1 /* remove.c -- core functions for removing files and directories
2 Copyright (C) 88, 90, 91, 1994-2005 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;
152 hash_compare_strings (void const *x, void const *y)
154 return STREQ (x, y) ? true : false;
158 push_dir (Dirstack_state *ds, const char *dir_name)
160 size_t len = strlen (dir_name);
162 /* Append the string onto the stack. */
163 obstack_grow (&ds->dir_stack, dir_name, len);
165 /* Append a trailing slash. */
166 obstack_1grow (&ds->dir_stack, '/');
168 /* Add one for the slash. */
171 /* Push the length (including slash) onto its stack. */
172 obstack_grow (&ds->len_stack, &len, sizeof (len));
175 /* Return the entry name of the directory on the top of the stack
176 in malloc'd storage. */
178 top_dir (Dirstack_state const *ds)
180 size_t n_lengths = obstack_object_size (&ds->len_stack) / sizeof (size_t);
181 size_t *length = obstack_base (&ds->len_stack);
182 size_t top_len = length[n_lengths - 1];
183 char const *p = obstack_next_free (&ds->dir_stack) - top_len;
184 char *q = xmalloc (top_len);
185 memcpy (q, p, top_len - 1);
191 pop_dir (Dirstack_state *ds)
193 size_t n_lengths = obstack_object_size (&ds->len_stack) / sizeof (size_t);
194 size_t *length = obstack_base (&ds->len_stack);
196 assert (n_lengths > 0);
197 size_t top_len = length[n_lengths - 1];
198 assert (top_len >= 2);
200 /* Pop the specified length of file name. */
201 assert (obstack_object_size (&ds->dir_stack) >= top_len);
202 obstack_blank (&ds->dir_stack, -top_len);
204 /* Pop the length stack, too. */
205 assert (obstack_object_size (&ds->len_stack) >= sizeof (size_t));
206 obstack_blank (&ds->len_stack, -(int) sizeof (size_t));
209 /* Copy the SRC_LEN bytes of data beginning at SRC into the DST_LEN-byte
210 buffer, DST, so that the last source byte is at the end of the destination
211 buffer. If SRC_LEN is longer than DST_LEN, then set *TRUNCATED.
212 Set *RESULT to point to the beginning of (the portion of) the source data
213 in DST. Return the number of bytes remaining in the destination buffer. */
216 right_justify (char *dst, size_t dst_len, const char *src, size_t src_len,
217 char **result, bool *truncated)
222 if (src_len <= dst_len)
225 dp = dst + (dst_len - src_len);
230 sp = src + (src_len - dst_len);
236 *result = memcpy (dp, sp, src_len);
237 return dst_len - src_len;
240 /* Using the global directory name obstack, create the full name FILENAME.
241 Return it in sometimes-realloc'd space that should not be freed by the
242 caller. Realloc as necessary. If realloc fails, use a static buffer
243 and put as long a suffix in that buffer as possible. */
245 #define full_filename(Filename) full_filename_ (ds, Filename)
247 full_filename_ (Dirstack_state const *ds, const char *filename)
249 static char *buf = NULL;
250 static size_t n_allocated = 0;
252 size_t dir_len = obstack_object_size (&ds->dir_stack);
253 char *dir_name = obstack_base (&ds->dir_stack);
254 size_t n_bytes_needed;
257 filename_len = strlen (filename);
258 n_bytes_needed = dir_len + filename_len + 1;
260 if (n_allocated < n_bytes_needed)
262 /* This code requires that realloc accept NULL as the first arg.
263 This function must not use xrealloc. Otherwise, an out-of-memory
264 error involving a file name to be expanded here wouldn't ever
265 be issued. Use realloc and fall back on using a static buffer
266 if memory allocation fails. */
267 char *new_buf = realloc (buf, n_bytes_needed);
268 n_allocated = n_bytes_needed;
272 #define SBUF_SIZE 512
273 #define ELLIPSES_PREFIX "[...]"
274 static char static_buf[SBUF_SIZE];
280 len = right_justify (static_buf, SBUF_SIZE, filename,
281 filename_len + 1, &p, &truncated);
282 right_justify (static_buf, len, dir_name, dir_len, &p, &truncated);
285 memcpy (static_buf, ELLIPSES_PREFIX,
286 sizeof (ELLIPSES_PREFIX) - 1);
294 if (filename_len == 1 && *filename == '.' && dir_len)
296 /* FILENAME is just `.' and dir_len is nonzero.
