rsyslog/template.c

/* This is the template processing code of rsyslog.
 * Please see syslogd.c for license information.
 * This code is placed under the GPL.
 * begun 2004-11-17 rgerhards
 */
#include <stdio.h>
#include <malloc.h>
#include <string.h>
#include <ctype.h>
#include <assert.h>
#include "liblogging-stub.h"
#include "stringbuf.h"
#include "template.h"
#include "syslogd.h"

static struct template *tplRoot = NULL;	/* the root of the template list */
static struct template *tplLast = NULL;	/* points to the last element of the template list */

/* Constructs a template entry object. Returns pointer to it
 * or NULL (if it fails). Pointer to associated template list entry 
 * must be provided.
 */
struct templateEntry* tpeConstruct(struct template *pTpl)
{
	struct templateEntry *pTpe;

	assert(pTpl != NULL);

	if((pTpe = calloc(1, sizeof(struct templateEntry))) == NULL)
		return NULL;
	
	/* basic initialisaion is done via calloc() - need to
	 * initialize only values != 0. */

	if(pTpl->pEntryLast == NULL)
	{ /* we are the first element! */
		pTpl->pEntryRoot = pTpl->pEntryLast  = pTpe;
	}
	else
	{
		pTpl->pEntryLast->pNext = pTpe;
		pTpl->pEntryLast  = pTpe;
	}
	pTpl->tpenElements++;

	return(pTpe);
}


/* Constructs a template list object. Returns pointer to it
 * or NULL (if it fails).
 */
struct template* tplConstruct(void)
{
	struct template *pTpl;
	if((pTpl = calloc(1, sizeof(struct template))) == NULL)
		return NULL;
	
	/* basic initialisaion is done via calloc() - need to
	 * initialize only values != 0. */

	if(tplLast == NULL)
	{ /* we are the first element! */
		tplRoot = tplLast = pTpl;
	}
	else
	{
		tplLast->pNext = pTpl;
		tplLast = pTpl;
	}

	return(pTpl);
}


/* helper to tplAddLine. Parses a constant and generates
 * the necessary structure.
 * returns: 0 - ok, 1 - failure
 */
static int do_Constant(char **pp, struct template *pTpl)
{
	register char *p;
	sbStrBObj *pStrB;
	struct templateEntry *pTpe;
	int i;

	assert(pp != NULL);
	assert(*pp != NULL);
	assert(pTpl != NULL);

	p = *pp;

	if((pStrB = sbStrBConstruct()) == NULL)
		 return 1;
	sbStrBSetAllocIncrement(pStrB, 32);
	/* TODO: implement escape characters! */
	while(*p && *p != '%' && *p != '\"') {
		if(*p == '\\') {
			switch(*++p) {
				case '\0':	
					/* the best we can do - it's invalid anyhow... */
					sbStrBAppendChar(pStrB, *p);
					break;
				case 'n':
					sbStrBAppendChar(pStrB, '\n');
					++p;
					break;
				case 'r':
					sbStrBAppendChar(pStrB, '\r');
					++p;
					break;
				case '\\':
					sbStrBAppendChar(pStrB, '\\');
					++p;
					break;
				case '%':
					sbStrBAppendChar(pStrB, '%');
					++p;
					break;
				case '0': /* numerical escape sequence */
				case '1':
				case '2':
				case '3':
				case '4':
				case '5':
				case '6':
				case '7':
				case '8':
				case '9':
					i = 0;
					while(*p && isdigit(*p)) {
						i = i * 10 + *p++ - '0';
					}
					sbStrBAppendChar(pStrB, i);
					break;
				default:
					sbStrBAppendChar(pStrB, *p++);
					break;
			}
		}
		else
			sbStrBAppendChar(pStrB, *p++);
	}

	if((pTpe = tpeConstruct(pTpl)) == NULL) {
		/* TODO: add handler */
		return 1;
	}
	pTpe->eEntryType = CONSTANT;
	pTpe->data.constant.pConstant = sbStrBFinish(pStrB);
	/* we need to call strlen() below because of the escape sequneces.
	 * due to them p -*pp is NOT the rigt size!
	 */
	pTpe->data.constant.iLenConstant = strlen(pTpe->data.constant.pConstant);

