struct sockaddr is defined something like this:

           struct sockaddr {
               sa_family_t sa_family;
               char        sa_data[14];
           }

In posix.vapi the data field is named inconsistently:
	[CCode (cname = "struct sockaddr", cheader_filename = "sys/socket.h", destroy_function = "")]
	public struct SockAddr {
		public int sa_family;
		[CCode (array_length = false)]
		public char[] data;
	}

Attaching patch.