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"
30 #include "euidaccess.h"
31 #include "euidaccess-stat.h"
32 #include "file-type.h"
40 #include "root-dev-ino.h"
41 #include "unlinkdir.h"
44 /* Avoid shadowing warnings because these are functions declared
45 in dirname.h as well as locals used below. */
46 #define dir_name rm_dir_name
47 #define dir_len rm_dir_len
49 #define obstack_chunk_alloc malloc
50 #define obstack_chunk_free free
52 /* This is the maximum number of consecutive readdir/unlink calls that
53 can be made (with no intervening rewinddir or closedir/opendir) before
54 triggering a bug that makes readdir return NULL even though some
55 directory entries have not been processed. The bug afflicts SunOS's
56 readdir when applied to ufs file systems and Darwin 6.5's (and OSX
57 v.10.3.8's) HFS+. This maximum is conservative in that demonstrating
58 the problem requires a directory containing at least 16 deletable
59 entries (which doesn't count . and ..).
60 This problem also affects Darwin 7.9.0 (aka MacOS X 10.3.9) on HFS+
61 and NFS-mounted file systems, but not vfat ones. */
64 CONSECUTIVE_READDIR_UNLINK_THRESHOLD = 10
67 /* FIXME: in 2009, or whenever Darwin 7.9.0 (aka MacOS X 10.3.9) is no
68 longer relevant, remove this work-around code. Then, there will be
69 no need to perform the extra rewinddir call, ever. */
70 #define NEED_REWIND(readdir_unlink_count) \
71 (CONSECUTIVE_READDIR_UNLINK_THRESHOLD <= (readdir_unlink_count))
79 typedef enum Ternary Ternary;
81 /* The prompt function may be called twice for a given directory.
82 The first time, we ask whether to descend into it, and the
83 second time, we ask whether to remove it. */
86 PA_DESCEND_INTO_DIR = 2,
90 /* Initial capacity of per-directory hash table of entries that have
91 been processed but not been deleted. */
92 enum { HT_UNREMOVABLE_INITIAL_CAPACITY = 13 };
94 /* An entry in the active directory stack.
95 Each entry corresponds to an `active' directory. */
98 /* For a given active directory, this is the set of names of
99 entries in that directory that could/should not be removed.
100 For example, `.' and `..', as well as files/dirs for which
101 unlink/rmdir failed e.g., due to access restrictions. */
102 Hash_table *unremovable;
104 /* Record the status for a given active directory; we need to know
105 whether an entry was not removed, either because of an error or
106 because the user declined. */
107 enum RM_status status;
109 /* The directory's dev/ino. Used to ensure that a malicious user does
110 not replace a directory we're about to process with a symlink to
111 some other directory. */
112 struct dev_ino dev_ino;
115 extern char *program_name;
117 struct dirstack_state
119 /* The name of the directory (starting with and relative to a command
120 line argument) being processed. When a subdirectory is entered, a new
121 component is appended (pushed). Remove (pop) the top component
122 upon chdir'ing out of a directory. This is used to form the full
123 name of the current directory or a file therein, when necessary. */
124 struct obstack dir_stack;
126 /* Stack of lengths of directory names (including trailing slash)
127 appended to dir_stack. We have to have a separate stack of lengths
128 (rather than just popping back to previous slash) because the first
129 element pushed onto the dir stack may contain slashes. */
130 struct obstack len_stack;
132 /* Stack of active directory entries.
133 The first `active' directory is the initial working directory.
134 Additional active dirs are pushed onto the stack as we `chdir'
135 into each directory to be processed. When finished with the
136 hierarchy under a directory, pop the active dir stack. */
137 struct obstack Active_dir;
139 /* Used to detect cycles. */
140 struct cycle_check_state cycle_check_state;
142 /* Target of a longjmp in case rm has to stop processing the current
143 command-line argument. This happens 1) when rm detects a directory
144 cycle or 2) when it has processed one or more directories, but then
145 is unable to return to the initial working directory to process
146 additional `.'-relative command-line arguments. */
147 jmp_buf current_arg_jumpbuf;
149 typedef struct dirstack_state Dirstack_state;
151 /* Like fstatat, but cache the result. If ST->st_size is -1, the
152 status has not been gotten yet. If less than -1, fstatat failed
153 with errno == -1 - ST->st_size. Otherwise, the status has already
154 been gotten, so return 0. */
156 cache_fstatat (int fd, char const *file, struct stat *st, int flag)
158 if (st->st_size == -1 && fstatat (fd, file, st, flag) != 0)
159 st->st_size = -1 - errno;
160 if (0 <= st->st_size)
162 errno = -1 - st->st_size;
166 /* Initialize a fstatat cache *ST. Return ST for convenience. */
167 static inline struct stat *
168 cache_stat_init (struct stat *st)
174 /* Return true if *ST has been statted. */
176 cache_statted (struct stat *st)
178 return (st->st_size != -1);
181 /* Return true if *ST has been statted successfully. */
183 cache_stat_ok (struct stat *st)
185 return (0 <= st->st_size);
196 hash_compare_strings (void const *x, void const *y)
198 return STREQ (x, y) ? true : false;
202 push_dir (Dirstack_state *ds, const char *dir_name)
204 size_t len = strlen (dir_name);
206 /* Append the string onto the stack. */
207 obstack_grow (&ds->dir_stack, dir_name, len);
209 /* Append a trailing slash. */
210 obstack_1grow (&ds->dir_stack, '/');
212 /* Add one for the slash. */
215 /* Push the length (including slash) onto its stack. */
216 obstack_grow (&ds->len_stack, &len, sizeof (len));
219 /* Return the entry name of the directory on the top of the stack
220 in malloc'd storage. */
222 top_dir (Dirstack_state const *ds)
224 size_t n_lengths = obstack_object_size (&ds->len_stack) / sizeof (size_t);
225 size_t *length = obstack_base (&ds->len_stack);
226 size_t top_len = length[n_lengths - 1];
227 char const *p = obstack_next_free (&ds->dir_stack) - top_len;
228 char *q = xmalloc (top_len);
229 memcpy (q, p, top_len - 1);
235 pop_dir (Dirstack_state *ds)
237 size_t n_lengths = obstack_object_size (&ds->len_stack) / sizeof (size_t);
238 size_t *length = obstack_base (&ds->len_stack);
240 assert (n_lengths > 0);
241 size_t top_len = length[n_lengths - 1];
242 assert (top_len >= 2);
244 /* Pop the specified length of file name. */
245 assert (obstack_object_size (&ds->dir_stack) >= top_len);
246 obstack_blank (&ds->dir_stack, -top_len);
248 /* Pop the length stack, too. */
249 assert (obstack_object_size (&ds->len_stack) >= sizeof (size_t));
250 obstack_blank (&ds->len_stack, -(int) sizeof (size_t));
253 /* Copy the SRC_LEN bytes of data beginning at SRC into the DST_LEN-byte
254 buffer, DST, so that the last source byte is at the end of the destination
255 buffer. If SRC_LEN is longer than DST_LEN, then set *TRUNCATED.
