Adding upstream version 3.2.7.upstream/3.2.7

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 379 insertions, 0 deletions

diff --git a/support/rrsync b/support/rrsync
new file mode 100755
index 0000000..94c85f5
--- /dev/null
+++ b/support/rrsync
@@ -0,0 +1,379 @@
+#!/usr/bin/env python3
+
+# Restricts rsync to subdirectory declared in .ssh/authorized_keys.  See
+# the rrsync man page for details of how to make use of this script.
+
+# NOTE: install python3 braceexpand to support brace expansion in the args!
+
+# Originally a perl script by: Joe Smith <js-cgi@inwap.com> 30-Sep-2004
+# Python version by: Wayne Davison <wayne@opencoder.net>
+
+# You may configure these 2 values to your liking.  See also the section of
+# short & long options if you want to disable any options that rsync accepts.
+RSYNC = '/usr/bin/rsync'
+LOGFILE = 'rrsync.log' # NOTE: the file must exist for a line to be appended!
+
+# The following options are mainly the options that a client rsync can send
+# to the server, and usually just in the one option format that the stock
+# rsync produces. However, there are some additional convenience options
+# added as well, and thus a few options are present in both the short and
+# long lists (such as --group, --owner, and --perms).
+
+# NOTE when disabling: check for both a short & long version of the option!
+
+### START of options data produced by the cull-options script. ###
+
+# To disable a short-named option, add its letter to this string:
+short_disabled = 's'
+
+# These are also disabled when the restricted dir is not "/":
+short_disabled_subdir = 'KLk'
+
+# These are all possible short options that we will accept (when not disabled above):
+short_no_arg = 'ACDEHIJKLNORSUWXbcdgklmnopqrstuvxyz' # DO NOT REMOVE ANY
+short_with_num = '@B' # DO NOT REMOVE ANY
+
+# To disable a long-named option, change its value to a -1.  The values mean:
+# 0 = the option has no arg; 1 = the arg doesn't need any checking; 2 = only
+# check the arg when receiving; and 3 = always check the arg.
+long_opts = {
+  'append': 0,
+  'backup-dir': 2,
+  'block-size': 1,
+  'bwlimit': 1,
+  'checksum-choice': 1,
+  'checksum-seed': 1,
+  'compare-dest': 2,
+  'compress-choice': 1,
+  'compress-level': 1,
+  'copy-dest': 2,
+  'copy-devices': -1,
+  'copy-unsafe-links': 0,
+  'daemon': -1,
+  'debug': 1,
+  'delay-updates': 0,
+  'delete': 0,
+  'delete-after': 0,
+  'delete-before': 0,
+  'delete-delay': 0,
+  'delete-during': 0,
+  'delete-excluded': 0,
+  'delete-missing-args': 0,
+  'existing': 0,
+  'fake-super': 0,
+  'files-from': 3,
+  'force': 0,
+  'from0': 0,
+  'fsync': 0,
+  'fuzzy': 0,
+  'group': 0,
+  'groupmap': 1,
+  'hard-links': 0,
+  'iconv': 1,
+  'ignore-errors': 0,
+  'ignore-existing': 0,
+  'ignore-missing-args': 0,
+  'ignore-times': 0,
+  'info': 1,
+  'inplace': 0,
+  'link-dest': 2,
+  'links': 0,
+  'list-only': 0,
+  'log-file': 3,
+  'log-format': 1,
+  'max-alloc': 1,
+  'max-delete': 1,
+  'max-size': 1,
+  'min-size': 1,
+  'mkpath': 0,
+  'modify-window': 1,
+  'msgs2stderr': 0,
+  'munge-links': 0,
+  'new-compress': 0,
+  'no-W': 0,
+  'no-implied-dirs': 0,
+  'no-msgs2stderr': 0,
+  'no-munge-links': -1,
+  'no-r': 0,
+  'no-relative': 0,
+  'no-specials': 0,
+  'numeric-ids': 0,
+  'old-compress': 0,
+  'one-file-system': 0,
+  'only-write-batch': 1,
+  'open-noatime': 0,
+  'owner': 0,
+  'partial': 0,
+  'partial-dir': 2,
+  'perms': 0,
+  'preallocate': 0,
+  'recursive': 0,
+  'remove-sent-files': 0,
+  'remove-source-files': 0,
+  'safe-links': 0,
+  'sender': 0,
+  'server': 0,
+  'size-only': 0,
+  'skip-compress': 1,
+  'specials': 0,
+  'stats': 0,
+  'stderr': 1,
+  'suffix': 1,
+  'super': 0,
+  'temp-dir': 2,
+  'timeout': 1,
+  'times': 0,
+  'use-qsort': 0,
+  'usermap': 1,
+  'write-devices': -1,
+}
+
+### END of options data produced by the cull-options script. ###
+
+import os, sys, re, argparse, glob, socket, time, subprocess
+from argparse import RawTextHelpFormatter
+
+try:
+    from braceexpand import braceexpand
+except:
+    braceexpand = lambda x: [ DE_BACKSLASH_RE.sub(r'\1', x) ]
+
+HAS_DOT_DOT_RE = re.compile(r'(^|/)\.\.(/|$)')
+LONG_OPT_RE = re.compile(r'^--([^=]+)(?:=(.*))?$')
+DE_BACKSLASH_RE = re.compile(r'\\(.)')
