tools/lexer.c - net/ipfilter - Rivoreo Source Code Repositories

 /*
  * Copyright (C) 2002-2006 by Darren Reed.
  *
  * See the IPFILTER.LICENCE file for details on licencing.
  */
 #include <ctype.h>
 #include "ipf.h"
 #ifdef	IPFILTER_SCAN
 # include "netinet/ip_scan.h"
 #endif
 #include <sys/ioctl.h>
 #include <syslog.h>
 #ifdef	TEST_LEXER
 # define	NO_YACC
 union	{
 	int		num;
 	char		*str;
 	struct in_addr	ipa;
 	i6addr_t	ip6;
 } yylval;
 #endif
 #include "lexer.h"
 #include "y.tab.h"

 FILE *yyin;

 #define	ishex(c)	(ISDIGIT(c) || ((c) >= 'a' && (c) <= 'f') || \
 			 ((c) >= 'A' && (c) <= 'F'))
 #define	TOOLONG		-3

 extern int	string_start;
 extern int	string_end;
 extern char	*string_val;
 extern int	pos;
 extern int	yydebug;

 char		*yystr = NULL;
 int		yytext[YYBUFSIZ+1];
 char		yychars[YYBUFSIZ+1];
 int		yylineNum = 1;
 int		yypos = 0;
 int		yylast = -1;
 int		yyexpectaddr = 0;
 int		yybreakondot = 0;
 int		yyvarnext = 0;
 int		yytokentype = 0;
 wordtab_t	*yywordtab = NULL;
 int		yysavedepth = 0;
 wordtab_t	*yysavewords[30];


 static	wordtab_t	*yyfindkey __P((char *));
 static	int		yygetc __P((int));
 static	void		yyunputc __P((int));
 static	int		yyswallow __P((int));
 static	char		*yytexttostr __P((int, int));
 static	void		yystrtotext __P((char *));
 static	char		*yytexttochar __P((void));

 static int yygetc(docont)
 int docont;
 {
 	int c;

 	if (yypos < yylast) {
 		c = yytext[yypos++];
 		if (c == '\n')
 			yylineNum++;
 		return c;
 	}

 	if (yypos == YYBUFSIZ)
 		return TOOLONG;

 	if (pos >= string_start && pos <= string_end) {
 		c = string_val[pos - string_start];
 		yypos++;
 	} else {
 		c = fgetc(yyin);
 		if (docont && (c == '\\')) {
 			c = fgetc(yyin);
 			if (c == '\n') {
 				yylineNum++;
 				c = fgetc(yyin);
 			}
 		}
 	}
 	if (c == '\n')
 		yylineNum++;
 	yytext[yypos++] = c;
 	yylast = yypos;
 	yytext[yypos] = '\0';

 	return c;
 }


 static void yyunputc(c)
 int c;
 {
 	if (c == '\n')
 		yylineNum--;
 	yytext[--yypos] = c;
 }


 static int yyswallow(last)
 int last;
 {
 	int c;

 	while (((c = yygetc(0)) > '\0') && (c != last))
 		;

 	if (c != EOF)
 		yyunputc(c);
 	if (c == last)
 		return 0;
 	return -1;
 }


 static char *yytexttochar()
 {
 	int i;

 	for (i = 0; i < yypos; i++)
 		yychars[i] = (char)(yytext[i] & 0xff);
 	yychars[i] = '\0';
 	return yychars;
 }


 static void yystrtotext(str)
 char *str;
 {
 	int len;
 	char *s;

 	len = strlen(str);
 	if (len > YYBUFSIZ)
 		len = YYBUFSIZ;

 	for (s = str; *s != '\0' && len > 0; s++, len--)
 		yytext[yylast++] = *s;
 	yytext[yylast] = '\0';
 }


 static char *yytexttostr(offset, max)
 int offset, max;
 {
 	char *str;
 	int i;

