1 files changed, 916 insertions, 0 deletions

diff --git a/tools/testing/selftests/net/txtimestamp.c b/tools/testing/selftests/net/txtimestamp.c
new file mode 100644
index 000000000000..011b0da6b033
--- /dev/null
+++ b/tools/testing/selftests/net/txtimestamp.c
@@ -0,0 +1,916 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2014 Google Inc.
+ * Author: willemb@google.com (Willem de Bruijn)
+ *
+ * Test software tx timestamping, including
+ *
+ * - SCHED, SND and ACK timestamps
+ * - RAW, UDP and TCP
+ * - IPv4 and IPv6
+ * - various packet sizes (to test GSO and TSO)
+ *
+ * Consult the command line arguments for help on running
+ * the various testcases.
+ *
+ * This test requires a dummy TCP server.
+ * A simple `nc6 [-u] -l -p $DESTPORT` will do
+ */
+
+#define _GNU_SOURCE
+
+#include <arpa/inet.h>
+#include <asm/types.h>
+#include <error.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <linux/errqueue.h>
+#include <linux/if_ether.h>
+#include <linux/ipv6.h>
+#include <linux/net_tstamp.h>
+#include <netdb.h>
+#include <net/if.h>
+#include <netinet/in.h>
+#include <netinet/ip.h>
+#include <netinet/udp.h>
+#include <netinet/tcp.h>
+#include <netpacket/packet.h>
+#include <poll.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/epoll.h>
+#include <sys/ioctl.h>
+#include <sys/select.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+
+#define NSEC_PER_USEC	1000L
+#define USEC_PER_SEC	1000000L
+#define NSEC_PER_SEC	1000000000LL
+
+/* command line parameters */
+static int cfg_proto = SOCK_STREAM;
+static int cfg_ipproto = IPPROTO_TCP;
+static int cfg_num_pkts = 4;
+static int do_ipv4 = 1;
+static int do_ipv6 = 1;
+static int cfg_payload_len = 10;
+static int cfg_poll_timeout = 100;
+static int cfg_delay_snd;
+static int cfg_delay_ack;
+static bool cfg_show_payload;
+static bool cfg_do_pktinfo;
+static bool cfg_busy_poll;
+static int cfg_sleep_usec = 50 * 1000;
+static bool cfg_loop_nodata;
+static bool cfg_use_cmsg;
+static bool cfg_use_pf_packet;
+static bool cfg_use_epoll;
+static bool cfg_epollet;
+static bool cfg_do_listen;
+static uint16_t dest_port = 9000;
+static bool cfg_print_nsec;
+
+static struct sockaddr_in daddr;
+static struct sockaddr_in6 daddr6;
+static struct timespec ts_usr;
+
+static int saved_tskey = -1;
+static int saved_tskey_type = -1;
+
+struct timing_event {
+	int64_t min;
+	int64_t max;
+	int64_t total;
+	int count;
+};
+
+static struct timing_event usr_enq;
+static struct timing_event usr_snd;
+static struct timing_event usr_ack;
+
+static bool test_failed;
+
+static int64_t timespec_to_ns64(struct timespec *ts)
+{
+	return ts->tv_sec * NSEC_PER_SEC + ts->tv_nsec;
+}
+
+static int64_t timespec_to_us64(struct timespec *ts)
+{
+	return ts->tv_sec * USEC_PER_SEC + ts->tv_nsec / NSEC_PER_USEC;
+}
+
+static void init_timing_event(struct timing_event *te)
+{