256 Set *RESULT to point to the beginning of (the portion of) the source data
257 in DST. Return the number of bytes remaining in the destination buffer. */
260 right_justify (char *dst, size_t dst_len, const char *src, size_t src_len,
261 char **result, bool *truncated)
266 if (src_len <= dst_len)
269 dp = dst + (dst_len - src_len);
274 sp = src + (src_len - dst_len);
280 *result = memcpy (dp, sp, src_len);
281 return dst_len - src_len;
284 /* Using the global directory name obstack, create the full name FILENAME.
285 Return it in sometimes-realloc'd space that should not be freed by the
286 caller. Realloc as necessary. If realloc fails, use a static buffer
287 and put as long a suffix in that buffer as possible. */
289 #define full_filename(Filename) full_filename_ (ds, Filename)
291 full_filename_ (Dirstack_state const *ds, const char *filename)
293 static char *buf = NULL;
294 static size_t n_allocated = 0;
296 size_t dir_len = obstack_object_size (&ds->dir_stack);
297 char *dir_name = obstack_base (&ds->dir_stack);
298 size_t n_bytes_needed;
301 filename_len = strlen (filename);
302 n_bytes_needed = dir_len + filename_len + 1;
304 if (n_allocated < n_bytes_needed)
306 /* This code requires that realloc accept NULL as the first arg.
307 This function must not use xrealloc. Otherwise, an out-of-memory
308 error involving a file name to be expanded here wouldn't ever
309 be issued. Use realloc and fall back on using a static buffer
310 if memory allocation fails. */
311 char *new_buf = realloc (buf, n_bytes_needed);
312 n_allocated = n_bytes_needed;
316 #define SBUF_SIZE 512
317 #define ELLIPSES_PREFIX "[...]"
318 static char static_buf[SBUF_SIZE];
324 len = right_justify (static_buf, SBUF_SIZE, filename,
325 filename_len + 1, &p, &truncated);
326 right_justify (static_buf, len, dir_name, dir_len, &p, &truncated);
329 memcpy (static_buf, ELLIPSES_PREFIX,
330 sizeof (ELLIPSES_PREFIX) - 1);
338 if (filename_len == 1 && *filename == '.' && dir_len)
340 /* FILENAME is just `.' and dir_len is nonzero.
341 Copy the directory part, omitting the trailing slash,
342 and append a trailing zero byte. */
343 char *p = mempcpy (buf, dir_name, dir_len - 1);
348 /* Copy the directory part, including trailing slash, and then
349 append the filename part, including a trailing zero byte. */
350 memcpy (mempcpy (buf, dir_name, dir_len), filename, filename_len + 1);
351 assert (strlen (buf) + 1 == n_bytes_needed);
358 AD_stack_height (Dirstack_state const *ds)
360 return obstack_object_size (&ds->Active_dir) / sizeof (struct AD_ent);
363 static inline struct AD_ent *
364 AD_stack_top (Dirstack_state const *ds)
366 return (struct AD_ent *)
367 ((char *) obstack_next_free (&ds->Active_dir) - sizeof (struct AD_ent));
371 AD_stack_pop (Dirstack_state *ds)
373 assert (0 < AD_stack_height (ds));
375 /* operate on Active_dir. pop and free top entry */
376 struct AD_ent *top = AD_stack_top (ds);
377 if (top->unremovable)
378 hash_free (top->unremovable);
379 obstack_blank (&ds->Active_dir, -(int) sizeof (struct AD_ent));
383 AD_stack_clear (Dirstack_state *ds)
385 while (0 < AD_stack_height (ds))
391 static Dirstack_state *
394 Dirstack_state *ds = xmalloc (sizeof *ds);
395 obstack_init (&ds->dir_stack);
396 obstack_init (&ds->len_stack);
397 obstack_init (&ds->Active_dir);
402 ds_clear (Dirstack_state *ds)
404 obstack_free (&ds->dir_stack, obstack_finish (&ds->dir_stack));
405 obstack_free (&ds->len_stack, obstack_finish (&ds->len_stack));
406 while (0 < AD_stack_height (ds))
408 obstack_free (&ds->Active_dir, obstack_finish (&ds->Active_dir));
412 ds_free (Dirstack_state *ds)
414 obstack_free (&ds->dir_stack, NULL);
415 obstack_free (&ds->len_stack, NULL);
416 obstack_free (&ds->Active_dir, NULL);
420 /* Pop the active directory (AD) stack and move *DIRP `up' one level,
421 safely. Moving `up' usually means opening `..', but when we've just
422 finished recursively processing a command-line directory argument,
423 there's nothing left on the stack, so set *DIRP to NULL in that case.
