1struct msghdr {
2	void *msg_name;
3	socklen_t msg_namelen;
4	struct iovec *msg_iov;
5	int msg_iovlen, __pad1;
6	void *msg_control;
7	socklen_t msg_controllen, __pad2;
8	int msg_flags;
9};
10
11struct cmsghdr {
12	socklen_t cmsg_len;
13	int __pad1;
14	int cmsg_level;
15	int cmsg_type;
16};
17