Add SCTP information to --json output (#1731)

* Add SCTP information to --json output

* Fix compile error when SCTP is not supported

Author: davidBar-On

src/iperf.h

@@ -83,6 +83,14 @@ typedef atomic_uint_fast64_t atomic_iperf_size_t;
 typedef unsigned int uint
 #endif // __vxworks or __VXWORKS__
 
+struct iperf_sctp_info
+{
+    long rtt;
+    long pmtu;
+    uint32_t wnd;
+    uint32_t cwnd;
+};
+
 struct iperf_interval_results
 {
     atomic_iperf_size_t bytes_transferred; /* bytes transferred in this interval */
@@ -107,6 +115,9 @@ struct iperf_interval_results
     /* Just placeholders, never accessed. */
     char *tcpInfo;
 #endif
+#if defined(HAVE_SCTP_H)
+    struct iperf_sctp_info sctp_info;
+#endif /* HAVE_SCTP_H */
     long interval_retrans;
     long snd_cwnd;
     long snd_wnd;

src/iperf_api.c

@@ -3362,8 +3362,14 @@ iperf_stats_callback(struct iperf_test *test)
     struct iperf_interval_results *irp, temp;
     struct iperf_time temp_time;
     iperf_size_t total_interval_bytes_transferred = 0;
+#if defined(HAVE_SCTP_H)
+    struct iperf_sctp_info sctp_info;
+#endif /* HAVE_SCTP_H */
 
     temp.omitted = test->omitting;
+    temp.rtt = 0;
+    temp.rttvar = 0;
+    temp.pmtu = 0;
     SLIST_FOREACH(sp, &test->streams, streams) {
         rp = sp->result;
 	temp.bytes_transferred = sp->sender ? rp->bytes_sent_this_interval : rp->bytes_received_this_interval;
@@ -3431,6 +3437,36 @@ iperf_stats_callback(struct iperf_test *test)
 	    temp.outoforder_packets = sp->outoforder_packets;
 	    temp.cnt_error = sp->cnt_error;
 	}
+
+#if defined(HAVE_SCTP_H)
+	if (test->protocol->id == Psctp) {
+            if (iperf_sctp_get_info(sp, &sctp_info) >= 0) {;
+                temp.pmtu = sctp_info.pmtu;
+                temp.rtt = sctp_info.rtt;
+                temp.snd_cwnd = sctp_info.cwnd;
+                temp.snd_wnd = sctp_info.wnd;
+                if (temp.snd_cwnd > rp->stream_max_snd_cwnd) {
+                    rp->stream_max_snd_cwnd = temp.snd_cwnd;
+                }
+                if (temp.snd_wnd > rp->stream_max_snd_wnd) {
+                    rp->stream_max_snd_wnd = temp.snd_wnd;
+                }
+                if (temp.rtt >= 0) {
+                    temp.rtt = sctp_info.rtt;
+                    if (temp.rtt > rp->stream_max_rtt) {
+                        rp->stream_max_rtt = temp.rtt;
+                    }
+                    if (rp->stream_min_rtt == 0 ||
+                        temp.rtt < rp->stream_min_rtt) {
+                        rp->stream_min_rtt = temp.rtt;
+                    }
+                    rp->stream_sum_rtt += temp.rtt;
+                    rp->stream_count_rtt++;
+                }
+            }
+        }
+#endif /* HAVE_SCTP_H */
+
         add_to_interval_list(rp, &temp);
         rp->bytes_sent_this_interval = rp->bytes_received_this_interval = 0;
     }
@@ -3871,7 +3907,7 @@ iperf_print_results(struct iperf_test *test)
                 }
                 unit_snprintf(nbuf, UNIT_LEN, bandwidth, test->settings->unit_format);
                 if (test->protocol->id == Ptcp || test->protocol->id == Psctp) {
-                    if (test->sender_has_retransmits) {
+                    if (test->sender_has_retransmits || test->protocol->id == Psctp) {
                         /* Sender summary, TCP and SCTP with retransmits. */
                         if (test->json_output)
                             cJSON_AddItemToObject(json_summary_stream, report_sender, iperf_json_printf("socket: %d  start: %f  end: %f  seconds: %f  bytes: %d  bits_per_second: %f  retransmits: %d  max_snd_cwnd:  %d  max_snd_wnd:  %d  max_rtt:  %d  min_rtt:  %d  mean_rtt:  %d sender: %b", (int64_t) sp->socket, (double) start_time, (double) sender_time, (double) sender_time, (int64_t) bytes_sent, bandwidth * 8, (int64_t) sp->result->stream_retrans, (int64_t) sp->result->stream_max_snd_cwnd, (int64_t) sp->result->stream_max_snd_wnd, (int64_t) sp->result->stream_max_rtt, (int64_t) sp->result->stream_min_rtt, (int64_t) ((sp->result->stream_count_rtt == 0) ? 0 : sp->result->stream_sum_rtt / sp->result->stream_count_rtt), stream_must_be_sender));
@@ -4322,7 +4358,7 @@ print_interval_results(struct iperf_test *test, struct iperf_stream *sp, cJSON *
     et = iperf_time_in_secs(&temp_time);
 