	*pp = p;

	return 0;
}


/* Helper to do_Parameter(). This parses the formatting options
 * specified in a template variable. It returns the passed-in pointer
 * updated to the next processed character.
 */
static void doOptions(char **pp, struct templateEntry *pTpe)
{
	register char *p;
	char Buf[64];
	int i;

	assert(pp != NULL);
	assert(*pp != NULL);
	assert(pTpe != NULL);

	p = *pp;

	while(*p && *p != '%') {
		/* outer loop - until end of options */
		i = 0;
		while((i < sizeof(Buf) / sizeof(char)) &&
		      *p && *p != '%' && *p != ',') {
			/* inner loop - until end of ONE option */
			Buf[i++] = tolower(*p);
			++p;
		}
		Buf[i] = '\0'; /* terminate */
		/* check if we need to skip oversize option */
		while(*p && *p != '%' && *p != ',')
			++p;	/* just skip */
		/* OK, we got the option, so now lets look what
		 * it tells us...
		 */
		 if(!strcmp(Buf, "date-mysql")) {
			pTpe->data.field.eDateFormat = tplFmtMySQLDate;
		 } else if(!strcmp(Buf, "date-rfc3164")) {
			pTpe->data.field.eDateFormat = tplFmtRFC3164Date;
		 } else if(!strcmp(Buf, "date-rfc3339")) {
			pTpe->data.field.eDateFormat = tplFmtRFC3339Date;
		 } else if(!strcmp(Buf, "lowercase")) {
			pTpe->data.field.eCaseConv = tplCaseConvLower;
		 } else if(!strcmp(Buf, "uppercase")) {
			pTpe->data.field.eCaseConv = tplCaseConvUpper;
		 } else {
			dprintf("Invalid field option '%s' specified - ignored.\n", Buf);
		 }
	}

	*pp = p;
}


/* helper to tplAddLine. Parses a parameter and generates
 * the necessary structure.
 * returns: 0 - ok, 1 - failure
 */
static int do_Parameter(char **pp, struct template *pTpl)
{
	char *p;
	sbStrBObj *pStrB;
	struct templateEntry *pTpe;

	assert(pp != NULL);
	assert(*pp != NULL);
	assert(pTpl != NULL);

	p = *pp;

	if((pStrB = sbStrBConstruct()) == NULL)
		 return 1;

	if((pTpe = tpeConstruct(pTpl)) == NULL) {
		/* TODO: add handler */
		dprintf("Could not allocate memory for template parameter!\n");
		return 1;
	}
	pTpe->eEntryType = FIELD;

	while(*p && *p != '%' && *p != ':') {
		sbStrBAppendChar(pStrB, *p++);
	}

	/* got the name*/
	pTpe->data.field.pPropRepl = sbStrBFinish(pStrB);


	/* check frompos */
	if(*p == ':') {
		++p; /* eat ':' */
		while(*p && *p != '%' && *p != ':') {
			/* for now, just skip it */
			++p;
		}
	}

	/* check topos */
	if(*p == ':') {
		++p; /* eat ':' */
		while(*p && *p != '%' && *p != ':') {
			/* for now, just skip it */
			++p;
		}
	}

	/* check options */
	if(*p == ':') {
		++p; /* eat ':' */
		doOptions(&p, pTpe);
	}

	if(*p) ++p; /* eat '%' */

	*pp = p;
	return 0;
}


/* Add a new template line
 * returns pointer to new object if it succeeds, NULL otherwise.
 */
struct template *tplAddLine(char* pName, char** ppRestOfConfLine)
{
	struct template *pTpl;
 	char *p;
	int bDone;
	char optBuf[128]; /* buffer for options - should be more than enough... */
	int i;

	assert(pName != NULL);
	assert(ppRestOfConfLine != NULL);

	if((pTpl = tplConstruct()) == NULL)
		return NULL;
	
	pTpl->iLenName = strlen(pName);
	pTpl->pszName = (char*) malloc(sizeof(char) * pTpl->iLenName);
	if(pTpl->pszName == NULL) {
		dprintf("tplAddLine could not alloc memory for template name!");
		pTpl->iLenName = 0;
		return NULL;
		/* I know - we create a memory leak here - but I deem
		 * it acceptable as it is a) a very small leak b) very
		 * unlikely to happen. rgerhards 2004-11-17
		 */
	}
	memcpy(pTpl->pszName, pName, pTpl->iLenName + 1);

#if 0
	pTpl->iLenTemplate = strlen(pName);
	pTpl->pszTemplate = (char*) malloc(sizeof(char) * pTpl->iLenTemplate);
	if(pTpl->pszTemplate == NULL) {
		/rintf("could not alloc memory Template"); /* TODO: change to dprintf()! */
		free(pTpl->pszName);
		pTpl->pszName = NULL;
		pTpl->iLenName = 0;
		pTpl->iLenTemplate = 0;
		return NULL;
		/* see note on leak above */
	}
#endif

