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 #include <sys/types.h>
  20 #include <sys/stat.h>
  21 #include <stdbool.h>
  22 #include <unistd.h>
  23 #include <fcntl.h>
  24 #include <stdio.h>
  25 #include <ctype.h>
  26
  27 #define LINEBUF 32
  28 #define LINEBUF_MAX     4096
  29
  30 static void uci_parse_error(struct uci_context *ctx, char *pos, char *reason)
  31 {
  32         struct uci_parse_context *pctx = ctx->pctx;
  33
  34         pctx->reason = reason;
  35         pctx->byte = pos - pctx->buf;
  36         UCI_THROW(ctx, UCI_ERR_PARSE);
  37 }
  38
  39 /*
  40  * Fetch a new line from the input stream and resize buffer if necessary
  41  */
  42 static void uci_getln(struct uci_context *ctx, int offset)
  43 {
  44         struct uci_parse_context *pctx = ctx->pctx;
  45         char *p;
  46         int ofs;
  47
  48         if (pctx->buf == NULL) {
  49                 pctx->buf = uci_malloc(ctx, LINEBUF);
  50                 pctx->bufsz = LINEBUF;
  51         }
  52
  53         ofs = offset;
  54         do {
  55                 p = &pctx->buf[ofs];
  56                 p[ofs] = 0;
  57
  58                 p = fgets(p, pctx->bufsz - ofs, pctx->file);
  59                 if (!p || !*p)
  60                         return;
  61
  62                 ofs += strlen(p);
  63                 if (pctx->buf[ofs - 1] == '\n') {
  64                         pctx->line++;
  65                         pctx->buf[ofs - 1] = 0;
  66                         return;
  67                 }
  68
  69                 if (pctx->bufsz > LINEBUF_MAX/2)
  70                         uci_parse_error(ctx, p, "line too long");
  71
  72                 pctx->bufsz *= 2;
  73                 pctx->buf = uci_realloc(ctx, pctx->buf, pctx->bufsz);
  74         } while (1);
  75 }
  76
  77 /*
  78  * Clean up all extra memory used by the parser and exporter
  79  */
  80 static void uci_file_cleanup(struct uci_context *ctx)
  81 {
  82         struct uci_parse_context *pctx;
  83
  84         if (ctx->buf) {
  85                 free(ctx->buf);
  86                 ctx->buf = NULL;
  87                 ctx->bufsz = 0;
  88         }
  89
  90         pctx = ctx->pctx;
  91         if (!pctx)
  92                 return;
  93
  94         ctx->pctx = NULL;
  95         if (pctx->package)
  96                 uci_free_package(&pctx->package);
  97
  98         if (pctx->buf)
  99                 free(pctx->buf);
 100
 101         free(pctx);
 102 }
 103
 104 /*
 105  * parse a character escaped by '\'
 106  * returns true if the escaped character is to be parsed
 107  * returns false if the escaped character is to be ignored
 108  */
 109 static inline bool parse_backslash(struct uci_context *ctx, char **str)
 110 {
 111         /* skip backslash */
 112         *str += 1;
 113
 114         /* undecoded backslash at the end of line, fetch the next line */
 115         if (!**str) {
 116                 *str += 1;
 117                 uci_getln(ctx, *str - ctx->pctx->buf);
 118                 return false;
 119         }
 120
 121         /* FIXME: decode escaped char, necessary? */
 122         return true;
 123 }
 124
 125 /*
 126  * move the string pointer forward until a non-whitespace character or
 127  * EOL is reached
 128  */
 129 static void skip_whitespace(struct uci_context *ctx, char **str)
 130 {
 131 restart:
 132         while (**str && isspace(**str))
 133                 *str += 1;
 134
 135         if (**str == '\\') {
 136                 if (!parse_backslash(ctx, str))
 137                         goto restart;
 138         }
 139 }
 140
 141 static inline void addc(char **dest, char **src)
 142 {
 143         **dest = **src;
 144         *dest += 1;
