summaryrefslogtreecommitdiffstats
path: root/src/sync-ftfw.c
blob: e026b1cde4d7ff02c7a86cc030045d9e13a3d4c9 (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
/*
 * (C) 2006-2008 by Pablo Neira Ayuso <pablo@netfilter.org>
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include "conntrackd.h"
#include "sync.h"
#include "queue.h"
#include "network.h"
#include "alarm.h"
#include "log.h"
#include "cache.h"
#include "fds.h"

#include <string.h>
#include <errno.h>

#if 0 
#define dp printf
#else
#define dp(...)
#endif

struct queue *rs_queue;
static uint32_t exp_seq;
static uint32_t window;
static uint32_t ack_from;
static int ack_from_set = 0;
static struct alarm_block alive_alarm;

enum {
	HELLO_INIT,
	HELLO_SAY,
	HELLO_DONE,
};
static int hello_state = HELLO_INIT;
static int say_hello_back;

/* XXX: alive message expiration configurable */
#define ALIVE_INT 1

struct cache_ftfw {
	struct queue_node	qnode;
	uint32_t 		seq;
};

static void cache_ftfw_add(struct cache_object *obj, void *data)
{
	struct cache_ftfw *cn = data;
	/* These nodes are not inserted in the list */
	queue_node_init(&cn->qnode, Q_ELEM_OBJ);
}

static void cache_ftfw_del(struct cache_object *obj, void *data)
{
	struct cache_ftfw *cn = data;
	queue_del(&cn->qnode);
}

static struct cache_extra cache_ftfw_extra = {
	.size 		= sizeof(struct cache_ftfw),
	.add		= cache_ftfw_add,
	.destroy	= cache_ftfw_del
};

static void nethdr_set_hello(struct nethdr *net)
{
	switch(hello_state) {
	case HELLO_INIT:
		hello_state = HELLO_SAY;
		/* fall through */
	case HELLO_SAY:
		net->flags |= NET_F_HELLO;
		break;
	}
	if (say_hello_back) {
		net->flags |= NET_F_HELLO_BACK;
		say_hello_back = 0;
	}
}

static void tx_queue_add_ctlmsg(uint32_t flags, uint32_t from, uint32_t to)
{
	struct queue_object *qobj;
	struct nethdr_ack *ack;

	qobj = queue_object_new(Q_ELEM_CTL, sizeof(struct nethdr_ack));
	if (qobj == NULL)
		return;

	ack		= (struct nethdr_ack *)qobj->data;
	ack->type 	= NET_T_CTL;
	ack->flags	= flags;
	ack->from	= from;
	ack->to		= to;

	queue_add(STATE_SYNC(tx_queue), &qobj->qnode);
}

static void tx_queue_add_ctlmsg2(uint32_t flags)
{
	struct queue_object *qobj;
	struct nethdr *ctl;

	qobj = queue_object_new(Q_ELEM_CTL, sizeof(struct nethdr_ack));
	if (qobj == NULL)
		return;

	ctl		= (struct nethdr *)qobj->data;
	ctl->type 	= NET_T_CTL;
	ctl->flags	= flags;

	queue_add(STATE_SYNC(tx_queue), &qobj->qnode);
}

/* this function is called from the alarm framework */
static void do_alive_alarm(struct alarm_block *a, void *data)
{
	if (ack_from_set && nethdr_track_is_seq_set()) {
		/* exp_seq contains the last update received */
		tx_queue_add_ctlmsg(NET_F_ACK,
				    ack_from,
				    STATE_SYNC(last_seq_recv));
		ack_from_set = 0;
	} else
		tx_queue_add_ctlmsg2(NET_F_ALIVE);

	add_alarm(&alive_alarm, ALIVE_INT, 0);
}

static int ftfw_init(void)
{
	rs_queue = queue_create(CONFIG(resend_queue_size), 0);
	if (rs_queue == NULL) {
		dlog(LOG_ERR, "cannot create rs queue");
		return -1;
	}

	init_alarm(&alive_alarm, NULL, do_alive_alarm);
	add_alarm(&alive_alarm, ALIVE_INT, 0);

