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, size_t offset)
  42 {
  43         struct uci_parse_context *pctx = ctx->pctx;
  44         char *p;
  45         size_t 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                 pctx->buf_filled = ofs;
  68                 if (pctx->buf[ofs - 1] == '\n') {
  69                         pctx->line++;
  70                         return;
  71                 }
  72
  73                 pctx->bufsz *= 2;
  74                 pctx->buf = uci_realloc(ctx, pctx->buf, pctx->bufsz);
  75         } while (1);
  76 }
  77
  78 /*
  79  * parse a character escaped by '\'
  80  * returns true if the escaped character is to be parsed
  81  * returns false if the escaped character is to be ignored
  82  */
  83 static bool parse_backslash(struct uci_context *ctx)
  84 {
  85         struct uci_parse_context *pctx = ctx->pctx;
  86
  87         /* skip backslash */
  88         pctx->pos += 1;
  89
  90         /* undecoded backslash at the end of line, fetch the next line */
  91         if (!pctx_cur_char(pctx) ||
  92             pctx_cur_char(pctx) == '\n' ||
  93             (pctx_cur_char(pctx) == '\r' &&
  94              pctx_char(pctx, pctx_pos(pctx) + 1) == '\n' &&
  95              !pctx_char(pctx, pctx_pos(pctx) + 2))) {
  96                 uci_getln(ctx, pctx->pos);
  97                 return false;
  98         }
  99
 100         /* FIXME: decode escaped char, necessary? */
 101         return true;
 102 }
 103
 104 /*
 105  * move the string pointer forward until a non-whitespace character or
 106  * EOL is reached
 107  */
 108 static void skip_whitespace(struct uci_context *ctx)
 109 {
 110         struct uci_parse_context *pctx = ctx->pctx;
 111
 112         while (pctx_cur_char(pctx) && isspace(pctx_cur_char(pctx)))
 113                 pctx->pos += 1;
 114 }
 115
 116 static inline void addc(struct uci_context *ctx, size_t *pos_dest, size_t *pos_src)
 117 {
 118         struct uci_parse_context *pctx = ctx->pctx;
 119
 120         pctx_char(pctx, *pos_dest) = pctx_char(pctx, *pos_src);
 121         *pos_dest += 1;
 122         *pos_src += 1;
 123 }
 124
 125 static int uci_increase_pos(struct uci_parse_context *pctx, size_t add)
 126 {
 127         if (pctx->pos + add > pctx->buf_filled)
 128                 return -EINVAL;
 129
 130         pctx->pos += add;
 131         return 0;
 132 }
 133
 134 /*
 135  * parse a double quoted string argument from the command line
 136  */
 137 static void parse_double_quote(struct uci_context *ctx, size_t *target)
 138 {
 139         struct uci_parse_context *pctx = ctx->pctx;
 140         char c;
 141
 142         /* skip quote character */
 143         pctx->pos += 1;
 144
 145         while (1) {
 146                 c = pctx_cur_char(pctx);
 147                 switch(c) {
 148                 case '"':
 149                         pctx->pos += 1;
 150                         return;
 151                 case 0:
 152                         /* Multi-line str value */
 153                         uci_getln(ctx, pctx->pos);
 154                         if (!pctx_cur_char(pctx)) {
 155                                 uci_parse_error(ctx, "EOF with unterminated \"");
 156                         }
 157                         break;
 158                 case '\\':
 159                         if (!parse_backslash(ctx))
 160                                 continue;
 161                         /* fall through */
 162                 default:
 163                         addc(ctx, target, &pctx->pos);
 164                         break;
 165                 }
 166         }
 167 }
 168
 169 /*
 170  * parse a single quoted string argument from the command line
 171  */
 172 static void parse_single_quote(struct uci_context *ctx, size_t *target)
 173 {
 174         struct uci_parse_context *pctx = ctx->pctx;
 175         char c;
 176         /* skip quote character */
 177         pctx->pos += 1;
 178
 179         while (1) {
