1 /* remove.c -- core functions for removing files and directories
2 Copyright (C) 88, 90, 91, 1994-2006 Free Software Foundation, Inc.
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2, or (at your option)
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.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software Foundation,
16 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
18 /* Extracted from rm.c and librarified, then rewritten by Jim Meyering. */
22 #include <sys/types.h>
27 #include "cycle-check.h"
31 #include "euidaccess.h"
32 #include "euidaccess-stat.h"
33 #include "file-type.h"
41 #include "root-dev-ino.h"
42 #include "unlinkdir.h"
45 /* Avoid shadowing warnings because these are functions declared
46 in dirname.h as well as locals used below. */
47 #define dir_name rm_dir_name
48 #define dir_len rm_dir_len
50 #define obstack_chunk_alloc malloc
51 #define obstack_chunk_free free
53 /* This is the maximum number of consecutive readdir/unlink calls that
54 can be made (with no intervening rewinddir or closedir/opendir)
55 before triggering a bug that makes readdir return NULL even though
56 some directory entries have not been processed. The bug afflicts
57 SunOS's readdir when applied to ufs file systems and Darwin 6.5's
58 (and OSX v.10.3.8's) HFS+. This maximum is conservative in that
59 demonstrating the problem seems to require a directory containing
60 at least 254 deletable entries (which doesn't count . and ..), so
61 we could conceivably increase the maximum value to 254. */
64 CONSECUTIVE_READDIR_UNLINK_THRESHOLD = 200
73 typedef enum Ternary Ternary;
75 /* The prompt function may be called twice for a given directory.
76 The first time, we ask whether to descend into it, and the
77 second time, we ask whether to remove it. */
80 PA_DESCEND_INTO_DIR = 2,
84 /* Initial capacity of per-directory hash table of entries that have
85 been processed but not been deleted. */
86 enum { HT_UNREMOVABLE_INITIAL_CAPACITY = 13 };
88 /* An entry in the active directory stack.
89 Each entry corresponds to an `active' directory. */
92 /* For a given active directory, this is the set of names of
93 entries in that directory that could/should not be removed.
94 For example, `.' and `..', as well as files/dirs for which
95 unlink/rmdir failed e.g., due to access restrictions. */
96 Hash_table *unremovable;
98 /* Record the status for a given active directory; we need to know
99 whether an entry was not removed, either because of an error or
100 because the user declined. */
101 enum RM_status status;
103 /* The directory's dev/ino. Used to ensure that a malicious user does
104 not replace a directory we're about to process with a symlink to
105 some other directory. */
106 struct dev_ino dev_ino;
109 extern char *program_name;
111 struct dirstack_state
113 /* The name of the directory (starting with and relative to a command
114 line argument) being processed. When a subdirectory is entered, a new
115 component is appended (pushed). Remove (pop) the top component
116 upon chdir'ing out of a directory. This is used to form the full
117 name of the current directory or a file therein, when necessary. */
118 struct obstack dir_stack;
120 /* Stack of lengths of directory names (including trailing slash)
121 appended to dir_stack. We have to have a separate stack of lengths
122 (rather than just popping back to previous slash) because the first
123 element pushed onto the dir stack may contain slashes. */
124 struct obstack len_stack;
126 /* Stack of active directory entries.
127 The first `active' directory is the initial working directory.
128 Additional active dirs are pushed onto the stack as we `chdir'
129 into each directory to be processed. When finished with the
130 hierarchy under a directory, pop the active dir stack. */
131 struct obstack Active_dir;
133 /* Used to detect cycles. */
134 struct cycle_check_state cycle_check_state;
136 /* Target of a longjmp in case rm has to stop processing the current
137 command-line argument. This happens 1) when rm detects a directory
138 cycle or 2) when it has processed one or more directories, but then
139 is unable to return to the initial working directory to process
140 additional `.'-relative command-line arguments. */
141 jmp_buf current_arg_jumpbuf;
143 typedef struct dirstack_state Dirstack_state;
145 /* Just like close(fd), but don't modify errno. */
147 close_preserve_errno (int fd)
149 int saved_errno = errno;
150 int result = close (fd);
162 hash_compare_strings (void const *x, void const *y)
164 return STREQ (x, y) ? true : false;
168 push_dir (Dirstack_state *ds, const char *dir_name)
170 size_t len = strlen (dir_name);
172 /* Append the string onto the stack. */
173 obstack_grow (&ds->dir_stack, dir_name, len);
175 /* Append a trailing slash. */
176 obstack_1grow (&ds->dir_stack, '/');
178 /* Add one for the slash. */
181 /* Push the length (including slash) onto its stack. */
182 obstack_grow (&ds->len_stack, &len, sizeof (len));
185 /* Return the entry name of the directory on the top of the stack
186 in malloc'd storage. */
188 top_dir (Dirstack_state const *ds)
190 size_t n_lengths = obstack_object_size (&ds->len_stack) / sizeof (size_t);
191 size_t *length = obstack_base (&ds->len_stack);
192 size_t top_len = length[n_lengths - 1];
193 char const *p = obstack_next_free (&ds->dir_stack) - top_len;
194 char *q = xmalloc (top_len);
195 memcpy (q, p, top_len - 1);
201 pop_dir (Dirstack_state *ds)
203 size_t n_lengths = obstack_object_size (&ds->len_stack) / sizeof (size_t);
204 size_t *length = obstack_base (&ds->len_stack);
206 assert (n_lengths > 0);
207 size_t top_len = length[n_lengths - 1];
208 assert (top_len >= 2);
210 /* Pop the specified length of file name. */
211 assert (obstack_object_size (&ds->dir_stack) >= top_len);
212 obstack_blank (&ds->dir_stack, -top_len);
214 /* Pop the length stack, too. */
215 assert (obstack_object_size (&ds->len_stack) >= sizeof (size_t));
216 obstack_blank (&ds->len_stack, -(int) sizeof (size_t));
219 /* Copy the SRC_LEN bytes of data beginning at SRC into the DST_LEN-byte
220 buffer, DST, so that the last source byte is at the end of the destination
221 buffer. If SRC_LEN is longer than DST_LEN, then set *TRUNCATED.
