test: add msg_zerocopy test (07b65c5b) · Commits · 戴 / test

tools/testing/selftests/net/.gitignore

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Original line number	Diff line number	Diff line
		msg_zerocopy
		socket
		psock_fanout
		psock_tpacket

tools/testing/selftests/net/Makefile

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Original line number	Diff line number	Diff line
		@@ -7,7 +7,7 @@ TEST_PROGS := run_netsocktests run_afpackettests test_bpf.sh netdevice.sh
		TEST_GEN_FILES = socket
		TEST_GEN_FILES += psock_fanout psock_tpacket
		TEST_GEN_FILES += reuseport_bpf reuseport_bpf_cpu reuseport_bpf_numa
		TEST_GEN_FILES += reuseport_dualstack
		TEST_GEN_FILES += reuseport_dualstack msg_zerocopy

		include ../lib.mk

tools/testing/selftests/net/msg_zerocopy.c

0 → 100644

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Original line number	Diff line number	Diff line
		/* Evaluate MSG_ZEROCOPY
		*
		* Send traffic between two processes over one of the supported
		* protocols and modes:
		*
		* PF_INET/PF_INET6
		* - SOCK_STREAM
		* - SOCK_DGRAM
		* - SOCK_DGRAM with UDP_CORK
		* - SOCK_RAW
		* - SOCK_RAW with IP_HDRINCL
		*
		* PF_PACKET
		* - SOCK_DGRAM
		* - SOCK_RAW
		*
		* Start this program on two connected hosts, one in send mode and
		* the other with option '-r' to put it in receiver mode.
		*
		* If zerocopy mode ('-z') is enabled, the sender will verify that
		* the kernel queues completions on the error queue for all zerocopy
		* transfers.
		*/

		#define _GNU_SOURCE

		#include <arpa/inet.h>
		#include <error.h>
		#include <errno.h>
		#include <limits.h>
		#include <linux/errqueue.h>
		#include <linux/if_packet.h>
		#include <linux/ipv6.h>
		#include <linux/socket.h>
		#include <linux/sockios.h>
		#include <net/ethernet.h>
		#include <net/if.h>
		#include <netinet/ip.h>
		#include <netinet/ip6.h>
		#include <netinet/tcp.h>
		#include <netinet/udp.h>
		#include <poll.h>
		#include <sched.h>
		#include <stdbool.h>
		#include <stdio.h>
		#include <stdint.h>
		#include <stdlib.h>
		#include <string.h>
		#include <sys/ioctl.h>
		#include <sys/socket.h>
		#include <sys/stat.h>
		#include <sys/time.h>
		#include <sys/types.h>
		#include <sys/wait.h>
		#include <unistd.h>

		#ifndef SO_EE_ORIGIN_ZEROCOPY
		#define SO_EE_ORIGIN_ZEROCOPY SO_EE_ORIGIN_UPAGE
		#endif

		#ifndef SO_ZEROCOPY
		#define SO_ZEROCOPY 59
		#endif

		#ifndef SO_EE_CODE_ZEROCOPY_COPIED
		#define SO_EE_CODE_ZEROCOPY_COPIED 1
		#endif

		#ifndef MSG_ZEROCOPY
		#define MSG_ZEROCOPY 0x4000000
		#endif

		static int cfg_cork;
		static bool cfg_cork_mixed;
		static int cfg_cpu = -1; /* default: pin to last cpu */
		static int cfg_family = PF_UNSPEC;
		static int cfg_ifindex = 1;
		static int cfg_payload_len;
		static int cfg_port = 8000;
		static bool cfg_rx;
		static int cfg_runtime_ms = 4200;
		static int cfg_verbose;
		static int cfg_waittime_ms = 500;
		static bool cfg_zerocopy;

		static socklen_t cfg_alen;
		static struct sockaddr_storage cfg_dst_addr;
		static struct sockaddr_storage cfg_src_addr;

		static char payload[IP_MAXPACKET];
		static long packets, bytes, completions, expected_completions;
		static int zerocopied = -1;
		static uint32_t next_completion;