+	te->min = INT64_MAX;
+	te->max = 0;
+	te->total = 0;
+	te->count = 0;
+}
+
+static void add_timing_event(struct timing_event *te,
+		struct timespec *t_start, struct timespec *t_end)
+{
+	int64_t ts_delta = timespec_to_ns64(t_end) - timespec_to_ns64(t_start);
+
+	te->count++;
+	if (ts_delta < te->min)
+		te->min = ts_delta;
+	if (ts_delta > te->max)
+		te->max = ts_delta;
+	te->total += ts_delta;
+}
+
+static void validate_key(int tskey, int tstype)
+{
+	int stepsize;
+
+	/* compare key for each subsequent request
+	 * must only test for one type, the first one requested
+	 */
+	if (saved_tskey == -1)
+		saved_tskey_type = tstype;
+	else if (saved_tskey_type != tstype)
+		return;
+
+	stepsize = cfg_proto == SOCK_STREAM ? cfg_payload_len : 1;
+	if (tskey != saved_tskey + stepsize) {
+		fprintf(stderr, "ERROR: key %d, expected %d\n",
+				tskey, saved_tskey + stepsize);
+		test_failed = true;
+	}
+
+	saved_tskey = tskey;
+}
+
+static void validate_timestamp(struct timespec *cur, int min_delay)
+{
+	int max_delay = min_delay + 500 /* processing time upper bound */;
+	int64_t cur64, start64;
+
+	cur64 = timespec_to_us64(cur);
+	start64 = timespec_to_us64(&ts_usr);
+
+	if (cur64 < start64 + min_delay || cur64 > start64 + max_delay) {
+		fprintf(stderr, "ERROR: %lu us expected between %d and %d\n",
+				cur64 - start64, min_delay, max_delay);
+		test_failed = true;
+	}
+}
+
+static void __print_ts_delta_formatted(int64_t ts_delta)
+{
+	if (cfg_print_nsec)
+		fprintf(stderr, "%lu ns", ts_delta);
+	else
+		fprintf(stderr, "%lu us", ts_delta / NSEC_PER_USEC);
+}
+
+static void __print_timestamp(const char *name, struct timespec *cur,
+			      uint32_t key, int payload_len)
+{
+	int64_t ts_delta;
+
+	if (!(cur->tv_sec | cur->tv_nsec))
+		return;
+
+	if (cfg_print_nsec)
+		fprintf(stderr, "  %s: %lu s %lu ns (seq=%u, len=%u)",
+				name, cur->tv_sec, cur->tv_nsec,
+				key, payload_len);
+	else
+		fprintf(stderr, "  %s: %lu s %lu us (seq=%u, len=%u)",
+				name, cur->tv_sec, cur->tv_nsec / NSEC_PER_USEC,
+				key, payload_len);
+
+	if (cur != &ts_usr) {
+		ts_delta = timespec_to_ns64(cur) - timespec_to_ns64(&ts_usr);
+		fprintf(stderr, "  (USR +");
+		__print_ts_delta_formatted(ts_delta);
+		fprintf(stderr, ")");
+	}
+
+	fprintf(stderr, "\n");
+}
+
+static void print_timestamp_usr(void)
+{
+	if (clock_gettime(CLOCK_REALTIME, &ts_usr))
+		error(1, errno, "clock_gettime");
+
+	__print_timestamp("  USR", &ts_usr, 0, 0);
+}
+
+static void print_timestamp(struct scm_timestamping *tss, int tstype,
+			    int tskey, int payload_len)
+{
+	const char *tsname;
+
+	validate_key(tskey, tstype);
+
+	switch (tstype) {
+	case SCM_TSTAMP_SCHED:
+		tsname = "  ENQ";
+		validate_timestamp(&tss->ts[0], 0);
+		add_timing_event(&usr_enq, &ts_usr, &tss->ts[0]);
+		break;
+	case SCM_TSTAMP_SND:
+		tsname = "  SND";
