Support the specification of a range of destination ports e.g.

	netsend 127.0.0.1 6666-7777 [payloadsize] [packet_rate] [duration]

This is useful to test the behaviour of systems that do some kind
of flow classifications and so exhibit different behaviour depending
on the number of flows that hit them.
I plan to add a similar extension to sweep on a range of IP addresses,
so we can issue a single command to flood (obviously, for testing
purposes!) a number of different destinations.

When there is only one destination, we do a preliminary connect()
of the socket so we can use send() instead of sendto().
When we have multiple ports, the socket is not connect()'ed and we
do a sendto() instead. There is a performance hit in this case,
as the throughput on the loopback interface (with a firewall rule
that blocks the transmission) goes down from 900kpps to 490kpps on
my test machine.

If the number of different destinations is limited, one option to
explore is to have multiple connect()ed sockets.

MFC after:	1 month

1 files changed, 88 insertions, 51 deletions

diff --git a/tools/tools/netrate/netsend/netsend.c b/tools/tools/netrate/netsend/netsend.c
index b47c509..5e41f2d 100644
--- a/tools/tools/netrate/netsend/netsend.c
+++ b/tools/tools/netrate/netsend/netsend.c
@@ -39,12 +39,23 @@
 #include <stdlib.h>
 #include <string.h>
 
+/* program arguments */
+struct _a {
+	int s;
+	struct timespec interval;
+	int port, port_max;
+	long duration;
+	struct sockaddr_in sin;
+	int packet_len;
+	void *packet;
+};
+
 static void
 usage(void)
 {
 
 	fprintf(stderr,
-	    "netsend [ip] [port] [payloadsize] [rate] [duration]\n");
+	    "netsend [ip] [port[-port_max]] [payloadsize] [packet_rate] [duration]\n");
 	exit(-1);
 }
 
@@ -114,10 +125,12 @@ wait_time(struct timespec ts, struct timespec *wakeup_ts, long long *waited)
  * Calculate a second-aligned starting time for the packet stream.  Busy
  * wait between our calculated interval and dropping the provided packet
  * into the socket.  If we hit our duration limit, bail.
+ * We sweep the ports from a->port to a->port_max included.
+ * If the two ports are the same we connect() the socket upfront, which
+ * almost halves the cost of the sendto() call.
  */
 static int
-timing_loop(int s, struct timespec interval, long duration, u_char *packet,
-    u_int packet_len)
+timing_loop(struct _a *a)
 {
 	struct timespec nexttime, starttime, tmptime;
 	long long waited;
@@ -127,18 +140,19 @@ timing_loop(int s, struct timespec interval, long duration, u_char *packet,
 	/* do not call gettimeofday more than every 20us */
 	long minres_ns = 20000;
 	int ic, gettimeofday_cycles;
+	int cur_port;
 
 	if (clock_getres(CLOCK_REALTIME, &tmptime) == -1) {
 		perror("clock_getres");
 		return (-1);
 	}
 
-	if (timespec_ge(&tmptime, &interval))
+	if (timespec_ge(&tmptime, &a->interval))
 		fprintf(stderr,
 		    "warning: interval (%jd.%09ld) less than resolution (%jd.%09ld)\n",
-		    (intmax_t)interval.tv_sec, interval.tv_nsec,
+		    (intmax_t)a->interval.tv_sec, a->interval.tv_nsec,
 		    (intmax_t)tmptime.tv_sec, tmptime.tv_nsec);
-	if (tmptime.tv_nsec < minres_ns) {
+	if (a->interval.tv_nsec < minres_ns) {
 		gettimeofday_cycles = minres_ns/(tmptime.tv_nsec + 1);
 		fprintf(stderr,
 		    "calling time every %d cycles\n", gettimeofday_cycles);
@@ -156,14 +170,23 @@ timing_loop(int s, struct timespec interval, long duration, u_char *packet,
 	if (wait_time(starttime, NULL, NULL) == -1)
 		return (-1);
 	nexttime = starttime;
-	finishtime = starttime.tv_sec + duration;
+	finishtime = starttime.tv_sec + a->duration;
 
 	send_errors = send_calls = 0;
 	counter = 0;
 	waited = 0;
 	ic = gettimeofday_cycles;
+	cur_port = a->port;
+	if (a->port == a->port_max) {
+		if (connect(a->s, (struct sockaddr *)&a->sin, sizeof(a->sin))) {
+			perror("connect");
+			return (-1);
+		}
+	}
 	while (1) {
-		timespec_add(&nexttime, &interval);
+		int ret;
+
+		timespec_add(&nexttime, &a->interval);
 		if (--ic <= 0) {
 			ic = gettimeofday_cycles;
 			if (wait_time(nexttime, &tmptime, &waited) == -1)
@@ -178,17 +201,28 @@ timing_loop(int s, struct timespec interval, long duration, u_char *packet,
 		 * previous send, the error will turn up the current send
 		 * operation, causing the current sequence number also to be
 		 * skipped.
+		 * The counter is incremented only on the initial port number,
+		 * so all destinations will see the same set of packets.
 		 *
 		 * XXXRW: Note alignment assumption.
 		 */
-		if (packet_len >= 4) {
-			*((u_int32_t *)packet) = htonl(counter);
+		if (cur_port == a->port && a->packet_len >= 4) {
+			*((u_int32_t *)a->packet) = htonl(counter);
 			counter++;
 		}
-		if (send(s, packet, packet_len, 0) < 0)
+		if (a->port == a->port_max) { /* socket already bound */
+			ret = send(a->s, a->packet, a->packet_len, 0);
+		} else {
+			a->sin.sin_port = htons(cur_port++);
+			if (cur_port > a->port_max)
+				cur_port = a->port;
+			ret = sendto(a->s, a->packet, a->packet_len, 0,
+				(struct sockaddr *)&a->sin, sizeof(a->sin));
+		}
+		if (ret < 0)
 			send_errors++;
 		send_calls++;
-		if (duration != 0 && tmptime.tv_sec >= finishtime)
+		if (a->duration != 0 && tmptime.tv_sec >= finishtime)
 			goto done;
 	}
 
