Fix a bug in FQ pacing, where application pacing wasn't completely disabled.

It was therefore possible to have multiple levels of pacing happening,
which resulted in very nicely smoothed traffic, but wasn't really
the original design.

Do pacing correctly in iperf_check_throttle() and remove a hack in
iperf_send() where we were explicitly checking for the type of
pacing, but didn't really need to.

It turns out that with UDP and only-FQ pacing, iperf3 sends and throws
packets on the floor as fast as it can.  This isn't really desirable,
and probably not what was wanted in a test anyway, so if we're not
doing TCP tests, force the use of application-level pacing.

src/iperf_api.c

@@ -1008,6 +1008,17 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
     }
     test->settings->blksize = blksize;
 
+    /* 
+     * If we're not doing TCP, then be sure we're doing application
+     * pacing and not per-socket fair-queue pacing.
+     */
+    if (test->role == 'c' && test->protocol->id != Ptcp) {
+	if (!test->no_fq_socket_pacing) {
+	    printf("Warning, forcing application pacing on non-TCP test\n");
+	    test->no_fq_socket_pacing = 1;
+	}
+    }
+
     if (!rate_flag)
 	test->settings->rate = test->protocol->id == Pudp ? UDP_RATE : 0;
 
@@ -1061,7 +1072,8 @@ iperf_check_throttle(struct iperf_stream *sp, struct timeval *nowP)
         return;
     seconds = timeval_diff(&sp->result->start_time_fixed, nowP);
     bits_per_second = sp->result->bytes_sent * 8 / seconds;
-    if (bits_per_second < sp->test->settings->rate) {
+    if (! sp->test->no_fq_socket_pacing ||
+	bits_per_second < sp->test->settings->rate) {
         sp->green_light = 1;
         FD_SET(sp->socket, &sp->test->write_set);
     } else {
@@ -1090,8 +1102,7 @@ iperf_send(struct iperf_test *test, fd_set *write_setP)
 	    gettimeofday(&now, NULL);
 	streams_active = 0;
 	SLIST_FOREACH(sp, &test->streams, streams) {
-	    if (! test->no_fq_socket_pacing ||
-		(sp->green_light &&
+	    if ((sp->green_light &&
 		 (write_setP == NULL || FD_ISSET(sp->socket, write_setP)))) {
 		if ((r = sp->snd(sp)) < 0) {
 		    if (r == NET_SOFTERROR)