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_add_section: Add an unnamed section
162 * @p: package to add the section to
163 * @type: section type
164 * @res: pointer to store a reference to the new section in
166 extern int uci_add_section(struct uci_context *ctx, struct uci_package *p, char *type, struct uci_section **res);
169 * uci_set_element_value: Replace an element's value with a new one
171 * @element: pointer to an uci_element struct pointer
174 * Only valid for uci_option and uci_section. Will replace the type string
175 * when used with an uci_section
177 extern int uci_set_element_value(struct uci_context *ctx, struct uci_element **element, char *value);
180 * uci_set: Set an element's value; create the element if necessary
182 * @package: package name
183 * @section: section name
184 * @option: option name
185 * @value: value (option) or type (section)
186 * @result: store the updated element in this variable (optional)
188 extern int uci_set(struct uci_context *ctx, struct uci_package *p, char *section, char *option, char *value, struct uci_element **result);
191 * uci_rename: Rename an element
193 * @package: package name
194 * @section: section name
195 * @option: option name
198 extern int uci_rename(struct uci_context *ctx, struct uci_package *p, char *section, char *option, char *name);
201 * uci_delete_element: Delete a section or option
203 * @e: element (section or option)
205 extern int uci_delete_element(struct uci_context *ctx, struct uci_element *e);
208 * uci_delete: Delete a section or option
211 * @section: section name
212 * @option: option name (optional)
214 extern int uci_delete(struct uci_context *ctx, struct uci_package *p, char *section, char *option);
217 * uci_save: save change history for a package
219 * @p: uci_package struct
221 extern int uci_save(struct uci_context *ctx, struct uci_package *p);
224 * uci_commit: commit changes to a package
226 * @p: uci_package struct pointer
227 * @overwrite: overwrite existing config data and flush history
229 * committing may reload the whole uci_package data,
230 * the supplied pointer is updated accordingly
232 extern int uci_commit(struct uci_context *ctx, struct uci_package **p, bool overwrite);
235 * uci_list_configs: List available uci config files
238 extern int uci_list_configs(struct uci_context *ctx, char ***list);
241 * uci_set_savedir: override the default history save directory
243 * @dir: directory name
245 extern int uci_set_savedir(struct uci_context *ctx, const char *dir);
248 * uci_set_savedir: override the default config storage directory
250 * @dir: directory name
252 extern int uci_set_confdir(struct uci_context *ctx, const char *dir);
255 * uci_add_history_path: add a directory to the search path for change history files
257 * @dir: directory name
259 * This function allows you to add directories, which contain 'overlays'
260 * for the active config, that will never be committed.
262 extern int uci_add_history_path(struct uci_context *ctx, const char *dir);
265 * uci_revert: revert all changes to a config item
267 * @p: pointer to a uci_package struct ptr (will be replaced by the revert)
268 * @section: section name (optional)
269 * @option option name (optional)
271 extern int uci_revert(struct uci_context *ctx, struct uci_package **p, char *section, char *option);
274 * uci_parse_argument: parse a shell-style argument, with an arbitrary quoting style
276 * @stream: input stream
277 * @str: pointer to the current line (use NULL for parsing the next line)
278 * @result: pointer for the result
280 extern int uci_parse_argument(struct uci_context *ctx, FILE *stream, char **str, char **result);
282 /* UCI data structures */
284 UCI_TYPE_HISTORY = 0,
285 UCI_TYPE_PACKAGE = 1,
286 UCI_TYPE_SECTION = 2,
292 UCI_FLAG_STRICT = (1 << 0), /* strict mode for the parser */
293 UCI_FLAG_PERROR = (1 << 1), /* print parser error messages */
294 UCI_FLAG_EXPORT_NAME = (1 << 2), /* when exporting, name unnamed sections */
295 UCI_FLAG_SAVED_HISTORY = (1 << 3), /* store the saved history in memory as well */
300 struct uci_list list;
307 /* list of config packages */
308 struct uci_list root;
310 /* parser context, use for error handling only */
311 struct uci_parse_context *pctx;
313 /* uci runtime flags */
314 enum uci_flags flags;
319 /* search path for history files */
320 struct uci_list history_path;
333 struct uci_element e;
334 struct uci_list sections;
335 struct uci_context *ctx;
341 struct uci_list history;
342 struct uci_list saved_history;
347 struct uci_element e;
348 struct uci_list options;
349 struct uci_package *package;
356 struct uci_element e;
357 struct uci_section *section;
370 struct uci_element e;
371 enum uci_command cmd;
376 /* linked list handling */
378 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
382 * container_of - cast a member of a structure out to the containing structure
383 * @ptr: the pointer to the member.