		static unsigned long gettimeofday_ms(void)
		{
		struct timeval tv;

		gettimeofday(&tv, NULL);
		return (tv.tv_sec * 1000) + (tv.tv_usec / 1000);
		}

		static uint16_t get_ip_csum(const uint16_t *start, int num_words)
		{
		unsigned long sum = 0;
		int i;

		for (i = 0; i < num_words; i++)
		sum += start[i];

		while (sum >> 16)
		sum = (sum & 0xFFFF) + (sum >> 16);

		return ~sum;
		}

		static int do_setcpu(int cpu)
		{
		cpu_set_t mask;

		CPU_ZERO(&mask);
		CPU_SET(cpu, &mask);
		if (sched_setaffinity(0, sizeof(mask), &mask))
		error(1, 0, "setaffinity %d", cpu);

		if (cfg_verbose)
		fprintf(stderr, "cpu: %u\n", cpu);

		return 0;
		}

		static void do_setsockopt(int fd, int level, int optname, int val)
		{
		if (setsockopt(fd, level, optname, &val, sizeof(val)))
		error(1, errno, "setsockopt %d.%d: %d", level, optname, val);
		}

		static int do_poll(int fd, int events)
		{
		struct pollfd pfd;
		int ret;

		pfd.events = events;
		pfd.revents = 0;
		pfd.fd = fd;

		ret = poll(&pfd, 1, cfg_waittime_ms);
		if (ret == -1)
		error(1, errno, "poll");

		return ret && (pfd.revents & events);
		}

		static int do_accept(int fd)
		{
		int fda = fd;

		fd = accept(fda, NULL, NULL);
		if (fd == -1)
		error(1, errno, "accept");
		if (close(fda))
		error(1, errno, "close listen sock");

		return fd;
		}

		static bool do_sendmsg(int fd, struct msghdr *msg, bool do_zerocopy)
		{
		int ret, len, i, flags;

		len = 0;
		for (i = 0; i < msg->msg_iovlen; i++)
		len += msg->msg_iov[i].iov_len;

		flags = MSG_DONTWAIT;
		if (do_zerocopy)
		flags \|= MSG_ZEROCOPY;

		ret = sendmsg(fd, msg, flags);
		if (ret == -1 && errno == EAGAIN)
		return false;
		if (ret == -1)
		error(1, errno, "send");
		if (cfg_verbose && ret != len)
		fprintf(stderr, "send: ret=%u != %u\n", ret, len);

		if (len) {
		packets++;
		bytes += ret;
		if (do_zerocopy && ret)
		expected_completions++;
		}

		return true;
		}

		static void do_sendmsg_corked(int fd, struct msghdr *msg)
		{
		bool do_zerocopy = cfg_zerocopy;
		int i, payload_len, extra_len;

		/* split up the packet. for non-multiple, make first buffer longer */
		payload_len = cfg_payload_len / cfg_cork;
		extra_len = cfg_payload_len - (cfg_cork * payload_len);

		do_setsockopt(fd, IPPROTO_UDP, UDP_CORK, 1);

		for (i = 0; i < cfg_cork; i++) {

		/* in mixed-frags mode, alternate zerocopy and copy frags
		* start with non-zerocopy, to ensure attach later works
		*/
		if (cfg_cork_mixed)
		do_zerocopy = (i & 1);

		msg->msg_iov[0].iov_len = payload_len + extra_len;
		extra_len = 0;

		do_sendmsg(fd, msg, do_zerocopy);
		}

		do_setsockopt(fd, IPPROTO_UDP, UDP_CORK, 0);
		}

		static int setup_iph(struct iphdr *iph, uint16_t payload_len)
		{
		struct sockaddr_in daddr = (void ) &cfg_dst_addr;
		struct sockaddr_in saddr = (void ) &cfg_src_addr;

		memset(iph, 0, sizeof(*iph));

