file.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 the code for parsing uci config files
  17  */
  18
  19 #define _GNU_SOURCE
  20 #include <sys/types.h>
  21 #include <sys/file.h>
  22 #include <stdbool.h>
  23 #include <unistd.h>
  24 #include <fcntl.h>
  25 #include <stdio.h>
  26 #include <ctype.h>
  27
  28 /*
  29  * Clean up all extra memory used by the parser and exporter
  30  */
  31 static void uci_file_cleanup(struct uci_context *ctx)
  32 {
  33         struct uci_parse_context *pctx;
  34
  35         if (ctx->buf) {
  36                 free(ctx->buf);
  37                 ctx->buf = NULL;
  38                 ctx->bufsz = 0;
  39         }
  40
  41         pctx = ctx->pctx;
  42         if (!pctx)
  43                 return;
  44
  45         ctx->pctx = NULL;
  46         if (pctx->package)
  47                 uci_free_package(&pctx->package);
  48
  49         if (pctx->buf)
  50                 free(pctx->buf);
  51
  52         free(pctx);
  53 }
  54
  55
  56 /*
  57  * verify that the end of the line or command is reached.
  58  * throw an error if extra arguments are given on the command line
  59  */
  60 static void assert_eol(struct uci_context *ctx, char **str)
  61 {
  62         char *tmp;
  63
  64         tmp = next_arg(ctx, str, false, false);
  65         if (*tmp && (ctx->flags & UCI_FLAG_STRICT))
  66                 uci_parse_error(ctx, *str, "too many arguments");
  67 }
  68
  69 /*
  70  * switch to a different config, either triggered by uci_load, or by a
  71  * 'package <...>' statement in the import file
  72  */
  73 static void uci_switch_config(struct uci_context *ctx)
  74 {
  75         struct uci_parse_context *pctx;
  76         struct uci_element *e;
  77         const char *name;
  78
  79         pctx = ctx->pctx;
  80         name = pctx->name;
  81
  82         /* add the last config to main config file list */
  83         if (pctx->package) {
  84                 uci_list_add(&ctx->root, &pctx->package->e.list);
  85
  86                 pctx->package = NULL;
  87                 pctx->section = NULL;
  88         }
  89
  90         if (!name)
  91                 return;
  92
  93         /*
  94          * if an older config under the same name exists, unload it
  95          * ignore errors here, e.g. if the config was not found
  96          */
  97         e = uci_lookup_list(ctx, &ctx->root, name);
  98         if (e)
  99                 UCI_THROW(ctx, UCI_ERR_DUPLICATE);
 100         pctx->package = uci_alloc_package(ctx, name);
 101 }
 102
 103 /*
 104  * parse the 'package' uci command (next config package)
 105  */
 106 static void uci_parse_package(struct uci_context *ctx, char **str, bool single)
 107 {
 108         char *name = NULL;
 109
 110         /* command string null-terminated by strtok */
 111         *str += strlen(*str) + 1;
 112
 113         name = next_arg(ctx, str, true, true);
 114         assert_eol(ctx, str);
 115         if (single)
 116                 return;
 117
 118         ctx->pctx->name = name;
 119         uci_switch_config(ctx);
 120 }
 121
 122 /*
 123  * parse the 'config' uci command (open a section)
 124  */
 125 static void uci_parse_config(struct uci_context *ctx, char **str)
 126 {
 127         struct uci_parse_context *pctx = ctx->pctx;
 128         char *name = NULL;
 129         char *type = NULL;
 130
 131         uci_fixup_section(ctx, ctx->pctx->section);
 132         if (!ctx->pctx->package) {
 133                 if (!ctx->pctx->name)
 134                         uci_parse_error(ctx, *str, "attempting to import a file without a package name");
 135
 136                 uci_switch_config(ctx);
 137         }
 138
 139         /* command string null-terminated by strtok */
 140         *str += strlen(*str) + 1;
 141
 142         type = next_arg(ctx, str, true, false);
 143         if (!uci_validate_str(type, false))
 144                 uci_parse_error(ctx, type, "invalid character in field");
 145         name = next_arg(ctx, str, false, true);
 146         assert_eol(ctx, str);
 147
 148         if (pctx->merge) {
 149                 UCI_TRAP_SAVE(ctx, error);
 150                 uci_set(ctx, pctx->package, name, NULL, type, NULL);
 151                 UCI_TRAP_RESTORE(ctx);
 152                 return;
 153 error:
 154                 UCI_THROW(ctx, ctx->errno);
 155         } else
 156                 pctx->section = uci_alloc_section(pctx->package, type, name);
 157 }
 158
 159 /*
 160  * parse the 'option' uci command (open a value)
 161  */
 162 static void uci_parse_option(struct uci_context *ctx, char **str)
 163 {
 164         struct uci_parse_context *pctx = ctx->pctx;
 165         char *name = NULL;
 166         char *value = NULL;