+		validate_timestamp(&tss->ts[0], cfg_delay_snd);
+		add_timing_event(&usr_snd, &ts_usr, &tss->ts[0]);
+		break;
+	case SCM_TSTAMP_ACK:
+		tsname = "  ACK";
+		validate_timestamp(&tss->ts[0], cfg_delay_ack);
+		add_timing_event(&usr_ack, &ts_usr, &tss->ts[0]);
+		break;
+	default:
+		error(1, 0, "unknown timestamp type: %u",
+		tstype);
+	}
+	__print_timestamp(tsname, &tss->ts[0], tskey, payload_len);
+}
+
+static void print_timing_event(char *name, struct timing_event *te)
+{
+	if (!te->count)
+		return;
+
+	fprintf(stderr, "    %s: count=%d", name, te->count);
+	fprintf(stderr, ", avg=");
+	__print_ts_delta_formatted((int64_t)(te->total / te->count));
+	fprintf(stderr, ", min=");
+	__print_ts_delta_formatted(te->min);
+	fprintf(stderr, ", max=");
+	__print_ts_delta_formatted(te->max);
+	fprintf(stderr, "\n");
+}
+
+/* TODO: convert to check_and_print payload once API is stable */
+static void print_payload(char *data, int len)
+{
+	int i;
+
+	if (!len)
+		return;
+
+	if (len > 70)
+		len = 70;
+
+	fprintf(stderr, "payload: ");
+	for (i = 0; i < len; i++)
+		fprintf(stderr, "%02hhx ", data[i]);
+	fprintf(stderr, "\n");
+}
+
+static void print_pktinfo(int family, int ifindex, void *saddr, void *daddr)
+{
+	char sa[INET6_ADDRSTRLEN], da[INET6_ADDRSTRLEN];
+
+	fprintf(stderr, "         pktinfo: ifindex=%u src=%s dst=%s\n",
+		ifindex,
+		saddr ? inet_ntop(family, saddr, sa, sizeof(sa)) : "unknown",
+		daddr ? inet_ntop(family, daddr, da, sizeof(da)) : "unknown");
+}
+
+static void __epoll(int epfd)
+{
+	struct epoll_event events;
+	int ret;
+
+	memset(&events, 0, sizeof(events));
+	ret = epoll_wait(epfd, &events, 1, cfg_poll_timeout);
+	if (ret != 1)
+		error(1, errno, "epoll_wait");
+}
+
+static void __poll(int fd)
+{
+	struct pollfd pollfd;
+	int ret;
+
+	memset(&pollfd, 0, sizeof(pollfd));
+	pollfd.fd = fd;
+	ret = poll(&pollfd, 1, cfg_poll_timeout);
+	if (ret != 1)
+		error(1, errno, "poll");
+}
+
+static void __recv_errmsg_cmsg(struct msghdr *msg, int payload_len)
+{
+	struct sock_extended_err *serr = NULL;
+	struct scm_timestamping *tss = NULL;
+	struct cmsghdr *cm;
+	int batch = 0;
+
+	for (cm = CMSG_FIRSTHDR(msg);
+	     cm && cm->cmsg_len;
+	     cm = CMSG_NXTHDR(msg, cm)) {
+		if (cm->cmsg_level == SOL_SOCKET &&
+		    cm->cmsg_type == SCM_TIMESTAMPING) {
+			tss = (void *) CMSG_DATA(cm);
+		} else 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)) {
+			serr = (void *) CMSG_DATA(cm);
+			if (serr->ee_errno != ENOMSG ||
+			    serr->ee_origin != SO_EE_ORIGIN_TIMESTAMPING) {
+				fprintf(stderr, "unknown ip error %d %d\n",
+						serr->ee_errno,
+						serr->ee_origin);
+				serr = NULL;
+			}
+		} else if (cm->cmsg_level == SOL_IP &&
+			   cm->cmsg_type == IP_PKTINFO) {
+			struct in_pktinfo *info = (void *) CMSG_DATA(cm);
+			print_pktinfo(AF_INET, info->ipi_ifindex,
