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