def address_exists(config, name, value):
ip = IPRoute()
if value.version == 4:
family = socket.AF_INET
elif value.version == 6:
family = socket.AF_INET6
else:
raise AssertionError("Unknown version {}".format(value.version))
if ip.get_addr(family=family, address=value.ip, prefixlen=value.prefixlen):
raise ConfigError(name, "No such address {}".format(value))
def address_exists(cls, config, value):
ip = IPRoute()
if value.version == 4:
family = socket.AF_INET
elif value.version == 6:
family = socket.AF_INET6
else:
raise AssertionError("Unknown version {}".format(value.version))
if ip.get_addr(family=family, address=value.ip, prefixlen=value.prefixlen):
raise OptionCheckError("No such address {}".format(value),
option=cls.__name__)
def address_exists(option, config, value):
ip = IPRoute()
if value.version == 4:
family = socket.AF_INET
elif value.version == 6:
family = socket.AF_INET6
else:
raise AssertionError("Unknown version {}".format(value.version))
if ip.get_addr(family=family, address=value.ip, prefixlen=value.prefixlen):
raise OptionCheckError("No such address {}".format(value),
option=option.__name__)
def main():
"""
Program entry point when run interactively.
"""
# prepare option parser
parser = ArgumentParser(usage="usage: %(prog)s [options]",
description="Executes a UDP broadcast to test for "
"connectivity")
parser.add_argument("-i",
"--interface",
dest="interface",
default="poprow0",
action="store",
metavar="ifname",
help="Interface to use [default: %(default)s]")
parser.add_argument("-p",
"--port",
dest="port",
type=int,
default=12345,
action="store",
help="UDP port [default: %(default)s]",
metavar="PORT")
parser.add_argument(
"-n",
"--count",
dest="count",
type=int,
default=100,
action="store",
help="Number of packets to send [default: %(default)s]",
metavar="COUNT")
parser.add_argument("-t",
"--interval",
dest="interval",
type=float,
default=0.2,
action="store",
help="Packet interval [default: %(default)s]")
parser.add_argument("-v", "--verbose", dest="verbose", action="store_true")
# parse options
args = parser.parse_args()
# copy options
interface = args.interface
port = args.port
count = args.count
interval = args.interval
verbose = args.verbose
ip = IPRoute()
if_index = ip.link_lookup(ifname=interface)
if len(if_index) == 0:
print >> sys.stderr, "Can't find interface %s" % interface
sys.exit(1)
# from the given interface find unicast and broadcast addresses
if_info = ip.get_addr(index=if_index[0])[0]
address = if_info.get_attr("IFA_ADDRESS")
netmask = if_info["prefixlen"]
network = ipaddr.IPv4Network("%s/%d" % (address, netmask))
broadcast = str(network.broadcast)
# get hostname as additional information to send in the packets
hostname = socket.gethostname()
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
i = 0
run = True
while i < count and run:
try:
payload = "POPROWPING %d %s" % (i, hostname)
if verbose:
print >> sys.stderr, "Sending packet #%d to %s:%d" % \
(i+1, broadcast, port)
sock.sendto(payload, (broadcast, port))
i += 1
time.sleep(interval)
except SystemExit:
run = False
if verbose:
print >> sys.stderr, "Catching SystemExit. Quitting"
except KeyboardInterrupt:
run = False
if verbose:
print >> sys.stderr, "Keyboard Interrupt. Quitting"
except:
run = False
if verbose:
print >> sys.stderr, "Error while sending packet. Quitting"
sock.close()
def main():
"""
Program entry point when run interactively.
