github.com/amnezia-vpn/amneziawg-go@v0.2.8/conn/errors_linux.go (about)

     1  /* SPDX-License-Identifier: MIT
     2   *
     3   * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
     4   */
     5  
     6  package conn
     7  
     8  import (
     9  	"errors"
    10  	"os"
    11  
    12  	"golang.org/x/sys/unix"
    13  )
    14  
    15  func errShouldDisableUDPGSO(err error) bool {
    16  	var serr *os.SyscallError
    17  	if errors.As(err, &serr) {
    18  		// EIO is returned by udp_send_skb() if the device driver does not have
    19  		// tx checksumming enabled, which is a hard requirement of UDP_SEGMENT.
    20  		// See:
    21  		// https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/man7/udp.7?id=806eabd74910447f21005160e90957bde4db0183#n228
    22  		// https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/net/ipv4/udp.c?h=v6.2&id=c9c3395d5e3dcc6daee66c6908354d47bf98cb0c#n942
    23  		// If gso_size + udp + ip headers > fragment size EINVAL is returned.
    24  		// It occurs when the peer mtu + wg headers is greater than path mtu.
    25  		return serr.Err == unix.EIO || serr.Err == unix.EINVAL
    26  	}
    27  	return false
    28  }