From ed5f291a2283dd2882a39a3019e82fd325079631 Mon Sep 17 00:00:00 2001 From: Maxime Peim Date: Thu, 17 Nov 2022 15:29:10 +0000 Subject: policer: adding documentation Type: docs Several kinds of policers are implemented in VPP. However, they could differ from the RFCs it is said they are from. Additionally, the CLI command's help has been updated with the current list of acceptable parameters. Signed-off-by: Maxime Peim Change-Id: Ic9bf94e1094bea0fcc87ccaa882c2c5f88824041 --- docs/_images/policer-1r2c-aware.png | Bin 0 -> 73985 bytes docs/_images/policer-1r2c-blind.png | Bin 0 -> 67455 bytes docs/_images/policer-1r2c-bucket.png | Bin 0 -> 54000 bytes docs/_images/policer-1r3c-aware.png | Bin 0 -> 69156 bytes docs/_images/policer-1r3c-blind.png | Bin 0 -> 48057 bytes docs/_images/policer-1r3c-bucket.png | Bin 0 -> 116653 bytes docs/_images/policer-2r3c-aware.png | Bin 0 -> 73084 bytes docs/_images/policer-2r3c-blind.png | Bin 0 -> 59999 bytes docs/_images/policer-2r3c-bucket.png | Bin 0 -> 101915 bytes docs/developer/corefeatures/index.rst | 1 + docs/developer/corefeatures/policer.rst | 1 + docs/spelling_wordlist.txt | 3 + src/vnet/policer/policer.c | 18 ++- src/vnet/policer/policer.rst | 217 ++++++++++++++++++++++++++++++++ 14 files changed, 236 insertions(+), 4 deletions(-) create mode 100644 docs/_images/policer-1r2c-aware.png create mode 100644 docs/_images/policer-1r2c-blind.png create mode 100644 docs/_images/policer-1r2c-bucket.png create mode 100644 docs/_images/policer-1r3c-aware.png create mode 100644 docs/_images/policer-1r3c-blind.png create mode 100644 docs/_images/policer-1r3c-bucket.png create mode 100644 docs/_images/policer-2r3c-aware.png create mode 100644 docs/_images/policer-2r3c-blind.png create mode 100644 docs/_images/policer-2r3c-bucket.png create mode 120000 docs/developer/corefeatures/policer.rst create mode 100644 src/vnet/policer/policer.rst diff --git a/docs/_images/policer-1r2c-aware.png b/docs/_images/policer-1r2c-aware.png new file mode 100644 index 00000000000..8eb4f8d341f Binary files /dev/null and b/docs/_images/policer-1r2c-aware.png differ diff --git a/docs/_images/policer-1r2c-blind.png b/docs/_images/policer-1r2c-blind.png new file mode 100644 index 00000000000..ec8a1dd62f4 Binary files /dev/null and b/docs/_images/policer-1r2c-blind.png differ diff --git a/docs/_images/policer-1r2c-bucket.png b/docs/_images/policer-1r2c-bucket.png new file mode 100644 index 00000000000..dc4587074d7 Binary files /dev/null and b/docs/_images/policer-1r2c-bucket.png differ diff --git a/docs/_images/policer-1r3c-aware.png b/docs/_images/policer-1r3c-aware.png new file mode 100644 index 00000000000..6a904b5abc7 Binary files /dev/null and b/docs/_images/policer-1r3c-aware.png differ diff --git a/docs/_images/policer-1r3c-blind.png b/docs/_images/policer-1r3c-blind.png new file mode 100644 index 00000000000..1bcef6adf6d Binary files /dev/null and b/docs/_images/policer-1r3c-blind.png differ diff --git a/docs/_images/policer-1r3c-bucket.png b/docs/_images/policer-1r3c-bucket.png new file mode 100644 index 00000000000..24094ee79f8 Binary files /dev/null and b/docs/_images/policer-1r3c-bucket.png differ diff --git a/docs/_images/policer-2r3c-aware.png b/docs/_images/policer-2r3c-aware.png new file mode 100644 index 00000000000..214dc62c6aa Binary files /dev/null and b/docs/_images/policer-2r3c-aware.png differ diff --git a/docs/_images/policer-2r3c-blind.png b/docs/_images/policer-2r3c-blind.png new file mode 100644 index 00000000000..a2faa1fb9f4 Binary files /dev/null and b/docs/_images/policer-2r3c-blind.png differ diff --git a/docs/_images/policer-2r3c-bucket.png b/docs/_images/policer-2r3c-bucket.png new file mode 100644 index 00000000000..a0c427281be Binary files /dev/null and b/docs/_images/policer-2r3c-bucket.png differ diff --git a/docs/developer/corefeatures/index.rst b/docs/developer/corefeatures/index.rst index 1012387a17a..8daadaabc27 100644 --- a/docs/developer/corefeatures/index.rst +++ b/docs/developer/corefeatures/index.rst @@ -20,3 +20,4 @@ Core Features eventviewer stats selinux_doc + policer diff --git a/docs/developer/corefeatures/policer.rst b/docs/developer/corefeatures/policer.rst new file mode 120000 index 00000000000..cc75a1a6ec0 --- /dev/null +++ b/docs/developer/corefeatures/policer.rst @@ -0,0 +1 @@ +../../../src/vnet/policer/policer.rst \ No