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 Lesser General Public License for more details.
  13  */
  14
  15 static bool uci_list_set_pos(struct uci_list *head, struct uci_list *ptr, int pos)
  16 {
  17         struct uci_list *old_head = ptr->prev;
  18         struct uci_list *new_head = head;
  19         struct uci_element *p = NULL;
  20
  21         uci_list_del(ptr);
  22         uci_foreach_element(head, p) {
  23                 if (pos-- <= 0)
  24                         break;
  25                 new_head = &p->list;
  26         }
  27
  28         uci_list_add(new_head->next, ptr);
  29
  30         return (old_head != new_head);
  31 }
  32
  33 static inline void uci_list_fixup(struct uci_list *ptr)
  34 {
  35         ptr->prev->next = ptr;
  36         ptr->next->prev = ptr;
  37 }
  38
  39 /*
  40  * uci_alloc_generic allocates a new uci_element with payload
  41  * payload is appended to the struct to save memory and reduce fragmentation
  42  */
  43 __private struct uci_element *
  44 uci_alloc_generic(struct uci_context *ctx, int type, const char *name, int size)
  45 {
  46         struct uci_element *e;
  47         int datalen = size;
  48         void *ptr;
  49
  50         ptr = uci_malloc(ctx, datalen);
  51         e = (struct uci_element *) ptr;
  52         e->type = type;
  53         if (name) {
  54                 UCI_TRAP_SAVE(ctx, error);
  55                 e->name = uci_strdup(ctx, name);
  56                 UCI_TRAP_RESTORE(ctx);
  57         }
  58         uci_list_init(&e->list);
  59         goto done;
  60
  61 error:
  62         free(ptr);
  63         UCI_THROW(ctx, ctx->err);
  64
  65 done:
  66         return e;
  67 }
  68
  69 __private void
  70 uci_free_element(struct uci_element *e)
  71 {
  72         free(e->name);
  73         if (!uci_list_empty(&e->list))
  74                 uci_list_del(&e->list);
  75         free(e);
  76 }
  77
  78 static struct uci_option *
  79 uci_alloc_option(struct uci_section *s, const char *name, const char *value)
  80 {
  81         struct uci_package *p = s->package;
  82         struct uci_context *ctx = p->ctx;
  83         struct uci_option *o;
  84
  85         o = uci_alloc_element(ctx, option, name, strlen(value) + 1);
  86         o->type = UCI_TYPE_STRING;
  87         o->v.string = uci_dataptr(o);
  88         o->section = s;
  89         strcpy(o->v.string, value);
  90         uci_list_add(&s->options, &o->e.list);
  91
  92         return o;
  93 }
  94
  95 static inline void
  96 uci_free_option(struct uci_option *o)
  97 {
  98         struct uci_element *e, *tmp;
  99
 100         switch(o->type) {
 101         case UCI_TYPE_STRING:
 102                 if ((o->v.string != uci_dataptr(o)) &&
 103                         (o->v.string != NULL))
 104                         free(o->v.string);
 105                 break;
 106         case UCI_TYPE_LIST:
 107                 uci_foreach_element_safe(&o->v.list, tmp, e) {
 108                         uci_free_element(e);
 109                 }
 110                 break;
 111         default:
 112                 break;
 113         }
 114         uci_free_element(&o->e);
 115 }
 116
 117 static struct uci_option *
 118 uci_alloc_list(struct uci_section *s, const char *name)
 119 {
 120         struct uci_package *p = s->package;
 121         struct uci_context *ctx = p->ctx;
 122         struct uci_option *o;
 123
 124         o = uci_alloc_element(ctx, option, name, 0);
 125         o->type = UCI_TYPE_LIST;
 126         o->section = s;
 127         uci_list_init(&o->v.list);
 128         uci_list_add(&s->options, &o->e.list);
 129
 130         return o;
 131 }
 132
 133 /* Based on an efficient hash function published by D. J. Bernstein */
 134 static unsigned int djbhash(unsigned int hash, char *str)
 135 {
 136         int len = strlen(str);
 137         int i;
 138
 139         /* initial value */
 140         if (hash == ~0U)
 141                 hash = 5381;
 142
 143         for(i = 0; i < len; i++) {
 144                 hash = ((hash << 5) + hash) + str[i];
 145         }
 146         return (hash & 0x7FFFFFFF);
 147 }
 148
 149 /* fix up an unnamed section, e.g. after adding options to it */
 150 static void uci_fixup_section(struct uci_context *ctx, struct uci_section *s)
 151 {
 152         unsigned int hash = ~0U;
 153         struct uci_element *e;
 154         char buf[16];
 155
 156         if (!s || s->e.name)
 157                 return;
 158
 159         /*
 160          * Generate a name for unnamed sections. This is used as reference
 161          * when locating or updating the section from apps/scripts.