 167
 168         if (!pctx->section)
 169                 uci_parse_error(ctx, *str, "option command found before the first section");
 170
 171         /* command string null-terminated by strtok */
 172         *str += strlen(*str) + 1;
 173
 174         name = next_arg(ctx, str, true, true);
 175         value = next_arg(ctx, str, false, false);
 176         assert_eol(ctx, str);
 177
 178         if (pctx->merge) {
 179                 UCI_TRAP_SAVE(ctx, error);
 180                 uci_set(ctx, pctx->package, pctx->section->e.name, name, value, NULL);
 181                 UCI_TRAP_RESTORE(ctx);
 182                 return;
 183 error:
 184                 UCI_THROW(ctx, ctx->errno);
 185         } else
 186                 uci_alloc_option(pctx->section, name, value);
 187 }
 188
 189
 190 /*
 191  * parse a complete input line, split up combined commands by ';'
 192  */
 193 static void uci_parse_line(struct uci_context *ctx, bool single)
 194 {
 195         struct uci_parse_context *pctx = ctx->pctx;
 196         char *word, *brk = NULL;
 197
 198         for (word = strtok_r(pctx->buf, ";", &brk);
 199                  word;
 200                  word = strtok_r(NULL, ";", &brk)) {
 201
 202                 char *pbrk = NULL;
 203                 word = strtok_r(word, " \t", &pbrk);
 204
 205                 if (!word)
 206                         continue;
 207
 208                 switch(word[0]) {
 209                         case '#':
 210                                 return;
 211                         case 'p':
 212                                 if ((word[1] == 0) || !strcmp(word + 1, "ackage"))
 213                                         uci_parse_package(ctx, &word, single);
 214                                 break;
 215                         case 'c':
 216                                 if ((word[1] == 0) || !strcmp(word + 1, "onfig"))
 217                                         uci_parse_config(ctx, &word);
 218                                 break;
 219                         case 'o':
 220                                 if ((word[1] == 0) || !strcmp(word + 1, "ption"))
 221                                         uci_parse_option(ctx, &word);
 222                                 break;
 223                         default:
 224                                 uci_parse_error(ctx, word, "unterminated command");
 225                                 break;
 226                 }
 227         }
 228 }
 229
 230 /* max number of characters that escaping adds to the string */
 231 #define UCI_QUOTE_ESCAPE        "'\\''"
 232
 233 /*
 234  * escape an uci string for export
 235  */
 236 static char *uci_escape(struct uci_context *ctx, char *str)
 237 {
 238         char *s, *p;
 239         int pos = 0;
 240
 241         if (!ctx->buf) {
 242                 ctx->bufsz = LINEBUF;
 243                 ctx->buf = malloc(LINEBUF);
 244         }
 245
 246         s = str;
 247         p = strchr(str, '\'');
 248         if (!p)
 249                 return str;
 250
 251         do {
 252                 int len = p - s;
 253                 if (len > 0) {
 254                         if (p + sizeof(UCI_QUOTE_ESCAPE) - str >= ctx->bufsz) {
 255                                 ctx->bufsz *= 2;
 256                                 ctx->buf = realloc(ctx->buf, ctx->bufsz);
 257                                 if (!ctx->buf)
 258                                         UCI_THROW(ctx, UCI_ERR_MEM);
 259                         }
 260                         memcpy(&ctx->buf[pos], s, len);
 261                         pos += len;
 262                 }
 263                 strcpy(&ctx->buf[pos], UCI_QUOTE_ESCAPE);
 264                 pos += sizeof(UCI_QUOTE_ESCAPE);
 265                 s = p + 1;
 266         } while ((p = strchr(s, '\'')));
 267
 268         return ctx->buf;
 269 }
 270
 271
 272 /*
 273  * export a single config package to a file stream
 274  */
 275 static void uci_export_package(struct uci_package *p, FILE *stream, bool header)
 276 {
 277         struct uci_context *ctx = p->ctx;
 278         struct uci_element *s, *o;
 279
 280         if (header)
 281                 fprintf(stream, "package '%s'\n", uci_escape(ctx, p->e.name));
 282         uci_foreach_element(&p->sections, s) {
 283                 struct uci_section *sec = uci_to_section(s);
 284                 fprintf(stream, "\nconfig '%s'", uci_escape(ctx, sec->type));
 285                 if (!sec->anonymous || (ctx->flags & UCI_FLAG_EXPORT_NAME))
 286                         fprintf(stream, " '%s'", uci_escape(ctx, sec->e.name));
 287                 fprintf(stream, "\n");
 288                 uci_foreach_element(&sec->options, o) {