222 Set *RESULT to point to the beginning of (the portion of) the source data
223 in DST. Return the number of bytes remaining in the destination buffer. */
226 right_justify (char *dst, size_t dst_len, const char *src, size_t src_len,
227 char **result, bool *truncated)
232 if (src_len <= dst_len)
235 dp = dst + (dst_len - src_len);
240 sp = src + (src_len - dst_len);
246 *result = memcpy (dp, sp, src_len);
247 return dst_len - src_len;
250 /* Using the global directory name obstack, create the full name FILENAME.
251 Return it in sometimes-realloc'd space that should not be freed by the
252 caller. Realloc as necessary. If realloc fails, use a static buffer
253 and put as long a suffix in that buffer as possible. */
255 #define full_filename(Filename) full_filename_ (ds, Filename)
257 full_filename_ (Dirstack_state const *ds, const char *filename)
259 static char *buf = NULL;
260 static size_t n_allocated = 0;
262 size_t dir_len = obstack_object_size (&ds->dir_stack);
263 char *dir_name = obstack_base (&ds->dir_stack);
264 size_t n_bytes_needed;
267 filename_len = strlen (filename);
268 n_bytes_needed = dir_len + filename_len + 1;
270 if (n_allocated < n_bytes_needed)
272 /* This code requires that realloc accept NULL as the first arg.
273 This function must not use xrealloc. Otherwise, an out-of-memory
274 error involving a file name to be expanded here wouldn't ever
275 be issued. Use realloc and fall back on using a static buffer
276 if memory allocation fails. */
277 char *new_buf = realloc (buf, n_bytes_needed);
278 n_allocated = n_bytes_needed;
282 #define SBUF_SIZE 512
283 #define ELLIPSES_PREFIX "[...]"
284 static char static_buf[SBUF_SIZE];
290 len = right_justify (static_buf, SBUF_SIZE, filename,
291 filename_len + 1, &p, &truncated);
292 right_justify (static_buf, len, dir_name, dir_len, &p, &truncated);
295 memcpy (static_buf, ELLIPSES_PREFIX,
296 sizeof (ELLIPSES_PREFIX) - 1);
304 if (filename_len == 1 && *filename == '.' && dir_len)
306 /* FILENAME is just `.' and dir_len is nonzero.
307 Copy the directory part, omitting the trailing slash,
308 and append a trailing zero byte. */
309 char *p = mempcpy (buf, dir_name, dir_len - 1);
314 /* Copy the directory part, including trailing slash, and then
315 append the filename part, including a trailing zero byte. */
316 memcpy (mempcpy (buf, dir_name, dir_len), filename, filename_len + 1);
317 assert (strlen (buf) + 1 == n_bytes_needed);
324 AD_stack_height (Dirstack_state const *ds)
326 return obstack_object_size (&ds->Active_dir) / sizeof (struct AD_ent);
329 static inline struct AD_ent *
330 AD_stack_top (Dirstack_state const *ds)
332 return (struct AD_ent *)
333 ((char *) obstack_next_free (&ds->Active_dir) - sizeof (struct AD_ent));
337 AD_stack_pop (Dirstack_state *ds)
339 assert (0 < AD_stack_height (ds));
341 /* operate on Active_dir. pop and free top entry */
342 struct AD_ent *top = AD_stack_top (ds);
343 if (top->unremovable)
344 hash_free (top->unremovable);
345 obstack_blank (&ds->Active_dir, -(int) sizeof (struct AD_ent));
348 static Dirstack_state *
351 Dirstack_state *ds = xmalloc (sizeof *ds);
352 obstack_init (&ds->dir_stack);
353 obstack_init (&ds->len_stack);
354 obstack_init (&ds->Active_dir);
359 ds_clear (Dirstack_state *ds)
361 obstack_free (&ds->dir_stack, obstack_finish (&ds->dir_stack));
362 obstack_free (&ds->len_stack, obstack_finish (&ds->len_stack));
363 while (0 < AD_stack_height (ds))
365 obstack_free (&ds->Active_dir, obstack_finish (&ds->Active_dir));
369 ds_free (Dirstack_state *ds)
371 obstack_free (&ds->dir_stack, NULL);
372 obstack_free (&ds->len_stack, NULL);
373 obstack_free (&ds->Active_dir, NULL);
377 /* Pop the active directory (AD) stack and move *DIRP `up' one level,
378 safely. Moving `up' usually means opening `..', but when we've just
379 finished recursively processing a command-line directory argument,
380 there's nothing left on the stack, so set *DIRP to NULL in that case.
