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/stat.h>
  22 #include <sys/file.h>
  23 #include <stdbool.h>
  24 #include <unistd.h>
  25 #include <fcntl.h>
  26 #include <stdio.h>
  27 #include <ctype.h>
  28
  29 #define LINEBUF 32
  30 #define LINEBUF_MAX     4096
  31
  32 static void uci_parse_error(struct uci_context *ctx, char *pos, char *reason)
  33 {
  34         struct uci_parse_context *pctx = ctx->pctx;
  35
  36         pctx->reason = reason;
  37         pctx->byte = pos - pctx->buf;
  38         UCI_THROW(ctx, UCI_ERR_PARSE);
  39 }
  40
  41 /*
  42  * Fetch a new line from the input stream and resize buffer if necessary
  43  */
  44 static void uci_getln(struct uci_context *ctx, int offset)
  45 {
  46         struct uci_parse_context *pctx = ctx->pctx;
  47         char *p;
  48         int ofs;
  49
  50         if (pctx->buf == NULL) {
  51                 pctx->buf = uci_malloc(ctx, LINEBUF);
  52                 pctx->bufsz = LINEBUF;
  53         }
  54
  55         ofs = offset;
  56         do {
  57                 p = &pctx->buf[ofs];
  58                 p[ofs] = 0;
  59
  60                 p = fgets(p, pctx->bufsz - ofs, pctx->file);
  61                 if (!p || !*p)
  62                         return;
  63
  64                 ofs += strlen(p);
  65                 if (pctx->buf[ofs - 1] == '\n') {
  66                         pctx->line++;
  67                         pctx->buf[ofs - 1] = 0;
  68                         return;
  69                 }
  70
  71                 if (pctx->bufsz > LINEBUF_MAX/2)
  72                         uci_parse_error(ctx, p, "line too long");
  73
  74                 pctx->bufsz *= 2;
  75                 pctx->buf = uci_realloc(ctx, pctx->buf, pctx->bufsz);
  76         } while (1);
  77 }
  78
  79 /*
  80  * Clean up all extra memory used by the parser and exporter
  81  */
  82 static void uci_file_cleanup(struct uci_context *ctx)
  83 {
  84         struct uci_parse_context *pctx;
  85
  86         if (ctx->buf) {
  87                 free(ctx->buf);
  88                 ctx->buf = NULL;
  89                 ctx->bufsz = 0;
  90         }
  91
  92         pctx = ctx->pctx;
  93         if (!pctx)
  94                 return;
  95
  96         ctx->pctx = NULL;
  97         if (pctx->package)
  98                 uci_free_package(&pctx->package);
  99
 100         if (pctx->buf)
 101                 free(pctx->buf);
 102
 103         free(pctx);
 104 }
 105
 106 /*
 107  * parse a character escaped by '\'
 108  * returns true if the escaped character is to be parsed
 109  * returns false if the escaped character is to be ignored
 110  */
 111 static inline bool parse_backslash(struct uci_context *ctx, char **str)
 112 {
 113         /* skip backslash */
 114         *str += 1;
 115
 116         /* undecoded backslash at the end of line, fetch the next line */
 117         if (!**str) {
 118                 *str += 1;
 119                 uci_getln(ctx, *str - ctx->pctx->buf);
 120                 return false;
 121         }
 122
 123         /* FIXME: decode escaped char, necessary? */
 124         return true;
 125 }
 126
 127 /*
 128  * move the string pointer forward until a non-whitespace character or
 129  * EOL is reached
 130  */
 131 static void skip_whitespace(struct uci_context *ctx, char **str)
 132 {
 133 restart:
 134         while (**str && isspace(**str))
 135                 *str += 1;
 136
 137         if (**str == '\\') {
 138                 if (!parse_backslash(ctx, str))
 139                         goto restart;
 140         }
 141 }
 142
 143 static inline void addc(char **dest, char **src)
 144 {
 145         **dest = **src;
 146         *dest += 1;
