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
99 extern int uci_export(struct uci_context *ctx, FILE *stream, struct uci_package *package);
102 * uci_load: Parse an uci config file and store it in the uci context
105 * @name: name of the config file (relative to the config directory)
106 * @package: store the loaded config package in this variable
108 extern int uci_load(struct uci_context *ctx, const char *name, struct uci_package **package);
111 * uci_unload: Unload a config file from the uci context
114 * @package: pointer to the uci_package struct
116 extern int uci_unload(struct uci_context *ctx, struct uci_package *p);
119 * uci_cleanup: Clean up after an error
123 extern int uci_cleanup(struct uci_context *ctx);
126 * uci_lookup: Look up an uci element
129 * @res: where to store the result
130 * @package: uci_package struct
131 * @section: config section (optional)
132 * @option: option to search for (optional)
134 * If section is omitted, then a pointer to the config package is returned
135 * If option is omitted, then a pointer to the config section is returned
137 extern int uci_lookup(struct uci_context *ctx, struct uci_element **res, struct uci_package *package, char *section, char *option);
140 * uci_set_element_value: Replace an element's value with a new one
142 * @element: pointer to an uci_element struct pointer
145 * Only valid for uci_option and uci_section. Will replace the type string
146 * when used with an uci_section
148 extern int uci_set_element_value(struct uci_context *ctx, struct uci_element **element, char *value);
151 * uci_set: Set an element's value; create the element if necessary
153 * @package: package name
154 * @section: section name
155 * @option: option name
156 * @value: value (option) or type (section)
158 extern int uci_set(struct uci_context *ctx, char *package, char *section, char *option, char *value);
161 * uci_list_configs: List available uci config files
165 extern char **uci_list_configs(struct uci_context *ctx);
167 /* UCI data structures */
169 UCI_TYPE_PACKAGE = 0,
170 UCI_TYPE_SECTION = 1,
176 struct uci_list list;
183 /* list of config packages */
184 struct uci_list root;
186 /* parser context, use for error handling only */
187 struct uci_parse_context *pctx;
197 struct uci_parse_context
205 struct uci_package *package;
206 struct uci_section *section;
215 struct uci_element e;
216 struct uci_list sections;
217 struct uci_context *ctx;
223 struct uci_list history;
228 struct uci_element e;
229 struct uci_list options;
230 struct uci_package *package;
236 struct uci_element e;
237 struct uci_section *section;
249 struct uci_list list;
250 enum uci_command cmd;
256 /* linked list handling */
258 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
262 * container_of - cast a member of a structure out to the containing structure
263 * @ptr: the pointer to the member.
264 * @type: the type of the container struct this is embedded in.
265 * @member: the name of the member within the struct.
267 #define container_of(ptr, type, member) \
268 ((type *) ((char *)ptr - offsetof(type,member)))
272 * uci_list_entry: casts an uci_list pointer to the containing struct.
273 * @_type: config, section or option
274 * @_ptr: pointer to the uci_list struct
276 #define element_to(type, ptr) \
277 container_of(ptr, struct uci_ ## type, e)
279 #define list_to_element(ptr) \
280 container_of(ptr, struct uci_element, list)
283 * uci_foreach_entry: loop through a list of uci elements
284 * @_list: pointer to the uci_list struct
285 * @_ptr: iteration variable, struct uci_element
287 * use like a for loop, e.g:
288 * uci_foreach(&list, p) {
292 #define uci_foreach_element(_list, _ptr) \
293 for(_ptr = list_to_element((_list)->next); \
294 &_ptr->list != (_list); \
295 _ptr = list_to_element(_ptr->list.next))
298 * uci_foreach_entry_safe: like uci_foreach_safe, but safe for deletion
299 * @_list: pointer to the uci_list struct
300 * @_tmp: temporary variable, struct uci_element *
301 * @_ptr: iteration variable, struct uci_element *
303 * use like a for loop, e.g:
304 * uci_foreach(&list, p) {
308 #define uci_foreach_element_safe(_list, _tmp, _ptr) \
309 for(_ptr = list_to_element((_list)->next), \
310 _tmp = list_to_element(_ptr->list.next); \
311 &_ptr->list != (_list); \
312 _ptr = _tmp, _tmp = list_to_element(_ptr->list.next))
315 * uci_list_empty: returns true if a list is empty
318 #define uci_list_empty(list) ((list)->next == (list))
320 /* wrappers for dynamic type handling */
321 #define uci_type_package UCI_TYPE_PACKAGE
322 #define uci_type_section UCI_TYPE_SECTION
323 #define uci_type_option UCI_TYPE_OPTION
325 /* element typecasting */
326 #ifdef UCI_DEBUG_TYPECAST
327 static const char *uci_typestr[] = {
328 [uci_type_package] = "package",
329 [uci_type_section] = "section",
330 [uci_type_option] = "option"
333 static void uci_typecast_error(int from, int to)
335 fprintf(stderr, "Invalid typecast from '%s' to '%s'\n", uci_typestr[from], uci_typestr[to]);
338 #define BUILD_CAST(_type) \
339 static inline struct uci_ ## _type *uci_to_ ## _type (struct uci_element *e) \
341 if (e->type != uci_type_ ## _type) { \
342 uci_typecast_error(e->type, uci_type_ ## _type); \
344 return (struct uci_ ## _type *) e; \
352 #define uci_to_package(ptr) container_of(ptr, struct uci_package, e)
353 #define uci_to_section(ptr) container_of(ptr, struct uci_section, e)
354 #define uci_to_option(ptr) container_of(ptr, struct uci_option, e)
358 * uci_alloc_element: allocate a generic uci_element, reserve a buffer and typecast
360 * @type: {package,section,option}
361 * @name: string containing the name of the element
362 * @datasize: additional buffer size to reserve at the end of the struct
364 #define uci_alloc_element(ctx, type, name, datasize) \
365 uci_to_ ## type (uci_alloc_generic(ctx, uci_type_ ## type, name, sizeof(struct uci_ ## type) + datasize))
367 #define uci_dataptr(ptr) \
368 (((char *) ptr) + sizeof(*ptr))