"""
# prepare option parser
parser = ArgumentParser(usage="usage: %(prog)s [options]",
description="Listens to UDP broadcasts to test for "
"connectivity")
parser.add_argument("-i", "--interface", dest="interface",
default="poprow0", action="store", metavar="ifname",
help="Interface to use [default: %(default)s]")
parser.add_argument("-p", "--port", dest="port", type=int, default=12345,
action="store", help="UDP port [default: %(default)s]",
metavar="PORT")
parser.add_argument("-f", "--filename", dest="filename", default="",
action="store",
help="Output file where to store results [default: "
"stdout]", metavar="FILENAME")
parser.add_argument("-v", "--verbose", dest="verbose", action="store_true")
parser.add_argument("-d", "--daemon", dest="daemon", action="store_true",
help="Daemonize the process")
# parse options
args = parser.parse_args()
# copy options
interface = args.interface
port = args.port
filename = args.filename
verbose = args.verbose
daemon = args.daemon
ip = IPRoute()
if_index = ip.link_lookup(ifname=interface)
if len(if_index) == 0:
print >> sys.stderr, "Can't find interface %s" % interface
sys.exit(1)
# from the given interface find unicast and broadcast addresses
if_info = ip.get_addr(index=if_index[0])[0]
address = if_info.get_attr("IFA_ADDRESS")
netmask = if_info["prefixlen"]
network = ipaddr.IPv4Network("%s/%d" % (address, netmask))
broadcast = str(network.broadcast)
# get hostname as additional information for the log file
hostname = socket.gethostname()
if not daemon:
signal.signal(signal.SIGTERM, signal_handler)
else:
daemonize()
# setup output file
if filename == "":
outfile = sys.stdout
else:
outfile = open(filename, "w")
if verbose:
print >> sys.stderr, "Host with IP %s listening for packets on " \
"broadcast IP %s" % (address, broadcast)
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.bind((broadcast, port))
run = True
while run:
try:
datagram = sock.recvfrom(1024)
payload = datagram[0].split(' ')
src = datagram[1][0]
src_port = datagram[1][1]
# check that this is really our app message
if payload[0] != "POPROWPING":
continue
count = int(payload[1])
remote_host = payload[2]
if verbose:
print >> sys.stderr, "Received packet #%d from %s:%d" % \
(count, src, src_port)
outfile.write("%s,%s,%s,%s,%d\n" % (hostname, address, remote_host,
src, count))
outfile.flush()
except SystemExit:
run = False
if verbose:
print >> sys.stderr, "Catching SystemExit. Quitting"
except KeyboardInterrupt:
run = False
if verbose:
print >> sys.stderr, "Keyboard Interrupt. Quitting"
except:
run = False
if verbose:
print >> sys.stderr, "Error while receiving packet. Quitting"
sock.close()
outfile.flush()
outfile.close()
class NetworkInterfaceConfig(object):
'''High-level abstraction of a network interface's configuration
NetworkInterfaceConfig is designed to abstract most of the pain of
work with (rt)netlink directly, and use pythonic methods for manipulating
network configuration. At a high level, this interface is protocol-neutral,
though only support for IPv4 and IPv6 has been added.
Each function call does sanity checks to try and prevent undefined behavior,
such as defining a link-local address by accident. For ease of use, this
interface does not use the kernel netlink bind() functionality, and instead
works in an async fashion. Manipulation of interfaces is rechecked at
the end of each function to make sure that the state changed properly, and
to make sure there wasn't some sort of silent failure.
A single IPRoute() socket is open per instance of this class for performance
reasons. This class is thread-safe.
'''
def __init__(self, interface):
'''Manipulations the configuration of a given interface
Args:
interface - name of the interface to manipulate (i.e. 'eth0')
Raises:
InvalidNetworkDevice - if the interface does not exist
'''
self.interface = interface
self.iproute_api = IPRoute()
# Confirm this is a valid interface
# This will chuck a IndexError exception if it doesn't exist
self.interface_index = self._get_interface_index()
def __del__(self):
self.iproute_api.close()
def _get_interface_index(self):
'''Private API to get the interface index number
Raises:
InvalidNetworkDevice - if an interface isn't found by pyroute2
'''
try:
idx = self.iproute_api.link_lookup(ifname=self.interface)[0]
except IndexError:
# IndexError means the interface wasn't found. Send a cleaner message up the pipe
raise InvalidNetworkDevice("Interface not found")
return idx
def get_ips(self):
'''Returns all a list IPs for a given interface. None if no IPs are configures
IPs are returned in a list of dictionaries for easy enumeration.
