kern/45352: pty(4)/tty(4) have a 1024 bytes transfer limit

[Matthew Mondor <mm_lists%pulsar-zone.net@localhost>]

>Number:         45352
>Category:       kern
>Synopsis:       pty(4)/tty(4) have a 1024 bytes transfer limit
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          change-request
>Submitter-Id:   net
>Arrival-Date:   Fri Sep 09 13:50:00 +0000 2011
>Originator:     Matthew Mondor
>Release:        NetBSD 5.1_STABLE
>Organization:
>Environment:
System: NetBSD behemoth.xisop 5.1_STABLE NetBSD 5.1_STABLE (GENERIC_MM) #0: Mon 
Aug 1 12:19:58 EDT 2011 
root@behemoth.xisop:/usr/obj/sys/arch/i386/compile/GENERIC_MM i386
Architecture: i386
Machine: i386
>Description:

Although for terminal applications the 1024 bytes limit is not of
concern in general, when a pty(4) is used to provide a tty(4) for
pppd(8) for instance, this limits the MRU/MTU size.

At least of interest appears to be:

/usr/include/sys/tty.h:#define  TTYHOG  1024

Although other developers suggest there are more fixed values to change.

>How-To-Repeat:
Tunnel ppp using a userland application
>Fix: