Python Netlink library


Keywords
bsd, freebsd, generic-netlink, genl, linux, namespace, netlink, netns, network, network-namespace, nfnetlink, nl80211, openbsd, python, rtnl, wireguard
Licenses
CNRI-Python-GPL-Compatible/Apache-2.0
Install
pip install pyroute2==0.5.6

Documentation

Pyroute2

Pyroute2 is a pure Python netlink library. The core requires only Python stdlib, no 3rd party libraries. The library was started as an RTNL protocol implementation, so the name is pyroute2, but now it supports many netlink protocols. Some supported netlink families and protocols:

  • rtnl, network settings --- addresses, routes, traffic controls
  • nfnetlink --- netfilter API
  • ipq --- simplest userspace packet filtering, iptables QUEUE target
  • devlink --- manage and monitor devlink-enabled hardware
  • generic --- generic netlink families
  • uevent --- same uevent messages as in udev

Netfilter API:

  • ipset --- IP sets
  • nftables --- packet filtering
  • nfct --- connection tracking

Generic netlink:

  • ethtool --- low-level network interface setup
  • wireguard --- VPN setup
  • nl80211 --- wireless functions API (basic support)
  • taskstats --- extended process statistics
  • acpi_events --- ACPI events monitoring
  • thermal_events --- thermal events monitoring
  • VFS_DQUOT --- disk quota events monitoring

On the low level the library provides socket objects with an extended API. The additional functionality aims to:

  • Help to open/bind netlink sockets
  • Discover generic netlink protocols and multicast groups
  • Construct, encode and decode netlink and PF_ROUTE messages

Supported systems

Pyroute2 runs natively on Linux and emulates some limited subset of RTNL netlink API on BSD systems on top of PF_ROUTE notifications and standard system tools.

Other platforms are not supported.

NDB -- high level RTNL API

Key features:

  • Data integrity
  • Transactions with commit/rollback changes
  • State synchronization
  • Multiple sources, including netns and remote systems

A "Hello world" example:

from pyroute2 import NDB

with NDB() as ndb:
    with ndb.interfaces['eth0'] as eth0:
        # set one parameter
        eth0.set(state='down')
        eth0.commit()  # make sure that the interface is down
        # or multiple parameters at once
        eth0.set(ifname='hello_world!', state='up')
        eth0.commit()  # rename, bring up and wait for success
    # --> <-- here you can be sure that the interface is up & renamed

More examples:

from pyroute2 import NDB

ndb = NDB(log='debug')

for record in ndb.interfaces.summary():
    print(record.ifname, record.address, record.state)

if_dump = ndb.interfaces.dump()
if_dump.select_records(state='up')
if_dump.select_fields('index', 'ifname', 'kind')
for line in if_dump.format('json'):
    print(line)

addr_summary = ndb.addresses.summary()
addr_summary.select_records(ifname='eth0')
for line in addr_summary.format('csv'):
    print(line)

with ndb.interfaces.create(ifname='br0', kind='bridge') as br0:
    br0.add_port('eth0')
    br0.add_port('eth1')
    br0.add_ip('10.0.0.1/24')
    br0.add_ip('192.168.0.1/24')
    br0.set(
        br_stp_state=1,  # set STP on
        br_group_fwd_mask=0x4000,  # set LLDP forwarding
        state='up',  # bring the interface up
    )
# --> <-- commit() will be run by the context manager

# operate on netns:
ndb.sources.add(netns='testns')  # connect to a namespace

with (
    ndb.interfaces.create(
        ifname='veth0',  # create veth
        kind='veth',
        peer={
            'ifname': 'eth0',  # setup peer
            'net_ns_fd': 'testns',  # in a namespace
        },
        state='up',
    )
) as veth0:
    veth0.add_ip(address='172.16.230.1', prefixlen=24)

with ndb.interfaces.wait(
    target='testns', ifname='eth0'
) as peer:  # wait for the peer
    peer.set(state='up')  # bring it up
    peer.add_ip('172.16.230.2/24')  # add address

IPRoute -- Low level RTNL API

Low-level IPRoute utility --- Linux network configuration. The IPRoute class is a 1-to-1 RTNL mapping. There are no implicit interface lookups and so on.

Get notifications about network settings changes with IPRoute:

from pyroute2 import IPRoute
with IPRoute() as ipr:
    # With IPRoute objects you have to call bind() manually
    ipr.bind()
    for message in ipr.get():
        print(message)

More examples:

from socket import AF_INET
from pyroute2 import IPRoute

# get access to the netlink socket
ipr = IPRoute()
# no monitoring here -- thus no bind()

# print interfaces
for link in ipr.get_links():
    print(link)

# create VETH pair and move v0p1 to netns 'test'
ipr.link('add', ifname='v0p0', peer='v0p1', kind='veth')
# wait for the devices:
peer, veth = ipr.poll(
    ipr.link, 'dump', timeout=5, ifname=lambda x: x in ('v0p0', 'v0p1')
)
ipr.link('set', index=peer['index'], net_ns_fd='test')

# bring v0p0 up and add an address
ipr.link('set', index=veth['index'], state='up')
ipr.addr('add', index=veth['index'], address='10.0.0.1', prefixlen=24)

# release Netlink socket
ip.close()

Network namespace examples

Network namespace manipulation:

from pyroute2 import netns
# create netns
netns.create('test')
# list
print(netns.listnetns())
# remove netns
netns.remove('test')

Create veth interfaces pair and move to netns:

from pyroute2 import IPRoute

with IPRoute() as ipr:

    # create interface pair
    ipr.link('add', ifname='v0p0', kind='veth',  peer='v0p1')

    # wait for the peer
    (peer,) = ipr.poll(ipr.link, 'dump', timeout=5, ifname='v0p1')

    # move the peer to the 'test' netns:
    ipr.link('set', index=peer['index'], net_ns_fd='test')

List interfaces in some netns:

from pyroute2 import NetNS
from pprint import pprint

ns = NetNS('test')
pprint(ns.get_links())
ns.close()

More details and samples see in the documentation.

Installation

Using pypi:

pip install pyroute2

Using git:

pip install git+https://github.com/svinota/pyroute2.git

Using source, requires make and nox

git clone https://github.com/svinota/pyroute2.git
cd pyroute2
make install

Requirements

Python >= 3.6

Links