C++ CInternetSession connexion lost - c++

Question

I use CInternetSession to get and post request. But when a connexion time out occurs, I lost the connexion and I always get invalid server request error, I don't understand why. Moreover, there is also a memory leak.
#include "stdafx.h"
#include "httpConnexion.h"
#include "TSException.h"
ChttpConnexion::ChttpConnexion()
: CInternetSession(AfxGetAppName(), INTERNET_OPEN_TYPE_DIRECT, NULL, NULL, NULL, INTERNET_FLAG_DONT_CACHE)
, m_lastRequest()
{
SetOption(INTERNET_OPTION_CONNECT_TIMEOUT, 10000);
SetOption(INTERNET_OPTION_RECEIVE_TIMEOUT, 10000);
m_bAttente = true;
}
ChttpConnexion::~ChttpConnexion()
{
}
std::string ChttpConnexion::sendRequest(const std::string& strUrl)
{
DWORD dwServiceType;
CString strServerName;
CString strObject;
INTERNET_PORT nPort;
AfxParseURL(strUrl.c_str(), dwServiceType, strServerName, strObject, nPort);
CString strHeaders = _T("User-Agent: User-Agent=Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36\r\nAccept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8\r\nAccept-Language: fr-FR,fr;q=0.9,en-US;q=0.8,en;q=0.7\r\nConnection: keep-alive\r\nContent-Type: application/x-www-form-urlencoded");
CString strTmp = "", strResult = "";
CHttpConnection* pHttpConnexion = NULL;
CHttpFile* pHttpFile = NULL;
try
{
//Creation de la connexion Http
pHttpConnexion = GetHttpConnection(strServerName, INTERNET_FLAG_RELOAD | INTERNET_FLAG_DONT_CACHE, nPort, NULL, NULL);
//Creation de la requete GET
pHttpFile = pHttpConnexion->OpenRequest(CHttpConnection::HTTP_VERB_GET, strObject, NULL, 1, NULL, NULL, INTERNET_FLAG_RELOAD | INTERNET_FLAG_DONT_CACHE);
//Envoi de la requéte
BOOL bRequestSend = pHttpFile->SendRequest(strHeaders);
CString headers;headers.Empty();
DWORD dwRet;
pHttpFile->QueryInfo(HTTP_QUERY_RAW_HEADERS_CRLF,headers);
pHttpFile->QueryInfoStatusCode(dwRet);
//Lecture du résultat
while ( pHttpFile->ReadString(strTmp))
{
strResult += strTmp;
}
//Fermeture de la requéte
pHttpFile->Close();
//Fermeture de la connexion
pHttpConnexion->Close();
//Suppression des objets
if (pHttpFile != NULL)
delete pHttpFile;
if (pHttpConnexion != NULL)
delete pHttpConnexion;
}
catch(CInternetException* exp)
{
exp->Delete();
//Fermeture de la requéte
if (pHttpFile != NULL)
{
pHttpFile->Close();
delete pHttpFile;
}
//Fermeture de la connexion
if (pHttpConnexion != NULL)
{
pHttpConnexion->Close();
delete pHttpConnexion;
}
throw CTSException("sendRequest");
}
return strResult.GetString();
}
std::string ChttpConnexion::postRequest(const std::string& strUrl, const std::string& postData)
{
DWORD dwServiceType;
CString strServerName;
CString strObject;
INTERNET_PORT nPort;
AfxParseURL(strUrl.c_str(), dwServiceType, strServerName, strObject, nPort);
CString strHeaders = _T("User-Agent: User-Agent=Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36\r\nAccept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8\r\nAccept-Language: fr-FR,fr;q=0.9,en-US;q=0.8,en;q=0.7\r\nConnection: keep-alive\r\nContent-Type: application/x-www-form-urlencoded");
CString strTmp = "", strResult = "";
CHttpConnection* pHttpConnexion = NULL;
CHttpFile* pHttpFile = NULL;
try
{
//Creation de la connexion Http
pHttpConnexion = GetHttpConnection(strServerName, INTERNET_FLAG_RELOAD | INTERNET_FLAG_DONT_CACHE, nPort, NULL, NULL);
//Creation de la requete GET
pHttpFile = pHttpConnexion->OpenRequest(CHttpConnection::HTTP_VERB_POST, strObject, NULL, 1, NULL, NULL, INTERNET_FLAG_RELOAD | INTERNET_FLAG_DONT_CACHE);
//Envoi de la requéte
BOOL bRequestSend = pHttpFile->SendRequest(strHeaders, (LPVOID) (LPCTSTR) postData.c_str(), postData.length());
CString headers;headers.Empty();
DWORD dwRet;
pHttpFile->QueryInfo(HTTP_QUERY_RAW_HEADERS_CRLF,headers);
pHttpFile->QueryInfoStatusCode(dwRet);
CString data;
GetCookie(strServerName, "sess_id", data);
//Lecture du résultat
while ( pHttpFile->ReadString(strTmp))
{
strResult += strTmp;
}
//Fermeture de la requéte
pHttpFile->Close();
//Fermeture de la connexion
pHttpConnexion->Close();
//Suppression des objets
if (pHttpFile != NULL)
delete pHttpFile;
if (pHttpConnexion != NULL)
delete pHttpConnexion;
}
catch(CInternetException* exp)
{
exp->Delete();
//Fermeture de la requéte
if (pHttpFile != NULL)
{
pHttpFile->Close();
delete pHttpFile;
}
//Fermeture de la connexion
if (pHttpConnexion != NULL)
{
pHttpConnexion->Close();
delete pHttpConnexion;
}
throw CTSException("postRequest");
}
return strResult.GetString();
}
Thanks for helping!

Answer 1

when you construct your object and you call CInternetSession constructor, why the 3rd param is NULL? It should be something like PRE_CONFIG_INTERNET_ACCESS. You may need to use the proxy settings if you are behind a proxy.
check the content of strServerName, it may be invalid and GetHttpConnection fails because of that.
in your try, you GetHttpConnection and OpenRequest, but you don't check if the results aren't NULL. You only check later (too late) if they aren't NULL to delete them. You should check them after GetHttpConnection and OpenRequest, before using them. (But I guess the exception occurs during GetHttpConnection)
if the timeout occurs after 10sec, maybe it's because your timeout is too low (in your constructor).
there were some old reports that https may be a problem. But you didn't mentioned what was your request and what you were requesting.
in your request header, you are requesting different file formats (xml, html, png, etc...), but you are using a GetString and appending it to a string. If you are getting a binary data, it may not work. You should use a char[] buffer. Check this example.
after using your object ChttpConnexion, did you call .Close() on it?
In the end, I would recommend attaching a debugger and put a breakpoint in the catch to see where exactly the error occurs, or add some debug logs. This may help.