app/test/test_pcapng.c - main - phprus/github_dpdk

app/test/test_pcapng.c
701 строка17 KB
Stephen Hemminger
test/pcapng: add some leeway to timestamp test
02 июл 2026, 23:58
02 июл 2026, 23:58e7d4bce
/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright (c) 2021 Microsoft Corporation
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#ifdef RTE_EXEC_ENV_WINDOWS
#include <winsock2.h>
#include <io.h>
#include <fcntl.h>
#include <windows.h>
#else
#include <unistd.h>
#endif

#include <rte_bus_vdev.h>
#include <rte_ethdev.h>
#include <rte_ether.h>
#include <rte_ip.h>
#include <rte_mbuf.h>
#include <rte_mempool.h>
#include <rte_net.h>
#include <rte_pcapng.h>
#include <rte_random.h>
#include <rte_reciprocal.h>
#include <rte_time.h>
#include <rte_udp.h>

#include <pcap/pcap.h>

#include "test.h"

#ifdef RTE_EXEC_ENV_WINDOWS
static uint64_t
current_timestamp(void)
{
	FILETIME ft;
	ULARGE_INTEGER ul;

	GetSystemTimeAsFileTime(&ft);
	ul.LowPart = ft.dwLowDateTime;
	ul.HighPart = ft.dwHighDateTime;
	/* FILETIME is 100ns intervals since 1601-01-01, convert to ns since Unix epoch */
	return (ul.QuadPart - 116444736000000000ULL) * 100;
}

/*
 * Create temporary file with suffix for Windows.
 * Returns file descriptor or -1 on failure.
 */
static int
mkstemps(char *tmpl, int suffixlen)
{
	char temp_dir[MAX_PATH];
	char temp_file[MAX_PATH];
	DWORD ret;

	ret = GetTempPathA(sizeof(temp_dir), temp_dir);
	if (ret == 0 || ret > sizeof(temp_dir))
		return -1;

	if (GetTempFileNameA(temp_dir, "pcap", 0, temp_file) == 0)
		return -1;

	/*
	 * GetTempFileNameA with uUnique=0 creates the file to reserve the name.
	 * Remove it since we open a different name with the original suffix appended.
	 */
	DeleteFileA(temp_file);

	/* Append the original suffix (e.g. ".pcapng") to the temp file */
	strlcat(temp_file, tmpl + strlen(tmpl) - suffixlen, sizeof(temp_file));
	strlcpy(tmpl, temp_file, PATH_MAX);

	return _open(tmpl, _O_RDWR | _O_BINARY | _O_CREAT | _O_EXCL, 0666);
}
#endif /* RTE_EXEC_ENV_WINDOWS */

#define PCAPNG_TEST_DEBUG 0

/*
 * Want to write enough packets to exercise timestamp logic.
 * On fast CPU's TSC wraps around 32 bits in 4 seconds.
 */
#define TOTAL_PACKETS	10000
#define MAX_BURST	32
#define NUM_BURSTS	(TOTAL_PACKETS / MAX_BURST)
#define TEST_TIME_SEC	4
#define GAP_US		((TEST_TIME_SEC * US_PER_S) / NUM_BURSTS)

#define DUMMY_MBUF_NUM	2

static struct rte_mempool *mp;
static uint16_t port_id;
static const char null_dev[] = "net_null0";

/* first mbuf in the packet, should always be at offset 0 */
struct dummy_mbuf {
	struct rte_mbuf mb[DUMMY_MBUF_NUM];
	uint8_t buf[DUMMY_MBUF_NUM][RTE_MBUF_DEFAULT_BUF_SIZE];
};

#define MAX_DATA_SIZE (RTE_MBUF_DEFAULT_BUF_SIZE - RTE_PKTMBUF_HEADROOM)

