[fwd] / conf.h

/* -*-c-*-
 *
 * $Id: conf.h,v 1.3 1999/07/27 18:30:14 mdw Exp $
 *
 * Configuration parsing
 *
 * (c) 1999 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------* 
 *
 * This file is part of the `fw' port forwarder.
 *
 * `fw' 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 2 of the License, or
 * (at your option) any later version.
 * 
 * `fw' 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 `fw'; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/*----- Revision history --------------------------------------------------* 
 *
 * $Log: conf.h,v $
 * Revision 1.3  1999/07/27 18:30:14  mdw
 * Improve documentation and layout for @CONF_BEGIN@ and friends.  Remove
 * irritating warning about unused label by introducing a spurious `goto'.
 *
 * Revision 1.2  1999/07/26 23:28:39  mdw
 * Major reconstruction work for new design.
 *
 * Revision 1.1.1.1  1999/07/01 08:56:23  mdw
 * Initial revision.
 *
 */

#ifndef CONF_H
#define CONF_H

#ifdef __cplusplus
  extern "C" {
#endif

/*----- Header files ------------------------------------------------------*/

#include <mLib/dstr.h>

#ifndef SCAN_H
#  include "scan.h"
#endif

/*----- Magic numbers -----------------------------------------------------*/

#define CTOK_EOF (-1)
#define CTOK_WORD 256

/*----- Functions provided ------------------------------------------------*/

/* --- @token@ --- *
 *
 * Arguments:	@scanner *sc@ = pointer to scanner definition
 *
 * Returns:	Type of token scanned.
 *
 * Use:		Reads the next token from the character scanner.
 */

extern int token(scanner */*sc*/);

/* --- @error@ --- *
 *
 * Arguments:	@scanner *sc@ = pointer to scanner definition
 *		@const char *msg@ = message skeleton string
 *		@...@ = extra arguments for the skeleton
 *
 * Returns:	Doesn't
 *
 * Use:		Reports an error at the current scanner location.
 */

extern void error(scanner */*sc*/, const char */*msg*/, ...);

/* --- @conf_enum@ --- *
 *
 * Arguments:	@scanner *sc@ = pointer to a scanner object
 *		@const char *list@ = comma-separated things to allow
 *		@unsigned @f = flags for the search
 *		@const char *err@ = error message if not found
 *
 * Returns:	Index into list, zero-based, or @-1@.
 *
 * Use:		Checks whether the current token is a string which matches
 *		one of the comma-separated items given.  If not, an error is
 *		reported; otherwise the index of the matched item is
 *		returned.
 */

#define ENUM_ABBREV 1u
#define ENUM_NONE 2u

extern int conf_enum(scanner */*sc*/, const char */*list*/,
		     unsigned /*flags*/, const char */*err*/);

/* --- @conf_prefix@ --- *
 *
 * Arguments:	@scanner *sc@ = pointer to a scanner object
 *		@const char *p@ = pointer to prefix string to check
 *
 * Returns:	Nonzero if the prefix matches.
 *
 * Use:		If the current token is a word matching the given prefix
 *		string, then it and an optional `.' character are removed and
 *		a nonzero result is returned.  Otherwise the current token is
 *		left as it is, and zero is returned.
 *
 *		Typical options parsing code would remove an expected prefix,
 *		scan an option anyway (since qualifying prefixes are
 *		optional) and if a match is found, claim the option.  If no
 *		match is found, and a prefix was stripped, then an error
 *		should be reported.
 */

extern int conf_prefix(scanner */*sc*/, const char */*p*/);

/* --- @CONF_BEGIN@, @CONF_END@ --- *
 *
 * Arguments:	@sc@ = scanner to read from
 *		@prefix@ = prefix to scan for
 *		@desc@ = description of what we're parsing
 *
 * Use:		Bracket an options parsing routine.  The current token is
 *		checked to see whether it matches the prefix.  If so, it is
 *		removed and the following token examined.  If that's a `.'
 *		then it's removed.  If it's a `{' then the enclosed
 *		option-parsing code is executed in a loop until a matching
 *		'}' is found.  If the options parser doesn't accept an
 *		option, the behaviour is dependent on whether a prefix was
 *		seen: if so, an error is reported; otherwse a zero return is
 *		made.
 */

