wimlib.net Git - wimlib/blob - src/unix_capture.c

   1 /*
   2  * unix_capture.c:  Capture a directory tree on UNIX.
   3  */
   4
   5 /*
   6  * Copyright (C) 2012, 2013, 2014 Eric Biggers
   7  *
   8  * This file is free software; you can redistribute it and/or modify it under
   9  * the terms of the GNU Lesser General Public License as published by the Free
  10  * Software Foundation; either version 3 of the License, or (at your option) any
  11  * later version.
  12  *
  13  * This file is distributed in the hope that it will be useful, but WITHOUT
  14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  15  * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
  16  * details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public License
  19  * along with this file; if not, see http://www.gnu.org/licenses/.
  20  */
  21
  22 #ifndef __WIN32__
  23
  24 #ifdef HAVE_CONFIG_H
  25 #  include "config.h"
  26 #endif
  27
  28 #include <dirent.h>
  29 #include <errno.h>
  30 #include <fcntl.h>
  31 #include <limits.h> /* for PATH_MAX */
  32 #include <sys/stat.h>
  33 #include <unistd.h>
  34
  35 #include "wimlib/blob_table.h"
  36 #include "wimlib/capture.h"
  37 #include "wimlib/dentry.h"
  38 #include "wimlib/error.h"
  39 #include "wimlib/reparse.h"
  40 #include "wimlib/timestamp.h"
  41 #include "wimlib/unix_data.h"
  42
  43 #ifdef HAVE_FDOPENDIR
  44 #  define my_fdopendir(dirfd_p) fdopendir(*(dirfd_p))
  45 #else
  46 static DIR *
  47 my_fdopendir(int *dirfd_p)
  48 {
  49         DIR *dir = NULL;
  50         int old_pwd;
  51
  52         old_pwd = open(".", O_RDONLY);
  53         if (old_pwd >= 0) {
  54                 if (!fchdir(*dirfd_p)) {
  55                         dir = opendir(".");
  56                         if (dir) {
  57                                 close(*dirfd_p);
  58                                 *dirfd_p = dirfd(dir);
  59                         }
  60                         fchdir(old_pwd);
  61                 }
  62                 close(old_pwd);
  63         }
  64         return dir;
  65 }
  66 #endif
  67
  68 #ifdef HAVE_OPENAT
  69 #  define my_openat(full_path, dirfd, relpath, flags) \
  70                 openat((dirfd), (relpath), (flags))
  71 #else
  72 #  define my_openat(full_path, dirfd, relpath, flags) \
  73                 open((full_path), (flags))
  74 #endif
  75
  76 #ifdef HAVE_READLINKAT
  77 #  define my_readlinkat(full_path, dirfd, relpath, buf, bufsize) \
  78                 readlinkat((dirfd), (relpath), (buf), (bufsize))
  79 #else
  80 #  define my_readlinkat(full_path, dirfd, relpath, buf, bufsize) \
  81                 readlink((full_path), (buf), (bufsize))
  82 #endif
  83
  84 #ifdef HAVE_FSTATAT
  85 #  define my_fstatat(full_path, dirfd, relpath, stbuf, flags)   \
  86         fstatat((dirfd), (relpath), (stbuf), (flags))
  87 #else
  88 #  define my_fstatat(full_path, dirfd, relpath, stbuf, flags)   \
  89         ((flags) & AT_SYMLINK_NOFOLLOW) ? \
  90                 lstat((full_path), (stbuf)) : \
  91                 stat((full_path), (stbuf))
  92 #endif
  93
  94 #ifndef AT_FDCWD
  95 #  define AT_FDCWD      -100
  96 #endif
  97
  98 #ifndef AT_SYMLINK_NOFOLLOW
  99 #  define AT_SYMLINK_NOFOLLOW   0x100
 100 #endif
 101
 102 static int
 103 unix_scan_regular_file(const char *path, u64 size, struct wim_inode *inode,
 104                        struct list_head *unhashed_blobs)
 105 {
 106         struct blob_descriptor *blob;
 107         struct wim_inode_stream *strm;
 108
 109         inode->i_attributes = FILE_ATTRIBUTE_NORMAL;
 110
 111         if (size) {
 112                 char *file_on_disk = STRDUP(path);
 113                 if (!file_on_disk)
 114                         return WIMLIB_ERR_NOMEM;
 115                 blob = new_blob_descriptor();
 116                 if (!blob) {
 117                         FREE(file_on_disk);
 118                         return WIMLIB_ERR_NOMEM;
 119                 }
 120                 blob->file_on_disk = file_on_disk;
 121                 blob->file_inode = inode;
 122                 blob->blob_location = BLOB_IN_FILE_ON_DISK;
 123                 blob->size = size;
 124         } else {
 125                 blob = NULL;
 126         }
 127
 128         strm = inode_add_stream(inode, STREAM_TYPE_DATA, NO_STREAM_NAME, blob);
 129         if (!strm) {
 130                 free_blob_descriptor(blob);
 131                 return WIMLIB_ERR_NOMEM;
 132         }
