From 8aad93c582fcf9628a4d81da515f5fca31efca24 Mon Sep 17 00:00:00 2001
From: Rainer Gerhards <rgerhards@adiscon.com>
Date: Tue, 26 Feb 2013 09:58:17 +0100
Subject: imuxsock: add capability to ignore messages from ourselfes

This helps prevent message routing loops, and is vital to have
if omjournal is used together with traditional syslog.
---
 ChangeLog                     |  3 +++
 doc/imuxsock.html             | 12 ++++++++++++
 plugins/imuxsock/imuxsock.c   | 18 +++++++++++++++++-
 plugins/omjournal/omjournal.c |  3 +++
 runtime/glbl.c                |  3 ++-
 runtime/glbl.h                |  6 ++++++
 tools/syslogd.c               | 11 +++++------
 7 files changed, 48 insertions(+), 8 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 67d02d60..9b8168c7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,9 @@
 ---------------------------------------------------------------------------
 Version 7.3.7  [devel] 2013-02-??
 - add support for writing to the Linux Journal (omjournal)
+- imuxsock: add capability to ignore messages from ourselfes
+  This helps prevent message routing loops, and is vital to have
+  if omjournal is used together with traditional syslog.
 - field() function now supports a string as field delimiter
 - bugfix: mmjsonparse segfault if new-style config was used
 - bugfix: script == comparison did not work properly on JSON objects
diff --git a/doc/imuxsock.html b/doc/imuxsock.html
index a962f814..ee9e2a05 100644
--- a/doc/imuxsock.html
+++ b/doc/imuxsock.html
@@ -65,6 +65,12 @@ you must turn it on (via SysSock.Annotate and Annotate).
 <li><b>SysSock.IgnoreTimestamp</b> [<b>on</b>/off]<br>
 Ignore timestamps included in the messages, applies to messages received via the system log socket.
 </li>
+<li><b>SysSock.IgnoreOwnMessages</b> [<b>on</b>/off] (available since 7.3.7)<br>
+Ignores messages that originated from the same instance of rsyslogd. There usually
+is no reason to receive messages from ourselfs. This setting is vital
+when writing messages to the Linux journal. See <a href="omjournal.html">omjournal</a>
+module documentation for a more in-depth description.
+</li>
 <li><b>SysSock.Use</b> (imuxsock) [on/<b>off</b>] 
 do NOT listen for the local log socket. This is most useful if you run multiple
 instances of rsyslogd where only one shall handle the system log socket.
@@ -98,6 +104,12 @@ properties for the system log socket.</li>
 <ul>
 <li><b>IgnoreTimestamp</b> [<b>on</b>/off]
 <br>Ignore timestamps included in the message. Applies to the next socket being added.</li>
+<li><b>IgnoreOwnMessages</b> [<b>on</b>/off] (available since 7.3.7)<br>
+Ignore messages that originated from the same instance of rsyslogd. There usually
+is no reason to receive messages from ourselfs. This setting is vital
+when writing messages to the Linux journal. See <a href="omjournal.html">omjournal</a>
+module documentation for a more in-depth description.
+</li>
 <li><b>FlowControl</b> [on/<b>off</b>] - specifies if flow control should be applied
 to the next socket.</li>
 <li><b>RateLimit.Interval</b> [number] - specifies the rate-limiting
diff --git a/plugins/imuxsock/imuxsock.c b/plugins/imuxsock/imuxsock.c
index 66a1c648..1fde9982 100644
--- a/plugins/imuxsock/imuxsock.c
+++ b/plugins/imuxsock/imuxsock.c
@@ -6,7 +6,7 @@
  *
  * File begun on 2007-12-20 by RGerhards (extracted from syslogd.c)
  *
- * Copyright 2007-2012 Rainer Gerhards and Adiscon GmbH.
+ * Copyright 2007-2013 Rainer Gerhards and Adiscon GmbH.
  *
  * This file is part of rsyslog.
  *
@@ -144,6 +144,7 @@ typedef struct lstn_s {
 	sbool bAnnotate;	/* annotate events with trusted properties */
 	sbool bParseTrusted;	/* parse trusted properties */
 	sbool bWritePid;	/* write original PID into tag */
+	sbool bDiscardOwnMsgs;	/* discard messages that originated from ourselves */
 	sbool bUseSysTimeStamp;	/* use timestamp from system (instead of from message) */
 } lstn_t;
 static lstn_t listeners[MAXFUNIX];
@@ -199,6 +200,7 @@ struct instanceConf_s {
 	int ratelimitSeverity;
 	int bAnnotate;			/* annotate trusted properties */
 	int bParseTrusted;		/* parse trusted properties */
+	sbool bDiscardOwnMsgs;		/* discard messages that originated from our own pid? */
 	struct instanceConf_s *next;
 };
 