Keys that are always available:
ip_address - assigned address
family - protocol family of the returned IP. Either AF_INET, or AF_INET6
prefix_length - Length of the network prefix assigned to this interface
This is the CIDR representation of the netmask.
if family == AF_INET
broadcast - broadcast address for an interface
'''
# I'd like to use label= here, but IPv6 information is not returned
# when doing so. Possibly a bug in pyroute2
ip_cfgs = self.iproute_api.get_addr(index=self.interface_index)
# get_addr returns IPs in a nasty to praise format. We need to look at the attrs
# section of each item we get, and find IFA_ADDRESS, and check the second element
# of the tuple to get the IP address
# Here's an example of what we're praising
#
# [{'attrs': [['IFA_ADDRESS', '10.0.241.123'],
# ['IFA_LOCAL', '10.0.241.123'],
# ['IFA_BROADCAST', '10.0.241.255'],
# ['IFA_LABEL', 'dummy0'],
# ['IFA_CACHEINFO',
# {'cstamp': 181814615,
# 'ifa_prefered': 4294967295,
# 'ifa_valid': 4294967295,
# 'tstamp': 181814615}]],
# 'event': 'RTM_NEWADDR',
# 'family': 2,
# 'flags': 128,
# 'header': {'error': None,
# 'flags': 2,
# 'length': 80,
# 'pid': 4294395048,
# 'sequence_number': 255,
# 'type': 20},
# 'index': 121,
# 'prefixlen': 24,
# 'scope': 0}]'''
# Walk the list
ips = []
for ip_cfg in ip_cfgs:
ip_address = None
family = None
broadcast = None
prefixlen = None
ip_attrs = ip_cfg['attrs']
for attribute in ip_attrs:
if attribute[0] == "IFA_ADDRESS":
ip_address = attribute[1]
if attribute[0] == "IFA_BROADCAST":
broadcast = attribute[1]
prefixlen = ip_cfg['prefixlen']
family = ip_cfg['family'] # 2 for AF_INET, 10 for AF_INET6
# Build IP dictionary
ip_dict = {'ip_address': ip_address,
'prefix_length': prefixlen,
'family' : family}
# Handle v4-only information
if broadcast:
ip_dict['broadcast'] = broadcast
# Push it onto the list to be returned
ips.append(ip_dict)
# And break!
return ips
def get_full_ip_info(self, wanted_address):
'''Returns an ip_dict for an individual IP address. Format identical to get_ips()
Args:
wanted_address - a valid v4 or v6 address to search for. Value is normalized
by ipaddress.ip_address when returning
Raises:
ValueError - wanted_address is not a valid IP address
IPNotFound - this interface doesn't have this IP address
'''
wanted_address = check.validate_and_normalize_ip(wanted_address)
ips = self.get_ips()
# Walk the IP table and find the specific IP we want
for ip_address in ips:
if ip_address['ip_address'] == wanted_address:
return ip_address
# If we get here, the IP wasn't found
raise IPNotFound("IP not found on interface")
def add_v4_ip(self, ip_address, prefix_length):
'''Wrapper for add_ip - adds an IPv4 address to this interface
Args:
ip_address = IPv4 address to add
prefix_length - Network prefix size; netmask and broadcast addresses
Raises: - see add_ip()
'''
ip_dict = {'ip_address': ip_address,
'family': AF_INET,
'prefix_length': prefix_length}
self.add_ip(ip_dict)
def add_v6_ip(self, ip_address, prefix_length):
'''Wrapper for add_ip - adds an IPv6 address to this interface
Args:
ip_address - IPv6 address to add
prefix_length - Network prefix size; netmask and broadcast addresses
Raises: - see add_ip()
'''
ip_dict = {'ip_address': ip_address,
'family': AF_INET6,
'prefix_length': prefix_length}
self.add_ip(ip_dict)
def add_ip(self, ip_dict):
'''Adds an IP to an interface. Lower-level function to add an IP address
Args:
ip_dict - takes an IP dictionary (see get_ips) and adds it to an interface
directorly
Raises:
ValueError
IP address invalid. See message for more info
DuplicateIPError
This IP is already configured
InterfaceConfigurationError
The ip_dict was valid, but the IP failed add
'''
check.validate_and_normalize_ip_dict(ip_dict)
