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/capture.h"
  36 #include "wimlib/dentry.h"
  37 #include "wimlib/error.h"
  38 #include "wimlib/lookup_table.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_streams)
 105 {
 106         struct wim_lookup_table_entry *lte;
 107         char *file_on_disk;
 108
 109         inode->i_attributes = FILE_ATTRIBUTE_NORMAL;
 110
 111         /* Empty files do not have to have a lookup table entry. */
 112         if (!size)
 113                 return 0;
 114
 115         file_on_disk = STRDUP(path);
 116         if (!file_on_disk)
 117                 return WIMLIB_ERR_NOMEM;
 118         lte = new_lookup_table_entry();
 119         if (!lte) {
 120                 FREE(file_on_disk);
 121                 return WIMLIB_ERR_NOMEM;
 122         }
 123         lte->file_on_disk = file_on_disk;
 124         lte->file_inode = inode;
 125         lte->resource_location = RESOURCE_IN_FILE_ON_DISK;
 126         lte->size = size;
 127         add_unhashed_stream(lte, inode, 0, unhashed_streams);
 128         inode->i_lte = lte;
 129         return 0;
 130 }
 131
 132 static int
 133 unix_build_dentry_tree_recursive(struct wim_dentry **tree_ret,
 134                                  char *path, size_t path_len,
 135                                  int dirfd, const char *relpath,
 136                                  struct capture_params *params);
 137
 138 static int
 139 unix_scan_directory(struct wim_dentry *dir_dentry,
 140                     char *full_path, size_t full_path_len,
 141                     int parent_dirfd, const char *dir_relpath,
 142                     struct capture_params *params)
 143 {
 144
 145         int dirfd;
 146         DIR *dir;
 147         int ret;
 148
 149         dirfd = my_openat(full_path, parent_dirfd, dir_relpath, O_RDONLY);
 150         if (dirfd < 0) {
 151                 ERROR_WITH_ERRNO("\"%s\": Can't open directory", full_path);
 152                 return WIMLIB_ERR_OPENDIR;
 153         }
 154
 155         dir_dentry->d_inode->i_attributes = FILE_ATTRIBUTE_DIRECTORY;
 156         dir = my_fdopendir(&dirfd);
 157         if (!dir) {
 158                 ERROR_WITH_ERRNO("\"%s\": Can't open directory", full_path);
 159                 close(dirfd);
 160                 return WIMLIB_ERR_OPENDIR;
 161         }
 162
 163         ret = 0;
 164         for (;;) {
 165                 struct dirent *entry;
 166                 struct wim_dentry *child;
 167                 size_t name_len;
 168
 169                 errno = 0;
 170                 entry = readdir(dir);
 171                 if (!entry) {
 172                         if (errno) {
 173                                 ret = WIMLIB_ERR_READ;
 174                                 ERROR_WITH_ERRNO("\"%s\": Error reading directory",
 175                                                  full_path);
 176                         }
 177                         break;
 178                 }
 179
 180                 if (entry->d_name[0] == '.' &&
 181                     (entry->d_name[1] == '\0' ||
 182                      (entry->d_name[1] == '.' && entry->d_name[2] == '\0')))
 183                         continue;
 184
 185                 full_path[full_path_len] = '/';
 186                 name_len = strlen(entry->d_name);
 187                 memcpy(&full_path[full_path_len + 1], entry->d_name, name_len + 1);
 188                 ret = unix_build_dentry_tree_recursive(&child,
 189                                                        full_path,
 190                                                        full_path_len + 1 + name_len,
 191                                                        dirfd,
 192                                                        &full_path[full_path_len + 1],
 193                                                        params);
 194                 full_path[full_path_len] = '\0';
 195                 if (ret)
 196                         break;
 197                 if (child)
 198                         dentry_add_child(dir_dentry, child);
 199         }
 200         closedir(dir);
 201         return ret;
 202 }
 203
 204 /* Given an absolute symbolic link target @dest (UNIX-style, beginning
 205  * with '/'), determine whether it points into the directory specified by
 206  * @ino and @dev.  If so, return the target modified to be "absolute"
 207  * relative to this directory.  Otherwise, return NULL.  */
 208 static char *
 209 unix_fixup_abslink(char *dest, u64 ino, u64 dev)
 210 {
 211         char *p = dest;
 212
 213         do {
 214                 char save;
 215                 struct stat stbuf;
 216                 int ret;
 217
 218                 /* Skip non-slashes.  */
 219                 while (*p && *p != '/')
 220                         p++;
 221
 222                 /* Skip slashes.  */
 223                 while (*p && *p == '/')
 224                         p++;
 225
 226                 /* Get inode and device for this prefix.  */
 227                 save = *p;
 228                 *p = '\0';
 229                 ret = stat(dest, &stbuf);
 230                 *p = save;
 231
 232                 if (ret) {
 233                         /* stat() failed.  Assume the link points outside the
 234                          * directory tree being captured.  */
 235                         break;
 236                 }
 237
 238                 if (stbuf.st_ino == ino && stbuf.st_dev == dev) {
 239                         /* Link points inside directory tree being captured.