#define CS_PLAIN 0
#define CS_PREFIX 1
#define CS_BRACE 2
#define CS_UNKNOWN 3

#define CONF_BEGIN(sc, prefix, desc) do {				\
  scanner *_conf_sc = (sc);						\
  const char *_conf_desc = (desc);					\
  int _conf_state = CS_PLAIN;						\
									\
  /* --- Read the initial prefix --- */					\
									\
  if (_conf_sc->t == CTOK_WORD &&					\
      strcmp(_conf_sc->d.buf, (prefix)) == 0) {				\
    token(_conf_sc);							\
    _conf_state = CS_PREFIX;						\
    if (_conf_sc->t == '.')						\
      token(_conf_sc);							\
    else if (_conf_sc->t == '{') {					\
      token(_conf_sc);							\
      _conf_state = CS_BRACE;						\
    }									\
  }									\
									\
  /* --- Ensure the next token is a word --- */				\
									\
  if (_conf_sc->t != CTOK_WORD)						\
    error(_conf_sc, "parse error, expected option keyword");		\
  do {

#define CONF_END							\
									\
    /* --- Reject an option --- *					\
     *									\
     * We could get here as a result of an explicit @CONF_REJECT@ or	\
     * because the option wasn't accepted.				\
     */									\
									\
     goto _conf_reject;							\
  _conf_reject:								\
    if (_conf_state == CS_PLAIN)					\
      _conf_state = CS_UNKNOWN;						\
    else {								\
      error(_conf_sc, "unknown %s option `%s'",				\
	    _conf_desc, _conf_sc->d.buf);				\
    }									\
									\
    /* --- Accept an option --- *					\
     *									\
     * It's safe to drop through from above.  Either an error will have	\
     * been reported, or the state is not @CS_BRACE@.			\
     */									\
									\
  _conf_accept:								\
    if (_conf_state == CS_BRACE && _conf_sc->t == ';')			\
      token(_conf_sc);							\
  } while (_conf_state == CS_BRACE && _conf_sc->t == CTOK_WORD);	\
									\
  /* --- Check for a closing brace --- */				\
									\
  if (_conf_state == CS_BRACE) {					\
    if (_conf_sc->t == '}')						\
      token(_conf_sc);							\
    else								\
      error(_conf_sc, "parse error, expected `}'");			\
  }									\
									\
  /* --- Return an appropriate value --- */				\
									\
  return (_conf_state != CS_UNKNOWN);					\
} while (0)

/* --- @CONF_ACCEPT@, @CONF_REJECT@ --- *
 *
 * Arguments:	---
 *
 * Use:		Within an options parser (between @CONF_BEGIN@ and
 *		@CONF_END@), accept or reject an option.
 */

#define CONF_ACCEPT goto _conf_accept
#define CONF_REJECT goto _conf_reject

/* --- @CONF_QUAL@ --- *
 *
 * Arguments:	---
 *
 * Use:		Evaluates to a nonzero value if the current option is
 *		qualified.  This can be used to decide whether abbreviations
 *		for options should be accepted.
 */

#define CONF_QUAL (_conf_state != CS_PLAIN)

/* --- @conf_name@ --- *
 *
 * Arguments:	@scanner *sc@ = pointer to scanner
 *		@char delim@ = delimiter character to look for
 *		@dstr *d@ = pointer to dynamic string for output
 *
 * Returns:	---
 *
 * Use:		Reads in a compound name consisting of words separated by
 *		delimiters.  Leading and trailing delimiters are permitted,
 *		although they'll probably cause confusion if used.  The name
 *		may be enclosed in square brackets if that helps at all.
 *
 *		Examples of compound names are filenames (delimited by `/')
 *		and IP addresses (delimited by `.').
 */

extern void conf_name(scanner */*sc*/, char /*delim*/, dstr */*d*/);

/* --- @conf_parse@ --- *
 *
 * Arguments:	@scanner *sc@ = pointer to a scanner structure
 *
 * Returns:	---
 *
 * Use:		Parses a configuration file fragment from the scanner
 */

extern void conf_parse(scanner *sc);

