list.c

   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 General Public License for more details.
  13  */
  14
  15 #include <glob.h>
  16
  17 /* initialize a list head/item */
  18 static inline void uci_list_init(struct uci_list *ptr)
  19 {
  20         ptr->prev = ptr;
  21         ptr->next = ptr;
  22 }
  23
  24 /* inserts a new list entry after a given entry */
  25 static inline void uci_list_insert(struct uci_list *list, struct uci_list *ptr)
  26 {
  27         list->next->prev = ptr;
  28         ptr->prev = list;
  29         ptr->next = list->next;
  30         list->next = ptr;
  31 }
  32
  33 /* inserts a new list entry at the tail of the list */
  34 static inline void uci_list_add(struct uci_list *head, struct uci_list *ptr)
  35 {
  36         /* NB: head->prev points at the tail */
  37         uci_list_insert(head->prev, ptr);
  38 }
  39
  40 static inline void uci_list_del(struct uci_list *ptr)
  41 {
  42         struct uci_list *next, *prev;
  43
  44         next = ptr->next;
  45         prev = ptr->prev;
  46
  47         prev->next = next;
  48         next->prev = prev;
  49
  50         uci_list_init(ptr);
  51 }
  52
  53 /*
  54  * uci_alloc_generic allocates a new uci_element with payload
  55  * payload is appended to the struct to save memory and reduce fragmentation
  56  */
  57 static struct uci_element *
  58 uci_alloc_generic(struct uci_context *ctx, int type, const char *name, int size)
  59 {
  60         struct uci_element *e;
  61         int datalen = size;
  62         void *ptr;
  63
  64         ptr = uci_malloc(ctx, datalen);
  65         e = (struct uci_element *) ptr;
  66         e->type = type;
  67         if (name) {
  68                 UCI_TRAP_SAVE(ctx, error);
  69                 e->name = uci_strdup(ctx, name);
  70                 UCI_TRAP_RESTORE(ctx);
  71         }
  72         uci_list_init(&e->list);
  73         goto done;
  74
  75 error:
  76         free(ptr);
  77         UCI_THROW(ctx, ctx->err);
  78
  79 done:
  80         return e;
  81 }
  82
  83 static void
  84 uci_free_element(struct uci_element *e)
  85 {
  86         if (e->name)
  87                 free(e->name);
  88         if (!uci_list_empty(&e->list))
  89                 uci_list_del(&e->list);
  90         free(e);
  91 }
  92
  93 static struct uci_option *
  94 uci_alloc_option(struct uci_section *s, const char *name, const char *value)
  95 {
  96         struct uci_package *p = s->package;
  97         struct uci_context *ctx = p->ctx;
  98         struct uci_option *o;
  99
 100         o = uci_alloc_element(ctx, option, name, strlen(value) + 1);
 101         o->type = UCI_TYPE_STRING;
 102         o->v.string = uci_dataptr(o);
 103         o->section = s;
 104         strcpy(o->v.string, value);
 105         uci_list_add(&s->options, &o->e.list);
 106
 107         return o;
 108 }
 109
 110 static inline void
 111 uci_free_option(struct uci_option *o)
 112 {
 113         switch(o->type) {
 114         case UCI_TYPE_STRING:
 115                 if ((o->v.string != uci_dataptr(o)) &&
 116                         (o->v.string != NULL))
 117                         free(o->v.string);
 118                 break;
 119         default:
 120                 break;
 121         }
 122         uci_free_element(&o->e);
 123 }
 124
 125 /* fix up an unnamed section, e.g. after adding options to it */
 126 static void uci_fixup_section(struct uci_context *ctx, struct uci_section *s)
 127 {
 128         unsigned int hash = ~0;
 129         struct uci_element *e;
 130         char buf[16];
 131
 132         if (!s || s->e.name)
 133                 return;
 134
 135         /*
 136          * Generate a name for unnamed sections. This is used as reference
 137          * when locating or updating the section from apps/scripts.
 138          * To make multiple concurrent versions somewhat safe for updating,
 139          * the name is generated from a hash of its type and name/value
 140          * pairs of its option, and it is prefixed by a counter value.
 141          * If the order of the unnamed sections changes for some reason,
 142          * updates to them will be rejected.
