Add option to set the ToS of the control connection.

Author: Liam McBirnie

docs/invoking.rst

@@ -226,6 +226,16 @@ the executable.
                  iperf3  versions.   Use this option to preserve the less secure,
                  but more compatible, behavior.
    
+          --control-tos n
+                 Set the IP type of service bits of the control connection.   The
+                 usual prefixes for octal and hex can be used,   i.e. 52, 064 and
+                 0x34 all specify the same value.
+
+          --control-dscp dscp
+                 Set the IP DSCP bits of the control connection. Both numeric and
+                 symbolic values are accepted. Numeric values can be specified in
+                 decimal, octal and hex (see --control-tos above).
+
           -m, --mptcp
                  Use the MPTCP variant for the current protocol.  This  only  ap-
                  plies to TCP and enables MPTCP usage.

src/iperf.h

@@ -170,6 +170,7 @@ struct iperf_settings
     int       mss;                  /* for TCP MSS */
     int       ttl;                  /* IP TTL option */
     int       tos;                  /* type of service bit */
+    int       ctrl_tos;             /* type of service for control socket */
     int       flowlabel;            /* IPv6 flow label */
     iperf_size_t bytes;             /* number of bytes to send */
     iperf_size_t blocks;            /* number of blocks (packets) to send */

src/iperf_api.c

@@ -1135,6 +1135,8 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
         {"version6", no_argument, NULL, '6'},
         {"tos", required_argument, NULL, 'S'},
         {"dscp", required_argument, NULL, OPT_DSCP},
+        {"control-tos", required_argument, NULL, OPT_CONTROL_TOS},
+        {"control-dscp", required_argument, NULL, OPT_CONTROL_DSCP},
 	{"extra-data", required_argument, NULL, OPT_EXTRA_DATA},
 #if defined(HAVE_FLOWLABEL)
         {"flowlabel", required_argument, NULL, 'L'},
@@ -1505,6 +1507,22 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
 		}
 		client_flag = 1;
                 break;
+            case OPT_CONTROL_TOS:
+                test->settings->ctrl_tos = strtol(optarg, &endptr, 0);
+		if (endptr == optarg ||
+		    test->settings->ctrl_tos < 0 ||
+		    test->settings->ctrl_tos > 255) {
+		    i_errno = IEBADTOS;
+		    return -1;
+		}
+                break;
+	    case OPT_CONTROL_DSCP:
+                test->settings->ctrl_tos = parse_qos(optarg);
+		if(test->settings->ctrl_tos < 0) {
+			i_errno = IEBADTOS;
+			return -1;
+		}
+                break;
 	    case OPT_EXTRA_DATA:
 		test->extra_data = strdup(optarg);
 		client_flag = 1;
@@ -5487,6 +5505,34 @@ iflush(struct iperf_test *test)
     return rc2;
 }
 
+int
+iperf_set_tos(int s, int tos)
+{
+    if (tos) {
+        if (getsockdomain(s) == AF_INET6) {
+#ifdef IPV6_TCLASS
+            if (setsockopt(s, IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0) {
+                i_errno = IESETCOS;
+                return -1;
+            }
+            if (setsockopt(s, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0) {
+                /* ignore any failure of v4 TOS in IPv6 case */
+            }
+#else
+            i_errno = IESETCOS;
+            return -1;
+#endif
+        } else {
+            if (setsockopt(s, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0) {
+                i_errno = IESETTOS;
+                return -1;
+            }
+        }
+    }
+
+    return 0;
+}
+
 #if defined (HAVE_TCP_KEEPALIVE)
 // Set Control Connection TCP Keepalive (especially useful for long UDP test sessions)
 int

src/iperf_api.h

@@ -106,6 +106,8 @@ typedef atomic_uint_fast64_t atomic_iperf_size_t;
 #define OPT_SKIP_RX_COPY 32
 #define OPT_JSON_STREAM_FULL_OUTPUT 33
 #define OPT_SERVER_MAX_DURATION 34
+#define OPT_CONTROL_TOS 35
+#define OPT_CONTROL_DSCP 36
 
 /* states */
 #define TEST_START 1
@@ -319,6 +321,12 @@ void      iperf_free_stream(struct iperf_stream * sp);
  */
 int       iperf_common_sockopts(struct iperf_test *, int s);
 
