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->errno);
  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 static struct uci_section *
 119 uci_alloc_section(struct uci_package *p, const char *type, const char *name)
 120 {
 121         struct uci_context *ctx = p->ctx;
 122         struct uci_section *s;
 123
 124         if (name && !name[0])
 125                 name = NULL;
 126
 127         s = uci_alloc_element(ctx, section, name, strlen(type) + 1);
 128         uci_list_init(&s->options);
 129         s->type = uci_dataptr(s);
 130         s->package = p;
 131         strcpy(s->type, type);
 132         if (name == NULL)
 133                 s->anonymous = true;
 134
 135         uci_list_add(&p->sections, &s->e.list);
 136
 137         return s;
 138 }
 139
 140 static void
 141 uci_free_section(struct uci_section *s)
 142 {
 143         struct uci_element *o, *tmp;
 144
 145         uci_foreach_element_safe(&s->options, tmp, o) {
 146                 uci_free_option(uci_to_option(o));
 147         }
 148         if ((s->type != uci_dataptr(s)) &&
 149                 (s->type != NULL))
 150                 free(s->type);
 151         uci_free_element(&s->e);
 152 }
 153
 154 /* record a change that was done to a package */
 155 static void
 156 uci_add_history(struct uci_context *ctx, struct uci_package *p, int cmd, char *section, char *option, char *value)
 157 {
 158         struct uci_history *h;
 159         int size = strlen(section) + 1;
 160         char *ptr;
 161
 162         if (!p->confdir)
 163                 return;
 164
 165         if (value)
 166                 size += strlen(section) + 1;
 167
 168         h = uci_alloc_element(ctx, history, option, size);
 169         ptr = uci_dataptr(h);
 170         h->cmd = cmd;
 171         h->section = strcpy(ptr, section);
 172         if (value) {
 173                 ptr += strlen(ptr) + 1;
 174                 h->value = strcpy(ptr, value);
 175         }
 176         uci_list_add(&p->history, &h->e.list);
 177 }
 178
 179 static void
 180 uci_free_history(struct uci_history *h)
 181 {
 182         if (!h)
 183                 return;
 184         if ((h->section != NULL) &&
 185                 (h->section != uci_dataptr(h))) {
 186                 free(h->section);
 187                 free(h->value);
 188         }
 189         uci_free_element(&h->e);
 190 }
 191
 192 static struct uci_package *
 193 uci_alloc_package(struct uci_context *ctx, const char *name)
 194 {
 195         struct uci_package *p;
 196
 197         p = uci_alloc_element(ctx, package, name, 0);
 198         p->ctx = ctx;
 199         uci_list_init(&p->sections);
 200         uci_list_init(&p->history);
 201         return p;
 202 }
 203
 204 static void
 205 uci_free_package(struct uci_package **package)
 206 {
 207         struct uci_element *e, *tmp;
 208         struct uci_package *p = *package;
 209
 210         if(!p)
 211                 return;
 212
 213         if (p->path)
 214                 free(p->path);
 215         uci_foreach_element_safe(&p->sections, tmp, e) {
 216                 uci_free_section(uci_to_section(e));
 217         }
 218         uci_foreach_element_safe(&p->history, tmp, e) {
 219                 uci_free_history(uci_to_history(e));
 220         }
 221         uci_free_element(&p->e);
 222         *package = NULL;
 223 }
 224
 225 static struct uci_element *uci_lookup_list(struct uci_context *ctx, struct uci_list *list, const char *name)
 226 {
 227         struct uci_element *e;
 228
 229         uci_foreach_element(list, e) {
 230                 if (!strcmp(e->name, name))
 231                         return e;
 232         }
 233         return NULL;
 234 }
 235
 236 int uci_lookup(struct uci_context *ctx, struct uci_element **res, struct uci_package *p, char *section, char *option)
 237 {
 238         struct uci_element *e;
 239         struct uci_section *s;
 240
 241         UCI_HANDLE_ERR(ctx);
 242         UCI_ASSERT(ctx, res != NULL);
 243         UCI_ASSERT(ctx, p != NULL);
 244         UCI_ASSERT(ctx, uci_validate_name(section));
 245         if (option)
 246                 UCI_ASSERT(ctx, uci_validate_name(option));
 247
 248         e = uci_lookup_list(ctx, &p->sections, section);
 249         if (!e)
 250                 goto notfound;
 251
 252         if (option) {
