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 **package)
 199 {
 200         struct uci_element *e, *tmp;
 201         struct uci_package *p = *package;
 202
 203         if(!p)
 204                 return;
 205
 206         if (p->path)
 207                 free(p->path);
 208         uci_foreach_element_safe(&p->sections, tmp, e) {
 209                 uci_free_section(uci_to_section(e));
 210         }
 211         uci_foreach_element_safe(&p->history, tmp, e) {
 212                 uci_free_history(uci_to_history(e));
 213         }
 214         uci_free_element(&p->e);
 215         *package = NULL;
 216 }
 217
 218 static struct uci_element *uci_lookup_list(struct uci_context *ctx, struct uci_list *list, const char *name)
 219 {
 220         struct uci_element *e;
 221
 222         uci_foreach_element(list, e) {
 223                 if (!strcmp(e->name, name))
 224                         return e;
 225         }
 226         return NULL;
 227 }
 228
 229 int uci_lookup(struct uci_context *ctx, struct uci_element **res, struct uci_package *p, char *section, char *option)
 230 {
 231         struct uci_element *e;
 232         struct uci_section *s;
 233         struct uci_option *o;
 234
 235         UCI_HANDLE_ERR(ctx);
 236         UCI_ASSERT(ctx, res != NULL);
 237         UCI_ASSERT(ctx, p != NULL);
 238         UCI_ASSERT(ctx, section != NULL);
 239
 240         e = uci_lookup_list(ctx, &p->sections, section);
 241         if (!e)
 242                 goto notfound;
 243
 244         if (option) {
 245                 s = uci_to_section(e);
 246                 e = uci_lookup_list(ctx, &s->options, option);
 247         }
 248
 249         *res = e;
 250         return 0;
 251
 252 notfound:
 253         UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 254         return 0;
 255 }
 256
 257 int uci_del_element(struct uci_context *ctx, struct uci_element *e)
 258 {
 259         /* NB: UCI_INTERNAL use means without history tracking */
 260         bool internal = ctx->internal;
 261         struct uci_package *p = NULL;
 262         struct uci_section *s = NULL;
 263         struct uci_option *o = NULL;
 264         struct uci_element *i, *tmp;
 265         char *option = NULL;
 266
 267         UCI_HANDLE_ERR(ctx);
 268         UCI_ASSERT(ctx, e != NULL);
 269
 270         switch(e->type) {
 271         case UCI_TYPE_SECTION:
 272                 s = uci_to_section(e);
 273                 uci_foreach_element_safe(&s->options, tmp, i) {
 274                         uci_del_element(ctx, i);
 275                 }
 276                 break;
 277         case UCI_TYPE_OPTION:
 278                 o = uci_to_option(e);
 279                 s = o->section;
 280                 p = s->package;
 281                 option = e->name;
 282                 break;
 283         default:
 284                 UCI_THROW(ctx, UCI_ERR_INVAL);
 285                 break;
 286         }
 287
 288         p = s->package;
 289         if (!internal)
 290                 uci_add_history(ctx, p, UCI_CMD_REMOVE, s->e.name, option, NULL);
 291
 292         switch(e->type) {
 293         case UCI_TYPE_SECTION:
 294                 uci_free_section(s);
 295                 break;
 296         case UCI_TYPE_OPTION:
 297                 uci_free_option(o);
 298                 break;
 299         default:
 300                 break;
 301         }
 302         return 0;
 303 }
 304
 305 int uci_set_element_value(struct uci_context *ctx, struct uci_element **element, char *value)
 306 {
 307         /* NB: UCI_INTERNAL use means without history tracking */
 308         bool internal = ctx->internal;
 309         struct uci_list *list;
 310         struct uci_element *e;
 311         struct uci_package *p;
 312         struct uci_section *s;
 313         char *section;
 314         char *option;
 315         char *str;
 316         int size;
 317
 318         UCI_HANDLE_ERR(ctx);
 319         UCI_ASSERT(ctx, value != NULL);
 320         UCI_ASSERT(ctx, element != NULL);
 321         UCI_ASSERT(ctx, *element != NULL);
 322
 323         /* what the 'value' of an element means depends on the type
 324          * for a section, the 'value' means its type
 325          * for an option, the 'value' means its value string
 326          * when changing the value, shrink the element to its actual size
 327          * (it may have been allocated with a bigger size, to include
 328          *  its buffer)
 329          * then duplicate the string passed on the command line and
 330          * insert it into the structure.
