summaryrefslogtreecommitdiffstats
path: root/VNFs/DPPD-PROX/rx_pkt.c
blob: f6adeb4b772a4c73ad6744039dc4d67e5d74661a (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
/*
// Copyright (c) 2010-2017 Intel Corporation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
*/

#include <rte_cycles.h>
#include <rte_ethdev.h>
#include <rte_version.h>

#include "rx_pkt.h"
#include "task_base.h"
#include "clock.h"
#include "stats.h"
#include "log.h"
#include "mbuf_utils.h"
#include "prefetch.h"
#include "arp.h"
#include "tx_pkt.h"
#include "handle_master.h"
#include "input.h" /* Needed for callback on dump */

/* _param version of the rx_pkt_hw functions are used to create two
   instances of very similar variations of these functions. The
   variations are specified by the "multi" parameter which significies
   that the rte_eth_rx_burst function should be called multiple times.
   The reason for this is that with the vector PMD, the maximum number
   of packets being returned is 32. If packets have been split in
   multiple mbufs then rte_eth_rx_burst might even receive less than
   32 packets.
   Some algorithms (like QoS) only work correctly if more than 32
   packets are received if the dequeue step involves finding 32 packets.
*/

#define MIN_PMD_RX 32

static uint16_t rx_pkt_hw_port_queue(struct port_queue *pq, struct rte_mbuf **mbufs, int multi)
{
	uint16_t nb_rx, n;

	nb_rx = rte_eth_rx_burst(pq->port, pq->queue, mbufs, MAX_PKT_BURST);

	if (multi) {
		n = nb_rx;
		while (n != 0 && MAX_PKT_BURST - nb_rx >= MIN_PMD_RX) {
			n = rte_eth_rx_burst(pq->port, pq->queue, mbufs + nb_rx, MIN_PMD_RX);
			nb_rx += n;
			PROX_PANIC(nb_rx > 64, "Received %d packets while expecting maximum %d\n", n, MIN_PMD_RX);
		}
	}
	return nb_rx;
}

static void next_port(struct rx_params_hw *rx_params_hw)
{
	++rx_params_hw->last_read_portid;
	if (unlikely(rx_params_hw->last_read_portid == rx_params_hw->nb_rxports)) {
		rx_params_hw->last_read_portid = 0;
	}
}

static void next_port_pow2(struct rx_params_hw *rx_params_hw)
{
	rx_params_hw->last_read_portid = (rx_params_hw->last_read_portid + 1) & rx_params_hw->rxport_mask;
}

static inline void dump_l3(struct task_base *tbase, struct rte_mbuf *mbuf)
{
	if (unlikely(tbase->aux->task_rt_dump.n_print_rx)) {
		if ((tbase->aux->task_rt_dump.input == NULL) || (tbase->aux->task_rt_dump.input->reply == NULL)) {
			plogdx_info(mbuf, "RX: ");
		} else {
			struct input *input = tbase->aux->task_rt_dump.input;
			char tmp[128];
			int strlen;
#if RTE_VERSION >= RTE_VERSION_NUM(1,8,0,0)
			int port_id = mbuf->port;
#else
			int port_id = mbuf->pkt.in_port;
#endif
			strlen = snprintf(tmp, sizeof(tmp), "pktdump,%d,%d\n", port_id,
			      rte_pktmbuf_pkt_len(mbuf));
			input->reply(input, tmp, strlen);
			input->reply(input, rte_pktmbuf_mtod(mbuf, char *), rte_pktmbuf_pkt_len(mbuf));
			input->reply(input, "\n", 1);
		}
		tbase->aux->task_rt_dump.n_print_rx --;
		if (0 == tbase->aux->task_rt_dump.n_print_rx) {
			task_base_del_rx_pkt_function(tbase, rx_pkt_dump);
		}
	}
	if (unlikely(tbase->aux->task_rt_dump.n_trace)) {
		plogdx_info(mbuf, "RX: ");
		tbase->aux->task_rt_dump.n_trace--;
	}
}

static uint16_t rx_pkt_hw_param(struct task_base *tbase, struct rte_mbuf ***mbufs_ptr, int multi,
				void (*next)(struct rx_params_hw *rx_param_hw), int l3)
{
	uint8_t last_read_portid;
	uint16_t nb_rx;
	int skip = 0;

