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   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 part of wimlib, a library for working with WIM files.
   9  *
  10  * wimlib is free software; you can redistribute it and/or modify it under the
  11  * terms of the GNU General Public License as published by the Free
  12  * Software Foundation; either version 3 of the License, or (at your option)
  13  * any later version.
  14  *
  15  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
  16  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  17  * A PARTICULAR PURPOSE. See the GNU General Public License for more
  18  * details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with wimlib; if not, see http://www.gnu.org/licenses/.
  22  */
  23
  24 #ifndef __WIN32__
  25
  26 #ifdef HAVE_CONFIG_H
  27 #  include "config.h"
  28 #endif
  29
  30 #include <dirent.h>
  31 #include <errno.h>
  32 #include <fcntl.h>
  33 #include <limits.h> /* for PATH_MAX */
  34 #include <sys/stat.h>
  35 #include <unistd.h>
  36
  37 #include "wimlib/capture.h"
  38 #include "wimlib/dentry.h"
  39 #include "wimlib/error.h"
  40 #include "wimlib/lookup_table.h"
  41 #include "wimlib/reparse.h"
  42 #include "wimlib/timestamp.h"
  43
  44 #ifdef HAVE_FDOPENDIR
  45 #  define my_fdopendir(dirfd_p) fdopendir(*(dirfd_p))
  46 #else
  47 static DIR *
  48 my_fdopendir(int *dirfd_p)
  49 {
  50         DIR *dir = NULL;
  51         int old_pwd;
  52
  53         old_pwd = open(".", O_RDONLY);
  54         if (old_pwd >= 0) {
  55                 if (!fchdir(*dirfd_p)) {
  56                         dir = opendir(".");
  57                         if (dir) {
  58                                 close(*dirfd_p);
  59                                 *dirfd_p = dirfd(dir);
  60                         }
  61                         fchdir(old_pwd);
  62                 }
  63                 close(old_pwd);
  64         }
  65         return dir;
  66 }
  67 #endif
  68
  69 #ifdef HAVE_OPENAT
  70 #  define my_openat(full_path, dirfd, relpath, flags) \
  71                 openat((dirfd), (relpath), (flags))
  72 #else
  73 #  define my_openat(full_path, dirfd, relpath, flags) \
  74                 open((full_path), (flags))
  75 #endif
  76
  77 #ifdef HAVE_READLINKAT
  78 #  define my_readlinkat(full_path, dirfd, relpath, buf, bufsize) \
  79                 readlinkat((dirfd), (relpath), (buf), (bufsize))
  80 #else
  81 #  define my_readlinkat(full_path, dirfd, relpath, buf, bufsize) \
  82                 readlink((full_path), (buf), (bufsize))
  83 #endif
  84
  85 #ifdef HAVE_FSTATAT
  86 #  define my_fstatat(full_path, dirfd, relpath, stbuf, flags)   \
  87         fstatat((dirfd), (relpath), (stbuf), (flags))
  88 #else
  89 #  define my_fstatat(full_path, dirfd, relpath, stbuf, flags)   \
  90         ((flags) & AT_SYMLINK_NOFOLLOW) ? \
  91                 lstat((full_path), (stbuf)) : \
  92                 stat((full_path), (stbuf))
  93 #endif
  94
  95 #ifndef AT_FDCWD
  96 #  define AT_FDCWD      -100
  97 #endif
  98
  99 #ifndef AT_SYMLINK_NOFOLLOW
 100 #  define AT_SYMLINK_NOFOLLOW   0x100
 101 #endif
 102
 103 static int
 104 unix_scan_regular_file(const char *path, u64 size, struct wim_inode *inode,
 105                        struct list_head *unhashed_streams)
 106 {
 107         struct wim_lookup_table_entry *lte;
 108         char *file_on_disk;
 109
 110         inode->i_attributes = FILE_ATTRIBUTE_NORMAL;
 111
 112         /* Empty files do not have to have a lookup table entry. */
 113         if (!size)
 114                 return 0;
 115
 116         file_on_disk = STRDUP(path);
 117         if (!file_on_disk)
 118                 return WIMLIB_ERR_NOMEM;
 119         lte = new_lookup_table_entry();
 120         if (!lte) {
 121                 FREE(file_on_disk);
 122                 return WIMLIB_ERR_NOMEM;
 123         }
 124         lte->file_on_disk = file_on_disk;
 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 add_image_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 add_image_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(struct wim_dentry **root_p, const char *full_path,
 254                   int dirfd, const char *relpath,
 255                   struct wim_inode *inode, struct add_image_params *params)
 256 {
 257         char deref_name_buf[4096];
 258         ssize_t deref_name_len;
 259         char *dest;
 260         int ret;
 261
 262         inode->i_attributes = FILE_ATTRIBUTE_REPARSE_POINT;
 263         inode->i_reparse_tag = WIM_IO_REPARSE_TAG_SYMLINK;
 264
 265         /* The idea here is to call readlink() to get the UNIX target of the
