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 Lesser 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 #include <glob.h>
  29 #include <string.h>
  30 #include <stdlib.h>
  31 #include <errno.h>
  32
  33 #include "uci.h"
  34 #include "uci_internal.h"
  35
  36 #define LINEBUF 32
  37
  38 /*
  39  * Fetch a new line from the input stream and resize buffer if necessary
  40  */
  41 __private void uci_getln(struct uci_context *ctx, int offset)
  42 {
  43         struct uci_parse_context *pctx = ctx->pctx;
  44         char *p;
  45         int ofs;
  46
  47         if (pctx->buf == NULL) {
  48                 pctx->buf = uci_malloc(ctx, LINEBUF);
  49                 pctx->bufsz = LINEBUF;
  50         }
  51         /* It takes 2 slots for fgets to read 1 char. */
  52         if (offset >= pctx->bufsz - 1) {
  53                 pctx->bufsz *= 2;
  54                 pctx->buf = uci_realloc(ctx, pctx->buf, pctx->bufsz);
  55         }
  56
  57         ofs = offset;
  58         do {
  59                 p = &pctx->buf[ofs];
  60                 p[0] = 0;
  61
  62                 p = fgets(p, pctx->bufsz - ofs, pctx->file);
  63                 if (!p || !*p)
  64                         return;
  65
  66                 ofs += strlen(p);
  67                 if (pctx->buf[ofs - 1] == '\n') {
  68                         pctx->line++;
  69                         return;
  70                 }
  71
  72                 pctx->bufsz *= 2;
  73                 pctx->buf = uci_realloc(ctx, pctx->buf, pctx->bufsz);
  74         } while (1);
  75 }
  76
  77 /*
  78  * parse a character escaped by '\'
  79  * returns true if the escaped character is to be parsed
  80  * returns false if the escaped character is to be ignored
  81  */
  82 static bool parse_backslash(struct uci_context *ctx)
  83 {
  84         struct uci_parse_context *pctx = ctx->pctx;
  85
  86         /* skip backslash */
  87         pctx->pos += 1;
  88
  89         /* undecoded backslash at the end of line, fetch the next line */
  90         if (!pctx_cur_char(pctx) ||
  91             pctx_cur_char(pctx) == '\n' ||
  92             (pctx_cur_char(pctx) == '\r' &&
  93              pctx_char(pctx, pctx_pos(pctx) + 1) == '\n' &&
  94              !pctx_char(pctx, pctx_pos(pctx) + 2))) {
  95                 uci_getln(ctx, pctx->pos);
  96                 return false;
  97         }
  98
  99         /* FIXME: decode escaped char, necessary? */
 100         return true;
 101 }
 102
 103 /*
 104  * move the string pointer forward until a non-whitespace character or
 105  * EOL is reached
 106  */
 107 static void skip_whitespace(struct uci_context *ctx)
 108 {
 109         struct uci_parse_context *pctx = ctx->pctx;
 110
 111         while (pctx_cur_char(pctx) && isspace(pctx_cur_char(pctx)))
 112                 pctx->pos += 1;
 113 }
 114
 115 static inline void addc(struct uci_context *ctx, int *pos_dest, int *pos_src)
 116 {
 117         struct uci_parse_context *pctx = ctx->pctx;
 118
 119         pctx_char(pctx, *pos_dest) = pctx_char(pctx, *pos_src);
 120         *pos_dest += 1;
 121         *pos_src += 1;
 122 }
 123
 124 /*
 125  * parse a double quoted string argument from the command line
 126  */
 127 static void parse_double_quote(struct uci_context *ctx, int *target)
 128 {
 129         struct uci_parse_context *pctx = ctx->pctx;
 130         char c;
 131
 132         /* skip quote character */
 133         pctx->pos += 1;
 134
 135         while (1) {
 136                 c = pctx_cur_char(pctx);
 137                 switch(c) {
 138                 case '"':
 139                         pctx->pos += 1;
 140                         return;
 141                 case 0:
 142                         /* Multi-line str value */
 143                         uci_getln(ctx, pctx->pos);
 144                         if (!pctx_cur_char(pctx)) {
 145                                 uci_parse_error(ctx, "EOF with unterminated \"");
 146                         }
 147                         break;
