Merge pull request #34 from aboch/portmapper

Issue #33: Move portmapper and portallocator into libnetwork

Author: mavenugo

drivers/bridge/setup_ip_tables.go

@@ -4,9 +4,9 @@ import (
 	"fmt"
 	"net"
 
-	"github.com/docker/docker/daemon/networkdriver"
-	"github.com/docker/docker/daemon/networkdriver/portmapper"
 	"github.com/docker/docker/pkg/iptables"
+	"github.com/docker/libnetwork"
+	"github.com/docker/libnetwork/portmapper"
 )
 
 // DockerChain: DOCKER iptable chain name
@@ -20,7 +20,7 @@ func setupIPTables(i *bridgeInterface) error {
 		return fmt.Errorf("Unexpected request to set IP tables for interface: %s", i.Config.BridgeName)
 	}
 
-	addrv4, _, err := networkdriver.GetIfaceAddr(i.Config.BridgeName)
+	addrv4, _, err := libnetwork.GetIfaceAddr(i.Config.BridgeName)
 	if err != nil {
 		return fmt.Errorf("Failed to setup IP tables, cannot acquire Interface address: %s", err.Error())
 	}

portallocator/portallocator.go

@@ -0,0 +1,162 @@
+package portallocator
+
+import (
+	"errors"
+	"fmt"
+	"net"
+	"sync"
+)
+
+type portMap struct {
+	p    map[int]struct{}
+	last int
+}
+
+func newPortMap() *portMap {
+	return &portMap{
+		p:    map[int]struct{}{},
+		last: EndPortRange,
+	}
+}
+
+type protoMap map[string]*portMap
+
+func newProtoMap() protoMap {
+	return protoMap{
+		"tcp": newPortMap(),
+		"udp": newPortMap(),
+	}
+}
+
+type ipMapping map[string]protoMap
+
+const (
+	// BeginPortRange indicates the first port in port range
+	BeginPortRange = 49153
+	// EndPortRange indicates the last port in port range
+	EndPortRange = 65535
+)
+
+var (
+	// ErrAllPortsAllocated is returned when no more ports are available
+	ErrAllPortsAllocated = errors.New("all ports are allocated")
+	// ErrUnknownProtocol is returned when an unknown protocol was specified
+	ErrUnknownProtocol = errors.New("unknown protocol")
+)
+
+var (
+	mutex sync.Mutex
+
+	defaultIP = net.ParseIP("0.0.0.0")
+	globalMap = ipMapping{}
+)
+
+// ErrPortAlreadyAllocated is the returned error information when a requested port is already being used
+type ErrPortAlreadyAllocated struct {
+	ip   string
+	port int
+}
+
+func newErrPortAlreadyAllocated(ip string, port int) ErrPortAlreadyAllocated {
+	return ErrPortAlreadyAllocated{
+		ip:   ip,
+		port: port,
+	}
+}
+
+// IP returns the address to which the used port is associated
+func (e ErrPortAlreadyAllocated) IP() string {
+	return e.ip
+}
+
+// Port returns the value of the already used port
+func (e ErrPortAlreadyAllocated) Port() int {
+	return e.port
+}
+
+// IPPort returns the address and the port in the form ip:port
+func (e ErrPortAlreadyAllocated) IPPort() string {
+	return fmt.Sprintf("%s:%d", e.ip, e.port)
+}
+
+// Error is the implementation of error.Error interface
+func (e ErrPortAlreadyAllocated) Error() string {
+	return fmt.Sprintf("Bind for %s:%d failed: port is already allocated", e.ip, e.port)
+}
+
+// RequestPort requests new port from global ports pool for specified ip and proto.
+// If port is 0 it returns first free port. Otherwise it cheks port availability
+// in pool and return that port or error if port is already busy.
+func RequestPort(ip net.IP, proto string, port int) (int, error) {
+	mutex.Lock()
+	defer mutex.Unlock()
+
+	if proto != "tcp" && proto != "udp" {
+		return 0, ErrUnknownProtocol
+	}
+
+	if ip == nil {
+		ip = defaultIP
+	}
+	ipstr := ip.String()
+	protomap, ok := globalMap[ipstr]
+	if !ok {
+		protomap = newProtoMap()
+		globalMap[ipstr] = protomap
+	}
+	mapping := protomap[proto]
+	if port > 0 {
+		if _, ok := mapping.p[port]; !ok {
+			mapping.p[port] = struct{}{}
+			return port, nil
+		}
+		return 0, newErrPortAlreadyAllocated(ipstr, port)
+	}
+
+	port, err := mapping.findPort()
+	if err != nil {
+		return 0, err
+	}
+	return port, nil
+}
+
+// ReleasePort releases port from global ports pool for specified ip and proto.
+func ReleasePort(ip net.IP, proto string, port int) error {
+	mutex.Lock()
+	defer mutex.Unlock()
+
+	if ip == nil {
+		ip = defaultIP
+	}
+	protomap, ok := globalMap[ip.String()]
+	if !ok {
+		return nil
+	}
+	delete(protomap[proto].p, port)
+	return nil
+}
+
+// ReleaseAll releases all ports for all ips.
+func ReleaseAll() error {
+	mutex.Lock()
+	globalMap = ipMapping{}
+	mutex.Unlock()
+	return nil
+}
+
+func (pm *portMap) findPort() (int, error) {
+	port := pm.last
+	for i := 0; i <= EndPortRange-BeginPortRange; i++ {
+		port++
+		if port > EndPortRange {
+			port = BeginPortRange
+		}
+
+		if _, ok := pm.p[port]; !ok {
+			pm.p[port] = struct{}{}
+			pm.last = port
+			return port, nil
+		}
+	}
+	return 0, ErrAllPortsAllocated
+}