The last half year I've been working on a replacement TTY layer for the
FreeBSD kernel. The new TTY layer was designed to improve the following:
- Improved driver model:
The old TTY layer has a driver model that is not abstract enough to
make it friendly to use. A good example is the output path, where the
device drivers directly access the output buffers. This means that an
in-kernel PPP implementation must always convert network buffers into
TTY buffers.
If a PPP implementation would be built on top of the new TTY layer
(still needs a hooks layer, though), it would allow the PPP
implementation to directly hand the data to the TTY driver.
- Improved hotplugging:
With the old TTY layer, it isn't entirely safe to destroy TTY's from
the system. This implementation has a two-step destructing design,
where the driver first abandons the TTY. After all threads have left
the TTY, the TTY layer calls a routine in the driver, which can be
used to free resources (unit numbers, etc).
The pts(4) driver also implements this feature, which means
posix_openpt() will now return PTY's that are created on the fly.
- Improved performance:
One of the major improvements is the per-TTY mutex, which is expected
to improve scalability when compared to the old Giant locking.
Another change is the unbuffered copying to userspace, which is both
used on TTY device nodes and PTY masters.
Upgrading should be quite straightforward. Unlike previous versions,
existing kernel configuration files do not need to be changed, except
when they reference device drivers that are listed in UPDATING.
Obtained from: //depot/projects/mpsafetty/...
Approved by: philip (ex-mentor)
Discussed: on the lists, at BSDCan, at the DevSummit
Sponsored by: Snow B.V., the Netherlands
dcons(4) fixed by: kan
password quality, not login.conf(5).
- Move warnexpire and warnpasswd from the ``Accounting Limits''
section to ``Authentication'', and nix everything else in the
former section. The accounting knobs are not available in
the base system, and the subset of them available in ports
should be documented in the ports' manpages.
PR: 47960
Reviewed by: mike (mentor), doc
is not defined in the capability type list. Provide a definition for
'bool', if a slightly less than elegant one. Note that this definition
does not include the complete scope of available behavior defined
in cgetcap(3), and could probably be improved.
to be applied to the value given. This does not break installed
/etc/login.conf files, since un-suffixed numbers are interpreted as
they were before.
PR: 19750
Submitted by: Paul Herman <pherman@frenchfries.net>
"passwordtime" is what passwd(1) has actually been using. I suspect
passwordperiod was the original intent. I can't figure-out which,
if either, BSDi uses. If anyone knows...
