Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

  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
/* SPDX-License-Identifier: GPL-2.0
 * Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc.
 */
static const char *__doc__ = " XDP RX-queue info extract example\n\n"
	"Monitor how many packets per sec (pps) are received\n"
	"per NIC RX queue index and which CPU processed the packet\n"
	;

#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <unistd.h>
#include <locale.h>
#include <sys/resource.h>
#include <getopt.h>
#include <net/if.h>
#include <time.h>

#include <arpa/inet.h>
#include <linux/if_link.h>

#include "bpf.h"
#include "libbpf.h"
#include "bpf_util.h"

static int ifindex = -1;
static char ifname_buf[IF_NAMESIZE];
static char *ifname;
static __u32 prog_id;

static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;

static struct bpf_map *stats_global_map;
static struct bpf_map *rx_queue_index_map;

/* Exit return codes */
#define EXIT_OK		0
#define EXIT_FAIL		1
#define EXIT_FAIL_OPTION	2
#define EXIT_FAIL_XDP		3
#define EXIT_FAIL_BPF		4
#define EXIT_FAIL_MEM		5

static const struct option long_options[] = {
	{"help",	no_argument,		NULL, 'h' },
	{"dev",		required_argument,	NULL, 'd' },
	{"skb-mode",	no_argument,		NULL, 'S' },
	{"sec",		required_argument,	NULL, 's' },
	{"no-separators", no_argument,		NULL, 'z' },
	{"action",	required_argument,	NULL, 'a' },
	{"readmem", 	no_argument,		NULL, 'r' },
	{"swapmac", 	no_argument,		NULL, 'm' },
	{"force",	no_argument,		NULL, 'F' },
	{0, 0, NULL,  0 }
};

static void int_exit(int sig)
{
	__u32 curr_prog_id = 0;

	if (ifindex > -1) {
		if (bpf_get_link_xdp_id(ifindex, &curr_prog_id, xdp_flags)) {
			printf("bpf_get_link_xdp_id failed\n");
			exit(EXIT_FAIL);
		}
		if (prog_id == curr_prog_id) {
			fprintf(stderr,
				"Interrupted: Removing XDP program on ifindex:%d device:%s\n",
				ifindex, ifname);
			bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
		} else if (!curr_prog_id) {
			printf("couldn't find a prog id on a given iface\n");
		} else {
			printf("program on interface changed, not removing\n");
		}
	}
	exit(EXIT_OK);
}

struct config {
	__u32 action;
	int ifindex;
	__u32 options;
};
enum cfg_options_flags {
	NO_TOUCH = 0x0U,
	READ_MEM = 0x1U,
	SWAP_MAC = 0x2U,
};
#define XDP_ACTION_MAX (XDP_TX + 1)
#define XDP_ACTION_MAX_STRLEN 11
static const char *xdp_action_names[XDP_ACTION_MAX] = {
	[XDP_ABORTED]	= "XDP_ABORTED",
	[XDP_DROP]	= "XDP_DROP",
	[XDP_PASS]	= "XDP_PASS",
	[XDP_TX]	= "XDP_TX",
};

static const char *action2str(int action)
{
	if (action < XDP_ACTION_MAX)
		return xdp_action_names[action];
	return NULL;
}

static int parse_xdp_action(char *action_str)
{
	size_t maxlen;
	__u64 action = -1;
	int i;

	for (i = 0; i < XDP_ACTION_MAX; i++) {
		maxlen = XDP_ACTION_MAX_STRLEN;
		if (strncmp(xdp_action_names[i], action_str, maxlen) == 0) {
			action = i;
			break;
		}
	}
	return action;
}

static void list_xdp_actions(void)
{
	int i;

	printf("Available XDP --action <options>\n");
	for (i = 0; i < XDP_ACTION_MAX; i++)
		printf("\t%s\n", xdp_action_names[i]);
	printf("\n");
}

static char* options2str(enum cfg_options_flags flag)
{
	if (flag == NO_TOUCH)
		return "no_touch";
	if (flag & SWAP_MAC)
		return "swapmac";
	if (flag & READ_MEM)
		return "read";
	fprintf(stderr, "ERR: Unknown config option flags");
	exit(EXIT_FAIL);
}

static void usage(char *argv[])
{
	int i;

	printf("\nDOCUMENTATION:\n%s\n", __doc__);
	printf(" Usage: %s (options-see-below)\n", argv[0]);
	printf(" Listing options:\n");
	for (i = 0; long_options[i].name != 0; i++) {
		printf(" --%-12s", long_options[i].name);
		if (long_options[i].flag != NULL)
			printf(" flag (internal value:%d)",
				*long_options[i].flag);
		else
			printf(" short-option: -%c",
				long_options[i].val);
		printf("\n");
	}
	printf("\n");
	list_xdp_actions();
}

