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/file.h>
  22 #include <stdbool.h>
  23 #include <unistd.h>
  24 #include <fcntl.h>
  25 #include <stdio.h>
  26 #include <ctype.h>
  27
  28 /*
  29  * Clean up all extra memory used by the parser and exporter
  30  */
  31 static void uci_file_cleanup(struct uci_context *ctx)
  32 {
  33 }
  34
  35
  36 /*
  37  * verify that the end of the line or command is reached.
  38  * throw an error if extra arguments are given on the command line
  39  */
  40 static void assert_eol(struct uci_context *ctx, char **str)
  41 {
  42         char *tmp;
  43
  44         tmp = next_arg(ctx, str, false, false);
  45         if (*tmp && (ctx->flags & UCI_FLAG_STRICT))
  46                 uci_parse_error(ctx, *str, "too many arguments");
  47 }
  48
  49 /*
  50  * switch to a different config, either triggered by uci_load, or by a
  51  * 'package <...>' statement in the import file
  52  */
  53 static void uci_switch_config(struct uci_context *ctx)
  54 {
  55         struct uci_parse_context *pctx;
  56         struct uci_element *e;
  57         const char *name;
  58
  59         pctx = ctx->pctx;
  60         name = pctx->name;
  61
  62         /* add the last config to main config file list */
  63         if (pctx->package) {
  64                 uci_list_add(&ctx->root, &pctx->package->e.list);
  65
  66                 pctx->package = NULL;
  67                 pctx->section = NULL;
  68         }
  69
  70         if (!name)
  71                 return;
  72
  73         /*
  74          * if an older config under the same name exists, unload it
  75          * ignore errors here, e.g. if the config was not found
  76          */
  77         e = uci_lookup_list(ctx, &ctx->root, name);
  78         if (e)
  79                 UCI_THROW(ctx, UCI_ERR_DUPLICATE);
  80         pctx->package = uci_alloc_package(ctx, name);
  81 }
  82
  83 /*
  84  * parse the 'package' uci command (next config package)
  85  */
  86 static void uci_parse_package(struct uci_context *ctx, char **str, bool single)
  87 {
  88         char *name = NULL;
  89
  90         /* command string null-terminated by strtok */
  91         *str += strlen(*str) + 1;
  92
  93         name = next_arg(ctx, str, true, true);
  94         assert_eol(ctx, str);
  95         if (single)
  96                 return;
  97
  98         ctx->pctx->name = name;
  99         uci_switch_config(ctx);
 100 }
 101
 102 /*
 103  * parse the 'config' uci command (open a section)
 104  */
 105 static void uci_parse_config(struct uci_context *ctx, char **str)
 106 {
 107         struct uci_parse_context *pctx = ctx->pctx;
 108         char *name = NULL;
 109         char *type = NULL;
 110
 111         uci_fixup_section(ctx, ctx->pctx->section);
 112         if (!ctx->pctx->package) {
 113                 if (!ctx->pctx->name)
 114                         uci_parse_error(ctx, *str, "attempting to import a file without a package name");
 115
 116                 uci_switch_config(ctx);
 117         }
 118
 119         /* command string null-terminated by strtok */
 120         *str += strlen(*str) + 1;
 121
 122         type = next_arg(ctx, str, true, false);
 123         if (!uci_validate_str(type, false))
 124                 uci_parse_error(ctx, type, "invalid character in field");
 125         name = next_arg(ctx, str, false, true);
 126         assert_eol(ctx, str);
 127
 128         if (pctx->merge) {
 129                 UCI_TRAP_SAVE(ctx, error);
 130                 uci_set(ctx, pctx->package, name, NULL, type, NULL);
 131                 UCI_TRAP_RESTORE(ctx);
 132                 return;
 133 error:
 134                 UCI_THROW(ctx, ctx->errno);
 135         } else
 136                 pctx->section = uci_alloc_section(pctx->package, type, name);
 137 }
 138
 139 /*
 140  * parse the 'option' uci command (open a value)
 141  */
 142 static void uci_parse_option(struct uci_context *ctx, char **str)
 143 {
 144         struct uci_parse_context *pctx = ctx->pctx;
 145         char *name = NULL;
 146         char *value = NULL;
 147
 148         if (!pctx->section)
 149                 uci_parse_error(ctx, *str, "option command found before the first section");
 150
 151         /* command string null-terminated by strtok */
 152         *str += strlen(*str) + 1;
 153
 154         name = next_arg(ctx, str, true, true);
 155         value = next_arg(ctx, str, false, false);
 156         assert_eol(ctx, str);
 157
 158         if (pctx->merge) {
 159                 UCI_TRAP_SAVE(ctx, error);
