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 '#':
 214                         **str = 0;
 215                         /* fall through */
 216                 case 0:
 217                         goto done;
 218                 case '\\':
 219                         if (!parse_backslash(ctx, str))
 220                                 continue;
 221                         /* fall through */
 222                 default:
 223                         addc(target, str);
 224                         break;
 225                 }
 226         } while (**str && !isspace(**str));
 227 done:
 228
 229         /*
 230          * if the string was unquoted and we've stopped at a whitespace
 231          * character, skip to the next one, because the whitespace will
 232          * be overwritten by a null byte here
 233          */
 234         if (**str)
 235                 *str += 1;
 236
 237         /* terminate the parsed string */
 238         **target = 0;
 239 }
 240
 241 /*
 242  * extract the next argument from the command line
 243  */
 244 static char *next_arg(struct uci_context *ctx, char **str, bool required, bool name)
 245 {
 246         char *val;
 247         char *ptr;
 248
 249         val = ptr = *str;
 250         skip_whitespace(ctx, str);
 251         parse_str(ctx, str, &ptr);
 252         if (!*val) {
 253                 if (required)
 254                         uci_parse_error(ctx, *str, "insufficient arguments");
 255                 goto done;
 256         }
 257
 258         if (name && !uci_validate_name(val))
 259                 uci_parse_error(ctx, val, "invalid character in field");
 260
 261 done:
 262         return val;
 263 }
 264
 265 /*
 266  * verify that the end of the line or command is reached.
 267  * throw an error if extra arguments are given on the command line
 268  */
 269 static void assert_eol(struct uci_context *ctx, char **str)
 270 {
 271         char *tmp;
 272
 273         tmp = next_arg(ctx, str, false, false);
 274         if (tmp && *tmp && (ctx->flags & UCI_FLAG_STRICT))
 275                 uci_parse_error(ctx, *str, "too many arguments");
 276 }
 277
 278 /*
 279  * switch to a different config, either triggered by uci_load, or by a
 280  * 'package <...>' statement in the import file
 281  */
 282 static void uci_switch_config(struct uci_context *ctx)
 283 {
 284         struct uci_parse_context *pctx;
 285         struct uci_element *e;
 286         const char *name;
 287
 288         pctx = ctx->pctx;
 289         name = pctx->name;
 290
 291         /* add the last config to main config file list */
 292         if (pctx->package) {
 293                 uci_list_add(&ctx->root, &pctx->package->e.list);
 294
 295                 pctx->package = NULL;
 296                 pctx->section = NULL;
 297         }
 298
 299         if (!name)
 300                 return;
 301
 302         /*
 303          * if an older config under the same name exists, unload it
 304          * ignore errors here, e.g. if the config was not found
 305          */
 306         e = uci_lookup_list(ctx, &ctx->root, name);
 307         if (e)
 308                 UCI_THROW(ctx, UCI_ERR_DUPLICATE);
 309         pctx->package = uci_alloc_package(ctx, name);
 310 }
 311
 312 /*
 313  * parse the 'package' uci command (next config package)
 314  */
 315 static void uci_parse_package(struct uci_context *ctx, char **str, bool single)
 316 {
 317         char *name = NULL;
 318
 319         /* command string null-terminated by strtok */
 320         *str += strlen(*str) + 1;
 321
 322         name = next_arg(ctx, str, true, true);
 323         assert_eol(ctx, str);
 324         if (single)
 325                 return;
 326
 327         ctx->pctx->name = name;
 328         uci_switch_config(ctx);
 329 }
 330
 331 /* Based on an efficient hash function published by D. J. Bernstein */
 332 static unsigned int djbhash(unsigned int hash, char *str)
 333 {
 334         int len = strlen(str);
 335         int i;
 336
 337         /* initial value */
 338         if (hash == ~0)
 339                 hash = 5381;
 340
 341         for(i = 0; i < len; i++) {
 342                 hash = ((hash << 5) + hash) + str[i];
 343         }
 344         return (hash & 0x7FFFFFFF);
 345 }
 346
 347 /* fix up an unnamed section */
 348 static void uci_fixup_section(struct uci_context *ctx, struct uci_section *s)
 349 {
 350         unsigned int hash = ~0;
 351         struct uci_element *e;
 352         char buf[16];
 353
 354         if (!s || s->e.name)
 355                 return;
 356
 357         /*
 358          * Generate a name for unnamed sections. This is used as reference
 359          * when locating or updating the section from apps/scripts.
