/* imrelp.c
 *
 * This is the implementation of the RELP input module.
 *
 * File begun on 2008-03-13 by RGerhards
 *
 * Copyright 2008, 2009 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 <stdlib.h>
#include <assert.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <stdarg.h>
#include <ctype.h>
#include <netinet/in.h>
#include <netdb.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <librelp.h>
#include "rsyslog.h"
#include "dirty.h"
#include "errmsg.h"
#include "cfsysline.h"
#include "module-template.h"
#include "net.h"
#include "msg.h"
#include "unicode-helper.h"
#include "prop.h"

MODULE_TYPE_INPUT
MODULE_TYPE_NOKEEP
MODULE_CNFNAME("imrelp")

/* static data */
DEF_IMOD_STATIC_DATA
DEFobjCurrIf(net)
DEFobjCurrIf(prop)
DEFobjCurrIf(errmsg)

/* forward definitions */
static rsRetVal resetConfigVariables(uchar __attribute__((unused)) *pp, void __attribute__((unused)) *pVal);


/* Module static data */
static relpEngine_t *pRelpEngine;	/* our relp engine */
static prop_t *pInputName = NULL;	/* there is only one global inputName for all messages generated by this module */

struct instanceConf_s {
	uchar *pszBindPort;		/* port to bind to */
	struct instanceConf_s *next;
};


struct modConfData_s {
	rsconf_t *pConf;		/* our overall config object */
	instanceConf_t *root, *tail;
	int iTCPSessMax; /* max number of sessions */
	int iTCPLstnMax; /* max number of sessions */
	int iStrmDrvrMode; /* mode for stream driver, driver-dependent (0 mostly means plain tcp) */
	int bEmitMsgOnClose; /* emit an informational message on close by remote peer */
	int iAddtlFrameDelim; /* addtl frame delimiter, e.g. for netscreen, default none */
	int bDisableLFDelim; /* disable standard LF delimiter */
	int bUseFlowControl; /* use flow control, what means indicate ourselfs a "light delayable" */
	uchar *pszStrmDrvrAuthMode; /* authentication mode to use */
};

static modConfData_t *loadModConf = NULL;/* modConf ptr to use for the current load process */
static modConfData_t *runModConf = NULL;/* modConf ptr to use for the current load process */

//#include "im-helper.h" /* must be included AFTER the type definitions! */


/* ------------------------------ callbacks ------------------------------ */

/* callback for receiving syslog messages. This function is invoked from the
 * RELP engine when a syslog message arrived. It must return a relpRetVal,
 * with anything else but RELP_RET_OK terminating the relp session. Please note
 * that RELP_RET_OK is equal to RS_RET_OK and the other libRELP error codes
 * are different from our rsRetVal. So we can simply use our own iRet system
 * to fulfill the requirement.
 * rgerhards, 2008-03-21
 * Note: librelp 1.0.0 is required in order to receive the IP address, otherwise
 * we will only see the hostname (twice). -- rgerhards, 2009-10-14
 */
static relpRetVal
onSyslogRcv(uchar *pHostname, uchar *pIP, uchar *pMsg, size_t lenMsg)
{
	DEFiRet;
	parseAndSubmitMessage(pHostname, pIP, pMsg, lenMsg, PARSE_HOSTNAME,
			      eFLOWCTL_LIGHT_DELAY, pInputName, NULL, 0);

	RETiRet;
}


/* ------------------------------ end callbacks ------------------------------ */


/* This function is called when a new listener instace shall be added to 
 * the current config object via the legacy config system. It just shuffles
 * all parameters to the listener in-memory instance.
 * rgerhards, 2011-05-04
 */
static rsRetVal addInstance(void __attribute__((unused)) *pVal, uchar *pNewVal)
{
	instanceConf_t *inst;
	DEFiRet;

	CHKmalloc(inst = MALLOC(sizeof(instanceConf_t)));

	if(pNewVal == NULL || *pNewVal == '\0') {
		errmsg.LogError(0, NO_ERRCODE, "imrelp: port number must be specified, listener ignored");
	}
	inst->pszBindPort = pNewVal;
	inst->next = NULL;

	/* node created, let's add to config */
	if(loadModConf->tail == NULL) {
		loadModConf->tail = loadModConf->root = inst;
	} else {
		loadModConf->tail->next = inst;
		loadModConf->tail = inst;
	}

finalize_it:
	RETiRet;
}


static rsRetVal
addListner(modConfData_t __attribute__((unused)) *modConf, instanceConf_t *inst)
{
	DEFiRet;
	if(pRelpEngine == NULL) {
		CHKiRet(relpEngineConstruct(&pRelpEngine));
		CHKiRet(relpEngineSetDbgprint(pRelpEngine, dbgprintf));
		CHKiRet(relpEngineSetEnableCmd(pRelpEngine, (uchar*) "syslog", eRelpCmdState_Required));
		CHKiRet(relpEngineSetSyslogRcv(pRelpEngine, onSyslogRcv));
	}