/*----- That's all, folks -------------------------------------------------*/

#ifdef __cplusplus
  }
#endif

#endif
Commit	Line	Data
e82f7154	1	/* --c--
e82f7154	2	*
022008ac	3	* $Id: conf.h,v 1.3 1999/07/27 18:30:14 mdw Exp $
e82f7154	4	*
	5	* Configuration parsing
	6	*
61e3dbdf	7	* (c) 1999 Straylight/Edgeware
e82f7154	8	*/
	9
	10	/----- Licensing notice --------------------------------------------------
	11	*
	12	* This file is part of the `fw' port forwarder.
	13	*
	14	* `fw' is free software; you can redistribute it and/or modify
	15	* it under the terms of the GNU General Public License as published by
	16	* the Free Software Foundation; either version 2 of the License, or
	17	* (at your option) any later version.
	18	*
	19	* `fw' is distributed in the hope that it will be useful,
	20	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	21	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	22	* GNU General Public License for more details.
	23	*
	24	* You should have received a copy of the GNU General Public License
	25	* along with `fw'; if not, write to the Free Software Foundation,
	26	* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	27	*/
	28
	29	/----- Revision history --------------------------------------------------
	30	*
	31	* $Log: conf.h,v $
022008ac	32	* Revision 1.3 1999/07/27 18:30:14 mdw
	33	* Improve documentation and layout for @CONF_BEGIN@ and friends. Remove
	34	* irritating warning about unused label by introducing a spurious `goto'.
	35	*
61e3dbdf	36	* Revision 1.2 1999/07/26 23:28:39 mdw
	37	* Major reconstruction work for new design.
	38	*
	39	* Revision 1.1.1.1 1999/07/01 08:56:23 mdw
	40	* Initial revision.
e82f7154	41	*
	42	*/
	43
	44	#ifndef CONF_H
	45	#define CONF_H
	46
	47	#ifdef __cplusplus
	48	extern "C" {
	49	#endif
	50
	51	/----- Header files ------------------------------------------------------/
	52
61e3dbdf	53	#include <mLib/dstr.h>
61e3dbdf	54
e82f7154	55	#ifndef SCAN_H
	56	# include "scan.h"
	57	#endif
	58
61e3dbdf	59	/----- Magic numbers -----------------------------------------------------/
	60
	61	#define CTOK_EOF (-1)
	62	#define CTOK_WORD 256
	63
e82f7154	64	/----- Functions provided ------------------------------------------------/
e82f7154	65
61e3dbdf	66	/* --- @token@ --- *
	67	*
	68	* Arguments: @scanner *sc@ = pointer to scanner definition
	69	*
	70	* Returns: Type of token scanned.
	71	*
	72	* Use: Reads the next token from the character scanner.
	73	*/
	74
	75	extern int token(scanner /sc*/);
	76
	77	/* --- @error@ --- *
	78	*
	79	* Arguments: @scanner *sc@ = pointer to scanner definition
	80	* @const char *msg@ = message skeleton string
	81	* @...@ = extra arguments for the skeleton
	82	*
	83	* Returns: Doesn't
	84	*
	85	* Use: Reports an error at the current scanner location.
	86	*/
	87
	88	extern void error(scanner /sc/, const char /msg/, ...);
	89
	90	/* --- @conf_enum@ --- *
	91	*
	92	* Arguments: @scanner *sc@ = pointer to a scanner object
	93	* @const char *list@ = comma-separated things to allow
	94	* @unsigned @f = flags for the search
	95	* @const char *err@ = error message if not found
	96	*
	97	* Returns: Index into list, zero-based, or @-1@.
	98	*
	99	* Use: Checks whether the current token is a string which matches
	100	* one of the comma-separated items given. If not, an error is
	101	* reported; otherwise the index of the matched item is
	102	* returned.
	103	*/
	104
	105	#define ENUM_ABBREV 1u
	106	#define ENUM_NONE 2u
	107
	108	extern int conf_enum(scanner /sc/, const char /list/,
	109	unsigned /flags/, const char /err*/);
	110
	111	/* --- @conf_prefix@ --- *
	112	*
	113	* Arguments: @scanner *sc@ = pointer to a scanner object
	114	* @const char *p@ = pointer to prefix string to check
	115	*
	116	* Returns: Nonzero if the prefix matches.
	117	*
	118	* Use: If the current token is a word matching the given prefix
	119	* string, then it and an optional `.' character are removed and
	120	* a nonzero result is returned. Otherwise the current token is
	121	* left as it is, and zero is returned.
	122	*
	123	* Typical options parsing code would remove an expected prefix,
	124	* scan an option anyway (since qualifying prefixes are
	125	* optional) and if a match is found, claim the option. If no
	126	* match is found, and a prefix was stripped, then an error
	127	* should be reported.
	128	*/
	129
130	extern int conf_prefix(scanner /sc/, const char /p/);
131
022008ac	132	/* --- @CONF_BEGIN@, @CONF_END@ --- *
61e3dbdf	133	*
	134	* Arguments: @sc@ = scanner to read from
