xref: /dpdk/app/dumpcap/main.c (revision daa02b5cddbb8e11b31d41e2bf7bb1ae64dcae2f)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2019-2020 Microsoft Corporation
3  *
4  * DPDK application to dump network traffic
5  * This is designed to look and act like the Wireshark
6  * dumpcap program.
7  */
8 
9 #include <errno.h>
10 #include <fcntl.h>
11 #include <getopt.h>
12 #include <inttypes.h>
13 #include <limits.h>
14 #include <signal.h>
15 #include <stdbool.h>
16 #include <stdint.h>
17 #include <stdio.h>
18 #include <stdlib.h>
19 #include <string.h>
20 #include <sys/queue.h>
21 #include <sys/types.h>
22 #include <sys/utsname.h>
23 #include <time.h>
24 #include <unistd.h>
25 
26 #include <rte_alarm.h>
27 #include <rte_bpf.h>
28 #include <rte_config.h>
29 #include <rte_debug.h>
30 #include <rte_eal.h>
31 #include <rte_errno.h>
32 #include <rte_ethdev.h>
33 #include <rte_lcore.h>
34 #include <rte_malloc.h>
35 #include <rte_mbuf.h>
36 #include <rte_mempool.h>
37 #include <rte_pcapng.h>
38 #include <rte_pdump.h>
39 #include <rte_ring.h>
40 #include <rte_string_fns.h>
41 #include <rte_time.h>
42 #include <rte_version.h>
43 
44 #include <pcap/pcap.h>
45 #include <pcap/bpf.h>
46 
47 #define RING_NAME "capture-ring"
48 #define MONITOR_INTERVAL  (500 * 1000)
49 #define MBUF_POOL_CACHE_SIZE 32
50 #define BURST_SIZE 32
51 #define SLEEP_THRESHOLD 1000
52 
53 /* command line flags */
54 static const char *progname;
55 static bool quit_signal;
56 static bool group_read;
57 static bool quiet;
58 static bool promiscuous_mode = true;
59 static bool use_pcapng = true;
60 static char *output_name;
61 static const char *filter_str;
62 static unsigned int ring_size = 2048;
63 static const char *capture_comment;
64 static uint32_t snaplen = RTE_MBUF_DEFAULT_BUF_SIZE;
65 static bool dump_bpf;
66 static struct {
67 	uint64_t  duration;	/* nanoseconds */
68 	unsigned long packets;  /* number of packets in file */
69 	size_t size;		/* file size (bytes) */
70 } stop;
71 
72 /* Running state */
73 static struct rte_bpf_prm *bpf_prm;
74 static uint64_t start_time, end_time;
75 static uint64_t packets_received;
76 static size_t file_size;
77 
78 struct interface {
79 	TAILQ_ENTRY(interface) next;
80 	uint16_t port;
81 	char name[RTE_ETH_NAME_MAX_LEN];
82 
83 	struct rte_rxtx_callback *rx_cb[RTE_MAX_QUEUES_PER_PORT];
84 };
85 
86 TAILQ_HEAD(interface_list, interface);
87 static struct interface_list interfaces = TAILQ_HEAD_INITIALIZER(interfaces);
88 static struct interface *port2intf[RTE_MAX_ETHPORTS];
89 
90 /* Can do either pcap or pcapng format output */
91 typedef union {
92 	rte_pcapng_t  *pcapng;
93 	pcap_dumper_t *dumper;
94 } dumpcap_out_t;
95 
96 static void usage(void)
97 {
98 	printf("Usage: %s [options] ...\n\n", progname);
99 	printf("Capture Interface:\n"
100 	       "  -i <interface>           name or port index of interface\n"
101 	       "  -f <capture filter>      packet filter in libpcap filter syntax\n");
102 	printf("  -s <snaplen>, --snapshot-length <snaplen>\n"
103 	       "                           packet snapshot length (def: %u)\n",
104 	       RTE_MBUF_DEFAULT_BUF_SIZE);
105 	printf("  -p, --no-promiscuous-mode\n"
106 	       "                           don't capture in promiscuous mode\n"
107 	       "  -D, --list-interfaces    print list of interfaces and exit\n"
108 	       "  -d                       print generated BPF code for capture filter\n"
109 	       "\n"
110 	       "Stop conditions:\n"
111 	       "  -c <packet count>        stop after n packets (def: infinite)\n"
112 	       "  -a <autostop cond.> ..., --autostop <autostop cond.> ...\n"