297 Copy the directory part, omitting the trailing slash,
298 and append a trailing zero byte. */
299 char *p = mempcpy (buf, dir_name, dir_len - 1);
304 /* Copy the directory part, including trailing slash, and then
305 append the filename part, including a trailing zero byte. */
306 memcpy (mempcpy (buf, dir_name, dir_len), filename, filename_len + 1);
307 assert (strlen (buf) + 1 == n_bytes_needed);
314 AD_stack_height (Dirstack_state const *ds)
316 return obstack_object_size (&ds->Active_dir) / sizeof (struct AD_ent);
319 static struct AD_ent *
320 AD_stack_top (Dirstack_state const *ds)
322 return (struct AD_ent *)
323 ((char *) obstack_next_free (&ds->Active_dir) - sizeof (struct AD_ent));
327 AD_stack_pop (Dirstack_state *ds)
329 assert (0 < AD_stack_height (ds));
331 /* operate on Active_dir. pop and free top entry */
332 struct AD_ent *top = AD_stack_top (ds);
333 if (top->unremovable)
334 hash_free (top->unremovable);
335 obstack_blank (&ds->Active_dir, -(int) sizeof (struct AD_ent));
338 static Dirstack_state *
341 Dirstack_state *ds = xmalloc (sizeof *ds);
342 obstack_init (&ds->dir_stack);
343 obstack_init (&ds->len_stack);
344 obstack_init (&ds->Active_dir);
349 ds_clear (Dirstack_state *ds)
351 obstack_free (&ds->dir_stack, obstack_finish (&ds->dir_stack));
352 obstack_free (&ds->len_stack, obstack_finish (&ds->len_stack));
353 while (0 < AD_stack_height (ds))
355 obstack_free (&ds->Active_dir, obstack_finish (&ds->Active_dir));
359 ds_free (Dirstack_state *ds)
361 obstack_free (&ds->dir_stack, NULL);
362 obstack_free (&ds->len_stack, NULL);
363 obstack_free (&ds->Active_dir, NULL);
367 /* Pop the active directory (AD) stack and move *DIRP `up' one level,
368 safely. Moving `up' usually means opening `..', but when we've just
369 finished recursively processing a command-line directory argument,
370 there's nothing left on the stack, so set *DIRP to NULL in that case.
371 The idea is to return with *DIRP opened on the parent directory,
372 assuming there are entries in that directory that we need to remove.
374 Whenever using chdir '..' (virtually, now, via openat), verify
375 that the post-chdir dev/ino numbers for `.' match the saved ones.
376 If any system call fails or if dev/ino don't match then give a
377 diagnostic and longjump out.
378 Set *PREV_DIR to the name (in malloc'd storage) of the
379 directory (usually now empty) from which we're coming, and which
380 corresponds to the input value of *DIRP. */
382 AD_pop_and_chdir (DIR **dirp, Dirstack_state *ds, char **prev_dir)
384 enum RM_status old_status = AD_stack_top(ds)->status;
387 /* Get the name of the current (but soon to be `previous') directory
388 from the top of the stack. */
389 *prev_dir = top_dir (ds);
393 top = AD_stack_top (ds);
395 /* Propagate any failure to parent. */
396 UPDATE_STATUS (top->status, old_status);
398 assert (AD_stack_height (ds));
400 if (1 < AD_stack_height (ds))
403 int fd = openat (dirfd (*dirp), "..", O_RDONLY);
404 if (CLOSEDIR (*dirp) != 0)
406 error (0, errno, _("FATAL: failed to close directory %s"),
407 quote (full_filename (*prev_dir)));
408 longjmp (ds->current_arg_jumpbuf, 1);
411 /* The above fails with EACCES when *DIRP is readable but not
412 searchable, when using Solaris' openat. Without this openat
413 call, tests/rm2 would fail to remove directories a/2 and a/3. */
415 fd = openat (AT_FDCWD, full_filename ("."), O_RDONLY);
419 error (0, errno, _("FATAL: cannot open .. from %s"),
420 quote (full_filename (*prev_dir)));
421 longjmp (ds->current_arg_jumpbuf, 1);
427 _("FATAL: cannot ensure %s (returned to via ..) is safe"),
428 quote (full_filename (".")));
430 longjmp (ds->current_arg_jumpbuf, 1);
433 /* Ensure that post-chdir dev/ino match the stored ones. */
434 if ( ! SAME_INODE (sb, top->dev_ino))
436 error (0, 0, _("FATAL: directory %s changed dev/ino"),
437 quote (full_filename (".")));
439 longjmp (ds->current_arg_jumpbuf, 1);
442 *dirp = fdopendir (fd);
445 error (0, errno, _("FATAL: cannot return to .. from %s"),
446 quote (full_filename (".")));
448 longjmp (ds->current_arg_jumpbuf, 1);
453 if (CLOSEDIR (*dirp) != 0)
455 error (0, errno, _("FATAL: failed to close directory %s"),
456 quote (full_filename (*prev_dir)));
457 longjmp (ds->current_arg_jumpbuf, 1);
463 /* Initialize *HT if it is NULL.
