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 static void uci_list_set_pos(struct uci_list *head, struct uci_list *ptr, int pos)
  16 {
  17         struct uci_list *new_head = head;
  18         struct uci_element *p = NULL;
  19
  20         uci_list_del(ptr);
  21         uci_foreach_element(head, p) {
  22                 new_head = &p->list;
  23                 if (pos-- <= 0)
  24                         break;
  25         }
  26         uci_list_add(new_head, ptr);
  27 }
  28
  29 static inline void uci_list_fixup(struct uci_list *ptr)
  30 {
  31         ptr->prev->next = ptr;
  32         ptr->next->prev = ptr;
  33 }
  34
  35 /*
  36  * uci_alloc_generic allocates a new uci_element with payload
  37  * payload is appended to the struct to save memory and reduce fragmentation
  38  */
  39 static struct uci_element *
  40 uci_alloc_generic(struct uci_context *ctx, int type, const char *name, int size)
  41 {
  42         struct uci_element *e;
  43         int datalen = size;
  44         void *ptr;
  45
  46         ptr = uci_malloc(ctx, datalen);
  47         e = (struct uci_element *) ptr;
  48         e->type = type;
  49         if (name) {
  50                 UCI_TRAP_SAVE(ctx, error);
  51                 e->name = uci_strdup(ctx, name);
  52                 UCI_TRAP_RESTORE(ctx);
  53         }
  54         uci_list_init(&e->list);
  55         goto done;
  56
  57 error:
  58         free(ptr);
  59         UCI_THROW(ctx, ctx->err);
  60
  61 done:
  62         return e;
  63 }
  64
  65 static void
  66 uci_free_element(struct uci_element *e)
  67 {
  68         if (e->name)
  69                 free(e->name);
  70         if (!uci_list_empty(&e->list))
  71                 uci_list_del(&e->list);
  72         free(e);
  73 }
  74
  75 static struct uci_option *
  76 uci_alloc_option(struct uci_section *s, const char *name, const char *value)
  77 {
  78         struct uci_package *p = s->package;
  79         struct uci_context *ctx = p->ctx;
  80         struct uci_option *o;
  81
  82         o = uci_alloc_element(ctx, option, name, strlen(value) + 1);
  83         o->type = UCI_TYPE_STRING;
  84         o->v.string = uci_dataptr(o);
  85         o->section = s;
  86         strcpy(o->v.string, value);
  87         uci_list_add(&s->options, &o->e.list);
  88
  89         return o;
  90 }
  91
  92 static inline void
  93 uci_free_option(struct uci_option *o)
  94 {
  95         struct uci_element *e, *tmp;
  96
  97         switch(o->type) {
  98         case UCI_TYPE_STRING:
  99                 if ((o->v.string != uci_dataptr(o)) &&
 100                         (o->v.string != NULL))
 101                         free(o->v.string);
 102                 break;
 103         case UCI_TYPE_LIST:
 104                 uci_foreach_element_safe(&o->v.list, tmp, e) {
 105                         uci_free_element(e);
 106                 }
 107                 break;
 108         default:
 109                 break;
 110         }
 111         uci_free_element(&o->e);
 112 }
 113
 114 static struct uci_option *
 115 uci_alloc_list(struct uci_section *s, const char *name)
 116 {
 117         struct uci_package *p = s->package;
 118         struct uci_context *ctx = p->ctx;
 119         struct uci_option *o;
 120
 121         o = uci_alloc_element(ctx, option, name, 0);
 122         o->type = UCI_TYPE_LIST;
 123         o->section = s;
 124         uci_list_init(&o->v.list);
 125         uci_list_add(&s->options, &o->e.list);
 126
 127         return o;
 128 }
 129
 130 /* Based on an efficient hash function published by D. J. Bernstein */
 131 static unsigned int djbhash(unsigned int hash, char *str)
 132 {
 133         int len = strlen(str);
 134         int i;
 135
 136         /* initial value */
 137         if (hash == ~0)
 138                 hash = 5381;
 139
 140         for(i = 0; i < len; i++) {
 141                 hash = ((hash << 5) + hash) + str[i];
 142         }
 143         return (hash & 0x7FFFFFFF);
 144 }
 145
 146 /* fix up an unnamed section, e.g. after adding options to it */
 147 __private void uci_fixup_section(struct uci_context *ctx, struct uci_section *s)
 148 {
 149         unsigned int hash = ~0;
 150         struct uci_element *e;
 151         char buf[16];
 152
 153         if (!s || s->e.name)
 154                 return;
 155
 156         /*
 157          * Generate a name for unnamed sections. This is used as reference
 158          * when locating or updating the section from apps/scripts.