 147         *src += 1;
 148 }
 149
 150 /*
 151  * parse a double quoted string argument from the command line
 152  */
 153 static void parse_double_quote(struct uci_context *ctx, char **str, char **target)
 154 {
 155         char c;
 156
 157         /* skip quote character */
 158         *str += 1;
 159
 160         while ((c = **str)) {
 161                 switch(c) {
 162                 case '"':
 163                         **target = 0;
 164                         *str += 1;
 165                         return;
 166                 case '\\':
 167                         if (!parse_backslash(ctx, str))
 168                                 continue;
 169                         /* fall through */
 170                 default:
 171                         addc(target, str);
 172                         break;
 173                 }
 174         }
 175         uci_parse_error(ctx, *str, "unterminated \"");
 176 }
 177
 178 /*
 179  * parse a single quoted string argument from the command line
 180  */
 181 static void parse_single_quote(struct uci_context *ctx, char **str, char **target)
 182 {
 183         char c;
 184         /* skip quote character */
 185         *str += 1;
 186
 187         while ((c = **str)) {
 188                 switch(c) {
 189                 case '\'':
 190                         **target = 0;
 191                         *str += 1;
 192                         return;
 193                 default:
 194                         addc(target, str);
 195                 }
 196         }
 197         uci_parse_error(ctx, *str, "unterminated '");
 198 }
 199
 200 /*
 201  * parse a string from the command line and detect the quoting style
 202  */
 203 static void parse_str(struct uci_context *ctx, char **str, char **target)
 204 {
 205         do {
 206                 switch(**str) {
 207                 case '\'':
 208                         parse_single_quote(ctx, str, target);
 209                         break;
 210                 case '"':
 211                         parse_double_quote(ctx, str, target);
 212                         break;
 213                 case 0:
 214                         goto done;
 215                 case '\\':
 216                         if (!parse_backslash(ctx, str))
 217                                 continue;
 218                         /* fall through */
 219                 default:
 220                         addc(target, str);
 221                         break;
 222                 }
 223         } while (**str && !isspace(**str));
 224 done:
 225
 226         /*
 227          * if the string was unquoted and we've stopped at a whitespace
 228          * character, skip to the next one, because the whitespace will
 229          * be overwritten by a null byte here
 230          */
 231         if (**str)
 232                 *str += 1;
 233
 234         /* terminate the parsed string */
 235         **target = 0;
 236 }
 237
 238 /*
 239  * extract the next argument from the command line
 240  */
 241 static char *next_arg(struct uci_context *ctx, char **str, bool required, bool name)
 242 {
 243         char *val;
 244         char *ptr;
 245
 246         val = ptr = *str;
 247         skip_whitespace(ctx, str);
 248         parse_str(ctx, str, &ptr);
 249         if (!*val) {
 250                 if (required)
 251                         uci_parse_error(ctx, *str, "insufficient arguments");
 252                 goto done;
 253         }
 254
 255         if (name && !uci_validate_name(val))
 256                 uci_parse_error(ctx, val, "invalid character in field");
 257
 258 done:
 259         return val;
 260 }
 261
 262 /*
 263  * verify that the end of the line or command is reached.
