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 == ~0)
 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 = ~0;
 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 static struct uci_section *
 186 uci_alloc_section(struct uci_package *p, const char *type, const char *name)
 187 {
 188         struct uci_context *ctx = p->ctx;
 189         struct uci_section *s;
 190
 191         if (name && !name[0])
 192                 name = NULL;
 193
 194         s = uci_alloc_element(ctx, section, name, strlen(type) + 1);
 195         uci_list_init(&s->options);
 196         s->type = uci_dataptr(s);
 197         s->package = p;
 198         strcpy(s->type, type);
 199         if (name == NULL)
 200                 s->anonymous = true;
 201         p->n_section++;
 202
 203         uci_list_add(&p->sections, &s->e.list);
 204
 205         return s;
 206 }
 207
 208 static void
 209 uci_free_section(struct uci_section *s)
 210 {
 211         struct uci_element *o, *tmp;
 212
 213         uci_foreach_element_safe(&s->options, tmp, o) {
 214                 uci_free_option(uci_to_option(o));
 215         }
 216         if ((s->type != uci_dataptr(s)) &&
 217                 (s->type != NULL))
 218                 free(s->type);
 219         uci_free_element(&s->e);
 220 }
 221
 222 __private struct uci_package *
 223 uci_alloc_package(struct uci_context *ctx, const char *name)
 224 {
 225         struct uci_package *p;
 226
 227         p = uci_alloc_element(ctx, package, name, 0);
 228         p->ctx = ctx;
 229         uci_list_init(&p->sections);
 230         uci_list_init(&p->delta);
 231         uci_list_init(&p->saved_delta);
 232         return p;
 233 }
 234
 235 __private void
 236 uci_free_package(struct uci_package **package)
 237 {
 238         struct uci_element *e, *tmp;
 239         struct uci_package *p = *package;
 240
 241         if(!p)
 242                 return;
 243
 244         free(p->path);
 245         uci_foreach_element_safe(&p->sections, tmp, e) {
 246                 uci_free_section(uci_to_section(e));
 247         }
 248         uci_foreach_element_safe(&p->delta, tmp, e) {
 249                 uci_free_delta(uci_to_delta(e));
 250         }
 251         uci_foreach_element_safe(&p->saved_delta, tmp, e) {
 252                 uci_free_delta(uci_to_delta(e));
 253         }
 254         uci_free_element(&p->e);
 255         *package = NULL;
 256 }
 257
 258 static void
 259 uci_free_any(struct uci_element **e)
 260 {
 261         switch((*e)->type) {
 262         case UCI_TYPE_SECTION:
 263                 uci_free_section(uci_to_section(*e));
 264                 break;
 265         case UCI_TYPE_OPTION:
 266                 uci_free_option(uci_to_option(*e));
 267                 break;
 268         default:
 269                 break;
 270         }
 271         *e = NULL;
 272 }
 273
 274 __private struct uci_element *
 275 uci_lookup_list(struct uci_list *list, const char *name)
 276 {
 277         struct uci_element *e;
 278
 279         uci_foreach_element(list, e) {
 280                 if (!strcmp(e->name, name))
 281                         return e;
 282         }
 283         return NULL;
 284 }
 285
 286 static struct uci_element *
 287 uci_lookup_ext_section(struct uci_context *ctx, struct uci_ptr *ptr)
 288 {
 289         char *idxstr, *t, *section, *name;
 290         struct uci_element *e = NULL;
 291         struct uci_section *s;
 292         int idx, c;
 293
 294         section = uci_strdup(ctx, ptr->section);
 295         name = idxstr = section + 1;
 296
 297         if (section[0] != '@')
 298                 goto error;
 299
 300         /* parse the section index part */
 301         idxstr = strchr(idxstr, '[');
 302         if (!idxstr)
 303                 goto error;
 304         *idxstr = 0;
 305         idxstr++;