@@ -216,6 +218,7 @@ struct modConfData_s {
 	sbool bOmitLocalLogging;
 	sbool bWritePidSysSock;
 	sbool bUseSysTimeStamp;
+	sbool bDiscardOwnMsgs;
 	sbool configSetViaV2Method;
 };
 static modConfData_t *loadModConf = NULL;/* modConf ptr to use for the current load process */
@@ -226,6 +229,7 @@ static struct cnfparamdescr modpdescr[] = {
 	{ "syssock.use", eCmdHdlrBinary, 0 },
 	{ "syssock.name", eCmdHdlrGetWord, 0 },
 	{ "syssock.ignoretimestamp", eCmdHdlrBinary, 0 },
+	{ "syssock.ignoreownmessages", eCmdHdlrBinary, 0 },
 	{ "syssock.flowcontrol", eCmdHdlrBinary, 0 },
 	{ "syssock.usesystimestamp", eCmdHdlrBinary, 0 },
 	{ "syssock.annotate", eCmdHdlrBinary, 0 },
@@ -245,6 +249,7 @@ static struct cnfparamdescr inppdescr[] = {
 	{ "socket", eCmdHdlrString, CNFPARAM_REQUIRED }, /* legacy: addunixlistensocket */
 	{ "createpath", eCmdHdlrBinary, 0 },
 	{ "parsetrusted", eCmdHdlrBinary, 0 },
+	{ "ignoreownmessages", eCmdHdlrBinary, 0 },
 	{ "hostname", eCmdHdlrString, 0 },
 	{ "ignoretimestamp", eCmdHdlrBinary, 0 },
 	{ "flowcontrol", eCmdHdlrBinary, 0 },
@@ -288,6 +293,7 @@ createInstance(instanceConf_t **pinst)
 	inst->bWritePid = 0;
 	inst->bAnnotate = 0;
 	inst->bParseTrusted = 0;
+	inst->bDiscardOwnMsgs = 1;
 	inst->next = NULL;
 
 	/* node created, let's add to config */
@@ -391,6 +397,7 @@ addListner(instanceConf_t *inst)
 		listeners[nfd].bUseCreds = (inst->bWritePid || inst->ratelimitInterval || inst->bAnnotate) ? 1 : 0;
 		listeners[nfd].bAnnotate = inst->bAnnotate;
 		listeners[nfd].bParseTrusted = inst->bParseTrusted;
+		listeners[nfd].bDiscardOwnMsgs = inst->bDiscardOwnMsgs;
 		listeners[nfd].bWritePid = inst->bWritePid;
 		listeners[nfd].bUseSysTimeStamp = inst->bUseSysTimeStamp;
 		CHKiRet(ratelimitNew(&listeners[nfd].dflt_ratelimiter, "imuxsock", NULL));
@@ -732,6 +739,9 @@ SubmitMsg(uchar *pRcv, int lenRcv, lstn_t *pLstn, struct ucred *cred, struct tim
 	struct json_object *json = NULL, *jval;
 	DEFiRet;
 
