build: move e2e dependencies into e2e/go.mod

Several packages are only used while running the e2e suite. These
packages are less important to update, as the they can not influence the
final executable that is part of the Ceph-CSI container-image.

By moving these dependencies out of the main Ceph-CSI go.mod, it is
easier to identify if a reported CVE affects Ceph-CSI, or only the
testing (like most of the Kubernetes CVEs).

Signed-off-by: Niels de Vos <ndevos@ibm.com>

e2e/vendor/k8s.io/utils/net/ipfamily.go

@@ -0,0 +1,181 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package net
+
+import (
+	"fmt"
+	"net"
+)
+
+// IPFamily refers to a specific family if not empty, i.e. "4" or "6".
+type IPFamily string
+
+// Constants for valid IPFamilys:
+const (
+	IPFamilyUnknown IPFamily = ""
+
+	IPv4 IPFamily = "4"
+	IPv6 IPFamily = "6"
+)
+
+// IsDualStackIPs returns true if:
+// - all elements of ips are valid
+// - at least one IP from each family (v4 and v6) is present
+func IsDualStackIPs(ips []net.IP) (bool, error) {
+	v4Found := false
+	v6Found := false
+	for i, ip := range ips {
+		switch IPFamilyOf(ip) {
+		case IPv4:
+			v4Found = true
+		case IPv6:
+			v6Found = true
+		default:
+			return false, fmt.Errorf("invalid IP[%d]: %v", i, ip)
+		}
+	}
+
+	return (v4Found && v6Found), nil
+}
+
+// IsDualStackIPStrings returns true if:
+// - all elements of ips can be parsed as IPs
+// - at least one IP from each family (v4 and v6) is present
+func IsDualStackIPStrings(ips []string) (bool, error) {
+	parsedIPs := make([]net.IP, 0, len(ips))
+	for i, ip := range ips {
+		parsedIP := ParseIPSloppy(ip)
+		if parsedIP == nil {
+			return false, fmt.Errorf("invalid IP[%d]: %v", i, ip)
+		}
+		parsedIPs = append(parsedIPs, parsedIP)
+	}
+	return IsDualStackIPs(parsedIPs)
+}
+
+// IsDualStackCIDRs returns true if:
+// - all elements of cidrs are non-nil
+// - at least one CIDR from each family (v4 and v6) is present
+func IsDualStackCIDRs(cidrs []*net.IPNet) (bool, error) {
+	v4Found := false
+	v6Found := false
+	for i, cidr := range cidrs {
+		switch IPFamilyOfCIDR(cidr) {
+		case IPv4:
+			v4Found = true
+		case IPv6:
+			v6Found = true
+		default:
+			return false, fmt.Errorf("invalid CIDR[%d]: %v", i, cidr)
+		}
+	}
+
+	return (v4Found && v6Found), nil
+}
+
+// IsDualStackCIDRStrings returns if
+// - all elements of cidrs can be parsed as CIDRs
+// - at least one CIDR from each family (v4 and v6) is present
+func IsDualStackCIDRStrings(cidrs []string) (bool, error) {
+	parsedCIDRs, err := ParseCIDRs(cidrs)
+	if err != nil {
+		return false, err
+	}
+	return IsDualStackCIDRs(parsedCIDRs)
+}
+
+// IPFamilyOf returns the IP family of ip, or IPFamilyUnknown if it is invalid.