381 The idea is to return with *DIRP opened on the parent directory,
382 assuming there are entries in that directory that we need to remove.
384 Whenever using chdir '..' (virtually, now, via openat), verify
385 that the post-chdir dev/ino numbers for `.' match the saved ones.
386 If any system call fails or if dev/ino don't match then give a
387 diagnostic and longjump out.
388 Set *PREV_DIR to the name (in malloc'd storage) of the
389 directory (usually now empty) from which we're coming, and which
390 corresponds to the input value of *DIRP. */
392 AD_pop_and_chdir (DIR **dirp, Dirstack_state *ds, char **prev_dir)
394 enum RM_status old_status = AD_stack_top(ds)->status;
397 /* Get the name of the current (but soon to be `previous') directory
398 from the top of the stack. */
399 *prev_dir = top_dir (ds);
403 top = AD_stack_top (ds);
405 /* Propagate any failure to parent. */
406 UPDATE_STATUS (top->status, old_status);
408 assert (AD_stack_height (ds));
410 if (1 < AD_stack_height (ds))
413 int fd = openat (dirfd (*dirp), "..", O_RDONLY);
414 if (CLOSEDIR (*dirp) != 0)
416 error (0, errno, _("FATAL: failed to close directory %s"),
417 quote (full_filename (*prev_dir)));
418 goto next_cmdline_arg;
421 /* The above fails with EACCES when *DIRP is readable but not
422 searchable, when using Solaris' openat. Without this openat
423 call, tests/rm2 would fail to remove directories a/2 and a/3. */
425 fd = openat (AT_FDCWD, full_filename ("."), O_RDONLY);
429 error (0, errno, _("FATAL: cannot open .. from %s"),
430 quote (full_filename (*prev_dir)));
431 goto next_cmdline_arg;
437 _("FATAL: cannot ensure %s (returned to via ..) is safe"),
438 quote (full_filename (".")));
442 /* Ensure that post-chdir dev/ino match the stored ones. */
443 if ( ! SAME_INODE (sb, top->dev_ino))
445 error (0, 0, _("FATAL: directory %s changed dev/ino"),
446 quote (full_filename (".")));
450 *dirp = fdopendir (fd);
453 error (0, errno, _("FATAL: cannot return to .. from %s"),
454 quote (full_filename (".")));
460 longjmp (ds->current_arg_jumpbuf, 1);
465 if (CLOSEDIR (*dirp) != 0)
467 error (0, errno, _("FATAL: failed to close directory %s"),
468 quote (full_filename (*prev_dir)));
469 goto next_cmdline_arg;
475 /* Initialize *HT if it is NULL.
476 Insert FILENAME into HT. */
478 AD_mark_helper (Hash_table **ht, char const *filename)
482 *ht = hash_initialize (HT_UNREMOVABLE_INITIAL_CAPACITY, NULL, hash_pjw,
483 hash_compare_strings, hash_freer);
487 if (! hash_insert (*ht, filename))
491 /* Mark FILENAME (in current directory) as unremovable. */
493 AD_mark_as_unremovable (Dirstack_state *ds, char const *filename)
495 AD_mark_helper (&AD_stack_top(ds)->unremovable, xstrdup (filename));
498 /* Mark the current directory as unremovable. I.e., mark the entry
499 in the parent directory corresponding to `.'.
500 This happens e.g., when an opendir fails and the only name
501 the caller has conveniently at hand is `.'. */
503 AD_mark_current_as_unremovable (Dirstack_state *ds)
505 struct AD_ent *top = AD_stack_top (ds);
506 char const *curr = top_dir (ds);
508 assert (1 < AD_stack_height (ds));
511 AD_mark_helper (&top->unremovable, curr);
514 /* Push an initial dummy entry onto the stack.
515 This will always be the bottommost entry on the stack. */
517 AD_push_initial (Dirstack_state *ds)
521 /* Extend the stack. */
522 obstack_blank (&ds->Active_dir, sizeof (struct AD_ent));
524 /* Fill in the new values. */
525 top = AD_stack_top (ds);
526 top->unremovable = NULL;
528 /* These should never be used.
529 Give them values that might look suspicious
530 in a debugger or in a diagnostic. */
531 top->dev_ino.st_dev = TYPE_MAXIMUM (dev_t);
532 top->dev_ino.st_ino = TYPE_MAXIMUM (ino_t);
535 /* Push info about the current working directory (".") onto the
536 active directory stack. DIR is the ./-relative name through
537 which we've just `chdir'd to this directory. DIR_SB_FROM_PARENT
538 is the result of calling lstat on DIR from the parent of DIR.