# Throw an error if we try to add an existing address.
existing_ip_check = None
try:
existing_ip_check = self.get_full_ip_info(ip_dict['ip_address'])
except IPNotFound:
pass
if existing_ip_check:
raise DuplicateIPError("This IP has already been assigned!")
# We call add slightly differently based on socket family
if ip_dict['family'] == AF_INET:
self.iproute_api.addr('add',
index=self.interface_index,
family=AF_INET,
address=ip_dict['ip_address'],
broadcast=ip_dict['broadcast'],
prefixlen=ip_dict['prefix_length'])
if ip_dict['family'] == AF_INET6:
self.iproute_api.addr('add',
index=self.interface_index,
family=AF_INET6,
address=ip_dict['ip_address'],
prefixlen=ip_dict['prefix_length'])
# Do a sanity check and make sure the IP actually got added
ip_check = self.get_full_ip_info(ip_dict['ip_address'])
if not (ip_check['ip_address'] == ip_dict['ip_address'] and
ip_check['prefix_length'] == ip_dict['prefix_length']):
raise InterfaceConfigurationError("IP failed to add!")
def remove_ip(self, ip_address):
'''Removes an IP from an interface. Full details are looked up via
get_full_ip_info for removal
Args:
ip_address - IP address to remove
Raises:
ValueError
The IP address provided was invalid
IPNotFound
The IP is not configured on this interface
InterfaceConfigurationError
The IP address was valid, but the IP was not successfully removed
'''
# San check
ip_address = check.validate_and_normalize_ip(ip_address)
# Get the full set of IP information
ip_info = self.get_full_ip_info(ip_address)
# Attempt to delete
if ip_info['family'] == AF_INET:
self.iproute_api.addr('delete',
index=self.interface_index,
address=ip_info['ip_address'],
broadcast=ip_info['broadcast'],
prefixlen=ip_info['prefix_length'])
if ip_info['family'] == AF_INET6:
self.iproute_api.addr('delete',
index=self.interface_index,
address=ip_info['ip_address'],
prefixlen=ip_info['prefix_length'])
# Confirm the delete. get_full_ip_info will throw an exception if it can't find it
try:
self.get_full_ip_info(ip_address)
except IPNotFound:
# We got it!
return
# Didn't get it. Throw an exception and bail
raise InterfaceConfigurationError("IP deletion failure")
def add_default_gateway(self, gateway, prefix_length):
'''Adds a default gateway for a given prefix length'''
raise NotImplementedError
def add_static_route(self, source, destination):
'''Sets a static route for an interface'''
raise NotImplementedError
def add_route(self, route_info):
'''Adds a route for a given interface'''
raise NotImplementedError
def remove_route(self, route_info):
'''Removes a route from an interface'''
raise NotImplementedError
def get_routes(self):
'''Gets routes for an interface'''
# The only way to get routes for an interface is to pull the entire routing table, and
# filter entries for this interface. Miserable interfaces are miserable. Furthermore,
# I can only get the v4 and v6 routes as a separate transaction
# In theory, we can apply a filter to returned routes, but I can't figure out if
# we can exclude things like cache entries, so we'll just grab stuff on a per family
# level, and filter for ourselves
# Pull the v4 and v6 global routing table
v4_routing_table = self.iproute_api.get_routes(family=AF_INET)
v6_routing_table = self.iproute_api.get_routes(family=AF_INET6)
kernel_routing_table = self._filter_routing_table(v4_routing_table + v6_routing_table)
# _filter_routing_table got rid of most of the junk we don't care about
# so now we need to walk the table and make it something far similar to
# praise without ripping our hair out. We also filter out link-local
# addresses in this step because we need the full prefix to know if its
# a link-local network
routing_table = []
for route in kernel_routing_table:
route_dict = {}
# Let's get the easy stuff first
for attribute in route['attrs']:
if attribute[0] == 'RTA_PREFSRC':
route_dict['source'] = attribute[1]
if attribute[0] == 'RTA_DST':
route_dict['destination'] = attribute[1]
if attribute[0] == 'RTA_GATEWAY':
route_dict['gateway'] = attribute[1]
# Family is mapped straight through so AF_INET and AF_INET6 just match
route_dict['family'] = route['family']
# Attach prefixes if they're non-zero
if route['src_len'] != 0 and 'source' in route_dict:
route_dict['source'] += ("/%s" % route['src_len'])
if route['dst_len'] != 0 and 'destination' in route_dict:
route_dict['destination'] += ("/%s" % route['dst_len'])
# Check for link-local here
if ipaddress.ip_network(route_dict['destination']).is_link_local:
continue # skip the route
if route['dst_len'] != 0 and 'gateway' in route_dict:
route_dict['gateway'] += ("/%s" % route['dst_len'])
# Map the protocol to something human-readable
route_dict['protocol'] = map_protocol_number_to_string(route['proto'])
route_dict['type'] = determine_route_type(route_dict)
routing_table.append(route_dict)
return routing_table
def determine_if_route_exists(self):
'''Checks if a route exists'''
raise NotImplementedError
def validate_route_dict(self):
'''Validates a routing information dict'''
raise NotImplementedError
def _filter_routing_table(self, routing_table):
'''Internal API. Takes output of get_routes, and filters down to what we care about'''
