Merge pull request kubernetes#86534 from liggitt/ipallocator-range

Restore IPAllocator ipv4 range handling

Author: k8s-ci-robot

pkg/registry/core/service/ipallocator/BUILD

@@ -13,8 +13,6 @@ go_library(
     deps = [
         "//pkg/apis/core:go_default_library",
         "//pkg/registry/core/service/allocator:go_default_library",
-        "//vendor/k8s.io/utils/integer:go_default_library",
-        "//vendor/k8s.io/utils/net:go_default_library",
     ],
 )
 

pkg/registry/core/service/ipallocator/allocator.go

@@ -19,14 +19,10 @@ package ipallocator
 import (
 	"errors"
 	"fmt"
-
-	"math/big"
-	"net"
-
 	api "k8s.io/kubernetes/pkg/apis/core"
 	"k8s.io/kubernetes/pkg/registry/core/service/allocator"
-	"k8s.io/utils/integer"
-	utilnet "k8s.io/utils/net"
+	"math/big"
+	"net"
 )
 
 // Interface manages the allocation of IP addresses out of a range. Interface
@@ -84,8 +80,8 @@ type Range struct {
 
 // NewAllocatorCIDRRange creates a Range over a net.IPNet, calling allocatorFactory to construct the backing store.
 func NewAllocatorCIDRRange(cidr *net.IPNet, allocatorFactory allocator.AllocatorFactory) (*Range, error) {
-	max := integer.Int64Min(utilnet.RangeSize(cidr), 1<<16)
-	base := utilnet.BigForIP(cidr.IP)
+	max := RangeSize(cidr)
+	base := bigForIP(cidr.IP)
 	rangeSpec := cidr.String()
 
 	r := Range{
@@ -173,7 +169,7 @@ func (r *Range) AllocateNext() (net.IP, error) {
 	if !ok {
 		return nil, ErrFull
 	}
-	return utilnet.AddIPOffset(r.base, offset), nil
+	return addIPOffset(r.base, offset), nil
 }
 
 // Release releases the IP back to the pool. Releasing an
@@ -191,7 +187,7 @@ func (r *Range) Release(ip net.IP) error {
 // ForEach calls the provided function for each allocated IP.
 func (r *Range) ForEach(fn func(net.IP)) {
 	r.alloc.ForEach(func(offset int) {
-		ip, _ := utilnet.GetIndexedIP(r.net, offset+1) // +1 because Range doesn't store IP 0
+		ip, _ := GetIndexedIP(r.net, offset+1) // +1 because Range doesn't store IP 0
 		fn(ip)
 	})
 }
@@ -249,8 +245,49 @@ func (r *Range) contains(ip net.IP) (bool, int) {
 	return true, offset
 }
 
+// bigForIP creates a big.Int based on the provided net.IP
+func bigForIP(ip net.IP) *big.Int {
+	b := ip.To4()
+	if b == nil {
+		b = ip.To16()
+	}
+	return big.NewInt(0).SetBytes(b)
+}
+
+// addIPOffset adds the provided integer offset to a base big.Int representing a
+// net.IP
+func addIPOffset(base *big.Int, offset int) net.IP {
+	return net.IP(big.NewInt(0).Add(base, big.NewInt(int64(offset))).Bytes())
+}
+
 // calculateIPOffset calculates the integer offset of ip from base such that
 // base + offset = ip. It requires ip >= base.
 func calculateIPOffset(base *big.Int, ip net.IP) int {
-	return int(big.NewInt(0).Sub(utilnet.BigForIP(ip), base).Int64())
+	return int(big.NewInt(0).Sub(bigForIP(ip), base).Int64())
+}
+
+// RangeSize returns the size of a range in valid addresses.
+func RangeSize(subnet *net.IPNet) int64 {
+	ones, bits := subnet.Mask.Size()
+	if bits == 32 && (bits-ones) >= 31 || bits == 128 && (bits-ones) >= 127 {
+		return 0
+	}
+	// For IPv6, the max size will be limited to 65536
+	// This is due to the allocator keeping track of all the
+	// allocated IP's in a bitmap. This will keep the size of
+	// the bitmap to 64k.
+	if bits == 128 && (bits-ones) >= 16 {
+		return int64(1) << uint(16)
+	} else {
+		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
 }

pkg/registry/core/service/ipallocator/allocator_test.go

@@ -66,7 +66,6 @@ func TestAllocate(t *testing.T) {
 			t.Fatal(err)
 		}
 		t.Logf("base: %v", r.base.Bytes())
-		t.Logf("max: %v", r.max)
 		if f := r.Free(); f != tc.free {
 			t.Errorf("Test %s unexpected free %d", tc.name, f)
 		}
@@ -214,6 +213,51 @@ func TestAllocateSmall(t *testing.T) {
 	t.Logf("allocated: %v", found)
 }
 
+func TestRangeSize(t *testing.T) {
+	testCases := []struct {
+		name  string
+		cidr  string
+		addrs int64
+	}{
+		{
+			name:  "supported IPv4 cidr",
+			cidr:  "192.168.1.0/24",
+			addrs: 256,
+		},
+		{
+			name:  "supported large IPv4 cidr",
+			cidr:  "10.96.0.0/12",
+			addrs: 1048576,
+		},
+		{
+			name:  "unsupported IPv4 cidr",
+			cidr:  "192.168.1.0/1",
+			addrs: 0,
+		},
+		{
+			name:  "supported IPv6 cidr",
+			cidr:  "2001:db8::/48",
+			addrs: 65536,
+		},
+		{
+			name:  "unsupported IPv6 mask",
+			cidr:  "2001:db8::/1",
+			addrs: 0,
+		},
+	}
+
+	for _, tc := range testCases {
+		_, cidr, err := net.ParseCIDR(tc.cidr)
+		if err != nil {
+			t.Errorf("failed to parse cidr for test %s, unexpected error: '%s'", tc.name, err)
+		}
+		if size := RangeSize(cidr); size != tc.addrs {
+			t.Errorf("test %s failed. %s should have a range size of %d, got %d",
+				tc.name, tc.cidr, tc.addrs, size)
+		}
+	}
+}
+
 func TestForEach(t *testing.T) {
 	_, cidr, err := net.ParseCIDR("192.168.1.0/24")
 	if err != nil {