add range port support for forwarder node

internal/net/addr.go

@@ -0,0 +1,72 @@
+package net
+
+import (
+	"fmt"
+	"net"
+	"strconv"
+	"strings"
+)
+
+// AddrPortRange is the network address with port range supported.
+// e.g. 192.168.1.1:0-65535
+type AddrPortRange string
+
+func (p AddrPortRange) Addrs() (addrs []string) {
+	h, sp, err := net.SplitHostPort(string(p))
+	if err != nil {
+		return nil
+	}
+
+	pr := PortRange{}
+	pr.Parse(sp)
+
+	for i := pr.Min; i <= pr.Max; i++ {
+		addrs = append(addrs, net.JoinHostPort(h, strconv.Itoa(i)))
+	}
+	return addrs
+}
+
+// Port range is a range of port list.
+type PortRange struct {
+	Min int
+	Max int
+}
+
+// Parse parses the s to PortRange.
+// The s can be a single port number and will be converted to port range port-port.
+func (pr *PortRange) Parse(s string) error {
+	minmax := strings.Split(s, "-")
+	switch len(minmax) {
+	case 1:
+		port, err := strconv.Atoi(s)
+		if err != nil {
+			return err
+		}
+		if port < 0 || port > 65535 {
+			return fmt.Errorf("invalid port: %s", s)
+		}
+
+		pr.Min, pr.Max = port, port
+		return nil
+
+	case 2:
+		min, err := strconv.Atoi(minmax[0])
+		if err != nil {
+			return err
+		}
+		max, err := strconv.Atoi(minmax[1])
+		if err != nil {
+			return err
+		}
+
+		pr.Min, pr.Max = min, max
+		return nil
+
+	default:
+		return fmt.Errorf("invalid range: %s", s)
+	}
+}
+
+func (pr *PortRange) Contains(port int) bool {
+	return port >= pr.Min && port <= pr.Max
+}