 162          * To make multiple concurrent versions somewhat safe for updating,
 163          * the name is generated from a hash of its type and name/value
 164          * pairs of its option, and it is prefixed by a counter value.
 165          * If the order of the unnamed sections changes for some reason,
 166          * updates to them will be rejected.
 167          */
 168         hash = djbhash(hash, s->type);
 169         uci_foreach_element(&s->options, e) {
 170                 struct uci_option *o;
 171                 hash = djbhash(hash, e->name);
 172                 o = uci_to_option(e);
 173                 switch(o->type) {
 174                 case UCI_TYPE_STRING:
 175                         hash = djbhash(hash, o->v.string);
 176                         break;
 177                 default:
 178                         break;
 179                 }
 180         }
 181         sprintf(buf, "cfg%02x%04x", s->package->n_section, hash % (1 << 16));
 182         s->e.name = uci_strdup(ctx, buf);
 183 }
 184
 185 /* fix up option list HEAD pointers and pointer to section in options */
 186 static void uci_section_fixup_options(struct uci_section *s, bool no_options)
 187 {
 188         struct uci_element *e;
 189
 190         if (no_options) {
 191                 /*
 192                  * enforce empty list pointer state (s->next == s) when original
 193                  * section had no options in the first place
 194                  */
 195                 uci_list_init(&s->options);
 196                 return;
 197         }
 198
 199         /* fix pointers to HEAD at end/beginning of list */
 200         uci_list_fixup(&s->options);
 201
 202         /* fix back pointer to section in options */
 203         uci_foreach_element(&s->options, e) {
 204                 struct uci_option *o;
 205
 206                 o = uci_to_option(e);
 207                 o->section = s;
 208         }
 209 }
 210
 211 static struct uci_section *
 212 uci_alloc_section(struct uci_package *p, const char *type, const char *name)
 213 {
 214         struct uci_context *ctx = p->ctx;
 215         struct uci_section *s;
 216
 217         if (name && !name[0])
 218                 name = NULL;
 219
 220         s = uci_alloc_element(ctx, section, name, strlen(type) + 1);
 221         uci_list_init(&s->options);
 222         s->type = uci_dataptr(s);
 223         s->package = p;
 224         strcpy(s->type, type);
 225         if (name == NULL)
 226                 s->anonymous = true;
 227         p->n_section++;
 228
 229         uci_list_add(&p->sections, &s->e.list);
 230
 231         return s;
 232 }
 233
 234 static void
 235 uci_free_section(struct uci_section *s)
 236 {
 237         struct uci_element *o, *tmp;
 238
 239         uci_foreach_element_safe(&s->options, tmp, o) {
 240                 uci_free_option(uci_to_option(o));
 241         }
 242         if ((s->type != uci_dataptr(s)) &&
 243                 (s->type != NULL))
 244                 free(s->type);
 245         uci_free_element(&s->e);
 246 }
 247
 248 __private struct uci_package *
 249 uci_alloc_package(struct uci_context *ctx, const char *name)
 250 {
 251         struct uci_package *p;
 252
 253         p = uci_alloc_element(ctx, package, name, 0);
 254         p->ctx = ctx;
 255         uci_list_init(&p->sections);
 256         uci_list_init(&p->delta);
 257         uci_list_init(&p->saved_delta);
 258         return p;
 259 }
 260
 261 __private void
 262 uci_free_package(struct uci_package **package)
 263 {
 264         struct uci_element *e, *tmp;
 265         struct uci_package *p = *package;
 266
 267         if(!p)
 268                 return;
 269
 270         free(p->path);
 271         uci_foreach_element_safe(&p->sections, tmp, e) {
 272                 uci_free_section(uci_to_section(e));
 273         }
 274         uci_foreach_element_safe(&p->delta, tmp, e) {
 275                 uci_free_delta(uci_to_delta(e));
 276         }
 277         uci_foreach_element_safe(&p->saved_delta, tmp, e) {
 278                 uci_free_delta(uci_to_delta(e));
 279         }
 280         uci_free_element(&p->e);
 281         *package = NULL;
 282 }
 283
 284 static void
 285 uci_free_any(struct uci_element **e)