 360          * To make multiple concurrent versions somewhat safe for updating,
 361          * the name is generated from a hash of its type and name/value
 362          * pairs of its option, and it is prefixed by a counter value.
 363          * If the order of the unnamed sections changes for some reason,
 364          * updates to them will be rejected.
 365          */
 366         hash = djbhash(hash, s->type);
 367         uci_foreach_element(&s->options, e) {
 368                 hash = djbhash(hash, e->name);
 369                 hash = djbhash(hash, uci_to_option(e)->value);
 370         }
 371         sprintf(buf, "cfg%02x%04x", ++s->package->n_section, hash % (1 << 16));
 372         s->e.name = uci_strdup(ctx, buf);
 373 }
 374
 375 /*
 376  * parse the 'config' uci command (open a section)
 377  */
 378 static void uci_parse_config(struct uci_context *ctx, char **str)
 379 {
 380         struct uci_parse_context *pctx = ctx->pctx;
 381         char *name = NULL;
 382         char *type = NULL;
 383
 384         uci_fixup_section(ctx, ctx->pctx->section);
 385         if (!ctx->pctx->package) {
 386                 if (!ctx->pctx->name)
 387                         uci_parse_error(ctx, *str, "attempting to import a file without a package name");
 388
 389                 uci_switch_config(ctx);
 390         }
 391
 392         /* command string null-terminated by strtok */
 393         *str += strlen(*str) + 1;
 394
 395         type = next_arg(ctx, str, true, true);
 396         name = next_arg(ctx, str, false, true);
 397         assert_eol(ctx, str);
 398
 399         if (pctx->merge) {
 400                 UCI_TRAP_SAVE(ctx, error);
 401                 uci_set(ctx, pctx->package, name, NULL, type);
 402                 UCI_TRAP_RESTORE(ctx);
 403                 return;
 404 error:
 405                 UCI_THROW(ctx, ctx->errno);
 406         } else
 407                 pctx->section = uci_alloc_section(pctx->package, type, name);
 408 }
 409
 410 /*
 411  * parse the 'option' uci command (open a value)
 412  */
 413 static void uci_parse_option(struct uci_context *ctx, char **str)
 414 {
 415         struct uci_parse_context *pctx = ctx->pctx;
 416         char *name = NULL;
 417         char *value = NULL;
 418
 419         if (!pctx->section)
 420                 uci_parse_error(ctx, *str, "option command found before the first section");
 421
 422         /* command string null-terminated by strtok */
 423         *str += strlen(*str) + 1;
 424
 425         name = next_arg(ctx, str, true, true);
 426         value = next_arg(ctx, str, true, false);
 427         assert_eol(ctx, str);
 428
 429         if (pctx->merge) {
 430                 UCI_TRAP_SAVE(ctx, error);
 431                 uci_set(ctx, pctx->package, pctx->section->e.name, name, value);
 432                 UCI_TRAP_RESTORE(ctx);
 433                 return;
 434 error:
 435                 UCI_THROW(ctx, ctx->errno);
 436         } else
 437                 uci_alloc_option(pctx->section, name, value);
 438 }
 439
 440
 441 /*
 442  * parse a complete input line, split up combined commands by ';'
 443  */
 444 static void uci_parse_line(struct uci_context *ctx, bool single)
 445 {
 446         struct uci_parse_context *pctx = ctx->pctx;
 447         char *word, *brk = NULL;
 448
 449         for (word = strtok_r(pctx->buf, ";", &brk);
 450                  word;
 451                  word = strtok_r(NULL, ";", &brk)) {
 452
 453                 char *pbrk = NULL;
 454                 word = strtok_r(word, " \t", &pbrk);
 455
 456                 switch(word[0]) {
 457                         case '#':
 458                                 return;
 459                         case 'p':
 460                                 if ((word[1] == 0) || !strcmp(word + 1, "ackage"))