newline at end of file diff --git a/docs/spelling_wordlist.txt b/docs/spelling_wordlist.txt index 97bd0b573e1..8ab46744793 100644 --- a/docs/spelling_wordlist.txt +++ b/docs/spelling_wordlist.txt @@ -113,6 +113,7 @@ buildingrst builtin builtinurl Builtinurl +burstiness busybox BV bvi @@ -843,6 +844,8 @@ Pnat PoC podSubnet policer +Policer +policers Policers Pollable portranges diff --git a/src/vnet/policer/policer.c b/src/vnet/policer/policer.c index 9dd50b83d24..8389a5ead48 100644 --- a/src/vnet/policer/policer.c +++ b/src/vnet/policer/policer.c @@ -694,13 +694,23 @@ done: VLIB_CLI_COMMAND (configure_policer_command, static) = { .path = "configure policer", - .short_help = "configure policer name ", + .short_help = "configure policer name [type 1r2c | 1r3c | 2r3c-2698 " + "| 2r3c-4115] [color-aware] [cir ] [cb ] [eir ] " + "[eb ] [rate kbps | pps] [round closest | up | down] " + "[conform-action drop | transmit | mark-and-transmit ] " + "[exceed-action drop | transmit | mark-and-transmit ] " + "[violate-action drop | transmit | mark-and-transmit ]", .function = policer_add_command_fn, }; VLIB_CLI_COMMAND (policer_add_command, static) = { .path = "policer add", - .short_help = "policer name ", + .short_help = "policer name [type 1r2c | 1r3c | 2r3c-2698 | " + "2r3c-4115] [color-aware] [cir ] [cb ] [eir ] " + "[eb ] [rate kbps | pps] [round closest | up | down] " + "[conform-action drop | transmit | mark-and-transmit ] " + "[exceed-action drop | transmit | mark-and-transmit ] " + "[violate-action drop | transmit | mark-and-transmit ]", .function = policer_add_command_fn, }; @@ -718,14 +728,14 @@ VLIB_CLI_COMMAND (policer_bind_command, static) = { VLIB_CLI_COMMAND (policer_input_command, static) = { .path = "policer input", - .short_help = "policer input [unapply] name ", + .short_help = "policer input [unapply] name ", .function = policer_input_command_fn, .function_arg = VLIB_RX, }; VLIB_CLI_COMMAND (policer_output_command, static) = { .path = "policer output", - .short_help = "policer output [unapply] name ", + .short_help = "policer output [unapply] name ", .function = policer_input_command_fn, .function_arg = VLIB_TX, }; diff --git a/src/vnet/policer/policer.rst b/src/vnet/policer/policer.rst new file mode 100644 index 00000000000..0e7369e373b --- /dev/null +++ b/src/vnet/policer/policer.rst @@ -0,0 +1,217 @@ +.. _policer: + +Policing +======== + +VPP implements several policer types, that don't always conform +to the related RFCs [#rfc2697]_ [#rfc2698]_ [#rfc4115]_. +Only policers implemented in VPP will be presented, along with +the differences they have compared to RFCs. + +.. contents:: :local: + :depth: 1 + + +1 rate 2 color (1r2c) +--------------------- + +This is the most straightforward policer. There is no RFC describing it, +however we can found its description in many documentation [#juniper]_ [#cisco]_ . + +A 1r2c policer is great to classify incoming packets into two categories: +conforming packets (said green), and violating ones (said red). + +Parameters +~~~~~~~~~~ + +To set-up such a policer, only two parameters are needed: + +Committed Information Rate (CIR) + Given in bytes per second, this parameter is the average + throughput allowed by the policer. + + It sets the limit between conforming arriving packets (those making the + traffic fall below the CIR), and violating arriving packets + (those making the traffic exceed the CIR). + +Committed Burst Size (CBS) + It represents the size (in bytes) of a token bucket used to allow + some burstiness from the incoming traffic. + +.. figure:: /_images/policer-1r2c-bucket.png + :align: center + :scale: 25% + + Figure 1: 1r2c bucket filling logic + +The committed token bucket (C) is filling up at CIR tokens (bytes) +per second, up to CBS tokens. All overflowing tokens are lost. + +Color-Blind algorithm +~~~~~~~~~~~~~~~~~~~~~ + +.. image:: /_images/policer-1r2c-blind.png + :align: center + :scale: 75% + +| + +Color-Aware algorithm +~~~~~~~~~~~~~~~~~~~~~ + +In online documentation, there is no trace of a color-aware 1r2c policer. +However, VPP implementation allows such a thing. + +.. image:: /_images/policer-1r2c-aware.png + :align: center + :scale: 75% + +| + + +1 rate 3 color (1r3c) RFC 2697 [#rfc2697]_ +------------------------------------------ + +As for the `1 rate 2 color (1r2c)`_ policer, only one rate parameters