Commit Graph

174 Commits

Author SHA1 Message Date
netchild
32d31c91c0 - Move videodev headers from compat/linux to contrib/v4l (cp from vendor and
apply diff to compat/linux versions).
- The cp implies an update of videodev2.h to the linux kernel 2.6.34.14 one.

The update makes video in skype v4 work on FreeBSD.

Tested by:	Artyom Mirgorodskiy <artyom.mirgorodsky@gmail.com>
		(update of header only)
2013-07-06 19:59:06 +00:00
cperciva
748c98fc62 MFS security patches which seem to have accidentally not reached HEAD:
Fix insufficient message length validation for EAP-TLS messages.

Fix Linux compatibility layer input validation error.

Security:	FreeBSD-SA-12:07.hostapd
Security:	FreeBSD-SA-12:08.linux
Security:	CVE-2012-4445, CVE-2012-4576
With hat:	so@
2012-11-23 01:48:31 +00:00
uqs
d61d88a310 Convert files to UTF-8 2012-01-15 13:23:18 +00:00
dim
d106f2fd7c In sys/compat/linux/linux_ioctl.c, work around a warning when a pointer
is compared to an integer, by casting the pointer to l_uintptr_t.  No
functional difference on both i386 and amd64.

Reviewed by:	ed, jhb
MFC after:	1 week
2012-01-03 18:49:39 +00:00
kmacy
99851f359e In order to maximize the re-usability of kernel code in user space this
patch modifies makesyscalls.sh to prefix all of the non-compatibility
calls (e.g. not linux_, freebsd32_) with sys_ and updates the kernel
entry points and all places in the code that use them. It also
fixes an additional name space collision between the kernel function
psignal and the libc function of the same name by renaming the kernel
psignal kern_psignal(). By introducing this change now we will ease future
MFCs that change syscalls.

Reviewed by:	rwatson
Approved by:	re (bz)
2011-09-16 13:58:51 +00:00
rwatson
4af919b491 Second-to-last commit implementing Capsicum capabilities in the FreeBSD
kernel for FreeBSD 9.0:

Add a new capability mask argument to fget(9) and friends, allowing system
call code to declare what capabilities are required when an integer file
descriptor is converted into an in-kernel struct file *.  With options
CAPABILITIES compiled into the kernel, this enforces capability
protection; without, this change is effectively a no-op.

Some cases require special handling, such as mmap(2), which must preserve
information about the maximum rights at the time of mapping in the memory
map so that they can later be enforced in mprotect(2) -- this is done by
narrowing the rights in the existing max_protection field used for similar
purposes with file permissions.

In namei(9), we assert that the code is not reached from within capability
mode, as we're not yet ready to enforce namespace capabilities there.
This will follow in a later commit.

Update two capability names: CAP_EVENT and CAP_KEVENT become
CAP_POST_KEVENT and CAP_POLL_KEVENT to more accurately indicate what they
represent.

Approved by:	re (bz)
Submitted by:	jonathan
Sponsored by:	Google Inc
2011-08-11 12:30:23 +00:00
netchild
897499f709 Add FEATURE macros for v4l and v4l2 to the linuxulator.
Suggested by:	ae
2011-05-04 09:52:34 +00:00
netchild
939c0e0ef5 This is v4l2 support for the linuxulator. This allows to access FreeBSD
native devices which support the v4l2 API from processes running within
the linuxulator, e.g. skype or flash can access the multimedia/pwcbsd
or multimedia/webcamd supplied drivers.

Submitted by:	nox
MFC after:	1 month
2011-05-04 09:05:39 +00:00
scf
3e36dcd710 Fix the LINUX_SOUND_MIXER_INFO ioctl to return success after the
information is set to FreeBSD.  It had been falling through to the end
of linux_ioctl_sound() and returning ENOIOCTL.  Noticed when running the
Linux ALSA amixer tool.

Add a LINUX_SOUND_MIXER_READ_CAPS ioctl which is used by the Skype
v2.1.0.81 binary.

