func allocateDaemonPort(addr string) error {
host, port, err := net.SplitHostPort(addr)
if err != nil {
return err
}
intPort, err := strconv.Atoi(port)
if err != nil {
return err
}
var hostIPs []net.IP
if parsedIP := net.ParseIP(host); parsedIP != nil {
hostIPs = append(hostIPs, parsedIP)
} else if hostIPs, err = net.LookupIP(host); err != nil {
return fmt.Errorf("failed to lookup %s address in host specification", host)
}
for _, hostIP := range hostIPs {
if _, err := portallocator.RequestPort(hostIP, "tcp", intPort); err != nil {
return fmt.Errorf("failed to allocate daemon listening port %d (err: %v)", intPort, err)
}
}
return nil
}
func Map(container net.Addr, hostIP net.IP, hostPort int) (host net.Addr, err error) {
lock.Lock()
defer lock.Unlock()
var (
m *mapping
proto string
allocatedHostPort int
)
switch container.(type) {
case *net.TCPAddr:
proto = "tcp"
if allocatedHostPort, err = portallocator.RequestPort(hostIP, proto, hostPort); err != nil {
return nil, err
}
m = &mapping{
proto: proto,
host: &net.TCPAddr{IP: hostIP, Port: allocatedHostPort},
container: container,
}
case *net.UDPAddr:
proto = "udp"
if allocatedHostPort, err = portallocator.RequestPort(hostIP, proto, hostPort); err != nil {
return nil, err
}
m = &mapping{
proto: proto,
host: &net.UDPAddr{IP: hostIP, Port: allocatedHostPort},
container: container,
}
default:
return nil, ErrUnknownBackendAddressType
}
// release the allocated port on any further error during return.
defer func() {
if err != nil {
portallocator.ReleasePort(hostIP, proto, allocatedHostPort)
}
}()
key := getKey(m.host)
if _, exists := currentMappings[key]; exists {
return nil, ErrPortMappedForIP
}
containerIP, containerPort := getIPAndPort(m.container)
if err := forward(iptables.Add, m.proto, hostIP, allocatedHostPort, containerIP.String(), containerPort); err != nil {
return nil, err
}
p, err := newProxy(m.host, m.container)
if err != nil {
// need to undo the iptables rules before we return
forward(iptables.Delete, m.proto, hostIP, allocatedHostPort, containerIP.String(), containerPort)
return nil, err
}
m.userlandProxy = p
currentMappings[key] = m
go p.Run()
return m.host, nil
}
func Map(container net.Addr, hostIP net.IP, hostPort int) (host net.Addr, err error) {
lock.Lock()
defer lock.Unlock()
var (
m *mapping
proto string
allocatedHostPort int
proxy UserlandProxy
)
switch container.(type) {
case *net.TCPAddr:
proto = "tcp"
if allocatedHostPort, err = portallocator.RequestPort(hostIP, proto, hostPort); err != nil {
return nil, err
}
m = &mapping{
proto: proto,
host: &net.TCPAddr{IP: hostIP, Port: allocatedHostPort},
container: container,
}
proxy = NewProxy(proto, hostIP, allocatedHostPort, container.(*net.TCPAddr).IP, container.(*net.TCPAddr).Port)
case *net.UDPAddr:
proto = "udp"
if allocatedHostPort, err = portallocator.RequestPort(hostIP, proto, hostPort); err != nil {
return nil, err
}
m = &mapping{
proto: proto,
host: &net.UDPAddr{IP: hostIP, Port: allocatedHostPort},
container: container,
}
proxy = NewProxy(proto, hostIP, allocatedHostPort, container.(*net.UDPAddr).IP, container.(*net.UDPAddr).Port)
default:
return nil, ErrUnknownBackendAddressType
}
// release the allocated port on any further error during return.
defer func() {
if err != nil {
portallocator.ReleasePort(hostIP, proto, allocatedHostPort)
}
}()
key := getKey(m.host)
if _, exists := currentMappings[key]; exists {
return nil, ErrPortMappedForIP
}
containerIP, containerPort := getIPAndPort(m.container)
if err := forward(iptables.Append, m.proto, hostIP, allocatedHostPort, containerIP.String(), containerPort); err != nil {
return nil, err
}
cleanup := func() error {
// need to undo the iptables rules before we return
proxy.Stop()
forward(iptables.Delete, m.proto, hostIP, allocatedHostPort, containerIP.String(), containerPort)
if err := portallocator.ReleasePort(hostIP, m.proto, allocatedHostPort); err != nil {
return err
}
return nil
}
if err := proxy.Start(); err != nil {
if err := cleanup(); err != nil {
return nil, fmt.Errorf("Error during port allocation cleanup: %v", err)
}
return nil, err
}
m.userlandProxy = proxy
currentMappings[key] = m
return m.host, nil
}