1 /* 2 * libuci - Library for the Unified Configuration Interface 3 * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org> 4 * 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 8 * 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 Lesser General Public License for more details. 13 */ 14 15 #ifndef __LIBUCI_H 16 #define __LIBUCI_H 17 18 #ifdef __cplusplus 19 extern "C" { 20 #endif 21 22 #include "uci_config.h" 23 24 /* 25 * you can use these defines to enable debugging behavior for 26 * apps compiled against libuci: 27 * 28 * #define UCI_DEBUG_TYPECAST: 29 * enable uci_element typecast checking at run time 30 * 31 */ 32 33 #include <stdbool.h> 34 #include <setjmp.h> 35 #include <stdio.h> 36 #include <stdint.h> 37 38 #define UCI_CONFDIR "/etc/config" 39 #define UCI_SAVEDIR "/tmp/.uci" 40 #define UCI_DIRMODE 0700 41 #define UCI_FILEMODE 0600 42 43 enum 44 { 45 UCI_OK = 0, 46 UCI_ERR_MEM, 47 UCI_ERR_INVAL, 48 UCI_ERR_NOTFOUND, 49 UCI_ERR_IO, 50 UCI_ERR_PARSE, 51 UCI_ERR_DUPLICATE, 52 UCI_ERR_UNKNOWN, 53 UCI_ERR_LAST 54 }; 55 56 struct uci_list; 57 struct uci_list 58 { 59 struct uci_list *next; 60 struct uci_list *prev; 61 }; 62 63 struct uci_ptr; 64 struct uci_element; 65 struct uci_package; 66 struct uci_section; 67 struct uci_option; 68 struct uci_delta; 69 struct uci_context; 70 struct uci_backend; 71 struct uci_parse_option; 72 struct uci_parse_context; 73 74 75 /** 76 * uci_alloc_context: Allocate a new uci context 77 */ 78 extern struct uci_context *uci_alloc_context(void); 79 80 /** 81 * uci_free_context: Free the uci context including all of its data 82 */ 83 extern void uci_free_context(struct uci_context *ctx); 84 85 /** 86 * uci_perror: Print the last uci error that occured 87 * @ctx: uci context 88 * @str: string to print before the error message 89 */ 90 extern void uci_perror(struct uci_context *ctx, const char *str); 91 92 /** 93 * uci_geterror: Get an error string for the last uci error 94 * @ctx: uci context 95 * @dest: target pointer for the string 96 * @str: prefix for the error message 97 * 98 * Note: string must be freed by the caller 99 */ 100 extern void uci_get_errorstr(struct uci_context *ctx, char **dest, const char *str); 101 102 /** 103 * uci_import: Import uci config data from a stream 104 * @ctx: uci context 105 * @stream: file stream to import from 106 * @name: (optional) assume the config has the given name 107 * @package: (optional) store the last parsed config package in this variable 108 * @single: ignore the 'package' keyword and parse everything into a single package 109 * 110 * the name parameter is for config files that don't explicitly use the 'package <...>' keyword 111 * if 'package' points to a non-null struct pointer, enable delta tracking and merge 112 */ 113 extern int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_package **package, bool single); 114 115 /** 116 * uci_export: Export one or all uci config packages 117 * @ctx: uci context 118 * @stream: output stream 119 * @package: (optional) uci config package to export 120 * @header: include the package header 121 */ 122 extern int uci_export(struct uci_context *ctx, FILE *stream, struct uci_package *package, bool header); 123 124 /** 125 * uci_load: Parse an uci config file and store it in the uci context 126 * 127 * @ctx: uci context 128 * @name: name of the config file (relative to the config directory) 129 * @package: store the loaded config package in this variable 130 */ 131 extern int uci_load(struct uci_context *ctx, const char *name, struct uci_package **package); 132 133 /** 134 * uci_unload: Unload a config file from the uci context 135 * 136 * @ctx: uci context 137 * @package: pointer to the uci_package struct 138 */ 139 extern int uci_unload(struct uci_context *ctx, struct uci_package *p); 140 141 /** 142 * uci_lookup_ptr: Split an uci tuple string and look up an element tree 143 * @ctx: uci context 144 * @ptr: lookup result struct 145 * @str: uci tuple string to look up 146 * @extended: allow extended syntax lookup 147 * 148 * if extended is set to true, uci_lookup_ptr supports the following 149 * extended syntax: 150 * 151 * Examples: 152 * network.