summaryrefslogtreecommitdiffstats
path: root/runtime/parser.c
diff options
context:
space:
mode:
authorRainer Gerhards <rgerhards@adiscon.com>2009-11-03 10:41:47 +0100
committerRainer Gerhards <rgerhards@adiscon.com>2009-11-03 10:41:47 +0100
commit7d78b3bdfd357dd921797ce983eb96532c56a7f6 (patch)
tree358f820bbfe724733638320ed3c467fca78a7498 /runtime/parser.c
parentf291d5c570052f163004cbf31f24bb0884dc6681 (diff)
downloadrsyslog-7d78b3bdfd357dd921797ce983eb96532c56a7f6.tar.gz
rsyslog-7d78b3bdfd357dd921797ce983eb96532c56a7f6.tar.xz
rsyslog-7d78b3bdfd357dd921797ce983eb96532c56a7f6.zip
restructured parser part of rsyslog
now cleaner and hopefully usuable as a basis for loadable parser modules. I also cleaned up/consolidated some of the internal message generation functionality in rsyslogd.
Diffstat (limited to 'runtime/parser.c')
-rw-r--r--runtime/parser.c382
1 files changed, 382 insertions, 0 deletions
diff --git a/runtime/parser.c b/runtime/parser.c
index e29f3b0b..89e59f87 100644
--- a/runtime/parser.c
+++ b/runtime/parser.c
@@ -37,7 +37,10 @@
#include "dirty.h"
#include "msg.h"
#include "obj.h"
+#include "datetime.h"
#include "errmsg.h"
+#include "unicode-helper.h"
+#include "dirty.h"
/* some defines */
#define DEFUPRI (LOG_USER|LOG_NOTICE)
@@ -46,6 +49,7 @@
DEFobjStaticHelpers
DEFobjCurrIf(glbl)
DEFobjCurrIf(errmsg)
+DEFobjCurrIf(datetime)
/* static data */
@@ -60,11 +64,389 @@ rsRetVal parserClassInit(void)
CHKiRet(objGetObjInterface(&obj)); /* this provides the root pointer for all other queries */
CHKiRet(objUse(glbl, CORE_COMPONENT));
CHKiRet(objUse(errmsg, CORE_COMPONENT));
+ CHKiRet(objUse(datetime, CORE_COMPONENT));
// TODO: free components! see action.c
finalize_it:
RETiRet;
}
+/***************************RFC 5425 PARSER ******************************************************/
+
+
+/* Helper to parseRFCSyslogMsg. This function parses a field up to
+ * (and including) the SP character after it. The field contents is
+ * returned in a caller-provided buffer. The parsepointer is advanced
+ * to after the terminating SP. The caller must ensure that the
+ * provided buffer is large enough to hold the to be extracted value.
+ * Returns 0 if everything is fine or 1 if either the field is not
+ * SP-terminated or any other error occurs. -- rger, 2005-11-24
+ * The function now receives the size of the string and makes sure
+ * that it does not process more than that. The *pLenStr counter is
+ * updated on exit. -- rgerhards, 2009-09-23
+ */
+static int parseRFCField(uchar **pp2parse, uchar *pResult, int *pLenStr)
+{
+ uchar *p2parse;
+ int iRet = 0;
+
+ assert(pp2parse != NULL);
+ assert(*pp2parse != NULL);
+ assert(pResult != NULL);
+
+ p2parse = *pp2parse;
+
+ /* this is the actual parsing loop */
+ while(*pLenStr > 0 && *p2parse != ' ') {
+ *pResult++ = *p2parse++;
+ --(*pLenStr);
+ }
+
+ if(*pLenStr > 0 && *p2parse == ' ') {
+ ++p2parse; /* eat SP, but only if not at end of string */
+ --(*pLenStr);
+ } else {
+ iRet = 1; /* there MUST be an SP! */
+ }
+ *pResult = '\0';
+
+ /* set the new parse pointer */
+ *pp2parse = p2parse;
+ return 0;
+}
+
+
+/* Helper to parseRFCSyslogMsg. This function parses the structured
+ * data field of a message. It does NOT parse inside structured data,
+ * just gets the field as whole. Parsing the single entities is left
+ * to other functions. The parsepointer is advanced
+ * to after the terminating SP. The caller must ensure that the
+ * provided buffer is large enough to hold the to be extracted value.