Reviewed by:	gavin
MFC after:	2 weeks
2010-12-30 02:18:04 +00:00
mdf
ab3a8b533a Replace sbuf_overflowed() with sbuf_error(), which returns any error
code associated with overflow or with the drain function.  While this
function is not expected to be used often, it produces more information
in the form of an errno that sbuf_overflowed() did.
2010-09-10 16:42:16 +00:00
wkoszek
ab9f5dbe35 Bring USB fixes for linux(4).
Intention of this commit is to let us take a full advantage
of libusb(8) ported to Linux. This decreases a possibility of getting
any collisions within ioctl() "command" space, especially with
relation to  LINUX_SNDCTL_SEQ... stuff.

Basically, we provide commands, that will be mapped in the kernel
to correct ones and forward those to the USB layer. Port enabling
functionality brought with this patch is here:

	http://www.freebsd.org/cgi/query-pr.cgi?pr=146895

Bump __FreeBSD_version to catch, since which version installing a
port makes sense.

This patch should bring no regressions. So far, only i386 is tested.

Tested by:	thompsa@
Reviewed by:	thompsa@
OKed by:	netchild@
2010-05-24 07:04:00 +00:00
netchild
88731dce0c - #ifdef out the cliplist part, skype seems like using an uninitialized
variable and can cause problems, without the cliplist handling it works
  without problems
- improve the cliplist error handling
- fix VIDIOCGTUNER and VIDIOCSMICROCODE (still no hardware available to test)

Submitted by:	J.R. Oldroyd <jr@opal.com>
X-MFC after:	soon (together with all the v4l stuff)
2010-05-03 14:19:58 +00:00
netchild
db8514f06a Fix some problems which may lead to a panic:
- right order of src and dst in memcpy
 - NULL out the clips after freeing to prevent an accident

Noticed by:	hselasky
2010-03-26 08:42:11 +00:00
wkoszek
260e3efd2e Let us to use our libusb(3) in Linuxolator.
With this change, Linux binaries can work with our libusb(3) when
it's compiled against our header files on GNU/Linux system -- this
solves the problem with differences between /dev layouts.

With ported libusb(3), I am able to use my USB JTAG cable with Linux
binaries that support it.

Reviewed by:	thompsa
2010-01-18 22:46:06 +00:00
netchild
7cde5eb62d Whitespace change to be able to provide the correct commit log for r202364:
---snip---
Add video clipping support but with the caveats below.

Background info:

Video clipping allows the user to provide either a series of clip rectangles
or a clip bitmap to the driver and have the driver mask the video according
to the clipping specs provided.

Adding support for clipping to the FreeBSD Linux emulator is problematic
because it seems that this feature is not supported by many drivers and
therefore it is ignored by many applications. Unfortunately, when not
using it, rather than passing in a null clipping list, some apps leave the
clipping fields uninitialized, casuing random values to be passed in. In
the case where the driver does not use the clipping info, this is not a
problem (although it is bad form). But the Linux emulator does not know
which drivers will use this and which won't, so the Linux emulator must
try to handle this clip list, and deal gracefully with cases where the
values seem to be uninitialized.

Video clipping info is passed in using the VIDIOCSWIN ioctl in two fields
in the video_window structure: the integer clipcount and the pointer clips.

How the linuxulator handles this from this commit on:

    * if (clipcount == VIDEO_CLIP_BITMAP)
      The clips variable is a void * pointer to a 128*625 byte
      (1024*625 bit) memory area containing a bitmap of the clipping area.
      The pointer in the video_window structure is copied, but no
      video_clip structures are copied.
    * if (clipcount > 0 && clipcount <= 16384)
      The clips variable is pointer to a list of video_clip structures. Up
      to clipcount structures are copied and passed to the driver.
      The upper limit of 16384 was imposed here so that user code that does
      not properly initialize clipcount falls through below and no attempt
      is made to copy an uninitialized list. This value was found by
      examining Linux drivers that support the clip list.
    * else
      The clipcount is either negative (but not VIDEO_CLIP_BITMAP), zero or
      positive (> 16384).
      All these cases are treated as invalid data. Both the clipcount field
      and clips pointer are forced to zero/NULL and passed to the driver.