113 	       "                           duration:NUM - stop after NUM seconds\n"
114 	       "                           filesize:NUM - stop this file after NUM kB\n"
115 	       "                            packets:NUM - stop after NUM packets\n"
116 	       "Output (files):\n"
117 	       "  -w <filename>            name of file to save (def: tempfile)\n"
118 	       "  -g                       enable group read access on the output file(s)\n"
119 	       "  -n                       use pcapng format instead of pcap (default)\n"
120 	       "  -P                       use libpcap format instead of pcapng\n"
121 	       "  --capture-comment <comment>\n"
122 	       "                           add a capture comment to the output file\n"
123 	       "\n"
124 	       "Miscellaneous:\n"
125 	       "  -q                       don't report packet capture counts\n"
126 	       "  -v, --version            print version information and exit\n"
127 	       "  -h, --help               display this help and exit\n"
128 	       "\n"
129 	       "Use Ctrl-C to stop capturing at any time.\n");
130 }
131 
132 static const char *version(void)
133 {
134 	static char str[128];
135 
136 	snprintf(str, sizeof(str),
137 		 "%s 1.0 (%s)\n", progname, rte_version());
138 	return str;
139 }
140 
141 /* Parse numeric argument from command line */
142 static unsigned long get_uint(const char *arg, const char *name,
143 			     unsigned int limit)
144 {
145 	unsigned long u;
146 	char *endp;
147 
148 	u = strtoul(arg, &endp, 0);
149 	if (*arg == '\0' || *endp != '\0')
150 		rte_exit(EXIT_FAILURE,
151 			 "Specified %s \"%s\" is not a valid number\n",
152 			 name, arg);
153 	if (limit && u > limit)
154 		rte_exit(EXIT_FAILURE,
155 			 "Specified %s \"%s\" is too large (greater than %u)\n",
156 			 name, arg, limit);
157 
158 	return u;
159 }
160 
161 /* Set auto stop values */
162 static void auto_stop(char *opt)
163 {
164 	char *value, *endp;
165 
166 	value = strchr(opt, ':');
167 	if (value == NULL)
168 		rte_exit(EXIT_FAILURE,
169 			 "Missing colon in auto stop parameter\n");
170 
171 	*value++ = '\0';
172 	if (strcmp(opt, "duration") == 0) {
173 		double interval = strtod(value, &endp);
174 
175 		if (*value == '\0' || *endp != '\0' || interval <= 0)
176 			rte_exit(EXIT_FAILURE,
177 				 "Invalid duration \"%s\"\n", value);
178 		stop.duration = NSEC_PER_SEC * interval;
179 	} else if (strcmp(opt, "filesize") == 0) {
180 		stop.size = get_uint(value, "filesize", 0) * 1024;
181 	} else if (strcmp(opt, "packets") == 0) {
182 		stop.packets = get_uint(value, "packets", 0);
183 	} else {
184 		rte_exit(EXIT_FAILURE,
185 			 "Unknown autostop parameter \"%s\"\n", opt);
186 	}
187 }
188 
189 /* Add interface to list of interfaces to capture */
190 static void add_interface(uint16_t port, const char *name)
191 {
192 	struct interface *intf;
193 
194 	intf = malloc(sizeof(*intf));
195 	if (!intf)
196 		rte_exit(EXIT_FAILURE, "no memory for interface\n");
197 
198 	memset(intf, 0, sizeof(*intf));
199 	rte_strscpy(intf->name, name, sizeof(intf->name));
200 
201 	printf("Capturing on '%s'\n", name);
202 
203 	port2intf[port] = intf;
204 	TAILQ_INSERT_TAIL(&interfaces, intf, next);
205 }
206 
207 /* Select all valid DPDK interfaces */
208 static void select_all_interfaces(void)
209 {
210 	char name[RTE_ETH_NAME_MAX_LEN];
211 	uint16_t p;
212 
213 	RTE_ETH_FOREACH_DEV(p) {
214 		if (rte_eth_dev_get_name_by_port(p, name) < 0)
215 			continue;
216 		add_interface(p, name);
217 	}
218 }
219 
220 /*
221  * Choose interface to capture if no -i option given.