424 The idea is to return with *DIRP opened on the parent directory,
425 assuming there are entries in that directory that we need to remove.
427 Whenever using chdir '..' (virtually, now, via openat), verify
428 that the post-chdir dev/ino numbers for `.' match the saved ones.
429 If any system call fails or if dev/ino don't match then give a
430 diagnostic and longjump out.
431 Return the name (in malloc'd storage) of the
432 directory (usually now empty) from which we're coming, and which
433 corresponds to the input value of *DIRP. */
435 AD_pop_and_chdir (DIR **dirp, Dirstack_state *ds)
437 struct AD_ent *leaf_dir_ent = AD_stack_top(ds);
438 struct dev_ino leaf_dev_ino = leaf_dir_ent->dev_ino;
439 enum RM_status old_status = leaf_dir_ent->status;
442 /* Get the name of the current (but soon to be `previous') directory
443 from the top of the stack. */
444 char *prev_dir = top_dir (ds);
448 top = AD_stack_top (ds);
450 /* If the directory we're about to leave (and try to rmdir)
451 is the one whose dev_ino is being used to detect a cycle,
452 reset cycle_check_state.dev_ino to that of the parent.
453 Otherwise, once that directory is removed, its dev_ino
454 could be reused in the creation (by some other process)
455 of a directory that this rm process would encounter,
456 which would result in a false-positive cycle indication. */
457 CYCLE_CHECK_REFLECT_CHDIR_UP (&ds->cycle_check_state,
458 top->dev_ino, leaf_dev_ino);
460 /* Propagate any failure to parent. */
461 UPDATE_STATUS (top->status, old_status);
463 assert (AD_stack_height (ds));
465 if (1 < AD_stack_height (ds))
468 int fd = openat (dirfd (*dirp), "..", O_RDONLY);
469 if (closedir (*dirp) != 0)
471 error (0, errno, _("FATAL: failed to close directory %s"),
472 quote (full_filename (prev_dir)));
473 goto next_cmdline_arg;
476 /* The above fails with EACCES when *DIRP is readable but not
477 searchable, when using Solaris' openat. Without this openat
478 call, tests/rm2 would fail to remove directories a/2 and a/3. */
480 fd = openat (AT_FDCWD, full_filename ("."), O_RDONLY);
484 error (0, errno, _("FATAL: cannot open .. from %s"),
485 quote (full_filename (prev_dir)));
486 goto next_cmdline_arg;
492 _("FATAL: cannot ensure %s (returned to via ..) is safe"),
493 quote (full_filename (".")));
497 /* Ensure that post-chdir dev/ino match the stored ones. */
498 if ( ! SAME_INODE (sb, top->dev_ino))
500 error (0, 0, _("FATAL: directory %s changed dev/ino"),
501 quote (full_filename (".")));
505 *dirp = fdopendir (fd);
508 error (0, errno, _("FATAL: cannot return to .. from %s"),
509 quote (full_filename (".")));
516 longjmp (ds->current_arg_jumpbuf, 1);
521 if (closedir (*dirp) != 0)
523 error (0, errno, _("FATAL: failed to close directory %s"),
524 quote (full_filename (prev_dir)));
525 goto next_cmdline_arg;
533 /* Initialize *HT if it is NULL. Return *HT. */
535 AD_ensure_initialized (Hash_table **ht)
539 *ht = hash_initialize (HT_UNREMOVABLE_INITIAL_CAPACITY, NULL, hash_pjw,
540 hash_compare_strings, hash_freer);
548 /* Initialize *HT if it is NULL.
549 Insert FILENAME into HT. */
551 AD_mark_helper (Hash_table **ht, char *filename)
553 void *ent = hash_insert (AD_ensure_initialized (ht), filename);
563 /* Mark FILENAME (in current directory) as unremovable. */
565 AD_mark_as_unremovable (Dirstack_state *ds, char const *filename)
567 AD_mark_helper (&AD_stack_top(ds)->unremovable, xstrdup (filename));
570 /* Mark the current directory as unremovable. I.e., mark the entry
571 in the parent directory corresponding to `.'.
572 This happens e.g., when an opendir fails and the only name
573 the caller has conveniently at hand is `.'. */
575 AD_mark_current_as_unremovable (Dirstack_state *ds)
577 struct AD_ent *top = AD_stack_top (ds);
578 char *curr = top_dir (ds);
580 assert (1 < AD_stack_height (ds));
583 AD_mark_helper (&top->unremovable, curr);
586 /* Push an initial dummy entry onto the stack.
587 This will always be the bottommost entry on the stack. */
589 AD_push_initial (Dirstack_state *ds)
593 /* Extend the stack. */
594 obstack_blank (&ds->Active_dir, sizeof (struct AD_ent));
596 /* Fill in the new values. */
597 top = AD_stack_top (ds);
598 top->unremovable = NULL;
600 /* These should never be used.
601 Give them values that might look suspicious
602 in a debugger or in a diagnostic. */
603 top->dev_ino.st_dev = TYPE_MAXIMUM (dev_t);
604 top->dev_ino.st_ino = TYPE_MAXIMUM (ino_t);
607 /* Push info about the current working directory (".") onto the
608 active directory stack. DIR is the ./-relative name through
609 which we've just `chdir'd to this directory. DIR_SB_FROM_PARENT
610 is the result of calling lstat on DIR from the parent of DIR.
