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