 180                 c = pctx_cur_char(pctx);
 181                 switch(c) {
 182                 case '\'':
 183                         pctx->pos += 1;
 184                         return;
 185                 case 0:
 186                         /* Multi-line str value */
 187                         uci_getln(ctx, pctx->pos);
 188                         if (!pctx_cur_char(pctx))
 189                                 uci_parse_error(ctx, "EOF with unterminated '");
 190
 191                         break;
 192                 default:
 193                         addc(ctx, target, &pctx->pos);
 194                 }
 195         }
 196 }
 197
 198 /*
 199  * parse a string from the command line and detect the quoting style
 200  */
 201 static void parse_str(struct uci_context *ctx, size_t *target)
 202 {
 203         struct uci_parse_context *pctx = ctx->pctx;
 204         bool next = true;
 205         do {
 206                 switch(pctx_cur_char(pctx)) {
 207                 case '\'':
 208                         parse_single_quote(ctx, target);
 209                         break;
 210                 case '"':
 211                         parse_double_quote(ctx, target);
 212                         break;
 213                 case '#':
 214                         pctx_cur_char(pctx) = 0;
 215                         /* fall through */
 216                 case 0:
 217                         goto done;
 218                 case ';':
 219                         next = false;
 220                         goto done;
 221                 case '\\':
 222                         if (!parse_backslash(ctx))
 223                                 continue;
 224                         /* fall through */
 225                 default:
 226                         addc(ctx, target, &pctx->pos);
 227                         break;
 228                 }
 229         } while (pctx_cur_char(pctx) && !isspace(pctx_cur_char(pctx)));
 230 done:
 231
 232         /*
 233          * if the string was unquoted and we've stopped at a whitespace
 234          * character, skip to the next one, because the whitespace will
 235          * be overwritten by a null byte here
 236          */
 237         if (pctx_cur_char(pctx) && next)
 238                 pctx->pos += 1;
 239
 240         /* terminate the parsed string */
 241         pctx_char(pctx, *target) = 0;
 242 }
 243
 244 /*
 245  * extract the next argument from the command line
 246  */
 247 static int next_arg(struct uci_context *ctx, bool required, bool name, bool package)
 248 {
 249         struct uci_parse_context *pctx = ctx->pctx;
 250         size_t val, ptr;
 251
 252         skip_whitespace(ctx);
 253         val = ptr = pctx_pos(pctx);
 254         if (pctx_cur_char(pctx) == ';') {
 255                 pctx_cur_char(pctx) = 0;
 256                 pctx->pos += 1;
 257         } else {
 258                 parse_str(ctx, &ptr);
 259         }
 260         if (!pctx_char(pctx, val)) {
 261                 if (required)
 262                         uci_parse_error(ctx, "insufficient arguments");
 263                 goto done;
 264         }
 265
 266         if (name && !uci_validate_str(pctx_str(pctx, val), name, package))
 267                 uci_parse_error(ctx, "invalid character in name field");
 268
 269 done:
 270         return val;
 271 }
 272
 273 int uci_parse_argument(struct uci_context *ctx, FILE *stream, char **str, char **result)
 274 {
 275         int ofs_result;
 276
 277         UCI_HANDLE_ERR(ctx);
 278         UCI_ASSERT(ctx, str != NULL);
 279         UCI_ASSERT(ctx, result != NULL);
 280
 281         if (ctx->pctx && (ctx->pctx->file != stream))
 282                 uci_cleanup(ctx);
 283
 284         if (!ctx->pctx)
 285                 uci_alloc_parse_context(ctx);
 286
 287         ctx->pctx->file = stream;
 288         if (!*str) {
 289                 ctx->pctx->pos = 0;
 290                 uci_getln(ctx, 0);
 291         }
 292