611 Longjump out (skipping the entire command line argument we're
612 dealing with) if `fstat (FD_CWD, ...' fails or if someone has
613 replaced DIR with e.g., a symlink to some other directory. */
615 AD_push (int fd_cwd, Dirstack_state *ds, char const *dir,
616 struct stat const *dir_sb_from_parent)
622 /* If our uses of openat are guaranteed not to
623 follow a symlink, then we can skip this check. */
624 if (! HAVE_WORKING_O_NOFOLLOW)
627 if (fstat (fd_cwd, &sb) != 0)
629 error (0, errno, _("FATAL: cannot enter directory %s"),
630 quote (full_filename (".")));
631 longjmp (ds->current_arg_jumpbuf, 1);
634 if ( ! SAME_INODE (sb, *dir_sb_from_parent))
637 _("FATAL: just-changed-to directory %s changed dev/ino"),
638 quote (full_filename (".")));
639 longjmp (ds->current_arg_jumpbuf, 1);
643 if (cycle_check (&ds->cycle_check_state, dir_sb_from_parent))
646 WARNING: Circular directory structure.\n\
647 This almost certainly means that you have a corrupted file system.\n\
648 NOTIFY YOUR SYSTEM MANAGER.\n\
649 The following directory is part of the cycle:\n %s\n"),
650 quote (full_filename (".")));
651 longjmp (ds->current_arg_jumpbuf, 1);
654 /* Extend the stack. */
655 obstack_blank (&ds->Active_dir, sizeof (struct AD_ent));
657 /* The active directory stack must be one larger than the length stack. */
658 assert (AD_stack_height (ds) ==
659 1 + obstack_object_size (&ds->len_stack) / sizeof (size_t));
661 /* Fill in the new values. */
662 top = AD_stack_top (ds);
663 top->dev_ino.st_dev = dir_sb_from_parent->st_dev;
664 top->dev_ino.st_ino = dir_sb_from_parent->st_ino;
665 top->unremovable = NULL;
669 AD_is_removable (Dirstack_state const *ds, char const *file)
671 struct AD_ent *top = AD_stack_top (ds);
672 return ! (top->unremovable && hash_lookup (top->unremovable, file));
675 /* Return true if DIR is determined to be an empty directory. */
677 is_empty_dir (int fd_cwd, char const *dir)
680 struct dirent const *dp;
682 int fd = openat (fd_cwd, dir,
683 (O_RDONLY | O_DIRECTORY
684 | O_NOCTTY | O_NOFOLLOW | O_NONBLOCK));
689 dirp = fdopendir (fd);
697 dp = readdir_ignoring_dot_and_dotdot (dirp);
702 return saved_errno == 0 ? true : false;
705 /* Return true if FILE is determined to be an unwritable non-symlink.
706 Otherwise, return false (including when lstat'ing it fails).
707 Set *BUF to the file status.
708 This is to avoid calling euidaccess when FILE is a symlink. */
710 write_protected_non_symlink (int fd_cwd,
712 Dirstack_state const *ds,
715 if (cache_fstatat (fd_cwd, file, buf, AT_SYMLINK_NOFOLLOW) != 0)
717 if (S_ISLNK (buf->st_mode))
719 /* Here, we know FILE is not a symbolic link. */
721 /* In order to be reentrant -- i.e., to avoid changing the working
722 directory, and at the same time to be able to deal with alternate
723 access control mechanisms (ACLs, xattr-style attributes) and
724 arbitrarily deep trees -- we need a function like eaccessat, i.e.,
725 like Solaris' eaccess, but fd-relative, in the spirit of openat. */
727 /* In the absence of a native eaccessat function, here are some of
728 the implementation choices [#4 and #5 were suggested by Paul Eggert]:
729 1) call openat with O_WRONLY|O_NOCTTY
730 Disadvantage: may create the file and doesn't work for directory,
731 may mistakenly report `unwritable' for EROFS or ACLs even though
732 perm bits say the file is writable.
734 2) fake eaccessat (save_cwd, fchdir, call euidaccess, restore_cwd)
735 Disadvantage: changes working directory (not reentrant) and can't
736 work if save_cwd fails.
738 3) if (euidaccess (full_filename (file), W_OK) == 0)
739 Disadvantage: doesn't work if full_filename is too long.
740 Inefficient for very deep trees (O(Depth^2)).
742 4) If the full pathname is sufficiently short (say, less than
743 PATH_MAX or 8192 bytes, whichever is shorter):
744 use method (3) (i.e., euidaccess (full_filename (file), W_OK));
745 Otherwise: vfork, fchdir in the child, run euidaccess in the
746 child, then the child exits with a status that tells the parent
747 whether euidaccess succeeded.
749 This avoids the O(N**2) algorithm of method (3), and it also avoids
750 the failure-due-to-too-long-file-names of method (3), but it's fast
751 in the normal shallow case. It also avoids the lack-of-reentrancy
752 and the save_cwd problems.
753 Disadvantage; it uses a process slot for very-long file names,
754 and would be very slow for hierarchies with many such files.
756 5) If the full file name is sufficiently short (say, less than
757 PATH_MAX or 8192 bytes, whichever is shorter):
758 use method (3) (i.e., euidaccess (full_filename (file), W_OK));
759 Otherwise: look just at the file bits. Perhaps issue a warning
760 the first time this occurs.
762 This is like (4), except for the "Otherwise" case where it isn't as
763 "perfect" as (4) but is considerably faster. It conforms to current
764 POSIX, and is uniformly better than what Solaris and FreeBSD do (they
765 mess up with long file names). */
768 /* This implements #5: */
770 = obstack_object_size (&ds->dir_stack) + strlen (file);
772 return (file_name_len < MIN (PATH_MAX, 8192)
773 ? euidaccess (full_filename (file), W_OK) != 0 && errno == EACCES
774 : euidaccess_stat (buf, W_OK) != 0);
778 /* Prompt whether to remove FILENAME, if required via a combination of
779 the options specified by X and/or file attributes. If the file may
780 be removed, return RM_OK. If the user declines to remove the file,
781 return RM_USER_DECLINED. If not ignoring missing files and we
782 cannot lstat FILENAME, then return RM_ERROR.
784 Depending on MODE, ask whether to `descend into' or to `remove' the
785 directory FILENAME. MODE is ignored when FILENAME is not a directory.