+	if(cred->pid == glblGetOurPid())
+		FINALIZE;
+
 	/* TODO: handle format errors?? */
 	/* we need to parse the pri first, because we need the severity for
 	 * rate-limiting as well.
@@ -1041,6 +1051,7 @@ activateListeners()
 	listeners[0].bWritePid = runModConf->bWritePidSysSock;
 	listeners[0].bAnnotate = runModConf->bAnnotateSysSock;
 	listeners[0].bParseTrusted = runModConf->bParseTrusted;
+	listeners[0].bDiscardOwnMsgs = runModConf->bDiscardOwnMsgs;
 	listeners[0].bUseSysTimeStamp = runModConf->bUseSysTimeStamp;
 	listeners[0].flags = runModConf->bIgnoreTimestamp ? IGNDATE : NOFLAG;
 	listeners[0].flowCtl = runModConf->bUseFlowCtl ? eFLOWCTL_LIGHT_DELAY : eFLOWCTL_NO_DELAY;
@@ -1123,6 +1134,8 @@ CODESTARTsetModCnf
 			loadModConf->pLogSockName = (uchar*)es_str2cstr(pvals[i].val.d.estr, NULL);
 		} else if(!strcmp(modpblk.descr[i].name, "syssock.ignoretimestamp")) {
 			loadModConf->bIgnoreTimestamp = (int) pvals[i].val.d.n;
+		} else if(!strcmp(modpblk.descr[i].name, "syssock.ignoreownmessages")) {
+			loadModConf->bDiscardOwnMsgs = (int) pvals[i].val.d.n;
 		} else if(!strcmp(modpblk.descr[i].name, "syssock.flowcontrol")) {
 			loadModConf->bUseFlowCtl = (int) pvals[i].val.d.n;
 		} else if(!strcmp(modpblk.descr[i].name, "syssock.usesystimestamp")) {
@@ -1183,6 +1196,8 @@ CODESTARTnewInpInst
 			inst->bCreatePath = (int) pvals[i].val.d.n;
 		} else if(!strcmp(modpblk.descr[i].name, "parsetrusted")) {
 			inst->bParseTrusted = (int) pvals[i].val.d.n;
+		} else if(!strcmp(modpblk.descr[i].name, "ignoreownmessages")) {
+			inst->bDiscardOwnMsgs = (int) pvals[i].val.d.n;
 		} else if(!strcmp(modpblk.descr[i].name, "hostname")) {
 			inst->pLogHostName = (uchar*)es_str2cstr(pvals[i].val.d.estr, NULL);
 		} else if(!strcmp(modpblk.descr[i].name, "ignoretimestamp")) {
@@ -1472,6 +1487,7 @@ CODEmodInit_QueryRegCFSLineHdlr
 	listeners[0].bUseCreds = 0;
 	listeners[0].bAnnotate = 0;
 	listeners[0].bParseTrusted = 0;
+	listeners[0].bDiscardOwnMsgs = 1;
 	listeners[0].bCreatePath = 0;
 	listeners[0].bUseSysTimeStamp = 1;
 
diff --git a/plugins/omjournal/omjournal.c b/plugins/omjournal/omjournal.c
index bb095ee2..300aafea 100644
--- a/plugins/omjournal/omjournal.c
+++ b/plugins/omjournal/omjournal.c
@@ -133,6 +133,9 @@ BEGINdoAction
 CODESTARTdoAction
 	pMsg = (msg_t*) ppString[0];
 	MsgGetSeverity(pMsg, &sev);
+	/* we can use more properties here, but let's see if there
+	 * is some real user interest. We can always add later...
+	 */
 	r = sd_journal_send("MESSAGE=%s", getMSG(pMsg),
                 "PRIORITY=%d", sev,
                 NULL);
diff --git a/runtime/glbl.c b/runtime/glbl.c
index 0e5cac20..727f8392 100644
--- a/runtime/glbl.c
+++ b/runtime/glbl.c
@@ -7,7 +7,7 @@
  *
  * Module begun 2008-04-16 by Rainer Gerhards
  *
- * Copyright 2008-2011 Rainer Gerhards and Adiscon GmbH.
+ * Copyright 2008-2013 Rainer Gerhards and Adiscon GmbH.
  *
  * This file is part of the rsyslog runtime library.
  *
@@ -82,6 +82,7 @@ static uchar *pszDfltNetstrmDrvrCAF = NULL; /* default CA file for the netstrm d
 static uchar *pszDfltNetstrmDrvrKeyFile = NULL; /* default key file for the netstrm driver (server) */
 static uchar *pszDfltNetstrmDrvrCertFile = NULL; /* default cert file for the netstrm driver (server) */
 static int bTerminateInputs = 0;		/* global switch that inputs shall terminate ASAP (1=> terminate) */
+pid_t glbl_ourpid;
 #ifndef HAVE_ATOMIC_BUILTINS
 static DEF_ATOMIC_HELPER_MUT(mutTerminateInputs);
 #endif
diff --git a/runtime/glbl.h b/runtime/glbl.h
index d2d1e66a..e95e48f7 100644
--- a/runtime/glbl.h
+++ b/runtime/glbl.h
@@ -30,11 +30,14 @@
 #ifndef GLBL_H_INCLUDED
 #define GLBL_H_INCLUDED
 