+func IPFamilyOf(ip net.IP) IPFamily {
+	switch {
+	case ip.To4() != nil:
+		return IPv4
+	case ip.To16() != nil:
+		return IPv6
+	default:
+		return IPFamilyUnknown
+	}
+}
+
+// IPFamilyOfString returns the IP family of ip, or IPFamilyUnknown if ip cannot
+// be parsed as an IP.
+func IPFamilyOfString(ip string) IPFamily {
+	return IPFamilyOf(ParseIPSloppy(ip))
+}
+
+// IPFamilyOfCIDR returns the IP family of cidr.
+func IPFamilyOfCIDR(cidr *net.IPNet) IPFamily {
+	if cidr == nil {
+		return IPFamilyUnknown
+	}
+	return IPFamilyOf(cidr.IP)
+}
+
+// IPFamilyOfCIDRString returns the IP family of cidr.
+func IPFamilyOfCIDRString(cidr string) IPFamily {
+	ip, _, _ := ParseCIDRSloppy(cidr)
+	return IPFamilyOf(ip)
+}
+
+// IsIPv6 returns true if netIP is IPv6 (and false if it is IPv4, nil, or invalid).
+func IsIPv6(netIP net.IP) bool {
+	return IPFamilyOf(netIP) == IPv6
+}
+
+// IsIPv6String returns true if ip contains a single IPv6 address and nothing else. It
+// returns false if ip is an empty string, an IPv4 address, or anything else that is not a
+// single IPv6 address.
+func IsIPv6String(ip string) bool {
+	return IPFamilyOfString(ip) == IPv6
+}
+
+// IsIPv6CIDR returns true if a cidr is a valid IPv6 CIDR. It returns false if cidr is
+// nil or an IPv4 CIDR. Its behavior is not defined if cidr is invalid.
+func IsIPv6CIDR(cidr *net.IPNet) bool {
+	return IPFamilyOfCIDR(cidr) == IPv6
+}
+
+// IsIPv6CIDRString returns true if cidr contains a single IPv6 CIDR and nothing else. It
+// returns false if cidr is an empty string, an IPv4 CIDR, or anything else that is not a
+// single valid IPv6 CIDR.
+func IsIPv6CIDRString(cidr string) bool {
+	return IPFamilyOfCIDRString(cidr) == IPv6
+}
+
+// IsIPv4 returns true if netIP is IPv4 (and false if it is IPv6, nil, or invalid).
+func IsIPv4(netIP net.IP) bool {
+	return IPFamilyOf(netIP) == IPv4
+}
+
+// IsIPv4String returns true if ip contains a single IPv4 address and nothing else. It
+// returns false if ip is an empty string, an IPv6 address, or anything else that is not a
+// single IPv4 address.
+func IsIPv4String(ip string) bool {
+	return IPFamilyOfString(ip) == IPv4
+}
+
+// IsIPv4CIDR returns true if cidr is a valid IPv4 CIDR. It returns false if cidr is nil
+// or an IPv6 CIDR. Its behavior is not defined if cidr is invalid.
+func IsIPv4CIDR(cidr *net.IPNet) bool {
+	return IPFamilyOfCIDR(cidr) == IPv4
+}
+
+// IsIPv4CIDRString returns true if cidr contains a single IPv4 CIDR and nothing else. It
+// returns false if cidr is an empty string, an IPv6 CIDR, or anything else that is not a
+// single valid IPv4 CIDR.
+func IsIPv4CIDRString(cidr string) bool {
+	return IPFamilyOfCIDRString(cidr) == IPv4
+}

