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 #include <glob.h>
  16
  17 /* initialize a list head/item */
  18 static inline void uci_list_init(struct uci_list *ptr)
  19 {
  20         ptr->prev = ptr;
  21         ptr->next = ptr;
  22 }
  23
  24 /* inserts a new list entry after a given entry */
  25 static inline void uci_list_insert(struct uci_list *list, struct uci_list *ptr)
  26 {
  27         list->next->prev = ptr;
  28         ptr->prev = list;
  29         ptr->next = list->next;
  30         list->next = ptr;
  31 }
  32
  33 /* inserts a new list entry at the tail of the list */
  34 static inline void uci_list_add(struct uci_list *head, struct uci_list *ptr)
  35 {
  36         /* NB: head->prev points at the tail */
  37         uci_list_insert(head->prev, ptr);
  38 }
  39
  40 static inline void uci_list_del(struct uci_list *ptr)
  41 {
  42         struct uci_list *next, *prev;
  43
  44         next = ptr->next;
  45         prev = ptr->prev;
  46
  47         prev->next = next;
  48         next->prev = prev;
  49
  50         uci_list_init(ptr);
  51 }
  52
  53 /*
  54  * uci_alloc_generic allocates a new uci_element with payload
  55  * payload is appended to the struct to save memory and reduce fragmentation
  56  */
  57 static struct uci_element *
  58 uci_alloc_generic(struct uci_context *ctx, int type, const char *name, int size)
  59 {
  60         struct uci_element *e;
  61         int datalen = size;
  62         void *ptr;
  63
  64         ptr = uci_malloc(ctx, datalen);
  65         e = (struct uci_element *) ptr;
  66         e->type = type;
  67         if (name) {
  68                 UCI_TRAP_SAVE(ctx, error);
  69                 e->name = uci_strdup(ctx, name);
  70                 UCI_TRAP_RESTORE(ctx);
  71         }
  72         uci_list_init(&e->list);
  73         goto done;
  74
  75 error:
  76         free(ptr);
  77         UCI_THROW(ctx, ctx->err);
  78
  79 done:
  80         return e;
  81 }
  82
  83 static void
  84 uci_free_element(struct uci_element *e)
  85 {
  86         if (e->name)
  87                 free(e->name);
  88         if (!uci_list_empty(&e->list))
  89                 uci_list_del(&e->list);
  90         free(e);
  91 }
  92
  93 static struct uci_option *
  94 uci_alloc_option(struct uci_section *s, const char *name, const char *value)
  95 {
  96         struct uci_package *p = s->package;
  97         struct uci_context *ctx = p->ctx;
  98         struct uci_option *o;
  99
 100         o = uci_alloc_element(ctx, option, name, strlen(value) + 1);
 101         o->value = uci_dataptr(o);
 102         o->section = s;
 103         strcpy(o->value, value);
 104         uci_list_add(&s->options, &o->e.list);
 105
 106         return o;
 107 }
 108
 109 static inline void
 110 uci_free_option(struct uci_option *o)
 111 {
 112         if ((o->value != uci_dataptr(o)) &&
 113                 (o->value != NULL))
 114                 free(o->value);
 115         uci_free_element(&o->e);
 116 }
 117
 118 /* fix up an unnamed section, e.g. after adding options to it */
 119 static void uci_fixup_section(struct uci_context *ctx, struct uci_section *s)
 120 {
 121         unsigned int hash = ~0;
 122         struct uci_element *e;
 123         char buf[16];
 124
 125         if (!s || s->e.name)
 126                 return;
 127
 128         /*
 129          * Generate a name for unnamed sections. This is used as reference
 130          * when locating or updating the section from apps/scripts.
 131          * To make multiple concurrent versions somewhat safe for updating,
 132          * the name is generated from a hash of its type and name/value
 133          * pairs of its option, and it is prefixed by a counter value.
 134          * If the order of the unnamed sections changes for some reason,
 135          * updates to them will be rejected.
