enh: Add support for SO_PRIORITY socket option.

configure.ac

@@ -242,6 +242,18 @@ if test "x$iperf3_cv_header_so_bindtodevice" = "xyes"; then
     AC_DEFINE([HAVE_SO_BINDTODEVICE], [1], [Have SO_BINDTODEVICE sockopt.])
 fi
 
+# Check for SO_PRIORITY sockopt (believed to be Linux only)
+AC_CACHE_CHECK([SO_PRIORITY socket option],
+[iperf3_cv_header_so_priority],
+AC_COMPILE_IFELSE(
+  [AC_LANG_PROGRAM([[#include <sys/socket.h>]],
+                   [[int foo = SO_PRIORITY;]])],
+  iperf3_cv_header_so_priority=yes,
+  iperf3_cv_header_so_priority=no))
+if test "x$iperf3_cv_header_so_priority" = "xyes"; then
+    AC_DEFINE([HAVE_SO_PRIORITY], [1], [Have SO_PRIORITY sockopt.])
+fi
+
 # Check for IP_MTU_DISCOVER (mostly on Linux)
 AC_CACHE_CHECK([IP_MTU_DISCOVER socket option],
 [iperf3_cv_header_ip_mtu_discover],

docs/invoking.rst

@@ -375,6 +375,14 @@ the executable.
                  set the IP type of service. The usual prefixes for octal and hex
                  can be used, i.e. 52, 064 and 0x34 all specify the same value.
 
+          --sock-prio n
+		 Set the protocol-defined priority for all packets to be sent
+		 on this socket.  Linux uses this value to order the networking
+		 queues: packets with a higher priority may be processed first
+		 depending on the selected device queueing discipline.  Setting
+		 a priority outside the range 0 to 6 requires the CAP_NET_ADMIN
+		 capability
+
           --dscp dscp
                  set  the  IP  DSCP  bits.   Both numeric and symbolic values are
                  accepted. Numeric values can be specified in decimal, octal  and

src/iperf.h

@@ -151,6 +151,9 @@ struct iperf_settings
     int       mss;                  /* for TCP MSS */
     int       ttl;                  /* IP TTL option */
     int       tos;                  /* type of service bit */
+#if defined(HAVE_SO_PRIORITY)
+    int       sock_prio;            /* protocol-defined priority */
+#endif // HAVE_SO_PRIORITY
     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

@@ -881,7 +881,13 @@ void
 iperf_on_test_start(struct iperf_test *test)
 {
     if (test->json_output) {
-	cJSON_AddItemToObject(test->json_start, "test_start", iperf_json_printf("protocol: %s  num_streams: %d  blksize: %d  omit: %d  duration: %d  bytes: %d  blocks: %d  reverse: %d  tos: %d  target_bitrate: %d bidir: %d fqrate: %d", test->protocol->name, (int64_t) test->num_streams, (int64_t) test->settings->blksize, (int64_t) test->omit, (int64_t) test->duration, (int64_t) test->settings->bytes, (int64_t) test->settings->blocks, test->reverse?(int64_t)1:(int64_t)0, (int64_t) test->settings->tos, (int64_t) test->settings->rate, (int64_t) test->bidirectional, (uint64_t) test->settings->fqrate));
+	cJSON_AddItemToObject(test->json_start, "test_start", iperf_json_printf("protocol: %s  num_streams: %d  blksize: %d  omit: %d  duration: %d  bytes: %d  blocks: %d  reverse: %d  tos: %d  target_bitrate: %d bidir: %d fqrate: %d sock_prio: %d", test->protocol->name, (int64_t) test->num_streams, (int64_t) test->settings->blksize, (int64_t) test->omit, (int64_t) test->duration, (int64_t) test->settings->bytes, (int64_t) test->settings->blocks, test->reverse?(int64_t)1:(int64_t)0, (int64_t) test->settings->tos, (int64_t) test->settings->rate, (int64_t) test->bidirectional, (uint64_t) test->settings->fqrate,
+#if defined(HAVE_SO_PRIORITY)
+										(int64_t) test->settings->sock_prio
+#else /* HAVE_SO_PRIORITY */
+										0
+#endif
+										));
     } else {
 	if (test->verbose) {
 	    if (test->settings->bytes)
@@ -1083,6 +1089,9 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
         {"version4", no_argument, NULL, '4'},
         {"version6", no_argument, NULL, '6'},
         {"tos", required_argument, NULL, 'S'},
+#if defined(HAVE_SO_PRIORITY)
+        {"sock-prio", required_argument, NULL, OPT_SOCK_PRIO},
+#endif /* HAVE_SO_PRIORITY */
         {"dscp", required_argument, NULL, OPT_DSCP},
 	{"extra-data", required_argument, NULL, OPT_EXTRA_DATA},
 #if defined(HAVE_FLOWLABEL)
@@ -1404,6 +1413,21 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
 		}
 		client_flag = 1;
                 break;
+	    case OPT_SOCK_PRIO:
+#if defined(HAVE_SO_PRIORITY)
+                test->settings->sock_prio = strtol(optarg, &endptr, 0);
+		if (endptr == optarg ||
+		    test->settings->sock_prio < 0 ||
+		    test->settings->sock_prio > 15) {
+		    i_errno = IEBADSOPRIO;
+		    return -1;
+		}
+		client_flag = 1;
+#else /* HAVE_SO_PRIORITY */
+                i_errno = IEUNIMP;
+                return -1;
+#endif /* HAVE_SO_PRIORITY */
+                break;
 	    case OPT_DSCP:
                 test->settings->tos = parse_qos(optarg);
 		if(test->settings->tos < 0) {
@@ -2210,6 +2234,10 @@ send_parameters(struct iperf_test *test)
 	    cJSON_AddNumberToObject(j, "burst", test->settings->burst);
 	if (test->settings->tos)
 	    cJSON_AddNumberToObject(j, "TOS", test->settings->tos);
+#if defined(HAVE_SO_PRIORITY)
+	if (test->settings->sock_prio)
+	    cJSON_AddNumberToObject(j, "SOCK_PRIO", test->settings->sock_prio);
+#endif /* HAVE_SO_PRIORITY */
 	if (test->settings->flowlabel)
 	    cJSON_AddNumberToObject(j, "flowlabel", test->settings->flowlabel);
 	if (test->title)
@@ -2326,6 +2354,10 @@ get_parameters(struct iperf_test *test)
 	    test->settings->burst = j_p->valueint;
 	if ((j_p = cJSON_GetObjectItem(j, "TOS")) != NULL)
 	    test->settings->tos = j_p->valueint;
+#if defined(HAVE_SO_PRIORITY)
+	if ((j_p = cJSON_GetObjectItem(j, "SOCK_PRIO")) != NULL)
+	    test->settings->sock_prio = j_p->valueint;
+#endif /* HAVE_SO_PRIORITY */
 	if ((j_p = cJSON_GetObjectItem(j, "flowlabel")) != NULL)
 	    test->settings->flowlabel = j_p->valueint;
 	if ((j_p = cJSON_GetObjectItem(j, "title")) != NULL)
@@ -3188,6 +3220,9 @@ iperf_reset_test(struct iperf_test *test)
     test->settings->burst = 0;
     test->settings->mss = 0;
     test->settings->tos = 0;
+#if defined(HAVE_SO_PRIORITY)
+    test->settings->sock_prio = 0;
+#endif /* HAVE_SO_PRIORITY */
     test->settings->dont_fragment = 0;
     test->zerocopy = 0;
 
