/* omlibdbi.c
 * This is the implementation of the dbi output module.
 *
 * NOTE: read comments in module-template.h to understand how this file
 *       works!
 *
 * This depends on libdbi being present with the proper settings. Older
 * versions do not necessarily have them. Please visit this bug tracker
 * for details: http://bugzilla.adiscon.com/show_bug.cgi?id=31
 *
 * File begun on 2008-02-14 by RGerhards (extracted from syslogd.c)
 *
 * Copyright 2008 Rainer Gerhards and Adiscon GmbH.
 *
 * This file is part of rsyslog.
 *
 * Rsyslog is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Rsyslog 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Rsyslog.  If not, see <http://www.gnu.org/licenses/>.
 *
 * A copy of the GPL can be found in the file "COPYING" in this distribution.
 */
#include "config.h"
#include "rsyslog.h"
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <signal.h>
#include <errno.h>
#include <time.h>
#include <dbi/dbi.h>
#include "syslogd.h"
#include "syslogd-types.h"
#include "cfsysline.h"
#include "srUtils.h"
#include "template.h"
#include "module-template.h"
#include "debug.h"

MODULE_TYPE_OUTPUT

/* internal structures
 */
DEF_OMOD_STATIC_DATA
static int bDbiInitialized = 0;	/* dbi_initialize() can only be called one - this keeps track of it */

typedef struct _instanceData {
	dbi_conn conn;		/* handle to database */
	uchar *drvrName;	/* driver to use */
	uchar *host;		/* host to connect to */
	uchar *usrName;		/* user name for connect */
	uchar *pwd;		/* password for connect */
	uchar *dbName;		/* database to use */
	unsigned uLastDBErrno;	/* last errno returned by libdbi or 0 if all is well */
} instanceData;


/* config settings */
static uchar *dbiDrvrDir = NULL;/* global: where do the dbi drivers reside? */
static uchar *drvrName = NULL;	/* driver to use */
static uchar *host = NULL;	/* host to connect to */
static uchar *usrName = NULL;	/* user name for connect */
static uchar *pwd = NULL;	/* password for connect */
static uchar *dbName = NULL;	/* database to use */
#ifdef HAVE_DBI_R
static dbi_inst dbiInst;
#endif


BEGINcreateInstance
CODESTARTcreateInstance
ENDcreateInstance


BEGINisCompatibleWithFeature
CODESTARTisCompatibleWithFeature
	/* we do not like repeated message reduction inside the database */
ENDisCompatibleWithFeature


/* The following function is responsible for closing a
 * database connection.
 */
static void closeConn(instanceData *pData)
{
	ASSERT(pData != NULL);

	if(pData->conn != NULL) {	/* just to be on the safe side... */
		dbi_conn_close(pData->conn);
		pData->conn = NULL;
	}
}

BEGINfreeInstance
CODESTARTfreeInstance
	closeConn(pData);
ENDfreeInstance


BEGINneedUDPSocket
CODESTARTneedUDPSocket
ENDneedUDPSocket


BEGINdbgPrintInstInfo
CODESTARTdbgPrintInstInfo
	/* nothing special here */
ENDdbgPrintInstInfo


/* log a database error with descriptive message.
 * We check if we have a valid database handle. If not, we simply
 * report an error, but can not be specific. RGerhards, 2007-01-30
 */
static void
reportDBError(instanceData *pData, int bSilent)
{
	unsigned uDBErrno;
	char errMsg[1024];
	const char *pszDbiErr;

	BEGINfunc
	ASSERT(pData != NULL);

	/* output log message */
	errno = 0;
	if(pData->conn == NULL) {
		logerror("unknown DB error occured - could not obtain connection handle");
	} else { /* we can ask dbi for the error description... */
		uDBErrno = dbi_conn_error(pData->conn, &pszDbiErr);
		snprintf(errMsg, sizeof(errMsg)/sizeof(char), "db error (%d): %s\n", uDBErrno, pszDbiErr);
		if(bSilent || uDBErrno == pData->uLastDBErrno)
			dbgprintf("libdbi, DBError(silent): %s\n", errMsg);
		else {
			pData->uLastDBErrno = uDBErrno;
			logerror(errMsg);
		}
	}
		
	ENDfunc
}


/* The following function is responsible for initializing a connection
 */
static rsRetVal initConn(instanceData *pData, int bSilent)
{
	DEFiRet;
	int iDrvrsLoaded;

