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"
37 #define UCI_SAVEDIR "/tmp/.uci"
55 struct uci_list *next;
56 struct uci_list *prev;
65 struct uci_parse_context;
69 * uci_parse_tuple: Parse an uci tuple
72 * @package: output package pointer
73 * @section: output section pointer
74 * @option: output option pointer
75 * @value: output value pointer
77 * format: <package>[.<section>[.<option>]][=<value>]
79 extern int uci_parse_tuple(struct uci_context *ctx, char *str, char **package, char **section, char **option, char **value);
82 * uci_alloc_context: Allocate a new uci context
84 extern struct uci_context *uci_alloc_context(void);
87 * uci_free_context: Free the uci context including all of its data
89 extern void uci_free_context(struct uci_context *ctx);
92 * uci_perror: Print the last uci error that occured
94 * @str: string to print before the error message
96 extern void uci_perror(struct uci_context *ctx, const char *str);
99 * uci_import: Import uci config data from a stream
101 * @stream: file stream to import from
102 * @name: (optional) assume the config has the given name
103 * @package: (optional) store the last parsed config package in this variable
104 * @single: ignore the 'package' keyword and parse everything into a single package
106 * the name parameter is for config files that don't explicitly use the 'package <...>' keyword
108 extern int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_package **package, bool single);
111 * uci_export: Export one or all uci config packages
113 * @stream: output stream
114 * @package: (optional) uci config package to export
115 * @header: include the package header
117 extern int uci_export(struct uci_context *ctx, FILE *stream, struct uci_package *package, bool header);
120 * uci_load: Parse an uci config file and store it in the uci context
123 * @name: name of the config file (relative to the config directory)
124 * @package: store the loaded config package in this variable
126 extern int uci_load(struct uci_context *ctx, const char *name, struct uci_package **package);
129 * uci_unload: Unload a config file from the uci context
132 * @package: pointer to the uci_package struct
134 extern int uci_unload(struct uci_context *ctx, struct uci_package *p);
137 * uci_cleanup: Clean up after an error
141 extern int uci_cleanup(struct uci_context *ctx);
144 * uci_lookup: Look up an uci element
147 * @res: where to store the result
148 * @package: uci_package struct
149 * @section: config section (optional)
150 * @option: option to search for (optional)
152 * If section is omitted, then a pointer to the config package is returned
153 * If option is omitted, then a pointer to the config section is returned
155 extern int uci_lookup(struct uci_context *ctx, struct uci_element **res, struct uci_package *package, char *section, char *option);
158 * uci_set_element_value: Replace an element's value with a new one
160 * @element: pointer to an uci_element struct pointer
163 * Only valid for uci_option and uci_section. Will replace the type string
164 * when used with an uci_section
166 extern int uci_set_element_value(struct uci_context *ctx, struct uci_element **element, char *value);
169 * uci_set: Set an element's value; create the element if necessary
171 * @package: package name
172 * @section: section name
173 * @option: option name
174 * @value: value (option) or type (section)
176 extern int uci_set(struct uci_context *ctx, char *package, char *section, char *option, char *value);
179 * uci_save: save change history for a package
181 * @p: uci_package struct
183 extern int uci_save(struct uci_context *ctx, struct uci_package *p);
186 * uci_commit: commit changes to a package
188 * @p: uci_package struct
190 extern int uci_commit(struct uci_context *ctx, struct uci_package *p);
193 * uci_list_configs: List available uci config files
197 extern char **uci_list_configs(struct uci_context *ctx);
199 /* UCI data structures */
201 UCI_TYPE_HISTORY = 0,
202 UCI_TYPE_PACKAGE = 1,
203 UCI_TYPE_SECTION = 2,
209 struct uci_list list;
216 /* list of config packages */
217 struct uci_list root;
219 /* parser context, use for error handling only */
220 struct uci_parse_context *pctx;
231 struct uci_parse_context
239 struct uci_package *package;
240 struct uci_section *section;
249 struct uci_element e;
250 struct uci_list sections;
251 struct uci_context *ctx;
257 struct uci_list history;
262 struct uci_element e;
263 struct uci_list options;
264 struct uci_package *package;
270 struct uci_element e;
271 struct uci_section *section;
283 struct uci_element e;
284 enum uci_command cmd;
289 /* linked list handling */
291 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
295 * container_of - cast a member of a structure out to the containing structure
296 * @ptr: the pointer to the member.