	START_EMPTY_MEASSURE();
	*mbufs_ptr = tbase->ws_mbuf->mbuf[0] +
		(RTE_ALIGN_CEIL(tbase->ws_mbuf->idx[0].prod, 2) & WS_MBUF_MASK);

	last_read_portid = tbase->rx_params_hw.last_read_portid;
	struct port_queue *pq = &tbase->rx_params_hw.rx_pq[last_read_portid];

	nb_rx = rx_pkt_hw_port_queue(pq, *mbufs_ptr, multi);
	next(&tbase->rx_params_hw);

	if (l3) {
		struct rte_mbuf **mbufs = *mbufs_ptr;
		int i;
		struct ether_hdr_arp *hdr[MAX_PKT_BURST];
		for (i = 0; i < nb_rx; i++) {
			PREFETCH0(mbufs[i]);
		}
		for (i = 0; i < nb_rx; i++) {
			hdr[i] = rte_pktmbuf_mtod(mbufs[i], struct ether_hdr_arp *);
			PREFETCH0(hdr[i]);
		}
		for (i = 0; i < nb_rx; i++) {
			if (unlikely(hdr[i]->ether_hdr.ether_type == ETYPE_ARP)) {
				dump_l3(tbase, mbufs[i]);
				tx_ring(tbase, tbase->l3.ctrl_plane_ring, ARP_TO_CTRL, mbufs[i]);
				skip++;
			} else if (unlikely(skip)) {
				mbufs[i - skip] = mbufs[i];
			}
		}
	}

	if (skip)
		TASK_STATS_ADD_DROP_HANDLED(&tbase->aux->stats, skip);
	if (likely(nb_rx > 0)) {
		TASK_STATS_ADD_RX(&tbase->aux->stats, nb_rx);
		return nb_rx - skip;
	}
	TASK_STATS_ADD_IDLE(&tbase->aux->stats, rte_rdtsc() - cur_tsc);
	return 0;
}

static inline uint16_t rx_pkt_hw1_param(struct task_base *tbase, struct rte_mbuf ***mbufs_ptr, int multi, int l3)
{
	uint16_t nb_rx, n;
	int skip = 0;

	START_EMPTY_MEASSURE();
	*mbufs_ptr = tbase->ws_mbuf->mbuf[0] +
		(RTE_ALIGN_CEIL(tbase->ws_mbuf->idx[0].prod, 2) & WS_MBUF_MASK);

	nb_rx = rte_eth_rx_burst(tbase->rx_params_hw1.rx_pq.port,
				 tbase->rx_params_hw1.rx_pq.queue,
				 *mbufs_ptr, MAX_PKT_BURST);

	if (multi) {
		n = nb_rx;
		while ((n != 0) && (MAX_PKT_BURST - nb_rx >= MIN_PMD_RX)) {
			n = rte_eth_rx_burst(tbase->rx_params_hw1.rx_pq.port,
				 tbase->rx_params_hw1.rx_pq.queue,
				 *mbufs_ptr + nb_rx, MIN_PMD_RX);
			nb_rx += n;
			PROX_PANIC(nb_rx > 64, "Received %d packets while expecting maximum %d\n", n, MIN_PMD_RX);
		}
	}

	if (l3) {
		struct rte_mbuf **mbufs = *mbufs_ptr;
		int i;
		struct ether_hdr_arp *hdr[MAX_PKT_BURST];
		for (i = 0; i < nb_rx; i++) {
			PREFETCH0(mbufs[i]);
		}
		for (i = 0; i < nb_rx; i++) {
			hdr[i] = rte_pktmbuf_mtod(mbufs[i], struct ether_hdr_arp *);
			PREFETCH0(hdr[i]);
		}
		for (i = 0; i < nb_rx; i++) {
			if (unlikely(hdr[i]->ether_hdr.ether_type == ETYPE_ARP)) {
				dump_l3(tbase, mbufs[i]);
				tx_ring(tbase, tbase->l3.ctrl_plane_ring, ARP_TO_CTRL, mbufs[i]);
				skip++;
			} else if (unlikely(skip)) {
				mbufs[i - skip] = mbufs[i];
			}
		}
	}