 148                 case '\\':
 149                         if (!parse_backslash(ctx))
 150                                 continue;
 151                         /* fall through */
 152                 default:
 153                         addc(ctx, target, &pctx->pos);
 154                         break;
 155                 }
 156         }
 157 }
 158
 159 /*
 160  * parse a single quoted string argument from the command line
 161  */
 162 static void parse_single_quote(struct uci_context *ctx, int *target)
 163 {
 164         struct uci_parse_context *pctx = ctx->pctx;
 165         char c;
 166         /* skip quote character */
 167         pctx->pos += 1;
 168
 169         while (1) {
 170                 c = pctx_cur_char(pctx);
 171                 switch(c) {
 172                 case '\'':
 173                         pctx->pos += 1;
 174                         return;
 175                 case 0:
 176                         /* Multi-line str value */
 177                         uci_getln(ctx, pctx->pos);
 178                         if (!pctx_cur_char(pctx))
 179                                 uci_parse_error(ctx, "EOF with unterminated '");
 180
 181                         break;
 182                 default:
 183                         addc(ctx, target, &pctx->pos);
 184                 }
 185         }
 186 }
 187
 188 /*
 189  * parse a string from the command line and detect the quoting style
 190  */
 191 static void parse_str(struct uci_context *ctx, int *target)
 192 {
 193         struct uci_parse_context *pctx = ctx->pctx;
 194         bool next = true;
 195         do {
 196                 switch(pctx_cur_char(pctx)) {
 197                 case '\'':
 198                         parse_single_quote(ctx, target);
 199                         break;
 200                 case '"':
 201                         parse_double_quote(ctx, target);
 202                         break;
 203                 case '#':
 204                         pctx_cur_char(pctx) = 0;
 205                         /* fall through */
 206                 case 0:
 207                         goto done;
 208                 case ';':
 209                         next = false;
 210                         goto done;
 211                 case '\\':
 212                         if (!parse_backslash(ctx))
 213                                 continue;
 214                         /* fall through */
 215                 default:
 216                         addc(ctx, target, &pctx->pos);
 217                         break;
 218                 }
 219         } while (pctx_cur_char(pctx) && !isspace(pctx_cur_char(pctx)));
 220 done:
 221
 222         /*
 223          * if the string was unquoted and we've stopped at a whitespace
 224          * character, skip to the next one, because the whitespace will
 225          * be overwritten by a null byte here
 226          */
 227         if (pctx_cur_char(pctx) && next)
 228                 pctx->pos += 1;
 229
 230         /* terminate the parsed string */
 231         pctx_char(pctx, *target) = 0;
 232 }
 233
 234 /*
 235  * extract the next argument from the command line
 236  */
 237 static int next_arg(struct uci_context *ctx, bool required, bool name, bool package)
 238 {
 239         struct uci_parse_context *pctx = ctx->pctx;
 240         int val, ptr;
 241
 242         skip_whitespace(ctx);
 243         val = ptr = pctx_pos(pctx);
 244         if (pctx_cur_char(pctx) == ';') {
 245                 pctx_cur_char(pctx) = 0;
 246                 pctx->pos += 1;
 247         } else {
 248                 parse_str(ctx, &ptr);
 249         }
 250         if (!pctx_char(pctx, val)) {
 251                 if (required)
 252                         uci_parse_error(ctx, "insufficient arguments");
 253                 goto done;
 254         }
 255
 256         if (name && !uci_validate_str(pctx_str(pctx, val), name, package))
 257                 uci_parse_error(ctx, "invalid character in name field");
 258
 259 done:
 260         return val;
 261 }
 262