		iph->version = 4;
		iph->tos = 0;
		iph->ihl = 5;
		iph->ttl = 2;
		iph->saddr = saddr->sin_addr.s_addr;
		iph->daddr = daddr->sin_addr.s_addr;
		iph->protocol = IPPROTO_EGP;
		iph->tot_len = htons(sizeof(*iph) + payload_len);
		iph->check = get_ip_csum((void *) iph, iph->ihl << 1);

		return sizeof(*iph);
		}

		static int setup_ip6h(struct ipv6hdr *ip6h, uint16_t payload_len)
		{
		struct sockaddr_in6 daddr = (void ) &cfg_dst_addr;
		struct sockaddr_in6 saddr = (void ) &cfg_src_addr;

		memset(ip6h, 0, sizeof(*ip6h));

		ip6h->version = 6;
		ip6h->payload_len = htons(payload_len);
		ip6h->nexthdr = IPPROTO_EGP;
		ip6h->hop_limit = 2;
		ip6h->saddr = saddr->sin6_addr;
		ip6h->daddr = daddr->sin6_addr;

		return sizeof(*ip6h);
		}

		static void setup_sockaddr(int domain, const char str_addr, void sockaddr)
		{
		struct sockaddr_in6 addr6 = (void ) sockaddr;
		struct sockaddr_in addr4 = (void ) sockaddr;

		switch (domain) {
		case PF_INET:
		addr4->sin_family = AF_INET;
		addr4->sin_port = htons(cfg_port);
		if (inet_pton(AF_INET, str_addr, &(addr4->sin_addr)) != 1)
		error(1, 0, "ipv4 parse error: %s", str_addr);
		break;
		case PF_INET6:
		addr6->sin6_family = AF_INET6;
		addr6->sin6_port = htons(cfg_port);
		if (inet_pton(AF_INET6, str_addr, &(addr6->sin6_addr)) != 1)
		error(1, 0, "ipv6 parse error: %s", str_addr);
		break;
		default:
		error(1, 0, "illegal domain");
		}
		}

		static int do_setup_tx(int domain, int type, int protocol)
		{
		int fd;

		fd = socket(domain, type, protocol);
		if (fd == -1)
		error(1, errno, "socket t");

		do_setsockopt(fd, SOL_SOCKET, SO_SNDBUF, 1 << 21);
		if (cfg_zerocopy)
		do_setsockopt(fd, SOL_SOCKET, SO_ZEROCOPY, 1);

		if (domain != PF_PACKET)
		if (connect(fd, (void *) &cfg_dst_addr, cfg_alen))
		error(1, errno, "connect");

		return fd;
		}

		static bool do_recv_completion(int fd)
		{
		struct sock_extended_err *serr;
		struct msghdr msg = {};
		struct cmsghdr *cm;
		uint32_t hi, lo, range;
		int ret, zerocopy;
		char control[100];

		msg.msg_control = control;
		msg.msg_controllen = sizeof(control);

		ret = recvmsg(fd, &msg, MSG_ERRQUEUE);
		if (ret == -1 && errno == EAGAIN)
		return false;
		if (ret == -1)
		error(1, errno, "recvmsg notification");
		if (msg.msg_flags & MSG_CTRUNC)
		error(1, errno, "recvmsg notification: truncated");

		cm = CMSG_FIRSTHDR(&msg);
		if (!cm)
		error(1, 0, "cmsg: no cmsg");
		if (!((cm->cmsg_level == SOL_IP && cm->cmsg_type == IP_RECVERR) \|\|
		(cm->cmsg_level == SOL_IPV6 && cm->cmsg_type == IPV6_RECVERR) \|\|
		(cm->cmsg_level == SOL_PACKET && cm->cmsg_type == PACKET_TX_TIMESTAMP)))
		error(1, 0, "serr: wrong type: %d.%d",
		cm->cmsg_level, cm->cmsg_type);

		serr = (void *) CMSG_DATA(cm);
		if (serr->ee_origin != SO_EE_ORIGIN_ZEROCOPY)
		error(1, 0, "serr: wrong origin: %u", serr->ee_origin);
		if (serr->ee_errno != 0)
		error(1, 0, "serr: wrong error code: %u", serr->ee_errno);

		hi = serr->ee_data;
		lo = serr->ee_info;
		range = hi - lo + 1;

