A buffer overrun has occurred in my project

// udtsendfile.cpp : main project file.


#include "stdafx.h"
#include<iostream>
#include<udt.h>
#include<string.h>
#include<fstream>
#include<stdio.h>
using namespace std;
using namespace System;
using namespace System::Text;


int main()
{ 
 

   // use this function to initialize the UDT library
   UDT::startup();

   UDTSOCKET serv = UDT::socket(AF_INET, SOCK_STREAM, 0);

   int port = 9000;
   sockaddr_in my_addr;
   my_addr.sin_family = AF_INET;
   my_addr.sin_port = htons(9000);
   memset(&(my_addr.sin_zero), '\0', 8);

   if (UDT::ERROR == UDT::bind(serv, (sockaddr*)&my_addr, sizeof(my_addr)))
   {
      cout << "bind: " << UDT::getlasterror().getErrorMessage() << endl;
      return 0;
   
   }
   cout << "server is ready at port: " << port << endl;

   UDT::listen(serv, 10);

   sockaddr_in their_addr;
   int namelen = sizeof(their_addr);

   UDTSOCKET fhandle;

   if (UDT::INVALID_SOCK == (fhandle = UDT::accept(serv, (sockaddr*)&their_addr, &namelen)))
   {
      cout << "accept: " << UDT::getlasterror().getErrorMessage() << endl;
      return 0;
   }

    UDT::close(serv);

   // aquiring file name information from client
   char file[1024];
   int len;



   if (UDT::ERROR == UDT::recv(fhandle, (char*)&len, sizeof(int), 0))
   {
      cout << "recv: " << UDT::getlasterror().getErrorMessage() << endl;
      return 0;
   }



   if (UDT::ERROR == UDT::recv(fhandle, file, len, 0))
   {
      cout << "recv: " << UDT::getlasterror().getErrorMessage() << endl;
      return 0;
   }
   file[len] = '\0';

   // open the file
   fstream ifs(file, ios::in | ios::binary);

   ifs.seekg(0, ios::end);
   int64_t size = ifs.tellg();
   ifs.seekg(0, ios::beg);

   // send file size information
   if (UDT::ERROR == UDT::send(fhandle, (char*)&size, sizeof(int64_t), 0))
   {
      cout << "send: " << UDT::getlasterror().getErrorMessage() << endl;
      return 0;
   }

   UDT::TRACEINFO trace;
   UDT::perfmon(fhandle, &trace);

   // send the file
   if (UDT::ERROR == UDT::sendfile(fhandle, ifs, 0, size))
   {
      cout << "sendfile: " << UDT::getlasterror().getErrorMessage() << endl;
      return 0;
   }

   UDT::perfmon(fhandle, &trace);
   cout << "speed = " << trace.mbpsSendRate << "Mbits/sec" << endl;

   UDT::close(fhandle);

   ifs.close();

   // use this function to release the UDT library
   UDT::cleanup();

   return 1;
  
}

// udtreceivefile.cpp : main project file.


#include "stdafx.h"
#include<iostream>
#include<udt.h>
#include<string.h>
#include<fstream>
#include<stdio.h>
using namespace std;
using namespace System;

int main()
{
 

   // use this function to initialize the UDT library
   UDT::startup();

   UDTSOCKET fhandle = UDT::socket(AF_INET, SOCK_STREAM, 0);

   sockaddr_in serv_addr;
   serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(9000);

    serv_addr.sin_addr.S_un.S_un_b.s_b1=127;
    serv_addr.sin_addr.S_un.S_un_b.s_b2=0;
    serv_addr.sin_addr.S_un.S_un_b.s_b3=0;
    serv_addr.sin_addr.S_un.S_un_b.s_b4=1;
    memset(&(serv_addr.sin_zero), '\0', 8);

   if (UDT::ERROR == UDT::connect(fhandle, (sockaddr*)&serv_addr, sizeof(serv_addr)))
   {
      cout << "connect: " << UDT::getlasterror().getErrorMessage() << endl;
      return 0;
   }

   // send name information of the requested file
   char filepath[]="C:\\t.txt";
   int len = strlen(filepath);

   if (UDT::ERROR == UDT::send(fhandle, (char*)&len, sizeof(int), 0))
   {
      cout << "send: " << UDT::getlasterror().getErrorMessage() << endl;
      return 0;
   }

    if (UDT::ERROR == UDT::send(fhandle, filepath, len, 0))
   {
      cout << "send: " << UDT::getlasterror().getErrorMessage() << endl;
      return 0;
   }

   // get size information
   int64_t size;

   if (UDT::ERROR == UDT::recv(fhandle, (char*)&size, sizeof(int64_t), 0))
   {
      cout << "send: " << UDT::getlasterror().getErrorMessage() << endl;
      return 0;
   }

   // receive the file
   char filenamen[]="t.txt";
   fstream ofs("t.txt", ios::out | ios::binary | ios::trunc);
   int64_t recvsize; 

   if (UDT::ERROR == (recvsize = UDT::recvfile(fhandle, ofs, 0, size)))
   {
      cout << "recvfile: " << UDT::getlasterror().getErrorMessage() << endl;
      return 0;
   }

   UDT::close(fhandle);

   ofs.close();

   // use this function to release the UDT library
   UDT::cleanup();

   return 1;
}