	/* now actually parse the line */
	p = *ppRestOfConfLine;
	assert(p != NULL);

	while(isspace(*p))/* skip whitespace */
		++p;
	
	if(*p != '"') {
		dprintf("Template invalid, does not start with '\"'!\n");
		/* TODO: Free mem! */
		return NULL;
	}
	++p;

	/* we finally got to the actual template string - so let's have some fun... */
	bDone = *p ? 0 : 1;
	while(!bDone) {
		switch(*p) {
			case '\0':
				bDone = 1;
				break;
			case '%': /* parameter */
				++p; /* eat '%' */
				do_Parameter(&p, pTpl);
				break;
			default: /* constant */
				do_Constant(&p, pTpl);
				break;
		}
		if(*p == '"') {/* end of template string? */
			++p;	/* eat it! */
			bDone = 1;
		}
	}
	
	/* we now have the template - let's look at the options (if any)
	 * we process options until we reach the end of the string or 
	 * an error occurs - whichever is first.
	 */
	while(*p) {
		while(isspace(*p))/* skip whitespace */
			++p;
		
		if(*p != ',')
			return(pTpl);
		++p; /* eat ',' */

		while(isspace(*p))/* skip whitespace */
			++p;
		
		/* read option word */
		i = 0;
		while(i < sizeof(optBuf) / sizeof(char) - 1
		      && *p && *p != '=' && *p !=',' && *p != '\n') {
			optBuf[i++] = tolower(*p);
			++p;
		}
		optBuf[i] = '\0';

		if(*p == '\n')
			++p;

		/* as of now, the no form is nonsense... but I do include
		 * it anyhow... ;) rgerhards 2004-11-22
		 */
		if(!strcmp(optBuf, "sql")) {
			pTpl->optFormatForSQL = 1;
		} else if(!strcmp(optBuf, "nosql")) {
			pTpl->optFormatForSQL = 0;
		} else {
			dprintf("Invalid option '%s' ignored.\n", optBuf);
		}
	}

	*ppRestOfConfLine = p;
	return(pTpl);
}


/* Find a template object based on name. Search
 * currently is case-senstive (should we change?).
 * returns pointer to template object if found and
 * NULL otherwise.
 * rgerhards 2004-11-17
 */
struct template *tplFind(char *pName, int iLenName)
{
	struct template *pTpl;

	assert(pName != NULL);

	pTpl = tplRoot;
	while(pTpl != NULL &&
	      !(pTpl->iLenName == iLenName &&
	        !strcmp(pTpl->pszName, pName)
	        ))
		{
			pTpl = pTpl->pNext;
		}
	return(pTpl);
}

/* Print the template structure. This is more or less a 
 * debug or test aid, but anyhow I think it's worth it...
 */
void tplPrintList(void)
{
	struct template *pTpl;
	struct templateEntry *pTpe;

	pTpl = tplRoot;
	while(pTpl != NULL) {
		dprintf("Template: Name='%s' ", pTpl->pszName == NULL? "NULL" : pTpl->pszName);
		if(pTpl->optFormatForSQL)
			dprintf("[SQL-Format] ");
		dprintf("\n");
		pTpe = pTpl->pEntryRoot;
		while(pTpe != NULL) {
			dprintf("\tEntry(%x): type %d, ", (unsigned) pTpe, pTpe->eEntryType);
			switch(pTpe->eEntryType) {
			case UNDEFINED:
				dprintf("(UNDEFINED)");
				break;
			case CONSTANT:
				dprintf("(CONSTANT), value: '%s'",
					pTpe->data.constant.pConstant);
				break;
			case FIELD:
				dprintf("(FIELD), value: '%s' ", pTpe->data.field.pPropRepl);
				switch(pTpe->data.field.eDateFormat) {
				case tplFmtDefault:
					break;
				case tplFmtMySQLDate:
					dprintf("[Format as MySQL-Date] ");
					break;
				case tplFmtRFC3164Date:
					dprintf("[Format as RFC3164-Date] ");
					break;
				case tplFmtRFC3339Date:
					dprintf("[Format as RFC3339-Date] ");
					break;
				}
				switch(pTpe->data.field.eCaseConv) {
				case tplCaseConvNo:
					break;
				case tplCaseConvLower:
					dprintf("[Converted to Lower Case] ");
					break;
				case tplCaseConvUpper:
					dprintf("[Converted to Upper Case] ");
					break;
				}
				break;
			}
			dprintf("\n");
			pTpe = pTpe->pNext;
		}
		pTpl = pTpl->pNext; /* done, go next */
	}
}

int tplGetEntryCount(struct template *pTpl)
{
	assert(pTpl != NULL);
	return(pTpl->tpenElements);
}
/*
 * vi:set ai:
 */