fix #2289: improve regex to give expected results

3 files changed, 34 insertions, 55 deletions

diff --git a/cmd/gobgp/policy.go b/cmd/gobgp/policy.go
index 710fdb38..f90b68b0 100644
--- a/cmd/gobgp/policy.go
+++ b/cmd/gobgp/policy.go
@@ -31,65 +31,15 @@ import (
 
 	api "github.com/osrg/gobgp/api"
 	"github.com/osrg/gobgp/internal/pkg/config"
+	table "github.com/osrg/gobgp/internal/pkg/table"
 	"github.com/osrg/gobgp/pkg/packet/bgp"
 )
 
 var (
 	_regexpCommunity      = regexp.MustCompile(`\^\^(\S+)\$\$`)
-	repexpCommunity       = regexp.MustCompile(`(\d+.)*\d+:\d+`)
-	regexpLargeCommunity  = regexp.MustCompile(`\d+:\d+:\d+`)
 	regexpCommunityString = regexp.MustCompile(`[\^\$]`)
 )
 
-func parseCommunityRegexp(arg string) (*regexp.Regexp, error) {
-	i, err := strconv.ParseUint(arg, 10, 32)
-	if err == nil {
-		return regexp.Compile(fmt.Sprintf("^%d:%d$", i>>16, i&0x0000ffff))
-	}
-	if repexpCommunity.MatchString(arg) {
-		return regexp.Compile(fmt.Sprintf("^%s$", arg))
-	}
-	for i, v := range bgp.WellKnownCommunityNameMap {
-		if strings.Replace(strings.ToLower(arg), "_", "-", -1) == v {
-			return regexp.Compile(fmt.Sprintf("^%d:%d$", i>>16, i&0x0000ffff))
-		}
-	}
-	exp, err := regexp.Compile(arg)
-	if err != nil {
-		return nil, fmt.Errorf("invalid community format: %s", arg)
-	}
-	return exp, nil
-}
-
-func parseExtCommunityRegexp(arg string) (bgp.ExtendedCommunityAttrSubType, *regexp.Regexp, error) {
-	var subtype bgp.ExtendedCommunityAttrSubType
-	elems := strings.SplitN(arg, ":", 2)
-	if len(elems) < 2 {
-		return subtype, nil, fmt.Errorf("invalid ext-community format([rt|soo]:<value>)")
-	}
-	switch strings.ToLower(elems[0]) {
-	case "rt":
-		subtype = bgp.EC_SUBTYPE_ROUTE_TARGET
-	case "soo":
-		subtype = bgp.EC_SUBTYPE_ROUTE_ORIGIN
-	default:
-		return subtype, nil, fmt.Errorf("unknown ext-community subtype. rt, soo is supported")
-	}
-	exp, err := parseCommunityRegexp(elems[1])
-	return subtype, exp, err
-}
-
-func parseLargeCommunityRegexp(arg string) (*regexp.Regexp, error) {
-	if regexpLargeCommunity.MatchString(arg) {
-		return regexp.Compile(fmt.Sprintf("^%s$", arg))
-	}
-	exp, err := regexp.Compile(arg)
-	if err != nil {
-		return nil, fmt.Errorf("invalid large-community format: %s", arg)
-	}
-	return exp, nil
-}
-
 func routeTypePrettyString(s api.Conditions_RouteType) string {
 	switch s {
 	case api.Conditions_ROUTE_TYPE_EXTERNAL:
@@ -370,7 +320,7 @@ func parseCommunitySet(args []string) (*api.DefinedSet, error) {
 	name := args[0]
 	args = args[1:]
 	for _, arg := range args {
-		if _, err := parseCommunityRegexp(arg); err != nil {
+		if _, err := table.ParseCommunityRegexp(arg); err != nil {
 			return nil, err
 		}
 	}
@@ -388,7 +338,7 @@ func parseExtCommunitySet(args []string) (*api.DefinedSet, error) {
 	name := args[0]
 	args = args[1:]
 	for _, arg := range args {
-		if _, _, err := parseExtCommunityRegexp(arg); err != nil {
+		if _, _, err := table.ParseExtCommunityRegexp(arg); err != nil {
 			return nil, err
 		}
 	}
@@ -406,7 +356,7 @@ func parseLargeCommunitySet(args []string) (*api.DefinedSet, error) {
 	name := args[0]
 	args = args[1:]
 	for _, arg := range args {
-		if _, err := parseLargeCommunityRegexp(arg); err != nil {
+		if _, err := table.ParseLargeCommunityRegexp(arg); err != nil {
 			return nil, err
 		}
 	}
diff --git a/internal/pkg/table/policy.go b/internal/pkg/table/policy.go
index 08636991..d2e4f5ef 100644
--- a/internal/pkg/table/policy.go
+++ b/internal/pkg/table/policy.go
@@ -1135,7 +1135,7 @@ func ParseExtCommunity(arg string) (bgp.ExtendedCommunityInterface, error) {
 	return bgp.ParseExtendedCommunity(subtype, value)
 }
 
-var _regexpCommunity2 = regexp.MustCompile(`(\d+.)*\d+:\d+`)
+var _regexpCommunity2 = regexp.MustCompile(`^(\d+.)*\d+:\d+$`)
 
 func ParseCommunityRegexp(arg string) (*regexp.Regexp, error) {
 	i, err := strconv.ParseUint(arg, 10, 32)
diff --git a/internal/pkg/table/policy_test.go b/internal/pkg/table/policy_test.go
index 7c2d7a64..9f74f32c 100644
--- a/internal/pkg/table/policy_test.go
+++ b/internal/pkg/table/policy_test.go
@@ -2771,6 +2771,35 @@ func TestParseCommunityRegexp(t *testing.T) {
 	assert.Equal(t, nil, err)
 	assert.Equal(t, true, exp.MatchString("65000:1"))
 	assert.Equal(t, false, exp.MatchString("65000:100"))
+
+	// test if the parseCommunityRegexp function behaves as expected
+
+	l1 := "6830:24370$"
+	r1, _ := ParseCommunityRegexp("6830:24370$")
+
+	l2 := "^6830:24370$"
+	r2, _ := ParseCommunityRegexp("^6830:24370$")
+
+	l3 := "^65001:100$"
+	r3, _ := ParseCommunityRegexp("65001:100")
+
+	l4 := "^65001:400$"
+	r4, _ := ParseCommunityRegexp("4259905936")
+
+	l5 := "^[0-9]*:300$"
+	r5, _ := ParseCommunityRegexp("^[0-9]*:300$")
+
+	l6 := "^" + strconv.Itoa(int(bgp.COMMUNITY_INTERNET)) + ":" + strconv.Itoa(int(bgp.COMMUNITY_INTERNET)) + "$"
+	r6, _ := ParseCommunityRegexp("INTERNET")
+
+	fmt.Printf("%v %v", l2, r2)
+
+	assert.Equal(t, l1, r1.String())
+	assert.Equal(t, l2, r2.String())
+	assert.Equal(t, l3, r3.String())
+	assert.Equal(t, l4, r4.String())
+	assert.Equal(t, l5, r5.String())
+	assert.Equal(t, l6, r6.String())
 }
 
 func TestLocalPrefAction(t *testing.T) {