moved files to the runtime

there are still some files left which could go into the
runtime, but I think we will delete most of them once we
are done with the full modularization.

1 files changed, 803 insertions, 0 deletions

diff --git a/runtime/modules.c b/runtime/modules.c
new file mode 100644
index 00000000..f10390c7
--- /dev/null
+++ b/runtime/modules.c
@@ -0,0 +1,803 @@
+/* modules.c
+ * This is the implementation of syslogd modules object.
+ * This object handles plug-ins and build-in modules of all kind.
+ *
+ * Modules are reference-counted. Anyone who access a module must call
+ * Use() before any function is accessed and Release() when he is done.
+ * When the reference count reaches 0, rsyslog unloads the module (that
+ * may be changed in the future to cache modules). Rsyslog does NOT
+ * unload modules with a reference count > 0, even if the unload
+ * method is called!
+ *
+ * File begun on 2007-07-22 by RGerhards
+ *
+ * Copyright 2007 Rainer Gerhards and Adiscon GmbH.
+ *
+ * This file is part of the rsyslog runtime library.
+ *
+ * The rsyslog runtime library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * The rsyslog runtime library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with the rsyslog runtime library.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * A copy of the GPL can be found in the file "COPYING" in this distribution.
+ * A copy of the LGPL can be found in the file "COPYING.LESSER" in this distribution.
+ */
+#include "config.h"
+#include "rsyslog.h"
+#include <stdio.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <assert.h>
+#include <errno.h>
+#ifdef	OS_BSD
+#	include "libgen.h"
+#endif
+
+#include <dlfcn.h> /* TODO: replace this with the libtools equivalent! */
+
+#include <unistd.h>
+#include <sys/file.h>
+
+#include "syslogd.h"
+#include "cfsysline.h"
+#include "modules.h"
+#include "errmsg.h"
+
+/* static data */
+DEFobjStaticHelpers
+DEFobjCurrIf(errmsg)
+
+static modInfo_t *pLoadedModules = NULL;	/* list of currently-loaded modules */
+static modInfo_t *pLoadedModulesLast = NULL;	/* tail-pointer */
+
+/* config settings */
+uchar	*pModDir = NULL; /* read-only after startup */
+
+
+#ifdef DEBUG
+/* we add some home-grown support to track our users (and detect who does not free us). In
+ * the long term, this should probably be migrated into debug.c (TODO). -- rgerhards, 2008-03-11
+ */
+
+/* add a user to the current list of users (always at the root) */
+static void
+modUsrAdd(modInfo_t *pThis, char *pszUsr)
+{
+	modUsr_t *pUsr;
+
+	BEGINfunc
+	if((pUsr = calloc(1, sizeof(modUsr_t))) == NULL)
+		goto finalize_it;
+
+	if((pUsr->pszFile = strdup(pszUsr)) == NULL) {
+		free(pUsr);
+		goto finalize_it;
+	}
+
+	if(pThis->pModUsrRoot != NULL) {
+		pUsr->pNext = pThis->pModUsrRoot;
+	}
+	pThis->pModUsrRoot = pUsr;
+
+finalize_it:
+	ENDfunc;
+}
+
+
+/* remove a user from the current user list
+ * rgerhards, 2008-03-11
+ */
+static void
+modUsrDel(modInfo_t *pThis, char *pszUsr)
+{
+	modUsr_t *pUsr;
+	modUsr_t *pPrev = NULL;
+
+	for(pUsr = pThis->pModUsrRoot ; pUsr != NULL ; pUsr = pUsr->pNext) {
+		if(!strcmp(pUsr->pszFile, pszUsr))
+			break;
+		else
+			pPrev = pUsr;
+	}
+
+	if(pUsr == NULL) {
+		dbgprintf("oops - tried to delete user %s from module %s and it wasn't registered as one...\n",
+			  pszUsr, pThis->pszName);
+	} else {
+		if(pPrev == NULL) {
+			/* This was at the root! */
+			pThis->pModUsrRoot = pUsr->pNext;
+		} else {
+			pPrev->pNext = pUsr->pNext;
+		}
+		/* free ressources */
+		free(pUsr->pszFile);
+		free(pUsr);
+		pUsr = NULL; /* just to make sure... */
+	}
+}
+
+
+/* print a short list all all source files using the module in question
+ * rgerhards, 2008-03-11
+ */
+static void
+modUsrPrint(modInfo_t *pThis)
+{
+	modUsr_t *pUsr;
+
+	for(pUsr = pThis->pModUsrRoot ; pUsr != NULL ; pUsr = pUsr->pNext) {
+		dbgprintf("\tmodule %s is currently in use by file %s\n",
+			  pThis->pszName, pUsr->pszFile);
+	}
+}
+
+
+/* print all loaded modules and who is accessing them. This is primarily intended
+ * to be called at end of run to detect "module leaks" and who is causing them.
