From 7d78b3bdfd357dd921797ce983eb96532c56a7f6 Mon Sep 17 00:00:00 2001 From: Rainer Gerhards Date: Tue, 3 Nov 2009 10:41:47 +0100 Subject: 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. --- runtime/parser.c | 382 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 382 insertions(+) (limited to 'runtime') 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: + * + * VERSION SP TIMESTAMP SP HOSTNAME SP APP-NAME SP PROCID SP MSGID SP [SD-ID]s SP MSG + * + * 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. -- cgit