 160                 uci_set(ctx, pctx->package, pctx->section->e.name, name, value, NULL);
 161                 UCI_TRAP_RESTORE(ctx);
 162                 return;
 163 error:
 164                 UCI_THROW(ctx, ctx->errno);
 165         } else
 166                 uci_alloc_option(pctx->section, name, value);
 167 }
 168
 169
 170 /*
 171  * parse a complete input line, split up combined commands by ';'
 172  */
 173 static void uci_parse_line(struct uci_context *ctx, bool single)
 174 {
 175         struct uci_parse_context *pctx = ctx->pctx;
 176         char *word, *brk = NULL;
 177
 178         for (word = strtok_r(pctx->buf, ";", &brk);
 179                  word;
 180                  word = strtok_r(NULL, ";", &brk)) {
 181
 182                 char *pbrk = NULL;
 183                 word = strtok_r(word, " \t", &pbrk);
 184
 185                 if (!word)
 186                         continue;
 187
 188                 switch(word[0]) {
 189                         case '#':
 190                                 return;
 191                         case 'p':
 192                                 if ((word[1] == 0) || !strcmp(word + 1, "ackage"))
 193                                         uci_parse_package(ctx, &word, single);
 194                                 break;
 195                         case 'c':
 196                                 if ((word[1] == 0) || !strcmp(word + 1, "onfig"))
 197                                         uci_parse_config(ctx, &word);
 198                                 break;
 199                         case 'o':
 200                                 if ((word[1] == 0) || !strcmp(word + 1, "ption"))
 201                                         uci_parse_option(ctx, &word);
 202                                 break;
 203                         default:
 204                                 uci_parse_error(ctx, word, "unterminated command");
 205                                 break;
 206                 }
 207         }
 208 }
 209
 210 /* max number of characters that escaping adds to the string */
 211 #define UCI_QUOTE_ESCAPE        "'\\''"
 212
 213 /*
 214  * escape an uci string for export
 215  */
 216 static char *uci_escape(struct uci_context *ctx, char *str)
 217 {
 218         char *s, *p;
 219         int pos = 0;
 220
 221         if (!ctx->buf) {
 222                 ctx->bufsz = LINEBUF;
 223                 ctx->buf = malloc(LINEBUF);
 224         }
 225
 226         s = str;
 227         p = strchr(str, '\'');
 228         if (!p)
 229                 return str;
 230
 231         do {
 232                 int len = p - s;
 233                 if (len > 0) {
 234                         if (p + sizeof(UCI_QUOTE_ESCAPE) - str >= ctx->bufsz) {
 235                                 ctx->bufsz *= 2;
 236                                 ctx->buf = realloc(ctx->buf, ctx->bufsz);
 237                                 if (!ctx->buf)
 238                                         UCI_THROW(ctx, UCI_ERR_MEM);
 239                         }
 240                         memcpy(&ctx->buf[pos], s, len);
 241                         pos += len;
 242                 }
 243                 strcpy(&ctx->buf[pos], UCI_QUOTE_ESCAPE);
 244                 pos += sizeof(UCI_QUOTE_ESCAPE);
 245                 s = p + 1;
 246         } while ((p = strchr(s, '\'')));
 247
 248         return ctx->buf;
 249 }
 250
 251
 252 /*
 253  * export a single config package to a file stream
 254  */
 255 static void uci_export_package(struct uci_package *p, FILE *stream, bool header)
 256 {
 257         struct uci_context *ctx = p->ctx;
 258         struct uci_element *s, *o;
 259
 260         if (header)
 261                 fprintf(stream, "package '%s'\n", uci_escape(ctx, p->e.name));
 262         uci_foreach_element(&p->sections, s) {
 263                 struct uci_section *sec = uci_to_section(s);
 264                 fprintf(stream, "\nconfig '%s'", uci_escape(ctx, sec->type));
 265                 if (!sec->anonymous || (ctx->flags & UCI_FLAG_EXPORT_NAME))
 266                         fprintf(stream, " '%s'", uci_escape(ctx, sec->e.name));
 267                 fprintf(stream, "\n");
 268                 uci_foreach_element(&sec->options, o) {
 269                         struct uci_option *opt = uci_to_option(o);
 270                         fprintf(stream, "\toption '%s'", uci_escape(ctx, opt->e.name));
 271                         fprintf(stream, " '%s'\n", uci_escape(ctx, opt->value));
 272                 }
 273         }
 274         fprintf(stream, "\n");
 275 }
 276
