Annotation of embedaddon/rsync/support/rrsync, revision 1.1.1.3

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;
1.1.1.3 ! misho      18: Use 'command="$0 [-ro|-wo] SUBDIR"'
1.1       misho      19:        in front of lines in $ENV{HOME}/.ssh/authorized_keys
                     20: EOM
                     21: 
1.1.1.3 ! misho      22: # Handle the -ro and -wo options.
        !            23: our $only = '';
        !            24: while (@ARGV && $ARGV[0] =~ /^-([rw])o$/) {
        !            25:     my $r_or_w = $1;
        !            26:     if ($only && $only ne $r_or_w) {
        !            27:        die "$0: the -ro and -wo options conflict.\n";
        !            28:     }
        !            29:     $only = $r_or_w;
        !            30:     shift;
        !            31: }
        !            32: 
1.1       misho      33: our $subdir = shift;
                     34: die "$0: No subdirectory specified\n$Usage" unless defined $subdir;
                     35: $subdir = abs_path($subdir);
                     36: die "$0: Restricted directory does not exist!\n" if $subdir ne '/' && !-d $subdir;
                     37: 
                     38: # The client uses "rsync -av -e ssh src/ server:dir/", and sshd on the server
                     39: # executes this program when .ssh/authorized_keys has 'command="..."'.
                     40: # For example:
                     41: # command="rrsync logs/client" ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIEAzGhEeNlPr...
                     42: # command="rrsync -ro results" ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIEAmkHG1WCjC...
                     43: #
1.1.1.3 ! misho      44: # Format of the environment variables set by sshd:
1.1       misho      45: # SSH_ORIGINAL_COMMAND=rsync --server          -vlogDtpr --partial . ARG # push
                     46: # SSH_ORIGINAL_COMMAND=rsync --server --sender -vlogDtpr --partial . ARGS # pull
                     47: # SSH_CONNECTION=client_addr client_port server_port
                     48: 
                     49: my $command = $ENV{SSH_ORIGINAL_COMMAND};
                     50: die "$0: Not invoked via sshd\n$Usage" unless defined $command;
                     51: die "$0: SSH_ORIGINAL_COMMAND='$command' is not rsync\n" unless $command =~ s/^rsync\s+//;
                     52: die "$0: --server option is not first\n" unless $command =~ /^--server\s/;
                     53: our $am_sender = $command =~ /^--server\s+--sender\s/; # Restrictive on purpose!
1.1.1.3 ! misho      54: die "$0 sending to read-only server not allowed\n" if $only eq 'r' && !$am_sender;
        !            55: die "$0 reading from write-only server not allowed\n" if $only eq 'w' && $am_sender;
1.1       misho      56: 
                     57: ### START of options data produced by the cull_options script. ###
                     58: 
                     59: # These options are the only options that rsync might send to the server,
                     60: # and only in the option format that the stock rsync produces.
                     61: 
                     62: # To disable a short-named option, add its letter to this string:
                     63: our $short_disabled = 's';
                     64: 
1.1.1.3 ! misho      65: our $short_no_arg = 'ACDEHIJKLORSWXbcdgklmnoprstuvxyz'; # DO NOT REMOVE ANY
1.1       misho      66: our $short_with_num = 'B'; # DO NOT REMOVE ANY
                     67: 
                     68: # To disable a long-named option, change its value to a -1.  The values mean:
                     69: # 0 = the option has no arg; 1 = the arg doesn't need any checking; 2 = only
                     70: # check the arg when receiving; and 3 = always check the arg.