 263 int uci_parse_argument(struct uci_context *ctx, FILE *stream, char **str, char **result)
 264 {
 265         int ofs_result;
 266
 267         UCI_HANDLE_ERR(ctx);
 268         UCI_ASSERT(ctx, str != NULL);
 269         UCI_ASSERT(ctx, result != NULL);
 270
 271         if (ctx->pctx && (ctx->pctx->file != stream))
 272                 uci_cleanup(ctx);
 273
 274         if (!ctx->pctx)
 275                 uci_alloc_parse_context(ctx);
 276
 277         ctx->pctx->file = stream;
 278         if (!*str) {
 279                 ctx->pctx->pos = 0;
 280                 uci_getln(ctx, 0);
 281         }
 282
 283         ofs_result = next_arg(ctx, false, false, false);
 284         *result = pctx_str(ctx->pctx, ofs_result);
 285         *str = pctx_cur_str(ctx->pctx);
 286
 287         return 0;
 288 }
 289
 290 static int
 291 uci_fill_ptr(struct uci_context *ctx, struct uci_ptr *ptr, struct uci_element *e)
 292 {
 293         UCI_ASSERT(ctx, ptr != NULL);
 294         UCI_ASSERT(ctx, e != NULL);
 295
 296         memset(ptr, 0, sizeof(struct uci_ptr));
 297         switch(e->type) {
 298         case UCI_TYPE_OPTION:
 299                 ptr->o = uci_to_option(e);
 300                 goto fill_option;
 301         case UCI_TYPE_SECTION:
 302                 ptr->s = uci_to_section(e);
 303                 goto fill_section;
 304         case UCI_TYPE_PACKAGE:
 305                 ptr->p = uci_to_package(e);
 306                 goto fill_package;
 307         default:
 308                 UCI_THROW(ctx, UCI_ERR_INVAL);
 309         }
 310
 311 fill_option:
 312         ptr->option = ptr->o->e.name;
 313         ptr->s = ptr->o->section;
 314 fill_section:
 315         ptr->section = ptr->s->e.name;
 316         ptr->p = ptr->s->package;
 317 fill_package:
 318         ptr->package = ptr->p->e.name;
 319
 320         ptr->flags |= UCI_LOOKUP_DONE;
 321
 322         return 0;
 323 }
 324
 325
 326
 327 /*
 328  * verify that the end of the line or command is reached.
 329  * throw an error if extra arguments are given on the command line
 330  */
 331 static void assert_eol(struct uci_context *ctx)
 332 {
 333         char *tmp;
 334         int ofs_tmp;
 335
 336         skip_whitespace(ctx);
 337         ofs_tmp = next_arg(ctx, false, false, false);
 338         tmp = pctx_str(ctx->pctx, ofs_tmp);
 339         if (*tmp && (ctx->flags & UCI_FLAG_STRICT))
 340                 uci_parse_error(ctx, "too many arguments");
 341 }
 342
 343 /*
 344  * switch to a different config, either triggered by uci_load, or by a
 345  * 'package <...>' statement in the import file
 346  */
 347 static void uci_switch_config(struct uci_context *ctx)
 348 {
 349         struct uci_parse_context *pctx;
 350         struct uci_element *e;
 351         const char *name;
 352
 353         pctx = ctx->pctx;
 354         name = pctx->name;
 355
 356         /* add the last config to main config file list */
 357         if (pctx->package) {
 358                 pctx->package->backend = ctx->backend;
 359                 uci_list_add(&ctx->root, &pctx->package->e.list);
 360
 361                 pctx->package = NULL;
 362                 pctx->section = NULL;
 363         }
 364
 365         if (!name)
 366                 return;
 367
 368         /*
 369          * if an older config under the same name exists, unload it
 370          * ignore errors here, e.g. if the config was not found
 371          */
 372         e = uci_lookup_list(&ctx->root, name);
 373         if (e)
 374                 UCI_THROW(ctx, UCI_ERR_DUPLICATE);
 375         pctx->package = uci_alloc_package(ctx, name);
 376 }
 377
 378 /*
 379  * parse the 'package' uci command (next config package)
 380  */
 381 static void uci_parse_package(struct uci_context *ctx, bool single)
 382 {
 383         struct uci_parse_context *pctx = ctx->pctx;
 384         int ofs_name;
 385         char *name;
 386
 387         /* command string null-terminated by strtok */
 388         pctx->pos += strlen(pctx_cur_str(pctx)) + 1;
 389
