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   1 /*
   2  * wildcard.c
   3  *
   4  * Wildcard matching functions.
   5  */
   6
   7 /*
   8  * Copyright (C) 2013 Eric Biggers
   9  *
  10  * This file is part of wimlib, a library for working with WIM files.
  11  *
  12  * wimlib is free software; you can redistribute it and/or modify it under the
  13  * terms of the GNU General Public License as published by the Free
  14  * Software Foundation; either version 3 of the License, or (at your option)
  15  * any later version.
  16  *
  17  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
  18  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  19  * A PARTICULAR PURPOSE. See the GNU General Public License for more
  20  * details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with wimlib; if not, see http://www.gnu.org/licenses/.
  24  */
  25
  26 #ifdef HAVE_CONFIG_H
  27 #  include "config.h"
  28 #endif
  29
  30 #include <ctype.h>
  31 #include "wimlib/dentry.h"
  32 #include "wimlib/encoding.h"
  33 #include "wimlib/error.h"
  34 #include "wimlib/metadata.h"
  35 #include "wimlib/paths.h"
  36 #include "wimlib/wildcard.h"
  37
  38 struct match_dentry_ctx {
  39         int (*consume_dentry)(struct wim_dentry *, void *);
  40         void *consume_dentry_ctx;
  41         size_t consume_dentry_count;
  42         tchar *wildcard_path;
  43         size_t cur_component_offset;
  44         size_t cur_component_len;
  45         bool case_insensitive;
  46 };
  47
  48 static bool
  49 do_match_wildcard(const tchar *string, size_t string_len,
  50                   const tchar *wildcard, size_t wildcard_len,
  51                   bool ignore_case)
  52 {
  53         for (;;) {
  54                 if (string_len == 0) {
  55                         while (wildcard_len != 0 && *wildcard == T('*')) {
  56                                 wildcard++;
  57                                 wildcard_len--;
  58                         }
  59                         return (wildcard_len == 0);
  60                 } else if (wildcard_len == 0) {
  61                         return false;
  62                 } else if (*string == *wildcard || *wildcard == T('?') ||
  63                            (ignore_case && totlower(*string) == totlower(*wildcard)))
  64                 {
  65                         string++;
  66                         string_len--;
  67                         wildcard_len--;
  68                         wildcard++;
  69                         continue;
  70                 } else if (*wildcard == T('*')) {
  71                         return do_match_wildcard(string, string_len,
  72                                                  wildcard + 1, wildcard_len - 1,
  73                                                  ignore_case) ||
  74                                do_match_wildcard(string + 1, string_len - 1,
  75                                                  wildcard, wildcard_len,
  76                                                  ignore_case);
  77                 } else {
  78                         return false;
  79                 }
  80         }
  81 }
  82
  83 static bool
  84 match_wildcard(const tchar *string, const tchar *wildcard,
  85                size_t wildcard_len, bool ignore_case)
  86 {
  87         return do_match_wildcard(string, tstrlen(string),
  88                                  wildcard, wildcard_len, ignore_case);
  89 }
  90
  91 /*
  92  * Determines whether a path matches a wildcard pattern.
  93  *
  94  * @path
  95  *      The path to match.  Assumptions:  All path separators must be @path_sep,
  96  *      there cannot be consecutive path separators, there cannot be a trailing
  97  *      path separator, and there must be exactly one leading path separator.
  98  *
  99  * @path_nchars
 100  *      Number of characters in @path.
 101  *
 102  * @wildcard
 103  *      The wildcard pattern to match.  It can contain the wildcard characters
 104  *      '*' and '?'.  The former matches zero or more characters except
 105  *      @path_sep, and the latter matches any character except @path_sep.  All
 106  *      path separators in the pattern must be @path_sep, and there cannot be
 107  *      consecutive path separators, and there cannot be a trailing path
 108  *      separator.  If there is a leading path separator, the match is attempted
 109  *      with the filename only; otherwise, the match is attempted with the whole
 110  *      path.
 111  *
 112  * @path_sep
 113  *      Path separator character used in @path and @wildcard.
 114  *
 115  * @prefix_ok
 116  *      If %true, allow a prefix of @path, terminated by a path separator, to
 117  *      match the pattern, in addition to @path itself.  In other words, return
 118  *      %true if the pattern actually matches one of the ancestor directories of
 119  *      @path.
 120  *
 121  * Returns %true if there was a match; %false if there was not.