@interface[0].ifname ('ifname' option of the first interface section) 153 * network.@interface[-1] (last interface section) 154 * Note: uci_lookup_ptr will automatically load a config package if necessary 155 * @str must not be constant, as it will be modified and used for the strings inside @ptr, 156 * thus it must also be available as long as @ptr is in use. 157 * 158 * This function returns UCI_ERR_NOTFOUND if the package specified in the tuple 159 * string cannot be found. Otherwise it will return UCI_OK. 160 * 161 * Note that failures in looking up other parts, if they are also specfied, 162 * including section and option, will also have a return value UCI_OK but with 163 * ptr->flags * UCI_LOOKUP_COMPLETE not set. 164 */ 165 extern int uci_lookup_ptr(struct uci_context *ctx, struct uci_ptr *ptr, char *str, bool extended); 166 167 /** 168 * uci_add_section: Add an unnamed section 169 * @ctx: uci context 170 * @p: package to add the section to 171 * @type: section type 172 * @res: pointer to store a reference to the new section in 173 */ 174 extern int uci_add_section(struct uci_context *ctx, struct uci_package *p, const char *type, struct uci_section **res); 175 176 /** 177 * uci_set: Set an element's value; create the element if necessary 178 * @ctx: uci context 179 * @ptr: uci pointer 180 * 181 * The updated/created element is stored in ptr->last 182 */ 183 extern int uci_set(struct uci_context *ctx, struct uci_ptr *ptr); 184 185 /** 186 * uci_add_list: Append a string to an element list 187 * @ctx: uci context 188 * @ptr: uci pointer (with value) 189 * 190 * Note: if the given option already contains a string value, 191 * it will be converted to an 1-element-list before appending the next element 192 */ 193 extern int uci_add_list(struct uci_context *ctx, struct uci_ptr *ptr); 194 195 /** 196 * uci_del_list: Remove a string from an element list 197 * @ctx: uci context 198 * @ptr: uci pointer (with value) 199 * 200 */ 201 extern int uci_del_list(struct uci_context *ctx, struct uci_ptr *ptr); 202 203 /** 204 * uci_reorder: Reposition a section 205 * @ctx: uci context 206 * @s: uci section to reposition 207 * @pos: new position in the section list 208 */ 209 extern int uci_reorder_section(struct uci_context *ctx, struct uci_section *s, int pos); 210 211 /** 212 * uci_rename: Rename an element 213 * @ctx: uci context 214 * @ptr: uci pointer (with value) 215 */ 216 extern int uci_rename(struct uci_context *ctx, struct uci_ptr *ptr); 217 218 /** 219 * uci_delete: Delete a section or option 220 * @ctx: uci context 221 * @ptr: uci pointer 222 */ 223 extern int uci_delete(struct uci_context *ctx, struct uci_ptr *ptr); 224 225 /** 226 * uci_save: save change delta for a package 227 * @ctx: uci context 228 * @p: uci_package struct 229 */ 230 extern int uci_save(struct uci_context *ctx, struct uci_package *p); 231 232 /** 233 * uci_commit: commit changes to a package 234 * @ctx: uci context 235 * @p: uci_package struct pointer 236 * @overwrite: overwrite existing config data and flush delta 237 * 238 * committing may reload the whole uci_package data, 239 * the supplied pointer is updated accordingly 240 */ 241 extern int uci_commit(struct uci_context *ctx, struct uci_package **p, bool overwrite); 242 243 /** 244 * uci_list_configs: List available uci config files 245 * @ctx: uci context 246 * 247 * caller is responsible for freeing the allocated memory behind list 248 */ 249 extern int uci_list_configs(struct uci_context *ctx, char ***list); 250 251 /** 252 * uci_set_savedir: override the default delta save directory 253 * @ctx: uci context 254 * @dir: directory name 255 * 256 * This will also try adding the specified dir to the end of delta pathes. 