 289                         struct uci_option *opt = uci_to_option(o);
 290                         fprintf(stream, "\toption '%s'", uci_escape(ctx, opt->e.name));
 291                         fprintf(stream, " '%s'\n", uci_escape(ctx, opt->value));
 292                 }
 293         }
 294         fprintf(stream, "\n");
 295 }
 296
 297 int uci_export(struct uci_context *ctx, FILE *stream, struct uci_package *package, bool header)
 298 {
 299         struct uci_element *e;
 300
 301         UCI_HANDLE_ERR(ctx);
 302         UCI_ASSERT(ctx, stream != NULL);
 303
 304         if (package)
 305                 uci_export_package(package, stream, header);
 306         else {
 307                 uci_foreach_element(&ctx->root, e) {
 308                         uci_export_package(uci_to_package(e), stream, header);
 309                 }
 310         }
 311
 312         return 0;
 313 }
 314
 315 int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_package **package, bool single)
 316 {
 317         struct uci_parse_context *pctx;
 318         UCI_HANDLE_ERR(ctx);
 319
 320         /* make sure no memory from previous parse attempts is leaked */
 321         uci_file_cleanup(ctx);
 322
 323         uci_alloc_parse_context(ctx);
 324         pctx = ctx->pctx;
 325         pctx->file = stream;
 326         if (*package && single) {
 327                 pctx->package = *package;
 328                 pctx->merge = true;
 329         }
 330
 331         /*
 332          * If 'name' was supplied, assume that the supplied stream does not contain
 333          * the appropriate 'package <name>' string to specify the config name
 334          * NB: the config file can still override the package name
 335          */
 336         if (name) {
 337                 UCI_ASSERT(ctx, uci_validate_name(name));
 338                 pctx->name = name;
 339         }
 340
 341         while (!feof(pctx->file)) {
 342                 uci_getln(ctx, 0);
 343                 UCI_TRAP_SAVE(ctx, error);
 344                 if (pctx->buf[0])
 345                         uci_parse_line(ctx, single);
 346                 UCI_TRAP_RESTORE(ctx);
 347                 continue;
 348 error:
 349                 if (ctx->flags & UCI_FLAG_PERROR)
 350                         uci_perror(ctx, NULL);
 351                 if ((ctx->errno != UCI_ERR_PARSE) ||
 352                         (ctx->flags & UCI_FLAG_STRICT))
 353                         UCI_THROW(ctx, ctx->errno);
 354         }
 355
 356         uci_fixup_section(ctx, ctx->pctx->section);
 357         if (package)
 358                 *package = pctx->package;
 359         if (pctx->merge)
 360                 pctx->package = NULL;
 361
 362         pctx->name = NULL;
 363         uci_switch_config(ctx);
 364
 365         /* no error happened, we can get rid of the parser context now */
 366         uci_file_cleanup(ctx);
 367
 368         return 0;
 369 }
 370
 371
 372 static char *uci_config_path(struct uci_context *ctx, const char *name)
 373 {
 374         char *filename;
 375
 376         UCI_ASSERT(ctx, uci_validate_name(name));
 377         filename = uci_malloc(ctx, strlen(name) + strlen(ctx->confdir) + 2);
 378         sprintf(filename, "%s/%s", ctx->confdir, name);
 379
 380         return filename;
 381 }
 382
 383 int uci_load(struct uci_context *ctx, const char *name, struct uci_package **package)
 384 {
 385         char *filename;
 386         bool confdir;
 387         FILE *file = NULL;
 388
 389         UCI_HANDLE_ERR(ctx);
 390
 391         switch (name[0]) {
 392         case '.':
 393                 /* relative path outside of /etc/config */
 394                 if (name[1] != '/')
 395                         UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 396                 /* fall through */
 397         case '/':
 398                 /* absolute path outside of /etc/config */
 399                 filename = uci_strdup(ctx, name);
 400                 name = strrchr(name, '/') + 1;
 401                 confdir = false;
 402                 break;
 403         default:
 404                 /* config in /etc/config */
 405                 filename = uci_config_path(ctx, name);
 406                 confdir = true;
 407                 break;
 408         }
 409
 410         file = uci_open_stream(ctx, filename, SEEK_SET, false, false);
 411         ctx->errno = 0;
 412         UCI_TRAP_SAVE(ctx, done);
 413         UCI_INTERNAL(uci_import, ctx, file, name, package, true);
 414         UCI_TRAP_RESTORE(ctx);
 415
 416         if (*package) {
 417                 (*package)->path = filename;
 418                 (*package)->confdir = confdir;
 419                 uci_load_history(ctx, *package, false);
 420         }
 421
 422 done:
 423         uci_close_stream(file);
 424         return ctx->errno;
 425 }
 426
 427 int uci_commit(struct uci_context *ctx, struct uci_package **package, bool overwrite)
 428 {
 429         struct uci_package *p;
 430         FILE *f = NULL;
 431         char *name = NULL;
 432         char *path = NULL;
 433
 434         UCI_HANDLE_ERR(ctx);
 435         UCI_ASSERT(ctx, package != NULL);
 436         p = *package;
 437
 438         UCI_ASSERT(ctx, p != NULL);
 439         if (!p->path) {
 440                 if (overwrite)
 441                         p->path = uci_config_path(ctx, p->e.name);
 442                 else
 443                         UCI_THROW(ctx, UCI_ERR_INVAL);
 444         }
 445
 446
 447         /* open the config file for writing now, so that it is locked */
 448         f = uci_open_stream(ctx, p->path, SEEK_SET, true, true);
 449
 450         /* flush unsaved changes and reload from history file */
 451         UCI_TRAP_SAVE(ctx, done);
 452         if (p->confdir) {
 453                 if (!overwrite) {
 454                         name = uci_strdup(ctx, p->e.name);
 455                         path = uci_strdup(ctx, p->path);
 456                         /* dump our own changes to the history file */
 457                         if (!uci_list_empty(&p->history))
 458                                 UCI_INTERNAL(uci_save, ctx, p);
 459
 460                         /*
 461                          * other processes might have modified the config
 462                          * as well. dump and reload
 463                          */
 464                         uci_free_package(&p);
 465                         uci_file_cleanup(ctx);
 466                         UCI_INTERNAL(uci_import, ctx, f, name, &p, true);
 467
 468                         p->path = path;
 469                         p->confdir = true;
 470                         *package = p;
 471
 472                         /* freed together with the uci_package */
 473                         path = NULL;
 474
 475                         /* check for updated history, flush */
 476                         if (!uci_load_history(ctx, p, true))
 477                                 goto done;
 478                 } else {
 479                         /* flush history */
 480                         if (!uci_load_history(ctx, NULL, true))
 481                                 goto done;
 482                 }
 483         }
 484
 485         rewind(f);
 486         ftruncate(fileno(f), 0);
 487
 488         uci_export(ctx, f, p, false);
 489         UCI_TRAP_RESTORE(ctx);
 490
 491 done:
 492         if (name)
 493                 free(name);
 494         if (path)
 495                 free(path);
 496         uci_close_stream(f);
 497         if (ctx->errno)
 498                 UCI_THROW(ctx, ctx->errno);
 499
 500         return 0;
 501 }
 502
 503
 504 /*
 505  * This function returns the filename by returning the string
 506  * after the last '/' character. By checking for a non-'\0'
 507  * character afterwards, directories are ignored (glob marks
 508  * those with a trailing '/'
 509  */
 510 static inline char *get_filename(char *path)
 511 {
 512         char *p;
 513
 514         p = strrchr(path, '/');
 515         p++;
 516         if (!*p)
 517                 return NULL;
 518         return p;
 519 }
 520
 521 int uci_list_configs(struct uci_context *ctx, char ***list)
 522 {
 523         char **configs;
 524         glob_t globbuf;
 525         int size, i;
 526         char *buf;
 527         char *dir;
 528
 529         UCI_HANDLE_ERR(ctx);
 530
 531         dir = uci_malloc(ctx, strlen(ctx->confdir) + 1 + sizeof("/*"));
 532         sprintf(dir, "%s/*", ctx->confdir);
 533         if (glob(dir, GLOB_MARK, NULL, &globbuf) != 0)
 534                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 535
 536         size = sizeof(char *) * (globbuf.gl_pathc + 1);
 537         for(i = 0; i < globbuf.gl_pathc; i++) {
 538                 char *p;
 539
 540                 p = get_filename(globbuf.gl_pathv[i]);
 541                 if (!p)
 542                         continue;
 543
 544                 size += strlen(p) + 1;
 545         }
 546
 547         configs = uci_malloc(ctx, size);
 548         buf = (char *) &configs[globbuf.gl_pathc + 1];
 549         for(i = 0; i < globbuf.gl_pathc; i++) {
 550                 char *p;
 551
 552                 p = get_filename(globbuf.gl_pathv[i]);
 553                 if (!p)
 554                         continue;
 555
 556                 configs[i] = buf;
 557                 strcpy(buf, p);
 558                 buf += strlen(buf) + 1;
 559         }
 560         *list = configs;
 561         free(dir);
 562
 563         return 0;
 564 }
 565