 133         prepare_unhashed_blob(blob, inode, strm->stream_id, unhashed_blobs);
 134         return 0;
 135 }
 136
 137 static int
 138 unix_build_dentry_tree_recursive(struct wim_dentry **tree_ret,
 139                                  char *path, size_t path_len,
 140                                  int dirfd, const char *relpath,
 141                                  struct capture_params *params);
 142
 143 static int
 144 unix_scan_directory(struct wim_dentry *dir_dentry,
 145                     char *full_path, size_t full_path_len,
 146                     int parent_dirfd, const char *dir_relpath,
 147                     struct capture_params *params)
 148 {
 149
 150         int dirfd;
 151         DIR *dir;
 152         int ret;
 153
 154         dirfd = my_openat(full_path, parent_dirfd, dir_relpath, O_RDONLY);
 155         if (dirfd < 0) {
 156                 ERROR_WITH_ERRNO("\"%s\": Can't open directory", full_path);
 157                 return WIMLIB_ERR_OPENDIR;
 158         }
 159
 160         dir_dentry->d_inode->i_attributes = FILE_ATTRIBUTE_DIRECTORY;
 161         dir = my_fdopendir(&dirfd);
 162         if (!dir) {
 163                 ERROR_WITH_ERRNO("\"%s\": Can't open directory", full_path);
 164                 close(dirfd);
 165                 return WIMLIB_ERR_OPENDIR;
 166         }
 167
 168         ret = 0;
 169         for (;;) {
 170                 struct dirent *entry;
 171                 struct wim_dentry *child;
 172                 size_t name_len;
 173
 174                 errno = 0;
 175                 entry = readdir(dir);
 176                 if (!entry) {
 177                         if (errno) {
 178                                 ret = WIMLIB_ERR_READ;
 179                                 ERROR_WITH_ERRNO("\"%s\": Error reading directory",
 180                                                  full_path);
 181                         }
 182                         break;
 183                 }
 184
 185                 if (entry->d_name[0] == '.' &&
 186                     (entry->d_name[1] == '\0' ||
 187                      (entry->d_name[1] == '.' && entry->d_name[2] == '\0')))
 188                         continue;
 189
 190                 full_path[full_path_len] = '/';
 191                 name_len = strlen(entry->d_name);
 192                 memcpy(&full_path[full_path_len + 1], entry->d_name, name_len + 1);
 193                 ret = unix_build_dentry_tree_recursive(&child,
 194                                                        full_path,
 195                                                        full_path_len + 1 + name_len,
 196                                                        dirfd,
 197                                                        &full_path[full_path_len + 1],
 198                                                        params);
 199                 full_path[full_path_len] = '\0';
 200                 if (ret)
 201                         break;
 202                 if (child)
 203                         dentry_add_child(dir_dentry, child);
 204         }
 205         closedir(dir);
 206         return ret;
 207 }
 208
 209 /* Given an absolute symbolic link target @dest (UNIX-style, beginning
 210  * with '/'), determine whether it points into the directory specified by
 211  * @ino and @dev.  If so, return the target modified to be "absolute"
 212  * relative to this directory.  Otherwise, return NULL.  */
 213 static char *
 214 unix_fixup_abslink(char *dest, u64 ino, u64 dev)
 215 {
 216         char *p = dest;
 217
 218         do {
 219                 char save;
 220                 struct stat stbuf;
 221                 int ret;
 222
 223                 /* Skip non-slashes.  */
 224                 while (*p && *p != '/')
 225                         p++;
 226
 227                 /* Skip slashes.  */
 228                 while (*p && *p == '/')
 229                         p++;
 230
 231                 /* Get inode and device for this prefix.  */
 232                 save = *p;
 233                 *p = '\0';
 234                 ret = stat(dest, &stbuf);
 235                 *p = save;
 236
 237                 if (ret) {
 238                         /* stat() failed.  Assume the link points outside the
 239                          * directory tree being captured.  */
 240                         break;
 241                 }
 242
 243                 if (stbuf.st_ino == ino && stbuf.st_dev == dev) {
 244                         /* Link points inside directory tree being captured.
