linux-pinenote/tools/testing/selftests/net/psock_tpacket.c

/*
 * Copyright 2013 Red Hat, Inc.
 * Author: Daniel Borkmann <dborkman@redhat.com>
 *
 * A basic test of packet socket's TPACKET_V1/TPACKET_V2/TPACKET_V3 behavior.
 *
 * Control:
 *   Test the setup of the TPACKET socket with different patterns that are
 *   known to fail (TODO) resp. succeed (OK).
 *
 * Datapath:
 *   Open a pair of packet sockets and send resp. receive an a priori known
 *   packet pattern accross the sockets and check if it was received resp.
 *   sent correctly. Fanout in combination with RX_RING is currently not
 *   tested here.
 *
 *   The test currently runs for
 *   - TPACKET_V1: RX_RING, TX_RING
 *   - TPACKET_V2: RX_RING, TX_RING
 *   - TPACKET_V3: RX_RING
 *
 * License (GPLv2):
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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.,
 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/mman.h>
#include <linux/if_packet.h>
#include <linux/filter.h>
#include <ctype.h>
#include <fcntl.h>
#include <unistd.h>
#include <bits/wordsize.h>
#include <net/ethernet.h>
#include <netinet/ip.h>
#include <arpa/inet.h>
#include <stdint.h>
#include <string.h>
#include <assert.h>
#include <net/if.h>
#include <inttypes.h>
#include <poll.h>

#include "psock_lib.h"

#ifndef bug_on
# define bug_on(cond)		assert(!(cond))
#endif

#ifndef __aligned_tpacket
# define __aligned_tpacket	__attribute__((aligned(TPACKET_ALIGNMENT)))
#endif

#ifndef __align_tpacket
# define __align_tpacket(x)	__attribute__((aligned(TPACKET_ALIGN(x))))
#endif

#define BLOCK_STATUS(x)		((x)->h1.block_status)
#define BLOCK_NUM_PKTS(x)	((x)->h1.num_pkts)
#define BLOCK_O2FP(x)		((x)->h1.offset_to_first_pkt)
#define BLOCK_LEN(x)		((x)->h1.blk_len)
#define BLOCK_SNUM(x)		((x)->h1.seq_num)
#define BLOCK_O2PRIV(x)		((x)->offset_to_priv)
#define BLOCK_PRIV(x)		((void *) ((uint8_t *) (x) + BLOCK_O2PRIV(x)))
#define BLOCK_HDR_LEN		(ALIGN_8(sizeof(struct block_desc)))
#define ALIGN_8(x)		(((x) + 8 - 1) & ~(8 - 1))
#define BLOCK_PLUS_PRIV(sz_pri)	(BLOCK_HDR_LEN + ALIGN_8((sz_pri)))

#define NUM_PACKETS		100

struct ring {
	struct iovec *rd;
	uint8_t *mm_space;
	size_t mm_len, rd_len;
	struct sockaddr_ll ll;
	void (*walk)(int sock, struct ring *ring);
	int type, rd_num, flen, version;
	union {
		struct tpacket_req  req;
		struct tpacket_req3 req3;
	};
};

struct block_desc {
	uint32_t version;
	uint32_t offset_to_priv;
	struct tpacket_hdr_v1 h1;
};

union frame_map {
	struct {
		struct tpacket_hdr tp_h __aligned_tpacket;
		struct sockaddr_ll s_ll __align_tpacket(sizeof(struct tpacket_hdr));
	} *v1;
	struct {
		struct tpacket2_hdr tp_h __aligned_tpacket;
		struct sockaddr_ll s_ll __align_tpacket(sizeof(struct tpacket2_hdr));
	} *v2;
	void *raw;
};

static unsigned int total_packets, total_bytes;

static int pfsocket(int ver)
{
	int ret, sock = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
	if (sock == -1) {
		perror("socket");
		exit(1);
	}

	ret = setsockopt(sock, SOL_PACKET, PACKET_VERSION, &ver, sizeof(ver));
	if (ret == -1) {
		perror("setsockopt");
		exit(1);
	}

	return sock;
}

static void status_bar_update(void)
{
	if (total_packets % 10 == 0) {
		fprintf(stderr, ".");
		fflush(stderr);
	}
}

static void test_payload(void *pay, size_t len)
{
	struct ethhdr *eth = pay;

	if (len < sizeof(struct ethhdr)) {
		fprintf(stderr, "test_payload: packet too "
			"small: %zu bytes!\n", len);
		exit(1);
	}

	if (eth->h_proto != htons(ETH_P_IP)) {
		fprintf(stderr, "test_payload: wrong ethernet "
			"type: 0x%x!\n", ntohs(eth->h_proto));
		exit(1);
	}
}

static void create_payload(void *pay, size_t *len)
{
	int i;
	struct ethhdr *eth = pay;
	struct iphdr *ip = pay + sizeof(*eth);

