The uuidgen command, by means of the uuidgen syscall, generates one
or more Universally Unique Identifiers compatible with OSF/DCE 1.1
version 1 UUIDs.
From the Perforce logs (change 11995):
Round of cleanups:
o Give uuidgen() the correct prototype in syscalls.master
o Define struct uuid according to DCE 1.1 in sys/uuid.h
o Use struct uuid instead of uuid_t. The latter is defined
in sys/uuid.h but should not be used in kernel land.
o Add snprintf_uuid(), printf_uuid() and sbuf_printf_uuid()
to kern_uuid.c for use in the kernel (currently geom_gpt.c).
o Rename the non-standard struct uuid in kern/kern_uuid.c
to struct uuid_private and give it a slightly better definition
for better byte-order handling. See below.
o In sys/gpt.h, fix the broken uuid definitions to match the now
compliant struct uuid definition. See below.
o In usr.bin/uuidgen/uuidgen.c catch up with struct uuid change.
A note about byte-order:
The standard failed to provide a non-conflicting and
unambiguous definition for the binary representation. My initial
implementation always wrote the timestamp as a 64-bit little-endian
(2s-complement) integral. The clock sequence was always written
as a 16-bit big-endian (2s-complement) integral. After a good
nights sleep and couple of Pan Galactic Gargle Blasters (not
necessarily in that order :-) I reread the spec and came to the
conclusion that the time fields are always written in the native
by order, provided the the low, mid and hi chopping still occurs.
The spec mentions that you "might need to swap bytes if you talk
to a machine that has a different byte-order". The clock sequence
is always written in big-endian order (as is the IEEE 802 address)
because its division is resulting in bytes, making the ordering
unambiguous.
environment needed at boot time to a dynamic subsystem when VM is
up. The dynamic kernel environment is protected by an sx lock.
This adds some new functions to manipulate the kernel environment :
freeenv(), setenv(), unsetenv() and testenv(). freeenv() has to be
called after every getenv() when you have finished using the string.
testenv() only tests if an environment variable is present, and
doesn't require a freeenv() call. setenv() and unsetenv() are self
explanatory.
The kenv(2) syscall exports these new functionalities to userland,
mainly for kenv(1).
Reviewed by: peter
my tree for ages (~2 years) waiting for an excuse to commit it. Now Linux
has implemented it and it seems that Staroffice (when using the
linux_base6.1 port's libc) calls this in the linux emulator and dies in
setup. The Linux emulator can call these now.
Make gratuitous style(9) fixes (me, not the submitter) to make the aio
code more readable.
PR: kern/12053
Submitted by: Chris Sedore <cmsedore@maxwell.syr.edu>
-----------------------------
The core of the signalling code has been rewritten to operate
on the new sigset_t. No methodological changes have been made.
Most references to a sigset_t object are through macros (see
signalvar.h) to create a level of abstraction and to provide
a basis for further improvements.
The NSIG constant has not been changed to reflect the maximum
number of signals possible. The reason is that it breaks
programs (especially shells) which assume that all signals
have a non-null name in sys_signame. See src/bin/sh/trap.c
for an example. Instead _SIG_MAXSIG has been introduced to
hold the maximum signal possible with the new sigset_t.
struct sigprop has been moved from signalvar.h to kern_sig.c
because a) it is only used there, and b) access must be done
though function sigprop(). The latter because the table doesn't
holds properties for all signals, but only for the first NSIG
signals.
signal.h has been reorganized to make reading easier and to
add the new and/or modified structures. The "old" structures
are moved to signalvar.h to prevent namespace polution.
Especially the coda filesystem suffers from the change, because
it contained lines like (p->p_sigmask == SIGIO), which is easy
to do for integral types, but not for compound types.
NOTE: kdump (and port linux_kdump) must be recompiled.
Thanks to Garrett Wollman and Daniel Eischen for pressing the
importance of changing sigreturn as well.
This is a seriously beefed up chroot kind of thing. The process
is jailed along the same lines as a chroot does it, but with
additional tough restrictions imposed on what the superuser can do.
For all I know, it is safe to hand over the root bit inside a
prison to the customer living in that prison, this is what
it was developed for in fact: "real virtual servers".
Each prison has an ip number associated with it, which all IP
communications will be coerced to use and each prison has its own
hostname.
Needless to say, you need more RAM this way, but the advantage is
that each customer can run their own particular version of apache
and not stomp on the toes of their neighbors.
It generally does what one would expect, but setting up a jail
still takes a little knowledge.
A few notes:
I have no scripts for setting up a jail, don't ask me for them.
The IP number should be an alias on one of the interfaces.
mount a /proc in each jail, it will make ps more useable.
/proc/<pid>/status tells the hostname of the prison for
jailed processes.
Quotas are only sensible if you have a mountpoint per prison.
There are no privisions for stopping resource-hogging.
Some "#ifdef INET" and similar may be missing (send patches!)
If somebody wants to take it from here and develop it into
more of a "virtual machine" they should be most welcome!
Tools, comments, patches & documentation most welcome.
Have fun...
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