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|
package portallocator
import (
"errors"
"github.com/dotcloud/docker/pkg/collections"
"net"
"sync"
)
const (
BeginPortRange = 49153
EndPortRange = 65535
)
type (
portMappings map[string]*collections.OrderedIntSet
ipMapping map[string]portMappings
)
var (
ErrAllPortsAllocated = errors.New("all ports are allocated")
ErrPortAlreadyAllocated = errors.New("port has already been allocated")
ErrUnknownProtocol = errors.New("unknown protocol")
)
var (
currentDynamicPort = map[string]int{
"tcp": BeginPortRange - 1,
"udp": BeginPortRange - 1,
}
defaultIP = net.ParseIP("0.0.0.0")
defaultAllocatedPorts = portMappings{}
otherAllocatedPorts = ipMapping{}
lock = sync.Mutex{}
)
func init() {
defaultAllocatedPorts["tcp"] = collections.NewOrderedIntSet()
defaultAllocatedPorts["udp"] = collections.NewOrderedIntSet()
}
// RequestPort returns an available port if the port is 0
// If the provided port is not 0 then it will be checked if
// it is available for allocation
func RequestPort(ip net.IP, proto string, port int) (int, error) {
lock.Lock()
defer lock.Unlock()
if err := validateProtocol(proto); err != nil {
return 0, err
}
// If the user requested a specific port to be allocated
if port > 0 {
if err := registerSetPort(ip, proto, port); err != nil {
return 0, err
}
return port, nil
}
return registerDynamicPort(ip, proto)
}
// ReleasePort will return the provided port back into the
// pool for reuse
func ReleasePort(ip net.IP, proto string, port int) error {
lock.Lock()
defer lock.Unlock()
if err := validateProtocol(proto); err != nil {
return err
}
allocated := defaultAllocatedPorts[proto]
allocated.Remove(port)
if !equalsDefault(ip) {
registerIP(ip)
// Remove the port for the specific ip address
allocated = otherAllocatedPorts[ip.String()][proto]
allocated.Remove(port)
}
return nil
}
func ReleaseAll() error {
lock.Lock()
defer lock.Unlock()
currentDynamicPort["tcp"] = BeginPortRange - 1
currentDynamicPort["udp"] = BeginPortRange - 1
defaultAllocatedPorts = portMappings{}
defaultAllocatedPorts["tcp"] = collections.NewOrderedIntSet()
defaultAllocatedPorts["udp"] = collections.NewOrderedIntSet()
otherAllocatedPorts = ipMapping{}
return nil
}
func registerDynamicPort(ip net.IP, proto string) (int, error) {
if !equalsDefault(ip) {
registerIP(ip)
ipAllocated := otherAllocatedPorts[ip.String()][proto]
port, err := findNextPort(proto, ipAllocated)
if err != nil {
return 0, err
}
ipAllocated.Push(port)
return port, nil
} else {
allocated := defaultAllocatedPorts[proto]
port, err := findNextPort(proto, allocated)
if err != nil {
return 0, err
}
allocated.Push(port)
return port, nil
}
}
func registerSetPort(ip net.IP, proto string, port int) error {
allocated := defaultAllocatedPorts[proto]
if allocated.Exists(port) {
return ErrPortAlreadyAllocated
}
if !equalsDefault(ip) {
registerIP(ip)
ipAllocated := otherAllocatedPorts[ip.String()][proto]
if ipAllocated.Exists(port) {
return ErrPortAlreadyAllocated
}
ipAllocated.Push(port)
} else {
allocated.Push(port)
}
return nil
}
func equalsDefault(ip net.IP) bool {
return ip == nil || ip.Equal(defaultIP)
}
func findNextPort(proto string, allocated *collections.OrderedIntSet) (int, error) {
port := nextPort(proto)
startSearchPort := port
for allocated.Exists(port) {
port = nextPort(proto)
if startSearchPort == port {
return 0, ErrAllPortsAllocated
}
}
return port, nil
}
func nextPort(proto string) int {
c := currentDynamicPort[proto] + 1
if c > EndPortRange {
c = BeginPortRange
}
currentDynamicPort[proto] = c
return c
}
func registerIP(ip net.IP) {
if _, exists := otherAllocatedPorts[ip.String()]; !exists {
otherAllocatedPorts[ip.String()] = portMappings{
"tcp": collections.NewOrderedIntSet(),
"udp": collections.NewOrderedIntSet(),
}
}
}
func validateProtocol(proto string) error {
if _, exists := defaultAllocatedPorts[proto]; !exists {
return ErrUnknownProtocol
}
return nil
}
|