 286 {
 287         switch((*e)->type) {
 288         case UCI_TYPE_SECTION:
 289                 uci_free_section(uci_to_section(*e));
 290                 break;
 291         case UCI_TYPE_OPTION:
 292                 uci_free_option(uci_to_option(*e));
 293                 break;
 294         default:
 295                 break;
 296         }
 297         *e = NULL;
 298 }
 299
 300 __private struct uci_element *
 301 uci_lookup_list(struct uci_list *list, const char *name)
 302 {
 303         struct uci_element *e;
 304
 305         uci_foreach_element(list, e) {
 306                 if (!strcmp(e->name, name))
 307                         return e;
 308         }
 309         return NULL;
 310 }
 311
 312 static struct uci_element *
 313 uci_lookup_ext_section(struct uci_context *ctx, struct uci_ptr *ptr)
 314 {
 315         char *idxstr, *t, *section, *name;
 316         struct uci_element *e = NULL;
 317         struct uci_section *s;
 318         int idx, c;
 319
 320         section = uci_strdup(ctx, ptr->section);
 321         name = idxstr = section + 1;
 322
 323         if (section[0] != '@')
 324                 goto error;
 325
 326         /* parse the section index part */
 327         idxstr = strchr(idxstr, '[');
 328         if (!idxstr)
 329                 goto error;
 330         *idxstr = 0;
 331         idxstr++;
 332
 333         t = strchr(idxstr, ']');
 334         if (!t)
 335                 goto error;
 336         if (t[1] != 0)
 337                 goto error;
 338         *t = 0;
 339
 340         t = NULL;
 341         idx = strtol(idxstr, &t, 10);
 342         if (t && *t)
 343                 goto error;
 344
 345         if (!*name)
 346                 name = NULL;
 347         else if (!uci_validate_type(name))
 348                 goto error;
 349
 350         /* if the given index is negative, it specifies the section number from
 351          * the end of the list */
 352         if (idx < 0) {
 353                 c = 0;
 354                 uci_foreach_element(&ptr->p->sections, e) {
 355                         s = uci_to_section(e);
 356                         if (name && (strcmp(s->type, name) != 0))
 357                                 continue;
 358
 359                         c++;
 360                 }
 361                 idx += c;
 362         }
 363
 364         c = 0;
 365         uci_foreach_element(&ptr->p->sections, e) {
 366                 s = uci_to_section(e);
 367                 if (name && (strcmp(s->type, name) != 0))
 368                         continue;
 369
 370                 if (idx == c)
 371                         goto done;
 372                 c++;
 373         }
 374         e = NULL;
 375         goto done;
 376
 377 error:
 378         free(section);
 379         memset(ptr, 0, sizeof(struct uci_ptr));
 380         UCI_THROW(ctx, UCI_ERR_INVAL);
 381 done:
 382         free(section);
 383         if (e)
 384                 ptr->section = e->name;
 385         return e;
 386 }
 387
 388 int
 389 uci_lookup_next(struct uci_context *ctx, struct uci_element **e, struct uci_list *list, const char *name)
 390 {
 391         UCI_HANDLE_ERR(ctx);
 392
 393         *e = uci_lookup_list(list, name);
 394         if (!*e)
 395                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 396
 397         return 0;
 398 }
 399
 400 int
 401 uci_lookup_ptr(struct uci_context *ctx, struct uci_ptr *ptr, char *str, bool extended)
 402 {
 403         struct uci_element *e;
 404
 405         UCI_HANDLE_ERR(ctx);
 406         UCI_ASSERT(ctx, ptr != NULL);
 407
 408         if (str)
 409                 UCI_INTERNAL(uci_parse_ptr, ctx, ptr, str);
 410
 411         ptr->flags |= UCI_LOOKUP_DONE;
 412
 413         /* look up the package first */
 414         if (ptr->p)
 415                 e = &ptr->p->e;
 416         else
 417                 e = uci_lookup_list(&ctx->root, ptr->package);
 418
 419         if (!e) {
 420                 UCI_INTERNAL(uci_load, ctx, ptr->package, &ptr->p);
 421                 if (!ptr->p)
 422                         goto notfound;
 423                 ptr->last = &ptr->p->e;
 424         } else {
 425                 ptr->p = uci_to_package(e);
