104 lines
1.9 KiB
Go
104 lines
1.9 KiB
Go
package node
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import (
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"log"
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"net"
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"net/netip"
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"vppn/fasttime"
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)
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type connWriter struct {
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*net.UDPConn
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localIP byte
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buf []byte
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counters [256]uint64
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lookup func(byte) *peer
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}
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func newConnWriter(conn *net.UDPConn, localIP byte, lookup func(byte) *peer) *connWriter {
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w := &connWriter{
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UDPConn: conn,
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localIP: localIP,
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buf: make([]byte, bufferSize),
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lookup: lookup,
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}
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for i := range w.counters {
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w.counters[i] = uint64(fasttime.Now() << 30)
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}
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return w
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}
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func (w *connWriter) WriteTo(remoteIP, packetType byte, data []byte) error {
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peer := w.lookup(remoteIP)
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if peer == nil || peer.Addr == nil {
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log.Printf("No peer: %d", remoteIP)
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return nil
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}
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w.counters[remoteIP]++
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h := header{
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Counter: w.counters[remoteIP],
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SourceIP: w.localIP,
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ViaIP: 0,
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DestIP: remoteIP,
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PacketType: packetType,
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DataSize: uint16(len(data)),
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}
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buf := w.buf[:len(data)+headerSize]
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h.Marshal(buf)
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copy(buf[headerSize:], data)
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_, err := w.WriteToUDPAddrPort(buf, *peer.Addr)
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return err
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}
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// ----------------------------------------------------------------------------
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type connReader struct {
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*net.UDPConn
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localIP byte
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counters [256]uint64
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lookup func(byte) *peer
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}
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func newConnReader(conn *net.UDPConn, localIP byte, lookup func(byte) *peer) *connReader {
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return &connReader{
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UDPConn: conn,
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localIP: localIP,
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lookup: lookup,
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}
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}
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func (r *connReader) Read(buf []byte) (remoteAddr netip.AddrPort, h header, data []byte, err error) {
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var n int
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for {
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n, remoteAddr, err = r.ReadFromUDPAddrPort(buf[:bufferSize])
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if err != nil {
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return
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}
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buf = buf[:n]
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if n < headerSize {
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continue // Packet it soo short.
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}
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h.Parse(buf)
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data = buf[headerSize:]
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if len(data) != int(h.DataSize) {
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continue // Packet is corrupt.
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}
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if h.Counter > r.counters[h.SourceIP] {
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r.counters[h.SourceIP] = h.Counter
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}
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return
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}
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}
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