Mini Shell

/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */

#ifndef ISCCFG_CFG_H
#define ISCCFG_CFG_H 1

/*****
 ***** Module Info
 *****/

/*! \file isccfg/cfg.h
 * \brief
 * This is the new, table-driven, YACC-free configuration file parser.
 */

/***
 *** Imports
 ***/

#include <inttypes.h>
#include <stdbool.h>

#include <isc/formatcheck.h>
#include <isc/lang.h>
#include <isc/types.h>
#include <isc/list.h>

/***
 *** Types
 ***/

/*%
 * A configuration parser.
 */
typedef struct cfg_parser cfg_parser_t;

/*%
 * A configuration type definition object.  There is a single
 * static cfg_type_t object for each data type supported by
 * the configuration parser.
 */
typedef struct cfg_type cfg_type_t;

/*%
 * A configuration object.  This is the basic building block of the
 * configuration parse tree.  It contains a value (which may be
 * of one of several types) and information identifying the file
 * and line number the value came from, for printing error
 * messages.
 */
typedef struct cfg_obj cfg_obj_t;

/*%
 * A configuration object list element.
 */
typedef struct cfg_listelt cfg_listelt_t;

/*%
 * A callback function to be called when parsing an option
 * that needs to be interpreted at parsing time, like
 * "directory".
 */
typedef isc_result_t
(*cfg_parsecallback_t)(const char *clausename, const cfg_obj_t *obj, void *arg);

/***
 *** Functions
 ***/

ISC_LANG_BEGINDECLS

void
cfg_parser_attach(cfg_parser_t *src, cfg_parser_t **dest);
/*%<
 * Reference a parser object.
 */

isc_result_t
cfg_parser_create(isc_mem_t *mctx, isc_log_t *lctx, cfg_parser_t **ret);
/*%<
 * Create a configuration file parser.  Any warning and error
 * messages will be logged to 'lctx'.
 *
 * The parser object returned can be used for a single call
 * to cfg_parse_file() or cfg_parse_buffer().  It must not
 * be reused for parsing multiple files or buffers.
 */

void
cfg_parser_setcallback(cfg_parser_t *pctx,
		       cfg_parsecallback_t callback,
		       void *arg);
/*%<
 * Make the parser call 'callback' whenever it encounters
 * a configuration clause with the callback attribute,
 * passing it the clause name, the clause value,
 * and 'arg' as arguments.
 *
 * To restore the default of not invoking callbacks, pass
 * callback==NULL and arg==NULL.
 */

isc_result_t
cfg_parse_file(cfg_parser_t *pctx, const char *file,
	       const cfg_type_t *type, cfg_obj_t **ret);

isc_result_t
cfg_parse_buffer(cfg_parser_t *pctx, isc_buffer_t *buffer,
		 const cfg_type_t *type, cfg_obj_t **ret);
isc_result_t
cfg_parse_buffer2(cfg_parser_t *pctx, isc_buffer_t *buffer,
		  const char *file, const cfg_type_t *type,
		  cfg_obj_t **ret);
isc_result_t
cfg_parse_buffer3(cfg_parser_t *pctx, isc_buffer_t *buffer,
		  const char *file, unsigned int line,
		  const cfg_type_t *type, cfg_obj_t **ret);
isc_result_t
cfg_parse_buffer4(cfg_parser_t *pctx, isc_buffer_t *buffer,
		  const char *file, unsigned int line,
		  const cfg_type_t *type, unsigned int flags,
		  cfg_obj_t **ret);
/*%<
 * Read a configuration containing data of type 'type'
 * and make '*ret' point to its parse tree.
 *
 * The configuration is read from the file 'filename'
 * (isc_parse_file()) or the buffer 'buffer'
 * (isc_parse_buffer()).
 *
 * If 'file' is not NULL, it is the name of the file, or a name to use
 * for the buffer in place of the filename, when logging errors.
 *
 * If 'line' is not 0, then it is the beginning line number to report
 * when logging errors. This is useful when passing text that has been
 * read from the middle of a file.
 *
 * Returns an error if the file or buffer does not parse correctly.
 *
 * Requires:
 *\li 	"filename" is valid.
 *\li 	"mem" is valid.
 *\li	"type" is valid.
 *\li 	"cfg" is non-NULL and "*cfg" is NULL.
 *\li   "flags" be one or more of CFG_PCTX_NODEPRECATED or zero.
 *
 * Returns:
 *     \li #ISC_R_SUCCESS                 - success
 *\li      #ISC_R_NOMEMORY                - no memory available
 *\li      #ISC_R_INVALIDFILE             - file doesn't exist or is unreadable
 *\li      others	                      - file contains errors
 */