 136          */
 137         hash = djbhash(hash, s->type);
 138         uci_foreach_element(&s->options, e) {
 139                 hash = djbhash(hash, e->name);
 140                 hash = djbhash(hash, uci_to_option(e)->value);
 141         }
 142         sprintf(buf, "cfg%02x%04x", ++s->package->n_section, hash % (1 << 16));
 143         s->e.name = uci_strdup(ctx, buf);
 144 }
 145
 146 static struct uci_section *
 147 uci_alloc_section(struct uci_package *p, const char *type, const char *name)
 148 {
 149         struct uci_context *ctx = p->ctx;
 150         struct uci_section *s;
 151
 152         if (name && !name[0])
 153                 name = NULL;
 154
 155         s = uci_alloc_element(ctx, section, name, strlen(type) + 1);
 156         uci_list_init(&s->options);
 157         s->type = uci_dataptr(s);
 158         s->package = p;
 159         strcpy(s->type, type);
 160         if (name == NULL)
 161                 s->anonymous = true;
 162         p->n_section++;
 163
 164         uci_list_add(&p->sections, &s->e.list);
 165
 166         return s;
 167 }
 168
 169 static void
 170 uci_free_section(struct uci_section *s)
 171 {
 172         struct uci_element *o, *tmp;
 173
 174         uci_foreach_element_safe(&s->options, tmp, o) {
 175                 uci_free_option(uci_to_option(o));
 176         }
 177         if ((s->type != uci_dataptr(s)) &&
 178                 (s->type != NULL))
 179                 free(s->type);
 180         uci_free_element(&s->e);
 181 }
 182
 183 __plugin struct uci_package *
 184 uci_alloc_package(struct uci_context *ctx, const char *name)
 185 {
 186         struct uci_package *p;
 187
 188         p = uci_alloc_element(ctx, package, name, 0);
 189         p->ctx = ctx;
 190         uci_list_init(&p->sections);
 191         uci_list_init(&p->history);
 192         uci_list_init(&p->saved_history);
 193         return p;
 194 }
 195
 196 static void
 197 uci_free_package(struct uci_package **package)
 198 {
 199         struct uci_element *e, *tmp;
 200         struct uci_package *p = *package;
 201
 202         if(!p)
 203                 return;
 204
 205         if (p->path)
 206                 free(p->path);
 207         uci_foreach_element_safe(&p->sections, tmp, e) {
 208                 uci_free_section(uci_to_section(e));
 209         }
 210         uci_foreach_element_safe(&p->history, tmp, e) {
 211                 uci_free_history(uci_to_history(e));
 212         }
 213         uci_foreach_element_safe(&p->saved_history, tmp, e) {
 214                 uci_free_history(uci_to_history(e));
 215         }
 216         uci_free_element(&p->e);
 217         *package = NULL;
 218 }
 219
 220 static struct uci_element *uci_lookup_list(struct uci_list *list, const char *name)
 221 {
 222         struct uci_element *e;
 223
 224         uci_foreach_element(list, e) {
 225                 if (!strcmp(e->name, name))
 226                         return e;
 227         }
 228         return NULL;
 229 }
 230
 231 int uci_lookup(struct uci_context *ctx, struct uci_element **res, struct uci_package *p, const char *section, const char *option)
 232 {
 233         struct uci_element *e;
 234         struct uci_section *s;
 235
 236         UCI_HANDLE_ERR(ctx);
 237         UCI_ASSERT(ctx, res != NULL);
 238         UCI_ASSERT(ctx, p != NULL);
 239         UCI_ASSERT(ctx, section && uci_validate_name(section));
 240         if (option)
 241                 UCI_ASSERT(ctx, uci_validate_name(option));
 242
 243         e = uci_lookup_list(&p->sections, section);
 244         if (!e)
 245                 goto notfound;
 246
 247         if (option) {
 248                 s = uci_to_section(e);
 249                 e = uci_lookup_list(&s->options, option);
 250                 if (!e)
 251                         goto notfound;
 252         }
 253
 254         *res = e;
 255         return 0;
 256
 257 notfound:
 258         UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 259         return 0;
 260 }
 261
 262 int uci_del_element(struct uci_context *ctx, struct uci_element *e)
 263 {
 264         /* NB: UCI_INTERNAL use means without history tracking */
 265         bool internal = ctx->internal;
 266         struct uci_package *p = NULL;
 267         struct uci_section *s = NULL;
 268         struct uci_option *o = NULL;
 269         struct uci_element *i, *tmp;
 270         char *option = NULL;
 271
 272         UCI_HANDLE_ERR(ctx);
 273         UCI_ASSERT(ctx, e != NULL);
 274
 275         switch(e->type) {
 276         case UCI_TYPE_SECTION:
 277                 s = uci_to_section(e);