+ * rgerhards, 2008-03-11
+ */
+//static void
+void
+modUsrPrintAll(void)
+{
+	modInfo_t *pMod;
+
+	BEGINfunc
+	for(pMod = pLoadedModules ; pMod != NULL ; pMod = pMod->pNext) {
+		dbgprintf("printing users of loadable module %s, refcount %u, ptr %p, type %d\n", pMod->pszName, pMod->uRefCnt, pMod, pMod->eType);
+		modUsrPrint(pMod);
+	}
+	ENDfunc
+}
+
+#endif /* #ifdef DEBUG */
+
+
+/* Construct a new module object
+ */
+static rsRetVal moduleConstruct(modInfo_t **pThis)
+{
+	modInfo_t *pNew;
+
+	if((pNew = calloc(1, sizeof(modInfo_t))) == NULL)
+		return RS_RET_OUT_OF_MEMORY;
+
+	/* OK, we got the element, now initialize members that should
+	 * not be zero-filled.
+	 */
+
+	*pThis = pNew;
+	return RS_RET_OK;
+}
+
+
+/* Destructs a module object. The object must not be linked to the
+ * linked list of modules. Please note that all other dependencies on this
+ * modules must have been removed before (e.g. CfSysLineHandlers!)
+ */
+static void moduleDestruct(modInfo_t *pThis)
+{
+	assert(pThis != NULL);
+	if(pThis->pszName != NULL)
+		free(pThis->pszName);
+	if(pThis->pModHdlr != NULL) {
+#	ifdef	VALGRIND
+#		warning "dlclose disabled for valgrind"
+#	else
+		dlclose(pThis->pModHdlr);
+#	endif
+	}
+
+	free(pThis);
+}
+
+
+/* The following function is the queryEntryPoint for host-based entry points.
+ * Modules may call it to get access to core interface functions. Please note
+ * that utility functions can be accessed via shared libraries - at least this
+ * is my current shool of thinking.
+ * Please note that the implementation as a query interface allows to take
+ * care of plug-in interface version differences. -- rgerhards, 2007-07-31
+ */
+static rsRetVal queryHostEtryPt(uchar *name, rsRetVal (**pEtryPoint)())
+{
+	DEFiRet;
+
+	if((name == NULL) || (pEtryPoint == NULL))
+		return RS_RET_PARAM_ERROR;
+
+	if(!strcmp((char*) name, "regCfSysLineHdlr")) {
+		*pEtryPoint = regCfSysLineHdlr;
+	} else if(!strcmp((char*) name, "objGetObjInterface")) {
+		*pEtryPoint = objGetObjInterface;
+	} else {
+		*pEtryPoint = NULL; /* to  be on the safe side */
+		ABORT_FINALIZE(RS_RET_ENTRY_POINT_NOT_FOUND);
+	}
+
+finalize_it:
+	RETiRet;
+}
+
+
+/* get the name of a module
+ */
+static uchar *modGetName(modInfo_t *pThis)
+{
+	return((pThis->pszName == NULL) ? (uchar*) "" : pThis->pszName);
+}
+
+
+/* get the state-name of a module. The state name is its name
+ * together with a short description of the module state (which
+ * is pulled from the module itself.
+ * rgerhards, 2007-07-24
+ * TODO: the actual state name is not yet pulled
+ */
+static uchar *modGetStateName(modInfo_t *pThis)
+{
+	return(modGetName(pThis));
+}
+
+
+/* Add a module to the loaded module linked list
+ */
+static inline void
+addModToList(modInfo_t *pThis)
+{
+	assert(pThis != NULL);
+
+	if(pLoadedModules == NULL) {
+		pLoadedModules = pLoadedModulesLast = pThis;
+	} else {
+		/* there already exist entries */
+		pThis->pPrev = pLoadedModulesLast;
+		pLoadedModulesLast->pNext = pThis;
+		pLoadedModulesLast = pThis;
+	}
+}
+
+
+/* Get the next module pointer - this is used to traverse the list.