464 Insert FILENAME into HT. */
466 AD_mark_helper (Hash_table **ht, char const *filename)
470 *ht = hash_initialize (HT_UNREMOVABLE_INITIAL_CAPACITY, NULL, hash_pjw,
471 hash_compare_strings, hash_freer);
475 if (! hash_insert (*ht, filename))
479 /* Mark FILENAME (in current directory) as unremovable. */
481 AD_mark_as_unremovable (Dirstack_state *ds, char const *filename)
483 AD_mark_helper (&AD_stack_top(ds)->unremovable, xstrdup (filename));
486 /* Mark the current directory as unremovable. I.e., mark the entry
487 in the parent directory corresponding to `.'.
488 This happens e.g., when an opendir fails and the only name
489 the caller has conveniently at hand is `.'. */
491 AD_mark_current_as_unremovable (Dirstack_state *ds)
493 struct AD_ent *top = AD_stack_top (ds);
494 char const *curr = top_dir (ds);
496 assert (1 < AD_stack_height (ds));
499 AD_mark_helper (&top->unremovable, curr);
502 /* Push an initial dummy entry onto the stack.
503 This will always be the bottommost entry on the stack. */
505 AD_push_initial (Dirstack_state *ds)
509 /* Extend the stack. */
510 obstack_blank (&ds->Active_dir, sizeof (struct AD_ent));
512 /* Fill in the new values. */
513 top = AD_stack_top (ds);
514 top->unremovable = NULL;
516 /* These should never be used.
517 Give them values that might look suspicious
518 in a debugger or in a diagnostic. */
519 top->dev_ino.st_dev = TYPE_MAXIMUM (dev_t);
520 top->dev_ino.st_ino = TYPE_MAXIMUM (ino_t);
523 /* Push info about the current working directory (".") onto the
524 active directory stack. DIR is the ./-relative name through
525 which we've just `chdir'd to this directory. DIR_SB_FROM_PARENT
526 is the result of calling lstat on DIR from the parent of DIR.
527 Longjump out (skipping the entire command line argument we're
528 dealing with) if `fstat (FD_CWD, ...' fails or if someone has
529 replaced DIR with e.g., a symlink to some other directory. */
531 AD_push (int fd_cwd, Dirstack_state *ds, char const *dir,
532 struct stat const *dir_sb_from_parent)
538 /* If our uses of openat are guaranteed not to
539 follow a symlink, then we can skip this check. */
543 if (fstat (fd_cwd, &sb) != 0)
545 error (0, errno, _("FATAL: cannot enter directory %s"),
546 quote (full_filename (".")));
547 longjmp (ds->current_arg_jumpbuf, 1);
550 if ( ! SAME_INODE (sb, *dir_sb_from_parent))
553 _("FATAL: just-changed-to directory %s changed dev/ino"),
554 quote (full_filename (".")));
555 longjmp (ds->current_arg_jumpbuf, 1);
559 /* Extend the stack. */
560 obstack_blank (&ds->Active_dir, sizeof (struct AD_ent));
563 size_t n_lengths = obstack_object_size (&ds->len_stack) / sizeof (size_t);
564 assert (AD_stack_height (ds) == n_lengths + 1);
567 /* Fill in the new values. */
568 top = AD_stack_top (ds);
569 top->dev_ino.st_dev = dir_sb_from_parent->st_dev;
570 top->dev_ino.st_ino = dir_sb_from_parent->st_ino;
571 top->unremovable = NULL;
575 AD_is_removable (Dirstack_state const *ds, char const *file)
577 struct AD_ent *top = AD_stack_top (ds);
578 return ! (top->unremovable && hash_lookup (top->unremovable, file));
581 /* Return true if DIR is determined to be an empty directory
582 or if fdopendir or readdir fails. */
584 is_empty_dir (int fd_cwd, char const *dir)
587 struct dirent const *dp;
589 int fd = openat (fd_cwd, dir, O_RDONLY | O_NDELAY);
594 dirp = fdopendir (fd);
602 dp = readdir_ignoring_dot_and_dotdot (dirp);
607 return saved_errno == 0 ? true : false;
610 /* Return true if FILE is determined to be an unwritable non-symlink.
