+struct msghdr {
+ void *msg_name;
+ socklen_t msg_namelen;
+ struct iovec *msg_iov;
+#if __LONG_MAX > 0x7fffffff && __BYTE_ORDER == __BIG_ENDIAN
+ int __pad1;
+#endif
+ int msg_iovlen;
+#if __LONG_MAX > 0x7fffffff && __BYTE_ORDER == __LITTLE_ENDIAN
+ int __pad1;
+#endif
+ void *msg_control;
+#if __LONG_MAX > 0x7fffffff && __BYTE_ORDER == __BIG_ENDIAN
+ int __pad2;
+#endif
+ socklen_t msg_controllen;
+#if __LONG_MAX > 0x7fffffff && __BYTE_ORDER == __LITTLE_ENDIAN
+ int __pad2;
+#endif
+ int msg_flags;
+};
+
+struct cmsghdr {
+#if __LONG_MAX > 0x7fffffff && __BYTE_ORDER == __BIG_ENDIAN
+ int __pad1;
+#endif
+ socklen_t cmsg_len;
+#if __LONG_MAX > 0x7fffffff && __BYTE_ORDER == __LITTLE_ENDIAN
+ int __pad1;
+#endif
+ int cmsg_level;
+ int cmsg_type;
+};
+