Merge pull request #92 from cloudflare/filters-validation

More strict filter validation

filters/filter.go

@@ -57,43 +57,49 @@ func NewFilter(expression string) FilterT {
 	invalid := alwaysInvalidFilter{}
 	invalid.init("", nil, expression, false, expression)
 
+	reExp := fmt.Sprintf("^(?P<matched>(%s))(?P<operator>(%s))(?P<value>(.*))", filterRegex, matcherRegex)
+	re := regexp.MustCompile(reExp)
+	match := re.FindStringSubmatch(expression)
+	result := make(map[string]string)
+	for i, name := range re.SubexpNames() {
+		if name != "" && i > 0 && i <= len(match) {
+			result[name] = match[i]
+		}
+	}
+
+	matched, _ := result["matched"]
+	operator, _ := result["operator"]
+	value, _ := result["value"]
+
+	if matched == "" && operator == "" && value == "" {
+		// no "filter=" part, just the value, use fuzzy filter
+		f := newFuzzyFilter()
+		matcher, err := newMatcher(regexpOperator)
+		if err != nil {
+			f.init("", nil, expression, false, expression)
+		} else {
+			f.init("", &matcher, expression, true, expression)
+		}
+		return f
+	}
+
+	if value == "" {
+		// there's no value, so it's always invalid
+		return &invalid
+	}
+
+	if operator == "" {
+		// no operator, no valid filter here
+		return &invalid
+	}
+
+	// we have "filter=" part, lookup filter that matches
 	for _, fc := range AllFilters {
 		f := fc.Factory()
-
-		reExp := fmt.Sprintf("^(?P<matched>(%s))(?P<operator>(%s))(?P<value>(.*))", fc.Label, matcherRegex)
-		re := regexp.MustCompile(reExp)
-		match := re.FindStringSubmatch(expression)
-		result := make(map[string]string)
-		for i, name := range re.SubexpNames() {
-			if name != "" && i > 0 && i <= len(match) {
-				result[name] = match[i]
-			}
-		}
-
-		matched, found := result["matched"]
-		if !found && fc.IsSimple {
-			matcher, err := newMatcher(regexpOperator)
-			if err != nil {
-				f.init("", nil, expression, false, expression)
-			} else {
-				f.init("", &matcher, expression, true, expression)
-			}
-			return f
-		}
-		if !found {
+		if !fc.LabelRe.MatchString(matched) {
+			// filter name doesn't match, keep searching
 			continue
 		}
-		if value, ok := result["value"]; !ok || value == "" {
-			// value group not found in the expression
-			// example: 'label=''
-			return &invalid
-		}
-		operator, found := result["operator"]
-		if !found {
-			// used operator is not supported by the filter
-			// example: @limit=~0
-			return &invalid
-		}
 		if !stringInSlice(fc.SupportedOperators, operator) {
 			return &invalid
 		}
@@ -101,13 +107,13 @@ func NewFilter(expression string) FilterT {
 		if err != nil {
 			f.init(matched, nil, expression, false, "")
 		} else {
-			if value, found := result["value"]; found {
+			if value != "" {
 				f.init(matched, &matcher, expression, true, value)
 				return f
 			}
 			f.init(matched, &matcher, expression, false, "")
 		}
-
 	}
+
 	return &invalid
 }

filters/filter_test.go

@@ -406,6 +406,30 @@ var tests = []filterTest{
 		Expression: "^abb[****].*****",
 		IsValid:    false,
 	},
+	filterTest{
+		Expression: "@silenced=true",
+		IsValid:    false,
+	},
+	filterTest{
+		Expression: "@silenced!=false",
+		IsValid:    false,
+	},
+	filterTest{
+		Expression: "@silenced=~false",
+		IsValid:    false,
+	},
+	filterTest{
+		Expression: "@inhibited=true",
+		IsValid:    false,
+	},
+	filterTest{
+		Expression: "@inhibited!=false",
+		IsValid:    false,
+	},
+	filterTest{
+		Expression: "@inhibited=~false",
+		IsValid:    false,
+	},
 }
 
 func TestFilters(t *testing.T) {

filters/registry.go

@@ -1,5 +1,7 @@
 package filters
 
+import "regexp"
+
 const (
 	equalOperator         string = "="
 	notEqualOperator      string = "!="
@@ -15,6 +17,9 @@ const (
 // a===b should yield an error
 var matcherRegex = "[=!<>~]+"
 
+// same as matcherRegex but for the filter name part
+var filterRegex = "^(@)?[a-zA-Z_][a-zA-Z0-9_]*"
+
 var matcherConfig = map[string]matcherT{
 	equalOperator:         &equalMatcher{},
 	notEqualOperator:      &notEqualMatcher{},
@@ -25,8 +30,8 @@ var matcherConfig = map[string]matcherT{
 }
 
 type filterConfig struct {
-	IsSimple           bool
 	Label              string
+	LabelRe            *regexp.Regexp
 	SupportedOperators []string
 	Factory            newFilterFactory
 	Autocomplete       autocompleteFactory
@@ -37,42 +42,44 @@ type filterConfig struct {
 var AllFilters = []filterConfig{
 	filterConfig{
 		Label:              "@status",
+		LabelRe:            regexp.MustCompile("^@status$"),
 		SupportedOperators: []string{equalOperator, notEqualOperator},
 		Factory:            newstatusFilter,
 		Autocomplete:       statusAutocomplete,
 	},
 	filterConfig{
 		Label:              "@age",
+		LabelRe:            regexp.MustCompile("^@age$"),
 		SupportedOperators: []string{lessThanOperator, moreThanOperator},
 		Factory:            newAgeFilter,
 		Autocomplete:       ageAutocomplete,
 	},
 	filterConfig{
 		Label:              "@silence_jira",
+		LabelRe:            regexp.MustCompile("^@silence_jira$"),
 		SupportedOperators: []string{regexpOperator, negativeRegexOperator, equalOperator, notEqualOperator},
 		Factory:            newSilenceJiraFilter,
 		Autocomplete:       sinceJiraIDAutocomplete,
 	},
 	filterConfig{
 		Label:              "@silence_author",
+		LabelRe:            regexp.MustCompile("^@silence_author$"),
 		SupportedOperators: []string{regexpOperator, negativeRegexOperator, equalOperator, notEqualOperator},
 		Factory:            newSilenceAuthorFilter,
 		Autocomplete:       sinceAuthorAutocomplete,
 	},
 	filterConfig{
 		Label:              "@limit",
+		LabelRe:            regexp.MustCompile("^@limit$"),
 		SupportedOperators: []string{equalOperator},
 		Factory:            newLimitFilter,
 		Autocomplete:       limitAutocomplete,
 	},
 	filterConfig{
 		Label:              "[a-zA-Z_][a-zA-Z0-9_]*",
+		LabelRe:            regexp.MustCompile("^[a-zA-Z_][a-zA-Z0-9_]*$"),
 		SupportedOperators: []string{regexpOperator, negativeRegexOperator, equalOperator, notEqualOperator, lessThanOperator, moreThanOperator},
 		Factory:            newLabelFilter,
 		Autocomplete:       labelAutocomplete,
 	},
-	filterConfig{
-		IsSimple: true,
-		Factory:  newFuzzyFilter,
-	},
 }