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-rw-r--r--ChangeLog4
-rw-r--r--doc/rsyslog_conf.html1
-rw-r--r--runtime/netstrm.c10
-rw-r--r--runtime/netstrm.h1
-rw-r--r--runtime/nsd.h3
-rw-r--r--runtime/nsd_gtls.c12
-rw-r--r--runtime/nsd_ptcp.c29
-rw-r--r--tcpclt.c36
-rw-r--r--tcpclt.h4
-rw-r--r--tools/omfwd.c7
10 files changed, 94 insertions, 13 deletions
diff --git a/ChangeLog b/ChangeLog
index 190c659d..2cc995bd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -2,6 +2,10 @@
Version 3.19.7 (rgerhards), 2008-06-??
- added new property replacer option "date-subseconds" that enables
to query just the subsecond part of a high-precision timestamp
+- somewhat improved plain tcp syslog reliability by doing a connection
+ check before sending. Credits to Martin Schuette for providing the
+ idea. Details are available at
+ http://blog.gerhards.net/2008/06/reliable-plain-tcp-syslog-once-again.html
---------------------------------------------------------------------------
Version 3.19.6 (rgerhards), 2008-06-06
- enhanced property replacer to support multiple regex matches
diff --git a/doc/rsyslog_conf.html b/doc/rsyslog_conf.html
index efb3ad0c..3946a2d3 100644
--- a/doc/rsyslog_conf.html
+++ b/doc/rsyslog_conf.html
@@ -120,6 +120,7 @@ default 60000 (1 minute)]</li>
<li>$ActionQueueWorkerThreadMinumumMessages &lt;number&gt;, default 100</li>
<li><a href="rsconf1_actionresumeinterval.html">$ActionResumeInterval</a></li>
<li>$ActionResumeRetryCount &lt;number&gt; [default 0, -1 means eternal]</li>
+<li>$ActionSendResendLastMsgOnReconn &lt;[on/<b>off</b>]&gt; specifies if the last message is to be resend when a connecition broken and has been reconnedcted. May increase reliability, but comes at the risk of message duplication.
<li>$ActionSendStreamDriver &lt;driver basename&gt; just like $DefaultNetstreamDriver, but for the specific action
</li><li>$ActionSendStreamDriverMode &lt;mode&gt;, default 0, mode to use with the stream driver
(driver-specific)</li><li>$ActionSendStreamDriverAuthMode &lt;mode&gt;,&nbsp; authentication mode to use with the stream driver
diff --git a/runtime/netstrm.c b/runtime/netstrm.c
index 786ba7f8..2f4a1964 100644
--- a/runtime/netstrm.c
+++ b/runtime/netstrm.c
@@ -234,6 +234,15 @@ Send(netstrm_t *pThis, uchar *pBuf, ssize_t *pLenBuf)
}
+/* check connection - slim wrapper for NSD driver function */
+static void
+CheckConnection(netstrm_t *pThis)
+{
+ ISOBJ_TYPE_assert(pThis, netstrm);
+ pThis->Drvr.CheckConnection(pThis->pDrvrData);
+}
+
+
/* get remote hname - slim wrapper for NSD driver function */
static rsRetVal
GetRemoteHName(netstrm_t *pThis, uchar **ppsz)
@@ -314,6 +323,7 @@ CODESTARTobjQueryInterface(netstrm)
pIf->SetDrvrMode = SetDrvrMode;
pIf->SetDrvrAuthMode = SetDrvrAuthMode;
pIf->SetDrvrPermPeers = SetDrvrPermPeers;
+ pIf->CheckConnection = CheckConnection;
pIf->GetSock = GetSock;
finalize_it:
ENDobjQueryInterface(netstrm)
diff --git a/runtime/netstrm.h b/runtime/netstrm.h
index ae135beb..1a97ef23 100644
--- a/runtime/netstrm.h
+++ b/runtime/netstrm.h
@@ -52,6 +52,7 @@ BEGINinterface(netstrm) /* name must also be changed in ENDinterface macro! */
rsRetVal (*SetDrvrMode)(netstrm_t *pThis, int iMode);
rsRetVal (*SetDrvrAuthMode)(netstrm_t *pThis, uchar*);
rsRetVal (*SetDrvrPermPeers)(netstrm_t *pThis, permittedPeers_t*);
+ void (*CheckConnection)(netstrm_t *pThis); /* This is a trick mostly for plain tcp syslog */
/* the GetSock() below is a hack to make imgssapi work. In the long term,
