> (try setting an IP address with a write() or ioctl())

    ioctl(sock_fd, SIOCSIFADDR, &ifreq_pointer);

is a thing, although it targets a socket on the interface, not the interface itself.

Generally I think there's some cases where they try to push too much through limited interfaces, e.g. ptrace feels like "ok, we have an API already, lets push this unrelated functionality through it too so we don't have to design and add a new one"