+ * The function returns the next pointer or NULL, if there is no next one.
+ * The last object must be provided to the function. If NULL is provided,
+ * it starts at the root of the list. Even in this case, NULL may be 
+ * returned - then, the list is empty.
+ * rgerhards, 2007-07-23
+ */
+static modInfo_t *GetNxt(modInfo_t *pThis)
+{
+	modInfo_t *pNew;
+
+	if(pThis == NULL)
+		pNew = pLoadedModules;
+	else
+		pNew = pThis->pNext;
+
+	return(pNew);
+}
+
+
+/* this function is like GetNxt(), but it returns pointers to
+ * modules of specific type only. As we currently deal just with output modules,
+ * it is a dummy, to be filled with real code later.
+ * rgerhards, 2007-07-24
+ */
+static modInfo_t *GetNxtType(modInfo_t *pThis, eModType_t rqtdType)
+{
+	modInfo_t *pMod = pThis;
+
+	do {
+		pMod = GetNxt(pMod);
+	} while(!(pMod == NULL || pMod->eType == rqtdType)); /* warning: do ... while() */
+
+	return pMod;
+}
+
+
+/* Prepare a module for unloading.
+ * This is currently a dummy, to be filled when we have a plug-in
+ * interface - rgerhards, 2007-08-09
+ * rgerhards, 2007-11-21:
+ * When this function is called, all instance-data must already have
+ * been destroyed. In the case of output modules, this happens when the
+ * rule set is being destroyed. When we implement other module types, we
+ * need to think how we handle it there (and if we have any instance data).
+ * rgerhards, 2008-03-10: reject unload request if the module has a reference
+ * count > 0.
+ */
+static rsRetVal
+modPrepareUnload(modInfo_t *pThis)
+{
+	DEFiRet;
+	void *pModCookie;
+
+	assert(pThis != NULL);
+
+	if(pThis->uRefCnt > 0) {
+		dbgprintf("rejecting unload of module '%s' because it has a refcount of %d\n",
+			  pThis->pszName, pThis->uRefCnt);
+		ABORT_FINALIZE(RS_RET_MODULE_STILL_REFERENCED);
+	}
+
+	CHKiRet(pThis->modGetID(&pModCookie));
+	pThis->modExit(); /* tell the module to get ready for unload */
+	CHKiRet(unregCfSysLineHdlrs4Owner(pModCookie));
+
+finalize_it:
+	RETiRet;
+}
+
+
+/* Add an already-loaded module to the module linked list. This function does
+ * everything needed to fully initialize the module.
+ */
+static rsRetVal
+doModInit(rsRetVal (*modInit)(int, int*, rsRetVal(**)(), rsRetVal(*)(), modInfo_t*), uchar *name, void *pModHdlr)
+{
+	DEFiRet;
+	modInfo_t *pNew = NULL;
+	rsRetVal (*modGetType)(eModType_t *pType);
+
+	assert(modInit != NULL);
+
+	if((iRet = moduleConstruct(&pNew)) != RS_RET_OK) {
+		pNew = NULL;
+		ABORT_FINALIZE(iRet);
+	}
+
+	CHKiRet((*modInit)(CURR_MOD_IF_VERSION, &pNew->iIFVers, &pNew->modQueryEtryPt, queryHostEtryPt, pNew));
+
+	if(pNew->iIFVers != CURR_MOD_IF_VERSION) {
+		ABORT_FINALIZE(RS_RET_MISSING_INTERFACE);
+	}
+
+	/* We now poll the module to see what type it is. We do this only once as this
+	 * can never change in the lifetime of an module. -- rgerhards, 2007-12-14
+	 */
+	CHKiRet((*pNew->modQueryEtryPt)((uchar*)"getType", &modGetType));
+	CHKiRet((iRet = (*modGetType)(&pNew->eType)) != RS_RET_OK);
+	dbgprintf("module of type %d being loaded.\n", pNew->eType);
+	
+	/* OK, we know we can successfully work with the module. So we now fill the
+	 * rest of the data elements. First we load the interfaces common to all
+	 * module types.
