libuci.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 /*
  16  * This file contains some common code for the uci library
  17  */
  18
  19 #define _GNU_SOURCE
  20 #include <sys/types.h>
  21 #include <stdbool.h>
  22 #include <string.h>
  23 #include <stdlib.h>
  24 #include <stdio.h>
  25 #include <dlfcn.h>
  26 #include <glob.h>
  27 #include "uci.h"
  28
  29 static const char *uci_confdir = UCI_CONFDIR;
  30 static const char *uci_savedir = UCI_SAVEDIR;
  31
  32 static const char *uci_errstr[] = {
  33         [UCI_OK] =            "Success",
  34         [UCI_ERR_MEM] =       "Out of memory",
  35         [UCI_ERR_INVAL] =     "Invalid argument",
  36         [UCI_ERR_NOTFOUND] =  "Entry not found",
  37         [UCI_ERR_IO] =        "I/O error",
  38         [UCI_ERR_PARSE] =     "Parse error",
  39         [UCI_ERR_DUPLICATE] = "Duplicate entry",
  40         [UCI_ERR_UNKNOWN] =   "Unknown error",
  41 };
  42
  43 static void uci_cleanup(struct uci_context *ctx);
  44 static void uci_unload_plugin(struct uci_context *ctx, struct uci_plugin *p);
  45
  46 #include "uci_internal.h"
  47 #include "util.c"
  48 #include "list.c"
  49 #include "history.c"
  50 #include "file.c"
  51
  52 /* exported functions */
  53 struct uci_context *uci_alloc_context(void)
  54 {
  55         struct uci_context *ctx;
  56
  57         ctx = (struct uci_context *) malloc(sizeof(struct uci_context));
  58         if (!ctx)
  59                 return NULL;
  60
  61         memset(ctx, 0, sizeof(struct uci_context));
  62         uci_list_init(&ctx->root);
  63         uci_list_init(&ctx->history_path);
  64         uci_list_init(&ctx->backends);
  65         uci_list_init(&ctx->hooks);
  66         uci_list_init(&ctx->plugins);
  67         ctx->flags = UCI_FLAG_STRICT | UCI_FLAG_SAVED_HISTORY;
  68
  69         ctx->confdir = (char *) uci_confdir;
  70         ctx->savedir = (char *) uci_savedir;
  71
  72         uci_list_add(&ctx->backends, &uci_file_backend.e.list);
  73         ctx->backend = &uci_file_backend;
  74
  75         return ctx;
  76 }
  77
  78 void uci_free_context(struct uci_context *ctx)
  79 {
  80         struct uci_element *e, *tmp;
  81
  82         if (ctx->confdir != uci_confdir)
  83                 free(ctx->confdir);
  84         if (ctx->savedir != uci_savedir)
  85                 free(ctx->savedir);
  86
  87         uci_cleanup(ctx);
  88         UCI_TRAP_SAVE(ctx, ignore);
  89         uci_foreach_element_safe(&ctx->root, tmp, e) {
  90                 struct uci_package *p = uci_to_package(e);
  91                 uci_free_package(&p);
  92         }
  93         uci_foreach_element_safe(&ctx->history_path, tmp, e) {
  94                 uci_free_element(e);
  95         }
  96         UCI_TRAP_RESTORE(ctx);
  97         uci_foreach_element_safe(&ctx->root, tmp, e) {
  98                 uci_unload_plugin(ctx, uci_to_plugin(e));
  99         }
 100         free(ctx);
 101
 102 ignore:
 103         return;
 104 }
 105
 106 int uci_set_confdir(struct uci_context *ctx, const char *dir)
 107 {
 108         char *cdir;
 109
 110         UCI_HANDLE_ERR(ctx);
 111         UCI_ASSERT(ctx, dir != NULL);
 112
 113         cdir = uci_strdup(ctx, dir);
 114         if (ctx->confdir != uci_confdir)
 115                 free(ctx->confdir);
 116         ctx->confdir = cdir;
 117         return 0;
 118 }
 119
 120 static void uci_cleanup(struct uci_context *ctx)
 121 {
 122         struct uci_parse_context *pctx;
 123
 124         if (ctx->buf) {
 125                 free(ctx->buf);
 126                 ctx->buf = NULL;
 127                 ctx->bufsz = 0;
 128         }
 129
 130         pctx = ctx->pctx;
 131         if (!pctx)
 132                 return;
 133
 134         ctx->pctx = NULL;
 135         if (pctx->package)
 136                 uci_free_package(&pctx->package);
 137
 138         if (pctx->buf)
 139                 free(pctx->buf);
 140
 141         free(pctx);
 142 }
 143
 144 void
 145 uci_perror(struct uci_context *ctx, const char *str)
 146 {
 147         uci_get_errorstr(ctx, NULL, str);