 143          */
 144         hash = djbhash(hash, s->type);
 145         uci_foreach_element(&s->options, e) {
 146                 struct uci_option *o;
 147                 hash = djbhash(hash, e->name);
 148                 o = uci_to_option(e);
 149                 switch(o->type) {
 150                 case UCI_TYPE_STRING:
 151                         hash = djbhash(hash, o->v.string);
 152                         break;
 153                 default:
 154                         break;
 155                 }
 156         }
 157         sprintf(buf, "cfg%02x%04x", ++s->package->n_section, hash % (1 << 16));
 158         s->e.name = uci_strdup(ctx, buf);
 159 }
 160
 161 static struct uci_section *
 162 uci_alloc_section(struct uci_package *p, const char *type, const char *name)
 163 {
 164         struct uci_context *ctx = p->ctx;
 165         struct uci_section *s;
 166
 167         if (name && !name[0])
 168                 name = NULL;
 169
 170         s = uci_alloc_element(ctx, section, name, strlen(type) + 1);
 171         uci_list_init(&s->options);
 172         s->type = uci_dataptr(s);
 173         s->package = p;
 174         strcpy(s->type, type);
 175         if (name == NULL)
 176                 s->anonymous = true;
 177         p->n_section++;
 178
 179         uci_list_add(&p->sections, &s->e.list);
 180
 181         return s;
 182 }
 183
 184 static void
 185 uci_free_section(struct uci_section *s)
 186 {
 187         struct uci_element *o, *tmp;
 188
 189         uci_foreach_element_safe(&s->options, tmp, o) {
 190                 uci_free_option(uci_to_option(o));
 191         }
 192         if ((s->type != uci_dataptr(s)) &&
 193                 (s->type != NULL))
 194                 free(s->type);
 195         uci_free_element(&s->e);
 196 }
 197
 198 __plugin struct uci_package *
 199 uci_alloc_package(struct uci_context *ctx, const char *name)
 200 {
 201         struct uci_package *p;
 202
 203         p = uci_alloc_element(ctx, package, name, 0);
 204         p->ctx = ctx;
 205         uci_list_init(&p->sections);
 206         uci_list_init(&p->history);
 207         uci_list_init(&p->saved_history);
 208         return p;
 209 }
 210
 211 static void
 212 uci_free_package(struct uci_package **package)
 213 {
 214         struct uci_element *e, *tmp;
 215         struct uci_package *p = *package;
 216
 217         if(!p)
 218                 return;
 219
 220         if (p->path)
 221                 free(p->path);
 222         uci_foreach_element_safe(&p->sections, tmp, e) {
 223                 uci_free_section(uci_to_section(e));
 224         }
 225         uci_foreach_element_safe(&p->history, tmp, e) {
 226                 uci_free_history(uci_to_history(e));
 227         }
 228         uci_foreach_element_safe(&p->saved_history, tmp, e) {
 229                 uci_free_history(uci_to_history(e));
 230         }
 231         uci_free_element(&p->e);
 232         *package = NULL;
 233 }
 234
 235 static struct uci_element *uci_lookup_list(struct uci_list *list, const char *name)
 236 {
 237         struct uci_element *e;
 238
 239         uci_foreach_element(list, e) {
 240                 if (!strcmp(e->name, name))
 241                         return e;
 242         }
 243         return NULL;
 244 }
 245
 246 int uci_lookup_ext(struct uci_context *ctx, struct uci_element **res, char *ptr)
 247 {
 248         struct uci_package *p = NULL;
 249         struct uci_element *e;
 250         struct uci_section *s;
 251         char *package = NULL;
 252         char *section = NULL;
 253         char *option = NULL;
 254         char *idxstr, *t;
 255         int idx, c;
 256
 257         UCI_HANDLE_ERR(ctx);
 258         UCI_ASSERT(ctx, res != NULL);
 259         UCI_ASSERT(ctx, ptr != NULL);
 260
 261         UCI_INTERNAL(uci_parse_tuple, ctx, ptr, &package, &section, &option, NULL);
 262
 263         /* look up the package first */
 264         e = uci_lookup_list(&ctx->root, package);
 265         if (!e) {
 266                 UCI_INTERNAL(uci_load, ctx, package, &p);
 267                 if (!p)
 268                         goto notfound;
 269                 e = &p->e;
 270         } else {
 271                 p = uci_to_package(e);
 272         }
 273
 274         if (!section)
 275                 goto done;
 276
 277         /* if the section name validates as a regular name, pass through
 278          * to the regular uci_lookup function call */