 253                 s = uci_to_section(e);
 254                 e = uci_lookup_list(ctx, &s->options, option);
 255         }
 256
 257         *res = e;
 258         return 0;
 259
 260 notfound:
 261         UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 262         return 0;
 263 }
 264
 265 int uci_del_element(struct uci_context *ctx, struct uci_element *e)
 266 {
 267         /* NB: UCI_INTERNAL use means without history tracking */
 268         bool internal = ctx->internal;
 269         struct uci_package *p = NULL;
 270         struct uci_section *s = NULL;
 271         struct uci_option *o = NULL;
 272         struct uci_element *i, *tmp;
 273         char *option = NULL;
 274
 275         UCI_HANDLE_ERR(ctx);
 276         UCI_ASSERT(ctx, e != NULL);
 277
 278         switch(e->type) {
 279         case UCI_TYPE_SECTION:
 280                 s = uci_to_section(e);
 281                 uci_foreach_element_safe(&s->options, tmp, i) {
 282                         uci_del_element(ctx, i);
 283                 }
 284                 break;
 285         case UCI_TYPE_OPTION:
 286                 o = uci_to_option(e);
 287                 s = o->section;
 288                 p = s->package;
 289                 option = e->name;
 290                 break;
 291         default:
 292                 UCI_THROW(ctx, UCI_ERR_INVAL);
 293                 break;
 294         }
 295
 296         p = s->package;
 297         if (!internal)
 298                 uci_add_history(ctx, p, UCI_CMD_REMOVE, s->e.name, option, NULL);
 299
 300         switch(e->type) {
 301         case UCI_TYPE_SECTION:
 302                 uci_free_section(s);
 303                 break;
 304         case UCI_TYPE_OPTION:
 305                 uci_free_option(o);
 306                 break;
 307         default:
 308                 break;
 309         }
 310         return 0;
 311 }
 312
 313 int uci_set_element_value(struct uci_context *ctx, struct uci_element **element, char *value)
 314 {
 315         /* NB: UCI_INTERNAL use means without history tracking */
 316         bool internal = ctx->internal;
 317         struct uci_list *list;
 318         struct uci_element *e;
 319         struct uci_package *p;
 320         struct uci_section *s;
 321         char *section;
 322         char *option;
 323         char *str;
 324         int size;
 325
 326         UCI_HANDLE_ERR(ctx);
 327         UCI_ASSERT(ctx, (element != NULL) && (*element != NULL));
 328
 329         /* what the 'value' of an element means depends on the type
 330          * for a section, the 'value' means its type
 331          * for an option, the 'value' means its value string
 332          * when changing the value, shrink the element to its actual size
 333          * (it may have been allocated with a bigger size, to include
 334          *  its buffer)
 335          * then duplicate the string passed on the command line and
 336          * insert it into the structure.
 337          */
 338         e = *element;
 339         list = e->list.prev;
 340         switch(e->type) {
 341         case UCI_TYPE_SECTION:
 342                 UCI_ASSERT(ctx, uci_validate_name(value));
 343                 size = sizeof(struct uci_section);
 344                 s = uci_to_section(e);
 345                 section = e->name;
 346                 option = NULL;
 347                 break;
 348         case UCI_TYPE_OPTION:
 349                 UCI_ASSERT(ctx, value != NULL);
 350                 size = sizeof(struct uci_option);
 351                 s = uci_to_option(e)->section;
 352                 section = s->e.name;
 353                 option = e->name;
 354                 break;
 355         default:
 356                 UCI_THROW(ctx, UCI_ERR_INVAL);
 357                 return 0;
 358         }
 359         p = s->package;
 360         if (!internal)
 361                 uci_add_history(ctx, p, UCI_CMD_CHANGE, section, option, value);
 362
 363         uci_list_del(&e->list);
 364         e = uci_realloc(ctx, e, size);
 365         str = uci_strdup(ctx, value);
 366         uci_list_insert(list, &e->list);
 367         *element = e;
 368
 369         switch(e->type) {
 370         case UCI_TYPE_SECTION:
 371                 uci_to_section(e)->type = str;
 372                 break;
 373         case UCI_TYPE_OPTION:
