func leaveIPv4Group(fd int, ifi *net.Interface, grp net.IP) error {
mreq := syscall.IPMreq{Multiaddr: [4]byte{grp[0], grp[1], grp[2], grp[3]}}
if err := setSyscallIPMreq(&mreq, ifi); err != nil {
return err
}
return os.NewSyscallError("setsockopt", syscall.SetsockoptIPMreq(fd, ianaProtocolIP, syscall.IP_DROP_MEMBERSHIP, &mreq))
}
// ListenMulticastIPv4 creates a net.IPConn to receive multicast messages for the given group
// address. laddr specifies which network interface to use when joining the group.
func ListenMulticastIPv4(gaddr, laddr net.IP) (*net.IPConn, error) {
gaddr = gaddr.To4()
laddr = laddr.To4()
c, err := net.ListenIP("ip4:112", &net.IPAddr{IP: gaddr})
if err != nil {
return nil, err
}
f, err := c.File()
if err != nil {
return nil, err
}
defer f.Close()
mreq := &syscall.IPMreq{
Multiaddr: [4]byte{gaddr[0], gaddr[1], gaddr[2], gaddr[3]},
Interface: [4]byte{laddr[0], laddr[1], laddr[2], laddr[3]},
}
err = syscall.SetsockoptIPMreq(int(f.Fd()), syscall.IPPROTO_IP, syscall.IP_ADD_MEMBERSHIP, mreq)
if err != nil {
return nil, err
}
return c, nil
}
func joinIPv4Group(fd int, ifi *net.Interface, grp net.IP) error {
mreq := syscall.IPMreq{Multiaddr: [4]byte{grp[0], grp[1], grp[2], grp[3]}}
if err := setSysIPMreqInterface(&mreq, ifi); err != nil {
return err
}
return os.NewSyscallError("setsockopt", syscall.SetsockoptIPMreq(fd, ianaProtocolIP, sysSockoptJoinGroup, &mreq))
}
func leaveIPv4Group(fd *netFD, ifi *Interface, ip IP) error {
mreq := &syscall.IPMreq{Multiaddr: [4]byte{ip[0], ip[1], ip[2], ip[3]}}
if err := setIPv4MreqToInterface(mreq, ifi); err != nil {
return err
}
fd.incref()
defer fd.decref()
return os.NewSyscallError("setsockopt", syscall.SetsockoptIPMreq(fd.sysfd, syscall.IPPROTO_IP, syscall.IP_DROP_MEMBERSHIP, mreq))
}
func leaveIPv4GroupUDP(c *UDPConn, ifi *Interface, ip IP) error {
mreq := &syscall.IPMreq{Multiaddr: [4]byte{ip[0], ip[1], ip[2], ip[3]}}
if err := setIPv4InterfaceToJoin(mreq, ifi); err != nil {
return &OpError{"leaveipv4group", "udp", &IPAddr{ip}, err}
}
if err := os.NewSyscallError("setsockopt", syscall.SetsockoptIPMreq(c.fd.sysfd, syscall.IPPROTO_IP, syscall.IP_DROP_MEMBERSHIP, mreq)); err != nil {
return &OpError{"leaveipv4group", "udp", &IPAddr{ip}, err}
}
return nil
}
func leaveIPv4Group(fd int, ifi *net.Interface, grp net.IP) error {
mreq := &syscall.IPMreq{Multiaddr: [4]byte{grp[0], grp[1], grp[2], grp[3]}}
if err := setSyscallIPMreq(mreq, ifi); err != nil {
return err
}
err := syscall.SetsockoptIPMreq(fd, syscall.IPPROTO_IP, syscall.IP_DROP_MEMBERSHIP, mreq)
if err != nil {
return os.NewSyscallError("setsockopt", err)
}
return nil
}
func joinIPv4Group(fd *netFD, ifi *Interface, ip IP) error {
mreq := &syscall.IPMreq{Multiaddr: [4]byte{ip[0], ip[1], ip[2], ip[3]}}
if err := setIPv4MreqToInterface(mreq, ifi); err != nil {
return err
}
if err := fd.incref(false); err != nil {
return err
}
defer fd.decref()
err := syscall.SetsockoptIPMreq(fd.sysfd, syscall.IPPROTO_IP, syscall.IP_ADD_MEMBERSHIP, mreq)
if err != nil {
return os.NewSyscallError("setsockopt", err)
}
return nil
}
// LeaveGroup exits the IPv4 multicast group named by addr.
func (c *UDPConn) LeaveGroup(addr IP) os.Error {
if !c.ok() {
return os.EINVAL
}
ip := addr.To4()
if ip == nil {
return &OpError{"leavegroup", "udp", &IPAddr{ip}, errInvalidMulticast}
}
mreq := &syscall.IPMreq{
Multiaddr: [4]byte{ip[0], ip[1], ip[2], ip[3]},
}
err := os.NewSyscallError("setsockopt", syscall.SetsockoptIPMreq(c.fd.sysfd, syscall.IPPROTO_IP, syscall.IP_DROP_MEMBERSHIP, mreq))
if err != nil {
return &OpError{"leavegroup", "udp", &IPAddr{ip}, err}
}
return nil
}
func (s *Ssdp) createSocket() error {
// create the socket
var err error
s.socket.socket, err = syscall.Socket(syscall.AF_INET, syscall.SOCK_DGRAM, syscall.IPPROTO_UDP)
if err != nil {
return err
}
// make sure we can reuse it / share it
if err := syscall.SetsockoptInt(s.socket.socket, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1); err != nil {
syscall.Closesocket(s.socket.socket)
s.socket.socket = 0
return err
}
// going to broadcast
if err := syscall.SetsockoptInt(s.socket.socket, syscall.SOL_SOCKET, syscall.SO_BROADCAST, 1); err != nil {
syscall.Closesocket(s.socket.socket)
s.socket.socket = 0
return err
}
// bind it to the ssdp port
lsa := &syscall.SockaddrInet4{Port: 1900, Addr: [4]byte{0, 0, 0, 0}}
err = syscall.Bind(s.socket.socket, lsa)
if err != nil {
syscall.Closesocket(s.socket.socket)
s.socket.socket = 0
return err
}
iter, err := net.Interfaces()
if err != nil {
syscall.Closesocket(s.socket.socket)
s.socket.socket = 0
return err
}
wasFound := false
for i := range iter {
if iter[i].Flags&net.FlagMulticast == 0 {
continue
}
addrs, err := iter[i].Addrs()
if err != nil {
continue
}
for k := range addrs {
as4 := addrs[k].(*net.IPAddr).IP.To4()
// join the multicast group
mreq := &syscall.IPMreq{Multiaddr: [4]byte{239, 255, 255, 250}, Interface: [4]byte{as4[0], as4[1], as4[2], as4[3]}}
if err := syscall.SetsockoptIPMreq(s.socket.socket, syscall.IPPROTO_IP, syscall.IP_ADD_MEMBERSHIP, mreq); err != nil {
syscall.Closesocket(s.socket.socket)
s.socket.socket = 0
return err
}
wasFound = true
}
}
// if we couldn't join a group, fall back to just 0.0.0.0
if !wasFound {
mreq := &syscall.IPMreq{Multiaddr: [4]byte{239, 255, 255, 250}, Interface: [4]byte{0, 0, 0, 0}}
if err := syscall.SetsockoptIPMreq(s.socket.socket, syscall.IPPROTO_IP, syscall.IP_ADD_MEMBERSHIP, mreq); err != nil {
syscall.Closesocket(s.socket.socket)
s.socket.socket = 0
return err
}
}
s.socket.readBytes = make([]byte, 2048)
return nil
}