_CMSG_DATA_ALIGN
(unsigned int)_CMSG_DATA_ALIGN(sizeof (struct cmsghdr)));
((unsigned char *)_CMSG_DATA_ALIGN((struct cmsghdr *)(c) + 1))
((unsigned int)_CMSG_DATA_ALIGN(sizeof (struct cmsghdr)) + (l))
((unsigned char *)_CMSG_DATA_ALIGN((struct cmsghdr *)(c) + 1))
((unsigned int)_CMSG_DATA_ALIGN(sizeof (struct cmsghdr)) + (l))