 461                                         uci_parse_package(ctx, &word, single);
 462                                 break;
 463                         case 'c':
 464                                 if ((word[1] == 0) || !strcmp(word + 1, "onfig"))
 465                                         uci_parse_config(ctx, &word);
 466                                 break;
 467                         case 'o':
 468                                 if ((word[1] == 0) || !strcmp(word + 1, "ption"))
 469                                         uci_parse_option(ctx, &word);
 470                                 break;
 471                         default:
 472                                 uci_parse_error(ctx, word, "unterminated command");
 473                                 break;
 474                 }
 475         }
 476 }
 477
 478 /* max number of characters that escaping adds to the string */
 479 #define UCI_QUOTE_ESCAPE        "'\\''"
 480
 481 /*
 482  * escape an uci string for export
 483  */
 484 static char *uci_escape(struct uci_context *ctx, char *str)
 485 {
 486         char *s, *p;
 487         int pos = 0;
 488
 489         if (!ctx->buf) {
 490                 ctx->bufsz = LINEBUF;
 491                 ctx->buf = malloc(LINEBUF);
 492         }
 493
 494         s = str;
 495         p = strchr(str, '\'');
 496         if (!p)
 497                 return str;
 498
 499         do {
 500                 int len = p - s;
 501                 if (len > 0) {
 502                         if (p + sizeof(UCI_QUOTE_ESCAPE) - str >= ctx->bufsz) {
 503                                 ctx->bufsz *= 2;
 504                                 ctx->buf = realloc(ctx->buf, ctx->bufsz);
 505                                 if (!ctx->buf)
 506                                         UCI_THROW(ctx, UCI_ERR_MEM);
 507                         }
 508                         memcpy(&ctx->buf[pos], s, len);
 509                         pos += len;
 510                 }
 511                 strcpy(&ctx->buf[pos], UCI_QUOTE_ESCAPE);
 512                 pos += sizeof(UCI_QUOTE_ESCAPE);
 513                 s = p + 1;
 514         } while ((p = strchr(s, '\'')));
 515
 516         return ctx->buf;
 517 }
 518
 519
 520 /*
 521  * export a single config package to a file stream
 522  */
 523 static void uci_export_package(struct uci_package *p, FILE *stream, bool header)
 524 {
 525         struct uci_context *ctx = p->ctx;
 526         struct uci_element *s, *o;
 527
 528         if (header)
 529                 fprintf(stream, "package '%s'\n", uci_escape(ctx, p->e.name));
 530         uci_foreach_element(&p->sections, s) {
 531                 struct uci_section *sec = uci_to_section(s);
 532                 fprintf(stream, "\nconfig '%s'", uci_escape(ctx, sec->type));
 533                 if (!sec->anonymous || (ctx->flags & UCI_FLAG_EXPORT_NAME))
 534                         fprintf(stream, " '%s'", uci_escape(ctx, sec->e.name));
 535                 fprintf(stream, "\n");
 536                 uci_foreach_element(&sec->options, o) {
 537                         struct uci_option *opt = uci_to_option(o);
 538                         fprintf(stream, "\toption '%s'", uci_escape(ctx, opt->e.name));
 539                         fprintf(stream, " '%s'\n", uci_escape(ctx, opt->value));
 540                 }
 541         }
 542         fprintf(stream, "\n");
 543 }
 544
 545 int uci_export(struct uci_context *ctx, FILE *stream, struct uci_package *package, bool header)
 546 {
 547         struct uci_element *e;
 548
 549         UCI_HANDLE_ERR(ctx);
 550         UCI_ASSERT(ctx, stream != NULL);
 551
 552         if (package)
 553                 uci_export_package(package, stream, header);
 554         else {
 555                 uci_foreach_element(&ctx->root, e) {
 556                         uci_export_package(uci_to_package(e), stream, header);
