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