 148 }
 149
 150 void
 151 uci_get_errorstr(struct uci_context *ctx, char **dest, const char *prefix)
 152 {
 153         static char error_info[128];
 154         int err;
 155         const char *format =
 156                 "%s%s" /* prefix */
 157                 "%s%s" /* function */
 158                 "%s" /* error */
 159                 "%s"; /* details */
 160
 161         error_info[0] = 0;
 162
 163         if (!ctx)
 164                 err = UCI_ERR_INVAL;
 165         else
 166                 err = ctx->err;
 167
 168         if ((err < 0) || (err >= UCI_ERR_LAST))
 169                 err = UCI_ERR_UNKNOWN;
 170
 171         switch (err) {
 172         case UCI_ERR_PARSE:
 173                 if (ctx->pctx) {
 174                         snprintf(error_info, sizeof(error_info) - 1, " (%s) at line %d, byte %d", (ctx->pctx->reason ? ctx->pctx->reason : "unknown"), ctx->pctx->line, ctx->pctx->byte);
 175                         break;
 176                 }
 177                 break;
 178         default:
 179                 break;
 180         }
 181         if (dest) {
 182                 err = asprintf(dest, format,
 183                         (prefix ? prefix : ""), (prefix ? ": " : ""),
 184                         (ctx->func ? ctx->func : ""), (ctx->func ? ": " : ""),
 185                         uci_errstr[err],
 186                         error_info);
 187                 if (err < 0)
 188                         *dest = NULL;
 189         } else {
 190                 strcat(error_info, "\n");
 191                 fprintf(stderr, format,
 192                         (prefix ? prefix : ""), (prefix ? ": " : ""),
 193                         (ctx->func ? ctx->func : ""), (ctx->func ? ": " : ""),
 194                         uci_errstr[err],
 195                         error_info);
 196         }
 197 }
 198
 199 int uci_list_configs(struct uci_context *ctx, char ***list)
 200 {
 201         UCI_HANDLE_ERR(ctx);
 202         UCI_ASSERT(ctx, list != NULL);
 203         UCI_ASSERT(ctx, ctx->backend && ctx->backend->list_configs);
 204         *list = ctx->backend->list_configs(ctx);
 205         return 0;
 206 }
 207
 208 int uci_commit(struct uci_context *ctx, struct uci_package **package, bool overwrite)
 209 {
 210         struct uci_package *p;
 211         UCI_HANDLE_ERR(ctx);
 212         UCI_ASSERT(ctx, package != NULL);
 213         p = *package;
 214         UCI_ASSERT(ctx, p != NULL);
 215         UCI_ASSERT(ctx, p->backend && p->backend->commit);
 216         p->backend->commit(ctx, package, overwrite);
 217         return 0;
 218 }
 219
 220 int uci_load(struct uci_context *ctx, const char *name, struct uci_package **package)
 221 {
 222         struct uci_package *p;
 223         struct uci_element *e;
 224
 225         UCI_HANDLE_ERR(ctx);
 226         UCI_ASSERT(ctx, ctx->backend && ctx->backend->load);
 227         p = ctx->backend->load(ctx, name);
 228         uci_foreach_element(&ctx->hooks, e) {
 229                 struct uci_hook *h = uci_to_hook(e);
 230                 if (h->ops->load)
 231                         h->ops->load(h->ops, p);
 232         }
 233         if (package)
 234                 *package = p;
 235
 236         return 0;
 237 }
 238
 239 #ifdef UCI_PLUGIN_SUPPORT
 240
 241 __plugin int uci_add_backend(struct uci_context *ctx, struct uci_backend *b)
 242 {
 243         struct uci_element *e;
 244         UCI_HANDLE_ERR(ctx);
 245
 246         e = uci_lookup_list(&ctx->backends, b->e.name);
 247         if (e)
 248                 UCI_THROW(ctx, UCI_ERR_DUPLICATE);
 249
 250         e = uci_malloc(ctx, sizeof(struct uci_backend));
 251         memcpy(e, b, sizeof(struct uci_backend));
 252
 253         uci_list_add(&ctx->backends, &e->list);
 254         return 0;
 255 }
 256
 257 __plugin int uci_del_backend(struct uci_context *ctx, struct uci_backend *b)
 258 {
 259         struct uci_element *e, *tmp;
 260
 261         UCI_HANDLE_ERR(ctx);
 262
 263         e = uci_lookup_list(&ctx->backends, b->e.name);