e2e/vendor/k8s.io/utils/net/ipnet.go

@@ -0,0 +1,221 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package net
+
+import (
+	"fmt"
+	"net"
+	"strings"
+)
+
+// IPNetSet maps string to net.IPNet.
+type IPNetSet map[string]*net.IPNet
+
+// ParseIPNets parses string slice to IPNetSet.
+func ParseIPNets(specs ...string) (IPNetSet, error) {
+	ipnetset := make(IPNetSet)
+	for _, spec := range specs {
+		spec = strings.TrimSpace(spec)
+		_, ipnet, err := ParseCIDRSloppy(spec)
+		if err != nil {
+			return nil, err
+		}
+		k := ipnet.String() // In case of normalization
+		ipnetset[k] = ipnet
+	}
+	return ipnetset, nil
+}
+
+// Insert adds items to the set.
+func (s IPNetSet) Insert(items ...*net.IPNet) {
+	for _, item := range items {
+		s[item.String()] = item
+	}
+}
+
+// Delete removes all items from the set.
+func (s IPNetSet) Delete(items ...*net.IPNet) {
+	for _, item := range items {
+		delete(s, item.String())
+	}
+}
+
+// Has returns true if and only if item is contained in the set.
+func (s IPNetSet) Has(item *net.IPNet) bool {
+	_, contained := s[item.String()]
+	return contained
+}
+
+// HasAll returns true if and only if all items are contained in the set.
+func (s IPNetSet) HasAll(items ...*net.IPNet) bool {
+	for _, item := range items {
+		if !s.Has(item) {
+			return false
+		}
+	}
+	return true
+}
+
+// Difference returns a set of objects that are not in s2
+// For example:
+// s1 = {a1, a2, a3}
+// s2 = {a1, a2, a4, a5}
+// s1.Difference(s2) = {a3}
+// s2.Difference(s1) = {a4, a5}
+func (s IPNetSet) Difference(s2 IPNetSet) IPNetSet {
+	result := make(IPNetSet)
+	for k, i := range s {
+		_, found := s2[k]
+		if found {
+			continue
+		}
+		result[k] = i
+	}
+	return result
+}
+
+// StringSlice returns a []string with the String representation of each element in the set.
+// Order is undefined.
+func (s IPNetSet) StringSlice() []string {
+	a := make([]string, 0, len(s))
+	for k := range s {
+		a = append(a, k)
+	}
+	return a
+}
+
+// IsSuperset returns true if and only if s1 is a superset of s2.
+func (s IPNetSet) IsSuperset(s2 IPNetSet) bool {
+	for k := range s2 {
+		_, found := s[k]
+		if !found {
+			return false
+		}
+	}
+	return true
+}
+
+// Equal returns true if and only if s1 is equal (as a set) to s2.
+// Two sets are equal if their membership is identical.
+// (In practice, this means same elements, order doesn't matter)
+func (s IPNetSet) Equal(s2 IPNetSet) bool {
+	return len(s) == len(s2) && s.IsSuperset(s2)
+}
+
+// Len returns the size of the set.
+func (s IPNetSet) Len() int {
+	return len(s)
+}
+
+// IPSet maps string to net.IP
+type IPSet map[string]net.IP
+
+// ParseIPSet parses string slice to IPSet
+func ParseIPSet(items ...string) (IPSet, error) {
+	ipset := make(IPSet)
+	for _, item := range items {
+		ip := ParseIPSloppy(strings.TrimSpace(item))
+		if ip == nil {
+			return nil, fmt.Errorf("error parsing IP %q", item)
+		}
+
+		ipset[ip.String()] = ip
+	}
+
+	return ipset, nil
+}
+
+// Insert adds items to the set.
+func (s IPSet) Insert(items ...net.IP) {
+	for _, item := range items {
+		s[item.String()] = item
+	}
+}
+
+// Delete removes all items from the set.
+func (s IPSet) Delete(items ...net.IP) {
+	for _, item := range items {
+		delete(s, item.String())
+	}
+}
+
+// Has returns true if and only if item is contained in the set.
+func (s IPSet) Has(item net.IP) bool {
+	_, contained := s[item.String()]
+	return contained
+}
+
+// HasAll returns true if and only if all items are contained in the set.
+func (s IPSet) HasAll(items ...net.IP) bool {
+	for _, item := range items {
+		if !s.Has(item) {
+			return false
+		}
+	}
+	return true
+}
+
+// Difference returns a set of objects that are not in s2
+// For example:
+// s1 = {a1, a2, a3}
+// s2 = {a1, a2, a4, a5}
+// s1.Difference(s2) = {a3}
+// s2.Difference(s1) = {a4, a5}
+func (s IPSet) Difference(s2 IPSet) IPSet {
+	result := make(IPSet)
+	for k, i := range s {
+		_, found := s2[k]
+		if found {
+			continue
+		}
+		result[k] = i
+	}
+	return result
+}
+
+// StringSlice returns a []string with the String representation of each element in the set.
+// Order is undefined.
+func (s IPSet) StringSlice() []string {
+	a := make([]string, 0, len(s))
+	for k := range s {
+		a = append(a, k)
+	}
+	return a
+}
+
+// IsSuperset returns true if and only if s1 is a superset of s2.
+func (s IPSet) IsSuperset(s2 IPSet) bool {
+	for k := range s2 {
+		_, found := s[k]
+		if !found {
+			return false
+		}
+	}
+	return true
+}
+
+// Equal returns true if and only if s1 is equal (as a set) to s2.
+// Two sets are equal if their membership is identical.
+// (In practice, this means same elements, order doesn't matter)
+func (s IPSet) Equal(s2 IPSet) bool {
+	return len(s) == len(s2) && s.IsSuperset(s2)
+}
+
+// Len returns the size of the set.
+func (s IPSet) Len() int {
+	return len(s)
+}

