/* pmaixforwardedfrom.c
 *
 * this cleans up messages forwarded from AIX
 *
 * instead of actually parsing the message, this modifies the message and then falls through to allow a
 * later parser to handle the now modified message
 *
 * created 2010-12-13 by David Lang based on pmlastmsg
 *
 * This file is part of rsyslog.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *       -or-
 *       see COPYING.ASL20 in the source distribution
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include "config.h"
#include "rsyslog.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <ctype.h>
#include "conf.h"
#include "syslogd-types.h"
#include "template.h"
#include "msg.h"
#include "module-template.h"
#include "glbl.h"
#include "errmsg.h"
#include "parser.h"
#include "datetime.h"
#include "unicode-helper.h"

MODULE_TYPE_PARSER
MODULE_TYPE_NOKEEP
PARSER_NAME("rsyslog.aixforwardedfrom")

/* internal structures
 */
DEF_PMOD_STATIC_DATA
DEFobjCurrIf(glbl)
DEFobjCurrIf(parser)
DEFobjCurrIf(datetime)


/* static data */
static int bParseHOSTNAMEandTAG;	/* cache for the equally-named global param - performance enhancement */


BEGINisCompatibleWithFeature
CODESTARTisCompatibleWithFeature
	if(eFeat == sFEATUREAutomaticSanitazion)
		iRet = RS_RET_OK;
	if(eFeat == sFEATUREAutomaticPRIParsing)
		iRet = RS_RET_OK;
ENDisCompatibleWithFeature


BEGINparse
	uchar *p2parse;
	int lenMsg;
	int skipLen = 0;
#define OpeningText "Message forwarded from "
#define OpeningText2 "From "
CODESTARTparse
	dbgprintf("Message will now be parsed by fix AIX Forwarded From parser.\n");
	assert(pMsg != NULL);
	assert(pMsg->pszRawMsg != NULL);
	lenMsg = pMsg->iLenRawMsg - pMsg->offAfterPRI;
	/* note: offAfterPRI is already the number of PRI chars (do not add one!) */
	p2parse = pMsg->pszRawMsg + pMsg->offAfterPRI; /* point to start of text, after PRI */

	/* check if this message is of the type we handle in this (very limited) parser */
	/* first, we permit SP */
	while(lenMsg && *p2parse == ' ') {
		--lenMsg;
		++p2parse;
	}
	if((unsigned) lenMsg < 24) {
		/* too short, can not be "our" message */
		/* minimum message, 16 character timestamp, 'From ", 1 character name, ': '*/
		ABORT_FINALIZE(RS_RET_COULD_NOT_PARSE);
	}

	/* skip over timestamp */
	lenMsg -=16;
	p2parse +=16;
	/* if there is the string "Message forwarded from " were the hostname should be */
	if(!strncasecmp((char*) p2parse, OpeningText, sizeof(OpeningText)-1))
		skipLen = 23;
	/* or "From " */
	if(!strncasecmp((char*) p2parse, OpeningText2, sizeof(OpeningText2)-1))
		skipLen = 5;
	DBGPRINTF("pmaixforwardedfrom: skipLen %d\n", skipLen);
	if(!skipLen) {
		/* wrong opening text */
	DBGPRINTF("not a AIX message forwarded from mangled log!\n");
		ABORT_FINALIZE(RS_RET_COULD_NOT_PARSE);
	}
	/* bump the message portion up by skipLen(23 or 5) characters to overwrite the "Message forwarded from
" or "From " with the hostname */
	lenMsg -=skipLen;
	if(lenMsg < 2) {
		dbgprintf("not a AIX message forwarded from message has nothing after header\n");
		ABORT_FINALIZE(RS_RET_COULD_NOT_PARSE);
	}
	memmove(p2parse, p2parse + skipLen, lenMsg);
	*(p2parse + lenMsg) = '\n';
	*(p2parse + lenMsg + 1)  = '\0';
	pMsg->iLenRawMsg -=skipLen;
	pMsg->iLenMSG -=skipLen;
	/* now look for the : after the hostname to walk past the hostname, also watch for a space in case this isn't
really an AIX log, but has a similar preamble */
	while(lenMsg && *p2parse != ' ' && *p2parse != ':') {
		--lenMsg;
		++p2parse;
	}
	if (lenMsg < 1) {
		dbgprintf("not a AIX message forwarded from message has nothing after colon "
			"or no colon at all\n");
		ABORT_FINALIZE(RS_RET_COULD_NOT_PARSE);
	}
	if (lenMsg && *p2parse != ':') {
	DBGPRINTF("not a AIX message forwarded from mangled log but similar enough that the preamble has "
		"been removed\n");
		ABORT_FINALIZE(RS_RET_COULD_NOT_PARSE);
	}
	/* bump the message portion up by one character to overwrite the extra : */
	lenMsg -=1;
	memmove(p2parse, p2parse + 1, lenMsg);
	*(p2parse + lenMsg) = '\n';
	*(p2parse + lenMsg + 1)  = '\0';
	pMsg->iLenRawMsg -=1;
	pMsg->iLenMSG -=1;
	/* now, claim to abort so that something else can parse the now modified message */
	DBGPRINTF("pmaixforwardedfrom: new mesage: [%d]'%s'\n", lenMsg, pMsg->pszRawMsg + pMsg->offAfterPRI);
	ABORT_FINALIZE(RS_RET_COULD_NOT_PARSE);

finalize_it:
ENDparse


BEGINmodExit
CODESTARTmodExit
	/* release what we no longer need */
	objRelease(glbl, CORE_COMPONENT);
	objRelease(parser, CORE_COMPONENT);
	objRelease(datetime, CORE_COMPONENT);
ENDmodExit


BEGINqueryEtryPt
CODESTARTqueryEtryPt
CODEqueryEtryPt_STD_PMOD_QUERIES
CODEqueryEtryPt_IsCompatibleWithFeature_IF_OMOD_QUERIES
ENDqueryEtryPt


BEGINmodInit()
CODESTARTmodInit
	*ipIFVersProvided = CURR_MOD_IF_VERSION; /* we only support the current interface specification */
CODEmodInit_QueryRegCFSLineHdlr
	CHKiRet(objUse(glbl, CORE_COMPONENT));
	CHKiRet(objUse(parser, CORE_COMPONENT));
	CHKiRet(objUse(datetime, CORE_COMPONENT));

	DBGPRINTF("aixforwardedfrom parser init called, compiled with version %s\n", VERSION);
	bParseHOSTNAMEandTAG = glbl.GetParseHOSTNAMEandTAG();
	/* cache value, is set only during rsyslogd option processing */


ENDmodInit

/* vim:set ai:
 */
