Documentation/networking/timestamping/txtimestamp.c - LeafOS-Devices/android_kernel_samsung_gta4xl - Gitiles

 /*
  * 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
  *
  *
  * 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 <arpa/inet.h>
 #include <asm/types.h>
 #include <error.h>
 #include <errno.h>
 #include <linux/errqueue.h>
 #include <linux/if_ether.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 <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.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>

 /* 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 uint16_t dest_port = 9000;

 static struct sockaddr_in daddr;
 static struct sockaddr_in6 daddr6;
 static struct timespec ts_prev;

 static void __print_timestamp(const char *name, struct timespec *cur,
 			      uint32_t key, int payload_len)
 {
 	if (!(cur->tv_sec | cur->tv_nsec))
 		return;

 	fprintf(stderr, "  %s: %lu s %lu us (seq=%u, len=%u)",
 			name, cur->tv_sec, cur->tv_nsec / 1000,
 			key, payload_len);

 	if ((ts_prev.tv_sec | ts_prev.tv_nsec)) {
 		int64_t cur_ms, prev_ms;

 		cur_ms = (long) cur->tv_sec * 1000 * 1000;
 		cur_ms += cur->tv_nsec / 1000;

 		prev_ms = (long) ts_prev.tv_sec * 1000 * 1000;
 		prev_ms += ts_prev.tv_nsec / 1000;

 		fprintf(stderr, "  (%+ld us)", cur_ms - prev_ms);
 	}

 	ts_prev = *cur;
 	fprintf(stderr, "\n");
 }

 static void print_timestamp_usr(void)
 {
 	struct timespec ts;
 	struct timeval tv;	/* avoid dependency on -lrt */

 	gettimeofday(&tv, NULL);
 	ts.tv_sec = tv.tv_sec;
 	ts.tv_nsec = tv.tv_usec * 1000;

 	__print_timestamp("  USR", &ts, 0, 0);
 }

 static void print_timestamp(struct scm_timestamping *tss, int tstype,
 			    int tskey, int payload_len)
 {
 	const char *tsname;

 	switch (tstype) {
 	case SCM_TSTAMP_SCHED:
 		tsname = "  ENQ";
 		break;
 	case SCM_TSTAMP_SND:
 		tsname = "  SND";
 		break;
 	case SCM_TSTAMP_ACK:
 		tsname = "  ACK";
 		break;
 	default:
 		error(1, 0, "unknown timestamp type: %u",
 		tstype);
 	}
 	__print_timestamp(tsname, &tss->ts[0], tskey, payload_len);
 }

 static void __poll(int fd)
 {
 	struct pollfd pollfd;
 	int ret;

 	memset(&pollfd, 0, sizeof(pollfd));
 	pollfd.fd = fd;
 	ret = poll(&pollfd, 1, 100);
 	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;

 	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)) {

 			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
 			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);
 }

 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");

 	__recv_errmsg_cmsg(&msg, ret);

 	free(data);
 	return ret == -1;
 }

 static void do_test(int family, unsigned int opt)
 {
 	char *buf;
 	int fd, i, val, total_len;

 	if (family == IPPROTO_IPV6 && cfg_proto != SOCK_STREAM) {
 		/* due to lack of checksum generation code */
 		fprintf(stderr, "test: skipping datagram over IPv6\n");
 		return;
 	}

 	total_len = cfg_payload_len;
 	if (cfg_proto == SOCK_RAW) {
 		total_len += sizeof(struct udphdr);
 		if (cfg_ipproto == IPPROTO_RAW)
 			total_len += sizeof(struct iphdr);
 	}

 	buf = malloc(total_len);
 	if (!buf)
 		error(1, 0, "malloc");

 	fd = socket(family, cfg_proto, cfg_ipproto);
 	if (fd < 0)
 		error(1, errno, "socket");

 	if (cfg_proto == SOCK_STREAM) {
 		val = 1;
 		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");
 		}
 	}

 	opt |= SOF_TIMESTAMPING_SOFTWARE |
 	       SOF_TIMESTAMPING_OPT_ID;
 	if (setsockopt(fd, SOL_SOCKET, SO_TIMESTAMPING,
 		       (char *) &opt, sizeof(opt)))
 		error(1, 0, "setsockopt timestamping");

 	for (i = 0; i < cfg_num_pkts; i++) {
 		memset(&ts_prev, 0, sizeof(ts_prev));
 		memset(buf, 'a' + i, total_len);
 		buf[total_len - 2] = '\n';
 		buf[total_len - 1] = '\0';

 		if (cfg_proto == SOCK_RAW) {
 			struct udphdr *udph;
 			int off = 0;

 			if (cfg_ipproto == IPPROTO_RAW) {
 				struct iphdr *iph = (void *) buf;

 				memset(iph, 0, sizeof(*iph));
 				iph->ihl      = 5;
 				iph->version  = 4;
 				iph->ttl      = 2;
 				iph->daddr    = daddr.sin_addr.s_addr;
 				iph->protocol = IPPROTO_UDP;
 				/* kernel writes saddr, csum, len */

