sockopt_bsd.go

Documentation: net

		 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  // +build darwin dragonfly freebsd netbsd openbsd
		 7  
		 8  package net
		 9  
		10  import (
		11  	"os"
		12  	"runtime"
		13  	"syscall"
		14  )
		15  
		16  func setDefaultSockopts(s, family, sotype int, ipv6only bool) error {
		17  	if runtime.GOOS == "dragonfly" && sotype != syscall.SOCK_RAW {
		18  		// On DragonFly BSD, we adjust the ephemeral port
		19  		// range because unlike other BSD systems its default
		20  		// port range doesn't conform to IANA recommendation
		21  		// as described in RFC 6056 and is pretty narrow.
		22  		switch family {
		23  		case syscall.AF_INET:
		24  			syscall.SetsockoptInt(s, syscall.IPPROTO_IP, syscall.IP_PORTRANGE, syscall.IP_PORTRANGE_HIGH)
		25  		case syscall.AF_INET6:
		26  			syscall.SetsockoptInt(s, syscall.IPPROTO_IPV6, syscall.IPV6_PORTRANGE, syscall.IPV6_PORTRANGE_HIGH)
		27  		}
		28  	}
		29  	if family == syscall.AF_INET6 && sotype != syscall.SOCK_RAW && supportsIPv4map() {
		30  		// Allow both IP versions even if the OS default
		31  		// is otherwise. Note that some operating systems
		32  		// never admit this option.
		33  		syscall.SetsockoptInt(s, syscall.IPPROTO_IPV6, syscall.IPV6_V6ONLY, boolint(ipv6only))
		34  	}
		35  	if (sotype == syscall.SOCK_DGRAM || sotype == syscall.SOCK_RAW) && family != syscall.AF_UNIX {
		36  		// Allow broadcast.
		37  		return os.NewSyscallError("setsockopt", syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_BROADCAST, 1))
		38  	}
		39  	return nil
		40  }
		41  
		42  func setDefaultListenerSockopts(s int) error {
		43  	// Allow reuse of recently-used addresses.
		44  	return os.NewSyscallError("setsockopt", syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1))
		45  }
		46  
		47  func setDefaultMulticastSockopts(s int) error {
		48  	// Allow multicast UDP and raw IP datagram sockets to listen
		49  	// concurrently across multiple listeners.
		50  	if err := syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1); err != nil {
		51  		return os.NewSyscallError("setsockopt", err)
		52  	}
		53  	// Allow reuse of recently-used ports.
		54  	// This option is supported only in descendants of 4.4BSD,
		55  	// to make an effective multicast application that requires
		56  	// quick draw possible.
		57  	return os.NewSyscallError("setsockopt", syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEPORT, 1))
		58  }
		59
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