diff options
Diffstat (limited to 'contrail-agent/hooks/charmhelpers/contrib/network')
4 files changed, 1085 insertions, 0 deletions
diff --git a/contrail-agent/hooks/charmhelpers/contrib/network/__init__.py b/contrail-agent/hooks/charmhelpers/contrib/network/__init__.py new file mode 100644 index 0000000..d7567b8 --- /dev/null +++ b/contrail-agent/hooks/charmhelpers/contrib/network/__init__.py @@ -0,0 +1,13 @@ +# Copyright 2014-2015 Canonical Limited. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. diff --git a/contrail-agent/hooks/charmhelpers/contrib/network/ip.py b/contrail-agent/hooks/charmhelpers/contrib/network/ip.py new file mode 100644 index 0000000..15f6596 --- /dev/null +++ b/contrail-agent/hooks/charmhelpers/contrib/network/ip.py @@ -0,0 +1,593 @@ +# Copyright 2014-2015 Canonical Limited. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +import glob +import re +import subprocess +import six +import socket + +from functools import partial + +from charmhelpers.fetch import apt_install, apt_update +from charmhelpers.core.hookenv import ( + config, + log, + network_get_primary_address, + unit_get, + WARNING, +) + +from charmhelpers.core.host import ( + lsb_release, + CompareHostReleases, +) + +try: + import netifaces +except ImportError: + apt_update(fatal=True) + if six.PY2: + apt_install('python-netifaces', fatal=True) + else: + apt_install('python3-netifaces', fatal=True) + import netifaces + +try: + import netaddr +except ImportError: + apt_update(fatal=True) + if six.PY2: + apt_install('python-netaddr', fatal=True) + else: + apt_install('python3-netaddr', fatal=True) + import netaddr + + +def _validate_cidr(network): + try: + netaddr.IPNetwork(network) + except (netaddr.core.AddrFormatError, ValueError): + raise ValueError("Network (%s) is not in CIDR presentation format" % + network) + + +def no_ip_found_error_out(network): + errmsg = ("No IP address found in network(s): %s" % network) + raise ValueError(errmsg) + + +def _get_ipv6_network_from_address(address): + """Get an netaddr.IPNetwork for the given IPv6 address + :param address: a dict as returned by netifaces.ifaddresses + :returns netaddr.IPNetwork: None if the address is a link local or loopback + address + """ + if address['addr'].startswith('fe80') or address['addr'] == "::1": + return None + + prefix = address['netmask'].split("/") + if len(prefix) > 1: + netmask = prefix[1] + else: + netmask = address['netmask'] + return netaddr.IPNetwork("%s/%s" % (address['addr'], + netmask)) + + +def get_address_in_network(network, fallback=None, fatal=False): + """Get an IPv4 or IPv6 address within the network from the host. + + :param network (str): CIDR presentation format. For example, + '192.168.1.0/24'. Supports multiple networks as a space-delimited list. + :param fallback (str): If no address is found, return fallback. + :param fatal (boolean): If no address is found, fallback is not + set and fatal is True then exit(1). + """ + if network is None: + if fallback is not None: + return fallback + + if fatal: + no_ip_found_error_out(network) + else: + return None + + networks = network.split() or [network] + for network in networks: + _validate_cidr(network) + network = netaddr.IPNetwork(network) + for iface in netifaces.interfaces(): + addresses = netifaces.ifaddresses(iface) + if network.version == 4 and netifaces.AF_INET in addresses: + for addr in addresses[netifaces.AF_INET]: + cidr = netaddr.IPNetwork("%s/%s" % (addr['addr'], + addr['netmask'])) + if cidr in network: + return str(cidr.ip) + + if network.version == 6 and netifaces.AF_INET6 in addresses: + for addr in addresses[netifaces.AF_INET6]: + cidr = _get_ipv6_network_from_address(addr) + if cidr and cidr in network: + return str(cidr.ip) + + if fallback is not None: + return fallback + + if fatal: + no_ip_found_error_out(network) + + return None + + +def is_ipv6(address): + """Determine whether provided address is IPv6 or not.""" + try: + address = netaddr.IPAddress(address) + except netaddr.AddrFormatError: + # probably a hostname - so not an address at all! + return False + + return address.version == 6 + + +def is_address_in_network(network, address): + """ + Determine whether the provided address is within a network range. + + :param network (str): CIDR presentation format. For example, + '192.168.1.0/24'. + :param address: An individual IPv4 or IPv6 address without a net + mask or subnet prefix. For example, '192.168.1.1'. + :returns boolean: Flag indicating whether address is in network. + """ + try: + network = netaddr.IPNetwork(network) + except (netaddr.core.AddrFormatError, ValueError): + raise ValueError("Network (%s) is not in CIDR presentation format" % + network) + + try: + address = netaddr.IPAddress(address) + except (netaddr.core.AddrFormatError, ValueError): + raise ValueError("Address (%s) is not in correct presentation format" % + address) + + if address in network: + return True + else: + return False + + +def _get_for_address(address, key): + """Retrieve an attribute of or the physical interface that + the IP address provided could be bound to. + + :param address (str): An individual IPv4 or IPv6 address without a net + mask or subnet prefix. For example, '192.168.1.1'. + :param key: 'iface' for the physical interface name or an attribute + of the configured interface, for example 'netmask'. + :returns str: Requested attribute or None if address is not bindable. + """ + address = netaddr.IPAddress(address) + for iface in netifaces.interfaces(): + addresses = netifaces.ifaddresses(iface) + if address.version == 4 and netifaces.AF_INET in addresses: + addr = addresses[netifaces.AF_INET][0]['addr'] + netmask = addresses[netifaces.AF_INET][0]['netmask'] + network = netaddr.IPNetwork("%s/%s" % (addr, netmask)) + cidr = network.cidr + if address in cidr: + if key == 'iface': + return iface + else: + return addresses[netifaces.AF_INET][0][key] + + if address.version == 6 and netifaces.AF_INET6 in addresses: + for addr in addresses[netifaces.AF_INET6]: + network = _get_ipv6_network_from_address(addr) + if not network: + continue + + cidr = network.cidr + if address in cidr: + if key == 'iface': + return iface + elif key == 'netmask' and cidr: + return str(cidr).split('/')[1] + else: + return addr[key] + return None + + +get_iface_for_address = partial(_get_for_address, key='iface') + + +get_netmask_for_address = partial(_get_for_address, key='netmask') + + +def resolve_network_cidr(ip_address): + ''' + Resolves the full address cidr of an ip_address based on + configured network interfaces + ''' + netmask = get_netmask_for_address(ip_address) + return str(netaddr.IPNetwork("%s/%s" % (ip_address, netmask)).cidr) + + +def format_ipv6_addr(address): + """If address is IPv6, wrap it in '[]' otherwise return None. + + This is required by most configuration files when specifying IPv6 + addresses. + """ + if is_ipv6(address): + return "[%s]" % address + + return None + + +def is_ipv6_disabled(): + try: + result = subprocess.check_output( + ['sysctl', 'net.ipv6.conf.all.disable_ipv6'], + stderr=subprocess.STDOUT) + except subprocess.CalledProcessError: + return True + if six.PY3: + result = result.decode('UTF-8') + return "net.ipv6.conf.all.disable_ipv6 = 1" in result + + +def get_iface_addr(iface='eth0', inet_type='AF_INET', inc_aliases=False, + fatal=True, exc_list=None): + """Return the assigned IP address for a given interface, if any. + + :param iface: network interface on which address(es) are expected to + be found. + :param inet_type: inet address family + :param