+				      &info->ipi_spec_dst, &info->ipi_addr);
+		} else if (cm->cmsg_level == SOL_IPV6 &&
+			   cm->cmsg_type == IPV6_PKTINFO) {
+			struct in6_pktinfo *info6 = (void *) CMSG_DATA(cm);
+			print_pktinfo(AF_INET6, info6->ipi6_ifindex,
+				      NULL, &info6->ipi6_addr);
+		} else
+			fprintf(stderr, "unknown cmsg %d,%d\n",
+					cm->cmsg_level, cm->cmsg_type);
+
+		if (serr && tss) {
+			print_timestamp(tss, serr->ee_info, serr->ee_data,
+					payload_len);
+			serr = NULL;
+			tss = NULL;
+			batch++;
+		}
+	}
+
+	if (batch > 1)
+		fprintf(stderr, "batched %d timestamps\n", batch);
+}
+
+static int recv_errmsg(int fd)
+{
+	static char ctrl[1024 /* overprovision*/];
+	static struct msghdr msg;
+	struct iovec entry;
+	static char *data;
+	int ret = 0;
+
+	data = malloc(cfg_payload_len);
+	if (!data)
+		error(1, 0, "malloc");
+
+	memset(&msg, 0, sizeof(msg));
+	memset(&entry, 0, sizeof(entry));
+	memset(ctrl, 0, sizeof(ctrl));
+
+	entry.iov_base = data;
+	entry.iov_len = cfg_payload_len;
+	msg.msg_iov = &entry;
+	msg.msg_iovlen = 1;
+	msg.msg_name = NULL;
+	msg.msg_namelen = 0;
+	msg.msg_control = ctrl;
+	msg.msg_controllen = sizeof(ctrl);
+
+	ret = recvmsg(fd, &msg, MSG_ERRQUEUE);
+	if (ret == -1 && errno != EAGAIN)
+		error(1, errno, "recvmsg");
+
+	if (ret >= 0) {
+		__recv_errmsg_cmsg(&msg, ret);
+		if (cfg_show_payload)
+			print_payload(data, cfg_payload_len);
+	}
+
+	free(data);
+	return ret == -1;
+}
+
+static uint16_t get_ip_csum(const uint16_t *start, int num_words,
+			    unsigned long sum)
+{
+	int i;
+
+	for (i = 0; i < num_words; i++)
+		sum += start[i];
+
+	while (sum >> 16)
+		sum = (sum & 0xFFFF) + (sum >> 16);
+
+	return ~sum;
+}
+
+static uint16_t get_udp_csum(const struct udphdr *udph, int alen)
+{
+	unsigned long pseudo_sum, csum_len;
+	const void *csum_start = udph;
+
+	pseudo_sum = htons(IPPROTO_UDP);
+	pseudo_sum += udph->len;
+
+	/* checksum ip(v6) addresses + udp header + payload */
+	csum_start -= alen * 2;
+	csum_len = ntohs(udph->len) + alen * 2;
+
+	return get_ip_csum(csum_start, csum_len >> 1, pseudo_sum);
+}
+
+static int fill_header_ipv4(void *p)
+{
+	struct iphdr *iph = p;
+
+	memset(iph, 0, sizeof(*iph));
+
+	iph->ihl	= 5;
+	iph->version	= 4;
+	iph->ttl	= 2;
+	iph->saddr	= daddr.sin_addr.s_addr;	/* set for udp csum calc */
+	iph->daddr	= daddr.sin_addr.s_addr;
+	iph->protocol	= IPPROTO_UDP;
+
+	/* kernel writes saddr, csum, len */
+
+	return sizeof(*iph);
+}
+
+static int fill_header_ipv6(void *p)
+{
+	struct ipv6hdr *ip6h = p;
+
+	memset(ip6h, 0, sizeof(*ip6h));
+
+	ip6h->version		= 6;
+	ip6h->payload_len	= htons(sizeof(struct udphdr) + cfg_payload_len);
+	ip6h->nexthdr		= IPPROTO_UDP;
+	ip6h->hop_limit		= 64;
+
+	ip6h->saddr             = daddr6.sin6_addr;
+	ip6h->daddr		= daddr6.sin6_addr;
+
+	/* kernel does not write saddr in case of ipv6 */
+