297 * @type: the type of the container struct this is embedded in.
298 * @member: the name of the member within the struct.
300 #define container_of(ptr, type, member) \
301 ((type *) ((char *)ptr - offsetof(type,member)))
305 * uci_list_entry: casts an uci_list pointer to the containing struct.
306 * @_type: config, section or option
307 * @_ptr: pointer to the uci_list struct
309 #define element_to(type, ptr) \
310 container_of(ptr, struct uci_ ## type, e)
312 #define list_to_element(ptr) \
313 container_of(ptr, struct uci_element, list)
316 * uci_foreach_entry: loop through a list of uci elements
317 * @_list: pointer to the uci_list struct
318 * @_ptr: iteration variable, struct uci_element
320 * use like a for loop, e.g:
321 * uci_foreach(&list, p) {
325 #define uci_foreach_element(_list, _ptr) \
326 for(_ptr = list_to_element((_list)->next); \
327 &_ptr->list != (_list); \
328 _ptr = list_to_element(_ptr->list.next))
331 * uci_foreach_entry_safe: like uci_foreach_safe, but safe for deletion
332 * @_list: pointer to the uci_list struct
333 * @_tmp: temporary variable, struct uci_element *
334 * @_ptr: iteration variable, struct uci_element *
336 * use like a for loop, e.g:
337 * uci_foreach(&list, p) {
341 #define uci_foreach_element_safe(_list, _tmp, _ptr) \
342 for(_ptr = list_to_element((_list)->next), \
343 _tmp = list_to_element(_ptr->list.next); \
344 &_ptr->list != (_list); \
345 _ptr = _tmp, _tmp = list_to_element(_ptr->list.next))
348 * uci_list_empty: returns true if a list is empty
351 #define uci_list_empty(list) ((list)->next == (list))
353 /* wrappers for dynamic type handling */
354 #define uci_type_history UCI_TYPE_HISTORY
355 #define uci_type_package UCI_TYPE_PACKAGE
356 #define uci_type_section UCI_TYPE_SECTION
357 #define uci_type_option UCI_TYPE_OPTION
359 /* element typecasting */
360 #ifdef UCI_DEBUG_TYPECAST
361 static const char *uci_typestr[] = {
362 [uci_type_history] = "history",
363 [uci_type_package] = "package",
364 [uci_type_section] = "section",
365 [uci_type_option] = "option",
368 static void uci_typecast_error(int from, int to)
370 fprintf(stderr, "Invalid typecast from '%s' to '%s'\n", uci_typestr[from], uci_typestr[to]);
373 #define BUILD_CAST(_type) \
374 static inline struct uci_ ## _type *uci_to_ ## _type (struct uci_element *e) \
376 if (e->type != uci_type_ ## _type) { \
377 uci_typecast_error(e->type, uci_type_ ## _type); \
379 return (struct uci_ ## _type *) e; \
388 #define uci_to_history(ptr) container_of(ptr, struct uci_history, e)
389 #define uci_to_package(ptr) container_of(ptr, struct uci_package, e)
390 #define uci_to_section(ptr) container_of(ptr, struct uci_section, e)
391 #define uci_to_option(ptr) container_of(ptr, struct uci_option, e)
395 * uci_alloc_element: allocate a generic uci_element, reserve a buffer and typecast
397 * @type: {package,section,option}
398 * @name: string containing the name of the element
399 * @datasize: additional buffer size to reserve at the end of the struct
401 #define uci_alloc_element(ctx, type, name, datasize) \
402 uci_to_ ## type (uci_alloc_generic(ctx, uci_type_ ## type, name, sizeof(struct uci_ ## type) + datasize))
404 #define uci_dataptr(ptr) \
405 (((char *) ptr) + sizeof(*ptr))