e2e/vendor/k8s.io/utils/net/multi_listen.go

@@ -0,0 +1,195 @@
+/*
+Copyright 2024 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package net
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"sync"
+)
+
+// connErrPair pairs conn and error which is returned by accept on sub-listeners.
+type connErrPair struct {
+	conn net.Conn
+	err  error
+}
+
+// multiListener implements net.Listener
+type multiListener struct {
+	listeners []net.Listener
+	wg        sync.WaitGroup
+
+	// connCh passes accepted connections, from child listeners to parent.
+	connCh chan connErrPair
+	// stopCh communicates from parent to child listeners.
+	stopCh chan struct{}
+}
+
+// compile time check to ensure *multiListener implements net.Listener
+var _ net.Listener = &multiListener{}
+
+// MultiListen returns net.Listener which can listen on and accept connections for
+// the given network on multiple addresses. Internally it uses stdlib to create
+// sub-listener and multiplexes connection requests using go-routines.
+// The network must be "tcp", "tcp4" or "tcp6".
+// It follows the semantics of net.Listen that primarily means:
+//  1. If the host is an unspecified/zero IP address with "tcp" network, MultiListen
+//     listens on all available unicast and anycast IP addresses of the local system.
+//  2. Use "tcp4" or "tcp6" to exclusively listen on IPv4 or IPv6 family, respectively.
+//  3. The host can accept names (e.g, localhost) and it will create a listener for at
+//     most one of the host's IP.
+func MultiListen(ctx context.Context, network string, addrs ...string) (net.Listener, error) {
+	var lc net.ListenConfig
+	return multiListen(
+		ctx,
+		network,
+		addrs,
+		func(ctx context.Context, network, address string) (net.Listener, error) {
+			return lc.Listen(ctx, network, address)
+		})
+}
+
+// multiListen implements MultiListen by consuming stdlib functions as dependency allowing
+// mocking for unit-testing.
+func multiListen(
+	ctx context.Context,
+	network string,
+	addrs []string,
+	listenFunc func(ctx context.Context, network, address string) (net.Listener, error),
+) (net.Listener, error) {
+	if !(network == "tcp" || network == "tcp4" || network == "tcp6") {
+		return nil, fmt.Errorf("network %q not supported", network)
+	}
+	if len(addrs) == 0 {
+		return nil, fmt.Errorf("no address provided to listen on")
+	}
+
+	ml := &multiListener{
+		connCh: make(chan connErrPair),
+		stopCh: make(chan struct{}),
+	}
+	for _, addr := range addrs {
+		l, err := listenFunc(ctx, network, addr)
+		if err != nil {
+			// close all the sub-listeners and exit
+			_ = ml.Close()
+			return nil, err
+		}
+		ml.listeners = append(ml.listeners, l)
+	}
+
+	for _, l := range ml.listeners {
+		ml.wg.Add(1)
+		go func(l net.Listener) {
+			defer ml.wg.Done()
+			for {
+				// Accept() is blocking, unless ml.Close() is called, in which
+				// case it will return immediately with an error.
+				conn, err := l.Accept()
+				// This assumes that ANY error from Accept() will terminate the
+				// sub-listener. We could maybe be more precise, but it
+				// doesn't seem necessary.
+				terminate := err != nil
+
+				select {
+				case ml.connCh <- connErrPair{conn: conn, err: err}:
+				case <-ml.stopCh:
+					// In case we accepted a connection AND were stopped, and
+					// this select-case was chosen, just throw away the
+					// connection.  This avoids potentially blocking on connCh
+					// or leaking a connection.
+					if conn != nil {
+						_ = conn.Close()
+					}
+					terminate = true
+				}
+				// Make sure we don't loop on Accept() returning an error and
+				// the select choosing the channel case.
+				if terminate {
+					return
+				}
+			}
+		}(l)
+	}
+	return ml, nil
+}
+
+// Accept implements net.Listener. It waits for and returns a connection from
+// any of the sub-listener.
+func (ml *multiListener) Accept() (net.Conn, error) {
+	// wait for any sub-listener to enqueue an accepted connection
+	connErr, ok := <-ml.connCh
+	if !ok {
+		// The channel will be closed only when Close() is called on the
+		// multiListener. Closing of this channel implies that all
+		// sub-listeners are also closed, which causes a "use of closed
+		// network connection" error on their Accept() calls. We return the
+		// same error for multiListener.Accept() if multiListener.Close()
+		// has already been called.
+		return nil, fmt.Errorf("use of closed network connection")
+	}
+	return connErr.conn, connErr.err
+}
+
+// Close implements net.Listener. It will close all sub-listeners and wait for
+// the go-routines to exit.
+func (ml *multiListener) Close() error {
+	// Make sure this can be called repeatedly without explosions.
+	select {
+	case <-ml.stopCh:
+		return fmt.Errorf("use of closed network connection")
+	default:
+	}
+
+	// Tell all sub-listeners to stop.
+	close(ml.stopCh)
+
+	// Closing the listeners causes Accept() to immediately return an error in
+	// the sub-listener go-routines.
+	for _, l := range ml.listeners {
+		_ = l.Close()
+	}
+
+	// Wait for all the sub-listener go-routines to exit.
+	ml.wg.Wait()
+	close(ml.connCh)
+
+	// Drain any already-queued connections.
+	for connErr := range ml.connCh {
+		if connErr.conn != nil {
+			_ = connErr.conn.Close()
+		}
+	}
+	return nil
+}
+
+// Addr is an implementation of the net.Listener interface.  It always returns
+// the address of the first listener.  Callers should  use conn.LocalAddr() to
+// obtain the actual local address of the sub-listener.
+func (ml *multiListener) Addr() net.Addr {
+	return ml.listeners[0].Addr()
+}
+
+// Addrs is like Addr, but returns the address for all registered listeners.
+func (ml *multiListener) Addrs() []net.Addr {
+	var ret []net.Addr
+	for _, l := range ml.listeners {
+		ret = append(ret, l.Addr())
+	}
+	return ret
+}

