[th/host-name-max-as-64] all: hardcode HOST_NAME_MAX to 64
On glibc, HOST_NAME_MAX
is defined as 64. Also, Linux'
sethostname()
enforces that limit (__NEW_UTS_LEN). Also,
man gethostname
comments that HOST_NAME_MAX
on Linux is
64.
However, when building against musl, HOST_NAME_MAX
is defined as 255.
That seems wrong. We use this limit to validate the hostname, and that
should not depend on the libc or on the compilation.
Hardcode the value to 64.