 145         *src += 1;
 146 }
 147
 148 /*
 149  * parse a double quoted string argument from the command line
 150  */
 151 static void parse_double_quote(struct uci_context *ctx, char **str, char **target)
 152 {
 153         char c;
 154
 155         /* skip quote character */
 156         *str += 1;
 157
 158         while ((c = **str)) {
 159                 switch(c) {
 160                 case '"':
 161                         **target = 0;
 162                         *str += 1;
 163                         return;
 164                 case '\\':
 165                         if (!parse_backslash(ctx, str))
 166                                 continue;
 167                         /* fall through */
 168                 default:
 169                         addc(target, str);
 170                         break;
 171                 }
 172         }
 173         uci_parse_error(ctx, *str, "unterminated \"");
 174 }
 175
 176 /*
 177  * parse a single quoted string argument from the command line
 178  */
 179 static void parse_single_quote(struct uci_context *ctx, char **str, char **target)
 180 {
 181         char c;
 182         /* skip quote character */
 183         *str += 1;
 184
 185         while ((c = **str)) {
 186                 switch(c) {
 187                 case '\'':
 188                         **target = 0;
 189                         *str += 1;
 190                         return;
 191                 default:
 192                         addc(target, str);
 193                 }
 194         }
 195         uci_parse_error(ctx, *str, "unterminated '");
 196 }
 197
 198 /*
 199  * parse a string from the command line and detect the quoting style
 200  */
 201 static void parse_str(struct uci_context *ctx, char **str, char **target)
 202 {
 203         do {
 204                 switch(**str) {
 205                 case '\'':
 206                         parse_single_quote(ctx, str, target);
 207                         break;
 208                 case '"':
 209                         parse_double_quote(ctx, str, target);
 210                         break;
 211                 case 0:
 212                         goto done;
 213                 case '\\':
 214                         if (!parse_backslash(ctx, str))
 215                                 continue;
 216                         /* fall through */
 217                 default:
 218                         addc(target, str);
 219                         break;
 220                 }
 221         } while (**str && !isspace(**str));
 222 done:
 223
 224         /*
 225          * if the string was unquoted and we've stopped at a whitespace
 226          * character, skip to the next one, because the whitespace will
 227          * be overwritten by a null byte here
 228          */
 229         if (**str)
 230                 *str += 1;
 231
 232         /* terminate the parsed string */
 233         **target = 0;
 234 }
 235
 236 /*
 237  * extract the next argument from the command line
 238  */
 239 static char *next_arg(struct uci_context *ctx, char **str, bool required, bool name)
 240 {
 241         char *val;
 242         char *ptr;
 243
 244         val = ptr = *str;
 245         skip_whitespace(ctx, str);
 246         parse_str(ctx, str, &ptr);
 247         if (!*val) {
 248                 if (required)
 249                         uci_parse_error(ctx, *str, "insufficient arguments");
 250                 goto done;
 251         }
 252
 253         if (name && !uci_validate_name(val))
 254                 uci_parse_error(ctx, val, "invalid character in field");
 255
 256 done:
 257         return val;
 258 }
 259
 260 /*
 261  * verify that the end of the line or command is reached.
