#!/usr/bin/env python
"""
auto.maton: script for use with Linux's autofs, mounted on /net
Copyright 2006 Adam Sampson <ats@offog.org>

The aim is to allow this to be mounted on /net, and to support various
kinds of network mounts for users within a group. At the moment it'll
only do CIFS.
"""

USER = "anime"
GROUP = "anime"
FMODE = 0644
DMODE = 0755

import os, sys, re, socket, pwd, grp

def die(*s):
	sys.stderr.write("auto.maton: fatal: " + "".join(map(str, s)) + "\n")
	sys.exit(1)

def hostlookup(host):
	try:
		return socket.gethostbyname(host)
	except:
		return None

def nmblookup(host):
	f = os.popen("nmblookup " + host + " 2>/dev/null")
	addr = None
	for l in f.readlines():
		m = re.match(r'^([0-9.]+)\s', l)
		if m is not None:
			addr = m.group(1)
	f.close()
	return addr

def smblist(host, args):
	exports = []
	f = os.popen("smbclient -gNL " + host + " 2>/dev/null")
	for l in f.readlines():
		if not l.startswith("Disk|"):
			continue
		fs = l.split("|")
		if fs[1].endswith("$"):
			continue
		exports.append((fs[1], "://" + host + "/" + fs[1]))
	f.close()

	opts = "-fstype=cifs,guest,uid=%(uid)d,gid=%(gid)d,file_mode=%(fmode)04o,dir_mode=%(dmode)04o,ip=%(addr)s" % args
	return (opts, exports)

def main(args):
	if len(args) != 1:
		die("Usage: auto.maton key")

	key = args[0]
	if not re.match(r'^[a-zA-Z._-]+$', key):
		die("Bad key: ", repr(key))
	host = key

	addr = None
	for f in (hostlookup, nmblookup):
		addr = f(host)
		if addr is not None:
			break
	if addr is None:
		die("Cannot look up host ", host)

	args = {
		"addr": addr,
		"uid": pwd.getpwnam(USER)[2],
		"gid": grp.getgrnam(GROUP)[2],
		"fmode": FMODE,
		"dmode": DMODE,
		}

	(opts, exports) = smblist(host, args)
	if len(exports) == 0:
		# It would be nicer to show an empty directory, but we have to
		# mount *something*...
		sys.exit(1)
	if len(exports) == 1:
		# automount doesn't parse multimount lines properly when
		# there's only one mount, so add a dummy item.
		exports.append((".dummy", exports[0][1]))

	sys.stdout.write(opts)
	for (name, path) in exports:
		sys.stdout.write(" \\\n\t/" + name + " " + path)
	sys.stdout.write("\n")

	sys.exit(0)

if __name__ == "__main__":
	main(sys.argv[1:])