~mdw / fwd / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Require mLib 2.0.3 for connection stuff.
[fwd] / conf.h
1 /* -*-c-*-
2 *
3 * $Id: conf.h,v 1.8 2003/11/25 14:08:23 mdw Exp $
4 *
5 * Configuration parsing
6 *
7 * (c) 1999 Straylight/Edgeware
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 $
32 * Revision 1.8 2003/11/25 14:08:23 mdw
33 * Debianization. Socket target options. Internet binding.
34 *
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.
38 *
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.
42 *
43 * Revision 1.5 1999/10/22 22:46:44 mdw
44 * Improve documentation for conf_enum.
45 *
46 * Revision 1.4 1999/08/19 18:32:48 mdw
47 * Improve lexical analysis. In particular, `chmod' patterns don't have to
48 * be quoted any more.
49 *
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'.
53 *
54 * Revision 1.2 1999/07/26 23:28:39 mdw
55 * Major reconstruction work for new design.
56 *
57 * Revision 1.1.1.1 1999/07/01 08:56:23 mdw
58 * Initial revision.
59 *
60 */
61
62 #ifndef CONF_H
63 #define CONF_H
64
65 #ifdef __cplusplus
66 extern "C" {
67 #endif
68
69 /*----- Header files ------------------------------------------------------*/
70
71 #include <mLib/dstr.h>
72
73 #ifndef SCAN_H
74 # include "scan.h"
75 #endif
76
77 /*----- Magic numbers -----------------------------------------------------*/
78
79 #define CTOK_EOF (-1)
80 #define CTOK_WORD 256
81
82 /*----- Functions provided ------------------------------------------------*/
83
84 /* --- @conf_undelim@ --- *
85 *
86 * Arguments: @scanner *sc@ = pointer to scanner definition
87 * @const char *d, *dd@ = pointer to characters to escape
88 *
89 * Returns: ---
90 *
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.
94 */
95
96 extern void conf_undelim(scanner */*sc*/,
97 const char */*d*/, const char */*dd*/);
98
99 /* --- @token@ --- *
100 *
101 * Arguments: @scanner *sc@ = pointer to scanner definition
102 *
103 * Returns: Type of token scanned.
104 *
105 * Use: Reads the next token from the character scanner.
106 */
107
108 extern int token(scanner */*sc*/);
109
110 /* --- @error@ --- *
111 *
112 * Arguments: @scanner *sc@ = pointer to scanner definition
113 * @const char *msg@ = message skeleton string
114 * @...@ = extra arguments for the skeleton
115 *
116 * Returns: Doesn't
117 *
118 * Use: Reports an error at the current scanner location.
119 */
120
121 extern void error(scanner */*sc*/, const char */*msg*/, ...);
122
123 /* --- @pushback@ --- *
124 *
125 * Arguments: @scanner *sc@ = pointer to scanner definition
126 *
127 * Returns: ---
128 *
129 * Use: Pushes the current token back. This is normally a precursor
130 * to pushing a new scanner source.
131 */
132
133 extern void pushback(scanner */*sc*/);
134
135 /* --- @conf_enum@ --- *
136 *
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
141 *
142 * Returns: Index into list, zero-based, or @-1@.
143 *
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.
147 *
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
153 * terminated.
154 */
155
156 #define ENUM_ABBREV 1u
157 #define ENUM_NONE 2u
158
159 extern int conf_enum(scanner */*sc*/, const char */*list*/,
160 unsigned /*flags*/, const char */*err*/);
161
162 /* --- @conf_prefix@ --- *
163 *
164 * Arguments: @scanner *sc@ = pointer to a scanner object
165 * @const char *p@ = pointer to prefix string to check
166 *
167 * Returns: Nonzero if the prefix matches.
168 *
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.
173 *
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.
