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rm: do not resort to stat'ing very long names even on deficient systems

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This change affects only systems that have neither *at function support
nor the /proc/self/fd support required to emulate those *at functions.
* src/remove.c (write_protected_non_symlink): Call faccessat
unconditionally.  Thus we no longer need euidaccess_stat, which was
the sole function used here to operate on a full relative file name.
Remove full_name parameter and update caller.
* lib/euidaccess-stat.h: Remove file.
* lib/euidaccess-stat.c: Likewise.
* m4/euidaccess-stat.m4: Likewise.
* po/POTFILES.in: Remove lib/euidaccess-stat.c.
* m4/prereq.m4 (gl_PREREQ): Don't require gl_EUIDACCESS_STAT.
Prompted by a report from Bruno Haible that the rm/deep-2
test was failing on HP-UX 11.31.
See http://thread.gmane.org/gmane.comp.gnu.coreutils.general/1748
This commit is contained in:
Jim Meyering
2011-10-09 10:52:52 +02:00
parent c977d5de8d
commit d12ca9764b
6 changed files with 5 additions and 184 deletions
Download Patch File Download Diff File Expand all files Collapse all files
lib/euidaccess-stat.c
-134
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@@ -1,134 +0,0 @@
/* euidaccess-stat -- check if effective user id can access lstat'd file
This function is probably useful only for choosing whether to issue
a prompt in an implementation of POSIX-specified rm.
Copyright (C) 2005-2006, 2009-2011 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* Adapted for use in GNU remove.c by Jim Meyering. */
#include <config.h>
#include "euidaccess-stat.h"
#include <unistd.h>
#include "stat-macros.h"
/* Return true if the current user has permission of type MODE
on the file from which stat buffer *ST was obtained, ignoring
ACLs, attributes, `read-only'ness, etc...
Otherwise, return false.
Like the reentrant version of euidaccess, but starting with
a stat buffer rather than a file name. Hence, this function
never calls access or accessx, and doesn't take into account
whether the file has ACLs or other attributes, or resides on
a read-only file system. */
bool
euidaccess_stat (struct stat const *st, int mode)
{
uid_t euid;
unsigned int granted;
/* Convert the mode to traditional form, clearing any bogus bits. */
if (R_OK == 4 && W_OK == 2 && X_OK == 1 && F_OK == 0)
mode &= 7;
else
mode = ((mode & R_OK ? 4 : 0)
+ (mode & W_OK ? 2 : 0)
+ (mode & X_OK ? 1 : 0));
if (mode == 0)
return true; /* The file exists. */
euid = geteuid ();
/* The super-user can read and write any file, and execute any file
that anyone can execute. */
if (euid == 0 && ((mode & X_OK) == 0
|| (st->st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))))
return true;
/* Convert the file's permission bits to traditional form. */
if ( S_IRUSR == (4 << 6)
&& S_IWUSR == (2 << 6)
&& S_IXUSR == (1 << 6)
&& S_IRGRP == (4 << 3)
&& S_IWGRP == (2 << 3)
&& S_IXGRP == (1 << 3)
&& S_IROTH == (4 << 0)
&& S_IWOTH == (2 << 0)
&& S_IXOTH == (1 << 0))
granted = st->st_mode;
else
granted = ( (st->st_mode & S_IRUSR ? 4 << 6 : 0)
+ (st->st_mode & S_IWUSR ? 2 << 6 : 0)
+ (st->st_mode & S_IXUSR ? 1 << 6 : 0)
+ (st->st_mode & S_IRGRP ? 4 << 3 : 0)
+ (st->st_mode & S_IWGRP ? 2 << 3 : 0)
+ (st->st_mode & S_IXGRP ? 1 << 3 : 0)
+ (st->st_mode & S_IROTH ? 4 << 0 : 0)
+ (st->st_mode & S_IWOTH ? 2 << 0 : 0)
+ (st->st_mode & S_IXOTH ? 1 << 0 : 0));
if (euid == st->st_uid)
granted >>= 6;
else
{
gid_t egid = getegid ();
if (egid == st->st_gid || group_member (st->st_gid))
granted >>= 3;
}
if ((mode & ~granted) == 0)
return true;
return false;
}
#ifdef TEST
# include <errno.h>
# include <stdio.h>
# include <stdlib.h>
# include "error.h"
# define _(msg) msg
char *program_name;
int
main (int argc, char **argv)
{
char *file;
int mode;
bool ok;
struct stat st;
program_name = argv[0];
if (argc < 3)
abort ();
file = argv[1];
mode = atoi (argv[2]);
if (lstat (file, &st) != 0)
error (EXIT_FAILURE, errno, _("cannot stat %s"), file);
ok = euidaccess_stat (&st, mode);
printf ("%s: %s\n", file, ok ? "y" : "n");
return 0;
}
#endif
lib/euidaccess-stat.h
-5
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@@ -1,5 +0,0 @@
#include <sys/types.h>
#include <sys/stat.h>
#include <stdbool.h>
bool euidaccess_stat (struct stat const *st, int mode);
m4/euidaccess-stat.m4
-11
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@@ -1,11 +0,0 @@
# serial 1
dnl Copyright (C) 2005, 2009-2011 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
AC_DEFUN([gl_EUIDACCESS_STAT],
[
AC_LIBSOURCES([euidaccess-stat.c, euidaccess-stat.h])
AC_LIBOBJ([euidaccess-stat])
])
m4/prereq.m4
+1 -2
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@@ -1,4 +1,4 @@
#serial 77
#serial 78
dnl We use gl_ for non Autoconf macros.