 262  * throw an error if extra arguments are given on the command line
 263  */
 264 static void assert_eol(struct uci_context *ctx, char **str)
 265 {
 266         char *tmp;
 267
 268         tmp = next_arg(ctx, str, false, false);
 269         if (tmp && *tmp)
 270                 uci_parse_error(ctx, *str, "too many arguments");
 271 }
 272
 273 /*
 274  * switch to a different config, either triggered by uci_load, or by a
 275  * 'package <...>' statement in the import file
 276  */
 277 static void uci_switch_config(struct uci_context *ctx)
 278 {
 279         struct uci_parse_context *pctx;
 280         struct uci_element *e;
 281         const char *name;
 282
 283         pctx = ctx->pctx;
 284         name = pctx->name;
 285
 286         /* add the last config to main config file list */
 287         if (pctx->package) {
 288                 uci_list_add(&ctx->root, &pctx->package->e.list);
 289
 290                 pctx->package = NULL;
 291                 pctx->section = NULL;
 292         }
 293
 294         if (!name)
 295                 return;
 296
 297         /*
 298          * if an older config under the same name exists, unload it
 299          * ignore errors here, e.g. if the config was not found
 300          */
 301         e = uci_lookup_list(ctx, &ctx->root, name);
 302         if (e)
 303                 UCI_THROW(ctx, UCI_ERR_DUPLICATE);
 304         pctx->package = uci_alloc_package(ctx, name);
 305 }
 306
 307 /*
 308  * parse the 'package' uci command (next config package)
 309  */
 310 static void uci_parse_package(struct uci_context *ctx, char **str, bool single)
 311 {
 312         char *name = NULL;
 313
 314         /* command string null-terminated by strtok */
 315         *str += strlen(*str) + 1;
 316
 317         name = next_arg(ctx, str, true, true);
 318         assert_eol(ctx, str);
 319         if (single)
 320                 return;
 321
 322         ctx->pctx->name = name;
 323         uci_switch_config(ctx);
 324 }
 325
 326 /* Based on an efficient hash function published by D. J. Bernstein */
 327 static unsigned int djbhash(unsigned int hash, char *str)
 328 {
 329         int len = strlen(str);
 330         int i;
 331
 332         /* initial value */
 333         if (hash == ~0)
 334                 hash = 5381;
 335
 336         for(i = 0; i < len; i++) {
 337                 hash = ((hash << 5) + hash) + str[i];
 338         }
 339         return (hash & 0x7FFFFFFF);
 340 }
 341
 342 /* fix up an unnamed section */
 343 static void uci_fixup_section(struct uci_context *ctx, struct uci_section *s)
 344 {
 345         unsigned int hash = ~0;
 346         struct uci_element *e;
 347         char buf[16];
 348
 349         if (!s || s->e.name)
 350                 return;
 351
 352         /*
 353          * Generate a name for unnamed sections. This is used as reference
 354          * when locating or updating the section from apps/scripts.
 355          * To make multiple concurrent versions somewhat safe for updating,
 356          * the name is generated from a hash of its type and name/value
 357          * pairs of its option, and it is prefixed by a counter value.
 358          * If the order of the unnamed sections changes for some reason,
 359          * updates to them will be rejected.
 360          */
 361         hash = djbhash(hash, s->type);
 362         uci_foreach_element(&s->options, e) {
 363                 hash = djbhash(hash, e->name);
 364                 hash = djbhash(hash, uci_to_option(e)->value);
 365         }
 366         sprintf(buf, "cfg%02x%04x", ++s->package->n_section, hash % (1 << 16));
 367         s->e.name = uci_strdup(ctx, buf);
 368 }
 369
 370 /*
 371  * parse the 'config' uci command (open a section)
 372  */
 373 static void uci_parse_config(struct uci_context *ctx, char **str)
 374 {
 375         struct uci_parse_context *pctx = ctx->pctx;
 376         struct uci_section *s;
 377         char *name = NULL;
 378         char *type = NULL;
 379
 380         uci_fixup_section(ctx, ctx->pctx->section);
 381         if (!ctx->pctx->package) {
 382                 if (!ctx->pctx->name)
 383                         uci_parse_error(ctx, *str, "attempting to import a file without a package name");
 384
