Annotation of embedaddon/rsync/support/rrsync, revision 1.1.1.2

1.1       misho       1: #!/usr/bin/perl
                      2: # Name: /usr/local/bin/rrsync (should also have a symlink in /usr/bin)
                      3: # Purpose: Restricts rsync to subdirectory declared in .ssh/authorized_keys
                      4: # Author: Joe Smith <js-cgi@inwap.com> 30-Sep-2004
                      5: # Modified by: Wayne Davison <wayned@samba.org>
                      6: use strict;
                      7: 
                      8: use Socket;
                      9: use Cwd 'abs_path';
                     10: use File::Glob ':glob';
                     11: 
                     12: # You may configure these values to your liking.  See also the section
                     13: # of options if you want to disable any options that rsync accepts.
                     14: use constant RSYNC => '/usr/bin/rsync';
                     15: use constant LOGFILE => 'rrsync.log';
                     16: 
                     17: my $Usage = <<EOM;
                     18: Use 'command="$0 [-ro] SUBDIR"'
                     19:        in front of lines in $ENV{HOME}/.ssh/authorized_keys
                     20: EOM
                     21: 
                     22: our $ro = (@ARGV && $ARGV[0] eq '-ro') ? shift : '';   # -ro = Read-Only
                     23: our $subdir = shift;
                     24: die "$0: No subdirectory specified\n$Usage" unless defined $subdir;
                     25: $subdir = abs_path($subdir);
                     26: die "$0: Restricted directory does not exist!\n" if $subdir ne '/' && !-d $subdir;
                     27: 
                     28: # The client uses "rsync -av -e ssh src/ server:dir/", and sshd on the server
                     29: # executes this program when .ssh/authorized_keys has 'command="..."'.
                     30: # For example:
                     31: # command="rrsync logs/client" ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIEAzGhEeNlPr...
                     32: # command="rrsync -ro results" ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIEAmkHG1WCjC...
                     33: #
                     34: # Format of the envrionment variables set by sshd:
                     35: # SSH_ORIGINAL_COMMAND=rsync --server          -vlogDtpr --partial . ARG # push
                     36: # SSH_ORIGINAL_COMMAND=rsync --server --sender -vlogDtpr --partial . ARGS # pull
                     37: # SSH_CONNECTION=client_addr client_port server_port
                     38: 
                     39: my $command = $ENV{SSH_ORIGINAL_COMMAND};
                     40: die "$0: Not invoked via sshd\n$Usage" unless defined $command;
                     41: die "$0: SSH_ORIGINAL_COMMAND='$command' is not rsync\n" unless $command =~ s/^rsync\s+//;
                     42: die "$0: --server option is not first\n" unless $command =~ /^--server\s/;
                     43: our $am_sender = $command =~ /^--server\s+--sender\s/; # Restrictive on purpose!
                     44: die "$0 -ro: sending to read-only server not allowed\n" if $ro && !$am_sender;
                     45: 
                     46: ### START of options data produced by the cull_options script. ###
                     47: 
                     48: # These options are the only options that rsync might send to the server,
                     49: # and only in the option format that the stock rsync produces.
                     50: 
                     51: # To disable a short-named option, add its letter to this string:
                     52: our $short_disabled = 's';
                     53: 
                     54: our $short_no_arg = 'ACDEHIKLORSWXbcdgklmnoprstuvxz'; # DO NOT REMOVE ANY
                     55: our $short_with_num = 'B'; # DO NOT REMOVE ANY
                     56: 
                     57: # To disable a long-named option, change its value to a -1.  The values mean:
                     58: # 0 = the option has no arg; 1 = the arg doesn't need any checking; 2 = only
                     59: # check the arg when receiving; and 3 = always check the arg.
                     60: our %long_opt = (
                     61:   'append' => 0,
                     62:   'backup-dir' => 2,
                     63:   'bwlimit' => 1,
                     64:   'checksum-seed' => 1,
                     65:   'compare-dest' => 2,
                     66:   'compress-level' => 1,
                     67:   'copy-dest' => 2,
                     68:   'copy-unsafe-links' => 0,
                     69:   'daemon' => -1,
                     70:   'delay-updates' => 0,
                     71:   'delete' => 0,
                     72:   'delete-after' => 0,
                     73:   'delete-before' => 0,
                     74:   'delete-delay' => 0,
                     75:   'delete-during' => 0,
                     76:   'delete-excluded' => 0,
1.1.1.2 ! misho      77:   'delete-missing-args' => 0,
1.1       misho      78:   'existing' => 0,
                     79:   'fake-super' => 0,
                     80:   'files-from' => 3,
                     81:   'force' => 0,
                     82:   'from0' => 0,
                     83:   'fuzzy' => 0,
1.1.1.2 ! misho      84:   'groupmap' => 1,
1.1       misho      85:   'iconv' => 1,
                     86:   'ignore-errors' => 0,
                     87:   'ignore-existing' => 0,
1.1.1.2 ! misho      88:   'ignore-missing-args' => 0,
1.1       misho      89:   'inplace' => 0,
                     90:   'link-dest' => 2,
                     91:   'list-only' => 0,
                     92:   'log-file' => 3,
                     93:   'log-format' => 1,
                     94:   'max-delete' => 1,
                     95:   'max-size' => 1,
                     96:   'min-size' => 1,
                     97:   'modify-window' => 1,
                     98:   'no-implied-dirs' => 0,
                     99:   'no-r' => 0,
                    100:   'no-relative' => 0,
                    101:   'no-specials' => 0,
                    102:   'numeric-ids' => 0,
                    103:   'only-write-batch' => 1,