#define NANOSEC_PER_SEC 1000000000 /* 10^9 */
static __u64 gettime(void)
{
	struct timespec t;
	int res;

	res = clock_gettime(CLOCK_MONOTONIC, &t);
	if (res < 0) {
		fprintf(stderr, "Error with gettimeofday! (%i)\n", res);
		exit(EXIT_FAIL);
	}
	return (__u64) t.tv_sec * NANOSEC_PER_SEC + t.tv_nsec;
}

/* Common stats data record shared with _kern.c */
struct datarec {
	__u64 processed;
	__u64 issue;
};
struct record {
	__u64 timestamp;
	struct datarec total;
	struct datarec *cpu;
};
struct stats_record {
	struct record stats;
	struct record *rxq;
};

static struct datarec *alloc_record_per_cpu(void)
{
	unsigned int nr_cpus = bpf_num_possible_cpus();
	struct datarec *array;
	size_t size;

	size = sizeof(struct datarec) * nr_cpus;
	array = malloc(size);
	memset(array, 0, size);
	if (!array) {
		fprintf(stderr, "Mem alloc error (nr_cpus:%u)\n", nr_cpus);
		exit(EXIT_FAIL_MEM);
	}
	return array;
}

static struct record *alloc_record_per_rxq(void)
{
	unsigned int nr_rxqs = bpf_map__def(rx_queue_index_map)->max_entries;
	struct record *array;
	size_t size;

	size = sizeof(struct record) * nr_rxqs;
	array = malloc(size);
	memset(array, 0, size);
	if (!array) {
		fprintf(stderr, "Mem alloc error (nr_rxqs:%u)\n", nr_rxqs);
		exit(EXIT_FAIL_MEM);
	}
	return array;
}

static struct stats_record *alloc_stats_record(void)
{
	unsigned int nr_rxqs = bpf_map__def(rx_queue_index_map)->max_entries;
	struct stats_record *rec;
	int i;

	rec = malloc(sizeof(*rec));
	memset(rec, 0, sizeof(*rec));
	if (!rec) {
		fprintf(stderr, "Mem alloc error\n");
		exit(EXIT_FAIL_MEM);
	}
	rec->rxq = alloc_record_per_rxq();
	for (i = 0; i < nr_rxqs; i++)
		rec->rxq[i].cpu = alloc_record_per_cpu();

	rec->stats.cpu = alloc_record_per_cpu();
	return rec;
}

static void free_stats_record(struct stats_record *r)
{
	unsigned int nr_rxqs = bpf_map__def(rx_queue_index_map)->max_entries;
	int i;

	for (i = 0; i < nr_rxqs; i++)
		free(r->rxq[i].cpu);

	free(r->rxq);
	free(r->stats.cpu);
	free(r);
}

static bool map_collect_percpu(int fd, __u32 key, struct record *rec)
{
	/* For percpu maps, userspace gets a value per possible CPU */
	unsigned int nr_cpus = bpf_num_possible_cpus();
	struct datarec values[nr_cpus];
	__u64 sum_processed = 0;
	__u64 sum_issue = 0;
	int i;

	if ((bpf_map_lookup_elem(fd, &key, values)) != 0) {
		fprintf(stderr,
			"ERR: bpf_map_lookup_elem failed key:0x%X\n", key);
		return false;
	}
	/* Get time as close as possible to reading map contents */
	rec->timestamp = gettime();

	/* Record and sum values from each CPU */
	for (i = 0; i < nr_cpus; i++) {
		rec->cpu[i].processed = values[i].processed;
		sum_processed        += values[i].processed;
		rec->cpu[i].issue = values[i].issue;
		sum_issue        += values[i].issue;
	}
	rec->total.processed = sum_processed;
	rec->total.issue     = sum_issue;
	return true;
}

static void stats_collect(struct stats_record *rec)
{
	int fd, i, max_rxqs;

	fd = bpf_map__fd(stats_global_map);
	map_collect_percpu(fd, 0, &rec->stats);

	fd = bpf_map__fd(rx_queue_index_map);
	max_rxqs = bpf_map__def(rx_queue_index_map)->max_entries;
	for (i = 0; i < max_rxqs; i++)
		map_collect_percpu(fd, i, &rec->rxq[i]);
}

static double calc_period(struct record *r, struct record *p)
{
	double period_ = 0;
	__u64 period = 0;

