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         struct uci_option *o;
 241
 242         UCI_HANDLE_ERR(ctx);
 243         UCI_ASSERT(ctx, res != NULL);
 244         UCI_ASSERT(ctx, p != NULL);
 245         UCI_ASSERT(ctx, section != NULL);
 246
 247         e = uci_lookup_list(ctx, &p->sections, section);
 248         if (!e)
 249                 goto notfound;
 250
 251         if (option) {
 252                 s = uci_to_section(e);
 253                 e = uci_lookup_list(ctx, &s->options, option);
 254         }
 255
 256         *res = e;
 257         return 0;
 258
 259 notfound:
 260         UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 261         return 0;
 262 }
 263
 264 int uci_del_element(struct uci_context *ctx, struct uci_element *e)
 265 {
 266         /* NB: UCI_INTERNAL use means without history tracking */
 267         bool internal = ctx->internal;
 268         struct uci_package *p = NULL;
 269         struct uci_section *s = NULL;
 270         struct uci_option *o = NULL;
 271         struct uci_element *i, *tmp;
 272         char *option = NULL;
 273
 274         UCI_HANDLE_ERR(ctx);
 275         UCI_ASSERT(ctx, e != NULL);
 276
 277         switch(e->type) {
 278         case UCI_TYPE_SECTION:
 279                 s = uci_to_section(e);
 280                 uci_foreach_element_safe(&s->options, tmp, i) {
 281                         uci_del_element(ctx, i);
 282                 }
 283                 break;
 284         case UCI_TYPE_OPTION:
 285                 o = uci_to_option(e);
 286                 s = o->section;
 287                 p = s->package;
 288                 option = e->name;
 289                 break;
 290         default:
 291                 UCI_THROW(ctx, UCI_ERR_INVAL);
 292                 break;
 293         }
 294
 295         p = s->package;
 296         if (!internal)
 297                 uci_add_history(ctx, p, UCI_CMD_REMOVE, s->e.name, option, NULL);
 298
 299         switch(e->type) {
 300         case UCI_TYPE_SECTION:
 301                 uci_free_section(s);
 302                 break;
 303         case UCI_TYPE_OPTION:
 304                 uci_free_option(o);
 305                 break;
 306         default:
 307                 break;
 308         }
 309         return 0;
 310 }
 311
 312 int uci_set_element_value(struct uci_context *ctx, struct uci_element **element, char *value)
 313 {
 314         /* NB: UCI_INTERNAL use means without history tracking */
 315         bool internal = ctx->internal;
 316         struct uci_list *list;
 317         struct uci_element *e;
 318         struct uci_package *p;
 319         struct uci_section *s;
 320         char *section;
 321         char *option;
 322         char *str;
 323         int size;
 324
 325         UCI_HANDLE_ERR(ctx);
 326         UCI_ASSERT(ctx, value != NULL);
 327         UCI_ASSERT(ctx, element != NULL);
 328         UCI_ASSERT(ctx, *element != NULL);
 329
 330         /* what the 'value' of an element means depends on the type
 331          * for a section, the 'value' means its type
 332          * for an option, the 'value' means its value string
 333          * when changing the value, shrink the element to its actual size
 334          * (it may have been allocated with a bigger size, to include
 335          *  its buffer)
 336          * then duplicate the string passed on the command line and
 337          * insert it into the structure.