+
+def main():
+    if not os.path.isdir(args.dir):
+        die("Restricted directory does not exist!")
+
+    # The format of the environment variables set by sshd:
+    #   SSH_ORIGINAL_COMMAND:
+    #     rsync --server          -vlogDtpre.iLsfxCIvu --etc . ARG  # push
+    #     rsync --server --sender -vlogDtpre.iLsfxCIvu --etc . ARGS # pull
+    #   SSH_CONNECTION (client_ip client_port server_ip server_port):
+    #     192.168.1.100 64106 192.168.1.2 22
+
+    command = os.environ.get('SSH_ORIGINAL_COMMAND', None)
+    if not command:
+        die("Not invoked via sshd")
+    command = command.split(' ', 2)
+    if command[0:1] != ['rsync']:
+        die("SSH_ORIGINAL_COMMAND does not run rsync")
+    if command[1:2] != ['--server']:
+        die("--server option is not the first arg")
+    command = '' if len(command) < 3 else command[2]
+
+    global am_sender
+    am_sender = command.startswith("--sender ") # Restrictive on purpose!
+    if args.ro and not am_sender:
+        die("sending to read-only server is not allowed")
+    if args.wo and am_sender:
+        die("reading from write-only server is not allowed")
+
+    if args.wo or not am_sender:
+        long_opts['sender'] = -1
+    if args.no_del:
+        for opt in long_opts:
+            if opt.startswith(('remove', 'delete')):
+                long_opts[opt] = -1
+    if args.ro:
+        long_opts['log-file'] = -1
+
+    if args.dir != '/':
+        global short_disabled
+        short_disabled += short_disabled_subdir
+
+    short_no_arg_re = short_no_arg
+    short_with_num_re = short_with_num
+    if short_disabled:
+        for ltr in short_disabled:
+            short_no_arg_re = short_no_arg_re.replace(ltr, '')
+            short_with_num_re = short_with_num_re.replace(ltr, '')
+        short_disabled_re = re.compile(r'^-[%s]*([%s])' % (short_no_arg_re, short_disabled))
+    short_no_arg_re = re.compile(r'^-(?=.)[%s]*(e\d*\.\w*)?$' % short_no_arg_re)
+    short_with_num_re = re.compile(r'^-[%s]\d+$' % short_with_num_re)
+
+    log_fh = open(LOGFILE, 'a') if os.path.isfile(LOGFILE) else None
+
+    try:
+        os.chdir(args.dir)
+    except OSError as e:
+        die('unable to chdir to restricted dir:', str(e))
+
+    rsync_opts = [ '--server' ]
+    rsync_args = [ ]
+    saw_the_dot_arg = False
+    last_opt = check_type = None
+
+    for arg in re.findall(r'(?:[^\s\\]+|\\.[^\s\\]*)+', command):
+        if check_type:
+            rsync_opts.append(validated_arg(last_opt, arg, check_type))
+            check_type = None
+        elif saw_the_dot_arg:
+            # NOTE: an arg that starts with a '-' is safe due to our use of "--" in the cmd tuple.
+            try:
+                b_e = braceexpand(arg) # Also removes backslashes
+            except: # Handle errors such as unbalanced braces by just de-backslashing the arg:
+                b_e = [ DE_BACKSLASH_RE.sub(r'\1', arg) ]
+            for xarg in b_e:
+                rsync_args += validated_arg('arg', xarg, wild=True)
+        else: # parsing the option args
+            if arg == '.':
+                saw_the_dot_arg = True
+                continue
+            rsync_opts.append(arg)
+            if short_no_arg_re.match(arg) or short_with_num_re.match(arg):
+                continue
+            disabled = False
+            m = LONG_OPT_RE.match(arg)
+            if m:
+                opt = m.group(1)
+                opt_arg = m.group(2)
+                ct = long_opts.get(opt, None)
+                if ct is None:
+                    break # Generate generic failure due to unfinished arg parsing
+                if ct == 0:
+                    continue
+                opt = '--' + opt
+                if ct > 0:
+                    if opt_arg is not None:
+                        rsync_opts[-1] = opt + '=' + validated_arg(opt, opt_arg, ct)
+                    else:
+                        check_type = ct
+                        last_opt = opt
+                    continue
+                disabled = True
+            elif short_disabled:
+                m = short_disabled_re.match(arg)
+                if m:
+                    disabled = True
+                    opt = '-' + m.group(1)
+
+            if disabled:
+                die("option", opt, "has been disabled on this server.")