 159          * To make multiple concurrent versions somewhat safe for updating,
 160          * the name is generated from a hash of its type and name/value
 161          * pairs of its option, and it is prefixed by a counter value.
 162          * If the order of the unnamed sections changes for some reason,
 163          * updates to them will be rejected.
 164          */
 165         hash = djbhash(hash, s->type);
 166         uci_foreach_element(&s->options, e) {
 167                 struct uci_option *o;
 168                 hash = djbhash(hash, e->name);
 169                 o = uci_to_option(e);
 170                 switch(o->type) {
 171                 case UCI_TYPE_STRING:
 172                         hash = djbhash(hash, o->v.string);
 173                         break;
 174                 default:
 175                         break;
 176                 }
 177         }
 178         sprintf(buf, "cfg%02x%04x", ++s->package->n_section, hash % (1 << 16));
 179         s->e.name = uci_strdup(ctx, buf);
 180 }
 181
 182 static struct uci_section *
 183 uci_alloc_section(struct uci_package *p, const char *type, const char *name)
 184 {
 185         struct uci_context *ctx = p->ctx;
 186         struct uci_section *s;
 187
 188         if (name && !name[0])
 189                 name = NULL;
 190
 191         s = uci_alloc_element(ctx, section, name, strlen(type) + 1);
 192         uci_list_init(&s->options);
 193         s->type = uci_dataptr(s);
 194         s->package = p;
 195         strcpy(s->type, type);
 196         if (name == NULL)
 197                 s->anonymous = true;
 198         p->n_section++;
 199
 200         uci_list_add(&p->sections, &s->e.list);
 201
 202         return s;
 203 }
 204
 205 static void
 206 uci_free_section(struct uci_section *s)
 207 {
 208         struct uci_element *o, *tmp;
 209
 210         uci_foreach_element_safe(&s->options, tmp, o) {
 211                 uci_free_option(uci_to_option(o));
 212         }
 213         if ((s->type != uci_dataptr(s)) &&
 214                 (s->type != NULL))
 215                 free(s->type);
 216         uci_free_element(&s->e);
 217 }
 218
 219 __plugin struct uci_package *
 220 uci_alloc_package(struct uci_context *ctx, const char *name)
 221 {
 222         struct uci_package *p;
 223
 224         p = uci_alloc_element(ctx, package, name, 0);
 225         p->ctx = ctx;
 226         uci_list_init(&p->sections);
 227         uci_list_init(&p->history);
 228         uci_list_init(&p->saved_history);
 229         return p;
 230 }
 231
 232 __private void
 233 uci_free_package(struct uci_package **package)
 234 {
 235         struct uci_element *e, *tmp;
 236         struct uci_package *p = *package;
 237
 238         if(!p)
 239                 return;
 240
 241         if (p->path)
 242                 free(p->path);
 243         uci_foreach_element_safe(&p->sections, tmp, e) {
 244                 uci_free_section(uci_to_section(e));
 245         }
 246         uci_foreach_element_safe(&p->history, tmp, e) {
 247                 uci_free_history(uci_to_history(e));
 248         }
 249         uci_foreach_element_safe(&p->saved_history, tmp, e) {
 250                 uci_free_history(uci_to_history(e));
 251         }
 252         uci_free_element(&p->e);
 253         *package = NULL;
 254 }
 255
 256 static void
 257 uci_free_any(struct uci_element **e)
 258 {
 259         switch((*e)->type) {
 260         case UCI_TYPE_SECTION:
 261                 uci_free_section(uci_to_section(*e));
 262                 break;
 263         case UCI_TYPE_OPTION:
 264                 uci_free_option(uci_to_option(*e));
 265                 break;
 266         default:
 267                 break;
 268         }
 269         *e = NULL;
 270 }
 271
 272 __private struct uci_element *
 273 uci_lookup_list(struct uci_list *list, const char *name)
 274 {
 275         struct uci_element *e;
 276
 277         uci_foreach_element(list, e) {
 278                 if (!strcmp(e->name, name))
 279                         return e;
 280         }
 281         return NULL;
 282 }
 283
 284 static struct uci_element *
 285 uci_lookup_ext_section(struct uci_context *ctx, struct uci_ptr *ptr)
 286 {
 287         char *idxstr, *t, *section, *name;
 288         struct uci_element *e = NULL;