e2e/vendor/k8s.io/utils/net/net.go

@@ -0,0 +1,91 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package net
+
+import (
+	"errors"
+	"fmt"
+	"math"
+	"math/big"
+	"net"
+	"strconv"
+)
+
+// ParseCIDRs parses a list of cidrs and return error if any is invalid.
+// order is maintained
+func ParseCIDRs(cidrsString []string) ([]*net.IPNet, error) {
+	cidrs := make([]*net.IPNet, 0, len(cidrsString))
+	for i, cidrString := range cidrsString {
+		_, cidr, err := ParseCIDRSloppy(cidrString)
+		if err != nil {
+			return nil, fmt.Errorf("invalid CIDR[%d]: %v (%v)", i, cidr, err)
+		}
+		cidrs = append(cidrs, cidr)
+	}
+	return cidrs, nil
+}
+
+// ParsePort parses a string representing an IP port.  If the string is not a
+// valid port number, this returns an error.
+func ParsePort(port string, allowZero bool) (int, error) {
+	portInt, err := strconv.ParseUint(port, 10, 16)
+	if err != nil {
+		return 0, err
+	}
+	if portInt == 0 && !allowZero {
+		return 0, errors.New("0 is not a valid port number")
+	}
+	return int(portInt), nil
+}
+
+// BigForIP creates a big.Int based on the provided net.IP
+func BigForIP(ip net.IP) *big.Int {
+	// NOTE: Convert to 16-byte representation so we can
+	// handle v4 and v6 values the same way.
+	return big.NewInt(0).SetBytes(ip.To16())
+}
+
+// AddIPOffset adds the provided integer offset to a base big.Int representing a net.IP
+// NOTE: If you started with a v4 address and overflow it, you get a v6 result.
+func AddIPOffset(base *big.Int, offset int) net.IP {
+	r := big.NewInt(0).Add(base, big.NewInt(int64(offset))).Bytes()
+	r = append(make([]byte, 16), r...)
+	return net.IP(r[len(r)-16:])
+}
+
+// RangeSize returns the size of a range in valid addresses.
+// returns the size of the subnet (or math.MaxInt64 if the range size would overflow int64)
+func RangeSize(subnet *net.IPNet) int64 {
+	ones, bits := subnet.Mask.Size()
+	if bits == 32 && (bits-ones) >= 31 || bits == 128 && (bits-ones) >= 127 {
+		return 0
+	}
+	// this checks that we are not overflowing an int64
+	if bits-ones >= 63 {
+		return math.MaxInt64
+	}
+	return int64(1) << uint(bits-ones)
+}
+
+// GetIndexedIP returns a net.IP that is subnet.IP + index in the contiguous IP space.
+func GetIndexedIP(subnet *net.IPNet, index int) (net.IP, error) {
+	ip := AddIPOffset(BigForIP(subnet.IP), index)
+	if !subnet.Contains(ip) {
+		return nil, fmt.Errorf("can't generate IP with index %d from subnet. subnet too small. subnet: %q", index, subnet)
+	}
+	return ip, nil
+}

e2e/vendor/k8s.io/utils/net/parse.go

@@ -0,0 +1,33 @@
+/*
+Copyright 2021 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package net
+
+import (
+	forkednet "k8s.io/utils/internal/third_party/forked/golang/net"
+)
+
+// ParseIPSloppy is identical to Go's standard net.ParseIP, except that it allows
+// leading '0' characters on numbers.  Go used to allow this and then changed
+// the behavior in 1.17.  We're choosing to keep it for compat with potential
+// stored values.
+var ParseIPSloppy = forkednet.ParseIP
+
+// ParseCIDRSloppy is identical to Go's standard net.ParseCIDR, except that it allows
+// leading '0' characters on numbers.  Go used to allow this and then changed
+// the behavior in 1.17.  We're choosing to keep it for compat with potential
+// stored values.
+var ParseCIDRSloppy = forkednet.ParseCIDR

