From ae7fa03b5414c82c50e311232aac7dfe7bba1332 Mon Sep 17 00:00:00 2001
From: Ralph Ronnquist <ralph.ronnquist@gmail.com>
Date: Sun, 26 Mar 2023 10:43:43 +1100
Subject: [PATCH] added heartbeat rate configuration

---
 debian/changelog |  6 ++++++
 rrqnet.8.adoc    |  9 ++++++++-
 rrqnet.c         | 33 ++++++++++++++++++++++++++-------
 3 files changed, 40 insertions(+), 8 deletions(-)

diff --git a/debian/changelog b/debian/changelog
index 3e588f3..d988a1c 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,9 @@
+rrqnet (1.6.2) unstable; urgency=medium
+
+  * add configuration of "heartbeat" messaging rate.
+
+ -- Ralph Ronnquist <ralph.ronnquist@gmail.com>  Sun, 26 Mar 2023 10:42:42 +1100
+
 rrqnet (1.6.1) unstable; urgency=medium
 
   * limiting dest IP capture to downlinks
diff --git a/rrqnet.8.adoc b/rrqnet.8.adoc
index ccc35c1..e6ed668 100644
--- a/rrqnet.8.adoc
+++ b/rrqnet.8.adoc
@@ -25,7 +25,7 @@ OPTIONS
 
 Note that any options must be given or omitted in the fixed order:
 
-  [-v] [-tpg] [-4] [-B n] [-T n] [-m mcast] [-t tap] [-S source]
+  [-v] [-tpg] [-4] [-B n] [-T n] [-H r] [-m mcast] [-t tap] [-S source]
 
 *-v*::
 
@@ -60,6 +60,13 @@ where it immediately puts received packets into the buffer queue which
 is serviced by the dispatch threads for optional decryption, dispatch
 decision, optional encryption and delivery.
 
+*-H* _r_::
+
+This sets the number of seconds *rrqnet* should wait between "heart
+beat" messages to uplinks. The default is 30. This is used to hold the
+uplink open for return traffic through NAT routers. Set to 0 to
+disable the heartbeat messages.
+
 *-m* _mcast_::
 
 This tells *rrqnet* to open an ipv4 UDP multicast channel as an
diff --git a/rrqnet.c b/rrqnet.c
index 193e673..b06c3ab 100644
--- a/rrqnet.c
+++ b/rrqnet.c
@@ -99,8 +99,7 @@ typedef struct _ReaderData {
 } ReaderData;
 
 // heartbeat interval, in seconds
-#define HEARTBEAT 30
-#define HEARTBEAT_MICROS ( HEARTBEAT * 1000000 )
+#define HEARTBEAT_MICROS ( heart_rate * 1000000 )
 
 // Macros for timing, for struct timeval variables
 #define TIME_MICROS(TM) (((int64_t) (TM)->tv_sec * 1000000) + (TM)->tv_usec )
@@ -184,6 +183,7 @@ static int udp_fd;
 static int udp_port;
 static int threads_count = 0;
 static int buffers_count = 0;
+static int heart_rate = 30;
 
 // Setup for multicast channel
 static struct {
@@ -691,6 +691,14 @@ static int parse_threads_count(char *arg) {
     return 0;
 }
 
+static int parse_heartbeat_rate(char *arg) {
+    if ( ( sscanf( arg, "%u", &heart_rate ) != 1 ) || heart_rate < 0 ) {
+	return 1;
+    }
+    VERBOSEOUT( "** Heartbeat rate = %d\n", heart_rate );
+    return 0;
+}
+
 static int parse_buffers_count(char *arg) {
     if ( ( sscanf( arg, "%u", &buffers_count ) != 1 ) || buffers_count < 1 ) {
 	return 1;
@@ -1461,7 +1469,7 @@ static void heartbeat(int fd) {
 	r = (struct Remote *) tmp;
 	VERBOSE3OUT( "heartbeat check %s\n", inet_stoa( &r->uaddr ) );
 	if ( r->spec && is_uplink( r->spec ) ) {
-	    if ( DIFF_MICROS( &now, &r->rec_when ) > HEARTBEAT_MICROS ) {
+	    if ( DIFF_MICROS( &now, &r->rec_when ) >= HEARTBEAT_MICROS ) {
 		VERBOSE3OUT( "heartbeat %s\n", inet_stoa( &r->uaddr ) );
 		write_remote( data, 0, r );
 	    }
@@ -1626,6 +1634,15 @@ int main(int argc, char *argv[]) {
 	i += 2;
 	ENSUREARGS( 1 );
     }
+    // then: optional -H seconds
+    if ( strncmp( "-H", argv[i], 2 ) == 0 ) {
+	ENSUREARGS( 2 );
+	if ( parse_heartbeat_rate( argv[i+1] ) ) {
+	    usage();
+	}
+	i += 2;
+	ENSUREARGS( 1 );
+    }
     // then: optional -m mcast
     if ( strncmp( "-m", argv[i], 2 ) == 0 ) {
 	ENSUREARGS( 2 );
@@ -1789,10 +1806,12 @@ int main(int argc, char *argv[]) {
 	pthread_create( &thread, 0, doreadTap, &tap_reader );
     }
 
-    // Start heartbeating to uplinks
-    for ( ;; ) {
-	sleep( HEARTBEAT );
-	heartbeat( udp_fd );
+    if ( heart_rate == 0 ) {
+	// Start heartbeating to uplinks
+	for ( ;; ) {
+	    sleep( heart_rate );
+	    heartbeat( udp_fd );
+	}
     }
     return 0;
 }
-- 
2.39.2