@@ -4438,6 +4473,16 @@ iperf_common_sockopts(struct iperf_test *test, int s)
             }
         }
     }
+
+#if defined(HAVE_SO_PRIORITY)
+    if ((opt = test->settings->sock_prio)) {
+	if (setsockopt(s, SOL_SOCKET, SO_PRIORITY, &opt, sizeof(opt)) < 0) {
+	    i_errno = IESETSOPRIO;
+	    return -1;
+	}
+    }
+#endif /* HAVE_SO_PRIORITY */
+
     return 0;
 }
 

src/iperf_api.h

@@ -90,6 +90,7 @@ typedef uint64_t iperf_size_t;
 #define OPT_DONT_FRAGMENT 26
 #define OPT_RCV_TIMEOUT 27
 #define OPT_SND_TIMEOUT 28
+#define OPT_SOCK_PRIO 29
 
 /* states */
 #define TEST_START 1
@@ -406,6 +407,7 @@ 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
+    IEBADSOPRIO = 35,	    // Bad socket priority value
     /* Test errors */
     IENEWTEST = 100,        // Unable to create a new test (check perror)
     IEINITTEST = 101,       // Test initialization failed (check perror)
@@ -456,6 +458,7 @@ enum {
     IEBINDDEVNOSUPPORT = 146,  // `ip%%dev` is not supported as system does not support bind to device
     IEHOSTDEV = 147,        // host device name (ip%%<dev>) is supported (and required) only for IPv6 link-local address
     IESETUSERTIMEOUT = 148, // Unable to set TCP USER_TIMEOUT (check perror)
+    IESETSOPRIO = 149,      // Unable to set socket priority (check perror)
     /* Stream errors */
     IECREATESTREAM = 200,   // Unable to create a new stream (check herror/perror)
     IEINITSTREAM = 201,     // Unable to initialize stream (check herror/perror)

src/iperf_locale.c

@@ -202,6 +202,9 @@ const char usage_longstr[] = "Usage: iperf3 [-s|-c host] [options]\n"
                            "  --dscp N or --dscp val    set the IP dscp value, either 0-63 or symbolic.\n"
                            "                            Numeric values can be specified in decimal,\n"
                            "                            octal and hex (see --tos above).\n"
+#if defined(HAVE_SO_PRIORITY)
+                           "      --sock-prio N         set the socket priority (only supported on Linux)\n"
+#endif /* HAVE_SO_PRIORITY */
 #if defined(HAVE_FLOWLABEL)
                            "  -L, --flowlabel N         set the IPv6 flow label (only supported on Linux)\n"
 #endif /* HAVE_FLOWLABEL */