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 #include "uci_internal.h"
  41 #include "list.c"
  42
  43 __private const char *uci_confdir = UCI_CONFDIR;
  44 __private const char *uci_savedir = UCI_SAVEDIR;
  45
  46 /* exported functions */
  47 struct uci_context *uci_alloc_context(void)
  48 {
  49         struct uci_context *ctx;
  50
  51         ctx = (struct uci_context *) malloc(sizeof(struct uci_context));
  52         if (!ctx)
  53                 return NULL;
  54
  55         memset(ctx, 0, sizeof(struct uci_context));
  56         uci_list_init(&ctx->root);
  57         uci_list_init(&ctx->delta_path);
  58         uci_list_init(&ctx->backends);
  59         uci_list_init(&ctx->hooks);
  60         ctx->flags = UCI_FLAG_STRICT | UCI_FLAG_SAVED_DELTA;
  61
  62         ctx->confdir = (char *) uci_confdir;
  63         ctx->savedir = (char *) uci_savedir;
  64
  65         uci_list_add(&ctx->backends, &uci_file_backend.e.list);
  66         ctx->backend = &uci_file_backend;
  67
  68         return ctx;
  69 }
  70
  71 void uci_free_context(struct uci_context *ctx)
  72 {
  73         struct uci_element *e, *tmp;
  74
  75         if (ctx->confdir != uci_confdir)
  76                 free(ctx->confdir);
  77         if (ctx->savedir != uci_savedir)
  78                 free(ctx->savedir);
  79
  80         uci_cleanup(ctx);
  81         UCI_TRAP_SAVE(ctx, ignore);
  82         uci_foreach_element_safe(&ctx->root, tmp, e) {
  83                 struct uci_package *p = uci_to_package(e);
  84                 uci_free_package(&p);
  85         }
  86         uci_foreach_element_safe(&ctx->delta_path, tmp, e) {
  87                 uci_free_element(e);
  88         }
  89         UCI_TRAP_RESTORE(ctx);
  90         free(ctx);
  91
  92 ignore:
  93         return;
  94 }
  95
  96 int uci_set_confdir(struct uci_context *ctx, const char *dir)
  97 {
  98         char *cdir;
  99
 100         UCI_HANDLE_ERR(ctx);
 101         UCI_ASSERT(ctx, dir != NULL);
 102
 103         cdir = uci_strdup(ctx, dir);
 104         if (ctx->confdir != uci_confdir)
 105                 free(ctx->confdir);
 106         ctx->confdir = cdir;
 107         return 0;
 108 }
 109
 110 __private void uci_cleanup(struct uci_context *ctx)
 111 {
 112         struct uci_parse_context *pctx;
 113
 114         if (ctx->buf) {
 115                 free(ctx->buf);
 116                 ctx->buf = NULL;
 117                 ctx->bufsz = 0;
 118         }
 119
 120         pctx = ctx->pctx;
 121         if (!pctx)
 122                 return;
 123
 124         ctx->pctx = NULL;
 125         if (pctx->package)
 126                 uci_free_package(&pctx->package);
 127
 128         if (pctx->buf)
 129                 free(pctx->buf);
 130
 131         free(pctx);
 132 }
 133
 134 void
 135 uci_perror(struct uci_context *ctx, const char *str)
 136 {
 137         uci_get_errorstr(ctx, NULL, str);
 138 }
 139
 140 void
 141 uci_get_errorstr(struct uci_context *ctx, char **dest, const char *prefix)
 142 {
 143         static char error_info[128];
 144         int err;
 145         const char *format =
 146                 "%s%s" /* prefix */
 147                 "%s%s" /* function */
 148                 "%s" /* error */
 149                 "%s"; /* details */
 150
 151         error_info[0] = 0;
 152
 153         if (!ctx)
 154                 err = UCI_ERR_INVAL;
 155         else
 156                 err = ctx->err;
 157
 158         if ((err < 0) || (err >= UCI_ERR_LAST))
 159                 err = UCI_ERR_UNKNOWN;
 160
 161         switch (err) {
 162         case UCI_ERR_PARSE:
 163                 if (ctx->pctx) {
 164                         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);
 165                         break;
 166                 }
 167                 break;
 168         default:
