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