611 Otherwise, return false (including when lstat'ing it fails).
612 If lstat (aka fstatat) succeeds, set *BUF_P to BUF.
613 This is to avoid calling euidaccess when FILE is a symlink. */
615 write_protected_non_symlink (int fd_cwd,
617 Dirstack_state const *ds,
621 if (fstatat (fd_cwd, file, buf, AT_SYMLINK_NOFOLLOW) != 0)
624 if (S_ISLNK (buf->st_mode))
626 /* Here, we know FILE is not a symbolic link. */
628 /* In order to be reentrant -- i.e., to avoid changing the working
629 directory, and at the same time to be able to deal with alternate
630 access control mechanisms (ACLs, xattr-style attributes) and
631 arbitrarily deep trees -- we need a function like eaccessat, i.e.,
632 like Solaris' eaccess, but fd-relative, in the spirit of openat. */
634 /* In the absence of a native eaccessat function, here are some of
635 the implementation choices [#4 and #5 were suggested by Paul Eggert]:
636 1) call openat with O_WRONLY|O_NOCTTY
637 Disadvantage: may create the file and doesn't work for directory,
638 may mistakenly report `unwritable' for EROFS or ACLs even though
639 perm bits say the file is writable.
641 2) fake eaccessat (save_cwd, fchdir, call euidaccess, restore_cwd)
642 Disadvantage: changes working directory (not reentrant) and can't
643 work if save_cwd fails.
645 3) if (euidaccess (full_filename (file), W_OK) == 0)
646 Disadvantage: doesn't work if full_filename is too long.
647 Inefficient for very deep trees (O(Depth^2)).
649 4) If the full pathname is sufficiently short (say, less than
650 PATH_MAX or 8192 bytes, whichever is shorter):
651 use method (3) (i.e., euidaccess (full_filename (file), W_OK));
652 Otherwise: vfork, fchdir in the child, run euidaccess in the
653 child, then the child exits with a status that tells the parent
654 whether euidaccess succeeded.
656 This avoids the O(N**2) algorithm of method (3), and it also avoids
657 the failure-due-to-too-long-file-names of method (3), but it's fast
658 in the normal shallow case. It also avoids the lack-of-reentrancy
659 and the save_cwd problems.
660 Disadvantage; it uses a process slot for very-long file names,
661 and would be very slow for hierarchies with many such files.
663 5) If the full file name is sufficiently short (say, less than
664 PATH_MAX or 8192 bytes, whichever is shorter):
665 use method (3) (i.e., euidaccess (full_filename (file), W_OK));
666 Otherwise: look just at the file bits. Perhaps issue a warning
667 the first time this occurs.
669 This is like (4), except for the "Otherwise" case where it isn't as
670 "perfect" as (4) but is considerably faster. It conforms to current
671 POSIX, and is uniformly better than what Solaris and FreeBSD do (they
672 mess up with long file names). */
675 /* This implements #5: */
677 = obstack_object_size (&ds->dir_stack) + strlen (file);
679 return (file_name_len < MIN (PATH_MAX, 8192)
680 ? euidaccess (full_filename (file), W_OK) != 0 && errno == EACCES
681 : euidaccess_stat (buf, W_OK) != 0);
685 /* Prompt whether to remove FILENAME, if required via a combination of
686 the options specified by X and/or file attributes. If the file may
687 be removed, return RM_OK. If the user declines to remove the file,
688 return RM_USER_DECLINED. If not ignoring missing files and we
689 cannot lstat FILENAME, then return RM_ERROR.
691 Depending on MODE, ask whether to `descend into' or to `remove' the
692 directory FILENAME. MODE is ignored when FILENAME is not a directory.
693 Set *IS_EMPTY to T_YES if FILENAME is an empty directory, and it is
694 appropriate to try to remove it with rmdir (e.g. recursive mode).
695 Don't even try to set *IS_EMPTY when MODE == PA_REMOVE_DIR.
696 Set *IS_DIR to T_YES or T_NO if we happen to determine whether
697 FILENAME is a directory. */
698 static enum RM_status
699 prompt (int fd_cwd, Dirstack_state const *ds, char const *filename,
700 struct rm_options const *x, enum Prompt_action mode,
701 Ternary *is_dir, Ternary *is_empty)
703 bool write_protected = false;
704 struct stat *sbuf = NULL;
707 *is_empty = T_UNKNOWN;
710 if (((!x->ignore_missing_files & (x->interactive | x->stdin_tty))
711 && (write_protected = write_protected_non_symlink (fd_cwd, filename,
718 if (fstatat (fd_cwd, filename, sbuf, AT_SYMLINK_NOFOLLOW))
720 /* lstat failed. This happens e.g., with `rm '''. */
721 error (0, errno, _("cannot remove %s"),
722 quote (full_filename (filename)));
727 if (S_ISDIR (sbuf->st_mode) && !x->recursive)
729 error (0, EISDIR, _("cannot remove directory %s"),
730 quote (full_filename (filename)));
734 /* Using permissions doesn't make sense for symlinks. */
735 if (S_ISLNK (sbuf->st_mode))
737 if ( ! x->interactive)
739 write_protected = false;
742 /* Issue the prompt. */
744 char const *quoted_name = quote (full_filename (filename));
746 *is_dir = (S_ISDIR (sbuf->st_mode) ? T_YES : T_NO);
748 /* FIXME: use a variant of error (instead of fprintf) that doesn't
749 append a newline. Then we won't have to declare program_name in
751 if (S_ISDIR (sbuf->st_mode)
753 && mode == PA_DESCEND_INTO_DIR
754 && ((*is_empty = (is_empty_dir (fd_cwd, filename) ? T_YES : T_NO))
758 ? _("%s: descend into write-protected directory %s? ")
759 : _("%s: descend into directory %s? ")),
760 program_name, quoted_name);
763 /* TRANSLATORS: You may find it more convenient to translate
764 the equivalent of _("%s: remove %s (write-protected) %s? ").
