#!/usr/bin/env python

#

# Copyright 2008 LShift Ltd

# Copyright 2005-2007 by Intevation GmbH <intevation@intevation.de>

# Authors:

# Paul Crowley <paul@lshift.net>

# Thomas Arendsen Hein <thomas@intevation.de>

# with ideas from  Mathieu PASQUET <kiorky@cryptelium.net>

#

# This software may be used and distributed according to the terms

# of the GNU General Public License, incorporated herein by reference.

"""

hg-ssh - limit access to hg repositories reached via ssh.  Part of

hg-admin-tools.

This script is called by hg-ssh-wrapper with no arguments - everything

should be in enviroment variables:

HG_ACCESS_RULES_FILE identifies the path to the rules file

REMOTE_USER the remote user (which is the key used by ssh)

SSH_ORIGINAL_COMMAND the command the user was trying to run

It uses SSH_ORIGINAL_COMMAND to determine what the user was trying to

do and to what repository, and then checks each rule in the rule file

in turn for a matching rule which decides what to do, defaulting to

disallowing the action.

"""

# enable importing on demand to reduce startup time

from mercurial import demandimport; demandimport.enable()

from mercurial import dispatch

import sys, os

import rules

def fail(message):

    #logfile.write("Fail: %s\n" % message)

    sys.stderr.write(message + "\n")

    sys.exit(-1)

def getpath(path):

    if path.endswith("/"):

        path = path[:-1]

    if not rules.goodpath(path):

        fail("Disallowing path: %s" % path)

    return path

def get_cmd(rules, cmd):

    if cmd.startswith('hg -R ') and cmd.endswith(' serve --stdio'):

        repo = getpath(cmd[6:-14])

        if rules.allow("read", repo=repo):

            os.environ["HG_REPO_PATH"] = repo

            return ['-R', repo, 'serve', '--stdio']

    elif cmd.startswith('hg init '):

        repo = getpath(cmd[8:])

        if rules.allow("init", repo=repo):

            os.environ["HG_REPO_PATH"] = repo

            return ['init', repo]

    fail("Illegal command %r" % cmd)

#logfile = open("/tmp/hg-ssh.%d.txt" % os.getpid(), "w")

#logfile.write("Started: %s\n" % sys.argv)

if len(sys.argv) != 1:

    fail("hg-ssh must have no arguments (%s)" 

        % sys.argv)

rules = rules.Ruleset.readfile(os.environ['HG_ACCESS_RULES_FILE'])

rules.set(remoteuser = getpath(os.environ['REMOTE_USER']))

rules.set(branch = None, file = None)

todispatch = get_cmd(rules, 

    os.environ.get('SSH_ORIGINAL_COMMAND', '?'))

dispatch.dispatch(todispatch)