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Diffstat (limited to 'plugins/pmsnare/pmsnare.c')
| -rw-r--r-- | plugins/pmsnare/pmsnare.c | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/plugins/pmsnare/pmsnare.c b/plugins/pmsnare/pmsnare.c new file mode 100644 index 00000000..f3658d11 --- /dev/null +++ b/plugins/pmsnare/pmsnare.c @@ -0,0 +1,239 @@ +/* pmsnare.c + * + * this detects logs sent by Snare and cleans them up so that they can be processed by the normal parser + * + * there are two variations of this, if the client is set to 'syslog' mode it sends + * + * <pri>timestamp<sp>hostname<sp>tag<tab>otherstuff + * + * if the client is not set to syslog it sends + * + * hostname<tab>tag<tab>otherstuff + * + * ToDo, take advantage of items in the message itself to set more friendly information + * where the normal parser will find it by re-writing more of the message + * + * Intereting information includes: + * + * in the case of windows snare messages: + * the system hostname is field 12 + * the severity is field 3 (criticality ranging form 0 to 4) + * the source of the log is field 4 and may be able to be mapped to facility + * + * + * created 2010-12-13 by David Lang based on pmlastmsg + * + * 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 <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.snare") + +/* internal structures + */ +DEF_PMOD_STATIC_DATA +DEFobjCurrIf(errmsg) +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 snaremessage; + int tablength; + +CODESTARTparse + #define TabRepresentation "#011" + tablength=sizeof(TabRepresentation); + dbgprintf("Message will now be parsed by fix Snare parser.\n"); + assert(pMsg != NULL); + assert(pMsg->pszRawMsg != NULL); + + /* check if this message is of the type we handle in this (very limited) parser + + find out if we have a space separated or tab separated for the first item + if tab separated see if the second word is one of our expected tags + if so replace the tabs with spaces so that hostname and syslog tag are going to be parsed properly + optionally replace the hostname at the beginning of the message with one from later in the message + else, wrong message, abort + else, assume that we have a valid timestamp, move over to the syslog tag + if that is tab separated from the rest of the message and one of our expected tags + if so, replace the tab with a space so that it will be parsed properly + optionally replace the hostname at the beginning of the message withone from later in the message + + */ + snaremessage=0; + 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 */ + dbgprintf("pmsnare: msg to look at: [%d]'%s'\n", lenMsg, p2parse); + if((unsigned) lenMsg < 30) { + /* too short, can not be "our" message */ + dbgprintf("msg too short!\n"); + ABORT_FINALIZE(RS_RET_COULD_NOT_PARSE); + } + + while(lenMsg && *p2parse != ' ' && *p2parse != '\t' && *p2parse != '#') { + --lenMsg; + ++p2parse; + } + dbgprintf("pmsnare: separator [%d]'%s' msg after the first separator: [%d]'%s'\n", tablength,TabRepresentation,lenMsg, p2parse); + if ((lenMsg > tablength) && (*p2parse == '\t' || strncasecmp((char*) p2parse, TabRepresentation , tablength-1) == 0)) { + //if ((lenMsg > tablength) && (*p2parse == '\t' || *p2parse == '#')) { + dbgprintf("pmsnare: tab separated message\n"); + if(strncasecmp((char*) (p2parse + tablength - 1), "MSWinEventLog", 13) == 0) { + snaremessage=13; /* 0 means not a snare message, a number is how long the tag is */ + } + if(strncasecmp((char*) (p2parse + tablength - 1), "LinuxKAudit", 11) == 0) { + snaremessage=11; /* 0 means not a snare message, a number is how long the tag is */ + } + if(snaremessage) { + /* replace the tab with a space and if needed move the message portion up by the length of TabRepresentation -2 characters to overwrite the extra : */ + *p2parse = ' '; + lenMsg -=(tablength-2); + p2parse++; + lenMsg--; + memmove(p2parse, p2parse + (tablength-2), lenMsg); + *(p2parse + lenMsg) = '\n'; + *(p2parse + lenMsg + 1) = '\0'; + pMsg->iLenRawMsg -=(tablength-2); + pMsg->iLenMSG -=(tablength-2); + p2parse += snaremessage; + lenMsg -= snaremessage; + *p2parse = ' '; + p2parse++; + lenMsg--; + lenMsg -=(tablength-2); + memmove(p2parse, p2parse + (tablength-2), lenMsg); + *(p2parse + lenMsg) = '\n'; + *(p2parse + lenMsg + 1) = '\0'; + pMsg->iLenRawMsg -=(tablength-2); + pMsg->iLenMSG -=(tablength-2); + dbgprintf("found a Snare message with snare not set to send syslog messages\n"); + } + } else { + /* go back to the beginning of the message */ + 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 */ + /* skip over timestamp and space*/ + lenMsg -=17; + p2parse +=17; + /* skip over what should be the hostname */ + while(lenMsg && *p2parse != ' ') { + --lenMsg; + ++p2parse; + } + if (lenMsg){ + --lenMsg; + ++p2parse; + } + dbgprintf("pmsnare: separator [%d]'%s' msg after the timestamp and hostname: [%d]'%s'\n", tablength,TabRepresentation,lenMsg, p2parse); + if(lenMsg > 13 && strncasecmp((char*) p2parse, "MSWinEventLog", 13) == 0) { + snaremessage=13; /* 0 means not a snare message, a number is how long the tag is */ + } + if(lenMsg > 11 && strncasecmp((char*) p2parse, "LinuxKAudit", 11) == 0) { + snaremessage=11; /* 0 means not a snare message, a number is how long the tag is */ + } + if(snaremessage) { + p2parse += snaremessage; + lenMsg -= snaremessage; + *p2parse = ' '; + p2parse++; + lenMsg--; + lenMsg -=(tablength-2); + memmove(p2parse, p2parse + (tablength-2), lenMsg); + *(p2parse + lenMsg) = '\n'; + *(p2parse + lenMsg + 1) = '\0'; + pMsg->iLenRawMsg -=(tablength-2); + pMsg->iLenMSG -=(tablength-2); + dbgprintf("found a Snare message with snare set to send syslog messages\n"); + } + + } + DBGPRINTF("pmsnare: new message: [%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(errmsg, CORE_COMPONENT); + 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(errmsg, CORE_COMPONENT)); + CHKiRet(objUse(parser, CORE_COMPONENT)); + CHKiRet(objUse(datetime, CORE_COMPONENT)); + + DBGPRINTF("snare 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: + */ |