135 lines
2.9 KiB
Go
135 lines
2.9 KiB
Go
package stun
|
|
|
|
import (
|
|
"fmt"
|
|
"io"
|
|
"net"
|
|
"strconv"
|
|
)
|
|
|
|
// MappedAddress represents MAPPED-ADDRESS attribute.
|
|
//
|
|
// This attribute is used only by servers for achieving backwards
|
|
// compatibility with RFC 3489 clients.
|
|
//
|
|
// RFC 5389 Section 15.1
|
|
type MappedAddress struct {
|
|
IP net.IP
|
|
Port int
|
|
}
|
|
|
|
// AlternateServer represents ALTERNATE-SERVER attribute.
|
|
//
|
|
// RFC 5389 Section 15.11
|
|
type AlternateServer struct {
|
|
IP net.IP
|
|
Port int
|
|
}
|
|
|
|
// OtherAddress represents OTHER-ADDRESS attribute.
|
|
//
|
|
// RFC 5780 Section 7.4
|
|
type OtherAddress struct {
|
|
IP net.IP
|
|
Port int
|
|
}
|
|
|
|
// AddTo adds ALTERNATE-SERVER attribute to message.
|
|
func (s *AlternateServer) AddTo(m *Message) error {
|
|
a := (*MappedAddress)(s)
|
|
return a.addAs(m, AttrAlternateServer)
|
|
}
|
|
|
|
// GetFrom decodes ALTERNATE-SERVER from message.
|
|
func (s *AlternateServer) GetFrom(m *Message) error {
|
|
a := (*MappedAddress)(s)
|
|
return a.getAs(m, AttrAlternateServer)
|
|
}
|
|
|
|
func (a MappedAddress) String() string {
|
|
return net.JoinHostPort(a.IP.String(), strconv.Itoa(a.Port))
|
|
}
|
|
|
|
func (a *MappedAddress) getAs(m *Message, t AttrType) error {
|
|
v, err := m.Get(t)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if len(v) <= 4 {
|
|
return io.ErrUnexpectedEOF
|
|
}
|
|
family := bin.Uint16(v[0:2])
|
|
if family != familyIPv6 && family != familyIPv4 {
|
|
return newDecodeErr("xor-mapped address", "family",
|
|
fmt.Sprintf("bad value %d", family),
|
|
)
|
|
}
|
|
ipLen := net.IPv4len
|
|
if family == familyIPv6 {
|
|
ipLen = net.IPv6len
|
|
}
|
|
// Ensuring len(a.IP) == ipLen and reusing a.IP.
|
|
if len(a.IP) < ipLen {
|
|
a.IP = a.IP[:cap(a.IP)]
|
|
for len(a.IP) < ipLen {
|
|
a.IP = append(a.IP, 0)
|
|
}
|
|
}
|
|
a.IP = a.IP[:ipLen]
|
|
for i := range a.IP {
|
|
a.IP[i] = 0
|
|
}
|
|
a.Port = int(bin.Uint16(v[2:4]))
|
|
copy(a.IP, v[4:])
|
|
return nil
|
|
}
|
|
|
|
func (a *MappedAddress) addAs(m *Message, t AttrType) error {
|
|
var (
|
|
family = familyIPv4
|
|
ip = a.IP
|
|
)
|
|
if len(a.IP) == net.IPv6len {
|
|
if isIPv4(ip) {
|
|
ip = ip[12:16] // like in ip.To4()
|
|
} else {
|
|
family = familyIPv6
|
|
}
|
|
} else if len(ip) != net.IPv4len {
|
|
return ErrBadIPLength
|
|
}
|
|
value := make([]byte, 128)
|
|
value[0] = 0 // first 8 bits are zeroes
|
|
bin.PutUint16(value[0:2], family)
|
|
bin.PutUint16(value[2:4], uint16(a.Port))
|
|
copy(value[4:], ip)
|
|
m.Add(t, value[:4+len(ip)])
|
|
return nil
|
|
}
|
|
|
|
// AddTo adds MAPPED-ADDRESS to message.
|
|
func (a *MappedAddress) AddTo(m *Message) error {
|
|
return a.addAs(m, AttrMappedAddress)
|
|
}
|
|
|
|
// GetFrom decodes MAPPED-ADDRESS from message.
|
|
func (a *MappedAddress) GetFrom(m *Message) error {
|
|
return a.getAs(m, AttrMappedAddress)
|
|
}
|
|
|
|
// AddTo adds OTHER-ADDRESS attribute to message.
|
|
func (o *OtherAddress) AddTo(m *Message) error {
|
|
a := (*MappedAddress)(o)
|
|
return a.addAs(m, AttrOtherAddress)
|
|
}
|
|
|
|
// GetFrom decodes OTHER-ADDRESS from message.
|
|
func (o *OtherAddress) GetFrom(m *Message) error {
|
|
a := (*MappedAddress)(o)
|
|
return a.getAs(m, AttrOtherAddress)
|
|
}
|
|
|
|
func (o OtherAddress) String() string {
|
|
return net.JoinHostPort(o.IP.String(), strconv.Itoa(o.Port))
|
|
}
|