 	if ((yytext[offset] == '\'' || yytext[offset] == '"') &&
 	    (yytext[offset] == yytext[offset + max - 1])) {
 		offset++;
 		max--;
 	}

 	if (max > yylast)
 		max = yylast;
 	str = malloc(max + 1);
 	if (str != NULL) {
 		for (i = offset; i < max; i++)
 			str[i - offset] = (char)(yytext[i] & 0xff);
 		str[i - offset] = '\0';
 	}
 	return str;
 }


 int yylex()
 {
 	int c, n, isbuilding, rval, lnext, nokey = 0;
 	char *name;

 	isbuilding = 0;
 	lnext = 0;
 	rval = 0;

 	if (yystr != NULL) {
 		free(yystr);
 		yystr = NULL;
 	}

 nextchar:
 	c = yygetc(0);
 	if (yydebug > 1)
 		printf("yygetc = (%x) %c [%*.*s]\n", c, c, yypos, yypos, yytexttochar());

 	switch (c)
 	{
 	case '\n' :
 		lnext = 0;
 		nokey = 0;
 	case '\t' :
 	case '\r' :
 	case ' ' :
 		if (isbuilding == 1) {
 			yyunputc(c);
 			goto done;
 		}
 		if (yylast > yypos) {
 			bcopy(yytext + yypos, yytext,
 			      sizeof(yytext[0]) * (yylast - yypos + 1));
 		}
 		yylast -= yypos;
 		yypos = 0;
 		lnext = 0;
 		nokey = 0;
 		goto nextchar;

 	case '\\' :
 		if (lnext == 0) {
 			lnext = 1;
 			if (yylast == yypos) {
 				yylast--;
 				yypos--;
 			} else
 				yypos--;
 			if (yypos == 0)
 				nokey = 1;
 			goto nextchar;
 		}
 		break;
 	}

 	if (lnext == 1) {
 		lnext = 0;
 		if ((isbuilding == 0) && !ISALNUM(c)) {
 			return c;
 		}
 		goto nextchar;
 	}

 	switch (c)
 	{
 	case '#' :
 		if (isbuilding == 1) {
 			yyunputc(c);
 			goto done;
 		}
 		yyswallow('\n');
 		rval = YY_COMMENT;
 		goto done;

 	case '$' :
 		if (isbuilding == 1) {
 			yyunputc(c);
 			goto done;
 		}
 		n = yygetc(0);
 		if (n == '{') {
 			if (yyswallow('}') == -1) {
 				rval = -2;
 				goto done;
 			}
 			(void) yygetc(0);
 		} else {
 			if (!ISALPHA(n)) {
 				yyunputc(n);
 				break;
 			}
 			do {
 				n = yygetc(1);
 			} while (ISALPHA(n) || ISDIGIT(n) || n == '_');
 			yyunputc(n);
 		}

 		name = yytexttostr(1, yypos);		/* skip $ */

 		if (name != NULL) {
 			string_val = get_variable(name, NULL, yylineNum);
 			free(name);
 			if (string_val != NULL) {
 				name = yytexttostr(yypos, yylast);
 				if (name != NULL) {
 					yypos = 0;
 					yylast = 0;
 					yystrtotext(string_val);
 					yystrtotext(name);
 					free(string_val);
 					free(name);
 					goto nextchar;
 				}
 				free(string_val);
 			}
 		}
 		break;

 	case '\'':
 	case '"' :
 		if (isbuilding == 1) {
 			goto done;
 		}
 		do {
 			n = yygetc(1);
 			if (n == EOF || n == TOOLONG) {
 				rval = -2;
 				goto done;
 			}
 			if (n == '\n') {
 				yyunputc(' ');
 				yypos++;
 			}
 		} while (n != c);
 		rval = YY_STR;
 		goto done;
 		/* NOTREACHED */

 	case EOF :
 		yylineNum = 1;
 		yypos = 0;
 		yylast = -1;
 		yyexpectaddr = 0;
 		yybreakondot = 0;
 		yyvarnext = 0;
 		yytokentype = 0;
 		return 0;
 	}

