|  | // Copyright 2011 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. | 
|  |  | 
|  | // +build darwin freebsd netbsd openbsd | 
|  |  | 
|  | // IP-level socket options for BSD variants | 
|  |  | 
|  | package net | 
|  |  | 
|  | import ( | 
|  | "os" | 
|  | "syscall" | 
|  | ) | 
|  |  | 
|  | func ipv4MulticastTTL(fd *netFD) (int, error) { | 
|  | if err := fd.incref(false); err != nil { | 
|  | return 0, err | 
|  | } | 
|  | defer fd.decref() | 
|  | v, err := syscall.GetsockoptByte(fd.sysfd, syscall.IPPROTO_IP, syscall.IP_MULTICAST_TTL) | 
|  | if err != nil { | 
|  | return 0, os.NewSyscallError("getsockopt", err) | 
|  | } | 
|  | return int(v), nil | 
|  | } | 
|  |  | 
|  | func setIPv4MulticastTTL(fd *netFD, v int) error { | 
|  | if err := fd.incref(false); err != nil { | 
|  | return err | 
|  | } | 
|  | defer fd.decref() | 
|  | err := syscall.SetsockoptByte(fd.sysfd, syscall.IPPROTO_IP, syscall.IP_MULTICAST_TTL, byte(v)) | 
|  | if err != nil { | 
|  | return os.NewSyscallError("setsockopt", err) | 
|  | } | 
|  | return nil | 
|  | } | 
|  |  | 
|  | func ipv6TrafficClass(fd *netFD) (int, error) { | 
|  | if err := fd.incref(false); err != nil { | 
|  | return 0, err | 
|  | } | 
|  | defer fd.decref() | 
|  | v, err := syscall.GetsockoptInt(fd.sysfd, syscall.IPPROTO_IPV6, syscall.IPV6_TCLASS) | 
|  | if err != nil { | 
|  | return 0, os.NewSyscallError("getsockopt", err) | 
|  | } | 
|  | return v, nil | 
|  | } | 
|  |  | 
|  | func setIPv6TrafficClass(fd *netFD, v int) error { | 
|  | if err := fd.incref(false); err != nil { | 
|  | return err | 
|  | } | 
|  | defer fd.decref() | 
|  | err := syscall.SetsockoptInt(fd.sysfd, syscall.IPPROTO_IPV6, syscall.IPV6_TCLASS, v) | 
|  | if err != nil { | 
|  | return os.NewSyscallError("setsockopt", err) | 
|  | } | 
|  | return nil | 
|  | } |