code review 7449046: syscall: handle getsockname for unix sockets on openbsd 5.2

syscall: handle getsockname for unix sockets on openbsd 5.2

On OpenBSD 5.2, calling getsockname on an unbound Unix domain socket
results in a successful syscall, however the AF is unset and the length
is returned as zero. This has been changed to more portable behaviour,
which will be included in the OpenBSD 5.3 release.

For now, work around this by treating a successful getsockname() call
that returns a family of AF_UNSPEC and length of zero as a AF_UNIX
socket.

Makes TestPassFD work on OpenBSD 5.2.

Fixes issue 4956.

[jsing, 2013-03-01 15:20:10]

Hello golang-dev@googlegroups.com,

I'd like you to review this change to
https://go.googlecode.com/hg/

[minux1, 2013-03-01 15:28:21]

Fixes issue 4956.

[jsing, 2013-03-01 15:31:52]

On 2013/03/01 15:28:21, minux wrote:
> Fixes issue 4956.

Heh. New issues appearing while working on fixes. PTAL.

[minux1, 2013-03-01 15:45:47]

Is this "bug" documented anywhere?
I couldn't find at http://www.openbsd.org/plus.html.

On my OpenBSD/amd64 5.2 VM, the test could pass, and I tried that with this
CL,
the result doesn't change (obviously).
so LGTM, let's see if it fixes the builder.

[rsc, 2013-03-01 21:49:47]

LGTM

Please edit the test to re-enable it, and add to this CL before submitting.

[mikio, 2013-03-01 23:52:19]

LGTM

https://codereview.appspot.com/7449046/diff/5001/src/pkg/syscall/syscall_bsd.go
File src/pkg/syscall/syscall_bsd.go (right):

https://codereview.appspot.com/7449046/diff/5001/src/pkg/syscall/syscall_bsd....
src/pkg/syscall/syscall_bsd.go:331: if runtime.GOOS == "openbsd" &&
rsa.Addr.Family == 0 && rsa.Addr.Len == 0 {
Family == AF_UNSPEC

[jsing, 2013-03-05 10:39:50]

On 2013/03/01 15:45:47, minux wrote:
> Is this "bug" documented anywhere?
> I couldn't find at http://www.openbsd.org/plus.html.

The best source is the commit message for uipc_usrreq.c r1.69:

http://www.openbsd.org/cgi-bin/cvsweb/src/sys/kern/uipc_usrreq.c#rev1.69

> On my OpenBSD/amd64 5.2 VM, the test could pass, and I tried that with this
> CL, the result doesn't change (obviously).
> so LGTM, let's see if it fixes the builder.

I suspect that you are running 5.2-current and not 5.2 release.

[jsing, 2013-03-05 10:40:46]

*** Submitted as https://code.google.com/p/go/source/detail?r=84a41a2c376b ***

syscall: handle getsockname for unix sockets on openbsd 5.2

On OpenBSD 5.2, calling getsockname on an unbound Unix domain socket
results in a successful syscall, however the AF is unset and the length
is returned as zero. This has been changed to more portable behaviour,
which will be included in the OpenBSD 5.3 release.

For now, work around this by treating a successful getsockname() call
that returns a family of AF_UNSPEC and length of zero as a AF_UNIX
socket.

Makes TestPassFD work on OpenBSD 5.2.

Fixes issue 4956.

R=golang-dev, minux.ma, rsc, mikioh.mikioh
CC=golang-dev
https://codereview.appspot.com/7449046