765 It should avoid grammatical problems with the output
769 ? _("%s: remove write-protected %s %s? ")
770 : _("%s: remove %s %s? ")),
771 program_name, file_type (sbuf), quoted_name);
775 return RM_USER_DECLINED;
781 /* Return true if FILENAME is a directory (and not a symlink to a directory).
782 Otherwise, including the case in which lstat fails, return false.
783 Do not modify errno. */
785 is_dir_lstat (char const *filename)
788 int saved_errno = errno;
789 bool is_dir = lstat (filename, &sbuf) == 0 && S_ISDIR (sbuf.st_mode);
794 #if HAVE_STRUCT_DIRENT_D_TYPE
796 /* True if the type of the directory entry D is known. */
797 # define DT_IS_KNOWN(d) ((d)->d_type != DT_UNKNOWN)
799 /* True if the type of the directory entry D must be T. */
800 # define DT_MUST_BE(d, t) ((d)->d_type == (t))
803 # define DT_IS_KNOWN(d) false
804 # define DT_MUST_BE(d, t) false
807 #define DO_UNLINK(Fd_cwd, Filename, X) \
810 if (unlinkat (Fd_cwd, Filename, 0) == 0) \
813 printf (_("removed %s\n"), quote (full_filename (Filename))); \
817 if (errno == ENOENT && (X)->ignore_missing_files) \
822 #define DO_RMDIR(Fd_cwd, Filename, X) \
825 if (unlinkat (Fd_cwd, Filename, AT_REMOVEDIR) == 0) /* rmdir */ \
828 printf (_("removed directory: %s\n"), \
829 quote (full_filename (Filename))); \
833 if (errno == ENOENT && (X)->ignore_missing_files) \
836 if (errno == ENOTEMPTY || errno == EEXIST) \
837 return RM_NONEMPTY_DIR; \
841 /* Remove the file or directory specified by FILENAME.
842 Return RM_OK if it is removed, and RM_ERROR or RM_USER_DECLINED if not.
843 But if FILENAME specifies a non-empty directory, return RM_NONEMPTY_DIR. */
845 static enum RM_status
846 remove_entry (int fd_cwd, Dirstack_state const *ds, char const *filename,
847 struct rm_options const *x, struct dirent const *dp)
850 Ternary is_empty_directory;
851 enum RM_status s = prompt (fd_cwd, ds, filename, x, PA_DESCEND_INTO_DIR,
852 &is_dir, &is_empty_directory);
857 /* Why bother with the following if/else block? Because on systems with
858 an unlink function that *can* unlink directories, we must determine the
859 type of each entry before removing it. Otherwise, we'd risk unlinking
860 an entire directory tree simply by unlinking a single directory; then
861 all the storage associated with that hierarchy would not be freed until
862 the next fsck. Not nice. To avoid that, on such slightly losing
863 systems, we need to call lstat to determine the type of each entry,
864 and that represents extra overhead that -- it turns out -- we can
865 avoid on non-losing systems, since there, unlink will never remove
866 a directory. Also, on systems where unlink may unlink directories,
867 we're forced to allow a race condition: we lstat a non-directory, then
868 go to unlink it, but in the mean time, a malicious someone could have
869 replaced it with a directory. */
871 if (cannot_unlink_dir ())
873 if (is_dir == T_YES && ! x->recursive)
875 error (0, EISDIR, _("cannot remove directory %s"),
876 quote (full_filename (filename)));
880 /* is_empty_directory is set iff it's ok to use rmdir.
