Rework udp for linux into just 2 files, add more mips targets

udp_linux_64.go

@@ -0,0 +1,53 @@
+// +build linux
+// +build amd64 arm64 ppc64 ppc64le mips64 mips64le s390x
+
+package nebula
+
+import "unsafe"
+
+type iovec struct {
+	Base *byte
+	Len  uint64
+}
+
+type msghdr struct {
+	Name       *byte
+	Namelen    uint32
+	Pad0       [4]byte
+	Iov        *iovec
+	Iovlen     uint64
+	Control    *byte
+	Controllen uint64
+	Flags      int32
+	Pad1       [4]byte
+}
+
+type rawMessage struct {
+	Hdr  msghdr
+	Len  uint32
+	Pad0 [4]byte
+}
+
+func (u *udpConn) PrepareRawMessages(n int) ([]rawMessage, [][]byte, [][]byte) {
+	msgs := make([]rawMessage, n)
+	buffers := make([][]byte, n)
+	names := make([][]byte, n)
+
+	for i := range msgs {
+		buffers[i] = make([]byte, mtu)
+		names[i] = make([]byte, 0x1c) //TODO = sizeofSockaddrInet6
+
+		//TODO: this is still silly, no need for an array
+		vs := []iovec{
+			{Base: (*byte)(unsafe.Pointer(&buffers[i][0])), Len: uint64(len(buffers[i]))},
+		}
+
+		msgs[i].Hdr.Iov = &vs[0]
+		msgs[i].Hdr.Iovlen = uint64(len(vs))
+
+		msgs[i].Hdr.Name = (*byte)(unsafe.Pointer(&names[i][0]))
+		msgs[i].Hdr.Namelen = uint32(len(names[i]))
+	}
+
+	return msgs, buffers, names
+}