 306
 307         t = strchr(idxstr, ']');
 308         if (!t)
 309                 goto error;
 310         if (t[1] != 0)
 311                 goto error;
 312         *t = 0;
 313
 314         t = NULL;
 315         idx = strtol(idxstr, &t, 10);
 316         if (t && *t)
 317                 goto error;
 318
 319         if (!*name)
 320                 name = NULL;
 321         else if (!uci_validate_type(name))
 322                 goto error;
 323
 324         /* if the given index is negative, it specifies the section number from
 325          * the end of the list */
 326         if (idx < 0) {
 327                 c = 0;
 328                 uci_foreach_element(&ptr->p->sections, e) {
 329                         s = uci_to_section(e);
 330                         if (name && (strcmp(s->type, name) != 0))
 331                                 continue;
 332
 333                         c++;
 334                 }
 335                 idx += c;
 336         }
 337
 338         c = 0;
 339         uci_foreach_element(&ptr->p->sections, e) {
 340                 s = uci_to_section(e);
 341                 if (name && (strcmp(s->type, name) != 0))
 342                         continue;
 343
 344                 if (idx == c)
 345                         goto done;
 346                 c++;
 347         }
 348         e = NULL;
 349         goto done;
 350
 351 error:
 352         free(section);
 353         memset(ptr, 0, sizeof(struct uci_ptr));
 354         UCI_THROW(ctx, UCI_ERR_INVAL);
 355 done:
 356         free(section);
 357         if (e)
 358                 ptr->section = e->name;
 359         return e;
 360 }
 361
 362 int
 363 uci_lookup_next(struct uci_context *ctx, struct uci_element **e, struct uci_list *list, const char *name)
 364 {
 365         UCI_HANDLE_ERR(ctx);
 366
 367         *e = uci_lookup_list(list, name);
 368         if (!*e)
 369                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 370
 371         return 0;
 372 }
 373
 374 int
 375 uci_lookup_ptr(struct uci_context *ctx, struct uci_ptr *ptr, char *str, bool extended)
 376 {
 377         struct uci_element *e;
 378
 379         UCI_HANDLE_ERR(ctx);
 380         UCI_ASSERT(ctx, ptr != NULL);
 381
 382         if (str)
 383                 UCI_INTERNAL(uci_parse_ptr, ctx, ptr, str);
 384
 385         ptr->flags |= UCI_LOOKUP_DONE;
 386
 387         /* look up the package first */
 388         if (ptr->p)
 389                 e = &ptr->p->e;
 390         else
 391                 e = uci_lookup_list(&ctx->root, ptr->package);
 392
 393         if (!e) {
 394                 UCI_INTERNAL(uci_load, ctx, ptr->package, &ptr->p);
 395                 if (!ptr->p)
 396                         goto notfound;
 397                 ptr->last = &ptr->p->e;
 398         } else {
 399                 ptr->p = uci_to_package(e);
 400                 ptr->last = e;
 401         }
 402
 403         if (!ptr->section && !ptr->s)
 404                 goto complete;
 405
 406         /* if the section name validates as a regular name, pass through
 407          * to the regular uci_lookup function call */
 408         if (ptr->s) {
 409                 e = &ptr->s->e;
 410         } else if (ptr->flags & UCI_LOOKUP_EXTENDED) {
 411                 if (extended)
 412                         e = uci_lookup_ext_section(ctx, ptr);
 413                 else
 414                         UCI_THROW(ctx, UCI_ERR_INVAL);
 415         } else {
 416                 e = uci_lookup_list(&ptr->p->sections, ptr->section);
 417         }
 418
 419         if (!e)
 420                 goto abort;
 421
 422         ptr->last = e;
 423         ptr->s = uci_to_section(e);
 424
 425         if (ptr->option) {
 426                 e = uci_lookup_list(&ptr->s->options, ptr->option);
 427                 if (!e)