	/* Lets create some broken crap, that still passes
	 * our BPF filter.
	 */

	*len = DATA_LEN + 42;

	memset(pay, 0xff, ETH_ALEN * 2);
	eth->h_proto = htons(ETH_P_IP);

	for (i = 0; i < sizeof(*ip); ++i)
		((uint8_t *) pay)[i + sizeof(*eth)] = (uint8_t) rand();

	ip->ihl = 5;
	ip->version = 4;
	ip->protocol = 0x11;
	ip->frag_off = 0;
	ip->ttl = 64;
	ip->tot_len = htons((uint16_t) *len - sizeof(*eth));

	ip->saddr = htonl(INADDR_LOOPBACK);
	ip->daddr = htonl(INADDR_LOOPBACK);

	memset(pay + sizeof(*eth) + sizeof(*ip),
	       DATA_CHAR, DATA_LEN);
}

static inline int __v1_rx_kernel_ready(struct tpacket_hdr *hdr)
{
	return ((hdr->tp_status & TP_STATUS_USER) == TP_STATUS_USER);
}

static inline void __v1_rx_user_ready(struct tpacket_hdr *hdr)
{
	hdr->tp_status = TP_STATUS_KERNEL;
	__sync_synchronize();
}

static inline int __v2_rx_kernel_ready(struct tpacket2_hdr *hdr)
{
	return ((hdr->tp_status & TP_STATUS_USER) == TP_STATUS_USER);
}

static inline void __v2_rx_user_ready(struct tpacket2_hdr *hdr)
{
	hdr->tp_status = TP_STATUS_KERNEL;
	__sync_synchronize();
}

static inline int __v1_v2_rx_kernel_ready(void *base, int version)
{
	switch (version) {
	case TPACKET_V1:
		return __v1_rx_kernel_ready(base);
	case TPACKET_V2:
		return __v2_rx_kernel_ready(base);
	default:
		bug_on(1);
		return 0;
	}
}

static inline void __v1_v2_rx_user_ready(void *base, int version)
{
	switch (version) {
	case TPACKET_V1:
		__v1_rx_user_ready(base);
		break;
	case TPACKET_V2:
		__v2_rx_user_ready(base);
		break;
	}
}

static void walk_v1_v2_rx(int sock, struct ring *ring)
{
	struct pollfd pfd;
	int udp_sock[2];
	union frame_map ppd;
	unsigned int frame_num = 0;

	bug_on(ring->type != PACKET_RX_RING);

	pair_udp_open(udp_sock, PORT_BASE);
	pair_udp_setfilter(sock);

	memset(&pfd, 0, sizeof(pfd));
	pfd.fd = sock;
	pfd.events = POLLIN | POLLERR;
	pfd.revents = 0;

	pair_udp_send(udp_sock, NUM_PACKETS);

	while (total_packets < NUM_PACKETS * 2) {
		while (__v1_v2_rx_kernel_ready(ring->rd[frame_num].iov_base,
					       ring->version)) {
			ppd.raw = ring->rd[frame_num].iov_base;

			switch (ring->version) {
			case TPACKET_V1:
				test_payload((uint8_t *) ppd.raw + ppd.v1->tp_h.tp_mac,
					     ppd.v1->tp_h.tp_snaplen);
				total_bytes += ppd.v1->tp_h.tp_snaplen;
				break;

			case TPACKET_V2:
				test_payload((uint8_t *) ppd.raw + ppd.v2->tp_h.tp_mac,
					     ppd.v2->tp_h.tp_snaplen);
				total_bytes += ppd.v2->tp_h.tp_snaplen;
				break;
			}

			status_bar_update();
			total_packets++;