/* RFC 864 chargen pattern used for comment testing */
#define FILL_LINE_LENGTH 72
#define FILL_START	0x21 /* ! */
#define FILL_END	0x7e /* ~ */
#define FILL_RANGE	(FILL_END - FILL_START)

static void
fill_mbuf(struct rte_mbuf *mb)
{
	unsigned int len = rte_pktmbuf_tailroom(mb);
	char *buf = rte_pktmbuf_append(mb, len);
	unsigned int n = 0;
	unsigned int line = 0;

	if (len == 0)
		return;

	while (n < len - 1) {
		char ch = FILL_START + (line % FILL_RANGE);
		unsigned int i;

		for (i = 0; i < FILL_LINE_LENGTH && n < len - 1; i++) {
			buf[n++] = ch;
			if (++ch > FILL_END)
				ch = FILL_START;
		}
		if (n < len - 1)
			buf[n++] = '\n';
		line++;
	}
}

static void
dummy_mbuf_prep(struct rte_mbuf *mb, uint8_t buf[], uint32_t buf_len)
{
	mb->buf_addr = buf;
	rte_mbuf_iova_set(mb, (uintptr_t)buf);
	mb->buf_len = buf_len;
	rte_mbuf_refcnt_set(mb, 1);

	/* set pool pointer to dummy value, test doesn't use it */
	mb->pool = (void *)buf;

	rte_pktmbuf_reset(mb);
}

/* Make an IP packet consisting of chain of one packets */
static void
mbuf1_prepare(struct dummy_mbuf *dm)
{
	struct {
		struct rte_ether_hdr eth;
		struct rte_ipv4_hdr ip;
		struct rte_udp_hdr udp;
	} pkt = {
		.eth = {
			.dst_addr.addr_bytes = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff },
			.ether_type = rte_cpu_to_be_16(RTE_ETHER_TYPE_IPV4),
		},
		.ip = {
			.version_ihl = RTE_IPV4_VHL_DEF,
			.time_to_live = 1,
			.next_proto_id = IPPROTO_UDP,
			.src_addr = rte_cpu_to_be_32(RTE_IPV4_LOOPBACK),
			.dst_addr = rte_cpu_to_be_32(RTE_IPV4_BROADCAST),
		},
		.udp = {
			.src_port = rte_cpu_to_be_16(19), /* Chargen port */
			.dst_port = rte_cpu_to_be_16(9), /* Discard port */
		},
	};

	memset(dm, 0, sizeof(*dm));
	dummy_mbuf_prep(&dm->mb[0], dm->buf[0], sizeof(dm->buf[0]));
	dummy_mbuf_prep(&dm->mb[1], dm->buf[1], sizeof(dm->buf[1]));

	rte_eth_random_addr(pkt.eth.src_addr.addr_bytes);
	memcpy(rte_pktmbuf_append(&dm->mb[0], sizeof(pkt)), &pkt, sizeof(pkt));

	fill_mbuf(&dm->mb[1]);
	rte_pktmbuf_chain(&dm->mb[0], &dm->mb[1]);

	rte_mbuf_sanity_check(&dm->mb[0], 1);
	rte_mbuf_sanity_check(&dm->mb[1], 0);
}

static void
mbuf1_resize(struct dummy_mbuf *dm, uint16_t len)
{
	struct {
		struct rte_ether_hdr eth;
		struct rte_ipv4_hdr ip;
		struct rte_udp_hdr udp;
	} *pkt = rte_pktmbuf_mtod(&dm->mb[0], void *);

	dm->mb[1].data_len = len;
	dm->mb[0].pkt_len = dm->mb[0].data_len + dm->mb[1].data_len;

	len += sizeof(struct rte_udp_hdr);
	pkt->udp.dgram_len = rte_cpu_to_be_16(len);

	len += sizeof(struct rte_ipv4_hdr);
	pkt->ip.total_length = rte_cpu_to_be_16(len);
	pkt->ip.hdr_checksum = 0;
	pkt->ip.hdr_checksum = rte_ipv4_cksum(&pkt->ip);

	rte_mbuf_sanity_check(&dm->mb[0], 1);
	rte_mbuf_sanity_check(&dm->mb[1], 0);
}

static int
test_setup(void)
{
	port_id = rte_eth_dev_count_avail();