                    104:   'partial' => 0,
                    105:   'partial-dir' => 2,
                    106:   'remove-sent-files' => $ro ? -1 : 0,
                    107:   'remove-source-files' => $ro ? -1 : 0,
                    108:   'safe-links' => 0,
                    109:   'sender' => 0,
                    110:   'server' => 0,
                    111:   'size-only' => 0,
                    112:   'skip-compress' => 1,
                    113:   'specials' => 0,
                    114:   'stats' => 0,
                    115:   'suffix' => 1,
                    116:   'super' => 0,
                    117:   'temp-dir' => 2,
                    118:   'timeout' => 1,
                    119:   'use-qsort' => 0,
1.1.1.2 ! misho     120:   'usermap' => 1,
1.1       misho     121: );
                    122: 
                    123: ### END of options data produced by the cull_options script. ###
                    124: 
                    125: if ($short_disabled ne '') {
                    126:     $short_no_arg =~ s/[$short_disabled]//go;
                    127:     $short_with_num =~ s/[$short_disabled]//go;
                    128: }
                    129: $short_no_arg = "[$short_no_arg]" if length($short_no_arg) > 1;
                    130: $short_with_num = "[$short_with_num]" if length($short_with_num) > 1;
                    131: 
                    132: my $write_log = -f LOGFILE && open(LOG, '>>', LOGFILE);
                    133: 
                    134: chdir($subdir) or die "$0: Unable to chdir to restricted dir: $!\n";
                    135: 
                    136: my(@opts, @args);
                    137: my $in_options = 1;
                    138: my $last_opt = '';
                    139: my $check_type;
                    140: while ($command =~ /((?:[^\s\\]+|\\.[^\s\\]*)+)/g) {
                    141:   $_ = $1;
                    142:   if ($check_type) {
                    143:     push(@opts, check_arg($last_opt, $_, $check_type));
                    144:     $check_type = 0;
                    145:   } elsif ($in_options) {
                    146:     push(@opts, $_);
                    147:     if ($_ eq '.') {
                    148:       $in_options = 0;
                    149:     } else {
                    150:       die "$0: invalid option: '-'\n" if $_ eq '-';
                    151:       next if /^-$short_no_arg*(e\d*\.\w*)?$/o || /^-$short_with_num\d+$/o;
                    152: 
                    153:       my($opt,$arg) = /^--([^=]+)(?:=(.*))?$/;
                    154:       my $disabled;
                    155:       if (defined $opt) {
                    156:        my $ct = $long_opt{$opt};
                    157:        last unless defined $ct;
                    158:        next if $ct == 0;
                    159:        if ($ct > 0) {
                    160:          if (!defined $arg) {
                    161:            $check_type = $ct;
                    162:            $last_opt = $opt;
                    163:            next;
                    164:          }
                    165:          $arg = check_arg($opt, $arg, $ct);
                    166:          $opts[-1] =~ s/=.*/=$arg/;
                    167:          next;
                    168:        }
                    169:        $disabled = 1;
                    170:        $opt = "--$opt";
                    171:       } elsif ($short_disabled ne '') {
                    172:        $disabled = /^-$short_no_arg*([$short_disabled])/o;
                    173:        $opt = "-$1";
                    174:       }
                    175: 
                    176:       last unless $disabled; # Generate generic failure
                    177:       die "$0: option $opt has been disabled on this server.\n";
                    178:     }
                    179:   } else {
                    180:     if ($subdir ne '/') {
                    181:       # Validate args to ensure they don't try to leave our restricted dir.
                    182:       s{//+}{/}g;
                    183:       s{^/}{};
                    184:       s{^$}{.};
                    185:       die "$0: do not use .. in any path!\n" if m{(^|/)\\?\.\\?\.(\\?/|$)};
                    186:     }
                    187:     push(@args, bsd_glob($_, GLOB_LIMIT|GLOB_NOCHECK|GLOB_BRACE|GLOB_QUOTE));
                    188:   }
                    189: }
                    190: die "$0: invalid rsync-command syntax or options\n" if $in_options;
                    191: 
                    192: @args = ( '.' ) if !@args;
                    193: 
                    194: if ($write_log) {
                    195:   my ($mm,$hh) = (localtime)[1,2];
                    196:   my $host = $ENV{SSH_CONNECTION} || 'unknown';
                    197:   $host =~ s/ .*//; # Keep only the client's IP addr
                    198:   $host =~ s/^::ffff://;
                    199:   $host = gethostbyaddr(inet_aton($host),AF_INET) || $host;
                    200:   printf LOG "%02d:%02d %-13s [%s]\n", $hh, $mm, $host, "@opts @args";
                    201:   close LOG;
                    202: }
                    203: 
                    204: # Note: This assumes that the rsync protocol will not be maliciously hijacked.
                    205: exec(RSYNC, @opts, @args) or die "exec(rsync @opts @args) failed: $? $!";
                    206: 
                    207: sub check_arg
                    208: {
                    209:   my($opt, $arg, $type) = @_;
                    210:   $arg =~ s/\\(.)/$1/g;
                    211:   if ($subdir ne '/' && ($type == 3 || ($type == 2 && !$am_sender))) {
                    212:     $arg =~ s{//}{/}g;
                    213:     die "Do not use .. in --$opt; anchor the path at the root of your restricted dir.\n"
                    214:       if $arg =~ m{(^|/)\.\.(/|$)};
                    215:     $arg =~ s{^/}{$subdir/};
                    216:   }
                    217:   $arg;
                    218: }

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