+/**
+ * iperf_set_tos -- set socket TOS
+ *
+ */
+int       iperf_set_tos(int s, int tos);
+
 #if defined (HAVE_TCP_KEEPALIVE)
 /**
  * iperf_set_control_keepalive -- set control connection TCP keepalive

src/iperf_client_api.c

@@ -33,6 +33,7 @@
 #include <signal.h>
 #include <sys/types.h>
 #include <netinet/in.h>
+#include <netdb.h>
 #include <sys/select.h>
 #include <sys/uio.h>
 #include <arpa/inet.h>
@@ -409,6 +410,37 @@ iperf_handle_message_client(struct iperf_test *test)
     return 0;
 }
 
+/*
+ * Make connection to server
+ * This is derived from netdial() but also sets the tos before connection.
+ */
+static int
+netdial_with_tos(int domain, int proto, const char *local, const char *bind_dev, int local_port, const char *server, int port, int timeout, int tos)
+{
+    struct addrinfo *server_res = NULL;
+    int s, saved_errno;
+
+    s = create_socket(domain, proto, 0, local, bind_dev, local_port, server, port, &server_res);
+    if (s < 0) {
+      return -1;
+    }
+
+    // Set IP TOS
+    if (iperf_set_tos(s, tos) < 0) {
+        return -1;
+    }
+
+    if (timeout_connect(s, (struct sockaddr *) server_res->ai_addr, server_res->ai_addrlen, timeout) < 0 && errno != EINPROGRESS) {
+	saved_errno = errno;
+	close(s);
+	freeaddrinfo(server_res);
+	errno = saved_errno;
+        return -1;
+    }
+
+    freeaddrinfo(server_res);
+    return s;
+}
 
 
 /* iperf_connect -- client to server connection function */
@@ -430,8 +462,9 @@ iperf_connect(struct iperf_test *test)
 
     /* Create and connect the control channel */
     if (test->ctrl_sck < 0)
-	// Create the control channel using an ephemeral port
-	test->ctrl_sck = netdial(test->settings->domain, Ptcp, test->bind_address, test->bind_dev, 0, test->server_hostname, test->server_port, test->settings->connect_timeout);
+    // Create the control channel using an ephemeral port
+    test->ctrl_sck = netdial_with_tos(test->settings->domain, Ptcp, test->bind_address, test->bind_dev, 0, test->server_hostname,
+                                      test->server_port, test->settings->connect_timeout, test->settings->ctrl_tos);
     if (test->ctrl_sck < 0) {
         i_errno = IECONNECT;
         return -1;

src/iperf_locale.c

@@ -159,6 +159,13 @@ const char usage_longstr[] = "Usage: iperf3 [-s|-c host] [options]\n"
                            "                            and client during the authentication process\n"
                            "  --use-pkcs1-padding       use pkcs1 padding at your own risk\n"
 #endif //HAVE_SSL
+                           "  --control-tos N           set the IP type of service of the control connection, 0-255.\n"
+                           "                            The usual prefixes for octal and hex can be used,\n"
+                           "                            i.e. 52, 064 and 0x34 all specify the same value.\n"
+
+                           "  --control-dscp val        set the IP dscp value of the control connection, either 0-63 or symbolic.\n"
+                           "                            Numeric values can be specified in decimal,\n"
+                           "                            octal and hex (see --control-tos above).\n"
                            "Client specific:\n"
                            "  -c, --client <host>[%%<dev>] run in client mode, connecting to <host>\n"
                            "                              (option <dev> equivalent to `--bind-dev <dev>`)\n"

src/iperf_server_api.c

@@ -129,6 +129,12 @@ iperf_server_listen(struct iperf_test *test)
 	}
     }
 
+    // Set IP TOS
+    if (iperf_set_tos(test->listener, test->settings->ctrl_tos) < 0) {
+        close(test->listener);
+        return -1;
+    }
+
     if (!test->json_output) {
         if (test->server_last_run_rc != 2)
             test->server_test_number +=1;
@@ -174,6 +180,11 @@ iperf_accept(struct iperf_test *test)
             goto error_handling;
         }
 
+        // Set IP TOS
+        if (iperf_set_tos(test->ctrl_sck, test->settings->ctrl_tos) < 0) {
+            goto error_handling;
+        }
+
 #if defined(HAVE_TCP_USER_TIMEOUT)
         int opt;
         if ((opt = test->settings->snd_timeout)) {