 122  */
 123 bool
 124 match_path(const tchar *path, size_t path_nchars,
 125            const tchar *wildcard, tchar path_sep, bool prefix_ok)
 126 {
 127         if (*wildcard != path_sep) {
 128                 /* Pattern doesn't begin with path separator.  Try to match the
 129                  * file name only.  */
 130                 return match_wildcard(path_basename_with_len(path, path_nchars),
 131                                       wildcard, tstrlen(wildcard),
 132                                       default_ignore_case);
 133         } else {
 134                 /* Pattern begins with path separator.  Try to match the whole
 135                  * path.  */
 136                 do {
 137                         if (!*wildcard) {
 138                                 /* Path has more components than pattern  */
 139                                 return prefix_ok;
 140                         }
 141
 142                         size_t path_component_len = 0;
 143                         size_t wildcard_component_len = 0;
 144
 145                         do {
 146                                 path_component_len++;
 147                         } while (path[path_component_len] != path_sep &&
 148                                  path[path_component_len] != T('\0'));
 149                         do {
 150                                 wildcard_component_len++;
 151                         } while (wildcard[wildcard_component_len] != path_sep &&
 152                                  wildcard[wildcard_component_len] != T('\0'));
 153                         if (!do_match_wildcard(path, path_component_len,
 154                                                wildcard, wildcard_component_len,
 155                                                default_ignore_case))
 156                                 return false;
 157                         path += path_component_len;
 158                         wildcard += wildcard_component_len;
 159                 } while (*path);
 160
 161                 return (*wildcard == '\0');
 162         }
 163 }
 164
 165 static int
 166 expand_wildcard_recursive(struct wim_dentry *cur_dentry,
 167                           struct match_dentry_ctx *ctx);
 168
 169 enum {
 170         WILDCARD_STATUS_DONE_FULLY,
 171         WILDCARD_STATUS_DONE_TRAILING_SLASHES,
 172         WILDCARD_STATUS_NOT_DONE,
 173 };
 174
 175 static int
 176 wildcard_status(const tchar *wildcard)
 177 {
 178         if (*wildcard == T('\0'))
 179                 return WILDCARD_STATUS_DONE_FULLY;
 180         while (*wildcard == WIM_PATH_SEPARATOR)
 181                 wildcard++;
 182         if (*wildcard == T('\0'))
 183                 return WILDCARD_STATUS_DONE_TRAILING_SLASHES;
 184
 185         return WILDCARD_STATUS_NOT_DONE;
 186 }
 187
 188 static int
 189 match_dentry(struct wim_dentry *cur_dentry, struct match_dentry_ctx *ctx)
 190 {
 191         const tchar *name;
 192         size_t name_nchars;
 193         int ret;
 194
 195         if (cur_dentry->file_name_nbytes == 0)
 196                 return 0;
 197
 198         ret = utf16le_get_tstr(cur_dentry->file_name,
 199                                cur_dentry->file_name_nbytes,
 200                                &name, &name_nchars);
 201         if (ret)
 202                 return ret;
 203         name_nchars /= sizeof(tchar);
 204
 205         if (do_match_wildcard(name,
 206                               name_nchars,
 207                               &ctx->wildcard_path[ctx->cur_component_offset],
 208                               ctx->cur_component_len,
 209                               ctx->case_insensitive))
 210         {
 211                 switch (wildcard_status(&ctx->wildcard_path[
 212                                 ctx->cur_component_offset +
 213                                 ctx->cur_component_len]))
 214                 {
 215                 case WILDCARD_STATUS_DONE_TRAILING_SLASHES:
 216                         if (!dentry_is_directory(cur_dentry)) {
 217                                 ret = 0;
 218                                 break;
 219                         }
 220                         /* Fall through  */
 221                 case WILDCARD_STATUS_DONE_FULLY:
 222                         ret = (*ctx->consume_dentry)(cur_dentry,
 223                                                      ctx->consume_dentry_ctx);
 224                         ctx->consume_dentry_count++;
 225                         break;
 226                 case WILDCARD_STATUS_NOT_DONE:
 227                         ret = expand_wildcard_recursive(cur_dentry, ctx);
 228                         break;
 229                 }
 230         } else {
 231                 ret = 0;
 232         }
 233
 234         utf16le_put_tstr(name);
 235
 236         return ret;
 237 }
 238
 239 static int
 240 expand_wildcard_recursive(struct wim_dentry *cur_dentry,
 241                           struct match_dentry_ctx *ctx)
 242 {
 243         tchar *w;
 244         size_t begin;
 245         size_t end;
 246         size_t len;
 247         size_t offset_save;
 248         size_t len_save;
 249         int ret;
 250         struct wim_dentry *child;
 251
 252         w = ctx->wildcard_path;
 253
 254         begin = ctx->cur_component_offset + ctx->cur_component_len;
 255         while (w[begin] == WIM_PATH_SEPARATOR)
 256                 begin++;
 257
 258         end = begin;
 259
 260         while (w[end] != T('\0') && w[end] != WIM_PATH_SEPARATOR)
 261                 end++;
 262
 263         len = end - begin;
 264
 265         if (len == 0)
 266                 return 0;
 267
 268         offset_save = ctx->cur_component_offset;
 269         len_save = ctx->cur_component_len;
 270
 271         ctx->cur_component_offset = begin;
 272         ctx->cur_component_len = len;
 273
 274         ret = 0;
 275         for_dentry_child(child, cur_dentry) {
 276                 ret = match_dentry(child, ctx);
 277                 if (ret)
 278                         break;
 279         }
 280
 281         ctx->cur_component_len = len_save;
 282         ctx->cur_component_offset = offset_save;
 283
 284         return ret;
 285 }
 286
 287 /* Expand a wildcard relative to the current WIM image.