 240                          * Return abbreviated path.  */
 241                         *--p = '/';
 242                         while (p > dest && *(p - 1) == '/')
 243                                 p--;
 244                         return p;
 245                 }
 246         } while (*p);
 247
 248         /* Link does not point inside directory tree being captured.  */
 249         return NULL;
 250 }
 251
 252 static int
 253 unix_scan_symlink(const char *full_path, int dirfd, const char *relpath,
 254                   struct wim_inode *inode, struct capture_params *params)
 255 {
 256         char deref_name_buf[4096];
 257         ssize_t deref_name_len;
 258         char *dest;
 259         int ret;
 260
 261         inode->i_attributes = FILE_ATTRIBUTE_REPARSE_POINT;
 262         inode->i_reparse_tag = WIM_IO_REPARSE_TAG_SYMLINK;
 263
 264         /* The idea here is to call readlink() to get the UNIX target of the
 265          * symbolic link, then turn the target into a reparse point data buffer
 266          * that contains a relative or absolute symbolic link. */
 267         deref_name_len = my_readlinkat(full_path, dirfd, relpath,
 268                                        deref_name_buf, sizeof(deref_name_buf) - 1);
 269         if (deref_name_len < 0) {
 270                 ERROR_WITH_ERRNO("\"%s\": Can't read target of symbolic link",
 271                                  full_path);
 272                 return WIMLIB_ERR_READLINK;
 273         }
 274
 275         dest = deref_name_buf;
 276
 277         dest[deref_name_len] = '\0';
 278
 279         if ((params->add_flags & WIMLIB_ADD_FLAG_RPFIX) &&
 280              dest[0] == '/')
 281         {
 282                 char *fixed_dest;
 283
 284                 /* RPFIX (reparse point fixup) mode:  Change target of absolute
 285                  * symbolic link to be "absolute" relative to the tree being
 286                  * captured.  */
 287                 fixed_dest = unix_fixup_abslink(dest,
 288                                                 params->capture_root_ino,
 289                                                 params->capture_root_dev);
 290                 params->progress.scan.cur_path = full_path;
 291                 params->progress.scan.symlink_target = deref_name_buf;
 292                 if (fixed_dest) {
 293                         /* Link points inside the tree being captured, so it was
 294                          * fixed.  */
 295                         inode->i_not_rpfixed = 0;
 296                         dest = fixed_dest;
 297                         ret = do_capture_progress(params,
 298                                                   WIMLIB_SCAN_DENTRY_FIXED_SYMLINK,
 299                                                   NULL);
 300                 } else {
 301                         /* Link points outside the tree being captured, so it
 302                          * was not fixed.  */
 303                         ret = do_capture_progress(params,
 304                                                   WIMLIB_SCAN_DENTRY_NOT_FIXED_SYMLINK,
 305                                                   NULL);
 306                 }
 307                 if (ret)
 308                         return ret;
 309         }
 310         ret = wim_inode_set_symlink(inode, dest, params->lookup_table);
 311         if (ret)
 312                 return ret;
 313
 314         /* Unfortunately, Windows seems to have the concept of "file" symbolic
 315          * links as being different from "directory" symbolic links...  so
 316          * FILE_ATTRIBUTE_DIRECTORY needs to be set on the symbolic link if the
 317          * *target* of the symbolic link is a directory.  */
 318         struct stat stbuf;
 319         if (my_fstatat(full_path, dirfd, relpath, &stbuf, 0) == 0 &&