 426                 ptr->last = e;
 427         }
 428
 429         if (!ptr->section && !ptr->s)
 430                 goto complete;
 431
 432         /* if the section name validates as a regular name, pass through
 433          * to the regular uci_lookup function call */
 434         if (ptr->s) {
 435                 e = &ptr->s->e;
 436         } else if (ptr->flags & UCI_LOOKUP_EXTENDED) {
 437                 if (extended)
 438                         e = uci_lookup_ext_section(ctx, ptr);
 439                 else
 440                         UCI_THROW(ctx, UCI_ERR_INVAL);
 441         } else {
 442                 e = uci_lookup_list(&ptr->p->sections, ptr->section);
 443         }
 444
 445         if (!e)
 446                 goto abort;
 447
 448         ptr->last = e;
 449         ptr->s = uci_to_section(e);
 450
 451         if (ptr->option) {
 452                 e = uci_lookup_list(&ptr->s->options, ptr->option);
 453                 if (!e)
 454                         goto abort;
 455
 456                 ptr->o = uci_to_option(e);
 457                 ptr->last = e;
 458         }
 459
 460 complete:
 461         ptr->flags |= UCI_LOOKUP_COMPLETE;
 462 abort:
 463         return UCI_OK;
 464
 465 notfound:
 466         UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 467         /* not a chance here */
 468         return UCI_ERR_NOTFOUND;
 469 }
 470
 471 __private struct uci_element *
 472 uci_expand_ptr(struct uci_context *ctx, struct uci_ptr *ptr, bool complete)
 473 {
 474         UCI_ASSERT(ctx, ptr != NULL);
 475
 476         if (!(ptr->flags & UCI_LOOKUP_DONE))
 477                 UCI_INTERNAL(uci_lookup_ptr, ctx, ptr, NULL, 1);
 478         if (complete && !(ptr->flags & UCI_LOOKUP_COMPLETE))
 479                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 480         UCI_ASSERT(ctx, ptr->p != NULL);
 481
 482         /* fill in missing string info */
 483         if (ptr->p && !ptr->package)
 484                 ptr->package = ptr->p->e.name;
 485         if (ptr->s && !ptr->section)
 486                 ptr->section = ptr->s->e.name;
 487         if (ptr->o && !ptr->option)
 488                 ptr->option = ptr->o->e.name;
 489
 490         if (ptr->o)
 491                 return &ptr->o->e;
 492         if (ptr->s)
 493                 return &ptr->s->e;
 494         if (ptr->p)
 495                 return &ptr->p->e;
 496         else
 497                 return NULL;
 498 }
 499
 500 static void uci_add_element_list(struct uci_context *ctx, struct uci_ptr *ptr, bool internal)
 501 {
 502         struct uci_element *e;
 503         struct uci_package *p;
 504
 505         p = ptr->p;
 506         if (!internal && p->has_delta)
 507                 uci_add_delta(ctx, &p->delta, UCI_CMD_LIST_ADD, ptr->section, ptr->option, ptr->value);
 508
 509         e = uci_alloc_generic(ctx, UCI_TYPE_ITEM, ptr->value, sizeof(struct uci_option));
 510         uci_list_add(&ptr->o->v.list, &e->list);
 511 }
 512
 513 int uci_rename(struct uci_context *ctx, struct uci_ptr *ptr)
 514 {
 515         /* NB: UCI_INTERNAL use means without delta tracking */
 516         bool internal = ctx && ctx->internal;
 517         struct uci_element *e;
 518         struct uci_package *p;
 519         char *n;
 520
 521         UCI_HANDLE_ERR(ctx);
 522
 523         e = uci_expand_ptr(ctx, ptr, true);
 524         p = ptr->p;
 525
 526         UCI_ASSERT(ctx, ptr->s);
 527         UCI_ASSERT(ctx, ptr->value);
 528
 529         if (!internal && p->has_delta)
 530                 uci_add_delta(ctx, &p->delta, UCI_CMD_RENAME, ptr->section, ptr->option, ptr->value);
 531
 532         n = uci_strdup(ctx, ptr->value);
 533         free(e->name);
 534         e->name = n;
 535
 536         if (e->type == UCI_TYPE_SECTION)
 537                 uci_to_section(e)->anonymous = false;
 538
 539         return 0;
 540 }
 541
 542 int uci_reorder_section(struct uci_context *ctx, struct uci_section *s, int pos)
 543 {
 544         struct uci_package *p = s->package;
 545         bool internal = ctx && ctx->internal;
 546         bool changed = false;
 547         char order[32];
 548
 549         UCI_HANDLE_ERR(ctx);
 550
 551         changed = uci_list_set_pos(&s->package->sections, &s->e.list, pos);