222  * Select the first DPDK port, this matches what dumpcap does.
223  */
224 static void set_default_interface(void)
225 {
226 	char name[RTE_ETH_NAME_MAX_LEN];
227 	uint16_t p;
228 
229 	RTE_ETH_FOREACH_DEV(p) {
230 		if (rte_eth_dev_get_name_by_port(p, name) < 0)
231 			continue;
232 		add_interface(p, name);
233 		return;
234 	}
235 	rte_exit(EXIT_FAILURE, "No usable interfaces found\n");
236 }
237 
238 /* Lookup interface by name or port and add it to the list */
239 static void select_interface(const char *arg)
240 {
241 	uint16_t port;
242 
243 	if (strcmp(arg, "*"))
244 		select_all_interfaces();
245 	else if (rte_eth_dev_get_port_by_name(arg, &port) == 0)
246 		add_interface(port, arg);
247 	else {
248 		char name[RTE_ETH_NAME_MAX_LEN];
249 
250 		port = get_uint(arg, "port_number", UINT16_MAX);
251 		if (rte_eth_dev_get_name_by_port(port, name) < 0)
252 			rte_exit(EXIT_FAILURE, "Invalid port number %u\n",
253 				 port);
254 		add_interface(port, name);
255 	}
256 }
257 
258 /* Display list of possible interfaces that can be used. */
259 static void show_interfaces(void)
260 {
261 	char name[RTE_ETH_NAME_MAX_LEN];
262 	uint16_t p;
263 
264 	RTE_ETH_FOREACH_DEV(p) {
265 		if (rte_eth_dev_get_name_by_port(p, name) < 0)
266 			continue;
267 		printf("%u. %s\n", p, name);
268 	}
269 }
270 
271 static void compile_filter(void)
272 {
273 	struct bpf_program bf;
274 	pcap_t *pcap;
275 
276 	pcap = pcap_open_dead(DLT_EN10MB, snaplen);
277 	if (!pcap)
278 		rte_exit(EXIT_FAILURE, "can not open pcap\n");
279 
280 	if (pcap_compile(pcap, &bf, filter_str,
281 			 1, PCAP_NETMASK_UNKNOWN) != 0)
282 		rte_exit(EXIT_FAILURE, "pcap filter string not valid (%s)\n",
283 			 pcap_geterr(pcap));
284 
285 	bpf_prm = rte_bpf_convert(&bf);
286 	if (bpf_prm == NULL)
287 		rte_exit(EXIT_FAILURE,
288 			 "bpf convert failed\n");
289 
290 	if (dump_bpf) {
291 		printf("cBPF program (%u insns)\n", bf.bf_len);
292 		bpf_dump(&bf, 1);
293 		printf("\neBPF program (%u insns)\n", bpf_prm->nb_ins);
294 		rte_bpf_dump(stdout, bpf_prm->ins, bpf_prm->nb_ins);
295 		exit(0);
296 	}
297 
298 	/* Don't care about original program any more */
299 	pcap_freecode(&bf);
300 	pcap_close(pcap);
301 }
302 
303 /*
304  * Parse command line options.
305  * These are chosen to be similar to dumpcap command.