 	if (strchr("=,/;{}()@", c) != NULL) {
 		if (isbuilding == 1) {
 			yyunputc(c);
 			goto done;
 		}
 		rval = c;
 		goto done;
 	} else if (c == '.') {
 		if (isbuilding == 0) {
 			rval = c;
 			goto done;
 		}
 		if (yybreakondot != 0) {
 			yyunputc(c);
 			goto done;
 		}
 	}

 	switch (c)
 	{
 	case '-' :
 		if (yyexpectaddr)
 			break;
 		if (isbuilding == 1)
 			break;
 		n = yygetc(0);
 		if (n == '>') {
 			isbuilding = 1;
 			goto done;
 		}
 		yyunputc(n);
 		rval = '-';
 		goto done;

 	case '!' :
 		if (isbuilding == 1) {
 			yyunputc(c);
 			goto done;
 		}
 		n = yygetc(0);
 		if (n == '=') {
 			rval = YY_CMP_NE;
 			goto done;
 		}
 		yyunputc(n);
 		rval = '!';
 		goto done;

 	case '<' :
 		if (yyexpectaddr)
 			break;
 		if (isbuilding == 1) {
 			yyunputc(c);
 			goto done;
 		}
 		n = yygetc(0);
 		if (n == '=') {
 			rval = YY_CMP_LE;
 			goto done;
 		}
 		if (n == '>') {
 			rval = YY_RANGE_OUT;
 			goto done;
 		}
 		yyunputc(n);
 		rval = YY_CMP_LT;
 		goto done;

 	case '>' :
 		if (yyexpectaddr)
 			break;
 		if (isbuilding == 1) {
 			yyunputc(c);
 			goto done;
 		}
 		n = yygetc(0);
 		if (n == '=') {
 			rval = YY_CMP_GE;
 			goto done;
 		}
 		if (n == '<') {
 			rval = YY_RANGE_IN;
 			goto done;
 		}
 		yyunputc(n);
 		rval = YY_CMP_GT;
 		goto done;
 	}

 	/*
 	 * Now for the reason this is here...IPv6 address parsing.
 	 * The longest string we can expect is of this form:
 	 * 0000:0000:0000:0000:0000:0000:000.000.000.000
 	 * not:
 	 * 0000:0000:0000:0000:0000:0000:0000:0000
 	 */
 #ifdef	USE_INET6
 	if (yyexpectaddr == 1 && isbuilding == 0 && (ishex(c) || c == ':')) {
 		char ipv6buf[45 + 1], *s, oc;
 		int start;

 		start = yypos;
 		s = ipv6buf;
 		oc = c;

 		/*
 		 * Perhaps we should implement stricter controls on what we
 		 * swallow up here, but surely it would just be duplicating
 		 * the code in inet_pton() anyway.
 		 */
 		do {
 			*s++ = c;
 			c = yygetc(1);
 		} while ((ishex(c) || c == ':' || c == '.') &&
 			 (s - ipv6buf < 46));
 		yyunputc(c);
 		*s = '\0';

 		if (inet_pton(AF_INET6, ipv6buf, &yylval.ip6) == 1) {
 			rval = YY_IPV6;
 			yyexpectaddr = 0;
 			goto done;
 		}
 		yypos = start;
 		c = oc;
 	}
 #endif

 	if (c == ':') {
 		if (isbuilding == 1) {
 			yyunputc(c);
 			goto done;
 		}
 		rval = ':';
 		goto done;
 	}

 	if (isbuilding == 0 && c == '0') {
 		n = yygetc(0);
 		if (n == 'x') {
 			do {
 				n = yygetc(1);
 			} while (ishex(n));
 			yyunputc(n);
 			rval = YY_HEX;
 			goto done;
 		}
 		yyunputc(n);
 	}