 320             S_ISDIR(stbuf.st_mode))
 321                 inode->i_attributes |= FILE_ATTRIBUTE_DIRECTORY;
 322         return 0;
 323 }
 324
 325 static int
 326 unix_build_dentry_tree_recursive(struct wim_dentry **tree_ret,
 327                                  char *full_path, size_t full_path_len,
 328                                  int dirfd, const char *relpath,
 329                                  struct capture_params *params)
 330 {
 331         struct wim_dentry *tree = NULL;
 332         struct wim_inode *inode = NULL;
 333         int ret;
 334         struct stat stbuf;
 335         int stat_flags;
 336
 337         ret = try_exclude(full_path, full_path_len, params);
 338         if (ret < 0) /* Excluded? */
 339                 goto out_progress;
 340         if (ret > 0) /* Error? */
 341                 goto out;
 342
 343         if (params->add_flags & (WIMLIB_ADD_FLAG_DEREFERENCE |
 344                                  WIMLIB_ADD_FLAG_ROOT))
 345                 stat_flags = 0;
 346         else
 347                 stat_flags = AT_SYMLINK_NOFOLLOW;
 348
 349         ret = my_fstatat(full_path, dirfd, relpath, &stbuf, stat_flags);
 350
 351         if (ret) {
 352                 ERROR_WITH_ERRNO("\"%s\": Can't read metadata", full_path);
 353                 ret = WIMLIB_ERR_STAT;
 354                 goto out;
 355         }
 356
 357         if (!(params->add_flags & WIMLIB_ADD_FLAG_UNIX_DATA)) {
 358                 if (unlikely(!S_ISREG(stbuf.st_mode) &&
 359                              !S_ISDIR(stbuf.st_mode) &&
 360                              !S_ISLNK(stbuf.st_mode)))
 361                 {
 362                         if (params->add_flags &
 363                             WIMLIB_ADD_FLAG_NO_UNSUPPORTED_EXCLUDE)
 364                         {
 365                                 ERROR("\"%s\": File type is unsupported",
 366                                       full_path);
 367                                 ret = WIMLIB_ERR_UNSUPPORTED_FILE;
 368                                 goto out;
 369                         }
 370                         params->progress.scan.cur_path = full_path;
 371                         ret = do_capture_progress(params,
 372                                                   WIMLIB_SCAN_DENTRY_UNSUPPORTED,
 373                                                   NULL);
 374                         goto out;
 375                 }
 376         }
 377
 378         ret = inode_table_new_dentry(params->inode_table, relpath,
 379                                      stbuf.st_ino, stbuf.st_dev,
 380                                      S_ISDIR(stbuf.st_mode), &tree);
 381         if (ret)
 382                 goto out;
 383
 384         inode = tree->d_inode;
 385
 386         /* Already seen this inode?  */
 387         if (inode->i_nlink > 1)
 388                 goto out_progress;
 389
 390 #ifdef HAVE_STAT_NANOSECOND_PRECISION
 391         inode->i_creation_time = timespec_to_wim_timestamp(&stbuf.st_mtim);
 392         inode->i_last_write_time = timespec_to_wim_timestamp(&stbuf.st_mtim);
 393         inode->i_last_access_time = timespec_to_wim_timestamp(&stbuf.st_atim);
 394 #else
 395         inode->i_creation_time = time_t_to_wim_timestamp(stbuf.st_mtime);
 396         inode->i_last_write_time = time_t_to_wim_timestamp(stbuf.st_mtime);
 397         inode->i_last_access_time = time_t_to_wim_timestamp(stbuf.st_atime);
 398 #endif
 399         inode->i_resolved = 1;
 400         if (params->add_flags & WIMLIB_ADD_FLAG_UNIX_DATA) {
 401                 struct wimlib_unix_data unix_data;
 402
 403                 unix_data.uid = stbuf.st_uid;
 404                 unix_data.gid = stbuf.st_gid;
 405                 unix_data.mode = stbuf.st_mode;
