/* pmlastmsg.c * This is a parser module specifically for those horrible * "last message repeated n times" messages notoriously generated * by some syslog implementations. Note that this parser should be placed * on top of the parser stack -- it takes out only these messages and * leaves all others for processing by the other parsers. * * NOTE: read comments in module-template.h to understand how this file * works! * * File begun on 2010-07-13 by RGerhards * * Copyright 2014-2016 Rainer Gerhards and Adiscon GmbH. * * 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 #include #include #include #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" #include "rsconf.h" MODULE_TYPE_PARSER MODULE_TYPE_NOKEEP PARSER_NAME("rsyslog.lastline") /* 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 /* parse a legay-formatted syslog message. */ BEGINparse uchar *p2parse; int lenMsg; #define OpeningText "last message repeated " #define ClosingText " times" CODESTARTparse dbgprintf("Message will now be parsed by \"last message repated n times\" 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 < sizeof(OpeningText)-1 + sizeof(ClosingText)-1 + 1) { /* too short, can not be "our" message */ ABORT_FINALIZE(RS_RET_COULD_NOT_PARSE); } if(strncasecmp((char*) p2parse, OpeningText, sizeof(OpeningText)-1) != 0) { /* wrong opening text */ ABORT_FINALIZE(RS_RET_COULD_NOT_PARSE); } lenMsg -= sizeof(OpeningText) - 1; p2parse += sizeof(OpeningText) - 1; /* now we need an integer --> digits */ while(lenMsg && isdigit(*p2parse)) { --lenMsg; ++p2parse; } if(lenMsg != sizeof(ClosingText)-1) { /* size must fit, else it is not "our" message... */ ABORT_FINALIZE(RS_RET_COULD_NOT_PARSE); } if(strncasecmp((char*) p2parse, ClosingText, lenMsg) != 0) { /* wrong closing text */ ABORT_FINALIZE(RS_RET_COULD_NOT_PARSE); } /* OK, now we know we need to process this message, so we do that * (and it is fairly simple in our case...) */ DBGPRINTF("pmlastmsg detected a \"last message repeated n times\" message\n"); setProtocolVersion(pMsg, MSG_LEGACY_PROTOCOL); memcpy(&pMsg->tTIMESTAMP, &pMsg->tRcvdAt, sizeof(struct syslogTime)); MsgSetMSGoffs(pMsg, pMsg->offAfterPRI); /* we don't have a header! */ MsgSetTAG(pMsg, (uchar*)"", 0); 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("lastmsg parser init called, compiled with version %s\n", VERSION); bParseHOSTNAMEandTAG = glbl.GetParseHOSTNAMEandTAG(loadConf); /* cache value, is set only during rsyslogd option processing */ ENDmodInit /* vim:set ai: */