 557                 }
 558         }
 559
 560         return 0;
 561 }
 562
 563 int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_package **package, bool single)
 564 {
 565         struct uci_parse_context *pctx;
 566         UCI_HANDLE_ERR(ctx);
 567
 568         /* make sure no memory from previous parse attempts is leaked */
 569         uci_file_cleanup(ctx);
 570
 571         pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
 572         ctx->pctx = pctx;
 573         pctx->file = stream;
 574         if (*package && single) {
 575                 pctx->package = *package;
 576                 pctx->merge = true;
 577         }
 578
 579         /*
 580          * If 'name' was supplied, assume that the supplied stream does not contain
 581          * the appropriate 'package <name>' string to specify the config name
 582          * NB: the config file can still override the package name
 583          */
 584         if (name) {
 585                 UCI_ASSERT(ctx, uci_validate_name(name));
 586                 pctx->name = name;
 587         }
 588
 589         while (!feof(pctx->file)) {
 590                 uci_getln(ctx, 0);
 591                 UCI_TRAP_SAVE(ctx, error);
 592                 if (pctx->buf[0])
 593                         uci_parse_line(ctx, single);
 594                 UCI_TRAP_RESTORE(ctx);
 595                 continue;
 596 error:
 597                 if (ctx->flags & UCI_FLAG_PERROR)
 598                         uci_perror(ctx, NULL);
 599                 if ((ctx->errno != UCI_ERR_PARSE) ||
 600                         (ctx->flags & UCI_FLAG_STRICT))
 601                         UCI_THROW(ctx, ctx->errno);
 602         }
 603
 604         uci_fixup_section(ctx, ctx->pctx->section);
 605         if (package)
 606                 *package = pctx->package;
 607         if (pctx->merge)
 608                 pctx->package = NULL;
 609
 610         pctx->name = NULL;
 611         uci_switch_config(ctx);
 612
 613         /* no error happened, we can get rid of the parser context now */
 614         uci_file_cleanup(ctx);
 615
 616         return 0;
 617 }
 618
 619 /*
 620  * open a stream and go to the right position
 621  *
 622  * note: when opening for write and seeking to the beginning of
 623  * the stream, truncate the file
 624  */
 625 static FILE *uci_open_stream(struct uci_context *ctx, const char *filename, int pos, bool write, bool create)
 626 {
 627         struct stat statbuf;
 628         FILE *file = NULL;
 629         int fd, ret;
 630         int mode = (write ? O_RDWR : O_RDONLY);
 631
 632         if (create)
 633                 mode |= O_CREAT;
 634
 635         if (!write && ((stat(filename, &statbuf) < 0) ||
 636                 ((statbuf.st_mode &  S_IFMT) != S_IFREG))) {
 637                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 638         }
 639
 640         fd = open(filename, mode, UCI_FILEMODE);
 641         if (fd <= 0)
 642                 goto error;
 643
 644         if (flock(fd, (write ? LOCK_EX : LOCK_SH)) < 0)
 645                 goto error;
 646
 647         ret = lseek(fd, 0, pos);
 648
 649         if (ret < 0)
 650                 goto error;
 651
 652         file = fdopen(fd, (write ? "w+" : "r"));
 653         if (file)
 654                 goto done;
 655
 656 error:
 657         UCI_THROW(ctx, UCI_ERR_IO);
 658 done:
 659         return file;
 660 }
 661
 662 static void uci_close_stream(FILE *stream)
 663 {
 664         int fd;
 665
 666         if (!stream)
 667                 return;
 668
 669         fd = fileno(stream);
 670         flock(fd, LOCK_UN);
 671         fclose(stream);
 672 }
 673
 674 static void uci_parse_history_line(struct uci_context *ctx, struct uci_package *p, char *buf)
 675 {
 676         bool delete = false;