 338          */
 339         e = *element;
 340         list = e->list.prev;
 341         switch(e->type) {
 342         case UCI_TYPE_SECTION:
 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                 size = sizeof(struct uci_option);
 350                 s = uci_to_option(e)->section;
 351                 section = s->e.name;
 352                 option = e->name;
 353                 break;
 354         default:
 355                 UCI_THROW(ctx, UCI_ERR_INVAL);
 356                 return 0;
 357         }
 358         p = s->package;
 359         if (!internal)
 360                 uci_add_history(ctx, p, UCI_CMD_CHANGE, section, option, value);
 361
 362         uci_list_del(&e->list);
 363         e = uci_realloc(ctx, e, size);
 364         str = uci_strdup(ctx, value);
 365         uci_list_insert(list, &e->list);
 366         *element = e;
 367
 368         switch(e->type) {
 369         case UCI_TYPE_SECTION:
 370                 uci_to_section(e)->type = str;
 371                 break;
 372         case UCI_TYPE_OPTION:
 373                 uci_to_option(e)->value = str;
 374                 break;
 375         default:
 376                 break;
 377         }
 378
 379         return 0;
 380 }
 381
 382 int uci_rename(struct uci_context *ctx, struct uci_package *p, char *section, char *option, char *name)
 383 {
 384         /* NB: UCI_INTERNAL use means without history tracking */
 385         bool internal = ctx->internal;
 386         struct uci_element *e;
 387         struct uci_section *s = NULL;
 388         struct uci_option *o = NULL;
 389
 390         UCI_HANDLE_ERR(ctx);
 391         UCI_ASSERT(ctx, p != NULL);
 392         UCI_ASSERT(ctx, section != NULL);
 393
 394         UCI_INTERNAL(uci_lookup, ctx, &e, p, section, option);
 395
 396         if (!internal)
 397                 uci_add_history(ctx, p, UCI_CMD_RENAME, section, option, name);
 398
 399         name = uci_strdup(ctx, name);
 400         if (e->name)
 401                 free(e->name);
 402         e->name = name;
 403
 404         return 0;
 405 }
 406
 407
 408 int uci_delete(struct uci_context *ctx, struct uci_package *p, char *section, char *option)
 409 {
 410         /* NB: pass on internal flag to uci_del_element */
 411         bool internal = ctx->internal;
 412         struct uci_element *e;
 413         struct uci_section *s = NULL;
 414         struct uci_option *o = NULL;
 415
 416         UCI_HANDLE_ERR(ctx);
 417         UCI_ASSERT(ctx, p != NULL);
 418         UCI_ASSERT(ctx, section != NULL);
 419
 420         UCI_INTERNAL(uci_lookup, ctx, &e, p, section, option);
 421
 422         if (!internal)
 423                 return uci_del_element(ctx, e);
 424         UCI_INTERNAL(uci_del_element, ctx, e);
 425
 426         return 0;
 427 }
 428
 429 int uci_set(struct uci_context *ctx, struct uci_package *p, char *section, char *option, char *value)
 430 {
 431         /* NB: UCI_INTERNAL use means without history tracking */
 432         bool internal = ctx->internal;
 433         struct uci_element *e = NULL;
 434         struct uci_section *s = NULL;
 435         struct uci_option *o = NULL;
 436         struct uci_history *h;
 437
 438         UCI_HANDLE_ERR(ctx);
 439         UCI_ASSERT(ctx, p != NULL);
 440         UCI_ASSERT(ctx, section != NULL);
 441         UCI_ASSERT(ctx, value != NULL);
 442
 443         /*
 444          * look up the package, section and option (if set)
 445          * if the section/option is to be modified and it is not found
 446          * create a new element in the appropriate list
 447          */
 448         e = uci_lookup_list(ctx, &p->sections, section);
 449         if (!e)
 450                 goto notfound;
 451
 452         s = uci_to_section(e);
 453         if (option) {
 454                 e = uci_lookup_list(ctx, &s->options, option);
 455                 if (!e)
 456                         goto notfound;
 457                 o = uci_to_option(e);
 458         } else if (internal && ctx->pctx) {
 459                 ctx->pctx->section = s;
 460         }
 461
 462         /*
 463          * no unknown element was supplied, assume that we can just update
 464          * an existing entry
 465          */
 466         if (o)
 467                 e = &o->e;
 468         else
 469                 e = &s->e;
 470
 471         if (!internal)
 472                 return uci_set_element_value(ctx, &e, value);
 473
 474         UCI_INTERNAL(uci_set_element_value, ctx, &e, value);
 475         return 0;
 476
 477 notfound:
 478         /*
 479          * the entry that we need to update was not found,
 480          * check if the search failed prematurely.
 481          * this can happen if the package was not found, or if
 482          * an option was supplied, but the section wasn't found
 483          */
 484         if (!p || (!s && option))
 485                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 486
 487         /* now add the missing entry */
 488         if (!internal)
 489                 uci_add_history(ctx, p, UCI_CMD_ADD, section, option, value);
 490         if (s)
 491                 uci_alloc_option(s, option, value);
 492         else
 493                 uci_alloc_section(p, value, section);
 494
 495         return 0;
 496 }
 497
 498 int uci_unload(struct uci_context *ctx, struct uci_package *p)
 499 {
 500         struct uci_element *e;
 501
 502         UCI_HANDLE_ERR(ctx);
 503         UCI_ASSERT(ctx, p != NULL);
 504
 505         uci_free_package(&p);
 506         return 0;
 507 }
 508