 264  * throw an error if extra arguments are given on the command line
 265  */
 266 static void assert_eol(struct uci_context *ctx, char **str)
 267 {
 268         char *tmp;
 269
 270         tmp = next_arg(ctx, str, false, false);
 271         if (tmp && *tmp && (ctx->flags & UCI_FLAG_STRICT))
 272                 uci_parse_error(ctx, *str, "too many arguments");
 273 }
 274
 275 /*
 276  * switch to a different config, either triggered by uci_load, or by a
 277  * 'package <...>' statement in the import file
 278  */
 279 static void uci_switch_config(struct uci_context *ctx)
 280 {
 281         struct uci_parse_context *pctx;
 282         struct uci_element *e;
 283         const char *name;
 284
 285         pctx = ctx->pctx;
 286         name = pctx->name;
 287
 288         /* add the last config to main config file list */
 289         if (pctx->package) {
 290                 uci_list_add(&ctx->root, &pctx->package->e.list);
 291
 292                 pctx->package = NULL;
 293                 pctx->section = NULL;
 294         }
 295
 296         if (!name)
 297                 return;
 298
 299         /*
 300          * if an older config under the same name exists, unload it
 301          * ignore errors here, e.g. if the config was not found
 302          */
 303         e = uci_lookup_list(ctx, &ctx->root, name);
 304         if (e)
 305                 UCI_THROW(ctx, UCI_ERR_DUPLICATE);
 306         pctx->package = uci_alloc_package(ctx, name);
 307 }
 308
 309 /*
 310  * parse the 'package' uci command (next config package)
 311  */
 312 static void uci_parse_package(struct uci_context *ctx, char **str, bool single)
 313 {
 314         char *name = NULL;
 315
 316         /* command string null-terminated by strtok */
 317         *str += strlen(*str) + 1;
 318
 319         name = next_arg(ctx, str, true, true);
 320         assert_eol(ctx, str);
 321         if (single)
 322                 return;
 323
 324         ctx->pctx->name = name;
 325         uci_switch_config(ctx);
 326 }
 327
 328 /* Based on an efficient hash function published by D. J. Bernstein */
 329 static unsigned int djbhash(unsigned int hash, char *str)
 330 {
 331         int len = strlen(str);
 332         int i;
 333
 334         /* initial value */
 335         if (hash == ~0)
 336                 hash = 5381;
 337
 338         for(i = 0; i < len; i++) {
 339                 hash = ((hash << 5) + hash) + str[i];
 340         }
 341         return (hash & 0x7FFFFFFF);
 342 }
 343
 344 /* fix up an unnamed section */
 345 static void uci_fixup_section(struct uci_context *ctx, struct uci_section *s)
 346 {
 347         unsigned int hash = ~0;
 348         struct uci_element *e;
 349         char buf[16];
 350
 351         if (!s || s->e.name)
 352                 return;
 353
 354         /*
 355          * Generate a name for unnamed sections. This is used as reference
 356          * when locating or updating the section from apps/scripts.
 357          * To make multiple concurrent versions somewhat safe for updating,
 358          * the name is generated from a hash of its type and name/value
 359          * pairs of its option, and it is prefixed by a counter value.
 360          * If the order of the unnamed sections changes for some reason,
 361          * updates to them will be rejected.
 362          */
 363         hash = djbhash(hash, s->type);
 364         uci_foreach_element(&s->options, e) {
 365                 hash = djbhash(hash, e->name);
 366                 hash = djbhash(hash, uci_to_option(e)->value);
 367         }
 368         sprintf(buf, "cfg%02x%04x", ++s->package->n_section, hash % (1 << 16));
 369         s->e.name = uci_strdup(ctx, buf);
 370 }
 371
 372 /*
 373  * parse the 'config' uci command (open a section)
 374  */
 375 static void uci_parse_config(struct uci_context *ctx, char **str)
 376 {
 377         struct uci_parse_context *pctx = ctx->pctx;
 378         char *name = NULL;
 379         char *type = NULL;
 380
 381         uci_fixup_section(ctx, ctx->pctx->section);
 382         if (!ctx->pctx->package) {
 383                 if (!ctx->pctx->name)
 384                         uci_parse_error(ctx, *str, "attempting to import a file without a package name");
 385
 386                 uci_switch_config(ctx);
 387         }
 388
