cloudflared-mirror/vendor/github.com/lucas-clemente/quic-go/sys_conn.go

81 lines
2.3 KiB
Go

package quic
import (
"net"
"syscall"
"time"
"github.com/lucas-clemente/quic-go/internal/protocol"
"github.com/lucas-clemente/quic-go/internal/utils"
)
// OOBCapablePacketConn is a connection that allows the reading of ECN bits from the IP header.
// If the PacketConn passed to Dial or Listen satisfies this interface, quic-go will use it.
// In this case, ReadMsgUDP() will be used instead of ReadFrom() to read packets.
type OOBCapablePacketConn interface {
net.PacketConn
SyscallConn() (syscall.RawConn, error)
ReadMsgUDP(b, oob []byte) (n, oobn, flags int, addr *net.UDPAddr, err error)
WriteMsgUDP(b, oob []byte, addr *net.UDPAddr) (n, oobn int, err error)
}
var _ OOBCapablePacketConn = &net.UDPConn{}
func wrapConn(pc net.PacketConn) (rawConn, error) {
conn, ok := pc.(interface {
SyscallConn() (syscall.RawConn, error)
})
if ok {
rawConn, err := conn.SyscallConn()
if err != nil {
return nil, err
}
if _, ok := pc.LocalAddr().(*net.UDPAddr); ok {
// Only set DF on sockets that we expect to be able to handle that configuration.
err = setDF(rawConn)
if err != nil {
return nil, err
}
}
}
c, ok := pc.(OOBCapablePacketConn)
if !ok {
utils.DefaultLogger.Infof("PacketConn is not a net.UDPConn. Disabling optimizations possible on UDP connections.")
return &basicConn{PacketConn: pc}, nil
}
return newConn(c)
}
// The basicConn is the most trivial implementation of a connection.
// It reads a single packet from the underlying net.PacketConn.
// It is used when
// * the net.PacketConn is not a OOBCapablePacketConn, and
// * when the OS doesn't support OOB.
type basicConn struct {
net.PacketConn
}
var _ rawConn = &basicConn{}
func (c *basicConn) ReadPacket() (*receivedPacket, error) {
buffer := getPacketBuffer()
// The packet size should not exceed protocol.MaxPacketBufferSize bytes
// If it does, we only read a truncated packet, which will then end up undecryptable
buffer.Data = buffer.Data[:protocol.MaxPacketBufferSize]
n, addr, err := c.PacketConn.ReadFrom(buffer.Data)
if err != nil {
return nil, err
}
return &receivedPacket{
remoteAddr: addr,
rcvTime: time.Now(),
data: buffer.Data[:n],
buffer: buffer,
}, nil
}
func (c *basicConn) WritePacket(b []byte, addr net.Addr, _ []byte) (n int, err error) {
return c.PacketConn.WriteTo(b, addr)
}