inc_aliases: include alias interfaces in search + :param fatal: if True, raise exception if address not found + :param exc_list: list of addresses to ignore + :return: list of ip addresses + """ + # Extract nic if passed /dev/ethX + if '/' in iface: + iface = iface.split('/')[-1] + + if not exc_list: + exc_list = [] + + try: + inet_num = getattr(netifaces, inet_type) + except AttributeError: + raise Exception("Unknown inet type '%s'" % str(inet_type)) + + interfaces = netifaces.interfaces() + if inc_aliases: + ifaces = [] + for _iface in interfaces: + if iface == _iface or _iface.split(':')[0] == iface: + ifaces.append(_iface) + + if fatal and not ifaces: + raise Exception("Invalid interface '%s'" % iface) + + ifaces.sort() + else: + if iface not in interfaces: + if fatal: + raise Exception("Interface '%s' not found " % (iface)) + else: + return [] + + else: + ifaces = [iface] + + addresses = [] + for netiface in ifaces: + net_info = netifaces.ifaddresses(netiface) + if inet_num in net_info: + for entry in net_info[inet_num]: + if 'addr' in entry and entry['addr'] not in exc_list: + addresses.append(entry['addr']) + + if fatal and not addresses: + raise Exception("Interface '%s' doesn't have any %s addresses." % + (iface, inet_type)) + + return sorted(addresses) + + +get_ipv4_addr = partial(get_iface_addr, inet_type='AF_INET') + + +def get_iface_from_addr(addr): + """Work out on which interface the provided address is configured.""" + for iface in netifaces.interfaces(): + addresses = netifaces.ifaddresses(iface) + for inet_type in addresses: + for _addr in addresses[inet_type]: + _addr = _addr['addr'] + # link local + ll_key = re.compile("(.+)%.*") + raw = re.match(ll_key, _addr) + if raw: + _addr = raw.group(1) + + if _addr == addr: + log("Address '%s' is configured on iface '%s'" % + (addr, iface)) + return iface + + msg = "Unable to infer net iface on which '%s' is configured" % (addr) + raise Exception(msg) + + +def sniff_iface(f): + """Ensure decorated function is called with a value for iface. + + If no iface provided, inject net iface inferred from unit private address. + """ + def iface_sniffer(*args, **kwargs): + if not kwargs.get('iface', None): + kwargs['iface'] = get_iface_from_addr(unit_get('private-address')) + + return f(*args, **kwargs) + + return iface_sniffer + + +@sniff_iface +def get_ipv6_addr(iface=None, inc_aliases=False, fatal=True, exc_list=None, + dynamic_only=True): + """Get assigned IPv6 address for a given interface. + + Returns list of addresses found. If no address found, returns empty list. + + If iface is None, we infer the current primary interface by doing a reverse + lookup on the unit private-address. + + We currently only support scope global IPv6 addresses i.e. non-temporary + addresses. If no global IPv6 address is found, return the first one found + in the ipv6 address list. + + :param iface: network interface on which ipv6 address(es) are expected to + be found. + :param inc_aliases: include alias interfaces in search + :param fatal: if True, raise exception if address not found + :param exc_list: list of addresses to ignore + :param dynamic_only: only recognise dynamic addresses + :return: list of ipv6 addresses + """ + addresses = get_iface_addr(iface=iface, inet_type='AF_INET6', + inc_aliases=inc_aliases, fatal=fatal, + exc_list=exc_list) + + if addresses: + global_addrs = [] + for addr in addresses: + key_scope_link_local = re.compile("^fe80::..(.+)%(.+)") + m = re.match(key_scope_link_local, addr) + if m: + eui_64_mac = m.group(1) + iface = m.group(2) + else: + global_addrs.append(addr) + + if global_addrs: + # Make sure any found global addresses are not temporary + cmd = ['ip', 'addr', 'show', iface] + out = subprocess.check_output(cmd).decode('UTF-8') + if dynamic_only: + key = re.compile("inet6 (.