 389         /* command string null-terminated by strtok */
 390         *str += strlen(*str) + 1;
 391
 392         type = next_arg(ctx, str, true, true);
 393         name = next_arg(ctx, str, false, true);
 394         assert_eol(ctx, str);
 395
 396         if (pctx->merge) {
 397                 UCI_TRAP_SAVE(ctx, error);
 398                 uci_set(ctx, pctx->package, name, NULL, type);
 399                 UCI_TRAP_RESTORE(ctx);
 400                 return;
 401 error:
 402                 UCI_THROW(ctx, ctx->errno);
 403         } else
 404                 pctx->section = uci_alloc_section(pctx->package, type, name);
 405 }
 406
 407 /*
 408  * parse the 'option' uci command (open a value)
 409  */
 410 static void uci_parse_option(struct uci_context *ctx, char **str)
 411 {
 412         struct uci_parse_context *pctx = ctx->pctx;
 413         char *name = NULL;
 414         char *value = NULL;
 415
 416         if (!pctx->section)
 417                 uci_parse_error(ctx, *str, "option command found before the first section");
 418
 419         /* command string null-terminated by strtok */
 420         *str += strlen(*str) + 1;
 421
 422         name = next_arg(ctx, str, true, true);
 423         value = next_arg(ctx, str, true, false);
 424         assert_eol(ctx, str);
 425
 426         if (pctx->merge) {
 427                 UCI_TRAP_SAVE(ctx, error);
 428                 uci_set(ctx, pctx->package, pctx->section->e.name, name, value);
 429                 UCI_TRAP_RESTORE(ctx);
 430                 return;
 431 error:
 432                 UCI_THROW(ctx, ctx->errno);
 433         } else
 434                 uci_alloc_option(pctx->section, name, value);
 435 }
 436
 437
 438 /*
 439  * parse a complete input line, split up combined commands by ';'
 440  */
 441 static void uci_parse_line(struct uci_context *ctx, bool single)
 442 {
 443         struct uci_parse_context *pctx = ctx->pctx;
 444         char *word, *brk = NULL;
 445
 446         for (word = strtok_r(pctx->buf, ";", &brk);
 447                  word;
 448                  word = strtok_r(NULL, ";", &brk)) {
 449
 450                 char *pbrk = NULL;
 451                 word = strtok_r(word, " \t", &pbrk);
 452
 453                 switch(word[0]) {
 454                         case 'p':
 455                                 if ((word[1] == 0) || !strcmp(word + 1, "ackage"))
 456                                         uci_parse_package(ctx, &word, single);
 457                                 break;
 458                         case 'c':
 459                                 if ((word[1] == 0) || !strcmp(word + 1, "onfig"))
 460                                         uci_parse_config(ctx, &word);
 461                                 break;
 462                         case 'o':
 463                                 if ((word[1] == 0) || !strcmp(word + 1, "ption"))
 464                                         uci_parse_option(ctx, &word);
 465                                 break;
 466                         default:
 467                                 uci_parse_error(ctx, word, "unterminated command");
 468                                 break;
 469                 }
 470         }
 471 }
 472
 473 /* max number of characters that escaping adds to the string */
 474 #define UCI_QUOTE_ESCAPE        "'\\''"
 475
 476 /*
 477  * escape an uci string for export
 478  */
 479 static char *uci_escape(struct uci_context *ctx, char *str)
 480 {
 481         char *s, *p;
 482         int pos = 0;
 483
 484         if (!ctx->buf) {
 485                 ctx->bufsz = LINEBUF;
 486                 ctx->buf = malloc(LINEBUF);
 487         }
 488
 489         s = str;
 490         p = strchr(str, '\'');
 491         if (!p)
 492                 return str;
 493
 494         do {
 495                 int len = p - s;
 496                 if (len > 0) {
 497                         if (p + sizeof(UCI_QUOTE_ESCAPE) - str >= ctx->bufsz) {
 498                                 ctx->bufsz *= 2;
 499                                 ctx->buf = realloc(ctx->buf, ctx->bufsz);
 500                                 if (!ctx->buf)
 501                                         UCI_THROW(ctx, UCI_ERR_MEM);
 502                         }
 503                         memcpy(&ctx->buf[pos], s, len);