539 Longjump out (skipping the entire command line argument we're
540 dealing with) if `fstat (FD_CWD, ...' fails or if someone has
541 replaced DIR with e.g., a symlink to some other directory. */
543 AD_push (int fd_cwd, Dirstack_state *ds, char const *dir,
544 struct stat const *dir_sb_from_parent)
550 /* If our uses of openat are guaranteed not to
551 follow a symlink, then we can skip this check. */
555 if (fstat (fd_cwd, &sb) != 0)
557 error (0, errno, _("FATAL: cannot enter directory %s"),
558 quote (full_filename (".")));
559 longjmp (ds->current_arg_jumpbuf, 1);
562 if ( ! SAME_INODE (sb, *dir_sb_from_parent))
565 _("FATAL: just-changed-to directory %s changed dev/ino"),
566 quote (full_filename (".")));
567 longjmp (ds->current_arg_jumpbuf, 1);
571 /* Extend the stack. */
572 obstack_blank (&ds->Active_dir, sizeof (struct AD_ent));
574 /* The active directory stack must be one larger than the length stack. */
575 assert (AD_stack_height (ds) ==
576 1 + obstack_object_size (&ds->len_stack) / sizeof (size_t));
578 /* Fill in the new values. */
579 top = AD_stack_top (ds);
580 top->dev_ino.st_dev = dir_sb_from_parent->st_dev;
581 top->dev_ino.st_ino = dir_sb_from_parent->st_ino;
582 top->unremovable = NULL;
586 AD_is_removable (Dirstack_state const *ds, char const *file)
588 struct AD_ent *top = AD_stack_top (ds);
589 return ! (top->unremovable && hash_lookup (top->unremovable, file));
592 /* Return true if DIR is determined to be an empty directory. */
594 is_empty_dir (int fd_cwd, char const *dir)
597 struct dirent const *dp;
599 int fd = openat (fd_cwd, dir,
600 (O_RDONLY | O_DIRECTORY
601 | O_NOCTTY | O_NOFOLLOW | O_NONBLOCK));
606 dirp = fdopendir (fd);
614 dp = readdir_ignoring_dot_and_dotdot (dirp);
619 return saved_errno == 0 ? true : false;
622 /* Return true if FILE is determined to be an unwritable non-symlink.
623 Otherwise, return false (including when lstat'ing it fails).
624 If lstat (aka fstatat) succeeds, set *BUF_P to BUF.
625 This is to avoid calling euidaccess when FILE is a symlink. */
627 write_protected_non_symlink (int fd_cwd,
629 Dirstack_state const *ds,
633 if (fstatat (fd_cwd, file, buf, AT_SYMLINK_NOFOLLOW) != 0)
636 if (S_ISLNK (buf->st_mode))
638 /* Here, we know FILE is not a symbolic link. */
640 /* In order to be reentrant -- i.e., to avoid changing the working
641 directory, and at the same time to be able to deal with alternate
642 access control mechanisms (ACLs, xattr-style attributes) and
643 arbitrarily deep trees -- we need a function like eaccessat, i.e.,
644 like Solaris' eaccess, but fd-relative, in the spirit of openat. */
646 /* In the absence of a native eaccessat function, here are some of
647 the implementation choices [#4 and #5 were suggested by Paul Eggert]:
648 1) call openat with O_WRONLY|O_NOCTTY
649 Disadvantage: may create the file and doesn't work for directory,
650 may mistakenly report `unwritable' for EROFS or ACLs even though
651 perm bits say the file is writable.
653 2) fake eaccessat (save_cwd, fchdir, call euidaccess, restore_cwd)
654 Disadvantage: changes working directory (not reentrant) and can't
655 work if save_cwd fails.
657 3) if (euidaccess (full_filename (file), W_OK) == 0)
658 Disadvantage: doesn't work if full_filename is too long.
659 Inefficient for very deep trees (O(Depth^2)).
661 4) If the full pathname is sufficiently short (say, less than
662 PATH_MAX or 8192 bytes, whichever is shorter):
663 use method (3) (i.e., euidaccess (full_filename (file), W_OK));
664 Otherwise: vfork, fchdir in the child, run euidaccess in the
665 child, then the child exits with a status that tells the parent
666 whether euidaccess succeeded.
668 This avoids the O(N**2) algorithm of method (3), and it also avoids
669 the failure-due-to-too-long-file-names of method (3), but it's fast
670 in the normal shallow case. It also avoids the lack-of-reentrancy
671 and the save_cwd problems.
672 Disadvantage; it uses a process slot for very-long file names,
673 and would be very slow for hierarchies with many such files.
675 5) If the full file name is sufficiently short (say, less than
676 PATH_MAX or 8192 bytes, whichever is shorter):
677 use method (3) (i.e., euidaccess (full_filename (file), W_OK));
678 Otherwise: look just at the file bits. Perhaps issue a warning
679 the first time this occurs.
681 This is like (4), except for the "Otherwise" case where it isn't as
682 "perfect" as (4) but is considerably faster. It conforms to current
683 POSIX, and is uniformly better than what Solaris and FreeBSD do (they
684 mess up with long file names). */
687 /* This implements #5: */
689 = obstack_object_size (&ds->dir_stack) + strlen (file);
691 return (file_name_len < MIN (PATH_MAX, 8192)
692 ? euidaccess (full_filename (file), W_OK) != 0 && errno == EACCES
693 : euidaccess_stat (buf, W_OK) != 0);
697 /* Prompt whether to remove FILENAME, if required via a combination of
698 the options specified by X and/or file attributes. If the file may
699 be removed, return RM_OK. If the user declines to remove the file,
700 return RM_USER_DECLINED. If not ignoring missing files and we
701 cannot lstat FILENAME, then return RM_ERROR.
703 Depending on MODE, ask whether to `descend into' or to `remove' the
704 directory FILENAME. MODE is ignored when FILENAME is not a directory.
705 Set *IS_EMPTY to T_YES if FILENAME is an empty directory, and it is
706 appropriate to try to remove it with rmdir (e.g. recursive mode).
