Backward compatibility added with some enhancements

src/iperf.h

@@ -279,6 +279,8 @@ struct iperf_test
     TAILQ_HEAD(xbind_addrhead, xbind_entry) xbind_addrs; /* all -X opts */
     int       bind_port;                        /* --cport option */
     int       server_port;
+    int       num_server_ports;                 /* second value of --port option */
+    int       server_udp_streams_accepted;      /* offset of last server port used - 0 means none used */
     int       omit;                             /* duration of omit period (-O flag) */
     int       duration;                         /* total duration of test (-t flag) */
     char     *diskfile_name;			/* -F option */
@@ -433,9 +435,15 @@ extern int gerror; /* error value from getaddrinfo(3), for use in internal error
 /* UDP "connect" message and reply (textual value for Wireshark, etc. readability - legacy was numeric) */
 #define UDP_CONNECT_MSG 0x36373839          // "6789" - legacy value was 123456789
 #define UDP_CONNECT_REPLY 0x39383736        // "9876" - legacy value was 987654321
+#define UDP_CONNECT_REPLY_NEXT_PORT 0x39383735 // "9875": for Windows - indicates use next port
 #define LEGACY_UDP_CONNECT_REPLY 987654321  // Old servers may still reply with the legacy value
 
 /* In Reverse mode, maximum number of packets to wait for "accept" response - to handle out of order packets */
 #define MAX_REVERSE_OUT_OF_ORDER_PACKETS 2
 
+/* Any type of WIndows OS or Cygwin */
+#if (defined(__CYGWIN__) || defined(_WIN32) || defined(_WIN64) || defined(__WINDOWS__))
+#define WINDOWS_ANY 1
+#endif /* Any Windows type */
+
 #endif /* !__IPERF_H */

src/iperf_api.c

@@ -63,9 +63,9 @@
 #include <sys/cpuset.h>
 #endif /* HAVE_CPUSET_SETAFFINITY */
 
-#if defined(__CYGWIN__) || defined(_WIN32) || defined(_WIN64) || defined(__WINDOWS__)
+#if defined(WINDOWS_ANY)
 #define CPU_SETSIZE __CPU_SETSIZE
-#endif /* __CYGWIN__, _WIN32, _WIN64, __WINDOWS__ */
+#endif /* WINDOWS_ANY */
 
 #if defined(HAVE_SETPROCESSAFFINITYMASK)
 #include <Windows.h>
@@ -1131,12 +1131,30 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
     while ((flag = getopt_long(argc, argv, "p:f:i:D1VJvsc:ub:t:n:k:l:P:Rw:B:M:N46S:L:ZO:F:A:T:C:dI:hX:", longopts, NULL)) != -1) {
         switch (flag) {
             case 'p':
-		portno = atoi(optarg);
-		if (portno < 1 || portno > 65535) {
-		    i_errno = IEBADPORT;
-		    return -1;
+                slash = optarg;
+#if defined(WINDOWS_ANY)
+            	slash = strchr(optarg, '/');
+		if (slash) {
+		    *slash = '\0';
+		    ++slash;
+                    if (*slash != '\0') {
+                        test->num_server_ports = atoi(slash);
+                        if (test->num_server_ports < 1 || test->num_server_ports > MAX_STREAMS) {
+                            i_errno = IENUMPORTS;
+                            return -1;
+                        }
+                        server_flag = 1;
+                    }
 		}
-		test->server_port = portno;
+#endif /* WINDOWS_ANY */
+                if (!slash || strlen(optarg) > 0) {
+		    portno = atoi(optarg);
+		    if (portno < 1 || portno > 65535) {
+		        i_errno = IEBADPORT;
+		        return -1;
+		    }
+		    test->server_port = portno;
+                }
                 break;
             case 'f':
 		if (!optarg) {
@@ -1289,7 +1307,7 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
                 break;
             case 'P':
                 test->num_streams = atoi(optarg);
-                if (test->num_streams > MAX_STREAMS) {
+                if (test->num_streams > MAX_STREAMS || test->num_streams < 1) {
                     i_errno = IENUMSTREAMS;
                     return -1;
                 }
@@ -2071,6 +2089,17 @@ iperf_exchange_parameters(struct iperf_test *test)
         if (get_parameters(test) < 0)
             return -1;
 
