// 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"
	"syscall"
	"unsafe"
)

type sysSockoptLen int32

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 = [ssoMax]sockOpt{
		ssoTOS:                {sysIP_TOS, ssoTypeInt},
		ssoTTL:                {sysIP_TTL, ssoTypeInt},
		ssoMulticastTTL:       {sysIP_MULTICAST_TTL, ssoTypeByte},
		ssoMulticastInterface: {sysIP_MULTICAST_IF, ssoTypeInterface},
		ssoMulticastLoopback:  {sysIP_MULTICAST_LOOP, ssoTypeInt},
		ssoReceiveTTL:         {sysIP_RECVTTL, ssoTypeInt},
		ssoReceiveDst:         {sysIP_RECVDSTADDR, ssoTypeInt},
		ssoReceiveInterface:   {sysIP_RECVIF, ssoTypeInt},
		ssoHeaderPrepend:      {sysIP_HDRINCL, ssoTypeInt},
		ssoJoinGroup:          {sysMCAST_JOIN_GROUP, ssoTypeGroupReq},
		ssoLeaveGroup:         {sysMCAST_LEAVE_GROUP, ssoTypeGroupReq},
		ssoJoinSourceGroup:    {sysMCAST_JOIN_SOURCE_GROUP, ssoTypeGroupSourceReq},
		ssoLeaveSourceGroup:   {sysMCAST_LEAVE_SOURCE_GROUP, ssoTypeGroupSourceReq},
		ssoBlockSourceGroup:   {sysMCAST_BLOCK_SOURCE, ssoTypeGroupSourceReq},
		ssoUnblockSourceGroup: {sysMCAST_UNBLOCK_SOURCE, ssoTypeGroupSourceReq},
	}
)

func init() {
	freebsdVersion, _ = syscall.SysctlUint32("kern.osreldate")
	if freebsdVersion >= 1000000 {
		sockOpts[ssoMulticastInterface].typ = ssoTypeIPMreqn
	}
}

func (gr *sysGroupReq) setGroup(grp net.IP) {
	sa := (*sysSockaddrInet)(unsafe.Pointer(&gr.Group))
	sa.Len = sysSizeofSockaddrInet
	sa.Family = syscall.AF_INET
	copy(sa.Addr[:], grp)
}

func (gsr *sysGroupSourceReq) setSourceGroup(grp, src net.IP) {
	sa := (*sysSockaddrInet)(unsafe.Pointer(&gsr.Group))
	sa.Len = sysSizeofSockaddrInet
	sa.Family = syscall.AF_INET
	copy(sa.Addr[:], grp)
	sa = (*sysSockaddrInet)(unsafe.Pointer(&gsr.Source))
	sa.Len = sysSizeofSockaddrInet
	sa.Family = syscall.AF_INET
	copy(sa.Addr[:], src)
}