257 */ 258 extern int uci_set_savedir(struct uci_context *ctx, const char *dir); 259 260 /** 261 * uci_set_savedir: override the default config storage directory 262 * @ctx: uci context 263 * @dir: directory name 264 */ 265 extern int uci_set_confdir(struct uci_context *ctx, const char *dir); 266 267 /** 268 * uci_add_delta_path: add a directory to the search path for change delta files 269 * @ctx: uci context 270 * @dir: directory name 271 * 272 * This function allows you to add directories, which contain 'overlays' 273 * for the active config, that will never be committed. 274 * 275 * Adding a duplicate directory will cause UCI_ERR_DUPLICATE be returned. 276 */ 277 extern int uci_add_delta_path(struct uci_context *ctx, const char *dir); 278 279 /** 280 * uci_revert: revert all changes to a config item 281 * @ctx: uci context 282 * @ptr: uci pointer 283 */ 284 extern int uci_revert(struct uci_context *ctx, struct uci_ptr *ptr); 285 286 /** 287 * uci_parse_argument: parse a shell-style argument, with an arbitrary quoting style 288 * @ctx: uci context 289 * @stream: input stream 290 * @str: pointer to the current line (use NULL for parsing the next line) 291 * @result: pointer for the result 292 */ 293 extern int uci_parse_argument(struct uci_context *ctx, FILE *stream, char **str, char **result); 294 295 /** 296 * uci_set_backend: change the default backend 297 * @ctx: uci context 298 * @name: name of the backend 299 * 300 * The default backend is "file", which uses /etc/config for config storage 301 */ 302 extern int uci_set_backend(struct uci_context *ctx, const char *name); 303 304 /** 305 * uci_validate_text: validate a value string for uci options 306 * @str: value 307 * 308 * this function checks whether a given string is acceptable as value 309 * for uci options 310 */ 311 extern bool uci_validate_text(const char *str); 312 313 /** 314 * uci_parse_ptr: parse a uci string into a uci_ptr 315 * @ctx: uci context 316 * @ptr: target data structure 317 * @str: string to parse 318 * 319 * str is modified by this function 320 */ 321 int uci_parse_ptr(struct uci_context *ctx, struct uci_ptr *ptr, char *str); 322 323 /** 324 * uci_lookup_next: lookup a child element 325 * @ctx: uci context 326 * @e: target element pointer 327 * @list: list of elements 328 * @name: name of the child element 329 * 330 * if parent is NULL, the function looks up the package with the given name 331 */ 332 int uci_lookup_next(struct uci_context *ctx, struct uci_element **e, struct uci_list *list, const char *name); 333 334 /** 335 * uci_parse_section: look up a set of options 336 * @s: uci section 337 * @opts: list of options to look up 338 * @n_opts: number of options to look up 339 * @tb: array of pointers to found options 340 */ 341 void uci_parse_section(struct uci_section *s, const struct uci_parse_option *opts, 342 int n_opts, struct uci_option **tb); 343 344 /** 345 * uci_hash_options: build a hash over a list of options 346 * @tb: list of option pointers 347 * @n_opts: number of options 348 */ 349 uint32_t uci_hash_options(struct uci_option **tb, int n_opts); 350 351 352 /* UCI data structures */ 353 enum uci_type { 354 UCI_TYPE_UNSPEC = 0, 355 UCI_TYPE_DELTA = 1, 356 UCI_TYPE_PACKAGE = 2, 357 UCI_TYPE_SECTION = 3, 358 UCI_TYPE_OPTION = 4, 359 UCI_TYPE_PATH = 5, 360 UCI_TYPE_BACKEND = 6, 361 UCI_TYPE_ITEM = 7, 362 UCI_TYPE_HOOK = 8, 363 }; 364 365 enum uci_option_type { 366 UCI_TYPE_STRING = 0, 367 UCI_TYPE_LIST = 1, 368 }; 369 370 enum uci_flags { 371 UCI_FLAG_STRICT = (1 << 0), /* strict mode for the parser */ 372 UCI_FLAG_PERROR = (1 << 1), /* print parser error messages */ 373 UCI_FLAG_EXPORT_NAME = (1 << 2), /* when exporting, name unnamed sections */ 374 UCI_FLAG_SAVED_DELTA = (1 << 3), /* store the saved delta in memory as well */ 375 }; 376 377 struct uci_element 378 { 379 struct uci_list list; 380 enum uci_type type; 381 char *name; 382 }; 383 384 struct uci_backend 385 { 386 struct uci_element e; 387 char **(*list_configs)(struct uci_context *ctx); 388 struct uci_package *(*load)(struct uci_context *ctx, const char *name); 389 void (*commit)(struct uci_context *ctx, struct uci_package **p, bool overwrite); 390 391 /* private: */ 392 const void *ptr; 393 void *priv; 394 }; 395 396 struct uci_context 397 { 398 /* list of config packages */ 399 struct uci_list