forked from quic-go/quic-go
eb6bdfdfc1
When the server is listening on multiple interfaces or interfaces with multiple IPs, the outgoing datagrams are sometime delivered with the wrong source IP address. In order to fix that, each quic connection needs to extract the destination IP (and optionally interface id) of the received datagrams, and set it as source IP (and interface) on the sent datagrams. On most platforms, this can be done using ancillary data with recvmsg() and sendmsg(). Some of the machinery for this is already there for ECN, this change extends it to read the destination IP info and write it to the outgoing packets. Fix #1736
66 lines
1.8 KiB
Go
66 lines
1.8 KiB
Go
package quic
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import (
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"io"
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"net"
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"syscall"
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"time"
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"github.com/lucas-clemente/quic-go/internal/protocol"
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"github.com/lucas-clemente/quic-go/internal/utils"
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)
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type connection interface {
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ReadPacket() (*receivedPacket, error)
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WritePacket(b []byte, addr net.Addr, info *packetInfo) (int, error)
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LocalAddr() net.Addr
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io.Closer
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}
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// If the PacketConn passed to Dial or Listen satisfies this interface, quic-go will read the ECN bits from the IP header.
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// In this case, ReadMsgUDP() will be used instead of ReadFrom() to read packets.
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type OOBCapablePacketConn interface {
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net.PacketConn
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SyscallConn() (syscall.RawConn, error)
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ReadMsgUDP(b, oob []byte) (n, oobn, flags int, addr *net.UDPAddr, err error)
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WriteMsgUDP(b, oob []byte, addr *net.UDPAddr) (n, oobn int, err error)
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}
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var _ OOBCapablePacketConn = &net.UDPConn{}
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func wrapConn(pc net.PacketConn) (connection, error) {
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c, ok := pc.(OOBCapablePacketConn)
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if !ok {
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utils.DefaultLogger.Infof("PacketConn is not a net.UDPConn. Disabling optimizations possible on UDP connections.")
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return &basicConn{PacketConn: pc}, nil
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}
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return newConn(c)
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}
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type basicConn struct {
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net.PacketConn
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}
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var _ connection = &basicConn{}
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func (c *basicConn) ReadPacket() (*receivedPacket, error) {
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buffer := getPacketBuffer()
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// The packet size should not exceed protocol.MaxPacketBufferSize bytes
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// If it does, we only read a truncated packet, which will then end up undecryptable
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buffer.Data = buffer.Data[:protocol.MaxPacketBufferSize]
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n, addr, err := c.PacketConn.ReadFrom(buffer.Data)
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if err != nil {
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return nil, err
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}
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return &receivedPacket{
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remoteAddr: addr,
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rcvTime: time.Now(),
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data: buffer.Data[:n],
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buffer: buffer,
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}, nil
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}
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func (c *basicConn) WritePacket(b []byte, addr net.Addr, info *packetInfo) (n int, err error) {
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return c.PacketConn.WriteTo(b, addr)
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}
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