+ * Returns 0 if everything is fine or 1 if either the field is not
+ * SP-terminated or any other error occurs. -- rger, 2005-11-24
+ * The function now receives the size of the string and makes sure
+ * that it does not process more than that. The *pLenStr counter is
+ * updated on exit. -- rgerhards, 2009-09-23
+ */
+static int parseRFCStructuredData(uchar **pp2parse, uchar *pResult, int *pLenStr)
+{
+ uchar *p2parse;
+ int bCont = 1;
+ int iRet = 0;
+ int lenStr;
+
+ assert(pp2parse != NULL);
+ assert(*pp2parse != NULL);
+ assert(pResult != NULL);
+
+ p2parse = *pp2parse;
+ lenStr = *pLenStr;
+
+ /* this is the actual parsing loop
+ * Remeber: structured data starts with [ and includes any characters
+ * until the first ] followed by a SP. There may be spaces inside
+ * structured data. There may also be \] inside the structured data, which
+ * do NOT terminate an element.
+ */
+ if(lenStr == 0 || *p2parse != '[')
+ return 1; /* this is NOT structured data! */
+
+ if(*p2parse == '-') { /* empty structured data? */
+ *pResult++ = '-';
+ ++p2parse;
+ --lenStr;
+ } else {
+ while(bCont) {
+ if(lenStr < 2) {
+ /* we now need to check if we have only structured data */
+ if(lenStr > 0 && *p2parse == ']') {
+ *pResult++ = *p2parse;
+ p2parse++;
+ lenStr--;
+ bCont = 0;
+ } else {
+ iRet = 1; /* this is not valid! */
+ bCont = 0;
+ }
+ } else if(*p2parse == '\\' && *(p2parse+1) == ']') {
+ /* this is escaped, need to copy both */
+ *pResult++ = *p2parse++;
+ *pResult++ = *p2parse++;
+ lenStr -= 2;
+ } else if(*p2parse == ']' && *(p2parse+1) == ' ') {
+ /* found end, just need to copy the ] and eat the SP */
+ *pResult++ = *p2parse;
+ p2parse += 2;
+ lenStr -= 2;
+ bCont = 0;
+ } else {
+ *pResult++ = *p2parse++;
+ --lenStr;
+ }
+ }
+ }
+
+ if(lenStr > 0 && *p2parse == ' ') {
+ ++p2parse; /* eat SP, but only if not at end of string */
+ --lenStr;
+ } else {
+ iRet = 1; /* there MUST be an SP! */
+ }
+ *pResult = '\0';
+
+ /* set the new parse pointer */
+ *pp2parse = p2parse;
+ *pLenStr = lenStr;
+ return 0;
+}
+
+/* parse a RFC5424-formatted syslog message. This function returns
+ * 0 if processing of the message shall continue and 1 if something
+ * went wrong and this messe should be ignored. This function has been
+ * implemented in the effort to support syslog-protocol. Please note that
+ * the name (parse *RFC*) stems from the hope that syslog-protocol will
+ * some time become an RFC. Do not confuse this with informational
+ * RFC 3164 (which is legacy syslog).
+ *
+ * currently supported format:
+ *
+ * <PRI>VERSION SP TIMESTAMP SP HOSTNAME SP APP-NAME SP PROCID SP MSGID SP [SD-ID]s SP MSG
+ *
+ * <PRI> is already stripped when this function is entered. VERSION already
+ * has been confirmed to be "1", but has NOT been stripped from the message.
+ *
+ * rger, 2005-11-24
+ */
+static int parseRFCSyslogMsg(msg_t *pMsg, int flags)
+{
+ uchar *p2parse;
+ uchar *pBuf;
+ int lenMsg;
+ int bContParse = 1;
+
+ BEGINfunc
+ assert(pMsg != NULL);
+ assert(pMsg->pszRawMsg != NULL);
+ p2parse = pMsg->pszRawMsg + pMsg->offAfterPRI; /* point to start of text, after PRI */
+ lenMsg = pMsg->iLenRawMsg - pMsg->offAfterPRI;
+
+ /* do a sanity check on the version and eat it (the caller checked this already) */
+ assert(p2parse[0] == '1' && p2parse[1] == ' ');
+ p2parse += 2;
+ lenMsg -= 2;
+
+ /* Now get us some memory we can use as a work buffer while parsing.
+ * We simply allocated a buffer sufficiently large to hold all of the
+ * message, so we can not run into any troubles. I think this is
+ * more wise then to use individual buffers.
+ */
+ if((pBuf = MALLOC(sizeof(uchar) * (lenMsg + 1))) == NULL)
+ return 1;
+
+ /* IMPORTANT NOTE:
+ * Validation is not actually done below nor are any errors handled. I have
+ * NOT included this for the current proof of concept. However, it is strongly
+ * advisable to add it when this code actually goes into production.
