From 812b87ab487518075fdd43a885ef6deea8cd4746 Mon Sep 17 00:00:00 2001
From: blotus <sebastien@crowdsec.net>
Date: Fri, 10 Feb 2023 14:44:42 +0100
Subject: [PATCH] Add `IsIPV4()` and `IsIP()` helpers (#2050)

---
 pkg/exprhelpers/exprlib.go      | 20 +++++++
 pkg/exprhelpers/exprlib_test.go | 93 +++++++++++++++++++++++++++++----
 2 files changed, 102 insertions(+), 11 deletions(-)

diff --git a/pkg/exprhelpers/exprlib.go b/pkg/exprhelpers/exprlib.go
index db61ef4b6..b830507af 100644
--- a/pkg/exprhelpers/exprlib.go
+++ b/pkg/exprhelpers/exprlib.go
@@ -72,6 +72,8 @@ func GetExprEnv(ctx map[string]interface{}) map[string]interface{} {
 		"XMLGetNodeValue":        XMLGetNodeValue,
 		"IpToRange":              IpToRange,
 		"IsIPV6":                 IsIPV6,
+		"IsIPV4":                 IsIPV4,
+		"IsIP":                   IsIP,
 		"LookupHost":             LookupHost,
 		"GetDecisionsCount":      GetDecisionsCount,
 		"GetDecisionsSinceCount": GetDecisionsSinceCount,
@@ -234,6 +236,24 @@ func IsIPV6(ip string) bool {
 	return ipParsed.To4() == nil
 }
 
+func IsIPV4(ip string) bool {
+	ipParsed := net.ParseIP(ip)
+	if ipParsed == nil {
+		log.Debugf("'%s' is not a valid IP", ip)
+		return false
+	}
+	return ipParsed.To4() != nil
+}
+
+func IsIP(ip string) bool {
+	ipParsed := net.ParseIP(ip)
+	if ipParsed == nil {
+		log.Debugf("'%s' is not a valid IP", ip)
+		return false
+	}
+	return true
+}
+
 func IpToRange(ip string, cidr string) string {
 	cidr = strings.TrimPrefix(cidr, "/")
 	mask, err := strconv.Atoi(cidr)
diff --git a/pkg/exprhelpers/exprlib_test.go b/pkg/exprhelpers/exprlib_test.go
index 97a274695..2f7f9de4e 100644
--- a/pkg/exprhelpers/exprlib_test.go
+++ b/pkg/exprhelpers/exprlib_test.go
@@ -9,10 +9,10 @@ import (
 	"github.com/pkg/errors"
 
 	"github.com/crowdsecurity/crowdsec/pkg/csconfig"
+	"github.com/crowdsecurity/crowdsec/pkg/cstest"
 	"github.com/crowdsecurity/crowdsec/pkg/database"
 	"github.com/crowdsecurity/crowdsec/pkg/models"
 	"github.com/crowdsecurity/crowdsec/pkg/types"
-	"github.com/crowdsecurity/crowdsec/pkg/cstest"
 	log "github.com/sirupsen/logrus"
 
 	"testing"
@@ -981,25 +981,25 @@ func TestParseUnixTime(t *testing.T) {
 		expectedErr string
 	}{
 		{
-			name: "ParseUnix() test: valid value with milli",
-			value: "1672239773.3590894",
+			name:     "ParseUnix() test: valid value with milli",
+			value:    "1672239773.3590894",
 			expected: time.Date(2022, 12, 28, 15, 02, 53, 0, time.UTC),
 		},
 		{
-			name: "ParseUnix() test: valid value without milli",
-			value: "1672239773",
+			name:     "ParseUnix() test: valid value without milli",
+			value:    "1672239773",
 			expected: time.Date(2022, 12, 28, 15, 02, 53, 0, time.UTC),
 		},
 		{
-			name: "ParseUnix() test: invalid input",
-			value: "AbcDefG!#",
-			expected: time.Time{},
+			name:        "ParseUnix() test: invalid input",
+			value:       "AbcDefG!#",
+			expected:    time.Time{},
 			expectedErr: "unable to parse AbcDefG!# as unix timestamp",
 		},
 		{
-			name: "ParseUnix() test: negative value",
-			value: "-1000",
-			expected: time.Time{},
+			name:        "ParseUnix() test: negative value",
+			value:       "-1000",
+			expected:    time.Time{},
 			expectedErr: "unable to parse -1000 as unix timestamp",
 		},
 	}
@@ -1016,3 +1016,74 @@ func TestParseUnixTime(t *testing.T) {
 		})
 	}
 }
+
+func TestIsIp(t *testing.T) {
+	tests := []struct {
+		name     string
+		method   func(string) bool
+		value    string
+		expected bool
+	}{
+		{
+			name:     "IsIPV4() test: valid IPv4",
+			method:   IsIPV4,
+			value:    "1.2.3.4",
+			expected: true,
+		},
+		{
+			name:     "IsIPV6() test: valid IPv6",
+			method:   IsIPV6,
+			value:    "1.2.3.4",
+			expected: false,
+		},
+		{
+			name:     "IsIPV6() test: valid IPv6",
+			method:   IsIPV6,
+			value:    "2001:0db8:85a3:0000:0000:8a2e:0370:7334",
+			expected: true,
+		},
+		{
+			name:     "IsIPV4() test: valid IPv6",
+			method:   IsIPV4,
+			value:    "2001:0db8:85a3:0000:0000:8a2e:0370:7334",
+			expected: false,
+		},
+		{
+			name:     "IsIP() test: invalid IP",
+			method:   IsIP,
+			value:    "foo.bar",
+			expected: false,
+		},
+		{
+			name:     "IsIP() test: valid IPv4",
+			method:   IsIP,
+			value:    "1.2.3.4",
+			expected: true,
+		},
+		{
+			name:     "IsIP() test: valid IPv6",
+			method:   IsIP,
+			value:    "2001:0db8:85a3:0000:0000:8a2e:0370:7334",
+			expected: true,
+		},
+		{
+			name:     "IsIPV4() test: invalid IPv4",
+			method:   IsIPV4,
+			value:    "foo.bar",
+			expected: false,
+		},
+		{
+			name:     "IsIPV6() test: invalid IPv6",
+			method:   IsIPV6,
+			value:    "foo.bar",
+			expected: false,
+		},
+	}
+	for _, tc := range tests {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			output := tc.method(tc.value)
+			require.Equal(t, tc.expected, output)
+		})
+	}
+}