306  */
307 static void parse_opts(int argc, char **argv)
308 {
309 	static const struct option long_options[] = {
310 		{ "autostop",        required_argument, NULL, 'a' },
311 		{ "capture-comment", required_argument, NULL, 0 },
312 		{ "help",            no_argument,       NULL, 'h' },
313 		{ "interface",       required_argument, NULL, 'i' },
314 		{ "list-interfaces", no_argument,       NULL, 'D' },
315 		{ "no-promiscuous-mode", no_argument,   NULL, 'p' },
316 		{ "output-file",     required_argument, NULL, 'w' },
317 		{ "ring-buffer",     required_argument, NULL, 'b' },
318 		{ "snapshot-length", required_argument, NULL, 's' },
319 		{ "version",         no_argument,       NULL, 'v' },
320 		{ NULL },
321 	};
322 	int option_index, c;
323 
324 	for (;;) {
325 		c = getopt_long(argc, argv, "a:b:c:dDf:ghi:nN:pPqs:vw:",
326 				long_options, &option_index);
327 		if (c == -1)
328 			break;
329 
330 		switch (c) {
331 		case 0:
332 			switch (option_index) {
333 			case 0:
334 				capture_comment = optarg;
335 				break;
336 			default:
337 				usage();
338 				exit(1);
339 			}
340 			break;
341 		case 'a':
342 			auto_stop(optarg);
343 			break;
344 		case 'b':
345 			rte_exit(EXIT_FAILURE,
346 				 "multiple files not implemented\n");
347 			break;
348 		case 'c':
349 			stop.packets = get_uint(optarg, "packet_count", 0);
350 			break;
351 		case 'd':
352 			dump_bpf = true;
353 			break;
354 		case 'D':
355 			show_interfaces();
356 			exit(0);
357 		case 'f':
358 			filter_str = optarg;
359 			break;
360 		case 'g':
361 			group_read = true;
362 			break;
363 		case 'h':
364 			printf("%s\n\n", version());
365 			usage();
366 			exit(0);
367 		case 'i':
368 			select_interface(optarg);
369 			break;
370 		case 'n':
371 			use_pcapng = true;
372 			break;
373 		case 'N':
374 			ring_size = get_uint(optarg, "packet_limit", 0);
375 			break;
376 		case 'p':
377 			promiscuous_mode = false;
378 			break;
379 		case 'P':
380 			use_pcapng = false;
381 			break;
382 		case 'q':
383 			quiet = true;
384 			break;
385 		case 's':
386 			snaplen = get_uint(optarg, "snap_len", 0);
387 			break;
388 		case 'w':
389 			output_name = optarg;
390 			break;
391 		case 'v':
392 			printf("%s\n", version());
393 			exit(0);
394 		default:
395 			fprintf(stderr, "Invalid option: %s\n",
396 				argv[optind - 1]);
397 			usage();
398 			exit(1);
399 		}
400 	}
401 }
402 
403 static void
404 signal_handler(int sig_num __rte_unused)
405 {
406 	__atomic_store_n(&quit_signal, true, __ATOMIC_RELAXED);
407 }
408 
409 /* Return the time since 1/1/1970 in nanoseconds */
410 static uint64_t create_timestamp(void)
411 {
412 	struct timespec now;
413 
414 	clock_gettime(CLOCK_MONOTONIC, &now);
415 	return rte_timespec_to_ns(&now);
416 }
417 
418 static void
419 cleanup_pdump_resources(void)
420 {
421 	struct interface *intf;
422 
423 	TAILQ_FOREACH(intf, &interfaces, next) {
424 		rte_pdump_disable(intf->port,
425 				  RTE_PDUMP_ALL_QUEUES, RTE_PDUMP_FLAG_RXTX);
426 		if (promiscuous_mode)
427 			rte_eth_promiscuous_disable(intf->port);
428 	}
429 }
430 
431 /* Alarm signal handler, used to check that primary process */
432 static void
433 monitor_primary(void *arg __rte_unused)
434 {
435 	if (__atomic_load_n(&quit_signal, __ATOMIC_RELAXED))
436 		return;
437 
438 	if (rte_eal_primary_proc_alive(NULL)) {
439 		rte_eal_alarm_set(MONITOR_INTERVAL, monitor_primary, NULL);
440 	} else {
441 		fprintf(stderr,
442 			"Primary process is no longer active, exiting...\n");
443 		__atomic_store_n(&quit_signal, true, __ATOMIC_RELAXED);
444 	}
445 }
446 
447 /* Setup handler to check when primary exits. */
448 static void
449 enable_primary_monitor(void)
450 {
451 	int ret;
452 
453 	/* Once primary exits, so will pdump. */
454 	ret = rte_eal_alarm_set(MONITOR_INTERVAL, monitor_primary, NULL);
455 	if (ret < 0)
456 		fprintf(stderr, "Fail to enable monitor:%d\n", ret);
457 }
458 
459 static void
460 disable_primary_monitor(void)
461 {
462 	int ret;
463 
464 	ret = rte_eal_alarm_cancel(monitor_primary, NULL);
465 	if (ret < 0)
466 		fprintf(stderr, "Fail to disable monitor:%d\n", ret);
467 }
468 
469 static void
470 report_packet_stats(dumpcap_out_t out)
471 {
472 	struct rte_pdump_stats pdump_stats;
473 	struct interface *intf;
474 	uint64_t ifrecv, ifdrop;
475 	double percent;
476 
477 	fputc('\n', stderr);
478 	TAILQ_FOREACH(intf, &interfaces, next) {
479 		if (rte_pdump_stats(intf->port, &pdump_stats) < 0)
480 			continue;
481 
482 		/* do what Wiretap does */
483 		ifrecv = pdump_stats.accepted + pdump_stats.filtered;
484 		ifdrop = pdump_stats.nombuf + pdump_stats.ringfull;
485 
486 		if (use_pcapng)
487 			rte_pcapng_write_stats(out.pcapng, intf->port, NULL,
488 					       start_time, end_time,
489 					       ifrecv, ifdrop);
490 
491 		if (ifrecv == 0)
492 			percent = 0;
493 		else
494 			percent = 100. * ifrecv / (ifrecv + ifdrop);
495 
496 		fprintf(stderr,
497 			"Packets received/dropped on interface '%s': "
498 			"%"PRIu64 "/%" PRIu64 " (%.1f)\n",
499 			intf->name, ifrecv, ifdrop, percent);
500 	}
501 }
502 
503 /*
504  * Start DPDK EAL with arguments.