 				off = sizeof(*iph);
 			}

 			udph = (void *) buf + off;
 			udph->source = ntohs(9000); 	/* random spoof */
 			udph->dest   = ntohs(dest_port);
 			udph->len    = ntohs(sizeof(*udph) + cfg_payload_len);
 			udph->check  = 0;	/* not allowed for IPv6 */
 		}

 		print_timestamp_usr();
 		if (cfg_proto != SOCK_STREAM) {
 			if (family == PF_INET)
 				val = sendto(fd, buf, total_len, 0, (void *) &daddr, sizeof(daddr));
 			else
 				val = sendto(fd, buf, total_len, 0, (void *) &daddr6, sizeof(daddr6));
 		} else {
 			val = send(fd, buf, cfg_payload_len, 0);
 		}
 		if (val != total_len)
 			error(1, errno, "send");

 		/* wait for all errors to be queued, else ACKs arrive OOO */
 		usleep(50 * 1000);

 		__poll(fd);

 		while (!recv_errmsg(fd)) {}
 	}

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

 	free(buf);
 	usleep(400 * 1000);
 }

 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"
 			"  -l N: send N bytes at a time\n"
 			"  -r:   use raw\n"
 			"  -R:   use raw (IP_HDRINCL)\n"
 			"  -p N: connect to port N\n"
 			"  -u:   use udp\n",
 			filepath);
 	exit(1);
 }

 static void parse_opt(int argc, char **argv)
 {
 	int proto_count = 0;
 	char c;

 	while ((c = getopt(argc, argv, "46hl:p:rRu")) != -1) {
 		switch (c) {
 		case '4':
 			do_ipv6 = 0;
 			break;
 		case '6':
 			do_ipv4 = 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 'u':
 			proto_count++;
 			cfg_proto = SOCK_DGRAM;
 			cfg_ipproto = IPPROTO_UDP;
 			break;
 		case 'l':
 			cfg_payload_len = strtoul(optarg, NULL, 10);
 			break;
 		case 'p':
 			dest_port = strtoul(optarg, NULL, 10);
 			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 -r, -R or -u, not multiple");

 	if (optind != argc - 1)
 		error(1, 0, "missing required hostname argument");
 }

 static void resolve_hostname(const char *hostname)
 {
 	struct addrinfo *addrs, *cur;
 	int have_ipv4 = 0, have_ipv6 = 0;

 	if (getaddrinfo(hostname, NULL, NULL, &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);

 	do_ipv4 &= have_ipv4;
 	do_ipv6 &= have_ipv6;
 }

 static void do_main(int family)
 {
 	fprintf(stderr, "family:       %s\n",
 			family == PF_INET ? "INET" : "INET6");

 	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)
 		do_main(PF_INET);
 	if (do_ipv6)
 		do_main(PF_INET6);

 	return 0;
 }
	/*
	* 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
	*
	*
	* 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 <arpa/inet.h>
	#include <asm/types.h>
	#include <error.h>
	#include <errno.h>
	#include <linux/errqueue.h>
	#include <linux/if_ether.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 <stdint.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.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>

	/* 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 uint16_t dest_port = 9000;

	static struct sockaddr_in daddr;
	static struct sockaddr_in6 daddr6;
	static struct timespec ts_prev;

	static void __print_timestamp(const char name, struct timespec cur,
	uint32_t key, int payload_len)
	{
	if (!(cur->tv_sec \| cur->tv_nsec))
	return;

	fprintf(stderr, " %s: %lu s %lu us (seq=%u, len=%u)",
	name, cur->tv_sec, cur->tv_nsec / 1000,
	key, payload_len);

	if ((ts_prev.tv_sec \| ts_prev.tv_nsec)) {
	int64_t cur_ms, prev_ms;

	cur_ms = (long) cur->tv_sec * 1000 * 1000;
	cur_ms += cur->tv_nsec / 1000;

	prev_ms = (long) ts_prev.tv_sec * 1000 * 1000;
	prev_ms += ts_prev.tv_nsec / 1000;

	fprintf(stderr, " (%+ld us)", cur_ms - prev_ms);
	}

	ts_prev = *cur;
	fprintf(stderr, "\n");
	}

	static void print_timestamp_usr(void)
	{
	struct timespec ts;
	struct timeval tv; /* avoid dependency on -lrt */

	gettimeofday(&tv, NULL);
	ts.tv_sec = tv.tv_sec;
	ts.tv_nsec = tv.tv_usec * 1000;

	__print_timestamp(" USR", &ts, 0, 0);
	}

	static void print_timestamp(struct scm_timestamping *tss, int tstype,
	int tskey, int payload_len)
	{
	const char *tsname;

	switch (tstype) {
	case SCM_TSTAMP_SCHED:
	tsname = " ENQ";
	break;
	case SCM_TSTAMP_SND:
	tsname = " SND";
	break;
	case SCM_TSTAMP_ACK:
	tsname = " ACK";
	break;
	default:
	error(1, 0, "unknown timestamp type: %u",
	tstype);
	}
	__print_timestamp(tsname, &tss->ts[0], tskey, payload_len);
	}

	static void __poll(int fd)
	{
	struct pollfd pollfd;
	int ret;

	memset(&pollfd, 0, sizeof(pollfd));
	pollfd.fd = fd;
	ret = poll(&pollfd, 1, 100);
	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;

