selftests/txtimestamp: Add more configurable parameters

Add a way to configure if poll() should wait forever for an event, the
number of packets that should be sent for each and if there should be
any delay between packets.

Signed-off-by: Vinicius Costa Gomes <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

tools/testing/selftests/networking/timestamping/txtimestamp.c

···
 static int do_ipv4 = 1;
 static int do_ipv6 = 1;
 static int cfg_payload_len = 10;
+static int cfg_poll_timeout = 100;
 static bool cfg_show_payload;
 static bool cfg_do_pktinfo;
 static bool cfg_loop_nodata;
+static bool cfg_no_delay;
 static uint16_t dest_port = 9000;
 
 static struct sockaddr_in daddr;
···
 
 	memset(&pollfd, 0, sizeof(pollfd));
 	pollfd.fd = fd;
-	ret = poll(&pollfd, 1, 100);
+	ret = poll(&pollfd, 1, cfg_poll_timeout);
 	if (ret != 1)
 		error(1, errno, "poll");
 }
···
 			error(1, errno, "send");
 
 		/* wait for all errors to be queued, else ACKs arrive OOO */
-		usleep(50 * 1000);
+		if (!cfg_no_delay)
+			usleep(50 * 1000);
 
 		__poll(fd);
 
···
 			"  -4:   only IPv4\n"
 			"  -6:   only IPv6\n"
 			"  -h:   show this message\n"
+			"  -c N: number of packets for each test\n"
+			"  -D:   no delay between packets\n"
+			"  -F:   poll() waits forever for an event\n"
 			"  -I:   request PKTINFO\n"
 			"  -l N: send N bytes at a time\n"
 			"  -n:   set no-payload option\n"
···
 	int proto_count = 0;
 	char c;
 
-	while ((c = getopt(argc, argv, "46hIl:np:rRux")) != -1) {
+	while ((c = getopt(argc, argv, "46c:DFhIl:np:rRux")) != -1) {
 		switch (c) {
 		case '4':
 			do_ipv6 = 0;
 			break;
 		case '6':
 			do_ipv4 = 0;
+			break;
+		case 'c':
+			cfg_num_pkts = strtoul(optarg, NULL, 10);
+			break;
+		case 'D':
+			cfg_no_delay = true;
+			break;
+		case 'F':
+			cfg_poll_timeout = -1;
 			break;
 		case 'I':
 			cfg_do_pktinfo = true;