77 lines
2.4 KiB
Go
77 lines
2.4 KiB
Go
/* SPDX-License-Identifier: MIT
|
|
*
|
|
* Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
|
|
*/
|
|
|
|
package tun
|
|
|
|
import (
|
|
"os"
|
|
)
|
|
|
|
type Event int
|
|
|
|
const (
|
|
EventUp = 1 << iota
|
|
EventDown
|
|
EventMTUUpdate
|
|
)
|
|
|
|
type Device interface {
|
|
// File returns the file descriptor of the device.
|
|
File() *os.File
|
|
|
|
// Read one or more packets from the Device (without any additional headers).
|
|
// On a successful read it returns the number of packets read, and sets
|
|
// packet lengths within the sizes slice. len(sizes) must be >= len(bufs).
|
|
// A nonzero offset can be used to instruct the Device on where to begin
|
|
// reading into each element of the bufs slice.
|
|
Read(bufs [][]byte, sizes []int, offset int) (n int, err error)
|
|
|
|
// Write one or more packets to the device (without any additional headers).
|
|
// On a successful write it returns the number of packets written. A nonzero
|
|
// offset can be used to instruct the Device on where to begin writing from
|
|
// each packet contained within the bufs slice.
|
|
Write(bufs [][]byte, offset int) (int, error)
|
|
|
|
// MTU returns the MTU of the Device.
|
|
MTU() (int, error)
|
|
|
|
// Name returns the current name of the Device.
|
|
Name() (string, error)
|
|
|
|
// Events returns a channel of type Event, which is fed Device events.
|
|
Events() <-chan Event
|
|
|
|
// Close stops the Device and closes the Event channel.
|
|
Close() error
|
|
|
|
// BatchSize returns the preferred/max number of packets that can be read or
|
|
// written in a single read/write call. BatchSize must not change over the
|
|
// lifetime of a Device.
|
|
BatchSize() int
|
|
}
|
|
|
|
// GRODevice is a Device extended with methods for disabling GRO. Certain OS
|
|
// versions may have offload bugs. Where these bugs negatively impact throughput
|
|
// or break connectivity entirely we can use these methods to disable the
|
|
// related offload.
|
|
//
|
|
// Linux has the following known, GRO bugs.
|
|
//
|
|
// torvalds/linux@e269d79c7d35aa3808b1f3c1737d63dab504ddc8 broke virtio_net
|
|
// TCP & UDP GRO causing GRO writes to return EINVAL. The bug was then
|
|
// resolved later in
|
|
// torvalds/linux@89add40066f9ed9abe5f7f886fe5789ff7e0c50e. The offending
|
|
// commit was pulled into various LTS releases.
|
|
//
|
|
// UDP GRO writes end up blackholing/dropping packets destined for a
|
|
// vxlan/geneve interface on kernel versions prior to 6.8.5.
|
|
type GRODevice interface {
|
|
Device
|
|
// DisableUDPGRO disables UDP GRO if it is enabled.
|
|
DisableUDPGRO()
|
|
// DisableTCPGRO disables TCP GRO if it is enabled.
|
|
DisableTCPGRO()
|
|
}
|