+	return sizeof(*ip6h);
+}
+
+static void fill_header_udp(void *p, bool is_ipv4)
+{
+	struct udphdr *udph = p;
+
+	udph->source = ntohs(dest_port + 1);	/* spoof */
+	udph->dest   = ntohs(dest_port);
+	udph->len    = ntohs(sizeof(*udph) + cfg_payload_len);
+	udph->check  = 0;
+
+	udph->check  = get_udp_csum(udph, is_ipv4 ? sizeof(struct in_addr) :
+						    sizeof(struct in6_addr));
+}
+
+static void do_test(int family, unsigned int report_opt)
+{
+	char control[CMSG_SPACE(sizeof(uint32_t))];
+	struct sockaddr_ll laddr;
+	unsigned int sock_opt;
+	struct cmsghdr *cmsg;
+	struct msghdr msg;
+	struct iovec iov;
+	char *buf;
+	int fd, i, val = 1, total_len, epfd = 0;
+
+	init_timing_event(&usr_enq);
+	init_timing_event(&usr_snd);
+	init_timing_event(&usr_ack);
+
+	total_len = cfg_payload_len;
+	if (cfg_use_pf_packet || cfg_proto == SOCK_RAW) {
+		total_len += sizeof(struct udphdr);
+		if (cfg_use_pf_packet || cfg_ipproto == IPPROTO_RAW)
+			if (family == PF_INET)
+				total_len += sizeof(struct iphdr);
+			else
+				total_len += sizeof(struct ipv6hdr);
+
+		/* special case, only rawv6_sendmsg:
+		 * pass proto in sin6_port if not connected
+		 * also see ANK comment in net/ipv4/raw.c
+		 */
+		daddr6.sin6_port = htons(cfg_ipproto);
+	}
+
+	buf = malloc(total_len);
+	if (!buf)
+		error(1, 0, "malloc");
+
+	fd = socket(cfg_use_pf_packet ? PF_PACKET : family,
+		    cfg_proto, cfg_ipproto);
+	if (fd < 0)
+		error(1, errno, "socket");
+
+	if (cfg_use_epoll) {
+		struct epoll_event ev;
+
+		memset(&ev, 0, sizeof(ev));
+		ev.data.fd = fd;
+		if (cfg_epollet)
+			ev.events |= EPOLLET;
+		epfd = epoll_create(1);
+		if (epfd <= 0)
+			error(1, errno, "epoll_create");
+		if (epoll_ctl(epfd, EPOLL_CTL_ADD, fd, &ev))
+			error(1, errno, "epoll_ctl");
+	}
+
+	/* reset expected key on each new socket */
+	saved_tskey = -1;
+
+	if (cfg_proto == SOCK_STREAM) {
+		if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY,
+			       (char*) &val, sizeof(val)))
+			error(1, 0, "setsockopt no nagle");
+
+		if (family == PF_INET) {
+			if (connect(fd, (void *) &daddr, sizeof(daddr)))
+				error(1, errno, "connect ipv4");
+		} else {
+			if (connect(fd, (void *) &daddr6, sizeof(daddr6)))
+				error(1, errno, "connect ipv6");
+		}
+	}
+
+	if (cfg_do_pktinfo) {
+		if (family == AF_INET6) {
+			if (setsockopt(fd, SOL_IPV6, IPV6_RECVPKTINFO,
+				       &val, sizeof(val)))
+				error(1, errno, "setsockopt pktinfo ipv6");
+		} else {
+			if (setsockopt(fd, SOL_IP, IP_PKTINFO,
+				       &val, sizeof(val)))
+				error(1, errno, "setsockopt pktinfo ipv4");
+		}
+	}
+
+	sock_opt = SOF_TIMESTAMPING_SOFTWARE |
+		   SOF_TIMESTAMPING_OPT_CMSG |
+		   SOF_TIMESTAMPING_OPT_ID;
+
+	if (!cfg_use_cmsg)
+		sock_opt |= report_opt;
+
+	if (cfg_loop_nodata)
+		sock_opt |= SOF_TIMESTAMPING_OPT_TSONLY;
+
+	if (setsockopt(fd, SOL_SOCKET, SO_TIMESTAMPING,
