215 lines
7.0 KiB
Groff
215 lines
7.0 KiB
Groff
.\" Copyright (c) 2005 Nuno Antunes <nuno.antunes@gmail.com>
|
|
.\" Copyright (c) 2007 Alexander Motin <mav@FreeBSD.org>
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd November 13, 2012
|
|
.Dt NG_CAR 4
|
|
.Os
|
|
.Sh NAME
|
|
.Nm ng_car
|
|
.Nd Committed Access Rate netgraph node type
|
|
.Sh SYNOPSIS
|
|
.In netgraph/ng_car.h
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm car
|
|
node type limits traffic flowing through it using:
|
|
.Pp
|
|
.Bl -bullet -compact
|
|
.It
|
|
Single rate three color marker as described in RFC 2697,
|
|
.It
|
|
Two rate three color marker as described in RFC 2698,
|
|
.It
|
|
RED-like rate limit algorithm used by Cisco,
|
|
.It
|
|
Traffic shaping with RED.
|
|
.El
|
|
.Sh HOOKS
|
|
This node type supports the following hooks:
|
|
.Bl -tag -width ".Va upper"
|
|
.It Va upper
|
|
Hook leading to upper layer protocols.
|
|
.It Va lower
|
|
Hook leading to lower layer protocols.
|
|
.El
|
|
.Pp
|
|
Traffic flowing from
|
|
.Va upper
|
|
to
|
|
.Va lower
|
|
is considered
|
|
.Sy downstream
|
|
traffic.
|
|
Traffic flowing from
|
|
.Va lower
|
|
to
|
|
.Va upper
|
|
is considered
|
|
.Sy upstream
|
|
traffic.
|
|
.Sh MODES OF OPERATION
|
|
Each hook can operate in one of the following modes:
|
|
.Bl -tag -width foo
|
|
.It Dv NG_CAR_SINGLE_RATE
|
|
Single rate three color marker as described in RFC 2697.
|
|
Committed burst packets are counted as green, extended burst packets are
|
|
counted as yellow and exceeding packets are counted as red.
|
|
Committed burst getting refilled with CIR (Committed Information Rate) speed.
|
|
When it is full, exceeded burst getting refilled.
|
|
.It Dv NG_CAR_DOUBLE_RATE
|
|
Two rate three color marker as described in RFC 2698.
|
|
Committed burst packets are counted as green, peak burst packets are counted
|
|
as yellow and exceeding packets are counted as red.
|
|
Committed burst getting refilled with CIR speed.
|
|
Peak burst getting refilled with PIR (Peak Information Rate) speed at the
|
|
same time.
|
|
.It Dv NG_CAR_RED
|
|
Similar to
|
|
.Dv NG_CAR_SINGLE_RATE ,
|
|
but with different understanding of extended burst.
|
|
When normal burst exceeded and extended burst is used, packets are counted
|
|
red with probability equal to part of extended burst consumed.
|
|
Extended burst getting refilled first.
|
|
When it is full, committed burst getting refilled.
|
|
This behavior is similar to RED active queue management algorithm.
|
|
.Pp
|
|
This algorithm is more polite to the TCP traffic than NG_CAR_SINGLE_RATE.
|
|
.It Dv NG_CAR_SHAPE
|
|
Committed burst packets are counted as green, exceeding packets are delayed
|
|
by queue with RED management and counted as yellow.
|
|
Packets dropped by queue counted as red.
|
|
Queue parameters are hardcoded: length 99 packets, min_th 8 packets, max_p 100%.
|
|
.Pp
|
|
Traffic shaping is much more polite to the TCP traffic than rate limit on
|
|
links with bandwidth * delay product less than 6-8 TCP segments, but it
|
|
consumes additional system resources for queue processing.
|
|
.El
|
|
By default, all information rates are measured in bits per second and bursts
|
|
are measured in bytes. But when NG_CAR_COUNT_PACKETS option is enabled,
|
|
rates are measured in packets per second and bursts are in packets.
|
|
.Sh CONTROL MESSAGES
|
|
This node type supports the generic control messages and the following
|
|
specific messages.
