sys_asmreqn.go (1051B)
1 // Copyright 2014 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 || freebsd || linux 6 // +build darwin freebsd linux 7 8 package ipv4 9 10 import ( 11 "net" 12 "unsafe" 13 14 "golang.org/x/net/internal/socket" 15 16 "golang.org/x/sys/unix" 17 ) 18 19 func (so *sockOpt) getIPMreqn(c *socket.Conn) (*net.Interface, error) { 20 b := make([]byte, so.Len) 21 if _, err := so.Get(c, b); err != nil { 22 return nil, err 23 } 24 mreqn := (*unix.IPMreqn)(unsafe.Pointer(&b[0])) 25 if mreqn.Ifindex == 0 { 26 return nil, nil 27 } 28 ifi, err := net.InterfaceByIndex(int(mreqn.Ifindex)) 29 if err != nil { 30 return nil, err 31 } 32 return ifi, nil 33 } 34 35 func (so *sockOpt) setIPMreqn(c *socket.Conn, ifi *net.Interface, grp net.IP) error { 36 var mreqn unix.IPMreqn 37 if ifi != nil { 38 mreqn.Ifindex = int32(ifi.Index) 39 } 40 if grp != nil { 41 mreqn.Multiaddr = [4]byte{grp[0], grp[1], grp[2], grp[3]} 42 } 43 b := (*[unix.SizeofIPMreqn]byte)(unsafe.Pointer(&mreqn))[:unix.SizeofIPMreqn] 44 return so.Set(c, b) 45 }