From d4a8b7e34dd619a4debf9a206c81db26d1402ea6 Mon Sep 17 00:00:00 2001 From: Damien Miller Date: Wed, 27 Oct 1999 13:42:43 +1000 Subject: Initial revision --- nchan.ms | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100644 nchan.ms (limited to 'nchan.ms') diff --git a/nchan.ms b/nchan.ms new file mode 100644 index 00000000..b01512f7 --- /dev/null +++ b/nchan.ms @@ -0,0 +1,71 @@ +.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 of the channel to the +remote peer. +Data sent by the peer is received on the OUTPUT-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. -- cgit v1.2.1