Portability, possible?

[liveforeverx]

@RoadRunnr Seems, like it is not portable for Darwin, FreeBSD, (Solaris) and is really Linux only:

c_src/gen_socket_nif.c:452:5: warning: implicit declaration of function 'setns' is invalid in C99 [-Wimplicit-function-declaration]
    setns(nsfd, CLONE_NEWNET);
    ^
c_src/gen_socket_nif.c:452:17: error: use of undeclared identifier 'CLONE_NEWNET'
    setns(nsfd, CLONE_NEWNET);
                ^
c_src/gen_socket_nif.c:455:21: error: use of undeclared identifier 'CLONE_NEWNET'
    setns(old_nsfd, CLONE_NEWNET);
                    ^
c_src/gen_socket_nif.c:620:14: error: use of undeclared identifier 'MSG_NOSIGNAL'
    flags |= MSG_NOSIGNAL;
             ^
c_src/gen_socket_nif.c:660:14: error: use of undeclared identifier 'MSG_NOSIGNAL'
    flags |= MSG_NOSIGNAL;
             ^
1 warning and 4 errors generated.