Add validation primitives to util

Part 2 in a series of changes towards data validation.

pkg/util/validation.go

@@ -0,0 +1,53 @@
+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+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 util
+
+import (
+	"regexp"
+)
+
+var dnsLabelFmt string = "[a-z0-9]([-a-z0-9]*[a-z0-9])?"
+var dnsLabelRegexp *regexp.Regexp = regexp.MustCompile("^" + dnsLabelFmt + "$")
+
+// IsDNSLabel tests for a string that conforms to the definition of a label in
+// DNS (RFC 1035/1123).  This checks the format, but not the length.
+func IsDNSLabel(value string) bool {
+	return dnsLabelRegexp.MatchString(value)
+}
+
+var dnsSubdomainFmt string = dnsLabelFmt + "(\\." + dnsLabelFmt + ")*"
+var dnsSubdomainRegexp *regexp.Regexp = regexp.MustCompile("^" + dnsSubdomainFmt + "$")
+
+// IsDNSSubdomain tests for a string that conforms to the definition of a
+// subdomain in DNS (RFC 1035/1123).  This checks the format, but not the length.
+func IsDNSSubdomain(value string) bool {
+	return dnsSubdomainRegexp.MatchString(value)
+}
+
+var cIdentifierFmt string = "[A-Za-z_][A-Za-z0-9_]*"
+var cIdentifierRegexp *regexp.Regexp = regexp.MustCompile("^" + cIdentifierFmt + "$")
+
+// IsCIdentifier tests for a string that conforms the definition of an identifier
+// in C. This checks the format, but not the length.
+func IsCIdentifier(value string) bool {
+	return cIdentifierRegexp.MatchString(value)
+}
+
+// IsValidPortNum tests that the argument is a valid, non-zero port number.
+func IsValidPortNum(port int) bool {
+	return 0 < port && port < 65536
+}

pkg/util/validation_test.go

@@ -0,0 +1,122 @@
+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+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 util
+
+import (
+	"testing"
+)
+
+func TestIsDNSLabel(t *testing.T) {
+	goodValues := []string{
+		"a", "ab", "abc", "a1", "a-1", "a--1--2--b",
+		"0", "01", "012", "1a", "1-a", "1--a--b--2",
+	}
+	for _, val := range goodValues {
+		if !IsDNSLabel(val) {
+			t.Errorf("expected true for '%s'", val)
+		}
+	}
+
+	badValues := []string{
+		"", "A", "ABC", "aBc", "A1", "A-1", "1-A",
+		"-", "a-", "-a", "1-", "-1",
+		"_", "a_", "_a", "a_b", "1_", "_1", "1_2",
+		".", "a.", ".a", "a.b", "1.", ".1", "1.2",
+		" ", "a ", " a", "a b", "1 ", " 1", "1 2",
+	}
+	for _, val := range badValues {
+		if IsDNSLabel(val) {
+			t.Errorf("expected false for '%s'", val)
+		}
+	}
+}
+
+func TestIsDNSSubdomain(t *testing.T) {
+	goodValues := []string{
+		"a", "ab", "abc", "a1", "a-1", "a--1--2--b",
+		"0", "01", "012", "1a", "1-a", "1--a--b--2",
+		"a.a", "ab.a", "abc.a", "a1.a", "a-1.a", "a--1--2--b.a",
+		"a.1", "ab.1", "abc.1", "a1.1", "a-1.1", "a--1--2--b.1",
+		"0.a", "01.a", "012.a", "1a.a", "1-a.a", "1--a--b--2",
+		"0.1", "01.1", "012.1", "1a.1", "1-a.1", "1--a--b--2.1",
+		"a.b.c.d.e", "aa.bb.cc.dd.ee", "1.2.3.4.5", "11.22.33.44.55",
+	}
+	for _, val := range goodValues {
+		if !IsDNSSubdomain(val) {
+			t.Errorf("expected true for '%s'", val)
+		}
+	}
+
+	badValues := []string{
+		"", "A", "ABC", "aBc", "A1", "A-1", "1-A",
+		"-", "a-", "-a", "1-", "-1",
+		"_", "a_", "_a", "a_b", "1_", "_1", "1_2",
+		".", "a.", ".a", "a..b", "1.", ".1", "1..2",
+		" ", "a ", " a", "a b", "1 ", " 1", "1 2",
+		"A.a", "aB.a", "ab.A", "A1.a", "a1.A",
+		"A.1", "aB.1", "A1.1", "1A.1",
+		"0.A", "01.A", "012.A", "1A.a", "1a.A",
+		"A.B.C.D.E", "AA.BB.CC.DD.EE", "a.B.c.d.e", "aa.bB.cc.dd.ee",
+		"a@b", "a,b", "a_b", "a;b",
+		"a:b", "a%b", "a?b", "a$b",
+	}
+	for _, val := range badValues {
+		if IsDNSSubdomain(val) {
+			t.Errorf("expected false for '%s'", val)
+		}
+	}
+}
+
+func TestIsCIdentifier(t *testing.T) {
+	goodValues := []string{
+		"a", "ab", "abc", "a1", "_a", "a_", "a_b", "a_1", "a__1__2__b", "__abc_123",
+		"A", "AB", "AbC", "A1", "_A", "A_", "A_B", "A_1", "A__1__2__B", "__123_ABC",
+	}
+	for _, val := range goodValues {
+		if !IsCIdentifier(val) {
+			t.Errorf("expected true for '%s'", val)
+		}
+	}
+
+	badValues := []string{
+		"", "1", "123", "1a",
+		"-", "a-", "-a", "1-", "-1", "1_", "1_2",
+		".", "a.", ".a", "a.b", "1.", ".1", "1.2",
+		" ", "a ", " a", "a b", "1 ", " 1", "1 2",
+	}
+	for _, val := range badValues {
+		if IsCIdentifier(val) {
+			t.Errorf("expected false for '%s'", val)
+		}
+	}
+}
+
+func TestIsValidPortNum(t *testing.T) {
+	goodValues := []int{1, 2, 1000, 16384, 32768, 65535}
+	for _, val := range goodValues {
+		if !IsValidPortNum(val) {
+			t.Errorf("expected true for '%s'", val)
+		}
+	}
+
+	badValues := []int{0, -1, 65536, 100000}
+	for _, val := range badValues {
+		if IsValidPortNum(val) {
+			t.Errorf("expected false for '%s'", val)
+		}
+	}
+}