881 Note that it's set only in interactive mode -- in which case it's
882 an optimization that arranges so that the user is asked just
883 once whether to remove the directory. */
884 if (is_empty_directory == T_YES)
885 DO_RMDIR (fd_cwd, filename, x);
887 /* If we happen to know that FILENAME is a directory, return now
888 and let the caller remove it -- this saves the overhead of a failed
889 unlink call. If FILENAME is a command-line argument, then dp is NULL,
890 so we'll first try to unlink it. Using unlink here is ok, because it
891 cannot remove a directory. */
892 if ((dp && DT_MUST_BE (dp, DT_DIR)) || is_dir == T_YES)
893 return RM_NONEMPTY_DIR;
895 DO_UNLINK (fd_cwd, filename, x);
897 /* Upon a failed attempt to unlink a directory, most non-Linux systems
898 set errno to the POSIX-required value EPERM. In that case, change
899 errno to EISDIR so that we emit a better diagnostic. */
900 if (! x->recursive && errno == EPERM && is_dir_lstat (filename))
904 || errno == ENOENT || errno == ENOTDIR
905 || errno == ELOOP || errno == ENAMETOOLONG)
907 /* Either --recursive is not in effect, or the file cannot be a
908 directory. Report the unlink problem and fail. */
909 error (0, errno, _("cannot remove %s"),
910 quote (full_filename (filename)));
916 /* If we don't already know whether FILENAME is a directory, find out now.
917 Then, if it's a non-directory, we can use unlink on it. */
918 if (is_dir == T_UNKNOWN)
920 if (dp && DT_IS_KNOWN (dp))
921 is_dir = DT_MUST_BE (dp, DT_DIR) ? T_YES : T_NO;
925 if (fstatat (fd_cwd, filename, &sbuf, AT_SYMLINK_NOFOLLOW))
927 if (errno == ENOENT && x->ignore_missing_files)
930 error (0, errno, _("cannot remove %s"),
931 quote (full_filename (filename)));
935 is_dir = S_ISDIR (sbuf.st_mode) ? T_YES : T_NO;
941 /* At this point, barring race conditions, FILENAME is known
942 to be a non-directory, so it's ok to try to unlink it. */
943 DO_UNLINK (fd_cwd, filename, x);
945 /* unlink failed with some other error code. report it. */
946 error (0, errno, _("cannot remove %s"),
947 quote (full_filename (filename)));
953 error (0, EISDIR, _("cannot remove directory %s"),
954 quote (full_filename (filename)));
958 if (is_empty_directory == T_YES)
960 DO_RMDIR (fd_cwd, filename, x);
961 /* Don't diagnose any failure here.
962 It'll be detected when the caller tries another way. */
966 return RM_NONEMPTY_DIR;
969 /* Given FD_CWD, the file descriptor for an open directory,
970 open its subdirectory F (F is already `known' to be a directory,
971 so if it is no longer one, someone is playing games), return a DIR*
972 pointer for F, and put F's `stat' data in *SUBDIR_SB.
973 Upon failure give a diagnostic and return NULL.
974 If PREV_ERRNO is nonzero, it is the errno value from a preceding failed
975 unlink- or rmdir-like system call -- use that value instead of ENOTDIR
976 if an opened file turns out not to be a directory. This is important
977 when the preceding non-dir-unlink failed due to e.g., EPERM or EACCES.
978 The caller must use a nonnnull CWD_ERRNO the first
979 time this function is called for each command-line-specified directory.
980 If CWD_ERRNO is not null, set *CWD_ERRNO to the appropriate error number
981 if this function fails to restore the initial working directory.
982 If it is null, report an error and exit if the working directory
985 fd_to_subdirp (int fd_cwd, char const *f,
986 struct rm_options const *x, int prev_errno,
987 struct stat *subdir_sb, Dirstack_state *ds,
988 int *cwd_errno ATTRIBUTE_UNUSED)
990 int fd_sub = openat_permissive (fd_cwd, f, O_RDONLY | O_NOFOLLOW,
993 /* Record dev/ino of F. We may compare them against saved values
994 to thwart any attempt to subvert the traversal. They are also used
995 to detect directory cycles. */
996 if (fd_sub < 0 || fstat (fd_sub, subdir_sb) != 0)
998 if (errno != ENOENT || !x->ignore_missing_files)
1000 _("cannot remove %s"), quote (full_filename (f)));
1006 if (! S_ISDIR (subdir_sb->st_mode))
1008 error (0, prev_errno ? prev_errno : ENOTDIR, _("cannot remove %s"),
1009 quote (full_filename (f)));
1014 DIR *subdir_dirp = fdopendir (fd_sub);
1015 if (subdir_dirp == NULL)
1017 if (errno != ENOENT || !x->ignore_missing_files)
1018 error (0, errno, _("cannot open directory %s"),
1019 quote (full_filename (f)));
