This CL expands upon CL 340369 by exporting the Ifreq type along with methods
for setting and getting data to/from the ifreq union in a type-safe way.
ifreqData remains unexported as we can keep adding helpers similar to the
IoctlGetEthtoolDrvinfo to expose those operations in a less error-prone way.
A test is also added to verify interface index data using IoctlIfreq against
the modern rtnetlink API used by the standard library.
Change-Id: Ic6980cbcd3792cc341cd614061cce32fa1f851e7
Reviewed-on: https://go-review.googlesource.com/c/sys/+/340370
Trust: Matt Layher <mdlayher@gmail.com>
Run-TryBot: Matt Layher <mdlayher@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The existing ioctl stubs for all UNIX-like platforms take a value of type
uintptr for the arg parameter. However, arguments which are cast from
unsafe.Pointer to uintptr technically violate the rules for package unsafe.
unsafe only allows a conversion from unsafe.Pointer to uintptr directly
within a call to Syscall.
ioctl is used on all UNIX-like operating systems and each one will have
to be updated accordingly where pointer arguments are passed to system
calls. To remedy this on Linux, we generate a new function called
ioctlPtr which takes a value of type unsafe.Pointer for arg. More
operating systems can be updated in future CLs by folks who have access
to those systems and can run the appropriate code generator.
Updates golang/go#44834
Change-Id: Ia9424be424b3dba91bb44d3a7a12bfb2179f0d86
Reviewed-on: https://go-review.googlesource.com/c/sys/+/340915
Trust: Matt Layher <mdlayher@gmail.com>
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Matt Layher <mdlayher@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
ifreq is difficult to use in Go due to the union field in particular. This
situation is made worse due to the need to comply with Go's unsafe.Pointer
rules. This CL generates the raw ifreq type and also adds an ifreqData type
of the same size which is specialized for use with unsafe.Pointer.
We also replace the existing ifreqEthtool (which was not padded to the correct
size) with the new APIs and add a test to verify that IoctlGetEthtoolDrvinfo
functions properly by checking the name of the driver for each network interface.
Future uses of ifreq in package unix can expand upon this type with additional
getter and setter methods to deal with the unsafe casts to and from the union
byte array. We may also consider exporting ifreq and ifreqData if necessary.
Change-Id: Ibf73a10e774b4336815c674bb867bbb7ec1b9c71
Reviewed-on: https://go-review.googlesource.com/c/sys/+/340369
Run-TryBot: Matt Layher <mdlayher@gmail.com>
Trust: Matt Layher <mdlayher@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
