From 9b8a97db9ec4b795e29e72289005fbc58484ebeb Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Tue, 9 Apr 2024 15:14:35 +0200 Subject: Adding upstream version 6.8.0. Signed-off-by: Daniel Baumann --- man/man8/tc-sample.8 | 122 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 122 insertions(+) create mode 100644 man/man8/tc-sample.8 (limited to 'man/man8/tc-sample.8') diff --git a/man/man8/tc-sample.8 b/man/man8/tc-sample.8 new file mode 100644 index 0000000..44fc262 --- /dev/null +++ b/man/man8/tc-sample.8 @@ -0,0 +1,122 @@ +.TH "Packet sample action in tc" 8 "31 Jan 2017" "iproute2" "Linux" + +.SH NAME +sample - packet sampling tc action +.SH SYNOPSIS +.in +8 +.ti -8 + +.BR tc " ... " "action sample rate" +.I RATE +.BR "group" +.I GROUP +.RB "[ " trunc +.IR SIZE " ] " +.RB "[ " index +.IR INDEX " ] " +.ti -8 + +.BR tc " ... " "action sample index " +.I INDEX +.ti -8 + +.SH DESCRIPTION +The +.B sample +action allows sampling packets matching classifier. + +The packets are chosen randomly according to the +.B rate +parameter, and are sampled using the +.B psample +generic netlink channel. The user can also specify packet truncation to save +user-kernel traffic. Each sample includes some informative metadata about the +original packet, which is sent using netlink attributes, alongside the original +packet data. + +The user can either specify the sample action parameters as presented in the +first form above, or use an existing sample action using its index, as presented +in the second form. + +.SH SAMPLED PACKETS METADATA FIELDS +The metadata are delivered to userspace applications using the +.B psample +generic netlink channel, where each sample includes the following netlink +attributes: +.TP +.BI PSAMPLE_ATTR_IIFINDEX +The input interface index of the packet, if there is one. +.TP +.BI PSAMPLE_ATTR_OIFINDEX +The output interface index of the packet. This field is not relevant on ingress +sampling +.TP +.BI PSAMPLE_ATTR_ORIGSIZE +The size of the original packet (before truncation) +.TP +.BI PSAMPLE_ATTR_SAMPLE_GROUP +The +.B psample +group the packet was sent to +.TP +.BI PSAMPLE_ATTR_GROUP_SEQ +A sequence number of the sampled packet. This number is incremented with each +sampled packet of the current +.B psample +group +.TP +.BI PSAMPLE_ATTR_SAMPLE_RATE +The rate the packet was sampled with + +.SH OPTIONS +.TP +.BI rate " RATE" +The packet sample rate. +.I "RATE" +is the expected ratio between observed packets and sampled packets. For example, +.I "RATE" +of 100 will lead to an average of one sampled packet out of every 100 observed. +.TP +.BI trunc " SIZE" +Upon set, defines the maximum size of the sampled packets, and causes truncation +if needed +.TP +.BI group " GROUP" +The +.B psample +group the packet will be sent to. The +.B psample +module defines the concept of groups, which allows the user to match specific +sampled packets in the case of multiple sampling rules, thus identify only the +packets that came from a specific rule. +.TP +.BI index " INDEX" +Is a unique ID for an action. When creating new action instance, this parameter +allows one to set the new action index. When using existing action, this parameter +allows one to specify the existing action index. The index must 32bit unsigned +integer greater than zero. +.SH EXAMPLES +Sample one of every 100 packets flowing into interface eth0 to psample group 12: + +.RS +.EX +tc qdisc add dev eth0 handle ffff: ingress +tc filter add dev eth0 parent ffff: matchall \\ + action sample rate 100 group 12 index 19 +.EE +.RE + +Use the same action instance to sample eth1 too: + +.RS +.EX +tc qdisc add dev eth1 handle ffff: ingress +tc filter add dev eth1 parent ffff: matchall \\ + action sample index 19 +.EE +.RE + +.SH SEE ALSO +.BR tc (8), +.BR tc-matchall (8) +.BR psample (1) -- cgit v1.2.3