1027 /* Remove entries in the directory open on DIRP
1028 Upon finding a directory that is both non-empty and that can be chdir'd
1029 into, return RM_OK and set *SUBDIR and fill in SUBDIR_SB, where
1030 SUBDIR is the malloc'd name of the subdirectory if the chdir succeeded,
1031 NULL otherwise (e.g., if opendir failed or if there was no subdirectory).
1032 Likewise, SUBDIR_SB is the result of calling lstat on SUBDIR.
1033 Return RM_OK if all entries are removed. Return RM_ERROR if any
1034 entry cannot be removed. Otherwise, return RM_USER_DECLINED if
1035 the user declines to remove at least one entry. Remove as much as
1036 possible, continuing even if we fail to remove some entries. */
1037 static enum RM_status
1038 remove_cwd_entries (DIR **dirp,
1039 Dirstack_state *ds, char **subdir, struct stat *subdir_sb,
1040 struct rm_options const *x)
1042 struct AD_ent *top = AD_stack_top (ds);
1043 enum RM_status status = top->status;
1044 size_t n_unlinked_since_opendir_or_last_rewind = 0;
1046 assert (VALID_STATUS (status));
1051 struct dirent const *dp;
1052 enum RM_status tmp_status;
1055 /* Set errno to zero so we can distinguish between a readdir failure
1056 and when readdir simply finds that there are no more entries. */
1058 dp = readdir_ignoring_dot_and_dotdot (*dirp);
1065 else if (CONSECUTIVE_READDIR_UNLINK_THRESHOLD
1066 < n_unlinked_since_opendir_or_last_rewind)
1068 /* Call rewinddir if we've called unlink or rmdir so many times
1069 (since the opendir or the previous rewinddir) that this
1070 NULL-return may be the symptom of a buggy readdir. */
1072 n_unlinked_since_opendir_or_last_rewind = 0;
1080 /* Skip files we've already tried/failed to remove. */
1081 if ( ! AD_is_removable (ds, f))
1084 /* Pass dp->d_type info to remove_entry so the non-glibc
1085 case can decide whether to use unlink or chdir.
1086 Systems without the d_type member will have to endure
1087 the performance hit of first calling lstat F. */
1088 tmp_status = remove_entry (dirfd (*dirp), ds, f, x, dp);
1092 /* Count how many files we've unlinked since the initial
1093 opendir or the last rewinddir. On buggy systems, if you
1094 remove too many, readdir returns NULL even though there
1095 remain unprocessed directory entries. */
1096 ++n_unlinked_since_opendir_or_last_rewind;
1100 case RM_USER_DECLINED:
1101 AD_mark_as_unremovable (ds, f);
1102 UPDATE_STATUS (status, tmp_status);
1105 case RM_NONEMPTY_DIR:
1107 DIR *subdir_dirp = fd_to_subdirp (dirfd (*dirp), f,
1108 x, errno, subdir_sb, ds, NULL);
1109 if (subdir_dirp == NULL)
1111 AD_mark_as_unremovable (ds, f);
1116 if (cycle_check (&ds->cycle_check_state, subdir_sb))
1119 WARNING: Circular directory structure.\n\
1120 This almost certainly means that you have a corrupted file system.\n\
1121 NOTIFY YOUR SYSTEM MANAGER.\n\
1122 The following directory is part of the cycle:\n %s\n"),
1123 quote (full_filename (".")));
1124 longjmp (ds->current_arg_jumpbuf, 1);
1127 *subdir = xstrdup (f);
1128 if (CLOSEDIR (*dirp) != 0)
1130 error (0, 0, _("failed to close directory %s"),
1131 quote (full_filename (".")));
1134 *dirp = subdir_dirp;
1140 /* Record status for this directory. */
1141 UPDATE_STATUS (top->status, status);
1147 /* Ensure that *dirp is not NULL and that its file descriptor is valid. */
1148 assert (*dirp != NULL);
1149 assert (0 <= fcntl (dirfd (*dirp), F_GETFD));
1154 /* Do this after each call to AD_push or AD_push_initial.
1155 Because the status = RM_OK bit is too remove-specific to
1156 go into the general-purpose AD_* package. */
1157 #define AD_INIT_OTHER_MEMBERS() \
1160 AD_stack_top(ds)->status = RM_OK; \
1164 /* Remove the hierarchy rooted at DIR.
1165 Do that by changing into DIR, then removing its contents, then
1166 returning to the original working directory and removing DIR itself.
1167 Don't use recursion. Be careful when using chdir ".." that we
1168 return to the same directory from which we came, if necessary.