 428                         goto abort;
 429
 430                 ptr->o = uci_to_option(e);
 431                 ptr->last = e;
 432         }
 433
 434 complete:
 435         ptr->flags |= UCI_LOOKUP_COMPLETE;
 436 abort:
 437         return UCI_OK;
 438
 439 notfound:
 440         UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 441         /* not a chance here */
 442         return UCI_ERR_NOTFOUND;
 443 }
 444
 445 __private struct uci_element *
 446 uci_expand_ptr(struct uci_context *ctx, struct uci_ptr *ptr, bool complete)
 447 {
 448         UCI_ASSERT(ctx, ptr != NULL);
 449
 450         if (!(ptr->flags & UCI_LOOKUP_DONE))
 451                 UCI_INTERNAL(uci_lookup_ptr, ctx, ptr, NULL, 1);
 452         if (complete && !(ptr->flags & UCI_LOOKUP_COMPLETE))
 453                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 454         UCI_ASSERT(ctx, ptr->p != NULL);
 455
 456         /* fill in missing string info */
 457         if (ptr->p && !ptr->package)
 458                 ptr->package = ptr->p->e.name;
 459         if (ptr->s && !ptr->section)
 460                 ptr->section = ptr->s->e.name;
 461         if (ptr->o && !ptr->option)
 462                 ptr->option = ptr->o->e.name;
 463
 464         if (ptr->o)
 465                 return &ptr->o->e;
 466         if (ptr->s)
 467                 return &ptr->s->e;
 468         if (ptr->p)
 469                 return &ptr->p->e;
 470         else
 471                 return NULL;
 472 }
 473
 474 static void uci_add_element_list(struct uci_context *ctx, struct uci_ptr *ptr, bool internal)
 475 {
 476         struct uci_element *e;
 477         struct uci_package *p;
 478
 479         p = ptr->p;
 480         if (!internal && p->has_delta)
 481                 uci_add_delta(ctx, &p->delta, UCI_CMD_LIST_ADD, ptr->section, ptr->option, ptr->value);
 482
 483         e = uci_alloc_generic(ctx, UCI_TYPE_ITEM, ptr->value, sizeof(struct uci_option));
 484         uci_list_add(&ptr->o->v.list, &e->list);
 485 }
 486
 487 int uci_rename(struct uci_context *ctx, struct uci_ptr *ptr)
 488 {
 489         /* NB: UCI_INTERNAL use means without delta tracking */
 490         bool internal = ctx && ctx->internal;
 491         struct uci_element *e;
 492         struct uci_package *p;
 493         char *n;
 494
 495         UCI_HANDLE_ERR(ctx);
 496
 497         e = uci_expand_ptr(ctx, ptr, true);
 498         p = ptr->p;
 499
 500         UCI_ASSERT(ctx, ptr->s);
 501         UCI_ASSERT(ctx, ptr->value);
 502
 503         if (!internal && p->has_delta)
 504                 uci_add_delta(ctx, &p->delta, UCI_CMD_RENAME, ptr->section, ptr->option, ptr->value);
 505
 506         n = uci_strdup(ctx, ptr->value);
 507         free(e->name);
 508         e->name = n;
 509
 510         if (e->type == UCI_TYPE_SECTION)
 511                 uci_to_section(e)->anonymous = false;
 512
 513         return 0;
 514 }
 515
 516 int uci_reorder_section(struct uci_context *ctx, struct uci_section *s, int pos)
 517 {
 518         struct uci_package *p = s->package;
 519         bool internal = ctx && ctx->internal;
 520         bool changed = false;
 521         char order[32];
 522
 523         UCI_HANDLE_ERR(ctx);
 524
 525         changed = uci_list_set_pos(&s->package->sections, &s->e.list, pos);
 526         if (!internal && p->has_delta && changed) {
 527                 sprintf(order, "%d", pos);
 528                 uci_add_delta(ctx, &p->delta, UCI_CMD_REORDER, s->e.name, NULL, order);
 529         }
 530
 531         return 0;
 532 }
 533
 534 int uci_add_section(struct uci_context *ctx, struct uci_package *p, const char *type, struct uci_section **res)
 535 {
 536         bool internal = ctx && ctx->internal;
 537         struct uci_section *s;
 538
 539         UCI_HANDLE_ERR(ctx);