 279         if (!*section || uci_validate_name(section)) {
 280                 UCI_INTERNAL(uci_lookup, ctx, &e, p, section, option);
 281                 goto done;
 282         }
 283
 284         /* name did not validate, that means we have an extended lookup call
 285          * parse it here. for now only the section index syntax is supported */
 286         if (section[0] != '@')
 287                 goto error;
 288
 289         section++;
 290
 291         /* parse the section index part */
 292         idxstr = strchr(section, '[');
 293         if (!idxstr)
 294                 goto error;
 295         *idxstr = 0;
 296         idxstr++;
 297
 298         t = strchr(idxstr, ']');
 299         if (!t)
 300                 goto error;
 301         if (t[1] != 0)
 302                 goto error;
 303         *t = 0;
 304
 305         t = NULL;
 306         idx = strtol(idxstr, &t, 10);
 307         if (t && *t)
 308                 goto error;
 309
 310         if (!*section)
 311                 section = NULL;
 312         if (section && !uci_validate_str(section, false))
 313                 goto error;
 314
 315         /* if the given index is negative, it specifies the section number from
 316          * the end of the list */
 317         if (idx < 0) {
 318                 c = 0;
 319                 uci_foreach_element(&p->sections, e) {
 320                         s = uci_to_section(e);
 321                         if (section && (strcmp(s->type, section) != 0))
 322                                 continue;
 323
 324                         c++;
 325                 }
 326                 idx += c;
 327         }
 328
 329         c = 0;
 330         uci_foreach_element(&p->sections, e) {
 331                 s = uci_to_section(e);
 332                 if (section && (strcmp(s->type, section) != 0))
 333                         continue;
 334
 335                 if (idx == c)
 336                         goto found;
 337                 c++;
 338         }
 339         goto notfound;
 340
 341 found:
 342         if (option)
 343                 e = uci_lookup_list(&s->options, option);
 344 done:
 345         *res = e;
 346         return 0;
 347
 348 notfound:
 349         UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 350 error:
 351         UCI_THROW(ctx, UCI_ERR_INVAL);
 352         return 0;
 353 }
 354
 355 int uci_lookup(struct uci_context *ctx, struct uci_element **res, struct uci_package *p, const char *section, const char *option)
 356 {
 357         struct uci_element *e;
 358         struct uci_section *s;
 359
 360         UCI_HANDLE_ERR(ctx);
 361         UCI_ASSERT(ctx, res != NULL);
 362         UCI_ASSERT(ctx, p != NULL);
 363         UCI_ASSERT(ctx, section && uci_validate_name(section));
 364         if (option)
 365                 UCI_ASSERT(ctx, uci_validate_name(option));
 366
 367         e = uci_lookup_list(&p->sections, section);
 368         if (!e)
 369                 goto notfound;
 370
 371         if (option) {
 372                 s = uci_to_section(e);
 373                 e = uci_lookup_list(&s->options, option);
 374                 if (!e)
 375                         goto notfound;
 376         }
 377
 378         *res = e;
 379         return 0;
 380
 381 notfound:
 382         UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 383         return 0;
 384 }
 385
 386 int uci_del_element(struct uci_context *ctx, struct uci_element *e)
 387 {
 388         /* NB: UCI_INTERNAL use means without history tracking */
 389         bool internal = ctx->internal;
 390         struct uci_package *p = NULL;
 391         struct uci_section *s = NULL;
 392         struct uci_option *o = NULL;
 393         struct uci_element *i, *tmp;
 394         char *option = NULL;
 395
 396         UCI_HANDLE_ERR(ctx);
 397         UCI_ASSERT(ctx, e != NULL);
 398
 399         switch(e->type) {
 400         case UCI_TYPE_SECTION:
 401                 s = uci_to_section(e);
 402                 uci_foreach_element_safe(&s->options, tmp, i) {
 403                         uci_del_element(ctx, i);
 404                 }
 405                 break;
 406         case UCI_TYPE_OPTION:
 407                 o = uci_to_option(e);
 408                 s = o->section;
 409                 p = s->package;
 410                 option = e->name;
 411                 break;
 412         default:
 413                 UCI_THROW(ctx, UCI_ERR_INVAL);