	if (skip)
		TASK_STATS_ADD_DROP_HANDLED(&tbase->aux->stats, skip);
	if (likely(nb_rx > 0)) {
		TASK_STATS_ADD_RX(&tbase->aux->stats, nb_rx);
		return nb_rx - skip;
	}
	TASK_STATS_ADD_IDLE(&tbase->aux->stats, rte_rdtsc() - cur_tsc);
	return 0;
}

uint16_t rx_pkt_hw(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	return rx_pkt_hw_param(tbase, mbufs, 0, next_port, 0);
}

uint16_t rx_pkt_hw_pow2(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	return rx_pkt_hw_param(tbase, mbufs, 0, next_port_pow2, 0);
}

uint16_t rx_pkt_hw1(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	return rx_pkt_hw1_param(tbase, mbufs, 0, 0);
}

uint16_t rx_pkt_hw_multi(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	return rx_pkt_hw_param(tbase, mbufs, 1, next_port, 0);
}

uint16_t rx_pkt_hw_pow2_multi(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	return rx_pkt_hw_param(tbase, mbufs, 1, next_port_pow2, 0);
}

uint16_t rx_pkt_hw1_multi(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	return rx_pkt_hw1_param(tbase, mbufs, 1, 0);
}

uint16_t rx_pkt_hw_l3(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	return rx_pkt_hw_param(tbase, mbufs, 0, next_port, 1);
}

uint16_t rx_pkt_hw_pow2_l3(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	return rx_pkt_hw_param(tbase, mbufs, 0, next_port_pow2, 1);
}

uint16_t rx_pkt_hw1_l3(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	return rx_pkt_hw1_param(tbase, mbufs, 0, 1);
}

uint16_t rx_pkt_hw_multi_l3(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	return rx_pkt_hw_param(tbase, mbufs, 1, next_port, 1);
}

uint16_t rx_pkt_hw_pow2_multi_l3(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	return rx_pkt_hw_param(tbase, mbufs, 1, next_port_pow2, 1);
}

uint16_t rx_pkt_hw1_multi_l3(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	return rx_pkt_hw1_param(tbase, mbufs, 1, 1);
}

/* The following functions implement ring access */
uint16_t ring_deq(struct rte_ring *r, struct rte_mbuf **mbufs)
{
	void **v_mbufs = (void **)mbufs;
#ifdef BRAS_RX_BULK
#if RTE_VERSION < RTE_VERSION_NUM(17,5,0,1)
	return rte_ring_sc_dequeue_bulk(r, v_mbufs, MAX_RING_BURST) < 0? 0 : MAX_RING_BURST;
#else
	return rte_ring_sc_dequeue_bulk(r, v_mbufs, MAX_RING_BURST, NULL);
#endif
#else
#if RTE_VERSION < RTE_VERSION_NUM(17,5,0,1)
	return rte_ring_sc_dequeue_burst(r, v_mbufs, MAX_RING_BURST);
#else
	return rte_ring_sc_dequeue_burst(r, v_mbufs, MAX_RING_BURST, NULL);
#endif
#endif
}

uint16_t rx_pkt_sw(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	START_EMPTY_MEASSURE();
	*mbufs = tbase->ws_mbuf->mbuf[0] + (tbase->ws_mbuf->idx[0].prod & WS_MBUF_MASK);
	uint8_t lr = tbase->rx_params_sw.last_read_ring;
	uint16_t nb_rx;

	do {
		nb_rx = ring_deq(tbase->rx_params_sw.rx_rings[lr], *mbufs);
		lr = lr + 1 == tbase->rx_params_sw.nb_rxrings? 0 : lr + 1;
	} while(!nb_rx && lr != tbase->rx_params_sw.last_read_ring);

	tbase->rx_params_sw.last_read_ring = lr;

	if (nb_rx != 0) {
		TASK_STATS_ADD_RX(&tbase->aux->stats, nb_rx);
		return nb_rx;
	}
	else {
		TASK_STATS_ADD_IDLE(&tbase->aux->stats, rte_rdtsc() - cur_tsc);
		return 0;
	}
}