 552         if (!internal && p->has_delta && changed) {
 553                 sprintf(order, "%d", pos);
 554                 uci_add_delta(ctx, &p->delta, UCI_CMD_REORDER, s->e.name, NULL, order);
 555         }
 556
 557         return 0;
 558 }
 559
 560 int uci_add_section(struct uci_context *ctx, struct uci_package *p, const char *type, struct uci_section **res)
 561 {
 562         bool internal = ctx && ctx->internal;
 563         struct uci_section *s;
 564
 565         UCI_HANDLE_ERR(ctx);
 566         UCI_ASSERT(ctx, p != NULL);
 567         s = uci_alloc_section(p, type, NULL);
 568         if (s && s->anonymous)
 569                 uci_fixup_section(ctx, s);
 570         *res = s;
 571         if (!internal && p->has_delta)
 572                 uci_add_delta(ctx, &p->delta, UCI_CMD_ADD, s->e.name, NULL, type);
 573
 574         return 0;
 575 }
 576
 577 int uci_delete(struct uci_context *ctx, struct uci_ptr *ptr)
 578 {
 579         /* NB: pass on internal flag to uci_del_element */
 580         bool internal = ctx && ctx->internal;
 581         struct uci_package *p;
 582         struct uci_element *e1, *e2, *tmp;
 583         int index;
 584
 585         UCI_HANDLE_ERR(ctx);
 586
 587         e1 = uci_expand_ptr(ctx, ptr, true);
 588         p = ptr->p;
 589
 590         UCI_ASSERT(ctx, ptr->s);
 591
 592         if (ptr->o && ptr->o->type == UCI_TYPE_LIST && ptr->value && *ptr->value) {
 593                 if (!sscanf(ptr->value, "%d", &index))
 594                         return 1;
 595
 596                 uci_foreach_element_safe(&ptr->o->v.list, tmp, e2) {
 597                         if (index == 0) {
 598                                 if (!internal && p->has_delta)
 599                                         uci_add_delta(ctx, &p->delta, UCI_CMD_REMOVE, ptr->section, ptr->option, ptr->value);
 600                                 uci_free_option(uci_to_option(e2));
 601                                 return 0;
 602                         }
 603                         index--;
 604                 }
 605
 606                 return 0;
 607         }
 608
 609         if (!internal && p->has_delta)
 610                 uci_add_delta(ctx, &p->delta, UCI_CMD_REMOVE, ptr->section, ptr->option, NULL);
 611
 612         uci_free_any(&e1);
 613
 614         if (ptr->option)
 615                 ptr->o = NULL;
 616         else if (ptr->section)
 617                 ptr->s = NULL;
 618
 619         return 0;
 620 }
 621
 622 int uci_add_list(struct uci_context *ctx, struct uci_ptr *ptr)
 623 {
 624         /* NB: UCI_INTERNAL use means without delta tracking */
 625         bool internal = ctx && ctx->internal;
 626         struct uci_option *volatile prev = NULL;
 627         const char *volatile value2 = NULL;
 628
 629         UCI_HANDLE_ERR(ctx);
 630
 631         uci_expand_ptr(ctx, ptr, false);
 632         UCI_ASSERT(ctx, ptr->s);
 633         UCI_ASSERT(ctx, ptr->value);
 634
 635         if (ptr->o) {
 636                 switch (ptr->o->type) {
 637                 case UCI_TYPE_STRING:
 638                         /* we already have a string value, convert that to a list */
 639                         prev = ptr->o;
 640                         value2 = ptr->value;
 641                         ptr->value = ptr->o->v.string;
 642                         break;
 643                 case UCI_TYPE_LIST:
 644                         uci_add_element_list(ctx, ptr, internal);
 645                         return 0;
 646                 default:
 647                         UCI_THROW(ctx, UCI_ERR_INVAL);
 648                         break;
 649                 }
 650         }
 651
 652         ptr->o = uci_alloc_list(ptr->s, ptr->option);
 653         if (prev) {
 654                 uci_add_element_list(ctx, ptr, true);
 655                 uci_free_option(prev);
 656                 ptr->value = value2;
 657         }
 658         uci_add_element_list(ctx, ptr, internal);
 659
 660         return 0;
 661 }
 662
 663 int uci_del_list(struct uci_context *ctx, struct uci_ptr *ptr)
 664 {
 665         /* NB: pass on internal flag to uci_del_element */
 666         bool internal = ctx && ctx->internal;
 667         struct uci_element *e, *tmp;