 277 int uci_export(struct uci_context *ctx, FILE *stream, struct uci_package *package, bool header)
 278 {
 279         struct uci_element *e;
 280
 281         UCI_HANDLE_ERR(ctx);
 282         UCI_ASSERT(ctx, stream != NULL);
 283
 284         if (package)
 285                 uci_export_package(package, stream, header);
 286         else {
 287                 uci_foreach_element(&ctx->root, e) {
 288                         uci_export_package(uci_to_package(e), stream, header);
 289                 }
 290         }
 291
 292         return 0;
 293 }
 294
 295 int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_package **package, bool single)
 296 {
 297         struct uci_parse_context *pctx;
 298         UCI_HANDLE_ERR(ctx);
 299
 300         /* make sure no memory from previous parse attempts is leaked */
 301         uci_file_cleanup(ctx);
 302
 303         uci_alloc_parse_context(ctx);
 304         pctx = ctx->pctx;
 305         pctx->file = stream;
 306         if (*package && single) {
 307                 pctx->package = *package;
 308                 pctx->merge = true;
 309         }
 310
 311         /*
 312          * If 'name' was supplied, assume that the supplied stream does not contain
 313          * the appropriate 'package <name>' string to specify the config name
 314          * NB: the config file can still override the package name
 315          */
 316         if (name) {
 317                 UCI_ASSERT(ctx, uci_validate_name(name));
 318                 pctx->name = name;
 319         }
 320
 321         while (!feof(pctx->file)) {
 322                 uci_getln(ctx, 0);
 323                 UCI_TRAP_SAVE(ctx, error);
 324                 if (pctx->buf[0])
 325                         uci_parse_line(ctx, single);
 326                 UCI_TRAP_RESTORE(ctx);
 327                 continue;
 328 error:
 329                 if (ctx->flags & UCI_FLAG_PERROR)
 330                         uci_perror(ctx, NULL);
 331                 if ((ctx->errno != UCI_ERR_PARSE) ||
 332                         (ctx->flags & UCI_FLAG_STRICT))
 333                         UCI_THROW(ctx, ctx->errno);
 334         }
 335
 336         uci_fixup_section(ctx, ctx->pctx->section);
 337         if (package)
 338                 *package = pctx->package;
 339         if (pctx->merge)
 340                 pctx->package = NULL;
 341
 342         pctx->name = NULL;
 343         uci_switch_config(ctx);
 344
 345         /* no error happened, we can get rid of the parser context now */
 346         uci_file_cleanup(ctx);
 347
 348         return 0;
 349 }
 350
 351
 352 static char *uci_config_path(struct uci_context *ctx, const char *name)
 353 {
 354         char *filename;
 355
 356         UCI_ASSERT(ctx, uci_validate_name(name));
 357         filename = uci_malloc(ctx, strlen(name) + strlen(ctx->confdir) + 2);
 358         sprintf(filename, "%s/%s", ctx->confdir, name);
 359
 360         return filename;
 361 }
 362
 363 int uci_load(struct uci_context *ctx, const char *name, struct uci_package **package)
 364 {
 365         char *filename;
 366         bool confdir;
 367         FILE *file = NULL;
 368
 369         UCI_HANDLE_ERR(ctx);
 370
 371         switch (name[0]) {
 372         case '.':
 373                 /* relative path outside of /etc/config */
 374                 if (name[1] != '/')
 375                         UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 376                 /* fall through */
 377         case '/':
 378                 /* absolute path outside of /etc/config */
 379                 filename = uci_strdup(ctx, name);
 380                 name = strrchr(name, '/') + 1;
 381                 confdir = false;
 382                 break;
 383         default:
 384                 /* config in /etc/config */
 385                 filename = uci_config_path(ctx, name);
 386                 confdir = true;
 387                 break;
 388         }
 389
 390         file = uci_open_stream(ctx, filename, SEEK_SET, false, false);
 391         ctx->errno = 0;
 392         UCI_TRAP_SAVE(ctx, done);
 393         UCI_INTERNAL(uci_import, ctx, file, name, package, true);
 394         UCI_TRAP_RESTORE(ctx);
 395
 396         if (*package) {
 397                 (*package)->path = filename;
 398                 (*package)->confdir = confdir;
 399                 uci_load_history(ctx, *package, false);
 400         }
 401
 402 done:
 403         uci_close_stream(file);
 404         return ctx->errno;
 405 }
 406
 407 int uci_commit(struct uci_context *ctx, struct uci_package **package, bool overwrite)
 408 {