 266          * symbolic link, then turn the target into a reparse point data buffer
 267          * that contains a relative or absolute symbolic link. */
 268         deref_name_len = my_readlinkat(full_path, dirfd, relpath,
 269                                        deref_name_buf, sizeof(deref_name_buf) - 1);
 270         if (deref_name_len < 0) {
 271                 ERROR_WITH_ERRNO("\"%s\": Can't read target of symbolic link",
 272                                  full_path);
 273                 return WIMLIB_ERR_READLINK;
 274         }
 275
 276         dest = deref_name_buf;
 277
 278         dest[deref_name_len] = '\0';
 279
 280         if ((params->add_flags & WIMLIB_ADD_FLAG_RPFIX) &&
 281              dest[0] == '/')
 282         {
 283                 dest = unix_fixup_abslink(dest,
 284                                           params->capture_root_ino,
 285                                           params->capture_root_dev);
 286                 if (!dest) {
 287                         /* RPFIX (reparse point fixup) mode:  Ignore
 288                          * absolute symbolic link that points out of the
 289                          * tree to be captured.  */
 290                         free_dentry(*root_p);
 291                         *root_p = NULL;
 292                         params->progress.scan.cur_path = full_path;
 293                         params->progress.scan.symlink_target = deref_name_buf;
 294                         do_capture_progress(params,
 295                                             WIMLIB_SCAN_DENTRY_EXCLUDED_SYMLINK,
 296                                             NULL);
 297                         return 0;
 298                 }
 299                 inode->i_not_rpfixed = 0;
 300         }
 301         ret = wim_inode_set_symlink(inode, dest, params->lookup_table);
 302         if (ret)
 303                 return ret;
 304
 305         /* Unfortunately, Windows seems to have the concept of "file" symbolic
 306          * links as being different from "directory" symbolic links...  so
 307          * FILE_ATTRIBUTE_DIRECTORY needs to be set on the symbolic link if the
 308          * *target* of the symbolic link is a directory.  */
 309         struct stat stbuf;
 310         if (my_fstatat(full_path, dirfd, relpath, &stbuf, 0) == 0 &&
 311             S_ISDIR(stbuf.st_mode))
 312                 inode->i_attributes |= FILE_ATTRIBUTE_DIRECTORY;
 313         return 0;
 314 }
 315
 316 static int
 317 unix_build_dentry_tree_recursive(struct wim_dentry **tree_ret,
 318                                  char *full_path, size_t full_path_len,
 319                                  int dirfd, const char *relpath,
 320                                  struct add_image_params *params)
 321 {
 322         struct wim_dentry *tree = NULL;
 323         struct wim_inode *inode = NULL;
 324         int ret;
 325         struct stat stbuf;
 326         int stat_flags;
 327
 328         if (should_exclude_path(full_path + params->capture_root_nchars,
 329                                 full_path_len - params->capture_root_nchars,
 330                                 params->config))
 331         {
 332                 ret = 0;
 333                 goto out_progress;
 334         }
 335
 336         if (params->add_flags & (WIMLIB_ADD_FLAG_DEREFERENCE |
 337                                  WIMLIB_ADD_FLAG_ROOT))
 338                 stat_flags = 0;
 339         else
 340                 stat_flags = AT_SYMLINK_NOFOLLOW;
 341
 342         ret = my_fstatat(full_path, dirfd, relpath, &stbuf, stat_flags);
 343
 344         if (ret) {
 345                 ERROR_WITH_ERRNO("\"%s\": Can't read metadata", full_path);
 346                 ret = WIMLIB_ERR_STAT;
 347                 goto out;
 348         }
 349
 350         if (unlikely(!S_ISREG(stbuf.st_mode) &&
 351                      !S_ISDIR(stbuf.st_mode) &&
 352                      !S_ISLNK(stbuf.st_mode)))
 353         {
 354                 if (params->add_flags & WIMLIB_ADD_FLAG_NO_UNSUPPORTED_EXCLUDE)
 355                 {
 356                         ERROR("\"%s\": File type is unsupported", full_path);
 357                         ret = WIMLIB_ERR_UNSUPPORTED_FILE;
 358                         goto out;
 359                 }
 360                 params->progress.scan.cur_path = full_path;
 361                 do_capture_progress(params, WIMLIB_SCAN_DENTRY_UNSUPPORTED, NULL);
 362                 ret = 0;
 363                 goto out;
 364         }
 365
 366         ret = inode_table_new_dentry(params->inode_table, relpath,
 367                                      stbuf.st_ino, stbuf.st_dev,