707 Don't even try to set *IS_EMPTY when MODE == PA_REMOVE_DIR.
708 Set *IS_DIR to T_YES or T_NO if we happen to determine whether
709 FILENAME is a directory. */
710 static enum RM_status
711 prompt (int fd_cwd, Dirstack_state const *ds, char const *filename,
712 struct rm_options const *x, enum Prompt_action mode,
713 Ternary *is_dir, Ternary *is_empty)
715 bool write_protected = false;
716 struct stat *sbuf = NULL;
719 *is_empty = T_UNKNOWN;
722 if (((!x->ignore_missing_files & (x->interactive | x->stdin_tty))
723 && (write_protected = write_protected_non_symlink (fd_cwd, filename,
730 if (fstatat (fd_cwd, filename, sbuf, AT_SYMLINK_NOFOLLOW))
732 /* lstat failed. This happens e.g., with `rm '''. */
733 error (0, errno, _("cannot remove %s"),
734 quote (full_filename (filename)));
739 if (S_ISDIR (sbuf->st_mode) && !x->recursive)
741 error (0, EISDIR, _("cannot remove directory %s"),
742 quote (full_filename (filename)));
746 /* Using permissions doesn't make sense for symlinks. */
747 if (S_ISLNK (sbuf->st_mode))
749 if ( ! x->interactive)
751 write_protected = false;
754 /* Issue the prompt. */
756 char const *quoted_name = quote (full_filename (filename));
758 *is_dir = (S_ISDIR (sbuf->st_mode) ? T_YES : T_NO);
760 /* FIXME: use a variant of error (instead of fprintf) that doesn't
761 append a newline. Then we won't have to declare program_name in
763 if (S_ISDIR (sbuf->st_mode)
765 && mode == PA_DESCEND_INTO_DIR
766 && ((*is_empty = (is_empty_dir (fd_cwd, filename) ? T_YES : T_NO))
770 ? _("%s: descend into write-protected directory %s? ")
771 : _("%s: descend into directory %s? ")),
772 program_name, quoted_name);
775 /* TRANSLATORS: You may find it more convenient to translate
776 the equivalent of _("%s: remove %s (write-protected) %s? ").
777 It should avoid grammatical problems with the output
781 ? _("%s: remove write-protected %s %s? ")
782 : _("%s: remove %s %s? ")),
783 program_name, file_type (sbuf), quoted_name);
787 return RM_USER_DECLINED;
793 /* Return true if FILENAME is a directory (and not a symlink to a directory).
794 Otherwise, including the case in which lstat fails, return false.
795 Do not modify errno. */
797 is_dir_lstat (char const *filename)
800 int saved_errno = errno;
801 bool is_dir = lstat (filename, &sbuf) == 0 && S_ISDIR (sbuf.st_mode);
806 #if HAVE_STRUCT_DIRENT_D_TYPE
808 /* True if the type of the directory entry D is known. */
809 # define DT_IS_KNOWN(d) ((d)->d_type != DT_UNKNOWN)
811 /* True if the type of the directory entry D must be T. */
812 # define DT_MUST_BE(d, t) ((d)->d_type == (t))
815 # define DT_IS_KNOWN(d) false
816 # define DT_MUST_BE(d, t) false
819 #define DO_UNLINK(Fd_cwd, Filename, X) \
822 if (unlinkat (Fd_cwd, Filename, 0) == 0) \
825 printf (_("removed %s\n"), quote (full_filename (Filename))); \
829 if (errno == ENOENT && (X)->ignore_missing_files) \
834 #define DO_RMDIR(Fd_cwd, Filename, X) \
837 if (unlinkat (Fd_cwd, Filename, AT_REMOVEDIR) == 0) /* rmdir */ \
840 printf (_("removed directory: %s\n"), \
841 quote (full_filename (Filename))); \
845 if (errno == ENOENT && (X)->ignore_missing_files) \
848 if (errno == ENOTEMPTY || errno == EEXIST) \
849 return RM_NONEMPTY_DIR; \
853 /* Remove the file or directory specified by FILENAME.
854 Return RM_OK if it is removed, and RM_ERROR or RM_USER_DECLINED if not.
855 But if FILENAME specifies a non-empty directory, return RM_NONEMPTY_DIR. */
857 static enum RM_status
858 remove_entry (int fd_cwd, Dirstack_state const *ds, char const *filename,
859 struct rm_options const *x, struct dirent const *dp)
862 Ternary is_empty_directory;
863 enum RM_status s = prompt (fd_cwd, ds, filename, x, PA_DESCEND_INTO_DIR,
864 &is_dir, &is_empty_directory);
869 /* Why bother with the following if/else block? Because on systems with
870 an unlink function that *can* unlink directories, we must determine the
871 type of each entry before removing it. Otherwise, we'd risk unlinking
872 an entire directory tree simply by unlinking a single directory; then
873 all the storage associated with that hierarchy would not be freed until
874 the next fsck. Not nice. To avoid that, on such slightly losing
875 systems, we need to call lstat to determine the type of each entry,
876 and that represents extra overhead that -- it turns out -- we can
877 avoid on non-losing systems, since there, unlink will never remove
878 a directory. Also, on systems where unlink may unlink directories,
879 we're forced to allow a race condition: we lstat a non-directory, then
880 go to unlink it, but in the mean time, a malicious someone could have
881 replaced it with a directory. */
883 if (cannot_unlink_dir ())
885 if (is_dir == T_YES && ! x->recursive)
887 error (0, EISDIR, _("cannot remove directory %s"),
888 quote (full_filename (filename)));
892 /* is_empty_directory is set iff it's ok to use rmdir.