 374                 uci_to_option(e)->value = str;
 375                 break;
 376         default:
 377                 break;
 378         }
 379
 380         return 0;
 381 }
 382
 383 int uci_rename(struct uci_context *ctx, struct uci_package *p, char *section, char *option, char *name)
 384 {
 385         /* NB: UCI_INTERNAL use means without history tracking */
 386         bool internal = ctx->internal;
 387         struct uci_element *e;
 388
 389         UCI_HANDLE_ERR(ctx);
 390
 391         /* NB: p, section, option validated by uci_lookup */
 392         UCI_INTERNAL(uci_lookup, ctx, &e, p, section, option);
 393
 394         if (!internal)
 395                 uci_add_history(ctx, p, UCI_CMD_RENAME, section, option, name);
 396
 397         name = uci_strdup(ctx, name);
 398         if (e->name)
 399                 free(e->name);
 400         e->name = name;
 401
 402         return 0;
 403 }
 404
 405
 406 int uci_delete(struct uci_context *ctx, struct uci_package *p, char *section, char *option)
 407 {
 408         /* NB: pass on internal flag to uci_del_element */
 409         bool internal = ctx->internal;
 410         struct uci_element *e;
 411
 412         UCI_HANDLE_ERR(ctx);
 413
 414         /* NB: p, section, option validated by uci_lookup */
 415         UCI_INTERNAL(uci_lookup, ctx, &e, p, section, option);
 416
 417         ctx->internal = internal;
 418         return uci_del_element(ctx, e);
 419 }
 420
 421 int uci_set(struct uci_context *ctx, struct uci_package *p, char *section, char *option, char *value)
 422 {
 423         /* NB: UCI_INTERNAL use means without history tracking */
 424         bool internal = ctx->internal;
 425         struct uci_element *e = NULL;
 426         struct uci_section *s = NULL;
 427         struct uci_option *o = NULL;
 428
 429         UCI_HANDLE_ERR(ctx);
 430         UCI_ASSERT(ctx, p != NULL);
 431         UCI_ASSERT(ctx, uci_validate_name(section));
 432         if (option) {
 433                 UCI_ASSERT(ctx, uci_validate_name(option));
 434                 UCI_ASSERT(ctx, value != NULL);
 435         } else {
 436                 UCI_ASSERT(ctx, uci_validate_name(value));
 437         }
 438
 439         /*
 440          * look up the package, section and option (if set)
 441          * if the section/option is to be modified and it is not found
 442          * create a new element in the appropriate list
 443          */
 444         e = uci_lookup_list(ctx, &p->sections, section);
 445         if (!e)
 446                 goto notfound;
 447
 448         s = uci_to_section(e);
 449         if (ctx->pctx)
 450                 ctx->pctx->section = s;
 451
 452         if (option) {
 453                 e = uci_lookup_list(ctx, &s->options, option);
 454                 if (!e)
 455                         goto notfound;
 456                 o = uci_to_option(e);
 457         }
 458
 459         /*
 460          * no unknown element was supplied, assume that we can just update
 461          * an existing entry
 462          */
 463         if (o)
 464                 e = &o->e;
 465         else
 466                 e = &s->e;
 467
 468         ctx->internal = internal;
 469         return uci_set_element_value(ctx, &e, value);
 470
 471 notfound:
 472         /*
 473          * the entry that we need to update was not found,
 474          * check if the search failed prematurely.
 475          * this can happen if the package was not found, or if
 476          * an option was supplied, but the section wasn't found
 477          */
 478         if (!p || (!s && option))
 479                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 480
 481         /* now add the missing entry */
 482         if (!internal)
 483                 uci_add_history(ctx, p, UCI_CMD_ADD, section, option, value);
 484         if (s)
 485                 uci_alloc_option(s, option, value);
 486         else {
 487                 s = uci_alloc_section(p, value, section);
 488                 if (ctx->pctx)
 489                         ctx->pctx->section = s;
 490         }
 491
 492         return 0;
 493 }
 494
 495 int uci_unload(struct uci_context *ctx, struct uci_package *p)
 496 {
 497         UCI_HANDLE_ERR(ctx);
 498         UCI_ASSERT(ctx, p != NULL);
 499
 500         uci_free_package(&p);
 501         return 0;
 502 }
 503