 406                 unix_data.rdev = stbuf.st_rdev;
 407                 if (!inode_set_unix_data(inode, &unix_data, UNIX_DATA_ALL)) {
 408                         ret = WIMLIB_ERR_NOMEM;
 409                         goto out;
 410                 }
 411         }
 412
 413         if (params->add_flags & WIMLIB_ADD_FLAG_ROOT) {
 414                 params->capture_root_ino = stbuf.st_ino;
 415                 params->capture_root_dev = stbuf.st_dev;
 416                 params->add_flags &= ~WIMLIB_ADD_FLAG_ROOT;
 417         }
 418
 419         if (S_ISREG(stbuf.st_mode)) {
 420                 ret = unix_scan_regular_file(full_path, stbuf.st_size,
 421                                              inode, params->unhashed_streams);
 422         } else if (S_ISDIR(stbuf.st_mode)) {
 423                 ret = unix_scan_directory(tree, full_path, full_path_len,
 424                                           dirfd, relpath, params);
 425         } else if (S_ISLNK(stbuf.st_mode)) {
 426                 ret = unix_scan_symlink(full_path, dirfd, relpath,
 427                                         inode, params);
 428         }
 429
 430         if (ret)
 431                 goto out;
 432
 433 out_progress:
 434         params->progress.scan.cur_path = full_path;
 435         if (likely(tree))
 436                 ret = do_capture_progress(params, WIMLIB_SCAN_DENTRY_OK, inode);
 437         else
 438                 ret = do_capture_progress(params, WIMLIB_SCAN_DENTRY_EXCLUDED, NULL);
 439 out:
 440         if (unlikely(ret)) {
 441                 free_dentry_tree(tree, params->lookup_table);
 442                 tree = NULL;
 443                 ret = report_capture_error(params, ret, full_path);
 444         }
 445         *tree_ret = tree;
 446         return ret;
 447 }
 448
 449 /*
 450  * unix_build_dentry_tree():
 451  *      Builds a tree of WIM dentries from an on-disk directory tree (UNIX
 452  *      version; no NTFS-specific data is captured).
 453  *
 454  * @root_ret:   Place to return a pointer to the root of the dentry tree.  Only
 455  *              modified if successful.  Set to NULL if the file or directory was
 456  *              excluded from capture.
 457  *
 458  * @root_disk_path:  The path to the root of the directory tree on disk.
 459  *
 460  * @params:     See doc for `struct capture_params'.
 461  *
 462  * @return:     0 on success, nonzero on failure.  It is a failure if any of
 463  *              the files cannot be `stat'ed, or if any of the needed
 464  *              directories cannot be opened or read.  Failure to add the files
 465  *              to the WIM may still occur later when trying to actually read
 466  *              the on-disk files during a call to wimlib_write() or
 467  *              wimlib_overwrite().
 468  */
 469 int
 470 unix_build_dentry_tree(struct wim_dentry **root_ret,
 471                        const char *root_disk_path,
 472                        struct capture_params *params)
 473 {
 474         size_t path_len;
 475         size_t path_bufsz;
 476         char *path_buf;
 477         int ret;
 478
 479         path_len = strlen(root_disk_path);
 480         path_bufsz = min(32790, PATH_MAX + 1);
 481
 482         if (path_len >= path_bufsz)
 483                 return WIMLIB_ERR_INVALID_PARAM;
 484
 485         path_buf = MALLOC(path_bufsz);
 486         if (!path_buf)
 487                 return WIMLIB_ERR_NOMEM;
 488         memcpy(path_buf, root_disk_path, path_len + 1);
 489
 490         params->capture_root_nchars = path_len;
 491
 492         ret = unix_build_dentry_tree_recursive(root_ret, path_buf, path_len,
 493                                                AT_FDCWD, path_buf, params);
 494         FREE(path_buf);
 495         return ret;
 496 }
 497
 498 #endif /* !__WIN32__ */