It should be noted that, at the time of developing this V4L emulator code,
the pwc(4) V4L driver does not support clipping.

Submitted by:	J.R. Oldroyd <fbsd@opal.com>
MFC after:	1 month
---snip---
2010-01-15 15:38:31 +00:00
netchild
9c3e54b694 This is v4l support for the linuxulator. This allows to access FreeBSD
native devices which support the v4l API from processes running within
the linuxulator, e.g. skype or flash can access the multimedia/pwcbsd driver.

Not tested is firmware upload, framebuffer stuff and video tuner stuff
due to lack of hardware.
The clipping part (VIDIOCSWIN) needs a little bit of further work (partly
in progress, but can not be tested due to lack of a suitable device).

The submitter tested this sucessfully with Skype and flash apps on amd64 and
i386 with the multimedia/pwcbsd driver.

Submitted by:	J.R. Oldroyd <fbsd@opal.com>
2010-01-15 14:58:19 +00:00
netchild
3b599cd6fa This is v4l support for the linuxulator. This allows to access FreeBSD
native devices which support the v4l API from processes running within
the linuxulator, e.g. skype or flash can access the multimedia/pwcbsd driver.

Not tested is firmware upload, framebuffer stuff and video tuner stuff
due to lack of hardware.
The clipping part (VIDIOCSWIN) needs a little bit of further work (partly
in progress, but can not be tested due to lack of a suitable device).

The submitter tested this sucessfully with Skype and flash apps on amd64 and
i386 with the multimedia/pwcbsd driver.

Submitted by:	J.R. Oldroyd <fbsd@opal.com>
2009-12-04 21:06:54 +00:00
zec
840419a4c4 Lock the ifnet list while iterating over it.
Submitted by:	julian
MFC after:	3 days
2009-09-13 21:30:18 +00:00
zec
e9ba936d59 Fix a few panics in linuxulator + VIMAGE due to curvnet not being set.
This change affects only options VIMAGE builds.

Reviewed by:	julian
MFC after:	3 days
2009-08-28 22:51:07 +00:00
rwatson
ef8d755d4d Rework global locks for interface list and index management, correcting
several critical bugs, including race conditions and lock order issues:

Replace the single rwlock, ifnet_lock, with two locks, an rwlock and an
sxlock.  Either can be held to stablize the lists and indexes, but both
are required to write.  This allows the list to be held stable in both
network interrupt contexts and sleepable user threads across sleeping
memory allocations or device driver interactions.  As before, writes to
the interface list must occur from sleepable contexts.

Reviewed by:	bz, julian
MFC after:	3 days
2009-08-23 20:40:19 +00:00
rwatson
fb9ffed650 Merge the remainder of kern_vimage.c and vimage.h into vnet.c and
vnet.h, we now use jails (rather than vimages) as the abstraction
for virtualization management, and what remained was specific to
virtual network stacks.  Minor cleanups are done in the process,
and comments updated to reflect these changes.

Reviewed by:	bz
Approved by:	re (vimage blanket)
2009-08-01 19:26:27 +00:00
rwatson
57ca4583e7 Build on Jeff Roberson's linker-set based dynamic per-CPU allocator
(DPCPU), as suggested by Peter Wemm, and implement a new per-virtual
network stack memory allocator.  Modify vnet to use the allocator
instead of monolithic global container structures (vinet, ...).  This
change solves many binary compatibility problems associated with
VIMAGE, and restores ELF symbols for virtualized global variables.

Each virtualized global variable exists as a "reference copy", and also
once per virtual network stack.  Virtualized global variables are
tagged at compile-time, placing the in a special linker set, which is
loaded into a contiguous region of kernel memory.  Virtualized global
variables in the base kernel are linked as normal, but those in modules
are copied and relocated to a reserved portion of the kernel's vnet
region with the help of a the kernel linker.