isc_result_t
cfg_parser_mapadd(cfg_parser_t *pctx, cfg_obj_t *mapobj,
		  cfg_obj_t *obj, const char *clause);
/*%<
 * Add the object 'obj' to the specified clause in mapbody 'mapobj'.
 * Used for adding new zones.
 *
 * Require:
 * \li     'obj' is a valid cfg_obj_t.
 * \li     'mapobj' is a valid cfg_obj_t of type map.
 * \li     'pctx' is a valid cfg_parser_t.
 */

void
cfg_parser_reset(cfg_parser_t *pctx);
/*%<
 * Reset an existing parser so it can be re-used for a new file or
 * buffer.
 */

void
cfg_parser_destroy(cfg_parser_t **pctxp);
/*%<
 * Remove a reference to a configuration parser; destroy it if there are no
 * more references.
 */

bool
cfg_obj_isvoid(const cfg_obj_t *obj);
/*%<
 * Return true iff 'obj' is of void type (e.g., an optional
 * value not specified).
 */

bool
cfg_obj_ismap(const cfg_obj_t *obj);
/*%<
 * Return true iff 'obj' is of a map type.
 */

bool
cfg_obj_isfixedpoint(const cfg_obj_t *obj);
/*%<
 * Return true iff 'obj' is of a fixedpoint type.
 */

bool
cfg_obj_ispercentage(const cfg_obj_t *obj);
/*%<
 * Return true iff 'obj' is of a percentage type.
 */

isc_result_t
cfg_map_get(const cfg_obj_t *mapobj, const char* name, const cfg_obj_t **obj);
/*%<
 * Extract an element from a configuration object, which
 * must be of a map type.
 *
 * Requires:
 * \li     'mapobj' points to a valid configuration object of a map type.
 * \li     'name' points to a null-terminated string.
 * \li	'obj' is non-NULL and '*obj' is NULL.
 *
 * Returns:
 * \li     #ISC_R_SUCCESS                  - success
 * \li     #ISC_R_NOTFOUND                 - name not found in map
 */

const cfg_obj_t *
cfg_map_getname(const cfg_obj_t *mapobj);
/*%<
 * Get the name of a named map object, like a server "key" clause.
 *
 * Requires:
 *    \li  'mapobj' points to a valid configuration object of a map type.
 *
 * Returns:
 * \li     A pointer to a configuration object naming the map object,
 *	or NULL if the map object does not have a name.
 */

unsigned int
cfg_map_count(const cfg_obj_t *mapobj);
/*%<
 * Get the number of elements defined in the symbol table of a map object.
 *
 * Requires:
 *    \li  'mapobj' points to a valid configuration object of a map type.
 *
 * Returns:
 * \li     The number of elements in the map object.
 */

bool
cfg_obj_istuple(const cfg_obj_t *obj);
/*%<
 * Return true iff 'obj' is of a map type.
 */

const cfg_obj_t *
cfg_tuple_get(const cfg_obj_t *tupleobj, const char *name);
/*%<
 * Extract an element from a configuration object, which
 * must be of a tuple type.
 *
 * Requires:
 * \li     'tupleobj' points to a valid configuration object of a tuple type.
 * \li     'name' points to a null-terminated string naming one of the
 *\li	fields of said tuple type.
 */

bool
cfg_obj_isuint32(const cfg_obj_t *obj);
/*%<
 * Return true iff 'obj' is of integer type.
 */