786 Set *IS_EMPTY to T_YES if FILENAME is an empty directory, and it is
787 appropriate to try to remove it with rmdir (e.g. recursive mode).
788 Don't even try to set *IS_EMPTY when MODE == PA_REMOVE_DIR. */
789 static enum RM_status
790 prompt (int fd_cwd, Dirstack_state const *ds, char const *filename,
792 struct rm_options const *x, enum Prompt_action mode,
795 bool write_protected = false;
797 *is_empty = T_UNKNOWN;
799 if (((!x->ignore_missing_files & (x->interactive | x->stdin_tty))
800 && (write_protected = write_protected_non_symlink (fd_cwd, filename,
804 if (cache_fstatat (fd_cwd, filename, sbuf, AT_SYMLINK_NOFOLLOW) != 0)
806 /* This happens, e.g., with `rm '''. */
807 error (0, errno, _("cannot remove %s"),
808 quote (full_filename (filename)));
812 if (S_ISDIR (sbuf->st_mode) && !x->recursive)
814 error (0, EISDIR, _("cannot remove %s"),
815 quote (full_filename (filename)));
819 /* Using permissions doesn't make sense for symlinks. */
820 if (S_ISLNK (sbuf->st_mode))
822 if ( ! x->interactive)
824 write_protected = false;
827 /* Issue the prompt. */
829 char const *quoted_name = quote (full_filename (filename));
831 /* FIXME: use a variant of error (instead of fprintf) that doesn't
832 append a newline. Then we won't have to declare program_name in
834 if (S_ISDIR (sbuf->st_mode)
836 && mode == PA_DESCEND_INTO_DIR
837 && ((*is_empty = (is_empty_dir (fd_cwd, filename) ? T_YES : T_NO))
841 ? _("%s: descend into write-protected directory %s? ")
842 : _("%s: descend into directory %s? ")),
843 program_name, quoted_name);
846 /* TRANSLATORS: You may find it more convenient to translate
847 the equivalent of _("%s: remove %s (write-protected) %s? ").
848 It should avoid grammatical problems with the output
852 ? _("%s: remove write-protected %s %s? ")
853 : _("%s: remove %s %s? ")),
854 program_name, file_type (sbuf), quoted_name);
858 return RM_USER_DECLINED;
864 /* Return true if FILENAME is a directory (and not a symlink to a directory).
865 Otherwise, including the case in which lstat fails, return false.
866 *ST is FILENAME's tstatus.
867 Do not modify errno. */
869 is_dir_lstat (char const *filename, struct stat *st)
871 int saved_errno = errno;
873 (cache_fstatat (AT_FDCWD, filename, st, AT_SYMLINK_NOFOLLOW) == 0
874 && S_ISDIR (st->st_mode));
879 #if HAVE_STRUCT_DIRENT_D_TYPE
881 /* True if the type of the directory entry D is known. */
882 # define DT_IS_KNOWN(d) ((d)->d_type != DT_UNKNOWN)
884 /* True if the type of the directory entry D must be T. */
885 # define DT_MUST_BE(d, t) ((d)->d_type == (t))
888 # define DT_IS_KNOWN(d) false
889 # define DT_MUST_BE(d, t) false
892 #define DO_UNLINK(Fd_cwd, Filename, X) \
895 if (unlinkat (Fd_cwd, Filename, 0) == 0) \
898 printf (_("removed %s\n"), quote (full_filename (Filename))); \
902 if (ignorable_missing (X, errno)) \
907 #define DO_RMDIR(Fd_cwd, Filename, X) \
910 if (unlinkat (Fd_cwd, Filename, AT_REMOVEDIR) == 0) /* rmdir */ \
913 printf (_("removed directory: %s\n"), \
914 quote (full_filename (Filename))); \
918 if (ignorable_missing (X, errno)) \
921 if (errno == ENOTEMPTY || errno == EEXIST) \
922 return RM_NONEMPTY_DIR; \
926 /* When a function like unlink, rmdir, or fstatat fails with an errno
927 value of ERRNUM, return true if the specified file system object
928 is guaranteed not to exist; otherwise, return false. */
930 nonexistent_file_errno (int errnum)
932 /* Do not include ELOOP here, since the specified file may indeed
933 exist, but be (in)accessible only via too long a symlink chain.
934 Likewise for ENAMETOOLONG, since rm -f ./././.../foo may fail
935 if the "..." part expands to a long enough sequence of "./"s,
936 even though ./foo does indeed exist. */
948 /* Encapsulate the test for whether the errno value, ERRNUM, is ignorable. */
950 ignorable_missing (struct rm_options const *x, int errnum)
952 return x->ignore_missing_files && nonexistent_file_errno (errnum);
955 /* Remove the file or directory specified by FILENAME.
956 Return RM_OK if it is removed, and RM_ERROR or RM_USER_DECLINED if not.
957 But if FILENAME specifies a non-empty directory, return RM_NONEMPTY_DIR. */
959 static enum RM_status
960 remove_entry (int fd_cwd, Dirstack_state const *ds, char const *filename,
962 struct rm_options const *x, struct dirent const *dp)
964 Ternary is_empty_directory;
965 enum RM_status s = prompt (fd_cwd, ds, filename, st, x, PA_DESCEND_INTO_DIR,
966 &is_empty_directory);
967 bool known_to_be_dir = (cache_stat_ok (st) && S_ISDIR (st->st_mode));
972 /* Why bother with the following if/else block? Because on systems with
973 an unlink function that *can* unlink directories, we must determine the
974 type of each entry before removing it. Otherwise, we'd risk unlinking
975 an entire directory tree simply by unlinking a single directory; then
976 all the storage associated with that hierarchy would not be freed until
977 the next fsck. Not nice. To avoid that, on such slightly losing
978 systems, we need to call lstat to determine the type of each entry,
979 and that represents extra overhead that -- it turns out -- we can
980 avoid on non-losing systems, since there, unlink will never remove
981 a directory. Also, on systems where unlink may unlink directories,
982 we're forced to allow a race condition: we lstat a non-directory, then
983 go to unlink it, but in the mean time, a malicious someone could have
984 replaced it with a directory. */
986 if (cannot_unlink_dir ())
988 if (known_to_be_dir && ! x->recursive)
990 error (0, EISDIR, _("cannot remove %s"),
991 quote (full_filename (filename)));
995 /* is_empty_directory is set iff it's ok to use rmdir.
