IPRoute module

iproute quickstart

IPRoute in two words:

$ sudo pip install pyroute2

$ cat example.py
from pyroute2 import IPRoute
ip = IPRoute()
print([x.get_attr('IFLA_IFNAME') for x in ip.get_links()])

$ python example.py
['lo', 'p6p1', 'wlan0', 'virbr0', 'virbr0-nic']

threaded vs. threadless architecture

Since v0.3.2, IPRoute class is threadless by default. It spawns no additional threads, and receives only responses to own requests, no broadcast messages. So, if you prefer not to cope with implicit threading, you can safely use this module.

To get broadcast messages, use IPRoute.bind() call. Please notice, that after calling IPRoute.bind() you MUST get all the messages in time. In the case of the kernel buffer overflow, you will have to restart the socket.

With IPRoute.bind(async=True) one can launch async message receiver thread with Queue-based buffer. The buffer is thread-safe and completely transparent from the programmer’s perspective. Please read also NetlinkSocket documentation to know more about async mode.

think about IPDB

If you plan to regularly fetch loads of objects, think about IPDB also. Unlike to IPRoute, IPDB does not fetch all the objects from OS every time you request them, but keeps a cache that is asynchronously updated by the netlink broadcasts. For a long-term running programs, that often retrieve info about hundreds or thousands of objects, it can be better to use IPDB as it will load CPU significantly less.

classes

class pyroute2.iproute.IPRoute(fileno=None)

Production class that provides iproute API over normal Netlink socket.

You can think of this class in some way as of plain old iproute2 utility.

class pyroute2.iproute.IPRouteMixin

IPRouteMixin should not be instantiated by itself. It is intended to be used as a mixin class that provides iproute2-like API. You should use IPRoute or NetNS classes.

All following info you can consider as IPRoute info as well.

It is an old-school API, that provides access to rtnetlink as is. It helps you to retrieve and change almost all the data, available through rtnetlink:

from pyroute2 import IPRoute
ipr = IPRoute()
    # lookup interface by name
dev = ipr.link_lookup(ifname='tap0')[0]
    # bring it down
ipr.link('set', dev, state='down')
    # change interface MAC address and rename it
ipr.link('set', dev, address='00:11:22:33:44:55', ifname='vpn')
    # add primary IP address
ipr.addr('add', dev, address='10.0.0.1', mask=24)
    # add secondary IP address
ipr.addr('add', dev, address='10.0.0.2', mask=24)
    # bring it up
ipr.link('set', dev, state='up')
addr(command, index, address, mask=24, family=None, scope=0, **kwarg)

Address operations

  • command – add, delete
  • index – device index
  • address – IPv4 or IPv6 address
  • mask – address mask
  • family – socket.AF_INET for IPv4 or socket.AF_INET6 for IPv6
  • scope – the address scope, see /etc/iproute2/rt_scopes

Example:

index = 62
ip.addr("add", index, address="10.0.0.1", mask=24)
ip.addr("add", index, address="10.0.0.2", mask=24)
flush_routes(*argv, **kwarg)

Flush routes – purge route records from a table. Arguments are the same as for get_routes() routine. Actually, this routine implements a pipe from get_routes() to nlm_request().

get_addr(family=0, index=None)

Get addresses:: ip.get_addr() # get all addresses ip.get_addr(index=2) # get addresses for the 2nd interface

get_classes(index=0)

Get classes for specified interface.

get_default_routes(family=0, table=254)

Get default routes

get_filters(index=0, handle=0, parent=0)

Get filters for specified interface, handle and parent.

Get network interfaces.

By default returns all interfaces. Arguments vector can contain interface indices or a special keyword ‘all’:

ip.get_links()
ip.get_links('all')
ip.get_links(1, 2, 3)

interfaces = [1, 2, 3]
ip.get_links(*interfaces)
get_neighbors(family=0)

Retrieve ARP cache records.

get_qdiscs(index=None)

Get all queue disciplines for all interfaces or for specified one.

get_routes(family=2, **kwarg)

Get all routes. You can specify the table. There are 255 routing classes (tables), and the kernel returns all the routes on each request. So the routine filters routes from full output.