	ASSERT(pData != NULL);
	ASSERT(pData->conn == NULL);

	if(bDbiInitialized == 0) {
		/* we need to init libdbi first */
#		ifdef HAVE_DBI_R
		iDrvrsLoaded = dbi_initialize_r((char*) dbiDrvrDir, &dbiInst);
#		else
		iDrvrsLoaded = dbi_initialize((char*) dbiDrvrDir);
#		endif
		if(iDrvrsLoaded == 0) {
			logerror("libdbi error: libdbi or libdbi drivers not present on this system - suspending.");
			ABORT_FINALIZE(RS_RET_SUSPENDED);
		} else if(iDrvrsLoaded < 0) {
			logerror("libdbi error: libdbi could not be initialized - suspending.");
			ABORT_FINALIZE(RS_RET_SUSPENDED);
		}
		bDbiInitialized = 1; /* we are done for the rest of our existence... */
	}

#	ifdef HAVE_DBI_R
	pData->conn = dbi_conn_new_r((char*)pData->drvrName, dbiInst);
#	else
	pData->conn = dbi_conn_new((char*)pData->drvrName);
#	endif
	if(pData->conn == NULL) {
		logerror("can not initialize libdbi connection");
		iRet = RS_RET_SUSPENDED;
	} else { /* we could get the handle, now on with work... */
		/* Connect to database */
		dbi_conn_set_option(pData->conn, "host",     (char*) pData->host);
		dbi_conn_set_option(pData->conn, "username", (char*) pData->usrName);
		dbi_conn_set_option(pData->conn, "dbname",   (char*) pData->dbName);
		if(pData->pwd != NULL)
			dbi_conn_set_option(pData->conn, "password", (char*) pData->pwd);
		if(dbi_conn_connect(pData->conn) < 0) {
			reportDBError(pData, bSilent);
			closeConn(pData); /* ignore any error we may get */
			iRet = RS_RET_SUSPENDED;
		}
	}

finalize_it:
	RETiRet;
}


/* The following function writes the current log entry
 * to an established database connection.
 */
rsRetVal writeDB(uchar *psz, instanceData *pData)
{
	DEFiRet;
	dbi_result dbiRes = NULL;

	ASSERT(psz != NULL);
	ASSERT(pData != NULL);

	/* see if we are ready to proceed */
	if(pData->conn == NULL) {
		CHKiRet(initConn(pData, 0));
	}

	/* try insert */
	if((dbiRes = dbi_conn_query(pData->conn, (const char*)psz)) == NULL) {
		/* error occured, try to re-init connection and retry */
		closeConn(pData); /* close the current handle */
		CHKiRet(initConn(pData, 0)); /* try to re-open */
		if((dbiRes = dbi_conn_query(pData->conn, (const char*)psz)) == NULL) { /* re-try insert */
			/* we failed, giving up for now */
			reportDBError(pData, 0);
			closeConn(pData); /* free ressources */
			ABORT_FINALIZE(RS_RET_SUSPENDED);
		}
	}

finalize_it:
	if(iRet == RS_RET_OK) {
		pData->uLastDBErrno = 0; /* reset error for error supression */
	}

	if(dbiRes != NULL)
		dbi_result_free(dbiRes);

	RETiRet;
}


BEGINtryResume
CODESTARTtryResume
	if(pData->conn == NULL) {
		iRet = initConn(pData, 1);
	}
ENDtryResume

BEGINdoAction
CODESTARTdoAction
	dbgprintf("\n");
	iRet = writeDB(ppString[0], pData);
ENDdoAction


BEGINparseSelectorAct
CODESTARTparseSelectorAct
CODE_STD_STRING_REQUESTparseSelectorAct(1)
	if(!strncmp((char*) p, ":omlibdbi:", sizeof(":omlibdbi:") - 1)) {
		p += sizeof(":omlibdbi:") - 1; /* eat indicator sequence (-1 because of '\0'!) */
	} else {
		ABORT_FINALIZE(RS_RET_CONFLINE_UNPROCESSED);
	}

	/* ok, if we reach this point, we have something for us */
	CHKiRet(createInstance(&pData));

