linuxlizard / pyroute2

Python Netlink and PF_ROUTE library — network setup and monitoring

Pyroute2

Pyroute2 is a pure Python netlink library. It 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: ipset, nftables, ...
• ipq --- simplest userspace packet filtering, iptables QUEUE target
• devlink --- manage and monitor devlink-enabled hardware
• generic --- generic netlink families
  • 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

Starting with 0.5.2 the library supports also PF_ROUTE sockets on BSD systems.

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.

The simplest usecase

The objects, provided by the library, are 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

Maybe the simplest usecase is to monitor events. Disk quota events::

from pyroute2 import DQuotSocket
# DQuotSocket automatically performs discovery and binding,
# since it has no other functionality beside of the monitoring
with DQuotSocket() as ds:
    for message in ds.get():
        print(message)

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)

RTNetlink examples

More samples you can read in the project documentation.

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.

Some examples::

from socket import AF_INET
from pyroute2 import IPRoute

# get access to the netlink socket
ip = IPRoute()

# no monitoring here -- thus no bind()

# print interfaces
print(ip.get_links())

# create VETH pair and move v0p1 to netns 'test'
ip.link('add', ifname='v0p0', peer='v0p1', kind='veth')
idx = ip.link_lookup(ifname='v0p1')[0]
ip.link('set',
        index=idx,
        net_ns_fd='test')

# bring v0p0 up and add an address
idx = ip.link_lookup(ifname='v0p0')[0]
ip.link('set',
        index=idx,
        state='up')
ip.addr('add',
        index=idx,
        address='10.0.0.1',
        broadcast='10.0.0.255',
        prefixlen=24)

# create a route with metrics
ip.route('add',
         dst='172.16.0.0/24',
         gateway='10.0.0.10',
         metrics={'mtu': 1400,
                  'hoplimit': 16})

# create MPLS lwtunnel
# $ sudo modprobe mpls_iptunnel
ip.route('add',
         dst='172.16.0.0/24',
         oif=idx,
         encap={'type': 'mpls',
                'labels': '200/300'})

# create MPLS route: push label
# $ sudo modprobe mpls_router
# $ sudo sysctl net.mpls.platform_labels=1024
ip.route('add',
         family=AF_MPLS,
         oif=idx,
         dst=0x200,
         newdst=[0x200, 0x300])

# create SEG6 tunnel encap mode
# Kernel >= 4.10
ip.route('add',
         dst='2001:0:0:10::2/128',
         oif=idx,
         encap={'type': 'seg6',
                'mode': 'encap',
                'segs': '2000::5,2000::6'})

# create SEG6 tunnel inline mode
# Kernel >= 4.10
ip.route('add',
         dst='2001:0:0:10::2/128',
         oif=idx,
         encap={'type': 'seg6',
                'mode': 'inline',
                'segs': ['2000::5', '2000::6']})

# create SEG6 tunnel with ip4ip6 encapsulation
# Kernel >= 4.14
ip.route('add',
         dst='172.16.0.0/24',
         oif=idx,
         encap={'type': 'seg6',
                'mode': 'encap',
                'segs': '2000::5,2000::6'})


# release Netlink socket
ip.close()

The project contains several modules for different types of netlink messages, not only RTNL.

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')

    # lookup the peer index
    idx = ipr.link_lookup(ifname='v0p1')[0]

    # move the peer to the 'test' netns:
    ipr.link('set',
             index='v0p1',
             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

make install or pip install pyroute2

Requirements

Python >= 2.7

The pyroute2 testing framework requirements:

• flake8
• coverage
• nosetests
• sphinx
• netaddr

Optional dependencies for testing:

• eventlet
• mitogen
• bottle
• team (http://libteam.org/)

Links

• home: https://pyroute2.org/
• srcs: https://github.com/svinota/pyroute2
• bugs: https://github.com/svinota/pyroute2/issues
• pypi: https://pypi.python.org/pypi/pyroute2
• docs: http://docs.pyroute2.org/
• list: https://groups.google.com/d/forum/pyroute2-dev