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Support for same port on multiple interfaces

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This commit improves upon the PortMapper and PortAllocator classes by changing
their internal data structures for port allocations to use a string rather than
a single integer. This string holds the network interface address as well as the
port number. This solves a previous problem where a port would be incorrectly
reported as being in use because it had been allocated for a different interface.

I've also added a basic test case for the PortMapper class, and extended the
existing test case for PortAllocator. In the case of PortMapper, this is done
by handing it a stub function for creating proxies rather than an actual
implementation.
This commit is contained in:
Emil Hernvall 2013-11-21 17:26:07 +01:00
parent 650d4cc644
commit 1cb1e08644
2 changed files with 139 additions and 52 deletions
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104
network.go
View file

@ -225,16 +225,22 @@ func getIfaceAddr(name string) (net.Addr, error) {
// up iptables rules.
// It keeps track of all mappings and is able to unmap at will
type PortMapper struct {
tcpMapping map[int]*net.TCPAddr
tcpProxies map[int]proxy.Proxy
udpMapping map[int]*net.UDPAddr
udpProxies map[int]proxy.Proxy
tcpMapping map[string]*net.TCPAddr
tcpProxies map[string]proxy.Proxy
udpMapping map[string]*net.UDPAddr
udpProxies map[string]proxy.Proxy
iptables *iptables.Chain
defaultIp net.IP
iptables *iptables.Chain
defaultIp net.IP
proxyFactoryFunc func(net.Addr, net.Addr) (proxy.Proxy, error)
}
func (mapper *PortMapper) Map(ip net.IP, port int, backendAddr net.Addr) error {
mapKey := (&net.TCPAddr{Port: port, IP: ip}).String()
if _, exists := mapper.tcpProxies[mapKey]; exists {
return fmt.Errorf("Port %s is already in use", mapKey)
}
if _, isTCP := backendAddr.(*net.TCPAddr); isTCP {
backendPort := backendAddr.(*net.TCPAddr).Port
backendIP := backendAddr.(*net.TCPAddr).IP
@ -243,13 +249,13 @@ func (mapper *PortMapper) Map(ip net.IP, port int, backendAddr net.Addr) error {
return err
}
}
mapper.tcpMapping[port] = backendAddr.(*net.TCPAddr)
proxy, err := proxy.NewProxy(&net.TCPAddr{IP: ip, Port: port}, backendAddr)
mapper.tcpMapping[mapKey] = backendAddr.(*net.TCPAddr)
proxy, err := mapper.proxyFactoryFunc(&net.TCPAddr{IP: ip, Port: port}, backendAddr)
if err != nil {
mapper.Unmap(ip, port, "tcp")
return err
}
mapper.tcpProxies[port] = proxy
mapper.tcpProxies[mapKey] = proxy
go proxy.Run()
} else {
backendPort := backendAddr.(*net.UDPAddr).Port
@ -259,49 +265,50 @@ func (mapper *PortMapper) Map(ip net.IP, port int, backendAddr net.Addr) error {
return err
}
}
mapper.udpMapping[port] = backendAddr.(*net.UDPAddr)
proxy, err := proxy.NewProxy(&net.UDPAddr{IP: ip, Port: port}, backendAddr)
mapper.udpMapping[mapKey] = backendAddr.(*net.UDPAddr)
proxy, err := mapper.proxyFactoryFunc(&net.UDPAddr{IP: ip, Port: port}, backendAddr)
if err != nil {
mapper.Unmap(ip, port, "udp")
return err
}
mapper.udpProxies[port] = proxy
mapper.udpProxies[mapKey] = proxy
go proxy.Run()
}
return nil
}
func (mapper *PortMapper) Unmap(ip net.IP, port int, proto string) error {