+)/[0-9]+ scope global.* dynamic.*") + else: + key = re.compile("inet6 (.+)/[0-9]+ scope global.*") + + addrs = [] + for line in out.split('\n'): + line = line.strip() + m = re.match(key, line) + if m and 'temporary' not in line: + # Return the first valid address we find + for addr in global_addrs: + if m.group(1) == addr: + if not dynamic_only or \ + m.group(1).endswith(eui_64_mac): + addrs.append(addr) + + if addrs: + return addrs + + if fatal: + raise Exception("Interface '%s' does not have a scope global " + "non-temporary ipv6 address." % iface) + + return [] + + +def get_bridges(vnic_dir='/sys/devices/virtual/net'): + """Return a list of bridges on the system.""" + b_regex = "%s/*/bridge" % vnic_dir + return [x.replace(vnic_dir, '').split('/')[1] for x in glob.glob(b_regex)] + + +def get_bridge_nics(bridge, vnic_dir='/sys/devices/virtual/net'): + """Return a list of nics comprising a given bridge on the system.""" + brif_regex = "%s/%s/brif/*" % (vnic_dir, bridge) + return [x.split('/')[-1] for x in glob.glob(brif_regex)] + + +def is_bridge_member(nic): + """Check if a given nic is a member of a bridge.""" + for bridge in get_bridges(): + if nic in get_bridge_nics(bridge): + return True + + return False + + +def is_ip(address): + """ + Returns True if address is a valid IP address. + """ + try: + # Test to see if already an IPv4/IPv6 address + address = netaddr.IPAddress(address) + return True + except (netaddr.AddrFormatError, ValueError): + return False + + +def ns_query(address): + try: + import dns.resolver + except ImportError: + if six.PY2: + apt_install('python-dnspython', fatal=True) + else: + apt_install('python3-dnspython', fatal=True) + import dns.resolver + + if isinstance(address, dns.name.Name): + rtype = 'PTR' + elif isinstance(address, six.string_types): + rtype = 'A' + else: + return None + + try: + answers = dns.resolver.query(address, rtype) + except dns.resolver.NXDOMAIN: + return None + + if answers: + return str(answers[0]) + return None + + +def get_host_ip(hostname, fallback=None): + """ + Resolves the IP for a given hostname, or returns + the input if it is already an IP. + """ + if is_ip(hostname): + return hostname + + ip_addr = ns_query(hostname) + if not ip_addr: + try: + ip_addr = socket.gethostbyname(hostname) + except: + log("Failed to resolve hostname '%s'" % (hostname), + level=WARNING) + return fallback + return ip_addr + + +def get_hostname(address, fqdn=True): + """ + Resolves hostname for given IP, or returns the input + if it is already a hostname. + """ + if is_ip(address): + try: + import dns.reversename + except ImportError: + if six.PY2: + apt_install("python-dnspython", fatal=True) + else: + apt_install("python3-dnspython", fatal=True) + import dns.reversename + + rev = dns.reversename.from_address(address) + result = ns_query(rev) + + if not result: + try: + result = socket.gethostbyaddr(address)[0] + except: + return None + else: + result = address + + if fqdn: + # strip trailing . + if result.endswith('.'): + return result[:-1] + else: + return result + else: + return result.split('.')[0] + + +def port_has_listener(address, port): + """ + Returns True if the address:port is open and being listened to, + else False. + + @param address: an IP address or hostname + @param port: integer port + + Note calls 'zc' via a subprocess shell + """ + cmd = ['nc', '-z', address, str(port)] + result = subprocess.call(cmd) + return not(bool(result)) + + +def assert_charm_supports_ipv6(): + """Check whether we are able to support charms ipv6.""" + release = lsb_release()['DISTRIB_CODENAME'].lower() + if CompareHostReleases(release) < "trusty": + raise Exception("IPv6 is not supported in the charms for Ubuntu " + "versions less