uint32_t
cfg_obj_asuint32(const cfg_obj_t *obj);
/*%<
 * Returns the value of a configuration object of 32-bit integer type.
 *
 * Requires:
 * \li     'obj' points to a valid configuration object of 32-bit integer type.
 *
 * Returns:
 * \li     A 32-bit unsigned integer.
 */

bool
cfg_obj_isuint64(const cfg_obj_t *obj);
/*%<
 * Return true iff 'obj' is of integer type.
 */

uint64_t
cfg_obj_asuint64(const cfg_obj_t *obj);
/*%<
 * Returns the value of a configuration object of 64-bit integer type.
 *
 * Requires:
 * \li     'obj' points to a valid configuration object of 64-bit integer type.
 *
 * Returns:
 * \li     A 64-bit unsigned integer.
 */

uint32_t
cfg_obj_asfixedpoint(const cfg_obj_t *obj);
/*%<
 * Returns the value of a configuration object of fixed point number.
 *
 * Requires:
 * \li     'obj' points to a valid configuration object of fixed point type.
 *
 * Returns:
 * \li     A 32-bit unsigned integer.
 */

uint32_t
cfg_obj_aspercentage(const cfg_obj_t *obj);
/*%<
 * Returns the value of a configuration object of percentage
 *
 * Requires:
 * \li     'obj' points to a valid configuration object of percentage type.
 *
 * Returns:
 * \li     A 32-bit unsigned integer.
 */

bool
cfg_obj_isstring(const cfg_obj_t *obj);
/*%<
 * Return true iff 'obj' is of string type.
 */

const char *
cfg_obj_asstring(const cfg_obj_t *obj);
/*%<
 * Returns the value of a configuration object of a string type
 * as a null-terminated string.
 *
 * Requires:
 * \li     'obj' points to a valid configuration object of a string type.
 *
 * Returns:
 * \li     A pointer to a null terminated string.
 */

bool
cfg_obj_isboolean(const cfg_obj_t *obj);
/*%<
 * Return true iff 'obj' is of a boolean type.
 */

bool
cfg_obj_asboolean(const cfg_obj_t *obj);
/*%<
 * Returns the value of a configuration object of a boolean type.
 *
 * Requires:
 * \li     'obj' points to a valid configuration object of a boolean type.
 *
 * Returns:
 * \li     A boolean value.
 */

bool
cfg_obj_issockaddr(const cfg_obj_t *obj);
/*%<
 * Return true iff 'obj' is a socket address.
 */

const isc_sockaddr_t *
cfg_obj_assockaddr(const cfg_obj_t *obj);
/*%<
 * Returns the value of a configuration object representing a socket address.
 *
 * Requires:
 * \li     'obj' points to a valid configuration object of a socket address type.
 *
 * Returns:
 * \li     A pointer to a sockaddr.  The sockaddr must be copied by the caller
 *      if necessary.
 */

isc_dscp_t
cfg_obj_getdscp(const cfg_obj_t *obj);
/*%<
 * Returns the DSCP value of a configuration object representing a
 * socket address.
 *
 * Requires:
 * \li     'obj' points to a valid configuration object of a
 *         socket address type.
 *
 * Returns:
 * \li     DSCP value associated with a sockaddr, or -1.
 */

bool
cfg_obj_isnetprefix(const cfg_obj_t *obj);
/*%<
 * Return true iff 'obj' is a network prefix.
 */

void
cfg_obj_asnetprefix(const cfg_obj_t *obj, isc_netaddr_t *netaddr,
		    unsigned int *prefixlen);
/*%<
 * Gets the value of a configuration object representing a network
 * prefix.  The network address is returned through 'netaddr' and the
 * prefix length in bits through 'prefixlen'.
 *
 * Requires:
 * \li     'obj' points to a valid configuration object of network prefix type.
 *\li	'netaddr' and 'prefixlen' are non-NULL.
 */

bool
cfg_obj_islist(const cfg_obj_t *obj);
/*%<
 * Return true iff 'obj' is of list type.
 */

