hotfix(firewall): fix ip prefix parsing for ipv6 (again)

internal/firewall/parse_test.go

@@ -82,3 +82,57 @@ func Test_parseIptablesInstruction(t *testing.T) {
 		})
 	}
 }
+
+func Test_parseIPPrefix(t *testing.T) {
+	t.Parallel()
+
+	testCases := map[string]struct {
+		value      string
+		prefix     netip.Prefix
+		errMessage string
+	}{
+		"empty": {
+			errMessage: `parsing IP address: ParseAddr(""): unable to parse IP`,
+		},
+		"invalid": {
+			value:      "invalid",
+			errMessage: `parsing IP address: ParseAddr("invalid"): unable to parse IP`,
+		},
+		"valid_ipv4_with_bits": {
+			value:  "10.0.0.0/16",
+			prefix: netip.PrefixFrom(netip.AddrFrom4([4]byte{10, 0, 0, 0}), 16),
+		},
+		"valid_ipv4_without_bits": {
+			value:  "10.0.0.4",
+			prefix: netip.PrefixFrom(netip.AddrFrom4([4]byte{10, 0, 0, 4}), 32),
+		},
+		"valid_ipv6_with_bits": {
+			value: "2001:db8::/32",
+			prefix: netip.PrefixFrom(
+				netip.AddrFrom16([16]byte{0x20, 0x01, 0x0d, 0xb8}),
+				32),
+		},
+		"valid_ipv6_without_bits": {
+			value: "2001:db8::",
+			prefix: netip.PrefixFrom(
+				netip.AddrFrom16([16]byte{0x20, 0x01, 0x0d, 0xb8}),
+				128),
+		},
+	}
+
+	for name, testCase := range testCases {
+		testCase := testCase
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			prefix, err := parseIPPrefix(testCase.value)
+
+			assert.Equal(t, testCase.prefix, prefix)
+			if testCase.errMessage != "" {
+				assert.EqualError(t, err, testCase.errMessage)
+			} else {
+				assert.NoError(t, err)
+			}
+		})
+	}
+}