From 43ae82ec0ea003ef3a04367d7d838ea1b0b2098b Mon Sep 17 00:00:00 2001
From: Andy Wang <cbeuw.andy@gmail.com>
Date: Wed, 8 Apr 2020 15:58:46 +0100
Subject: [PATCH] Fix test, improve err message and fix nil interface casting

---
 internal/multiplex/obfs.go         | 6 ++++--
 internal/multiplex/switchboard.go  | 6 ++++--
 internal/server/activeuser_test.go | 6 +++---
 3 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/internal/multiplex/obfs.go b/internal/multiplex/obfs.go
index edaf381..640e15a 100644
--- a/internal/multiplex/obfs.go
+++ b/internal/multiplex/obfs.go
@@ -103,9 +103,11 @@ func MakeDeobfs(salsaKey [32]byte, payloadCipher cipher.AEAD, hasRecordLayer boo
 	if hasRecordLayer {
 		rlLen = 5
 	}
+	// record layer length + stream header length + minimum data size (i.e. nonce size of salsa20)
+	minInputLen := rlLen + HEADER_LEN + 8
 	deobfs := func(in []byte) (*Frame, error) {
-		if len(in) < rlLen+HEADER_LEN+8 {
-			return nil, fmt.Errorf("Input cannot be shorter than %v bytes", rlLen+HEADER_LEN+8)
+		if len(in) < minInputLen {
+			return nil, fmt.Errorf("input size %v, but it cannot be shorter than %v bytes", len(in), minInputLen)
 		}
 
 		peeled := make([]byte, len(in)-rlLen)
diff --git a/internal/multiplex/switchboard.go b/internal/multiplex/switchboard.go
index 00d67ce..802c58d 100644
--- a/internal/multiplex/switchboard.go
+++ b/internal/multiplex/switchboard.go
@@ -87,8 +87,8 @@ func (sb *switchboard) send(data []byte, connId *uint32) (n int, err error) {
 		return writeAndRegUsage(conn, data)
 	case FIXED_CONN_MAPPING:
 		connI, ok := sb.conns.Load(*connId)
-		conn := connI.(net.Conn)
 		if ok {
+			conn := connI.(net.Conn)
 			return writeAndRegUsage(conn, data)
 		} else {
 			newConnId, conn, err := sb.pickRandConn()
@@ -161,7 +161,9 @@ func (sb *switchboard) deplex(connId uint32, conn net.Conn) {
 		sb.valve.AddRx(int64(n))
 		if err != nil {
 			log.Debugf("a connection for session %v has closed: %v", sb.session.id, err)
-			sb.close("a connection has dropped unexpectedly")
+			//sb.close("a connection has dropped unexpectedly")
+			//return
+			sb.conns.Delete(connId)
 			return
 		}
 
diff --git a/internal/server/activeuser_test.go b/internal/server/activeuser_test.go
index 7968981..0a4a7a4 100644
--- a/internal/server/activeuser_test.go
+++ b/internal/server/activeuser_test.go
@@ -10,12 +10,12 @@ import (
 	"testing"
 )
 
-func getSeshConfig(unordered bool) *mux.SessionConfig {
+func getSeshConfig(unordered bool) mux.SessionConfig {
 	var sessionKey [32]byte
 	rand.Read(sessionKey[:])
 	obfuscator, _ := mux.MakeObfuscator(0x00, sessionKey, true)
 
-	seshConfig := &mux.SessionConfig{
+	seshConfig := mux.SessionConfig{
 		Obfuscator: obfuscator,
 		Valve:      nil,
 		UnitRead:   util.ReadTLS,
@@ -49,7 +49,7 @@ func TestActiveUser_Bypass(t *testing.T) {
 	}
 
 	// get first session again
-	seshx, existing, err := user.GetSession(0, &mux.SessionConfig{})
+	seshx, existing, err := user.GetSession(0, mux.SessionConfig{})
 	if err != nil {
 		t.Fatal(err)
 	}