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diff --git a/share/man/man4/ng_deflate.4 b/share/man/man4/ng_deflate.4 new file mode 100644 index 0000000..ce46ab0 --- /dev/null +++ b/share/man/man4/ng_deflate.4 @@ -0,0 +1,159 @@ +.\" +.\" Author: Alexander Motin <mav@alkar.net> +.\" +.\" Copyright (c) 2006, Alexander Motin <mav@alkar.net> +.\" 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 unmodified, 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 December 23, 2006 +.Dt NG_DEFLATE 4 +.Os +.Sh NAME +.Nm ng_deflate +.Nd Deflate PPP compression (RFC 1979) netgraph node type +.Sh SYNOPSIS +.In sys/types.h +.In netgraph/ng_deflate.h +.Sh DESCRIPTION +The +.Nm deflate +node type implements the Deflate sub-protocols of the Compression Control +Protocol (CCP). +.Pp +The node has two hooks, +.Va comp +for compression and +.Va decomp +for decompression. +Only one of them can be connected at the same time, specifying node's +operation mode. +Typically that hooks would be connected to the +.Xr ng_ppp 4 +node type hook of the same name. +Corresponding +.Xr ng_ppp 4 +node hook must be switched to +.Dv NG_PPP_DECOMPRESS_FULL +mode to permit sending uncompressed frames. +.Sh HOOKS +This node type supports the following hooks: +.Pp +.Bl -tag -compact -width decomp +.It Va comp +Connection to +.Xr ng_ppp 4 +.Va comp +hook. +Incoming frames are compressed (if possible) and sent back out the same hook. +.It Va decomp +Connection to +.Xr ng_ppp 4 +.Va decomp +hook. +Incoming frames are decompressed (if they are compressed), and sent +back out the same hook. +.El +.Pp +Only one hook can be connected at the same time, specifying node's +operation mode. +.Sh CONTROL MESSAGES +This node type supports the generic control messages, plus the following: +.Bl -tag -width foo +.It Dv NGM_DEFLATE_CONFIG Pq Li config +This command resets and configures the node for a session +(i.e., for compression or decompression). +This command takes a +.Vt "struct ng_deflate_config" +as an argument: +.Bd -literal -offset 0n +struct ng_deflate_config { + u_char enable; /* node enabled */ + u_char windowBits; /* log2(Window size) */ +}; +.Ed +The +.Fa enabled +field enables traffic flow through the node. +The +.Fa windowBits +specify compression windows size as negotiated by the +Compression Control Protocol (CCP) in PPP. +The +.It Dv NGM_DEFLATE_RESETREQ Pq Li resetreq +This message contains no arguments, and is bi-directional. +If an error is detected during decompression, this message is sent by the +node to the originator of the +.Dv NGM_DEFLATE_CONFIG +message that initiated the session. +The receiver should respond by sending a PPP CCP Reset-Request to the peer. +.Pp +This message may also be received by this node type when a CCP Reset-Request +or Reset-Ack is received by the local PPP entity. +The node will respond by flushing its compression state so the sides +can resynchronize. +.It Dv NGM_DEFLATE_GET_STATS Pq Li getstats +This control message obtains statistics for a given hook. +The statistics are returned in +.Vt "struct ng_deflate_stats" : +.Bd -literal +struct ng_deflate_stats { + uint64_t FramesPlain; + uint64_t FramesComp; + uint64_t FramesUncomp; + uint64_t InOctets; + uint64_t OutOctets; + uint64_t Errors; +}; +.Ed +.It Dv NGM_DEFLATE_CLR_STATS Pq Li clrstats +This control message clears statistics for a given hook. +.It Dv NGM_DEFLATE_GETCLR_STATS Pq Li getclrstats +This control message obtains and clears statistics for a given hook. +.El +.Sh SHUTDOWN +This node shuts down upon receipt of a +.Dv NGM_SHUTDOWN +control message, or when hook have been disconnected. +.Sh SEE ALSO +.Xr netgraph 4 , +.Xr ng_ppp 4 , +.Xr ngctl 8 +.Rs +.%A J. Woods +.%T "PPP Deflate Protocol" +.%O RFC 1979 +.Re +.Rs +.%A W. Simpson +.%T "The Point-to-Point Protocol (PPP)" +.%O RFC 1661 +.Re +.Sh AUTHORS +.An Alexander Motin Aq mav@alkar.net +.Sh BUGS +Due to nature of netgraph PPP implementation there are possible race conditions +between data packet and ResetAck CCP packet in case of packet loss. As result, +packet loss can produce bigger performance degradation than supposed by protocol. |
