From 9c30a7268336f04cc61ecca09c61bdd3fd3670f4 Mon Sep 17 00:00:00 2001
From: Jef Driesen <jefdriesen@users.sourceforge.net>
Date: Fri, 16 May 2008 08:30:49 +0000
Subject: [PATCH] Added a public function to control the maximum number of
 retries.

---
 reefnet_sensusultra.c | 23 +++++++++++++++++++++++
 reefnet_sensusultra.h |  2 ++
 2 files changed, 25 insertions(+)

diff --git a/reefnet_sensusultra.c b/reefnet_sensusultra.c
index 9a69a97..8e70f06 100644
--- a/reefnet_sensusultra.c
+++ b/reefnet_sensusultra.c
@@ -22,6 +22,7 @@
 
 struct sensusultra {
 	struct serial *port;
+	unsigned int maxretries;
 };
 
 
@@ -40,6 +41,7 @@ reefnet_sensusultra_open (sensusultra **out, const char* name)
 
 	// Set the default values.
 	device->port = NULL;
+	device->maxretries = 2;
 
 	// Open the device.
 	int rc = serial_open (&device->port, name);
@@ -94,6 +96,17 @@ reefnet_sensusultra_close (sensusultra *device)
 }
 
 
+int
+reefnet_sensusultra_set_maxretries (sensusultra *device, unsigned int maxretries)
+{
+	if (device == NULL)
+		return REEFNET_ERROR;
+
+	device->maxretries = maxretries;
+
+	return REEFNET_SUCCESS;
+}
+
 static unsigned short
 reefnet_sensusultra_checksum (const unsigned char *data, unsigned int size)
 {
@@ -221,6 +234,7 @@ reefnet_sensusultra_handshake (sensusultra *device, unsigned char *data, unsigne
 	serial_flush (device->port, SERIAL_QUEUE_BOTH);
 
 	int rc = 0;
+	unsigned int nretries = 0;
 	unsigned char handshake[REEFNET_SENSUSULTRA_HANDSHAKE_SIZE + 2] = {0};
 	while ((rc = reefnet_sensusultra_packet (device, handshake, sizeof (handshake), 0)) != REEFNET_SUCCESS) {
 		// Automatically discard a corrupted handshake packet, 
@@ -228,6 +242,10 @@ reefnet_sensusultra_handshake (sensusultra *device, unsigned char *data, unsigne
 		if (rc != REEFNET_ERROR_PROTOCOL)
 			return rc;
 
+		// Abort if the maximum number of retries is reached.
+		if (nretries++ >= device->maxretries)
+			return rc;
+
 		// According to the developers guide, a 250 ms delay is suggested to
 		// guarantee that the prompt byte sent after the handshake packet is 
 		// not accidentally buffered by the host and (mis)interpreted as part 
@@ -277,6 +295,7 @@ reefnet_sensusultra_page (sensusultra *device, unsigned char *data, unsigned int
 		return REEFNET_ERROR;
 
 	int rc = 0;
+	unsigned int nretries = 0;
 	unsigned char package[REEFNET_SENSUSULTRA_PACKET_SIZE + 4] = {0};
 	while ((rc = reefnet_sensusultra_packet (device, package, sizeof (package), 2)) != REEFNET_SUCCESS) {
 		// Automatically discard a corrupted packet, 
@@ -284,6 +303,10 @@ reefnet_sensusultra_page (sensusultra *device, unsigned char *data, unsigned int
 		if (rc != REEFNET_ERROR_PROTOCOL)
 			return rc;
 
+		// Abort if the maximum number of retries is reached.
+		if (nretries++ >= device->maxretries)
+			return rc;
+
 		// Reject the packet.
 		rc = reefnet_sensusultra_send_uchar (device, REJECT);
 		if (rc != REEFNET_SUCCESS)
diff --git a/reefnet_sensusultra.h b/reefnet_sensusultra.h
index 644e2bb..1784238 100644
--- a/reefnet_sensusultra.h
+++ b/reefnet_sensusultra.h
@@ -18,6 +18,8 @@ int reefnet_sensusultra_open (sensusultra **device, const char* name);
 
 int reefnet_sensusultra_close (sensusultra *device);
 
+int reefnet_sensusultra_set_maxretries (sensusultra *device, unsigned int maxretries);
+
 int reefnet_sensusultra_handshake (sensusultra *device, unsigned char *data, unsigned int size);
 
 int reefnet_sensusultra_read_data (sensusultra *device, unsigned char *data, unsigned int size);