+	 */
+	CHKiRet((*pNew->modQueryEtryPt)((uchar*)"modGetID", &pNew->modGetID));
+	CHKiRet((*pNew->modQueryEtryPt)((uchar*)"modExit", &pNew->modExit));
+
+	/* ... and now the module-specific interfaces */
+	switch(pNew->eType) {
+		case eMOD_IN:
+			CHKiRet((*pNew->modQueryEtryPt)((uchar*)"runInput", &pNew->mod.im.runInput));
+			CHKiRet((*pNew->modQueryEtryPt)((uchar*)"willRun", &pNew->mod.im.willRun));
+			CHKiRet((*pNew->modQueryEtryPt)((uchar*)"afterRun", &pNew->mod.im.afterRun));
+			break;
+		case eMOD_OUT:
+			CHKiRet((*pNew->modQueryEtryPt)((uchar*)"freeInstance", &pNew->freeInstance));
+			CHKiRet((*pNew->modQueryEtryPt)((uchar*)"dbgPrintInstInfo", &pNew->dbgPrintInstInfo));
+			CHKiRet((*pNew->modQueryEtryPt)((uchar*)"doAction", &pNew->mod.om.doAction));
+			CHKiRet((*pNew->modQueryEtryPt)((uchar*)"parseSelectorAct", &pNew->mod.om.parseSelectorAct));
+			CHKiRet((*pNew->modQueryEtryPt)((uchar*)"isCompatibleWithFeature", &pNew->isCompatibleWithFeature));
+			CHKiRet((*pNew->modQueryEtryPt)((uchar*)"tryResume", &pNew->tryResume));
+			break;
+		case eMOD_LIB:
+			break;
+	}
+
+	pNew->pszName = (uchar*) strdup((char*)name); /* we do not care if strdup() fails, we can accept that */
+	pNew->pModHdlr = pModHdlr;
+	/* TODO: take this from module */
+	if(pModHdlr == NULL)
+		pNew->eLinkType = eMOD_LINK_STATIC;
+	else
+		pNew->eLinkType = eMOD_LINK_DYNAMIC_LOADED;
+
+	/* we initialized the structure, now let's add it to the linked list of modules */
+	addModToList(pNew);
+
+finalize_it:
+	if(iRet != RS_RET_OK) {
+		if(pNew != NULL)
+			moduleDestruct(pNew);
+	}
+
+	RETiRet;
+}
+
+/* Print loaded modules. This is more or less a 
+ * debug or test aid, but anyhow I think it's worth it...
+ * This only works if the dbgprintf() subsystem is initialized.
+ * TODO: update for new input modules!
+ */
+static void modPrintList(void)
+{
+	modInfo_t *pMod;
+
+	pMod = GetNxt(NULL);
+	while(pMod != NULL) {
+		dbgprintf("Loaded Module: Name='%s', IFVersion=%d, ",
+			(char*) modGetName(pMod), pMod->iIFVers);
+		dbgprintf("type=");
+		switch(pMod->eType) {
+		case eMOD_OUT:
+			dbgprintf("output");
+			break;
+		case eMOD_IN:
+			dbgprintf("input");
+			break;
+		case eMOD_LIB:
+			dbgprintf("library");
+			break;
+		}
+		dbgprintf(" module.\n");
+		dbgprintf("Entry points:\n");
+		dbgprintf("\tqueryEtryPt:        0x%lx\n", (unsigned long) pMod->modQueryEtryPt);
+		dbgprintf("\tdoAction:           0x%lx\n", (unsigned long) pMod->mod.om.doAction);
+		dbgprintf("\tparseSelectorAct:   0x%lx\n", (unsigned long) pMod->mod.om.parseSelectorAct);
+		dbgprintf("\tdbgPrintInstInfo:   0x%lx\n", (unsigned long) pMod->dbgPrintInstInfo);
+		dbgprintf("\tfreeInstance:       0x%lx\n", (unsigned long) pMod->freeInstance);
+		dbgprintf("\n");
+		pMod = GetNxt(pMod); /* done, go next */
+	}
+}
+
+
+/* unlink and destroy a module. The caller must provide a pointer to the module
+ * itself as well as one to its immediate predecessor.