m4_pattern_forbid([^gl_[ABCDEFGHIJKLMNOPQRSTUVXYZ]])dnl
@@ -36,7 +36,6 @@ AC_DEFUN([gl_PREREQ],
# Invoke macros of modules that may migrate into gnulib.
# There's no need to list gnulib modules here, since gnulib-tool
# handles that; see ../bootstrap.conf.
AC_REQUIRE([gl_EUIDACCESS_STAT])
AC_REQUIRE([gl_FD_REOPEN])
AC_REQUIRE([gl_FUNC_XATTR])
AC_REQUIRE([gl_FUNC_XFTS])
po/POTFILES.in
-1
View File
@@ -7,7 +7,6 @@ lib/closein.c
lib/closeout.c
lib/copy-acl.c
lib/error.c
lib/euidaccess-stat.c
lib/file-type.c
lib/gai_strerror.c
lib/getopt.c
src/remove.c
+4 -31
View File
@@ -23,7 +23,6 @@
#include "system.h"
#include "error.h"
#include "euidaccess-stat.h"
#include "file-type.h"
#include "ignore-value.h"
#include "quote.h"
@@ -106,13 +105,10 @@ cache_stat_ok (struct stat *st)
/* Return 1 if FILE is an unwritable non-symlink,
0 if it is writable or some other type of file,
-1 and set errno if there is some problem in determining the answer.
Use FULL_NAME only if necessary.
Set *BUF to the file status.
This is to avoid calling euidaccess when FILE is a symlink. */
Set *BUF to the file status. */
static int
write_protected_non_symlink (int fd_cwd,
char const *file,
char const *full_name,
struct stat *buf)
{
if (can_write_any_file ())
@@ -170,32 +166,10 @@ write_protected_non_symlink (int fd_cwd,
mess up with long file names). */
{
/* This implements #1: on decent systems, either faccessat is
native or /proc/self/fd allows us to skip a chdir. */
if (!openat_needs_fchdir ())
{
if (faccessat (fd_cwd, file, W_OK, AT_EACCESS) == 0)
return 0;
return errno == EACCES ? 1 : -1;
}
/* This implements #5: */
size_t file_name_len = strlen (full_name);
if (MIN (PATH_MAX, 8192) <= file_name_len)
return ! euidaccess_stat (buf, W_OK);
if (euidaccess (full_name, W_OK) == 0)
if (faccessat (fd_cwd, file, W_OK, AT_EACCESS) == 0)
return 0;
if (errno == EACCES)
{
errno = 0;
return 1;
}
/* Perhaps some other process has removed the file, or perhaps this
is a buggy NFS client. */
return -1;
return errno == EACCES ? 1 : -1;
}
}
@@ -244,8 +218,7 @@ prompt (FTS const *fts, FTSENT const *ent, bool is_dir,
&& ((x->interactive == RMI_ALWAYS) || x->stdin_tty)
&& dirent_type != DT_LNK)
{
write_protected = write_protected_non_symlink (fd_cwd, filename,
full_name, sbuf);
write_protected = write_protected_non_symlink (fd_cwd, filename, sbuf);
wp_errno = errno;
}