some cleanup and doc updates

Author: hujun-open

afconn_linux.go

@@ -83,6 +83,9 @@ func getVLANsFromAncDataAFPkt(existList []uint16, auxdata []interface{}) []uint1
 	return r
 }
 
+// NewRawSocketRelayPcap creates a new RawSocketRelay instance using AF_PACKET socket , bound to the interface ifname,
+// optionally with RelayOption functions.
+// This function will put the interface in promisc mode, which means it requires root privilage.
 func NewRawSocketRelay(parentctx context.Context, ifname string, options ...RelayOption) (*RawSocketRelay, error) {
 	//NOTE:interface must be put in promisc mode, otherwise only pkt with real mac will be received
 	err := SetPromisc(ifname)
@@ -102,7 +105,7 @@ func NewRawSocketRelay(parentctx context.Context, ifname string, options ...Rela
 	if err != nil {
 		return nil, fmt.Errorf("failed to create rawsocketrelay,%w", err)
 	}
-	return NewRawSocketRelayWithRelayConn(parentctx, ifname, conn, options...)
+	return newRawSocketRelayWithRelayConn(parentctx, ifname, conn, options...)
 
 }
 

etherconn_linux_test.go

@@ -51,9 +51,9 @@ func getRawRelay(ctx context.Context, relayType etherconn.RelayType, ifname stri
 
 	switch relayType {
 	case etherconn.RelayTypePCAP:
-		return etherconn.NewRawSocketRelayPcap(context.Background(), ifname, mods...)
+		return etherconn.NewRawSocketRelayPcap(ctx, ifname, mods...)
 	case etherconn.RelayTypeAFP:
-		return etherconn.NewRawSocketRelay(context.Background(), ifname, mods...)
+		return etherconn.NewRawSocketRelay(ctx, ifname, mods...)
 
 	}
 	return nil, fmt.Errorf("%v is not a supported raw relay type", relayType)

nd/nd.go

@@ -143,11 +143,13 @@ func (v6nd *IPv6ND) sendNA(reqsrc, target net.IP, targetmac, dstmac net.Hardware
 	}
 	respicmp6Layer.SetNetworkLayerForChecksum(iplayer)
 	opts := gopacket.SerializeOptions{FixLengths: true, ComputeChecksums: true}
-	gopacket.SerializeLayers(buf, opts,
+	err = gopacket.SerializeLayers(buf, opts,
 		iplayer,
 		respicmp6Layer,
 		resp)
-
+	if err != nil {
+		return err
+	}
 	_, err = v6nd.pktSendF(buf.Bytes(), dstmac)
 	return err
 }
@@ -213,11 +215,13 @@ func (v6nd *IPv6ND) probe(nei *Neighbor) (err error) {
 	}
 	respicmp6Layer.SetNetworkLayerForChecksum(iplayer)
 	opts := gopacket.SerializeOptions{FixLengths: true, ComputeChecksums: true}
-	gopacket.SerializeLayers(buf, opts,
+	err = gopacket.SerializeLayers(buf, opts,
 		iplayer,
 		respicmp6Layer,
 		resp)
-
+	if err != nil {
+		return err
+	}
 	_, err = v6nd.pktSendF(buf.Bytes(), GetMulticastMACfromIPv6Addr(nei.IPAddr))
 	return err
 
@@ -249,7 +253,7 @@ func (v6nd *IPv6ND) houseKeeping(ctx context.Context) {
 	}
 }
 
-//pkt is should be an IP packet
+// pkt is should be an IP packet
 func (v6nd *IPv6ND) handleNDPkt(pkt gopacket.Packet) error {
 	var mac net.HardwareAddr = nil
 	var addr, target netip.Addr
@@ -315,7 +319,7 @@ func (v6nd *IPv6ND) handleNDPkt(pkt gopacket.Packet) error {
 	return nil
 }
 
-//Resolve resolve addr to mac based on local list, if not found and activeProbe is true, then send probe
+// Resolve resolve addr to mac based on local list, if not found and activeProbe is true, then send probe
 func (v6nd *IPv6ND) Resolve(addr netip.Addr) net.HardwareAddr {
 	v6nd.listLock.RLock()
 	if nei, ok := v6nd.neiList[addr]; ok {

pcaprelay.go

@@ -65,11 +65,14 @@ func (pconn *PcapConn) isTimeout(err error) bool {
 	}
 }
 
+// NewRawSocketRelayPcap creates a new RawSocketRelay instance using libpcap, bound to the interface ifname,
+// optionally with RelayOption functions.
+// This function will put the interface in promisc mode, which means it requires root privilage.
 func NewRawSocketRelayPcap(parentctx context.Context, ifname string, options ...RelayOption) (*RawSocketRelay, error) {
 	conn, err := NewPcapConn(ifname)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create rawsocketrelay,%w", err)
 	}
-	return NewRawSocketRelayWithRelayConn(parentctx, ifname, conn, options...)
+	return newRawSocketRelayWithRelayConn(parentctx, ifname, conn, options...)
 