+ * rgerhards, 2008-02-26
+ */
+static rsRetVal
+modUnlinkAndDestroy(modInfo_t **ppThis)
+{
+	DEFiRet;
+	modInfo_t *pThis;
+
+	assert(ppThis != NULL);
+	pThis = *ppThis;
+	assert(pThis != NULL);
+
+	/* first check if we are permitted to unload */
+	if(pThis->eType == eMOD_LIB) {
+		if(pThis->uRefCnt > 0) {
+			dbgprintf("module %s NOT unloaded because it still has a refcount of %u\n",
+				  pThis->pszName, pThis->uRefCnt);
+#			ifdef DEBUG
+			//modUsrPrintAll();
+#			endif
+			ABORT_FINALIZE(RS_RET_MODULE_STILL_REFERENCED);
+		}
+	}
+
+	/* we need to unlink the module before we can destruct it -- rgerhards, 2008-02-26 */
+	if(pThis->pPrev == NULL) {
+		/* module is root, so we need to set a new root */
+		pLoadedModules = pThis->pNext;
+	} else {
+		pThis->pPrev->pNext = pThis->pNext;
+	}
+
+	if(pThis->pNext == NULL) {
+		pLoadedModulesLast = pThis->pPrev;
+	} else {
+		pThis->pNext->pPrev = pThis->pPrev;
+	}
+
+	/* finally, we are ready for the module to go away... */
+	dbgprintf("Unloading module %s\n", modGetName(pThis));
+	CHKiRet(modPrepareUnload(pThis));
+	*ppThis = pThis->pNext;
+
+	moduleDestruct(pThis);
+
+finalize_it:
+	RETiRet;
+}
+
+
+/* unload all loaded modules of a specific type (use eMOD_ALL if you want to
+ * unload all module types). The unload happens only if the module is no longer
+ * referenced. So some modules may survive this call.
+ * rgerhards, 2008-03-11
+ */
+static rsRetVal
+modUnloadAndDestructAll(eModLinkType_t modLinkTypesToUnload)
+{
+	DEFiRet;
+	modInfo_t *pModCurr; /* module currently being processed */
+
+	pModCurr = GetNxt(NULL);
+	while(pModCurr != NULL) {
+		if(modLinkTypesToUnload == eMOD_LINK_ALL || pModCurr->eLinkType == modLinkTypesToUnload) {
+			if(modUnlinkAndDestroy(&pModCurr) == RS_RET_MODULE_STILL_REFERENCED) {
+				pModCurr = GetNxt(pModCurr);
+			}
+			/* Note: if the module was successfully unloaded, it has updated the
+			 * pModCurr pointer to the next module. So we do NOT need to advance
+			 * to the next module on successful unload.
+			 */
+		} else {
+			pModCurr = GetNxt(pModCurr);
+		}
+	}
+
+#	ifdef DEBUG
+		if(pLoadedModules != NULL) {
+			dbgprintf("modules still loaded after module.UnloadAndDestructAll:\n");
+			modUsrPrintAll();
+		}
+#	endif
+
+	RETiRet;
+}
+
+
+/* load a module and initialize it, based on doModLoad() from conf.c
+ * rgerhards, 2008-03-05
+ * varmojfekoj added support for dynamically loadable modules on 2007-08-13
+ * rgerhards, 2007-09-25: please note that the non-threadsafe function dlerror() is
+ * called below. This is ok because modules are currently only loaded during
+ * configuration file processing, which is executed on a single thread. Should we
+ * change that design at any stage (what is unlikely), we need to find a
+ * replacement.
+ */
+static rsRetVal
+Load(uchar *pModName)
+{
+	DEFiRet;
+	
+	size_t iPathLen, iModNameLen;
+	uchar szPath[PATH_MAX];
+	uchar *pModNameCmp;
+	int bHasExtension;
+        void *pModHdlr, *pModInit;
+	modInfo_t *pModInfo;
+
+	assert(pModName != NULL);
+	dbgprintf("Requested to load module '%s'\n", pModName);