 289         struct uci_section *s;
 290         int idx, c;
 291
 292         section = uci_strdup(ctx, ptr->section);
 293         name = idxstr = section + 1;
 294
 295         if (section[0] != '@')
 296                 goto error;
 297
 298         /* parse the section index part */
 299         idxstr = strchr(idxstr, '[');
 300         if (!idxstr)
 301                 goto error;
 302         *idxstr = 0;
 303         idxstr++;
 304
 305         t = strchr(idxstr, ']');
 306         if (!t)
 307                 goto error;
 308         if (t[1] != 0)
 309                 goto error;
 310         *t = 0;
 311
 312         t = NULL;
 313         idx = strtol(idxstr, &t, 10);
 314         if (t && *t)
 315                 goto error;
 316
 317         if (!*name)
 318                 name = NULL;
 319         else if (!uci_validate_type(name))
 320                 goto error;
 321
 322         /* if the given index is negative, it specifies the section number from
 323          * the end of the list */
 324         if (idx < 0) {
 325                 c = 0;
 326                 uci_foreach_element(&ptr->p->sections, e) {
 327                         s = uci_to_section(e);
 328                         if (name && (strcmp(s->type, name) != 0))
 329                                 continue;
 330
 331                         c++;
 332                 }
 333                 idx += c;
 334         }
 335
 336         c = 0;
 337         uci_foreach_element(&ptr->p->sections, e) {
 338                 s = uci_to_section(e);
 339                 if (name && (strcmp(s->type, name) != 0))
 340                         continue;
 341
 342                 if (idx == c)
 343                         goto done;
 344                 c++;
 345         }
 346         e = NULL;
 347         goto done;
 348
 349 error:
 350         e = NULL;
 351         memset(ptr, 0, sizeof(struct uci_ptr));
 352         UCI_THROW(ctx, UCI_ERR_INVAL);
 353 done:
 354         free(section);
 355         if (e)
 356                 ptr->section = e->name;
 357         return e;
 358 }
 359
 360 int
 361 uci_lookup_ptr(struct uci_context *ctx, struct uci_ptr *ptr, char *str, bool extended)
 362 {
 363         struct uci_element *e;
 364
 365         UCI_HANDLE_ERR(ctx);
 366         UCI_ASSERT(ctx, ptr != NULL);
 367
 368         if (str)
 369                 UCI_INTERNAL(uci_parse_ptr, ctx, ptr, str);
 370
 371         ptr->flags |= UCI_LOOKUP_DONE;
 372
 373         /* look up the package first */
 374         e = uci_lookup_list(&ctx->root, ptr->package);
 375         if (!e) {
 376                 UCI_INTERNAL(uci_load, ctx, ptr->package, &ptr->p);
 377                 if (!ptr->p)
 378                         goto notfound;
 379                 ptr->last = &ptr->p->e;
 380         } else {
 381                 ptr->p = uci_to_package(e);
 382                 ptr->last = e;
 383         }
 384
 385         if (!ptr->section)
 386                 goto complete;
 387
 388         /* if the section name validates as a regular name, pass through
 389          * to the regular uci_lookup function call */
 390         if (ptr->flags & UCI_LOOKUP_EXTENDED)
 391                 e = uci_lookup_ext_section(ctx, ptr);
 392         else
 393                 e = uci_lookup_list(&ptr->p->sections, ptr->section);
 394
 395         if (!e)
 396                 goto abort;
 397
 398         ptr->last = e;
 399         ptr->s = uci_to_section(e);
 400
 401         if (ptr->option) {
 402                 e = uci_lookup_list(&ptr->s->options, ptr->option);
 403                 if (!e)
 404                         goto abort;
 405
 406                 ptr->o = uci_to_option(e);
 407                 ptr->last = e;
 408         }
 409
 410 complete:
 411         ptr->flags |= UCI_LOOKUP_COMPLETE;
 412 abort:
 413         return 0;
 414
 415 notfound:
 416         UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 417         return 0;
 418 }
 419
 420 static struct uci_element *
 421 expand_ptr(struct uci_context *ctx, struct uci_ptr *ptr, bool complete)
 422 {
 423         UCI_ASSERT(ctx, ptr != NULL);
 424
 425         if (!(ptr->flags & UCI_LOOKUP_DONE))
 426                 UCI_INTERNAL(uci_lookup_ptr, ctx, ptr, NULL, 1);
 427         if (complete && !(ptr->flags & UCI_LOOKUP_COMPLETE))
