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
36 #define UCI_CONFDIR "/etc/config"
53 struct uci_list *next;
54 struct uci_list *prev;
62 struct uci_parse_context;
66 * uci_alloc_context: Allocate a new uci context
68 extern struct uci_context *uci_alloc_context(void);
71 * uci_free_context: Free the uci context including all of its data
73 extern void uci_free_context(struct uci_context *ctx);
76 * uci_perror: Print the last uci error that occured
78 * @str: string to print before the error message
80 extern void uci_perror(struct uci_context *ctx, const char *str);
83 * uci_import: Import uci config data from a stream
85 * @stream: file stream to import from
86 * @name: (optional) assume the config has the given name
87 * @package: (optional) store the last parsed config package in this variable
89 * the name parameter is for config files that don't explicitly use the 'package <...>' keyword
91 extern int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_package **package);
94 * uci_export: Export one or all uci config packages
96 * @stream: output stream
97 * @package: (optional) uci config package to export
98 * @header: include the package header
100 extern int uci_export(struct uci_context *ctx, FILE *stream, struct uci_package *package, bool header);
103 * uci_load: Parse an uci config file and store it in the uci context
106 * @name: name of the config file (relative to the config directory)
107 * @package: store the loaded config package in this variable
109 extern int uci_load(struct uci_context *ctx, const char *name, struct uci_package **package);
112 * uci_unload: Unload a config file from the uci context
115 * @package: pointer to the uci_package struct
117 extern int uci_unload(struct uci_context *ctx, struct uci_package *p);
120 * uci_cleanup: Clean up after an error
124 extern int uci_cleanup(struct uci_context *ctx);
127 * uci_lookup: Look up an uci element
130 * @res: where to store the result
131 * @package: uci_package struct
132 * @section: config section (optional)
133 * @option: option to search for (optional)
135 * If section is omitted, then a pointer to the config package is returned
136 * If option is omitted, then a pointer to the config section is returned
138 extern int uci_lookup(struct uci_context *ctx, struct uci_element **res, struct uci_package *package, char *section, char *option);
141 * uci_set_element_value: Replace an element's value with a new one
143 * @element: pointer to an uci_element struct pointer
146 * Only valid for uci_option and uci_section. Will replace the type string
147 * when used with an uci_section
149 extern int uci_set_element_value(struct uci_context *ctx, struct uci_element **element, char *value);
152 * uci_set: Set an element's value; create the element if necessary
154 * @package: package name
155 * @section: section name
156 * @option: option name
157 * @value: value (option) or type (section)
159 extern int uci_set(struct uci_context *ctx, char *package, char *section, char *option, char *value);
162 * uci_commit: commit changes to a package
164 * @p: uci_package struct
166 extern int uci_commit(struct uci_context *ctx, struct uci_package *p);
169 * uci_list_configs: List available uci config files
173 extern char **uci_list_configs(struct uci_context *ctx);
175 /* UCI data structures */
177 UCI_TYPE_PACKAGE = 0,
178 UCI_TYPE_SECTION = 1,
184 struct uci_list list;
191 /* list of config packages */
192 struct uci_list root;
194 /* parser context, use for error handling only */
195 struct uci_parse_context *pctx;
205 struct uci_parse_context
213 struct uci_package *package;
214 struct uci_section *section;
223 struct uci_element e;
224 struct uci_list sections;
225 struct uci_context *ctx;
231 struct uci_list history;
236 struct uci_element e;
237 struct uci_list options;
238 struct uci_package *package;
244 struct uci_element e;
245 struct uci_section *section;
257 struct uci_list list;
258 enum uci_command cmd;
264 /* linked list handling */
266 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
270 * container_of - cast a member of a structure out to the containing structure
271 * @ptr: the pointer to the member.
272 * @type: the type of the container struct this is embedded in.
273 * @member: the name of the member within the struct.
275 #define container_of(ptr, type, member) \
276 ((type *) ((char *)ptr - offsetof(type,member)))
280 * uci_list_entry: casts an uci_list pointer to the containing struct.
281 * @_type: config, section or option
282 * @_ptr: pointer to the uci_list struct
284 #define element_to(type, ptr) \
285 container_of(ptr, struct uci_ ## type, e)
287 #define list_to_element(ptr) \
288 container_of(ptr, struct uci_element, list)
291 * uci_foreach_entry: loop through a list of uci elements
292 * @_list: pointer to the uci_list struct
293 * @_ptr: iteration variable, struct uci_element
295 * use like a for loop, e.g:
296 * uci_foreach(&list, p) {
300 #define uci_foreach_element(_list, _ptr) \
301 for(_ptr = list_to_element((_list)->next); \
302 &_ptr->list != (_list); \
303 _ptr = list_to_element(_ptr->list.next))
306 * uci_foreach_entry_safe: like uci_foreach_safe, but safe for deletion
307 * @_list: pointer to the uci_list struct
308 * @_tmp: temporary variable, struct uci_element *
309 * @_ptr: iteration variable, struct uci_element *
311 * use like a for loop, e.g:
312 * uci_foreach(&list, p) {
316 #define uci_foreach_element_safe(_list, _tmp, _ptr) \
317 for(_ptr = list_to_element((_list)->next), \
318 _tmp = list_to_element(_ptr->list.next); \
319 &_ptr->list != (_list); \
320 _ptr = _tmp, _tmp = list_to_element(_ptr->list.next))
323 * uci_list_empty: returns true if a list is empty
326 #define uci_list_empty(list) ((list)->next == (list))
328 /* wrappers for dynamic type handling */
329 #define uci_type_package UCI_TYPE_PACKAGE
330 #define uci_type_section UCI_TYPE_SECTION
331 #define uci_type_option UCI_TYPE_OPTION
333 /* element typecasting */
334 #ifdef UCI_DEBUG_TYPECAST
335 static const char *uci_typestr[] = {
336 [uci_type_package] = "package",
337 [uci_type_section] = "section",
338 [uci_type_option] = "option"
341 static void uci_typecast_error(int from, int to)
343 fprintf(stderr, "Invalid typecast from '%s' to '%s'\n", uci_typestr[from], uci_typestr[to]);
346 #define BUILD_CAST(_type) \
347 static inline struct uci_ ## _type *uci_to_ ## _type (struct uci_element *e) \
349 if (e->type != uci_type_ ## _type) { \
350 uci_typecast_error(e->type, uci_type_ ## _type); \
352 return (struct uci_ ## _type *) e; \
360 #define uci_to_package(ptr) container_of(ptr, struct uci_package, e)
361 #define uci_to_section(ptr) container_of(ptr, struct uci_section, e)
362 #define uci_to_option(ptr) container_of(ptr, struct uci_option, e)
366 * uci_alloc_element: allocate a generic uci_element, reserve a buffer and typecast
368 * @type: {package,section,option}
369 * @name: string containing the name of the element
370 * @datasize: additional buffer size to reserve at the end of the struct
372 #define uci_alloc_element(ctx, type, name, datasize) \
373 uci_to_ ## type (uci_alloc_generic(ctx, uci_type_ ## type, name, sizeof(struct uci_ ## type) + datasize))
375 #define uci_dataptr(ptr) \
376 (((char *) ptr) + sizeof(*ptr))