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 * caller is responsible for freeing the allocated memory behind list
234 extern int uci_list_configs(struct uci_context
*ctx
, char ***list
);
237 * uci_set_savedir: override the default history save directory
239 * @dir: directory name
241 extern int uci_set_savedir(struct uci_context
*ctx
, const char *dir
);
244 * uci_set_savedir: override the default config storage directory
246 * @dir: directory name
248 extern int uci_set_confdir(struct uci_context
*ctx
, const char *dir
);
251 * uci_add_history_path: add a directory to the search path for change history files
253 * @dir: directory name
255 * This function allows you to add directories, which contain 'overlays'
256 * for the active config, that will never be committed.
258 extern int uci_add_history_path(struct uci_context
*ctx
, const char *dir
);
261 * uci_revert: revert all changes to a config item
263 * @p: pointer to a uci_package struct ptr (will be replaced by the revert)
264 * @section: section name (optional)
265 * @option option name (optional)
267 extern int uci_revert(struct uci_context
*ctx
, struct uci_package
**p
, char *section
, char *option
);
270 * uci_parse_argument: parse a shell-style argument, with an arbitrary quoting style
272 * @stream: input stream
273 * @str: pointer to the current line (use NULL for parsing the next line)
274 * @result: pointer for the result
276 extern int uci_parse_argument(struct uci_context
*ctx
, FILE *stream
, char **str
, char **result
);
279 * uci_set_backend: change the default backend
281 * @name: name of the backend
283 * The default backend is "file", which uses /etc/config for config storage
285 extern int uci_set_backend(struct uci_context
*ctx
, const char *name
);
287 /* UCI data structures */
289 UCI_TYPE_HISTORY
= 0,
290 UCI_TYPE_PACKAGE
= 1,
291 UCI_TYPE_SECTION
= 2,
294 UCI_TYPE_BACKEND
= 5,
298 UCI_FLAG_STRICT
= (1 << 0), /* strict mode for the parser */
299 UCI_FLAG_PERROR
= (1 << 1), /* print parser error messages */
300 UCI_FLAG_EXPORT_NAME
= (1 << 2), /* when exporting, name unnamed sections */
301 UCI_FLAG_SAVED_HISTORY
= (1 << 3), /* store the saved history in memory as well */
306 struct uci_list list
;
313 struct uci_element e
;
314 char **(*list_configs
)(struct uci_context
*ctx
);
315 struct uci_package
*(*load
)(struct uci_context
*ctx
, const char *name
);
316 void (*commit
)(struct uci_context
*ctx
, struct uci_package
**p
, bool overwrite
);
321 /* list of config packages */
322 struct uci_list root
;
324 /* parser context, use for error handling only */
325 struct uci_parse_context
*pctx
;
327 /* backend for import and export */
328 struct uci_backend
*backend
;
329 struct uci_list backends
;
331 /* uci runtime flags */
332 enum uci_flags flags
;
337 /* search path for history files */
338 struct uci_list history_path
;
351 struct uci_element e
;
352 struct uci_list sections
;
353 struct uci_context
*ctx
;
358 struct uci_backend
*backend
;
361 struct uci_list history
;
362 struct uci_list saved_history
;
367 struct uci_element e
;
368 struct uci_list options
;
369 struct uci_package
*package
;
376 struct uci_element e
;
377 struct uci_section
*section
;
390 struct uci_element e
;
391 enum uci_command cmd
;
396 #define UCI_BACKEND(_var, _name, ...) \
397 struct uci_backend _var = { \
399 .next = &_var.e.list, \
400 .prev = &_var.e.list, \
403 .e.type = UCI_TYPE_BACKEND, \
408 /* linked list handling */
410 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
414 * container_of - cast a member of a structure out to the containing structure
415 * @ptr: the pointer to the member.
416 * @type: the type of the container struct this is embedded in.
417 * @member: the name of the member within the struct.
419 #define container_of(ptr, type, member) \
420 ((type *) ((char *)ptr - offsetof(type,member)))
424 * uci_list_entry: casts an uci_list pointer to the containing struct.
425 * @_type: config, section or option
426 * @_ptr: pointer to the uci_list struct
428 #define list_to_element(ptr) \
429 container_of(ptr, struct uci_element, list)
432 * uci_foreach_entry: loop through a list of uci elements
433 * @_list: pointer to the uci_list struct
434 * @_ptr: iteration variable, struct uci_element
436 * use like a for loop, e.g:
437 * uci_foreach(&list, p) {
441 #define uci_foreach_element(_list, _ptr) \
442 for(_ptr = list_to_element((_list)->next); \
443 &_ptr->list != (_list); \
444 _ptr = list_to_element(_ptr->list.next))
447 * uci_foreach_entry_safe: like uci_foreach_safe, but safe for deletion
448 * @_list: pointer to the uci_list struct
449 * @_tmp: temporary variable, struct uci_element *
450 * @_ptr: iteration variable, struct uci_element *
452 * use like a for loop, e.g:
453 * uci_foreach(&list, p) {
457 #define uci_foreach_element_safe(_list, _tmp, _ptr) \
458 for(_ptr = list_to_element((_list)->next), \
459 _tmp = list_to_element(_ptr->list.next); \
460 &_ptr->list != (_list); \
461 _ptr = _tmp, _tmp = list_to_element(_ptr->list.next))
464 * uci_list_empty: returns true if a list is empty
467 #define uci_list_empty(list) ((list)->next == (list))
469 /* wrappers for dynamic type handling */
470 #define uci_type_backend UCI_TYPE_BACKEND
471 #define uci_type_history UCI_TYPE_HISTORY
472 #define uci_type_package UCI_TYPE_PACKAGE
473 #define uci_type_section UCI_TYPE_SECTION
474 #define uci_type_option UCI_TYPE_OPTION
476 /* element typecasting */
477 #ifdef UCI_DEBUG_TYPECAST
478 static const char *uci_typestr
[] = {
479 [uci_type_backend
] = "backend",
480 [uci_type_history
] = "history",
481 [uci_type_package
] = "package",
482 [uci_type_section
] = "section",
483 [uci_type_option
] = "option",
486 static void uci_typecast_error(int from
, int to
)
488 fprintf(stderr
, "Invalid typecast from '%s' to '%s'\n", uci_typestr
[from
], uci_typestr
[to
]);
491 #define BUILD_CAST(_type) \
492 static inline struct uci_ ## _type *uci_to_ ## _type (struct uci_element *e) \
494 if (e->type != uci_type_ ## _type) { \
495 uci_typecast_error(e->type, uci_type_ ## _type); \
497 return (struct uci_ ## _type *) e; \
507 #define uci_to_backend(ptr) container_of(ptr, struct uci_backend, e)
508 #define uci_to_history(ptr) container_of(ptr, struct uci_history, e)
509 #define uci_to_package(ptr) container_of(ptr, struct uci_package, e)
510 #define uci_to_section(ptr) container_of(ptr, struct uci_section, e)
511 #define uci_to_option(ptr) container_of(ptr, struct uci_option, e)
515 * uci_alloc_element: allocate a generic uci_element, reserve a buffer and typecast
517 * @type: {package,section,option}
518 * @name: string containing the name of the element
519 * @datasize: additional buffer size to reserve at the end of the struct
521 #define uci_alloc_element(ctx, type, name, datasize) \
522 uci_to_ ## type (uci_alloc_generic(ctx, uci_type_ ## type, name, sizeof(struct uci_ ## type) + datasize))
524 #define uci_dataptr(ptr) \
525 (((char *) ptr) + sizeof(*ptr))