 677         bool rename = false;
 678         char *package = NULL;
 679         char *section = NULL;
 680         char *option = NULL;
 681         char *value = NULL;
 682
 683         if (buf[0] == '-') {
 684                 delete = true;
 685                 buf++;
 686         } else if (buf[0] == '@') {
 687                 rename = true;
 688                 buf++;
 689         }
 690
 691         UCI_INTERNAL(uci_parse_tuple, ctx, buf, &package, &section, &option, &value);
 692         if (!package || (strcmp(package, p->e.name) != 0))
 693                 goto error;
 694         if (!uci_validate_name(section))
 695                 goto error;
 696         if (option && !uci_validate_name(option))
 697                 goto error;
 698         if ((rename || !delete) && !uci_validate_name(value))
 699                 goto error;
 700
 701         if (rename)
 702                 UCI_INTERNAL(uci_rename, ctx, p, section, option, value);
 703         else if (delete)
 704                 UCI_INTERNAL(uci_delete, ctx, p, section, option);
 705         else
 706                 UCI_INTERNAL(uci_set, ctx, p, section, option, value);
 707
 708         return;
 709 error:
 710         UCI_THROW(ctx, UCI_ERR_PARSE);
 711 }
 712
 713 static void uci_parse_history(struct uci_context *ctx, FILE *stream, struct uci_package *p)
 714 {
 715         struct uci_parse_context *pctx;
 716
 717         /* make sure no memory from previous parse attempts is leaked */
 718         uci_file_cleanup(ctx);
 719
 720         pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
 721         ctx->pctx = pctx;
 722         pctx->file = stream;
 723
 724         while (!feof(pctx->file)) {
 725                 uci_getln(ctx, 0);
 726                 if (!pctx->buf[0])
 727                         continue;
 728
 729                 /*
 730                  * ignore parse errors in single lines, we want to preserve as much
 731                  * history as possible
 732                  */
 733                 UCI_TRAP_SAVE(ctx, error);
 734                 uci_parse_history_line(ctx, p, pctx->buf);
 735                 UCI_TRAP_RESTORE(ctx);
 736 error:
 737                 continue;
 738         }
 739
 740         /* no error happened, we can get rid of the parser context now */
 741         uci_file_cleanup(ctx);
 742 }
 743
 744 static void uci_load_history(struct uci_context *ctx, struct uci_package *p, bool flush)
 745 {
 746         char *filename = NULL;
 747         FILE *f = NULL;
 748
 749         if (!p->confdir)
 750                 return;
 751
 752         if ((asprintf(&filename, "%s/%s", UCI_SAVEDIR, p->e.name) < 0) || !filename)
 753                 UCI_THROW(ctx, UCI_ERR_MEM);
 754
 755         UCI_TRAP_SAVE(ctx, done);
 756         f = uci_open_stream(ctx, filename, SEEK_SET, flush, false);
 757         if (p)
 758                 uci_parse_history(ctx, f, p);
 759         UCI_TRAP_RESTORE(ctx);
 760
 761 done:
 762         if (flush && f) {
 763                 rewind(f);
 764                 ftruncate(fileno(f), 0);
 765         }
 766         if (filename)
 767                 free(filename);
 768         uci_close_stream(f);
 769         ctx->errno = 0;
 770 }
 771
 772
 773 static char *uci_config_path(struct uci_context *ctx, const char *name)
 774 {
 775         char *filename;
 776
 777         UCI_ASSERT(ctx, uci_validate_name(name));
 778         filename = uci_malloc(ctx, strlen(name) + sizeof(UCI_CONFDIR) + 2);
 779         sprintf(filename, UCI_CONFDIR "/%s", name);
 780
 781         return filename;
 782 }
 783
 784 int uci_load(struct uci_context *ctx, const char *name, struct uci_package **package)
 785 {
 786         char *filename;
 787         bool confdir;
 788         FILE *file = NULL;
 789
 790         UCI_HANDLE_ERR(ctx);
 791
 792         switch (name[0]) {