/* Same as rx_pkt_sw expect with a mask for the number of receive
   rings (can only be used if nb_rxring is a power of 2). */
uint16_t rx_pkt_sw_pow2(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	START_EMPTY_MEASSURE();
	*mbufs = tbase->ws_mbuf->mbuf[0] + (tbase->ws_mbuf->idx[0].prod & WS_MBUF_MASK);
	uint8_t lr = tbase->rx_params_sw.last_read_ring;
	uint16_t nb_rx;

	do {
		nb_rx = ring_deq(tbase->rx_params_sw.rx_rings[lr], *mbufs);
		lr = (lr + 1) & tbase->rx_params_sw.rxrings_mask;
	} while(!nb_rx && lr != tbase->rx_params_sw.last_read_ring);

	tbase->rx_params_sw.last_read_ring = lr;

	if (nb_rx != 0) {
		TASK_STATS_ADD_RX(&tbase->aux->stats, nb_rx);
		return nb_rx;
	}
	else {
		TASK_STATS_ADD_IDLE(&tbase->aux->stats, rte_rdtsc() - cur_tsc);
		return 0;
	}
}

uint16_t rx_pkt_self(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	START_EMPTY_MEASSURE();
	uint16_t nb_rx = tbase->ws_mbuf->idx[0].nb_rx;
	if (nb_rx) {
		tbase->ws_mbuf->idx[0].nb_rx = 0;
		*mbufs = tbase->ws_mbuf->mbuf[0] + (tbase->ws_mbuf->idx[0].prod & WS_MBUF_MASK);
		TASK_STATS_ADD_RX(&tbase->aux->stats, nb_rx);
		return nb_rx;
	}
	else {
		TASK_STATS_ADD_IDLE(&tbase->aux->stats, rte_rdtsc() - cur_tsc);
		return 0;
	}
}

/* Used for tasks that do not receive packets (i.e. Packet
generation).  Always returns 1 but never returns packets and does not
increment statistics. This function allows to use the same code path
as for tasks that actually receive packets. */
uint16_t rx_pkt_dummy(__attribute__((unused)) struct task_base *tbase,
		      __attribute__((unused)) struct rte_mbuf ***mbufs)
{
	return 1;
}

/* After the system has been configured, it is known if there is only
   one RX ring. If this is the case, a more specialized version of the
   function above can be used to save cycles. */
uint16_t rx_pkt_sw1(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	START_EMPTY_MEASSURE();
	*mbufs = tbase->ws_mbuf->mbuf[0] + (tbase->ws_mbuf->idx[0].prod & WS_MBUF_MASK);
	uint16_t nb_rx = ring_deq(tbase->rx_params_sw1.rx_ring, *mbufs);

	if (nb_rx != 0) {
		TASK_STATS_ADD_RX(&tbase->aux->stats, nb_rx);
		return nb_rx;
	}
	else {
		TASK_STATS_ADD_IDLE(&tbase->aux->stats, rte_rdtsc() - cur_tsc);
		return 0;
	}
}

static uint16_t call_prev_rx_pkt(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	uint16_t ret;

	tbase->aux->rx_prev_idx++;
	ret = tbase->aux->rx_pkt_prev[tbase->aux->rx_prev_idx - 1](tbase, mbufs);
	tbase->aux->rx_prev_idx--;

	return ret;
}

/* Only used when there are packets to be dumped. This function is
   meant as a debugging tool and is therefore not optimized. When the
   number of packets to dump falls back to 0, the original (optimized)
   rx function is restored. This allows to support dumping packets
   without any performance impact if the feature is not used. */
uint16_t rx_pkt_dump(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	uint16_t ret = call_prev_rx_pkt(tbase, mbufs);

	if (ret) {
		uint32_t n_dump = tbase->aux->task_rt_dump.n_print_rx;
		n_dump = ret < n_dump? ret : n_dump;

		if ((tbase->aux->task_rt_dump.input == NULL) || (tbase->aux->task_rt_dump.input->reply == NULL)) {
			for (uint32_t i = 0; i < n_dump; ++i) {
				plogdx_info((*mbufs)[i], "RX: ");
			}
		}
		else {
			struct input *input = tbase->aux->task_rt_dump.input;

			for (uint32_t i = 0; i < n_dump; ++i) {
				/* TODO: Execute callback with full
				   data in a single call. */
				char tmp[128];
				int strlen;

