[Winpcap-users] Access Violation when using first pcap function (pcap_findalldevs_ex) in debug mode...

[Ravi Sankar]

Hello All,

I am developing an recording application in Windows
2000 using VC++ Ver 6. 

When I try to use "pcap_findalldevs_ex" it gives
access violation. Error message "Unhandled Expression
in test.exe": 0x00000005:Access Violation". The code
what i have written

pcap_if_t *alldevs = NULL;
char errbuf[PCAP_ERRBUF_SIZE];

ZeroMemory (errbuf, PCAP_ERRBUF_SIZE);

/* Retrieve the device list */
if (pcap_findalldevs_ex(PCAP_SRC_IF_STRING, NULL,
&alldevs, errbuf) == -1)
{
	AfxMessageBox ("Error in finding devices");
	return FALSE;
}

	/* Jump to the selected adapter */
	for(d=alldevs, i=0; i< 1;d=d->next, i++); //to be
modified
	
	/* Open the adapter */
	if ( (m_pCaptureHandle= pcap_open(d->name,	// name of
the device
							 65536,		// portion of the packet to capture. 
										// 65536 grants that the whole packet will
be captured on all the MACs.
							 PCAP_OPENFLAG_PROMISCUOUS,			// promiscuous
mode
							 1000,		// read timeout
							 NULL,		// remote authentication
							 errbuf		// error buffer
							 ) ) == NULL)
	{
		l_strTemp.Format ("Unable to open the adapter : %s",
d->name);
		AfxMessageBox (l_strTemp);
		/* Free the device list */
		pcap_freealldevs(alldevs);
		return FALSE;
	}

While debugging it executes safely until ZeroMemory
but when executing pcap_findalldevs_ex it fails.

I tried to comment pcap_findalldevs_ex function and
run the next command "pcap_open" command then also it
fails at that function.

When running the program directly with out debugging
it is working fine. Only during debugging i face this
problem.

Is there any function to be called to initialize the
pcap library? If not can any one suggest what may be
problem?

Version of WinPCap: 3.1beta4

Thanks in advance
Ravi


		
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