996 Note that it's set only in interactive mode -- in which case it's
997 an optimization that arranges so that the user is asked just
998 once whether to remove the directory. */
999 if (is_empty_directory == T_YES)
1000 DO_RMDIR (fd_cwd, filename, x);
1002 /* If we happen to know that FILENAME is a directory, return now
1003 and let the caller remove it -- this saves the overhead of a failed
1004 unlink call. If FILENAME is a command-line argument, then dp is NULL,
1005 so we'll first try to unlink it. Using unlink here is ok, because it
1006 cannot remove a directory. */
1007 if ((dp && DT_MUST_BE (dp, DT_DIR)) || known_to_be_dir)
1008 return RM_NONEMPTY_DIR;
1010 DO_UNLINK (fd_cwd, filename, x);
1012 /* Upon a failed attempt to unlink a directory, most non-Linux systems
1013 set errno to the POSIX-required value EPERM. In that case, change
1014 errno to EISDIR so that we emit a better diagnostic. */
1015 if (! x->recursive && errno == EPERM && is_dir_lstat (filename, st))
1019 || errno == ENOENT || errno == ENOTDIR
1020 || errno == ELOOP || errno == ENAMETOOLONG)
1022 if (ignorable_missing (x, errno))
1025 /* Either --recursive is not in effect, or the file cannot be a
1026 directory. Report the unlink problem and fail. */
1027 error (0, errno, _("cannot remove %s"),
1028 quote (full_filename (filename)));
1034 /* If we don't already know whether FILENAME is a directory,
1035 find out now. Then, if it's a non-directory, we can use
1039 if (cache_statted (st))
1040 is_dir = known_to_be_dir;
1043 if (dp && DT_IS_KNOWN (dp))
1044 is_dir = DT_MUST_BE (dp, DT_DIR);
1047 if (fstatat (fd_cwd, filename, st, AT_SYMLINK_NOFOLLOW))
1049 if (ignorable_missing (x, errno))
1052 error (0, errno, _("cannot remove %s"),
1053 quote (full_filename (filename)));
1057 is_dir = !! S_ISDIR (st->st_mode);
1063 /* At this point, barring race conditions, FILENAME is known
1064 to be a non-directory, so it's ok to try to unlink it. */
1065 DO_UNLINK (fd_cwd, filename, x);
1067 /* unlink failed with some other error code. report it. */
1068 error (0, errno, _("cannot remove %s"),
1069 quote (full_filename (filename)));
1075 error (0, EISDIR, _("cannot remove %s"),
1076 quote (full_filename (filename)));
1080 if (is_empty_directory == T_YES)
1082 DO_RMDIR (fd_cwd, filename, x);
1083 /* Don't diagnose any failure here.
1084 It'll be detected when the caller tries another way. */
1088 return RM_NONEMPTY_DIR;
1091 /* Given FD_CWD, the file descriptor for an open directory,
1092 open its subdirectory F (F is already `known' to be a directory,
1093 so if it is no longer one, someone is playing games), return a DIR*
1094 pointer for F, and put F's `stat' data in *SUBDIR_SB.
1095 Upon failure give a diagnostic and return NULL.
1096 If PREV_ERRNO is nonzero, it is the errno value from a preceding failed
1097 unlink- or rmdir-like system call -- use that value instead of ENOTDIR
1098 if an opened file turns out not to be a directory. This is important
1099 when the preceding non-dir-unlink failed due to e.g., EPERM or EACCES.
1100 The caller must use a nonnnull CWD_ERRNO the first
1101 time this function is called for each command-line-specified directory.
1102 If CWD_ERRNO is not null, set *CWD_ERRNO to the appropriate error number
1103 if this function fails to restore the initial working directory.
1104 If it is null, report an error and exit if the working directory
1107 fd_to_subdirp (int fd_cwd, char const *f,
1108 struct rm_options const *x, int prev_errno,
1109 struct stat *subdir_sb,
1110 int *cwd_errno ATTRIBUTE_UNUSED)
1112 int open_flags = O_RDONLY | O_NOCTTY | O_NOFOLLOW | O_NONBLOCK;
1113 int fd_sub = openat_permissive (fd_cwd, f, open_flags, 0, cwd_errno);
1116 /* Record dev/ino of F. We may compare them against saved values
1117 to thwart any attempt to subvert the traversal. They are also used
1118 to detect directory cycles. */
1121 else if (fstat (fd_sub, subdir_sb) != 0)
1122 saved_errno = errno;
1123 else if (S_ISDIR (subdir_sb->st_mode))
1125 DIR *subdir_dirp = fdopendir (fd_sub);
1128 saved_errno = errno;
1131 saved_errno = (prev_errno ? prev_errno : ENOTDIR);
1134 errno = saved_errno;