 390         ofs_name = next_arg(ctx, true, true, true);
 391         name = pctx_str(pctx, ofs_name);
 392         assert_eol(ctx);
 393         if (single)
 394                 return;
 395
 396         ctx->pctx->name = name;
 397         uci_switch_config(ctx);
 398 }
 399
 400 /*
 401  * parse the 'config' uci command (open a section)
 402  */
 403 static void uci_parse_config(struct uci_context *ctx)
 404 {
 405         struct uci_parse_context *pctx = ctx->pctx;
 406         struct uci_element *e;
 407         struct uci_ptr ptr;
 408         int ofs_name, ofs_type;
 409         char *name;
 410         char *type;
 411
 412         if (!ctx->pctx->package) {
 413                 if (!ctx->pctx->name)
 414                         uci_parse_error(ctx, "attempting to import a file without a package name");
 415
 416                 uci_switch_config(ctx);
 417         }
 418
 419         /* command string null-terminated by strtok */
 420         pctx->pos += strlen(pctx_cur_str(pctx)) + 1;
 421
 422         ofs_type = next_arg(ctx, true, false, false);
 423         type = pctx_str(pctx, ofs_type);
 424         if (!uci_validate_type(type))
 425                 uci_parse_error(ctx, "invalid character in type field");
 426
 427         ofs_name = next_arg(ctx, false, true, false);
 428         assert_eol(ctx);
 429         type = pctx_str(pctx, ofs_type);
 430         name = pctx_str(pctx, ofs_name);
 431
 432         if (!name || !name[0]) {
 433                 ctx->internal = !pctx->merge;
 434                 UCI_NESTED(uci_add_section, ctx, pctx->package, type, &pctx->section);
 435         } else {
 436                 uci_fill_ptr(ctx, &ptr, &pctx->package->e);
 437                 e = uci_lookup_list(&pctx->package->sections, name);
 438                 if (e) {
 439                         ptr.s = uci_to_section(e);
 440
 441                         if ((ctx->flags & UCI_FLAG_STRICT) && strcmp(ptr.s->type, type))
 442                                 uci_parse_error(ctx, "section of different type overwrites prior section with same name");
 443                 }
 444
 445                 ptr.section = name;
 446                 ptr.value = type;
 447
 448                 ctx->internal = !pctx->merge;
 449                 UCI_NESTED(uci_set, ctx, &ptr);
 450                 pctx->section = uci_to_section(ptr.last);
 451         }
 452 }
 453
 454 /*
 455  * parse the 'option' uci command (open a value)
 456  */
 457 static void uci_parse_option(struct uci_context *ctx, bool list)
 458 {
 459         struct uci_parse_context *pctx = ctx->pctx;
 460         struct uci_element *e;
 461         struct uci_ptr ptr;
 462         int ofs_name, ofs_value;
 463         char *name = NULL;
 464         char *value = NULL;
 465
 466         if (!pctx->section)
 467                 uci_parse_error(ctx, "option/list command found before the first section");
 468
 469         /* command string null-terminated by strtok */
 470         pctx->pos += strlen(pctx_cur_str(pctx)) + 1;
 471
 472         ofs_name = next_arg(ctx, true, true, false);
 473         ofs_value = next_arg(ctx, false, false, false);
 474         name = pctx_str(pctx, ofs_name);
 475         value = pctx_str(pctx, ofs_value);
 476         assert_eol(ctx);
 477
 478         uci_fill_ptr(ctx, &ptr, &pctx->section->e);
 479         e = uci_lookup_list(&pctx->section->options, name);
 480         if (e)
 481                 ptr.o = uci_to_option(e);
 482         ptr.option = name;
 483         ptr.value = value;
 484
 485         ctx->internal = !pctx->merge;
 486         if (list)
 487                 UCI_NESTED(uci_add_list, ctx, &ptr);
 488         else
 489                 UCI_NESTED(uci_set, ctx, &ptr);
 490 }
 491
 492 /*
 493  * parse a complete input line, split up combined commands by ';'
 494  */
 495 static void uci_parse_line(struct uci_context *ctx, bool single)
 496 {
 497         struct uci_parse_context *pctx = ctx->pctx;
 498         char *word;
 499
 500         /* Skip whitespace characters at the start of line */
 501         skip_whitespace(ctx);
