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-rw-r--r--plugins/pmsnare/pmsnare.c238
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diff --git a/plugins/pmsnare/pmsnare.c b/plugins/pmsnare/pmsnare.c
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+/* 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
+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:
+ */
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