Virtualized global variables exist in per-vnet memory set up when the
network stack instance is created, and are initialized statically from
the reference copy.  Run-time access occurs via an accessor macro, which
converts from the current vnet and requested symbol to a per-vnet
address.  When "options VIMAGE" is not compiled into the kernel, normal
global ELF symbols will be used instead and indirection is avoided.

This change restores static initialization for network stack global
variables, restores support for non-global symbols and types, eliminates
the need for many subsystem constructors, eliminates large per-subsystem
structures that caused many binary compatibility issues both for
monitoring applications (netstat) and kernel modules, removes the
per-function INIT_VNET_*() macros throughout the stack, eliminates the
need for vnet_symmap ksym(2) munging, and eliminates duplicate
definitions of virtualized globals under VIMAGE_GLOBALS.

Bump __FreeBSD_version and update UPDATING.

Portions submitted by:  bz
Reviewed by:            bz, zec
Discussed with:         gnn, jamie, jeff, jhb, julian, sam
Suggested by:           peter
Approved by:            re (kensmith)
2009-07-14 22:48:30 +00:00
bz
0808d0b1a6 After cleaning up rt_tables from vnet.h and cleaning up opt_route.h
a lot of files no longer need route.h either. Garbage collect them.
While here remove now unneeded vnet.h #includes as well.
2009-06-23 17:03:45 +00:00
bz
48dc6805f8 Add explicit includes for jail.h to the files that need them and
remove the "hidden" one from vimage.h.
2009-06-17 15:01:01 +00:00
jamie
f950eed7d7 Get vnets from creds instead of threads where they're available, and from
passed threads instead of curthread.

Reviewed by:	zec, julian
Approved by:	bz (mentor)
2009-06-15 19:01:53 +00:00
bz
b7ff2bdc20 After r193232 rt_tables in vnet.h are no longer indirectly dependent on
the ROUTETABLES kernel option thus there is no need to include opt_route.h
anymore in all consumers of vnet.h and no longer depend on it for module
builds.

Remove the hidden include in flowtable.h as well and leave the two
explicit #includes in ip_input.c and ip_output.c.
2009-06-08 19:57:35 +00:00
avg
8466b56c6c linux_ioctl_cdrom: reduce stack usage
... by moving two ~2KB structures from stack to heap allocation.
I experienced stack overflow in linux emulation on i386 (8K stack)
when LINUX_DVD_READ_STRUCT ioctl was performed on atapicam cd
device and there was an error that resulted in additional quite
heavy stack use in cam layer.

Reviewed by:	dchagin
Approved by:	jhb (mentor)
2009-05-27 15:23:12 +00:00
dchagin
010f4da5f8 To avoid excessive code duplication move MI definitions to the MI
header file. As it is defined in Linux.

Approved by:	kib (mentor)
MFC after:	1 month
2009-05-07 09:39:20 +00:00
bz
df2be82cec For all files including net/vnet.h directly include opt_route.h and
net/route.h.

Remove the hidden include of opt_route.h and net/route.h from net/vnet.h.

We need to make sure that both opt_route.h and net/route.h are included
before net/vnet.h because of the way MRT figures out the number of FIBs
from the kernel option. If we do not, we end up with the default number
of 1 when including net/vnet.h and array sizes are wrong.

This does not change the list of files which depend on opt_route.h
but we can identify them now more easily.
2009-02-27 14:12:05 +00:00
bz
604d89458a Rather than using hidden includes (with cicular dependencies),
directly include only the header files needed. This reduces the
unneeded spamming of various headers into lots of files.

For now, this leaves us with very few modules including vnet.h
and thus needing to depend on opt_route.h.

Reviewed by:	brooks, gnn, des, zec, imp
Sponsored by:	The FreeBSD Foundation
2008-12-02 21:37:28 +00:00
des
66f807ed8b Retire the MALLOC and FREE macros. They are an abomination unto style(9).
MFC after:	3 months
2008-10-23 15:53:51 +00:00
zec
8797d4caec Step 1.5 of importing the network stack virtualization infrastructure
from the vimage project, as per plan established at devsummit 08/08:
http://wiki.freebsd.org/Image/Notes200808DevSummit

Introduce INIT_VNET_*() initializer macros, VNET_FOREACH() iterator
macros, and CURVNET_SET() context setting macros, all currently
resolving to NOPs.

