On Thu, Aug 05, 2021 at 22:55:12 +0200, Rhialto wrote:
> On Thu 05 Aug 2021 at 13:22:55 +0000, nia wrote:
> > The unix(4) man page incorrectly states:
> >
> > "A UNIX-domain socket supports two socket-level options for use with
> > setsockopt(2) and getsockopt(2): [...]"
> >
> > In reality, the protocol level when using these socket options
> > must be 0, which is a magic number not really documented anywhere
> > except the test suite.
>
> and getsockopt(2) says
>
> DESCRIPTION
> getsockopt(), setsockopt() and getsockopt2() manipulate the options
> associated with a socket. Options may exist at multiple protocol levels;
> they are always present at the uppermost "socket" level.
>
> which I interpret to mean that even if you use SOL_SOCKET for these
> options, it should work. Do I read that as intended?
Was that perhaps an artifact of an old implementation?
POSIX says
The getsockopt() function shall fail if:
[EINVAL]
The specified option is invalid at the specified socket level.
[ENOPROTOOPT]
The option is not supported by the protocol.
while our man page only has
[ENOPROTOOPT] The option is unknown at the level indicated.
which might actually be problematic, but I will leave the exegetic
exercise to someone more skilled.
-uwe
