list.c

   1 /*
   2  * libuci - Library for the Unified Configuration Interface
   3  * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU Lesser General Public License version 2.1
   7  * as published by the Free Software Foundation
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 static void uci_list_set_pos(struct uci_list *head, struct uci_list *ptr, int pos)
  16 {
  17         struct uci_list *new_head = head;
  18         struct uci_element *p = NULL;
  19
  20         uci_list_del(ptr);
  21         uci_foreach_element(head, p) {
  22                 new_head = &p->list;
  23                 if (pos-- <= 0)
  24                         break;
  25         }
  26         uci_list_add(new_head, ptr);
  27 }
  28
  29 static inline void uci_list_fixup(struct uci_list *ptr)
  30 {
  31         ptr->prev->next = ptr;
  32         ptr->next->prev = ptr;
  33 }
  34
  35 /*
  36  * uci_alloc_generic allocates a new uci_element with payload
  37  * payload is appended to the struct to save memory and reduce fragmentation
  38  */
  39 static struct uci_element *
  40 uci_alloc_generic(struct uci_context *ctx, int type, const char *name, int size)
  41 {
  42         struct uci_element *e;
  43         int datalen = size;
  44         void *ptr;
  45
  46         ptr = uci_malloc(ctx, datalen);
  47         e = (struct uci_element *) ptr;
  48         e->type = type;
  49         if (name) {
  50                 UCI_TRAP_SAVE(ctx, error);
  51                 e->name = uci_strdup(ctx, name);
  52                 UCI_TRAP_RESTORE(ctx);
  53         }
  54         uci_list_init(&e->list);
  55         goto done;
  56
  57 error:
  58         free(ptr);
  59         UCI_THROW(ctx, ctx->err);
  60
  61 done:
  62         return e;
  63 }
  64
  65 static void
  66 uci_free_element(struct uci_element *e)
  67 {
  68         if (e->name)
  69                 free(e->name);
  70         if (!uci_list_empty(&e->list))
  71                 uci_list_del(&e->list);
  72         free(e);
  73 }
  74
  75 static struct uci_option *
  76 uci_alloc_option(struct uci_section *s, const char *name, const char *value)
  77 {
  78         struct uci_package *p = s->package;
  79         struct uci_context *ctx = p->ctx;
  80         struct uci_option *o;
  81
  82         o = uci_alloc_element(ctx, option, name, strlen(value) + 1);
  83         o->type = UCI_TYPE_STRING;
  84         o->v.string = uci_dataptr(o);
  85         o->section = s;
  86         strcpy(o->v.string, value);
  87         uci_list_add(&s->options, &o->e.list);
  88
  89         return o;
  90 }
  91
  92 static inline void
  93 uci_free_option(struct uci_option *o)
  94 {
  95         struct uci_element *e, *tmp;
  96
  97         switch(o->type) {
  98         case UCI_TYPE_STRING:
  99                 if ((o->v.string != uci_dataptr(o)) &&
 100                         (o->v.string != NULL))
 101                         free(o->v.string);
 102                 break;
 103         case UCI_TYPE_LIST:
 104                 uci_foreach_element_safe(&o->v.list, tmp, e) {
 105                         uci_free_element(e);
 106                 }
 107                 break;
 108         default:
 109                 break;
 110         }
 111         uci_free_element(&o->e);
 112 }
 113
 114 static struct uci_option *
 115 uci_alloc_list(struct uci_section *s, const char *name)
 116 {
 117         struct uci_package *p = s->package;
 118         struct uci_context *ctx = p->ctx;
 119         struct uci_option *o;
 120
 121         o = uci_alloc_element(ctx, option, name, 0);
 122         o->type = UCI_TYPE_LIST;
 123         o->section = s;
 124         uci_list_init(&o->v.list);
 125         uci_list_add(&s->options, &o->e.list);
 126
 127         return o;
 128 }
 129
 130 /* fix up an unnamed section, e.g. after adding options to it */
 131 __private void uci_fixup_section(struct uci_context *ctx, struct uci_section *s)
 132 {
 133         unsigned int hash = ~0;
 134         struct uci_element *e;
 135         char buf[16];
 136
 137         if (!s || s->e.name)
 138                 return;
 139
 140         /*
 141          * Generate a name for unnamed sections. This is used as reference
 142          * when locating or updating the section from apps/scripts.
 143          * To make multiple concurrent versions somewhat safe for updating,
 144          * the name is generated from a hash of its type and name/value
 145          * pairs of its option, and it is prefixed by a counter value.