 793         case '.':
 794                 /* relative path outside of /etc/config */
 795                 if (name[1] != '/')
 796                         UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 797                 /* fall through */
 798         case '/':
 799                 /* absolute path outside of /etc/config */
 800                 filename = uci_strdup(ctx, name);
 801                 name = strrchr(name, '/') + 1;
 802                 confdir = false;
 803                 break;
 804         default:
 805                 /* config in /etc/config */
 806                 filename = uci_config_path(ctx, name);
 807                 confdir = true;
 808                 break;
 809         }
 810
 811         file = uci_open_stream(ctx, filename, SEEK_SET, false, false);
 812         ctx->errno = 0;
 813         UCI_TRAP_SAVE(ctx, done);
 814         UCI_INTERNAL(uci_import, ctx, file, name, package, true);
 815         UCI_TRAP_RESTORE(ctx);
 816
 817         if (*package) {
 818                 (*package)->path = filename;
 819                 (*package)->confdir = confdir;
 820                 uci_load_history(ctx, *package, false);
 821         }
 822
 823 done:
 824         uci_close_stream(file);
 825         return ctx->errno;
 826 }
 827
 828 int uci_save(struct uci_context *ctx, struct uci_package *p)
 829 {
 830         FILE *f = NULL;
 831         char *filename = NULL;
 832         struct uci_element *e, *tmp;
 833
 834         UCI_HANDLE_ERR(ctx);
 835         UCI_ASSERT(ctx, p != NULL);
 836
 837         /*
 838          * if the config file was outside of the /etc/config path,
 839          * don't save the history to a file, update the real file
 840          * directly.
 841          * does not modify the uci_package pointer
 842          */
 843         if (!p->confdir)
 844                 return uci_commit(ctx, &p, false);
 845
 846         if (uci_list_empty(&p->history))
 847                 return 0;
 848
 849         if ((asprintf(&filename, "%s/%s", UCI_SAVEDIR, p->e.name) < 0) || !filename)
 850                 UCI_THROW(ctx, UCI_ERR_MEM);
 851
 852         ctx->errno = 0;
 853         UCI_TRAP_SAVE(ctx, done);
 854         f = uci_open_stream(ctx, filename, SEEK_END, true, true);
 855         UCI_TRAP_RESTORE(ctx);
 856
 857         uci_foreach_element_safe(&p->history, tmp, e) {
 858                 struct uci_history *h = uci_to_history(e);
 859
 860                 if (h->cmd == UCI_CMD_REMOVE)
 861                         fprintf(f, "-");
 862                 else if (h->cmd == UCI_CMD_RENAME)
 863                         fprintf(f, "@");
 864
 865                 fprintf(f, "%s.%s", p->e.name, h->section);
 866                 if (e->name)
 867                         fprintf(f, ".%s", e->name);
 868
 869                 if (h->cmd == UCI_CMD_REMOVE)
 870                         fprintf(f, "\n");
 871                 else
 872                         fprintf(f, "=%s\n", h->value);
 873                 uci_free_history(h);
 874         }
 875
 876 done:
 877         uci_close_stream(f);
 878         if (filename)
 879                 free(filename);
 880         if (ctx->errno)
 881                 UCI_THROW(ctx, ctx->errno);
 882
 883         return 0;
 884 }
 885
 886 int uci_commit(struct uci_context *ctx, struct uci_package **package, bool overwrite)
 887 {
 888         struct uci_package *p;
 889         FILE *f = NULL;
 890         char *name = NULL;
 891         char *path = NULL;
 892
 893         UCI_HANDLE_ERR(ctx);
 894         UCI_ASSERT(ctx, package != NULL);
 895         p = *package;
 896
 897         UCI_ASSERT(ctx, p != NULL);
 898         if (!p->path) {
 899                 if (overwrite)
 900                         p->path = uci_config_path(ctx, p->e.name);
 901                 else
 902                         UCI_THROW(ctx, UCI_ERR_INVAL);