1138 /* Remove entries in the directory open on DIRP
1139 Upon finding a directory that is both non-empty and that can be chdir'd
1140 into, return RM_OK and set *SUBDIR and fill in SUBDIR_SB, where
1141 SUBDIR is the malloc'd name of the subdirectory if the chdir succeeded,
1142 NULL otherwise (e.g., if opendir failed or if there was no subdirectory).
1143 Likewise, SUBDIR_SB is the result of calling lstat on SUBDIR.
1144 Return RM_OK if all entries are removed. Return RM_ERROR if any
1145 entry cannot be removed. Otherwise, return RM_USER_DECLINED if
1146 the user declines to remove at least one entry. Remove as much as
1147 possible, continuing even if we fail to remove some entries. */
1148 static enum RM_status
1149 remove_cwd_entries (DIR **dirp,
1150 Dirstack_state *ds, char **subdir, struct stat *subdir_sb,
1151 struct rm_options const *x)
1153 struct AD_ent *top = AD_stack_top (ds);
1154 enum RM_status status = top->status;
1155 size_t n_unlinked_since_opendir_or_last_rewind = 0;
1157 assert (VALID_STATUS (status));
1162 struct dirent const *dp;
1163 enum RM_status tmp_status;
1166 /* Set errno to zero so we can distinguish between a readdir failure
1167 and when readdir simply finds that there are no more entries. */
1169 dp = readdir_ignoring_dot_and_dotdot (*dirp);
1176 else if (NEED_REWIND (n_unlinked_since_opendir_or_last_rewind))
1178 /* Call rewinddir if we've called unlink or rmdir so many times
1179 (since the opendir or the previous rewinddir) that this
1180 NULL-return may be the symptom of a buggy readdir. */
1182 n_unlinked_since_opendir_or_last_rewind = 0;
1190 /* Skip files we've already tried/failed to remove. */
1191 if ( ! AD_is_removable (ds, f))
1194 /* Pass dp->d_type info to remove_entry so the non-glibc
1195 case can decide whether to use unlink or chdir.
1196 Systems without the d_type member will have to endure
1197 the performance hit of first calling lstat F. */
1198 cache_stat_init (subdir_sb);
1199 tmp_status = remove_entry (dirfd (*dirp), ds, f, subdir_sb, x, dp);
1203 /* Count how many files we've unlinked since the initial
1204 opendir or the last rewinddir. On buggy systems, if you
1205 remove too many, readdir returns NULL even though there
1206 remain unprocessed directory entries. */
1207 ++n_unlinked_since_opendir_or_last_rewind;
1211 case RM_USER_DECLINED:
1212 AD_mark_as_unremovable (ds, f);
1213 UPDATE_STATUS (status, tmp_status);
1216 case RM_NONEMPTY_DIR:
1218 DIR *subdir_dirp = fd_to_subdirp (dirfd (*dirp), f,
1219 x, errno, subdir_sb, NULL);
1220 if (subdir_dirp == NULL)
1224 /* CAUTION: this test and diagnostic are identical to
1225 those following the other use of fd_to_subdirp. */
1226 if (ignorable_missing (x, errno))
1228 /* With -f, don't report "file not found". */
1232 /* Upon fd_to_subdirp failure, try to remove F directly,
1233 in case it's just an empty directory. */
1234 int saved_errno = errno;
1235 if (unlinkat (dirfd (*dirp), f, AT_REMOVEDIR) == 0)
1238 error (0, saved_errno,
1239 _("cannot remove %s"), quote (full_filename (f)));
1242 if (status == RM_ERROR)
1243 AD_mark_as_unremovable (ds, f);
1247 *subdir = xstrdup (f);
1248 if (closedir (*dirp) != 0)
1250 error (0, 0, _("failed to close directory %s"),
1251 quote (full_filename (".")));
1254 *dirp = subdir_dirp;
1260 /* Record status for this directory. */
1261 UPDATE_STATUS (top->status, status);
1267 /* Ensure that *dirp is not NULL and that its file descriptor is valid. */
1268 assert (*dirp != NULL);
1269 assert (0 <= fcntl (dirfd (*dirp), F_GETFD));
1274 /* Do this after each call to AD_push or AD_push_initial.
1275 Because the status = RM_OK bit is too remove-specific to
1276 go into the general-purpose AD_* package. */
1277 #define AD_INIT_OTHER_MEMBERS() \
1280 AD_stack_top(ds)->status = RM_OK; \
1284 /* Remove the hierarchy rooted at DIR.
1285 Do that by changing into DIR, then removing its contents, then
1286 returning to the original working directory and removing DIR itself.
1287 Don't use recursion. Be careful when using chdir ".." that we
1288 return to the same directory from which we came, if necessary.
