Add Time Flag For The Iperf Server Process (#1684)

* reject measurements from client's whose duration exceeds that of the server

* sum of test duration and omit must not exceed server's max duration

* client's test duration cannot be 0 when server sets max duration

* formatting

* add flag description to man page

* add server flag to case

* changes made for review comments

* handle errno

* man page capitalization

* adjust error code for server time max violation

* move validation to within get_parameters

* move validation to the end of the function

Author: manedurphy

src/iperf.h

@@ -312,6 +312,7 @@ struct iperf_test
     int       server_port;
     int       omit;                             /* duration of omit period (-O flag) */
     int       duration;                         /* total duration of test (-t flag) */
+    int       max_server_duration;               /* maximum possible duration of test as enforced by the server (--max-server-duration flag) */
     char     *diskfile_name;			/* -F option */
     int       affinity, server_affinity;	/* -A option */
 #if defined(HAVE_CPUSET_SETAFFINITY)

src/iperf3.1

@@ -250,6 +250,11 @@ Restart the server after \fIn\fR seconds in case it gets stuck.
 In one-off mode, this is the number of seconds the server will wait
 before exiting.
 .TP
+.BR --server-max-duration " "
+The maximum time, in seconds, that an iperf client can run against the server.
+When the sum of the client's time and omit values exceeds the max duration set by the server
+or the client's time value is 0, the measurement is rejected.
+.TP
 .BR --server-bitrate-limit " \fIn\fR[KMGT][/\fCn\fR]"
 Set a limit on the server side, which will cause a test to abort if
 the client specifies a test of more than \fIn\fR bits per second, or

src/iperf_api.c

@@ -1114,7 +1114,8 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
         {"udp", no_argument, NULL, 'u'},
         {"bitrate", required_argument, NULL, 'b'},
         {"bandwidth", required_argument, NULL, 'b'},
-	{"server-bitrate-limit", required_argument, NULL, OPT_SERVER_BITRATE_LIMIT},
+        {"server-bitrate-limit", required_argument, NULL, OPT_SERVER_BITRATE_LIMIT},
+        {"server-max-duration", required_argument, NULL, OPT_SERVER_MAX_DURATION},
         {"time", required_argument, NULL, 't'},
         {"bytes", required_argument, NULL, 'n'},
         {"blockcount", required_argument, NULL, 'k'},
@@ -1555,6 +1556,14 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
                 }
 		server_flag = 1;
 	        break;
+            case OPT_SERVER_MAX_DURATION:
+                test->max_server_duration = atoi(optarg);
+                if (test->max_server_duration < 0 || test->max_server_duration > MAX_TIME) {
+                    i_errno = IEDURATION;
+                    return -1;
+                }
+                server_flag = 1;
+                break;
             case OPT_RCV_TIMEOUT:
                 rcv_timeout_in = atoi(optarg);
                 if (rcv_timeout_in < MIN_NO_MSG_RCVD_TIMEOUT || rcv_timeout_in > MAX_TIME * SEC_TO_mS) {
@@ -2576,6 +2585,13 @@ get_parameters(struct iperf_test *test)
 	if (test->settings->rate)
 	    cJSON_AddNumberToObject(test->json_start, "target_bitrate", test->settings->rate);
 	cJSON_Delete(j);
+
+    /* Ensure that the client does not request to run longer than the server's configured max */
+    if ((test->max_server_duration > 0) && (((test->duration + test->omit) > test->max_server_duration) || (test->duration == 0))) {
+        i_errno = IEMAXSERVERTESTDURATIONEXCEEDED;
+        r = -1;
+    }
+
     }
     return r;
 }

src/iperf_api.h

@@ -105,6 +105,7 @@ typedef atomic_uint_fast64_t atomic_iperf_size_t;
 #define OPT_CNTL_KA 31
 #define OPT_SKIP_RX_COPY 32
 #define OPT_JSON_STREAM_FULL_OUTPUT 33
+#define OPT_SERVER_MAX_DURATION 34
 
 /* states */
 #define TEST_START 1
@@ -440,6 +441,7 @@ enum {
     IEUDPFILETRANSFER = 34, // Cannot transfer file using UDP
     IESERVERAUTHUSERS = 35,  // Cannot access authorized users file
     IECNTLKA = 36,          // Control connection Keepalive period should be larger than the full retry period (interval * count)
+    IEMAXSERVERTESTDURATIONEXCEEDED = 37, // Client's duration exceeds server's maximum duration
     /* Test errors */
     IENEWTEST = 100,        // Unable to create a new test (check perror)
     IEINITTEST = 101,       // Test initialization failed (check perror)

src/iperf_error.c

@@ -551,6 +551,9 @@ iperf_strerror(int int_errno)
             snprintf(errstr, len, "unable to set/get socket keepalive TCP number of retries (TCP_KEEPCNT) option");
             perr = 1;
             break;
+        case IEMAXSERVERTESTDURATIONEXCEEDED:
+            snprintf(errstr, len, "client's requested duration exceeds the server's maximum permitted limit");
+            break;
 	default:
 	    snprintf(errstr, len, "int_errno=%d", int_errno);
 	    perr = 1;

src/iperf_locale.c

@@ -149,6 +149,7 @@ const char usage_longstr[] = "Usage: iperf3 [-s|-c host] [options]\n"
 			   "                            total data rate.  Default is 5 seconds)\n"
                            "  --idle-timeout #          restart idle server after # seconds in case it\n"
                            "                            got stuck (default - no timeout)\n"
+                           "  --server-max-duration #   max time, in seconds, that an iperf test can run against the server\n"
 #if defined(HAVE_SSL)
                            "  --rsa-private-key-path    path to the RSA private key used to decrypt\n"
 			   "                            authentication credentials\n"