505  * Unlike most DPDK programs, this application does not use the
506  * typical EAL command line arguments.
507  * We don't want to expose all the DPDK internals to the user.
508  */
509 static void dpdk_init(void)
510 {
511 	static const char * const args[] = {
512 		"dumpcap", "--proc-type", "secondary",
513 		"--log-level", "notice"
514 
515 	};
516 	const int eal_argc = RTE_DIM(args);
517 	char **eal_argv;
518 	unsigned int i;
519 
520 	/* DPDK API requires mutable versions of command line arguments. */
521 	eal_argv = calloc(eal_argc + 1, sizeof(char *));
522 	if (eal_argv == NULL)
523 		rte_panic("No memory\n");
524 
525 	eal_argv[0] = strdup(progname);
526 	for (i = 1; i < RTE_DIM(args); i++)
527 		eal_argv[i] = strdup(args[i]);
528 
529 	if (rte_eal_init(eal_argc, eal_argv) < 0)
530 		rte_exit(EXIT_FAILURE, "EAL init failed: is primary process running?\n");
531 
532 	if (rte_eth_dev_count_avail() == 0)
533 		rte_exit(EXIT_FAILURE, "No Ethernet ports found\n");
534 }
535 
536 /* Create packet ring shared between callbacks and process */
537 static struct rte_ring *create_ring(void)
538 {
539 	struct rte_ring *ring;
540 	size_t size, log2;
541 
542 	/* Find next power of 2 >= size. */
543 	size = ring_size;
544 	log2 = sizeof(size) * 8 - __builtin_clzl(size - 1);
545 	size = 1u << log2;
546 
547 	if (size != ring_size) {
548 		fprintf(stderr, "Ring size %u rounded up to %zu\n",
549 			ring_size, size);
550 		ring_size = size;
551 	}
552 
553 	ring = rte_ring_lookup(RING_NAME);
554 	if (ring == NULL) {
555 		ring = rte_ring_create(RING_NAME, ring_size,
556 					rte_socket_id(), 0);
557 		if (ring == NULL)
558 			rte_exit(EXIT_FAILURE, "Could not create ring :%s\n",
559 				 rte_strerror(rte_errno));
560 	}
561 	return ring;
562 }
563 
564 static struct rte_mempool *create_mempool(void)
565 {
566 	static const char pool_name[] = "capture_mbufs";
567 	size_t num_mbufs = 2 * ring_size;
568 	struct rte_mempool *mp;
569 
570 	mp = rte_mempool_lookup(pool_name);
571 	if (mp)
572 		return mp;
573 
574 	mp = rte_pktmbuf_pool_create_by_ops(pool_name, num_mbufs,
575 					    MBUF_POOL_CACHE_SIZE, 0,
576 					    rte_pcapng_mbuf_size(snaplen),
577 					    rte_socket_id(), "ring_mp_sc");
578 	if (mp == NULL)
579 		rte_exit(EXIT_FAILURE,
580 			 "Mempool (%s) creation failed: %s\n", pool_name,
581 			 rte_strerror(rte_errno));
582 
583 	return mp;
584 }
585 
586 /*
587  * Get Operating System information.
