tailscale/wgengine/magicsock/peermtu_linux.go

50 lines
1.0 KiB
Go

// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
//go:build linux && !android
package magicsock
import (
"syscall"
)
func getDontFragOpt(network string) int {
if network == "udp4" {
return syscall.IP_MTU_DISCOVER
}
return syscall.IPV6_MTU_DISCOVER
}
func (c *Conn) setDontFragment(network string, enable bool) error {
optArg := syscall.IP_PMTUDISC_DO
if enable == false {
optArg = syscall.IP_PMTUDISC_DONT
}
var err error
rcErr := c.connControl(network, func(fd uintptr) {
err = syscall.SetsockoptInt(int(fd), getIPProto(network), getDontFragOpt(network), optArg)
})
if rcErr != nil {
return rcErr
}
return err
}
func (c *Conn) getDontFragment(network string) (bool, error) {
var v int
var err error
rcErr := c.connControl(network, func(fd uintptr) {
v, err = syscall.GetsockoptInt(int(fd), getIPProto(network), getDontFragOpt(network))
})
if rcErr != nil {
return false, rcErr
}
if v == syscall.IP_PMTUDISC_DO {
return true, err
}
return false, err
}