 428                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 429         UCI_ASSERT(ctx, ptr->p != NULL);
 430
 431         /* fill in missing string info */
 432         if (ptr->p && !ptr->package)
 433                 ptr->package = ptr->p->e.name;
 434         if (ptr->s && !ptr->section)
 435                 ptr->section = ptr->s->e.name;
 436         if (ptr->o && !ptr->option)
 437                 ptr->option = ptr->o->e.name;
 438
 439         if (ptr->o)
 440                 return &ptr->o->e;
 441         if (ptr->s)
 442                 return &ptr->s->e;
 443         if (ptr->p)
 444                 return &ptr->p->e;
 445         else
 446                 return NULL;
 447 }
 448
 449 static void uci_add_element_list(struct uci_context *ctx, struct uci_ptr *ptr, bool internal)
 450 {
 451         struct uci_element *e;
 452         struct uci_package *p;
 453
 454         p = ptr->p;
 455         if (!internal && p->has_history)
 456                 uci_add_history(ctx, &p->history, UCI_CMD_LIST_ADD, ptr->section, ptr->option, ptr->value);
 457
 458         e = uci_alloc_generic(ctx, UCI_TYPE_ITEM, ptr->value, sizeof(struct uci_option));
 459         uci_list_add(&ptr->o->v.list, &e->list);
 460 }
 461
 462 int uci_rename(struct uci_context *ctx, struct uci_ptr *ptr)
 463 {
 464         /* NB: UCI_INTERNAL use means without history tracking */
 465         bool internal = ctx->internal;
 466         struct uci_element *e;
 467         struct uci_package *p;
 468         char *n;
 469
 470         UCI_HANDLE_ERR(ctx);
 471
 472         e = expand_ptr(ctx, ptr, true);
 473         p = ptr->p;
 474
 475         UCI_ASSERT(ctx, ptr->s);
 476         UCI_ASSERT(ctx, ptr->value);
 477
 478         if (!internal && p->has_history)
 479                 uci_add_history(ctx, &p->history, UCI_CMD_RENAME, ptr->section, ptr->option, ptr->value);
 480
 481         n = uci_strdup(ctx, ptr->value);
 482         if (e->name)
 483                 free(e->name);
 484         e->name = n;
 485
 486         if (e->type == UCI_TYPE_SECTION)
 487                 uci_to_section(e)->anonymous = false;
 488
 489         return 0;
 490 }
 491
 492 int uci_reorder_section(struct uci_context *ctx, struct uci_section *s, int pos)
 493 {
 494         struct uci_package *p = s->package;
 495         char order[32];
 496
 497         UCI_HANDLE_ERR(ctx);
 498
 499         uci_list_set_pos(&s->package->sections, &s->e.list, pos);
 500         if (!ctx->internal && p->has_history) {
 501                 sprintf(order, "%d", pos);
 502                 uci_add_history(ctx, &p->history, UCI_CMD_REORDER, s->e.name, NULL, order);
 503         }
 504
 505         return 0;
 506 }
 507
 508 int uci_add_section(struct uci_context *ctx, struct uci_package *p, const char *type, struct uci_section **res)
 509 {
 510         bool internal = ctx->internal;
 511         struct uci_section *s;
 512
 513         UCI_HANDLE_ERR(ctx);
 514         UCI_ASSERT(ctx, p != NULL);
 515         s = uci_alloc_section(p, type, NULL);
 516         uci_fixup_section(ctx, s);
 517         *res = s;
 518         if (!internal && p->has_history)
 519                 uci_add_history(ctx, &p->history, UCI_CMD_ADD, s->e.name, NULL, type);
 520
 521         return 0;
 522 }
 523
 524 int uci_delete(struct uci_context *ctx, struct uci_ptr *ptr)
 525 {
 526         /* NB: pass on internal flag to uci_del_element */
 527         bool internal = ctx->internal;
 528         struct uci_package *p;
 529         struct uci_element *e;
 530
 531         UCI_HANDLE_ERR(ctx);
 532
 533         e = expand_ptr(ctx, ptr, true);
 534         p = ptr->p;
 535
 536         UCI_ASSERT(ctx, ptr->s);
 537
 538         if (!internal && p->has_history)
 539                 uci_add_history(ctx, &p->history, UCI_CMD_REMOVE, ptr->section, ptr->option, NULL);
 540
 541         uci_free_any(&e);
 542
 543         if (ptr->option)
 544                 ptr->o = NULL;
 545         else if (ptr->section)
 546                 ptr->s = NULL;
 547
 548         return 0;
 549 }
 550
 551 int uci_add_list(struct uci_context *ctx, struct uci_ptr *ptr)
 552 {
 553         /* NB: UCI_INTERNAL use means without history tracking */
 554         bool internal = ctx->internal;
 555         struct uci_option *prev = NULL;
