[PATCH] add -Q "connection quantum" to iperf 2, ending client conns after specified time

[nick black]

I've added a '-Q' '--quantum' option to iperf2 in our deployments, enforcing a time limit on client connections, after which they will be terminated by the server. This was necessary to keep our singly-threaded iperf from being tied up by an unresponsive client. I doubt that this patch will be accepted into iperf2, but you're welcome to take it.

If merged, please credit Nick Black of Luma, Inc.

diff -ur iperf-2.0.9/include/Settings.hpp dankperf-2.0.9/include/Settings.hpp
--- iperf-2.0.9/include/Settings.hpp    2016-06-20 19:41:31.000000000 -0400
+++ dankperf-2.0.9/include/Settings.hpp 2017-06-30 19:03:58.062194431 -0400
@@ -182,6 +182,7 @@
     Socklen_t size_local;
     nthread_t mTID;
     char* mCongestion;

+    max_size_t mQuantum;
 #if defined( HAVE_WIN32_THREAD )
     HANDLE mHandle;
 #endif
@@ -225,6 +226,7 @@
 #define FLAG_BWSET          0x01000000
 #define FLAG_ENHANCEDREPORT 0x02000000
 #define FLAG_SERVERMODETIME 0x04000000
+#define FLAG_SERVERQUANTUM  0x08000000

 #define isBuflenSet(settings)      ((settings->flags & FLAG_BUFLENSET) != 0)
 #define isCompat(settings)         ((settings->flags & FLAG_COMPAT) != 0)
@@ -255,6 +257,7 @@
 #define isBWSet(settings)          ((settings->flags & FLAG_BWSET) != 0)
 #define isEnhanced(settings)    ((settings->flags & FLAG_ENHANCEDREPORT) != 0)
 #define isServerModeTime(settings)    ((settings->flags & FLAG_SERVERMODETIME) != 0)
+#define isServerQuantum(settings)  ((settings->flags & FLAG_SERVERQUANTUM) != 0)

 #define setBuflenSet(settings)     settings->flags |= FLAG_BUFLENSET
 #define setCompat(settings)        settings->flags |= FLAG_COMPAT
@@ -283,6 +286,7 @@
 #define setBWSet(settings)         settings->flags |= FLAG_BWSET
 #define setEnhanced(settings)      settings->flags |= FLAG_ENHANCEDREPORT
 #define setServerModeTime(settings)      settings->flags |= FLAG_SERVERMODETIME
+#define setServerQuantum(settings) settings->flags |= FLAG_SERVERQUANTUM

 #define unsetBuflenSet(settings)   settings->flags &= ~FLAG_BUFLENSET
 #define unsetCompat(settings)      settings->flags &= ~FLAG_COMPAT
@@ -311,6 +315,7 @@
 #define unsetBWSet(settings)       settings->flags &= ~FLAG_BWSET
 #define unsetEnhanced(settings)    settings->flags &= ~FLAG_ENHANCEDREPORT
 #define unsetServerModeTime(settings)    settings->flags &= ~FLAG_SERVERMODETIME
+#define unsetServerQuantum(settings)     settings->flags &= ~FLAG_SERVERQUANTUM


 #define HEADER_VERSION1 0x80000000
diff -ur iperf-2.0.9/src/Locale.c dankperf-2.0.9/src/Locale.c
--- iperf-2.0.9/src/Locale.c    2016-06-20 19:41:31.000000000 -0400
+++ dankperf-2.0.9/src/Locale.c 2017-06-30 18:32:25.276839730 -0400
@@ -97,7 +97,8 @@
 Server specific:\n\
   -s, --server             run in server mode\n\
   -U, --single_udp         run in single threaded UDP mode\n\

-  -D, --daemon             run the server as a daemon\n"
+  -D, --daemon             run the server as a daemon\n\
+  -Q, --quantum            maximum time allowed each client connection\n"
 #ifdef WIN32
 "  -R, --remove             remove service in win32\n"
 #endif
diff -ur iperf-2.0.9/src/Server.cpp dankperf-2.0.9/src/Server.cpp
--- iperf-2.0.9/src/Server.cpp  2016-09-08 12:27:20.000000000 -0400
+++ dankperf-2.0.9/src/Server.cpp   2017-07-01 22:49:13.978249242 -0400
@@ -106,7 +106,7 @@
     max_size_t totLen = 0;
     ReportStruct *reportstruct = NULL;
     int running;
-    bool mMode_Time = isServerModeTime( mSettings );
+    bool mMode_Time = isServerModeTime( mSettings ) || isServerQuantum( mSettings );

     reportstruct = new ReportStruct;
     if ( reportstruct != NULL ) {
@@ -122,6 +122,8 @@
        sorcvtimer = (int) (mSettings->mInterval * 1e6) / 2;
    } else if (isModeTime(mSettings)) {
        sorcvtimer = (mSettings->mAmount * 1000) / 2;

