--- old/usr/src/cmd/ssh/doc/nchan.ms	Tue Aug 16 19:27:08 2016
+++ /dev/null	Tue Aug 16 19:26:53 2016
@@ -1,97 +0,0 @@
-.\" 
-.\" Copyright (c) 1999 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 1.5 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
-S4: ellipse "INPUT" "CLOSED"
-move down l from last ellipse.s
-S3: ellipse "INPUT" "WAIT" "OCLOSED"
-move down l from 1st ellipse.s
-S2: ellipse "INPUT" "WAIT" "DRAIN"
-arrow "" "rcvd OCLOSE/" "shutdown_read" "send IEOF" from S1.e to S4.w
-arrow "ibuf_empty/" "send IEOF" from S2.e to S3.w
-arrow from S1.s to S2.n
-box invis "read_failed/" "shutdown_read" with .e at last arrow.c
-arrow  from S3.n to S4.s
-box invis "rcvd OCLOSE/" "-" with .w at last arrow.c
-ellipse wid .9*ellipsewid ht .9*ellipseht at S4
-arrow "start" "" from S1.w+(-0.5,0) to S1.w
-arrow from S2.ne to S4.sw
-box invis "rcvd OCLOSE/     " with .e at last arrow.c
-box invis " send IEOF" with .w at last arrow.c
-.PE
-.SH
-Channel Output State Diagram
-.PS
-S1: ellipse "OUTPUT" "OPEN"
-move right 2*l from last ellipse.e
-S3: ellipse "OUTPUT" "WAIT" "IEOF"
-move down l from last ellipse.s
-S4: ellipse "OUTPUT" "CLOSED"
-move down l from 1st ellipse.s
-S2: ellipse "OUTPUT" "WAIT" "DRAIN"
-arrow "" "write_failed/" "shutdown_write" "send OCLOSE" from S1.e to S3.w
-arrow "obuf_empty ||" "write_failed/" "shutdown_write" "send OCLOSE" from S2.e to S4.w
-arrow from S1.s to S2.n
-box invis "rcvd IEOF/" "-" with .e at last arrow.c
-arrow from S3.s to S4.n
-box invis "rcvd IEOF/" "-" with .w 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 IEOF message to the peer.
-If the peer receives the IEOF and has consumed all
-data he replies with an OCLOSE.
-When the local instance receives the OCLOSE
-he considers the INPUT-half of the channel closed.
-The peer has his OUTOUT-half closed.
-.PP
-A channel can be deallocated by a protocol instance
-if both the INPUT- and the OUTOUT-half on his
-side of the channel are closed.
-Note that when an instance is unable to consume the
-received data, he is permitted to send an OCLOSE
-before the matching IEOF is received.
