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
108 * if 'package' points to a non-null struct pointer, enable history tracking and merge
110 extern int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_package **package, bool single);
113 * uci_export: Export one or all uci config packages
115 * @stream: output stream
116 * @package: (optional) uci config package to export
117 * @header: include the package header
119 extern int uci_export(struct uci_context *ctx, FILE *stream, struct uci_package *package, bool header);
122 * uci_load: Parse an uci config file and store it in the uci context
125 * @name: name of the config file (relative to the config directory)
126 * @package: store the loaded config package in this variable
128 extern int uci_load(struct uci_context *ctx, const char *name, struct uci_package **package);
131 * uci_unload: Unload a config file from the uci context
134 * @package: pointer to the uci_package struct
136 extern int uci_unload(struct uci_context *ctx, struct uci_package *p);
139 * uci_cleanup: Clean up after an error
143 extern int uci_cleanup(struct uci_context *ctx);
146 * uci_lookup: Look up an uci element
149 * @res: where to store the result
150 * @package: uci_package struct
151 * @section: config section (optional)
152 * @option: option to search for (optional)
154 * If section is omitted, then a pointer to the config package is returned
155 * If option is omitted, then a pointer to the config section is returned
157 extern int uci_lookup(struct uci_context *ctx, struct uci_element **res, struct uci_package *package, char *section, char *option);
160 * uci_set_element_value: Replace an element's value with a new one
162 * @element: pointer to an uci_element struct pointer
165 * Only valid for uci_option and uci_section. Will replace the type string
166 * when used with an uci_section
168 extern int uci_set_element_value(struct uci_context *ctx, struct uci_element **element, char *value);
171 * uci_set: Set an element's value; create the element if necessary
173 * @package: package name
174 * @section: section name
175 * @option: option name
176 * @value: value (option) or type (section)
178 extern int uci_set(struct uci_context *ctx, struct uci_package *p, char *section, char *option, char *value);
181 * uci_rename: Rename an element
183 * @package: package name
184 * @section: section name
185 * @option: option name
188 extern int uci_rename(struct uci_context *ctx, struct uci_package *p, char *section, char *option, char *name);
191 * uci_delete_element: Delete a section or option
193 * @e: element (section or option)
195 extern int uci_delete_element(struct uci_context *ctx, struct uci_element *e);
198 * uci_delete: Delete a section or option
201 * @section: section name
202 * @option: option name (optional)
204 extern int uci_delete(struct uci_context *ctx, struct uci_package *p, char *section, char *option);
207 * uci_save: save change history for a package
209 * @p: uci_package struct
211 extern int uci_save(struct uci_context *ctx, struct uci_package *p);
214 * uci_commit: commit changes to a package
216 * @p: uci_package struct pointer
217 * @overwrite: overwrite existing config data and flush history
219 * committing may reload the whole uci_package data,
220 * the supplied pointer is updated accordingly
222 extern int uci_commit(struct uci_context *ctx, struct uci_package **p, bool overwrite);
225 * uci_list_configs: List available uci config files
228 extern int uci_list_configs(struct uci_context *ctx, char ***list);
231 * uci_set_savedir: override the default history save directory
233 * @dir: directory name
235 extern int uci_set_savedir(struct uci_context *ctx, const char *dir);
238 * uci_set_savedir: override the default config storage directory
240 * @dir: directory name
242 extern int uci_set_confdir(struct uci_context *ctx, const char *dir);
245 * uci_add_history_path: add a directory to the search path for change history files
247 * @dir: directory name
249 * This function allows you to add directories, which contain 'overlays'
250 * for the active config, that will never be committed.
252 extern int uci_add_history_path(struct uci_context *ctx, const char *dir);
255 * uci_revert: revert all changes to a config item
257 * @p: pointer to a uci_package struct ptr (will be replaced by the revert)
258 * @section: section name (optional)
259 * @option option name (optional)
261 extern int uci_revert(struct uci_context *ctx, struct uci_package **p, char *section, char *option);
263 /* UCI data structures */
265 UCI_TYPE_HISTORY = 0,
266 UCI_TYPE_PACKAGE = 1,
267 UCI_TYPE_SECTION = 2,
273 UCI_FLAG_STRICT = (1 << 0), /* strict mode for the parser */
274 UCI_FLAG_PERROR = (1 << 1), /* print parser error messages */
275 UCI_FLAG_EXPORT_NAME = (1 << 2), /* when exporting, name unnamed sections */
280 struct uci_list list;
287 /* list of config packages */
288 struct uci_list root;
290 /* parser context, use for error handling only */
291 struct uci_parse_context *pctx;
293 /* uci runtime flags */
294 enum uci_flags flags;
299 /* search path for history files */
300 struct uci_list history_path;
311 struct uci_parse_context
319 struct uci_package *package;
320 struct uci_section *section;
330 struct uci_element e;
331 struct uci_list sections;
332 struct uci_context *ctx;
338 struct uci_list history;
343 struct uci_element e;
344 struct uci_list options;
345 struct uci_package *package;
352 struct uci_element e;
353 struct uci_section *section;
366 struct uci_element e;
367 enum uci_command cmd;
372 /* linked list handling */
374 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
378 * container_of - cast a member of a structure out to the containing structure
379 * @ptr: the pointer to the member.