 293         ofs_result = next_arg(ctx, false, false, false);
 294         *result = pctx_str(ctx->pctx, ofs_result);
 295         *str = pctx_cur_str(ctx->pctx);
 296
 297         return 0;
 298 }
 299
 300 static int
 301 uci_fill_ptr(struct uci_context *ctx, struct uci_ptr *ptr, struct uci_element *e)
 302 {
 303         UCI_ASSERT(ctx, ptr != NULL);
 304         UCI_ASSERT(ctx, e != NULL);
 305
 306         memset(ptr, 0, sizeof(struct uci_ptr));
 307         switch(e->type) {
 308         case UCI_TYPE_OPTION:
 309                 ptr->o = uci_to_option(e);
 310                 goto fill_option;
 311         case UCI_TYPE_SECTION:
 312                 ptr->s = uci_to_section(e);
 313                 goto fill_section;
 314         case UCI_TYPE_PACKAGE:
 315                 ptr->p = uci_to_package(e);
 316                 goto fill_package;
 317         default:
 318                 UCI_THROW(ctx, UCI_ERR_INVAL);
 319         }
 320
 321 fill_option:
 322         ptr->option = ptr->o->e.name;
 323         ptr->s = ptr->o->section;
 324 fill_section:
 325         ptr->section = ptr->s->e.name;
 326         ptr->p = ptr->s->package;
 327 fill_package:
 328         ptr->package = ptr->p->e.name;
 329
 330         ptr->flags |= UCI_LOOKUP_DONE;
 331
 332         return 0;
 333 }
 334
 335
 336
 337 /*
 338  * verify that the end of the line or command is reached.
 339  * throw an error if extra arguments are given on the command line
 340  */
 341 static void assert_eol(struct uci_context *ctx)
 342 {
 343         char *tmp;
 344         int ofs_tmp;
 345
 346         skip_whitespace(ctx);
 347         ofs_tmp = next_arg(ctx, false, false, false);
 348         tmp = pctx_str(ctx->pctx, ofs_tmp);
 349         if (*tmp && (ctx->flags & UCI_FLAG_STRICT))
 350                 uci_parse_error(ctx, "too many arguments");
 351 }
 352
 353 /*
 354  * switch to a different config, either triggered by uci_load, or by a
 355  * 'package <...>' statement in the import file
 356  */
 357 static void uci_switch_config(struct uci_context *ctx)
 358 {
 359         struct uci_parse_context *pctx;
 360         struct uci_element *e;
 361         const char *name;
 362
 363         pctx = ctx->pctx;
 364         name = pctx->name;
 365
 366         /* add the last config to main config file list */
 367         if (pctx->package) {
 368                 pctx->package->backend = ctx->backend;
 369                 uci_list_add(&ctx->root, &pctx->package->e.list);
 370
 371                 pctx->package = NULL;
 372                 pctx->section = NULL;
 373         }
 374
 375         if (!name)
 376                 return;
 377
 378         /*
 379          * if an older config under the same name exists, unload it
 380          * ignore errors here, e.g. if the config was not found
 381          */
 382         e = uci_lookup_list(&ctx->root, name);
 383         if (e)
 384                 UCI_THROW(ctx, UCI_ERR_DUPLICATE);
 385         pctx->package = uci_alloc_package(ctx, name);
 386 }
 387
 388 /*
 389  * parse the 'package' uci command (next config package)
 390  */
 391 static void uci_parse_package(struct uci_context *ctx, bool single)
 392 {
 393         struct uci_parse_context *pctx = ctx->pctx;
 394         int ofs_name;
 395         char *name;
 396
 397         /* command string null-terminated by strtok */
 398         if (uci_increase_pos(pctx, strlen(pctx_cur_str(pctx)) + 1))
 399                 uci_parse_error(ctx, "package without name");
 400
 401         ofs_name = next_arg(ctx, true, true, true);
 402         assert_eol(ctx);
 403         name = pctx_str(pctx, ofs_name);
 404         if (single)
 405                 return;
 406
 407         ctx->pctx->name = name;
 408         uci_switch_config(ctx);
 409 }
 410
 411 /*
 412  * parse the 'config' uci command (open a section)
 413  */
 414 static void uci_parse_config(struct uci_context *ctx)
 415 {
 416         struct uci_parse_context *pctx = ctx->pctx;
 417         struct uci_element *e;
 418         struct uci_ptr ptr;