 245                          * Return abbreviated path.  */
 246                         *--p = '/';
 247                         while (p > dest && *(p - 1) == '/')
 248                                 p--;
 249                         return p;
 250                 }
 251         } while (*p);
 252
 253         /* Link does not point inside directory tree being captured.  */
 254         return NULL;
 255 }
 256
 257 static int
 258 unix_scan_symlink(const char *full_path, int dirfd, const char *relpath,
 259                   struct wim_inode *inode, struct capture_params *params)
 260 {
 261         char deref_name_buf[4096];
 262         ssize_t deref_name_len;
 263         char *dest;
 264         int ret;
 265
 266         inode->i_attributes = FILE_ATTRIBUTE_REPARSE_POINT;
 267         inode->i_reparse_tag = WIM_IO_REPARSE_TAG_SYMLINK;
 268
 269         /* The idea here is to call readlink() to get the UNIX target of the
 270          * symbolic link, then turn the target into a reparse point data buffer
 271          * that contains a relative or absolute symbolic link. */
 272         deref_name_len = my_readlinkat(full_path, dirfd, relpath,
 273                                        deref_name_buf, sizeof(deref_name_buf) - 1);
 274         if (deref_name_len < 0) {
 275                 ERROR_WITH_ERRNO("\"%s\": Can't read target of symbolic link",
 276                                  full_path);
 277                 return WIMLIB_ERR_READLINK;
 278         }
 279
 280         dest = deref_name_buf;
 281
 282         dest[deref_name_len] = '\0';
 283
 284         if ((params->add_flags & WIMLIB_ADD_FLAG_RPFIX) &&
 285              dest[0] == '/')
 286         {
 287                 char *fixed_dest;
 288
 289                 /* RPFIX (reparse point fixup) mode:  Change target of absolute
 290                  * symbolic link to be "absolute" relative to the tree being
 291                  * captured.  */
 292                 fixed_dest = unix_fixup_abslink(dest,
 293                                                 params->capture_root_ino,
 294                                                 params->capture_root_dev);
 295                 params->progress.scan.cur_path = full_path;
 296                 params->progress.scan.symlink_target = deref_name_buf;
 297                 if (fixed_dest) {
 298                         /* Link points inside the tree being captured, so it was
 299                          * fixed.  */
 300                         inode->i_not_rpfixed = 0;
 301                         dest = fixed_dest;
 302                         ret = do_capture_progress(params,
 303                                                   WIMLIB_SCAN_DENTRY_FIXED_SYMLINK,
 304                                                   NULL);
 305                 } else {
 306                         /* Link points outside the tree being captured, so it
 307                          * was not fixed.  */
 308                         ret = do_capture_progress(params,
 309                                                   WIMLIB_SCAN_DENTRY_NOT_FIXED_SYMLINK,
 310                                                   NULL);
 311                 }
 312                 if (ret)
 313                         return ret;
 314         }
 315         ret = wim_inode_set_symlink(inode, dest, params->blob_table);
 316         if (ret)
 317                 return ret;
 318
 319         /* Unfortunately, Windows seems to have the concept of "file" symbolic
 320          * links as being different from "directory" symbolic links...  so
 321          * FILE_ATTRIBUTE_DIRECTORY needs to be set on the symbolic link if the
 322          * *target* of the symbolic link is a directory.  */
 323         struct stat stbuf;