 504                         pos += len;
 505                 }
 506                 strcpy(&ctx->buf[pos], UCI_QUOTE_ESCAPE);
 507                 pos += sizeof(UCI_QUOTE_ESCAPE);
 508                 s = p + 1;
 509         } while ((p = strchr(s, '\'')));
 510
 511         return ctx->buf;
 512 }
 513
 514
 515 /*
 516  * export a single config package to a file stream
 517  */
 518 static void uci_export_package(struct uci_package *p, FILE *stream, bool header)
 519 {
 520         struct uci_context *ctx = p->ctx;
 521         struct uci_element *s, *o;
 522
 523         if (header)
 524                 fprintf(stream, "package '%s'\n", uci_escape(ctx, p->e.name));
 525         uci_foreach_element(&p->sections, s) {
 526                 struct uci_section *sec = uci_to_section(s);
 527                 fprintf(stream, "\nconfig '%s'", uci_escape(ctx, sec->type));
 528                 if (!sec->anonymous || (ctx->flags & UCI_FLAG_EXPORT_NAME))
 529                         fprintf(stream, " '%s'", uci_escape(ctx, sec->e.name));
 530                 fprintf(stream, "\n");
 531                 uci_foreach_element(&sec->options, o) {
 532                         struct uci_option *opt = uci_to_option(o);
 533                         fprintf(stream, "\toption '%s'", uci_escape(ctx, opt->e.name));
 534                         fprintf(stream, " '%s'\n", uci_escape(ctx, opt->value));
 535                 }
 536         }
 537         fprintf(stream, "\n");
 538 }
 539
 540 int uci_export(struct uci_context *ctx, FILE *stream, struct uci_package *package, bool header)
 541 {
 542         struct uci_element *e;
 543
 544         UCI_HANDLE_ERR(ctx);
 545         UCI_ASSERT(ctx, stream != NULL);
 546
 547         if (package)
 548                 uci_export_package(package, stream, header);
 549         else {
 550                 uci_foreach_element(&ctx->root, e) {
 551                         uci_export_package(uci_to_package(e), stream, header);
 552                 }
 553         }
 554
 555         return 0;
 556 }
 557
 558 int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_package **package, bool single)
 559 {
 560         struct uci_parse_context *pctx;
 561         UCI_HANDLE_ERR(ctx);
 562
 563         /* make sure no memory from previous parse attempts is leaked */
 564         uci_file_cleanup(ctx);
 565
 566         pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
 567         ctx->pctx = pctx;
 568         pctx->file = stream;
 569         if (*package && single) {
 570                 pctx->package = *package;
 571                 pctx->merge = true;
 572         }
 573
 574         /*
 575          * If 'name' was supplied, assume that the supplied stream does not contain
 576          * the appropriate 'package <name>' string to specify the config name
 577          * NB: the config file can still override the package name
 578          */
 579         if (name) {
 580                 UCI_ASSERT(ctx, uci_validate_name(name));
 581                 pctx->name = name;
 582         }
 583
 584         while (!feof(pctx->file)) {
 585                 uci_getln(ctx, 0);
 586                 UCI_TRAP_SAVE(ctx, error);
 587                 if (pctx->buf[0])
 588                         uci_parse_line(ctx, single);
 589                 UCI_TRAP_RESTORE(ctx);
 590                 continue;
 591 error:
 592                 if (ctx->flags & UCI_FLAG_PERROR)
 593                         uci_perror(ctx, NULL);
 594                 if ((ctx->errno != UCI_ERR_PARSE) ||
 595                         (ctx->flags & UCI_FLAG_STRICT))
 596                         UCI_THROW(ctx, ctx->errno);
 597         }
 598
 599         uci_fixup_section(ctx, ctx->pctx->section);
 600         if (package)
 601                 *package = pctx->package;
 602         if (pctx->merge)
 603                 pctx->package = NULL;
 604
 605         pctx->name = NULL;
 606         uci_switch_config(ctx);
 607
 608         /* no error happened, we can get rid of the parser context now */
 609         uci_file_cleanup(ctx);
 610
 611         return 0;
 612 }
 613
 614 /*
 615  * open a stream and go to the right position
 616  *
 617  * note: when opening for write and seeking to the beginning of
 618  * the stream, truncate the file
 619  */
