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"
38 #define UCI_FILEMODE 0600
56 struct uci_list *next;
57 struct uci_list *prev;
66 struct uci_parse_context;
70 * uci_parse_tuple: Parse an uci tuple
73 * @package: output package pointer
74 * @section: output section pointer
75 * @option: output option pointer
76 * @value: output value pointer
78 * format: <package>[.<section>[.<option>]][=<value>]
80 extern int uci_parse_tuple(struct uci_context *ctx, char *str, char **package, char **section, char **option, char **value);
83 * uci_alloc_context: Allocate a new uci context
85 extern struct uci_context *uci_alloc_context(void);
88 * uci_free_context: Free the uci context including all of its data
90 extern void uci_free_context(struct uci_context *ctx);
93 * uci_perror: Print the last uci error that occured
95 * @str: string to print before the error message
97 extern void uci_perror(struct uci_context *ctx, const char *str);
100 * uci_import: Import uci config data from a stream
102 * @stream: file stream to import from
103 * @name: (optional) assume the config has the given name
104 * @package: (optional) store the last parsed config package in this variable
105 * @single: ignore the 'package' keyword and parse everything into a single package
107 * the name parameter is for config files that don't explicitly use the 'package <...>' keyword
109 extern int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_package **package, bool single);
112 * uci_export: Export one or all uci config packages
114 * @stream: output stream
115 * @package: (optional) uci config package to export
116 * @header: include the package header
118 extern int uci_export(struct uci_context *ctx, FILE *stream, struct uci_package *package, bool header);
121 * uci_load: Parse an uci config file and store it in the uci context
124 * @name: name of the config file (relative to the config directory)
125 * @package: store the loaded config package in this variable
127 extern int uci_load(struct uci_context *ctx, const char *name, struct uci_package **package);
130 * uci_unload: Unload a config file from the uci context
133 * @package: pointer to the uci_package struct
135 extern int uci_unload(struct uci_context *ctx, struct uci_package *p);
138 * uci_cleanup: Clean up after an error
142 extern int uci_cleanup(struct uci_context *ctx);
145 * uci_lookup: Look up an uci element
148 * @res: where to store the result
149 * @package: uci_package struct
150 * @section: config section (optional)
151 * @option: option to search for (optional)
153 * If section is omitted, then a pointer to the config package is returned
154 * If option is omitted, then a pointer to the config section is returned
156 extern int uci_lookup(struct uci_context *ctx, struct uci_element **res, struct uci_package *package, char *section, char *option);
159 * uci_set_element_value: Replace an element's value with a new one
161 * @element: pointer to an uci_element struct pointer
164 * Only valid for uci_option and uci_section. Will replace the type string
165 * when used with an uci_section
167 extern int uci_set_element_value(struct uci_context *ctx, struct uci_element **element, char *value);
170 * uci_set: Set an element's value; create the element if necessary
172 * @package: package name
173 * @section: section name
174 * @option: option name
175 * @value: value (option) or type (section)
177 extern int uci_set(struct uci_context *ctx, struct uci_package *p, char *section, char *option, char *value);
180 * uci_del_element: Delete a section or option
182 * @e: element (section or option)
184 extern int uci_del_element(struct uci_context *ctx, struct uci_element *e);
187 * uci_del: Delete a section or option
190 * @section: section name
191 * @option: option name (optional)
193 extern int uci_del(struct uci_context *ctx, struct uci_package *p, char *section, char *option);
196 * uci_save: save change history for a package
198 * @p: uci_package struct
200 extern int uci_save(struct uci_context *ctx, struct uci_package *p);
203 * uci_commit: commit changes to a package
205 * @p: uci_package struct pointer
207 * committing may reload the whole uci_package data,
208 * the supplied pointer is updated accordingly
210 extern int uci_commit(struct uci_context *ctx, struct uci_package **p);
213 * uci_list_configs: List available uci config files
217 extern int uci_list_configs(struct uci_context *ctx, char ***list);
219 /* UCI data structures */
221 UCI_TYPE_HISTORY = 0,
222 UCI_TYPE_PACKAGE = 1,
223 UCI_TYPE_SECTION = 2,
228 UCI_FLAG_STRICT = (1 << 0), /* strict mode for the parser */
229 UCI_FLAG_PERROR = (1 << 1), /* print error messages to stderr */
234 struct uci_list list;
241 /* list of config packages */
242 struct uci_list root;
244 /* parser context, use for error handling only */
245 struct uci_parse_context *pctx;
247 /* uci runtime flags */
248 enum uci_flags flags;
259 struct uci_parse_context
267 struct uci_package *package;
268 struct uci_section *section;
277 struct uci_element e;
278 struct uci_list sections;
279 struct uci_context *ctx;
285 struct uci_list history;
290 struct uci_element e;
291 struct uci_list options;
292 struct uci_package *package;
298 struct uci_element e;
299 struct uci_section *section;
311 struct uci_element e;
312 enum uci_command cmd;
317 /* linked list handling */
319 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
323 * container_of - cast a member of a structure out to the containing structure
324 * @ptr: the pointer to the member.
