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         memset(ctx, 0, sizeof(struct uci_context));
  59         uci_list_init(&ctx->root);
  60         uci_list_init(&ctx->history_path);
  61         uci_list_init(&ctx->backends);
  62         uci_list_init(&ctx->hooks);
  63         uci_list_init(&ctx->plugins);
  64         ctx->flags = UCI_FLAG_STRICT | UCI_FLAG_SAVED_HISTORY;
  65
  66         ctx->confdir = (char *) uci_confdir;
  67         ctx->savedir = (char *) uci_savedir;
  68
  69         uci_list_add(&ctx->backends, &uci_file_backend.e.list);
  70         ctx->backend = &uci_file_backend;
  71
  72         return ctx;
  73 }
  74
  75 void uci_free_context(struct uci_context *ctx)
  76 {
  77         struct uci_element *e, *tmp;
  78
  79         if (ctx->confdir != uci_confdir)
  80                 free(ctx->confdir);
  81         if (ctx->savedir != uci_savedir)
  82                 free(ctx->savedir);
  83
  84         uci_cleanup(ctx);
  85         UCI_TRAP_SAVE(ctx, ignore);
  86         uci_foreach_element_safe(&ctx->root, tmp, e) {
  87                 struct uci_package *p = uci_to_package(e);
  88                 uci_free_package(&p);
  89         }
  90         uci_foreach_element_safe(&ctx->history_path, tmp, e) {
  91                 uci_free_element(e);
  92         }
  93         UCI_TRAP_RESTORE(ctx);
  94         uci_foreach_element_safe(&ctx->root, tmp, e) {
  95                 uci_unload_plugin(ctx, uci_to_plugin(e));
  96         }
  97         free(ctx);
  98
  99 ignore:
 100         return;
 101 }
 102
 103 int uci_set_confdir(struct uci_context *ctx, const char *dir)
 104 {
 105         char *cdir;
 106
 107         UCI_HANDLE_ERR(ctx);
 108         UCI_ASSERT(ctx, dir != NULL);
 109
 110         cdir = uci_strdup(ctx, dir);
 111         if (ctx->confdir != uci_confdir)
 112                 free(ctx->confdir);
 113         ctx->confdir = cdir;
 114         return 0;
 115 }
 116
 117 static void uci_cleanup(struct uci_context *ctx)
 118 {
 119         struct uci_parse_context *pctx;
 120
 121         if (ctx->buf) {
 122                 free(ctx->buf);
 123                 ctx->buf = NULL;
 124                 ctx->bufsz = 0;
 125         }
 126
 127         pctx = ctx->pctx;
 128         if (!pctx)
 129                 return;
 130
 131         ctx->pctx = NULL;
 132         if (pctx->package)
 133                 uci_free_package(&pctx->package);
 134
 135         if (pctx->buf)
 136                 free(pctx->buf);
 137
 138         free(pctx);
 139 }
 140
 141 void
 142 uci_perror(struct uci_context *ctx, const char *str)
 143 {
 144         uci_get_errorstr(ctx, NULL, str);
 145 }
 146
 147 void
 148 uci_get_errorstr(struct uci_context *ctx, char **dest, const char *prefix)
 149 {
 150         static char error_info[128];
 151         int err;
 152         const char *format =
 153                 "%s%s" /* prefix */
 154                 "%s%s" /* function */
 155                 "%s" /* error */
 156                 "%s"; /* details */
 157
 158         error_info[0] = 0;
 159
 160         if (!ctx)
 161                 err = UCI_ERR_INVAL;
 162         else
 163                 err = ctx->err;
 164
 165         if ((err < 0) || (err >= UCI_ERR_LAST))
 166                 err = UCI_ERR_UNKNOWN;
 167
 168         switch (err) {
 169         case UCI_ERR_PARSE:
 170                 if (ctx->pctx) {
 171                         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);
 172                         break;
 173                 }
 174                 break;
 175         default:
 176                 break;
 177         }
 178         if (dest) {
 179                 err = asprintf(dest, format,
 180                         (prefix ? prefix : ""), (prefix ? ": " : ""),
 181                         (ctx->func ? ctx->func : ""), (ctx->func ? ": " : ""),
 182                         uci_errstr[err],
 183                         error_info);
 184                 if (err < 0)
 185                         *dest = NULL;
 186         } else {
 187                 strcat(error_info, "\n");
 188                 fprintf(stderr, format,
 189                         (prefix ? prefix : ""), (prefix ? ": " : ""),
 190                         (ctx->func ? ctx->func : ""), (ctx->func ? ": " : ""),
 191                         uci_errstr[err],
 192                         error_info);
 193         }
 194 }