+   } else if (isServerQuantum(mSettings)) {
+       sorcvtimer = (mSettings->mQuantum * 1000) / 2;
    }
    if (sorcvtimer > 0) {
 #ifdef WIN32
@@ -154,7 +156,11 @@
    // setup termination variables
    if ( mMode_Time ) {
        mEndTime.setnow();
-       mEndTime.add( mSettings->mAmount / 100.0 );
+       if (mSettings->mQuantum) {
+           mEndTime.add( mSettings->mQuantum / 100.0 );
+       } else {
+           mEndTime.add( mSettings->mAmount / 100.0 );
+       }
    }
         do {
        reportstruct->emptyreport=0;
@@ -205,9 +211,6 @@
         gettimeofday( &(reportstruct->packetTime), NULL );
 #endif // GETTIME           


-   if(0.0 == mSettings->mInterval) {
-       reportstruct->packetLen = totLen;
-        }
    ReportPacket( mSettings->reporthdr, reportstruct );
         CloseReport( mSettings->reporthdr, reportstruct );
     } else {
diff -ur iperf-2.0.9/src/Settings.cpp dankperf-2.0.9/src/Settings.cpp
--- iperf-2.0.9/src/Settings.cpp    2016-09-08 12:27:20.000000000 -0400
+++ dankperf-2.0.9/src/Settings.cpp 2017-07-01 22:32:50.343862497 -0400
@@ -116,6 +116,7 @@
 {"nodelay",          no_argument, NULL, 'N'},
 {"listenport", required_argument, NULL, 'L'},
 {"parallel",   required_argument, NULL, 'P'},
+{"quantum",    required_argument, NULL, 'Q'},
 {"remove",           no_argument, NULL, 'R'},
 {"tos",        required_argument, NULL, 'S'},
 {"ttl",        required_argument, NULL, 'T'},
@@ -161,6 +162,7 @@
 {"IPERF_NODELAY",          no_argument, NULL, 'N'},
 {"IPERF_LISTENPORT", required_argument, NULL, 'L'},
 {"IPERF_PARALLEL",   required_argument, NULL, 'P'},
+{"IPERF_QUANTUM",    required_argument, NULL, 'Q'},
 {"IPERF_TOS",        required_argument, NULL, 'S'},
 {"IPERF_TTL",        required_argument, NULL, 'T'},
 {"IPERF_SINGLE_UDP",       no_argument, NULL, 'U'},
@@ -172,7 +174,7 @@

 #define SHORT_OPTIONS()

-const char short_options[] = "1b:c:def:hi:l:mn:o:p:rst:uvw:x:y:zB:CDF:IL:M:NP:RS:T:UVWZ:";
+const char short_options[] = "1b:c:def:hi:l:mn:o:p:rst:uvw:x:y:zB:CDF:IL:M:NP:Q:RS:T:UVWZ:";

 /* -------------------------------------------------------------------

  * defaults
@@ -231,6 +233,7 @@
     //main->mMSS          = 0;           // -M,  ie. don't set MSS
     //main->mNodelay    = false;         // -N,  don't set nodelay
     //main->mThreads      = 0;           // -P,
+    //main->mQuantum      = 0;           // -Q,  don't use a server quantum
     //main->mRemoveService = false;      // -R,
     //main->mTOS          = 0;           // -S,  ie. don't set type of service
     main->mTTL          = 1;             // -T,  link-local TTL
@@ -586,7 +589,7 @@
            mExtSettings->mBindPort = atoi(results);
        }
        }
-       delete parsedopts;
+       delete[] parsedopts;
        if (mExtSettings->mLocalhost == NULL) {
        mExtSettings->mLocalhost = new char[ strlen( optarg ) + 1 ];
        strcpy( mExtSettings->mLocalhost, optarg );
@@ -668,6 +671,11 @@
 #endif
             break;


+        case 'Q': // time to allow each client in server mode
+            setServerQuantum( mExtSettings );
+            mExtSettings->mQuantum = (int) (atof( optarg ) * 100.0);
+            break;
+
         case 'R':
             setRemoveService( mExtSettings );
             break;

[Robert McMahon]

Curious, how is this different from setting -t on the server/listener?

Bob