 419         int ofs_name, ofs_type;
 420         char *name;
 421         char *type;
 422
 423         if (!ctx->pctx->package) {
 424                 if (!ctx->pctx->name)
 425                         uci_parse_error(ctx, "attempting to import a file without a package name");
 426
 427                 uci_switch_config(ctx);
 428         }
 429
 430         /* command string null-terminated by strtok */
 431         if (uci_increase_pos(pctx, strlen(pctx_cur_str(pctx)) + 1))
 432                 uci_parse_error(ctx, "config without name");
 433
 434         ofs_type = next_arg(ctx, true, false, false);
 435         type = pctx_str(pctx, ofs_type);
 436         if (!uci_validate_type(type))
 437                 uci_parse_error(ctx, "invalid character in type field");
 438
 439         ofs_name = next_arg(ctx, false, true, false);
 440         assert_eol(ctx);
 441         type = pctx_str(pctx, ofs_type);
 442         name = pctx_str(pctx, ofs_name);
 443
 444         if (!name || !name[0]) {
 445                 ctx->internal = !pctx->merge;
 446                 UCI_NESTED(uci_add_section, ctx, pctx->package, type, &pctx->section);
 447         } else {
 448                 uci_fill_ptr(ctx, &ptr, &pctx->package->e);
 449                 e = uci_lookup_list(&pctx->package->sections, name);
 450                 if (e) {
 451                         ptr.s = uci_to_section(e);
 452
 453                         if ((ctx->flags & UCI_FLAG_STRICT) && strcmp(ptr.s->type, type))
 454                                 uci_parse_error(ctx, "section of different type overwrites prior section with same name");
 455                 }
 456
 457                 ptr.section = name;
 458                 ptr.value = type;
 459
 460                 ctx->internal = !pctx->merge;
 461                 UCI_NESTED(uci_set, ctx, &ptr);
 462                 pctx->section = ptr.s;
 463         }
 464 }
 465
 466 /*
 467  * parse the 'option' uci command (open a value)
 468  */
 469 static void uci_parse_option(struct uci_context *ctx, bool list)
 470 {
 471         struct uci_parse_context *pctx = ctx->pctx;
 472         struct uci_element *e;
 473         struct uci_ptr ptr;
 474         int ofs_name, ofs_value;
 475         char *name = NULL;
 476         char *value = NULL;
 477
 478         if (!pctx->section)
 479                 uci_parse_error(ctx, "option/list command found before the first section");
 480
 481         /* command string null-terminated by strtok */
 482         if (uci_increase_pos(pctx, strlen(pctx_cur_str(pctx)) + 1))
 483                 uci_parse_error(ctx, "option without name");
 484
 485         ofs_name = next_arg(ctx, true, true, false);
 486         ofs_value = next_arg(ctx, false, false, false);
 487         assert_eol(ctx);
 488         name = pctx_str(pctx, ofs_name);
 489         value = pctx_str(pctx, ofs_value);
 490
 491         uci_fill_ptr(ctx, &ptr, &pctx->section->e);
 492         e = uci_lookup_list(&pctx->section->options, name);
 493         if (e)
 494                 ptr.o = uci_to_option(e);
 495         ptr.option = name;
 496         ptr.value = value;
 497
 498         ctx->internal = !pctx->merge;
 499         if (list)
 500                 UCI_NESTED(uci_add_list, ctx, &ptr);
 501         else
 502                 UCI_NESTED(uci_set, ctx, &ptr);
 503 }
 504
 505 /*
 506  * parse a complete input line, split up combined commands by ';'
 507  */
 508 static void uci_parse_line(struct uci_context *ctx, bool single)
 509 {
 510         struct uci_parse_context *pctx = ctx->pctx;
 511         char *word;
 512
 513         /* Skip whitespace characters at the start of line */
 514         skip_whitespace(ctx);
 515         do {
 516                 word = strtok(pctx_cur_str(pctx), " \t");
 517                 if (!word)
 518                         return;
 519
 520                 switch(word[0]) {
 521                         case 0:
 522                         case '#':
 523                                 return;