	/* Make a dummy null device to snoop on */
	if (rte_vdev_init(null_dev, NULL) != 0) {
		printf("Failed to create vdev '%s'\n", null_dev);
		goto fail;
	}

	/* Make a pool for cloned packets */
	mp = rte_pktmbuf_pool_create_by_ops("pcapng_test_pool",
					    MAX_BURST * 32, 0, 0,
					    rte_pcapng_mbuf_size(MAX_DATA_SIZE),
					    SOCKET_ID_ANY, "ring_mp_sc");
	if (mp == NULL) {
		printf("Cannot create mempool\n");
		goto fail;
	}

	return 0;

fail:
	rte_vdev_uninit(null_dev);
	rte_mempool_free(mp);
	return -1;
}

static int
fill_pcapng_file(rte_pcapng_t *pcapng)
{
	struct dummy_mbuf mbfs;
	struct rte_mbuf *orig;
	unsigned int burst_size;
	unsigned int count;
	struct timespec start_time;
	ssize_t len;
	/*
	 * These are some silly comments to test various lengths and alignments sprinkle
	 * into the file. You can see these comments by using the dumpcap program on the file
	 */
	static const char * const examples[] = {
		"Lockless and fearless - that’s how we roll in userspace.",
		"Memory pool deep / Mbufs swim in lockless rings / Zero copy dreams,",
		"Poll mode driver waits / No interrupts disturb its zen / Busy loop finds peace,",
		"Memory barriers / rte_atomic_thread_fence() / Guards our shared state",
		"Hugepages so vast / Two megabytes of glory / TLB misses weep",
		"Packets flow like streams / Through the graph node pipeline / Iterate in place",

		/* Long one to make sure we can do > 256 characters */
		("Dear future maintainer: I am sorry. This packet was captured at 3 AM while "
		 "debugging a priority flow control issue that turned out to be a loose cable. "
		 "The rte_eth_tx_burst() call you see here has been cargo-culted through four "
		 "generations of example code. The magic number 32 is not documented because "
		 "nobody remembers why. Trust the process."),
	};

	mbuf1_prepare(&mbfs);
	orig  = &mbfs.mb[0];

	clock_gettime(CLOCK_MONOTONIC, &start_time);

	for (count = 0; count < TOTAL_PACKETS; count += burst_size) {
		struct rte_mbuf *clones[MAX_BURST];
		struct timespec now;
		unsigned int i;

		/* break off writing if test is taking too long */
		clock_gettime(CLOCK_MONOTONIC, &now);
		if (now.tv_sec >= start_time.tv_sec + TEST_TIME_SEC)
			break;

		/* put 1 .. MAX_BURST packets in one write call */
		burst_size = rte_rand_max(MAX_BURST) + 1;
		for (i = 0; i < burst_size; i++) {
			struct rte_mbuf *mc;
			const char *comment = NULL;

			/* Put randomized comment on every 100th packet (1%) */
			if (count % 100 == 0)
				comment = examples[rte_rand_max(RTE_DIM(examples))];

			/* Vary the size of the packets, okay to allow 0 sized packet */
			mbuf1_resize(&mbfs, rte_rand_max(MAX_DATA_SIZE));

			mc = rte_pcapng_copy(port_id, 0, orig, mp, rte_pktmbuf_pkt_len(orig),
					     RTE_PCAPNG_DIRECTION_IN, comment);
			if (mc == NULL) {
				printf("Cannot copy packet\n");
				return -1;
			}
			clones[i] = mc;
		}