 556         const char *value2 = NULL;
 557
 558         UCI_HANDLE_ERR(ctx);
 559
 560         expand_ptr(ctx, ptr, false);
 561         UCI_ASSERT(ctx, ptr->s);
 562         UCI_ASSERT(ctx, ptr->value);
 563
 564         if (ptr->o) {
 565                 switch (ptr->o->type) {
 566                 case UCI_TYPE_STRING:
 567                         /* we already have a string value, convert that to a list */
 568                         prev = ptr->o;
 569                         value2 = ptr->value;
 570                         ptr->value = ptr->o->v.string;
 571                         break;
 572                 case UCI_TYPE_LIST:
 573                         uci_add_element_list(ctx, ptr, internal);
 574                         return 0;
 575                 default:
 576                         UCI_THROW(ctx, UCI_ERR_INVAL);
 577                         break;
 578                 }
 579         }
 580
 581         ptr->o = uci_alloc_list(ptr->s, ptr->option);
 582         if (prev) {
 583                 uci_add_element_list(ctx, ptr, true);
 584                 uci_free_option(prev);
 585                 ptr->value = value2;
 586         }
 587         uci_add_element_list(ctx, ptr, internal);
 588
 589         return 0;
 590 }
 591
 592 int uci_set(struct uci_context *ctx, struct uci_ptr *ptr)
 593 {
 594         /* NB: UCI_INTERNAL use means without history tracking */
 595         bool internal = ctx->internal;
 596
 597         UCI_HANDLE_ERR(ctx);
 598         expand_ptr(ctx, ptr, false);
 599         UCI_ASSERT(ctx, ptr->value);
 600         UCI_ASSERT(ctx, ptr->s || (!ptr->option && ptr->section));
 601         if (!ptr->option && ptr->value[0]) {
 602                 UCI_ASSERT(ctx, uci_validate_type(ptr->value));
 603         }
 604
 605         if (!ptr->o && ptr->s && ptr->option) {
 606                 struct uci_element *e;
 607                 e = uci_lookup_list(&ptr->s->options, ptr->option);
 608                 if (e)
 609                         ptr->o = uci_to_option(e);
 610         }
 611         if (!ptr->value[0]) {
 612                 /* if setting a nonexistant option/section to a nonexistant value,
 613                  * exit without errors */
 614                 if (!(ptr->flags & UCI_LOOKUP_COMPLETE))
 615                         return 0;
 616
 617                 return uci_delete(ctx, ptr);
 618         } else if (!ptr->o && ptr->option) { /* new option */
 619                 ptr->o = uci_alloc_option(ptr->s, ptr->option, ptr->value);
 620                 ptr->last = &ptr->o->e;
 621         } else if (!ptr->s && ptr->section) { /* new section */
 622                 ptr->s = uci_alloc_section(ptr->p, ptr->value, ptr->section);
 623                 ptr->last = &ptr->s->e;
 624         } else if (ptr->o && ptr->option) { /* update option */
 625                 if ((ptr->o->type == UCI_TYPE_STRING) &&
 626                         !strcmp(ptr->o->v.string, ptr->value))
 627                         return 0;
 628                 uci_free_option(ptr->o);
 629                 ptr->o = uci_alloc_option(ptr->s, ptr->option, ptr->value);
 630                 ptr->last = &ptr->o->e;
 631         } else if (ptr->s && ptr->section) { /* update section */
 632                 char *s = uci_strdup(ctx, ptr->value);
 633
 634                 if (ptr->s->type == uci_dataptr(ptr->s)) {
 635                         ptr->last = NULL;
 636                         ptr->last = uci_realloc(ctx, ptr->s, sizeof(struct uci_section));
 637                         ptr->s = uci_to_section(ptr->last);
 638                         uci_list_fixup(&ptr->s->e.list);
 639                 } else {
 640                         free(ptr->s->type);
 641                 }
 642                 ptr->s->type = s;
 643         } else {
 644                 UCI_THROW(ctx, UCI_ERR_INVAL);
 645         }
 646
 647         if (!internal && ptr->p->has_history)
 648                 uci_add_history(ctx, &ptr->p->history, UCI_CMD_CHANGE, ptr->section, ptr->option, ptr->value);
 649
 650         return 0;
 651 }
 652
 653 int uci_unload(struct uci_context *ctx, struct uci_package *p)
 654 {
 655         UCI_HANDLE_ERR(ctx);
 656         UCI_ASSERT(ctx, p != NULL);
 657
 658         uci_free_package(&p);
 659         return 0;
 660 }
 661