 385                 uci_switch_config(ctx);
 386         }
 387
 388         /* command string null-terminated by strtok */
 389         *str += strlen(*str) + 1;
 390
 391         type = next_arg(ctx, str, true, true);
 392         name = next_arg(ctx, str, false, true);
 393         assert_eol(ctx, str);
 394
 395         if (pctx->merge) {
 396                 UCI_TRAP_SAVE(ctx, error);
 397                 uci_set(ctx, pctx->package, name, NULL, type);
 398                 UCI_TRAP_RESTORE(ctx);
 399                 return;
 400 error:
 401                 UCI_THROW(ctx, ctx->errno);
 402         } else
 403                 pctx->section = uci_alloc_section(pctx->package, type, name);
 404 }
 405
 406 /*
 407  * parse the 'option' uci command (open a value)
 408  */
 409 static void uci_parse_option(struct uci_context *ctx, char **str)
 410 {
 411         struct uci_parse_context *pctx = ctx->pctx;
 412         char *name = NULL;
 413         char *value = NULL;
 414
 415         if (!pctx->section)
 416                 uci_parse_error(ctx, *str, "option command found before the first section");
 417
 418         /* command string null-terminated by strtok */
 419         *str += strlen(*str) + 1;
 420
 421         name = next_arg(ctx, str, true, true);
 422         value = next_arg(ctx, str, true, false);
 423         assert_eol(ctx, str);
 424
 425         if (pctx->merge) {
 426                 UCI_TRAP_SAVE(ctx, error);
 427                 uci_set(ctx, pctx->package, pctx->section->e.name, name, value);
 428                 UCI_TRAP_RESTORE(ctx);
 429                 return;
 430 error:
 431                 UCI_THROW(ctx, ctx->errno);
 432         } else
 433                 uci_alloc_option(pctx->section, name, value);
 434 }
 435
 436
 437 /*
 438  * parse a complete input line, split up combined commands by ';'
 439  */
 440 static void uci_parse_line(struct uci_context *ctx, bool single)
 441 {
 442         struct uci_parse_context *pctx = ctx->pctx;
 443         char *word, *brk = NULL;
 444
 445         for (word = strtok_r(pctx->buf, ";", &brk);
 446                  word;
 447                  word = strtok_r(NULL, ";", &brk)) {
 448
 449                 char *pbrk = NULL;
 450                 word = strtok_r(word, " \t", &pbrk);
 451
 452                 switch(word[0]) {
 453                         case 'p':
 454                                 if ((word[1] == 0) || !strcmp(word + 1, "ackage"))
 455                                         uci_parse_package(ctx, &word, single);
 456                                 break;
 457                         case 'c':
 458                                 if ((word[1] == 0) || !strcmp(word + 1, "onfig"))
 459                                         uci_parse_config(ctx, &word);
 460                                 break;
 461                         case 'o':
 462                                 if ((word[1] == 0) || !strcmp(word + 1, "ption"))
 463                                         uci_parse_option(ctx, &word);
 464                                 break;
 465                         default:
 466                                 uci_parse_error(ctx, word, "unterminated command");
 467                                 break;
 468                 }
 469         }
 470 }
 471
 472 /* max number of characters that escaping adds to the string */
 473 #define UCI_QUOTE_ESCAPE        "'\\''"
 474
 475 /*
 476  * escape an uci string for export
 477  */
 478 static char *uci_escape(struct uci_context *ctx, char *str)
 479 {
 480         char *s, *p;
 481         int pos = 0;
 482
 483         if (!ctx->buf) {
 484                 ctx->bufsz = LINEBUF;
 485                 ctx->buf = malloc(LINEBUF);
 486         }
 487
 488         s = str;
 489         p = strchr(str, '\'');
 490         if (!p)
 491                 return str;
 492
 493         do {
 494                 int len = p - s;
 495                 if (len > 0) {
 496                         if (p + sizeof(UCI_QUOTE_ESCAPE) - str >= ctx->bufsz) {
 497                                 ctx->bufsz *= 2;
 498                                 ctx->buf = realloc(ctx->buf, ctx->bufsz);
 499                                 if (!ctx->buf)
 500                                         UCI_THROW(ctx, UCI_ERR_MEM);
