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a5ae21a832
Add an enable/disable argument to setDontFragment() in preparation for dynamic enable/disable of peer path MTU discovery. Add getDontFragment() to get the status of the don't fragment bit from a socket. Updates #311 Co-authored-by: James Tucker <james@tailscale.com> Signed-off-by: Val <valerie@tailscale.com>
50 lines
1.0 KiB
Go
50 lines
1.0 KiB
Go
// Copyright (c) Tailscale Inc & AUTHORS
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// SPDX-License-Identifier: BSD-3-Clause
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//go:build linux && !android
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package magicsock
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import (
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"syscall"
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)
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func getDontFragOpt(network string) int {
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if network == "udp4" {
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return syscall.IP_MTU_DISCOVER
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}
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return syscall.IPV6_MTU_DISCOVER
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}
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func (c *Conn) setDontFragment(network string, enable bool) error {
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optArg := syscall.IP_PMTUDISC_DO
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if enable == false {
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optArg = syscall.IP_PMTUDISC_DONT
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}
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var err error
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rcErr := c.connControl(network, func(fd uintptr) {
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err = syscall.SetsockoptInt(int(fd), getIPProto(network), getDontFragOpt(network), optArg)
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})
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if rcErr != nil {
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return rcErr
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}
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return err
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}
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func (c *Conn) getDontFragment(network string) (bool, error) {
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var v int
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var err error
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rcErr := c.connControl(network, func(fd uintptr) {
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v, err = syscall.GetsockoptInt(int(fd), getIPProto(network), getDontFragOpt(network))
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})
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if rcErr != nil {
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return false, rcErr
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}
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if v == syscall.IP_PMTUDISC_DO {
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return true, err
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}
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return false, err
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}
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