than Trusty 14.04") + + +def get_relation_ip(interface, cidr_network=None): + """Return this unit's IP for the given interface. + + Allow for an arbitrary interface to use with network-get to select an IP. + Handle all address selection options including passed cidr network and + IPv6. + + Usage: get_relation_ip('amqp', cidr_network='10.0.0.0/8') + + @param interface: string name of the relation. + @param cidr_network: string CIDR Network to select an address from. + @raises Exception if prefer-ipv6 is configured but IPv6 unsupported. + @returns IPv6 or IPv4 address + """ + # Select the interface address first + # For possible use as a fallback bellow with get_address_in_network + try: + # Get the interface specific IP + address = network_get_primary_address(interface) + except NotImplementedError: + # If network-get is not available + address = get_host_ip(unit_get('private-address')) + + if config('prefer-ipv6'): + # Currently IPv6 has priority, eventually we want IPv6 to just be + # another network space. + assert_charm_supports_ipv6() + return get_ipv6_addr()[0] + elif cidr_network: + # If a specific CIDR network is passed get the address from that + # network. + return get_address_in_network(cidr_network, address) + + # Return the interface address + return address diff --git a/contrail-agent/hooks/charmhelpers/contrib/network/ovs/__init__.py b/contrail-agent/hooks/charmhelpers/contrib/network/ovs/__init__.py new file mode 100644 index 0000000..f044b60 --- /dev/null +++ b/contrail-agent/hooks/charmhelpers/contrib/network/ovs/__init__.py @@ -0,0 +1,163 @@ +# Copyright 2014-2015 Canonical Limited. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +''' Helpers for interacting with OpenvSwitch ''' +import subprocess +import os +import six + +from charmhelpers.fetch import apt_install + + +from charmhelpers.core.hookenv import ( + log, WARNING, INFO, DEBUG +) +from charmhelpers.core.host import ( + service +) + +BRIDGE_TEMPLATE = """\ +# This veth pair is required when neutron data-port is mapped to an existing linux bridge. lp:1635067 + +auto {linuxbridge_port} +iface {linuxbridge_port} inet manual + pre-up ip link add name {linuxbridge_port} type veth peer name {ovsbridge_port} + pre-up ip link set {ovsbridge_port} master {bridge} + pre-up ip link set {ovsbridge_port} up + up ip link set {linuxbridge_port} up + down ip link del {linuxbridge_port} +""" + + +def add_bridge(name, datapath_type=None): + ''' Add the named bridge to openvswitch ''' + log('Creating bridge {}'.format(name)) + cmd = ["ovs-vsctl", "--", "--may-exist", "add-br", name] + if datapath_type is not None: + cmd += ['--', 'set', 'bridge', name, + 'datapath_type={}'.format(datapath_type)] + subprocess.check_call(cmd) + + +def del_bridge(name): + ''' Delete the named bridge from openvswitch ''' + log('Deleting bridge {}'.format(name)) + subprocess.check_call(["ovs-vsctl", "--", "--if-exists", "del-br", name]) + + +def add_bridge_port(name, port, promisc=False): + ''' Add a port to the named openvswitch bridge ''' + log('Adding port {} to bridge {}'.format(port, name)) + subprocess.check_call(["ovs-vsctl", "--", "--may-exist", "add-port", + name, port]) + subprocess.check_call(["ip", "link", "set", port, "up"]) + if promisc: + subprocess.check_call(["ip", "link", "set", port, "promisc", "on"]) + else: + subprocess.check_call(["ip", "link", "set", port, "promisc", "off"]) + + +def del_bridge_port(name, port): + ''' Delete a port from the named openvswitch bridge ''' + log('Deleting port {} from bridge {}'.format(port, name)) + subprocess.check_call(["ovs-vsctl", "--", "--if-exists", "del-port", + name, port]) + subprocess.check_call(["ip", "link", "set", port, "down"]) + subprocess.check_call(["ip", "link", "set", port, "promisc", "off"]) + + +def