 501                         }
 502                         memcpy(&ctx->buf[pos], s, len);
 503                         pos += len;
 504                 }
 505                 strcpy(&ctx->buf[pos], UCI_QUOTE_ESCAPE);
 506                 pos += sizeof(UCI_QUOTE_ESCAPE);
 507                 s = p + 1;
 508         } while ((p = strchr(s, '\'')));
 509
 510         return ctx->buf;
 511 }
 512
 513
 514 /*
 515  * export a single config package to a file stream
 516  */
 517 static void uci_export_package(struct uci_package *p, FILE *stream, bool header)
 518 {
 519         struct uci_context *ctx = p->ctx;
 520         struct uci_element *s, *o;
 521
 522         if (header)
 523                 fprintf(stream, "package '%s'\n", uci_escape(ctx, p->e.name));
 524         uci_foreach_element(&p->sections, s) {
 525                 struct uci_section *sec = uci_to_section(s);
 526                 fprintf(stream, "\nconfig '%s'", uci_escape(ctx, sec->type));
 527                 if (!sec->anonymous)
 528                         fprintf(stream, " '%s'", uci_escape(ctx, sec->e.name));
 529                 fprintf(stream, "\n");
 530                 uci_foreach_element(&sec->options, o) {
 531                         struct uci_option *opt = uci_to_option(o);
 532                         fprintf(stream, "\toption '%s'", uci_escape(ctx, opt->e.name));
 533                         fprintf(stream, " '%s'\n", uci_escape(ctx, opt->value));
 534                 }
 535         }
 536         fprintf(stream, "\n");
 537 }
 538
 539 int uci_export(struct uci_context *ctx, FILE *stream, struct uci_package *package, bool header)
 540 {
 541         struct uci_element *e;
 542
 543         UCI_HANDLE_ERR(ctx);
 544         UCI_ASSERT(ctx, stream != NULL);
 545
 546         if (package)
 547                 uci_export_package(package, stream, header);
 548         else {
 549                 uci_foreach_element(&ctx->root, e) {
 550                         uci_export_package(uci_to_package(e), stream, header);
 551                 }
 552         }
 553
 554         return 0;
 555 }
 556
 557 int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_package **package, bool single)
 558 {
 559         struct uci_parse_context *pctx;
 560         UCI_HANDLE_ERR(ctx);
 561
 562         /* make sure no memory from previous parse attempts is leaked */
 563         uci_file_cleanup(ctx);
 564
 565         pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
 566         ctx->pctx = pctx;
 567         pctx->file = stream;
 568         if (*package && single) {
 569                 pctx->package = *package;
 570                 pctx->merge = true;
 571         }
 572
 573         /*
 574          * If 'name' was supplied, assume that the supplied stream does not contain
 575          * the appropriate 'package <name>' string to specify the config name
 576          * NB: the config file can still override the package name
 577          */
 578         if (name)
 579                 pctx->name = name;
 580
 581         while (!feof(pctx->file)) {
 582                 uci_getln(ctx, 0);
 583                 UCI_TRAP_SAVE(ctx, error);
 584                 if (pctx->buf[0])
 585                         uci_parse_line(ctx, single);
 586                 UCI_TRAP_RESTORE(ctx);
 587                 continue;
 588 error:
 589                 if (ctx->flags & UCI_FLAG_PERROR)
 590                         uci_perror(ctx, NULL);
 591                 if ((ctx->errno != UCI_ERR_PARSE) ||
 592                         (ctx->flags & UCI_FLAG_STRICT))
 593                         UCI_THROW(ctx, ctx->errno);
 594         }
 595
 596         uci_fixup_section(ctx, ctx->pctx->section);
 597         if (package)
 598                 *package = pctx->package;
 599         if (pctx->merge)
 600                 pctx->package = NULL;
 601
 602         pctx->name = NULL;
 603         uci_switch_config(ctx);
 604
 605         /* no error happened, we can get rid of the parser context now */
 606         uci_file_cleanup(ctx);
 607
 608         return 0;
 609 }
 610
 611 /*
 612  * open a stream and go to the right position
 613  *
 614  * note: when opening for write and seeking to the beginning of
 615  * the stream, truncate the file
 616  */