mapKey := (&net.TCPAddr{Port: port, IP: ip}).String()
if proto == "tcp" {
backendAddr, ok := mapper.tcpMapping[port]
backendAddr, ok := mapper.tcpMapping[mapKey]
if !ok {
return fmt.Errorf("Port tcp/%v is not mapped", port)
return fmt.Errorf("Port tcp/%s is not mapped", mapKey)
}
if proxy, exists := mapper.tcpProxies[port]; exists {
if proxy, exists := mapper.tcpProxies[mapKey]; exists {
proxy.Close()
delete(mapper.tcpProxies, port)
delete(mapper.tcpProxies, mapKey)
}
if mapper.iptables != nil {
if err := mapper.iptables.Forward(iptables.Delete, ip, port, proto, backendAddr.IP.String(), backendAddr.Port); err != nil {
return err
}
}
delete(mapper.tcpMapping, port)
delete(mapper.tcpMapping, mapKey)
} else {
backendAddr, ok := mapper.udpMapping[port]
backendAddr, ok := mapper.udpMapping[mapKey]
if !ok {
return fmt.Errorf("Port udp/%v is not mapped", port)
return fmt.Errorf("Port udp/%s is not mapped", mapKey)
}
if proxy, exists := mapper.udpProxies[port]; exists {
if proxy, exists := mapper.udpProxies[mapKey]; exists {
proxy.Close()
delete(mapper.udpProxies, port)
delete(mapper.udpProxies, mapKey)
}
if mapper.iptables != nil {
if err := mapper.iptables.Forward(iptables.Delete, ip, port, proto, backendAddr.IP.String(), backendAddr.Port); err != nil {
return err
}
}
delete(mapper.udpMapping, port)
delete(mapper.udpMapping, mapKey)
}
return nil
}
@ -321,12 +328,13 @@ func newPortMapper(config *DaemonConfig) (*PortMapper, error) {
}
mapper := &PortMapper{
tcpMapping: make(map[int]*net.TCPAddr),
tcpProxies: make(map[int]proxy.Proxy),
udpMapping: make(map[int]*net.UDPAddr),
udpProxies: make(map[int]proxy.Proxy),
iptables: chain,
defaultIp: config.DefaultIp,
tcpMapping: make(map[string]*net.TCPAddr),
tcpProxies: make(map[string]proxy.Proxy),
udpMapping: make(map[string]*net.UDPAddr),
udpProxies: make(map[string]proxy.Proxy),
iptables: chain,
defaultIp: config.DefaultIp,
proxyFactoryFunc: proxy.NewProxy,
}
return mapper, nil
}
@ -334,7 +342,7 @@ func newPortMapper(config *DaemonConfig) (*PortMapper, error) {
// Port allocator: Automatically allocate and release networking ports
type PortAllocator struct {
sync.Mutex
inUse map[int]struct{}
inUse map[string]struct{}
fountain chan int
quit chan bool
}
@ -354,20 +362,22 @@ func (alloc *PortAllocator) runFountain() {
}
// FIXME: Release can no longer fail, change its prototype to reflect that.
func (alloc *PortAllocator) Release(port int) error {
func (alloc *PortAllocator) Release(addr net.IP, port int) error {
mapKey := (&net.TCPAddr{Port: port, IP: addr}).String()
utils.Debugf("Releasing %d", port)
alloc.Lock()
delete(alloc.inUse, port)
delete(alloc.inUse, mapKey)
alloc.Unlock()
return nil
}
func (alloc *PortAllocator) Acquire(port int) (int, error) {
utils.Debugf("Acquiring %d", port)
func (alloc *PortAllocator) Acquire(addr net.IP, port int) (int, error) {
mapKey := (&net.TCPAddr{Port: port, IP: addr}).String()
utils.Debugf("Acquiring %s", mapKey)
if port == 0 {
// Allocate a port from the fountain
for port := range alloc.fountain {
if _, err := alloc.Acquire(port); err == nil {
if _, err := alloc.Acquire(addr, port); err == nil {
return port, nil
}
}
@ -375,10 +385,10 @@ func (alloc *PortAllocator) Acquire(port int) (int, error) {