			__v1_v2_rx_user_ready(ppd.raw, ring->version);

			frame_num = (frame_num + 1) % ring->rd_num;
		}

		poll(&pfd, 1, 1);
	}

	pair_udp_close(udp_sock);

	if (total_packets != 2 * NUM_PACKETS) {
		fprintf(stderr, "walk_v%d_rx: received %u out of %u pkts\n",
			ring->version, total_packets, NUM_PACKETS);
		exit(1);
	}

	fprintf(stderr, " %u pkts (%u bytes)", NUM_PACKETS, total_bytes >> 1);
}

static inline int __v1_tx_kernel_ready(struct tpacket_hdr *hdr)
{
	return !(hdr->tp_status & (TP_STATUS_SEND_REQUEST | TP_STATUS_SENDING));
}

static inline void __v1_tx_user_ready(struct tpacket_hdr *hdr)
{
	hdr->tp_status = TP_STATUS_SEND_REQUEST;
	__sync_synchronize();
}

static inline int __v2_tx_kernel_ready(struct tpacket2_hdr *hdr)
{
	return !(hdr->tp_status & (TP_STATUS_SEND_REQUEST | TP_STATUS_SENDING));
}

static inline void __v2_tx_user_ready(struct tpacket2_hdr *hdr)
{
	hdr->tp_status = TP_STATUS_SEND_REQUEST;
	__sync_synchronize();
}

static inline int __v1_v2_tx_kernel_ready(void *base, int version)
{
	switch (version) {
	case TPACKET_V1:
		return __v1_tx_kernel_ready(base);
	case TPACKET_V2:
		return __v2_tx_kernel_ready(base);
	default:
		bug_on(1);
		return 0;
	}
}

static inline void __v1_v2_tx_user_ready(void *base, int version)
{
	switch (version) {
	case TPACKET_V1:
		__v1_tx_user_ready(base);
		break;
	case TPACKET_V2:
		__v2_tx_user_ready(base);
		break;
	}
}

static void __v1_v2_set_packet_loss_discard(int sock)
{
	int ret, discard = 1;

	ret = setsockopt(sock, SOL_PACKET, PACKET_LOSS, (void *) &discard,
			 sizeof(discard));
	if (ret == -1) {
		perror("setsockopt");
		exit(1);
	}
}

static void walk_v1_v2_tx(int sock, struct ring *ring)
{
	struct pollfd pfd;
	int rcv_sock, ret;
	size_t packet_len;
	union frame_map ppd;
	char packet[1024];
	unsigned int frame_num = 0, got = 0;
	struct sockaddr_ll ll = {
		.sll_family = PF_PACKET,
		.sll_halen = ETH_ALEN,
	};

	bug_on(ring->type != PACKET_TX_RING);
	bug_on(ring->rd_num < NUM_PACKETS);

	rcv_sock = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
	if (rcv_sock == -1) {
		perror("socket");
		exit(1);
	}

	pair_udp_setfilter(rcv_sock);

	ll.sll_ifindex = if_nametoindex("lo");
	ret = bind(rcv_sock, (struct sockaddr *) &ll, sizeof(ll));
	if (ret == -1) {
		perror("bind");
		exit(1);
	}

	memset(&pfd, 0, sizeof(pfd));
	pfd.fd = sock;
	pfd.events = POLLOUT | POLLERR;
	pfd.revents = 0;

	total_packets = NUM_PACKETS;
	create_payload(packet, &packet_len);

	while (total_packets > 0) {
		while (__v1_v2_tx_kernel_ready(ring->rd[frame_num].iov_base,
					       ring->version) &&
		       total_packets > 0) {
			ppd.raw = ring->rd[frame_num].iov_base;

			switch (ring->version) {
			case TPACKET_V1:
				ppd.v1->tp_h.tp_snaplen = packet_len;
				ppd.v1->tp_h.tp_len = packet_len;

				memcpy((uint8_t *) ppd.raw + TPACKET_HDRLEN -
				       sizeof(struct sockaddr_ll), packet,
				       packet_len);
				total_bytes += ppd.v1->tp_h.tp_snaplen;
				break;

			case TPACKET_V2:
				ppd.v2->tp_h.tp_snaplen = packet_len;
				ppd.v2->tp_h.tp_len = packet_len;

				memcpy((uint8_t *) ppd.raw + TPACKET2_HDRLEN -
				       sizeof(struct sockaddr_ll), packet,
				       packet_len);
				total_bytes += ppd.v2->tp_h.tp_snaplen;
				break;
			}

			status_bar_update();
			total_packets--;