 617 static FILE *uci_open_stream(struct uci_context *ctx, const char *filename, int pos, bool write, bool create)
 618 {
 619         struct stat statbuf;
 620         FILE *file = NULL;
 621         int fd, ret;
 622         int mode = (write ? O_RDWR : O_RDONLY);
 623
 624         if (create)
 625                 mode |= O_CREAT;
 626
 627         if (!write && ((stat(filename, &statbuf) < 0) ||
 628                 ((statbuf.st_mode &  S_IFMT) != S_IFREG))) {
 629                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 630         }
 631
 632         fd = open(filename, mode, UCI_FILEMODE);
 633         if (fd <= 0)
 634                 goto error;
 635
 636         if (flock(fd, (write ? LOCK_EX : LOCK_SH)) < 0)
 637                 goto error;
 638
 639         ret = lseek(fd, 0, pos);
 640
 641         if (ret < 0)
 642                 goto error;
 643
 644         file = fdopen(fd, (write ? "w+" : "r"));
 645         if (file)
 646                 goto done;
 647
 648 error:
 649         UCI_THROW(ctx, UCI_ERR_IO);
 650 done:
 651         return file;
 652 }
 653
 654 static void uci_close_stream(FILE *stream)
 655 {
 656         int fd;
 657
 658         if (!stream)
 659                 return;
 660
 661         fd = fileno(stream);
 662         flock(fd, LOCK_UN);
 663         fclose(stream);
 664 }
 665
 666 static void uci_parse_history_line(struct uci_context *ctx, struct uci_package *p, char *buf)
 667 {
 668         bool delete = false;
 669         bool rename = false;
 670         char *package = NULL;
 671         char *section = NULL;
 672         char *option = NULL;
 673         char *value = NULL;
 674
 675         if (buf[0] == '-') {
 676                 delete = true;
 677                 buf++;
 678         } else if (buf[0] == '@') {
 679                 rename = true;
 680                 buf++;
 681         }
 682
 683         UCI_INTERNAL(uci_parse_tuple, ctx, buf, &package, &section, &option, &value);
 684         if (!package || !section || (!delete && !value))
 685                 goto error;
 686         if (strcmp(package, p->e.name) != 0)
 687                 goto error;
 688         if (!uci_validate_name(section))
 689                 goto error;
 690         if (option && !uci_validate_name(option))
 691                 goto error;
 692
 693         if (rename)
 694                 UCI_INTERNAL(uci_rename, ctx, p, section, option, value);
 695         else if (delete)
 696                 UCI_INTERNAL(uci_delete, ctx, p, section, option);
 697         else
 698                 UCI_INTERNAL(uci_set, ctx, p, section, option, value);
 699
 700         return;
 701 error:
 702         UCI_THROW(ctx, UCI_ERR_PARSE);
 703 }
 704
 705 static void uci_parse_history(struct uci_context *ctx, FILE *stream, struct uci_package *p)
 706 {
 707         struct uci_parse_context *pctx;
 708
 709         /* make sure no memory from previous parse attempts is leaked */
 710         uci_file_cleanup(ctx);
 711
 712         pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
 713         ctx->pctx = pctx;
 714         pctx->file = stream;
 715
 716         while (!feof(pctx->file)) {
 717                 uci_getln(ctx, 0);
 718                 if (!pctx->buf[0])
 719                         continue;
 720
 721                 /*
 722                  * ignore parse errors in single lines, we want to preserve as much
 723                  * history as possible
 724                  */
 725                 UCI_TRAP_SAVE(ctx, error);
 726                 uci_parse_history_line(ctx, p, pctx->buf);
 727                 UCI_TRAP_RESTORE(ctx);
 728 error:
 729                 continue;
 730         }
 731
 732         /* no error happened, we can get rid of the parser context now */
 733         uci_file_cleanup(ctx);
 734 }
 735
 736 static void uci_load_history(struct uci_context *ctx, struct uci_package *p, bool flush)
 737 {
 738         char *filename = NULL;
 739         FILE *f = NULL;
 740
 741         if (!p->confdir)
 742                 return;
 743         if ((asprintf(&filename, "%s/%s", UCI_SAVEDIR, p->e.name) < 0) || !filename)
 744                 UCI_THROW(ctx, UCI_ERR_MEM);
 745
 746         UCI_TRAP_SAVE(ctx, done);
 747         f = uci_open_stream(ctx, filename, SEEK_SET, flush, false);