 540         UCI_ASSERT(ctx, p != NULL);
 541         s = uci_alloc_section(p, type, NULL);
 542         if (s && s->anonymous)
 543                 uci_fixup_section(ctx, s);
 544         *res = s;
 545         if (!internal && p->has_delta)
 546                 uci_add_delta(ctx, &p->delta, UCI_CMD_ADD, s->e.name, NULL, type);
 547
 548         return 0;
 549 }
 550
 551 int uci_delete(struct uci_context *ctx, struct uci_ptr *ptr)
 552 {
 553         /* NB: pass on internal flag to uci_del_element */
 554         bool internal = ctx && ctx->internal;
 555         struct uci_package *p;
 556         struct uci_element *e1, *e2, *tmp;
 557         int index;
 558
 559         UCI_HANDLE_ERR(ctx);
 560
 561         e1 = uci_expand_ptr(ctx, ptr, true);
 562         p = ptr->p;
 563
 564         UCI_ASSERT(ctx, ptr->s);
 565
 566         if (ptr->o && ptr->o->type == UCI_TYPE_LIST && ptr->value && *ptr->value) {
 567                 if (!sscanf(ptr->value, "%d", &index))
 568                         return 1;
 569
 570                 uci_foreach_element_safe(&ptr->o->v.list, tmp, e2) {
 571                         if (index == 0) {
 572                                 if (!internal && p->has_delta)
 573                                         uci_add_delta(ctx, &p->delta, UCI_CMD_REMOVE, ptr->section, ptr->option, ptr->value);
 574                                 uci_free_option(uci_to_option(e2));
 575                                 return 0;
 576                         }
 577                         index--;
 578                 }
 579
 580                 return 0;
 581         }
 582
 583         if (!internal && p->has_delta)
 584                 uci_add_delta(ctx, &p->delta, UCI_CMD_REMOVE, ptr->section, ptr->option, NULL);
 585
 586         uci_free_any(&e1);
 587
 588         if (ptr->option)
 589                 ptr->o = NULL;
 590         else if (ptr->section)
 591                 ptr->s = NULL;
 592
 593         return 0;
 594 }
 595
 596 int uci_add_list(struct uci_context *ctx, struct uci_ptr *ptr)
 597 {
 598         /* NB: UCI_INTERNAL use means without delta tracking */
 599         bool internal = ctx && ctx->internal;
 600         struct uci_option *prev = NULL;
 601         const char *value2 = NULL;
 602
 603         UCI_HANDLE_ERR(ctx);
 604
 605         uci_expand_ptr(ctx, ptr, false);
 606         UCI_ASSERT(ctx, ptr->s);
 607         UCI_ASSERT(ctx, ptr->value);
 608
 609         if (ptr->o) {
 610                 switch (ptr->o->type) {
 611                 case UCI_TYPE_STRING:
 612                         /* we already have a string value, convert that to a list */
 613                         prev = ptr->o;
 614                         value2 = ptr->value;
 615                         ptr->value = ptr->o->v.string;
 616                         break;
 617                 case UCI_TYPE_LIST:
 618                         uci_add_element_list(ctx, ptr, internal);
 619                         return 0;
 620                 default:
 621                         UCI_THROW(ctx, UCI_ERR_INVAL);
 622                         break;
 623                 }
 624         }
 625
 626         ptr->o = uci_alloc_list(ptr->s, ptr->option);
 627         if (prev) {
 628                 uci_add_element_list(ctx, ptr, true);
 629                 uci_free_option(prev);
 630                 ptr->value = value2;
 631         }
 632         uci_add_element_list(ctx, ptr, internal);
 633
 634         return 0;
 635 }
 636
 637 int uci_del_list(struct uci_context *ctx, struct uci_ptr *ptr)
 638 {
 639         /* NB: pass on internal flag to uci_del_element */
 640         bool internal = ctx && ctx->internal;
 641         struct uci_element *e, *tmp;
 642         struct uci_package *p;
 643
 644         UCI_HANDLE_ERR(ctx);
 645
 646         uci_expand_ptr(ctx, ptr, false);
