Files
android_external_rsync/support/rrsync
2005-02-20 01:04:12 +00:00

75 lines
2.9 KiB
Perl

#!/usr/bin/perl
# Name: /usr/local/bin/rrsync (should also have a symlink in /usr/bin)
# Purpose: Restricts rsync to subdirectory declared in .ssh/authorized_keys
# Author: Joe Smith <js-cgi@inwap.com> 30-Sep-2004
# Modified by Wayne Davison <wayned@samba.org> 12-Jan-2005
use Socket;
use constant LOGFILE => 'rrsync.log';
my $Usage = <<EOM;
Use 'command="$0 [-ro] SUBDIR"'
in front of lines in $ENV{HOME}/.ssh/authorized_keys
EOM
my $ro = (@ARGV and $ARGV[0] eq '-ro') ? shift : ''; # -ro = Read-Only
my $subdir = shift;
die "No subdirectory specified\n$Usage" unless defined $subdir;
# The client uses "rsync -av -e ssh src/ server:dir/", and sshd on the server
# executes this program when .ssh/authorized_keys has 'command="..."'.
# For example:
# command="rrsync logs/client" ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIEAzGhEeNlPr...
# command="rrsync -ro results" ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIEAmkHG1WCjC...
#
# Format of the envrionment variables set by sshd:
# SSH_ORIGINAL_COMMAND=rsync --server -vlogDtpr --partial . dir # push
# SSH_ORIGINAL_COMMAND=rsync --server --sender -vlogDtpr --partial . dir # pull
# SSH_CONNECTION=client_addr client_port server_port
my $command = $ENV{SSH_ORIGINAL_COMMAND};
die "Not invoked via sshd\n$Usage" unless defined $command;
die "SSH_ORIGINAL_COMMAND='$command' is not rsync\n" unless $command =~ /^rsync\s/;
die "$0 -ro: sending to read-only server not allowed\n"
if $ro and $command !~ /^rsync --server --sender /;
die "$0 -ro: use of --remove-sent-files with read-only server not allowed\n"
if $ro and $command =~ /\s--remove-sent-files/;
my ($cmd,$dir) = $command =~ /^(rsync\s+(?:-[-a-zA-Z]+\s+)+\.) ?("[^"]*"|[^\s"]*)$/;
die "$0: invalid rsync-command syntax or options\n" if !defined $cmd;
# Enforce default of $subdir instead of the normal $HOME default.
my $orig = $dir;
my @dirs;
$dir =~ s/^"(.*?)"$/$1/;
$dir =~ s/^\s+//;
$dir =~ s/\s+$//;
foreach (split(/(?<!\\)\s+/, $dir)) {
s/\\(\s)/$1/g; # Unescape any escaped whitespace
if ($subdir eq '/') { # Less checking for '/' access
$dir = '/' if $dir eq '';
} else {
s#^/##; # Don't allow absolute paths
$_ = "$subdir/$_" unless m#^\Q$subdir\E(/|$)#;
1 while s#/\.\.(/|$)#/__/#g; # Don't allow foo/../../etc
}
tr#-_/a-zA-Z0-9.,+@^%: #_#c; # Don't allow '"&;|!=()[]{}<>*?#\$
s/(\s)/\\$1/g; # Re-escape whitespace
push(@dirs, $_);
}
push(@dirs, $subdir) unless @dirs;
$dir = join(' ', @dirs);
if (-f LOGFILE and open LOG,'>>',LOGFILE) {
my ($mm,$hh) = (localtime)[1,2];
my $host = $ENV{SSH_CONNECTION} || 'unknown';
$host =~ s/ .*//; # Keep only the client's IP addr
$host =~ s/^::ffff://;
$host = gethostbyaddr(inet_aton($host),AF_INET) || $host;
my $dir_result = $dir eq $orig ? " OK" : "> \"$dir\"";
printf LOG "%02d:%02d %-13s [%s] =%s\n", $hh, $mm, $host, $command, $dir_result;
close LOG;
}
exec "$cmd \"$dir\"" or die "exec($cmd \"$dir\") failed: $? $!";
# Note: This assumes that the rsync protocol will not be maliciously hijacked.