 }

rawrelay.go

@@ -52,7 +52,8 @@ type rawRelayConn interface {
 
 type LogFunc func(fmt string, a ...interface{})
 
-// RawSocketRelay implements PacketRelay interface, using AF_PACKET socket
+// RawSocketRelay implements PacketRelay interface, using AF_PACKET socket or libpcap.
+// use NewRawSocketRelayPcap or NewRawSocketRelay create new instances.
 type RawSocketRelay struct {
 	conn                 rawRelayConn
 	toSendChan           chan []byte
@@ -78,11 +79,11 @@ type RawSocketRelay struct {
 // RelayOption is a function use to provide customized option when creating RawSocketRelay
 type RelayOption func(*RawSocketRelay)
 
-// NewRawSocketRelay creates a new RawSocketRelay instance,
+// newRawSocketRelay creates a new RawSocketRelay instance,
 // bound to the interface ifname,
 // optionally along with RelayOption functions.
 // This function will put the interface in promisc mode, which means it requires root privilage
-func NewRawSocketRelayWithRelayConn(parentctx context.Context, ifname string, conn rawRelayConn, options ...RelayOption) (*RawSocketRelay, error) {
+func newRawSocketRelayWithRelayConn(parentctx context.Context, ifname string, conn rawRelayConn, options ...RelayOption) (*RawSocketRelay, error) {
 	r := &RawSocketRelay{}
 	var err error
 	r.ifName = ifname
@@ -198,6 +199,7 @@ func WithDefaultReceival(mirroring bool) RelayOption {
 	}
 }
 
+// Type returns rsr's type
 func (rsr *RawSocketRelay) Type() RelayType {
 	return rsr.conn.relayType()
 }

xdpconn_linux.go

@@ -246,9 +246,9 @@ func (s *xdpSock) recv(ctx context.Context) {
 				for i := 0; i < len(rxDescs); i++ {
 					pktData := make([]byte, len(s.sock.GetFrame(rxDescs[i])))
 					copy(pktData, s.sock.GetFrame(rxDescs[i]))
-					if s.relay.rxh != nil {
-						s.relay.rxh(pktData, s.qid)
-					}
+					// if s.relay.rxh != nil {
+					// 	s.relay.rxh(pktData, s.qid)
+					// }
 					handleRcvPkt(UnknownRelay, pktData, s.relay.stats, logf,
 						s.relay.recvList, s.relay.mirrorToDefault,
 						s.relay.defaultRecvChan, s.relay.multicastList, nil)
@@ -284,9 +284,9 @@ type XDPRelay struct {
 	defaultRecvChan   chan *RelayReceival
 	mirrorToDefault   bool
 	recvBytesChan     chan []byte
-	rxh, txh          XDPSocketPktHandler
-	sendingMode       XDPSendingMode
-	recvEtypes        []uint16
+	// rxh, txh          XDPSocketPktHandler
+	sendingMode XDPSendingMode
+	recvEtypes  []uint16
 }
 
 // XDPRelayOption could be used in NewXDPRelay to customize XDPRelay upon creation
@@ -400,18 +400,18 @@ func WithXDPExtProg(fname, prog, qmap, xskmap, etypemap string) XDPRelayOption {
 }
 
 // WithXDPRXPktHandler sets h as the rx packet handler
-func WithXDPRXPktHandler(h XDPSocketPktHandler) XDPRelayOption {
-	return func(relay *XDPRelay) {
-		relay.rxh = h
-	}
-}
+// func WithXDPRXPktHandler(h XDPSocketPktHandler) XDPRelayOption {
+// 	return func(relay *XDPRelay) {
+// 		relay.rxh = h
+// 	}
+// }
 
 // WithXDPTXPktHandler sets h as the tx packet handler
-func WithXDPTXPktHandler(h XDPSocketPktHandler) XDPRelayOption {
-	return func(relay *XDPRelay) {
-		relay.txh = h
-	}
-}
+// func WithXDPTXPktHandler(h XDPSocketPktHandler) XDPRelayOption {
+// 	return func(relay *XDPRelay) {
+// 		relay.txh = h
+// 	}
+// }
 
 const (
 	// DefaultXDPUMEMNumOfTrunk is the default number of UMEM trunks
@@ -611,7 +611,7 @@ func SetIfVLANOffloading(ifname string, enable bool) error {
 	return etool.Change(ifname, vlanoffloadingsetting)
 }
 
-const builtinProgFileName = "xdpethfilter_kern.o"
+// const builtinProgFileName = "xdpethfilter_kern.o"
 
 func loadEBPFProgViaReader(r io.ReaderAt, funcname, qidmapname, xskmapname, ethertypemap string) (*xdp.Program, *ebpf.Map, error) {
 	prog := new(xdp.Program)
@@ -633,7 +633,7 @@ func loadEBPFProgViaReader(r io.ReaderAt, funcname, qidmapname, xskmapname, ethe
 	if prog.Sockets, ok = col.Maps[xskmapname]; !ok {
 		return nil, nil, fmt.Errorf("can't find a socket map named %v", xskmapname)
 	}
-	var elist *ebpf.Map = nil
+	var elist *ebpf.Map
 	if elist, ok = col.Maps[ethertypemap]; !ok {
 		return nil, nil, fmt.Errorf("can't find a socket map named %v", xskmapname)
 	}