 524                         case 'p':
 525                                 if ((word[1] == 0) || !strcmp(word + 1, "ackage"))
 526                                         uci_parse_package(ctx, single);
 527                                 else
 528                                         goto invalid;
 529                                 break;
 530                         case 'c':
 531                                 if ((word[1] == 0) || !strcmp(word + 1, "onfig"))
 532                                         uci_parse_config(ctx);
 533                                 else
 534                                         goto invalid;
 535                                 break;
 536                         case 'o':
 537                                 if ((word[1] == 0) || !strcmp(word + 1, "ption"))
 538                                         uci_parse_option(ctx, false);
 539                                 else
 540                                         goto invalid;
 541                                 break;
 542                         case 'l':
 543                                 if ((word[1] == 0) || !strcmp(word + 1, "ist"))
 544                                         uci_parse_option(ctx, true);
 545                                 else
 546                                         goto invalid;
 547                                 break;
 548                         default:
 549                                 goto invalid;
 550                 }
 551                 continue;
 552 invalid:
 553                 uci_parse_error(ctx, "invalid command");
 554         } while (1);
 555 }
 556
 557 /* max number of characters that escaping adds to the string */
 558 #define UCI_QUOTE_ESCAPE        "'\\''"
 559
 560 /*
 561  * escape an uci string for export
 562  */
 563 static const char *uci_escape(struct uci_context *ctx, const char *str)
 564 {
 565         const char *end;
 566         int ofs = 0;
 567
 568         if (!ctx->buf) {
 569                 ctx->bufsz = LINEBUF;
 570                 ctx->buf = malloc(LINEBUF);
 571
 572                 if (!ctx->buf)
 573                         return str;
 574         }
 575
 576         while (1) {
 577                 int len;
 578
 579                 end = strchr(str, '\'');
 580                 if (!end)
 581                         end = str + strlen(str);
 582                 len = end - str;
 583
 584                 /* make sure that we have enough room in the buffer */
 585                 while (ofs + len + (int) sizeof(UCI_QUOTE_ESCAPE) + 1 > ctx->bufsz) {
 586                         ctx->bufsz *= 2;
 587                         ctx->buf = uci_realloc(ctx, ctx->buf, ctx->bufsz);
 588                 }
 589
 590                 /* copy the string until the character before the quote */
 591                 memcpy(&ctx->buf[ofs], str, len);
 592                 ofs += len;
 593
 594                 /* end of string? return the buffer */
 595                 if (*end == 0)
 596                         break;
 597
 598                 memcpy(&ctx->buf[ofs], UCI_QUOTE_ESCAPE, sizeof(UCI_QUOTE_ESCAPE));
 599                 ofs += strlen(&ctx->buf[ofs]);
 600                 str = end + 1;
 601         }
 602
 603         ctx->buf[ofs] = 0;
 604         return ctx->buf;
 605 }
 606
 607 /*
 608  * export a single config package to a file stream
 609  */
 610 static void uci_export_package(struct uci_package *p, FILE *stream, bool header)
 611 {
 612         struct uci_context *ctx = p->ctx;
 613         struct uci_element *s, *o, *i;
 614
 615         if (header)
 616                 fprintf(stream, "package %s\n", uci_escape(ctx, p->e.name));
 617         uci_foreach_element(&p->sections, s) {
 618                 struct uci_section *sec = uci_to_section(s);
 619                 fprintf(stream, "\nconfig %s", uci_escape(ctx, sec->type));
 620                 if (!sec->anonymous || (ctx->flags & UCI_FLAG_EXPORT_NAME))