588  * Returns an string allocated via malloc().
589  */
590 static char *get_os_info(void)
591 {
592 	struct utsname uts;
593 	char *osname = NULL;
594 
595 	if (uname(&uts) < 0)
596 		return NULL;
597 
598 	if (asprintf(&osname, "%s %s",
599 		     uts.sysname, uts.release) == -1)
600 		return NULL;
601 
602 	return osname;
603 }
604 
605 static dumpcap_out_t create_output(void)
606 {
607 	dumpcap_out_t ret;
608 	static char tmp_path[PATH_MAX];
609 	int fd;
610 
611 	/* If no filename specified make a tempfile name */
612 	if (output_name == NULL) {
613 		struct interface *intf;
614 		struct tm *tm;
615 		time_t now;
616 		char ts[32];
617 
618 		intf = TAILQ_FIRST(&interfaces);
619 		now = time(NULL);
620 		tm = localtime(&now);
621 		if (!tm)
622 			rte_panic("localtime failed\n");
623 
624 		strftime(ts, sizeof(ts), "%Y%m%d%H%M%S", tm);
625 
626 		snprintf(tmp_path, sizeof(tmp_path),
627 			 "/tmp/%s_%u_%s_%s.%s",
628 			 progname, intf->port, intf->name, ts,
629 			 use_pcapng ? "pcapng" : "pcap");
630 		output_name = tmp_path;
631 	}
632 
633 	if (strcmp(output_name, "-") == 0)
634 		fd = STDOUT_FILENO;
635 	else {
636 		mode_t mode = group_read ? 0640 : 0600;
637 
638 		fd = open(output_name, O_WRONLY | O_CREAT, mode);
639 		if (fd < 0)
640 			rte_exit(EXIT_FAILURE, "Can not open \"%s\": %s\n",
641 				 output_name, strerror(errno));
642 	}
643 
644 	if (use_pcapng) {
645 		char *os = get_os_info();
646 
647 		ret.pcapng = rte_pcapng_fdopen(fd, os, NULL,
648 					   version(), capture_comment);
649 		if (ret.pcapng == NULL)
650 			rte_exit(EXIT_FAILURE, "pcapng_fdopen failed: %s\n",
651 				 strerror(rte_errno));
652 		free(os);
653 	} else {
654 		pcap_t *pcap;
655 
656 		pcap = pcap_open_dead_with_tstamp_precision(DLT_EN10MB, snaplen,
657 							    PCAP_TSTAMP_PRECISION_NANO);
658 		if (pcap == NULL)
659 			rte_exit(EXIT_FAILURE, "pcap_open_dead failed\n");
660 
661 		ret.dumper = pcap_dump_fopen(pcap, fdopen(fd, "w"));
662 		if (ret.dumper == NULL)
663 			rte_exit(EXIT_FAILURE, "pcap_dump_fopen failed: %s\n",
664 				 pcap_geterr(pcap));
665 	}
666 
667 	return ret;
668 }
669 
670 static void enable_pdump(struct rte_ring *r, struct rte_mempool *mp)
671 {
672 	struct interface *intf;
673 	uint32_t flags;
674 	int ret;
675 
676 	flags = RTE_PDUMP_FLAG_RXTX;
677 	if (use_pcapng)
678 		flags |= RTE_PDUMP_FLAG_PCAPNG;
679 
680 	TAILQ_FOREACH(intf, &interfaces, next) {
681 		if (promiscuous_mode)
682 			rte_eth_promiscuous_enable(intf->port);
683 
684 		ret = rte_pdump_enable_bpf(intf->port, RTE_PDUMP_ALL_QUEUES,
685 					   flags, snaplen,
686 					   r, mp, bpf_prm);
687 		if (ret < 0)
688 			rte_exit(EXIT_FAILURE,
689 				 "Packet dump enable failed: %s\n",
690 				 rte_strerror(-ret));
691 	}
692 }
693 
694 /*
695  * Show current count of captured packets
696  * with backspaces to overwrite last value.
