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