+        // Check spcific conditions required for UDP under Windows as parallel streams
+        // using the same port numebr is not supported.
+#if defined(WINDOWS_ANY)
+        if (test->protocol->id == Pudp) {
+            if (test->num_server_ports < test->num_streams * (test->bidirectional ? 2 : 1)) {
+                i_errno = IEPORTNUM;
+                return -1;
+            }
+        }
+#endif /* WINDOWS_ANY */
+
 #if defined(HAVE_SSL)
         if (test_is_authorized(test) < 0){
             if (iperf_set_send_state(test, SERVER_ERROR) != 0)
@@ -2086,7 +2115,7 @@ iperf_exchange_parameters(struct iperf_test *test)
 #endif //HAVE_SSL
 
         if ((s = test->protocol->listen(test)) < 0) {
-	        if (iperf_set_send_state(test, SERVER_ERROR) != 0)
+	    if (iperf_set_send_state(test, SERVER_ERROR) != 0)
                 return -1;
             err = htonl(i_errno);
             if (Nwrite(test->ctrl_sck, (char*) &err, sizeof(err), Ptcp) < 0) {
@@ -2809,6 +2838,8 @@ iperf_defaults(struct iperf_test *testp)
     testp->congestion_used = NULL;
     testp->remote_congestion_used = NULL;
     testp->server_port = PORT;
+    testp->num_server_ports = 1;
+    testp->server_udp_streams_accepted = 0;
     testp->ctrl_sck = -1;
     testp->listener = -1;
     testp->prot_listener = -1;
@@ -3083,6 +3114,7 @@ iperf_reset_test(struct iperf_test *test)
     test->mode = RECEIVER;
     test->sender_has_retransmits = 0;
     set_protocol(test, Ptcp);
+    test->server_udp_streams_accepted = 0;
     test->omit = OMIT;
     test->duration = DURATION;
     test->server_affinity = -1;

src/iperf_api.h

@@ -402,6 +402,8 @@ enum {
     IERVRSONLYRCVTIMEOUT = 32,  // Client receive timeout is valid only in reverse mode
     IESNDTIMEOUT = 33,      // Illegal message send timeout
     IEUDPFILETRANSFER = 34, // Cannot transfer file using UDP
+    IENUMPORTS = 35,        // number of ports is less than 1 or larger than server limit
+    IEPORTNUM = 36,         // requested number of parallel streams is larger than the number of ports available for the server
     /* Test errors */
     IENEWTEST = 100,        // Unable to create a new test (check perror)
     IEINITTEST = 101,       // Test initialization failed (check perror)

src/iperf_error.c

@@ -440,7 +440,7 @@ iperf_strerror(int int_errno)
 	case IETOTALRATE:
 	    snprintf(errstr, len, "total required bandwidth is larger than server limit");
             break;
-    case IESKEWTHRESHOLD:
+        case IESKEWTHRESHOLD:
 	    snprintf(errstr, len, "skew threshold must be a positive number");
             break;
 	case IEIDLETIMEOUT:
@@ -458,12 +458,17 @@ iperf_strerror(int int_errno)
 	case IENOMSG:
 	    snprintf(errstr, len, "idle timeout for receiving data");
             break;
-    case IESETDONTFRAGMENT:
+        case IESETDONTFRAGMENT:
 	    snprintf(errstr, len, "unable to set IP Do-Not-Fragment flag");
             break;
         case IESETUSERTIMEOUT:
             snprintf(errstr, len, "unable to set TCP USER_TIMEOUT");
             perr = 1;
+        case IENUMPORTS:
+	    snprintf(errstr, len, "number of ports is less than 1 or larger than server limit");
+            break;
+        case IEPORTNUM:
+	    snprintf(errstr, len, "requested number of parallel streams is larger than the number of ports available for the server");
             break;
 	default:
 	    snprintf(errstr, len, "int_errno=%d", int_errno);

src/iperf_locale.c

@@ -97,7 +97,13 @@ const char usage_shortstr[] = "Usage: iperf3 [-s|-c host] [options]\n"
 const char usage_longstr[] = "Usage: iperf3 [-s|-c host] [options]\n"
                            "       iperf3 [-h|--help] [-v|--version]\n\n"
                            "Server or Client:\n"
+#if (defined(__CYGWIN__) || defined(_WIN32) || defined(_WIN64) || defined(__WINDOWS__))
+                           "  -p, --port      #[/#]     server port to listen on / connect to\n"
+                           "                            (optional for server UDP: pool size of ports starting with\n"
+                           "                            port # - required for parallel UDP sterams under Windows)\n"
+#else
                            "  -p, --port      #         server port to listen on/connect to\n"
+#endif /* any Windows type */
                            "  -f, --format   [kmgtKMGT] format to report: Kbits, Mbits, Gbits, Tbits\n"
                            "  -i, --interval  #         seconds between periodic throughput reports\n"
                            "  -I, --pidfile file        write PID file\n"

src/iperf_server_api.c

@@ -382,6 +382,7 @@ static void
 cleanup_server(struct iperf_test *test)
 {
     struct iperf_stream *sp;
+    int i;
 
     /* Close open streams */
     SLIST_FOREACH(sp, &test->streams, streams) {
@@ -407,6 +408,13 @@ cleanup_server(struct iperf_test *test)
         test->prot_listener = -1;
     }
 