 502         do {
 503                 word = strtok(pctx_cur_str(pctx), " \t");
 504                 if (!word)
 505                         return;
 506
 507                 switch(word[0]) {
 508                         case 0:
 509                         case '#':
 510                                 return;
 511                         case 'p':
 512                                 if ((word[1] == 0) || !strcmp(word + 1, "ackage"))
 513                                         uci_parse_package(ctx, single);
 514                                 else
 515                                         goto invalid;
 516                                 break;
 517                         case 'c':
 518                                 if ((word[1] == 0) || !strcmp(word + 1, "onfig"))
 519                                         uci_parse_config(ctx);
 520                                 else
 521                                         goto invalid;
 522                                 break;
 523                         case 'o':
 524                                 if ((word[1] == 0) || !strcmp(word + 1, "ption"))
 525                                         uci_parse_option(ctx, false);
 526                                 else
 527                                         goto invalid;
 528                                 break;
 529                         case 'l':
 530                                 if ((word[1] == 0) || !strcmp(word + 1, "ist"))
 531                                         uci_parse_option(ctx, true);
 532                                 else
 533                                         goto invalid;
 534                                 break;
 535                         default:
 536                                 goto invalid;
 537                 }
 538                 continue;
 539 invalid:
 540                 uci_parse_error(ctx, "invalid command");
 541         } while (1);
 542 }
 543
 544 /* max number of characters that escaping adds to the string */
 545 #define UCI_QUOTE_ESCAPE        "'\\''"
 546
 547 /*
 548  * escape an uci string for export
 549  */
 550 static const char *uci_escape(struct uci_context *ctx, const char *str)
 551 {
 552         const char *end;
 553         int ofs = 0;
 554
 555         if (!ctx->buf) {
 556                 ctx->bufsz = LINEBUF;
 557                 ctx->buf = malloc(LINEBUF);
 558
 559                 if (!ctx->buf)
 560                         return str;
 561         }
 562
 563         while (1) {
 564                 int len;
 565
 566                 end = strchr(str, '\'');
 567                 if (!end)
 568                         end = str + strlen(str);
 569                 len = end - str;
 570
 571                 /* make sure that we have enough room in the buffer */
 572                 while (ofs + len + (int) sizeof(UCI_QUOTE_ESCAPE) + 1 > ctx->bufsz) {
 573                         ctx->bufsz *= 2;
 574                         ctx->buf = uci_realloc(ctx, ctx->buf, ctx->bufsz);
 575                 }
 576
 577                 /* copy the string until the character before the quote */
 578                 memcpy(&ctx->buf[ofs], str, len);
 579                 ofs += len;
 580
 581                 /* end of string? return the buffer */
 582                 if (*end == 0)
 583                         break;
 584
 585                 memcpy(&ctx->buf[ofs], UCI_QUOTE_ESCAPE, sizeof(UCI_QUOTE_ESCAPE));
 586                 ofs += strlen(&ctx->buf[ofs]);
 587                 str = end + 1;
 588         }
 589
 590         ctx->buf[ofs] = 0;
 591         return ctx->buf;
 592 }
 593
 594 /*
 595  * export a single config package to a file stream
 596  */
 597 static void uci_export_package(struct uci_package *p, FILE *stream, bool header)
 598 {
 599         struct uci_context *ctx = p->ctx;
 600         struct uci_element *s, *o, *i;
 601
 602         if (header)
 603                 fprintf(stream, "package %s\n", uci_escape(ctx, p->e.name));
 604         uci_foreach_element(&p->sections, s) {
