2 * libuci - Library for the Unified Configuration Interface
3 * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
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
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.
19 * you can use these defines to enable debugging behavior for
20 * apps compiled against libuci:
22 * #define UCI_DEBUG_TYPECAST:
23 * enable uci_element typecast checking at run time
29 #define UCI_DEBUG_TYPECAST
35 #define UCI_CONFDIR "/etc/config"
52 struct uci_list *next;
53 struct uci_list *prev;
61 struct uci_parse_context;
65 * uci_alloc_context: Allocate a new uci context
67 extern struct uci_context *uci_alloc_context(void);
70 * uci_free_context: Free the uci context including all of its data
72 extern void uci_free_context(struct uci_context *ctx);
75 * uci_perror: Print the last uci error that occured
77 * @str: string to print before the error message
79 extern void uci_perror(struct uci_context *ctx, const char *str);
82 * uci_import: Import uci config data from a stream
84 * @stream: file stream to import from
85 * @name: (optional) assume the config has the given name
86 * @package: (optional) store the last parsed config package in this variable
88 * the name parameter is for config files that don't explicitly use the 'package <...>' keyword
90 extern int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_package **package);
93 * uci_export: Export one or all uci config packages
95 * @stream: output stream
96 * @package: (optional) uci config package to export
98 extern int uci_export(struct uci_context *ctx, FILE *stream, struct uci_package *package);
101 * uci_load: Parse an uci config file and store it in the uci context
104 * @name: name of the config file (relative to the config directory)
105 * @package: store the loaded config package in this variable
107 extern int uci_load(struct uci_context *ctx, const char *name, struct uci_package **package);
110 * uci_unload: Unload a config file from the uci context
113 * @name: name of the config file
115 extern int uci_unload(struct uci_context *ctx, const char *name);
118 * uci_cleanup: Clean up after an error
122 extern int uci_cleanup(struct uci_context *ctx);
125 * uci_lookup: Look up an uci element
128 * @res: where to store the result
129 * @package: config package
130 * @section: config section (optional)
131 * @option: option to search for (optional)
133 * If section is omitted, then a pointer to the config package is returned
134 * If option is omitted, then a pointer to the config section is returned
136 extern int uci_lookup(struct uci_context *ctx, struct uci_element **res, char *package, char *section, char *option);
139 * uci_set_element_value: Replace an element's value with a new one
141 * @element: pointer to an uci_element struct pointer
144 * Only valid for uci_option and uci_section. Will replace the type string
145 * when used with an uci_section
147 extern int uci_set_element_value(struct uci_context *ctx, struct uci_element **element, char *value);
150 * uci_set: Set an element's value; create the element if necessary
152 * @package: package name
153 * @section: section name
154 * @option: option name
155 * @value: value (option) or type (section)
157 extern int uci_set(struct uci_context *ctx, char *package, char *section, char *option, char *value);
160 * uci_list_configs: List available uci config files
164 extern char **uci_list_configs(struct uci_context *ctx);
166 /* UCI data structures */
168 UCI_TYPE_PACKAGE = 0,
169 UCI_TYPE_SECTION = 1,
175 struct uci_list list;
182 /* list of config packages */
183 struct uci_list root;
185 /* parser context, use for error handling only */
186 struct uci_parse_context *pctx;
196 struct uci_parse_context
204 struct uci_package *package;
205 struct uci_section *section;
214 struct uci_element e;
215 struct uci_list sections;
216 struct uci_context *ctx;
219 struct uci_list history;
224 struct uci_element e;
225 struct uci_list options;
226 struct uci_package *package;
232 struct uci_element e;
233 struct uci_section *section;
245 struct uci_list list;
246 enum uci_command cmd;
252 /* linked list handling */
254 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
258 * container_of - cast a member of a structure out to the containing structure
259 * @ptr: the pointer to the member.
260 * @type: the type of the container struct this is embedded in.
261 * @member: the name of the member within the struct.
263 #define container_of(ptr, type, member) \
264 ((type *) ((char *)ptr - offsetof(type,member)))
268 * uci_list_entry: casts an uci_list pointer to the containing struct.
269 * @_type: config, section or option
270 * @_ptr: pointer to the uci_list struct
272 #define element_to(type, ptr) \
273 container_of(ptr, struct uci_ ## type, e)
275 #define list_to_element(ptr) \
276 container_of(ptr, struct uci_element, list)
279 * uci_foreach_entry: loop through a list of uci elements
280 * @_list: pointer to the uci_list struct
281 * @_ptr: iteration variable, struct uci_element
283 * use like a for loop, e.g:
284 * uci_foreach(&list, p) {
288 #define uci_foreach_element(_list, _ptr) \
289 for(_ptr = list_to_element((_list)->next); \
290 &_ptr->list != (_list); \
291 _ptr = list_to_element(_ptr->list.next))
294 * uci_foreach_entry_safe: like uci_foreach_safe, but safe for deletion
295 * @_list: pointer to the uci_list struct
296 * @_tmp: temporary variable, struct uci_element *
297 * @_ptr: iteration variable, struct uci_element *
299 * use like a for loop, e.g:
300 * uci_foreach(&list, p) {
304 #define uci_foreach_element_safe(_list, _tmp, _ptr) \
305 for(_ptr = list_to_element((_list)->next), \
306 _tmp = list_to_element(_ptr->list.next); \
307 &_ptr->list != (_list); \
308 _ptr = _tmp, _tmp = list_to_element(_ptr->list.next))
310 /* returns true if a list is empty */
311 #define uci_list_empty(list) ((list)->next == (list))
313 /* wrappers for dynamic type handling */
314 #define uci_type_package UCI_TYPE_PACKAGE
315 #define uci_type_section UCI_TYPE_SECTION
316 #define uci_type_option UCI_TYPE_OPTION
318 /* element typecasting */
319 #ifdef UCI_DEBUG_TYPECAST
320 static const char *uci_typestr[] = {
321 [uci_type_package] = "package",
322 [uci_type_section] = "section",
323 [uci_type_option] = "option"
326 static void uci_typecast_error(int from, int to)
328 fprintf(stderr, "Invalid typecast from '%s' to '%s'\n", uci_typestr[from], uci_typestr[to]);
331 #define BUILD_CAST(_type) \
332 static inline struct uci_ ## _type *uci_to_ ## _type (struct uci_element *e) \
334 if (e->type != uci_type_ ## _type) { \
335 uci_typecast_error(e->type, uci_type_ ## _type); \
337 return (struct uci_ ## _type *) e; \
345 #define uci_to_package(ptr) container_of(ptr, struct uci_package, e)
346 #define uci_to_section(ptr) container_of(ptr, struct uci_section, e)
347 #define uci_to_option(ptr) container_of(ptr, struct uci_option, e)
351 * uci_alloc_element: allocate a generic uci_element, reserve a buffer and typecast
353 * @type: {package,section,option}
354 * @name: string containing the name of the element
355 * @datasize: additional buffer size to reserve at the end of the struct
357 #define uci_alloc_element(ctx, type, name, datasize) \
358 uci_to_ ## type (uci_alloc_generic(ctx, uci_type_ ## type, name, sizeof(struct uci_ ## type) + datasize))
360 #define uci_dataptr(ptr) \
361 (((char *) ptr) + sizeof(*ptr))