revamp error handling on tcp connection receive loop
- treat crypto decoding errors as errors instead of warnings - introduce helper for handling protocol messages - put conn.Shutdown in one place
This commit is contained in:
Matthias Radestock committed
1 parent
6253be6ecf
commit
3baa3c09a4
1 file changed
+63
-64
+63
-64
@@ -534,80 +534,79 @@ func (conn *LocalConnection) receiveTCP(decoder *gob.Decoder) {
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var msg []byte
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conn.extendReadDeadline()
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if err = decoder.Decode(&msg); err != nil {
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conn.Shutdown(err)
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return
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break
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}
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msg, err = receiver.Decode(msg)
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if err != nil {
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checkWarn(err)
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// remote peer may be using wrong password. Or there could
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// be some sort of injection attack going on. Just ignore
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// the traffic rather than shutting down.
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continue
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break
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}
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if len(msg) < 1 {
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conn.log("ignoring blank msg")
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continue
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}
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payload := msg[1:]
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switch ProtocolTag(msg[0]) {
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case ProtocolConnectionEstablished:
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// We sent fast heartbeats to the remote peer, which has
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// now received at least one of them and told us via this
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// message. We can now consider the connection as
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// established from our end.
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conn.SetEstablished()
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case ProtocolStartFragmentationTest:
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conn.Forward(false, &ForwardedFrame{
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srcPeer: conn.local,
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dstPeer: conn.remote,
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frame: FragTest},
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nil)
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case ProtocolFragmentationReceived:
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conn.setStackFrag(true)
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case ProtocolNonce:
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if usingPassword {
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conn.Decryptor.ReceiveNonce(payload)
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} else {
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conn.log("ignoring unexpected nonce on unencrypted connection")
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}
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case ProtocolFetchAll:
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// There are exactly two messages that relate to topology
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// updates.
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//
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// 1. FetchAll. This carries no payload. The receiver
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// responds with the entire topology model as the receiver
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// has it.
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//
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// 2. Update. This carries a topology payload. The
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// receiver merges it with its own topology model. If the
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// payload is a subset of the receiver's topology, no
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// further action is taken. Otherwise, the receiver sends
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// out to all its connections an "improved" update.
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conn.SendProtocolMsg(ProtocolMsg{ProtocolUpdate, conn.Router.Peers.EncodeAllPeers()})
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case ProtocolUpdate:
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newUpdate, err := conn.Router.Peers.ApplyUpdate(payload)
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if _, ok := err.(UnknownPeersError); err != nil && ok {
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// That update contained a peer we didn't know about;
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// request full update
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conn.SendProtocolMsg(ProtocolMsg{ProtocolFetchAll, nil})
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continue
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}
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if err != nil {
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conn.Shutdown(err)
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return
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}
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if len(newUpdate) != 0 {
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conn.Router.ConnectionMaker.Refresh()
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conn.Router.Routes.Recalculate()
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conn.Router.Ourself.SendProtocolMsg(ProtocolMsg{ProtocolUpdate, newUpdate})
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}
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case ProtocolPMTUVerified:
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conn.verifyPMTU <- int(binary.BigEndian.Uint16(payload))
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default:
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conn.log("received unknown msg:\n", msg)
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if err = conn.handleProtocolMsg(ProtocolTag(msg[0]), msg[1:]); err != nil {
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break
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}
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}
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conn.Shutdown(err)
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}
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func (conn *LocalConnection) handleProtocolMsg(tag ProtocolTag, payload []byte) error {
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switch tag {
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case ProtocolConnectionEstablished:
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// We sent fast heartbeats to the remote peer, which has now
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// received at least one of them and told us via this message.
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// We can now consider the connection as established from our
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// end.
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conn.SetEstablished()
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case ProtocolStartFragmentationTest:
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conn.Forward(false, &ForwardedFrame{
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srcPeer: conn.local,
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dstPeer: conn.remote,
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frame: FragTest},
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nil)
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case ProtocolFragmentationReceived:
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conn.setStackFrag(true)
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case ProtocolNonce:
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if conn.SessionKey == nil {
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return fmt.Errorf("unexpected nonce on unencrypted connection")
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}
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conn.Decryptor.ReceiveNonce(payload)
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case ProtocolFetchAll:
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// There are exactly two messages that relate to topology
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// updates.
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//
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// 1. FetchAll. This carries no payload. The receiver responds
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// with the entire topology model as the receiver has it.
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//
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// 2. Update. This carries a topology payload. The receiver
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// merges it with its own topology model. If the payload is a
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// subset of the receiver's topology, no further action is
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// taken. Otherwise, the receiver sends out to all its
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// connections an "improved" update.
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conn.SendProtocolMsg(ProtocolMsg{ProtocolUpdate, conn.Router.Peers.EncodeAllPeers()})
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case ProtocolUpdate:
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newUpdate, err := conn.Router.Peers.ApplyUpdate(payload)
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if _, ok := err.(UnknownPeersError); err != nil && ok {
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// That update contained a peer we didn't know about;
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// request full update
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conn.SendProtocolMsg(ProtocolMsg{ProtocolFetchAll, nil})
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break
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}
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if err != nil {
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return err
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}
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if len(newUpdate) != 0 {
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conn.Router.ConnectionMaker.Refresh()
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conn.Router.Routes.Recalculate()
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conn.Router.Ourself.SendProtocolMsg(ProtocolMsg{ProtocolUpdate, newUpdate})
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}
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case ProtocolPMTUVerified:
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conn.verifyPMTU <- int(binary.BigEndian.Uint16(payload))
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default:
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conn.log("ignoring unknown protocol tag:", tag)
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}
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return nil
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}
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func (conn *LocalConnection) extendReadDeadline() {
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