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Diffstat (limited to 'nchan2.ms')
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diff --git a/nchan2.ms b/nchan2.ms new file mode 100644 index 0000000..7001504 --- /dev/null +++ b/nchan2.ms @@ -0,0 +1,88 @@ +.\" $OpenBSD: nchan2.ms,v 1.4 2008/05/15 23:52:24 djm Exp $ +.\" +.\" Copyright (c) 2000 Markus Friedl. 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 ``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 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. +.\" +.TL +OpenSSH Channel Close Protocol 2.0 Implementation +.SH +Channel Input State Diagram +.PS +reset +l=1 +s=1.2 +ellipsewid=s*ellipsewid +boxwid=s*boxwid +ellipseht=s*ellipseht +S1: ellipse "INPUT" "OPEN" +move right 2*l from last ellipse.e +S3: ellipse invis +move down l from last ellipse.s +S4: ellipse "INPUT" "CLOSED" +move down l from 1st ellipse.s +S2: ellipse "INPUT" "WAIT" "DRAIN" +arrow from S1.e to S4.n +box invis "rcvd CLOSE/" "shutdown_read" with .sw at last arrow.c +arrow "ibuf_empty ||" "rcvd CLOSE/" "send EOF" "" from S2.e to S4.w +arrow from S1.s to S2.n +box invis "read_failed ||" "rcvd EOW/" "shutdown_read" with .e at last arrow.c +ellipse wid .9*ellipsewid ht .9*ellipseht at S4 +arrow "start" "" from S1.w+(-0.5,0) to S1.w +.PE +.SH +Channel Output State Diagram +.PS +S1: ellipse "OUTPUT" "OPEN" +move right 2*l from last ellipse.e +S3: ellipse invis +move down l from last ellipse.s +S4: ellipse "OUTPUT" "CLOSED" +move down l from 1st ellipse.s +S2: ellipse "OUTPUT" "WAIT" "DRAIN" +arrow from S1.e to S4.n +box invis "write_failed/" "shutdown_write" "send EOW" with .sw at last arrow.c +arrow "obuf_empty ||" "write_failed/" "shutdown_write" "" from S2.e to S4.w +arrow from S1.s to S2.n +box invis "rcvd EOF ||" "rcvd CLOSE/" "-" with .e at last arrow.c +ellipse wid .9*ellipsewid ht .9*ellipseht at S4 +arrow "start" "" from S1.w+(-0.5,0) to S1.w +.PE +.SH +Notes +.PP +The input buffer is filled with data from the socket +(the socket represents the local consumer/producer of the +forwarded channel). +The data is then sent over the INPUT-end (transmit-end) of the channel to the +remote peer. +Data sent by the peer is received on the OUTPUT-end (receive-end), +saved in the output buffer and written to the socket. +.PP +If the local protocol instance has forwarded all data on the +INPUT-end of the channel, it sends an EOF message to the peer. +.PP +A CLOSE message is sent to the peer if +both the INPUT- and the OUTOUT-half of the local +end of the channel are closed. +.PP +The channel can be deallocated by a protocol instance +if a CLOSE message he been both sent and received. |