mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-18 10:35:55 +00:00
65 lines
2.0 KiB
Plaintext
65 lines
2.0 KiB
Plaintext
.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/" "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" 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.
|