893 Note that it's set only in interactive mode -- in which case it's
894 an optimization that arranges so that the user is asked just
895 once whether to remove the directory. */
896 if (is_empty_directory == T_YES)
897 DO_RMDIR (fd_cwd, filename, x);
899 /* If we happen to know that FILENAME is a directory, return now
900 and let the caller remove it -- this saves the overhead of a failed
901 unlink call. If FILENAME is a command-line argument, then dp is NULL,
902 so we'll first try to unlink it. Using unlink here is ok, because it
903 cannot remove a directory. */
904 if ((dp && DT_MUST_BE (dp, DT_DIR)) || is_dir == T_YES)
905 return RM_NONEMPTY_DIR;
907 DO_UNLINK (fd_cwd, filename, x);
909 /* Upon a failed attempt to unlink a directory, most non-Linux systems
910 set errno to the POSIX-required value EPERM. In that case, change
911 errno to EISDIR so that we emit a better diagnostic. */
912 if (! x->recursive && errno == EPERM && is_dir_lstat (filename))
916 || errno == ENOENT || errno == ENOTDIR
917 || errno == ELOOP || errno == ENAMETOOLONG)
919 /* Either --recursive is not in effect, or the file cannot be a
920 directory. Report the unlink problem and fail. */
921 error (0, errno, _("cannot remove %s"),
922 quote (full_filename (filename)));
928 /* If we don't already know whether FILENAME is a directory, find out now.
929 Then, if it's a non-directory, we can use unlink on it. */
930 if (is_dir == T_UNKNOWN)
932 if (dp && DT_IS_KNOWN (dp))
933 is_dir = DT_MUST_BE (dp, DT_DIR) ? T_YES : T_NO;
937 if (fstatat (fd_cwd, filename, &sbuf, AT_SYMLINK_NOFOLLOW))
939 if (errno == ENOENT && x->ignore_missing_files)
942 error (0, errno, _("cannot remove %s"),
943 quote (full_filename (filename)));
947 is_dir = S_ISDIR (sbuf.st_mode) ? T_YES : T_NO;
953 /* At this point, barring race conditions, FILENAME is known
954 to be a non-directory, so it's ok to try to unlink it. */
955 DO_UNLINK (fd_cwd, filename, x);
957 /* unlink failed with some other error code. report it. */
958 error (0, errno, _("cannot remove %s"),
959 quote (full_filename (filename)));
965 error (0, EISDIR, _("cannot remove directory %s"),
966 quote (full_filename (filename)));
970 if (is_empty_directory == T_YES)
972 DO_RMDIR (fd_cwd, filename, x);
973 /* Don't diagnose any failure here.
974 It'll be detected when the caller tries another way. */
978 return RM_NONEMPTY_DIR;
981 /* Given FD_CWD, the file descriptor for an open directory,
982 open its subdirectory F (F is already `known' to be a directory,
983 so if it is no longer one, someone is playing games), return a DIR*
984 pointer for F, and put F's `stat' data in *SUBDIR_SB.
985 Upon failure give a diagnostic and return NULL.
986 If PREV_ERRNO is nonzero, it is the errno value from a preceding failed
987 unlink- or rmdir-like system call -- use that value instead of ENOTDIR
988 if an opened file turns out not to be a directory. This is important
989 when the preceding non-dir-unlink failed due to e.g., EPERM or EACCES.
990 The caller must use a nonnnull CWD_ERRNO the first
991 time this function is called for each command-line-specified directory.
992 If CWD_ERRNO is not null, set *CWD_ERRNO to the appropriate error number
993 if this function fails to restore the initial working directory.
994 If it is null, report an error and exit if the working directory
997 fd_to_subdirp (int fd_cwd, char const *f,
998 struct rm_options const *x, int prev_errno,
999 struct stat *subdir_sb, Dirstack_state *ds,
1000 int *cwd_errno ATTRIBUTE_UNUSED)
1002 int open_flags = O_RDONLY | O_NOCTTY | O_NOFOLLOW | O_NONBLOCK;
1003 int fd_sub = openat_permissive (fd_cwd, f, open_flags, 0, cwd_errno);
1005 /* Record dev/ino of F. We may compare them against saved values
1006 to thwart any attempt to subvert the traversal. They are also used
1007 to detect directory cycles. */
1008 if (fd_sub < 0 || fstat (fd_sub, subdir_sb) != 0)
1011 close_preserve_errno (fd_sub);
1015 if (! S_ISDIR (subdir_sb->st_mode))
1017 errno = prev_errno ? prev_errno : ENOTDIR;
1018 close_preserve_errno (fd_sub);
1022 DIR *subdir_dirp = fdopendir (fd_sub);
1023 if (subdir_dirp == NULL)
1025 close_preserve_errno (fd_sub);