root; 400 401 /* parser context, use for error handling only */ 402 struct uci_parse_context *pctx; 403 404 /* backend for import and export */ 405 struct uci_backend *backend; 406 struct uci_list backends; 407 408 /* uci runtime flags */ 409 enum uci_flags flags; 410 411 char *confdir; 412 char *savedir; 413 414 /* search path for delta files */ 415 struct uci_list delta_path; 416 417 /* private: */ 418 int err; 419 const char *func; 420 jmp_buf trap; 421 bool internal, nested; 422 char *buf; 423 int bufsz; 424 }; 425 426 struct uci_package 427 { 428 struct uci_element e; 429 struct uci_list sections; 430 struct uci_context *ctx; 431 bool has_delta; 432 char *path; 433 434 /* private: */ 435 struct uci_backend *backend; 436 void *priv; 437 int n_section; 438 struct uci_list delta; 439 struct uci_list saved_delta; 440 }; 441 442 struct uci_section 443 { 444 struct uci_element e; 445 struct uci_list options; 446 struct uci_package *package; 447 bool anonymous; 448 char *type; 449 }; 450 451 struct uci_option 452 { 453 struct uci_element e; 454 struct uci_section *section; 455 enum uci_option_type type; 456 union { 457 struct uci_list list; 458 char *string; 459 } v; 460 }; 461 462 /* 463 * UCI_CMD_ADD is used for anonymous sections or list values 464 */ 465 enum uci_command { 466 UCI_CMD_ADD, 467 UCI_CMD_REMOVE, 468 UCI_CMD_CHANGE, 469 UCI_CMD_RENAME, 470 UCI_CMD_REORDER, 471 UCI_CMD_LIST_ADD, 472 UCI_CMD_LIST_DEL, 473 __UCI_CMD_MAX, 474 __UCI_CMD_LAST = __UCI_CMD_MAX - 1 475 }; 476 extern char const uci_command_char[]; 477 478 struct uci_delta 479 { 480 struct uci_element e; 481 enum uci_command cmd; 482 char *section; 483 char *value; 484 }; 485 486 struct uci_ptr 487 { 488 enum uci_type target; 489 enum { 490 UCI_LOOKUP_DONE = (1 << 0), 491 UCI_LOOKUP_COMPLETE = (1 << 1), 492 UCI_LOOKUP_EXTENDED = (1 << 2), 493 } flags; 494 495 struct uci_package *p; 496 struct uci_section *s; 497 struct uci_option *o; 498 struct uci_element *last; 499 500 const char *package; 501 const char *section; 502 const char *option; 503 const char *value; 504 }; 505 506 struct uci_parse_option { 507 const char *name; 508 enum uci_option_type type; 509 }; 510 511 512 /* linked list handling */ 513 #ifndef offsetof 514 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER) 515 #endif 516 517 /** 518 * container_of - cast a member of a structure out to the containing structure 519 * @ptr: the pointer to the member. 520 * @type: the type of the container struct this is embedded in. 521 * @member: the name of the member within the struct. 522 */ 523 #ifndef container_of 524 #define container_of(ptr, type, member) \ 525 ((type *) ((char *)ptr - offsetof(type,member))) 526 #endif 527 528 529 /** 530 * uci_list_entry: casts an uci_list pointer to the containing struct. 531 * @_type: config, section or option 532 * @_ptr: pointer to the uci_list struct 533 */ 534 #define list_to_element(ptr) \ 535 container_of(ptr, struct uci_element, list) 536 537 /** 538 * uci_foreach_entry: loop through a list of uci elements 539 * @_list: pointer to the uci_list struct 540 * @_ptr: iteration variable, struct uci_element 541 * 542 * use like a for loop, e.g: 543 * uci_foreach(&list, p) { 544 * ... 545 * } 546 */ 547 #define uci_foreach_element(_list, _ptr) \ 548 for(_ptr = list_to_element((_list)->next); \ 549 &_ptr->list != (_list); \ 550 _ptr = list_to_element(_ptr->list.next)) 551 552 /** 553 * uci_foreach_entry_safe: like uci_foreach_safe, but safe for deletion 554 * @_list: pointer to the uci_list struct 555 * @_tmp: temporary variable, struct uci_element * 556 * @_ptr: iteration variable, struct uci_element * 557 * 558 * use like a for loop, e.g: 559 * uci_foreach(&list, p) { 560 * ... 