#if RTE_VERSION >= RTE_VERSION_NUM(1,8,0,0)
				int port_id = ((*mbufs)[i])->port;
#else
				int port_id = ((*mbufs)[i])->pkt.in_port;
#endif
				strlen = snprintf(tmp, sizeof(tmp), "pktdump,%d,%d\n", port_id,
						      rte_pktmbuf_pkt_len((*mbufs)[i]));

				input->reply(input, tmp, strlen);
				input->reply(input, rte_pktmbuf_mtod((*mbufs)[i], char *), rte_pktmbuf_pkt_len((*mbufs)[i]));
				input->reply(input, "\n", 1);
			}
		}

		tbase->aux->task_rt_dump.n_print_rx -= n_dump;

		if (0 == tbase->aux->task_rt_dump.n_print_rx) {
			task_base_del_rx_pkt_function(tbase, rx_pkt_dump);
		}
	}
	return ret;
}

uint16_t rx_pkt_trace(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	tbase->aux->task_rt_dump.cur_trace = 0;
	uint16_t ret = call_prev_rx_pkt(tbase, mbufs);

	if (ret) {
		uint32_t n_trace = tbase->aux->task_rt_dump.n_trace;
		n_trace = ret < n_trace? ret : n_trace;
		n_trace = n_trace <= MAX_RING_BURST ? n_trace : MAX_RING_BURST;

		for (uint32_t i = 0; i < n_trace; ++i) {
			uint8_t *pkt = rte_pktmbuf_mtod((*mbufs)[i], uint8_t *);
			rte_memcpy(tbase->aux->task_rt_dump.pkt_cpy[i], pkt, sizeof(tbase->aux->task_rt_dump.pkt_cpy[i]));
			tbase->aux->task_rt_dump.pkt_cpy_len[i] = rte_pktmbuf_pkt_len((*mbufs)[i]);
			tbase->aux->task_rt_dump.pkt_mbuf_addr[i] = (*mbufs)[i];
		}
		tbase->aux->task_rt_dump.cur_trace += n_trace;

		tbase->aux->task_rt_dump.n_trace -= n_trace;
		/* Unset by TX when n_trace = 0 */
	}
	return ret;
}

/* Gather the distribution of the number of packets that have been
   received from one RX call. Since the value is only modified by the
   task that receives the packet, no atomic operation is needed. */
uint16_t rx_pkt_distr(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	uint16_t ret = call_prev_rx_pkt(tbase, mbufs);

	if (likely(ret < RX_BUCKET_SIZE))
		tbase->aux->rx_bucket[ret]++;
	else
		tbase->aux->rx_bucket[RX_BUCKET_SIZE - 1]++;
	return ret;
}

uint16_t rx_pkt_bw(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	uint16_t ret = call_prev_rx_pkt(tbase, mbufs);
	uint32_t tot_bytes = 0;

	for (uint16_t i = 0; i < ret; ++i) {
		tot_bytes += mbuf_wire_size((*mbufs)[i]);
	}

	TASK_STATS_ADD_RX_BYTES(&tbase->aux->stats, tot_bytes);

	return ret;
}

uint16_t rx_pkt_tsc(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	uint64_t before = rte_rdtsc();
	uint16_t ret = call_prev_rx_pkt(tbase, mbufs);
	uint64_t after = rte_rdtsc();

	tbase->aux->tsc_rx.before = before;
	tbase->aux->tsc_rx.after = after;

	return ret;
}

uint16_t rx_pkt_all(struct task_base *tbase, struct rte_mbuf ***mbufs)
{
	uint16_t tot = 0;
	uint16_t ret = 0;
	struct rte_mbuf **new_mbufs;
	struct rte_mbuf **dst = tbase->aux->all_mbufs;

	/* In case we receive less than MAX_PKT_BURST packets in one
	   iteration, do no perform any copying of mbuf pointers. Use
	   the buffer itself instead. */
	ret = call_prev_rx_pkt(tbase, &new_mbufs);
	if (ret < MAX_PKT_BURST/2) {
		*mbufs = new_mbufs;
		return ret;
	}

	memcpy(dst + tot, new_mbufs, ret * sizeof(*dst));
	tot += ret;
	*mbufs = dst;

	do {
		ret = call_prev_rx_pkt(tbase, &new_mbufs);
		memcpy(dst + tot, new_mbufs, ret * sizeof(*dst));
		tot += ret;
	} while (ret == MAX_PKT_BURST/2 && tot < MAX_RX_PKT_ALL - MAX_PKT_BURST);

	if (tot >= MAX_RX_PKT_ALL - MAX_PKT_BURST) {
		plog_err("Could not receive all packets - buffer full\n");
	}

	return tot;
}