ipv6: StackIP and StackAsync.Addr refactor (#105)

* apply StackIP changes and internet package test passing * fix tests and examples * remove old Reset method on StackIP * use encapsulate for ipv6 * add TCP over IPv6 tests
2026-08-15 20:33:43 +00:00 · 2026-05-09 16:11:31 -03:00
parent a430f6c40a
commit bdbd38ab44
22 changed files with 609 additions and 357 deletions
@@ -0,0 +1,144 @@
+package internet
+
+import (
+	"log/slog"
+
+	"github.com/soypat/lneto"
+	"github.com/soypat/lneto/ipv6"
+	"github.com/soypat/lneto/tcp"
+	"github.com/soypat/lneto/udp"
+)
+
+// stackip6 is NOT a StackNode implementation.
+// It is meant to be embedded within StackNodes.
+// var _ lneto.StackNode = (*stackip6)(nil)
+
+type stackip6 struct {
+	handlers        handlers
+	vld             *lneto.Validator
+	ip6             [16]byte
+	acceptMulticast bool
+}
+
+func (si6 *stackip6) Register6(h lneto.StackNode) error {
+	proto := h.Protocol()
+	if proto > 255 {
+		return lneto.ErrInvalidConfig
+	}
+	return si6.handlers.registerByPortProto(nodeFromStackNode(h, h.LocalPort(), proto, nil))
+}
+
+func (si6 *stackip6) IsRegistered6(proto lneto.IPProto) bool {
+	return si6.handlers.nodeByProto(uint16(proto)) != nil
+}
+
+func (si6 *stackip6) SetAcceptMulticast6(accept bool) { si6.acceptMulticast = accept }
+func (si6 *stackip6) Addr6() [16]byte                 { return si6.ip6 }
+func (si6 *stackip6) SetAddr6(ip6 [16]byte)           { si6.ip6 = ip6 }
+
+func (si6 *stackip6) reset6(vld *lneto.Validator, maxNodes int) {
+	*si6 = stackip6{
+		handlers: si6.handlers,
+		vld:      vld,
+	}
+	si6.handlers.reset("stackip6", maxNodes)
+}
+
+func (si6 *stackip6) demux6(carrierData []byte, offset int) error {
+	debugLog("ip6:demux")
+	si6.handlers.info("StackIP6.Demux:start")
+	ifrm, err := ipv6.NewFrame(carrierData[offset:])
+	if err != nil {
+		return err
+	}
+	dst := ifrm.DestinationAddr()
+	if si6.ip6 != ([16]byte{}) && *dst != si6.ip6 {
+		if !si6.acceptMulticast || dst[0] != 0xFF {
+			si6.handlers.debug("ip6:not-for-us")
+			return lneto.ErrPacketDrop
+		}
+	}
+
+	si6.vld.ResetErr()
+	ifrm.ValidateSize(si6.vld)
+	if err = si6.vld.ErrPop(); err != nil {
+		si6.handlers.error("ip6:Demux.validate")
+		return err
+	}
+
+	proto := ifrm.NextHeader()
+	node := si6.handlers.nodeByProto(uint16(proto))
+	if node == nil {
+		si6.handlers.info("ip6:demux.drop", slog.String("proto", proto.String()))
+		return lneto.ErrPacketDrop
+	}
+	payload := ifrm.Payload()
+	var crc lneto.CRC791
+	switch proto {
+	case lneto.IPProtoTCP:
+		ifrm.CRCWritePseudo(&crc)
+		if crc.PayloadSum16(payload) != 0 {
+			si6.handlers.error("ip6:demux.tcpcrc")
+			return lneto.ErrBadCRC
+		}
+	case lneto.IPProtoUDP:
+		ufrm, err := udp.NewFrame(payload)
+		if err != nil {
+			return err
+		}
+		ufrm.ValidateSize(si6.vld)
+		if err = si6.vld.ErrPop(); err != nil {
+			si6.handlers.error("ip6:demux.udpvalidatesize")
+			return err
+		}
+		ifrm.CRCWritePseudo(&crc)
+		if crc.PayloadSum16(payload) != 0 {
+			si6.handlers.error("ip6:demux.udpcrc")
+			return lneto.ErrBadCRC
+		}
+	}
+	const headerlen = 40
+	plen := ifrm.PayloadLength()
+	si6.handlers.info("ip6Demux", slog.String("ipproto", proto.String()), slog.Int("plen", int(plen)))
+	err = node.callbacks.Demux(carrierData[offset:offset+headerlen+int(plen)], headerlen)
+	if si6.handlers.tryHandleError(node, err) {
+		si6.handlers.info("ip6close", slog.String("proto", proto.String()))
+		err = nil
+	}
+	return err
+}
+
+func (si6 *stackip6) encapsulate6(carrierData []byte, offsetToIP int) (int, error) {
+	ifrm, err := ipv6.NewFrame(carrierData[offsetToIP:])
+	if err != nil {
+		return 0, err
+	}
+	// Set default parameters which node is free to change.
+	ifrm.SetVersionTrafficAndFlow(6, 0, 0)
+	ifrm.SetHopLimit(64)
+	*ifrm.SourceAddr() = si6.ip6
+	const headerlen = 40
+	node, n, err := si6.handlers.encapsulateAny(carrierData, offsetToIP, offsetToIP+headerlen)
+	if n == 0 {
+		return n, err
+	}
+	proto := lneto.IPProto(node.proto)
+	ifrm.SetNextHeader(proto)
+	ifrm.SetPayloadLength(uint16(n))
+	var crc lneto.CRC791
+	payload := ifrm.Payload()
+	switch proto {
+	case lneto.IPProtoTCP:
+		ifrm.CRCWritePseudo(&crc)
+		tfrm, _ := tcp.NewFrame(payload)
+		tfrm.SetCRC(0)
+		tfrm.SetCRC(crc.PayloadSum16(payload))
+	case lneto.IPProtoUDP:
+		ufrm, _ := udp.NewFrame(payload)
+		ufrm.SetLength(uint16(n))
+		ifrm.CRCWritePseudo(&crc)
+		ufrm.SetCRC(0)
+		ufrm.SetCRC(lneto.NeverZeroSum(crc.PayloadSum16(payload)))
+	}
+	return headerlen + n, err
+}