 	/*
 	 * No negative numbers with leading - sign..
 	 */
 	if (isbuilding == 0 && ISDIGIT(c)) {
 		do {
 			n = yygetc(1);
 		} while (ISDIGIT(n));
 		yyunputc(n);
 		rval = YY_NUMBER;
 		goto done;
 	}

 	isbuilding = 1;
 	goto nextchar;

 done:
 	yystr = yytexttostr(0, yypos);

 	if (yydebug)
 		printf("isbuilding %d yyvarnext %d nokey %d\n",
 		       isbuilding, yyvarnext, nokey);
 	if (isbuilding == 1) {
 		wordtab_t *w;

 		w = NULL;
 		isbuilding = 0;

 		if ((yyvarnext == 0) && (nokey == 0)) {
 			w = yyfindkey(yystr);
 			if (w == NULL && yywordtab != NULL) {
 				yyresetdict();
 				w = yyfindkey(yystr);
 			}
 		} else
 			yyvarnext = 0;
 		if (w != NULL)
 			rval = w->w_value;
 		else
 			rval = YY_STR;
 	}

 	if (rval == YY_STR && yysavedepth > 0)
 		yyresetdict();

 	yytokentype = rval;

 	if (yydebug)
 		printf("lexed(%s) [%d,%d,%d] => %d @%d\n", yystr, string_start,
 			string_end, pos, rval, yysavedepth);

 	switch (rval)
 	{
 	case YY_NUMBER :
 		sscanf(yystr, "%u", &yylval.num);
 		break;

 	case YY_HEX :
 		sscanf(yystr, "0x%x", (u_int *)&yylval.num);
 		break;

 	case YY_STR :
 		yylval.str = strdup(yystr);
 		break;

 	default :
 		break;
 	}

 	if (yylast > 0) {
 		bcopy(yytext + yypos, yytext,
 		      sizeof(yytext[0]) * (yylast - yypos + 1));
 		yylast -= yypos;
 		yypos = 0;
 	}

 	return rval;
 }


 static wordtab_t *yyfindkey(key)
 char *key;
 {
 	wordtab_t *w;

 	if (yywordtab == NULL)
 		return NULL;

 	for (w = yywordtab; w->w_word != 0; w++)
 		if (strcasecmp(key, w->w_word) == 0)
 			return w;
 	return NULL;
 }


 char *yykeytostr(num)
 int num;
 {
 	wordtab_t *w;

 	if (yywordtab == NULL)
 		return "<unknown>";

 	for (w = yywordtab; w->w_word; w++)
 		if (w->w_value == num)
 			return w->w_word;
 	return "<unknown>";
 }


 wordtab_t *yysettab(words)
 wordtab_t *words;
 {
 	wordtab_t *save;

 	save = yywordtab;
 	yywordtab = words;
 	return save;
 }


 void yyerror(msg)
 char *msg;
 {
 	char *txt, letter[2];
 	int freetxt = 0;

 	if (yytokentype < 256) {
 		letter[0] = yytokentype;
 		letter[1] = '\0';
 		txt =  letter;
 	} else if (yytokentype == YY_STR || yytokentype == YY_HEX ||
 		   yytokentype == YY_NUMBER) {
 		if (yystr == NULL) {
 			txt = yytexttostr(yypos, YYBUFSIZ);
 			freetxt = 1;
 		} else
 			txt = yystr;
 	} else {
 		txt = yykeytostr(yytokentype);
 	}
 	fprintf(stderr, "%s error at \"%s\", line %d\n", msg, txt, yylineNum);
 	if (freetxt == 1)
 		free(txt);
 	exit(1);
 }


 void yysetdict(newdict)
 wordtab_t *newdict;
 {
 	if (yysavedepth == sizeof(yysavewords)/sizeof(yysavewords[0])) {
 		fprintf(stderr, "%d: at maximum dictionary depth\n",
 			yylineNum);
 		return;
 	}

 	yysavewords[yysavedepth++] = yysettab(newdict);
 	if (yydebug)
 		printf("yysavedepth++ => %d\n", yysavedepth);
 }

 void yyresetdict()
 {
 	if (yydebug)
 		printf("yyresetdict(%d)\n", yysavedepth);
 	if (yysavedepth > 0) {
 		yysettab(yysavewords[--yysavedepth]);
 		if (yydebug)
 			printf("yysavedepth-- => %d\n", yysavedepth);
 	}
 }