 278                 uci_foreach_element_safe(&s->options, tmp, i) {
 279                         uci_del_element(ctx, i);
 280                 }
 281                 break;
 282         case UCI_TYPE_OPTION:
 283                 o = uci_to_option(e);
 284                 s = o->section;
 285                 p = s->package;
 286                 option = e->name;
 287                 break;
 288         default:
 289                 UCI_THROW(ctx, UCI_ERR_INVAL);
 290                 break;
 291         }
 292
 293         p = s->package;
 294         if (!internal && p->has_history)
 295                 uci_add_history(ctx, &p->history, UCI_CMD_REMOVE, s->e.name, option, NULL);
 296
 297         switch(e->type) {
 298         case UCI_TYPE_SECTION:
 299                 uci_free_section(s);
 300                 break;
 301         case UCI_TYPE_OPTION:
 302                 uci_free_option(o);
 303                 break;
 304         default:
 305                 break;
 306         }
 307         return 0;
 308 }
 309
 310 int uci_set_element_value(struct uci_context *ctx, struct uci_element **element, const char *value)
 311 {
 312         /* NB: UCI_INTERNAL use means without history tracking */
 313         bool internal = ctx->internal;
 314         struct uci_list *list;
 315         struct uci_element *e;
 316         struct uci_package *p;
 317         struct uci_section *s;
 318         struct uci_option *o;
 319         char *section;
 320         char *option;
 321         char *str;
 322         int size;
 323
 324         UCI_HANDLE_ERR(ctx);
 325         UCI_ASSERT(ctx, (element != NULL) && (*element != NULL));
 326
 327         /* what the 'value' of an element means depends on the type
 328          * for a section, the 'value' means its type
 329          * for an option, the 'value' means its value string
 330          * when changing the value, shrink the element to its actual size
 331          * (it may have been allocated with a bigger size, to include
 332          *  its buffer)
 333          * then duplicate the string passed on the command line and
 334          * insert it into the structure.
 335          */
 336         e = *element;
 337         list = e->list.prev;
 338         switch(e->type) {
 339         case UCI_TYPE_SECTION:
 340                 UCI_ASSERT(ctx, uci_validate_str(value, false));
 341                 size = sizeof(struct uci_section);
 342                 s = uci_to_section(e);
 343                 section = e->name;
 344                 option = NULL;
 345                 /* matches the currently set value */
 346                 if (!strcmp(value, s->type))
 347                         return 0;
 348                 break;
 349         case UCI_TYPE_OPTION:
 350                 UCI_ASSERT(ctx, value != NULL);
 351                 size = sizeof(struct uci_option);
 352                 o = uci_to_option(e);
 353                 s = o->section;
 354                 section = s->e.name;
 355                 option = o->e.name;
 356                 /* matches the currently set value */
 357                 if (!strcmp(value, o->value))
 358                         return 0;
 359                 break;
 360         default:
 361                 UCI_THROW(ctx, UCI_ERR_INVAL);
 362                 return 0;
 363         }
 364         p = s->package;
 365         if (!internal && p->has_history)
 366                 uci_add_history(ctx, &p->history, UCI_CMD_CHANGE, section, option, value);
 367
 368         uci_list_del(&e->list);
 369         e = uci_realloc(ctx, e, size);
 370         str = uci_strdup(ctx, value);
 371         uci_list_insert(list, &e->list);
 372         *element = e;
 373
 374         switch(e->type) {
 375         case UCI_TYPE_SECTION:
 376                 uci_to_section(e)->type = str;
 377                 break;
 378         case UCI_TYPE_OPTION:
 379                 uci_to_option(e)->value = str;
 380                 break;
 381         default:
 382                 break;
 383         }
 384
 385         return 0;
 386 }
 387
 388 int uci_rename(struct uci_context *ctx, struct uci_package *p, char *section, char *option, char *name)
 389 {
 390         /* NB: UCI_INTERNAL use means without history tracking */
 391         bool internal = ctx->internal;
 392         struct uci_element *e;
 393
 394         UCI_HANDLE_ERR(ctx);
 395
 396         /* NB: p, section, option validated by uci_lookup */
 397         UCI_INTERNAL(uci_lookup, ctx, &e, p, section, option);
 398
 399         if (!internal && p->has_history)
 400                 uci_add_history(ctx, &p->history, UCI_CMD_RENAME, section, option, name);