Prepare for virtualization of selected SYSCTL objects by introducing a
family of SYSCTL_V_*() macros, currently resolving to their global
counterparts, i.e. SYSCTL_V_INT() == SYSCTL_INT().

Move selected #defines from sys/sys/vimage.h to newly introduced header
files specific to virtualized subsystems (sys/net/vnet.h,
sys/netinet/vinet.h etc.).

All the changes are verified to have zero functional impact at this
point in time by doing MD5 comparision between pre- and post-change
object files(*).

(*) netipsec/keysock.c did not validate depending on compile time options.

Implemented by:	julian, bz, brooks, zec
Reviewed by:	julian, bz, brooks, kris, rwatson, ...
Approved by:	julian (mentor)
Obtained from:	//depot/projects/vimage-commit2/...
X-MFC after:	never
Sponsored by:	NLnet Foundation, The FreeBSD Foundation
2008-10-02 15:37:58 +00:00
julian
18137ef251 All opt_x.h includes go at the top of other includes. 2008-08-25 04:55:29 +00:00
ed
cc3116a938 Integrate the new MPSAFE TTY layer to the FreeBSD operating system.
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
2008-08-20 08:31:58 +00:00
bz
1021d43b56 Commit step 1 of the vimage project, (network stack)
virtualization work done by Marko Zec (zec@).

This is the first in a series of commits over the course
of the next few weeks.

Mark all uses of global variables to be virtualized
with a V_ prefix.
Use macros to map them back to their global names for
now, so this is a NOP change only.

We hope to have caught at least 85-90% of what is needed
so we do not invalidate a lot of outstanding patches again.

Obtained from:	//depot/projects/vimage-commit2/...
Reviewed by:	brooks, des, ed, mav, julian,
		jamie, kris, rwatson, zec, ...
		(various people I forgot, different versions)
		md5 (with a bit of help)
Sponsored by:	NLnet Foundation, The FreeBSD Foundation
X-MFC after:	never
V_Commit_Message_Reviewed_By:	more people than the patch
2008-08-17 23:27:27 +00:00
ed
6b178cd86d Add TIOCPKT and TIOCSPTLCK to the Linuxolator.
We're very lucky, because the flags used by our TIOCPKT implementation
are the same as flags used by Linux. We can safely enable TIOCPKT,
assuming EXTPROC is not used.

TIOCSPTLCK is used by unlockpt(). Because we don't need unlockpt() in
our implementation, make this ioctl a no-op.

Approved by:	philip (mentor, implicit), rdivacky
Obtained from:	P4 (//depot/projects/mpsafetty/...)
2008-07-23 17:47:44 +00:00
kib
42f4fb0d92 Implement LINUX_SIOCGIFCOUNT and LINUX_SIOCGIFINDEX/LINUX_SIOGIFINDEX.
LINUX_SIOCGIFCOUNT just returns 0 since it is not implemented in the
Linux 2.6.16.

LINUX_SIOCGIFINDEX/LINUX_SIOGIFINDEX are mapped to the FreeBSD native
SIOCGIFINDEX.

Tested by:	Peter Kostouros <kpeter@melbpc.org.au>
Reviewed by:	brooks, rpaulo (on net@)
Submitted by:	rdivacky
MFC after:	1 week
2007-11-07 16:42:52 +00:00
scottl
1320f9f144 Add the CAM 'SG' peripheral device. This device implements a subset of the
Linux SCSI SG passthrough device API.  The intention is to allow for both
running of Linux apps that want to talk to /dev/sg* nodes, and to facilitate
porting of apps from Linux to FreeBSD.  As such, both native and linuxolator
entry points and definitions are provided.