 620 static FILE *uci_open_stream(struct uci_context *ctx, const char *filename, int pos, bool write, bool create)
 621 {
 622         struct stat statbuf;
 623         FILE *file = NULL;
 624         int fd, ret;
 625         int mode = (write ? O_RDWR : O_RDONLY);
 626
 627         if (create)
 628                 mode |= O_CREAT;
 629
 630         if (!write && ((stat(filename, &statbuf) < 0) ||
 631                 ((statbuf.st_mode &  S_IFMT) != S_IFREG))) {
 632                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 633         }
 634
 635         fd = open(filename, mode, UCI_FILEMODE);
 636         if (fd <= 0)
 637                 goto error;
 638
 639         if (flock(fd, (write ? LOCK_EX : LOCK_SH)) < 0)
 640                 goto error;
 641
 642         ret = lseek(fd, 0, pos);
 643
 644         if (ret < 0)
 645                 goto error;
 646
 647         file = fdopen(fd, (write ? "w+" : "r"));
 648         if (file)
 649                 goto done;
 650
 651 error:
 652         UCI_THROW(ctx, UCI_ERR_IO);
 653 done:
 654         return file;
 655 }
 656
 657 static void uci_close_stream(FILE *stream)
 658 {
 659         int fd;
 660
 661         if (!stream)
 662                 return;
 663
 664         fd = fileno(stream);
 665         flock(fd, LOCK_UN);
 666         fclose(stream);
 667 }
 668
 669 static void uci_parse_history_line(struct uci_context *ctx, struct uci_package *p, char *buf)
 670 {
 671         bool delete = false;
 672         bool rename = false;
 673         char *package = NULL;
 674         char *section = NULL;
 675         char *option = NULL;
 676         char *value = NULL;
 677
 678         if (buf[0] == '-') {
 679                 delete = true;
 680                 buf++;
 681         } else if (buf[0] == '@') {
 682                 rename = true;
 683                 buf++;
 684         }
 685
 686         UCI_INTERNAL(uci_parse_tuple, ctx, buf, &package, &section, &option, &value);
 687         if (!package || (strcmp(package, p->e.name) != 0))
 688                 goto error;
 689         if (!uci_validate_name(section))
 690                 goto error;
 691         if (option && !uci_validate_name(option))
 692                 goto error;
 693         if ((rename || !delete) && !uci_validate_name(value))
 694                 goto error;
 695
 696         if (rename)
 697                 UCI_INTERNAL(uci_rename, ctx, p, section, option, value);
 698         else if (delete)
 699                 UCI_INTERNAL(uci_delete, ctx, p, section, option);
 700         else
 701                 UCI_INTERNAL(uci_set, ctx, p, section, option, value);
 702
 703         return;
 704 error:
 705         UCI_THROW(ctx, UCI_ERR_PARSE);
 706 }
 707
 708 static void uci_parse_history(struct uci_context *ctx, FILE *stream, struct uci_package *p)
 709 {
 710         struct uci_parse_context *pctx;
 711
 712         /* make sure no memory from previous parse attempts is leaked */
 713         uci_file_cleanup(ctx);
 714
 715         pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
 716         ctx->pctx = pctx;
 717         pctx->file = stream;
 718
 719         while (!feof(pctx->file)) {
 720                 uci_getln(ctx, 0);
 721                 if (!pctx->buf[0])
 722                         continue;
 723
 724                 /*
 725                  * ignore parse errors in single lines, we want to preserve as much
 726                  * history as possible
 727                  */
 728                 UCI_TRAP_SAVE(ctx, error);
 729                 uci_parse_history_line(ctx, p, pctx->buf);
 730                 UCI_TRAP_RESTORE(ctx);
 731 error:
 732                 continue;
 733         }
 734
 735         /* no error happened, we can get rid of the parser context now */
 736         uci_file_cleanup(ctx);
 737 }
 738
 739 static void uci_load_history(struct uci_context *ctx, struct uci_package *p, bool flush)
 740 {
 741         char *filename = NULL;
 742         FILE *f = NULL;
 743
 744         if (!p->confdir)
 745                 return;
 746
 747         if ((asprintf(&filename, "%s/%s", UCI_SAVEDIR, p->e.name) < 0) || !filename)
 748                 UCI_THROW(ctx, UCI_ERR_MEM);
 749
 750         UCI_TRAP_SAVE(ctx, done);
 751         f = uci_open_stream(ctx, filename, SEEK_SET, flush, false);
 752         if (p)
 753                 uci_parse_history(ctx, f, p);