+ * rgerhards, 2005-11-24
+ */
+
+ /* TIMESTAMP */
+ if(datetime.ParseTIMESTAMP3339(&(pMsg->tTIMESTAMP), &p2parse, &lenMsg) == RS_RET_OK) {
+ if(flags & IGNDATE) {
+ /* we need to ignore the msg data, so simply copy over reception date */
+ memcpy(&pMsg->tTIMESTAMP, &pMsg->tRcvdAt, sizeof(struct syslogTime));
+ }
+ } else {
+ DBGPRINTF("no TIMESTAMP detected!\n");
+ bContParse = 0;
+ }
+
+ /* HOSTNAME */
+ if(bContParse) {
+ parseRFCField(&p2parse, pBuf, &lenMsg);
+ MsgSetHOSTNAME(pMsg, pBuf, ustrlen(pBuf));
+ }
+
+ /* APP-NAME */
+ if(bContParse) {
+ parseRFCField(&p2parse, pBuf, &lenMsg);
+ MsgSetAPPNAME(pMsg, (char*)pBuf);
+ }
+
+ /* PROCID */
+ if(bContParse) {
+ parseRFCField(&p2parse, pBuf, &lenMsg);
+ MsgSetPROCID(pMsg, (char*)pBuf);
+ }
+
+ /* MSGID */
+ if(bContParse) {
+ parseRFCField(&p2parse, pBuf, &lenMsg);
+ MsgSetMSGID(pMsg, (char*)pBuf);
+ }
+
+ /* STRUCTURED-DATA */
+ if(bContParse) {
+ parseRFCStructuredData(&p2parse, pBuf, &lenMsg);
+ MsgSetStructuredData(pMsg, (char*)pBuf);
+ }
+
+ /* MSG */
+ MsgSetMSGoffs(pMsg, p2parse - pMsg->pszRawMsg);
+
+ free(pBuf);
+ ENDfunc
+ return 0; /* all ok */
+}
+
+
+/*********************** END RFC5425 PARSER ******************************************/
+
+/***************************RFC 5425 PARSER ******************************************************/
+
+
+/* parse a legay-formatted syslog message. This function returns
+ * 0 if processing of the message shall continue and 1 if something
+ * went wrong and this messe should be ignored. This function has been
+ * implemented in the effort to support syslog-protocol.
+ * rger, 2005-11-24
+ * As of 2006-01-10, I am removing the logic to continue parsing only
+ * when a valid TIMESTAMP is detected. Validity of other fields already
+ * is ignored. This is due to the fact that the parser has grown smarter
+ * and is now more able to understand different dialects of the syslog
+ * message format. I do not expect any bad side effects of this change,
+ * but I thought I log it in this comment.
+ * rgerhards, 2006-01-10
+ */
+static int parseLegacySyslogMsg(msg_t *pMsg, int flags)
+{
+ uchar *p2parse;
+ int lenMsg;
+ int bTAGCharDetected;
+ int i; /* general index for parsing */
+ uchar bufParseTAG[CONF_TAG_MAXSIZE];
+ uchar bufParseHOSTNAME[CONF_TAG_HOSTNAME];
+ BEGINfunc
+
+ assert(pMsg != NULL);
+ assert(pMsg->pszRawMsg != NULL);
+ lenMsg = pMsg->iLenRawMsg - (pMsg->offAfterPRI + 1);
+ p2parse = pMsg->pszRawMsg + pMsg->offAfterPRI; /* point to start of text, after PRI */
+
+ /* Check to see if msg contains a timestamp. We start by assuming
+ * that the message timestamp is the time of reception (which we
+ * generated ourselfs and then try to actually find one inside the
+ * message. There we go from high-to low precison and are done
+ * when we find a matching one. -- rgerhards, 2008-09-16
+ */
+ if(datetime.ParseTIMESTAMP3339(&(pMsg->tTIMESTAMP), &p2parse, &lenMsg) == RS_RET_OK) {
+ /* we are done - parse pointer is moved by ParseTIMESTAMP3339 */;
+ } else if(datetime.ParseTIMESTAMP3164(&(pMsg->tTIMESTAMP), &p2parse, &lenMsg) == RS_RET_OK) {
+ /* we are done - parse pointer is moved by ParseTIMESTAMP3164 */;
+ } else if(*p2parse == ' ' && lenMsg > 1) { /* try to see if it is slighly malformed - HP procurve seems to do that sometimes */
+ ++p2parse; /* move over space */
+ --lenMsg;
+ if(datetime.ParseTIMESTAMP3164(&(pMsg->tTIMESTAMP), &p2parse, &lenMsg) == RS_RET_OK) {
+ /* indeed, we got it! */
+ /* we are done - parse pointer is moved by ParseTIMESTAMP3164 */;
+ } else {/* parse pointer needs to be restored, as we moved it off-by-one
+ * for this try.
