--- libaitmqtt/src/aitmqtt.c	2012/04/07 20:48:39	1.1.1.1.2.3
+++ libaitmqtt/src/aitmqtt.c	2012/04/25 16:25:52	1.1.1.1.2.6
@@ -3,7 +3,7 @@
 *  by Michael Pounov <misho@openbsd-bg.org>
 *
 * $Author: misho $
-* $Id: aitmqtt.c,v 1.1.1.1.2.3 2012/04/07 20:48:39 misho Exp $
+* $Id: aitmqtt.c,v 1.1.1.1.2.6 2012/04/25 16:25:52 misho Exp $
 *
 **************************************************************************
 The ELWIX and AITNET software is distributed under the following
@@ -53,10 +53,6 @@ char mqtt_Error[STRSIZ];
 
 #pragma GCC visibility pop
 
-//
-// Error maintenance functions ...
-//
-
 // mqtt_GetErrno() Get error code of last operation
 inline int
 mqtt_GetErrno()
@@ -85,7 +81,7 @@ mqtt_SetErr(int eno, char *estr, ...)
 }
 
 #pragma GCC visibility push(hidden)
-// _mqtt_readHEADER() read fixed header from MQTT message
+/* _mqtt_readHEADER() read fixed header from MQTT message */
 inline struct mqtthdr *
 _mqtt_readHEADER(mqtt_msg_t * __restrict buf, u_char cmd, int *bytes, int *len)
 {
@@ -106,7 +102,6 @@ _mqtt_readHEADER(mqtt_msg_t * __restrict buf, u_char c
 }
 #pragma GCC visibility pop
 
-// ----------------------------------------------------------
 
 /*
  * mqtt_msgFree() Free MQTT message
@@ -179,7 +174,7 @@ mqtt_msgRealloc(mqtt_msg_t * __restrict msg, u_short l
 	if (!msg)
 		return -1;
 
-	if (len == msg->msg_len)
+	if (len <= msg->msg_len)
 		return len;
 
 	p = realloc(msg->msg_base, len);
@@ -543,5 +538,66 @@ mqtt_sqlTopic(const char *csInput, char * __restrict p
 		*s = *pos;
 	}
 
+	return ret;
+}
+
+
+/*
+ * mqtt_KeepAlive() - Keep Alive check routine
+ *
+ * @sock = connected socket
+ * @ka = keep alive timeout
+ * @tries = tries for receive correct ping response, usually ==1
+ * return: -1 error, 0 host is alive, 1 timeout session or 2 broken session
+ */
+int
+mqtt_KeepAlive(int sock, u_short ka, u_char tries)
+{
+	int ret = 0;
+	struct pollfd pfd;
+	mqtt_msg_t msg = { NULL, 0 };
+
+	if (sock < 3)
+		return -1;	/* error */
+
+	pfd.fd = sock;
+	pfd.events = POLLOUT;
+	if ((ret = poll(&pfd, 1, ka * 1000)) == -1 || 
+			pfd.revents & (POLLERR | POLLHUP | POLLNVAL)) {
+		LOGERR;
+		return -1;	/* error */
+	} else if (!ret)
+		return 1;	/* session is abandoned ... must be disconnect! */
+	/* ping request */
+	if ((ret = mqtt_msgPINGREQ(&msg)) == -1)
+		return -1;	/* error */
+	if ((ret = send(sock, msg.msg_base, ret, MSG_NOSIGNAL)) == -1) {
+		LOGERR;
+		goto end;
+	}
+
+	pfd.events = POLLIN | POLLPRI;
+	while (tries--) {
+		if ((ret = poll(&pfd, 1, ka * 1000)) == -1 || 
+				pfd.revents & (POLLERR | POLLHUP | POLLNVAL)) {
+			LOGERR;
+			break;
+		} else if (!ret) {
+			ret = 1;	/* session is abandoned ... must be disconnect! */
+			continue;
+		}
+		/* receive & decode packet */
+		if ((ret = recv(sock, msg.msg_base, msg.msg_len, 0)) == -1) {
+			LOGERR;
+			break;
+		}
+		if (!mqtt_readPINGRESP(&msg)) {
+			ret = 0;	/* Host is alive */
+			break;
+		} else
+			ret = 2;	/* Session is broken ... must be disconnect! */
+	}
+end:
+	free(msg.msg_base);
 	return ret;
 }