 903         }
 904
 905
 906         /* open the config file for writing now, so that it is locked */
 907         f = uci_open_stream(ctx, p->path, SEEK_SET, true, true);
 908
 909         /* flush unsaved changes and reload from history file */
 910         UCI_TRAP_SAVE(ctx, done);
 911         if (p->confdir) {
 912                 if (!overwrite) {
 913                         name = uci_strdup(ctx, p->e.name);
 914                         path = uci_strdup(ctx, p->path);
 915                         /* dump our own changes to the history file */
 916                         if (!uci_list_empty(&p->history))
 917                                 UCI_INTERNAL(uci_save, ctx, p);
 918
 919                         /*
 920                          * other processes might have modified the config
 921                          * as well. dump and reload
 922                          */
 923                         uci_free_package(&p);
 924                         uci_file_cleanup(ctx);
 925                         UCI_INTERNAL(uci_import, ctx, f, name, &p, true);
 926
 927                         p->path = path;
 928                         p->confdir = true;
 929                         *package = p;
 930
 931                         /* freed together with the uci_package */
 932                         path = NULL;
 933
 934                         /* check for updated history, just in case */
 935                         uci_load_history(ctx, p, true);
 936                 } else {
 937                         /* flush history */
 938                         uci_load_history(ctx, NULL, true);
 939                 }
 940         }
 941
 942         rewind(f);
 943         ftruncate(fileno(f), 0);
 944
 945         uci_export(ctx, f, p, false);
 946         UCI_TRAP_RESTORE(ctx);
 947
 948 done:
 949         if (name)
 950                 free(name);
 951         if (path)
 952                 free(path);
 953         uci_close_stream(f);
 954         if (ctx->errno)
 955                 UCI_THROW(ctx, ctx->errno);
 956
 957         return 0;
 958 }
 959
 960
 961 /*
 962  * This function returns the filename by returning the string
 963  * after the last '/' character. By checking for a non-'\0'
 964  * character afterwards, directories are ignored (glob marks
 965  * those with a trailing '/'
 966  */
 967 static inline char *get_filename(char *path)
 968 {
 969         char *p;
 970
 971         p = strrchr(path, '/');
 972         p++;
 973         if (!*p)
 974                 return NULL;
 975         return p;
 976 }
 977
 978 int uci_list_configs(struct uci_context *ctx, char ***list)
 979 {
 980         char **configs;
 981         glob_t globbuf;
 982         int size, i;
 983         char *buf;
 984
 985         UCI_HANDLE_ERR(ctx);
 986
 987         if (glob(UCI_CONFDIR "/*", GLOB_MARK, NULL, &globbuf) != 0)
 988                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 989
 990         size = sizeof(char *) * (globbuf.gl_pathc + 1);
 991         for(i = 0; i < globbuf.gl_pathc; i++) {
 992                 char *p;
 993
 994                 p = get_filename(globbuf.gl_pathv[i]);
 995                 if (!p)
 996                         continue;
 997
 998                 size += strlen(p) + 1;
 999         }
1000
1001         configs = uci_malloc(ctx, size);
1002         buf = (char *) &configs[globbuf.gl_pathc + 1];
1003         for(i = 0; i < globbuf.gl_pathc; i++) {
1004                 char *p;
1005
1006                 p = get_filename(globbuf.gl_pathv[i]);
1007                 if (!p)
1008                         continue;
1009
1010                 configs[i] = buf;
1011                 strcpy(buf, p);
1012                 buf += strlen(buf) + 1;
1013         }
1014         *list = configs;
1015
1016         return 0;
1017 }
1018