	CHKiRet(relpEngineAddListner(pRelpEngine, inst->pszBindPort));

finalize_it:
	RETiRet;
}


BEGINbeginCnfLoad
CODESTARTbeginCnfLoad
	loadModConf = pModConf;
	pModConf->pConf = pConf;
	/* init legacy config variables */
	resetConfigVariables(NULL, NULL); /* dummy parameters just to fulfill interface def */
ENDbeginCnfLoad


BEGINendCnfLoad
CODESTARTendCnfLoad
	loadModConf = NULL; /* done loading */
ENDendCnfLoad


BEGINcheckCnf
CODESTARTcheckCnf
	/* so far, we have nothing to check... */
ENDcheckCnf


BEGINactivateCnfPrePrivDrop
	instanceConf_t *inst;
CODESTARTactivateCnfPrePrivDrop
	runModConf = pModConf;
	for(inst = runModConf->root ; inst != NULL ; inst = inst->next) {
		addListner(pModConf, inst);
	}
	if(pRelpEngine == NULL)
		ABORT_FINALIZE(RS_RET_NO_RUN);
finalize_it:
ENDactivateCnfPrePrivDrop

BEGINactivateCnf
CODESTARTactivateCnf
ENDactivateCnf


BEGINfreeCnf
CODESTARTfreeCnf
ENDfreeCnf

/* This function is called to gather input.
 */
BEGINrunInput
CODESTARTrunInput
	/* TODO: we must be careful to start the listener here. Currently, tcpsrv.c seems to
	 * do that in ConstructFinalize
	 */
	iRet = relpEngineRun(pRelpEngine);
ENDrunInput


BEGINwillRun
CODESTARTwillRun
ENDwillRun


BEGINafterRun
CODESTARTafterRun
	/* do cleanup here */
ENDafterRun


BEGINmodExit
CODESTARTmodExit
	if(pRelpEngine != NULL)
		iRet = relpEngineDestruct(&pRelpEngine);

	/* global variable cleanup */
	if(pInputName != NULL)
		prop.Destruct(&pInputName);

	/* release objects we used */
	objRelease(prop, CORE_COMPONENT);
	objRelease(net, LM_NET_FILENAME);
	objRelease(errmsg, CORE_COMPONENT);
ENDmodExit


static rsRetVal
resetConfigVariables(uchar __attribute__((unused)) *pp, void __attribute__((unused)) *pVal)
{
	return RS_RET_OK;
}



BEGINqueryEtryPt
CODESTARTqueryEtryPt
CODEqueryEtryPt_STD_IMOD_QUERIES
CODEqueryEtryPt_STD_CONF2_QUERIES
CODEqueryEtryPt_STD_CONF2_PREPRIVDROP_QUERIES
ENDqueryEtryPt


BEGINmodInit()
CODESTARTmodInit
	*ipIFVersProvided = CURR_MOD_IF_VERSION; /* we only support the current interface specification */
CODEmodInit_QueryRegCFSLineHdlr
	pRelpEngine = NULL;
	/* request objects we use */
	CHKiRet(objUse(prop, CORE_COMPONENT));
	CHKiRet(objUse(errmsg, CORE_COMPONENT));
	CHKiRet(objUse(net, LM_NET_FILENAME));

	/* register config file handlers */
	CHKiRet(omsdRegCFSLineHdlr((uchar *)"inputrelpserverrun", 0, eCmdHdlrGetWord,
				   addInstance, NULL, STD_LOADABLE_MODULE_ID, eConfObjGlobal));
	CHKiRet(omsdRegCFSLineHdlr((uchar *)"resetconfigvariables", 1, eCmdHdlrCustomHandler,
		resetConfigVariables, NULL, STD_LOADABLE_MODULE_ID, eConfObjGlobal));

	/* we need to create the inputName property (only once during our lifetime) */
	CHKiRet(prop.Construct(&pInputName));
	CHKiRet(prop.SetString(pInputName, UCHAR_CONSTANT("imrelp"), sizeof("imrelp") - 1));
	CHKiRet(prop.ConstructFinalize(pInputName));
ENDmodInit


/* vim:set ai:
 */