+		       (char *) &sock_opt, sizeof(sock_opt)))
+		error(1, 0, "setsockopt timestamping");
+
+	for (i = 0; i < cfg_num_pkts; i++) {
+		memset(&msg, 0, sizeof(msg));
+		memset(buf, 'a' + i, total_len);
+
+		if (cfg_use_pf_packet || cfg_proto == SOCK_RAW) {
+			int off = 0;
+
+			if (cfg_use_pf_packet || cfg_ipproto == IPPROTO_RAW) {
+				if (family == PF_INET)
+					off = fill_header_ipv4(buf);
+				else
+					off = fill_header_ipv6(buf);
+			}
+
+			fill_header_udp(buf + off, family == PF_INET);
+		}
+
+		print_timestamp_usr();
+
+		iov.iov_base = buf;
+		iov.iov_len = total_len;
+
+		if (cfg_proto != SOCK_STREAM) {
+			if (cfg_use_pf_packet) {
+				memset(&laddr, 0, sizeof(laddr));
+
+				laddr.sll_family	= AF_PACKET;
+				laddr.sll_ifindex	= 1;
+				laddr.sll_protocol	= htons(family == AF_INET ? ETH_P_IP : ETH_P_IPV6);
+				laddr.sll_halen		= ETH_ALEN;
+
+				msg.msg_name = (void *)&laddr;
+				msg.msg_namelen = sizeof(laddr);
+			} else if (family == PF_INET) {
+				msg.msg_name = (void *)&daddr;
+				msg.msg_namelen = sizeof(daddr);
+			} else {
+				msg.msg_name = (void *)&daddr6;
+				msg.msg_namelen = sizeof(daddr6);
+			}
+		}
+
+		msg.msg_iov = &iov;
+		msg.msg_iovlen = 1;
+
+		if (cfg_use_cmsg) {
+			memset(control, 0, sizeof(control));
+
+			msg.msg_control = control;
+			msg.msg_controllen = sizeof(control);
+
+			cmsg = CMSG_FIRSTHDR(&msg);
+			cmsg->cmsg_level = SOL_SOCKET;
+			cmsg->cmsg_type = SO_TIMESTAMPING;
+			cmsg->cmsg_len = CMSG_LEN(sizeof(uint32_t));
+
+			*((uint32_t *) CMSG_DATA(cmsg)) = report_opt;
+		}
+
+		val = sendmsg(fd, &msg, 0);
+		if (val != total_len)
+			error(1, errno, "send");
+
+		/* wait for all errors to be queued, else ACKs arrive OOO */
+		if (cfg_sleep_usec)
+			usleep(cfg_sleep_usec);
+
+		if (!cfg_busy_poll) {
+			if (cfg_use_epoll)
+				__epoll(epfd);
+			else
+				__poll(fd);
+		}
+
+		while (!recv_errmsg(fd)) {}
+	}
+
+	print_timing_event("USR-ENQ", &usr_enq);
+	print_timing_event("USR-SND", &usr_snd);
+	print_timing_event("USR-ACK", &usr_ack);
+
+	if (close(fd))
+		error(1, errno, "close");
+
+	free(buf);
+	usleep(100 * NSEC_PER_USEC);
+}
+
+static void __attribute__((noreturn)) usage(const char *filepath)
+{
+	fprintf(stderr, "\nUsage: %s [options] hostname\n"
+			"\nwhere options are:\n"
+			"  -4:   only IPv4\n"
+			"  -6:   only IPv6\n"
+			"  -h:   show this message\n"
+			"  -b:   busy poll to read from error queue\n"
+			"  -c N: number of packets for each test\n"
+			"  -C:   use cmsg to set tstamp recording options\n"
+			"  -e:   use level-triggered epoll() instead of poll()\n"
+			"  -E:   use event-triggered epoll() instead of poll()\n"
+			"  -F:   poll()/epoll() waits forever for an event\n"
+			"  -I:   request PKTINFO\n"
+			"  -l N: send N bytes at a time\n"
+			"  -L    listen on hostname and port\n"