}
alloc.Lock()
defer alloc.Unlock()
if _, inUse := alloc.inUse[port]; inUse {
if _, inUse := alloc.inUse[mapKey]; inUse {
return -1, fmt.Errorf("Port already in use: %d", port)
}
alloc.inUse[port] = struct{}{}
alloc.inUse[mapKey] = struct{}{}
return port, nil
}
@ -391,7 +401,7 @@ func (alloc *PortAllocator) Close() error {
func newPortAllocator() (*PortAllocator, error) {
allocator := &PortAllocator{
inUse: make(map[int]struct{}),
inUse: make(map[string]struct{}),
fountain: make(chan int),
quit: make(chan bool),
}
@ -546,25 +556,25 @@ func (iface *NetworkInterface) AllocatePort(port Port, binding PortBinding) (*Na
hostPort, _ := parsePort(nat.Binding.HostPort)
if nat.Port.Proto() == "tcp" {
extPort, err := iface.manager.tcpPortAllocator.Acquire(hostPort)
extPort, err := iface.manager.tcpPortAllocator.Acquire(ip, hostPort)
if err != nil {
return nil, err
}
backend := &net.TCPAddr{IP: iface.IPNet.IP, Port: containerPort}
if err := iface.manager.portMapper.Map(ip, extPort, backend); err != nil {
iface.manager.tcpPortAllocator.Release(extPort)
iface.manager.tcpPortAllocator.Release(ip, extPort)
return nil, err
}
nat.Binding.HostPort = strconv.Itoa(extPort)
} else {
extPort, err := iface.manager.udpPortAllocator.Acquire(hostPort)
extPort, err := iface.manager.udpPortAllocator.Acquire(ip, hostPort)
if err != nil {
return nil, err
}
backend := &net.UDPAddr{IP: iface.IPNet.IP, Port: containerPort}
if err := iface.manager.portMapper.Map(ip, extPort, backend); err != nil {
iface.manager.udpPortAllocator.Release(extPort)
iface.manager.udpPortAllocator.Release(ip, extPort)
return nil, err
}
nat.Binding.HostPort = strconv.Itoa(extPort)
@ -596,16 +606,19 @@ func (iface *NetworkInterface) Release() {
continue
}
ip := net.ParseIP(nat.Binding.HostIp)
utils.Debugf("Unmaping %s/%s", nat.Port.Proto, nat.Binding.HostPort)
utils.Debugf("Unmaping %s/%s:%s", nat.Port.Proto, ip.String(), nat.Binding.HostPort)
if err := iface.manager.portMapper.Unmap(ip, hostPort, nat.Port.Proto()); err != nil {
log.Printf("Unable to unmap port %s: %s", nat, err)
}
if nat.Port.Proto() == "tcp" {
if err := iface.manager.tcpPortAllocator.Release(hostPort); err != nil {
if err := iface.manager.tcpPortAllocator.Release(ip, hostPort); err != nil {
log.Printf("Unable to release port %s", nat)
}
} else if err := iface.manager.udpPortAllocator.Release(hostPort); err != nil {
log.Printf("Unable to release port %s: %s", nat, err)
} else if nat.Port.Proto() == "udp" {
if err := iface.manager.tcpPortAllocator.Release(ip, hostPort); err != nil {
log.Printf("Unable to release port %s: %s", nat, err)
}
}
}
@ -732,6 +745,7 @@ func newNetworkManager(config *DaemonConfig) (*NetworkManager, error) {
if err != nil {
return nil, err
}
udpPortAllocator, err := newPortAllocator()
if err != nil {
return nil, err

87
network_test.go
View file

@ -1,42 +1,52 @@
package docker
import (
"github.com/dotcloud/docker/iptables"
"github.com/dotcloud/docker/proxy"
"net"
"testing"
)
func TestPortAllocation(t *testing.T) {
ip := net.ParseIP("192.168.0.1")
ip2 := net.ParseIP("192.168.0.2")
allocator, err := newPortAllocator()
if err != nil {
t.Fatal(err)
}
if port, err := allocator.Acquire(80); err != nil {
