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         if (name)
  65                 datalen += strlen(name) + 1;
  66         ptr = uci_malloc(ctx, datalen);
  67         e = (struct uci_element *) ptr;
  68         e->type = type;
  69         if (name) {
  70                 e->name = (char *) ptr + size;
  71                 strcpy(e->name, name);
  72         }
  73         uci_list_init(&e->list);
  74
  75         return e;
  76 }
  77
  78 static void
  79 uci_free_element(struct uci_element *e)
  80 {
  81         if (!uci_list_empty(&e->list))
  82                 uci_list_del(&e->list);
  83         free(e);
  84 }
  85
  86 static struct uci_option *
  87 uci_alloc_option(struct uci_section *s, const char *name, const char *value)
  88 {
  89         struct uci_package *p = s->package;
  90         struct uci_context *ctx = p->ctx;
  91         struct uci_option *o;
  92
  93         o = uci_alloc_element(ctx, option, name, strlen(value) + 1);
  94         o->value = uci_dataptr(o);
  95         o->section = s;
  96         strcpy(o->value, value);
  97         uci_list_add(&s->options, &o->e.list);
  98
  99         return o;
 100 }
 101
 102 static inline void
 103 uci_free_option(struct uci_option *o)
 104 {
 105         if ((o->value != uci_dataptr(o)) &&
 106                 (o->value != NULL))
 107                 free(o->value);
 108         uci_free_element(&o->e);
 109 }
 110
 111 static struct uci_section *
 112 uci_alloc_section(struct uci_package *p, const char *type, const char *name)
 113 {
 114         struct uci_context *ctx = p->ctx;
 115         struct uci_section *s;
 116         char buf[16];
 117
 118         if (!name || !name[0]) {
 119                 snprintf(buf, 16, "cfg%d", p->n_section);
 120                 name = buf;
 121         }
 122
 123         s = uci_alloc_element(ctx, section, name, strlen(type) + 1);
 124         s->type = uci_dataptr(s);
 125         s->package = p;
 126         strcpy(s->type, type);
 127         uci_list_init(&s->options);
 128         uci_list_add(&p->sections, &s->e.list);
 129
 130         return s;
 131 }
 132
 133 static void
 134 uci_free_section(struct uci_section *s)
 135 {
 136         struct uci_element *o, *tmp;
 137
 138         uci_foreach_element_safe(&s->options, tmp, o) {
 139                 uci_free_option(uci_to_option(o));
 140         }
 141         if ((s->type != uci_dataptr(s)) &&
 142                 (s->type != NULL))
 143                 free(s->type);
 144         uci_free_element(&s->e);
 145 }
 146
 147 static struct uci_package *
 148 uci_alloc_package(struct uci_context *ctx, const char *name)
 149 {
 150         struct uci_package *p;
 151
 152         p = uci_alloc_element(ctx, package, name, 0);
 153         p->ctx = ctx;
 154         uci_list_init(&p->sections);
 155         uci_list_init(&p->history);
 156         return p;
 157 }
 158
 159 static void
 160 uci_free_package(struct uci_package *p)
 161 {
 162         struct uci_element *e, *tmp;
 163
 164         if(!p)
 165                 return;
 166
 167         if (p->path)
 168                 free(p->path);
 169         uci_foreach_element_safe(&p->sections, tmp, e) {
 170                 uci_free_section(uci_to_section(e));
 171         }
 172         uci_free_element(&p->e);
 173 }
 174
 175 /* record a change that was done to a package */
 176 static void
 177 uci_add_history(struct uci_context *ctx, struct uci_package *p, int cmd, char *section, char *option, char *value)
 178 {
 179         struct uci_history *h;
 180         int size = strlen(section) + 1;
 181         char *ptr;
 182
 183         if (!p->confdir)
 184                 return;
 185
 186         if (value)
 187                 size += strlen(section) + 1;
 188
 189         h = uci_alloc_element(ctx, history, option, size);
 190         ptr = uci_dataptr(h);
 191         h->cmd = cmd;
 192         h->section = strcpy(ptr, section);
 193         if (value) {
 194                 ptr += strlen(ptr) + 1;
 195                 h->value = strcpy(ptr, value);
 196         }
 197         uci_list_add(&p->history, &h->e.list);
 198 }
 199
 200 static void