                     71: our %long_opt = (
                     72:   'append' => 0,
                     73:   'backup-dir' => 2,
1.1.1.3 ! misho      74:   'block-size' => 1,
1.1       misho      75:   'bwlimit' => 1,
                     76:   'checksum-seed' => 1,
                     77:   'compare-dest' => 2,
                     78:   'compress-level' => 1,
                     79:   'copy-dest' => 2,
                     80:   'copy-unsafe-links' => 0,
                     81:   'daemon' => -1,
1.1.1.3 ! misho      82:   'debug' => 1,
1.1       misho      83:   'delay-updates' => 0,
                     84:   'delete' => 0,
                     85:   'delete-after' => 0,
                     86:   'delete-before' => 0,
                     87:   'delete-delay' => 0,
                     88:   'delete-during' => 0,
                     89:   'delete-excluded' => 0,
1.1.1.2   misho      90:   'delete-missing-args' => 0,
1.1       misho      91:   'existing' => 0,
                     92:   'fake-super' => 0,
                     93:   'files-from' => 3,
                     94:   'force' => 0,
                     95:   'from0' => 0,
                     96:   'fuzzy' => 0,
1.1.1.3 ! misho      97:   'group' => 0,
1.1.1.2   misho      98:   'groupmap' => 1,
1.1.1.3 ! misho      99:   'hard-links' => 0,
1.1       misho     100:   'iconv' => 1,
                    101:   'ignore-errors' => 0,
                    102:   'ignore-existing' => 0,
1.1.1.2   misho     103:   'ignore-missing-args' => 0,
1.1.1.3 ! misho     104:   'ignore-times' => 0,
        !           105:   'info' => 1,
1.1       misho     106:   'inplace' => 0,
                    107:   'link-dest' => 2,
1.1.1.3 ! misho     108:   'links' => 0,
1.1       misho     109:   'list-only' => 0,
                    110:   'log-file' => 3,
                    111:   'log-format' => 1,
                    112:   'max-delete' => 1,
                    113:   'max-size' => 1,
                    114:   'min-size' => 1,
                    115:   'modify-window' => 1,
1.1.1.3 ! misho     116:   'new-compress' => 0,
1.1       misho     117:   'no-implied-dirs' => 0,
                    118:   'no-r' => 0,
                    119:   'no-relative' => 0,
                    120:   'no-specials' => 0,
                    121:   'numeric-ids' => 0,
1.1.1.3 ! misho     122:   'one-file-system' => 0,
1.1       misho     123:   'only-write-batch' => 1,
1.1.1.3 ! misho     124:   'owner' => 0,
1.1       misho     125:   'partial' => 0,
                    126:   'partial-dir' => 2,
1.1.1.3 ! misho     127:   'perms' => 0,
        !           128:   'preallocate' => 0,
        !           129:   'recursive' => 0,
        !           130:   'remove-sent-files' => $only eq 'r' ? -1 : 0,
        !           131:   'remove-source-files' => $only eq 'r' ? -1 : 0,
1.1       misho     132:   'safe-links' => 0,
                    133:   'sender' => 0,
                    134:   'server' => 0,
                    135:   'size-only' => 0,
                    136:   'skip-compress' => 1,
                    137:   'specials' => 0,
                    138:   'stats' => 0,
                    139:   'suffix' => 1,
                    140:   'super' => 0,
                    141:   'temp-dir' => 2,
                    142:   'timeout' => 1,
1.1.1.3 ! misho     143:   'times' => 0,
1.1       misho     144:   'use-qsort' => 0,
1.1.1.2   misho     145:   'usermap' => 1,
1.1       misho     146: );
                    147: 
                    148: ### END of options data produced by the cull_options script. ###
                    149: 
                    150: if ($short_disabled ne '') {
                    151:     $short_no_arg =~ s/[$short_disabled]//go;
                    152:     $short_with_num =~ s/[$short_disabled]//go;
                    153: }
                    154: $short_no_arg = "[$short_no_arg]" if length($short_no_arg) > 1;
                    155: $short_with_num = "[$short_with_num]" if length($short_with_num) > 1;
                    156: 
                    157: my $write_log = -f LOGFILE && open(LOG, '>>', LOGFILE);
                    158: 
                    159: chdir($subdir) or die "$0: Unable to chdir to restricted dir: $!\n";
                    160: 
                    161: my(@opts, @args);
                    162: my $in_options = 1;
                    163: my $last_opt = '';
