf_size) {
			session->sflags.wirebuf_error = true;
			return NULL;
		}
		if (msg_size + 2 > wirebuf_msg_data_size) {
			return NULL;
		}
		if (msg_size == 0) {
			session->sflags.wirebuf_error = true;
			return NULL;
		}
		msg_start += 2;
	} else if (wirebuf_msg_data_size < UINT16_MAX) {
		msg_size = wirebuf_msg_data_size;
	} else {
		session->sflags.wirebuf_error = true;
		return NULL;
	}


	knot_pkt_t *pkt = knot_pkt_new(msg_start, msg_size, mm);
	session->sflags.wirebuf_error = (pkt == NULL);
	return pkt;
}

int session_discard_packet(struct session *session, const knot_pkt_t *pkt)
{
	uv_handle_t *handle = session->handle;
	/* Pointer to data start in wire_buf */
	uint8_t *wirebuf_data_start = &session->wire_buf[session->wire_buf_start_idx];
	/* Number of data bytes in wire_buf */
	size_t wirebuf_data_size = session->wire_buf_end_idx - session->wire_buf_start_idx;
	/* Pointer to message start in wire_buf */
	uint8_t *wirebuf_msg_start = wirebuf_data_start;
	/* Number of message bytes in wire_buf.
	 * For UDP it is the same number as wirebuf_data_size. */
	size_t wirebuf_msg_size = wirebuf_data_size;
	/* Wire data from parsed packet. */
	uint8_t *pkt_msg_start = pkt->wire;
	/* Number of bytes in packet wire buffer. */
	size_t pkt_msg_size = pkt->size;
	if (knot_pkt_has_tsig(pkt)) {
		pkt_msg_size += pkt->tsig_wire.len;
	}

	session->sflags.wirebuf_error = true;

	if (!handle) {
		return kr_error(EINVAL);
	} else if (handle->type == UV_TCP) {
		/* wire_buf contains TCP DNS message. */
		if (wirebuf_data_size < 2) {
			/* TCP message length field isn't in buffer, must not happen. */
			assert(0);
			session->wire_buf_start_idx = 0;
			session->wire_buf_end_idx = 0;
			return kr_error(EINVAL);
		}
		wirebuf_msg_size = knot_wire_read_u16(wirebuf_msg_start);
		wirebuf_msg_start += 2;
		if (wirebuf_msg_size + 2 > wirebuf_data_size) {
			/* TCP message length field is greater then
			 * number of bytes in buffer, must not happen. */
			assert(0);
			session->wire_buf_start_idx = 0;
			session->wire_buf_end_idx = 0;
			return kr_error(EINVAL);
		}
	}

	if (wirebuf_msg_start != pkt_msg_start) {
		/* packet wirebuf must be located at the beginning
		 * of the session wirebuf, must not happen. */
		assert(0);
		session->wire_buf_start_idx = 0;
		session->wire_buf_end_idx = 0;
		return kr_error(EINVAL);
	}

	if (wirebuf_msg_size < pkt_msg_size) {
		/* Message length field is lesser then packet size,
		 * must not happen. */
		assert(0);
		session->wire_buf_start_idx = 0;
		session->wire_buf_end_idx = 0;
		return kr_error(EINVAL);
	}

	if (handle->type == UV_TCP) {
		session->wire_buf_start_idx += wirebuf_msg_size + 2;
	} else {
		session->wire_buf_start_idx += pkt_msg_size;
	}
	session->sflags.wirebuf_error = false;

	wirebuf_data_size = session->wire_buf_end_idx - session->wire_buf_start_idx;
	if (wirebuf_data_size == 0) {
		session_wirebuf_discard(session);
	} else if (wirebuf_data_size < KNOT_WIRE_HEADER_SIZE) {
		session_wirebuf_compress(session);
	}

	return kr_ok();
}

void session_wirebuf_discard(struct session *session)
{
	session->wire_buf_start_idx = 0;
	session->wire_buf_end_idx = 0;
}

void session_wirebuf_compress(struct session *session)
{
	if (session->wire_buf_start_idx == 0) {
		return;
	}
	uint8_t *wirebuf_data_start = &session->wire_buf[session->wire_buf_start_idx];
	size_t wirebuf_data_size = session->wire_buf_end_idx - session->wire_buf_start_idx;
	if (session->wire_buf_start_idx < wirebuf_data_size) {
		memmove(session->wire_buf, wirebuf_data_start, wirebuf_data_size);
	} else {
		memcpy(session->wire_buf, wirebuf_data_start, wirebuf_data_size);
	}
	session->wire_buf_start_idx = 0;
	session->wire_buf_end_idx = wirebuf_data_size;
}

bool session_wirebuf_error(struct session *session)
{
	return session->sflags.wirebuf_error;
}

uint8_t *session_wirebuf_get_start(struct session *session)
{
	return session->wire_buf;
}

size_t session_wirebuf_get_size(struct session *session)
{
	return session->wire_buf_size;
}

uint8_t *session_wirebuf_get_free_start(struct session *session)
{
	return &session->wire_buf[session->wire_buf_end_idx];
}

size_t session_wirebuf_get_free_size(struct session *session)
{
	return session->wire_buf_size - session->wire_buf_end_idx;
}

void session_poison(struct session *session)
{
	kr_asan_poison(session, sizeof(*session));
}

void session_unpoison(struct session *session)
{
	kr_asan_unpoison(session, sizeof(*session));
}

int session_wirebuf_process(struct session *session, const struct sockaddr *peer)
{
	int ret = 0;
	if (session->wire_buf_start_idx == session->wire_buf_end_idx)
		return ret;

	size_t wirebuf_data_size = session->wire_buf_end_idx - session->wire_buf_start_idx;
	uint32_t max_iterations = (wirebuf_data_size /
		(KNOT_WIRE_HEADER_SIZE + KNOT_WIRE_QUESTION_MIN_SIZE)) + 1;
	knot_pkt_t *pkt = NULL;

	while (((pkt = session_produce_packet(session, &the_worker->pkt_pool)) != NULL) &&
	       (ret < max_iterations)) {
		assert (!session_wirebuf_error(session));
		int res = worker_submit(session, peer, NULL, NULL, NULL, pkt);
		/* Errors from worker_submit() are intetionally *not* handled in order to
		 * ensure the entire wire buffer is processed. */
		if (res == kr_ok())
			ret += 1;
		if (session_discard_packet(session, pkt) < 0) {
			/* Packet data isn't stored in memory as expected.
			 * something went wrong, normally should not happen. */
			break;
		}
	}

	/* worker_submit() may cause the session to close (e.g. due to IO
	 * write error when the packet triggers an immediate answer). This is
	 * an error state, as well as any wirebuf error. */
	if (session->sflags.closing || session_wirebuf_error(session))
		ret = -1;

	return ret;
}

void session_kill_ioreq(struct session *session, struct qr_task *task)
{
	if (!session) {
		return;
	}
	assert(session->sflags.outgoing && session->handle);
	if (session->sflags.closing) {
		return;
	}
	session_tasklist_del(session, task);
	if (session->handle->type == UV_UDP) {
		assert(session_tasklist_is_empty(session));
		session_close(session);
		return;
	}
}

/** Update timestamp */
void session_touch(struct session *session)
{
	session->last_activity = kr_now();
}

uint64_t session_last_activity(struct session *session)
{
	return session->last_activity;
}