1 // Copyright 2011 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
4 5 //go:build darwin || dragonfly || freebsd || netbsd || openbsd
6 7 package net
8 9 import (
10 "os"
11 "runtime"
12 "syscall"
13 )
14 15 func setDefaultSockopts(s, family, sotype int, ipv6only bool) error {
16 if runtime.GOOS == "dragonfly" && sotype != syscall.SOCK_RAW {
17 // On DragonFly BSD, we adjust the ephemeral port
18 // range because unlike other BSD systems its default
19 // port range doesn't conform to IANA recommendation
20 // as described in RFC 6056 and is pretty narrow.
21 switch family {
22 case syscall.AF_INET:
23 syscall.SetsockoptInt(s, syscall.IPPROTO_IP, syscall.IP_PORTRANGE, syscall.IP_PORTRANGE_HIGH)
24 case syscall.AF_INET6:
25 syscall.SetsockoptInt(s, syscall.IPPROTO_IPV6, syscall.IPV6_PORTRANGE, syscall.IPV6_PORTRANGE_HIGH)
26 }
27 }
28 if family == syscall.AF_INET6 && sotype != syscall.SOCK_RAW && supportsIPv4map() {
29 // Allow both IP versions even if the OS default
30 // is otherwise. Note that some operating systems
31 // never admit this option.
32 syscall.SetsockoptInt(s, syscall.IPPROTO_IPV6, syscall.IPV6_V6ONLY, boolint(ipv6only))
33 }
34 if (sotype == syscall.SOCK_DGRAM || sotype == syscall.SOCK_RAW) && family != syscall.AF_UNIX {
35 // Allow broadcast.
36 return os.NewSyscallError("setsockopt", syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_BROADCAST, 1))
37 }
38 return nil
39 }
40 41 func setDefaultListenerSockopts(s int) error {
42 // Allow reuse of recently-used addresses.
43 return os.NewSyscallError("setsockopt", syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1))
44 }
45 46 func setDefaultMulticastSockopts(s int) error {
47 // Allow multicast UDP and raw IP datagram sockets to listen
48 // concurrently across multiple listeners.
49 if err := syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1); err != nil {
50 return os.NewSyscallError("setsockopt", err)
51 }
52 // Allow reuse of recently-used ports.
53 // This option is supported only in descendants of 4.4BSD,
54 // to make an effective multicast application that requires
55 // quick draw possible.
56 return os.NewSyscallError("setsockopt", syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEPORT, 1))
57 }
58