 621                         fprintf(stream, " '%s'", uci_escape(ctx, sec->e.name));
 622                 fprintf(stream, "\n");
 623                 uci_foreach_element(&sec->options, o) {
 624                         struct uci_option *opt = uci_to_option(o);
 625                         switch(opt->type) {
 626                         case UCI_TYPE_STRING:
 627                                 fprintf(stream, "\toption %s", uci_escape(ctx, opt->e.name));
 628                                 fprintf(stream, " '%s'\n", uci_escape(ctx, opt->v.string));
 629                                 break;
 630                         case UCI_TYPE_LIST:
 631                                 uci_foreach_element(&opt->v.list, i) {
 632                                         fprintf(stream, "\tlist %s", uci_escape(ctx, opt->e.name));
 633                                         fprintf(stream, " '%s'\n", uci_escape(ctx, i->name));
 634                                 }
 635                                 break;
 636                         default:
 637                                 fprintf(stream, "\t# unknown type for option '%s'\n", uci_escape(ctx, opt->e.name));
 638                                 break;
 639                         }
 640                 }
 641         }
 642         fprintf(stream, "\n");
 643 }
 644
 645 int uci_export(struct uci_context *ctx, FILE *stream, struct uci_package *package, bool header)
 646 {
 647         struct uci_element *e;
 648
 649         UCI_HANDLE_ERR(ctx);
 650         UCI_ASSERT(ctx, stream != NULL);
 651
 652         if (package)
 653                 uci_export_package(package, stream, header);
 654         else {
 655                 uci_foreach_element(&ctx->root, e) {
 656                         uci_export_package(uci_to_package(e), stream, header);
 657                 }
 658         }
 659
 660         return 0;
 661 }
 662
 663 int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_package **package, bool single)
 664 {
 665         struct uci_parse_context *pctx;
 666         UCI_HANDLE_ERR(ctx);
 667
 668         /* make sure no memory from previous parse attempts is leaked */
 669         uci_cleanup(ctx);
 670
 671         uci_alloc_parse_context(ctx);
 672         pctx = ctx->pctx;
 673         pctx->file = stream;
 674         if (package && *package && single) {
 675                 pctx->package = *package;
 676                 pctx->merge = true;
 677         }
 678
 679         /*
 680          * If 'name' was supplied, assume that the supplied stream does not contain
 681          * the appropriate 'package <name>' string to specify the config name
 682          * NB: the config file can still override the package name
 683          */
 684         if (name) {
 685                 UCI_ASSERT(ctx, uci_validate_package(name));
 686                 pctx->name = name;
 687         }
 688
 689         while (!feof(pctx->file)) {
 690                 pctx->pos = 0;
 691                 uci_getln(ctx, 0);
 692                 UCI_TRAP_SAVE(ctx, error);
 693                 if (pctx->buf[0])
 694                         uci_parse_line(ctx, single);
 695                 UCI_TRAP_RESTORE(ctx);
 696                 continue;
 697 error:
 698                 if (ctx->flags & UCI_FLAG_PERROR)
 699                         uci_perror(ctx, NULL);
 700                 if ((ctx->err != UCI_ERR_PARSE) ||
 701                         (ctx->flags & UCI_FLAG_STRICT))
 702                         UCI_THROW(ctx, ctx->err);
 703         }
 704
 705         if (!pctx->package && name)
 706                 uci_switch_config(ctx);
 707         if (package)
 708                 *package = pctx->package;
 709         if (pctx->merge)
 710                 pctx->package = NULL;
 711
 712         pctx->name = NULL;
 713         uci_switch_config(ctx);
 714
 715         /* no error happened, we can get rid of the parser context now */
 716         uci_cleanup(ctx);
 717
 718         return 0;
 719 }
 720
 721
 722 static char *uci_config_path(struct uci_context *ctx, const char *name)