 146          * If the order of the unnamed sections changes for some reason,
 147          * updates to them will be rejected.
 148          */
 149         hash = djbhash(hash, s->type);
 150         uci_foreach_element(&s->options, e) {
 151                 struct uci_option *o;
 152                 hash = djbhash(hash, e->name);
 153                 o = uci_to_option(e);
 154                 switch(o->type) {
 155                 case UCI_TYPE_STRING:
 156                         hash = djbhash(hash, o->v.string);
 157                         break;
 158                 default:
 159                         break;
 160                 }
 161         }
 162         sprintf(buf, "cfg%02x%04x", ++s->package->n_section, hash % (1 << 16));
 163         s->e.name = uci_strdup(ctx, buf);
 164 }
 165
 166 static struct uci_section *
 167 uci_alloc_section(struct uci_package *p, const char *type, const char *name)
 168 {
 169         struct uci_context *ctx = p->ctx;
 170         struct uci_section *s;
 171
 172         if (name && !name[0])
 173                 name = NULL;
 174
 175         s = uci_alloc_element(ctx, section, name, strlen(type) + 1);
 176         uci_list_init(&s->options);
 177         s->type = uci_dataptr(s);
 178         s->package = p;
 179         strcpy(s->type, type);
 180         if (name == NULL)
 181                 s->anonymous = true;
 182         p->n_section++;
 183
 184         uci_list_add(&p->sections, &s->e.list);
 185
 186         return s;
 187 }
 188
 189 static void
 190 uci_free_section(struct uci_section *s)
 191 {
 192         struct uci_element *o, *tmp;
 193
 194         uci_foreach_element_safe(&s->options, tmp, o) {
 195                 uci_free_option(uci_to_option(o));
 196         }
 197         if ((s->type != uci_dataptr(s)) &&
 198                 (s->type != NULL))
 199                 free(s->type);
 200         uci_free_element(&s->e);
 201 }
 202
 203 __plugin struct uci_package *
 204 uci_alloc_package(struct uci_context *ctx, const char *name)
 205 {
 206         struct uci_package *p;
 207
 208         p = uci_alloc_element(ctx, package, name, 0);
 209         p->ctx = ctx;
 210         uci_list_init(&p->sections);
 211         uci_list_init(&p->history);
 212         uci_list_init(&p->saved_history);
 213         return p;
 214 }
 215
 216 __private void
 217 uci_free_package(struct uci_package **package)
 218 {
 219         struct uci_element *e, *tmp;
 220         struct uci_package *p = *package;
 221
 222         if(!p)
 223                 return;
 224
 225         if (p->path)
 226                 free(p->path);
 227         uci_foreach_element_safe(&p->sections, tmp, e) {
 228                 uci_free_section(uci_to_section(e));
 229         }
 230         uci_foreach_element_safe(&p->history, tmp, e) {
 231                 uci_free_history(uci_to_history(e));
 232         }
 233         uci_foreach_element_safe(&p->saved_history, tmp, e) {
 234                 uci_free_history(uci_to_history(e));
 235         }
 236         uci_free_element(&p->e);
 237         *package = NULL;
 238 }
 239
 240 static void
 241 uci_free_any(struct uci_element **e)
 242 {
 243         switch((*e)->type) {
 244         case UCI_TYPE_SECTION:
 245                 uci_free_section(uci_to_section(*e));
 246                 break;
 247         case UCI_TYPE_OPTION:
 248                 uci_free_option(uci_to_option(*e));
 249                 break;
 250         default:
 251                 break;
 252         }
 253         *e = NULL;
 254 }
 255
 256 __private struct uci_element *
 257 uci_lookup_list(struct uci_list *list, const char *name)
 258 {
 259         struct uci_element *e;
 260
 261         uci_foreach_element(list, e) {
 262                 if (!strcmp(e->name, name))
 263                         return e;
 264         }
 265         return NULL;
 266 }
 267
 268 static struct uci_element *
 269 uci_lookup_ext_section(struct uci_context *ctx, struct uci_ptr *ptr)
 270 {
 271         char *idxstr, *t, *section, *name;
 272         struct uci_element *e = NULL;
 273         struct uci_section *s;
 274         int idx, c;
 275
 276         section = uci_strdup(ctx, ptr->section);
 277         name = idxstr = section + 1;
 278