Caveats:
 - This does not support the procfs and sysfs nodes that the Linux SG
   driver provides.  Some Linux apps may rely on these for operation,
   others may only use them for informational purposes.
 - More ioctls need to be implemented.
 - Linux uses a naming scheme of "sg[a-z]" for devices, while FreeBSD uses a
   scheme of "sg[0-9]".  Devfs aliasis (symlinks) are automatically created
   to link the two together.  However, tools like camcontrol only see the
   native names.
 - Some operations were originally designed to return byte counts or other
   data directly as the syscall return value.  The linuxolator doesn't appear
   to support this well, so this driver just punts for these cases.

Now that the driver is in place, others are welcome to add missing
functionality.  Thanks to Roman Divacky for pushing this work along.
2007-04-07 19:40:58 +00:00
jhb
4d231459c7 - Protect the list of linux ioctl handlers with an sx lock.
- Hold Giant while calling linux ioctl handlers for now as they aren't all
  known to be MPSAFE yet.
- Mark linux_ioctl() MPSAFE.
2006-07-06 21:42:36 +00:00
netchild
326540d4d5 Now that we don't have a linuxolator on alpha anymore:
- unifdef __alpha__
 - revert rev. 1.66 of linux_socket.c
2006-05-10 20:38:16 +00:00
ru
106242f7bb Unbreak COMPAT_LINUX32 option support on amd64.
Broken by:	netchild
2006-03-19 11:10:33 +00:00
netchild
d1db96cb48 Fixup some problems in my previous commit (COMPAT_43).
Pointyhat to:	netchild
2006-03-18 20:47:36 +00:00
netchild
c1829f604c Get rid of the need of COMPAT_43 in the linuxolator.
Submitted by:	Divacky Roman <xdivac02@stud.fit.vutbr.cz>
Obtained from:	DragonFly (some parts)
2006-03-18 18:20:17 +00:00
cognet
d6ecc915cc Linux compat bits needed to make linux programs use the new ptys :
linux_ioctl.[ch] : Implement LINUX_TIOCGPTN, which returns the pty number
linux_stats.c :
	- Return the magic number for devfs.
	- In various stats()-related functions, check that we're stating a
file in /dev/pts, and if so, change the st_rdev field to match what linux
expects to be there for a slave pty device. The glibc checks for this, and
their openpty() fails if it is no correct.
2006-01-26 01:32:46 +00:00
delphij
53041c5448 In Linux, kernel parameters passed to ioctl are by value, while in FreeBSD
they are passed by reference.  Handle the difference within the
linux_ioctl_termio on the LINUX_TCFLSH path.

Submitted by:	Jaroslav Drzik <jaro_AT_coop-voz_dot_sk>
2005-12-13 15:32:52 +00:00
delphij
c829bf7c00 Fix kernel build.
Reported by:	tinderbox
2005-08-28 13:11:08 +00:00
rodrigc
3627dcf262 Rewrite linux_ifconf() to be more like ifconf() in net/if.c
so that we do not call uiomove() while IFNET_RLOCK() is held.
This eliminates the witness warning:

Calling uiomove() with the following non-sleepable locks held:
exclusive sleep mutex ifnet r = 0 (0xc096dd60) locked @
/usr/src/sys/modules/linux/../../compat/linux/linux_ioctl.c:2170

MFC after:	2 days
2005-08-27 14:44:10 +00:00
rwatson
5d770a09e8 Propagate rename of IFF_OACTIVE and IFF_RUNNING to IFF_DRV_OACTIVE and
IFF_DRV_RUNNING, as well as the move from ifnet.if_flags to
ifnet.if_drv_flags.  Device drivers are now responsible for
synchronizing access to these flags, as they are in if_drv_flags.  This
helps prevent races between the network stack and device driver in
maintaining the interface flags field.

Many __FreeBSD__ and __FreeBSD_version checks maintained and continued;
some less so.

Reviewed by:	pjd, bz
MFC after:	7 days
2005-08-09 10:20:02 +00:00
mdodd
91ee5f450f Implement SOUND_MIXER_INFO ioctl in compat layer. 2005-04-13 04:33:06 +00:00
brooks
f16c448930 Use the CTASSERT() macro instead of rolling my own, non-portable one
using #error.

Suggested by:	jhb
2005-03-24 19:26:50 +00:00