 288  *
 289  * @wim
 290  *      WIMStruct whose currently selected image is searched to expand the
 291  *      wildcard.
 292  * @wildcard_path
 293  *      Wildcard path to expand, which may contain the '?' and '*' characters.
 294  *      Path separators must be WIM_PATH_SEPARATOR.  Leading path separators are
 295  *      ignored, whereas one or more trailing path separators indicate that the
 296  *      wildcard path can only match directories (and not reparse points).
 297  * @consume_dentry
 298  *      Callback function which will receive each directory entry matched by the
 299  *      wildcard.
 300  * @consume_dentry_ctx
 301  *      Argument to pass to @consume_dentry.
 302  * @flags
 303  *      Zero or more of the following flags:
 304  *
 305  *      WILDCARD_FLAG_WARN_IF_NO_MATCH:
 306  *              Issue a warning if the wildcard does not match any dentries.
 307  *
 308  *      WILDCARD_FLAG_ERROR_IF_NO_MATCH:
 309  *              Issue an error and return WIMLIB_ERR_PATH_DOES_NOT_EXIST if the
 310  *              wildcard does not match any dentries.
 311  *
 312  *      WILDCARD_FLAG_CASE_INSENSITIVE:
 313  *              Perform the matching case insensitively.  Note that this may
 314  *              cause @wildcard to match multiple dentries, even if it does not
 315  *              contain wildcard characters.
 316  *
 317  * @return 0 on success; a positive error code on error; or the first nonzero
 318  * value returned by @consume_dentry.
 319  */
 320 int
 321 expand_wildcard(WIMStruct *wim,
 322                 const tchar *wildcard_path,
 323                 int (*consume_dentry)(struct wim_dentry *, void *),
 324                 void *consume_dentry_ctx,
 325                 u32 flags)
 326 {
 327         struct wim_dentry *root;
 328         int ret;
 329
 330         root = wim_get_current_root_dentry(wim);
 331         if (root == NULL)
 332                 goto no_match;
 333
 334         struct match_dentry_ctx ctx = {
 335                 .consume_dentry = consume_dentry,
 336                 .consume_dentry_ctx = consume_dentry_ctx,
 337                 .consume_dentry_count = 0,
 338                 .wildcard_path = TSTRDUP(wildcard_path),
 339                 .cur_component_offset = 0,
 340                 .cur_component_len = 0,
 341                 .case_insensitive = ((flags & WILDCARD_FLAG_CASE_INSENSITIVE) != 0),
 342         };
 343
 344         if (ctx.wildcard_path == NULL)
 345                 return WIMLIB_ERR_NOMEM;
 346
 347         ret = expand_wildcard_recursive(root, &ctx);
 348         FREE(ctx.wildcard_path);
 349         if (ret == 0 && ctx.consume_dentry_count == 0)
 350                 goto no_match;
 351         return ret;
 352
 353 no_match:
 354         ret = 0;
 355         if (flags & WILDCARD_FLAG_WARN_IF_NO_MATCH)
 356                 WARNING("No matches for wildcard path \"%"TS"\"", wildcard_path);
 357
 358         if (flags & WILDCARD_FLAG_ERROR_IF_NO_MATCH) {
 359                 ERROR("No matches for wildcard path \"%"TS"\"", wildcard_path);
 360                 ret = WIMLIB_ERR_PATH_DOES_NOT_EXIST;
 361         }
 362         return ret;
 363 }