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
7package net
8
9import (
10	"os"
11	"runtime"
12	"syscall"
13)
14
15func 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
41func 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
46func 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