 169                 break;
 170         }
 171         if (dest) {
 172                 err = asprintf(dest, format,
 173                         (prefix ? prefix : ""), (prefix ? ": " : ""),
 174                         (ctx && ctx->func ? ctx->func : ""), (ctx && ctx->func ? ": " : ""),
 175                         uci_errstr[err],
 176                         error_info);
 177                 if (err < 0)
 178                         *dest = NULL;
 179         } else {
 180                 strcat(error_info, "\n");
 181                 fprintf(stderr, format,
 182                         (prefix ? prefix : ""), (prefix ? ": " : ""),
 183                         (ctx && ctx->func ? ctx->func : ""), (ctx && ctx->func ? ": " : ""),
 184                         uci_errstr[err],
 185                         error_info);
 186         }
 187 }
 188
 189 int uci_list_configs(struct uci_context *ctx, char ***list)
 190 {
 191         UCI_HANDLE_ERR(ctx);
 192         UCI_ASSERT(ctx, list != NULL);
 193         UCI_ASSERT(ctx, ctx->backend && ctx->backend->list_configs);
 194         *list = ctx->backend->list_configs(ctx);
 195         return 0;
 196 }
 197
 198 int uci_commit(struct uci_context *ctx, struct uci_package **package, bool overwrite)
 199 {
 200         struct uci_package *p;
 201         UCI_HANDLE_ERR(ctx);
 202         UCI_ASSERT(ctx, package != NULL);
 203         p = *package;
 204         UCI_ASSERT(ctx, p != NULL);
 205         UCI_ASSERT(ctx, p->backend && p->backend->commit);
 206         p->backend->commit(ctx, package, overwrite);
 207         return 0;
 208 }
 209
 210 int uci_load(struct uci_context *ctx, const char *name, struct uci_package **package)
 211 {
 212         struct uci_package *p;
 213         struct uci_element *e;
 214
 215         UCI_HANDLE_ERR(ctx);
 216         UCI_ASSERT(ctx, ctx->backend && ctx->backend->load);
 217         p = ctx->backend->load(ctx, name);
 218         uci_foreach_element(&ctx->hooks, e) {
 219                 struct uci_hook *h = uci_to_hook(e);
 220                 if (h->ops->load)
 221                         h->ops->load(h->ops, p);
 222         }
 223         if (package)
 224                 *package = p;
 225
 226         return 0;
 227 }
 228
 229 int uci_set_backend(struct uci_context *ctx, const char *name)
 230 {
 231         struct uci_element *e;
 232
 233         UCI_HANDLE_ERR(ctx);
 234         UCI_ASSERT(ctx, name != NULL);
 235         e = uci_lookup_list(&ctx->backends, name);
 236         if (!e)
 237                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 238         ctx->backend = uci_to_backend(e);
 239         return 0;
 240 }
 241
 242 int uci_add_hook(struct uci_context *ctx, const struct uci_hook_ops *ops)
 243 {
 244         struct uci_element *e;
 245         struct uci_hook *h;
 246
 247         UCI_HANDLE_ERR(ctx);
 248
 249         /* check for duplicate elements */
 250         uci_foreach_element(&ctx->hooks, e) {
 251                 h = uci_to_hook(e);
 252                 if (h->ops == ops)
 253                         return UCI_ERR_INVAL;
 254         }
 255
 256         h = uci_alloc_element(ctx, hook, "", 0);
 257         h->ops = ops;
 258         uci_list_init(&h->e.list);
 259         uci_list_add(&ctx->hooks, &h->e.list);
 260
 261         return 0;
 262 }
 263
 264 int uci_remove_hook(struct uci_context *ctx, const struct uci_hook_ops *ops)
 265 {
 266         struct uci_element *e;
 267
 268         uci_foreach_element(&ctx->hooks, e) {
 269                 struct uci_hook *h = uci_to_hook(e);
 270                 if (h->ops == ops) {
 271                         uci_list_del(&e->list);
 272                         uci_free_element(e);
 273                         return 0;
 274                 }
 275         }
 276         return UCI_ERR_NOTFOUND;
 277 }