use rand port instead of sequential pattern

xtaci · Oct 15, 2022 · 208decc · 208decc
1 parent 2e5215a
commit 208decc
Showing 1 changed file with 9 additions and 7 deletions.
diff --git a/client/dial.go b/client/dial.go
@@ -1,6 +1,8 @@
 package main
 
 import (
+ "crypto/rand"
+ "encoding/binary"
  "fmt"
 
  "github.com/pkg/errors"
@@ -9,19 +11,19 @@ import (
  "github.com/xtaci/tcpraw"
 )
 
-var dialCount uint64
-
 func dial(config *Config, block kcp.BlockCrypt) (*kcp.UDPSession, error) {
- defer func() {
- dialCount++
- }()
-
  mp, err := generic.ParseMultiPort(config.RemoteAddr)
  if err != nil {
  return nil, err
  }
 
- remoteAddr := fmt.Sprintf("%v:%v", mp.Host, uint64(mp.MinPort)+dialCount%uint64(mp.MaxPort-mp.MinPort+1))
+ var randport uint64
+ err = binary.Read(rand.Reader, binary.LittleEndian, &randport)
+ if err != nil {
+ return nil, err
+ }
+
+ remoteAddr := fmt.Sprintf("%v:%v", mp.Host, uint64(mp.MinPort)+randport%uint64(mp.MaxPort-mp.MinPort+1))
 
  if config.TCP {
  conn, err := tcpraw.Dial("tcp", remoteAddr)