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