 748         if (p)
 749                 uci_parse_history(ctx, f, p);
 750         UCI_TRAP_RESTORE(ctx);
 751
 752 done:
 753         if (flush && f) {
 754                 rewind(f);
 755                 ftruncate(fileno(f), 0);
 756         }
 757         if (filename)
 758                 free(filename);
 759         uci_close_stream(f);
 760         ctx->errno = 0;
 761 }
 762
 763
 764 static char *uci_config_path(struct uci_context *ctx, const char *name)
 765 {
 766         char *filename;
 767
 768         if (strchr(name, '/'))
 769                 UCI_THROW(ctx, UCI_ERR_INVAL);
 770         filename = uci_malloc(ctx, strlen(name) + sizeof(UCI_CONFDIR) + 2);
 771         sprintf(filename, UCI_CONFDIR "/%s", name);
 772
 773         return filename;
 774 }
 775
 776 int uci_load(struct uci_context *ctx, const char *name, struct uci_package **package)
 777 {
 778         char *filename;
 779         bool confdir;
 780         FILE *file = NULL;
 781
 782         UCI_HANDLE_ERR(ctx);
 783         UCI_ASSERT(ctx, uci_validate_name(name));
 784
 785         switch (name[0]) {
 786         case '.':
 787                 /* relative path outside of /etc/config */
 788                 if (name[1] != '/')
 789                         UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 790                 /* fall through */
 791         case '/':
 792                 /* absolute path outside of /etc/config */
 793                 filename = uci_strdup(ctx, name);
 794                 name = strrchr(name, '/') + 1;
 795                 confdir = false;
 796                 break;
 797         default:
 798                 /* config in /etc/config */
 799                 filename = uci_config_path(ctx, name);
 800                 confdir = true;
 801                 break;
 802         }
 803
 804         file = uci_open_stream(ctx, filename, SEEK_SET, false, false);
 805         ctx->errno = 0;
 806         UCI_TRAP_SAVE(ctx, done);
 807         UCI_INTERNAL(uci_import, ctx, file, name, package, true);
 808         UCI_TRAP_RESTORE(ctx);
 809
 810         if (*package) {
 811                 (*package)->path = filename;
 812                 (*package)->confdir = confdir;
 813                 uci_load_history(ctx, *package, false);
 814         }
 815
 816 done:
 817         uci_close_stream(file);
 818         return ctx->errno;
 819 }
 820
 821 int uci_save(struct uci_context *ctx, struct uci_package *p)
 822 {
 823         FILE *f = NULL;
 824         char *filename = NULL;
 825         struct uci_element *e, *tmp;
 826
 827         UCI_HANDLE_ERR(ctx);
 828         UCI_ASSERT(ctx, p != NULL);
 829
 830         /*
 831          * if the config file was outside of the /etc/config path,
 832          * don't save the history to a file, update the real file
 833          * directly.
 834          * does not modify the uci_package pointer
 835          */
 836         if (!p->confdir)
 837                 return uci_commit(ctx, &p, false);
 838
 839         if (uci_list_empty(&p->history))
 840                 return 0;
 841
 842         if ((asprintf(&filename, "%s/%s", UCI_SAVEDIR, p->e.name) < 0) || !filename)
 843                 UCI_THROW(ctx, UCI_ERR_MEM);
 844
 845         ctx->errno = 0;
 846         UCI_TRAP_SAVE(ctx, done);
 847         f = uci_open_stream(ctx, filename, SEEK_END, true, true);
 848         UCI_TRAP_RESTORE(ctx);
 849
 850         uci_foreach_element_safe(&p->history, tmp, e) {
 851                 struct uci_history *h = uci_to_history(e);
 852
 853                 if (h->cmd == UCI_CMD_REMOVE)
 854                         fprintf(f, "-");
 855                 else if (h->cmd == UCI_CMD_RENAME)
 856                         fprintf(f, "@");
 857
 858                 fprintf(f, "%s.%s", p->e.name, h->section);
 859                 if (e->name)
 860                         fprintf(f, ".%s", e->name);
 861
 862                 if (h->cmd == UCI_CMD_REMOVE)
 863                         fprintf(f, "\n");
 864                 else
 865                         fprintf(f, "=%s\n", h->value);
 866                 uci_free_history(h);
 867         }
 868
 869 done:
 870         uci_close_stream(f);
 871         if (filename)
 872                 free(filename);