			__v1_v2_tx_user_ready(ppd.raw, ring->version);

			frame_num = (frame_num + 1) % ring->rd_num;
		}

		poll(&pfd, 1, 1);
	}

	bug_on(total_packets != 0);

	ret = sendto(sock, NULL, 0, 0, NULL, 0);
	if (ret == -1) {
		perror("sendto");
		exit(1);
	}

	while ((ret = recvfrom(rcv_sock, packet, sizeof(packet),
			       0, NULL, NULL)) > 0 &&
	       total_packets < NUM_PACKETS) {
		got += ret;
		test_payload(packet, ret);

		status_bar_update();
		total_packets++;
	}

	close(rcv_sock);

	if (total_packets != NUM_PACKETS) {
		fprintf(stderr, "walk_v%d_rx: received %u out of %u pkts\n",
			ring->version, total_packets, NUM_PACKETS);
		exit(1);
	}

	fprintf(stderr, " %u pkts (%u bytes)", NUM_PACKETS, got);
}

static void walk_v1_v2(int sock, struct ring *ring)
{
	if (ring->type == PACKET_RX_RING)
		walk_v1_v2_rx(sock, ring);
	else
		walk_v1_v2_tx(sock, ring);
}

static uint64_t __v3_prev_block_seq_num = 0;

void __v3_test_block_seq_num(struct block_desc *pbd)
{
	if (__v3_prev_block_seq_num + 1 != BLOCK_SNUM(pbd)) {
		fprintf(stderr, "\nprev_block_seq_num:%"PRIu64", expected "
			"seq:%"PRIu64" != actual seq:%"PRIu64"\n",
			__v3_prev_block_seq_num, __v3_prev_block_seq_num + 1,
			(uint64_t) BLOCK_SNUM(pbd));
		exit(1);
	}

	__v3_prev_block_seq_num = BLOCK_SNUM(pbd);
}

static void __v3_test_block_len(struct block_desc *pbd, uint32_t bytes, int block_num)
{
	if (BLOCK_NUM_PKTS(pbd)) {
		if (bytes != BLOCK_LEN(pbd)) {
			fprintf(stderr, "\nblock:%u with %upackets, expected "
				"len:%u != actual len:%u\n", block_num,
				BLOCK_NUM_PKTS(pbd), bytes, BLOCK_LEN(pbd));
			exit(1);
		}
	} else {
		if (BLOCK_LEN(pbd) != BLOCK_PLUS_PRIV(13)) {
			fprintf(stderr, "\nblock:%u, expected len:%lu != "
				"actual len:%u\n", block_num, BLOCK_HDR_LEN,
				BLOCK_LEN(pbd));
			exit(1);
		}
	}
}

static void __v3_test_block_header(struct block_desc *pbd, const int block_num)
{
	uint32_t block_status = BLOCK_STATUS(pbd);

	if ((block_status & TP_STATUS_USER) == 0) {
		fprintf(stderr, "\nblock %u: not in TP_STATUS_USER\n", block_num);
		exit(1);
	}

	__v3_test_block_seq_num(pbd);
}

static void __v3_walk_block(struct block_desc *pbd, const int block_num)
{
	int num_pkts = BLOCK_NUM_PKTS(pbd), i;
	unsigned long bytes = 0;
	unsigned long bytes_with_padding = BLOCK_PLUS_PRIV(13);
	struct tpacket3_hdr *ppd;

	__v3_test_block_header(pbd, block_num);

	ppd = (struct tpacket3_hdr *) ((uint8_t *) pbd + BLOCK_O2FP(pbd));
	for (i = 0; i < num_pkts; ++i) {
		bytes += ppd->tp_snaplen;

		if (ppd->tp_next_offset)
			bytes_with_padding += ppd->tp_next_offset;
		else
			bytes_with_padding += ALIGN_8(ppd->tp_snaplen + ppd->tp_mac);

		test_payload((uint8_t *) ppd + ppd->tp_mac, ppd->tp_snaplen);

		status_bar_update();
		total_packets++;

		ppd = (struct tpacket3_hdr *) ((uint8_t *) ppd + ppd->tp_next_offset);
		__sync_synchronize();
	}

