new feature: range section for mapping range ports

utils/util/util.go

@@ -19,6 +19,8 @@ import (
 	"crypto/rand"
 	"encoding/hex"
 	"fmt"
+	"strconv"
+	"strings"
 )
 
 // RandId return a rand string used in frp.
@@ -54,3 +56,48 @@ func CanonicalAddr(host string, port int) (addr string) {
 	}
 	return
 }
+
+func ParseRangeNumbers(rangeStr string) (numbers []int64, err error) {
+	rangeStr = strings.TrimSpace(rangeStr)
+	numbers = make([]int64, 0)
+	// e.g. 1000-2000,2001,2002,3000-4000
+	numRanges := strings.Split(rangeStr, ",")
+	for _, numRangeStr := range numRanges {
+		// 1000-2000 or 2001
+		numArray := strings.Split(numRangeStr, "-")
+		// length: only 1 or 2 is correct
+		rangeType := len(numArray)
+		if rangeType == 1 {
+			// single number
+			singleNum, errRet := strconv.ParseInt(strings.TrimSpace(numArray[0]), 10, 64)
+			if errRet != nil {
+				err = fmt.Errorf("range number is invalid, %v", errRet)
+				return
+			}
+			numbers = append(numbers, singleNum)
+		} else if rangeType == 2 {
+			// range numbers
+			min, errRet := strconv.ParseInt(strings.TrimSpace(numArray[0]), 10, 64)
+			if errRet != nil {
+				err = fmt.Errorf("range number is invalid, %v", errRet)
+				return
+			}
+			max, errRet := strconv.ParseInt(strings.TrimSpace(numArray[1]), 10, 64)
+			if errRet != nil {
+				err = fmt.Errorf("range number is invalid, %v", errRet)
+				return
+			}
+			if max < min {
+				err = fmt.Errorf("range number is invalid")
+				return
+			}
+			for i := min; i <= max; i++ {
+				numbers = append(numbers, i)
+			}
+		} else {
+			err = fmt.Errorf("range number is invalid")
+			return
+		}
+	}
+	return
+}