 754         UCI_TRAP_RESTORE(ctx);
 755
 756 done:
 757         if (flush && f) {
 758                 rewind(f);
 759                 ftruncate(fileno(f), 0);
 760         }
 761         if (filename)
 762                 free(filename);
 763         uci_close_stream(f);
 764         ctx->errno = 0;
 765 }
 766
 767
 768 static char *uci_config_path(struct uci_context *ctx, const char *name)
 769 {
 770         char *filename;
 771
 772         UCI_ASSERT(ctx, uci_validate_name(name));
 773         filename = uci_malloc(ctx, strlen(name) + sizeof(UCI_CONFDIR) + 2);
 774         sprintf(filename, UCI_CONFDIR "/%s", name);
 775
 776         return filename;
 777 }
 778
 779 int uci_load(struct uci_context *ctx, const char *name, struct uci_package **package)
 780 {
 781         char *filename;
 782         bool confdir;
 783         FILE *file = NULL;
 784
 785         UCI_HANDLE_ERR(ctx);
 786
 787         switch (name[0]) {
 788         case '.':
 789                 /* relative path outside of /etc/config */
 790                 if (name[1] != '/')
 791                         UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 792                 /* fall through */
 793         case '/':
 794                 /* absolute path outside of /etc/config */
 795                 filename = uci_strdup(ctx, name);
 796                 name = strrchr(name, '/') + 1;
 797                 confdir = false;
 798                 break;
 799         default:
 800                 /* config in /etc/config */
 801                 filename = uci_config_path(ctx, name);
 802                 confdir = true;
 803                 break;
 804         }
 805
 806         file = uci_open_stream(ctx, filename, SEEK_SET, false, false);
 807         ctx->errno = 0;
 808         UCI_TRAP_SAVE(ctx, done);
 809         UCI_INTERNAL(uci_import, ctx, file, name, package, true);
 810         UCI_TRAP_RESTORE(ctx);
 811
 812         if (*package) {
 813                 (*package)->path = filename;
 814                 (*package)->confdir = confdir;
 815                 uci_load_history(ctx, *package, false);
 816         }
 817
 818 done:
 819         uci_close_stream(file);
 820         return ctx->errno;
 821 }
 822
 823 int uci_save(struct uci_context *ctx, struct uci_package *p)
 824 {
 825         FILE *f = NULL;
 826         char *filename = NULL;
 827         struct uci_element *e, *tmp;
 828
 829         UCI_HANDLE_ERR(ctx);
 830         UCI_ASSERT(ctx, p != NULL);
 831
 832         /*
 833          * if the config file was outside of the /etc/config path,
 834          * don't save the history to a file, update the real file
 835          * directly.
 836          * does not modify the uci_package pointer
 837          */
 838         if (!p->confdir)
 839                 return uci_commit(ctx, &p, false);
 840
 841         if (uci_list_empty(&p->history))
 842                 return 0;
 843
 844         if ((asprintf(&filename, "%s/%s", UCI_SAVEDIR, p->e.name) < 0) || !filename)
 845                 UCI_THROW(ctx, UCI_ERR_MEM);
 846
 847         ctx->errno = 0;
 848         UCI_TRAP_SAVE(ctx, done);
 849         f = uci_open_stream(ctx, filename, SEEK_END, true, true);
 850         UCI_TRAP_RESTORE(ctx);
 851
 852         uci_foreach_element_safe(&p->history, tmp, e) {
 853                 struct uci_history *h = uci_to_history(e);
 854
 855                 if (h->cmd == UCI_CMD_REMOVE)
 856                         fprintf(f, "-");
 857                 else if (h->cmd == UCI_CMD_RENAME)
 858                         fprintf(f, "@");
 859
 860                 fprintf(f, "%s.%s", p->e.name, h->section);
 861                 if (e->name)
 862                         fprintf(f, ".%s", e->name);
 863
 864                 if (h->cmd == UCI_CMD_REMOVE)
 865                         fprintf(f, "\n");
 866                 else
 867                         fprintf(f, "=%s\n", h->value);
 868                 uci_free_history(h);
 869         }
 870
 871 done:
 872         uci_close_stream(f);
 873         if (filename)
 874                 free(filename);
 875         if (ctx->errno)
 876                 UCI_THROW(ctx, ctx->errno);
 877
 878         return 0;
 879 }
 880
 881 int uci_commit(struct uci_context *ctx, struct uci_package **package, bool overwrite)
 882 {