		/* write it to capture file */
		len = rte_pcapng_write_packets(pcapng, clones, burst_size);
		rte_pktmbuf_free_bulk(clones, burst_size);

		if (len <= 0) {
			printf("Write of packets failed: %s\n",
				rte_strerror(rte_errno));
			return -1;
		}

		rte_delay_us_block(rte_rand_max(2 * GAP_US));
	}

	return count;
}

/* Convert time in nanoseconds since 1/1/1970 to UTC time string */
static char *
fmt_time(char *buf, size_t size, uint64_t ts_ns)
{
	time_t sec;
	size_t len;

	sec = ts_ns / NS_PER_S;

	len = strftime(buf, size, "%T", gmtime(&sec));
	snprintf(buf + len, size - len, ".%09lu",
		 (unsigned long)(ts_ns % NS_PER_S));

	return buf;
}

/* Context for the pcap_loop callback */
struct pkt_print_ctx {
	pcap_t *pcap;
	unsigned int count;
	uint64_t start_ns;
	uint64_t end_ns;
};

static void
print_packet(uint64_t ts_ns, const struct rte_ether_hdr *eh, size_t len)
{
	char tbuf[128], src[64], dst[64];

	fmt_time(tbuf, sizeof(tbuf), ts_ns);
	rte_ether_format_addr(dst, sizeof(dst), &eh->dst_addr);
	rte_ether_format_addr(src, sizeof(src), &eh->src_addr);
	printf("%s: %s -> %s type %x length %zu\n",
	       tbuf, src, dst, rte_be_to_cpu_16(eh->ether_type), len);
	fflush(stdout);
}

/* Callback from pcap_loop used to validate packets in the file */
static void
parse_pcap_packet(u_char *user, const struct pcap_pkthdr *h,
		  const u_char *bytes)
{
	struct pkt_print_ctx *ctx = (struct pkt_print_ctx *)user;
	const struct rte_ether_hdr *eh;
	const struct rte_ipv4_hdr *ip;
	static unsigned int total_errors;
	uint64_t ns;

	eh = (const struct rte_ether_hdr *)bytes;
	ip = (const struct rte_ipv4_hdr *)(eh + 1);

	ctx->count += 1;

	/* The pcap library is misleading in reporting timestamp.
	 * packet header struct gives timestamp as a timeval (ie. usec);
	 * but the file is open in nanonsecond mode therefore
	 * the timestamp is really in timespec (ie. nanoseconds).
	 */
	ns = (uint64_t)h->ts.tv_sec * NS_PER_S + h->ts.tv_usec;
	if (ns < ctx->start_ns || ns > ctx->end_ns) {
		char tstart[128], tend[128];

		fmt_time(tstart, sizeof(tstart), ctx->start_ns);
		fmt_time(tend, sizeof(tend), ctx->end_ns);

		printf("Timestamp out of range [%s .. %s]\n",
		       tstart, tend);
		goto error;
	}

	if (!rte_is_broadcast_ether_addr(&eh->dst_addr)) {
		printf("Destination is not broadcast\n");
		goto error;
	}

	if (rte_ipv4_cksum(ip) != 0) {
		printf("Bad IPv4 checksum\n");
		goto error;
	}

	return;		/* packet is normal */

error:
	print_packet(ns, eh, h->len);

	/* Stop parsing at tenth error */
	if (++total_errors >= 10)
		pcap_breakloop(ctx->pcap);
}

#ifndef RTE_EXEC_ENV_WINDOWS
static uint64_t
current_timestamp(void)
{
	struct timespec ts;

	clock_gettime(CLOCK_REALTIME, &ts);
	return rte_timespec_to_ns(&ts);
}
#endif

/*
 * Open the resulting pcapng file with libpcap
 * Would be better to use capinfos from wireshark
 * but that creates an unwanted dependency.
 */
static int
valid_pcapng_file(const char *file_name, uint64_t started, unsigned int expected)
{
	char errbuf[PCAP_ERRBUF_SIZE];
	struct pkt_print_ctx ctx = { };
	int ret;

	ctx.start_ns = started;
	ctx.end_ns = current_timestamp() + NS_PER_S;

	ctx.pcap = pcap_open_offline_with_tstamp_precision(file_name,
							   PCAP_TSTAMP_PRECISION_NANO,
							   errbuf);
	if (ctx.pcap == NULL) {
		printf("pcap_open_offline('%s') failed: %s\n",
			file_name, errbuf);
		return -1;
	}

