uci.h

   1 /*
   2  * libuci - Library for the Unified Configuration Interface
   3  * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
   4  *
   5  * this program is free software; you can redistribute it and/or modify
   6  * it under the terms of the gnu lesser general public license version 2.1
   7  * as published by the free software foundation
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #ifndef __LIBUCI_H
  16 #define __LIBUCI_H
  17
  18 #include <setjmp.h>
  19 #include <stdio.h>
  20
  21 #define UCI_CONFDIR "/etc/config"
  22
  23 enum
  24 {
  25         UCI_OK = 0,
  26         UCI_ERR_MEM,
  27         UCI_ERR_INVAL,
  28         UCI_ERR_NOTFOUND,
  29         UCI_ERR_IO,
  30         UCI_ERR_PARSE,
  31         UCI_ERR_UNKNOWN,
  32         UCI_ERR_LAST
  33 };
  34
  35 struct uci_list
  36 {
  37         void *next;
  38         void *prev;
  39 };
  40
  41 struct uci_config;
  42 struct uci_section;
  43 struct uci_option;
  44 struct uci_parse_context;
  45
  46
  47 /**
  48  * uci_alloc: Allocate a new uci context
  49  */
  50 extern struct uci_context *uci_alloc(void);
  51
  52 /**
  53  * uci_free: Free the uci context including all of its data
  54  */
  55 extern void uci_free(struct uci_context *ctx);
  56
  57 /**
  58  * uci_perror: Print the last uci error that occured
  59  * @ctx: uci context
  60  * @str: string to print before the error message
  61  */
  62 extern void uci_perror(struct uci_context *ctx, const char *str);
  63
  64 /**
  65  * uci_import: Import uci config data from a stream
  66  * @ctx: uci context
  67  * @stream: file stream to import from
  68  * @name: (optional) assume the config has the given name
  69  * @cfg: (optional) store the last parsed config package in this variable
  70  *
  71  * the name parameter is for config files that don't explicitly use the 'package <...>' keyword
  72  */
  73 extern int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_config **cfg);
  74
  75 /**
  76  * uci_export: Export one or all uci config packages
  77  * @ctx: uci context
  78  * @stream: output stream
  79  * @cfg: (optional) uci config package to export
  80  */
  81 extern int uci_export(struct uci_context *ctx, FILE *stream, struct uci_config *cfg);
  82
  83 /**
  84  * uci_load: Parse an uci config file and store it in the uci context
  85  *
  86  * @ctx: uci context
  87  * @name: name of the config file (relative to the config directory)
  88  */
  89 extern int uci_load(struct uci_context *ctx, const char *name, struct uci_config **cfg);
  90
  91 /**
  92  * uci_unload: Unload a config file from the uci context
  93  *
  94  * @ctx: uci context
  95  * @name: name of the config file
  96  */
  97 extern int uci_unload(struct uci_context *ctx, const char *name);
  98
  99 /**
 100  * uci_cleanup: Clean up after an error
 101  *
 102  * @ctx: uci context
 103  */
 104 extern int uci_cleanup(struct uci_context *ctx);
 105
 106 /**
 107  * uci_list_configs: List available uci config files
 108  *
 109  * @ctx: uci context
 110  */
 111 extern char **uci_list_configs();
 112
 113 /* UCI data structures */
 114
 115 struct uci_context
 116 {
 117         /* list of config packages */
 118         struct uci_list root;
 119
 120         /* parser context, use for error handling only */
 121         struct uci_parse_context *pctx;
 122
 123         /* private: */
 124         int errno;
 125         jmp_buf trap;
 126         char *buf;
 127         int bufsz;
 128 };
 129
 130 struct uci_parse_context
 131 {
 132         /* error context */
 133         const char *reason;
 134         int line;
 135         int byte;
 136
 137         /* private: */
 138         struct uci_config *cfg;
 139         struct uci_section *section;
 140         FILE *file;
 141         const char *name;
 142         char *buf;
 143         int bufsz;
 144 };
 145
 146 struct uci_config
 147 {
 148         struct uci_list list;
 149         struct uci_list sections;
 150         struct uci_context *ctx;
 151         char *name;
 152         /* private: */
 153         int n_section;
 154 };
 155
 156 struct uci_section
 157 {
 158         struct uci_list list;
 159         struct uci_list options;
 160         struct uci_config *config;
 161         char *type;
 162         char *name;
 163 };
 164
 165 struct uci_option
 166 {
 167         struct uci_list list;
 168         struct uci_section *section;
 169         char *name;
 170         char *value;
 171 };
 172
 173 /* linked list handling */
 174 #ifndef offsetof
 175 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
 176 #endif
 177
 178 /* returns true if a list is empty */
 179 #define uci_list_empty(list) ((list)->next == (list))
 180
 181 /**
 182  * uci_list_entry: casts an uci_list pointer to the containing struct.
 183  * @_type: config, section or option
 184  * @_ptr: pointer to the uci_list struct
 185  */
 186 #define uci_list_entry(_type, _ptr) \
 187         ((struct uci_ ## _type *) ((char *)(_ptr) - offsetof(struct uci_ ## _type,list)))
 188
 189 /**
 190  * uci_foreach_entry: loop through a list of configs, sections or options
 191  * @_type: see uci_list_entry
 192  * @_list: pointer to the uci_list struct
 193  * @_ptr: iteration variable
 194  *
 195  * use like a for loop, e.g:
 196  *   uci_foreach(section, &list, p) {
 197  *      ...
 198  *   }
 199  */
 200 #define uci_foreach_entry(_type, _list, _ptr)           \
 201         for(_ptr = uci_list_entry(_type, (_list)->next);        \
 202                 &_ptr->list != (_list);                 \
 203                 _ptr = uci_list_entry(_type, _ptr->list.next))
 204
 205 #endif