+
+	iModNameLen = strlen((char *) pModName);
+	if(iModNameLen > 3 && !strcmp((char *) pModName + iModNameLen - 3, ".so")) {
+		iModNameLen -= 3;
+		bHasExtension = TRUE;
+	} else
+		bHasExtension = FALSE;
+
+	pModInfo = GetNxt(NULL);
+	while(pModInfo != NULL) {
+		if(!strncmp((char *) pModName, (char *) (pModNameCmp = modGetName(pModInfo)), iModNameLen) &&
+		   (!*(pModNameCmp + iModNameLen) || !strcmp((char *) pModNameCmp + iModNameLen, ".so"))) {
+			dbgprintf("Module '%s' already loaded\n", pModName);
+			ABORT_FINALIZE(RS_RET_OK);
+		}
+		pModInfo = GetNxt(pModInfo);
+	}
+
+	/* now build our load module name */
+	if(*pModName == '/') {
+		*szPath = '\0';	/* we do not need to append the path - its already in the module name */
+		iPathLen = 0;
+	} else {
+		*szPath = '\0';
+		strncat((char *) szPath, (pModDir == NULL) ? _PATH_MODDIR : (char*) pModDir, sizeof(szPath) - 1);
+		iPathLen = strlen((char*) szPath);
+		if((szPath[iPathLen - 1] != '/')) {
+			if((iPathLen <= sizeof(szPath) - 2)) {
+				szPath[iPathLen++] = '/';
+				szPath[iPathLen] = '\0';
+			} else {
+				errmsg.LogError(NO_ERRCODE, "could not load module '%s', path too long\n", pModName);
+				ABORT_FINALIZE(RS_RET_MODULE_LOAD_ERR_PATHLEN);
+			}
+		}
+	}
+
+	/* ... add actual name ... */
+	strncat((char *) szPath, (char *) pModName, sizeof(szPath) - iPathLen - 1);
+
+	/* now see if we have an extension and, if not, append ".so" */
+	if(!bHasExtension) {
+		/* we do not have an extension and so need to add ".so"
+		 * TODO: I guess this is highly importable, so we should change the
+		 * algo over time... -- rgerhards, 2008-03-05
+		 */
+		/* ... so now add the extension */
+		strncat((char *) szPath, ".so", sizeof(szPath) - strlen((char*) szPath) - 1);
+		iPathLen += 3;
+	}
+
+	if(iPathLen + strlen((char*) pModName) >= sizeof(szPath)) {
+		errmsg.LogError(NO_ERRCODE, "could not load module '%s', path too long\n", pModName);
+		ABORT_FINALIZE(RS_RET_MODULE_LOAD_ERR_PATHLEN);
+	}
+
+	/* complete load path constructed, so ... GO! */
+	dbgprintf("loading module '%s'\n", szPath);
+	if(!(pModHdlr = dlopen((char *) szPath, RTLD_NOW))) {
+		errmsg.LogError(NO_ERRCODE, "could not load module '%s', dlopen: %s\n", szPath, dlerror());
+		ABORT_FINALIZE(RS_RET_MODULE_LOAD_ERR_DLOPEN);
+	}
+	if(!(pModInit = dlsym(pModHdlr, "modInit"))) {
+		errmsg.LogError(NO_ERRCODE, "could not load module '%s', dlsym: %s\n", szPath, dlerror());
+		dlclose(pModHdlr);
+		ABORT_FINALIZE(RS_RET_MODULE_LOAD_ERR_NO_INIT);
+	}
+	if((iRet = doModInit(pModInit, (uchar*) pModName, pModHdlr)) != RS_RET_OK) {
+		errmsg.LogError(NO_ERRCODE, "could not load module '%s', rsyslog error %d\n", szPath, iRet);
+		dlclose(pModHdlr);
+		ABORT_FINALIZE(RS_RET_MODULE_LOAD_ERR_INIT_FAILED);
+	}
+
+finalize_it:
+	RETiRet;
+}
+
+
+/* set the default module load directory. A NULL value may be provided, in
+ * which case any previous value is deleted but no new one set. The caller-provided
+ * string is duplicated. If it needs to be freed, that's the caller's duty.
