mirror of
git://anongit.mindrot.org/openssh.git
synced 2024-11-24 10:53:24 +08:00
5428f646ad
- Merged OpenBSD CVS changes:
- [channels.c]
report from mrwizard@psu.edu via djm@ibs.com.au
- [channels.c]
set SO_REUSEADDR and SO_LINGER for forwarded ports.
chip@valinux.com via damien@ibs.com.au
- [nchan.c]
it's not an error() if shutdown_write failes in nchan.
- [readconf.c]
remove dead #ifdef-0-code
- [readconf.c servconf.c]
strcasecmp instead of tolower
- [scp.c]
progress meter overflow fix from damien@ibs.com.au
- [ssh-add.1 ssh-add.c]
SSH_ASKPASS support
- [ssh.1 ssh.c]
postpone fork_after_authentication until command execution,
request/patch from jahakala@cc.jyu.fi via damien@ibs.com.au
plus: use daemon() for backgrounding
100 lines
4.0 KiB
Plaintext
100 lines
4.0 KiB
Plaintext
.\"
|
|
.\" 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.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by Markus Friedl.
|
|
.\" 4. The name of the author may not be used to endorse or promote products
|
|
.\" derived from this software without specific prior written permission.
|
|
.\"
|
|
.\" 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
|
|
.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 comsumer/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 comsumed 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 comsume the
|
|
received data, he is permitted to send an OCLOSE
|
|
before the matching IEOF is received.
|