is required +to setup a 1r3c policer. However, such a policer adds another kind of packet category: +exceeding ones (said yellow). + +Parameters +~~~~~~~~~~ + +To set-up such a policer, three parameters are needed: + +Committed Information Rate (CIR) + As in the `1 rate 2 color (1r2c)`_ policer. + +Committed Burst Size (CBS) + As in the `1 rate 2 color (1r2c)`_ policer. + +Excess Burst Size (EBS) + It represents the size (in bytes) of a second token bucket used + to allow an additional burstiness from the incoming traffic, when + traffic as been below the CIR for some time. + +.. figure:: /_images/policer-1r3c-bucket.png + :align: center + :scale: 25% + + Figure 2: 1r3c buckets filling logic + +The committed token bucket (C) is filling up at CIR tokens (bytes) +per second, up to CBS tokens. When C is full, tokens are overflowing +into the excess token bucket (E), up to EBS tokens. Only overflowing +tokens from E are lost. + +Color-Blind algorithm +~~~~~~~~~~~~~~~~~~~~~ + +.. image:: /_images/policer-1r3c-blind.png + :align: center + :scale: 75% + +| + +Color-Aware algorithm +~~~~~~~~~~~~~~~~~~~~~ + +.. image:: /_images/policer-1r3c-aware.png + :align: center + :scale: 75% + +| + +Notes +~~~~~ + +In the RFC 2697 [#rfc2697]_ describing the 1r3c policer, conforming (green) packets +only consume tokens from the token bucket C. Whereas, in VPP, they also consume tokens from E. + +One way to stick to the RFC is then to set the EBS parameter to be superior to CBS, so that +EBS - CBS corresponds to the EBS from the RFC. + +However, VPP does not enforce setting EBS > CBS, which could result in undesired behavior. + +2 rate 3 color (2r3c) RFC 2698 [#rfc2698]_ +------------------------------------------ + +Instead of setting the limit between yellow and red packets in terms of bursts, +as it is done by `1 rate 3 color (1r3c) RFC 2697`_ policers, two rate policers introduce +another rate parameter to discriminate between those two kinds of packets. + +Parameters +~~~~~~~~~~ + +To set-up such a policer, four parameters are needed: + +Committed Information Rate (CIR) + As in the `1 rate 2 color (1r2c)`_ policer. + +Committed Burst Size (CBS) + As in the `1 rate 2 color (1r2c)`_ policer. + +Peak Information Rate (PIR) + Given in bytes per second, this parameter is the average + throughput allowed by the policer when there is a peak in + traffic. + + It sets a second limit between exceeding arriving packets + (those making the traffic fall below the PIR, but above CIR), + and violating arriving packets (those making the traffic exceed the PIR). + +Peak Burst Size (PBS) + It represents the size (in bytes) of a second token bucket used + to allow an additional peak traffic. + +.. figure:: /_images/policer-2r3c-bucket.png + :align: center + :scale: 25% + + Figure 2: 2r3c-rfc2698 buckets filling logic + +The committed token bucket (C) is filling up at CIR tokens (bytes) +per second, up to CBS tokens. In the meantime, the peak token bucket (P) +is filling up at PIR tokens per second, up to PBS. All overflowing tokens +from C and P are lost. + +Color-Blind algorithm +~~~~~~~~~~~~~~~~~~~~~ + +.. image:: /_images/policer-2r3c-blind.png + :align: center + :scale: 75% + +| + +Color-Aware algorithm +~~~~~~~~~~~~~~~~~~~~~ + +.. image:: /_images/policer-2r3c-aware.png + :align: center + :scale: 50% + +| + +Notes +~~~~~ + +To have a working policer, the condition PIR >= CIR needs to hold. +Indeed, since we assume that peak traffic should have a greater +rate than committed ones. + + +2 rate 3 color (2r3c) RFC 4115 [#rfc4115]_ +------------------------------------------ + +The 2r3c-RFC4115 is an allowed choice by VPP. However, there is currently +no implementation of such a policer. Hence, the only two rate policer VPP +implements is the `2 rate 3 color (2r3c) RFC 2698`_ policer. + + +.. rubric:: References: + +.. [#juniper] https://www.juniper.net/documentation/us/en/software/junos/traffic-mgmt-nfx/routing-policy/topics/concept/tcm-overview-cos-qfx-series-understanding.html +.. [#cisco] https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/qos_mqc/configuration/xe-16-8/qos-mqc-xe-16-8-book/qos-pkt-policing.html +.. [#rfc2697] https://www.rfc-editor.org/rfc/rfc2697.html +.. [#rfc2698] https://www.rfc-editor.org/rfc/rfc2698.html +.. [#rfc4115] https://www.rfc-editor.org/rfc/rfc4115.html -- cgit 1.2.3-korg