		/* Detect notification gaps. These should not happen often, if at all.
		* Gaps can occur due to drops, reordering and retransmissions.
		*/
		if (lo != next_completion)
		fprintf(stderr, "gap: %u..%u does not append to %u\n",
		lo, hi, next_completion);
		next_completion = hi + 1;

		zerocopy = !(serr->ee_code & SO_EE_CODE_ZEROCOPY_COPIED);
		if (zerocopied == -1)
		zerocopied = zerocopy;
		else if (zerocopied != zerocopy) {
		fprintf(stderr, "serr: inconsistent\n");
		zerocopied = zerocopy;
		}

		if (cfg_verbose >= 2)
		fprintf(stderr, "completed: %u (h=%u l=%u)\n",
		range, hi, lo);

		completions += range;
		return true;
		}

		/* Read all outstanding messages on the errqueue */
		static void do_recv_completions(int fd)
		{
		while (do_recv_completion(fd)) {}
		}

		/* Wait for all remaining completions on the errqueue */
		static void do_recv_remaining_completions(int fd)
		{
		int64_t tstop = gettimeofday_ms() + cfg_waittime_ms;

		while (completions < expected_completions &&
		gettimeofday_ms() < tstop) {
		if (do_poll(fd, POLLERR))
		do_recv_completions(fd);
		}

		if (completions < expected_completions)
		error(1, 0, "missing notifications: %lu < %lu\n",
		completions, expected_completions);
		}

		static void do_tx(int domain, int type, int protocol)
		{
		struct iovec iov[3] = { {0} };
		struct sockaddr_ll laddr;
		struct msghdr msg = {0};
		struct ethhdr eth;
		union {
		struct ipv6hdr ip6h;
		struct iphdr iph;
		} nh;
		uint64_t tstop;
		int fd;

		fd = do_setup_tx(domain, type, protocol);

		if (domain == PF_PACKET) {
		uint16_t proto = cfg_family == PF_INET ? ETH_P_IP : ETH_P_IPV6;

		/* sock_raw passes ll header as data */
		if (type == SOCK_RAW) {
		memset(eth.h_dest, 0x06, ETH_ALEN);
		memset(eth.h_source, 0x02, ETH_ALEN);
		eth.h_proto = htons(proto);
		iov[0].iov_base = ð
		iov[0].iov_len = sizeof(eth);
		msg.msg_iovlen++;
		}

		/* both sock_raw and sock_dgram expect name */
		memset(&laddr, 0, sizeof(laddr));
		laddr.sll_family = AF_PACKET;
		laddr.sll_ifindex = cfg_ifindex;
		laddr.sll_protocol = htons(proto);
		laddr.sll_halen = ETH_ALEN;

		memset(laddr.sll_addr, 0x06, ETH_ALEN);

		msg.msg_name = &laddr;
		msg.msg_namelen = sizeof(laddr);
		}

		/* packet and raw sockets with hdrincl must pass network header */
		if (domain == PF_PACKET \|\| protocol == IPPROTO_RAW) {
		if (cfg_family == PF_INET)
		iov[1].iov_len = setup_iph(&nh.iph, cfg_payload_len);
		else
		iov[1].iov_len = setup_ip6h(&nh.ip6h, cfg_payload_len);

		iov[1].iov_base = (void *) &nh;
		msg.msg_iovlen++;
		}

		iov[2].iov_base = payload;
		iov[2].iov_len = cfg_payload_len;
		msg.msg_iovlen++;
		msg.msg_iov = &iov[3 - msg.msg_iovlen];

		tstop = gettimeofday_ms() + cfg_runtime_ms;
		do {
		if (cfg_cork)
		do_sendmsg_corked(fd, &msg);
		else
		do_sendmsg(fd, &msg, cfg_zerocopy);

		while (!do_poll(fd, POLLOUT)) {
		if (cfg_zerocopy)
		do_recv_completions(fd);
		}

