Using Npcap with Qt Creator 6.4.3

[__d4ve__]

Hi all,

I try to use npcap functions in Qt Creator

Version : Qt Creator 10.0.1
Based on Qt 6.4.3 (MSVC 2019, x86_64)

Npcap 1.75

same function works on visual studio 2022

that's how i included npcap libraries :

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/'../../../../../../../Program Files/Npcap/Lib/' -lwpcap
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/'../../../../../../../Program Files/Npcap/Lib/' -lwpcap


INCLUDEPATH += $$PWD/'../../../../../../../Program Files/Npcap/Include'
DEPENDPATH += $$PWD/'../../../../../../../Program Files/Npcap/Include'

the error i receive on compilation:

mainwindow.obj:-1: error: LNK2019: unresolved external symbol pcap_findalldevs referenced in function "struct pcap_if * __cdecl find_devices(void)" (?find_devices@@YAPEAUpcap_if@@XZ)

Here is the the piece of code that makes the error :

pcap_if_t* find_devices()
{
    pcap_if_t* alldevs = nullptr; // Initialize the pointer to nullptr
    char errbuf[PCAP_ERRBUF_SIZE];
    if (pcap_findalldevs(&alldevs, errbuf) == -1) {
        std::cerr << "Error finding network interfaces: " << errbuf << std::endl;
        return nullptr; // Return nullptr on error
    }

    return alldevs; // Return the pointer to pcap_if_t
}

[JonB]

@__d4ve__ said in Using Npcap with Qt Creator 6.4.3:

C:\Program Files\Npcap\Lib\wpcap.lib : warning LNK4272: library machine type 'x86' conflicts with target machine type 'x64'

Until you resolve this nothing will link.

[JonB]

@__d4ve__
I would start by copying and pasting the exact full linker command being executed from Creator. And make sure your (embedded) ' (single-quote) quoting is good for Windows.

[__d4ve__]

@JonB If i understand you right that , you advise me changing the linked libraries to be with "

I used 'Add Library' Functionality of Qt Creator to attach NPCAP

anyway I tried that , same issue occurs

[JonB]

@__d4ve__

@JonB said in Using Npcap with Qt Creator 6.4.3:

I would start by copying and pasting the exact full linker command being executed from Creator.

[__d4ve__]

@JonB

17:33:19: Running steps for project Packet_Capture_GUI...
17:33:19: Configuration unchanged, skipping qmake step.
17:33:19: Starting: "C:\QT\Tools\QtCreator\bin\jom\jom.exe" 
	C:\QT\Tools\QtCreator\bin\jom\jom.exe -f Makefile.Debug
	link /NOLOGO /DYNAMICBASE /NXCOMPAT /DEBUG /SUBSYSTEM:WINDOWS "/MANIFESTDEPENDENCY:type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' publicKeyToken='6595b64144ccf1df' language='*' processorArchitecture='*'" /MANIFEST:embed /OUT:debug\Packet_Capture_GUI.exe @C:\Users\Dave\AppData\Local\Temp\Packet_Capture_GUI.exe.23536.31.jom
mainwindow.obj : error LNK2019: unresolved external symbol pcap_findalldevs referenced in function "struct pcap_if * __cdecl find_devices(void)" (?find_devices@@YAPEAUpcap_if@@XZ)
C:\Program Files\Npcap\Lib\wpcap.lib : warning LNK4272: library machine type 'x86' conflicts with target machine type 'x64'
debug\Packet_Capture_GUI.exe : fatal error LNK1120: 1 unresolved externals
jom: C:\Users\Dave\Desktop\C++ Exercises\Qt Creator Projects\Project 1 - Network Packet GUI\build-Packet_Capture_GUI-Desktop_Qt_6_5_1_MSVC2019_64bit-Debug\Makefile.Debug [debug\Packet_Capture_GUI.exe] Error 1120
jom: C:\Users\Dave\Desktop\C++ Exercises\Qt Creator Projects\Project 1 - Network Packet GUI\build-Packet_Capture_GUI-Desktop_Qt_6_5_1_MSVC2019_64bit-Debug\Makefile [debug] Error 2
17:33:20: The process "C:\QT\Tools\QtCreator\bin\jom\jom.exe" exited with code 2.
Error while building/deploying project Packet_Capture_GUI (kit: Desktop Qt 6.5.1 MSVC2019 64bit)
When executing step "Make"
17:33:20: Elapsed time: 00:00.

I have tried linking against 32bit and against 64bit and both as well

[JonB]

@__d4ve__ said in Using Npcap with Qt Creator 6.4.3:

C:\Program Files\Npcap\Lib\wpcap.lib : warning LNK4272: library machine type 'x86' conflicts with target machine type 'x64'

Until you resolve this nothing will link.

[__d4ve__]

@JonB You are right , so I have linked it against the x64 bit and it works now , Thank you.