* we should migrate imgssapi to a stream driver, which will relieve us of
* this problem. Please note that nobody else should use GetSock(). Using it
diff --git a/runtime/nsd.h b/runtime/nsd.h
index 53693b59..1811f078 100644
--- a/runtime/nsd.h
+++ b/runtime/nsd.h
@@ -53,6 +53,7 @@ BEGINinterface(nsd) /* name must also be changed in ENDinterface macro! */
rsRetVal (*SetMode)(nsd_t *pThis, int mode); /* sets a driver specific mode - see driver doc for details */
rsRetVal (*SetAuthMode)(nsd_t *pThis, uchar*); /* sets a driver specific mode - see driver doc for details */
rsRetVal (*SetPermPeers)(nsd_t *pThis, permittedPeers_t*); /* sets driver permitted peers for auth needs */
+ void (*CheckConnection)(nsd_t *pThis); /* This is a trick mostly for plain tcp syslog */
rsRetVal (*GetSock)(nsd_t *pThis, int *pSock);
rsRetVal (*SetSock)(nsd_t *pThis, int sock);
/* GetSock() and SetSock() return an error if the driver does not use plain
@@ -60,7 +61,7 @@ BEGINinterface(nsd) /* name must also be changed in ENDinterface macro! */
* those drivers that utilize the nsd_ptcp to do some of their work.
*/
ENDinterface(nsd)
-#define nsdCURR_IF_VERSION 2 /* increment whenever you change the interface structure! */
+#define nsdCURR_IF_VERSION 3 /* increment whenever you change the interface structure! */
/* interface for the select call */
BEGINinterface(nsdsel) /* name must also be changed in ENDinterface macro! */
diff --git a/runtime/nsd_gtls.c b/runtime/nsd_gtls.c
index 0440f149..567701dc 100644
--- a/runtime/nsd_gtls.c
+++ b/runtime/nsd_gtls.c
@@ -1243,6 +1243,17 @@ finalize_it:
}
+/* This function checks if the connection is still alive - well, kind of...
+ * This is a dummy here. For details, check function common in ptcp driver.
+ * rgerhards, 2008-06-09
+ */
+static void
+CheckConnection(nsd_t __attribute__((unused)) *pNsd)
+{
+ /* dummy, do nothing */
+}
+
+
/* get the remote hostname. The returned hostname must be freed by the caller.
* rgerhards, 2008-04-25
*/
@@ -1507,6 +1518,7 @@ CODESTARTobjQueryInterface(nsd_gtls)
pIf->SetMode = SetMode;
pIf->SetAuthMode = SetAuthMode;
pIf->SetPermPeers =SetPermPeers;
+ pIf->CheckConnection = CheckConnection;
pIf->GetRemoteHName = GetRemoteHName;
pIf->GetRemoteIP = GetRemoteIP;
finalize_it:
diff --git a/runtime/nsd_ptcp.c b/runtime/nsd_ptcp.c
index 14c564a3..ff85619a 100644
--- a/runtime/nsd_ptcp.c
+++ b/runtime/nsd_ptcp.c
@@ -638,6 +638,34 @@ finalize_it:
}
+/* This function checks if the connection is still alive - well, kind of... It
+ * is primarily being used for plain TCP syslog and it is quite a hack. However,
+ * as it seems to work, it is worth supporting it. The bottom line is that it
+ * should not be called by anything else but a plain tcp syslog sender.
+ * In order for it to work, it must be called *immediately* *before* the send()
+ * call. For details about what is done, see here:
+ * http://blog.gerhards.net/2008/06/getting-bit-more-reliability-from-plain.html
+ * rgerhards, 2008-06-09
+ */
+static void
+CheckConnection(nsd_t *pNsd)
+{
+ int rc;
+ char msgbuf[1]; /* dummy */
+ nsd_ptcp_t *pThis = (nsd_ptcp_t*) pNsd;
+ ISOBJ_TYPE_assert(pThis, nsd_ptcp);
+
+ rc = recv(pThis->sock, msgbuf, 1, MSG_DONTWAIT | MSG_PEEK);
+ if(rc == 0) {
+ dbgprintf("CheckConnection detected broken connection - closing it\n");
+ /* in this case, the remote peer had shut down the connection and we
+ * need to close our side, too.