                    164: my $check_type;
                    165: while ($command =~ /((?:[^\s\\]+|\\.[^\s\\]*)+)/g) {
                    166:   $_ = $1;
                    167:   if ($check_type) {
                    168:     push(@opts, check_arg($last_opt, $_, $check_type));
                    169:     $check_type = 0;
                    170:   } elsif ($in_options) {
                    171:     push(@opts, $_);
                    172:     if ($_ eq '.') {
                    173:       $in_options = 0;
                    174:     } else {
                    175:       die "$0: invalid option: '-'\n" if $_ eq '-';
                    176:       next if /^-$short_no_arg*(e\d*\.\w*)?$/o || /^-$short_with_num\d+$/o;
                    177: 
                    178:       my($opt,$arg) = /^--([^=]+)(?:=(.*))?$/;
                    179:       my $disabled;
                    180:       if (defined $opt) {
                    181:        my $ct = $long_opt{$opt};
                    182:        last unless defined $ct;
                    183:        next if $ct == 0;
                    184:        if ($ct > 0) {
                    185:          if (!defined $arg) {
                    186:            $check_type = $ct;
                    187:            $last_opt = $opt;
                    188:            next;
                    189:          }
                    190:          $arg = check_arg($opt, $arg, $ct);
                    191:          $opts[-1] =~ s/=.*/=$arg/;
                    192:          next;
                    193:        }
                    194:        $disabled = 1;
                    195:        $opt = "--$opt";
                    196:       } elsif ($short_disabled ne '') {
                    197:        $disabled = /^-$short_no_arg*([$short_disabled])/o;
                    198:        $opt = "-$1";
                    199:       }
                    200: 
                    201:       last unless $disabled; # Generate generic failure
                    202:       die "$0: option $opt has been disabled on this server.\n";
                    203:     }
                    204:   } else {
                    205:     if ($subdir ne '/') {
                    206:       # Validate args to ensure they don't try to leave our restricted dir.
                    207:       s{//+}{/}g;
                    208:       s{^/}{};
                    209:       s{^$}{.};
                    210:       die "$0: do not use .. in any path!\n" if m{(^|/)\\?\.\\?\.(\\?/|$)};
                    211:     }
                    212:     push(@args, bsd_glob($_, GLOB_LIMIT|GLOB_NOCHECK|GLOB_BRACE|GLOB_QUOTE));
                    213:   }
                    214: }
                    215: die "$0: invalid rsync-command syntax or options\n" if $in_options;
                    216: 
                    217: @args = ( '.' ) if !@args;
                    218: 
                    219: if ($write_log) {
                    220:   my ($mm,$hh) = (localtime)[1,2];
                    221:   my $host = $ENV{SSH_CONNECTION} || 'unknown';
                    222:   $host =~ s/ .*//; # Keep only the client's IP addr
                    223:   $host =~ s/^::ffff://;
                    224:   $host = gethostbyaddr(inet_aton($host),AF_INET) || $host;
                    225:   printf LOG "%02d:%02d %-13s [%s]\n", $hh, $mm, $host, "@opts @args";
                    226:   close LOG;
                    227: }
                    228: 
                    229: # Note: This assumes that the rsync protocol will not be maliciously hijacked.
                    230: exec(RSYNC, @opts, @args) or die "exec(rsync @opts @args) failed: $? $!";
                    231: 
                    232: sub check_arg
                    233: {
                    234:   my($opt, $arg, $type) = @_;
                    235:   $arg =~ s/\\(.)/$1/g;
                    236:   if ($subdir ne '/' && ($type == 3 || ($type == 2 && !$am_sender))) {
                    237:     $arg =~ s{//}{/}g;
                    238:     die "Do not use .. in --$opt; anchor the path at the root of your restricted dir.\n"
                    239:       if $arg =~ m{(^|/)\.\.(/|$)};
                    240:     $arg =~ s{^/}{$subdir/};
                    241:   }
                    242:   $arg;
                    243: }

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