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