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| -rwxr-xr-x | unix/safe-rm | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/unix/safe-rm b/unix/safe-rm new file mode 100755 index 0000000..b9a855d --- /dev/null +++ b/unix/safe-rm @@ -0,0 +1,228 @@ +#!/usr/bin/perl -t + +use warnings; +use strict; +use Cwd 'realpath'; + +our $VERSION = '0.12'; + +my $homedir = $ENV{HOME} || q{}; +my $LEGACY_CONFIG_FILE = "$homedir/.safe-rm"; +my $USER_CONFIG_FILE = ($ENV{XDG_CONFIG_HOME} || "$homedir/.config") . "/safe-rm"; +my $GLOBAL_CONFIG_FILE = '/etc/safe-rm.conf'; + +my %default_protected_dirs = ( + '/bin' => 1, + '/boot' => 1, + '/dev' => 1, + '/etc' => 1, + '/home' => 1, + '/initrd' => 1, + '/lib' => 1, + '/lib32' => 1, + '/lib64' => 1, + '/proc' => 1, + '/root' => 1, + '/sbin' => 1, + '/sys' => 1, + '/usr' => 1, + '/usr/bin' => 1, + '/usr/include' => 1, + '/usr/lib' => 1, + '/usr/local' => 1, + '/usr/local/bin' => 1, + '/usr/local/include' => 1, + '/usr/local/sbin' => 1, + '/usr/local/share' => 1, + '/usr/sbin' => 1, + '/usr/share' => 1, + '/usr/src' => 1, + '/var' => 1, +); + +my %protected_dirs = (); + +sub read_config_file { + my $filename = shift; + + if ( -e $filename ) { + if ( open my $fh, '<', $filename ) { + while (<$fh>) { + chomp; + foreach my $file (glob) { + $protected_dirs{$file} = 1; + } + } + close $fh; # deliberatly ignore errors + } + else { + print {*STDERR} "Could not open configuration file: $filename\n"; + } + } + + return; +} + +read_config_file($GLOBAL_CONFIG_FILE); +read_config_file($LEGACY_CONFIG_FILE); +read_config_file($USER_CONFIG_FILE); + +if ( 0 == scalar keys %protected_dirs ) { + %protected_dirs = %default_protected_dirs; +} + +my @allowed_args = (); +foreach (@ARGV) { + my $pathname = $_; + + # Normalize the pathname + my $normalized_pathname = $pathname; + if ( $normalized_pathname =~ m{/}xms or -e "$normalized_pathname" ) { + + # Convert to an absolute path (e.g. remove "..") + $normalized_pathname = realpath($normalized_pathname); + if ( !$normalized_pathname ) { + $normalized_pathname = $pathname; + } + } + if ( $normalized_pathname =~ m{^(.+?)/+$}xms ) { + + # Trim trailing slashes + $normalized_pathname = $1; + } + + # Check against the blacklist + if ( exists $protected_dirs{$normalized_pathname} and not -l $pathname ) { + print {*STDERR} "safe-rm: skipping $pathname\n" || 0; + } + elsif ( $pathname =~ /(.*)/xms ) { # pointless untainting + push @allowed_args, $1; + } +} + +# Prepare for actually deleting the file +local $ENV{PATH} = q{}; # pointless untainting +local $ENV{CDPATH} = q{}; # pointless untainting +local $ENV{IFS} = " \t\n"; # pointless untainting +my $real_rm = '/bin/rm'; + +# Make sure we're not calling ourselves recursively +if ( realpath($real_rm) eq realpath($0) ) { + die 'safe-rm cannot find the real "rm" binary' . "\n"; +} + +# Run the real rm command, returning with the same error code +my $status = system $real_rm, @allowed_args; +my $errcode = $status >> 8; +exit $errcode; + +__END__ + +=head1 NAME + +safe-rm - wrapper around the rm command to prevent accidental deletions + +=head1 USAGE + +safe-rm [ ... ] +(same arguments as rm) + +=head1 DESCRIPTION + +safe-rm prevents the accidental deletion of important files by +replacing rm with a wrapper which checks the given arguments against a +configurable blacklist of files and directories which should never be +removed. + +Users who attempt to delete one of these protected files or +directories will not be able to do so and will be shown a warning +message instead. + +safe-rm is meant to replace the rm command so you can achieve this by +putting a symbolic link with the name "rm" in a directory which sits +at the front of your path. For example, given this path: + + PATH=/usr/local/bin:/bin:/usr/bin + +You could create the following symbolic link: + + ln -s /usr/local/bin/safe-rm /usr/local/bin/rm + +=head1 CONFIGURATION + +Protected paths can be set both at the site and user levels. + +Both of these configuration files can contain a list of important files +or directories (one per line): + + /etc/safe-rm.conf + ~/.config/safe-rm + +If both of these are empty, a default list of important paths will be +used. + +=for stopword Wildcards +Wildcards are allowed in the configuration files, but be careful + + /usr/lib/* + +will protect all of the files inside the /usr/lib directory if they are referred to directly, but it will not protect your system against: + + rm -rf /usr/lib + +For a full protection, you should include both of these lines: + + /usr/lib + /usr/lib/* + +=head1 EXIT STATUS + +Same exit status as the real rm command. + +Note that if all file arguments are skipped by safe-rm then the exit status +will be the same as the exit status of the real rm when no files arguments +are present. + +=head1 BUGS AND LIMITATIONS + +Note that if you put the following in your protected paths list: + + $ cat /etc/safe-rm.conf + /usr/lib + +Then safe-rm will prevent you from deleting the directory: + + $ rm -rf /usr/lib + Skipping /usr/lib + /bin/rm: missing operand + Try `/bin/rm --help' for more information. + +However it cannot protect you from the following: + + $ cd /usr/lib + $ rm -f * + +=head1 AUTHOR + +Francois Marier <francois@fmarier.org> + +=head1 SEE ALSO + +rm(1) + +=head1 LICENSE AND COPYRIGHT + +Copyright (C) 2008-2014 Francois Marier + +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/>. |