Family rt-route netlink specification

Summary

Route configuration over rtnetlink.

Operations

getroute

Dump route information.

attribute-set:

route-attrs

do:

request

attributes:

[src, dst, iif, oif, ip-proto, sport, dport, mark, uid, flowlabel]

reply

attributes:

[dst, src, iif, oif, gateway, priority, prefsrc, metrics, multipath, flow, cacheinfo, table, mark, mfc-stats, via, newdst, pref, encap-type, encap, expires, pad, uid, ttl-propagate, ip-proto, sport, dport, nh-id, flowlabel, del-reason]

dump:

request

attributes:

[]

reply

attributes:

[dst, src, iif, oif, gateway, priority, prefsrc, metrics, multipath, flow, cacheinfo, table, mark, mfc-stats, via, newdst, pref, encap-type, encap, expires, pad, uid, ttl-propagate, ip-proto, sport, dport, nh-id, flowlabel, del-reason]

newroute

Create a new route

attribute-set:

route-attrs

do:

request

attributes:

[dst, src, iif, oif, gateway, priority, prefsrc, metrics, multipath, flow, cacheinfo, table, mark, mfc-stats, via, newdst, pref, encap-type, encap, expires, pad, uid, ttl-propagate, ip-proto, sport, dport, nh-id, flowlabel]

delroute

Delete an existing route

attribute-set:

route-attrs

do:

request

attributes:

[dst, src, iif, oif, gateway, priority, prefsrc, metrics, multipath, flow, cacheinfo, table, mark, mfc-stats, via, newdst, pref, encap-type, encap, expires, pad, uid, ttl-propagate, ip-proto, sport, dport, nh-id, flowlabel]

newroute-ntf

Notification about a created route.

value:

24

notify:

getroute

delroute-ntf

Notification about a deleted route.

value:

25

notify:

getroute

Multicast groups

• rtnlgrp-ipv4-route

• rtnlgrp-ipv6-route

Definitions

rtm-type

name-prefix:

rtn-

enum-name:

None

type:

enum

entries:

• unspec

• unicast

• local

• broadcast

• anycast

• multicast

• blackhole

• unreachable

• prohibit

• throw

• nat

• xresolve

rtmsg

type:

struct

members:

rtm-family (u8):

rtm-dst-len (u8):

rtm-src-len (u8):

rtm-tos (u8):

rtm-table (u8):

rtm-protocol (u8):

rtm-scope (u8):

rtm-type (u8):

rtm-flags (u32):

rta-cacheinfo

type:

struct

members:

rta-clntref (u32):

rta-lastuse (u32):

rta-expires (u32):

rta-error (u32):

rta-used (u32):

del-reason

type:

enum

name-prefix:

rt-del-reason-

enum-name:

rt-del-reason

doc:

Why the kernel deleted a route. New causes may be appended. The value space is family-agnostic, a value is never reinterpreted per address family.

entries:

unspec:

The deletion path does not record a cause.

expired:

The RTF_EXPIRES lifetime ran out and the route was garbage collected.

ra-withdrawn:

A Router Advertisement withdrew the route with a zero lifetime.

Attribute sets

route-attrs

dst (binary)

display-hint:

ipv4-or-v6

src (binary)

display-hint:

ipv4-or-v6

iif (u32)

oif (u32)

gateway (binary)

display-hint:

ipv4-or-v6

priority (u32)

prefsrc (binary)

display-hint:

ipv4-or-v6

metrics (nest)

nested-attributes:

metrics

multipath (binary)

protoinfo (binary)

flow (u32)

cacheinfo (binary)

struct:

rta-cacheinfo

session (binary)

mp-algo (binary)

table (u32)

mark (u32)

mfc-stats (binary)

via (binary)

newdst (binary)

pref (u8)

encap-type (u16)

encap (binary)

expires (u32)

pad (binary)

uid (u32)

ttl-propagate (u8)

ip-proto (u8)

sport (u16)

dport (u16)

nh-id (u32)

flowlabel (u32)

byte-order:

big-endian

display-hint:

hex

del-reason (u32)

enum:

del-reason

doc:

Emitted only on RTM_DELROUTE notifications, and only when the deletion path records a cause. An absent attribute means either an older kernel or a deletion path that does not record its cause, consumers must treat absent and unspec identically. Currently only IPv6 deletion paths record a cause. The attribute is notification-only, the kernel rejects it in requests.

metrics

unspec (unused)

value:

0

lock (u32)

mtu (u32)

window (u32)

rtt (u32)

rttvar (u32)

ssthresh (u32)

cwnd (u32)

advmss (u32)

reordering (u32)

hoplimit (u32)

initcwnd (u32)

features (u32)

rto-min (u32)

initrwnd (u32)

quickack (u32)

cc-algo (string)

fastopen-no-cookie (u32)