 195
 196 int uci_list_configs(struct uci_context *ctx, char ***list)
 197 {
 198         UCI_HANDLE_ERR(ctx);
 199         UCI_ASSERT(ctx, list != NULL);
 200         UCI_ASSERT(ctx, ctx->backend && ctx->backend->list_configs);
 201         *list = ctx->backend->list_configs(ctx);
 202         return 0;
 203 }
 204
 205 int uci_commit(struct uci_context *ctx, struct uci_package **package, bool overwrite)
 206 {
 207         struct uci_package *p;
 208         UCI_HANDLE_ERR(ctx);
 209         UCI_ASSERT(ctx, package != NULL);
 210         p = *package;
 211         UCI_ASSERT(ctx, p != NULL);
 212         UCI_ASSERT(ctx, p->backend && p->backend->commit);
 213         p->backend->commit(ctx, package, overwrite);
 214         return 0;
 215 }
 216
 217 int uci_load(struct uci_context *ctx, const char *name, struct uci_package **package)
 218 {
 219         struct uci_package *p;
 220         struct uci_element *e;
 221
 222         UCI_HANDLE_ERR(ctx);
 223         UCI_ASSERT(ctx, ctx->backend && ctx->backend->load);
 224         p = ctx->backend->load(ctx, name);
 225         uci_foreach_element(&ctx->hooks, e) {
 226                 struct uci_hook *h = uci_to_hook(e);
 227                 if (h->ops->load)
 228                         h->ops->load(h->ops, p);
 229         }
 230         if (package)
 231                 *package = p;
 232
 233         return 0;
 234 }
 235
 236 #ifdef UCI_PLUGIN_SUPPORT
 237
 238 __plugin int uci_add_backend(struct uci_context *ctx, struct uci_backend *b)
 239 {
 240         struct uci_element *e;
 241         UCI_HANDLE_ERR(ctx);
 242
 243         e = uci_lookup_list(&ctx->backends, b->e.name);
 244         if (e)
 245                 UCI_THROW(ctx, UCI_ERR_DUPLICATE);
 246
 247         e = uci_malloc(ctx, sizeof(struct uci_backend));
 248         memcpy(e, b, sizeof(struct uci_backend));
 249
 250         uci_list_add(&ctx->backends, &e->list);
 251         return 0;
 252 }
 253
 254 __plugin int uci_del_backend(struct uci_context *ctx, struct uci_backend *b)
 255 {
 256         struct uci_element *e, *tmp;
 257
 258         UCI_HANDLE_ERR(ctx);
 259
 260         e = uci_lookup_list(&ctx->backends, b->e.name);
 261         if (!e || uci_to_backend(e)->ptr != b->ptr)
 262                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 263         b = uci_to_backend(e);
 264
 265         if (ctx->backend && ctx->backend->ptr == b->ptr)
 266                 ctx->backend = &uci_file_backend;
 267
 268         uci_foreach_element_safe(&ctx->root, tmp, e) {
 269                 struct uci_package *p = uci_to_package(e);
 270
 271                 if (!p->backend)
 272                         continue;
 273
 274                 if (p->backend->ptr == b->ptr)
 275                         UCI_INTERNAL(uci_unload, ctx, p);
 276         }
 277
 278         uci_list_del(&b->e.list);
 279         free(b);
 280
 281         return 0;
 282 }
 283
 284 #endif
 285
 286 int uci_set_backend(struct uci_context *ctx, const char *name)
 287 {
 288         struct uci_element *e;
 289
 290         UCI_HANDLE_ERR(ctx);
 291         UCI_ASSERT(ctx, name != NULL);
 292         e = uci_lookup_list(&ctx->backends, name);
 293         if (!e)
 294                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 295         ctx->backend = uci_to_backend(e);
 296         return 0;
 297 }
 298
 299 int uci_add_hook(struct uci_context *ctx, const struct uci_hook_ops *ops)
 300 {
 301         struct uci_element *e;
 302         struct uci_hook *h;
 303
 304         UCI_HANDLE_ERR(ctx);
 305
 306         /* check for duplicate elements */
 307         uci_foreach_element(&ctx->hooks, e) {
 308                 h = uci_to_hook(e);
 309                 if (h->ops == ops)
 310                         return UCI_ERR_INVAL;
 311         }
 312
 313         h = uci_alloc_element(ctx, hook, "", 0);
 314         h->ops = ops;
 315         uci_list_init(&h->e.list);
 316         uci_list_add(&ctx->hooks, &h->e.list);
 317
 318         return 0;
 319 }
 320
 321 int uci_remove_hook(struct uci_context *ctx, const struct uci_hook_ops *ops)
 322 {
 323         struct uci_element *e;
 324
 325         uci_foreach_element(&ctx->hooks, e) {
 326                 struct uci_hook *h = uci_to_hook(e);
 327                 if (h->ops == ops) {
 328                         uci_list_del(&e->list);
 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 }