homeContext refactoring

util/net.go

@@ -5,6 +5,60 @@ import (
 	"net"
 )
 
+// nolint (gocyclo)
+// Return TRUE if IP is within public Internet IP range
+func IsPublicIP(ip net.IP) bool {
+	ip4 := ip.To4()
+	if ip4 != nil {
+		switch ip4[0] {
+		case 0:
+			return false //software
+		case 10:
+			return false //private network
+		case 127:
+			return false //loopback
+		case 169:
+			if ip4[1] == 254 {
+				return false //link-local
+			}
+		case 172:
+			if ip4[1] >= 16 && ip4[1] <= 31 {
+				return false //private network
+			}
+		case 192:
+			if (ip4[1] == 0 && ip4[2] == 0) || //private network
+				(ip4[1] == 0 && ip4[2] == 2) || //documentation
+				(ip4[1] == 88 && ip4[2] == 99) || //reserved
+				(ip4[1] == 168) { //private network
+				return false
+			}
+		case 198:
+			if (ip4[1] == 18 || ip4[2] == 19) || //private network
+				(ip4[1] == 51 || ip4[2] == 100) { //documentation
+				return false
+			}
+		case 203:
+			if ip4[1] == 0 && ip4[2] == 113 { //documentation
+				return false
+			}
+		case 224:
+			if ip4[1] == 0 && ip4[2] == 0 { //multicast
+				return false
+			}
+		case 255:
+			if ip4[1] == 255 && ip4[2] == 255 && ip4[3] == 255 { //subnet
+				return false
+			}
+		}
+	} else {
+		if ip.IsLoopback() || ip.IsLinkLocalMulticast() || ip.IsLinkLocalUnicast() {
+			return false
+		}
+	}
+
+	return true
+}
+
 // CanBindPort - checks if we can bind to this port or not
 func CanBindPort(port int) (bool, error) {
 	addr, err := net.ResolveTCPAddr("tcp", fmt.Sprintf("127.0.0.1:%d", port))