+ */
+ sockClose(&pThis->sock);
+ }
+}
+
+
/* get the remote host's IP address. The returned string must be freed by the
* caller.
* rgerhards, 2008-04-24
@@ -684,6 +712,7 @@ CODESTARTobjQueryInterface(nsd_ptcp)
pIf->Connect = Connect;
pIf->GetRemoteHName = GetRemoteHName;
pIf->GetRemoteIP = GetRemoteIP;
+ pIf->CheckConnection = CheckConnection;
finalize_it:
ENDobjQueryInterface(nsd_ptcp)
diff --git a/tcpclt.c b/tcpclt.c
index 2bc2ea56..c53f00f7 100644
--- a/tcpclt.c
+++ b/tcpclt.c
@@ -305,16 +305,23 @@ Send(tcpclt_t *pThis, void *pData, char *msg, size_t len)
/* we are done, we also use this as indication that the previous
* message was succesfully received (it's not always the case, but its at
* least our best shot at it -- rgerhards, 2008-03-12
+ * As of 2008-06-09, we have implemented an algorithm which detects connection
+ * loss quite good in some (common) scenarios. Thus, the probability of
+ * message duplication due to the code below has increased. We so now have
+ * a config setting, default off, that enables the user to request retransmits.
+ * However, if not requested, we do NOT need to do all the stuff needed for it.
*/
- if(pThis->prevMsg != NULL)
- free(pThis->prevMsg);
- /* if we can not alloc a new buffer, we silently ignore it. The worst that
- * happens is that we lose our message recovery buffer - anything else would
- * be worse, so don't try anything ;) -- rgerhards, 2008-03-12
- */
- if((pThis->prevMsg = malloc(len)) != NULL) {
- memcpy(pThis->prevMsg, msg, len);
- pThis->lenPrevMsg = len;
+ if(pThis->bResendLastOnRecon == 1) {
+ if(pThis->prevMsg != NULL)
+ free(pThis->prevMsg);
+ /* if we can not alloc a new buffer, we silently ignore it. The worst that
+ * happens is that we lose our message recovery buffer - anything else would
+ * be worse, so don't try anything ;) -- rgerhards, 2008-03-12
+ */
+ if((pThis->prevMsg = malloc(len)) != NULL) {
+ memcpy(pThis->prevMsg, msg, len);
+ pThis->lenPrevMsg = len;
+ }
}
/* we are done with this record */
@@ -324,7 +331,8 @@ Send(tcpclt_t *pThis, void *pData, char *msg, size_t len)
++retry;
CHKiRet(pThis->prepRetryFunc(pData)); /* try to recover */
/* now try to send our stored previous message (which most probably
- * didn't make it
+ * didn't make it. Note that if bResendLastOnRecon is 0, prevMsg will
+ * never become non-NULL, so the check below covers all cases.
*/
if(pThis->prevMsg != NULL) {
CHKiRet(pThis->initFunc(pData));
@@ -346,6 +354,13 @@ finalize_it:
/* set functions */
static rsRetVal
+SetResendLastOnRecon(tcpclt_t *pThis, int bResendLastOnRecon)
+{
+ DEFiRet;
+ pThis->bResendLastOnRecon = (short) bResendLastOnRecon;
+ RETiRet;
+}
+static rsRetVal
SetSendInit(tcpclt_t *pThis, rsRetVal (*pCB)(void*))
{
DEFiRet;
@@ -425,6 +440,7 @@ CODESTARTobjQueryInterface(tcpclt)
pIf->Send = Send;
/* set functions */
+ pIf->SetResendLastOnRecon = SetResendLastOnRecon;
pIf->SetSendInit = SetSendInit;
pIf->SetSendFrame = SetSendFrame;
pIf->SetSendPrepRetry = SetSendPrepRetry;
diff --git a/tcpclt.h b/tcpclt.h
index b7aada65..1d704044 100644
--- a/tcpclt.h
+++ b/tcpclt.h
@@ -33,6 +33,7 @@ typedef struct tcpclt_s {
BEGINobjInstance; /**< Data to implement generic object - MUST be the first data element! */
TCPFRAMINGMODE tcp_framing;
char *prevMsg;
+ short bResendLastOnRecon; /* should the last message be resent on a successful reconnect? */