 723 {
 724         char *filename;
 725
 726         UCI_ASSERT(ctx, uci_validate_package(name));
 727         filename = uci_malloc(ctx, strlen(name) + strlen(ctx->confdir) + 2);
 728         sprintf(filename, "%s/%s", ctx->confdir, name);
 729
 730         return filename;
 731 }
 732
 733 static void uci_file_commit(struct uci_context *ctx, struct uci_package **package, bool overwrite)
 734 {
 735         struct uci_package *p = *package;
 736         FILE *f1, *f2 = NULL;
 737         char *volatile name = NULL;
 738         char *volatile path = NULL;
 739         char *filename = NULL;
 740         struct stat statbuf;
 741         volatile bool do_rename = false;
 742         int fd, sz;
 743
 744         if (!p->path) {
 745                 if (overwrite)
 746                         p->path = uci_config_path(ctx, p->e.name);
 747                 else
 748                         UCI_THROW(ctx, UCI_ERR_INVAL);
 749         }
 750
 751         sz = snprintf(NULL, 0, "%s/.%s.uci-XXXXXX", ctx->confdir, p->e.name);
 752         filename = alloca(sz + 1);
 753         snprintf(filename, sz + 1, "%s/.%s.uci-XXXXXX", ctx->confdir, p->e.name);
 754
 755         /* open the config file for writing now, so that it is locked */
 756         f1 = uci_open_stream(ctx, p->path, NULL, SEEK_SET, true, true);
 757
 758         /* flush unsaved changes and reload from delta file */
 759         UCI_TRAP_SAVE(ctx, done);
 760         if (p->has_delta) {
 761                 if (!overwrite) {
 762                         name = uci_strdup(ctx, p->e.name);
 763                         path = uci_strdup(ctx, p->path);
 764                         /* dump our own changes to the delta file */
 765                         if (!uci_list_empty(&p->delta))
 766                                 UCI_INTERNAL(uci_save, ctx, p);
 767
 768                         /*
 769                          * other processes might have modified the config
 770                          * as well. dump and reload
 771                          */
 772                         uci_free_package(&p);
 773                         uci_cleanup(ctx);
 774                         UCI_INTERNAL(uci_import, ctx, f1, name, &p, true);
 775
 776                         p->path = path;
 777                         p->has_delta = true;
 778                         *package = p;
 779
 780                         /* freed together with the uci_package */
 781                         path = NULL;
 782                 }
 783
 784                 /* flush delta */
 785                 if (!uci_load_delta(ctx, p, true))
 786                         goto done;
 787         }
 788
 789         fd = mkstemp(filename);
 790         if (fd == -1)
 791                 UCI_THROW(ctx, UCI_ERR_IO);
 792
 793         if ((flock(fd, LOCK_EX) < 0) && (errno != ENOSYS))
 794                 UCI_THROW(ctx, UCI_ERR_IO);
 795
 796         if (lseek(fd, 0, SEEK_SET) < 0)
 797                 UCI_THROW(ctx, UCI_ERR_IO);
 798
 799         f2 = fdopen(fd, "w+");
 800         if (!f2)
 801                 UCI_THROW(ctx, UCI_ERR_IO);
 802
 803         uci_export(ctx, f2, p, false);
 804
 805         fflush(f2);
 806         fsync(fileno(f2));
 807         uci_close_stream(f2);
 808
 809         do_rename = true;
 810
 811         UCI_TRAP_RESTORE(ctx);
 812
 813 done:
 814         free(name);
 815         free(path);
 816         uci_close_stream(f1);
 817         if (do_rename) {
 818                 path = realpath(p->path, NULL);
 819                 if (!path || stat(path, &statbuf) || chmod(filename, statbuf.st_mode) || rename(filename, path)) {
 820                         unlink(filename);
 821                         UCI_THROW(ctx, UCI_ERR_IO);
 822                 }
 823                 free(path);
 824         }
 825         if (ctx->err)
 826                 UCI_THROW(ctx, ctx->err);
 827 }
 828
 829
 830 /*
 831  * This function returns the filename by returning the string