 414                 break;
 415         }
 416
 417         p = s->package;
 418         if (!internal && p->has_history)
 419                 uci_add_history(ctx, &p->history, UCI_CMD_REMOVE, s->e.name, option, NULL);
 420
 421         switch(e->type) {
 422         case UCI_TYPE_SECTION:
 423                 uci_free_section(s);
 424                 break;
 425         case UCI_TYPE_OPTION:
 426                 uci_free_option(o);
 427                 break;
 428         default:
 429                 break;
 430         }
 431         return 0;
 432 }
 433
 434 int uci_set_element_value(struct uci_context *ctx, struct uci_element **element, const char *value)
 435 {
 436         /* NB: UCI_INTERNAL use means without history tracking */
 437         bool internal = ctx->internal;
 438         struct uci_list *list;
 439         struct uci_element *e;
 440         struct uci_package *p;
 441         struct uci_section *s;
 442         struct uci_option *o;
 443         char *section;
 444         char *option;
 445         char *str;
 446         int size;
 447
 448         UCI_HANDLE_ERR(ctx);
 449         UCI_ASSERT(ctx, (element != NULL) && (*element != NULL));
 450
 451         /* what the 'value' of an element means depends on the type
 452          * for a section, the 'value' means its type
 453          * for an option, the 'value' means its value string
 454          * when changing the value, shrink the element to its actual size
 455          * (it may have been allocated with a bigger size, to include
 456          *  its buffer)
 457          * then duplicate the string passed on the command line and
 458          * insert it into the structure.
 459          */
 460         e = *element;
 461         list = e->list.prev;
 462         switch(e->type) {
 463         case UCI_TYPE_SECTION:
 464                 UCI_ASSERT(ctx, uci_validate_str(value, false));
 465                 size = sizeof(struct uci_section);
 466                 s = uci_to_section(e);
 467                 section = e->name;
 468                 option = NULL;
 469                 /* matches the currently set value */
 470                 if (!strcmp(value, s->type))
 471                         return 0;
 472                 break;
 473         case UCI_TYPE_OPTION:
 474                 UCI_ASSERT(ctx, value != NULL);
 475                 size = sizeof(struct uci_option);
 476                 o = uci_to_option(e);
 477                 s = o->section;
 478                 section = s->e.name;
 479                 option = o->e.name;
 480                 if (o->type != UCI_TYPE_STRING)
 481                         UCI_THROW(ctx, UCI_ERR_INVAL);
 482                 /* matches the currently set value */
 483                 if (!strcmp(value, o->v.string))
 484                         return 0;
 485                 break;
 486         default:
 487                 UCI_THROW(ctx, UCI_ERR_INVAL);
 488                 return 0;
 489         }
 490         p = s->package;
 491         if (!internal && p->has_history)
 492                 uci_add_history(ctx, &p->history, UCI_CMD_CHANGE, section, option, value);
 493
 494         uci_list_del(&e->list);
 495         e = uci_realloc(ctx, e, size);
 496         str = uci_strdup(ctx, value);
 497         uci_list_insert(list, &e->list);
 498         *element = e;
 499
 500         switch(e->type) {
 501         case UCI_TYPE_SECTION:
 502                 uci_to_section(e)->type = str;
 503                 break;
 504         case UCI_TYPE_OPTION:
 505                 uci_to_option(e)->v.string = str;
 506                 break;
 507         default:
 508                 break;
 509         }
 510
 511         return 0;
 512 }
 513
 514 int uci_rename(struct uci_context *ctx, struct uci_package *p, char *section, char *option, char *name)
 515 {
 516         /* NB: UCI_INTERNAL use means without history tracking */
 517         bool internal = ctx->internal;
 518         struct uci_element *e;
 519
 520         UCI_HANDLE_ERR(ctx);
 521
 522         /* NB: p, section, option validated by uci_lookup */
 523         UCI_INTERNAL(uci_lookup, ctx, &e, p, section, option);
 524
 525         if (!internal && p->has_history)
 526                 uci_add_history(ctx, &p->history, UCI_CMD_RENAME, section, option, name);
 527
 528         name = uci_strdup(ctx, name);
 529         if (e->name)
 530                 free(e->name);
 531         e->name = name;