add_ovsbridge_linuxbridge(name, bridge): + ''' Add linux bridge to the named openvswitch bridge + :param name: Name of ovs bridge to be added to Linux bridge + :param bridge: Name of Linux bridge to be added to ovs bridge + :returns: True if veth is added between ovs bridge and linux bridge, + False otherwise''' + try: + import netifaces + except ImportError: + if six.PY2: + apt_install('python-netifaces', fatal=True) + else: + apt_install('python3-netifaces', fatal=True) + import netifaces + + ovsbridge_port = "veth-" + name + linuxbridge_port = "veth-" + bridge + log('Adding linuxbridge {} to ovsbridge {}'.format(bridge, name), + level=INFO) + interfaces = netifaces.interfaces() + for interface in interfaces: + if interface == ovsbridge_port or interface == linuxbridge_port: + log('Interface {} already exists'.format(interface), level=INFO) + return + + with open('/etc/network/interfaces.d/{}.cfg'.format( + linuxbridge_port), 'w') as config: + config.write(BRIDGE_TEMPLATE.format(linuxbridge_port=linuxbridge_port, + ovsbridge_port=ovsbridge_port, + bridge=bridge)) + + subprocess.check_call(["ifup", linuxbridge_port]) + add_bridge_port(name, linuxbridge_port) + + +def is_linuxbridge_interface(port): + ''' Check if the interface is a linuxbridge bridge + :param port: Name of an interface to check whether it is a Linux bridge + :returns: True if port is a Linux bridge''' + + if os.path.exists('/sys/class/net/' + port + '/bridge'): + log('Interface {} is a Linux bridge'.format(port), level=DEBUG) + return True + else: + log('Interface {} is not a Linux bridge'.format(port), level=DEBUG) + return False + + +def set_manager(manager): + ''' Set the controller for the local openvswitch ''' + log('Setting manager for local ovs to {}'.format(manager)) + subprocess.check_call(['ovs-vsctl', 'set-manager', + 'ssl:{}'.format(manager)]) + + +CERT_PATH = '/etc/openvswitch/ovsclient-cert.pem' + + +def get_certificate(): + ''' Read openvswitch certificate from disk ''' + if os.path.exists(CERT_PATH): + log('Reading ovs certificate from {}'.format(CERT_PATH)) + with open(CERT_PATH, 'r') as cert: + full_cert = cert.read() + begin_marker = "-----BEGIN CERTIFICATE-----" + end_marker = "-----END CERTIFICATE-----" + begin_index = full_cert.find(begin_marker) + end_index = full_cert.rfind(end_marker) + if end_index == -1 or begin_index == -1: + raise RuntimeError("Certificate does not contain valid begin" + " and end markers.") + full_cert = full_cert[begin_index:(end_index + len(end_marker))] + return full_cert + else: + log('Certificate not found', level=WARNING) + return None + + +def full_restart(): + ''' Full restart and reload of openvswitch ''' + if os.path.exists('/etc/init/openvswitch-force-reload-kmod.conf'): + service('start', 'openvswitch-force-reload-kmod') + else: + service('force-reload-kmod', 'openvswitch-switch') diff --git a/contrail-agent/hooks/charmhelpers/contrib/network/ufw.py b/contrail-agent/hooks/charmhelpers/contrib/network/ufw.py new file mode 100644 index 0000000..5cff71b --- /dev/null +++ b/contrail-agent/hooks/charmhelpers/contrib/network/ufw.py @@ -0,0 +1,316 @@ +# Copyright 2014-2015 Canonical Limited. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +""" +This module contains helpers to add and remove ufw rules. + +Examples: + +- open SSH port for subnet 10.0.3.0/24: + + >>> from charmhelpers.contrib.network import ufw + >>> ufw.enable() + >>> ufw.grant_access(src='10.0.3.0/24', dst='any', port='22', proto='tcp') + +- open service by name as defined in /etc/services: + + >>> from charmhelpers.contrib.network import ufw + >>> ufw.enable() + >>> ufw.service('ssh', 'open') + +- close service by port number: + + >>> from charmhelpers.contrib.network import ufw + >>> ufw.enable() + >>> ufw.service('4949', 