	135	* @prefix@ = prefix to scan for
	136	* @desc@ = description of what we're parsing
	137	*
022008ac	138	* Use: Bracket an options parsing routine. The current token is
	139	* checked to see whether it matches the prefix. If so, it is
	140	* removed and the following token examined. If that's a `.'
	141	* then it's removed. If it's a `{' then the enclosed
	142	* option-parsing code is executed in a loop until a matching
	143	* '}' is found. If the options parser doesn't accept an
	144	* option, the behaviour is dependent on whether a prefix was
	145	* seen: if so, an error is reported; otherwse a zero return is
	146	* made.
61e3dbdf	147	*/
	148
	149	#define CS_PLAIN 0
	150	#define CS_PREFIX 1
	151	#define CS_BRACE 2
	152	#define CS_UNKNOWN 3
	153
	154	#define CONF_BEGIN(sc, prefix, desc) do { \
	155	scanner *_conf_sc = (sc); \
	156	const char *_conf_desc = (desc); \
	157	int _conf_state = CS_PLAIN; \
022008ac	158	\
	159	/* --- Read the initial prefix --- */ \
	160	\
61e3dbdf	161	if (_conf_sc->t == CTOK_WORD && \
	162	strcmp(_conf_sc->d.buf, (prefix)) == 0) { \
	163	token(_conf_sc); \
	164	_conf_state = CS_PREFIX; \
	165	if (_conf_sc->t == '.') \
	166	token(_conf_sc); \
	167	else if (_conf_sc->t == '{') { \
	168	token(_conf_sc); \
	169	_conf_state = CS_BRACE; \
	170	} \
	171	} \
022008ac	172	\
	173	/* --- Ensure the next token is a word --- */ \
	174	\
61e3dbdf	175	if (_conf_sc->t != CTOK_WORD) \
	176	error(_conf_sc, "parse error, expected option keyword"); \
	177	do {
	178
61e3dbdf	179	#define CONF_END \
022008ac	180	\
	181	/* --- Reject an option --- * \
	182	* \
	183	* We could get here as a result of an explicit @CONF_REJECT@ or \
	184	* because the option wasn't accepted. \
	185	*/ \
	186	\
	187	goto _conf_reject; \
61e3dbdf	188	_conf_reject: \
	189	if (_conf_state == CS_PLAIN) \
	190	_conf_state = CS_UNKNOWN; \
	191	else { \
	192	error(_conf_sc, "unknown %s option `%s'", \
	193	_conf_desc, _conf_sc->d.buf); \
	194	} \
022008ac	195	\
	196	/* --- Accept an option --- * \
	197	* \
	198	* It's safe to drop through from above. Either an error will have \
	199	* been reported, or the state is not @CS_BRACE@. \
	200	*/ \
	201	\
61e3dbdf	202	_conf_accept: \
	203	if (_conf_state == CS_BRACE && _conf_sc->t == ';') \
	204	token(_conf_sc); \
	205	} while (_conf_state == CS_BRACE && _conf_sc->t == CTOK_WORD); \
022008ac	206	\
	207	/* --- Check for a closing brace --- */ \
	208	\
61e3dbdf	209	if (_conf_state == CS_BRACE) { \
	210	if (_conf_sc->t == '}') \
	211	token(_conf_sc); \
	212	else \
	213	error(_conf_sc, "parse error, expected `}'"); \
	214	} \
022008ac	215	\
	216	/* --- Return an appropriate value --- */ \
	217	\
61e3dbdf	218	return (_conf_state != CS_UNKNOWN); \
	219	} while (0)
	220
022008ac	221	/* --- @CONF_ACCEPT@, @CONF_REJECT@ --- *
	222	*
	223	* Arguments: ---
	224	*
	225	* Use: Within an options parser (between @CONF_BEGIN@ and
	226	* @CONF_END@), accept or reject an option.
	227	*/
	228
	229	#define CONF_ACCEPT goto _conf_accept
	230	#define CONF_REJECT goto _conf_reject
	231
	232	/* --- @CONF_QUAL@ --- *
	233	*
	234	* Arguments: ---
	235	*
	236	* Use: Evaluates to a nonzero value if the current option is
	237	* qualified. This can be used to decide whether abbreviations
	238	* for options should be accepted.
	239	*/
	240
	241	#define CONF_QUAL (_conf_state != CS_PLAIN)
	242
61e3dbdf	243	/* --- @conf_name@ --- *
	244	*
	245	* Arguments: @scanner *sc@ = pointer to scanner
	246	* @char delim@ = delimiter character to look for
	247	* @dstr *d@ = pointer to dynamic string for output
	248	*
	249	* Returns: ---
	250	*
	251	* Use: Reads in a compound name consisting of words separated by
	252	* delimiters. Leading and trailing delimiters are permitted,
	253	* although they'll probably cause confusion if used. The name
	254	* may be enclosed in square brackets if that helps at all.
	255	*
	256	* Examples of compound names are filenames (delimited by `/')
	257	* and IP addresses (delimited by `.').
	258	*/
	259
	260	extern void conf_name(scanner /sc/, char /delim/, dstr /d/);
	261
e82f7154	262	/* --- @conf_parse@ --- *
e82f7154	263	*
61e3dbdf	264	* Arguments: @scanner *sc@ = pointer to a scanner structure
e82f7154	265	*
	266	* Returns: ---
	267	*
	268	* Use: Parses a configuration file fragment from the scanner
	269	*/
	270
61e3dbdf	271	extern void conf_parse(scanner *sc);
e82f7154	272
	273	/----- That's all, folks -------------------------------------------------/
	274
	275	#ifdef __cplusplus
	276	}
	277	#endif
	278
	279	#endif