|
|
.Bl -tag -width foo
|
|
.It Dv NGM_CAR_SET_CONF Pq Ic setconf
|
|
Set node configuration to the specified at
|
|
.Vt "struct ng_car_bulkconf"
|
|
.It Dv NGM_CAR_GET_CONF Pq Ic getconf
|
|
Return current node configuration as
|
|
.Vt "struct ng_car_bulkconf"
|
|
.Bd -literal
|
|
struct ng_car_hookconf {
|
|
uint64_t cbs; /* Commited burst size (bytes) */
|
|
uint64_t ebs; /* Exceeded/Peak burst size (bytes) */
|
|
uint64_t cir; /* Commited information rate (bits/s) */
|
|
uint64_t pir; /* Peak information rate (bits/s) */
|
|
uint8_t green_action; /* Action for green packets */
|
|
uint8_t yellow_action; /* Action for yellow packets */
|
|
uint8_t red_action; /* Action for red packets */
|
|
uint8_t mode; /* single/double rate, ... */
|
|
uint8_t opt; /* color-aware or color-blind */
|
|
};
|
|
|
|
/* possible actions (..._action) */
|
|
enum {
|
|
NG_CAR_ACTION_FORWARD = 1,
|
|
NG_CAR_ACTION_DROP
|
|
};
|
|
|
|
/* operation modes (mode) */
|
|
enum {
|
|
NG_CAR_SINGLE_RATE = 0,
|
|
NG_CAR_DOUBLE_RATE,
|
|
NG_CAR_RED,
|
|
NG_CAR_SHAPE
|
|
};
|
|
|
|
/* mode options (opt) */
|
|
#define NG_CAR_COUNT_PACKETS 2
|
|
|
|
struct ng_car_bulkconf {
|
|
struct ng_car_hookconf upstream;
|
|
struct ng_car_hookconf downstream;
|
|
};
|
|
.Ed
|
|
.It Dv NGM_CAR_GET_STATS Pq Ic getstats
|
|
Return node statistics as
|
|
.Vt "struct ng_car_bulkstats"
|
|
.Bd -literal
|
|
struct ng_car_hookstats {
|
|
uint64_t passed_pkts; /* Counter for passed packets */
|
|
uint64_t droped_pkts; /* Counter for droped packets */
|
|
uint64_t green_pkts; /* Counter for green packets */
|
|
uint64_t yellow_pkts; /* Counter for yellow packets */
|
|
uint64_t red_pkts; /* Counter for red packets */
|
|
uint64_t errors; /* Counter for operation errors */
|
|
};
|
|
|
|
struct ng_car_bulkstats {
|
|
struct ng_car_hookstats upstream;
|
|
struct ng_car_hookstats downstream;
|
|
};
|
|
.Ed
|
|
.It Dv NGM_CAR_CLR_STATS Pq Ic clrstats
|
|
Clear node statistics.
|
|
.It Dv NGM_CAR_GETCLR_STATS Pq Ic getclrstats
|
|
Atomically return and clear node statistics.
|
|
.El
|
|
.Sh SHUTDOWN
|
|
This node shuts down upon receipt of a
|
|
.Dv NGM_SHUTDOWN
|
|
control message, or when all hooks have been disconnected.
|
|
.Sh EXAMPLES
|
|
Limit outgoing data rate over fxp0 Ethernet interface to 20Mbit/s
|
|
and incoming packet rate to 5000pps.
|
|
.Bd -literal -offset indent
|
|
/usr/sbin/ngctl -f- <<-SEQ
|
|
mkpeer fxp0: car lower lower
|
|
name fxp0:lower fxp0_car
|
|
connect fxp0: fxp0_car: upper upper
|
|
msg fxp0_car: setconf { downstream={ cir=20000000 cbs=2500000 ebs=2500000 greenAction=1 yellowAction=1 redAction=2 mode=2 } upstream={ cir=5000 cbs=100 ebs=100 greenAction=1 yellowAction=1 redAction=2 mode=2 opt=2 } }
|
|
SEQ
|
|
.Ed
|
|
.Sh SEE ALSO
|
|
.Xr netgraph 4 ,
|
|
.Xr ngctl 8
|
|
.Rs
|
|
.%A J. Heinanen
|
|
.%T "A Single Rate Three Color Marker"
|
|
.%O RFC 2697
|
|
.Re
|
|
.Rs
|
|
.%A J. Heinanen
|
|
.%T "A Two Rate Three Color Marker"
|
|
.%O RFC 2698
|
|
.Re
|
|
.Sh AUTHORS
|
|
.An Nuno Antunes Aq nuno.antunes@gmail.com
|
|
.An Alexander Motin Aq mav@FreeBSD.org
|
|
.Sh BUGS
|
|
At this moment only DROP and FORWARD actions are implemented.
|