384 * @type: the type of the container struct this is embedded in.
385 * @member: the name of the member within the struct.
387 #define container_of(ptr, type, member) \
388 ((type *) ((char *)ptr - offsetof(type,member)))
392 * uci_list_entry: casts an uci_list pointer to the containing struct.
393 * @_type: config, section or option
394 * @_ptr: pointer to the uci_list struct
396 #define element_to(type, ptr) \
397 container_of(ptr, struct uci_ ## type, e)
399 #define list_to_element(ptr) \
400 container_of(ptr, struct uci_element, list)
403 * uci_foreach_entry: loop through a list of uci elements
404 * @_list: pointer to the uci_list struct
405 * @_ptr: iteration variable, struct uci_element
407 * use like a for loop, e.g:
408 * uci_foreach(&list, p) {
412 #define uci_foreach_element(_list, _ptr) \
413 for(_ptr = list_to_element((_list)->next); \
414 &_ptr->list != (_list); \
415 _ptr = list_to_element(_ptr->list.next))
418 * uci_foreach_entry_safe: like uci_foreach_safe, but safe for deletion
419 * @_list: pointer to the uci_list struct
420 * @_tmp: temporary variable, struct uci_element *
421 * @_ptr: iteration variable, struct uci_element *
423 * use like a for loop, e.g:
424 * uci_foreach(&list, p) {
428 #define uci_foreach_element_safe(_list, _tmp, _ptr) \
429 for(_ptr = list_to_element((_list)->next), \
430 _tmp = list_to_element(_ptr->list.next); \
431 &_ptr->list != (_list); \
432 _ptr = _tmp, _tmp = list_to_element(_ptr->list.next))
435 * uci_list_empty: returns true if a list is empty
438 #define uci_list_empty(list) ((list)->next == (list))
440 /* wrappers for dynamic type handling */
441 #define uci_type_history UCI_TYPE_HISTORY
442 #define uci_type_package UCI_TYPE_PACKAGE
443 #define uci_type_section UCI_TYPE_SECTION
444 #define uci_type_option UCI_TYPE_OPTION
446 /* element typecasting */
447 #ifdef UCI_DEBUG_TYPECAST
448 static const char *uci_typestr[] = {
449 [uci_type_history] = "history",
450 [uci_type_package] = "package",
451 [uci_type_section] = "section",
452 [uci_type_option] = "option",
455 static void uci_typecast_error(int from, int to)
457 fprintf(stderr, "Invalid typecast from '%s' to '%s'\n", uci_typestr[from], uci_typestr[to]);
460 #define BUILD_CAST(_type) \
461 static inline struct uci_ ## _type *uci_to_ ## _type (struct uci_element *e) \
463 if (e->type != uci_type_ ## _type) { \
464 uci_typecast_error(e->type, uci_type_ ## _type); \
466 return (struct uci_ ## _type *) e; \
475 #define uci_to_history(ptr) container_of(ptr, struct uci_history, e)
476 #define uci_to_package(ptr) container_of(ptr, struct uci_package, e)
477 #define uci_to_section(ptr) container_of(ptr, struct uci_section, e)
478 #define uci_to_option(ptr) container_of(ptr, struct uci_option, e)
482 * uci_alloc_element: allocate a generic uci_element, reserve a buffer and typecast
484 * @type: {package,section,option}
485 * @name: string containing the name of the element
486 * @datasize: additional buffer size to reserve at the end of the struct
488 #define uci_alloc_element(ctx, type, name, datasize) \
489 uci_to_ ## type (uci_alloc_generic(ctx, uci_type_ ## type, name, sizeof(struct uci_ ## type) + datasize))
491 #define uci_dataptr(ptr) \
492 (((char *) ptr) + sizeof(*ptr))