	/* set ack window size */
	window = CONFIG(window_size);

	return 0;
}

static void ftfw_kill(void)
{
	queue_destroy(rs_queue);
}

static int do_cache_to_tx(void *data1, void *data2)
{
	struct cache_object *obj = data2;
	struct cache_ftfw *cn = cache_get_extra(STATE_SYNC(internal), obj);

	if (queue_in(rs_queue, &cn->qnode)) {
		queue_del(&cn->qnode);
		queue_add(STATE_SYNC(tx_queue), &cn->qnode);
	} else {
		if (queue_add(STATE_SYNC(tx_queue), &cn->qnode))
			cache_object_get(obj);
	}
	return 0;
}

static int rs_queue_dump(struct queue_node *n, const void *data2)
{
	const int *fd = data2;
	char buf[512];
	int size;

	switch(n->type) {
		case Q_ELEM_CTL: {
			struct nethdr *net = queue_node_data(n);
			size = sprintf(buf, "control -> seq:%u flags:%u\n",
					    net->seq, net->flags);
			break;
		}
		case Q_ELEM_OBJ: {
			struct cache_ftfw *cn = (struct cache_ftfw *) n;
			size = sprintf(buf, "object -> seq:%u\n", cn->seq);
		break;
		}
		default:
			return 0;
	}
	send(*fd, buf, size, 0);
	return 0;
}

static void ftfw_local_queue(int fd)
{
	char buf[512];
	int size;

	size = sprintf(buf, "resent queue (len=%u)\n", queue_len(rs_queue));
	send(fd, buf, size, 0);
	queue_iterate(rs_queue, &fd, rs_queue_dump);
}

static int ftfw_local(int fd, int type, void *data)
{
	int ret = 1;

	switch(type) {
	case REQUEST_DUMP:
		dlog(LOG_NOTICE, "request resync");
		tx_queue_add_ctlmsg(NET_F_RESYNC, 0, 0);
		break;
	case SEND_BULK:
		dlog(LOG_NOTICE, "sending bulk update");
		cache_iterate(STATE_SYNC(internal), NULL, do_cache_to_tx);
		break;
	case STATS_QUEUE:
		ftfw_local_queue(fd);
		break;
	default:
		ret = 0;
		break;
	}

	return ret;
}

static int rs_queue_to_tx(struct queue_node *n, const void *data)
{
	const struct nethdr_ack *nack = data;

	switch(n->type) {
	case Q_ELEM_CTL: {
		struct nethdr_ack *net = queue_node_data(n);

		if (before(net->seq, nack->from))
			return 0;	/* continue */
		else if (after(net->seq, nack->to))
			return 1;	/* break */

		dp("rs_queue_to_tx sq: %u fl:%u len:%u\n",
			net->seq, net->flags, net->len);

		queue_del(n);
		queue_add(STATE_SYNC(tx_queue), n);
		break;
	}
	case Q_ELEM_OBJ: {
		struct cache_ftfw *cn;

		cn = (struct cache_ftfw *) n;
		if (before(cn->seq, nack->from))
			return 0;
		else if (after(cn->seq, nack->to))
			return 1;

		dp("resending nack'ed (oldseq=%u)\n", cn->seq);

		queue_del(n);
		queue_add(STATE_SYNC(tx_queue), n);
		break;
	}
	}
	return 0;
}

static int rs_queue_empty(struct queue_node *n, const void *data)
{
	const struct nethdr_ack *h = data;

	switch(n->type) {
	case Q_ELEM_CTL: {
		struct nethdr_ack *net = queue_node_data(n);

		if (h == NULL) {
			queue_del(n);
			queue_object_free((struct queue_object *)n);
			return 0;
		}
		if (before(net->seq, h->from))
			return 0;	/* continue */
		else if (after(net->seq, h->to))
			return 1;	/* break */