# For every configured IP address, a couple of automatic routes are
# generated that we're not interested in.
#
# Understanding this code requires an understanding of how the Linux kernel
# handles routing and routing tables. For each interface, the kernel has a possible
# 255 tables to hold routes. These exist to allow for specific routing rules and
# preferences as the system goes from table 255->1 in determining which route
# will be used.
#
# On a default configuration, only three routing tables are defined:
# 255 - local
# 254 - main
# 253 - default
#
# Table names are controlled in /etc/iproutes.d/rt_tables
#
# The local table is special as it can only be added to by the kernel, and removing
# entries from it is explicitly done "at your own risk". It defines which IPs this
# machine owns so any attempt to communicate on it comes back to itself. As such
# we can simply filter out 255 to make our lives considerably easier
#
# Unfortunately, filtering 255 doesn't get rid of all the "line noise" so to speak.
#
# From this point forward, I've had to work from kernel source, and the source of
# iproute2 to understand what's going on from netlayer. But basically, here's the
# rundown of what we need to do
#
# Case 1 - Cached Entries
# This is a surprising complicated case. Cached entries are used by the kernel for
# automatically configured routes. I haven't seen the kernel v4 table populated, but
# that may just be because of my local usage
#
# IPv6 is a different story. Routing information for IPv6 can come in the form of
# routing announcements, static configuration, and so forth. It seems all IPv6 info is
# is marked as a cached entry. This is made more complicated that the kernel stores
# various IPv6 routing information in the table for "random" hosts accessed. For example.
# on my home system ...
#
# mcasadevall@perdition:~/workspace/mcdynipd$ route -6 -C
# Kernel IPv6 routing cache
# Destination Next Hop Flag Met Ref Use If
# 2001:4860:4860::8888/128 fe80::4216:7eff:fe6c:492 UGDAC 0 0 47 eth0
# 2607:f8b0:4001:c09::bc/128 fe80::4216:7eff:fe6c:492 UGDAC 0 1 17 eth0
# 2607:f8b0:4004:808::1013/128 fe80::4216:7eff:fe6c:492 UGDAC 0 1 21 eth0
# 2607:f8b0:4009:805::1005/128 fe80::4216:7eff:fe6c:492 UGDAC 0 0 3 eth0
# 2607:f8b0:4009:80a::200e/128 fe80::4216:7eff:fe6c:492 UGDAC 0 0 85 eth0
# 2607:f8b0:400d:c04::bd/128 fe80::4216:7eff:fe6c:492 UGDAC 0 1 76 eth0
#
# 2607:f8b0::/32 is owned by Google, and these were connections my system made to Google
# systems. Looking at my router (which runs a 6to4 HE tunnel), it appears 6to4 is handled
# via static routing and should show up sans CACHEINFO (untested - needs confirmation).
#
# Digging into iproute2, the proto field defines what defined a route. Here's the list
# defined in the source
#
# ----------------------------------------------------------------------------
# #define RTPROT_UNSPEC 0
# #define RTPROT_REDIRECT 1 /* Route installed by ICMP redirects;
# not used by current IPv4 */
# #define RTPROT_KERNEL 2 /* Route installed by kernel */
# #define RTPROT_BOOT 3 /* Route installed during boot */
# #define RTPROT_STATIC 4 /* Route installed by administrator */
#
# /* Values of protocol >= RTPROT_STATIC are not interpreted by kernel;
# they are just passed from user and back as is.