 324         if (my_fstatat(full_path, dirfd, relpath, &stbuf, 0) == 0 &&
 325             S_ISDIR(stbuf.st_mode))
 326                 inode->i_attributes |= FILE_ATTRIBUTE_DIRECTORY;
 327         return 0;
 328 }
 329
 330 static int
 331 unix_build_dentry_tree_recursive(struct wim_dentry **tree_ret,
 332                                  char *full_path, size_t full_path_len,
 333                                  int dirfd, const char *relpath,
 334                                  struct capture_params *params)
 335 {
 336         struct wim_dentry *tree = NULL;
 337         struct wim_inode *inode = NULL;
 338         int ret;
 339         struct stat stbuf;
 340         int stat_flags;
 341
 342         ret = try_exclude(full_path, full_path_len, params);
 343         if (ret < 0) /* Excluded? */
 344                 goto out_progress;
 345         if (ret > 0) /* Error? */
 346                 goto out;
 347
 348         if (params->add_flags & (WIMLIB_ADD_FLAG_DEREFERENCE |
 349                                  WIMLIB_ADD_FLAG_ROOT))
 350                 stat_flags = 0;
 351         else
 352                 stat_flags = AT_SYMLINK_NOFOLLOW;
 353
 354         ret = my_fstatat(full_path, dirfd, relpath, &stbuf, stat_flags);
 355
 356         if (ret) {
 357                 ERROR_WITH_ERRNO("\"%s\": Can't read metadata", full_path);
 358                 ret = WIMLIB_ERR_STAT;
 359                 goto out;
 360         }
 361
 362         if (!(params->add_flags & WIMLIB_ADD_FLAG_UNIX_DATA)) {
 363                 if (unlikely(!S_ISREG(stbuf.st_mode) &&
 364                              !S_ISDIR(stbuf.st_mode) &&
 365                              !S_ISLNK(stbuf.st_mode)))
 366                 {
 367                         if (params->add_flags &
 368                             WIMLIB_ADD_FLAG_NO_UNSUPPORTED_EXCLUDE)
 369                         {
 370                                 ERROR("\"%s\": File type is unsupported",
 371                                       full_path);
 372                                 ret = WIMLIB_ERR_UNSUPPORTED_FILE;
 373                                 goto out;
 374                         }
 375                         params->progress.scan.cur_path = full_path;
 376                         ret = do_capture_progress(params,
 377                                                   WIMLIB_SCAN_DENTRY_UNSUPPORTED,
 378                                                   NULL);
 379                         goto out;
 380                 }
 381         }
 382
 383         ret = inode_table_new_dentry(params->inode_table, relpath,
 384                                      stbuf.st_ino, stbuf.st_dev,
 385                                      S_ISDIR(stbuf.st_mode), &tree);
 386         if (ret)
 387                 goto out;
 388
 389         inode = tree->d_inode;
 390
 391         /* Already seen this inode?  */
 392         if (inode->i_nlink > 1)
 393                 goto out_progress;
 394
 395 #ifdef HAVE_STAT_NANOSECOND_PRECISION
 396         inode->i_creation_time = timespec_to_wim_timestamp(&stbuf.st_mtim);
 397         inode->i_last_write_time = timespec_to_wim_timestamp(&stbuf.st_mtim);
 398         inode->i_last_access_time = timespec_to_wim_timestamp(&stbuf.st_atim);
 399 #else
 400         inode->i_creation_time = time_t_to_wim_timestamp(stbuf.st_mtime);
 401         inode->i_last_write_time = time_t_to_wim_timestamp(stbuf.st_mtime);
 402         inode->i_last_access_time = time_t_to_wim_timestamp(stbuf.st_atime);
 403 #endif
 404         if (params->add_flags & WIMLIB_ADD_FLAG_UNIX_DATA) {
 405                 struct wimlib_unix_data unix_data;
 406
 407                 unix_data.uid = stbuf.st_uid;
 408                 unix_data.gid = stbuf.st_gid;
 409                 unix_data.mode = stbuf.st_mode;