		dp("remove from queue (seq=%u)\n", net->seq);
		queue_del(n);
		queue_object_free((struct queue_object *)n);
		break;
	}
	case Q_ELEM_OBJ: {
		struct cache_ftfw *cn;
		struct cache_object *obj;

		cn = (struct cache_ftfw *) n;
		if (h == NULL) {
			queue_del(n);
			obj = cache_data_get_object(STATE_SYNC(internal), cn);
			cache_object_put(obj);
			return 0;
		}
		if (before(cn->seq, h->from))
			return 0;
		else if (after(cn->seq, h->to))
			return 1;

		dp("queue: deleting from queue (seq=%u)\n", cn->seq);
		queue_del(n);
		obj = cache_data_get_object(STATE_SYNC(internal), cn);
		cache_object_put(obj);
		break;
	}
	}
	return 0;
}

static int digest_msg(const struct nethdr *net)
{
	if (IS_DATA(net))
		return MSG_DATA;

	else if (IS_ACK(net)) {
		const struct nethdr_ack *h = (const struct nethdr_ack *) net;

		if (before(h->to, h->from))
			return MSG_BAD;

		queue_iterate(rs_queue, h, rs_queue_empty);
		return MSG_CTL;

	} else if (IS_NACK(net)) {
		const struct nethdr_ack *nack = (const struct nethdr_ack *) net;

		if (before(nack->to, nack->from))
			return MSG_BAD;

		queue_iterate(rs_queue, nack, rs_queue_to_tx);
		return MSG_CTL;

	} else if (IS_RESYNC(net)) {
		dp("RESYNC ALL\n");
		cache_iterate(STATE_SYNC(internal), NULL, do_cache_to_tx);
		return MSG_CTL;

	} else if (IS_ALIVE(net))
		return MSG_CTL;

	return MSG_BAD;
}

static int digest_hello(const struct nethdr *net)
{
	int ret = 0;

	if (IS_HELLO(net)) {
		say_hello_back = 1;
		ret = 1;
	}
	if (IS_HELLO_BACK(net)) {
		/* this is a hello back for a requested hello */
		if (hello_state == HELLO_SAY)
			hello_state = HELLO_DONE;
	}

	return ret;
}

static int ftfw_recv(const struct nethdr *net)
{
	int ret = MSG_DATA;

	if (digest_hello(net)) {
		/* we have received a hello while we had data to acknowledge.
		 * reset the window, the other doesn't know anthing about it. */
		if (ack_from_set && before(net->seq, ack_from)) {
			window = CONFIG(window_size) - 1;
			ack_from = net->seq;
		}

		/* XXX: flush the resend queues since the other does not 
		 * know anything about that data, we are unreliable until 
		 * the helloing finishes */
		queue_iterate(rs_queue, NULL, rs_queue_empty);

		goto bypass;
	}

	switch (nethdr_track_seq(net->seq, &exp_seq)) {
	case SEQ_AFTER:
		ret = digest_msg(net);
		if (ret == MSG_BAD) {
			ret = MSG_BAD;
			goto out;
		}

		if (ack_from_set) {
			tx_queue_add_ctlmsg(NET_F_ACK, ack_from, exp_seq-1);
			ack_from_set = 0;
		}

		tx_queue_add_ctlmsg(NET_F_NACK, exp_seq, net->seq-1);

		/* count this message as part of the new window */
		window = CONFIG(window_size) - 1;
		ack_from = net->seq;
		ack_from_set = 1;
		break;

	case SEQ_BEFORE:
		/* we don't accept delayed packets */
		ret = MSG_DROP;
		break;

	case SEQ_UNSET:
	case SEQ_IN_SYNC:
bypass:
		ret = digest_msg(net);
		if (ret == MSG_BAD) {
			ret = MSG_BAD;
			goto out;
		}

		if (!ack_from_set) {
			ack_from_set = 1;
			ack_from = net->seq;
		}

		if (--window <= 0) {
			/* received a window, send an acknowledgement */
			tx_queue_add_ctlmsg(NET_F_ACK, ack_from, net->seq);
			window = CONFIG(window_size);
			ack_from_set = 0;
		}
	}

