#540 filter out private IP

Signed-off-by: Leo Chen <leo@harmony.one>

api/service/networkinfo/service.go

@@ -113,7 +113,7 @@ func (s *Service) Run() {
 
 // DoService does network info.
 func (s *Service) DoService() {
-	_, ipv4Net, err := net.ParseCIDR("100.64.0.0/10")
+	_, cgnPrefix, err := net.ParseCIDR("100.64.0.0/10")
 	if err != nil {
 		utils.GetLogInstance().Error("can't parse CIDR", "error", err)
 		return
@@ -137,7 +137,7 @@ func (s *Service) DoService() {
 						continue
 					}
 					nip := netaddr.(*net.TCPAddr).IP
-					if nip.IsGlobalUnicast() || ipv4Net.Contains(nip) {
+					if (nip.IsGlobalUnicast() && !utils.IsPrivateIP(nip)) || cgnPrefix.Contains(nip) {
 						ip = nip.String()
 						port = fmt.Sprintf("%d", netaddr.(*net.TCPAddr).Port)
 						break

internal/utils/utils.go

@@ -8,6 +8,7 @@ import (
 	"io"
 	"log"
 	mrand "math/rand"
+	"net"
 	"os"
 	"regexp"
 	"strconv"
@@ -19,6 +20,7 @@ import (
 )
 
 var lock sync.Mutex
+var privateNets []*net.IPNet
 
 // PrivKeyStore is used to persist private key to/from file
 type PrivKeyStore struct {
@@ -27,6 +29,18 @@ type PrivKeyStore struct {
 
 func init() {
 	bls.Init(bls.BLS12_381)
+
+	for _, cidr := range []string{
+		"127.0.0.0/8",    // IPv4 loopback
+		"10.0.0.0/8",     // RFC1918
+		"172.16.0.0/12",  // RFC1918
+		"192.168.0.0/16", // RFC1918
+		"::1/128",        // IPv6 loopback
+		"fe80::/10",      // IPv6 link-local
+	} {
+		_, block, _ := net.ParseCIDR(cidr)
+		privateNets = append(privateNets, block)
+	}
 }
 
 // Unmarshal is a function that unmarshals the data from the
@@ -214,3 +228,13 @@ func LoadKeyFromFile(keyfile string) (key p2p_crypto.PrivKey, pk p2p_crypto.PubK
 	key, pk, err = LoadPrivateKey(keyStruct.Key)
 	return key, pk, err
 }
+
+// IsPrivateIP checks if an IP address is private or not
+func IsPrivateIP(ip net.IP) bool {
+	for _, block := range privateNets {
+		if block.Contains(ip) {
+			return true
+		}
+	}
+	return false
+}

internal/utils/utils_test.go

@@ -3,6 +3,7 @@ package utils
 import (
 	"bytes"
 	"encoding/hex"
+	"net"
 	"os"
 	"testing"
 
@@ -157,3 +158,38 @@ func TestSaveLoadKeyFile(t *testing.T) {
 	os.Remove(filename)
 	os.Remove(nonexist)
 }
+
+func TestIsPrivateIP(t *testing.T) {
+	addr := []struct {
+		ip        net.IP
+		isPrivate bool
+	}{
+		{
+			net.IPv4(127, 0, 0, 1),
+			true,
+		},
+		{
+			net.IPv4(172, 31, 82, 23),
+			true,
+		},
+		{
+			net.IPv4(192, 168, 82, 23),
+			true,
+		},
+		{
+			net.IPv4(54, 172, 99, 189),
+			false,
+		},
+		{
+			net.IPv4(10, 1, 0, 1),
+			true,
+		},
+	}
+
+	for _, a := range addr {
+		r := IsPrivateIP(a.ip)
+		if r != a.isPrivate {
+			t.Errorf("IP: %v, IsPrivate: %v, Expected: %v", a.ip, r, a.isPrivate)
+		}
+	}
+}