Re: PR/56569 CVS commit: src/crypto/external/bsd/openssh/dist

[Mike Small <smallm%sdf.org@localhost>]

The following reply was made to PR bin/56569; it has been noted by GNATS.

From: Mike Small <smallm%sdf.org@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost
Subject: Re: PR/56569 CVS commit: src/crypto/external/bsd/openssh/dist
Date: Fri, 24 Dec 2021 21:24:36 +0000

 "Christos Zoulas" <christos%netbsd.org@localhost> writes:
 
 > The following reply was made to PR bin/56569; it has been noted by GNATS.
 >
 > From: "Christos Zoulas" <christos%netbsd.org@localhost>
 > To: gnats-bugs%gnats.NetBSD.org@localhost
 > Cc: 
 > Subject: PR/56569 CVS commit: src/crypto/external/bsd/openssh/dist
 > Date: Fri, 24 Dec 2021 13:16:11 -0500
 >
 >  Module Name:	src
 >  Committed By:	christos
 >  Date:		Fri Dec 24 18:16:11 UTC 2021
 >  
 >  Modified Files:
 >  	src/crypto/external/bsd/openssh/dist: channels.c
 >  
 >  Log Message:
 >  PR/56569: Mike Small: Remove unused code.
 >  
 >  
 >  To generate a diff of this commit:
 >  cvs rdiff -u -r1.32 -r1.33 src/crypto/external/bsd/openssh/dist/channels.c
 >  
 >  Please note that diffs are not public domain; they are subject to the
 >  copyright notices on the relevant files.
 >  
 
 Sorry if I've missed something in the tip version or otherwise, but I'm
 concerned that removing all of this will introduce a regression. It was
 mostly dead code but not entirely in that it gave c->tcpwinsz an initial
 value.
 
 In recent HPN patches Chris Rapier changes that struct member to a local
 variable which he populates before use in channel_check_window():
 https://github.com/rapier1/openssh-portable/blob/master/channels.c
 
 But that seems not the way in NetBSD code. I'm thinking the following
 condition will now always be false since c->tcpwinsz will always be zero:
 
 static int
 channel_check_window(struct ssh *ssh, Channel *c)
 {
 ...
 		/* adjust max window size if we are in a dynamic environment */
 		if (c->dynamic_window && (c->tcpwinsz > c->local_window_max)) {
 			/* grow the window somewhat aggressively to maintain 
 			 * pressure */
 			addition = 1.5*(c->tcpwinsz - c->local_window_max);
 			c->local_window_max += addition;
 		}
 ...
 		c->local_window += c->local_consumed + addition;
 ...
 }
 
 - Mike S.