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...
Sponsored by: http://www.rndassociates.com/
Run for almost a year by: http://www.servetheweb.com/
statement if blocks[*] when the else could be ambiguous, not defaulting
to int type and removal of some unused variables.
[*] This is explicitly allowed by style(9) when the single statement
spans more than one line.
Reviewed by: obrien, chuckr
by default, file(1) does not follow symlinks, the -L flag must be
specified.
PR: docs/8602
Submitted by: Kazuo Horikawa <k-horik@yk.rim.or.jp>
Reviewed by: nik
representation of the expression is quoted. Take care of this when
doing pattern matching in conjunction with trimming.
#!/bin/sh
c=d:e; echo "${c%:e}"
PR: NetBSD PR#7231
Noticed by: Havard Eidnes <Havard.Eidnes@runit.sintef.no>
and CPU runtime because it can't access the user area via /proc/<pid>/mem.
This is because the uarea is not mapped into the process address space
at USRSTACK on the alpha like it is on the x86.
Since I'm haven't been able to wrap my brain around the VM system enough
to be able to figure out how to achieve this mapping, and since it's
questionable that such an architectural change is correct, I implemented
a workaround to allow ps(1) to read the uarea from /dev/kmem using
kvm_read() instead of from the process address space via kvm_uread().
The kludge is hidden inside #ifdef __alpha__/#endif so as not to impact
the x86. (Note that top(1) probably uses this same gimmick since it works
on FreeBSD/alpha.)
Reviewed by: dfr
make /etc/rc interruptible in cases when programs hang with blocked
signals) isn't standard enough.
It is now switched off by default and a new switch -T enables it.
You should update /etc/rc to the version I'm about to commit in a few
minutes to keep it interruptible.
This takes the conditionals out of the code that has been tested by
various people for a while.
ps and friends (libkvm) will need a recompile as some proc structure
changes are made.
Submitted by: "Richard Seaman, Jr." <dick@tar.com>
Submitted by: "Richard Seaman, Jr." <lists@tar.com>
Obtained from: linux :-)
Code to allow Linux Threads to run under FreeBSD.
By default not enabled
This code is dependent on the conditional
COMPAT_LINUX_THREADS (suggested by Garret)
This is not yet a 'real' option but will be within some number of hours.
pattern matches will occur at offset zero of the source string. The bug causes
the input source string pointer to be incremented by the offset of the end of
the match, instead of it's length. The fix is to only increment the pointer by
the length of the pattern match (eo-so).
Of course, the one example in the man page shows a situation where the match
occurs at offset 0.
Submitted by: John W. DeBoskey <jwd@unx.sas.com>
Obtained from: freebsd-current@freebsd.org