 668         struct uci_package *p;
 669
 670         UCI_HANDLE_ERR(ctx);
 671
 672         uci_expand_ptr(ctx, ptr, false);
 673         UCI_ASSERT(ctx, ptr->s);
 674         UCI_ASSERT(ctx, ptr->value);
 675
 676         if (!(ptr->o && ptr->option))
 677                 return 0;
 678
 679         if ((ptr->o->type != UCI_TYPE_LIST))
 680                 return 0;
 681
 682         p = ptr->p;
 683         if (!internal && p->has_delta)
 684                 uci_add_delta(ctx, &p->delta, UCI_CMD_LIST_DEL, ptr->section, ptr->option, ptr->value);
 685
 686         uci_foreach_element_safe(&ptr->o->v.list, tmp, e) {
 687                 if (!strcmp(ptr->value, uci_to_option(e)->e.name)) {
 688                         uci_free_option(uci_to_option(e));
 689                 }
 690         }
 691
 692         return 0;
 693 }
 694
 695 int uci_set(struct uci_context *ctx, struct uci_ptr *ptr)
 696 {
 697         /* NB: UCI_INTERNAL use means without delta tracking */
 698         bool internal = ctx && ctx->internal;
 699
 700         UCI_HANDLE_ERR(ctx);
 701         uci_expand_ptr(ctx, ptr, false);
 702         UCI_ASSERT(ctx, ptr->value);
 703         UCI_ASSERT(ctx, ptr->s || (!ptr->option && ptr->section));
 704         if (!ptr->option && ptr->value[0]) {
 705                 UCI_ASSERT(ctx, uci_validate_type(ptr->value));
 706         }
 707
 708         if (!ptr->o && ptr->s && ptr->option) {
 709                 struct uci_element *e;
 710                 e = uci_lookup_list(&ptr->s->options, ptr->option);
 711                 if (e)
 712                         ptr->o = uci_to_option(e);
 713         }
 714         if (!ptr->value[0]) {
 715                 /* if setting a nonexistant option/section to a nonexistant value,
 716                  * exit without errors */
 717                 if (!(ptr->flags & UCI_LOOKUP_COMPLETE))
 718                         return 0;
 719
 720                 return uci_delete(ctx, ptr);
 721         } else if (!ptr->o && ptr->option) { /* new option */
 722                 ptr->o = uci_alloc_option(ptr->s, ptr->option, ptr->value);
 723                 ptr->last = &ptr->o->e;
 724         } else if (!ptr->s && ptr->section) { /* new section */
 725                 ptr->s = uci_alloc_section(ptr->p, ptr->value, ptr->section);
 726                 ptr->last = &ptr->s->e;
 727         } else if (ptr->o && ptr->option) { /* update option */
 728                 struct uci_option *o;
 729
 730                 if ((ptr->o->type == UCI_TYPE_STRING) &&
 731                         !strcmp(ptr->o->v.string, ptr->value))
 732                         return 0;
 733
 734                 o = ptr->o;
 735                 ptr->o = uci_alloc_option(ptr->s, ptr->option, ptr->value);
 736                 uci_free_option(o);
 737                 ptr->last = &ptr->o->e;
 738         } else if (ptr->s && ptr->section) { /* update section */
 739                 char *s = uci_strdup(ctx, ptr->value);
 740
 741                 if (ptr->s->type == uci_dataptr(ptr->s)) {
 742                         /* drop the in-section storage of type name */
 743                         bool no_options;
 744
 745                         no_options = uci_list_empty(&ptr->s->options);
 746                         ptr->last = NULL;
 747                         ptr->last = uci_realloc(ctx, ptr->s, sizeof(struct uci_section));
 748                         ptr->s = uci_to_section(ptr->last);
 749                         uci_list_fixup(&ptr->s->e.list);
 750                         uci_section_fixup_options(ptr->s, no_options);
 751                 } else {
 752                         free(ptr->s->type);
 753                 }
 754                 ptr->s->type = s;
 755         } else {
 756                 UCI_THROW(ctx, UCI_ERR_INVAL);
 757         }
 758
 759         if (!internal && ptr->p->has_delta)
 760                 uci_add_delta(ctx, &ptr->p->delta, UCI_CMD_CHANGE, ptr->section, ptr->option, ptr->value);
 761
 762         return 0;
 763 }
 764
 765 int uci_unload(struct uci_context *ctx, struct uci_package *p)
 766 {
 767         UCI_HANDLE_ERR(ctx);
 768         UCI_ASSERT(ctx, p != NULL);
 769
 770         uci_free_package(&p);
 771         return 0;
 772 }
 773