1032 /* Remove entries in the directory open on DIRP
1033 Upon finding a directory that is both non-empty and that can be chdir'd
1034 into, return RM_OK and set *SUBDIR and fill in SUBDIR_SB, where
1035 SUBDIR is the malloc'd name of the subdirectory if the chdir succeeded,
1036 NULL otherwise (e.g., if opendir failed or if there was no subdirectory).
1037 Likewise, SUBDIR_SB is the result of calling lstat on SUBDIR.
1038 Return RM_OK if all entries are removed. Return RM_ERROR if any
1039 entry cannot be removed. Otherwise, return RM_USER_DECLINED if
1040 the user declines to remove at least one entry. Remove as much as
1041 possible, continuing even if we fail to remove some entries. */
1042 static enum RM_status
1043 remove_cwd_entries (DIR **dirp,
1044 Dirstack_state *ds, char **subdir, struct stat *subdir_sb,
1045 struct rm_options const *x)
1047 struct AD_ent *top = AD_stack_top (ds);
1048 enum RM_status status = top->status;
1049 size_t n_unlinked_since_opendir_or_last_rewind = 0;
1051 assert (VALID_STATUS (status));
1056 struct dirent const *dp;
1057 enum RM_status tmp_status;
1060 /* Set errno to zero so we can distinguish between a readdir failure
1061 and when readdir simply finds that there are no more entries. */
1063 dp = readdir_ignoring_dot_and_dotdot (*dirp);
1070 else if (CONSECUTIVE_READDIR_UNLINK_THRESHOLD
1071 < n_unlinked_since_opendir_or_last_rewind)
1073 /* Call rewinddir if we've called unlink or rmdir so many times
1074 (since the opendir or the previous rewinddir) that this
1075 NULL-return may be the symptom of a buggy readdir. */
1077 n_unlinked_since_opendir_or_last_rewind = 0;
1085 /* Skip files we've already tried/failed to remove. */
1086 if ( ! AD_is_removable (ds, f))
1089 /* Pass dp->d_type info to remove_entry so the non-glibc
1090 case can decide whether to use unlink or chdir.
1091 Systems without the d_type member will have to endure
1092 the performance hit of first calling lstat F. */
1093 tmp_status = remove_entry (dirfd (*dirp), ds, f, x, dp);
1097 /* Count how many files we've unlinked since the initial
1098 opendir or the last rewinddir. On buggy systems, if you
1099 remove too many, readdir returns NULL even though there
1100 remain unprocessed directory entries. */
1101 ++n_unlinked_since_opendir_or_last_rewind;
1105 case RM_USER_DECLINED:
1106 AD_mark_as_unremovable (ds, f);
1107 UPDATE_STATUS (status, tmp_status);
1110 case RM_NONEMPTY_DIR:
1112 DIR *subdir_dirp = fd_to_subdirp (dirfd (*dirp), f,
1113 x, errno, subdir_sb, ds, NULL);
1114 if (subdir_dirp == NULL)
1116 /* CAUTION: this test and diagnostic are identical those
1117 following the other use of fd_to_subdirp. */
1118 if (errno != ENOENT || !x->ignore_missing_files)
1120 _("cannot remove %s"), quote (full_filename (f)));
1121 AD_mark_as_unremovable (ds, f);
1126 if (cycle_check (&ds->cycle_check_state, subdir_sb))
1129 WARNING: Circular directory structure.\n\
1130 This almost certainly means that you have a corrupted file system.\n\
1131 NOTIFY YOUR SYSTEM MANAGER.\n\
1132 The following directory is part of the cycle:\n %s\n"),
1133 quote (full_filename (".")));
1134 longjmp (ds->current_arg_jumpbuf, 1);
1137 *subdir = xstrdup (f);
1138 if (CLOSEDIR (*dirp) != 0)
1140 error (0, 0, _("failed to close directory %s"),
1141 quote (full_filename (".")));
1144 *dirp = subdir_dirp;
1150 /* Record status for this directory. */
1151 UPDATE_STATUS (top->status, status);
1157 /* Ensure that *dirp is not NULL and that its file descriptor is valid. */
1158 assert (*dirp != NULL);
1159 assert (0 <= fcntl (dirfd (*dirp), F_GETFD));
1164 /* Do this after each call to AD_push or AD_push_initial.
1165 Because the status = RM_OK bit is too remove-specific to
1166 go into the general-purpose AD_* package. */
1167 #define AD_INIT_OTHER_MEMBERS() \
1170 AD_stack_top(ds)->status = RM_OK; \
1174 /* Remove the hierarchy rooted at DIR.
1175 Do that by changing into DIR, then removing its contents, then
1176 returning to the original working directory and removing DIR itself.
1177 Don't use recursion. Be careful when using chdir ".." that we
1178 return to the same directory from which we came, if necessary.