 201 uci_free_history(struct uci_history *h)
 202 {
 203         if (!h)
 204                 return;
 205         if ((h->section != NULL) &&
 206                 (h->section != uci_dataptr(h))) {
 207                 free(h->section);
 208                 free(h->value);
 209         }
 210         uci_free_element(&h->e);
 211 }
 212
 213 static struct uci_element *uci_lookup_list(struct uci_context *ctx, struct uci_list *list, const char *name)
 214 {
 215         struct uci_element *e;
 216
 217         uci_foreach_element(list, e) {
 218                 if (!strcmp(e->name, name))
 219                         return e;
 220         }
 221         return NULL;
 222 }
 223
 224 int uci_lookup(struct uci_context *ctx, struct uci_element **res, struct uci_package *p, char *section, char *option)
 225 {
 226         struct uci_element *e;
 227         struct uci_section *s;
 228         struct uci_option *o;
 229
 230         UCI_HANDLE_ERR(ctx);
 231         UCI_ASSERT(ctx, res != NULL);
 232         UCI_ASSERT(ctx, p != NULL);
 233         UCI_ASSERT(ctx, section != NULL);
 234
 235         e = uci_lookup_list(ctx, &p->sections, section);
 236         if (!e)
 237                 goto notfound;
 238
 239         if (option) {
 240                 s = uci_to_section(e);
 241                 e = uci_lookup_list(ctx, &s->options, option);
 242         }
 243
 244         *res = e;
 245         return 0;
 246
 247 notfound:
 248         UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 249         return 0;
 250 }
 251
 252 int uci_del_element(struct uci_context *ctx, struct uci_element *e)
 253 {
 254         bool internal = ctx->internal;
 255         struct uci_package *p = NULL;
 256         struct uci_section *s = NULL;
 257         struct uci_option *o = NULL;
 258         struct uci_element *i, *tmp;
 259         char *option = NULL;
 260
 261         UCI_HANDLE_ERR(ctx);
 262         UCI_ASSERT(ctx, e != NULL);
 263
 264         switch(e->type) {
 265         case UCI_TYPE_SECTION:
 266                 s = uci_to_section(e);
 267                 uci_foreach_element_safe(&s->options, tmp, i) {
 268                         uci_del_element(ctx, i);
 269                 }
 270                 break;
 271         case UCI_TYPE_OPTION:
 272                 o = uci_to_option(e);
 273                 s = o->section;
 274                 p = s->package;
 275                 option = e->name;
 276                 break;
 277         default:
 278                 UCI_THROW(ctx, UCI_ERR_INVAL);
 279                 break;
 280         }
 281
 282         p = s->package;
 283         if (!internal)
 284                 uci_add_history(ctx, p, UCI_CMD_REMOVE, s->e.name, option, NULL);
 285
 286         switch(e->type) {
 287         case UCI_TYPE_SECTION:
 288                 uci_free_section(s);
 289                 break;
 290         case UCI_TYPE_OPTION:
 291                 uci_free_option(o);
 292                 break;
 293         default:
 294                 break;
 295         }
 296         return 0;
 297 }
 298
 299 int uci_set_element_value(struct uci_context *ctx, struct uci_element **element, char *value)
 300 {
 301         bool internal = ctx->internal;
 302         struct uci_list *list;
 303         struct uci_element *e;
 304         struct uci_package *p;
 305         struct uci_section *s;
 306         char *section;
 307         char *option;
 308         char *str;
 309         int size;
 310
 311         UCI_HANDLE_ERR(ctx);
 312         UCI_ASSERT(ctx, value != NULL);
 313         UCI_ASSERT(ctx, element != NULL);
 314         UCI_ASSERT(ctx, *element != NULL);
 315
 316         /* what the 'value' of an element means depends on the type
 317          * for a section, the 'value' means its type
 318          * for an option, the 'value' means its value string
 319          * when changing the value, shrink the element to its actual size
 320          * (it may have been allocated with a bigger size, to include
 321          *  its buffer)
 322          * then duplicate the string passed on the command line and
 323          * insert it into the structure.