 605                 struct uci_section *sec = uci_to_section(s);
 606                 fprintf(stream, "\nconfig %s", uci_escape(ctx, sec->type));
 607                 if (!sec->anonymous || (ctx->flags & UCI_FLAG_EXPORT_NAME))
 608                         fprintf(stream, " '%s'", uci_escape(ctx, sec->e.name));
 609                 fprintf(stream, "\n");
 610                 uci_foreach_element(&sec->options, o) {
 611                         struct uci_option *opt = uci_to_option(o);
 612                         switch(opt->type) {
 613                         case UCI_TYPE_STRING:
 614                                 fprintf(stream, "\toption %s", uci_escape(ctx, opt->e.name));
 615                                 fprintf(stream, " '%s'\n", uci_escape(ctx, opt->v.string));
 616                                 break;
 617                         case UCI_TYPE_LIST:
 618                                 uci_foreach_element(&opt->v.list, i) {
 619                                         fprintf(stream, "\tlist %s", uci_escape(ctx, opt->e.name));
 620                                         fprintf(stream, " '%s'\n", uci_escape(ctx, i->name));
 621                                 }
 622                                 break;
 623                         default:
 624                                 fprintf(stream, "\t# unknown type for option '%s'\n", uci_escape(ctx, opt->e.name));
 625                                 break;
 626                         }
 627                 }
 628         }
 629         fprintf(stream, "\n");
 630 }
 631
 632 int uci_export(struct uci_context *ctx, FILE *stream, struct uci_package *package, bool header)
 633 {
 634         struct uci_element *e;
 635
 636         UCI_HANDLE_ERR(ctx);
 637         UCI_ASSERT(ctx, stream != NULL);
 638
 639         if (package)
 640                 uci_export_package(package, stream, header);
 641         else {
 642                 uci_foreach_element(&ctx->root, e) {
 643                         uci_export_package(uci_to_package(e), stream, header);
 644                 }
 645         }
 646
 647         return 0;
 648 }
 649
 650 int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_package **package, bool single)
 651 {
 652         struct uci_parse_context *pctx;
 653         UCI_HANDLE_ERR(ctx);
 654
 655         /* make sure no memory from previous parse attempts is leaked */
 656         uci_cleanup(ctx);
 657
 658         uci_alloc_parse_context(ctx);
 659         pctx = ctx->pctx;
 660         pctx->file = stream;
 661         if (package && *package && single) {
 662                 pctx->package = *package;
 663                 pctx->merge = true;
 664         }
 665
 666         /*
 667          * If 'name' was supplied, assume that the supplied stream does not contain
 668          * the appropriate 'package <name>' string to specify the config name
 669          * NB: the config file can still override the package name
 670          */
 671         if (name) {
 672                 UCI_ASSERT(ctx, uci_validate_package(name));
 673                 pctx->name = name;
 674         }
 675
 676         while (!feof(pctx->file)) {
 677                 pctx->pos = 0;
 678                 uci_getln(ctx, 0);
 679                 UCI_TRAP_SAVE(ctx, error);
 680                 if (pctx->buf[0])
 681                         uci_parse_line(ctx, single);
 682                 UCI_TRAP_RESTORE(ctx);
 683                 continue;
 684 error:
 685                 if (ctx->flags & UCI_FLAG_PERROR)
 686                         uci_perror(ctx, NULL);
 687                 if ((ctx->err != UCI_ERR_PARSE) ||
 688                         (ctx->flags & UCI_FLAG_STRICT))
 689                         UCI_THROW(ctx, ctx->err);
 690         }
 691
 692         if (!pctx->package && name)
 693                 uci_switch_config(ctx);
 694         if (package)
 695                 *package = pctx->package;
 696         if (pctx->merge)
 697                 pctx->package = NULL;
 698
 699         pctx->name = NULL;
 700         uci_switch_config(ctx);
