/* -*-c-*-
*
- * $Id: conf.h,v 1.1 1999/07/01 08:56:23 mdw Exp $
- *
* Configuration parsing
*
- * (c) 1999 Mark Wooding
+ * (c) 1999 Straylight/Edgeware
*/
-/*----- Licensing notice --------------------------------------------------*
+/*----- Licensing notice --------------------------------------------------*
*
* This file is part of the `fw' port forwarder.
*
* 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 1.1 1999/07/01 08:56:23 mdw
- * Initial revision
- *
- */
-
#ifndef CONF_H
#define CONF_H
/*----- 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 ------------------------------------------------*/
-/* --- @conf_parse@ --- *
+/* --- @conf_undelim@ --- *
*
- * Arguments: @void *scp@ = pointer to a scanner structure
+ * Arguments: @scanner *sc@ = pointer to scanner definition
+ * @const char *d, *dd@ = pointer to characters to escape
*
* Returns: ---
*
- * Use: Parses a configuration file fragment from the scanner
+ * Use: Modifies the tokenizer. Characters in the first list will
+ * always be considered to begin a word. Characters in the
+ * second list will always be allowed to continue a word.
+ */
+
+extern void conf_undelim(scanner */*sc*/,
+ const char */*d*/, const char */*dd*/);
+
+/* --- @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*/, ...);
+
+/* --- @pushback@ --- *
+ *
+ * Arguments: @scanner *sc@ = pointer to scanner definition
+ *
+ * Returns: ---
+ *
+ * Use: Pushes the current token back. This is normally a precursor
+ * to pushing a new scanner source.
+ */
+
+extern void pushback(scanner */*sc*/);
+
+/* --- @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. The return value is
+ * the index (zero-based) of the matched string in the list.
+ *
+ * The flags control the behaviour if no exact match is found.
+ * If @ENUM_ABBREV@ is set, and the current token is a left
+ * substring of exactly one of the possibilities, then that one
+ * is chosen. If @ENUM_NONE@ is set, the value @-1@ is
+ * returned; otherwise an error is reported and the program is
+ * terminated.
+ */
+
+#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_parse(void */*scp*/);
+extern void conf_name(scanner */*sc*/, char /*delim*/, dstr */*d*/);
/*----- That's all, folks -------------------------------------------------*/