3 * $Id: conf.h,v 1.8 2003/11/25 14:08:23 mdw Exp $
5 * Configuration parsing
7 * (c) 1999 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of the `fw' port forwarder.
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.
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.
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.
29 /*----- Revision history --------------------------------------------------*
32 * Revision 1.8 2003/11/25 14:08:23 mdw
33 * Debianization. Socket target options. Internet binding.
35 * Revision 1.7 2002/02/22 23:42:56 mdw
36 * `fw'-specific configuration code moved out. This file might become part
37 * of a library some day.
39 * Revision 1.6 2002/01/13 14:48:16 mdw
40 * Make delimiters be a property of a scanner. Change the delimiter-
41 * changing functions' names.
43 * Revision 1.5 1999/10/22 22:46:44 mdw
44 * Improve documentation for conf_enum.
46 * Revision 1.4 1999/08/19 18:32:48 mdw
47 * Improve lexical analysis. In particular, `chmod' patterns don't have to
50 * Revision 1.3 1999/07/27 18:30:14 mdw
51 * Improve documentation and layout for @CONF_BEGIN@ and friends. Remove
52 * irritating warning about unused label by introducing a spurious `goto'.
54 * Revision 1.2 1999/07/26 23:28:39 mdw
55 * Major reconstruction work for new design.
57 * Revision 1.1.1.1 1999/07/01 08:56:23 mdw
69 /*----- Header files ------------------------------------------------------*/
71 #include <mLib/dstr.h>
77 /*----- Magic numbers -----------------------------------------------------*/
82 /*----- Functions provided ------------------------------------------------*/
84 /* --- @conf_undelim@ --- *
86 * Arguments: @scanner *sc@ = pointer to scanner definition
87 * @const char *d, *dd@ = pointer to characters to escape
91 * Use: Modifies the tokenizer. Characters in the first list will
92 * always be considered to begin a word. Characters in the
93 * second list will always be allowed to continue a word.
96 extern void conf_undelim(scanner */
*sc*/
,
97 const char */
*d*/
, const char */
*dd*/
);
101 * Arguments: @scanner *sc@ = pointer to scanner definition
103 * Returns: Type of token scanned.
105 * Use: Reads the next token from the character scanner.
108 extern int token(scanner */
*sc*/
);
112 * Arguments: @scanner *sc@ = pointer to scanner definition
113 * @const char *msg@ = message skeleton string
114 * @...@ = extra arguments for the skeleton
118 * Use: Reports an error at the current scanner location.
121 extern void error(scanner */
*sc*/
, const char */
*msg*/
, ...);
123 /* --- @pushback@ --- *
125 * Arguments: @scanner *sc@ = pointer to scanner definition
129 * Use: Pushes the current token back. This is normally a precursor
130 * to pushing a new scanner source.
133 extern void pushback(scanner */
*sc*/
);
135 /* --- @conf_enum@ --- *
137 * Arguments: @scanner *sc@ = pointer to a scanner object
138 * @const char *list@ = comma-separated things to allow
139 * @unsigned @f = flags for the search
140 * @const char *err@ = error message if not found
142 * Returns: Index into list, zero-based, or @-1@.
144 * Use: Checks whether the current token is a string which matches
145 * one of the comma-separated items given. The return value is
146 * the index (zero-based) of the matched string in the list.
148 * The flags control the behaviour if no exact match is found.
149 * If @ENUM_ABBREV@ is set, and the current token is a left
150 * substring of exactly one of the possibilities, then that one
151 * is chosen. If @ENUM_NONE@ is set, the value @-1@ is
152 * returned; otherwise an error is reported and the program is
156 #define ENUM_ABBREV 1u
159 extern int conf_enum(scanner */
*sc*/
, const char */
*list*/
,
160 unsigned /*flags*/, const char */
*err*/
);
162 /* --- @conf_prefix@ --- *
164 * Arguments: @scanner *sc@ = pointer to a scanner object
165 * @const char *p@ = pointer to prefix string to check
167 * Returns: Nonzero if the prefix matches.
169 * Use: If the current token is a word matching the given prefix
170 * string, then it and an optional `.' character are removed and
171 * a nonzero result is returned. Otherwise the current token is
172 * left as it is, and zero is returned.
