added support to control KEEPALIVE settings in imptcp

this has not yet been added to imtcp, but could be done on request

3 files changed, 83 insertions, 2 deletions

diff --git a/ChangeLog b/ChangeLog
index 69a91ce0..a9084201 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -4,6 +4,8 @@ Version 5.9.0  [V5-DEVEL] (rgerhards), 2011-03-??
   at the socket layer. This has not been added to imttcp, as the latter is
   only an experimental module, and one which did not prove to be useful.
   reference: http://kb.monitorware.com/post20791.html
+- added support to control KEEPALIVE settings in imptcp
+  this has not yet been added to imtcp, but could be done on request.
 - bugfix: do not open files with full privileges, if privs will be dropped
   This make the privilege drop code more bulletproof, but breaks Ubuntu's
   work-around for log files created by external programs with the wrong
diff --git a/doc/imptcp.html b/doc/imptcp.html
index 8784391e..386e691a 100644
--- a/doc/imptcp.html
+++ b/doc/imptcp.html
@@ -48,6 +48,21 @@ instructs imptcp to emit a message if the remote peer closes a connection.<br>
 <li><b>$InputPTCPServerKeepAlive</b> &lt;on/<b>off</b>&gt;<br>
 enable of disable keep-alive packets at the tcp socket layer. The default is
 to disable them.</li>
+<li><b>$InputPTCPServerKeepAlive_probes</b> &lt;number&gt;<br>
+The number of unacknowledged probes to send before considering the connection dead and notifying the application layer.
+The default, 0, means that the operating system defaults are used. This has only 
+effect if keep-alive is enabled. The functionality may not be available on
+all platforms.
+<li><b>$InputPTCPServerKeepAlive_intvl</b> &lt;number&gt;<br>
+The interval between subsequential keepalive probes, regardless of what the connection has exchanged in the meantime.
+The default, 0, means that the operating system defaults are used. This has only 
+effect if keep-alive is enabled. The functionality may not be available on
+all platforms.
+<li><b>$InputPTCPServerKeepAlive_time</b> &lt;number&gt;<br>
+The interval between the last data packet sent (simple ACKs are not considered data) and the first keepalive probe; after the connection is marked to need keepalive, this counter is not used any further.
+The default, 0, means that the operating system defaults are used. This has only 
+effect if keep-alive is enabled. The functionality may not be available on
+all platforms.
 <li><b>$InputPTCPServerRun</b> &lt;port&gt;<br>
 Starts a TCP server on selected port</li>
 <li>$InputPTCPServerInputName &lt;name&gt;<br>
diff --git a/plugins/imptcp/imptcp.c b/plugins/imptcp/imptcp.c
index 8333e050..8751637d 100644
--- a/plugins/imptcp/imptcp.c
+++ b/plugins/imptcp/imptcp.c
@@ -50,6 +50,7 @@
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/epoll.h>
+#include <netinet/tcp.h>
 #if HAVE_FCNTL_H
 #include <fcntl.h>
 #endif
@@ -89,6 +90,9 @@ DEFobjCurrIf(ruleset)
 /* config settings */
 typedef struct configSettings_s {
 	int bKeepAlive;			/* support keep-alive packets */
+	int iKeepAliveIntvl;
+	int iKeepAliveProbes;
+	int iKeepAliveTime;
 	int bEmitMsgOnClose;		/* emit an informational message on close by remote peer */
 	int iAddtlFrameDelim;		/* addtl frame delimiter, e.g. for netscreen, default none */
 	uchar *pszInputName;		/* value for inputname property, NULL is OK and handled by core engine */
@@ -113,6 +117,9 @@ struct ptcpsrv_s {
 	uchar *port;			/* Port to listen to */
 	uchar *lstnIP;			/* which IP we should listen on? */
 	int iAddtlFrameDelim;
+	int iKeepAliveIntvl;
+	int iKeepAliveProbes;
+	int iKeepAliveTime;
 	uchar *pszInputName;
 	prop_t *pInputName;		/* InputName in (fast to process) property format */
 	ruleset_t *pRuleset;
@@ -433,7 +440,7 @@ finalize_it:
 
 /* Enable KEEPALIVE handling on the socket.  */
 static inline rsRetVal
-EnableKeepAlive(int sock)
+EnableKeepAlive(ptcplstn_t *pLstn, int sock)
 {
 	int ret;
 	int optval;
@@ -448,6 +455,51 @@ EnableKeepAlive(int sock)
 		ABORT_FINALIZE(RS_RET_ERR);
 	}
 