Example:

ip.get_routes()  # get all the routes for all families
ip.get_routes(family=AF_INET6)  # get only IPv6 routes
ip.get_routes(table=254)  # get routes from 254 table
get_rules(family=0)

Get all rules. You can specify inet family, by default return rules for all families.

Example::
ip.get_rules() # get all the rules for all families ip.get_routes(family=AF_INET6) # get only IPv6 rules

Link operations.

  • command – set, add or delete
  • index – device index
  • **kwarg – keywords, NLA

Example:

x = 62  # interface index
ip.link("set", index=x, state="down")
ip.link("set", index=x, address="00:11:22:33:44:55", name="bala")
ip.link("set", index=x, mtu=1000, txqlen=2000)
ip.link("set", index=x, state="up")

Keywords “state”, “flags” and “mask” are reserved. State can be “up” or “down”, it is a shortcut:

state="up":   flags=1, mask=1
state="down": flags=0, mask=0

For more flags grep IFF in the kernel code, until we write human-readable flag resolver.

Other keywords are from ifinfmsg.nla_map, look into the corresponding module. You can use the form “ifname” as well as “IFLA_IFNAME” and so on, so that’s equal:

ip.link("set", index=x, mtu=1000)
ip.link("set", index=x, IFLA_MTU=1000)

You can also delete interface with:

ip.link("delete", index=x)

Create a link. The method parameters will be passed to the IPLinkRequest() constructor as a dictionary.

Examples:

ip.link_create(ifname='very_dummy', kind='dummy')
ip.link_create(ifname='br0', kind='bridge')
ip.link_create(ifname='v101', kind='vlan', vlan_id=101, link=1)

Switch an interface down unconditilnally.

Lookup interface index (indeces) by first level NLA value.

Example:

ip.link_lookup(address="52:54:00:9d:4e:3d")
ip.link_lookup(ifname="lo")
ip.link_lookup(operstate="UP")

Please note, that link_lookup() returns list, not one value.

Remove an interface

Rename an interface. Please note, that the interface must be in the DOWN state in order to be renamed, otherwise you will get an error.

Switch an interface up unconditionally.

route(command, rtype='RTN_UNICAST', rtproto='RTPROT_STATIC', rtscope='RT_SCOPE_UNIVERSE', **kwarg)

Route operations

  • command – add, delete, change, replace
  • prefix – route prefix
  • mask – route prefix mask
  • rtype – route type (default: “RTN_UNICAST”)
  • rtproto – routing protocol (default: “RTPROT_STATIC”)
  • rtscope – routing scope (default: “RT_SCOPE_UNIVERSE”)
  • family – socket.AF_INET (default) or socket.AF_INET6

pyroute2/netlink/rtnl/rtmsg.py rtmsg.nla_map:

  • table – routing table to use (default: 254)
  • gateway – via address
  • prefsrc – preferred source IP address
  • dst – the same as prefix
  • src – source address
  • iif – incoming traffic interface
  • oif – outgoing traffic interface

etc.

Example:

ip.route("add", dst="10.0.0.0", mask=24, gateway="192.168.0.1")

Commands change and replace have the same meanings, as in ip-route(8): change modifies only existing route, while replace creates a new one, if there is no such route yet.

rule(command, table, priority=32000, action='FR_ACT_NOP', family=2, src=None, src_len=None, dst=None, dst_len=None, fwmark=None, iifname=None, oifname=None)

Rule operations

  • command — add, delete

  • table — 0 < table id < 253

  • priority — 0 < rule’s priority < 32766

  • action — type of rule, default ‘FR_ACT_NOP’ (see fibmsg.py)

  • rtscope — routing scope, default RT_SCOPE_UNIVERSE

    (RT_SCOPE_UNIVERSE|RT_SCOPE_SITE| RT_SCOPE_LINK|RT_SCOPE_HOST|RT_SCOPE_NOWHERE)

  • family — rule’s family (socket.AF_INET (default) or

    socket.AF_INET6)

