src/shared/conf-parser.h

/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

#pragma once

/***
  This file is part of systemd.

  Copyright 2010 Lennart Poettering

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  systemd 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
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

#include <stdio.h>
#include <stdbool.h>

/* An abstract parser for simple, line based, shallow configuration
 * files consisting of variable assignments only. */

/* Prototype for a parser for a specific configuration setting */
typedef int (*ConfigParserCallback)(
                const char *filename,
                unsigned line,
                const char *section,
                const char *lvalue,
                int ltype,
                const char *rvalue,
                void *data,
                void *userdata);

/* Wraps information for parsing a specific configuration variable, to
 * be stored in a simple array */
typedef struct ConfigTableItem {
        const char *section;            /* Section */
        const char *lvalue;             /* Name of the variable */
        ConfigParserCallback parse;     /* Function that is called to parse the variable's value */
        int ltype;                      /* Distinguish different variables passed to the same callback */
        void *data;                     /* Where to store the variable's data */
} ConfigTableItem;

/* Wraps information for parsing a specific configuration variable, to
 * ve srored in a gperf perfect hashtable */
typedef struct ConfigPerfItem {
        const char *section_and_lvalue; /* Section + "." + name of the variable */
        ConfigParserCallback parse;     /* Function that is called to parse the variable's value */
        int ltype;                      /* Distinguish different variables passed to the same callback */
        size_t offset;                  /* Offset where to store data, from the beginning of userdata */
} ConfigPerfItem;

/* Prototype for a low-level gperf lookup function */
typedef const ConfigPerfItem* (*ConfigPerfItemLookup)(const char *section_and_lvalue, unsigned length);

/* Prototype for a generic high-level lookup function */
typedef int (*ConfigItemLookup)(
                void *table,
                const char *section,
                const char *lvalue,
                ConfigParserCallback *func,
                int *ltype,
                void **data,
                void *userdata);

/* Linear table search implementation of ConfigItemLookup, based on
 * ConfigTableItem arrays */
int config_item_table_lookup(void *table, const char *section, const char *lvalue, ConfigParserCallback *func, int *ltype, void **data, void *userdata);

/* gperf implementation of ConfigItemLookup, based on gperf
 * ConfigPerfItem tables */
int config_item_perf_lookup(void *table, const char *section, const char *lvalue, ConfigParserCallback *func, int *ltype, void **data, void *userdata);

int config_parse(
                const char *filename,
                FILE *f,
                const char *sections,  /* nulstr */
                ConfigItemLookup lookup,
                void *table,
                bool relaxed,
                void *userdata);

/* Generic parsers */
int config_parse_int(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_unsigned(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_long(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_uint64(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_double(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_bytes_size(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_bytes_off(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_bool(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_tristate(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_string(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_path(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_strv(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_path_strv(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_usec(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_nsec(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_mode(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_facility(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_level(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_set_status(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);

#define DEFINE_CONFIG_PARSE_ENUM(function,name,type,msg)                \
        int function(                                                   \
                        const char *filename,                           \
                        unsigned line,                                  \
                        const char *section,                            \
                        const char *lvalue,                             \
                        int ltype,                                      \
                        const char *rvalue,                             \
                        void *data,                                     \
                        void *userdata) {                               \
                                                                        \
                type *i = data, x;                                      \
                                                                        \
                assert(filename);                                       \
                assert(lvalue);                                         \
                assert(rvalue);                                         \
                assert(data);                                           \
                                                                        \
                if ((x = name##_from_string(rvalue)) < 0) {             \
                        log_error("[%s:%u] " msg ", ignoring: %s", filename, line, rvalue); \
                        return 0;                                       \
                }                                                       \
                                                                        \
                *i = x;                                                 \
                                                                        \
                return 0;                                               \
        }