 532
 533         return 0;
 534 }
 535
 536 int uci_add_section(struct uci_context *ctx, struct uci_package *p, const char *type, struct uci_section **res)
 537 {
 538         bool internal = ctx->internal;
 539         struct uci_section *s;
 540
 541         UCI_HANDLE_ERR(ctx);
 542         UCI_ASSERT(ctx, p != NULL);
 543         s = uci_alloc_section(p, type, NULL);
 544         uci_fixup_section(ctx, s);
 545         *res = s;
 546         if (!internal && p->has_history)
 547                 uci_add_history(ctx, &p->history, UCI_CMD_ADD, s->e.name, NULL, type);
 548
 549         return 0;
 550 }
 551
 552 int uci_delete(struct uci_context *ctx, struct uci_package *p, const char *section, const char *option)
 553 {
 554         /* NB: pass on internal flag to uci_del_element */
 555         bool internal = ctx->internal;
 556         struct uci_element *e;
 557
 558         UCI_HANDLE_ERR(ctx);
 559
 560         /* NB: p, section, option validated by uci_lookup */
 561         UCI_INTERNAL(uci_lookup, ctx, &e, p, section, option);
 562
 563         ctx->internal = internal;
 564         return uci_del_element(ctx, e);
 565 }
 566
 567 int uci_set(struct uci_context *ctx, struct uci_package *p, const char *section, const char *option, const char *value, struct uci_element **result)
 568 {
 569         /* NB: UCI_INTERNAL use means without history tracking */
 570         bool internal = ctx->internal;
 571         struct uci_element *e = NULL;
 572         struct uci_section *s = NULL;
 573         struct uci_option *o = NULL;
 574
 575         UCI_HANDLE_ERR(ctx);
 576         UCI_ASSERT(ctx, p != NULL);
 577         UCI_ASSERT(ctx, uci_validate_name(section));
 578         if (option) {
 579                 UCI_ASSERT(ctx, uci_validate_name(option));
 580                 UCI_ASSERT(ctx, value != NULL);
 581         } else {
 582                 UCI_ASSERT(ctx, uci_validate_str(value, false));
 583         }
 584
 585         /*
 586          * look up the package, section and option (if set)
 587          * if the section/option is to be modified and it is not found
 588          * create a new element in the appropriate list
 589          */
 590         e = uci_lookup_list(&p->sections, section);
 591         if (!e)
 592                 goto notfound;
 593
 594         s = uci_to_section(e);
 595         if (ctx->pctx && ctx->pctx->merge)
 596                 ctx->pctx->section = s;
 597
 598         if (option) {
 599                 e = uci_lookup_list(&s->options, option);
 600                 if (!e)
 601                         goto notfound;
 602                 o = uci_to_option(e);
 603         }
 604
 605         /*
 606          * no unknown element was supplied, assume that we can just update
 607          * an existing entry
 608          */
 609         if (o)
 610                 e = &o->e;
 611         else
 612                 e = &s->e;
 613         if (result)
 614                 *result = e;
 615         else
 616                 result = &e;
 617
 618         ctx->internal = internal;
 619         return uci_set_element_value(ctx, result, value);
 620
 621 notfound:
 622         /*
 623          * the entry that we need to update was not found,
 624          * check if the search failed prematurely.
 625          * this can happen if the package was not found, or if
 626          * an option was supplied, but the section wasn't found
 627          */
 628         if (!p || (!s && option))
 629                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 630
 631         /* now add the missing entry */
 632         if (!internal && p->has_history)
 633                 uci_add_history(ctx, &p->history, UCI_CMD_CHANGE, section, option, value);
 634         if (s) {
 635                 o = uci_alloc_option(s, option, value);
 636                 if (result)
 637                         *result = &o->e;
 638         } else {
 639                 s = uci_alloc_section(p, value, section);
 640                 if (result)
 641                         *result = &s->e;
 642                 if (ctx->pctx && ctx->pctx->merge)
 643                         ctx->pctx->section = s;
 644         }
 645
 646         return 0;
 647 }
 648
 649 int uci_unload(struct uci_context *ctx, struct uci_package *p)
 650 {
 651         UCI_HANDLE_ERR(ctx);
 652         UCI_ASSERT(ctx, p != NULL);
 653
 654         uci_free_package(&p);
 655         return 0;
 656 }
 657