 331          */
 332         e = *element;
 333         list = e->list.prev;
 334         switch(e->type) {
 335         case UCI_TYPE_SECTION:
 336                 size = sizeof(struct uci_section);
 337                 s = uci_to_section(e);
 338                 section = e->name;
 339                 option = NULL;
 340                 break;
 341         case UCI_TYPE_OPTION:
 342                 size = sizeof(struct uci_option);
 343                 s = uci_to_option(e)->section;
 344                 section = s->e.name;
 345                 option = e->name;
 346                 break;
 347         default:
 348                 UCI_THROW(ctx, UCI_ERR_INVAL);
 349                 return 0;
 350         }
 351         p = s->package;
 352         if (!internal)
 353                 uci_add_history(ctx, p, UCI_CMD_CHANGE, section, option, value);
 354
 355         uci_list_del(&e->list);
 356         e = uci_realloc(ctx, e, size);
 357         str = uci_strdup(ctx, value);
 358         uci_list_insert(list, &e->list);
 359         *element = e;
 360
 361         switch(e->type) {
 362         case UCI_TYPE_SECTION:
 363                 uci_to_section(e)->type = str;
 364                 break;
 365         case UCI_TYPE_OPTION:
 366                 uci_to_option(e)->value = str;
 367                 break;
 368         default:
 369                 break;
 370         }
 371
 372         return 0;
 373 }
 374
 375 int uci_del(struct uci_context *ctx, struct uci_package *p, char *section, char *option)
 376 {
 377         /* NB: pass on internal flag to uci_del_element */
 378         bool internal = ctx->internal;
 379         struct uci_element *e;
 380         struct uci_section *s = NULL;
 381         struct uci_option *o = NULL;
 382
 383         UCI_HANDLE_ERR(ctx);
 384         UCI_ASSERT(ctx, p != NULL);
 385         UCI_ASSERT(ctx, section != NULL);
 386
 387         UCI_INTERNAL(uci_lookup, ctx, &e, p, section, option);
 388
 389         if (!internal)
 390                 return uci_del_element(ctx, e);
 391         UCI_INTERNAL(uci_del_element, ctx, e);
 392
 393         return 0;
 394 }
 395
 396 int uci_set(struct uci_context *ctx, struct uci_package *p, char *section, char *option, char *value)
 397 {
 398         /* NB: UCI_INTERNAL use means without history tracking */
 399         bool internal = ctx->internal;
 400         struct uci_element *e = NULL;
 401         struct uci_section *s = NULL;
 402         struct uci_option *o = NULL;
 403         struct uci_history *h;
 404
 405         UCI_HANDLE_ERR(ctx);
 406         UCI_ASSERT(ctx, p != NULL);
 407         UCI_ASSERT(ctx, section != NULL);
 408         UCI_ASSERT(ctx, value != NULL);
 409
 410         /*
 411          * look up the package, section and option (if set)
 412          * if the section/option is to be modified and it is not found
 413          * create a new element in the appropriate list
 414          */
 415         e = uci_lookup_list(ctx, &p->sections, section);
 416         if (!e)
 417                 goto notfound;
 418
 419         s = uci_to_section(e);
 420         if (option) {
 421                 e = uci_lookup_list(ctx, &s->options, option);
 422                 if (!e)
 423                         goto notfound;
 424                 o = uci_to_option(e);
 425         }
 426
 427         /*
 428          * no unknown element was supplied, assume that we can just update
 429          * an existing entry
 430          */
 431         if (o)
 432                 e = &o->e;
 433         else
 434                 e = &s->e;
 435
 436         if (!internal)
 437                 return uci_set_element_value(ctx, &e, value);
 438
 439         UCI_INTERNAL(uci_set_element_value, ctx, &e, value);
 440         return 0;
 441
 442 notfound:
 443         /*
 444          * the entry that we need to update was not found,
 445          * check if the search failed prematurely.
 446          * this can happen if the package was not found, or if
 447          * an option was supplied, but the section wasn't found
 448          */
 449         if (!p || (!s && option))
 450                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 451
 452         /* now add the missing entry */
 453         if (!internal)
 454                 uci_add_history(ctx, p, UCI_CMD_ADD, section, option, value);
 455         if (s)
 456                 uci_alloc_option(s, option, value);
 457         else
 458                 uci_alloc_section(p, value, section);
 459
 460         return 0;
 461 }
 462
 463 int uci_unload(struct uci_context *ctx, struct uci_package *p)
 464 {
 465         struct uci_element *e;
 466
 467         UCI_HANDLE_ERR(ctx);
 468         UCI_ASSERT(ctx, p != NULL);
 469
 470         uci_free_package(&p);
 471         return 0;
 472 }
 473