+    /* Close all listening ports in case pool of listening ports is used */
+    for (i = 0; i <= test->server_udp_streams_accepted; i++) {
+        if (test->debug)
+            printf("Closing UDP port %d;\n", test->server_port + i);
+        close(test->server_port + i);
+    }
+
     /* Cancel any remaining timers. */
     if (test->stats_timer != NULL) {
 	tmr_cancel(test->stats_timer);

src/iperf_udp.c

@@ -380,6 +380,7 @@ iperf_udp_accept(struct iperf_test *test)
     socklen_t len;
     int       sz, s;
     int	      rc;
+    int       port;
 
     /*
      * Get the current outstanding socket.  This socket will be used to handle
@@ -450,10 +451,30 @@ iperf_udp_accept(struct iperf_test *test)
 	}
     }
 
+    port = test->server_port;
+    buf = UDP_CONNECT_REPLY;
+
+    /*
+     * Since Windows does not suppport parallel UDP streams using the same local and remote ports,
+     * different server port is used for each steam - indicated by replying with UDP_CONNECT_REPLY_NEXT_PORT.
+     * Each stream, the listening port number is increased by 1.
+     */
+#if (defined(WINDOWS_ANY))
+    if (test->num_server_ports > 1) {
+        test->server_udp_streams_accepted++;
+
+        /* Change port number for next stream (but not for the last for backward compatibility) */
+        if (test->server_udp_streams_accepted < test->num_streams * ((test->bidirectional ? 2 : 1))) {
+            port += test->server_udp_streams_accepted;
+            buf = UDP_CONNECT_REPLY_NEXT_PORT;
+        }
+    }
+#endif /* WINDOWS_ANY */
+
     /*
      * Create a new "listening" socket to replace the one we were using before.
      */
-    test->prot_listener = netannounce(test->settings->domain, Pudp, test->bind_address, test->bind_dev, test->server_port);
+    test->prot_listener = netannounce(test->settings->domain, Pudp, test->bind_address, test->bind_dev, port);
     if (test->prot_listener < 0) {
         i_errno = IESTREAMLISTEN;
         return -1;
@@ -462,8 +483,10 @@ iperf_udp_accept(struct iperf_test *test)
     FD_SET(test->prot_listener, &test->read_set);
     test->max_fd = (test->max_fd < test->prot_listener) ? test->prot_listener : test->max_fd;
 
-    /* Let the client know we're ready "accept" another UDP "stream" */
-    buf = UDP_CONNECT_REPLY;
+    /* 
+     * Let the client know we're ready "accept" another UDP "stream",
+     * and send the listening port when applicable.
+     */
     if (write(s, &buf, sizeof(buf)) < 0) {
         i_errno = IESTREAMWRITE;
         return -1;
@@ -600,19 +623,34 @@ iperf_udp_connect(struct iperf_test *test)
     do {
         if ((sz = recv(s, &buf, sizeof(buf), 0)) < 0) {
             i_errno = IESTREAMREAD;
+            if (test->num_server_ports > 1 && test->num_streams > 1) {
+                iperf_err(test, "accept response receive failed - may be caused by an old Windows client that does not support parallel UDP streams");
+            }
             return -1;
         }
         if (test->debug) {
             printf("Connect received for Socket %d, sz=%d, buf=%x, i=%d, max_len_wait_for_reply=%d\n", s, sz, buf, i, max_len_wait_for_reply);
         }
         i += sz;
-    } while (buf != UDP_CONNECT_REPLY && buf != LEGACY_UDP_CONNECT_REPLY && i < max_len_wait_for_reply);
+    } while (buf != UDP_CONNECT_REPLY && buf != UDP_CONNECT_REPLY_NEXT_PORT && buf != LEGACY_UDP_CONNECT_REPLY && i < max_len_wait_for_reply);
 
-    if (buf != UDP_CONNECT_REPLY  && buf != LEGACY_UDP_CONNECT_REPLY) {
+    /*
+     * Since Windows does not suppport parallel UDP streams using the same local and remote ports,
+     * different server port is used for each steam - indicated by UDP_CONNECT_REPLY_NEXT_PORT.
+     */
+    if (buf != UDP_CONNECT_REPLY && buf != UDP_CONNECT_REPLY_NEXT_PORT && buf != LEGACY_UDP_CONNECT_REPLY) {
         i_errno = IESTREAMREAD;
         return -1;
     }
 
+    /*
+     * On WIndows, to overcome the limit of not supporting parallel UDP streams using the same port,
+     * `buf` will be UDP_CONNECT_REPLY_NEXT_PORT - indicating different server port for the next connection.
+     */
+    if (buf == UDP_CONNECT_REPLY_NEXT_PORT) {
+        test->server_port += 1;
+    }
+
     return s;
 }