	__v3_test_block_len(pbd, bytes_with_padding, block_num);
	total_bytes += bytes;
}

void __v3_flush_block(struct block_desc *pbd)
{
	BLOCK_STATUS(pbd) = TP_STATUS_KERNEL;
	__sync_synchronize();
}

static void walk_v3_rx(int sock, struct ring *ring)
{
	unsigned int block_num = 0;
	struct pollfd pfd;
	struct block_desc *pbd;
	int udp_sock[2];

	bug_on(ring->type != PACKET_RX_RING);

	pair_udp_open(udp_sock, PORT_BASE);
	pair_udp_setfilter(sock);

	memset(&pfd, 0, sizeof(pfd));
	pfd.fd = sock;
	pfd.events = POLLIN | POLLERR;
	pfd.revents = 0;

	pair_udp_send(udp_sock, NUM_PACKETS);

	while (total_packets < NUM_PACKETS * 2) {
		pbd = (struct block_desc *) ring->rd[block_num].iov_base;

		while ((BLOCK_STATUS(pbd) & TP_STATUS_USER) == 0)
			poll(&pfd, 1, 1);

		__v3_walk_block(pbd, block_num);
		__v3_flush_block(pbd);

		block_num = (block_num + 1) % ring->rd_num;
	}

	pair_udp_close(udp_sock);

	if (total_packets != 2 * NUM_PACKETS) {
		fprintf(stderr, "walk_v3_rx: received %u out of %u pkts\n",
			total_packets, NUM_PACKETS);
		exit(1);
	}

	fprintf(stderr, " %u pkts (%u bytes)", NUM_PACKETS, total_bytes >> 1);
}

static void walk_v3(int sock, struct ring *ring)
{
	if (ring->type == PACKET_RX_RING)
		walk_v3_rx(sock, ring);
	else
		bug_on(1);
}

static void __v1_v2_fill(struct ring *ring, unsigned int blocks)
{
	ring->req.tp_block_size = getpagesize() << 2;
	ring->req.tp_frame_size = TPACKET_ALIGNMENT << 7;
	ring->req.tp_block_nr = blocks;

	ring->req.tp_frame_nr = ring->req.tp_block_size /
				ring->req.tp_frame_size *
				ring->req.tp_block_nr;

	ring->mm_len = ring->req.tp_block_size * ring->req.tp_block_nr;
	ring->walk = walk_v1_v2;
	ring->rd_num = ring->req.tp_frame_nr;
	ring->flen = ring->req.tp_frame_size;
}

static void __v3_fill(struct ring *ring, unsigned int blocks)
{
	ring->req3.tp_retire_blk_tov = 64;
	ring->req3.tp_sizeof_priv = 13;
	ring->req3.tp_feature_req_word |= TP_FT_REQ_FILL_RXHASH;

	ring->req3.tp_block_size = getpagesize() << 2;
	ring->req3.tp_frame_size = TPACKET_ALIGNMENT << 7;
	ring->req3.tp_block_nr = blocks;

	ring->req3.tp_frame_nr = ring->req3.tp_block_size /
				 ring->req3.tp_frame_size *
				 ring->req3.tp_block_nr;

	ring->mm_len = ring->req3.tp_block_size * ring->req3.tp_block_nr;
	ring->walk = walk_v3;
	ring->rd_num = ring->req3.tp_block_nr;
	ring->flen = ring->req3.tp_block_size;
}

static void setup_ring(int sock, struct ring *ring, int version, int type)
{
	int ret = 0;
	unsigned int blocks = 256;

	ring->type = type;
	ring->version = version;

	switch (version) {
	case TPACKET_V1:
	case TPACKET_V2:
		if (type == PACKET_TX_RING)
			__v1_v2_set_packet_loss_discard(sock);
		__v1_v2_fill(ring, blocks);
		ret = setsockopt(sock, SOL_PACKET, type, &ring->req,
				 sizeof(ring->req));
		break;

	case TPACKET_V3:
		__v3_fill(ring, blocks);
		ret = setsockopt(sock, SOL_PACKET, type, &ring->req3,
				 sizeof(ring->req3));
		break;
	}