		} while (gettimeofday_ms() < tstop);

		if (cfg_zerocopy)
		do_recv_remaining_completions(fd);

		if (close(fd))
		error(1, errno, "close");

		fprintf(stderr, "tx=%lu (%lu MB) txc=%lu zc=%c\n",
		packets, bytes >> 20, completions,
		zerocopied == 1 ? 'y' : 'n');
		}

		static int do_setup_rx(int domain, int type, int protocol)
		{
		int fd;

		/* If tx over PF_PACKET, rx over PF_INET(6)/SOCK_RAW,
		* to recv the only copy of the packet, not a clone
		*/
		if (domain == PF_PACKET)
		error(1, 0, "Use PF_INET/SOCK_RAW to read");

		if (type == SOCK_RAW && protocol == IPPROTO_RAW)
		error(1, 0, "IPPROTO_RAW: not supported on Rx");

		fd = socket(domain, type, protocol);
		if (fd == -1)
		error(1, errno, "socket r");

		do_setsockopt(fd, SOL_SOCKET, SO_RCVBUF, 1 << 21);
		do_setsockopt(fd, SOL_SOCKET, SO_RCVLOWAT, 1 << 16);
		do_setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, 1);

		if (bind(fd, (void *) &cfg_dst_addr, cfg_alen))
		error(1, errno, "bind");

		if (type == SOCK_STREAM) {
		if (listen(fd, 1))
		error(1, errno, "listen");
		fd = do_accept(fd);
		}

		return fd;
		}

		/* Flush all outstanding bytes for the tcp receive queue */
		static void do_flush_tcp(int fd)
		{
		int ret;

		/* MSG_TRUNC flushes up to len bytes */
		ret = recv(fd, NULL, 1 << 21, MSG_TRUNC \| MSG_DONTWAIT);
		if (ret == -1 && errno == EAGAIN)
		return;
		if (ret == -1)
		error(1, errno, "flush");
		if (!ret)
		return;

		packets++;
		bytes += ret;
		}

		/* Flush all outstanding datagrams. Verify first few bytes of each. */
		static void do_flush_datagram(int fd, int type)
		{
		int ret, off = 0;
		char buf[64];

		/* MSG_TRUNC will return full datagram length */
		ret = recv(fd, buf, sizeof(buf), MSG_DONTWAIT \| MSG_TRUNC);
		if (ret == -1 && errno == EAGAIN)
		return;

		/* raw ipv4 return with header, raw ipv6 without */
		if (cfg_family == PF_INET && type == SOCK_RAW) {
		off += sizeof(struct iphdr);
		ret -= sizeof(struct iphdr);
		}

		if (ret == -1)
		error(1, errno, "recv");
		if (ret != cfg_payload_len)
		error(1, 0, "recv: ret=%u != %u", ret, cfg_payload_len);
		if (ret > sizeof(buf) - off)
		ret = sizeof(buf) - off;
		if (memcmp(buf + off, payload, ret))
		error(1, 0, "recv: data mismatch");

		packets++;
		bytes += cfg_payload_len;
		}

		static void do_rx(int domain, int type, int protocol)
		{
		uint64_t tstop;
		int fd;

		fd = do_setup_rx(domain, type, protocol);

		tstop = gettimeofday_ms() + cfg_runtime_ms;
		do {
		if (type == SOCK_STREAM)
		do_flush_tcp(fd);
		else
		do_flush_datagram(fd, type);

		do_poll(fd, POLLIN);