 279         if (section[0] != '@')
 280                 goto error;
 281
 282         /* parse the section index part */
 283         idxstr = strchr(idxstr, '[');
 284         if (!idxstr)
 285                 goto error;
 286         *idxstr = 0;
 287         idxstr++;
 288
 289         t = strchr(idxstr, ']');
 290         if (!t)
 291                 goto error;
 292         if (t[1] != 0)
 293                 goto error;
 294         *t = 0;
 295
 296         t = NULL;
 297         idx = strtol(idxstr, &t, 10);
 298         if (t && *t)
 299                 goto error;
 300
 301         if (!*name)
 302                 name = NULL;
 303         else if (!uci_validate_type(name))
 304                 goto error;
 305
 306         /* if the given index is negative, it specifies the section number from
 307          * the end of the list */
 308         if (idx < 0) {
 309                 c = 0;
 310                 uci_foreach_element(&ptr->p->sections, e) {
 311                         s = uci_to_section(e);
 312                         if (name && (strcmp(s->type, name) != 0))
 313                                 continue;
 314
 315                         c++;
 316                 }
 317                 idx += c;
 318         }
 319
 320         c = 0;
 321         uci_foreach_element(&ptr->p->sections, e) {
 322                 s = uci_to_section(e);
 323                 if (name && (strcmp(s->type, name) != 0))
 324                         continue;
 325
 326                 if (idx == c)
 327                         goto done;
 328                 c++;
 329         }
 330         e = NULL;
 331         goto done;
 332
 333 error:
 334         e = NULL;
 335         memset(ptr, 0, sizeof(struct uci_ptr));
 336         UCI_THROW(ctx, UCI_ERR_INVAL);
 337 done:
 338         free(section);
 339         if (e)
 340                 ptr->section = e->name;
 341         return e;
 342 }
 343
 344 int
 345 uci_lookup_ptr(struct uci_context *ctx, struct uci_ptr *ptr, char *str, bool extended)
 346 {
 347         struct uci_element *e;
 348
 349         UCI_HANDLE_ERR(ctx);
 350         UCI_ASSERT(ctx, ptr != NULL);
 351
 352         if (str)
 353                 UCI_INTERNAL(uci_parse_ptr, ctx, ptr, str);
 354
 355         ptr->flags |= UCI_LOOKUP_DONE;
 356
 357         /* look up the package first */
 358         e = uci_lookup_list(&ctx->root, ptr->package);
 359         if (!e) {
 360                 UCI_INTERNAL(uci_load, ctx, ptr->package, &ptr->p);
 361                 if (!ptr->p)
 362                         goto notfound;
 363                 ptr->last = &ptr->p->e;
 364         } else {
 365                 ptr->p = uci_to_package(e);
 366                 ptr->last = e;
 367         }
 368
 369         if (!ptr->section)
 370                 goto complete;
 371
 372         /* if the section name validates as a regular name, pass through
 373          * to the regular uci_lookup function call */
 374         if (ptr->flags & UCI_LOOKUP_EXTENDED)
 375                 e = uci_lookup_ext_section(ctx, ptr);
 376         else
 377                 e = uci_lookup_list(&ptr->p->sections, ptr->section);
 378
 379         if (!e)
 380                 goto abort;
 381
 382         ptr->last = e;
 383         ptr->s = uci_to_section(e);
 384
 385         if (ptr->option) {
 386                 e = uci_lookup_list(&ptr->s->options, ptr->option);
 387                 if (!e)
 388                         goto abort;
 389
 390                 ptr->o = uci_to_option(e);
 391                 ptr->last = e;
 392         }
 393
 394 complete:
 395         ptr->flags |= UCI_LOOKUP_COMPLETE;
 396 abort:
 397         return 0;
 398
 399 notfound:
 400         UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 401         return 0;
 402 }
 403
 404 static struct uci_element *
 405 expand_ptr(struct uci_context *ctx, struct uci_ptr *ptr, bool complete)
 406 {
 407         UCI_ASSERT(ctx, ptr != NULL);
 408
 409         if (!(ptr->flags & UCI_LOOKUP_DONE))
 410                 UCI_INTERNAL(uci_lookup_ptr, ctx, ptr, NULL, 1);
 411         if (complete && !(ptr->flags & UCI_LOOKUP_COMPLETE))
 412                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 413         UCI_ASSERT(ctx, ptr->p != NULL);