if port, err := allocator.Acquire(ip, 80); err != nil {
t.Fatal(err)
} else if port != 80 {
t.Fatalf("Acquire(80) should return 80, not %d", port)
}
port, err := allocator.Acquire(0)
port, err := allocator.Acquire(ip, 0)
if err != nil {
t.Fatal(err)
}
if port <= 0 {
t.Fatalf("Acquire(0) should return a non-zero port")
}
if _, err := allocator.Acquire(port); err == nil {
if _, err := allocator.Acquire(ip, port); err == nil {
t.Fatalf("Acquiring a port already in use should return an error")
}
if newPort, err := allocator.Acquire(0); err != nil {
if newPort, err := allocator.Acquire(ip, 0); err != nil {
t.Fatal(err)
} else if newPort == port {
t.Fatalf("Acquire(0) allocated the same port twice: %d", port)
}
if _, err := allocator.Acquire(80); err == nil {
if _, err := allocator.Acquire(ip, 80); err == nil {
t.Fatalf("Acquiring a port already in use should return an error")
}
if err := allocator.Release(80); err != nil {
if _, err := allocator.Acquire(ip2, 80); err != nil {
t.Fatalf("It should be possible to allocate the same port on a different interface")
}
if _, err := allocator.Acquire(ip2, 80); err == nil {
t.Fatalf("Acquiring a port already in use should return an error")
}
if err := allocator.Release(ip, 80); err != nil {
t.Fatal(err)
}
if _, err := allocator.Acquire(80); err != nil {
if _, err := allocator.Acquire(ip, 80); err != nil {
t.Fatal(err)
}
}
@ -311,3 +321,66 @@ func TestCheckNameserverOverlaps(t *testing.T) {
t.Fatalf("%s should not overlap %v but it does", netX, nameservers)
}
}
type StubProxy struct {
frontendAddr *net.Addr
backendAddr *net.Addr
}
func (proxy *StubProxy) Run() {}
func (proxy *StubProxy) Close() {}
func (proxy *StubProxy) FrontendAddr() net.Addr { return *proxy.frontendAddr }
func (proxy *StubProxy) BackendAddr() net.Addr { return *proxy.backendAddr }
func NewStubProxy(frontendAddr, backendAddr net.Addr) (proxy.Proxy, error) {
return &StubProxy{
frontendAddr: &frontendAddr,
backendAddr: &backendAddr,
}, nil
}
func TestPortMapper(t *testing.T) {
var chain *iptables.Chain
mapper := &PortMapper{
tcpMapping: make(map[string]*net.TCPAddr),
tcpProxies: make(map[string]proxy.Proxy),
udpMapping: make(map[string]*net.UDPAddr),
udpProxies: make(map[string]proxy.Proxy),
iptables: chain,
defaultIp: net.IP("0.0.0.0"),
proxyFactoryFunc: NewStubProxy,
}
dstIp1 := net.ParseIP("192.168.0.1")
dstIp2 := net.ParseIP("192.168.0.2")
srcAddr1 := &net.TCPAddr{Port: 1080, IP: net.ParseIP("172.16.0.1")}
srcAddr2 := &net.TCPAddr{Port: 1080, IP: net.ParseIP("172.16.0.2")}
if err := mapper.Map(dstIp1, 80, srcAddr1); err != nil {
t.Fatalf("Failed to allocate port: %s", err)
}
if mapper.Map(dstIp1, 80, srcAddr1) == nil {
t.Fatalf("Port is in use - mapping should have failed")
}
if mapper.Map(dstIp1, 80, srcAddr2) == nil {
t.Fatalf("Port is in use - mapping should have failed")
}
if err := mapper.Map(dstIp2, 80, srcAddr2); err != nil {
t.Fatalf("Failed to allocate port: %s", err)
}
if mapper.Unmap(dstIp1, 80, "tcp") != nil {
t.Fatalf("Failed to release port")
}
if mapper.Unmap(dstIp2, 80, "tcp") != nil {
t.Fatalf("Failed to release port")
}
if mapper.Unmap(dstIp2, 80, "tcp") == nil {
t.Fatalf("Port already released, but no error reported")
}
}