after re-reading 2.2.2 of POSIX 2008, all of these are in the correct
reserved namespaces and do not need protection.
((struct cmsghdr *)__CMSG_NEXT(cmsg))))
#define CMSG_FIRSTHDR(mhdr) ((size_t) (mhdr)->msg_controllen >= sizeof (struct cmsghdr) ? (struct cmsghdr *) (mhdr)->msg_control : (struct cmsghdr *) 0)
-/* Are these valid? */
#define CMSG_ALIGN(len) (((len) + sizeof (size_t) - 1) & (size_t) ~(sizeof (size_t) - 1))
#define CMSG_SPACE(len) (CMSG_ALIGN (len) + CMSG_ALIGN (sizeof (struct cmsghdr)))
#define CMSG_LEN(len) (CMSG_ALIGN (sizeof (struct cmsghdr)) + (len))
#include <bits/in.h>
-#if 1 /* FIXME: namespace violation */
#define IN_CLASSA(a) ((((in_addr_t)(a)) & 0x80000000) == 0)
#define IN_CLASSA_NET 0xff000000
#define IN_CLASSA_NSHIFT 24
#define IN_MULTICAST(a) IN_CLASSD(a)
#define IN_EXPERIMENTAL(a) ((((in_addr_t)(a)) & 0xe0000000) == 0xe0000000)
#define IN_BADCLASS(a) ((((in_addr_t)(a)) & 0xf0000000) == 0xf0000000)
-#endif
#endif