	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)) {

	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
	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);
	}

	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");

	__recv_errmsg_cmsg(&msg, ret);

	free(data);
	return ret == -1;
	}

	static void do_test(int family, unsigned int opt)
	{
	char *buf;
	int fd, i, val, total_len;

	if (family == IPPROTO_IPV6 && cfg_proto != SOCK_STREAM) {
	/* due to lack of checksum generation code */
	fprintf(stderr, "test: skipping datagram over IPv6\n");
	return;
	}

	total_len = cfg_payload_len;
	if (cfg_proto == SOCK_RAW) {
	total_len += sizeof(struct udphdr);
	if (cfg_ipproto == IPPROTO_RAW)
	total_len += sizeof(struct iphdr);
	}

	buf = malloc(total_len);
	if (!buf)
	error(1, 0, "malloc");

	fd = socket(family, cfg_proto, cfg_ipproto);
	if (fd < 0)
	error(1, errno, "socket");

	if (cfg_proto == SOCK_STREAM) {
	val = 1;
	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");
	}
	}

	opt \|= SOF_TIMESTAMPING_SOFTWARE \|
	SOF_TIMESTAMPING_OPT_ID;
	if (setsockopt(fd, SOL_SOCKET, SO_TIMESTAMPING,
	(char *) &opt, sizeof(opt)))
	error(1, 0, "setsockopt timestamping");

	for (i = 0; i < cfg_num_pkts; i++) {
	memset(&ts_prev, 0, sizeof(ts_prev));
	memset(buf, 'a' + i, total_len);
	buf[total_len - 2] = '\n';
	buf[total_len - 1] = '\0';

	if (cfg_proto == SOCK_RAW) {
	struct udphdr *udph;
	int off = 0;

	if (cfg_ipproto == IPPROTO_RAW) {
	struct iphdr iph = (void ) buf;

	memset(iph, 0, sizeof(*iph));
	iph->ihl = 5;
	iph->version = 4;
	iph->ttl = 2;
	iph->daddr = daddr.sin_addr.s_addr;
	iph->protocol = IPPROTO_UDP;
	/* kernel writes saddr, csum, len */

	off = sizeof(*iph);
	}

	udph = (void *) buf + off;
	udph->source = ntohs(9000); /* random spoof */
	udph->dest = ntohs(dest_port);
	udph->len = ntohs(sizeof(*udph) + cfg_payload_len);
	udph->check = 0; /* not allowed for IPv6 */
	}

	print_timestamp_usr();
	if (cfg_proto != SOCK_STREAM) {
	if (family == PF_INET)
	val = sendto(fd, buf, total_len, 0, (void *) &daddr, sizeof(daddr));
	else
	val = sendto(fd, buf, total_len, 0, (void *) &daddr6, sizeof(daddr6));
	} else {
	val = send(fd, buf, cfg_payload_len, 0);
	}
	if (val != total_len)
	error(1, errno, "send");

	/* wait for all errors to be queued, else ACKs arrive OOO */
	usleep(50 * 1000);

	__poll(fd);

	while (!recv_errmsg(fd)) {}
	}

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

	free(buf);
	usleep(400 * 1000);
	}

	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"
	" -l N: send N bytes at a time\n"
	" -r: use raw\n"
	" -R: use raw (IP_HDRINCL)\n"
	" -p N: connect to port N\n"
	" -u: use udp\n",
	filepath);
	exit(1);
	}

	static void parse_opt(int argc, char **argv)
	{
	int proto_count = 0;
	char c;

	while ((c = getopt(argc, argv, "46hl:p:rRu")) != -1) {
	switch (c) {
	case '4':
	do_ipv6 = 0;
	break;
	case '6':
	do_ipv4 = 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 'u':
	proto_count++;
	cfg_proto = SOCK_DGRAM;
	cfg_ipproto = IPPROTO_UDP;
	break;
	case 'l':
	cfg_payload_len = strtoul(optarg, NULL, 10);
	break;
	case 'p':
	dest_port = strtoul(optarg, NULL, 10);
	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 -r, -R or -u, not multiple");

	if (optind != argc - 1)
	error(1, 0, "missing required hostname argument");
	}

	static void resolve_hostname(const char *hostname)
	{
	struct addrinfo addrs, cur;
	int have_ipv4 = 0, have_ipv6 = 0;

	if (getaddrinfo(hostname, NULL, NULL, &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);

	do_ipv4 &= have_ipv4;
	do_ipv6 &= have_ipv6;
	}

	static void do_main(int family)
	{
	fprintf(stderr, "family: %s\n",
	family == PF_INET ? "INET" : "INET6");

	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)
	do_main(PF_INET);
	if (do_ipv6)
	do_main(PF_INET6);

	return 0;
	}