  • src — IP source for Source Based (Policy Based) routing’s rule

  • dst — IP for Destination Based (Policy Based) routing’s rule

  • src_len — Mask for Source Based (Policy Based) routing’s rule

  • dst_len — Mask for Destination Based (Policy Based) routing’s

    rule

  • iifname — Input interface for Interface Based (Policy Based)

    routing’s rule

  • oifname — Output interface for Interface Based (Policy Based)

    routing’s rule

Example::
ip.rule(‘add’, 10, 32000)
Will create::
#ip ru sh ... 32000: from all lookup 10 ....
Example::
iproute.rule(‘add’, 11, 32001, ‘FR_ACT_UNREACHABLE’)
Will create::
#ip ru sh ... 32001: from all lookup 11 unreachable ....
Example::
iproute.rule(‘add’, 14, 32004, src=‘10.64.75.141’)
Will create::
#ip ru sh ... 32004: from 10.64.75.141 lookup 14 ...
Example::
iproute.rule(‘add’, 15, 32005, dst=‘10.64.75.141’, dst_len=24)
Will create::
#ip ru sh ... 32005: from 10.64.75.141/24 lookup 15 ...
Example::
iproute.rule(‘add’, 15, 32006, dst=‘10.64.75.141’, fwmark=10)
Will create::
#ip ru sh ... 32006: from 10.64.75.141 fwmark 0xa lookup 15 ...
tc(command, kind, index, handle=0, **kwarg)

“Swiss knife” for traffic control. With the method you can add, delete or modify qdiscs, classes and filters.

  • command – add or delete qdisc, class, filter.
  • kind – a string identifier – “sfq”, “htb”, “u32” and so on.
  • handle – integer or string

Command can be one of (“add”, “del”, “add-class”, “del-class”, “add-filter”, “del-filter”) (see commands dict in the code).

Handle notice: traditional iproute2 notation, like “1:0”, actually represents two parts in one four-bytes integer:

1:0    ->    0x10000
1:1    ->    0x10001
ff:0   ->   0xff0000
ffff:1 -> 0xffff0001

For pyroute2 tc() you can use both forms: integer like 0xffff0000 or string like ‘ffff:0000’. By default, handle is 0, so you can add simple classless queues w/o need to specify handle. Ingress queue causes handle to be 0xffff0000.

So, to set up sfq queue on interface 1, the function call will be like that:

ip = IPRoute()
ip.tc("add", "sfq", 1)

Instead of string commands (“add”, “del”...), you can use also module constants, RTM_NEWQDISC, RTM_DELQDISC and so on:

ip = IPRoute()
ip.tc(RTM_NEWQDISC, "sfq", 1)

More complex example with htb qdisc, lets assume eth0 == 2:

#          u32 -->    +--> htb 1:10 --> sfq 10:0
#          |          |
#          |          |
# eth0 -- htb 1:0 -- htb 1:1
#          |          |
#          |          |
#          u32 -->    +--> htb 1:20 --> sfq 20:0

eth0 = 2
# add root queue 1:0
ip.tc("add", "htb", eth0, 0x10000, default=0x200000)

# root class 1:1
ip.tc("add-class", "htb", eth0, 0x10001,
      parent=0x10000,
      rate="256kbit",
      burst=1024 * 6)

# two branches: 1:10 and 1:20
ip.tc("add-class", "htb", eth0, 0x10010,
      parent=0x10001,
      rate="192kbit",
      burst=1024 * 6,
      prio=1)
ip.tc("add-class", "htb", eht0, 0x10020,
      parent=0x10001,
      rate="128kbit",
      burst=1024 * 6,
      prio=2)

# two leaves: 10:0 and 20:0
ip.tc("add", "sfq", eth0, 0x100000,
      parent=0x10010,
      perturb=10)
ip.tc("add", "sfq", eth0, 0x200000,
      parent=0x10020,
      perturb=10)

# two filters: one to load packets into 1:10 and the
# second to 1:20
ip.tc("add-filter", "u32", eth0,
      parent=0x10000,
      prio=10,
      protocol=socket.AF_INET,
      target=0x10010,
      keys=["0x0006/0x00ff+8", "0x0000/0xffc0+2"])
ip.tc("add-filter", "u32", eth0,
      parent=0x10000,
      prio=10,
      protocol=socket.AF_INET,
      target=0x10020,
      keys=["0x5/0xf+0", "0x10/0xff+33"])

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