The returned length of AF_UNIX sockaddrs is significant, and generally
does not match the length of the entire structure. For filesystem
sockets, this is ignorable because the path is also NUL-terminated, but
for unbound sockets (e.g., a socketpair) or abstract-namespace
sockets (a Linux extension where the address is an arbitrary
bytestring), we need to keep track of the length.
Fixes#177. Also add a UnixAddr::new_abstract function and some better
handling of abstract-namespace socket addresses to fix#169.
The best specification for control message layout appears to be
[RFC 2292, section 4](https://tools.ietf.org/html/rfc2292#section-4),
despite this not being a wire protocol. These definitions have also been
checked against glibc 2.19 <bits/socket.h> and Linux 4.0
<linux/socket.h>, and tested on Debian 8.1 and FreeBSD 10.2 x86_64.
The API differs a bit from the cmsg(3) API for type-safety reasons (and
also because the cmsg(3) API is terrible). See test/sys/test_socket.rs
for an example.
Only supports SCM_RIGHTS at the moment.
Fixes#88.
The best specification for control message layout appears to be
[RFC 2292, section 4](https://tools.ietf.org/html/rfc2292#section-4),
despite this not being a wire protocol. These definitions have also been
checked against glibc 2.19 <bits/socket.h> and Linux 4.0
<linux/socket.h>, and tested on Debian 8.1 and FreeBSD 10.2 x86_64.
The API differs a bit from the cmsg(4) API for type-safety reasons (and
also because the cmsg(4) API is terrible). See test/sys/test_socket.rs
for an example.
Only supports SCM_RIGHTS at the moment.
Fixes#88.