const cfg_listelt_t *
cfg_list_first(const cfg_obj_t *obj);
/*%<
 * Returns the first list element in a configuration object of a list type.
 *
 * Requires:
 * \li     'obj' points to a valid configuration object of a list type or NULL.
 *
 * Returns:
 *   \li   A pointer to a cfg_listelt_t representing the first list element,
 * 	or NULL if the list is empty or nonexistent.
 */

const cfg_listelt_t *
cfg_list_next(const cfg_listelt_t *elt);
/*%<
 * Returns the next element of a list of configuration objects.
 *
 * Requires:
 * \li     'elt' points to cfg_listelt_t obtained from cfg_list_first() or
 *	a previous call to cfg_list_next().
 *
 * Returns:
 * \li     A pointer to a cfg_listelt_t representing the next element,
 * 	or NULL if there are no more elements.
 */

unsigned int
cfg_list_length(const cfg_obj_t *obj, bool recurse);
/*%<
 * Returns the length of a list of configure objects.  If obj is
 * not a list, returns 0.  If recurse is true, add in the length of
 * all contained lists.
 */

cfg_obj_t *
cfg_listelt_value(const cfg_listelt_t *elt);
/*%<
 * Returns the configuration object associated with cfg_listelt_t.
 *
 * Requires:
 * \li     'elt' points to cfg_listelt_t obtained from cfg_list_first() or
 *	cfg_list_next().
 *
 * Returns:
 * \li     A non-NULL pointer to a configuration object.
 */

void
cfg_print(const cfg_obj_t *obj,
	  void (*f)(void *closure, const char *text, int textlen),
	  void *closure);
void
cfg_printx(const cfg_obj_t *obj, unsigned int flags,
	   void (*f)(void *closure, const char *text, int textlen),
	   void *closure);

#define CFG_PRINTER_XKEY        0x1     /* '?' out shared keys. */
#define CFG_PRINTER_ONELINE     0x2     /* print config as a single line */

/*%<
 * Print the configuration object 'obj' by repeatedly calling the
 * function 'f', passing 'closure' and a region of text starting
 * at 'text' and comprising 'textlen' characters.
 *
 * If CFG_PRINTER_XKEY the contents of shared keys will be obscured
 * by replacing them with question marks ('?')
 */

void
cfg_print_grammar(const cfg_type_t *type,
	  void (*f)(void *closure, const char *text, int textlen),
	  void *closure);
/*%<
 * Print a summary of the grammar of the configuration type 'type'.
 */

bool
cfg_obj_istype(const cfg_obj_t *obj, const cfg_type_t *type);
/*%<
 * Return true iff 'obj' is of type 'type'.
 */

void
cfg_obj_attach(cfg_obj_t *src, cfg_obj_t **dest);
/*%<
 * Reference a configuration object.
 */

void
cfg_obj_destroy(cfg_parser_t *pctx, cfg_obj_t **obj);
/*%<
 * Delete a reference to a configuration object; destroy the object if
 * there are no more references.
 *
 * Require:
 * \li     '*obj' is a valid cfg_obj_t.
 * \li     'pctx' is a valid cfg_parser_t.
 */

void
cfg_obj_log(const cfg_obj_t *obj, isc_log_t *lctx, int level,
	    const char *fmt, ...)
	ISC_FORMAT_PRINTF(4, 5);
/*%<
 * Log a message concerning configuration object 'obj' to the logging
 * channel of 'pctx', at log level 'level'.  The message will be prefixed
 * with the file name(s) and line number where 'obj' was defined.
 */

const char *
cfg_obj_file(const cfg_obj_t *obj);
/*%<
 * Return the file that defined this object.
 */

unsigned int
cfg_obj_line(const cfg_obj_t *obj);
/*%<
 * Return the line in file where this object was defined.
 */

const char *
cfg_map_firstclause(const cfg_type_t *map, const void **clauses,
		    unsigned int *idx);
const char *
cfg_map_nextclause(const cfg_type_t *map, const void **clauses,
		   unsigned int *idx);

ISC_LANG_ENDDECLS

#endif /* ISCCFG_CFG_H */