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;
67 struct uci_parse_context;
71 * uci_parse_tuple: Parse an uci tuple
74 * @package: output package pointer
75 * @section: output section pointer
76 * @option: output option pointer
77 * @value: output value pointer
79 * format: <package>[.<section>[.<option>]][=<value>]
81 extern int uci_parse_tuple(struct uci_context *ctx, char *str, char **package, char **section, char **option, char **value);
84 * uci_alloc_context: Allocate a new uci context
86 extern struct uci_context *uci_alloc_context(void);
89 * uci_free_context: Free the uci context including all of its data
91 extern void uci_free_context(struct uci_context *ctx);
94 * uci_perror: Print the last uci error that occured
96 * @str: string to print before the error message
98 extern void uci_perror(struct uci_context *ctx, const char *str);
101 * uci_import: Import uci config data from a stream
103 * @stream: file stream to import from
104 * @name: (optional) assume the config has the given name
105 * @package: (optional) store the last parsed config package in this variable
106 * @single: ignore the 'package' keyword and parse everything into a single package
108 * the name parameter is for config files that don't explicitly use the 'package <...>' keyword
109 * if 'package' points to a non-null struct pointer, enable history tracking and merge
111 extern int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_package **package, bool single);
114 * uci_export: Export one or all uci config packages
116 * @stream: output stream
117 * @package: (optional) uci config package to export
118 * @header: include the package header
120 extern int uci_export(struct uci_context *ctx, FILE *stream, struct uci_package *package, bool header);
123 * uci_load: Parse an uci config file and store it in the uci context
126 * @name: name of the config file (relative to the config directory)
127 * @package: store the loaded config package in this variable
129 extern int uci_load(struct uci_context *ctx, const char *name, struct uci_package **package);
132 * uci_unload: Unload a config file from the uci context
135 * @package: pointer to the uci_package struct
137 extern int uci_unload(struct uci_context *ctx, struct uci_package *p);
140 * uci_lookup: Look up an uci element
143 * @res: where to store the result
144 * @package: uci_package struct
145 * @section: config section (optional)
146 * @option: option to search for (optional)
148 * If section is omitted, then a pointer to the config package is returned
149 * If option is omitted, then a pointer to the config section is returned
151 extern int uci_lookup(struct uci_context *ctx, struct uci_element **res, struct uci_package *package, char *section, char *option);
154 * uci_add_section: Add an unnamed section
156 * @p: package to add the section to
157 * @type: section type
158 * @res: pointer to store a reference to the new section in
160 extern int uci_add_section(struct uci_context *ctx, struct uci_package *p, char *type, struct uci_section **res);
163 * uci_set_element_value: Replace an element's value with a new one
165 * @element: pointer to an uci_element struct pointer
168 * Only valid for uci_option and uci_section. Will replace the type string
169 * when used with an uci_section
171 extern int uci_set_element_value(struct uci_context *ctx, struct uci_element **element, char *value);
174 * uci_set: Set an element's value; create the element if necessary
176 * @package: package name
177 * @section: section name
178 * @option: option name
179 * @value: value (option) or type (section)
180 * @result: store the updated element in this variable (optional)
182 extern int uci_set(struct uci_context *ctx, struct uci_package *p, char *section, char *option, char *value, struct uci_element **result);
185 * uci_rename: Rename an element
187 * @package: package name
188 * @section: section name
189 * @option: option name
192 extern int uci_rename(struct uci_context *ctx, struct uci_package *p, char *section, char *option, char *name);
195 * uci_delete_element: Delete a section or option
197 * @e: element (section or option)
199 extern int uci_delete_element(struct uci_context *ctx, struct uci_element *e);
202 * uci_delete: Delete a section or option
205 * @section: section name
206 * @option: option name (optional)
208 extern int uci_delete(struct uci_context *ctx, struct uci_package *p, char *section, char *option);
211 * uci_save: save change history for a package
213 * @p: uci_package struct
215 extern int uci_save(struct uci_context *ctx, struct uci_package *p);
218 * uci_commit: commit changes to a package
220 * @p: uci_package struct pointer
221 * @overwrite: overwrite existing config data and flush history
223 * committing may reload the whole uci_package data,
224 * the supplied pointer is updated accordingly
226 extern int uci_commit(struct uci_context *ctx, struct uci_package **p, bool overwrite);
229 * uci_list_configs: List available uci config files
232 extern int uci_list_configs(struct uci_context *ctx, char ***list);
235 * uci_set_savedir: override the default history save directory
237 * @dir: directory name
239 extern int uci_set_savedir(struct uci_context *ctx, const char *dir);
242 * uci_set_savedir: override the default config storage directory
244 * @dir: directory name
246 extern int uci_set_confdir(struct uci_context *ctx, const char *dir);
249 * uci_add_history_path: add a directory to the search path for change history files
251 * @dir: directory name
253 * This function allows you to add directories, which contain 'overlays'
254 * for the active config, that will never be committed.