 264         if (!e || uci_to_backend(e)->ptr != b->ptr)
 265                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 266         b = uci_to_backend(e);
 267
 268         if (ctx->backend && ctx->backend->ptr == b->ptr)
 269                 ctx->backend = &uci_file_backend;
 270
 271         uci_foreach_element_safe(&ctx->root, tmp, e) {
 272                 struct uci_package *p = uci_to_package(e);
 273
 274                 if (!p->backend)
 275                         continue;
 276
 277                 if (p->backend->ptr == b->ptr)
 278                         UCI_INTERNAL(uci_unload, ctx, p);
 279         }
 280
 281         uci_list_del(&b->e.list);
 282         free(b);
 283
 284         return 0;
 285 }
 286
 287 #endif
 288
 289 int uci_set_backend(struct uci_context *ctx, const char *name)
 290 {
 291         struct uci_element *e;
 292
 293         UCI_HANDLE_ERR(ctx);
 294         UCI_ASSERT(ctx, name != NULL);
 295         e = uci_lookup_list(&ctx->backends, name);
 296         if (!e)
 297                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 298         ctx->backend = uci_to_backend(e);
 299         return 0;
 300 }
 301
 302 int uci_add_hook(struct uci_context *ctx, const struct uci_hook_ops *ops)
 303 {
 304         struct uci_element *e;
 305         struct uci_hook *h;
 306
 307         UCI_HANDLE_ERR(ctx);
 308
 309         /* check for duplicate elements */
 310         uci_foreach_element(&ctx->hooks, e) {
 311                 h = uci_to_hook(e);
 312                 if (h->ops == ops)
 313                         return UCI_ERR_INVAL;
 314         }
 315
 316         h = uci_alloc_element(ctx, hook, "", 0);
 317         h->ops = ops;
 318         uci_list_init(&h->e.list);
 319         uci_list_add(&ctx->hooks, &h->e.list);
 320
 321         return 0;
 322 }
 323
 324 int uci_remove_hook(struct uci_context *ctx, const struct uci_hook_ops *ops)
 325 {
 326         struct uci_element *e;
 327
 328         uci_foreach_element(&ctx->hooks, e) {
 329                 struct uci_hook *h = uci_to_hook(e);
 330                 if (h->ops == ops) {
 331                         uci_list_del(&e->list);
 332                         return 0;
 333                 }
 334         }
 335         return UCI_ERR_NOTFOUND;
 336 }
 337
 338 int uci_load_plugin(struct uci_context *ctx, const char *filename)
 339 {
 340         struct uci_plugin *p;
 341         const struct uci_plugin_ops *ops;
 342         void *dlh;
 343
 344         UCI_HANDLE_ERR(ctx);
 345         dlh = dlopen(filename, RTLD_GLOBAL|RTLD_NOW);
 346         if (!dlh)
 347                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 348
 349         ops = dlsym(dlh, "uci_plugin");
 350         if (!ops || !ops->attach || (ops->attach(ctx) != 0)) {
 351                 if (!ops)
 352                         fprintf(stderr, "No ops\n");
 353                 else if (!ops->attach)
 354                         fprintf(stderr, "No attach\n");
 355                 else
 356                         fprintf(stderr, "Other weirdness\n");
 357                 dlclose(dlh);
 358                 UCI_THROW(ctx, UCI_ERR_INVAL);
 359         }
 360
 361         p = uci_alloc_element(ctx, plugin, filename, 0);
 362         p->dlh = dlh;
 363         p->ops = ops;
 364         uci_list_add(&ctx->plugins, &p->e.list);
 365
 366         return 0;
 367 }
 368
 369 static void uci_unload_plugin(struct uci_context *ctx, struct uci_plugin *p)
 370 {
 371         if (p->ops->detach)
 372                 p->ops->detach(ctx);
 373         dlclose(p->dlh);
 374         uci_free_element(&p->e);
 375 }
 376
 377 int uci_load_plugins(struct uci_context *ctx, const char *pattern)
 378 {
 379         glob_t gl;
 380         int i;
 381
 382         if (!pattern)
 383                 pattern = UCI_PREFIX "/lib/uci_*.so";
 384
 385         memset(&gl, 0, sizeof(gl));
 386         glob(pattern, 0, NULL, &gl);
 387         for (i = 0; i < gl.gl_pathc; i++)
 388                 uci_load_plugin(ctx, gl.gl_pathv[i]);
 389
 390         return 0;
 391 }