wip: migrate to mono-repo. SPN has already been moved to spn/

service/network/packet/parse.go

@@ -0,0 +1,160 @@
+package packet
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/google/gopacket"
+	"github.com/google/gopacket/layers"
+)
+
+var layerType2IPProtocol map[gopacket.LayerType]IPProtocol
+
+func genIPProtocolFromLayerType() {
+	layerType2IPProtocol = make(map[gopacket.LayerType]IPProtocol)
+	for k, v := range layers.IPProtocolMetadata {
+		layerType2IPProtocol[v.LayerType] = IPProtocol(k)
+	}
+}
+
+func parseIPv4(packet gopacket.Packet, info *Info) error {
+	if ipv4, ok := packet.NetworkLayer().(*layers.IPv4); ok {
+		info.Version = IPv4
+		info.Src = ipv4.SrcIP
+		info.Dst = ipv4.DstIP
+		info.Protocol = IPProtocol(ipv4.Protocol)
+	}
+	return nil
+}
+
+func parseIPv6(packet gopacket.Packet, info *Info) error {
+	if ipv6, ok := packet.NetworkLayer().(*layers.IPv6); ok {
+		info.Version = IPv6
+		info.Src = ipv6.SrcIP
+		info.Dst = ipv6.DstIP
+		// we set Protocol to NextHeader as a fallback. If TCP or
+		// UDP layers are detected (somewhere in the list of options)
+		// the Protocol field is adjusted correctly.
+		info.Protocol = IPProtocol(ipv6.NextHeader)
+	}
+	return nil
+}
+
+func parseTCP(packet gopacket.Packet, info *Info) error {
+	if tcp, ok := packet.TransportLayer().(*layers.TCP); ok {
+		info.Protocol = TCP
+		info.SrcPort = uint16(tcp.SrcPort)
+		info.DstPort = uint16(tcp.DstPort)
+	}
+	return nil
+}
+
+func parseUDP(packet gopacket.Packet, info *Info) error {
+	if udp, ok := packet.TransportLayer().(*layers.UDP); ok {
+		info.Protocol = UDP
+		info.SrcPort = uint16(udp.SrcPort)
+		info.DstPort = uint16(udp.DstPort)
+	}
+	return nil
+}
+
+/*
+func parseUDPLite(packet gopacket.Packet, info *Info) error {
+	if udpLite, ok := packet.TransportLayer().(*layers.UDPLite); ok {
+		info.Protocol = UDPLite
+		info.SrcPort = uint16(udpLite.SrcPort)
+		info.DstPort = uint16(udpLite.DstPort)
+	}
+	return nil
+}
+*/
+
+func parseICMPv4(packet gopacket.Packet, info *Info) error {
+	if icmp, ok := packet.Layer(layers.LayerTypeICMPv4).(*layers.ICMPv4); ok {
+		info.Protocol = ICMP
+		_ = icmp
+	}
+	return nil
+}
+
+func parseICMPv6(packet gopacket.Packet, info *Info) error {
+	if icmp6, ok := packet.Layer(layers.LayerTypeICMPv6).(*layers.ICMPv6); ok {
+		info.Protocol = ICMPv6
+		_ = icmp6
+	}
+	return nil
+}
+
+func parseIGMP(packet gopacket.Packet, info *Info) error {
+	// gopacket uses LayerTypeIGMP for v1, v2 and v3 and may thus
+	// either return layers.IGMP or layers.IGMPv1or2
+	if layer := packet.Layer(layers.LayerTypeIGMP); layer != nil {
+		info.Protocol = IGMP
+	}
+	return nil
+}
+
+func checkError(packet gopacket.Packet, info *Info) error {
+	// Check for known unparseable before checking the error layer.
+	if info.Protocol == AnyHostInternalProtocol61 {
+		return nil
+	}
+
+	if err := packet.ErrorLayer(); err != nil {
+		return err.Error()
+	}
+	return nil
+}
+
+// Parse parses an IP packet and saves the information in the given packet object.
+func Parse(packetData []byte, pktBase *Base) (err error) {
+	if len(packetData) == 0 {
+		return errors.New("empty packet")
+	}
+	pktBase.layer3Data = packetData
+
+	ipVersion := packetData[0] >> 4
+	var networkLayerType gopacket.LayerType
+
+	switch ipVersion {
+	case 4:
+		networkLayerType = layers.LayerTypeIPv4
+	case 6:
+		networkLayerType = layers.LayerTypeIPv6
+	default:
+		return fmt.Errorf("unknown IP version or network protocol: %02x", ipVersion)
+	}
+
+	packet := gopacket.NewPacket(packetData, networkLayerType, gopacket.DecodeOptions{
+		Lazy:   true,
+		NoCopy: true,
+	})
+
+	availableDecoders := []func(gopacket.Packet, *Info) error{
+		parseIPv4,
+		parseIPv6,
+		parseTCP,
+		parseUDP,
+		// parseUDPLite, // We don't yet support udplite.
+		parseICMPv4,
+		parseICMPv6,
+		parseIGMP,
+		checkError,
+	}
+
+	for _, dec := range availableDecoders {
+		if err := dec(packet, pktBase.Info()); err != nil {
+			return err
+		}
+	}
+
+	pktBase.layers = packet
+	if transport := packet.TransportLayer(); transport != nil {
+		pktBase.layer5Data = transport.LayerPayload()
+	}
+	return nil
+}
+
+func init() {
+	genIPProtocolFromLayerType()
+}