tests/rm/fail-eperm.xpl

   1 #!/usr/bin/perl -Tw
   2 # Ensure that rm gives the expected diagnostic when failing to remove a file
   3 # owned by some other user in a directory with the sticky bit set.
   4
   5 # Copyright (C) 2002-2024 Free Software Foundation, Inc.
   6
   7 # This program is free software: you can redistribute it and/or modify
   8 # it under the terms of the GNU General Public License as published by
   9 # the Free Software Foundation, either version 3 of the License, or
  10 # (at your option) any later version.
  11
  12 # This program is distributed in the hope that it will be useful,
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 # GNU General Public License for more details.
  16
  17 # You should have received a copy of the GNU General Public License
  18 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19
  20 use strict;
  21
  22 (my $ME = $0) =~ s|.*/||;
  23
  24 my $uid = $<;
  25 # skip if root
  26 $uid == 0
  27   and CuSkip::skip "$ME: can't run this test as root: skipping this test";
  28
  29 my $verbose = $ENV{VERBOSE} && $ENV{VERBOSE} eq 'yes';
  30
  31 # Ensure that the diagnostics are in English.
  32 $ENV{LC_ALL} = 'C';
  33
  34 # Set up a safe, well-known environment
  35 $ENV{IFS}  = '';
  36
  37 # Taint checking requires a sanitized $PATH.  This script performs no $PATH
  38 # search, so on most Unix-based systems, it is fine simply to clear $ENV{PATH}.
  39 # However, on Cygwin, it's used to find cygwin1.dll, so set it.
  40 $ENV{PATH} = '/bin:/usr/bin';
  41
  42 my @dir_list = qw(/tmp /var/tmp /usr/tmp);
  43 my $rm = "$ENV{abs_top_builddir}/src/rm";
  44
  45 # Untaint for upcoming popen.
  46 $rm =~ m!^([-+\@\w./]+)$!
  47   or CuSkip::skip "$ME: unusual absolute builddir name; skipping this test\n";
  48 $rm = $1;
  49
  50 # Find a directory with the sticky bit set.
  51 my $found_dir;
  52 my $found_file;
  53 foreach my $dir (@dir_list)
  54   {
  55     if (-d $dir && -k _ && -r _ && -w _ && -x _)
  56       {
  57         $found_dir = 1;
  58
  59         # Find a non-directory there that is owned by some other user.
  60         opendir DIR_HANDLE, $dir
  61           or die "$ME: couldn't open $dir: $!\n";
  62
  63         foreach my $f (readdir DIR_HANDLE)
  64           {
  65             # Consider only names containing "safe" characters.
  66             $f =~ /^([-\@\w.]+)$/
  67               or next;
  68             $f = $1;    # untaint $f
  69
  70             my $target_file = "$dir/$f";
  71             $verbose
  72               and warn "$ME: considering $target_file\n";
  73
  74             # Skip files owned by self, symlinks, and directories.
  75             # It's not technically necessary to skip symlinks, but it's simpler.
  76             # SVR4-like systems (e.g., Solaris 9) let you unlink files that
  77             # you can write, so skip writable files too.
  78             -l $target_file || -o _ || -d _ || -w _
  79               and next;
  80
  81             $found_file = 1;
  82
  83             # Invoke rm on this file and ensure that we get the
  84             # expected exit code and diagnostic.
  85             my $cmd = "$rm -f -- $target_file";
  86             open RM, "$cmd 2>&1 |"
  87               or die "$ME: cannot execute '$cmd'\n";
  88
  89             my $line = <RM>;
  90
  91             close RM;
  92             my $rc = $?;
  93             # This test opportunistically looks for files that can't
  94             # be removed but those files may already have been removed
  95             # by their owners by the time we get to them.  It is a
  96             # race condition.  If so then the rm is successful and our
  97             # test is thwarted.  Detect this case and ignore.
  98             if ($rc == 0)
  99               {
 100                 next if ! -e $target_file;
 101                 die "$ME: unexpected exit status from '$cmd';\n"
 102                   . "  got 0, expected 1\n";
 103               }
 104             if (0x80 < $rc)
 105               {
 106                 my $status = $rc >> 8;
 107                 $status == 1
 108                   or die "$ME: unexpected exit status from '$cmd';\n"
 109                     . "  got $status, expected 1\n";
 110               }
 111             else
 112               {
 113                 # Terminated by a signal.
 114                 my $sig_num = $rc & 0x7F;
 115                 die "$ME: command '$cmd' died with signal $sig_num\n";
 116               }
 117
 118             my $exp = "rm: cannot remove '$target_file':";
 119             $line
 120               or die "$ME: no output from '$cmd';\n"
 121                 . "expected something like '$exp ...'\n";
 122
 123             # Transform the actual diagnostic so that it starts with "rm:".
 124             # Depending on your system, it might be "rm:" already, or
 125             # "../../src/rm:".
 126             $line =~ s,^\Q$rm\E:,rm:,;
 127
 128             my $regex = quotemeta $exp;
 129             $line =~ /^$regex/
 130               or die "$ME: unexpected diagnostic from '$cmd';\n"
 131                 . "  got      $line"
 132                 . "  expected $exp ...\n";
 133
 134             last;
 135           }
 136
 137         closedir DIR_HANDLE;
 138         $found_file
 139           and last;
 140       }
 141   }
 142
 143 $found_dir
 144   or CuSkip::skip "$ME: couldn't find a directory with the sticky bit set;"
 145     . " skipping this test\n";
 146
 147 $found_file
 148   or CuSkip::skip "$ME: couldn't find a file not owned by you\n"
 149     . " in any of the following directories:\n  @dir_list\n"
 150     . "...so, skipping this test\n";