'close') # munin +""" +import re +import os +import subprocess + +from charmhelpers.core import hookenv +from charmhelpers.core.kernel import modprobe, is_module_loaded + +__author__ = "Felipe Reyes <felipe.reyes@canonical.com>" + + +class UFWError(Exception): + pass + + +class UFWIPv6Error(UFWError): + pass + + +def is_enabled(): + """ + Check if `ufw` is enabled + + :returns: True if ufw is enabled + """ + output = subprocess.check_output(['ufw', 'status'], + universal_newlines=True, + env={'LANG': 'en_US', + 'PATH': os.environ['PATH']}) + + m = re.findall(r'^Status: active\n', output, re.M) + + return len(m) >= 1 + + +def is_ipv6_ok(soft_fail=False): + """ + Check if IPv6 support is present and ip6tables functional + + :param soft_fail: If set to True and IPv6 support is broken, then reports + that the host doesn't have IPv6 support, otherwise a + UFWIPv6Error exception is raised. + :returns: True if IPv6 is working, False otherwise + """ + + # do we have IPv6 in the machine? + if os.path.isdir('/proc/sys/net/ipv6'): + # is ip6tables kernel module loaded? + if not is_module_loaded('ip6_tables'): + # ip6tables support isn't complete, let's try to load it + try: + modprobe('ip6_tables') + # great, we can load the module + return True + except subprocess.CalledProcessError as ex: + hookenv.log("Couldn't load ip6_tables module: %s" % ex.output, + level="WARN") + # we are in a world where ip6tables isn't working + if soft_fail: + # so we inform that the machine doesn't have IPv6 + return False + else: + raise UFWIPv6Error("IPv6 firewall support broken") + else: + # the module is present :) + return True + + else: + # the system doesn't have IPv6 + return False + + +def disable_ipv6(): + """ + Disable ufw IPv6 support in /etc/default/ufw + """ + exit_code = subprocess.call(['sed', '-i', 's/IPV6=.*/IPV6=no/g', + '/etc/default/ufw']) + if exit_code == 0: + hookenv.log('IPv6 support in ufw disabled', level='INFO') + else: + hookenv.log("Couldn't disable IPv6 support in ufw", level="ERROR") + raise UFWError("Couldn't disable IPv6 support in ufw") + + +def enable(soft_fail=False): + """ + Enable ufw + + :param soft_fail: If set to True silently disables IPv6 support in ufw, + otherwise a UFWIPv6Error exception is raised when IP6 + support is broken. + :returns: True if ufw is successfully enabled + """ + if is_enabled(): + return True + + if not is_ipv6_ok(soft_fail): + disable_ipv6() + + output = subprocess.check_output(['ufw', 'enable'], + universal_newlines=True, + env={'LANG': 'en_US', + 'PATH': os.environ['PATH']}) + + m = re.findall('^Firewall is active and enabled on system startup\n', + output, re.M) + hookenv.log(output, level='DEBUG') + + if len(m) == 0: + hookenv.log("ufw couldn't be enabled", level='WARN') + return False + else: + hookenv.log("ufw enabled", level='INFO') + return True + + +def disable(): + """ + Disable ufw + + :returns: True if ufw is successfully disabled + """ + if not is_enabled(): + return True + + output = subprocess.check_output(['ufw', 'disable'], + universal_newlines=True, + env={'LANG': 'en_US', + 'PATH': os.environ['PATH']}) + + m = re.findall(r'^Firewall stopped and disabled on system startup\n', + output, re.M) + hookenv.log(output, level='DEBUG') + + if len(m) == 0: + hookenv.log("ufw couldn't be disabled", level='WARN') + return False + else: + hookenv.log("ufw disabled", level='INFO') + return True + + +def default_policy(policy='deny', direction='incoming'): + """ + Changes the default policy for traffic `direction` + + :param policy: allow, deny or reject + :param direction: traffic direction, possible values: incoming, outgoing, + routed + """ + if policy not in ['allow', 'deny', 'reject']: + raise UFWError(('Unknown policy %s, valid values: ' + 