	/* no create the instance based on what we currently have */
	if(drvrName == NULL) {
		logerror("omlibdbi: no db driver name given - action can not be created");
		ABORT_FINALIZE(RS_RET_NO_DRIVERNAME);
	}

	if((pData->drvrName = (uchar*) strdup((char*)drvrName)) == NULL) ABORT_FINALIZE(RS_RET_OUT_OF_MEMORY);
	/* NULL values are supported because drivers have different needs.
	 * They will err out on connect. -- rgerhards, 2008-02-15
	 */
	if(host    != NULL)
		if((pData->host     = (uchar*) strdup((char*)host))     == NULL) ABORT_FINALIZE(RS_RET_OUT_OF_MEMORY);
	if(usrName != NULL)
		if((pData->usrName  = (uchar*) strdup((char*)usrName))  == NULL) ABORT_FINALIZE(RS_RET_OUT_OF_MEMORY);
	if(dbName  != NULL)
		if((pData->dbName   = (uchar*) strdup((char*)dbName))   == NULL) ABORT_FINALIZE(RS_RET_OUT_OF_MEMORY);
	if(pwd     != NULL)
		if((pData->pwd      = (uchar*) strdup((char*)""))       == NULL) ABORT_FINALIZE(RS_RET_OUT_OF_MEMORY);

	CHKiRet(cflineParseTemplateName(&p, *ppOMSR, 0, OMSR_RQD_TPL_OPT_SQL, (uchar*) " StdDBFmt"));

CODE_STD_FINALIZERparseSelectorAct
ENDparseSelectorAct


BEGINmodExit
CODESTARTmodExit
	/* if we initialized libdbi, we now need to cleanup */
	if(bDbiInitialized) {
#		ifdef HAVE_DBI_R
		dbi_shutdown_r(dbiInst);
#		else
		dbi_shutdown();
#		endif
	}
ENDmodExit


BEGINqueryEtryPt
CODESTARTqueryEtryPt
CODEqueryEtryPt_STD_OMOD_QUERIES
ENDqueryEtryPt


/* Reset config variables for this module to default values.
 */
static rsRetVal resetConfigVariables(uchar __attribute__((unused)) *pp, void __attribute__((unused)) *pVal)
{
	DEFiRet;

	if(dbiDrvrDir != NULL) {
		free(dbiDrvrDir);
		dbiDrvrDir = NULL;
	}

	if(drvrName != NULL) {
		free(drvrName);
		drvrName = NULL;
	}

	if(host != NULL) {
		free(host);
		host = NULL;
	}

	if(usrName != NULL) {
		free(usrName);
		usrName = NULL;
	}

	if(pwd != NULL) {
		free(pwd);
		pwd = NULL;
	}

	if(dbName != NULL) {
		free(dbName);
		dbName = NULL;
	}

	RETiRet;
}


BEGINmodInit()
CODESTARTmodInit
	*ipIFVersProvided = 1; /* so far, we only support the initial definition */
CODEmodInit_QueryRegCFSLineHdlr
	CHKiRet(omsdRegCFSLineHdlr(	(uchar *)"actionlibdbidriverdirectory", 0, eCmdHdlrGetWord, NULL, &dbiDrvrDir, STD_LOADABLE_MODULE_ID));
	CHKiRet(omsdRegCFSLineHdlr(	(uchar *)"actionlibdbidriver", 0, eCmdHdlrGetWord, NULL, &drvrName, STD_LOADABLE_MODULE_ID));
	CHKiRet(omsdRegCFSLineHdlr(	(uchar *)"actionlibdbihost", 0, eCmdHdlrGetWord, NULL, &host, STD_LOADABLE_MODULE_ID));
	CHKiRet(omsdRegCFSLineHdlr(	(uchar *)"actionlibdbiusername", 0, eCmdHdlrGetWord, NULL, &usrName, STD_LOADABLE_MODULE_ID));
	CHKiRet(omsdRegCFSLineHdlr(	(uchar *)"actionlibdbipassword", 0, eCmdHdlrGetWord, NULL, &pwd, STD_LOADABLE_MODULE_ID));
	CHKiRet(omsdRegCFSLineHdlr(	(uchar *)"actionlibdbidbname", 0, eCmdHdlrGetWord, NULL, &dbName, STD_LOADABLE_MODULE_ID));
	CHKiRet(omsdRegCFSLineHdlr(	(uchar *)"resetconfigvariables", 1, eCmdHdlrCustomHandler, resetConfigVariables, NULL, STD_LOADABLE_MODULE_ID));
ENDmodInit

/* vim:set ai:
 */