// Given an attribute that represents an address, this function returns the transport address (IP and port number).
//
// OUTPUT
// - The address' family (1 for IPV4 or 2 for IPV6).
// - The IP address.
// + Example for IPV4: "192.168.0.1"
// + Example for IPV6: "0011:2233:4455:6677:8899:AABB:CCDD:EEFF"
// - The port number.
// - The error flag.
func (v *StunAttribute) __getAddress() (uint16, string, uint16, error) {
var family, port uint16
var ip string
var err error
err = binary.Read(bytes.NewBuffer(v.Value[0:2]), binary.BigEndian, &family)
if nil != err {
return 0, "", 0, err
}
err = binary.Read(bytes.NewBuffer(v.Value[2:4]), binary.BigEndian, &port)
if nil != err {
return family, "", 0, err
}
ip, err = tools.BytesToIp(v.Value[4:])
if nil != err {
return family, "", port, errors.New("Invalid IP family.")
}
return family, ip, port, nil
}
// Given an attribute that represents a "XOR mapped" address, this function returns the transport address.
// See http://www.nexcom.fr/2012/06/stun-la-base/
//
// OUTPUT
// - The address' family (1 for IPV4 or 2 for IPV6).
// - The IP address.
// + Example for IPV4: "192.168.0.1"
// + Example for IPV6: "0011:2233:4455:6677:8899:AABB:CCDD:EEFF"
// - The port number.
// - The XORED IP address (should be equal to the mapped address).
// - The XORED port (should be equal to the mapped port).
// - The error flag.
func (v *StunAttribute) AttributeGetXorMappedAddress() (uint16, string, uint16, string, uint16, error) {
var family, port uint16
var ip_string string
var xored_ip_string string
var err error
var cookie []byte = []byte{0x21, 0x12, 0xA4, 0x42} // 0x2112A442
var xored_ip []byte = make([]byte, 0, 16)
var xored_port uint16
err = binary.Read(bytes.NewBuffer(v.Value[0:2]), binary.BigEndian, &family)
if nil != err {
return 0, "", 0, "", 0, err
}
if (STUN_ATTRIBUT_FAMILY_IPV4 != family) && (STUN_ATTRIBUT_FAMILY_IPV6 != family) {
return 0, "", 0, "", 0, errors.New(fmt.Sprintf("Invalid address' family: 0x%02x", family))
}
err = binary.Read(bytes.NewBuffer(v.Value[2:4]), binary.BigEndian, &port)
if nil != err {
return family, "", 0, "", 0, err
}
if STUN_ATTRIBUT_FAMILY_IPV4 == family { // IPV4
if len(v.Value[4:]) != 4 {
return 0, "", 0, "", 0, errors.New(fmt.Sprintf("Invalid IPV4 address: % x", v.Value[4:]))
}
for i := 0; i < 4; i++ {
xored_ip = append(xored_ip, v.Value[i+4]^cookie[i])
}
} else { // IPV6
var long_magic []byte = make([]byte, 0, 16)
if len(v.Value[4:]) != 16 {
return 0, "", 0, "", 0, errors.New(fmt.Sprintf("Invalid IPV6 address: % x", v.Value[4:]))
}
long_magic = append(long_magic, cookie...)
long_magic = append(long_magic, v.Packet.id[0:12]...)
for i := 0; i < 16; i++ {
xored_ip = append(xored_ip, v.Value[i+4]^cookie[i])
}
}
// Calculate the values to return.
// - family
// - ip_string
// - port
// - xored_ip_string
// - xored_port
ip_string, err = tools.BytesToIp(v.Value[4:])
if nil != err {
return 0, "", 0, "", 0, err
}
xored_ip_string, err = tools.BytesToIp(xored_ip)
if nil != err {
return 0, "", 0, "", 0, err
}
xored_port = port ^ 0x2112
return family, ip_string, port, xored_ip_string, xored_port, nil
}