	ret = pcap_loop(ctx.pcap, 0, parse_pcap_packet, (u_char *)&ctx);
	if (ret != 0) {
		printf("pcap_dispatch: failed: %s\n",
			pcap_geterr(ctx.pcap));
	} else if (ctx.count != expected) {
		printf("Only %u packets, expected %u\n",
		       ctx.count, expected);
		ret = -1;
	}

	pcap_close(ctx.pcap);

	return ret;
}

static int
test_add_interface(void)
{
	char file_name[PATH_MAX] = "/tmp/pcapng_test_XXXXXX.pcapng";
	static rte_pcapng_t *pcapng;
	int ret, tmp_fd;
	uint64_t now = current_timestamp();

	tmp_fd = mkstemps(file_name, strlen(".pcapng"));
	if (tmp_fd == -1) {
		perror("mkstemps() failure");
		goto fail;
	}
	printf("pcapng: output file %s\n", file_name);

	/* open a test capture file */
	pcapng = rte_pcapng_fdopen(tmp_fd, NULL, NULL, "pcapng_addif", NULL);
	if (pcapng == NULL) {
		printf("rte_pcapng_fdopen failed\n");
		close(tmp_fd);
		goto fail;
	}

	/* Add interface to the file */
	ret = rte_pcapng_add_interface(pcapng, port_id, DLT_EN10MB,
				       NULL, NULL, NULL);
	if (ret < 0) {
		printf("can not add port %u\n", port_id);
		goto fail;
	}

	/* Add interface with ifname and ifdescr */
	ret = rte_pcapng_add_interface(pcapng, port_id, DLT_EN10MB,
				       "myeth", "Some long description", NULL);
	if (ret < 0) {
		printf("can not add port %u with ifname\n", port_id);
		goto fail;
	}

	/* Add interface with filter */
	ret = rte_pcapng_add_interface(pcapng, port_id, DLT_EN10MB,
				       NULL, NULL, "tcp port 8080");
	if (ret < 0) {
		printf("can not add port %u with filter\n", port_id);
		goto fail;
	}

	rte_pcapng_close(pcapng);

	ret = valid_pcapng_file(file_name, now, 0);
	/* if test fails want to investigate the file */
	if (ret == 0)
		remove(file_name);

	return ret;

fail:
	rte_pcapng_close(pcapng);
	return -1;
}

static int
test_write_packets(void)
{
	char file_name[PATH_MAX] = "/tmp/pcapng_test_XXXXXX.pcapng";
	rte_pcapng_t *pcapng = NULL;
	int ret, tmp_fd, count;
	uint64_t now = current_timestamp();

	tmp_fd = mkstemps(file_name, strlen(".pcapng"));
	if (tmp_fd == -1) {
		perror("mkstemps() failure");
		goto fail;
	}
	printf("pcapng: output file %s\n", file_name);

	/* open a test capture file */
	pcapng = rte_pcapng_fdopen(tmp_fd, NULL, NULL, "pcapng_test", NULL);
	if (pcapng == NULL) {
		printf("rte_pcapng_fdopen failed\n");
		close(tmp_fd);
		goto fail;
	}

	/* Add interface to the file */
	ret = rte_pcapng_add_interface(pcapng, port_id, DLT_EN10MB,
				       NULL, NULL, NULL);
	if (ret < 0) {
		printf("can not add port %u\n", port_id);
		goto fail;
	}

	/* write a statistics block */
	ret = rte_pcapng_write_stats(pcapng, port_id, 0, 0, NULL);
	if (ret <= 0) {
		printf("Write of statistics failed\n");
		goto fail;
	}

	count = fill_pcapng_file(pcapng);
	if (count < 0)
		goto fail;