 409         struct uci_package *p;
 410         FILE *f = NULL;
 411         char *name = NULL;
 412         char *path = NULL;
 413
 414         UCI_HANDLE_ERR(ctx);
 415         UCI_ASSERT(ctx, package != NULL);
 416         p = *package;
 417
 418         UCI_ASSERT(ctx, p != NULL);
 419         if (!p->path) {
 420                 if (overwrite)
 421                         p->path = uci_config_path(ctx, p->e.name);
 422                 else
 423                         UCI_THROW(ctx, UCI_ERR_INVAL);
 424         }
 425
 426
 427         /* open the config file for writing now, so that it is locked */
 428         f = uci_open_stream(ctx, p->path, SEEK_SET, true, true);
 429
 430         /* flush unsaved changes and reload from history file */
 431         UCI_TRAP_SAVE(ctx, done);
 432         if (p->confdir) {
 433                 if (!overwrite) {
 434                         name = uci_strdup(ctx, p->e.name);
 435                         path = uci_strdup(ctx, p->path);
 436                         /* dump our own changes to the history file */
 437                         if (!uci_list_empty(&p->history))
 438                                 UCI_INTERNAL(uci_save, ctx, p);
 439
 440                         /*
 441                          * other processes might have modified the config
 442                          * as well. dump and reload
 443                          */
 444                         uci_free_package(&p);
 445                         uci_file_cleanup(ctx);
 446                         UCI_INTERNAL(uci_import, ctx, f, name, &p, true);
 447
 448                         p->path = path;
 449                         p->confdir = true;
 450                         *package = p;
 451
 452                         /* freed together with the uci_package */
 453                         path = NULL;
 454
 455                         /* check for updated history, flush */
 456                         if (!uci_load_history(ctx, p, true))
 457                                 goto done;
 458                 } else {
 459                         /* flush history */
 460                         if (!uci_load_history(ctx, NULL, true))
 461                                 goto done;
 462                 }
 463         }
 464
 465         rewind(f);
 466         ftruncate(fileno(f), 0);
 467
 468         uci_export(ctx, f, p, false);
 469         UCI_TRAP_RESTORE(ctx);
 470
 471 done:
 472         if (name)
 473                 free(name);
 474         if (path)
 475                 free(path);
 476         uci_close_stream(f);
 477         if (ctx->errno)
 478                 UCI_THROW(ctx, ctx->errno);
 479
 480         return 0;
 481 }
 482
 483
 484 /*
 485  * This function returns the filename by returning the string
 486  * after the last '/' character. By checking for a non-'\0'
 487  * character afterwards, directories are ignored (glob marks
 488  * those with a trailing '/'
 489  */
 490 static inline char *get_filename(char *path)
 491 {
 492         char *p;
 493
 494         p = strrchr(path, '/');
 495         p++;
 496         if (!*p)
 497                 return NULL;
 498         return p;
 499 }
 500
 501 int uci_list_configs(struct uci_context *ctx, char ***list)
 502 {
 503         char **configs;
 504         glob_t globbuf;
 505         int size, i;
 506         char *buf;
 507         char *dir;
 508
 509         UCI_HANDLE_ERR(ctx);
 510
 511         dir = uci_malloc(ctx, strlen(ctx->confdir) + 1 + sizeof("/*"));
 512         sprintf(dir, "%s/*", ctx->confdir);
 513         if (glob(dir, GLOB_MARK, NULL, &globbuf) != 0)
 514                 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 515
 516         size = sizeof(char *) * (globbuf.gl_pathc + 1);
 517         for(i = 0; i < globbuf.gl_pathc; i++) {
 518                 char *p;
 519
 520                 p = get_filename(globbuf.gl_pathv[i]);
 521                 if (!p)
 522                         continue;
 523
 524                 size += strlen(p) + 1;
 525         }
 526
 527         configs = uci_malloc(ctx, size);
 528         buf = (char *) &configs[globbuf.gl_pathc + 1];
 529         for(i = 0; i < globbuf.gl_pathc; i++) {
 530                 char *p;
 531
 532                 p = get_filename(globbuf.gl_pathv[i]);
 533                 if (!p)
 534                         continue;
 535
 536                 configs[i] = buf;
 537                 strcpy(buf, p);
 538                 buf += strlen(buf) + 1;
 539         }
 540         *list = configs;
 541         free(dir);
 542
 543         return 0;
 544 }
 545