 647         UCI_ASSERT(ctx, ptr->s);
 648         UCI_ASSERT(ctx, ptr->value);
 649
 650         if (!(ptr->o && ptr->option))
 651                 return 0;
 652
 653         if ((ptr->o->type != UCI_TYPE_LIST))
 654                 return 0;
 655
 656         p = ptr->p;
 657         if (!internal && p->has_delta)
 658                 uci_add_delta(ctx, &p->delta, UCI_CMD_LIST_DEL, ptr->section, ptr->option, ptr->value);
 659
 660         uci_foreach_element_safe(&ptr->o->v.list, tmp, e) {
 661                 if (!strcmp(ptr->value, uci_to_option(e)->e.name)) {
 662                         uci_free_option(uci_to_option(e));
 663                 }
 664         }
 665
 666         return 0;
 667 }
 668
 669 int uci_set(struct uci_context *ctx, struct uci_ptr *ptr)
 670 {
 671         /* NB: UCI_INTERNAL use means without delta tracking */
 672         bool internal = ctx && ctx->internal;
 673
 674         UCI_HANDLE_ERR(ctx);
 675         uci_expand_ptr(ctx, ptr, false);
 676         UCI_ASSERT(ctx, ptr->value);
 677         UCI_ASSERT(ctx, ptr->s || (!ptr->option && ptr->section));
 678         if (!ptr->option && ptr->value[0]) {
 679                 UCI_ASSERT(ctx, uci_validate_type(ptr->value));
 680         }
 681
 682         if (!ptr->o && ptr->s && ptr->option) {
 683                 struct uci_element *e;
 684                 e = uci_lookup_list(&ptr->s->options, ptr->option);
 685                 if (e)
 686                         ptr->o = uci_to_option(e);
 687         }
 688         if (!ptr->value[0]) {
 689                 /* if setting a nonexistant option/section to a nonexistant value,
 690                  * exit without errors */
 691                 if (!(ptr->flags & UCI_LOOKUP_COMPLETE))
 692                         return 0;
 693
 694                 return uci_delete(ctx, ptr);
 695         } else if (!ptr->o && ptr->option) { /* new option */
 696                 ptr->o = uci_alloc_option(ptr->s, ptr->option, ptr->value);
 697                 ptr->last = &ptr->o->e;
 698         } else if (!ptr->s && ptr->section) { /* new section */
 699                 ptr->s = uci_alloc_section(ptr->p, ptr->value, ptr->section);
 700                 ptr->last = &ptr->s->e;
 701         } else if (ptr->o && ptr->option) { /* update option */
 702                 struct uci_option *o;
 703
 704                 if ((ptr->o->type == UCI_TYPE_STRING) &&
 705                         !strcmp(ptr->o->v.string, ptr->value))
 706                         return 0;
 707
 708                 o = ptr->o;
 709                 ptr->o = uci_alloc_option(ptr->s, ptr->option, ptr->value);
 710                 uci_free_option(o);
 711                 ptr->last = &ptr->o->e;
 712         } else if (ptr->s && ptr->section) { /* update section */
 713                 char *s = uci_strdup(ctx, ptr->value);
 714
 715                 if (ptr->s->type == uci_dataptr(ptr->s)) {
 716                         ptr->last = NULL;
 717                         ptr->last = uci_realloc(ctx, ptr->s, sizeof(struct uci_section));
 718                         ptr->s = uci_to_section(ptr->last);
 719                         uci_list_fixup(&ptr->s->e.list);
 720                 } else {
 721                         free(ptr->s->type);
 722                 }
 723                 ptr->s->type = s;
 724         } else {
 725                 UCI_THROW(ctx, UCI_ERR_INVAL);
 726         }
 727
 728         if (!internal && ptr->p->has_delta)
 729                 uci_add_delta(ctx, &ptr->p->delta, UCI_CMD_CHANGE, ptr->section, ptr->option, ptr->value);
 730
 731         return 0;
 732 }
 733
 734 int uci_unload(struct uci_context *ctx, struct uci_package *p)
 735 {
 736         UCI_HANDLE_ERR(ctx);
 737         UCI_ASSERT(ctx, p != NULL);
 738
 739         uci_free_package(&p);
 740         return 0;
 741 }
 742