179 */
180
181 extern int conf_prefix(scanner */*sc*/, const char */*p*/);
182
183 /* --- @CONF_BEGIN@, @CONF_END@ --- *
184 *
185 * Arguments: @sc@ = scanner to read from
186 * @prefix@ = prefix to scan for
187 * @desc@ = description of what we're parsing
188 *
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
197 * made.
198 */
199
200 #define CS_PLAIN 0
201 #define CS_PREFIX 1
202 #define CS_BRACE 2
203 #define CS_UNKNOWN 3
204
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; \
209 \
210 /* --- Read the initial prefix --- */ \
211 \
212 if (_conf_sc->t == CTOK_WORD && \
213 strcmp(_conf_sc->d.buf, (prefix)) == 0) { \
214 token(_conf_sc); \
215 _conf_state = CS_PREFIX; \
216 if (_conf_sc->t == '.') \
217 token(_conf_sc); \
218 else if (_conf_sc->t == '{') { \
219 token(_conf_sc); \
220 _conf_state = CS_BRACE; \
221 } \
222 } \
223 \
224 /* --- Ensure the next token is a word --- */ \
225 \
226 if (_conf_sc->t != CTOK_WORD) \
227 error(_conf_sc, "parse error, expected option keyword"); \
228 do {
229
230 #define CONF_END \
231 \
232 /* --- Reject an option --- * \
233 * \
234 * We could get here as a result of an explicit @CONF_REJECT@ or \
235 * because the option wasn't accepted. \
236 */ \
237 \
238 goto _conf_reject; \
239 _conf_reject: \
240 if (_conf_state == CS_PLAIN) \
241 _conf_state = CS_UNKNOWN; \
242 else { \
243 error(_conf_sc, "unknown %s option `%s'", \
244 _conf_desc, _conf_sc->d.buf); \
245 } \
246 \
247 /* --- Accept an option --- * \
248 * \
249 * It's safe to drop through from above. Either an error will have \
250 * been reported, or the state is not @CS_BRACE@. \
251 */ \
252 \
253 _conf_accept: \
254 if (_conf_state == CS_BRACE && _conf_sc->t == ';') \
255 token(_conf_sc); \
256 } while (_conf_state == CS_BRACE && _conf_sc->t == CTOK_WORD); \
257 \
258 /* --- Check for a closing brace --- */ \
259 \
260 if (_conf_state == CS_BRACE) { \
261 if (_conf_sc->t == '}') \
262 token(_conf_sc); \
263 else \
264 error(_conf_sc, "parse error, expected `}'"); \
265 } \
266 \
267 /* --- Return an appropriate value --- */ \
268 \
269 return (_conf_state != CS_UNKNOWN); \
270 } while (0)
271
272 /* --- @CONF_ACCEPT@, @CONF_REJECT@ --- *
273 *
274 * Arguments: ---
275 *
276 * Use: Within an options parser (between @CONF_BEGIN@ and
277 * @CONF_END@), accept or reject an option.
278 */
279
280 #define CONF_ACCEPT goto _conf_accept
281 #define CONF_REJECT goto _conf_reject
282
283 /* --- @CONF_QUAL@ --- *
284 *
285 * Arguments: ---
286 *
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.
290 */
291
292 #define CONF_QUAL (_conf_state != CS_PLAIN)
293
294 /* --- @conf_name@ --- *
295 *
296 * Arguments: @scanner *sc@ = pointer to scanner
297 * @char delim@ = delimiter character to look for
298 * @dstr *d@ = pointer to dynamic string for output
299 *
300 * Returns: ---
301 *
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.
306 *
307 * Examples of compound names are filenames (delimited by `/')
308 * and IP addresses (delimited by `.').
309 */
310
311 extern void conf_name(scanner */*sc*/, char /*delim*/, dstr */*d*/);
312
313 /*----- That's all, folks -------------------------------------------------*/
314
315 #ifdef __cplusplus
316 }
317 #endif
318
319 #endif
Port forwarder with too many features