1169 Return an RM_status value to indicate success or failure. */
1171 static enum RM_status
1172 remove_dir (int fd_cwd, Dirstack_state *ds, char const *dir,
1173 struct rm_options const *x, int *cwd_errno)
1175 enum RM_status status;
1178 /* There is a race condition in that an attacker could replace the nonempty
1179 directory, DIR, with a symlink between the preceding call to rmdir
1180 (unlinkat, in our caller) and fd_to_subdirp's openat call. But on most
1181 systems, even those without openat, this isn't a problem, since we ensure
1182 that opening a symlink will fail, when that is possible. Otherwise,
1183 fd_to_subdirp's fstat, along with the `fstat' and the dev/ino
1184 comparison in AD_push ensure that we detect it and fail. */
1186 DIR *dirp = fd_to_subdirp (fd_cwd, dir, x, 0, &dir_sb, ds, cwd_errno);
1191 if (ROOT_DEV_INO_CHECK (x->root_dev_ino, &dir_sb))
1193 ROOT_DEV_INO_WARN (full_filename (dir));
1195 goto closedir_and_return;
1198 AD_push (dirfd (dirp), ds, dir, &dir_sb);
1199 AD_INIT_OTHER_MEMBERS ();
1205 char *subdir = NULL;
1206 struct stat subdir_sb;
1207 enum RM_status tmp_status;
1209 tmp_status = remove_cwd_entries (&dirp, ds, &subdir, &subdir_sb, x);
1211 if (tmp_status != RM_OK)
1213 UPDATE_STATUS (status, tmp_status);
1214 AD_mark_current_as_unremovable (ds);
1218 AD_push (dirfd (dirp), ds, subdir, &subdir_sb);
1219 AD_INIT_OTHER_MEMBERS ();
1225 /* Execution reaches this point when we've removed the last
1226 removable entry from the current directory. */
1228 /* The name of the directory that we have just processed,
1229 nominally removing all of its contents. */
1232 AD_pop_and_chdir (&dirp, ds, &empty_dir);
1233 int fd = (dirp != NULL ? dirfd (dirp) : AT_FDCWD);
1234 assert (dirp != NULL || AD_stack_height (ds) == 1);
1236 /* Try to remove EMPTY_DIR only if remove_cwd_entries succeeded. */
1237 if (tmp_status == RM_OK)
1239 /* This does a little more work than necessary when it actually
1240 prompts the user. E.g., we already know that D is a directory
1241 and that it's almost certainly empty, yet we lstat it.
1242 But that's no big deal since we're interactive. */
1245 enum RM_status s = prompt (fd, ds, empty_dir, x,
1246 PA_REMOVE_DIR, &is_dir, &is_empty);
1252 goto closedir_and_return;
1255 if (unlinkat (fd, empty_dir, AT_REMOVEDIR) == 0)
1258 printf (_("removed directory: %s\n"),
1259 quote (full_filename (empty_dir)));
1263 error (0, errno, _("cannot remove directory %s"),
1264 quote (full_filename (empty_dir)));
1265 AD_mark_as_unremovable (ds, empty_dir);
1267 UPDATE_STATUS (AD_stack_top(ds)->status, status);
1273 if (AD_stack_height (ds) == 1)
1278 /* If the first/final hash table of unremovable entries was used,
1282 closedir_and_return:;
1283 if (dirp != NULL && CLOSEDIR (dirp) != 0)
1285 error (0, 0, _("failed to close directory %s"),
1286 quote (full_filename (".")));
1293 /* Remove the file or directory specified by FILENAME.
1294 Return RM_OK if it is removed, and RM_ERROR or RM_USER_DECLINED if not. */
1296 static enum RM_status
1297 rm_1 (Dirstack_state *ds, char const *filename,
1298 struct rm_options const *x, int *cwd_errno)
1300 char const *base = base_name (filename);
1301 if (DOT_OR_DOTDOT (base))
1303 error (0, 0, _("cannot remove `.' or `..'"));
1307 AD_push_initial (ds);
1308 AD_INIT_OTHER_MEMBERS ();
1310 /* Put `status' in static storage, so it can't be clobbered
1311 by the potential longjmp into this function. */
1312 static enum RM_status status;
1313 int fd_cwd = AT_FDCWD;
1314 status = remove_entry (fd_cwd, ds, filename, x, NULL);
1315 if (status == RM_NONEMPTY_DIR)
1317 /* In the event that remove_dir->remove_cwd_entries detects
1318 a directory cycle, arrange to fail, give up on this FILE, but
1319 continue on with any other arguments. */
1320 if (setjmp (ds->current_arg_jumpbuf))
1323 status = remove_dir (fd_cwd, ds, filename, x, cwd_errno);
1331 /* Remove all files and/or directories specified by N_FILES and FILE.
1332 Apply the options in X. */
1333 extern enum RM_status
1334 rm (size_t n_files, char const *const *file, struct rm_options const *x)
1336 enum RM_status status = RM_OK;
1337 Dirstack_state *ds = ds_init ();
1341 for (i = 0; i < n_files; i++)
1343 if (cwd_errno && IS_RELATIVE_FILE_NAME (file[i]))
1345 error (0, 0, _("cannot remove relative-named %s"), quote (file[i]));
1350 cycle_check_init (&ds->cycle_check_state);
1351 enum RM_status s = rm_1 (ds, file[i], x, &cwd_errno);
1352 assert (VALID_STATUS (s));
1353 UPDATE_STATUS (status, s);
1356 if (x->require_restore_cwd && cwd_errno)
1358 error (0, cwd_errno,
1359 _("cannot restore current working directory"));