+ * rgerhards, 2008-03-07
+ */
+static rsRetVal
+SetModDir(uchar *pszModDir)
+{
+	DEFiRet;
+
+	dbgprintf("setting default module load directory '%s'\n", pszModDir);
+	if(pModDir != NULL) {
+		free(pModDir);
+	}
+
+	pModDir = (uchar*) strdup((char*)pszModDir);
+
+	RETiRet;
+}
+
+
+/* Reference-Counting object access: add 1 to the current reference count. Must be
+ * called by anyone interested in using a module. -- rgerhards, 20080-03-10
+ */
+static rsRetVal
+Use(char *srcFile, modInfo_t *pThis)
+{
+	DEFiRet;
+
+	assert(pThis != NULL);
+	pThis->uRefCnt++;
+	dbgprintf("source file %s requested reference for module '%s', reference count now %u\n",
+		  srcFile, pThis->pszName, pThis->uRefCnt);
+
+#	ifdef DEBUG
+	modUsrAdd(pThis, srcFile);
+#	endif
+
+	RETiRet;
+
+}
+
+
+/* Reference-Counting object access: subract one from the current refcount. Must
+ * by called by anyone who no longer needs a module. If count reaches 0, the 
+ * module is unloaded. -- rgerhards, 20080-03-10
+ */
+static rsRetVal
+Release(char *srcFile, modInfo_t **ppThis)
+{
+	DEFiRet;
+	modInfo_t *pThis;
+
+	assert(ppThis != NULL);
+	pThis = *ppThis;
+	assert(pThis != NULL);
+	if(pThis->uRefCnt == 0) {
+		/* oops, we are already at 0? */
+		dbgprintf("internal error: module '%s' already has a refcount of 0 (released by %s)!\n",
+			  pThis->pszName, srcFile);
+	} else {
+		--pThis->uRefCnt;
+		dbgprintf("file %s released module '%s', reference count now %u\n",
+			  srcFile, pThis->pszName, pThis->uRefCnt);
+#		ifdef DEBUG
+		modUsrDel(pThis, srcFile);
+		modUsrPrint(pThis);
+#		endif
+	}
+
+	if(pThis->uRefCnt == 0) {
+		/* we have a zero refcount, so we must unload the module */
+		dbgprintf("module '%s' has zero reference count, unloading...\n", pThis->pszName);
+		modUnlinkAndDestroy(&pThis);
+		/* we must NOT do a *ppThis = NULL, because ppThis now points into freed memory!
+		 * If in doubt, see obj.c::ReleaseObj() for how we are called.
+		 */
+	}
+
+	RETiRet;
+
+}
+
+
+/* exit our class
+ * rgerhards, 2008-03-11
+ */
+BEGINObjClassExit(module, OBJ_IS_LOADABLE_MODULE) /* CHANGE class also in END MACRO! */
+CODESTARTObjClassExit(module)
+	/* release objects we no longer need */
+	objRelease(errmsg, CORE_COMPONENT);
+
+#	ifdef DEBUG
+	modUsrPrintAll(); /* debug aid - TODO: integrate with debug.c, at least the settings! */
+#	endif
+ENDObjClassExit(module)
+
+
+/* queryInterface function
+ * rgerhards, 2008-03-05
+ */
+BEGINobjQueryInterface(module)
+CODESTARTobjQueryInterface(module)
+	if(pIf->ifVersion != moduleCURR_IF_VERSION) { /* check for current version, increment on each change */
+		ABORT_FINALIZE(RS_RET_INTERFACE_NOT_SUPPORTED);
+	}
+
+	/* ok, we have the right interface, so let's fill it
+	 * Please note that we may also do some backwards-compatibility
+	 * work here (if we can support an older interface version - that,
+	 * of course, also affects the "if" above).
+	 */
+	pIf->GetNxt = GetNxt;
+	pIf->GetNxtType = GetNxtType;
+	pIf->GetName = modGetName;
+	pIf->GetStateName = modGetStateName;
+	pIf->PrintList = modPrintList;
+	pIf->UnloadAndDestructAll = modUnloadAndDestructAll;
+	pIf->doModInit = doModInit;
+	pIf->SetModDir = SetModDir;
+	pIf->Load = Load;
+	pIf->Use = Use;
+	pIf->Release = Release;
+finalize_it:
+ENDobjQueryInterface(module)
+
+
+/* Initialize our class. Must be called as the very first method
+ * before anything else is called inside this class.
+ * rgerhards, 2008-03-05
+ */
+BEGINAbstractObjClassInit(module, 1, OBJ_IS_CORE_MODULE) /* class, version - CHANGE class also in END MACRO! */
+	uchar *pModPath;
+
+	/* use any module load path specified in the environment */
+	if((pModPath = (uchar*) getenv("RSYSLOG_MODDIR")) != NULL) {
+		SetModDir(pModPath);
+	}
+
+	/* now check if another module path was set via the command line (-M)
+	 * if so, that overrides the environment. Please note that we must use
+	 * a global setting here because the command line parser can NOT call
+	 * into the module object, because it is not initialized at that point. So
+	 * instead a global setting is changed and we pick it up as soon as we
+	 * initialize -- rgerhards, 2008-04-04
+	 */
+	if(glblModPath != NULL) {
+		SetModDir(glblModPath);
+	}
+
+	/* request objects we use */
+	CHKiRet(objUse(errmsg, CORE_COMPONENT));
+ENDObjClassInit(module)
+
+/* vi:set ai:
+ */