 873         if (ctx->errno)
 874                 UCI_THROW(ctx, ctx->errno);
 875
 876         return 0;
 877 }
 878
 879 int uci_commit(struct uci_context *ctx, struct uci_package **package, bool overwrite)
 880 {
 881         struct uci_package *p;
 882         FILE *f = NULL;
 883         char *name = NULL;
 884         char *path = NULL;
 885
 886         UCI_HANDLE_ERR(ctx);
 887         UCI_ASSERT(ctx, package != NULL);
 888         p = *package;
 889
 890         UCI_ASSERT(ctx, p != NULL);
 891         if (!p->path) {
 892                 if (overwrite)
 893                         p->path = uci_config_path(ctx, p->e.name);
 894                 else
 895                         UCI_THROW(ctx, UCI_ERR_INVAL);
 896         }
 897
 898
 899         /* open the config file for writing now, so that it is locked */
 900         f = uci_open_stream(ctx, p->path, SEEK_SET, true, true);
 901
 902         /* flush unsaved changes and reload from history file */
 903         UCI_TRAP_SAVE(ctx, done);
 904         if (p->confdir) {
 905                 if (!overwrite) {
 906                         name = uci_strdup(ctx, p->e.name);
 907                         path = uci_strdup(ctx, p->path);
 908                         if (!uci_list_empty(&p->history))
 909                                 UCI_INTERNAL(uci_save, ctx, p);
 910                         uci_free_package(&p);
 911                         uci_file_cleanup(ctx);
 912                         UCI_INTERNAL(uci_import, ctx, f, name, &p, true);
 913
 914                         p->path = path;
 915                         p->confdir = true;
 916                         *package = p;
 917
 918                         /* freed together with the uci_package */
 919                         path = NULL;
 920
 921                         /* check for updated history, just in case */
 922                         uci_load_history(ctx, p, true);
 923                 } else {
 924                         /* flush history */
 925                         uci_load_history(ctx, NULL, true);
 926                 }
 927         }
 928
 929         rewind(f);
 930         ftruncate(fileno(f), 0);
 931
 932         uci_export(ctx, f, p, false);
 933         UCI_TRAP_RESTORE(ctx);
 934
 935 done:
 936         if (name)
 937                 free(name);
 938         if (path)
 939                 free(path);
 940         uci_close_stream(f);
 941         if (ctx->errno)
 942                 UCI_THROW(ctx, ctx->errno);
 943
 944         return 0;
 945 }
 946
 947
 948 /*
 949  * This function returns the filename by returning the string
 950  * after the last '/' character. By checking for a non-'\0'
 951  * character afterwards, directories are ignored (glob marks
 952  * those with a trailing '/'
 953  */
 954 static inline char *get_filename(char *path)
 955 {
 956         char *p;
 957
 958         p = strrchr(path, '/');
 959         p++;
 960         if (!*p)
 961                 return NULL;
 962         return p;
 963 }
 964
 965 int uci_list_configs(struct uci_context *ctx, char ***list)
 966 {
 967         char **configs;
 968         glob_t globbuf;
 969         int size, i;
 970         char *buf;
 971
 972         UCI_HANDLE_ERR(ctx);
 973
 974         if (glob(UCI_CONFDIR "/*", GLOB_MARK, NULL, &globbuf) != 0)
 975                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 976
 977         size = sizeof(char *) * (globbuf.gl_pathc + 1);
 978         for(i = 0; i < globbuf.gl_pathc; i++) {
 979                 char *p;
 980
 981                 p = get_filename(globbuf.gl_pathv[i]);
 982                 if (!p)
 983                         continue;
 984
 985                 size += strlen(p) + 1;
 986         }
 987
 988         configs = uci_malloc(ctx, size);
 989         buf = (char *) &configs[globbuf.gl_pathc + 1];
 990         for(i = 0; i < globbuf.gl_pathc; i++) {
 991                 char *p;
 992
 993                 p = get_filename(globbuf.gl_pathv[i]);
 994                 if (!p)
 995                         continue;
 996
 997                 configs[i] = buf;
 998                 strcpy(buf, p);
 999                 buf += strlen(buf) + 1;
1000         }
1001         *list = configs;
1002
1003         return 0;
1004 }
1005