561 * } 562 */ 563 #define uci_foreach_element_safe(_list, _tmp, _ptr) \ 564 for(_ptr = list_to_element((_list)->next), \ 565 _tmp = list_to_element(_ptr->list.next); \ 566 &_ptr->list != (_list); \ 567 _ptr = _tmp, _tmp = list_to_element(_ptr->list.next)) 568 569 /** 570 * uci_list_empty: returns true if a list is empty 571 * @list: list head 572 */ 573 #define uci_list_empty(list) ((list)->next == (list)) 574 575 /* wrappers for dynamic type handling */ 576 #define uci_type_backend UCI_TYPE_BACKEND 577 #define uci_type_delta UCI_TYPE_DELTA 578 #define uci_type_package UCI_TYPE_PACKAGE 579 #define uci_type_section UCI_TYPE_SECTION 580 #define uci_type_option UCI_TYPE_OPTION 581 582 /* element typecasting */ 583 #ifdef UCI_DEBUG_TYPECAST 584 static const char *uci_typestr[] = { 585 [uci_type_backend] = "backend", 586 [uci_type_delta] = "delta", 587 [uci_type_package] = "package", 588 [uci_type_section] = "section", 589 [uci_type_option] = "option", 590 }; 591 592 static void uci_typecast_error(int from, int to) 593 { 594 fprintf(stderr, "Invalid typecast from '%s' to '%s'\n", uci_typestr[from], uci_typestr[to]); 595 } 596 597 #define BUILD_CAST(_type) \ 598 static inline struct uci_ ## _type *uci_to_ ## _type (struct uci_element *e) \ 599 { \ 600 if (e->type != uci_type_ ## _type) { \ 601 uci_typecast_error(e->type, uci_type_ ## _type); \ 602 } \ 603 return (struct uci_ ## _type *) e; \ 604 } 605 606 BUILD_CAST(backend) 607 BUILD_CAST(delta) 608 BUILD_CAST(package) 609 BUILD_CAST(section) 610 BUILD_CAST(option) 611 612 #else 613 #define uci_to_backend(ptr) container_of(ptr, struct uci_backend, e) 614 #define uci_to_delta(ptr) container_of(ptr, struct uci_delta, e) 615 #define uci_to_package(ptr) container_of(ptr, struct uci_package, e) 616 #define uci_to_section(ptr) container_of(ptr, struct uci_section, e) 617 #define uci_to_option(ptr) container_of(ptr, struct uci_option, e) 618 #endif 619 620 /** 621 * uci_alloc_element: allocate a generic uci_element, reserve a buffer and typecast 622 * @ctx: uci context 623 * @type: {package,section,option} 624 * @name: string containing the name of the element 625 * @datasize: additional buffer size to reserve at the end of the struct 626 */ 627 #define uci_alloc_element(ctx, type, name, datasize) \ 628 uci_to_ ## type (uci_alloc_generic(ctx, uci_type_ ## type, name, sizeof(struct uci_ ## type) + datasize)) 629 630 #define uci_dataptr(ptr) \ 631 (((char *) ptr) + sizeof(*ptr)) 632 633 /** 634 * uci_lookup_package: look up a package 635 * @ctx: uci context 636 * @name: name of the package 637 */ 638 static inline struct uci_package * 639 uci_lookup_package(struct uci_context *ctx, const char *name) 640 { 641 struct uci_element *e = NULL; 642 if (uci_lookup_next(ctx, &e, &ctx->root, name) == 0) 643 return uci_to_package(e); 644 else 645 return NULL; 646 } 647 648 /** 649 * uci_lookup_section: look up a section 650 * @ctx: uci context 651 * @p: package that the section belongs to 652 * @name: name of the section 653 */ 654 static inline struct uci_section * 655 uci_lookup_section(struct uci_context *ctx, struct uci_package *p, const char *name) 656 { 657 struct uci_element *e = NULL; 658 if (uci_lookup_next(ctx, &e, &p->sections, name) == 0) 659 return uci_to_section(e); 660 else 661 return NULL; 662 } 663 664 /** 665 * uci_lookup_option: look up an option 666 * @ctx: uci context 667 * @section: section that the option belongs to 668 * @name: name of the option 669 */ 670 static inline struct uci_option * 671 uci_lookup_option(struct uci_context *ctx, struct uci_section *s, const char *name) 672 { 673 struct uci_element *e = NULL; 674 if (uci_lookup_next(ctx, &e, &s->options, name) == 0) 675 return uci_to_option(e); 676 else 677 return NULL; 678 } 679 680 static inline const char * 681 uci_lookup_option_string(struct uci_context *ctx, struct uci_section *s, const char *name) 682 { 683 struct uci_option *o; 684 685 o = uci_lookup_option(ctx, s, name); 686 if (!o || o->type != UCI_TYPE_STRING) 687 return NULL; 688 689 return o->v.string; 690 } 691 692 #ifndef BITS_PER_LONG 693 #define BITS_PER_LONG (8 * sizeof(unsigned long)) 694 #endif 695 696 static inline void uci_bitfield_set(unsigned long *bits, int bit) 697 { 698 bits[bit / BITS_PER_LONG] |= (1UL << (bit % BITS_PER_LONG)); 699 } 700 701 #ifdef __cplusplus 702 } 703 #endif 704 705 #endif 706
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