 368                                      S_ISDIR(stbuf.st_mode), &tree);
 369         if (ret)
 370                 goto out;
 371
 372         inode = tree->d_inode;
 373
 374         if (inode->i_nlink > 1) {
 375                 /* Already seen this inode?  */
 376                 ret = 0;
 377                 goto out_progress;
 378         }
 379
 380 #ifdef HAVE_STAT_NANOSECOND_PRECISION
 381         inode->i_creation_time = timespec_to_wim_timestamp(stbuf.st_mtim);
 382         inode->i_last_write_time = timespec_to_wim_timestamp(stbuf.st_mtim);
 383         inode->i_last_access_time = timespec_to_wim_timestamp(stbuf.st_atim);
 384 #else
 385         inode->i_creation_time = unix_timestamp_to_wim(stbuf.st_mtime);
 386         inode->i_last_write_time = unix_timestamp_to_wim(stbuf.st_mtime);
 387         inode->i_last_access_time = unix_timestamp_to_wim(stbuf.st_atime);
 388 #endif
 389         inode->i_resolved = 1;
 390         if (params->add_flags & WIMLIB_ADD_FLAG_UNIX_DATA) {
 391                 inode->i_unix_data.uid = stbuf.st_uid;
 392                 inode->i_unix_data.gid = stbuf.st_gid;
 393                 inode->i_unix_data.mode = stbuf.st_mode;
 394         }
 395
 396         if (params->add_flags & WIMLIB_ADD_FLAG_ROOT) {
 397                 params->capture_root_ino = stbuf.st_ino;
 398                 params->capture_root_dev = stbuf.st_dev;
 399                 params->add_flags &= ~WIMLIB_ADD_FLAG_ROOT;
 400         }
 401
 402         if (S_ISREG(stbuf.st_mode)) {
 403                 ret = unix_scan_regular_file(full_path, stbuf.st_size,
 404                                              inode, params->unhashed_streams);
 405         } else if (S_ISDIR(stbuf.st_mode)) {
 406                 ret = unix_scan_directory(tree, full_path, full_path_len,
 407                                           dirfd, relpath, params);
 408         } else {
 409                 ret = unix_scan_symlink(&tree, full_path, dirfd, relpath,
 410                                         inode, params);
 411                 if (!tree)
 412                         goto out;
 413         }
 414
 415         if (ret)
 416                 goto out;
 417
 418 out_progress:
 419         params->progress.scan.cur_path = full_path;
 420         if (likely(tree))
 421                 do_capture_progress(params, WIMLIB_SCAN_DENTRY_OK, inode);
 422         else
 423                 do_capture_progress(params, WIMLIB_SCAN_DENTRY_EXCLUDED, NULL);
 424 out:
 425         if (likely(ret == 0))
 426                 *tree_ret = tree;
 427         else
 428                 free_dentry_tree(tree, params->lookup_table);
 429         return ret;
 430 }
 431
 432 /*
 433  * unix_build_dentry_tree():
 434  *      Builds a tree of WIM dentries from an on-disk directory tree (UNIX
 435  *      version; no NTFS-specific data is captured).
 436  *
 437  * @root_ret:   Place to return a pointer to the root of the dentry tree.  Only
 438  *              modified if successful.  Set to NULL if the file or directory was
 439  *              excluded from capture.
 440  *
 441  * @root_disk_path:  The path to the root of the directory tree on disk.
 442  *
 443  * @params:     See doc for `struct add_image_params'.
 444  *
 445  * @return:     0 on success, nonzero on failure.  It is a failure if any of
 446  *              the files cannot be `stat'ed, or if any of the needed
 447  *              directories cannot be opened or read.  Failure to add the files
 448  *              to the WIM may still occur later when trying to actually read
 449  *              the on-disk files during a call to wimlib_write() or
 450  *              wimlib_overwrite().
 451  */
 452 int
 453 unix_build_dentry_tree(struct wim_dentry **root_ret,
 454                        const char *root_disk_path,
 455                        struct add_image_params *params)
 456 {
 457         size_t path_len;
 458         size_t path_bufsz;
 459         char *path_buf;
 460         int ret;
 461
 462         path_len = strlen(root_disk_path);
 463         path_bufsz = min(32790, PATH_MAX + 1);
 464
 465         if (path_len >= path_bufsz)
 466                 return WIMLIB_ERR_INVALID_PARAM;
 467
 468         path_buf = MALLOC(path_bufsz);
 469         if (!path_buf)
 470                 return WIMLIB_ERR_NOMEM;
 471         memcpy(path_buf, root_disk_path, path_len + 1);
 472
 473         params->capture_root_nchars = path_len;
 474
 475         ret = unix_build_dentry_tree_recursive(root_ret, path_buf, path_len,
 476                                                AT_FDCWD, path_buf, params);
 477         FREE(path_buf);
 478         return ret;
 479 }
 480
 481 #endif /* !__WIN32__ */