 #ifdef	TEST_LEXER
 int main(argc, argv)
 int argc;
 char *argv[];
 {
 	int n;

 	yyin = stdin;

 	while ((n = yylex()) != 0)
 		printf("%d.n = %d [%s] %d %d\n",
 			yylineNum, n, yystr, yypos, yylast);
 }
 #endif
	/*
	* Copyright (C) 2002-2006 by Darren Reed.
	*
	* See the IPFILTER.LICENCE file for details on licencing.
	*/
	#include <ctype.h>
	#include "ipf.h"
	#ifdef IPFILTER_SCAN
	# include "netinet/ip_scan.h"
	#endif
	#include <sys/ioctl.h>
	#include <syslog.h>
	#ifdef TEST_LEXER
	# define NO_YACC
	union {
	int num;
	char *str;
	struct in_addr ipa;
	i6addr_t ip6;
	} yylval;
	#endif
	#include "lexer.h"
	#include "y.tab.h"

	FILE *yyin;

	#define ishex(c) (ISDIGIT(c) \|\| ((c) >= 'a' && (c) <= 'f') \|\| \
	((c) >= 'A' && (c) <= 'F'))
	#define TOOLONG -3

	extern int string_start;
	extern int string_end;
	extern char *string_val;
	extern int pos;
	extern int yydebug;

	char *yystr = NULL;
	int yytext[YYBUFSIZ+1];
	char yychars[YYBUFSIZ+1];
	int yylineNum = 1;
	int yypos = 0;
	int yylast = -1;
	int yyexpectaddr = 0;
	int yybreakondot = 0;
	int yyvarnext = 0;
	int yytokentype = 0;
	wordtab_t *yywordtab = NULL;
	int yysavedepth = 0;
	wordtab_t *yysavewords[30];


	static wordtab_t yyfindkey __P((char ));
	static int yygetc __P((int));
	static void yyunputc __P((int));
	static int yyswallow __P((int));
	static char *yytexttostr __P((int, int));
	static void yystrtotext __P((char *));
	static char *yytexttochar __P((void));

	static int yygetc(docont)
	int docont;
	{
	int c;

	if (yypos < yylast) {
	c = yytext[yypos++];
	if (c == '\n')
	yylineNum++;
	return c;
	}

	if (yypos == YYBUFSIZ)
	return TOOLONG;

	if (pos >= string_start && pos <= string_end) {
	c = string_val[pos - string_start];
	yypos++;
	} else {
	c = fgetc(yyin);
	if (docont && (c == '\\')) {
	c = fgetc(yyin);
	if (c == '\n') {
	yylineNum++;
	c = fgetc(yyin);
	}
	}
	}
	if (c == '\n')
	yylineNum++;
	yytext[yypos++] = c;
	yylast = yypos;
	yytext[yypos] = '\0';

	return c;
	}


	static void yyunputc(c)
	int c;
	{
	if (c == '\n')
	yylineNum--;
	yytext[--yypos] = c;
	}


	static int yyswallow(last)
	int last;
	{
	int c;

	while (((c = yygetc(0)) > '\0') && (c != last))
	;

	if (c != EOF)
	yyunputc(c);
	if (c == last)
	return 0;
	return -1;
	}


	static char *yytexttochar()
	{
	int i;

	for (i = 0; i < yypos; i++)
	yychars[i] = (char)(yytext[i] & 0xff);
	yychars[i] = '\0';
	return yychars;
	}


	static void yystrtotext(str)
	char *str;
	{
	int len;
	char *s;

	len = strlen(str);
	if (len > YYBUFSIZ)
	len = YYBUFSIZ;