	period = r->timestamp - p->timestamp;
	if (period > 0)
		period_ = ((double) period / NANOSEC_PER_SEC);

	return period_;
}

static __u64 calc_pps(struct datarec *r, struct datarec *p, double period_)
{
	__u64 packets = 0;
	__u64 pps = 0;

	if (period_ > 0) {
		packets = r->processed - p->processed;
		pps = packets / period_;
	}
	return pps;
}

static __u64 calc_errs_pps(struct datarec *r,
			    struct datarec *p, double period_)
{
	__u64 packets = 0;
	__u64 pps = 0;

	if (period_ > 0) {
		packets = r->issue - p->issue;
		pps = packets / period_;
	}
	return pps;
}

static void stats_print(struct stats_record *stats_rec,
			struct stats_record *stats_prev,
			int action, __u32 cfg_opt)
{
	unsigned int nr_rxqs = bpf_map__def(rx_queue_index_map)->max_entries;
	unsigned int nr_cpus = bpf_num_possible_cpus();
	double pps = 0, err = 0;
	struct record *rec, *prev;
	double t;
	int rxq;
	int i;

	/* Header */
	printf("\nRunning XDP on dev:%s (ifindex:%d) action:%s options:%s\n",
	       ifname, ifindex, action2str(action), options2str(cfg_opt));

	/* stats_global_map */
	{
		char *fmt_rx = "%-15s %-7d %'-11.0f %'-10.0f %s\n";
		char *fm2_rx = "%-15s %-7s %'-11.0f\n";
		char *errstr = "";

		printf("%-15s %-7s %-11s %-11s\n",
		       "XDP stats", "CPU", "pps", "issue-pps");

		rec  =  &stats_rec->stats;
		prev = &stats_prev->stats;
		t = calc_period(rec, prev);
		for (i = 0; i < nr_cpus; i++) {
			struct datarec *r = &rec->cpu[i];
			struct datarec *p = &prev->cpu[i];

			pps = calc_pps     (r, p, t);
			err = calc_errs_pps(r, p, t);
			if (err > 0)
				errstr = "invalid-ifindex";
			if (pps > 0)
				printf(fmt_rx, "XDP-RX CPU",
					i, pps, err, errstr);
		}
		pps  = calc_pps     (&rec->total, &prev->total, t);
		err  = calc_errs_pps(&rec->total, &prev->total, t);
		printf(fm2_rx, "XDP-RX CPU", "total", pps, err);
	}

	/* rx_queue_index_map */
	printf("\n%-15s %-7s %-11s %-11s\n",
	       "RXQ stats", "RXQ:CPU", "pps", "issue-pps");

	for (rxq = 0; rxq < nr_rxqs; rxq++) {
		char *fmt_rx = "%-15s %3d:%-3d %'-11.0f %'-10.0f %s\n";
		char *fm2_rx = "%-15s %3d:%-3s %'-11.0f\n";
		char *errstr = "";
		int rxq_ = rxq;

		/* Last RXQ in map catch overflows */
		if (rxq_ == nr_rxqs - 1)
			rxq_ = -1;

		rec  =  &stats_rec->rxq[rxq];
		prev = &stats_prev->rxq[rxq];
		t = calc_period(rec, prev);
		for (i = 0; i < nr_cpus; i++) {
			struct datarec *r = &rec->cpu[i];
			struct datarec *p = &prev->cpu[i];

			pps = calc_pps     (r, p, t);
			err = calc_errs_pps(r, p, t);
			if (err > 0) {
				if (rxq_ == -1)
					errstr = "map-overflow-RXQ";
				else
					errstr = "err";
			}
			if (pps > 0)
				printf(fmt_rx, "rx_queue_index",
				       rxq_, i, pps, err, errstr);
		}
		pps  = calc_pps     (&rec->total, &prev->total, t);
		err  = calc_errs_pps(&rec->total, &prev->total, t);
		if (pps || err)
			printf(fm2_rx, "rx_queue_index", rxq_, "sum", pps, err);
	}
}