 832  * after the last '/' character. By checking for a non-'\0'
 833  * character afterwards, directories are ignored (glob marks
 834  * those with a trailing '/'
 835  */
 836 static inline char *get_filename(char *path)
 837 {
 838         char *p;
 839
 840         p = strrchr(path, '/');
 841         p++;
 842         if (!*p)
 843                 return NULL;
 844         return p;
 845 }
 846
 847 static char **uci_list_config_files(struct uci_context *ctx)
 848 {
 849         char **configs;
 850         glob_t globbuf;
 851         int size, j, skipped;
 852         size_t i;
 853         char *buf;
 854         char *dir;
 855
 856         dir = uci_malloc(ctx, strlen(ctx->confdir) + 1 + sizeof("/*"));
 857         sprintf(dir, "%s/*", ctx->confdir);
 858         if (glob(dir, GLOB_MARK, NULL, &globbuf) != 0) {
 859                 free(dir);
 860                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 861         }
 862
 863         size = sizeof(char *) * (globbuf.gl_pathc + 1);
 864         skipped = 0;
 865         for(i = 0; i < globbuf.gl_pathc; i++) {
 866                 char *p;
 867
 868                 p = get_filename(globbuf.gl_pathv[i]);
 869                 if (!p) {
 870                         skipped++;
 871                         continue;
 872                 }
 873
 874                 size += strlen(p) + 1;
 875         }
 876
 877         configs = uci_malloc(ctx, size - skipped);
 878         buf = (char *) &configs[globbuf.gl_pathc + 1 - skipped];
 879         j = 0;
 880         for(i = 0; i < globbuf.gl_pathc; i++) {
 881                 char *p;
 882
 883                 p = get_filename(globbuf.gl_pathv[i]);
 884                 if (!p)
 885                         continue;
 886
 887                 if (!uci_validate_package(p))
 888                         continue;
 889
 890                 configs[j++] = buf;
 891                 strcpy(buf, p);
 892                 buf += strlen(buf) + 1;
 893         }
 894         free(dir);
 895         globfree(&globbuf);
 896         return configs;
 897 }
 898
 899 static struct uci_package *uci_file_load(struct uci_context *ctx,
 900                                          const char *volatile name)
 901 {
 902         struct uci_package *package = NULL;
 903         char *filename;
 904         bool confdir;
 905         FILE *volatile file = NULL;
 906
 907         switch (name[0]) {
 908         case '.':
 909                 /* relative path outside of /etc/config */
 910                 if (name[1] != '/')
 911                         UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 912                 /* fall through */
 913         case '/':
 914                 /* absolute path outside of /etc/config */
 915                 filename = uci_strdup(ctx, name);
 916                 name = strrchr(name, '/') + 1;
 917                 confdir = false;
 918                 break;
 919         default:
 920                 /* config in /etc/config */
 921                 filename = uci_config_path(ctx, name);
 922                 confdir = true;
 923                 break;
 924         }
 925
 926         UCI_TRAP_SAVE(ctx, done);
 927         file = uci_open_stream(ctx, filename, NULL, SEEK_SET, false, false);
 928         ctx->err = 0;
 929         UCI_INTERNAL(uci_import, ctx, file, name, &package, true);
 930         UCI_TRAP_RESTORE(ctx);
 931
 932         if (package) {
 933                 package->path = filename;
 934                 package->has_delta = confdir;
 935                 uci_load_delta(ctx, package, false);
 936         }
 937
 938 done:
 939         uci_close_stream(file);
 940         if (ctx->err) {
 941                 free(filename);
 942                 UCI_THROW(ctx, ctx->err);
 943         }
 944         return package;
 945 }
 946
 947 __private UCI_BACKEND(uci_file_backend, "file",
 948         .load = uci_file_load,
 949         .commit = uci_file_commit,
 950         .list_configs = uci_list_config_files,
 951 );