	if (ret == -1) {
		perror("setsockopt");
		exit(1);
	}

	ring->rd_len = ring->rd_num * sizeof(*ring->rd);
	ring->rd = malloc(ring->rd_len);
	if (ring->rd == NULL) {
		perror("malloc");
		exit(1);
	}

	total_packets = 0;
	total_bytes = 0;
}

static void mmap_ring(int sock, struct ring *ring)
{
	int i;

	ring->mm_space = mmap(0, ring->mm_len, PROT_READ | PROT_WRITE,
			      MAP_SHARED | MAP_LOCKED | MAP_POPULATE, sock, 0);
	if (ring->mm_space == MAP_FAILED) {
		perror("mmap");
		exit(1);
	}

	memset(ring->rd, 0, ring->rd_len);
	for (i = 0; i < ring->rd_num; ++i) {
		ring->rd[i].iov_base = ring->mm_space + (i * ring->flen);
		ring->rd[i].iov_len = ring->flen;
	}
}

static void bind_ring(int sock, struct ring *ring)
{
	int ret;

	ring->ll.sll_family = PF_PACKET;
	ring->ll.sll_protocol = htons(ETH_P_ALL);
	ring->ll.sll_ifindex = if_nametoindex("lo");
	ring->ll.sll_hatype = 0;
	ring->ll.sll_pkttype = 0;
	ring->ll.sll_halen = 0;

	ret = bind(sock, (struct sockaddr *) &ring->ll, sizeof(ring->ll));
	if (ret == -1) {
		perror("bind");
		exit(1);
	}
}

static void walk_ring(int sock, struct ring *ring)
{
	ring->walk(sock, ring);
}

static void unmap_ring(int sock, struct ring *ring)
{
	munmap(ring->mm_space, ring->mm_len);
	free(ring->rd);
}

static int test_kernel_bit_width(void)
{
	char in[512], *ptr;
	int num = 0, fd;
	ssize_t ret;

	fd = open("/proc/kallsyms", O_RDONLY);
	if (fd == -1) {
		perror("open");
		exit(1);
	}

	ret = read(fd, in, sizeof(in));
	if (ret <= 0) {
		perror("read");
		exit(1);
	}

	close(fd);

	ptr = in;
	while(!isspace(*ptr)) {
		num++;
		ptr++;
	}

	return num * 4;
}

static int test_user_bit_width(void)
{
	return __WORDSIZE;
}

static const char *tpacket_str[] = {
	[TPACKET_V1] = "TPACKET_V1",
	[TPACKET_V2] = "TPACKET_V2",
	[TPACKET_V3] = "TPACKET_V3",
};

static const char *type_str[] = {
	[PACKET_RX_RING] = "PACKET_RX_RING",
	[PACKET_TX_RING] = "PACKET_TX_RING",
};

static int test_tpacket(int version, int type)
{
	int sock;
	struct ring ring;

	fprintf(stderr, "test: %s with %s ", tpacket_str[version],
		type_str[type]);
	fflush(stderr);

	if (version == TPACKET_V1 &&
	    test_kernel_bit_width() != test_user_bit_width()) {
		fprintf(stderr, "test: skip %s %s since user and kernel "
			"space have different bit width\n",
			tpacket_str[version], type_str[type]);
		return 0;
	}

	sock = pfsocket(version);
	memset(&ring, 0, sizeof(ring));
	setup_ring(sock, &ring, version, type);
	mmap_ring(sock, &ring);
	bind_ring(sock, &ring);
	walk_ring(sock, &ring);
	unmap_ring(sock, &ring);
	close(sock);

	fprintf(stderr, "\n");
	return 0;
}

int main(void)
{
	int ret = 0;

	ret |= test_tpacket(TPACKET_V1, PACKET_RX_RING);
	ret |= test_tpacket(TPACKET_V1, PACKET_TX_RING);

	ret |= test_tpacket(TPACKET_V2, PACKET_RX_RING);
	ret |= test_tpacket(TPACKET_V2, PACKET_TX_RING);

	ret |= test_tpacket(TPACKET_V3, PACKET_RX_RING);

	if (ret)
		return 1;

	printf("OK. All tests passed\n");
	return 0;
}