697  */
698 static void show_count(uint64_t count)
699 {
700 	unsigned int i;
701 	static unsigned int bt;
702 
703 	for (i = 0; i < bt; i++)
704 		fputc('\b', stderr);
705 
706 	bt = fprintf(stderr, "%"PRIu64" ", count);
707 }
708 
709 /* Write multiple packets in older pcap format */
710 static ssize_t
711 pcap_write_packets(pcap_dumper_t *dumper,
712 		   struct rte_mbuf *pkts[], uint16_t n)
713 {
714 	uint8_t temp_data[snaplen];
715 	struct pcap_pkthdr header;
716 	uint16_t i;
717 	size_t total = 0;
718 
719 	gettimeofday(&header.ts, NULL);
720 
721 	for (i = 0; i < n; i++) {
722 		struct rte_mbuf *m = pkts[i];
723 
724 		header.len = rte_pktmbuf_pkt_len(m);
725 		header.caplen = RTE_MIN(header.len, snaplen);
726 
727 		pcap_dump((u_char *)dumper, &header,
728 			  rte_pktmbuf_read(m, 0, header.caplen, temp_data));
729 
730 		total += sizeof(header) + header.len;
731 	}
732 
733 	return total;
734 }
735 
736 /* Process all packets in ring and dump to capture file */
737 static int process_ring(dumpcap_out_t out, struct rte_ring *r)
738 {
739 	struct rte_mbuf *pkts[BURST_SIZE];
740 	unsigned int avail, n;
741 	static unsigned int empty_count;
742 	ssize_t written;
743 
744 	n = rte_ring_sc_dequeue_burst(r, (void **) pkts, BURST_SIZE,
745 				      &avail);
746 	if (n == 0) {
747 		/* don't consume endless amounts of cpu if idle */
748 		if (empty_count < SLEEP_THRESHOLD)
749 			++empty_count;
750 		else
751 			usleep(10);
752 		return 0;
753 	}
754 
755 	empty_count = (avail == 0);
756 
757 	if (use_pcapng)
758 		written = rte_pcapng_write_packets(out.pcapng, pkts, n);
759 	else
760 		written = pcap_write_packets(out.dumper, pkts, n);
761 
762 	rte_pktmbuf_free_bulk(pkts, n);
763 
764 	if (written < 0)
765 		return -1;
766 
767 	file_size += written;
768 	packets_received += n;
769 	if (!quiet)
770 		show_count(packets_received);
771 
772 	return 0;
773 }
774 
775 int main(int argc, char **argv)
776 {
777 	struct rte_ring *r;
778 	struct rte_mempool *mp;
779 	dumpcap_out_t out;
780 
781 	progname = argv[0];
782 
783 	dpdk_init();
784 	parse_opts(argc, argv);
785 
786 	if (filter_str)
787 		compile_filter();
788 
789 	if (TAILQ_EMPTY(&interfaces))
790 		set_default_interface();
791 
792 	r = create_ring();
793 	mp = create_mempool();
794 	out = create_output();
795 
796 	start_time = create_timestamp();
797 	enable_pdump(r, mp);
798 
799 	signal(SIGINT, signal_handler);
800 	signal(SIGPIPE, SIG_IGN);
801 
802 	enable_primary_monitor();
803 
804 	if (!quiet) {
805 		fprintf(stderr, "Packets captured: ");
806 		show_count(0);
807 	}
808 
809 	while (!__atomic_load_n(&quit_signal, __ATOMIC_RELAXED)) {
810 		if (process_ring(out, r) < 0) {
811 			fprintf(stderr, "pcapng file write failed; %s\n",
812 				strerror(errno));
813 			break;
814 		}
815 
816 		if (stop.size && file_size >= stop.size)
817 			break;
818 
819 		if (stop.packets && packets_received >= stop.packets)
820 			break;
821 
822 		if (stop.duration != 0 &&
823 		    create_timestamp() - start_time > stop.duration)
824 			break;
825 	}
826 
827 	end_time = create_timestamp();
828 	disable_primary_monitor();
829 
830 	if (rte_eal_primary_proc_alive(NULL))
831 		report_packet_stats(out);
832 
833 	if (use_pcapng)
834 		rte_pcapng_close(out.pcapng);
835 	else
836 		pcap_dump_close(out.dumper);
837 
838 	cleanup_pdump_resources();
839 	rte_free(bpf_filter);
840 	rte_ring_free(r);
841 	rte_mempool_free(mp);
842 
843 	return rte_eal_cleanup() ? EXIT_FAILURE : 0;
844 }
845