325 * @type: the type of the container struct this is embedded in.
326 * @member: the name of the member within the struct.
328 #define container_of(ptr, type, member) \
329 ((type *) ((char *)ptr - offsetof(type,member)))
333 * uci_list_entry: casts an uci_list pointer to the containing struct.
334 * @_type: config, section or option
335 * @_ptr: pointer to the uci_list struct
337 #define element_to(type, ptr) \
338 container_of(ptr, struct uci_ ## type, e)
340 #define list_to_element(ptr) \
341 container_of(ptr, struct uci_element, list)
344 * uci_foreach_entry: loop through a list of uci elements
345 * @_list: pointer to the uci_list struct
346 * @_ptr: iteration variable, struct uci_element
348 * use like a for loop, e.g:
349 * uci_foreach(&list, p) {
353 #define uci_foreach_element(_list, _ptr) \
354 for(_ptr = list_to_element((_list)->next); \
355 &_ptr->list != (_list); \
356 _ptr = list_to_element(_ptr->list.next))
359 * uci_foreach_entry_safe: like uci_foreach_safe, but safe for deletion
360 * @_list: pointer to the uci_list struct
361 * @_tmp: temporary variable, struct uci_element *
362 * @_ptr: iteration variable, struct uci_element *
364 * use like a for loop, e.g:
365 * uci_foreach(&list, p) {
369 #define uci_foreach_element_safe(_list, _tmp, _ptr) \
370 for(_ptr = list_to_element((_list)->next), \
371 _tmp = list_to_element(_ptr->list.next); \
372 &_ptr->list != (_list); \
373 _ptr = _tmp, _tmp = list_to_element(_ptr->list.next))
376 * uci_list_empty: returns true if a list is empty
379 #define uci_list_empty(list) ((list)->next == (list))
381 /* wrappers for dynamic type handling */
382 #define uci_type_history UCI_TYPE_HISTORY
383 #define uci_type_package UCI_TYPE_PACKAGE
384 #define uci_type_section UCI_TYPE_SECTION
385 #define uci_type_option UCI_TYPE_OPTION
387 /* element typecasting */
388 #ifdef UCI_DEBUG_TYPECAST
389 static const char *uci_typestr[] = {
390 [uci_type_history] = "history",
391 [uci_type_package] = "package",
392 [uci_type_section] = "section",
393 [uci_type_option] = "option",
396 static void uci_typecast_error(int from, int to)
398 fprintf(stderr, "Invalid typecast from '%s' to '%s'\n", uci_typestr[from], uci_typestr[to]);
401 #define BUILD_CAST(_type) \
402 static inline struct uci_ ## _type *uci_to_ ## _type (struct uci_element *e) \
404 if (e->type != uci_type_ ## _type) { \
405 uci_typecast_error(e->type, uci_type_ ## _type); \
407 return (struct uci_ ## _type *) e; \
416 #define uci_to_history(ptr) container_of(ptr, struct uci_history, e)
417 #define uci_to_package(ptr) container_of(ptr, struct uci_package, e)
418 #define uci_to_section(ptr) container_of(ptr, struct uci_section, e)
419 #define uci_to_option(ptr) container_of(ptr, struct uci_option, e)
423 * uci_alloc_element: allocate a generic uci_element, reserve a buffer and typecast
425 * @type: {package,section,option}
426 * @name: string containing the name of the element
427 * @datasize: additional buffer size to reserve at the end of the struct
429 #define uci_alloc_element(ctx, type, name, datasize) \
430 uci_to_ ## type (uci_alloc_generic(ctx, uci_type_ ## type, name, sizeof(struct uci_ ## type) + datasize))
432 #define uci_dataptr(ptr) \
433 (((char *) ptr) + sizeof(*ptr))