		} while (gettimeofday_ms() < tstop);

		if (close(fd))
		error(1, errno, "close");

		fprintf(stderr, "rx=%lu (%lu MB)\n", packets, bytes >> 20);
		}

		static void do_test(int domain, int type, int protocol)
		{
		int i;

		if (cfg_cork && (domain == PF_PACKET \|\| type != SOCK_DGRAM))
		error(1, 0, "can only cork udp sockets");

		do_setcpu(cfg_cpu);

		for (i = 0; i < IP_MAXPACKET; i++)
		payload[i] = 'a' + (i % 26);

		if (cfg_rx)
		do_rx(domain, type, protocol);
		else
		do_tx(domain, type, protocol);
		}

		static void usage(const char *filepath)
		{
		error(1, 0, "Usage: %s [options] <test>", filepath);
		}

		static void parse_opts(int argc, char **argv)
		{
		const int max_payload_len = sizeof(payload) -
		sizeof(struct ipv6hdr) -
		sizeof(struct tcphdr) -
		40 /* max tcp options */;
		int c;

		cfg_payload_len = max_payload_len;

		while ((c = getopt(argc, argv, "46c:C:D:i:mp:rs:S:t:vz")) != -1) {
		switch (c) {
		case '4':
		if (cfg_family != PF_UNSPEC)
		error(1, 0, "Pass one of -4 or -6");
		cfg_family = PF_INET;
		cfg_alen = sizeof(struct sockaddr_in);
		break;
		case '6':
		if (cfg_family != PF_UNSPEC)
		error(1, 0, "Pass one of -4 or -6");
		cfg_family = PF_INET6;
		cfg_alen = sizeof(struct sockaddr_in6);
		break;
		case 'c':
		cfg_cork = strtol(optarg, NULL, 0);
		break;
		case 'C':
		cfg_cpu = strtol(optarg, NULL, 0);
		break;
		case 'D':
		setup_sockaddr(cfg_family, optarg, &cfg_dst_addr);
		break;
		case 'i':
		cfg_ifindex = if_nametoindex(optarg);
		if (cfg_ifindex == 0)
		error(1, errno, "invalid iface: %s", optarg);
		break;
		case 'm':
		cfg_cork_mixed = true;
		break;
		case 'p':
		cfg_port = htons(strtoul(optarg, NULL, 0));
		break;
		case 'r':
		cfg_rx = true;
		break;
		case 's':
		cfg_payload_len = strtoul(optarg, NULL, 0);
		break;
		case 'S':
		setup_sockaddr(cfg_family, optarg, &cfg_src_addr);
		break;
		case 't':
		cfg_runtime_ms = 200 + strtoul(optarg, NULL, 10) * 1000;
		break;
		case 'v':
		cfg_verbose++;
		break;
		case 'z':
		cfg_zerocopy = true;
		break;
		}
		}

		if (cfg_payload_len > max_payload_len)
		error(1, 0, "-s: payload exceeds max (%d)", max_payload_len);
		if (cfg_cork_mixed && (!cfg_zerocopy \|\| !cfg_cork))
		error(1, 0, "-m: cork_mixed requires corking and zerocopy");

		if (optind != argc - 1)
		usage(argv[0]);
		}

		int main(int argc, char **argv)
		{
		const char *cfg_test;

		parse_opts(argc, argv);

		cfg_test = argv[argc - 1];

		if (!strcmp(cfg_test, "packet"))
		do_test(PF_PACKET, SOCK_RAW, 0);
		else if (!strcmp(cfg_test, "packet_dgram"))
		do_test(PF_PACKET, SOCK_DGRAM, 0);
		else if (!strcmp(cfg_test, "raw"))
		do_test(cfg_family, SOCK_RAW, IPPROTO_EGP);
		else if (!strcmp(cfg_test, "raw_hdrincl"))
		do_test(cfg_family, SOCK_RAW, IPPROTO_RAW);
		else if (!strcmp(cfg_test, "tcp"))
		do_test(cfg_family, SOCK_STREAM, 0);
		else if (!strcmp(cfg_test, "udp"))
		do_test(cfg_family, SOCK_DGRAM, 0);
		else
		error(1, 0, "unknown cfg_test %s", cfg_test);

		return 0;
		}

tools/testing/selftests/net/msg_zerocopy.sh

0 → 100755

+112 −0

Original line number	Diff line number	Diff line
		#!/bin/bash
		#
		# Send data between two processes across namespaces
		# Run twice: once without and once with zerocopy

		set -e

		readonly DEV="veth0"
		readonly DEV_MTU=65535
		readonly BIN="./msg_zerocopy"

		readonly RAND="$(mktemp -u XXXXXX)"
		readonly NSPREFIX="ns-${RAND}"
		readonly NS1="${NSPREFIX}1"
		readonly NS2="${NSPREFIX}2"

		readonly SADDR4='192.168.1.1'
		readonly DADDR4='192.168.1.2'
		readonly SADDR6='fd::1'
		readonly DADDR6='fd::2'

		readonly path_sysctl_mem="net.core.optmem_max"