	for (s = str; *s != '\0' && len > 0; s++, len--)
	yytext[yylast++] = *s;
	yytext[yylast] = '\0';
	}


	static char *yytexttostr(offset, max)
	int offset, max;
	{
	char *str;
	int i;

	if ((yytext[offset] == '\'' \|\| yytext[offset] == '"') &&
	(yytext[offset] == yytext[offset + max - 1])) {
	offset++;
	max--;
	}

	if (max > yylast)
	max = yylast;
	str = malloc(max + 1);
	if (str != NULL) {
	for (i = offset; i < max; i++)
	str[i - offset] = (char)(yytext[i] & 0xff);
	str[i - offset] = '\0';
	}
	return str;
	}


	int yylex()
	{
	int c, n, isbuilding, rval, lnext, nokey = 0;
	char *name;

	isbuilding = 0;
	lnext = 0;
	rval = 0;

	if (yystr != NULL) {
	free(yystr);
	yystr = NULL;
	}

	nextchar:
	c = yygetc(0);
	if (yydebug > 1)
	printf("yygetc = (%x) %c [%.s]\n", c, c, yypos, yypos, yytexttochar());

	switch (c)
	{
	case '\n' :
	lnext = 0;
	nokey = 0;
	case '\t' :
	case '\r' :
	case ' ' :
	if (isbuilding == 1) {
	yyunputc(c);
	goto done;
	}
	if (yylast > yypos) {
	bcopy(yytext + yypos, yytext,
	sizeof(yytext[0]) * (yylast - yypos + 1));
	}
	yylast -= yypos;
	yypos = 0;
	lnext = 0;
	nokey = 0;
	goto nextchar;

	case '\\' :
	if (lnext == 0) {
	lnext = 1;
	if (yylast == yypos) {
	yylast--;
	yypos--;
	} else
	yypos--;
	if (yypos == 0)
	nokey = 1;
	goto nextchar;
	}
	break;
	}

	if (lnext == 1) {
	lnext = 0;
	if ((isbuilding == 0) && !ISALNUM(c)) {
	return c;
	}
	goto nextchar;
	}

	switch (c)
	{
	case '#' :
	if (isbuilding == 1) {
	yyunputc(c);
	goto done;
	}
	yyswallow('\n');
	rval = YY_COMMENT;
	goto done;

	case '$' :
	if (isbuilding == 1) {
	yyunputc(c);
	goto done;
	}
	n = yygetc(0);
	if (n == '{') {
	if (yyswallow('}') == -1) {
	rval = -2;
	goto done;
	}
	(void) yygetc(0);
	} else {
	if (!ISALPHA(n)) {
	yyunputc(n);
	break;
	}
	do {
	n = yygetc(1);
	} while (ISALPHA(n) \|\| ISDIGIT(n) \|\| n == '_');
	yyunputc(n);
	}

	name = yytexttostr(1, yypos); /* skip $ */

	if (name != NULL) {
	string_val = get_variable(name, NULL, yylineNum);
	free(name);
	if (string_val != NULL) {
	name = yytexttostr(yypos, yylast);
	if (name != NULL) {
	yypos = 0;
	yylast = 0;
	yystrtotext(string_val);
	yystrtotext(name);
	free(string_val);
	free(name);
	goto nextchar;
	}
	free(string_val);
	}
	}
	break;

	case '\'':
	case '"' :
	if (isbuilding == 1) {
	goto done;
	}
	do {
	n = yygetc(1);
	if (n == EOF \|\| n == TOOLONG) {
	rval = -2;
	goto done;
	}
	if (n == '\n') {
	yyunputc(' ');
	yypos++;
	}
	} while (n != c);
	rval = YY_STR;
	goto done;
	/* NOTREACHED */

	case EOF :
	yylineNum = 1;
	yypos = 0;
	yylast = -1;
	yyexpectaddr = 0;
	yybreakondot = 0;
	yyvarnext = 0;
	yytokentype = 0;
	return 0;
	}