 414
 415         /* fill in missing string info */
 416         if (ptr->p && !ptr->package)
 417                 ptr->package = ptr->p->e.name;
 418         if (ptr->s && !ptr->section)
 419                 ptr->section = ptr->s->e.name;
 420         if (ptr->o && !ptr->option)
 421                 ptr->option = ptr->o->e.name;
 422
 423         if (ptr->o)
 424                 return &ptr->o->e;
 425         if (ptr->s)
 426                 return &ptr->s->e;
 427         if (ptr->p)
 428                 return &ptr->p->e;
 429         else
 430                 return NULL;
 431 }
 432
 433 static void uci_add_element_list(struct uci_context *ctx, struct uci_ptr *ptr, bool internal)
 434 {
 435         struct uci_element *e;
 436         struct uci_package *p;
 437
 438         p = ptr->p;
 439         if (!internal && p->has_history)
 440                 uci_add_history(ctx, &p->history, UCI_CMD_LIST_ADD, ptr->section, ptr->option, ptr->value);
 441
 442         e = uci_alloc_generic(ctx, UCI_TYPE_ITEM, ptr->value, sizeof(struct uci_option));
 443         uci_list_add(&ptr->o->v.list, &e->list);
 444 }
 445
 446 int uci_rename(struct uci_context *ctx, struct uci_ptr *ptr)
 447 {
 448         /* NB: UCI_INTERNAL use means without history tracking */
 449         bool internal = ctx->internal;
 450         struct uci_element *e;
 451         struct uci_package *p;
 452         char *n;
 453
 454         UCI_HANDLE_ERR(ctx);
 455
 456         e = expand_ptr(ctx, ptr, true);
 457         p = ptr->p;
 458
 459         UCI_ASSERT(ctx, ptr->s);
 460         UCI_ASSERT(ctx, ptr->value);
 461
 462         if (!internal && p->has_history)
 463                 uci_add_history(ctx, &p->history, UCI_CMD_RENAME, ptr->section, ptr->option, ptr->value);
 464
 465         n = uci_strdup(ctx, ptr->value);
 466         if (e->name)
 467                 free(e->name);
 468         e->name = n;
 469
 470         if (e->type == UCI_TYPE_SECTION)
 471                 uci_to_section(e)->anonymous = false;
 472
 473         return 0;
 474 }
 475
 476 int uci_reorder_section(struct uci_context *ctx, struct uci_section *s, int pos)
 477 {
 478         struct uci_package *p = s->package;
 479         char order[32];
 480
 481         UCI_HANDLE_ERR(ctx);
 482
 483         uci_list_set_pos(&s->package->sections, &s->e.list, pos);
 484         if (!ctx->internal && p->has_history) {
 485                 sprintf(order, "%d", pos);
 486                 uci_add_history(ctx, &p->history, UCI_CMD_REORDER, s->e.name, NULL, order);
 487         }
 488
 489         return 0;
 490 }
 491
 492 int uci_add_section(struct uci_context *ctx, struct uci_package *p, const char *type, struct uci_section **res)
 493 {
 494         bool internal = ctx->internal;
 495         struct uci_section *s;
 496
 497         UCI_HANDLE_ERR(ctx);
 498         UCI_ASSERT(ctx, p != NULL);
 499         s = uci_alloc_section(p, type, NULL);
 500         uci_fixup_section(ctx, s);
 501         *res = s;
 502         if (!internal && p->has_history)
 503                 uci_add_history(ctx, &p->history, UCI_CMD_ADD, s->e.name, NULL, type);
 504
 505         return 0;
 506 }
 507
 508 int uci_delete(struct uci_context *ctx, struct uci_ptr *ptr)
 509 {
 510         /* NB: pass on internal flag to uci_del_element */
 511         bool internal = ctx->internal;
 512         struct uci_package *p;
 513         struct uci_element *e;
 514
 515         UCI_HANDLE_ERR(ctx);
 516
 517         e = expand_ptr(ctx, ptr, true);
 518         p = ptr->p;
 519
 520         UCI_ASSERT(ctx, ptr->s);
 521
 522         if (!internal && p->has_history)
 523                 uci_add_history(ctx, &p->history, UCI_CMD_REMOVE, ptr->section, ptr->option, NULL);
 524
 525         uci_free_any(&e);
 526
 527         if (ptr->option)
 528                 ptr->o = NULL;
 529         else if (ptr->section)
 530                 ptr->s = NULL;
 531
 532         return 0;
 533 }
 534
 535 int uci_add_list(struct uci_context *ctx, struct uci_ptr *ptr)
 536 {
 537         /* NB: UCI_INTERNAL use means without history tracking */
 538         bool internal = ctx->internal;
 539         struct uci_option *prev = NULL;
 540         const char *value2 = NULL;
 541