380 * @type: the type of the container struct this is embedded in.
381 * @member: the name of the member within the struct.
383 #define container_of(ptr, type, member) \
384 ((type *) ((char *)ptr - offsetof(type,member)))
388 * uci_list_entry: casts an uci_list pointer to the containing struct.
389 * @_type: config, section or option
390 * @_ptr: pointer to the uci_list struct
392 #define element_to(type, ptr) \
393 container_of(ptr, struct uci_ ## type, e)
395 #define list_to_element(ptr) \
396 container_of(ptr, struct uci_element, list)
399 * uci_foreach_entry: loop through a list of uci elements
400 * @_list: pointer to the uci_list struct
401 * @_ptr: iteration variable, struct uci_element
403 * use like a for loop, e.g:
404 * uci_foreach(&list, p) {
408 #define uci_foreach_element(_list, _ptr) \
409 for(_ptr = list_to_element((_list)->next); \
410 &_ptr->list != (_list); \
411 _ptr = list_to_element(_ptr->list.next))
414 * uci_foreach_entry_safe: like uci_foreach_safe, but safe for deletion
415 * @_list: pointer to the uci_list struct
416 * @_tmp: temporary variable, struct uci_element *
417 * @_ptr: iteration variable, struct uci_element *
419 * use like a for loop, e.g:
420 * uci_foreach(&list, p) {
424 #define uci_foreach_element_safe(_list, _tmp, _ptr) \
425 for(_ptr = list_to_element((_list)->next), \
426 _tmp = list_to_element(_ptr->list.next); \
427 &_ptr->list != (_list); \
428 _ptr = _tmp, _tmp = list_to_element(_ptr->list.next))
431 * uci_list_empty: returns true if a list is empty
434 #define uci_list_empty(list) ((list)->next == (list))
436 /* wrappers for dynamic type handling */
437 #define uci_type_history UCI_TYPE_HISTORY
438 #define uci_type_package UCI_TYPE_PACKAGE
439 #define uci_type_section UCI_TYPE_SECTION
440 #define uci_type_option UCI_TYPE_OPTION
442 /* element typecasting */
443 #ifdef UCI_DEBUG_TYPECAST
444 static const char *uci_typestr[] = {
445 [uci_type_history] = "history",
446 [uci_type_package] = "package",
447 [uci_type_section] = "section",
448 [uci_type_option] = "option",
451 static void uci_typecast_error(int from, int to)
453 fprintf(stderr, "Invalid typecast from '%s' to '%s'\n", uci_typestr[from], uci_typestr[to]);
456 #define BUILD_CAST(_type) \
457 static inline struct uci_ ## _type *uci_to_ ## _type (struct uci_element *e) \
459 if (e->type != uci_type_ ## _type) { \
460 uci_typecast_error(e->type, uci_type_ ## _type); \
462 return (struct uci_ ## _type *) e; \
471 #define uci_to_history(ptr) container_of(ptr, struct uci_history, e)
472 #define uci_to_package(ptr) container_of(ptr, struct uci_package, e)
473 #define uci_to_section(ptr) container_of(ptr, struct uci_section, e)
474 #define uci_to_option(ptr) container_of(ptr, struct uci_option, e)
478 * uci_alloc_element: allocate a generic uci_element, reserve a buffer and typecast
480 * @type: {package,section,option}
481 * @name: string containing the name of the element
482 * @datasize: additional buffer size to reserve at the end of the struct
484 #define uci_alloc_element(ctx, type, name, datasize) \
485 uci_to_ ## type (uci_alloc_generic(ctx, uci_type_ ## type, name, sizeof(struct uci_ ## type) + datasize))
487 #define uci_dataptr(ptr) \
488 (((char *) ptr) + sizeof(*ptr))