 701
 702         /* no error happened, we can get rid of the parser context now */
 703         uci_cleanup(ctx);
 704
 705         return 0;
 706 }
 707
 708
 709 static char *uci_config_path(struct uci_context *ctx, const char *name)
 710 {
 711         char *filename;
 712
 713         UCI_ASSERT(ctx, uci_validate_package(name));
 714         filename = uci_malloc(ctx, strlen(name) + strlen(ctx->confdir) + 2);
 715         sprintf(filename, "%s/%s", ctx->confdir, name);
 716
 717         return filename;
 718 }
 719
 720 static void uci_file_commit(struct uci_context *ctx, struct uci_package **package, bool overwrite)
 721 {
 722         struct uci_package *p = *package;
 723         FILE *f1, *f2 = NULL;
 724         char *volatile name = NULL;
 725         char *volatile path = NULL;
 726         char *filename = NULL;
 727         volatile bool do_rename = false;
 728         int fd;
 729
 730         if (!p->path) {
 731                 if (overwrite)
 732                         p->path = uci_config_path(ctx, p->e.name);
 733                 else
 734                         UCI_THROW(ctx, UCI_ERR_INVAL);
 735         }
 736
 737         if ((asprintf(&filename, "%s/.%s.uci-XXXXXX", ctx->confdir, p->e.name) < 0) || !filename)
 738                 UCI_THROW(ctx, UCI_ERR_MEM);
 739
 740         /* open the config file for writing now, so that it is locked */
 741         f1 = uci_open_stream(ctx, p->path, NULL, SEEK_SET, true, true);
 742
 743         /* flush unsaved changes and reload from delta file */
 744         UCI_TRAP_SAVE(ctx, done);
 745         if (p->has_delta) {
 746                 if (!overwrite) {
 747                         name = uci_strdup(ctx, p->e.name);
 748                         path = uci_strdup(ctx, p->path);
 749                         /* dump our own changes to the delta file */
 750                         if (!uci_list_empty(&p->delta))
 751                                 UCI_INTERNAL(uci_save, ctx, p);
 752
 753                         /*
 754                          * other processes might have modified the config
 755                          * as well. dump and reload
 756                          */
 757                         uci_free_package(&p);
 758                         uci_cleanup(ctx);
 759                         UCI_INTERNAL(uci_import, ctx, f1, name, &p, true);
 760
 761                         p->path = path;
 762                         p->has_delta = true;
 763                         *package = p;
 764
 765                         /* freed together with the uci_package */
 766                         path = NULL;
 767                 }
 768
 769                 /* flush delta */
 770                 if (!uci_load_delta(ctx, p, true))
 771                         goto done;
 772         }
 773
 774         fd = mkstemp(filename);
 775         if (fd == -1)
 776                 UCI_THROW(ctx, UCI_ERR_IO);
 777
 778         if ((flock(fd, LOCK_EX) < 0) && (errno != ENOSYS))
 779                 UCI_THROW(ctx, UCI_ERR_IO);
 780
 781         if (lseek(fd, 0, SEEK_SET) < 0)
 782                 UCI_THROW(ctx, UCI_ERR_IO);
 783
 784         f2 = fdopen(fd, "w+");
 785         if (!f2)
 786                 UCI_THROW(ctx, UCI_ERR_IO);
 787
 788         uci_export(ctx, f2, p, false);
 789
 790         fflush(f2);
 791         fsync(fileno(f2));
 792         uci_close_stream(f2);
 793
 794         do_rename = true;
 795
 796         UCI_TRAP_RESTORE(ctx);
 797
 798 done:
 799         free(name);
 800         free(path);
 801         uci_close_stream(f1);
 802         if (do_rename) {
 803                 path = realpath(p->path, NULL);
 804                 if (!path || rename(filename, path)) {
 805                         unlink(filename);
 806                         UCI_THROW(ctx, UCI_ERR_IO);
 807                 }
 808                 free(path);
 809         }
 810         free(filename);
 811         if (ctx->err)
 812                 UCI_THROW(ctx, ctx->err);
 813 }
 814
 815
 816 /*