+ */
+ --p2parse;
+ ++lenMsg;
+ }
+ }
+
+ if(flags & IGNDATE) {
+ /* we need to ignore the msg data, so simply copy over reception date */
+ memcpy(&pMsg->tTIMESTAMP, &pMsg->tRcvdAt, sizeof(struct syslogTime));
+ }
+
+ /* rgerhards, 2006-03-13: next, we parse the hostname and tag. But we
+ * do this only when the user has not forbidden this. I now introduce some
+ * code that allows a user to configure rsyslogd to treat the rest of the
+ * message as MSG part completely. In this case, the hostname will be the
+ * machine that we received the message from and the tag will be empty. This
+ * is meant to be an interim solution, but for now it is in the code.
+ */
+ if(bParseHOSTNAMEandTAG && !(flags & INTERNAL_MSG)) {
+ /* parse HOSTNAME - but only if this is network-received!
+ * rger, 2005-11-14: we still have a problem with BSD messages. These messages
+ * do NOT include a host name. In most cases, this leads to the TAG to be treated
+ * as hostname and the first word of the message as the TAG. Clearly, this is not
+ * of advantage ;) I think I have now found a way to handle this situation: there
+ * are certain characters which are frequently used in TAG (e.g. ':'), which are
+ * *invalid* in host names. So while parsing the hostname, I check for these characters.
+ * If I find them, I set a simple flag but continue. After parsing, I check the flag.
+ * If it was set, then we most probably do not have a hostname but a TAG. Thus, I change
+ * the fields. I think this logic shall work with any type of syslog message.
+ * rgerhards, 2009-06-23: and I now have extended this logic to every character
+ * that is not a valid hostname.
+ */
+ bTAGCharDetected = 0;
+ if(lenMsg > 0 && flags & PARSE_HOSTNAME) {
+ i = 0;
+ while(i < lenMsg && (isalnum(p2parse[i]) || p2parse[i] == '.' || p2parse[i] == '.'
+ || p2parse[i] == '_' || p2parse[i] == '-') && i < CONF_TAG_MAXSIZE) {
+ bufParseHOSTNAME[i] = p2parse[i];
+ ++i;
+ }
+
+ if(i > 0 && p2parse[i] == ' ' && isalnum(p2parse[i-1])) {
+ /* we got a hostname! */
+ p2parse += i + 1; /* "eat" it (including SP delimiter) */
+ lenMsg -= i + 1;
+ bufParseHOSTNAME[i] = '\0';
+ MsgSetHOSTNAME(pMsg, bufParseHOSTNAME, i);
+ }
+ }
+
+ /* now parse TAG - that should be present in message from all sources.
+ * This code is somewhat not compliant with RFC 3164. As of 3164,
+ * the TAG field is ended by any non-alphanumeric character. In
+ * practice, however, the TAG often contains dashes and other things,
+ * which would end the TAG. So it is not desirable. As such, we only
+ * accept colon and SP to be terminators. Even there is a slight difference:
+ * a colon is PART of the TAG, while a SP is NOT part of the tag
+ * (it is CONTENT). Starting 2008-04-04, we have removed the 32 character
+ * size limit (from RFC3164) on the tag. This had bad effects on existing
+ * envrionments, as sysklogd didn't obey it either (probably another bug
+ * in RFC3164...). We now receive the full size, but will modify the
+ * outputs so that only 32 characters max are used by default.
+ */
+ i = 0;
+ while(lenMsg > 0 && *p2parse != ':' && *p2parse != ' ' && i < CONF_TAG_MAXSIZE) {
+ bufParseTAG[i++] = *p2parse++;
+ --lenMsg;
+ }
+ if(lenMsg > 0 && *p2parse == ':') {
+ ++p2parse;
+ --lenMsg;
+ bufParseTAG[i++] = ':';
+ }
+
+ /* no TAG can only be detected if the message immediatly ends, in which case an empty TAG
+ * is considered OK. So we do not need to check for empty TAG. -- rgerhards, 2009-06-23
+ */
+ bufParseTAG[i] = '\0'; /* terminate string */
+ MsgSetTAG(pMsg, bufParseTAG, i);
+ } else {/* we enter this code area when the user has instructed rsyslog NOT
+ * to parse HOSTNAME and TAG - rgerhards, 2006-03-13
+ */
+ if(!(flags & INTERNAL_MSG)) {
+ DBGPRINTF("HOSTNAME and TAG not parsed by user configuraton.\n");
+ }
+ }
+
+ /* The rest is the actual MSG */
+ MsgSetMSGoffs(pMsg, p2parse - pMsg->pszRawMsg);
+
+ ENDfunc
+ return 0; /* all ok */
+}
+
+
+/***************************END RFC 5425 PARSER ******************************************************/
+
/* uncompress a received message if it is compressed.
* pMsg->pszRawMsg buffer is updated.