 401
 402         name = uci_strdup(ctx, name);
 403         if (e->name)
 404                 free(e->name);
 405         e->name = name;
 406
 407         return 0;
 408 }
 409
 410 int uci_add_section(struct uci_context *ctx, struct uci_package *p, const char *type, struct uci_section **res)
 411 {
 412         bool internal = ctx->internal;
 413         struct uci_section *s;
 414
 415         UCI_HANDLE_ERR(ctx);
 416         UCI_ASSERT(ctx, p != NULL);
 417         s = uci_alloc_section(p, type, NULL);
 418         uci_fixup_section(ctx, s);
 419         *res = s;
 420         if (!internal && p->has_history)
 421                 uci_add_history(ctx, &p->history, UCI_CMD_ADD, s->e.name, NULL, type);
 422
 423         return 0;
 424 }
 425
 426 int uci_delete(struct uci_context *ctx, struct uci_package *p, const char *section, const char *option)
 427 {
 428         /* NB: pass on internal flag to uci_del_element */
 429         bool internal = ctx->internal;
 430         struct uci_element *e;
 431
 432         UCI_HANDLE_ERR(ctx);
 433
 434         /* NB: p, section, option validated by uci_lookup */
 435         UCI_INTERNAL(uci_lookup, ctx, &e, p, section, option);
 436
 437         ctx->internal = internal;
 438         return uci_del_element(ctx, e);
 439 }
 440
 441 int uci_set(struct uci_context *ctx, struct uci_package *p, const char *section, const char *option, const char *value, struct uci_element **result)
 442 {
 443         /* NB: UCI_INTERNAL use means without history tracking */
 444         bool internal = ctx->internal;
 445         struct uci_element *e = NULL;
 446         struct uci_section *s = NULL;
 447         struct uci_option *o = NULL;
 448
 449         UCI_HANDLE_ERR(ctx);
 450         UCI_ASSERT(ctx, p != NULL);
 451         UCI_ASSERT(ctx, uci_validate_name(section));
 452         if (option) {
 453                 UCI_ASSERT(ctx, uci_validate_name(option));
 454                 UCI_ASSERT(ctx, value != NULL);
 455         } else {
 456                 UCI_ASSERT(ctx, uci_validate_str(value, false));
 457         }
 458
 459         /*
 460          * look up the package, section and option (if set)
 461          * if the section/option is to be modified and it is not found
 462          * create a new element in the appropriate list
 463          */
 464         e = uci_lookup_list(&p->sections, section);
 465         if (!e)
 466                 goto notfound;
 467
 468         s = uci_to_section(e);
 469         if (ctx->pctx && ctx->pctx->merge)
 470                 ctx->pctx->section = s;
 471
 472         if (option) {
 473                 e = uci_lookup_list(&s->options, option);
 474                 if (!e)
 475                         goto notfound;
 476                 o = uci_to_option(e);
 477         }
 478
 479         /*
 480          * no unknown element was supplied, assume that we can just update
 481          * an existing entry
 482          */
 483         if (o)
 484                 e = &o->e;
 485         else
 486                 e = &s->e;
 487         if (result)
 488                 *result = e;
 489         else
 490                 result = &e;
 491
 492         ctx->internal = internal;
 493         return uci_set_element_value(ctx, result, value);
 494
 495 notfound:
 496         /*
 497          * the entry that we need to update was not found,
 498          * check if the search failed prematurely.
 499          * this can happen if the package was not found, or if
 500          * an option was supplied, but the section wasn't found
 501          */
 502         if (!p || (!s && option))
 503                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 504
 505         /* now add the missing entry */
 506         if (!internal && p->has_history)
 507                 uci_add_history(ctx, &p->history, UCI_CMD_CHANGE, section, option, value);
 508         if (s) {
 509                 o = uci_alloc_option(s, option, value);
 510                 if (result)
 511                         *result = &o->e;
 512         } else {
 513                 s = uci_alloc_section(p, value, section);
 514                 if (result)
 515                         *result = &s->e;
 516                 if (ctx->pctx && ctx->pctx->merge)
 517                         ctx->pctx->section = s;
 518         }
 519
 520         return 0;
 521 }
 522
 523 int uci_unload(struct uci_context *ctx, struct uci_package *p)
 524 {
 525         UCI_HANDLE_ERR(ctx);
 526         UCI_ASSERT(ctx, p != NULL);
 527
 528         uci_free_package(&p);
 529         return 0;
 530 }
 531