 817  * This function returns the filename by returning the string
 818  * after the last '/' character. By checking for a non-'\0'
 819  * character afterwards, directories are ignored (glob marks
 820  * those with a trailing '/'
 821  */
 822 static inline char *get_filename(char *path)
 823 {
 824         char *p;
 825
 826         p = strrchr(path, '/');
 827         p++;
 828         if (!*p)
 829                 return NULL;
 830         return p;
 831 }
 832
 833 static char **uci_list_config_files(struct uci_context *ctx)
 834 {
 835         char **configs;
 836         glob_t globbuf;
 837         int size, j, skipped;
 838         size_t i;
 839         char *buf;
 840         char *dir;
 841
 842         dir = uci_malloc(ctx, strlen(ctx->confdir) + 1 + sizeof("/*"));
 843         sprintf(dir, "%s/*", ctx->confdir);
 844         if (glob(dir, GLOB_MARK, NULL, &globbuf) != 0) {
 845                 free(dir);
 846                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 847         }
 848
 849         size = sizeof(char *) * (globbuf.gl_pathc + 1);
 850         skipped = 0;
 851         for(i = 0; i < globbuf.gl_pathc; i++) {
 852                 char *p;
 853
 854                 p = get_filename(globbuf.gl_pathv[i]);
 855                 if (!p) {
 856                         skipped++;
 857                         continue;
 858                 }
 859
 860                 size += strlen(p) + 1;
 861         }
 862
 863         configs = uci_malloc(ctx, size - skipped);
 864         buf = (char *) &configs[globbuf.gl_pathc + 1 - skipped];
 865         j = 0;
 866         for(i = 0; i < globbuf.gl_pathc; i++) {
 867                 char *p;
 868
 869                 p = get_filename(globbuf.gl_pathv[i]);
 870                 if (!p)
 871                         continue;
 872
 873                 if (!uci_validate_package(p))
 874                         continue;
 875
 876                 configs[j++] = buf;
 877                 strcpy(buf, p);
 878                 buf += strlen(buf) + 1;
 879         }
 880         free(dir);
 881         globfree(&globbuf);
 882         return configs;
 883 }
 884
 885 static struct uci_package *uci_file_load(struct uci_context *ctx,
 886                                          const char *volatile name)
 887 {
 888         struct uci_package *package = NULL;
 889         char *filename;
 890         bool confdir;
 891         FILE *volatile file = NULL;
 892
 893         switch (name[0]) {
 894         case '.':
 895                 /* relative path outside of /etc/config */
 896                 if (name[1] != '/')
 897                         UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 898                 /* fall through */
 899         case '/':
 900                 /* absolute path outside of /etc/config */
 901                 filename = uci_strdup(ctx, name);
 902                 name = strrchr(name, '/') + 1;
 903                 confdir = false;
 904                 break;
 905         default:
 906                 /* config in /etc/config */
 907                 filename = uci_config_path(ctx, name);
 908                 confdir = true;
 909                 break;
 910         }
 911
 912         UCI_TRAP_SAVE(ctx, done);
 913         file = uci_open_stream(ctx, filename, NULL, SEEK_SET, false, false);
 914         ctx->err = 0;
 915         UCI_INTERNAL(uci_import, ctx, file, name, &package, true);
 916         UCI_TRAP_RESTORE(ctx);
 917
 918         if (package) {
 919                 package->path = filename;
 920                 package->has_delta = confdir;
 921                 uci_load_delta(ctx, package, false);
 922         }
 923
 924 done:
 925         uci_close_stream(file);
 926         if (ctx->err) {
 927                 free(filename);
 928                 UCI_THROW(ctx, ctx->err);
 929         }
 930         return package;
 931 }
 932
 933 __private UCI_BACKEND(uci_file_backend, "file",
 934         .load = uci_file_load,
 935         .commit = uci_file_commit,
 936         .list_configs = uci_list_config_files,
 937 );