		# Argument parsing
		if [[ "$#" -lt "2" ]]; then
		echo "Usage: $0 [4\|6] [tcp\|udp\|raw\|raw_hdrincl\|packet\|packet_dgram] <args>"
		exit 1
		fi

		readonly IP="$1"
		shift
		readonly TXMODE="$1"
		shift
		readonly EXTRA_ARGS="$@"

		# Argument parsing: configure addresses
		if [[ "${IP}" == "4" ]]; then
		readonly SADDR="${SADDR4}"
		readonly DADDR="${DADDR4}"
		elif [[ "${IP}" == "6" ]]; then
		readonly SADDR="${SADDR6}"
		readonly DADDR="${DADDR6}"
		else
		echo "Invalid IP version ${IP}"
		exit 1
		fi

		# Argument parsing: select receive mode
		#
		# This differs from send mode for
		# - packet: use raw recv, because packet receives skb clones
		# - raw_hdrinc: use raw recv, because hdrincl is a tx-only option
		case "${TXMODE}" in
		'packet' \| 'packet_dgram' \| 'raw_hdrincl')
		RXMODE='raw'
		;;
		*)
		RXMODE="${TXMODE}"
		;;
		esac

		# Start of state changes: install cleanup handler
		save_sysctl_mem="$(sysctl -n ${path_sysctl_mem})"

		cleanup() {
		ip netns del "${NS2}"
		ip netns del "${NS1}"
		sysctl -w -q "${path_sysctl_mem}=${save_sysctl_mem}"
		}

		trap cleanup EXIT

		# Configure system settings
		sysctl -w -q "${path_sysctl_mem}=1000000"

		# Create virtual ethernet pair between network namespaces
		ip netns add "${NS1}"
		ip netns add "${NS2}"

		ip link add "${DEV}" mtu "${DEV_MTU}" netns "${NS1}" type veth \
		peer name "${DEV}" mtu "${DEV_MTU}" netns "${NS2}"

		# Bring the devices up
		ip -netns "${NS1}" link set "${DEV}" up
		ip -netns "${NS2}" link set "${DEV}" up

		# Set fixed MAC addresses on the devices
		ip -netns "${NS1}" link set dev "${DEV}" address 02:02:02:02:02:02
		ip -netns "${NS2}" link set dev "${DEV}" address 06:06:06:06:06:06

		# Add fixed IP addresses to the devices
		ip -netns "${NS1}" addr add 192.168.1.1/24 dev "${DEV}"
		ip -netns "${NS2}" addr add 192.168.1.2/24 dev "${DEV}"
		ip -netns "${NS1}" addr add fd::1/64 dev "${DEV}" nodad
		ip -netns "${NS2}" addr add fd::2/64 dev "${DEV}" nodad

		# Optionally disable sg or csum offload to test edge cases
		# ip netns exec "${NS1}" ethtool -K "${DEV}" sg off

		do_test() {
		local readonly ARGS="$1"

		echo "ipv${IP} ${TXMODE} ${ARGS}"
		ip netns exec "${NS2}" "${BIN}" "-${IP}" -i "${DEV}" -t 2 -C 2 -S "${SADDR}" -D "${DADDR}" ${ARGS} -r "${RXMODE}" &
		sleep 0.2
		ip netns exec "${NS1}" "${BIN}" "-${IP}" -i "${DEV}" -t 1 -C 3 -S "${SADDR}" -D "${DADDR}" ${ARGS} "${TXMODE}"
		wait
		}

		do_test "${EXTRA_ARGS}"
		do_test "-z ${EXTRA_ARGS}"
		echo ok

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