# It will be used by hypothetical multiple routing daemons.
# Note that protocol values should be standardized in order to
# avoid conflicts.
# */
#
# #define RTPROT_GATED 8 /* Apparently, GateD */
# #define RTPROT_RA 9 /* RDISC/ND router advertisements */
# #define RTPROT_MRT 10 /* Merit MRT */
# #define RTPROT_ZEBRA 11 /* Zebra */
# #define RTPROT_BIRD 12 /* BIRD */
# #define RTPROT_DNROUTED 13 /* DECnet routing daemon */
# #define RTPROT_XORP 14 /* XORP */
# #define RTPROT_NTK 15 /* Netsukuku */
# #define RTPROT_DHCP 16 /* DHCP client */
# #define RTPROT_MROUTED 17 /* Multicast daemon */
# ----------------------------------------------------------------------------
#
# Looking at the behavior of the kernel, if a given prefix has a route, it will
# place a proto 2 entry for it with no routing address. Cached table entries
# exist to the next point:
#
# 2001:4860:4860::8888/128 fe80::4216:7eff:fe6c:492 UGDAC 0 0 47 eth0
#
# (this shows up as proto 9 in the routing table)
#
# To get the default route of a device in IPv6, we need entries that ONLY have RTA_GATEWAY
# and not RTA_DEST, regardless of protocol. Otherwise, we filter out proto 9. This gets
# output identical to route aside from the multicast address (ff00::/8)
#
# As a final note to this saga, after I coded this, I found rtnetlink is documented on
# Linux systems. Run man 7 rtnetlink to save yourself a source dive :(
filtered_table = []
non_cached_table = []
# Pass 1. Exclude table 255, and any entries that have RTA_CACHEINFO
for route in routing_table:
# If this is a 255 entry, ignore it, we don't care
if route['table'] == 255:
continue
# Now the table cache
cached_entry = False
destination_address = None
gateway_address = None
routing_attributes = route['attrs']
for attribute in routing_attributes:
if attribute[0] == 'RTA_CACHEINFO':
cached_entry = True
if attribute[0] == 'RTA_DST':
destination_address = attribute[1]
if attribute[0] == 'RTA_GATEWAY':
gateway_address = attribute[1]
# If its not a cached entry, always keep it
if not cached_entry:
non_cached_table.append(route)
continue
# Keep it if proto != 9
if route['proto'] != 9:
non_cached_table.append(route)
continue
# If it only has DST or GATEWAY, its a default route, keep it
if ((gateway_address and not destination_address) or
(destination_address and not gateway_address)):
non_cached_table.append(route)
continue
for route in non_cached_table:
# Like IP addresses, most of the route information is stored
# in attributes. RTA_OIF (OIF = Outbound Interface), contains
# the index number of the interface this route is assigned to
routing_attributes = route['attrs']
for attribute in routing_attributes:
if attribute[0] == 'RTA_OIF' and attribute[1] == self.interface_index:
filtered_table.append(route)
# filtered_table should just contain our OIFs, pass this back up for
# processing
return filtered_table