/* Pointer swap trick */
static inline void swap(struct stats_record **a, struct stats_record **b)
{
	struct stats_record *tmp;

	tmp = *a;
	*a = *b;
	*b = tmp;
}

static void stats_poll(int interval, int action, __u32 cfg_opt)
{
	struct stats_record *record, *prev;

	record = alloc_stats_record();
	prev   = alloc_stats_record();
	stats_collect(record);

	while (1) {
		swap(&prev, &record);
		stats_collect(record);
		stats_print(record, prev, action, cfg_opt);
		sleep(interval);
	}

	free_stats_record(record);
	free_stats_record(prev);
}


int main(int argc, char **argv)
{
	__u32 cfg_options= NO_TOUCH ; /* Default: Don't touch packet memory */
	struct rlimit r = {10 * 1024 * 1024, RLIM_INFINITY};
	struct bpf_prog_load_attr prog_load_attr = {
		.prog_type	= BPF_PROG_TYPE_XDP,
	};
	struct bpf_prog_info info = {};
	__u32 info_len = sizeof(info);
	int prog_fd, map_fd, opt, err;
	bool use_separators = true;
	struct config cfg = { 0 };
	struct bpf_object *obj;
	struct bpf_map *map;
	char filename[256];
	int longindex = 0;
	int interval = 2;
	__u32 key = 0;


	char action_str_buf[XDP_ACTION_MAX_STRLEN + 1 /* for \0 */] = { 0 };
	int action = XDP_PASS; /* Default action */
	char *action_str = NULL;

	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
	prog_load_attr.file = filename;

	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
		perror("setrlimit(RLIMIT_MEMLOCK)");
		return 1;
	}

	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
		return EXIT_FAIL;

	map = bpf_map__next(NULL, obj);
	stats_global_map = bpf_map__next(map, obj);
	rx_queue_index_map = bpf_map__next(stats_global_map, obj);
	if (!map || !stats_global_map || !rx_queue_index_map) {
		printf("finding a map in obj file failed\n");
		return EXIT_FAIL;
	}
	map_fd = bpf_map__fd(map);

	if (!prog_fd) {
		fprintf(stderr, "ERR: load_bpf_file: %s\n", strerror(errno));
		return EXIT_FAIL;
	}

	/* Parse commands line args */
	while ((opt = getopt_long(argc, argv, "FhSrmzd:s:a:",
				  long_options, &longindex)) != -1) {
		switch (opt) {
		case 'd':
			if (strlen(optarg) >= IF_NAMESIZE) {
				fprintf(stderr, "ERR: --dev name too long\n");
				goto error;
			}
			ifname = (char *)&ifname_buf;
			strncpy(ifname, optarg, IF_NAMESIZE);
			ifindex = if_nametoindex(ifname);
			if (ifindex == 0) {
				fprintf(stderr,
					"ERR: --dev name unknown err(%d):%s\n",
					errno, strerror(errno));
				goto error;
			}
			break;
		case 's':
			interval = atoi(optarg);
			break;
		case 'S':
			xdp_flags |= XDP_FLAGS_SKB_MODE;
			break;
		case 'z':
			use_separators = false;
			break;
		case 'a':
			action_str = (char *)&action_str_buf;
			strncpy(action_str, optarg, XDP_ACTION_MAX_STRLEN);
			break;
		case 'r':
			cfg_options |= READ_MEM;
			break;
		case 'm':
			cfg_options |= SWAP_MAC;
			break;
		case 'F':
			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
			break;
		case 'h':
		error:
		default:
			usage(argv);
			return EXIT_FAIL_OPTION;
		}
	}
	/* Required option */
	if (ifindex == -1) {
		fprintf(stderr, "ERR: required option --dev missing\n");
		usage(argv);
		return EXIT_FAIL_OPTION;
	}
	cfg.ifindex = ifindex;

	/* Parse action string */
	if (action_str) {
		action = parse_xdp_action(action_str);
		if (action < 0) {
			fprintf(stderr, "ERR: Invalid XDP --action: %s\n",
				action_str);
			list_xdp_actions();
			return EXIT_FAIL_OPTION;
		}
	}
	cfg.action = action;

	/* XDP_TX requires changing MAC-addrs, else HW may drop */
	if (action == XDP_TX)
		cfg_options |= SWAP_MAC;
	cfg.options = cfg_options;

	/* Trick to pretty printf with thousands separators use %' */
	if (use_separators)
		setlocale(LC_NUMERIC, "en_US");

	/* User-side setup ifindex in config_map */
	err = bpf_map_update_elem(map_fd, &key, &cfg, 0);
	if (err) {
		fprintf(stderr, "Store config failed (err:%d)\n", err);
		exit(EXIT_FAIL_BPF);
	}

	/* Remove XDP program when program is interrupted or killed */
	signal(SIGINT, int_exit);
	signal(SIGTERM, int_exit);

	if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) {
		fprintf(stderr, "link set xdp fd failed\n");
		return EXIT_FAIL_XDP;
	}

	err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
	if (err) {
		printf("can't get prog info - %s\n", strerror(errno));
		return err;
	}
	prog_id = info.id;

	stats_poll(interval, action, cfg_options);
	return EXIT_OK;
}