def start_dhcp(self, subnets):
"""Start a DHCP server for the specified subnets.
This allows consumers of the access point objects to control DHCP.
Args:
subnets: A list of Subnets.
"""
return self._dhcp.start(config=dhcp_config.DhcpConfig(subnets))
def stop_ap(self, identifier):
"""Stops a running ap on this controller.
Args:
identifier: The identify of the ap that should be taken down.
"""
if identifier not in self._aps:
raise ValueError('Invalid identifer %s given' % identifier)
instance = self._aps.get(identifier)
instance.hostapd.stop()
self._dhcp.stop()
self._ip_cmd.clear_ipv4_addresses(identifier)
# DHCP server needs to refresh in order to tear down the subnet no
# longer being used. In the event that all interfaces are torn down
# then an exception gets thrown. We need to catch this exception and
# check that all interfaces should actually be down.
configured_subnets = [x.subnet for x in self._aps.values()]
if configured_subnets:
self._dhcp.start(dhcp_config.DhcpConfig(configured_subnets))
def start_ap(self, hostapd_config, additional_parameters=None):
"""Starts as an ap using a set of configurations.
This will start an ap on this host. To start an ap the controller
selects a network interface to use based on the configs given. It then
will start up hostapd on that interface. Next a subnet is created for
the network interface and dhcp server is refreshed to give out ips
for that subnet for any device that connects through that interface.
Args:
hostapd_config: hostapd_config.HostapdConfig, The configurations
to use when starting up the ap.
additional_parameters: A dictionary of parameters that can sent
directly into the hostapd config file. This
can be used for debugging and or adding one
off parameters into the config.
Returns:
An identifier for the ap being run. This identifier can be used
later by this controller to control the ap.
Raises:
Error: When the ap can't be brought up.
"""
if hostapd_config.frequency < 5000:
interface = self.wlan_2g
subnet = self._AP_2G_SUBNET
else:
interface = self.wlan_5g
subnet = self._AP_5G_SUBNET
# In order to handle dhcp servers on any interface, the initiation of
# the dhcp server must be done after the wlan interfaces are figured
# out as opposed to being in __init__
self._dhcp = dhcp_server.DhcpServer(self.ssh, interface=interface)
# For multi bssid configurations the mac address
# of the wireless interface needs to have enough space to mask out
# up to 8 different mac addresses. The easiest way to do this
# is to set the last byte to 0. While technically this could
# cause a duplicate mac address it is unlikely and will allow for
# one radio to have up to 8 APs on the interface.
interface_mac_orig = None
cmd = "ifconfig %s|grep ether|awk -F' ' '{print $2}'" % interface
interface_mac_orig = self.ssh.run(cmd)
hostapd_config.bssid = interface_mac_orig.stdout[:-1] + '0'
if interface in self._aps:
raise ValueError('No WiFi interface available for AP on '
'channel %d' % hostapd_config.channel)
apd = hostapd.Hostapd(self.ssh, interface)
new_instance = _ApInstance(hostapd=apd, subnet=subnet)
self._aps[interface] = new_instance
# Turn off the DHCP server, we're going to change its settings.
self._dhcp.stop()
# Clear all routes to prevent old routes from interfering.
self._route_cmd.clear_routes(net_interface=interface)
if hostapd_config.bss_lookup:
# The dhcp_bss dictionary is created to hold the key/value
# pair of the interface name and the ip scope that will be
# used for the particular interface. The a, b, c, d
# variables below are the octets for the ip address. The
# third octet is then incremented for each interface that
# is requested. This part is designed to bring up the
# hostapd interfaces and not the DHCP servers for each
# interface.
dhcp_bss = {}
counter = 1
for bss in hostapd_config.bss_lookup:
if interface_mac_orig:
hostapd_config.bss_lookup[
bss].bssid = interface_mac_orig.stdout[:-1] + str(
counter)
self._route_cmd.clear_routes(net_interface=str(bss))
if interface is self.wlan_2g:
starting_ip_range = self._AP_2G_SUBNET_STR
else:
starting_ip_range = self._AP_5G_SUBNET_STR
a, b, c, d = starting_ip_range.split('.')
dhcp_bss[bss] = dhcp_config.Subnet(
ipaddress.ip_network('%s.%s.%s.%s' %
(a, b, str(int(c) + counter), d)))
counter = counter + 1
apd.start(hostapd_config, additional_parameters=additional_parameters)
# The DHCP serer requires interfaces to have ips and routes before
# the server will come up.
interface_ip = ipaddress.ip_interface(
'%s/%s' % (subnet.router, subnet.network.netmask))
self._ip_cmd.set_ipv4_address(interface, interface_ip)
if hostapd_config.bss_lookup:
# This loop goes through each interface that was setup for
# hostapd and assigns the DHCP scopes that were defined but
# not used during the hostapd loop above. The k and v
# variables represent the interface name, k, and dhcp info, v.
for k, v in dhcp_bss.items():
bss_interface_ip = ipaddress.ip_interface(
'%s/%s' %
(dhcp_bss[k].router, dhcp_bss[k].network.netmask))
self._ip_cmd.set_ipv4_address(str(k), bss_interface_ip)
# Restart the DHCP server with our updated list of subnets.
configured_subnets = [x.subnet for x in self._aps.values()]
if hostapd_config.bss_lookup:
for k, v in dhcp_bss.items():
configured_subnets.append(v)
self._dhcp.start(config=dhcp_config.DhcpConfig(configured_subnets))
# The following three commands are needed to enable bridging between
# the WAN and LAN/WLAN ports. This means anyone connecting to the
# WLAN/LAN ports will be able to access the internet if the WAN port
# is connected to the internet.
self.ssh.run('iptables -t nat -F')
self.ssh.run('iptables -t nat -A POSTROUTING -o %s -j MASQUERADE' %
self.wan)
self.ssh.run('echo 1 > /proc/sys/net/ipv4/ip_forward')
return interface