+            break # Generate a generic failure
+
+    if not saw_the_dot_arg:
+        die("invalid rsync-command syntax or options")
+
+    if args.munge:
+        rsync_opts.append('--munge-links')
+
+    if not rsync_args:
+        rsync_args = [ '.' ]
+
+    cmd = (RSYNC, *rsync_opts, '--', '.', *rsync_args)
+
+    if log_fh:
+        now = time.localtime()
+        host = os.environ.get('SSH_CONNECTION', 'unknown').split()[0] # Drop everything after the IP addr
+        if host.startswith('::ffff:'):
+            host = host[7:]
+        try:
+            host = socket.gethostbyaddr(socket.inet_aton(host))
+        except:
+            pass
+        log_fh.write("%02d:%02d:%02d %-16s %s\n" % (now.tm_hour, now.tm_min, now.tm_sec, host, str(cmd)))
+        log_fh.close()
+
+    # NOTE: This assumes that the rsync protocol will not be maliciously hijacked.
+    if args.no_lock:
+        os.execlp(RSYNC, *cmd)
+        die("execlp(", RSYNC, *cmd, ')  failed')
+    child = subprocess.run(cmd)
+    if child.returncode != 0:
+        sys.exit(child.returncode)
+
+
+def validated_arg(opt, arg, typ=3, wild=False):
+    if opt != 'arg': # arg values already have their backslashes removed.
+        arg = DE_BACKSLASH_RE.sub(r'\1', arg)
+
+    orig_arg = arg
+    if arg.startswith('./'):
+        arg = arg[1:]
+    arg = arg.replace('//', '/')
+    if args.dir != '/':
+        if HAS_DOT_DOT_RE.search(arg):
+            die("do not use .. in", opt, "(anchor the path at the root of your restricted dir)")
+        if arg.startswith('/'):
+            arg = args.dir + arg
+
+    if wild:
+        got = glob.glob(arg)
+        if not got:
+            got = [ arg ]
+    else:
+        got = [ arg ]
+
+    ret = [ ]
+    for arg in got:
+        if args.dir != '/' and arg != '.' and (typ == 3 or (typ == 2 and not am_sender)):
+            arg_has_trailing_slash = arg.endswith('/')
+            if arg_has_trailing_slash:
+                arg = arg[:-1]
+            else:
+                arg_has_trailing_slash_dot = arg.endswith('/.')
+                if arg_has_trailing_slash_dot:
+                    arg = arg[:-2]
+            real_arg = os.path.realpath(arg)
+            if arg != real_arg and not real_arg.startswith(args.dir_slash):
+                die('unsafe arg:', orig_arg, [arg, real_arg])
+            if arg_has_trailing_slash:
+                arg += '/'
+            elif arg_has_trailing_slash_dot:
+                arg += '/.'
+            if opt == 'arg' and arg.startswith(args.dir_slash):
+                arg = arg[args.dir_slash_len:]
+                if arg == '':
+                    arg = '.'
+        ret.append(arg)
+
+    return ret if wild else ret[0]
+
+
+def lock_or_die(dirname):
+    import fcntl
+    global lock_handle
+    lock_handle = os.open(dirname, os.O_RDONLY)
+    try:
+        fcntl.flock(lock_handle, fcntl.LOCK_EX | fcntl.LOCK_NB)
+    except:
+        die('Another instance of rrsync is already accessing this directory.')
+
+
+def die(*msg):
+    print(sys.argv[0], 'error:', *msg, file=sys.stderr)
+    if sys.stdin.isatty():
+        arg_parser.print_help(sys.stderr)
+    sys.exit(1)
+
+
+# This class displays the --help to the user on argparse error IFF they're running it interactively.
+class OurArgParser(argparse.ArgumentParser):
+    def error(self, msg):
+        die(msg)
+
+
+if __name__ == '__main__':
+    our_desc = """Use "man rrsync" to learn how to restrict ssh users to using a restricted rsync command."""
+    arg_parser = OurArgParser(description=our_desc, add_help=False)
+    only_group = arg_parser.add_mutually_exclusive_group()
+    only_group.add_argument('-ro', action='store_true', help="Allow only reading from the DIR. Implies -no-del and -no-lock.")
+    only_group.add_argument('-wo', action='store_true', help="Allow only writing to the DIR.")
+    arg_parser.add_argument('-munge', action='store_true', help="Enable rsync's --munge-links on the server side.")
+    arg_parser.add_argument('-no-del', action='store_true', help="Disable rsync's --delete* and --remove* options.")
+    arg_parser.add_argument('-no-lock', action='store_true', help="Avoid the single-run (per-user) lock check.")
+    arg_parser.add_argument('-help', '-h', action='help', help="Output this help message and exit.")
+    arg_parser.add_argument('dir', metavar='DIR', help="The restricted directory to use.")
+    args = arg_parser.parse_args()
+    args.dir = os.path.realpath(args.dir)
+    args.dir_slash = args.dir + '/'
+    args.dir_slash_len = len(args.dir_slash)
+    if args.ro:
+        args.no_del = True
+    elif not args.no_lock:
+        lock_or_die(args.dir)
+    main()
+
+# vim: sw=4 et