+#include <sys/types.h>
 #include "rainerscript.h"
 #include "prop.h"
 
 #define glblGetIOBufSize() 4096 /* size of the IO buffer, e.g. for strm class */
 
+extern pid_t glbl_ourpid;
+
 /* interfaces */
 BEGINinterface(glbl) /* name must also be changed in ENDinterface macro! */
 	uchar* (*GetWorkDir)(void);
@@ -86,6 +89,9 @@ ENDinterface(glbl)
 /* the remaining prototypes */
 PROTOTYPEObj(glbl);
 
+static inline pid_t glblGetOurPid(void) { return glbl_ourpid; }
+static inline void glblSetOurPid(pid_t pid) { glbl_ourpid = pid; }
+
 void glblPrepCnf(void);
 void glblProcessCnf(struct cnfobj *o);
 void glblDoneLoadCnf(void);
diff --git a/tools/syslogd.c b/tools/syslogd.c
index ae1b3de5..c2928a8f 100644
--- a/tools/syslogd.c
+++ b/tools/syslogd.c
@@ -195,7 +195,6 @@ static prop_t *pInternalInputName = NULL;	/* there is only one global inputName
 static uchar	*ConfFile = (uchar*) _PATH_LOGCONF; /* read-only after startup */
 static char	*PidFile = _PATH_LOGPID; /* read-only after startup */
 
-static pid_t myPid;	/* our pid for use in self-generated messages, e.g. on startup */
 /* mypid is read-only after the initial fork() */
 static int bHadHUP = 0; /* did we have a HUP? */
 
@@ -795,7 +794,7 @@ die(int sig)
 		(void) snprintf(buf, sizeof(buf) / sizeof(char),
 		 " [origin software=\"rsyslogd\" " "swVersion=\"" VERSION \
 		 "\" x-pid=\"%d\" x-info=\"http://www.rsyslog.com\"]" " exiting on signal %d.",
-		 (int) myPid, sig);
+		 (int) glblGetOurPid(), sig);
 		errno = 0;
 		logmsgInternal(NO_ERRCODE, LOG_SYSLOG|LOG_INFO, (uchar*)buf, 0);
 	}
@@ -1169,7 +1168,7 @@ init(void)
                snprintf(bufStartUpMsg, sizeof(bufStartUpMsg)/sizeof(char),
 			 " [origin software=\"rsyslogd\" " "swVersion=\"" VERSION \
 			 "\" x-pid=\"%d\" x-info=\"http://www.rsyslog.com\"] start",
-			 (int) myPid);
+			 (int) glblGetOurPid());
 		logmsgInternal(NO_ERRCODE, LOG_SYSLOG|LOG_INFO, (uchar*)bufStartUpMsg, 0);
 	}
 
@@ -1248,7 +1247,7 @@ doHUP(void)
 		snprintf(buf, sizeof(buf) / sizeof(char),
 			 " [origin software=\"rsyslogd\" " "swVersion=\"" VERSION
 			 "\" x-pid=\"%d\" x-info=\"http://www.rsyslog.com\"] rsyslogd was HUPed",
-			 (int) myPid);
+			 (int) glblGetOurPid());
 			errno = 0;
 		logmsgInternal(NO_ERRCODE, LOG_SYSLOG|LOG_INFO, (uchar*)buf, 0);
 	}
@@ -1704,7 +1703,7 @@ doGlblProcessInit(void)
 		fputs("Pidfile (and pid) already exist.\n", stderr);
 		exit(1); /* exit during startup - questionable */
 	}
-	myPid = getpid(); 	/* save our pid for further testing (also used for messages) */
+	glblSetOurPid(getpid());
 
 	memset(&sigAct, 0, sizeof (sigAct));
 	sigemptyset(&sigAct.sa_mask);
@@ -2001,7 +2000,7 @@ int realMain(int argc, char **argv)
 	}
 
 	/* Send a signal to the parent so it can terminate.  */
-	if(myPid != ppid)
+	if(glblGetOurPid() != ppid)
 		kill(ppid, SIGTERM);
 
 
-- 
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