+#	if defined(TCP_KEEPCNT)
+	if(pLstn->pSrv->iKeepAliveProbes > 0) {
+		optval = pLstn->pSrv->iKeepAliveProbes;
+		optlen = sizeof(optval);
+		ret = setsockopt(sock, SOL_TCP, TCP_KEEPCNT, &optval, optlen);
+	} else {
+		ret = 0;
+	}
+#	else
+	ret = -1;
+#	endif
+	if(ret < 0) {
+		errmsg.LogError(ret, NO_ERRCODE, "imptcp cannot set keepalive probes - ignored");
+	}
+
+#	if defined(TCP_KEEPCNT)
+	if(pLstn->pSrv->iKeepAliveTime > 0) {
+		optval = pLstn->pSrv->iKeepAliveTime;
+		optlen = sizeof(optval);
+		ret = setsockopt(sock, SOL_TCP, TCP_KEEPIDLE, &optval, optlen);
+	} else {
+		ret = 0;
+	}
+#	else
+	ret = -1;
+#	endif
+	if(ret < 0) {
+		errmsg.LogError(ret, NO_ERRCODE, "imptcp cannot set keepalive time - ignored");
+	}
+
+#	if defined(TCP_KEEPCNT)
+	if(pLstn->pSrv->iKeepAliveIntvl > 0) {
+		optval = pLstn->pSrv->iKeepAliveIntvl;
+		optlen = sizeof(optval);
+		ret = setsockopt(sock, SOL_TCP, TCP_KEEPINTVL, &optval, optlen);
+	} else {
+		ret = 0;
+	}
+#	else
+	ret = -1;
+#	endif
+	if(ret < 0) {
+		errmsg.LogError(errno, NO_ERRCODE, "imptcp cannot set keepalive intvl - ignored");
+	}
+
 	dbgprintf("KEEPALIVE enabled for socket %d\n", sock);
 
 finalize_it:
@@ -476,7 +528,7 @@ AcceptConnReq(ptcplstn_t *pLstn, int *newSock, prop_t **peerName, prop_t **peerI
 	}
 
 	if(pLstn->pSrv->bKeepAlive)
-		EnableKeepAlive(iNewSock);	/* we ignore errors, best to do! */
+		EnableKeepAlive(pLstn, iNewSock);/* we ignore errors, best to do! */
 
 	
 	CHKiRet(getPeerNames(peerName, peerIP, (struct sockaddr*) &addr));
@@ -913,6 +965,9 @@ static rsRetVal addTCPListener(void __attribute__((unused)) *pVal, uchar *pNewVa
 	pSrv->pSess = NULL;
 	pSrv->pLstn = NULL;
 	pSrv->bKeepAlive = cs.bKeepAlive;
+	pSrv->iKeepAliveIntvl = cs.iKeepAliveTime;
+	pSrv->iKeepAliveProbes = cs.iKeepAliveProbes;
+	pSrv->iKeepAliveTime = cs.iKeepAliveTime;
 	pSrv->bEmitMsgOnClose = cs.bEmitMsgOnClose;
 	pSrv->port = pNewVal;
 	pSrv->iAddtlFrameDelim = cs.iAddtlFrameDelim;
@@ -1176,6 +1231,9 @@ resetConfigVariables(uchar __attribute__((unused)) *pp, void __attribute__((unus
 {
 	cs.bEmitMsgOnClose = 0;
 	cs.bKeepAlive = 0;
+	cs.iKeepAliveProbes = 0;
+	cs.iKeepAliveTime = 0;
+	cs.iKeepAliveIntvl = 0;
 	cs.iAddtlFrameDelim = TCPSRV_NO_ADDTL_DELIMITER;
 	free(cs.pszInputName);
 	cs.pszInputName = NULL;
@@ -1210,6 +1268,12 @@ CODEmodInit_QueryRegCFSLineHdlr
 				   addTCPListener, NULL, STD_LOADABLE_MODULE_ID));
 	CHKiRet(omsdRegCFSLineHdlr(UCHAR_CONSTANT("inputptcpserverkeepalive"), 0, eCmdHdlrBinary,
 				   NULL, &cs.bKeepAlive, STD_LOADABLE_MODULE_ID));
+	CHKiRet(omsdRegCFSLineHdlr(UCHAR_CONSTANT("inputptcpserverkeepalive_probes"), 0, eCmdHdlrInt,
+				   NULL, &cs.iKeepAliveProbes, STD_LOADABLE_MODULE_ID));
+	CHKiRet(omsdRegCFSLineHdlr(UCHAR_CONSTANT("inputptcpserverkeepalive_time"), 0, eCmdHdlrInt,
+				   NULL, &cs.iKeepAliveTime, STD_LOADABLE_MODULE_ID));
+	CHKiRet(omsdRegCFSLineHdlr(UCHAR_CONSTANT("inputptcpserverkeepalive_intvl"), 0, eCmdHdlrInt,
+				   NULL, &cs.iKeepAliveIntvl, STD_LOADABLE_MODULE_ID));
 	CHKiRet(omsdRegCFSLineHdlr(UCHAR_CONSTANT("inputptcpservernotifyonconnectionclose"), 0,
 				   eCmdHdlrBinary, NULL, &cs.bEmitMsgOnClose, STD_LOADABLE_MODULE_ID));
 	CHKiRet(omsdRegCFSLineHdlr(UCHAR_CONSTANT("inputptcpserveraddtlframedelimiter"), 0, eCmdHdlrInt,