Convert PortAllocator's ints to uint32 to avoid int overflows when picking ports

Author: geofffranks

src/code.cloudfoundry.org/garden-external-networker/config/config.go

@@ -11,8 +11,8 @@ type Config struct {
 	CniConfigDir               string   `json:"cni_config_dir"`
 	BindMountDir               string   `json:"bind_mount_dir"`
 	StateFilePath              string   `json:"state_file"`
-	StartPort                  int      `json:"start_port"`
-	TotalPorts                 int      `json:"total_ports"`
+	StartPort                  uint32   `json:"start_port"`
+	TotalPorts                 uint32   `json:"total_ports"`
 	LogPrefix                  string   `json:"log_prefix"`
 	SearchDomains              []string `json:"search_domains"`
 	IPTablesLockFile           string   `json:"iptables_lock_file"`

src/code.cloudfoundry.org/garden-external-networker/config/config_test.go

@@ -50,8 +50,8 @@ var _ = Describe("Config", func() {
 				Expect(c.CniConfigDir).To(Equal("bar"))
 				Expect(c.BindMountDir).To(Equal("baz"))
 				Expect(c.StateFilePath).To(Equal("some/path"))
-				Expect(c.StartPort).To(Equal(1234))
-				Expect(c.TotalPorts).To(Equal(56))
+				Expect(c.StartPort).To(Equal(uint32(1234)))
+				Expect(c.TotalPorts).To(Equal(uint32(56)))
 				Expect(c.LogPrefix).To(Equal("prefix"))
 				Expect(c.SearchDomains).Should(ConsistOf("pivotal.io", "foo.bar", "baz.me"))
 				Expect(c.IPTablesLockFile).To(Equal("some-lock-file"))

src/code.cloudfoundry.org/garden-external-networker/fakes/portAllocator.go

@@ -31,7 +31,7 @@ type mounter interface {
 
 //go:generate counterfeiter -o ../fakes/portAllocator.go --fake-name PortAllocator . portAllocator
 type portAllocator interface {
-	AllocatePort(handle string, port int) (int, error)
+	AllocatePort(handle string, port uint32) (uint32, error)
 	ReleaseAllPorts(handle string) error
 }
 
@@ -82,11 +82,11 @@ func (m *Manager) Up(containerHandle string, inputs UpInputs) (*UpOutputs, error
 	mappedPorts := []garden.PortMapping{}
 	for i := range inputs.NetIn {
 		if inputs.NetIn[i].HostPort == 0 {
-			hostPort, err := m.PortAllocator.AllocatePort(containerHandle, int(inputs.NetIn[i].HostPort))
+			hostPort, err := m.PortAllocator.AllocatePort(containerHandle, inputs.NetIn[i].HostPort)
 			if err != nil {
 				return nil, fmt.Errorf("allocating port: %s", err)
 			}
-			inputs.NetIn[i].HostPort = uint32(hostPort)
+			inputs.NetIn[i].HostPort = hostPort
 		}
 
 		mappedPorts = append(mappedPorts, garden.PortMapping{

src/code.cloudfoundry.org/garden-external-networker/fakes/tracker.go

@@ -276,7 +276,7 @@ var _ = Describe("Manager", func() {
 				Expect(portAllocator.AllocatePortCallCount()).To(Equal(1))
 				handle, port := portAllocator.AllocatePortArgsForCall(0)
 				Expect(handle).To(Equal("some-container-handle"))
-				Expect(port).To(Equal(0))
+				Expect(port).To(Equal(uint32(0)))
 
 				Expect(cniController.UpCallCount()).To(Equal(1))
 				_, handle, _, legacyNetConf := cniController.UpArgsForCall(0)

src/code.cloudfoundry.org/garden-external-networker/manager/manager.go

@@ -8,14 +8,14 @@ import (
 var ErrorPortPoolExhausted = errors.New("port pool exhausted")
 
 type Pool struct {
-	AcquiredPorts map[int]string
+	AcquiredPorts map[uint32]string
 }
 
 func (p *Pool) MarshalJSON() ([]byte, error) {
 	var jsonData struct {
-		AcquiredPorts map[string][]int `json:"acquired_ports"`
+		AcquiredPorts map[string][]uint32 `json:"acquired_ports"`
 	}
-	jsonData.AcquiredPorts = make(map[string][]int)
+	jsonData.AcquiredPorts = make(map[string][]uint32)
 
 	for port, handle := range p.AcquiredPorts {
 		jsonData.AcquiredPorts[handle] = append(jsonData.AcquiredPorts[handle], port)
@@ -25,14 +25,14 @@ func (p *Pool) MarshalJSON() ([]byte, error) {
 
 func (p *Pool) UnmarshalJSON(bytes []byte) error {
 	var jsonData struct {
-		AcquiredPorts map[string][]int `json:"acquired_ports"`
+		AcquiredPorts map[string][]uint32 `json:"acquired_ports"`
 	}
 	err := json.Unmarshal(bytes, &jsonData)
 	if err != nil {
 		return err
 	}
 
-	p.AcquiredPorts = make(map[int]string)
+	p.AcquiredPorts = make(map[uint32]string)
 	for handle, ports := range jsonData.AcquiredPorts {
 		for _, port := range ports {
 			p.AcquiredPorts[port] = handle
@@ -42,27 +42,27 @@ func (p *Pool) UnmarshalJSON(bytes []byte) error {
 }
 
 type Tracker struct {
-	StartPort int
-	Capacity  int
+	StartPort uint32
+	Capacity  uint32
 }
 
-func (t *Tracker) InRange(port int) bool {
+func (t *Tracker) InRange(port uint32) bool {
 	return port >= t.StartPort && port < t.StartPort+t.Capacity
 }
 
-func (t *Tracker) AcquireOne(pool *Pool, handler string) (int, error) {
+func (t *Tracker) AcquireOne(pool *Pool, handler string) (uint32, error) {
 	if pool.AcquiredPorts == nil {
-		pool.AcquiredPorts = make(map[int]string)
+		pool.AcquiredPorts = make(map[uint32]string)
 	}
 
-	for i := 0; i < t.Capacity; i++ {
+	for i := uint32(0); i < t.Capacity; i++ {
 		candidatePort := t.StartPort + i
 		if !contains(pool.AcquiredPorts, candidatePort) {
 			pool.AcquiredPorts[candidatePort] = handler
 			return candidatePort, nil
 		}
 	}
-	return -1, ErrorPortPoolExhausted
+	return 0, ErrorPortPoolExhausted
 }
 
 func (t *Tracker) ReleaseAll(pool *Pool, handle string) error {
@@ -74,7 +74,7 @@ func (t *Tracker) ReleaseAll(pool *Pool, handle string) error {
 	return nil
 }
 
-func contains(list map[int]string, candidate int) bool {
+func contains(list map[uint32]string, candidate uint32) bool {
 	_, ok := list[candidate]
 	return ok
 }