     if (test->protocol->id == Ptcp || test->protocol->id == Psctp) {
-	if (test->sender_has_retransmits == 1 && sp->sender) {
+	if ((test->sender_has_retransmits == 1 || test->protocol->id == Psctp) && sp->sender) {
 	    /* Interval, TCP with retransmits. */
 	    if (test->json_output)
 		cJSON_AddItemToArray(json_interval_streams, iperf_json_printf("socket: %d  start: %f  end: %f  seconds: %f  bytes: %d  bits_per_second: %f  retransmits: %d  snd_cwnd:  %d  snd_wnd:  %d  rtt:  %d  rttvar: %d  pmtu: %d  omitted: %b sender: %b", (int64_t) sp->socket, (double) st, (double) et, (double) irp->interval_duration, (int64_t) irp->bytes_transferred, bandwidth * 8, (int64_t) irp->interval_retrans, (int64_t) irp->snd_cwnd, (int64_t) irp->snd_wnd, (int64_t) irp->rtt, (int64_t) irp->rttvar, (int64_t) irp->pmtu, irp->omitted, sp->sender));

src/iperf_sctp.c

@@ -39,10 +39,6 @@
 #include <sys/select.h>
 #include <limits.h>
 
-#ifdef HAVE_NETINET_SCTP_H
-#include <netinet/sctp.h>
-#endif /* HAVE_NETINET_SCTP_H */
-
 #include "iperf.h"
 #include "iperf_api.h"
 #include "iperf_sctp.h"
@@ -734,3 +730,49 @@ iperf_sctp_bindx(struct iperf_test *test, int s, int is_server)
     return -1;
 #endif /* HAVE_SCTP_H */
 }
+
+
+/* iperf_sctp_get_rtt
+ *
+ * Get SCTP stream RTT.
+ * Assuming that iperf3 supports only one-toone SCTP associassion, and not one-to-many associassion.
+ * 
+ * Main resouses used are RFC-6458, man pages for SCTP,
+ * https://docs.oracle.com/cd/E19253-01/817-4415/sockets-199/index.html.
+ * 
+ */
+int
+iperf_sctp_get_info(struct iperf_stream *sp, struct iperf_sctp_info *sctp_info)
+{
+#if defined(HAVE_SCTP_H)
+    struct sctp_status status;
+    socklen_t len;
+    sctp_assoc_t assoc_id;
+    int rc = 0;
+
+    if (sp->test->protocol->id != Psctp) {
+        rc = -1;
+    } else {
+#ifdef SCTP_FUTURE_ASSOC
+        assoc_id = SCTP_FUTURE_ASSOC;
+#else
+	assoc_id = 0;
+#endif
+        len = sizeof(status);
+        rc = sctp_opt_info(sp->socket, assoc_id, SCTP_STATUS, &status, &len);
+        if (rc < 0) {
+            if (sp->test->debug_level >= DEBUG_LEVEL_ERROR)
+                iperf_err(sp->test, "sctp_opt_info get SCTP_STATUS for socket %d failed with errno %d - %s", sp->socket, errno, strerror(errno));
+        } else {
+            sctp_info->wnd = status.sstat_rwnd;
+            sctp_info->rtt = status.sstat_primary.spinfo_srtt;
+            sctp_info->pmtu = status.sstat_primary.spinfo_mtu;
+            sctp_info->cwnd = status.sstat_primary.spinfo_cwnd;
+        }
+    }
+
+    return rc;
+#else
+    return -1;
+#endif /* HAVE_SCTP_H */
+}

src/iperf_sctp.h

@@ -27,6 +27,10 @@
 #ifndef        IPERF_SCTP_H
 #define        IPERF_SCTP_H
 
+#ifdef HAVE_NETINET_SCTP_H
+#include <netinet/sctp.h>
+#endif /* HAVE_NETINET_SCTP_H */
+
 /**
  * iperf_sctp_accept -- accepts a new SCTP connection
  * on sctp_listener_socket for SCTP data and param/result
@@ -65,4 +69,6 @@ int iperf_sctp_init(struct iperf_test *test);
 
 int iperf_sctp_bindx(struct iperf_test *test, int s, int is_server);
 
+int iperf_sctp_get_info(struct iperf_stream *sp, struct iperf_sctp_info *sctp_info);
+
 #endif