121 lines
2.5 KiB
Go
121 lines
2.5 KiB
Go
package node
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import (
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"errors"
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"net/netip"
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)
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var (
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errMalformedPacket = errors.New("malformed packet")
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errUnknownPacketType = errors.New("unknown packet type")
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)
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const (
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packetTypeSyn = iota + 1
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packetTypeSynAck
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packetTypeAck
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packetTypeProbe
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packetTypeAddrDiscovery
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)
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// ----------------------------------------------------------------------------
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type synPacket struct {
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TraceID uint64 // TraceID to match response w/ request.
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SharedKey [32]byte // Our shared key.
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Direct bool
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FromAddr netip.AddrPort // The client's sending address.
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}
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func (p synPacket) Marshal(buf []byte) []byte {
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return newBinWriter(buf).
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Byte(packetTypeSyn).
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Uint64(p.TraceID).
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SharedKey(p.SharedKey).
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Bool(p.Direct).
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AddrPort(p.FromAddr).
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Build()
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}
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func parseSynPacket(buf []byte) (p synPacket, err error) {
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err = newBinReader(buf[1:]).
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Uint64(&p.TraceID).
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SharedKey(&p.SharedKey).
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Bool(&p.Direct).
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AddrPort(&p.FromAddr).
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Error()
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return
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}
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// ----------------------------------------------------------------------------
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type synAckPacket struct {
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TraceID uint64
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FromAddr netip.AddrPort
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}
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func (p synAckPacket) Marshal(buf []byte) []byte {
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return newBinWriter(buf).
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Byte(packetTypeSynAck).
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Uint64(p.TraceID).
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AddrPort(p.FromAddr).
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Build()
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}
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func parseSynAckPacket(buf []byte) (p synAckPacket, err error) {
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err = newBinReader(buf[1:]).
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Uint64(&p.TraceID).
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AddrPort(&p.FromAddr).
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Error()
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return
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}
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// ----------------------------------------------------------------------------
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type addrDiscoveryPacket struct {
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TraceID uint64
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ToAddr netip.AddrPort
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}
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func (p addrDiscoveryPacket) Marshal(buf []byte) []byte {
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return newBinWriter(buf).
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Byte(packetTypeAddrDiscovery).
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Uint64(p.TraceID).
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AddrPort(p.ToAddr).
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Build()
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}
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func parseAddrDiscoveryPacket(buf []byte) (p addrDiscoveryPacket, err error) {
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err = newBinReader(buf[1:]).
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Uint64(&p.TraceID).
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AddrPort(&p.ToAddr).
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Error()
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return
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}
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// ----------------------------------------------------------------------------
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// A probeReqPacket is sent from a client to a server to determine if direct
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// UDP communication can be used.
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type probePacket struct {
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TraceID uint64
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}
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func (p probePacket) Marshal(buf []byte) []byte {
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return newBinWriter(buf).
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Byte(packetTypeProbe).
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Uint64(p.TraceID).
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Build()
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}
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func parseProbePacket(buf []byte) (p probePacket, err error) {
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err = newBinReader(buf[1:]).
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Uint64(&p.TraceID).
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Error()
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return
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}
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// ----------------------------------------------------------------------------
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type localDiscoveryPacket struct{}
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