Family tcp_metrics netlink specification¶
Contents
Operations¶
get¶
Retrieve metrics.
- attribute-set
- dont-validate
[‘strict’, ‘dump’]
- do
- request
- attributes
[
addr-ipv4,addr-ipv6,saddr-ipv4,saddr-ipv6]
- reply
- attributes
[
addr-ipv4,addr-ipv6,saddr-ipv4,saddr-ipv6,age,vals,fopen-mss,fopen-syn-drops,fopen-syn-drop-ts,fopen-cookie]
- dump
- reply
- attributes
[
addr-ipv4,addr-ipv6,saddr-ipv4,saddr-ipv6,age,vals,fopen-mss,fopen-syn-drops,fopen-syn-drop-ts,fopen-cookie]
Definitions¶
tcp-fastopen-cookie-max¶
- type
const
- value
16
Attribute sets¶
tcp-metrics¶
addr-ipv4 (u32)¶
- byte-order
big-endian
- display-hint
ipv4
addr-ipv6 (binary)¶
- byte-order
big-endian
- display-hint
ipv6
age (u64)¶
tw-tsval (u32)¶
- doc
unused
tw-ts-stamp (s32)¶
- doc
unused
fopen-mss (u16)¶
fopen-syn-drops (u16)¶
fopen-syn-drop-ts (u64)¶
fopen-cookie (binary)¶
saddr-ipv4 (u32)¶
- byte-order
big-endian
- display-hint
ipv4
saddr-ipv6 (binary)¶
- byte-order
big-endian
- display-hint
ipv6
pad (pad)¶
metrics¶
Attributes with metrics. Note that the values here do not match the TCP_METRIC_* defines in the kernel, because kernel defines are off-by one (e.g. rtt is defined as enum 0, while netlink carries attribute type 1).
rtt (u32)¶
- doc
Round Trip Time (RTT), in msecs with 3 bits fractional (left-shift by 3 to get the msec value).
rttvar (u32)¶
- doc
Round Trip Time VARiance (RTT), in msecs with 2 bits fractional (left-shift by 2 to get the msec value).
ssthresh (u32)¶
- doc
Slow Start THRESHold.
cwnd (u32)¶
- doc
Congestion Window.
reodering (u32)¶
- doc
Reodering metric.
rtt-us (u32)¶
- doc
Round Trip Time (RTT), in usecs, with 3 bits fractional (left-shift by 3 to get the msec value).
rttvar-us (u32)¶
- doc
Round Trip Time (RTT), in usecs, with 2 bits fractional (left-shift by 3 to get the msec value).