contrib/hg-ssh

hg-ssh: use shlex for shell-like parsing of SSH_ORIGINAL_COMMAND

The Mercurial ssh protocol is defined as if it was ssh-ing to a shell account on
an ordinary ssh server, and where hg was available in $PATH and it executed
the command "hg -R REPOPATH serve --stdio".

The Mercurial ssh client can in most cases just pass REPOPATH to the shell, but
if it contains unsafe characters the client will have to quote it so the shell
will pass the right -R value to hg. Correct quoting of repopaths was introduced
in d8fa35c28335 and tweaked in 86fc364ca5f8.

hg-ssh doesn't create the command via a shell and used a simple parser instead.
It worked fine for simple paths without any quoting, but if any kind of quoting
was used it failed to parse the command like the shell would do it.

This makes hg-ssh behave more like a normal shell with hg in the path would do.

#!/usr/bin/env python
#
# Copyright 2005-2007 by Intevation GmbH <[e-mail]>
#
# Author(s):
# Thomas Arendsen Hein <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

"""
hg-ssh - a wrapper for ssh access to a limited set of mercurial repos

To be used in ~/.ssh/authorized_keys with the "command" option, see sshd(8):
command="hg-ssh path/to/repo1 /path/to/repo2 ~/repo3 ~user/repo4" ssh-dss ...
(probably together with these other useful options:
 no-port-forwarding,no-X11-forwarding,no-agent-forwarding)

This allows pull/push over ssh from/to the repositories given as arguments.

If all your repositories are subdirectories of a common directory, you can
allow shorter paths with:
command="cd path/to/my/repositories && hg-ssh repo1 subdir/repo2"

You can use pattern matching of your normal shell, e.g.:
command="cd repos && hg-ssh user/thomas/* projects/{mercurial,foo}"
"""

# enable importing on demand to reduce startup time
from mercurial import demandimport; demandimport.enable()

from mercurial import dispatch

import sys, os, shlex

cwd = os.getcwd()
allowed_paths = [os.path.normpath(os.path.join(cwd, os.path.expanduser(path)))
                 for path in sys.argv[1:]]
orig_cmd = os.getenv('SSH_ORIGINAL_COMMAND', '?')
try:
    cmdargv = shlex.split(orig_cmd)
except ValueError, e:
    sys.stderr.write("Illegal command %r: %s\n" % (orig_cmd, e))
    sys.exit(-1)

if cmdargv[:2] == ['hg', '-R'] and cmdargv[3:] == ['serve', '--stdio']:
    path = cmdargv[2]
    repo = os.path.normpath(os.path.join(cwd, os.path.expanduser(path)))
    if repo in allowed_paths:
        dispatch.dispatch(dispatch.request(['-R', repo, 'serve', '--stdio']))
    else:
        sys.stderr.write("Illegal repository %r\n" % repo)
        sys.exit(-1)
else:
    sys.stderr.write("Illegal command %r\n" % orig_cmd)
    sys.exit(-1)