 883         struct uci_package *p;
 884         FILE *f = NULL;
 885         char *name = NULL;
 886         char *path = NULL;
 887
 888         UCI_HANDLE_ERR(ctx);
 889         UCI_ASSERT(ctx, package != NULL);
 890         p = *package;
 891
 892         UCI_ASSERT(ctx, p != NULL);
 893         if (!p->path) {
 894                 if (overwrite)
 895                         p->path = uci_config_path(ctx, p->e.name);
 896                 else
 897                         UCI_THROW(ctx, UCI_ERR_INVAL);
 898         }
 899
 900
 901         /* open the config file for writing now, so that it is locked */
 902         f = uci_open_stream(ctx, p->path, SEEK_SET, true, true);
 903
 904         /* flush unsaved changes and reload from history file */
 905         UCI_TRAP_SAVE(ctx, done);
 906         if (p->confdir) {
 907                 if (!overwrite) {
 908                         name = uci_strdup(ctx, p->e.name);
 909                         path = uci_strdup(ctx, p->path);
 910                         /* dump our own changes to the history file */
 911                         if (!uci_list_empty(&p->history))
 912                                 UCI_INTERNAL(uci_save, ctx, p);
 913
 914                         /*
 915                          * other processes might have modified the config
 916                          * as well. dump and reload
 917                          */
 918                         uci_free_package(&p);
 919                         uci_file_cleanup(ctx);
 920                         UCI_INTERNAL(uci_import, ctx, f, name, &p, true);
 921
 922                         p->path = path;
 923                         p->confdir = true;
 924                         *package = p;
 925
 926                         /* freed together with the uci_package */
 927                         path = NULL;
 928
 929                         /* check for updated history, just in case */
 930                         uci_load_history(ctx, p, true);
 931                 } else {
 932                         /* flush history */
 933                         uci_load_history(ctx, NULL, true);
 934                 }
 935         }
 936
 937         rewind(f);
 938         ftruncate(fileno(f), 0);
 939
 940         uci_export(ctx, f, p, false);
 941         UCI_TRAP_RESTORE(ctx);
 942
 943 done:
 944         if (name)
 945                 free(name);
 946         if (path)
 947                 free(path);
 948         uci_close_stream(f);
 949         if (ctx->errno)
 950                 UCI_THROW(ctx, ctx->errno);
 951
 952         return 0;
 953 }
 954
 955
 956 /*
 957  * This function returns the filename by returning the string
 958  * after the last '/' character. By checking for a non-'\0'
 959  * character afterwards, directories are ignored (glob marks
 960  * those with a trailing '/'
 961  */
 962 static inline char *get_filename(char *path)
 963 {
 964         char *p;
 965
 966         p = strrchr(path, '/');
 967         p++;
 968         if (!*p)
 969                 return NULL;
 970         return p;
 971 }
 972
 973 int uci_list_configs(struct uci_context *ctx, char ***list)
 974 {
 975         char **configs;
 976         glob_t globbuf;
 977         int size, i;
 978         char *buf;
 979
 980         UCI_HANDLE_ERR(ctx);
 981
 982         if (glob(UCI_CONFDIR "/*", GLOB_MARK, NULL, &globbuf) != 0)
 983                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 984
 985         size = sizeof(char *) * (globbuf.gl_pathc + 1);
 986         for(i = 0; i < globbuf.gl_pathc; i++) {
 987                 char *p;
 988
 989                 p = get_filename(globbuf.gl_pathv[i]);
 990                 if (!p)
 991                         continue;
 992
 993                 size += strlen(p) + 1;
 994         }
 995
 996         configs = uci_malloc(ctx, size);
 997         buf = (char *) &configs[globbuf.gl_pathc + 1];
 998         for(i = 0; i < globbuf.gl_pathc; i++) {
 999                 char *p;
1000
1001                 p = get_filename(globbuf.gl_pathv[i]);
1002                 if (!p)
1003                         continue;
1004
1005                 configs[i] = buf;
1006                 strcpy(buf, p);
1007                 buf += strlen(buf) + 1;
1008         }
1009         *list = configs;
1010
1011         return 0;
1012 }
1013