+			"  -n:   set no-payload option\n"
+			"  -N:   print timestamps and durations in nsec (instead of usec)\n"
+			"  -p N: connect to port N\n"
+			"  -P:   use PF_PACKET\n"
+			"  -r:   use raw\n"
+			"  -R:   use raw (IP_HDRINCL)\n"
+			"  -S N: usec to sleep before reading error queue\n"
+			"  -u:   use udp\n"
+			"  -v:   validate SND delay (usec)\n"
+			"  -V:   validate ACK delay (usec)\n"
+			"  -x:   show payload (up to 70 bytes)\n",
+			filepath);
+	exit(1);
+}
+
+static void parse_opt(int argc, char **argv)
+{
+	int proto_count = 0;
+	int c;
+
+	while ((c = getopt(argc, argv,
+				"46bc:CeEFhIl:LnNp:PrRS:uv:V:x")) != -1) {
+		switch (c) {
+		case '4':
+			do_ipv6 = 0;
+			break;
+		case '6':
+			do_ipv4 = 0;
+			break;
+		case 'b':
+			cfg_busy_poll = true;
+			break;
+		case 'c':
+			cfg_num_pkts = strtoul(optarg, NULL, 10);
+			break;
+		case 'C':
+			cfg_use_cmsg = true;
+			break;
+		case 'e':
+			cfg_use_epoll = true;
+			break;
+		case 'E':
+			cfg_use_epoll = true;
+			cfg_epollet = true;
+		case 'F':
+			cfg_poll_timeout = -1;
+			break;
+		case 'I':
+			cfg_do_pktinfo = true;
+			break;
+		case 'l':
+			cfg_payload_len = strtoul(optarg, NULL, 10);
+			break;
+		case 'L':
+			cfg_do_listen = true;
+			break;
+		case 'n':
+			cfg_loop_nodata = true;
+			break;
+		case 'N':
+			cfg_print_nsec = true;
+			break;
+		case 'p':
+			dest_port = strtoul(optarg, NULL, 10);
+			break;
+		case 'P':
+			proto_count++;
+			cfg_use_pf_packet = true;
+			cfg_proto = SOCK_DGRAM;
+			cfg_ipproto = 0;
+			break;
+		case 'r':
+			proto_count++;
+			cfg_proto = SOCK_RAW;
+			cfg_ipproto = IPPROTO_UDP;
+			break;
+		case 'R':
+			proto_count++;
+			cfg_proto = SOCK_RAW;
+			cfg_ipproto = IPPROTO_RAW;
+			break;
+		case 'S':
+			cfg_sleep_usec = strtoul(optarg, NULL, 10);
+			break;
+		case 'u':
+			proto_count++;
+			cfg_proto = SOCK_DGRAM;
+			cfg_ipproto = IPPROTO_UDP;
+			break;
+		case 'v':
+			cfg_delay_snd = strtoul(optarg, NULL, 10);
+			break;
+		case 'V':
+			cfg_delay_ack = strtoul(optarg, NULL, 10);
+			break;
+		case 'x':
+			cfg_show_payload = true;
+			break;
+		case 'h':
+		default:
+			usage(argv[0]);
+		}
+	}
+
+	if (!cfg_payload_len)
+		error(1, 0, "payload may not be nonzero");
+	if (cfg_proto != SOCK_STREAM && cfg_payload_len > 1472)
+		error(1, 0, "udp packet might exceed expected MTU");
+	if (!do_ipv4 && !do_ipv6)
+		error(1, 0, "pass -4 or -6, not both");
+	if (proto_count > 1)
+		error(1, 0, "pass -P, -r, -R or -u, not multiple");
+	if (cfg_do_pktinfo && cfg_use_pf_packet)
+		error(1, 0, "cannot ask for pktinfo over pf_packet");
+	if (cfg_busy_poll && cfg_use_epoll)
+		error(1, 0, "pass epoll or busy_poll, not both");
+
+	if (optind != argc - 1)
+		error(1, 0, "missing required hostname argument");
+}
+
+static void resolve_hostname(const char *hostname)
+{
