deps: remove iplib in favor of net/netip

config/tomlloader.go

@@ -4,13 +4,13 @@ import (
 	"fmt"
 	"maps"
 	"net"
+	"net/netip"
 	"regexp"
 	"runtime"
 	"slices"
 	"strings"
 
 	"github.com/BurntSushi/toml"
-	"github.com/c-robinson/iplib"
 	"github.com/knqyf263/go-cpe/naming"
 	"golang.org/x/xerrors"
 
@@ -193,27 +193,32 @@ func enumerateHosts(host string) ([]string, error) {
 		return []string{host}, nil
 	}
 
-	ipAddr, ipNet, err := net.ParseCIDR(host)
+	prefix, err := netip.ParsePrefix(host)
 	if err != nil {
 		return nil, xerrors.Errorf("Failed to parse CIDR. err: %w", err)
 	}
-	maskLen, _ := ipNet.Mask.Size()
 
-	addrs := []string{}
-	if net.ParseIP(ipAddr.String()).To4() != nil {
-		n := iplib.NewNet4(ipAddr, int(maskLen))
-		for _, addr := range n.Enumerate(int(n.Count()), 0) {
-			addrs = append(addrs, addr.String())
-		}
-	} else if net.ParseIP(ipAddr.String()).To16() != nil {
-		n := iplib.NewNet6(ipAddr, int(maskLen), 0)
-		if !n.Count().IsInt64() {
-			return nil, xerrors.Errorf("Failed to enumerate IP address. err: mask bitsize too big")
-		}
-		for _, addr := range n.Enumerate(int(n.Count().Int64()), 0) {
-			addrs = append(addrs, addr.String())
-		}
+	hostBits := prefix.Addr().BitLen() - prefix.Bits()
+
+	// Cap at 2^16 = 65536 addresses (a /16 for IPv4, /112 for IPv6) to prevent OOM.
+	const maxHostBits = 16
+	if hostBits > maxHostBits {
+		return nil, xerrors.Errorf("Failed to enumerate IP address: prefix /%d too large (max host bits %d)", prefix.Bits(), maxHostBits)
 	}
+
+	count := int(1) << hostBits
+	addrs := make([]string, 0, count)
+	addr := prefix.Masked().Addr()
+	for range count {
+		addrs = append(addrs, addr.String())
+		addr = addr.Next()
+	}
+
+	// IPv4 with prefix < 31: strip network (first) and broadcast (last) addresses
+	if prefix.Addr().Is4() && prefix.Bits() < 31 && len(addrs) > 2 {
+		addrs = addrs[1 : len(addrs)-1]
+	}
+
 	return addrs, nil
 }
 

config/tomlloader_test.go

@@ -97,6 +97,38 @@ func TestHosts(t *testing.T) {
 	}
 }
 
+func TestEnumerateHosts(t *testing.T) {
+	t.Parallel()
+	tests := []struct {
+		in       string
+		expected []string
+		err      bool
+	}{
+		{in: "192.168.1.1", expected: []string{"192.168.1.1"}},
+		{in: "ssh/host", expected: []string{"ssh/host"}},
+		{in: "192.168.1.0/30", expected: []string{"192.168.1.1", "192.168.1.2"}},
+		{in: "192.168.1.0/31", expected: []string{"192.168.1.0", "192.168.1.1"}},
+		{in: "192.168.1.1/32", expected: []string{"192.168.1.1"}},
+		{in: "2001:db8::1/126", expected: []string{"2001:db8::", "2001:db8::1", "2001:db8::2", "2001:db8::3"}},
+		{in: "2001:db8::1/127", expected: []string{"2001:db8::", "2001:db8::1"}},
+		{in: "2001:db8::1/128", expected: []string{"2001:db8::1"}},
+		{in: "2001:db8::1/32", err: true},
+		{in: "10.0.0.0/0", err: true},
+		{in: "192.168.0.0/8", err: true},
+	}
+	for i, tt := range tests {
+		actual, err := enumerateHosts(tt.in)
+		if err != nil && !tt.err {
+			t.Errorf("[%d] unexpected error: %v", i, err)
+		} else if err == nil && tt.err {
+			t.Errorf("[%d] expected error but got none", i)
+		}
+		if !reflect.DeepEqual(actual, tt.expected) {
+			t.Errorf("[%d] in: %s, got: %q, want: %q", i, tt.in, actual, tt.expected)
+		}
+	}
+}
+
 func TestToCpeURI(t *testing.T) {
 	var tests = []struct {
 		in       string

go.mod

@@ -18,7 +18,6 @@ require (
 	github.com/aws/aws-sdk-go-v2/credentials v1.19.10
 	github.com/aws/aws-sdk-go-v2/service/s3 v1.96.2
 	github.com/aws/aws-sdk-go-v2/service/sts v1.41.7
-	github.com/c-robinson/iplib v1.0.8
 	github.com/cenkalti/backoff v2.2.1+incompatible
 	github.com/d4l3k/messagediff v1.2.2-0.20190829033028-7e0a312ae40b
 	github.com/emersion/go-sasl v0.0.0-20241020182733-b788ff22d5a6

go.sum

@@ -202,8 +202,6 @@ github.com/bshuster-repo/logrus-logstash-hook v1.0.0 h1:e+C0SB5R1pu//O4MQ3f9cFuP
 github.com/bshuster-repo/logrus-logstash-hook v1.0.0/go.mod h1:zsTqEiSzDgAa/8GZR7E1qaXrhYNDKBYy5/dWPTIflbk=
 github.com/bytecodealliance/wasmtime-go/v39 v39.0.1 h1:RibaT47yiyCRxMOj/l2cvL8cWiWBSqDXHyqsa9sGcCE=
 github.com/bytecodealliance/wasmtime-go/v39 v39.0.1/go.mod h1:miR4NYIEBXeDNamZIzpskhJ0z/p8al+lwMWylQ/ZJb4=
-github.com/c-robinson/iplib v1.0.8 h1:exDRViDyL9UBLcfmlxxkY5odWX5092nPsQIykHXhIn4=
-github.com/c-robinson/iplib v1.0.8/go.mod h1:i3LuuFL1hRT5gFpBRnEydzw8R6yhGkF4szNDIbF8pgo=
 github.com/cenkalti/backoff v2.2.1+incompatible h1:tNowT99t7UNflLxfYYSlKYsBpXdEet03Pg2g16Swow4=
 github.com/cenkalti/backoff v2.2.1+incompatible/go.mod h1:90ReRw6GdpyfrHakVjL/QHaoyV4aDUVVkXQJJJ3NXXM=
 github.com/cenkalti/backoff/v4 v4.3.0 h1:MyRJ/UdXutAwSAT+s3wNd7MfTIcy71VQueUuFK343L8=