	if (strchr("=,/;{}()@", c) != NULL) {
	if (isbuilding == 1) {
	yyunputc(c);
	goto done;
	}
	rval = c;
	goto done;
	} else if (c == '.') {
	if (isbuilding == 0) {
	rval = c;
	goto done;
	}
	if (yybreakondot != 0) {
	yyunputc(c);
	goto done;
	}
	}

	switch (c)
	{
	case '-' :
	if (yyexpectaddr)
	break;
	if (isbuilding == 1)
	break;
	n = yygetc(0);
	if (n == '>') {
	isbuilding = 1;
	goto done;
	}
	yyunputc(n);
	rval = '-';
	goto done;

	case '!' :
	if (isbuilding == 1) {
	yyunputc(c);
	goto done;
	}
	n = yygetc(0);
	if (n == '=') {
	rval = YY_CMP_NE;
	goto done;
	}
	yyunputc(n);
	rval = '!';
	goto done;

	case '<' :
	if (yyexpectaddr)
	break;
	if (isbuilding == 1) {
	yyunputc(c);
	goto done;
	}
	n = yygetc(0);
	if (n == '=') {
	rval = YY_CMP_LE;
	goto done;
	}
	if (n == '>') {
	rval = YY_RANGE_OUT;
	goto done;
	}
	yyunputc(n);
	rval = YY_CMP_LT;
	goto done;

	case '>' :
	if (yyexpectaddr)
	break;
	if (isbuilding == 1) {
	yyunputc(c);
	goto done;
	}
	n = yygetc(0);
	if (n == '=') {
	rval = YY_CMP_GE;
	goto done;
	}
	if (n == '<') {
	rval = YY_RANGE_IN;
	goto done;
	}
	yyunputc(n);
	rval = YY_CMP_GT;
	goto done;
	}

	/*
	* Now for the reason this is here...IPv6 address parsing.
	* The longest string we can expect is of this form:
	* 0000:0000:0000:0000:0000:0000:000.000.000.000
	* not:
	* 0000:0000:0000:0000:0000:0000:0000:0000
	*/
	#ifdef USE_INET6
	if (yyexpectaddr == 1 && isbuilding == 0 && (ishex(c) \|\| c == ':')) {
	char ipv6buf[45 + 1], *s, oc;
	int start;

	start = yypos;
	s = ipv6buf;
	oc = c;

	/*
	* Perhaps we should implement stricter controls on what we
	* swallow up here, but surely it would just be duplicating
	* the code in inet_pton() anyway.
	*/
	do {
	*s++ = c;
	c = yygetc(1);
	} while ((ishex(c) \|\| c == ':' \|\| c == '.') &&
	(s - ipv6buf < 46));
	yyunputc(c);
	*s = '\0';

	if (inet_pton(AF_INET6, ipv6buf, &yylval.ip6) == 1) {
	rval = YY_IPV6;
	yyexpectaddr = 0;
	goto done;
	}
	yypos = start;
	c = oc;
	}
	#endif

	if (c == ':') {
	if (isbuilding == 1) {
	yyunputc(c);
	goto done;
	}
	rval = ':';
	goto done;
	}

	if (isbuilding == 0 && c == '0') {
	n = yygetc(0);
	if (n == 'x') {
	do {
	n = yygetc(1);
	} while (ishex(n));
	yyunputc(n);
	rval = YY_HEX;
	goto done;
	}
	yyunputc(n);
	}

