端口管理器 和 传输层 基础框架

tcpip/header/udp.go

@@ -0,0 +1,38 @@
+package header
+
+import "netstack/tcpip"
+
+const (
+	udpSrcPort  = 0
+	udpDstPort  = 2
+	udpLength   = 4
+	udpChecksum = 6
+)
+
+// UDPFields contains the fields of a UDP packet. It is used to describe the
+// fields of a packet that needs to be encoded.
+// udp 首部字段
+type UDPFields struct {
+	// SrcPort is the "source port" field of a UDP packet.
+	SrcPort uint16
+
+	// DstPort is the "destination port" field of a UDP packet.
+	DstPort uint16
+
+	// Length is the "length" field of a UDP packet.
+	Length uint16
+
+	// Checksum is the "checksum" field of a UDP packet.
+	Checksum uint16
+}
+
+// UDP represents a UDP header stored in a byte array.
+type UDP []byte
+
+const (
+	// UDPMinimumSize is the minimum size of a valid UDP packet.
+	UDPMinimumSize = 8
+
+	// UDPProtocolNumber is UDP's transport protocol number.
+	UDPProtocolNumber tcpip.TransportProtocolNumber = 17
+)