1289 Return an RM_status value to indicate success or failure. */
1291 static enum RM_status
1292 remove_dir (int fd_cwd, Dirstack_state *ds, char const *dir,
1293 struct stat *dir_st,
1294 struct rm_options const *x, int *cwd_errno)
1296 enum RM_status status;
1297 dev_t current_dev = dir_st->st_dev;
1299 /* There is a race condition in that an attacker could replace the nonempty
1300 directory, DIR, with a symlink between the preceding call to rmdir
1301 (unlinkat, in our caller) and fd_to_subdirp's openat call. But on most
1302 systems, even those without openat, this isn't a problem, since we ensure
1303 that opening a symlink will fail, when that is possible. Otherwise,
1304 fd_to_subdirp's fstat, along with the `fstat' and the dev/ino
1305 comparison in AD_push ensure that we detect it and fail. */
1307 DIR *dirp = fd_to_subdirp (fd_cwd, dir, x, 0, dir_st, cwd_errno);
1311 /* CAUTION: this test and diagnostic are identical to
1312 those following the other use of fd_to_subdirp. */
1313 if (ignorable_missing (x, errno))
1315 /* With -f, don't report "file not found". */
1319 /* Upon fd_to_subdirp failure, try to remove DIR directly,
1320 in case it's just an empty directory. */
1321 int saved_errno = errno;
1322 if (unlinkat (fd_cwd, dir, AT_REMOVEDIR) == 0)
1325 error (0, saved_errno,
1326 _("cannot remove %s"), quote (full_filename (dir)));
1332 if (ROOT_DEV_INO_CHECK (x->root_dev_ino, dir_st))
1334 ROOT_DEV_INO_WARN (full_filename (dir));
1336 goto closedir_and_return;
1339 AD_push (dirfd (dirp), ds, dir, dir_st);
1340 AD_INIT_OTHER_MEMBERS ();
1346 char *subdir = NULL;
1347 struct stat subdir_sb;
1348 enum RM_status tmp_status;
1350 tmp_status = remove_cwd_entries (&dirp, ds, &subdir, &subdir_sb, x);
1352 if (tmp_status != RM_OK)
1354 UPDATE_STATUS (status, tmp_status);
1355 AD_mark_current_as_unremovable (ds);
1359 if ( ! x->one_file_system
1360 || subdir_sb.st_dev == current_dev)
1362 AD_push (dirfd (dirp), ds, subdir, &subdir_sb);
1363 AD_INIT_OTHER_MEMBERS ();
1368 /* Here, --one-file-system is in effect, and with remove_cwd_entries'
1369 traversal into the current directory, (known as SUBDIR, from ..),
1370 DIRP's device number is different from CURRENT_DEV. Arrange not
1371 to do anything more with this hierarchy. */
1372 error (0, errno, _("skipping %s, since it's on a different device"),
1373 quote (full_filename (subdir)));
1375 AD_mark_current_as_unremovable (ds);
1376 tmp_status = RM_ERROR;
1377 UPDATE_STATUS (status, tmp_status);
1380 /* Execution reaches this point when we've removed the last
1381 removable entry from the current directory -- or, with
1382 --one-file-system, when the current directory is on a
1383 different file system. */
1385 /* The name of the directory that we have just processed,
1386 nominally removing all of its contents. */
1387 char *empty_dir = AD_pop_and_chdir (&dirp, ds);
1388 int fd = (dirp != NULL ? dirfd (dirp) : AT_FDCWD);
1389 assert (dirp != NULL || AD_stack_height (ds) == 1);
1391 /* Try to remove EMPTY_DIR only if remove_cwd_entries succeeded. */
1392 if (tmp_status == RM_OK)
1394 /* This does a little more work than necessary when it actually
1395 prompts the user. E.g., we already know that D is a directory
1396 and that it's almost certainly empty, yet we lstat it.
1397 But that's no big deal since we're interactive. */
1398 struct stat empty_st;
1400 enum RM_status s = prompt (fd, ds, empty_dir,
1401 cache_stat_init (&empty_st), x,
1402 PA_REMOVE_DIR, &is_empty);
1408 goto closedir_and_return;
1411 if (unlinkat (fd, empty_dir, AT_REMOVEDIR) == 0)
1414 printf (_("removed directory: %s\n"),
1415 quote (full_filename (empty_dir)));
1419 error (0, errno, _("cannot remove directory %s"),
1420 quote (full_filename (empty_dir)));
1421 AD_mark_as_unremovable (ds, empty_dir);
1423 UPDATE_STATUS (AD_stack_top(ds)->status, status);
1429 if (AD_stack_height (ds) == 1)
1434 /* If the first/final hash table of unremovable entries was used,
1438 closedir_and_return:;
1439 if (dirp != NULL && closedir (dirp) != 0)
1441 error (0, 0, _("failed to close directory %s"),
1442 quote (full_filename (".")));
1449 /* Remove the file or directory specified by FILENAME.
1450 Return RM_OK if it is removed, and RM_ERROR or RM_USER_DECLINED if not. */
1452 static enum RM_status
1453 rm_1 (Dirstack_state *ds, char const *filename,
1454 struct rm_options const *x, int *cwd_errno)
1456 char const *base = last_component (filename);
1457 if (dot_or_dotdot (base))
1459 error (0, 0, _(base == filename
1460 ? "cannot remove directory %s"
1461 : "cannot remove %s directory %s"),
1462 quote_n (0, base), quote_n (1, filename));
1467 cache_stat_init (&st);
1468 cycle_check_init (&ds->cycle_check_state);
1469 if (x->root_dev_ino)
1471 if (cache_fstatat (AT_FDCWD, filename, &st, AT_SYMLINK_NOFOLLOW) != 0)
1473 if (ignorable_missing (x, errno))
1475 error (0, errno, _("cannot remove %s"), quote (filename));
1478 if (SAME_INODE (st, *(x->root_dev_ino)))
1480 error (0, 0, _("cannot remove root directory %s"), quote (filename));
1485 AD_push_initial (ds);
1486 AD_INIT_OTHER_MEMBERS ();
1488 enum RM_status status = remove_entry (AT_FDCWD, ds, filename, &st, x, NULL);
1489 if (status == RM_NONEMPTY_DIR)
1491 /* In the event that remove_dir->remove_cwd_entries detects
1492 a directory cycle, arrange to fail, give up on this FILE, but
1493 continue on with any other arguments. */
1494 if (setjmp (ds->current_arg_jumpbuf))
1497 status = remove_dir (AT_FDCWD, ds, filename, &st, x, cwd_errno);
1499 AD_stack_clear (ds);
1506 /* Remove all files and/or directories specified by N_FILES and FILE.
1507 Apply the options in X. */
1508 extern enum RM_status
1509 rm (size_t n_files, char const *const *file, struct rm_options const *x)
1511 enum RM_status status = RM_OK;
1512 Dirstack_state *ds = ds_init ();
1516 for (i = 0; i < n_files; i++)
1518 if (cwd_errno && IS_RELATIVE_FILE_NAME (file[i]))
1520 error (0, 0, _("cannot remove relative-named %s"), quote (file[i]));
1525 enum RM_status s = rm_1 (ds, file[i], x, &cwd_errno);
1526 assert (VALID_STATUS (s));
1527 UPDATE_STATUS (status, s);
1531 if (x->require_restore_cwd && cwd_errno)
1533 error (0, cwd_errno,
1534 _("cannot restore current working directory"));