 410                 unix_data.rdev = stbuf.st_rdev;
 411                 if (!inode_set_unix_data(inode, &unix_data, UNIX_DATA_ALL)) {
 412                         ret = WIMLIB_ERR_NOMEM;
 413                         goto out;
 414                 }
 415         }
 416
 417         if (params->add_flags & WIMLIB_ADD_FLAG_ROOT) {
 418                 params->capture_root_ino = stbuf.st_ino;
 419                 params->capture_root_dev = stbuf.st_dev;
 420                 params->add_flags &= ~WIMLIB_ADD_FLAG_ROOT;
 421         }
 422
 423         if (S_ISREG(stbuf.st_mode)) {
 424                 ret = unix_scan_regular_file(full_path, stbuf.st_size,
 425                                              inode, params->unhashed_blobs);
 426         } else if (S_ISDIR(stbuf.st_mode)) {
 427                 ret = unix_scan_directory(tree, full_path, full_path_len,
 428                                           dirfd, relpath, params);
 429         } else if (S_ISLNK(stbuf.st_mode)) {
 430                 ret = unix_scan_symlink(full_path, dirfd, relpath,
 431                                         inode, params);
 432         }
 433
 434         if (ret)
 435                 goto out;
 436
 437 out_progress:
 438         params->progress.scan.cur_path = full_path;
 439         if (likely(tree))
 440                 ret = do_capture_progress(params, WIMLIB_SCAN_DENTRY_OK, inode);
 441         else
 442                 ret = do_capture_progress(params, WIMLIB_SCAN_DENTRY_EXCLUDED, NULL);
 443 out:
 444         if (unlikely(ret)) {
 445                 free_dentry_tree(tree, params->blob_table);
 446                 tree = NULL;
 447                 ret = report_capture_error(params, ret, full_path);
 448         }
 449         *tree_ret = tree;
 450         return ret;
 451 }
 452
 453 /*
 454  * unix_build_dentry_tree():
 455  *      Builds a tree of WIM dentries from an on-disk directory tree (UNIX
 456  *      version; no NTFS-specific data is captured).
 457  *
 458  * @root_ret:   Place to return a pointer to the root of the dentry tree.  Only
 459  *              modified if successful.  Set to NULL if the file or directory was
 460  *              excluded from capture.
 461  *
 462  * @root_disk_path:  The path to the root of the directory tree on disk.
 463  *
 464  * @params:     See doc for `struct capture_params'.
 465  *
 466  * @return:     0 on success, nonzero on failure.  It is a failure if any of
 467  *              the files cannot be `stat'ed, or if any of the needed
 468  *              directories cannot be opened or read.  Failure to add the files
 469  *              to the WIM may still occur later when trying to actually read
 470  *              the on-disk files during a call to wimlib_write() or
 471  *              wimlib_overwrite().
 472  */
 473 int
 474 unix_build_dentry_tree(struct wim_dentry **root_ret,
 475                        const char *root_disk_path,
 476                        struct capture_params *params)
 477 {
 478         size_t path_len;
 479         size_t path_bufsz;
 480         char *path_buf;
 481         int ret;
 482
 483         path_len = strlen(root_disk_path);
 484         path_bufsz = min(32790, PATH_MAX + 1);
 485
 486         if (path_len >= path_bufsz)
 487                 return WIMLIB_ERR_INVALID_PARAM;
 488
 489         path_buf = MALLOC(path_bufsz);
 490         if (!path_buf)
 491                 return WIMLIB_ERR_NOMEM;
 492         memcpy(path_buf, root_disk_path, path_len + 1);
 493
 494         params->capture_root_nchars = path_len;
 495
 496         ret = unix_build_dentry_tree_recursive(root_ret, path_buf, path_len,
 497                                                AT_FDCWD, path_buf, params);
 498         FREE(path_buf);
 499         return ret;
 500 }
 501
 502 #endif /* !__WIN32__ */