Re: Creating adhoc wireless Network

[Dan Williams <dcbw redhat com>]

On Wed, 2009-07-01 at 12:28 -0400, Dan Williams wrote:
> On Wed, 2009-07-01 at 11:26 -0400, nexus aflb com wrote:
> > Thanks for this quick answer.
> > 
> > That's what I though. Adding a new connection isnot easy to do...
> > 
> > when you say "programmatically ask the system settings service to create it"
> > 
> > What do you mean ? Doing the same stuff as nm-applet but hardcoded ?
> 
> Same way nm-connection-editor asks the system settings service to create
> a new connection when the user hits "Apply": you call the
> AddConnection() method on the
> org.freedesktop.NetworkManagerSettings.System interface with the
> connection details you want to set.
> 
> Unfortunately we didn't define that method to return the object path of
> the newly created connection in 0.7 (will probably be fixed in 0.8), so
> you have to wait for the NewConnection signal that the
> system-settings-service emits, look for the UUID of the connection you
> just created to get the object path, and then tell NM to activate that
> connection.
> 
> It's pretty straightforward actually, once you know what needs to be
> done.  If PolicyKit throws up a dialog, use polkit-gnome-authorization
> to allow the user to always have the
> org.freedesktop.network-manager-settings.system.modify permission and
> the user won't ever get asked.

Check out the attached script.  It will create a WEP-enabled adhoc
connection if that connection (identified by UUID) doesn't already
exist, and then direct NetworkManager to activate that connection.  The
script is somewhat longer than it needs to be, simply because I made it
more readable, added comments so you can figure out what's going on, and
put some reasonable error checking in.

Dan
----

#!/bin/env python
# -*- Mode: Python; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
#
# Copyright (C) 2009 Red Hat, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#

import dbus
import glib
import sys
import posix
import time

uuid = "cabfaf9e-4043-4afb-8506-0e6f4a225636"

s_con = { 'id':          'My AdHoc',
          'uuid':        uuid,
          'type':        '802-11-wireless',
          'autoconnect': False,
          'name':        'connection' }

s_wifi = { 'ssid':     dbus.ByteArray("foobar"),
           'mode':     'adhoc', 
           'security': '802-11-wireless-security',
           'name':     '802-11-wireless' }

s_wsec = { 'key-mgmt': 'none',
           'wep-key0': '0123456789abcdef0123456789',
           'name':     '802-11-wireless-security' }

s_ip4 = { 'method': 'link-local',
          'name':   'ipv4' }

con = { 'connection': s_con,
        '802-11-wireless': s_wifi,
        '802-11-wireless-security': s_wsec,
        'ipv4': s_ip4 }

# init dbus
sys_bus = dbus.SystemBus()
ses_bus = dbus.SessionBus()

ss_proxy = sys_bus.get_object('org.freedesktop.NetworkManagerSystemSettings',
                          '/org/freedesktop/NetworkManagerSettings')
ss_iface = dbus.Interface(ss_proxy, 'org.freedesktop.NetworkManagerSettings')
ss_sys_iface = dbus.Interface(ss_proxy, 'org.freedesktop.NetworkManagerSettings.System')

nm_proxy = sys_bus.get_object('org.freedesktop.NetworkManager',
                              '/org/freedesktop/NetworkManager')
nm_iface = dbus.Interface(nm_proxy, 'org.freedesktop.NetworkManager')

pk_proxy = ses_bus.get_object('org.freedesktop.PolicyKit.AuthenticationAgent', '/')
pk_iface = dbus.Interface(pk_proxy, 'org.freedesktop.PolicyKit.AuthenticationAgent')

def find_connection(requested_uuid):
    for c in ss_iface.ListConnections():
        # get the details of the connection
        c_proxy = sys_bus.get_object('org.freedesktop.NetworkManagerSystemSettings', c)
        c_iface = dbus.Interface(c_proxy, 'org.freedesktop.NetworkManagerSettings.Connection')
        settings = c_iface.GetSettings()
        if settings['connection']['uuid'] == requested_uuid:
            # found our connection
            return c
    return None

def try_add(connection):
    try:
        # Ask the system settings service to create the connection
        ss_sys_iface.AddConnection(connection)
        return None
    except Exception, e:
        parts = str(e).split(' ')
        if parts[0].find('org.freedesktop.NetworkManagerSettings.System.NotPrivileged') < 0:
            # not a permission denied, give up and exit
            print e
            sys.exit(1)
        # yay, permission denied, we can handle this
        return parts[1]

# MAIN PROGRAM

con_path = find_connection(uuid)
if not con_path:
    # Try to create the connection, which could fail if we need authorization.
    # If auth is required, get the auth and try adding it again
    action = try_add(con)
    if action:
        gained = pk_iface.ObtainAuthorization(action, 0, posix.getpid())
        if gained:
            # Yay, we have the privilege now, try adding again
            action = try_add(con)
            if action:
                # hmm, something went wrong and PolicyKit wasn't able to auth the user
                sys.exit(1)

            con_path = find_connection(uuid)

# Check again in case it was just added
if not con_path:
    print "Couldn't get newly created connection from system settings"

# Find a wifi device to activate this connection on
dev_path = None
for dev in nm_iface.GetDevices():
    dev_proxy = sys_bus.get_object('org.freedesktop.NetworkManager', dev)
    dev_props_iface = dbus.Interface(dev_proxy, 'org.freedesktop.DBus.Properties')
    props = dev_props_iface.GetAll('org.freedesktop.NetworkManager.Device')
    if props['DeviceType'] == 2:   # wifi
        dev_path = dev
        break

if not dev_path:
    print "No wifi devices available"
    sys.exit(1)

# Now ask NM to activate that connection
active_path = nm_iface.ActivateConnection('org.freedesktop.NetworkManagerSystemSettings',
                                          con_path, dev_path, "/")
if not active_path:
    print "Couldn't activate connection"
    sys.exit(1)

# Wait for the connection to become active
active_proxy = sys_bus.get_object('org.freedesktop.NetworkManager', active_path)
active_props_iface = dbus.Interface(active_proxy, 'org.freedesktop.DBus.Properties')

state = 0
while state != 2:  # 2 == activated
    state = active_props_iface.Get('org.freedesktop.NetworkManager.Connection.Active', 'State')
    if state != 2:
        print "waiting for connection to become active..."
        time.sleep(1)

print "activated!"