	/*
	* No negative numbers with leading - sign..
	*/
	if (isbuilding == 0 && ISDIGIT(c)) {
	do {
	n = yygetc(1);
	} while (ISDIGIT(n));
	yyunputc(n);
	rval = YY_NUMBER;
	goto done;
	}

	isbuilding = 1;
	goto nextchar;

	done:
	yystr = yytexttostr(0, yypos);

	if (yydebug)
	printf("isbuilding %d yyvarnext %d nokey %d\n",
	isbuilding, yyvarnext, nokey);
	if (isbuilding == 1) {
	wordtab_t *w;

	w = NULL;
	isbuilding = 0;

	if ((yyvarnext == 0) && (nokey == 0)) {
	w = yyfindkey(yystr);
	if (w == NULL && yywordtab != NULL) {
	yyresetdict();
	w = yyfindkey(yystr);
	}
	} else
	yyvarnext = 0;
	if (w != NULL)
	rval = w->w_value;
	else
	rval = YY_STR;
	}

	if (rval == YY_STR && yysavedepth > 0)
	yyresetdict();

	yytokentype = rval;

	if (yydebug)
	printf("lexed(%s) [%d,%d,%d] => %d @%d\n", yystr, string_start,
	string_end, pos, rval, yysavedepth);

	switch (rval)
	{
	case YY_NUMBER :
	sscanf(yystr, "%u", &yylval.num);
	break;

	case YY_HEX :
	sscanf(yystr, "0x%x", (u_int *)&yylval.num);
	break;

	case YY_STR :
	yylval.str = strdup(yystr);
	break;

	default :
	break;
	}

	if (yylast > 0) {
	bcopy(yytext + yypos, yytext,
	sizeof(yytext[0]) * (yylast - yypos + 1));
	yylast -= yypos;
	yypos = 0;
	}

	return rval;
	}


	static wordtab_t *yyfindkey(key)
	char *key;
	{
	wordtab_t *w;

	if (yywordtab == NULL)
	return NULL;

	for (w = yywordtab; w->w_word != 0; w++)
	if (strcasecmp(key, w->w_word) == 0)
	return w;
	return NULL;
	}


	char *yykeytostr(num)
	int num;
	{
	wordtab_t *w;

	if (yywordtab == NULL)
	return "<unknown>";

	for (w = yywordtab; w->w_word; w++)
	if (w->w_value == num)
	return w->w_word;
	return "<unknown>";
	}


	wordtab_t *yysettab(words)
	wordtab_t *words;
	{
	wordtab_t *save;

	save = yywordtab;
	yywordtab = words;
	return save;
	}


	void yyerror(msg)
	char *msg;
	{
	char *txt, letter[2];
	int freetxt = 0;

	if (yytokentype < 256) {
	letter[0] = yytokentype;
	letter[1] = '\0';
	txt = letter;
	} else if (yytokentype == YY_STR \|\| yytokentype == YY_HEX \|\|
	yytokentype == YY_NUMBER) {
	if (yystr == NULL) {
	txt = yytexttostr(yypos, YYBUFSIZ);
	freetxt = 1;
	} else
	txt = yystr;
	} else {
	txt = yykeytostr(yytokentype);
	}
	fprintf(stderr, "%s error at \"%s\", line %d\n", msg, txt, yylineNum);
	if (freetxt == 1)
	free(txt);
	exit(1);
	}


	void yysetdict(newdict)
	wordtab_t *newdict;
	{
	if (yysavedepth == sizeof(yysavewords)/sizeof(yysavewords[0])) {
	fprintf(stderr, "%d: at maximum dictionary depth\n",
	yylineNum);
	return;
	}

	yysavewords[yysavedepth++] = yysettab(newdict);
	if (yydebug)
	printf("yysavedepth++ => %d\n", yysavedepth);
	}

	void yyresetdict()
	{
	if (yydebug)
	printf("yyresetdict(%d)\n", yysavedepth);
	if (yysavedepth > 0) {
	yysettab(yysavewords[--yysavedepth]);
	if (yydebug)
	printf("yysavedepth-- => %d\n", yysavedepth);
	}
	}



	#ifdef TEST_LEXER
	int main(argc, argv)
	int argc;
	char *argv[];
	{
	int n;

	yyin = stdin;

	while ((n = yylex()) != 0)
	printf("%d.n = %d [%s] %d %d\n",
	yylineNum, n, yystr, yypos, yylast);
	}
	#endif