Issue esnet#1107 support of IP Do-Not-Fragment flag (with debug)

configure

@@ -13813,9 +13813,7 @@ fi
 $as_echo "$iperf3_cv_header_tcp_congestion" >&6; }
 if test "x$iperf3_cv_header_tcp_congestion" = "xyes"; then
 
-# DBO >>> $as_echo "#define HAVE_TCP_CONGESTION 1" >>confdefs.h
-$as_echo "#undef HAVE_TCP_CONGESTION 1" >>confdefs.h
-# <<< DBO */
+$as_echo "#define HAVE_TCP_CONGESTION 1" >>confdefs.h
 
 fi
 

src/iperf.h

@@ -153,6 +153,7 @@ struct iperf_settings
     iperf_size_t blocks;            /* number of blocks (packets) to send */
     char      unit_format;          /* -f */
     int       num_ostreams;         /* SCTP initmsg settings */
+    int       dont_fragment;        /* Whether to set IP flag Do-Not_Fragment */
 #if defined(HAVE_SSL)
     char      *authtoken;           /* Authentication token */
     char      *client_username;

src/iperf_api.c

@@ -388,6 +388,12 @@ iperf_get_test_connect_timeout(struct iperf_test *ipt)
     return ipt->settings->connect_timeout;
 }
 
+int
+iperf_get_dont_fragment(struct iperf_test *ipt)
+{
+    return ipt->settings->dont_fragment;
+}
+
 /************** Setter routines for some fields inside iperf_test *************/
 
 void
@@ -719,6 +725,11 @@ iperf_set_test_connect_timeout(struct iperf_test* ipt, int ct)
     ipt->settings->connect_timeout = ct;
 }
 
+void
+iperf_set_dont_fragment(struct iperf_test* ipt, int dnf)
+{
+    ipt->settings->dont_fragment = dnf;
+}
 
 /********************** Get/set test protocol structure ***********************/
 
@@ -950,6 +961,7 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
     {"rsa-private-key-path", required_argument, NULL, OPT_SERVER_RSA_PRIVATE_KEY},
     {"authorized-users-path", required_argument, NULL, OPT_SERVER_AUTHORIZED_USERS},
     {"time-skew-threshold", required_argument, NULL, OPT_SERVER_SKEW_THRESHOLD},
+    {"dont-fragment", no_argument, NULL, OPT_DONT_FRAGMENT},
 #endif /* HAVE_SSL */
 	{"fq-rate", required_argument, NULL, OPT_FQ_RATE},
 	{"pacing-timer", required_argument, NULL, OPT_PACING_TIMER},
@@ -1369,6 +1381,10 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
                 return -1;
             }
             break;
+        case OPT_DONT_FRAGMENT:
+            test->settings->dont_fragment = 1;
+            client_flag = 1;
+            break;
 #endif /* HAVE_SSL */
 	    case OPT_PACING_TIMER:
 		test->settings->pacing_timer = unit_atoi(optarg);
@@ -4030,6 +4046,16 @@ iperf_init_stream(struct iperf_stream *sp, struct iperf_test *test)
         }
     }
 
+    /* Set Do-Not-Fragment */
+    if ((opt = test->settings->dont_fragment)) {
+        printf("SETTING DONT FRAGMENT\n");
+        opt = IP_PMTUDISC_DO;
+        if (setsockopt(sp->socket, IPPROTO_IP, IP_MTU_DISCOVER, &opt, sizeof(opt)) < 0) {
+            i_errno = IESETDONTFRAGMENT;
+            return -1;
+        }
+    }
+
     return 0;
 }
 

src/iperf_api.h

@@ -81,6 +81,7 @@ typedef uint64_t iperf_size_t;
 #define OPT_TIMESTAMPS 22
 #define OPT_SERVER_SKEW_THRESHOLD 23
 #define OPT_BIND_DEV 24
+#define OPT_DONT_FRAGMENT 25
 
 /* states */
 #define TEST_START 1
@@ -139,6 +140,7 @@ char*	iperf_get_extra_data( struct iperf_test* ipt );
 char*	iperf_get_iperf_version(void);
 int	iperf_get_test_no_delay( struct iperf_test* ipt );
 int	iperf_get_test_connect_timeout( struct iperf_test* ipt );
+int iperf_get_dont_fragment( struct iperf_test* ipt );
 
 /* Setter routines for some fields inside iperf_test. */
 void	iperf_set_verbose( struct iperf_test* ipt, int verbose );
@@ -176,6 +178,7 @@ void    iperf_set_test_tos( struct iperf_test* ipt, int tos );
 void	iperf_set_test_extra_data( struct iperf_test* ipt, const char *dat );
 void    iperf_set_test_bidirectional( struct iperf_test* ipt, int bidirectional);
 void    iperf_set_test_no_delay( struct iperf_test* ipt, int no_delay);
+void    iperf_set_dont_fragment( struct iperf_test* ipt, int dont_fragment );
 
 #if defined(HAVE_SSL)
 void    iperf_set_test_client_username(struct iperf_test *ipt, const char *client_username);
@@ -410,6 +413,7 @@ enum {
     IESETBUF2= 141,	    // Socket buffer size incorrect (written value != read value)
     IEAUTHTEST = 142,       // Test authorization failed
     IEBINDDEV = 143,        // Unable to bind-to-device (check perror, maybe permissions?)
+    IESETDONTFRAGMENT = 144,    // Unable to set IP Do-Not-Fragment
     /* Stream errors */
     IECREATESTREAM = 200,   // Unable to create a new stream (check herror/perror)
     IEINITSTREAM = 201,     // Unable to initialize stream (check herror/perror)

src/iperf_error.c

@@ -427,6 +427,9 @@ iperf_strerror(int int_errno)
     case IESKEWTHRESHOLD:
 	    snprintf(errstr, len, "skew threshold must be a positive number");
             break;
+        case IESETDONTFRAGMENT:
+	    snprintf(errstr, len, "unable to set IP Do-Not-Fragment flag");
+            break;
 	default:
 	    snprintf(errstr, len, "int_errno=%d", int_errno);
 	    perr = 1;

src/iperf_locale.c

@@ -187,6 +187,7 @@ const char usage_longstr[] = "Usage: iperf3 [-s|-c host] [options]\n"
                            "  --udp-counters-64bit      use 64-bit counters in UDP test packets\n"
                            "  --repeating-payload       use repeating pattern in payload, instead of\n"
                            "                            randomized payload (like in iperf2)\n"
+                           "  --dont-fragment           set IP Do-Not-fragment flag\n"
 #if defined(HAVE_SSL)
                            "  --username                username for authentication\n"
                            "  --rsa-public-key-path     path to the RSA public key used to encrypt\n"

src/tcp_info.c

@@ -95,7 +95,7 @@ void
 save_tcpinfo(struct iperf_stream *sp, struct iperf_interval_results *irp)
 {
 #if (defined(linux) || defined(__FreeBSD__) || defined(__NetBSD__)) && \
-	defined(TCP_INFO)/*DBO >>> */ && 0 /*<<<DBO*/
+	defined(TCP_INFO)
     socklen_t tcp_info_length = sizeof(struct tcp_info);
 
     if (getsockopt(sp->socket, IPPROTO_TCP, TCP_INFO, (void *)&irp->tcpInfo, &tcp_info_length) < 0)