tailscale/wgengine/magicsock/dontfrag_darwin.go

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// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
//go:build darwin && !ios
package magicsock
import (
"net"
"syscall"
"golang.org/x/sys/unix"
"tailscale.com/types/nettype"
)
func setDontFragment(pconn nettype.PacketConn, network string) (err error) {
if c, ok := pconn.(*net.UDPConn); ok {
rc, err := c.SyscallConn()
if err == nil {
rc.Control(func(fd uintptr) {
if network == "udp4" {
err = syscall.SetsockoptInt(int(fd), syscall.IPPROTO_IP, unix.IP_DONTFRAG, 1)
}
if network == "udp6" {
err = syscall.SetsockoptInt(int(fd), syscall.IPPROTO_IPV6, unix.IPV6_DONTFRAG, 1)
}
})
}
}
return err
}
func CanPMTUD() bool {
return debugPMTUD() // only if the envknob is for now.
}