// Copyright 2014 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. package ipv4 import ( "net" "strconv" "strings" "syscall" "unsafe" "golang.org/x/net/internal/iana" "golang.org/x/net/internal/socket" ) var ( ctlOpts = [ctlMax]ctlOpt{ ctlTTL: {sysIP_RECVTTL, 1, marshalTTL, parseTTL}, ctlDst: {sysIP_RECVDSTADDR, net.IPv4len, marshalDst, parseDst}, ctlInterface: {sysIP_RECVIF, syscall.SizeofSockaddrDatalink, marshalInterface, parseInterface}, } sockOpts = map[int]*sockOpt{ ssoTOS: {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_TOS, Len: 4}}, ssoTTL: {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_TTL, Len: 4}}, ssoMulticastTTL: {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_MULTICAST_TTL, Len: 1}}, ssoMulticastInterface: {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_MULTICAST_IF, Len: 4}}, ssoMulticastLoopback: {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_MULTICAST_LOOP, Len: 4}}, ssoReceiveTTL: {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_RECVTTL, Len: 4}}, ssoReceiveDst: {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_RECVDSTADDR, Len: 4}}, ssoReceiveInterface: {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_RECVIF, Len: 4}}, ssoHeaderPrepend: {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_HDRINCL, Len: 4}}, ssoStripHeader: {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_STRIPHDR, Len: 4}}, ssoJoinGroup: {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_ADD_MEMBERSHIP, Len: sizeofIPMreq}, typ: ssoTypeIPMreq}, ssoLeaveGroup: {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_DROP_MEMBERSHIP, Len: sizeofIPMreq}, typ: ssoTypeIPMreq}, } ) func init() { // Seems like kern.osreldate is veiled on latest OS X. We use // kern.osrelease instead. s, err := syscall.Sysctl("kern.osrelease") if err != nil { return } ss := strings.Split(s, ".") if len(ss) == 0 { return } // The IP_PKTINFO and protocol-independent multicast API were // introduced in OS X 10.7 (Darwin 11). But it looks like // those features require OS X 10.8 (Darwin 12) or above. // See http://support.apple.com/kb/HT1633. if mjver, err := strconv.Atoi(ss[0]); err != nil || mjver < 12 { return } ctlOpts[ctlPacketInfo].name = sysIP_PKTINFO ctlOpts[ctlPacketInfo].length = sizeofInetPktinfo ctlOpts[ctlPacketInfo].marshal = marshalPacketInfo ctlOpts[ctlPacketInfo].parse = parsePacketInfo sockOpts[ssoPacketInfo] = &sockOpt{Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_RECVPKTINFO, Len: 4}} sockOpts[ssoMulticastInterface] = &sockOpt{Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_MULTICAST_IF, Len: sizeofIPMreqn}, typ: ssoTypeIPMreqn} sockOpts[ssoJoinGroup] = &sockOpt{Option: socket.Option{Level: iana.ProtocolIP, Name: sysMCAST_JOIN_GROUP, Len: sizeofGroupReq}, typ: ssoTypeGroupReq} sockOpts[ssoLeaveGroup] = &sockOpt{Option: socket.Option{Level: iana.ProtocolIP, Name: sysMCAST_LEAVE_GROUP, Len: sizeofGroupReq}, typ: ssoTypeGroupReq} sockOpts[ssoJoinSourceGroup] = &sockOpt{Option: socket.Option{Level: iana.ProtocolIP, Name: sysMCAST_JOIN_SOURCE_GROUP, Len: sizeofGroupSourceReq}, typ: ssoTypeGroupSourceReq} sockOpts[ssoLeaveSourceGroup] = &sockOpt{Option: socket.Option{Level: iana.ProtocolIP, Name: sysMCAST_LEAVE_SOURCE_GROUP, Len: sizeofGroupSourceReq}, typ: ssoTypeGroupSourceReq} sockOpts[ssoBlockSourceGroup] = &sockOpt{Option: socket.Option{Level: iana.ProtocolIP, Name: sysMCAST_BLOCK_SOURCE, Len: sizeofGroupSourceReq}, typ: ssoTypeGroupSourceReq} sockOpts[ssoUnblockSourceGroup] = &sockOpt{Option: socket.Option{Level: iana.ProtocolIP, Name: sysMCAST_UNBLOCK_SOURCE, Len: sizeofGroupSourceReq}, typ: ssoTypeGroupSourceReq} } func (pi *inetPktinfo) setIfindex(i int) { pi.Ifindex = uint32(i) } func (gr *groupReq) setGroup(grp net.IP) { sa := (*sockaddrInet)(unsafe.Pointer(uintptr(unsafe.Pointer(gr)) + 4)) sa.Len = sizeofSockaddrInet sa.Family = syscall.AF_INET copy(sa.Addr[:], grp) } func (gsr *groupSourceReq) setSourceGroup(grp, src net.IP) { sa := (*sockaddrInet)(unsafe.Pointer(uintptr(unsafe.Pointer(gsr)) + 4)) sa.Len = sizeofSockaddrInet sa.Family = syscall.AF_INET copy(sa.Addr[:], grp) sa = (*sockaddrInet)(unsafe.Pointer(uintptr(unsafe.Pointer(gsr)) + 132)) sa.Len = sizeofSockaddrInet sa.Family = syscall.AF_INET copy(sa.Addr[:], src) }