size_t lenPrevMsg;
/* session specific callbacks */
rsRetVal (*initFunc)(void*);
@@ -49,12 +50,13 @@ BEGINinterface(tcpclt) /* name must also be changed in ENDinterface macro! */
int (*Send)(tcpclt_t *pThis, void*pData, char*msg, size_t len);
int (*CreateSocket)(struct addrinfo *addrDest);
/* set methods */
+ rsRetVal (*SetResendLastOnRecon)(tcpclt_t*, int);
rsRetVal (*SetSendInit)(tcpclt_t*, rsRetVal (*)(void*));
rsRetVal (*SetSendFrame)(tcpclt_t*, rsRetVal (*)(void*, char*, size_t));
rsRetVal (*SetSendPrepRetry)(tcpclt_t*, rsRetVal (*)(void*));
rsRetVal (*SetFraming)(tcpclt_t*, TCPFRAMINGMODE framing);
ENDinterface(tcpclt)
-#define tcpcltCURR_IF_VERSION 1 /* increment whenever you change the interface structure! */
+#define tcpcltCURR_IF_VERSION 2 /* increment whenever you change the interface structure! */
/* prototypes */
diff --git a/tools/omfwd.c b/tools/omfwd.c
index 317bc298..1783ef7d 100644
--- a/tools/omfwd.c
+++ b/tools/omfwd.c
@@ -97,7 +97,8 @@ typedef struct _instanceData {
/* config data */
static uchar *pszTplName = NULL; /* name of the default template to use */
static uchar *pszStrmDrvr = NULL; /* name of the stream driver to use */
-static int iStrmDrvrMode = 0; /* mode for stream driver, driver-dependent (0 mostly means plain tcp) */
+static short iStrmDrvrMode = 0; /* mode for stream driver, driver-dependent (0 mostly means plain tcp) */
+static short bResendLastOnRecon = 0; /* should the last message be re-sent on a successful reconnect? */
static uchar *pszStrmDrvrAuthMode = NULL; /* authentication mode to use */
static permittedPeers_t *pPermPeers = NULL;
@@ -254,6 +255,7 @@ static rsRetVal TCPSendFrame(void *pvData, char *msg, size_t len)
instanceData *pData = (instanceData *) pvData;
lenSend = len;
+ netstrm.CheckConnection(pData->pNetstrm); /* hack for plain tcp syslog - see ptcp driver for details */
CHKiRet(netstrm.Send(pData->pNetstrm, (uchar*)msg, &lenSend));
dbgprintf("TCP sent %ld bytes, requested %ld\n", (long) lenSend, (long) len);
@@ -605,6 +607,7 @@ CODE_STD_STRING_REQUESTparseSelectorAct(1)
if(pData->protocol == FORW_TCP) {
/* create our tcpclt */
CHKiRet(tcpclt.Construct(&pData->pTCPClt));
+ CHKiRet(tcpclt.SetResendLastOnRecon(pData->pTCPClt, bResendLastOnRecon));
/* and set callbacks */
CHKiRet(tcpclt.SetSendInit(pData->pTCPClt, TCPSendInit));
CHKiRet(tcpclt.SetSendFrame(pData->pTCPClt, TCPSendFrame));
@@ -679,6 +682,7 @@ static rsRetVal resetConfigVariables(uchar __attribute__((unused)) *pp, void __a
/* we now must reset all non-string values */
iStrmDrvrMode = 0;
+ bResendLastOnRecon = 0;
return RS_RET_OK;
}
@@ -697,6 +701,7 @@ CODEmodInit_QueryRegCFSLineHdlr
CHKiRet(regCfSysLineHdlr((uchar *)"actionsendstreamdrivermode", 0, eCmdHdlrInt, NULL, &iStrmDrvrMode, NULL));
CHKiRet(regCfSysLineHdlr((uchar *)"actionsendstreamdriverauthmode", 0, eCmdHdlrGetWord, NULL, &pszStrmDrvrAuthMode, NULL));
CHKiRet(regCfSysLineHdlr((uchar *)"actionsendstreamdriverpermittedpeer", 0, eCmdHdlrGetWord, setPermittedPeer, NULL, NULL));
+ CHKiRet(regCfSysLineHdlr((uchar *)"actionsendresendlastmsgonreconnect", 0, eCmdHdlrBinary, NULL, &bResendLastOnRecon, NULL));
CHKiRet(omsdRegCFSLineHdlr((uchar *)"resetconfigvariables", 1, eCmdHdlrCustomHandler, resetConfigVariables, NULL, STD_LOADABLE_MODULE_ID));
ENDmodInit