'allow, deny, reject') % policy) + + if direction not in ['incoming', 'outgoing', 'routed']: + raise UFWError(('Unknown direction %s, valid values: ' + 'incoming, outgoing, routed') % direction) + + output = subprocess.check_output(['ufw', 'default', policy, direction], + universal_newlines=True, + env={'LANG': 'en_US', + 'PATH': os.environ['PATH']}) + hookenv.log(output, level='DEBUG') + + m = re.findall("^Default %s policy changed to '%s'\n" % (direction, + policy), + output, re.M) + if len(m) == 0: + hookenv.log("ufw couldn't change the default policy to %s for %s" + % (policy, direction), level='WARN') + return False + else: + hookenv.log("ufw default policy for %s changed to %s" + % (direction, policy), level='INFO') + return True + + +def modify_access(src, dst='any', port=None, proto=None, action='allow', + index=None): + """ + Grant access to an address or subnet + + :param src: address (e.g. 192.168.1.234) or subnet + (e.g. 192.168.1.0/24). + :param dst: destiny of the connection, if the machine has multiple IPs and + connections to only one of those have to accepted this is the + field has to be set. + :param port: destiny port + :param proto: protocol (tcp or udp) + :param action: `allow` or `delete` + :param index: if different from None the rule is inserted at the given + `index`. + """ + if not is_enabled(): + hookenv.log('ufw is disabled, skipping modify_access()', level='WARN') + return + + if action == 'delete': + cmd = ['ufw', 'delete', 'allow'] + elif index is not None: + cmd = ['ufw', 'insert', str(index), action] + else: + cmd = ['ufw', action] + + if src is not None: + cmd += ['from', src] + + if dst is not None: + cmd += ['to', dst] + + if port is not None: + cmd += ['port', str(port)] + + if proto is not None: + cmd += ['proto', proto] + + hookenv.log('ufw {}: {}'.format(action, ' '.join(cmd)), level='DEBUG') + p = subprocess.Popen(cmd, stdout=subprocess.PIPE) + (stdout, stderr) = p.communicate() + + hookenv.log(stdout, level='INFO') + + if p.returncode != 0: + hookenv.log(stderr, level='ERROR') + hookenv.log('Error running: {}, exit code: {}'.format(' '.join(cmd), + p.returncode), + level='ERROR') + + +def grant_access(src, dst='any', port=None, proto=None, index=None): + """ + Grant access to an address or subnet + + :param src: address (e.g. 192.168.1.234) or subnet + (e.g. 192.168.1.0/24). + :param dst: destiny of the connection, if the machine has multiple IPs and + connections to only one of those have to accepted this is the + field has to be set. + :param port: destiny port + :param proto: protocol (tcp or udp) + :param index: if different from None the rule is inserted at the given + `index`. + """ + return modify_access(src, dst=dst, port=port, proto=proto, action='allow', + index=index) + + +def revoke_access(src, dst='any', port=None, proto=None): + """ + Revoke access to an address or subnet + + :param src: address (e.g. 192.168.1.234) or subnet + (e.g. 192.168.1.0/24). + :param dst: destiny of the connection, if the machine has multiple IPs and + connections to only one of those have to accepted this is the + field has to be set. + :param port: destiny port + :param proto: protocol (tcp or udp) + """ + return modify_access(src, dst=dst, port=port, proto=proto, action='delete') + + +def service(name, action): + """ + Open/close access to a service + + :param name: could be a service name defined in `/etc/services` or a port + number. + :param action: `open` or `close` + """ + if action == 'open': + subprocess.check_output(['ufw', 'allow', str(name)], + universal_newlines=True) + elif action == 'close': + subprocess.check_output(['ufw', 'delete', 'allow', str(name)], + universal_newlines=True) + else: + raise UFWError(("'{}' not supported, use 'allow' " + "or 'delete'").format(action)) |