174 * Typical options parsing code would remove an expected prefix,
175 * scan an option anyway (since qualifying prefixes are
176 * optional) and if a match is found, claim the option. If no
177 * match is found, and a prefix was stripped, then an error
178 * should be reported.
181 extern int conf_prefix(scanner */
*sc*/
, const char */
*p*/
);
183 /* --- @CONF_BEGIN@, @CONF_END@ --- *
185 * Arguments: @sc@ = scanner to read from
186 * @prefix@ = prefix to scan for
187 * @desc@ = description of what we're parsing
189 * Use: Bracket an options parsing routine. The current token is
190 * checked to see whether it matches the prefix. If so, it is
191 * removed and the following token examined. If that's a `.'
192 * then it's removed. If it's a `{' then the enclosed
193 * option-parsing code is executed in a loop until a matching
194 * '}' is found. If the options parser doesn't accept an
195 * option, the behaviour is dependent on whether a prefix was
196 * seen: if so, an error is reported; otherwse a zero return is
205 #define CONF_BEGIN(sc, prefix, desc) do { \
206 scanner *_conf_sc = (sc); \
207 const char *_conf_desc = (desc); \
208 int _conf_state = CS_PLAIN; \
210 /* --- Read the initial prefix --- */ \
212 if (_conf_sc->t == CTOK_WORD && \
213 strcmp(_conf_sc->d.buf, (prefix)) == 0) { \
215 _conf_state = CS_PREFIX; \
216 if (_conf_sc->t == '.') \
218 else if (_conf_sc->t == '{') { \
220 _conf_state = CS_BRACE; \
224 /* --- Ensure the next token is a word --- */ \
226 if (_conf_sc->t != CTOK_WORD) \
227 error(_conf_sc, "parse error, expected option keyword"); \
232 /* --- Reject an option --- * \
234 * We could get here as a result of an explicit @CONF_REJECT@ or \
235 * because the option wasn't accepted. \
240 if (_conf_state == CS_PLAIN) \
241 _conf_state = CS_UNKNOWN; \
243 error(_conf_sc, "unknown %s option `%s'", \
244 _conf_desc, _conf_sc->d.buf); \
247 /* --- Accept an option --- * \
249 * It's safe to drop through from above. Either an error will have \
250 * been reported, or the state is not @CS_BRACE@. \
254 if (_conf_state == CS_BRACE && _conf_sc->t == ';') \
256 } while (_conf_state == CS_BRACE && _conf_sc->t == CTOK_WORD); \
258 /* --- Check for a closing brace --- */ \
260 if (_conf_state == CS_BRACE) { \
261 if (_conf_sc->t == '}') \
264 error(_conf_sc, "parse error, expected `}'"); \
267 /* --- Return an appropriate value --- */ \
269 return (_conf_state != CS_UNKNOWN); \
272 /* --- @CONF_ACCEPT@, @CONF_REJECT@ --- *
276 * Use: Within an options parser (between @CONF_BEGIN@ and
277 * @CONF_END@), accept or reject an option.
280 #define CONF_ACCEPT goto _conf_accept
281 #define CONF_REJECT goto _conf_reject
283 /* --- @CONF_QUAL@ --- *
287 * Use: Evaluates to a nonzero value if the current option is
288 * qualified. This can be used to decide whether abbreviations
289 * for options should be accepted.
292 #define CONF_QUAL (_conf_state != CS_PLAIN)
294 /* --- @conf_name@ --- *
296 * Arguments: @scanner *sc@ = pointer to scanner
297 * @char delim@ = delimiter character to look for
298 * @dstr *d@ = pointer to dynamic string for output
302 * Use: Reads in a compound name consisting of words separated by
303 * delimiters. Leading and trailing delimiters are permitted,
304 * although they'll probably cause confusion if used. The name
305 * may be enclosed in square brackets if that helps at all.
307 * Examples of compound names are filenames (delimited by `/')
308 * and IP addresses (delimited by `.').
311 extern void conf_name(scanner */
*sc*/
, char /*delim*/, dstr */
*d*/
);
313 /*----- That's all, folks -------------------------------------------------*/