 324          */
 325         e = *element;
 326         list = e->list.prev;
 327         switch(e->type) {
 328         case UCI_TYPE_SECTION:
 329                 size = sizeof(struct uci_section);
 330                 s = uci_to_section(e);
 331                 section = e->name;
 332                 option = NULL;
 333                 break;
 334         case UCI_TYPE_OPTION:
 335                 size = sizeof(struct uci_option);
 336                 s = uci_to_option(e)->section;
 337                 section = s->e.name;
 338                 option = e->name;
 339                 break;
 340         default:
 341                 UCI_THROW(ctx, UCI_ERR_INVAL);
 342                 return 0;
 343         }
 344         p = s->package;
 345         if (!internal)
 346                 uci_add_history(ctx, p, UCI_CMD_CHANGE, section, option, value);
 347
 348         uci_list_del(&e->list);
 349         e = uci_realloc(ctx, e, size);
 350         str = uci_strdup(ctx, value);
 351         uci_list_insert(list, &e->list);
 352         *element = e;
 353
 354         switch(e->type) {
 355         case UCI_TYPE_SECTION:
 356                 uci_to_section(e)->type = str;
 357                 break;
 358         case UCI_TYPE_OPTION:
 359                 uci_to_option(e)->value = str;
 360                 break;
 361         default:
 362                 break;
 363         }
 364
 365         return 0;
 366 }
 367
 368 int uci_del(struct uci_context *ctx, struct uci_package *p, char *section, char *option)
 369 {
 370         bool internal = ctx->internal;
 371         struct uci_element *e;
 372         struct uci_section *s = NULL;
 373         struct uci_option *o = NULL;
 374
 375         UCI_HANDLE_ERR(ctx);
 376         UCI_ASSERT(ctx, p != NULL);
 377         UCI_ASSERT(ctx, section != NULL);
 378
 379         UCI_INTERNAL(uci_lookup, ctx, &e, p, section, option);
 380
 381         if (!internal)
 382                 return uci_del_element(ctx, e);
 383         UCI_INTERNAL(uci_del_element, ctx, e);
 384
 385         return 0;
 386 }
 387
 388 int uci_set(struct uci_context *ctx, struct uci_package *p, char *section, char *option, char *value)
 389 {
 390         bool internal = ctx->internal;
 391         struct uci_element *e = NULL;
 392         struct uci_section *s = NULL;
 393         struct uci_option *o = NULL;
 394         struct uci_history *h;
 395
 396         UCI_HANDLE_ERR(ctx);
 397         UCI_ASSERT(ctx, p != NULL);
 398         UCI_ASSERT(ctx, section != NULL);
 399         UCI_ASSERT(ctx, value != NULL);
 400
 401         /*
 402          * look up the package, section and option (if set)
 403          * if the section/option is to be modified and it is not found
 404          * create a new element in the appropriate list
 405          */
 406         UCI_INTERNAL(uci_lookup, ctx, &e, p, section, NULL);
 407         s = uci_to_section(e);
 408         if (option) {
 409                 e = uci_lookup_list(ctx, &s->options, option);
 410                 if (!e)
 411                         goto notfound;
 412                 o = uci_to_option(e);
 413         }
 414
 415         /*
 416          * no unknown element was supplied, assume that we can just update
 417          * an existing entry
 418          */
 419         if (o)
 420                 e = &o->e;
 421         else
 422                 e = &s->e;
 423
 424         if (!internal)
 425                 return uci_set_element_value(ctx, &e, value);
 426
 427         UCI_INTERNAL(uci_set_element_value, ctx, &e, value);
 428         return 0;
 429
 430 notfound:
 431         /*
 432          * the entry that we need to update was not found,
 433          * check if the search failed prematurely.
 434          * this can happen if the package was not found, or if
 435          * an option was supplied, but the section wasn't found
 436          */
 437         if (!p || (!s && option))
 438                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 439
 440         /* now add the missing entry */
 441         if (!internal)
 442                 uci_add_history(ctx, p, UCI_CMD_ADD, section, option, value);
 443         if (s)
 444                 uci_alloc_option(s, option, value);
 445         else
 446                 uci_alloc_section(p, value, section);
 447
 448         return 0;
 449 }
 450
 451 int uci_unload(struct uci_context *ctx, struct uci_package *p)
 452 {
 453         struct uci_element *e;
 454
 455         UCI_HANDLE_ERR(ctx);
 456         UCI_ASSERT(ctx, p != NULL);
 457
 458         uci_free_package(p);
 459         return 0;
 460 }
 461