out:
	if ((ret == MSG_DATA || ret == MSG_CTL))
		nethdr_track_update_seq(net->seq);

	return ret;
}

static void rs_queue_purge_full(void)
{
	struct queue_node *n;

	n = queue_del_head(rs_queue);
	switch(n->type) {
	case Q_ELEM_CTL: {
		struct queue_object *qobj = (struct queue_object *)n;
		queue_object_free(qobj);
		break;
	}
	case Q_ELEM_OBJ: {
		struct cache_ftfw *cn;
		struct cache_object *obj;

		cn = (struct cache_ftfw *)n;
		obj = cache_data_get_object(STATE_SYNC(internal), cn);
		cache_object_put(obj);
		break;
	}
	}
}

static int tx_queue_xmit(struct queue_node *n, const void *data)
{
	queue_del(n);

	switch(n->type) {
	case Q_ELEM_CTL: {
		struct nethdr *net = queue_node_data(n);

		nethdr_set_hello(net);

		if (IS_ACK(net) || IS_NACK(net) || IS_RESYNC(net)) {
			nethdr_set_ack(net);
		} else {
			nethdr_set_ctl(net);
		}
		HDR_HOST2NETWORK(net);

		dp("tx_queue sq: %u fl:%u len:%u\n",
	               ntohl(net->seq), net->flags, ntohs(net->len));

		multichannel_send(STATE_SYNC(channel), net);
		HDR_NETWORK2HOST(net);

		if (IS_ACK(net) || IS_NACK(net) || IS_RESYNC(net)) {
			if (queue_add(rs_queue, n) < 0) {
				if (errno == ENOSPC) {
					rs_queue_purge_full();
					queue_add(rs_queue, n);
				}
			}
		} else
			queue_object_free((struct queue_object *)n);
		break;
	}
	case Q_ELEM_OBJ: {
		struct cache_ftfw *cn;
		struct cache_object *obj;
		int type;
		struct nethdr *net;

		cn = (struct cache_ftfw *)n;
		obj = cache_data_get_object(STATE_SYNC(internal), cn);
		type = object_status_to_network_type(obj->status);
		net = BUILD_NETMSG(obj->ct, type);
		nethdr_set_hello(net);

		dp("tx_list sq: %u fl:%u len:%u\n",
	                ntohl(net->seq), net->flags, ntohs(net->len));

		multichannel_send(STATE_SYNC(channel), net);
		cn->seq = ntohl(net->seq);
		if (queue_add(rs_queue, &cn->qnode) < 0) {
			if (errno == ENOSPC) {
				rs_queue_purge_full();
				queue_add(rs_queue, &cn->qnode);
			}
		}
		/* we release the object once we get the acknowlegment */
		break;
	}
	}

	return 0;
}

static void ftfw_xmit(void)
{
	queue_iterate(STATE_SYNC(tx_queue), NULL, tx_queue_xmit);
	add_alarm(&alive_alarm, ALIVE_INT, 0);
	dp("tx_queue_len:%u rs_queue_len:%u\n", 
		queue_len(tx_queue), queue_len(rs_queue));
}

static void ftfw_enqueue(struct cache_object *obj, int type)
{
	struct cache_ftfw *cn = cache_get_extra(STATE_SYNC(internal), obj);
	if (queue_in(rs_queue, &cn->qnode)) {
		queue_del(&cn->qnode);
		queue_add(STATE_SYNC(tx_queue), &cn->qnode);
	} else {
		if (queue_add(STATE_SYNC(tx_queue), &cn->qnode))
			cache_object_get(obj);
	}
}

struct sync_mode sync_ftfw = {
	.internal_cache_flags	= NO_FEATURES,
	.external_cache_flags	= NO_FEATURES,
	.internal_cache_extra	= &cache_ftfw_extra,
	.init			= ftfw_init,
	.kill			= ftfw_kill,
	.local			= ftfw_local,
	.recv			= ftfw_recv,
	.enqueue		= ftfw_enqueue,
	.xmit			= ftfw_xmit,
};