round most of stack example

lneto_test.go

@@ -5,18 +5,18 @@ import (
 	"math/rand"
 	"testing"
 
-	"github.com/soypat/lneto/tcp"
+	"github.com/soypat/lneto/internal/ltesto"
 )
 
 func TestTCPMarshalUnmarshal(t *testing.T) {
 	rng := rand.New(rand.NewSource(1))
-	var gen packetGen
-	gen.randomizeAddrs(rng)
+	var gen ltesto.PacketGen
+	gen.RandomizeAddrs(rng)
 	const maxSize = 4096
 	src := make([]byte, maxSize)
 	dst := make([]byte, maxSize)
 	for i := 0; i < 512; i++ {
-		src = gen.appendRandomIPv4TCPPacket(src[:0], rng)
+		src = gen.AppendRandomIPv4TCPPacket(src[:0], rng)
 		dst = dst[:len(src)]
 		testMoveTCPPacket(t, src, dst)
 		if !bytes.Equal(src, dst) {
@@ -105,134 +105,3 @@ func testMoveTCPPacket(t *testing.T, src, dst []byte) {
 		t.Fatalf("payload mismatch %d %d", len(payload), len(tfrm2.Payload()))
 	}
 }
-
-type packetGen struct {
-	srcMAC, dstMAC   [6]byte // hardware address
-	srcIPv4, dstIPv4 [4]byte // address
-	srcTCP, dstTCP   uint16  // ports
-}
-
-func (gen *packetGen) randomizeAddrs(rng *rand.Rand) {
-	rng.Read(gen.srcMAC[:])
-	rng.Read(gen.dstMAC[:])
-	rng.Read(gen.srcIPv4[:])
-	rng.Read(gen.dstIPv4[:])
-	ports := rng.Uint32()
-	gen.srcTCP = uint16(ports)
-	gen.dstTCP = uint16(ports >> 16)
-}
-
-func (gen *packetGen) appendRandomIPv4TCPPacket(dst []byte, rng *rand.Rand) []byte {
-	ri := rng.Int()
-	var (
-		isVLAN     = ri&(1<<0) != 0
-		hasIPOpt   = ri&(1<<1) != 0
-		hasTCPOpt  = ri&(1<<2) != 0
-		hasPayload = ri&(1<<3) != 0
-	)
-	var etherType EtherType = EtherTypeIPv4
-	var ipOpts []byte
-	if hasIPOpt {
-		ipOpts = []byte{1, 2, 3, 4}
-	}
-	ethsize := 14
-	if isVLAN {
-		etherType = EtherTypeVLAN
-		ethsize = 18
-	}
-	var tcpOpts []byte
-	if hasTCPOpt {
-		tcpOpts = []byte{byte(tcp.OptSACKPermitted), 0, 1, 0}
-	}
-	var payloadLen int
-	if hasPayload {
-		payloadLen = (ri >> 16) % 1024
-	}
-	ipOptWLen := sizeWord(len(ipOpts))
-	tcpOptWlen := sizeWord(len(tcpOpts))
-	off := len(dst)
-	dst = append(dst, make([]byte, ethsize+sizeHeaderIPv4+4*int(ipOptWLen)+sizeHeaderTCP+4*int(tcpOptWlen)+payloadLen)...)
-	efrm, err := NewEthFrame(dst[off:])
-	if err != nil {
-		panic(err)
-	}
-	*efrm.DestinationHardwareAddr() = gen.dstMAC
-	*efrm.SourceHardwareAddr() = gen.srcMAC
-
-	efrm.SetEtherType(etherType)
-	if isVLAN {
-		efrm.SetVLANEtherType(EtherTypeIPv4)
-		efrm.SetVLANTag(1 << 4)
-	}
-	ethernetPayload := efrm.Payload()
-	ifrm, err := NewIPv4Frame(ethernetPayload)
-	if err != nil {
-		panic(err)
-	}
-	ifrm.SetVersionAndIHL(4, sizeWord(20+len(ipOpts)))
-	ifrm.SetToS(192)
-	ifrm.SetTotalLength(uint16(len(ethernetPayload)))
-	ifrm.SetID(uint16(rng.Uint32()))
-	ifrm.SetFlags(0x4001) // Don't fragment.
-	ifrm.SetTTL(64)
-	ifrm.SetProtocol(IPProtoTCP)
-	*ifrm.SourceAddr() = gen.srcIPv4
-	*ifrm.DestinationAddr() = gen.dstIPv4
-	ifrm.SetCRC(ifrm.CalculateHeaderCRC())
-
-	ipPayload := ifrm.Payload()
-	tfrm, err := NewTCPFrame(ipPayload)
-	if err != nil {
-		panic(err)
-	}
-	tfrm.SetSourcePort(gen.srcTCP)
-	tfrm.SetDestinationPort(gen.dstTCP)
-	tfrm.SetSeq(tcp.Value(rng.Uint32()))
-	tfrm.SetAck(tcp.Value(rng.Uint32()))
-	wlen := sizeWord(sizeHeaderTCP + len(tcpOpts))
-	tfrm.SetOffsetAndFlags(wlen, tcp.Flags(rng.Uint32()))
-	tfrm.SetWindowSize(uint16(rng.Uint32()))
-	urgPtr := uint16(rng.Uint32())
-	tfrm.SetUrgentPtr(urgPtr)
-	tcpPayload := tfrm.Payload()
-	var firstPayloadByte byte
-	if len(tcpPayload) > 0 {
-		rng.Read(tcpPayload)
-		firstPayloadByte = tcpPayload[0]
-	}
-	// Set Variable section of data.
-	copy(ifrm.Options(), ipOpts)
-	copy(tfrm.Options(), tcpOpts)
-	switch {
-	case gen.srcTCP != tfrm.SourcePort():
-		panic("IP options overwrite TCP header")
-	case !bytes.Equal(ifrm.Options(), ipOpts):
-		panic("bad ip options written, ensure ip options length is multiple of 4")
-	case !bytes.Equal(tfrm.Options(), tcpOpts):
-		panic("bad tcp options written, ensure tcp options length is multiple of 4")
-	case *ifrm.DestinationAddr() != gen.dstIPv4:
-		panic("IP options overwrite own header")
-	case tfrm.UrgentPtr() != urgPtr:
-		panic("TCP options overwrite urgent pointer field?")
-	case len(tcpPayload) > 0 && firstPayloadByte != tcpPayload[0]:
-		panic("TCP options overwrite payload")
-	}
-	var vld Validator
-	efrm.ValidateSize(&vld)
-	if err = vld.Err(); err != nil {
-		panic(err)
-	}
-	ifrm.Validate(&vld)
-	if err = vld.Err(); err != nil {
-		panic(err)
-	}
-	tfrm.ValidateSize(&vld)
-	if err = vld.Err(); err != nil {
-		panic(err)
-	}
-	return dst
-}
-
-func sizeWord(l int) uint8 {
-	return uint8((l + 3) / 4)
-}