	/* write a statistics block */
	ret = rte_pcapng_write_stats(pcapng, port_id,
				     count, 0, "end of test");
	if (ret <= 0) {
		printf("Write of statistics failed\n");
		goto fail;
	}

	rte_pcapng_close(pcapng);

	ret = valid_pcapng_file(file_name, now, count);
	/* if test fails want to investigate the file */
	if (ret == 0)
		remove(file_name);

	return ret;

fail:
	rte_pcapng_close(pcapng);
	return -1;
}

static int
test_write_before_open(void)
{
	char file_name[PATH_MAX] = "/tmp/pcapng_test_XXXXXX.pcapng";
	struct dummy_mbuf mbfs;
	struct rte_mbuf *clones[MAX_BURST];
	rte_pcapng_t *pcapng = NULL;
	int ret, tmp_fd, i;
	unsigned int count = 8;
	uint64_t now;
	ssize_t len;

	mbuf1_prepare(&mbfs);
	mbuf1_resize(&mbfs, rte_rand_max(MAX_DATA_SIZE));

	/* Copy packets BEFORE opening the pcapng file.
	 * This exercises the negative TSC delta path in tsc_to_ns_epoch().
	 */
	for (i = 0; i < (int)count; i++) {
		clones[i] = rte_pcapng_copy(port_id, 0, &mbfs.mb[0], mp,
					    rte_pktmbuf_pkt_len(&mbfs.mb[0]),
					    RTE_PCAPNG_DIRECTION_IN, NULL);
		if (clones[i] == NULL) {
			fprintf(stderr, "Cannot copy packet before open\n");
			rte_pktmbuf_free_bulk(clones, i);
			return -1;
		}
	}

	/* Small delay so fdopen's tsc_base is measurably after the copies */
	rte_delay_us_block(100);

	now = current_timestamp();

	tmp_fd = mkstemps(file_name, strlen(".pcapng"));
	if (tmp_fd == -1) {
		perror("mkstemps() failure");
		rte_pktmbuf_free_bulk(clones, count);
		return -1;
	}

	pcapng = rte_pcapng_fdopen(tmp_fd, NULL, NULL, "pcapng_preopen", NULL);
	if (pcapng == NULL) {
		fprintf(stderr, "rte_pcapng_fdopen failed\n");
		close(tmp_fd);
		rte_pktmbuf_free_bulk(clones, count);
		return -1;
	}

	ret = rte_pcapng_add_interface(pcapng, port_id, DLT_EN10MB,
				       NULL, NULL, NULL);
	if (ret < 0) {
		fprintf(stderr, "can not add port %u\n", port_id);
		goto fail;
	}

	/* Write the pre-captured packets — timestamps precede tsc_base */
	len = rte_pcapng_write_packets(pcapng, clones, count);
	rte_pktmbuf_free_bulk(clones, count);
	if (len <= 0) {
		fprintf(stderr, "Write of pre-open packets failed: %s\n",
			rte_strerror(rte_errno));
		goto fail;
	}

	rte_pcapng_close(pcapng);

	/* Validate the file is parseable — timestamps should be
	 * slightly before 'now' but still reasonable.
	 */
	ret = valid_pcapng_file(file_name, now - NS_PER_S, count);
	if (ret == 0)
		remove(file_name);

	return ret;

fail:
	rte_pcapng_close(pcapng);
	return -1;
}

static void
test_cleanup(void)
{
	rte_mempool_free(mp);
	rte_vdev_uninit(null_dev);
}

static struct
unit_test_suite test_pcapng_suite  = {
	.setup = test_setup,
	.teardown = test_cleanup,
	.suite_name = "Test Pcapng Unit Test Suite",
	.unit_test_cases = {
		TEST_CASE(test_add_interface),
		TEST_CASE(test_write_packets),
		TEST_CASE(test_write_before_open),
		TEST_CASES_END()
	}
};

static int
test_pcapng(void)
{
	return unit_test_suite_runner(&test_pcapng_suite);
}

REGISTER_FAST_TEST(pcapng_autotest, NOHUGE_OK, ASAN_OK, test_pcapng);