github.com/MerlinKodo/quic-go@v0.39.2/closed_conn.go (about)

     1  package quic
     2  
     3  import (
     4  	"math/bits"
     5  	"net"
     6  
     7  	"github.com/MerlinKodo/quic-go/internal/protocol"
     8  	"github.com/MerlinKodo/quic-go/internal/utils"
     9  )
    10  
    11  // A closedLocalConn is a connection that we closed locally.
    12  // When receiving packets for such a connection, we need to retransmit the packet containing the CONNECTION_CLOSE frame,
    13  // with an exponential backoff.
    14  type closedLocalConn struct {
    15  	counter     uint32
    16  	perspective protocol.Perspective
    17  	logger      utils.Logger
    18  
    19  	sendPacket func(net.Addr, packetInfo)
    20  }
    21  
    22  var _ packetHandler = &closedLocalConn{}
    23  
    24  // newClosedLocalConn creates a new closedLocalConn and runs it.
    25  func newClosedLocalConn(sendPacket func(net.Addr, packetInfo), pers protocol.Perspective, logger utils.Logger) packetHandler {
    26  	return &closedLocalConn{
    27  		sendPacket:  sendPacket,
    28  		perspective: pers,
    29  		logger:      logger,
    30  	}
    31  }
    32  
    33  func (c *closedLocalConn) handlePacket(p receivedPacket) {
    34  	c.counter++
    35  	// exponential backoff
    36  	// only send a CONNECTION_CLOSE for the 1st, 2nd, 4th, 8th, 16th, ... packet arriving
    37  	if bits.OnesCount32(c.counter) != 1 {
    38  		return
    39  	}
    40  	c.logger.Debugf("Received %d packets after sending CONNECTION_CLOSE. Retransmitting.", c.counter)
    41  	c.sendPacket(p.remoteAddr, p.info)
    42  }
    43  
    44  func (c *closedLocalConn) shutdown()                            {}
    45  func (c *closedLocalConn) destroy(error)                        {}
    46  func (c *closedLocalConn) getPerspective() protocol.Perspective { return c.perspective }
    47  
    48  // A closedRemoteConn is a connection that was closed remotely.
    49  // For such a connection, we might receive reordered packets that were sent before the CONNECTION_CLOSE.
    50  // We can just ignore those packets.
    51  type closedRemoteConn struct {
    52  	perspective protocol.Perspective
    53  }
    54  
    55  var _ packetHandler = &closedRemoteConn{}
    56  
    57  func newClosedRemoteConn(pers protocol.Perspective) packetHandler {
    58  	return &closedRemoteConn{perspective: pers}
    59  }
    60  
    61  func (s *closedRemoteConn) handlePacket(receivedPacket)          {}
    62  func (s *closedRemoteConn) shutdown()                            {}
    63  func (s *closedRemoteConn) destroy(error)                        {}
    64  func (s *closedRemoteConn) getPerspective() protocol.Perspective { return s.perspective }