e2e/vendor/k8s.io/utils/net/port.go

@@ -0,0 +1,129 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package net
+
+import (
+	"fmt"
+	"net"
+	"strconv"
+	"strings"
+)
+
+// Protocol is a network protocol support by LocalPort.
+type Protocol string
+
+// Constants for valid protocols:
+const (
+	TCP Protocol = "TCP"
+	UDP Protocol = "UDP"
+)
+
+// LocalPort represents an IP address and port pair along with a protocol
+// and potentially a specific IP family.
+// A LocalPort can be opened and subsequently closed.
+type LocalPort struct {
+	// Description is an arbitrary string.
+	Description string
+	// IP is the IP address part of a given local port.
+	// If this string is empty, the port binds to all local IP addresses.
+	IP string
+	// If IPFamily is not empty, the port binds only to addresses of this
+	// family.
+	// IF empty along with IP, bind to local addresses of any family.
+	IPFamily IPFamily
+	// Port is the port number.
+	// A value of 0 causes a port to be automatically chosen.
+	Port int
+	// Protocol is the protocol, e.g. TCP
+	Protocol Protocol
+}
+
+// NewLocalPort returns a LocalPort instance and ensures IPFamily and IP are
+// consistent and that the given protocol is valid.
+func NewLocalPort(desc, ip string, ipFamily IPFamily, port int, protocol Protocol) (*LocalPort, error) {
+	if protocol != TCP && protocol != UDP {
+		return nil, fmt.Errorf("Unsupported protocol %s", protocol)
+	}
+	if ipFamily != IPFamilyUnknown && ipFamily != IPv4 && ipFamily != IPv6 {
+		return nil, fmt.Errorf("Invalid IP family %s", ipFamily)
+	}
+	if ip != "" {
+		parsedIP := ParseIPSloppy(ip)
+		if parsedIP == nil {
+			return nil, fmt.Errorf("invalid ip address %s", ip)
+		}
+		if ipFamily != IPFamilyUnknown {
+			if IPFamily(parsedIP) != ipFamily {
+				return nil, fmt.Errorf("ip address and family mismatch %s, %s", ip, ipFamily)
+			}
+		}
+	}
+	return &LocalPort{Description: desc, IP: ip, IPFamily: ipFamily, Port: port, Protocol: protocol}, nil
+}
+
+func (lp *LocalPort) String() string {
+	ipPort := net.JoinHostPort(lp.IP, strconv.Itoa(lp.Port))
+	return fmt.Sprintf("%q (%s/%s%s)", lp.Description, ipPort, strings.ToLower(string(lp.Protocol)), lp.IPFamily)
+}
+
+// Closeable closes an opened LocalPort.
+type Closeable interface {
+	Close() error
+}
+
+// PortOpener can open a LocalPort and allows later closing it.
+type PortOpener interface {
+	OpenLocalPort(lp *LocalPort) (Closeable, error)
+}
+
+type listenPortOpener struct{}
+
+// ListenPortOpener opens ports by calling bind() and listen().
+var ListenPortOpener listenPortOpener
+
+// OpenLocalPort holds the given local port open.
+func (l *listenPortOpener) OpenLocalPort(lp *LocalPort) (Closeable, error) {
+	return openLocalPort(lp)
+}
+
+func openLocalPort(lp *LocalPort) (Closeable, error) {
+	var socket Closeable
+	hostPort := net.JoinHostPort(lp.IP, strconv.Itoa(lp.Port))
+	switch lp.Protocol {
+	case TCP:
+		network := "tcp" + string(lp.IPFamily)
+		listener, err := net.Listen(network, hostPort)
+		if err != nil {
+			return nil, err
+		}
+		socket = listener
+	case UDP:
+		network := "udp" + string(lp.IPFamily)
+		addr, err := net.ResolveUDPAddr(network, hostPort)
+		if err != nil {
+			return nil, err
+		}
+		conn, err := net.ListenUDP(network, addr)
+		if err != nil {
+			return nil, err
+		}
+		socket = conn
+	default:
+		return nil, fmt.Errorf("unknown protocol %q", lp.Protocol)
+	}
+	return socket, nil
+}