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"
54 struct uci_list *next;
55 struct uci_list *prev;
64 struct uci_parse_context;
68 * uci_parse_tuple: Parse an uci tuple
71 * @package: output package pointer
72 * @section: output section pointer
73 * @option: output option pointer
74 * @value: output value pointer
76 * format: <package>[.<section>[.<option>]][=<value>]
78 extern int uci_parse_tuple(struct uci_context *ctx, char *str, char **package, char **section, char **option, char **value);
81 * uci_alloc_context: Allocate a new uci context
83 extern struct uci_context *uci_alloc_context(void);
86 * uci_free_context: Free the uci context including all of its data
88 extern void uci_free_context(struct uci_context *ctx);
91 * uci_perror: Print the last uci error that occured
93 * @str: string to print before the error message
95 extern void uci_perror(struct uci_context *ctx, const char *str);
98 * uci_import: Import uci config data from a stream
100 * @stream: file stream to import from
101 * @name: (optional) assume the config has the given name
102 * @package: (optional) store the last parsed config package in this variable
103 * @single: ignore the 'package' keyword and parse everything into a single package
105 * the name parameter is for config files that don't explicitly use the 'package <...>' keyword
107 extern int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_package **package, bool single);
110 * uci_export: Export one or all uci config packages
112 * @stream: output stream
113 * @package: (optional) uci config package to export
114 * @header: include the package header
116 extern int uci_export(struct uci_context *ctx, FILE *stream, struct uci_package *package, bool header);
119 * uci_load: Parse an uci config file and store it in the uci context
122 * @name: name of the config file (relative to the config directory)
123 * @package: store the loaded config package in this variable
125 extern int uci_load(struct uci_context *ctx, const char *name, struct uci_package **package);
128 * uci_unload: Unload a config file from the uci context
131 * @package: pointer to the uci_package struct
133 extern int uci_unload(struct uci_context *ctx, struct uci_package *p);
136 * uci_cleanup: Clean up after an error
140 extern int uci_cleanup(struct uci_context *ctx);
143 * uci_lookup: Look up an uci element
146 * @res: where to store the result
147 * @package: uci_package struct
148 * @section: config section (optional)
149 * @option: option to search for (optional)
151 * If section is omitted, then a pointer to the config package is returned
152 * If option is omitted, then a pointer to the config section is returned
154 extern int uci_lookup(struct uci_context *ctx, struct uci_element **res, struct uci_package *package, char *section, char *option);
157 * uci_set_element_value: Replace an element's value with a new one
159 * @element: pointer to an uci_element struct pointer
162 * Only valid for uci_option and uci_section. Will replace the type string
163 * when used with an uci_section
165 extern int uci_set_element_value(struct uci_context *ctx, struct uci_element **element, char *value);
168 * uci_set: Set an element's value; create the element if necessary
170 * @package: package name
171 * @section: section name
172 * @option: option name
173 * @value: value (option) or type (section)
175 extern int uci_set(struct uci_context *ctx, char *package, char *section, char *option, char *value);
178 * uci_commit: commit changes to a package
180 * @p: uci_package struct
182 extern int uci_commit(struct uci_context *ctx, struct uci_package *p);
185 * uci_list_configs: List available uci config files
189 extern char **uci_list_configs(struct uci_context *ctx);
191 /* UCI data structures */
193 UCI_TYPE_PACKAGE = 0,
194 UCI_TYPE_SECTION = 1,
200 struct uci_list list;
207 /* list of config packages */
208 struct uci_list root;
210 /* parser context, use for error handling only */
211 struct uci_parse_context *pctx;
221 struct uci_parse_context
229 struct uci_package *package;
230 struct uci_section *section;
239 struct uci_element e;
240 struct uci_list sections;
241 struct uci_context *ctx;
247 struct uci_list history;
252 struct uci_element e;
253 struct uci_list options;
254 struct uci_package *package;
260 struct uci_element e;
261 struct uci_section *section;
273 struct uci_list list;
274 enum uci_command cmd;
280 /* linked list handling */
282 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
286 * container_of - cast a member of a structure out to the containing structure
287 * @ptr: the pointer to the member.
288 * @type: the type of the container struct this is embedded in.
289 * @member: the name of the member within the struct.
291 #define container_of(ptr, type, member) \
292 ((type *) ((char *)ptr - offsetof(type,member)))
296 * uci_list_entry: casts an uci_list pointer to the containing struct.
297 * @_type: config, section or option
298 * @_ptr: pointer to the uci_list struct
300 #define element_to(type, ptr) \
301 container_of(ptr, struct uci_ ## type, e)
303 #define list_to_element(ptr) \
304 container_of(ptr, struct uci_element, list)
307 * uci_foreach_entry: loop through a list of uci elements
308 * @_list: pointer to the uci_list struct
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(_list, _ptr) \
317 for(_ptr = list_to_element((_list)->next); \
318 &_ptr->list != (_list); \
319 _ptr = list_to_element(_ptr->list.next))
322 * uci_foreach_entry_safe: like uci_foreach_safe, but safe for deletion
323 * @_list: pointer to the uci_list struct
324 * @_tmp: temporary variable, struct uci_element *
325 * @_ptr: iteration variable, struct uci_element *
327 * use like a for loop, e.g:
328 * uci_foreach(&list, p) {
332 #define uci_foreach_element_safe(_list, _tmp, _ptr) \
333 for(_ptr = list_to_element((_list)->next), \
334 _tmp = list_to_element(_ptr->list.next); \
335 &_ptr->list != (_list); \
336 _ptr = _tmp, _tmp = list_to_element(_ptr->list.next))
339 * uci_list_empty: returns true if a list is empty
342 #define uci_list_empty(list) ((list)->next == (list))
344 /* wrappers for dynamic type handling */
345 #define uci_type_package UCI_TYPE_PACKAGE
346 #define uci_type_section UCI_TYPE_SECTION
347 #define uci_type_option UCI_TYPE_OPTION
349 /* element typecasting */
350 #ifdef UCI_DEBUG_TYPECAST
351 static const char *uci_typestr[] = {
352 [uci_type_package] = "package",
353 [uci_type_section] = "section",
354 [uci_type_option] = "option"
357 static void uci_typecast_error(int from, int to)
359 fprintf(stderr, "Invalid typecast from '%s' to '%s'\n", uci_typestr[from], uci_typestr[to]);
362 #define BUILD_CAST(_type) \
363 static inline struct uci_ ## _type *uci_to_ ## _type (struct uci_element *e) \
365 if (e->type != uci_type_ ## _type) { \
366 uci_typecast_error(e->type, uci_type_ ## _type); \
368 return (struct uci_ ## _type *) e; \
376 #define uci_to_package(ptr) container_of(ptr, struct uci_package, e)
377 #define uci_to_section(ptr) container_of(ptr, struct uci_section, e)
378 #define uci_to_option(ptr) container_of(ptr, struct uci_option, e)
382 * uci_alloc_element: allocate a generic uci_element, reserve a buffer and typecast
384 * @type: {package,section,option}
385 * @name: string containing the name of the element
386 * @datasize: additional buffer size to reserve at the end of the struct
388 #define uci_alloc_element(ctx, type, name, datasize) \
389 uci_to_ ## type (uci_alloc_generic(ctx, uci_type_ ## type, name, sizeof(struct uci_ ## type) + datasize))
391 #define uci_dataptr(ptr) \
392 (((char *) ptr) + sizeof(*ptr))