 542         UCI_HANDLE_ERR(ctx);
 543
 544         expand_ptr(ctx, ptr, false);
 545         UCI_ASSERT(ctx, ptr->s);
 546         UCI_ASSERT(ctx, ptr->value);
 547
 548         if (ptr->o) {
 549                 switch (ptr->o->type) {
 550                 case UCI_TYPE_STRING:
 551                         /* we already have a string value, convert that to a list */
 552                         prev = ptr->o;
 553                         value2 = ptr->value;
 554                         ptr->value = ptr->o->v.string;
 555                         break;
 556                 case UCI_TYPE_LIST:
 557                         uci_add_element_list(ctx, ptr, internal);
 558                         return 0;
 559                 default:
 560                         UCI_THROW(ctx, UCI_ERR_INVAL);
 561                         break;
 562                 }
 563         }
 564
 565         ptr->o = uci_alloc_list(ptr->s, ptr->option);
 566         if (prev) {
 567                 uci_add_element_list(ctx, ptr, true);
 568                 uci_free_option(prev);
 569                 ptr->value = value2;
 570         }
 571         uci_add_element_list(ctx, ptr, internal);
 572
 573         return 0;
 574 }
 575
 576 int uci_set(struct uci_context *ctx, struct uci_ptr *ptr)
 577 {
 578         /* NB: UCI_INTERNAL use means without history tracking */
 579         bool internal = ctx->internal;
 580
 581         UCI_HANDLE_ERR(ctx);
 582         expand_ptr(ctx, ptr, false);
 583         UCI_ASSERT(ctx, ptr->value);
 584         UCI_ASSERT(ctx, ptr->s || (!ptr->option && ptr->section));
 585         if (!ptr->option && ptr->value[0]) {
 586                 UCI_ASSERT(ctx, uci_validate_type(ptr->value));
 587         }
 588
 589         if (!ptr->o && ptr->s && ptr->option) {
 590                 struct uci_element *e;
 591                 e = uci_lookup_list(&ptr->s->options, ptr->option);
 592                 if (e)
 593                         ptr->o = uci_to_option(e);
 594         }
 595         if (!ptr->value[0]) {
 596                 /* if setting a nonexistant option/section to a nonexistant value,
 597                  * exit without errors */
 598                 if (!(ptr->flags & UCI_LOOKUP_COMPLETE))
 599                         return 0;
 600
 601                 return uci_delete(ctx, ptr);
 602         } else if (!ptr->o && ptr->option) { /* new option */
 603                 ptr->o = uci_alloc_option(ptr->s, ptr->option, ptr->value);
 604                 ptr->last = &ptr->o->e;
 605         } else if (!ptr->s && ptr->section) { /* new section */
 606                 ptr->s = uci_alloc_section(ptr->p, ptr->value, ptr->section);
 607                 ptr->last = &ptr->s->e;
 608         } else if (ptr->o && ptr->option) { /* update option */
 609                 if ((ptr->o->type == UCI_TYPE_STRING) &&
 610                         !strcmp(ptr->o->v.string, ptr->value))
 611                         return 0;
 612                 uci_free_option(ptr->o);
 613                 ptr->o = uci_alloc_option(ptr->s, ptr->option, ptr->value);
 614                 ptr->last = &ptr->o->e;
 615         } else if (ptr->s && ptr->section) { /* update section */
 616                 char *s = uci_strdup(ctx, ptr->value);
 617
 618                 if (ptr->s->type == uci_dataptr(ptr->s)) {
 619                         ptr->last = NULL;
 620                         ptr->last = uci_realloc(ctx, ptr->s, sizeof(struct uci_section));
 621                         ptr->s = uci_to_section(ptr->last);
 622                         uci_list_fixup(&ptr->s->e.list);
 623                 } else {
 624                         free(ptr->s->type);
 625                 }
 626                 ptr->s->type = s;
 627         } else {
 628                 UCI_THROW(ctx, UCI_ERR_INVAL);
 629         }
 630
 631         if (!internal && ptr->p->has_history)
 632                 uci_add_history(ctx, &ptr->p->history, UCI_CMD_CHANGE, ptr->section, ptr->option, ptr->value);
 633
 634         return 0;
 635 }
 636
 637 int uci_unload(struct uci_context *ctx, struct uci_package *p)
 638 {
 639         UCI_HANDLE_ERR(ctx);
 640         UCI_ASSERT(ctx, p != NULL);
 641
 642         uci_free_package(&p);
 643         return 0;
 644 }
 645