support '0' listening port, readme update, showcase added

src/route/tcp_route.go

@@ -7,6 +7,7 @@ import (
 	"sync"
 	"time"
 
+	T "github.com/yusing/go-proxy/proxy/fields"
 	U "github.com/yusing/go-proxy/utils"
 )
 
@@ -35,6 +36,8 @@ func (route *TCPRoute) Setup() error {
 	if err != nil {
 		return err
 	}
+	//! this read the allocated port from orginal ':0'
+	route.Port.ListeningPort = T.Port(in.Addr().(*net.TCPAddr).Port)
 	route.listener = in
 	return nil
 }

src/route/udp_route.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"net"
 
+	T "github.com/yusing/go-proxy/proxy/fields"
 	U "github.com/yusing/go-proxy/utils"
 	F "github.com/yusing/go-proxy/utils/functional"
 )
@@ -50,6 +51,9 @@ func (route *UDPRoute) Setup() error {
 		return err
 	}
 
+	//! this read the allocated listeningPort from orginal ':0'
+	route.Port.ListeningPort = T.Port(laddr.Port)
+
 	route.listeningConn = source
 	route.targetAddr = raddr
 	return nil

src/utils/string.go

@@ -1,6 +1,10 @@
 package utils
 
-import "strings"
+import (
+	"net/url"
+	"strconv"
+	"strings"
+)
 
 func CommaSeperatedList(s string) []string {
 	res := strings.Split(s, ",")
@@ -9,3 +13,11 @@ func CommaSeperatedList(s string) []string {
 	}
 	return res
 }
+
+func ExtractPort(fullURL string) (int, error) {
+	url, err := url.Parse(fullURL)
+	if err != nil {
+		return 0, err
+	}
+	return strconv.Atoi(url.Port())
+}