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_load: Parse an uci config file and store it in the uci context
  77  *
  78  * @ctx: uci context
  79  * @name: name of the config file (relative to the config directory)
  80  */
  81 extern int uci_load(struct uci_context *ctx, const char *name, struct uci_config **cfg);
  82
  83 /**
  84  * uci_unload: Unload a config file from the uci context
  85  *
  86  * @ctx: uci context
  87  * @name: name of the config file
  88  */
  89 extern int uci_unload(struct uci_context *ctx, const char *name);
  90
  91 /**
  92  * uci_cleanup: Clean up after an error
  93  *
  94  * @ctx: uci context
  95  */
  96 extern int uci_cleanup(struct uci_context *ctx);
  97
  98 /**
  99  * uci_list_configs: List available uci config files
 100  *
 101  * @ctx: uci context
 102  */
 103 extern char **uci_list_configs();
 104
 105 /* UCI data structures */
 106
 107 struct uci_context
 108 {
 109         /* list of config packages */
 110         struct uci_list root;
 111
 112         /* parser context, use for error handling only */
 113         struct uci_parse_context *pctx;
 114
 115         /* private: */
 116         int errno;
 117         jmp_buf trap;
 118 };
 119
 120 struct uci_parse_context
 121 {
 122         /* error context */
 123         const char *reason;
 124         int line;
 125         int byte;
 126
 127         /* private: */
 128         struct uci_config *cfg;
 129         struct uci_section *section;
 130         FILE *file;
 131         const char *name;
 132         char *buf;
 133         int bufsz;
 134 };
 135
 136 struct uci_config
 137 {
 138         struct uci_list list;
 139         struct uci_list sections;
 140         struct uci_context *ctx;
 141         char *name;
 142         /* private: */
 143         int n_section;
 144 };
 145
 146 struct uci_section
 147 {
 148         struct uci_list list;
 149         struct uci_list options;
 150         struct uci_config *config;
 151         char *type;
 152         char *name;
 153 };
 154
 155 struct uci_option
 156 {
 157         struct uci_list list;
 158         struct uci_section *section;
 159         char *name;
 160         char *value;
 161 };
 162
 163 /* linked list handling */
 164 #ifndef offsetof
 165 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
 166 #endif
 167
 168 /* returns true if a list is empty */
 169 #define uci_list_empty(list) ((list)->next == (list))
 170
 171 /**
 172  * uci_list_entry: casts an uci_list pointer to the containing struct.
 173  * @_type: config, section or option
 174  * @_ptr: pointer to the uci_list struct
 175  */
 176 #define uci_list_entry(_type, _ptr) \
 177         ((struct uci_ ## _type *) ((char *)(_ptr) - offsetof(struct uci_ ## _type,list)))
 178
 179 /**
 180  * uci_foreach_entry: loop through a list of configs, sections or options
 181  * @_type: see uci_list_entry
 182  * @_list: pointer to the uci_list struct
 183  * @_ptr: iteration variable
 184  *
 185  * use like a for loop, e.g:
 186  *   uci_foreach(section, &list, p) {
 187  *      ...
 188  *   }
 189  */
 190 #define uci_foreach_entry(_type, _list, _ptr)           \
 191         for(_ptr = uci_list_entry(_type, (_list)->next);        \
 192                 &_ptr->list != (_list);                 \
 193                 _ptr = uci_list_entry(_type, _ptr->list.next))
 194
 195 #endif