@@ -205,11 +239,11 @@ done:
 	    tmptime.tv_nsec);
 	printf("send calls:        %ld\n", send_calls);
 	printf("send errors:       %ld\n", send_errors);
-	printf("approx send rate:  %ld\n", (send_calls - send_errors) /
-	    duration);
+	printf("approx send rate:  %ld pps\n", (send_calls - send_errors) /
+	    a->duration);
 	printf("approx error rate: %ld\n", (send_errors / send_calls));
 	printf("waited:            %lld\n", waited);
-	printf("approx waits/sec:  %lld\n", (long long)(waited / duration));
+	printf("approx waits/sec:  %lld\n", (long long)(waited / a->duration));
 	printf("approx wait rate:  %lld\n", (long long)(waited / send_calls));
 
 	return (0);
@@ -218,27 +252,35 @@ done:
 int
 main(int argc, char *argv[])
 {
-	long rate, payloadsize, port, duration;
-	struct timespec interval;
-	struct sockaddr_in sin;
-	char *dummy, *packet;
-	int s;
+	long rate, payloadsize, port;
+	char *dummy;
+	struct _a a;	/* arguments */
+
+	bzero(&a, sizeof(a));
 
 	if (argc != 6)
 		usage();
 
-	bzero(&sin, sizeof(sin));
-	sin.sin_len = sizeof(sin);
-	sin.sin_family = AF_INET;
-	if (inet_aton(argv[1], &sin.sin_addr) == 0) {
+	a.sin.sin_len = sizeof(a.sin);
+	a.sin.sin_family = AF_INET;
+	if (inet_aton(argv[1], &a.sin.sin_addr) == 0) {
 		perror(argv[1]);
 		return (-1);
 	}
 
 	port = strtoul(argv[2], &dummy, 10);
-	if (port < 1 || port > 65535 || *dummy != '\0')
+	if (port < 1 || port > 65535)
 		usage();
-	sin.sin_port = htons(port);
+	if (*dummy != '\0' && *dummy != '-')
+		usage();
+	a.sin.sin_port = htons(port);
+	a.port = a.port_max = port;
+	if (*dummy == '-') {	/* set high port */
+		port = strtoul(dummy + 1, &dummy, 10);
+		if (port < a.port || port > 65535)
+			usage();
+		a.port_max = port;
+	}
 
 	payloadsize = strtoul(argv[3], &dummy, 10);
 	if (payloadsize < 0 || *dummy != '\0')
@@ -247,56 +289,51 @@ main(int argc, char *argv[])
 		fprintf(stderr, "payloadsize > 32768\n");
 		return (-1);
 	}
+	a.packet_len = payloadsize;
 
 	/*
 	 * Specify an arbitrary limit.  It's exactly that, not selected by
 	 * any particular strategy.  '0' is a special value meaning "blast",
 	 * and avoids the cost of a timing loop.
-	 * XXX 0 is not actually implemented.
 	 */
 	rate = strtoul(argv[4], &dummy, 10);
-	if (rate < 1 || *dummy != '\0')
+	if (rate < 0 || *dummy != '\0')
 		usage();
 	if (rate > MAX_RATE) {
-		fprintf(stderr, "rate > %d\n", MAX_RATE);
+		fprintf(stderr, "packet rate at most %d\n", MAX_RATE);
 		return (-1);
 	}
 
-	duration = strtoul(argv[5], &dummy, 10);
-	if (duration < 0 || *dummy != '\0')
+	a.duration = strtoul(argv[5], &dummy, 10);
+	if (a.duration < 0 || *dummy != '\0')
 		usage();
 
-	packet = malloc(payloadsize);
-	if (packet == NULL) {
+	a.packet = malloc(payloadsize);
+	if (a.packet == NULL) {
 		perror("malloc");
 		return (-1);
 	}
-	bzero(packet, payloadsize);
-
+	bzero(a.packet, payloadsize);
 	if (rate == 0) {
-		interval.tv_sec = 0;
-		interval.tv_nsec = 0;
+		a.interval.tv_sec = 0;
+		a.interval.tv_nsec = 0;
 	} else if (rate == 1) {
-		interval.tv_sec = 1;
-		interval.tv_nsec = 0;
+		a.interval.tv_sec = 1;
+		a.interval.tv_nsec = 0;
 	} else {
-		interval.tv_sec = 0;
-		interval.tv_nsec = ((1 * 1000000000) / rate);
+		a.interval.tv_sec = 0;
+		a.interval.tv_nsec = ((1 * 1000000000) / rate);
 	}
+
 	printf("Sending packet of payload size %ld every %jd.%09lds for %ld "
-	    "seconds\n", payloadsize, (intmax_t)interval.tv_sec,
-	    interval.tv_nsec, duration);
+	    "seconds\n", payloadsize, (intmax_t)a.interval.tv_sec,
+	    a.interval.tv_nsec, a.duration);
 
-	s = socket(PF_INET, SOCK_DGRAM, 0);
-	if (s == -1) {
+	a.s = socket(PF_INET, SOCK_DGRAM, 0);
+	if (a.s == -1) {
 		perror("socket");
 		return (-1);
 	}
 
-	if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
-		perror("connect");
-		return (-1);
-	}
-
-	return (timing_loop(s, interval, duration, packet, payloadsize));
+	return (timing_loop(&a));
 }