256 extern int uci_add_history_path(struct uci_context *ctx, const char *dir);
259 * uci_revert: revert all changes to a config item
261 * @p: pointer to a uci_package struct ptr (will be replaced by the revert)
262 * @section: section name (optional)
263 * @option option name (optional)
265 extern int uci_revert(struct uci_context *ctx, struct uci_package **p, char *section, char *option);
268 * uci_parse_argument: parse a shell-style argument, with an arbitrary quoting style
270 * @stream: input stream
271 * @str: pointer to the current line (use NULL for parsing the next line)
272 * @result: pointer for the result
274 extern int uci_parse_argument(struct uci_context *ctx, FILE *stream, char **str, char **result);
276 /* UCI data structures */
278 UCI_TYPE_HISTORY = 0,
279 UCI_TYPE_PACKAGE = 1,
280 UCI_TYPE_SECTION = 2,
286 UCI_FLAG_STRICT = (1 << 0), /* strict mode for the parser */
287 UCI_FLAG_PERROR = (1 << 1), /* print parser error messages */
288 UCI_FLAG_EXPORT_NAME = (1 << 2), /* when exporting, name unnamed sections */
289 UCI_FLAG_SAVED_HISTORY = (1 << 3), /* store the saved history in memory as well */
294 struct uci_list list;
302 char **(*list_configs)(struct uci_context *ctx);
303 struct uci_package *(*load)(struct uci_context *ctx, const char *name);
304 void (*commit)(struct uci_context *ctx, struct uci_package **p, bool overwrite);
310 /* list of config packages */
311 struct uci_list root;
313 /* parser context, use for error handling only */
314 struct uci_parse_context *pctx;
316 /* backend for import and export */
317 struct uci_backend *backend;
319 /* uci runtime flags */
320 enum uci_flags flags;
325 /* search path for history files */
326 struct uci_list history_path;
339 struct uci_element e;
340 struct uci_list sections;
341 struct uci_context *ctx;
346 struct uci_backend *backend;
348 struct uci_list history;
349 struct uci_list saved_history;
354 struct uci_element e;
355 struct uci_list options;
356 struct uci_package *package;
363 struct uci_element e;
364 struct uci_section *section;
377 struct uci_element e;
378 enum uci_command cmd;
383 /* linked list handling */
385 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
389 * container_of - cast a member of a structure out to the containing structure
390 * @ptr: the pointer to the member.
391 * @type: the type of the container struct this is embedded in.
392 * @member: the name of the member within the struct.
394 #define container_of(ptr, type, member) \
395 ((type *) ((char *)ptr - offsetof(type,member)))
399 * uci_list_entry: casts an uci_list pointer to the containing struct.
400 * @_type: config, section or option
401 * @_ptr: pointer to the uci_list struct
403 #define element_to(type, ptr) \
404 container_of(ptr, struct uci_ ## type, e)
406 #define list_to_element(ptr) \
407 container_of(ptr, struct uci_element, list)
410 * uci_foreach_entry: loop through a list of uci elements
411 * @_list: pointer to the uci_list struct
412 * @_ptr: iteration variable, struct uci_element
414 * use like a for loop, e.g:
415 * uci_foreach(&list, p) {
419 #define uci_foreach_element(_list, _ptr) \
420 for(_ptr = list_to_element((_list)->next); \
421 &_ptr->list != (_list); \
422 _ptr = list_to_element(_ptr->list.next))
425 * uci_foreach_entry_safe: like uci_foreach_safe, but safe for deletion
426 * @_list: pointer to the uci_list struct
427 * @_tmp: temporary variable, struct uci_element *
428 * @_ptr: iteration variable, struct uci_element *
430 * use like a for loop, e.g:
431 * uci_foreach(&list, p) {
435 #define uci_foreach_element_safe(_list, _tmp, _ptr) \
436 for(_ptr = list_to_element((_list)->next), \
437 _tmp = list_to_element(_ptr->list.next); \
438 &_ptr->list != (_list); \
439 _ptr = _tmp, _tmp = list_to_element(_ptr->list.next))
442 * uci_list_empty: returns true if a list is empty
445 #define uci_list_empty(list) ((list)->next == (list))
447 /* wrappers for dynamic type handling */
448 #define uci_type_history UCI_TYPE_HISTORY
449 #define uci_type_package UCI_TYPE_PACKAGE
450 #define uci_type_section UCI_TYPE_SECTION
451 #define uci_type_option UCI_TYPE_OPTION
453 /* element typecasting */
454 #ifdef UCI_DEBUG_TYPECAST
455 static const char *uci_typestr[] = {
456 [uci_type_history] = "history",
457 [uci_type_package] = "package",
458 [uci_type_section] = "section",
459 [uci_type_option] = "option",
462 static void uci_typecast_error(int from, int to)
464 fprintf(stderr, "Invalid typecast from '%s' to '%s'\n", uci_typestr[from], uci_typestr[to]);
467 #define BUILD_CAST(_type) \
468 static inline struct uci_ ## _type *uci_to_ ## _type (struct uci_element *e) \
470 if (e->type != uci_type_ ## _type) { \
471 uci_typecast_error(e->type, uci_type_ ## _type); \
473 return (struct uci_ ## _type *) e; \
482 #define uci_to_history(ptr) container_of(ptr, struct uci_history, e)
483 #define uci_to_package(ptr) container_of(ptr, struct uci_package, e)
484 #define uci_to_section(ptr) container_of(ptr, struct uci_section, e)
485 #define uci_to_option(ptr) container_of(ptr, struct uci_option, e)
489 * uci_alloc_element: allocate a generic uci_element, reserve a buffer and typecast
491 * @type: {package,section,option}
492 * @name: string containing the name of the element
493 * @datasize: additional buffer size to reserve at the end of the struct
495 #define uci_alloc_element(ctx, type, name, datasize) \
496 uci_to_ ## type (uci_alloc_generic(ctx, uci_type_ ## type, name, sizeof(struct uci_ ## type) + datasize))
498 #define uci_dataptr(ptr) \
499 (((char *) ptr) + sizeof(*ptr))