1179 Return an RM_status value to indicate success or failure. */
1181 static enum RM_status
1182 remove_dir (int fd_cwd, Dirstack_state *ds, char const *dir,
1183 struct rm_options const *x, int *cwd_errno)
1185 enum RM_status status;
1188 /* There is a race condition in that an attacker could replace the nonempty
1189 directory, DIR, with a symlink between the preceding call to rmdir
1190 (unlinkat, in our caller) and fd_to_subdirp's openat call. But on most
1191 systems, even those without openat, this isn't a problem, since we ensure
1192 that opening a symlink will fail, when that is possible. Otherwise,
1193 fd_to_subdirp's fstat, along with the `fstat' and the dev/ino
1194 comparison in AD_push ensure that we detect it and fail. */
1196 DIR *dirp = fd_to_subdirp (fd_cwd, dir, x, 0, &dir_sb, ds, cwd_errno);
1200 int saved_errno = errno;
1201 if (errno == EACCES)
1203 /* If fd_to_subdirp fails due to permissions, then try to
1204 remove DIR via rmdir, in case it's just an empty directory. */
1205 if (rmdir (dir) == 0)
1208 errno = saved_errno;
1211 /* CAUTION: this test and diagnostic are identical those
1212 following the other use of fd_to_subdirp. */
1213 if (errno != ENOENT || !x->ignore_missing_files)
1215 _("cannot remove %s"), quote (full_filename (dir)));
1220 if (ROOT_DEV_INO_CHECK (x->root_dev_ino, &dir_sb))
1222 ROOT_DEV_INO_WARN (full_filename (dir));
1224 goto closedir_and_return;
1227 AD_push (dirfd (dirp), ds, dir, &dir_sb);
1228 AD_INIT_OTHER_MEMBERS ();
1234 char *subdir = NULL;
1235 struct stat subdir_sb;
1236 enum RM_status tmp_status;
1238 tmp_status = remove_cwd_entries (&dirp, ds, &subdir, &subdir_sb, x);
1240 if (tmp_status != RM_OK)
1242 UPDATE_STATUS (status, tmp_status);
1243 AD_mark_current_as_unremovable (ds);
1247 AD_push (dirfd (dirp), ds, subdir, &subdir_sb);
1248 AD_INIT_OTHER_MEMBERS ();
1254 /* Execution reaches this point when we've removed the last
1255 removable entry from the current directory. */
1257 /* The name of the directory that we have just processed,
1258 nominally removing all of its contents. */
1261 AD_pop_and_chdir (&dirp, ds, &empty_dir);
1262 int fd = (dirp != NULL ? dirfd (dirp) : AT_FDCWD);
1263 assert (dirp != NULL || AD_stack_height (ds) == 1);
1265 /* Try to remove EMPTY_DIR only if remove_cwd_entries succeeded. */
1266 if (tmp_status == RM_OK)
1268 /* This does a little more work than necessary when it actually
1269 prompts the user. E.g., we already know that D is a directory
1270 and that it's almost certainly empty, yet we lstat it.
1271 But that's no big deal since we're interactive. */
1274 enum RM_status s = prompt (fd, ds, empty_dir, x,
1275 PA_REMOVE_DIR, &is_dir, &is_empty);
1281 goto closedir_and_return;
1284 if (unlinkat (fd, empty_dir, AT_REMOVEDIR) == 0)
1287 printf (_("removed directory: %s\n"),
1288 quote (full_filename (empty_dir)));
1292 error (0, errno, _("cannot remove directory %s"),
1293 quote (full_filename (empty_dir)));
1294 AD_mark_as_unremovable (ds, empty_dir);
1296 UPDATE_STATUS (AD_stack_top(ds)->status, status);
1302 if (AD_stack_height (ds) == 1)
1307 /* If the first/final hash table of unremovable entries was used,
1311 closedir_and_return:;
1312 if (dirp != NULL && CLOSEDIR (dirp) != 0)
1314 error (0, 0, _("failed to close directory %s"),
1315 quote (full_filename (".")));
1322 /* Remove the file or directory specified by FILENAME.
1323 Return RM_OK if it is removed, and RM_ERROR or RM_USER_DECLINED if not. */
1325 static enum RM_status
1326 rm_1 (Dirstack_state *ds, char const *filename,
1327 struct rm_options const *x, int *cwd_errno)
1329 char const *base = base_name (filename);
1330 if (DOT_OR_DOTDOT (base))
1332 error (0, 0, _("cannot remove `.' or `..'"));
1336 AD_push_initial (ds);
1337 AD_INIT_OTHER_MEMBERS ();
1339 int fd_cwd = AT_FDCWD;
1340 enum RM_status status = remove_entry (fd_cwd, ds, filename, x, NULL);
1341 if (status == RM_NONEMPTY_DIR)
1343 /* In the event that remove_dir->remove_cwd_entries detects
1344 a directory cycle, arrange to fail, give up on this FILE, but
1345 continue on with any other arguments. */
1346 if (setjmp (ds->current_arg_jumpbuf))
1349 status = remove_dir (fd_cwd, ds, filename, x, cwd_errno);
1357 /* Remove all files and/or directories specified by N_FILES and FILE.
1358 Apply the options in X. */
1359 extern enum RM_status
1360 rm (size_t n_files, char const *const *file, struct rm_options const *x)
1362 enum RM_status status = RM_OK;
1363 Dirstack_state *ds = ds_init ();
1367 for (i = 0; i < n_files; i++)
1369 if (cwd_errno && IS_RELATIVE_FILE_NAME (file[i]))
1371 error (0, 0, _("cannot remove relative-named %s"), quote (file[i]));
1376 cycle_check_init (&ds->cycle_check_state);
1377 enum RM_status s = rm_1 (ds, file[i], x, &cwd_errno);
1378 assert (VALID_STATUS (s));
1379 UPDATE_STATUS (status, s);
1382 if (x->require_restore_cwd && cwd_errno)
1384 error (0, cwd_errno,
1385 _("cannot restore current working directory"));