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- // Copyright 2017 The Go Authors. All rights reserved.
- // Use of this source code is governed by a BSD-style
- // license that can be found in the LICENSE file.
- //go:build aix || darwin || dragonfly || freebsd || hurd || linux || netbsd || openbsd || solaris
- package net
- import (
- "errors"
- "syscall"
- )
- func readRawConn(c syscall.RawConn, b []byte) (int, error) {
- var operr error
- var n int
- err := c.Read(func(s uintptr) bool {
- n, operr = syscall.Read(int(s), b)
- if operr == syscall.EAGAIN {
- return false
- }
- return true
- })
- if err != nil {
- return n, err
- }
- return n, operr
- }
- func writeRawConn(c syscall.RawConn, b []byte) error {
- var operr error
- err := c.Write(func(s uintptr) bool {
- _, operr = syscall.Write(int(s), b)
- if operr == syscall.EAGAIN {
- return false
- }
- return true
- })
- if err != nil {
- return err
- }
- return operr
- }
- func controlRawConn(c syscall.RawConn, addr Addr) error {
- var operr error
- fn := func(s uintptr) {
- _, operr = syscall.GetsockoptInt(int(s), syscall.SOL_SOCKET, syscall.SO_REUSEADDR)
- if operr != nil {
- return
- }
- switch addr := addr.(type) {
- case *TCPAddr:
- // There's no guarantee that IP-level socket
- // options work well with dual stack sockets.
- // A simple solution would be to take a look
- // at the bound address to the raw connection
- // and to classify the address family of the
- // underlying socket by the bound address:
- //
- // - When IP.To16() != nil and IP.To4() == nil,
- // we can assume that the raw connection
- // consists of an IPv6 socket using only
- // IPv6 addresses.
- //
- // - When IP.To16() == nil and IP.To4() != nil,
- // the raw connection consists of an IPv4
- // socket using only IPv4 addresses.
- //
- // - Otherwise, the raw connection is a dual
- // stack socket, an IPv6 socket using IPv6
- // addresses including IPv4-mapped or
- // IPv4-embedded IPv6 addresses.
- if addr.IP.To16() != nil && addr.IP.To4() == nil {
- operr = syscall.SetsockoptInt(int(s), syscall.IPPROTO_IPV6, syscall.IPV6_UNICAST_HOPS, 1)
- } else if addr.IP.To16() == nil && addr.IP.To4() != nil {
- operr = syscall.SetsockoptInt(int(s), syscall.IPPROTO_IP, syscall.IP_TTL, 1)
- }
- }
- }
- if err := c.Control(fn); err != nil {
- return err
- }
- return operr
- }
- func controlOnConnSetup(network string, address string, c syscall.RawConn) error {
- var operr error
- var fn func(uintptr)
- switch network {
- case "tcp", "udp", "ip":
- return errors.New("ambiguous network: " + network)
- case "unix", "unixpacket", "unixgram":
- fn = func(s uintptr) {
- _, operr = syscall.GetsockoptInt(int(s), syscall.SOL_SOCKET, syscall.SO_ERROR)
- }
- default:
- switch network[len(network)-1] {
- case '4':
- fn = func(s uintptr) {
- operr = syscall.SetsockoptInt(int(s), syscall.IPPROTO_IP, syscall.IP_TTL, 1)
- }
- case '6':
- fn = func(s uintptr) {
- operr = syscall.SetsockoptInt(int(s), syscall.IPPROTO_IPV6, syscall.IPV6_UNICAST_HOPS, 1)
- }
- default:
- return errors.New("unknown network: " + network)
- }
- }
- if err := c.Control(fn); err != nil {
- return err
- }
- return operr
- }
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