+	struct addrinfo hints = { .ai_family = do_ipv4 ? AF_INET : AF_INET6 };
+	struct addrinfo *addrs, *cur;
+	int have_ipv4 = 0, have_ipv6 = 0;
+
+retry:
+	if (getaddrinfo(hostname, NULL, &hints, &addrs))
+		error(1, errno, "getaddrinfo");
+
+	cur = addrs;
+	while (cur && !have_ipv4 && !have_ipv6) {
+		if (!have_ipv4 && cur->ai_family == AF_INET) {
+			memcpy(&daddr, cur->ai_addr, sizeof(daddr));
+			daddr.sin_port = htons(dest_port);
+			have_ipv4 = 1;
+		}
+		else if (!have_ipv6 && cur->ai_family == AF_INET6) {
+			memcpy(&daddr6, cur->ai_addr, sizeof(daddr6));
+			daddr6.sin6_port = htons(dest_port);
+			have_ipv6 = 1;
+		}
+		cur = cur->ai_next;
+	}
+	if (addrs)
+		freeaddrinfo(addrs);
+
+	if (do_ipv6 && hints.ai_family != AF_INET6) {
+		hints.ai_family = AF_INET6;
+		goto retry;
+	}
+
+	do_ipv4 &= have_ipv4;
+	do_ipv6 &= have_ipv6;
+}
+
+static void do_listen(int family, void *addr, int alen)
+{
+	int fd, type;
+
+	type = cfg_proto == SOCK_RAW ? SOCK_DGRAM : cfg_proto;
+
+	fd = socket(family, type, 0);
+	if (fd == -1)
+		error(1, errno, "socket rx");
+
+	if (bind(fd, addr, alen))
+		error(1, errno, "bind rx");
+
+	if (type == SOCK_STREAM && listen(fd, 10))
+		error(1, errno, "listen rx");
+
+	/* leave fd open, will be closed on process exit.
+	 * this enables connect() to succeed and avoids icmp replies
+	 */
+}
+
+static void do_main(int family)
+{
+	fprintf(stderr, "family:       %s %s\n",
+			family == PF_INET ? "INET" : "INET6",
+			cfg_use_pf_packet ? "(PF_PACKET)" : "");
+
+	fprintf(stderr, "test SND\n");
+	do_test(family, SOF_TIMESTAMPING_TX_SOFTWARE);
+
+	fprintf(stderr, "test ENQ\n");
+	do_test(family, SOF_TIMESTAMPING_TX_SCHED);
+
+	fprintf(stderr, "test ENQ + SND\n");
+	do_test(family, SOF_TIMESTAMPING_TX_SCHED |
+			SOF_TIMESTAMPING_TX_SOFTWARE);
+
+	if (cfg_proto == SOCK_STREAM) {
+		fprintf(stderr, "\ntest ACK\n");
+		do_test(family, SOF_TIMESTAMPING_TX_ACK);
+
+		fprintf(stderr, "\ntest SND + ACK\n");
+		do_test(family, SOF_TIMESTAMPING_TX_SOFTWARE |
+				SOF_TIMESTAMPING_TX_ACK);
+
+		fprintf(stderr, "\ntest ENQ + SND + ACK\n");
+		do_test(family, SOF_TIMESTAMPING_TX_SCHED |
+				SOF_TIMESTAMPING_TX_SOFTWARE |
+				SOF_TIMESTAMPING_TX_ACK);
+	}
+}
+
+const char *sock_names[] = { NULL, "TCP", "UDP", "RAW" };
+
+int main(int argc, char **argv)
+{
+	if (argc == 1)
+		usage(argv[0]);
+
+	parse_opt(argc, argv);
+	resolve_hostname(argv[argc - 1]);
+
+	fprintf(stderr, "protocol:     %s\n", sock_names[cfg_proto]);
+	fprintf(stderr, "payload:      %u\n", cfg_payload_len);
+	fprintf(stderr, "server port:  %u\n", dest_port);
+	fprintf(stderr, "\n");
+
+	if (do_ipv4) {
+		if (cfg_do_listen)
+			do_listen(PF_INET, &daddr, sizeof(daddr));
+		do_main(PF_INET);
+	}
+
+	if (do_ipv6) {
+		if (cfg_do_listen)
+			do_listen(PF_INET6, &daddr6, sizeof(daddr6));
+		do_main(PF_INET6);
+	}
+
+	return test_failed;
+}