Writing this AutoIt function in C++

[FaridAgl]

Here is the function:

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Func IsProcessConnectedToPort($iProcessId, $iPort)
    Local $avResult = DllCall("iphlpapi.dll", "DWORD", "GetExtendedTcpTable", _
            "ptr", 0, _
            "DWORD*", 0, _
            "BOOL", True, _
            "ULONG", 2, _ ;AF_INET
            "DWORD", 4, _ ;TCP_TABLE_OWNER_PID_CONNECTIONS
            "ULONG", 0)
    If ($avResult[0] <> 0x7A) Then Return False ;ERROR_INSUFFICIENT_BUFFER

    Local $dwSize = $avResult[2]
    Local $tTcpTable = DllStructCreate("BYTE[" & $dwSize & "]")

    $avResult = DllCall("iphlpapi.dll", "DWORD", "GetExtendedTcpTable", _
            "ptr", DllStructGetPtr($tTcpTable), _
            "DWORD*", $dwSize, _
            "BOOL", True, _
            "ULONG", 2, _ ;AF_INET
            "DWORD", 4, _ ;TCP_TABLE_OWNER_PID_CONNECTIONS
            "ULONG", 0)
    If ($avResult[0]) Then Return False

    Local $tMIB_TCPTABLE_OWNER_PID = DllStructCreate("DWORD[" & Ceiling($dwSize / 4) & "]", DllStructGetPtr($tTcpTable))

    Local $dwNumEntries = DllStructGetData($tMIB_TCPTABLE_OWNER_PID, 1)
    If ($dwNumEntries = 0) Then Return False

    Local $iOffset
    Local $iConnectionProcessId, $iConnectionRemotePort

    For $i = 0 To $dwNumEntries - 1
        $iOffset = ($i * 6) + 1

        $iConnectionProcessId = DllStructGetData($tMIB_TCPTABLE_OWNER_PID, 1, $iOffset + 6)
        $iConnectionRemotePort = Dec(Hex(BinaryMid(DllStructGetData($tMIB_TCPTABLE_OWNER_PID, 1, $iOffset + 5), 1, 2)))

        If ($iConnectionProcessId = $iProcessId And $iConnectionRemotePort = $iPort) Then Return True
    Next

    Return False
EndFunc

It takes a PID and a port number and returns true if the specified process is connected to the specified port.

Any help would be really great.

[FaridAgl]

Well, I have done it Thanks

[trancexx]

Would you mind showing your code. I would like to see your progress since the last time.

[FaridAgl]

Yes, of course, here it is:

BOOL IsProcessConnectedToPort(DWORD dwProcessId, u_short uPort)
{
    DWORD dwSize = 0;
    GetExtendedTcpTable(0, &dwSize, TRUE, AF_INET, TCP_TABLE_OWNER_PID_CONNECTIONS, 0);

    PVOID pTcpTable = VirtualAlloc(NULL, dwSize, MEM_COMMIT, PAGE_READWRITE);
    if (GetExtendedTcpTable(pTcpTable, &dwSize, TRUE, AF_INET, TCP_TABLE_OWNER_PID_CONNECTIONS, 0) != NO_ERROR)
    {
        VirtualFree(pTcpTable, NULL, MEM_RELEASE);
        return FALSE;
    }

    MIB_TCPROW_OWNER_PID TcpRow;
    for (DWORD i = 0; i < ((PMIB_TCPTABLE_OWNER_PID)pTcpTable)->dwNumEntries; i++)
    {
        TcpRow = ((PMIB_TCPTABLE_OWNER_PID)pTcpTable)->table[i];

        if (TcpRow.dwOwningPid == dwProcessId && htons((u_short)TcpRow.dwRemotePort) == uPort)
        {
            VirtualFree(pTcpTable, NULL, MEM_RELEASE);
            return TRUE;
        }
    }

    VirtualFree(pTcpTable, NULL, MEM_RELEASE);
    return FALSE;
}

@trancexx

Any hints or tips are always welcomed.

Edited April 21, 2014 by D4RKON3

[trancexx]

If I were you I would try to write it more c++ alike. Try it just for practice to see advantages of c++ over c.

...I dare you.

Edited April 21, 2014 by trancexx

[FaridAgl]

I guess you mean the functions I'm using, functions like VirtualAlloc and VirtualFree, or even the keywords like TRUE, FALSE, BOOL instead of true, false and bool, am I correct?

Well, I feel so safe when I call VirtualAlloc and I'm able to tell the function what to do exactly. I mean the allocation type, memory protection etc.

I just can't trust functions like malloc yet!

[trancexx]

No, that's not what I meant. Besides, malloc isn't c++.

[FaridAgl]

Well, may I ask about what you meant? Just want your advice.

[trancexx]

I meant writing that function respecting the language you use. C++ isnt AutoIt, nor is simple C.

For example add little local class that would take care of allocation in constructor and free allocated memory in destructor so that you don't have to think about possible memory leaks on return.

C style cast is evil thing (makes people dumb) that you ahould use only when there is absolute need.

[monoceres]

C style cast is evil thing (makes people dumb) that you ahould use only when there is absolute need.

 

Unfortunately the overly verbose casting syntax in C++ makes you crazy instead!

[jchd]

For both dumb and crazy, turn to typecasting private types in Ada: it's twice the bang.

[FaridAgl]

trancexx

You know, I've always been a fan of Classes, I saw the power of OOP to handle lots of things when the project start growing, both in college lessons and personal experiences.

I'm agree with you about using a classes for preventing the memory leak (Handling it in a nicer way).

Personally, when the project wouldn't get that big, usually when it's simple enough, I won't even think about using classes, I believe OO concepts makes little projects so complicated, however they are the key to make huge projects simpler and more understandable.

[trancexx]

But your function is nice little example where young programmer could learn and benefit from using C++ features (I'm not talking about standard library, only the core language).

You don't need large project to justify using this and that. I was hoping you would at least try. This is really great small example where one can learn how to define class with custom constructor, deatructor, operaror overloading, stack allocation, automatic memory managment. And all that in 10 lines.

But ok, you learn C++ on large projects.

[FaridAgl]

Well, you are definitely right.

It's 4:12 AM here, I will try what you said tomorrow.

Thanks.

[Ascend4nt]

This is really great small example where one can learn how to define class with custom constructor, deatructor, operaror overloading, stack allocation, automatic memory managment. And all that in 10 lines.

But ok, you learn C++ on large projects.

This is absurd everything-OOP thinking.  One single function is actually a reason not to use object oriented programming.  Part of being a good programmer is knowing when to use a particular programming style and when not to.

The function could possibly benefit from RAII-style resource management (unique_ptr is fine), better pointer casts, native types (booleans are native in C as well), and an iterator-style indexing mechanism, but not much else needs to be done. Creating an object with a constructor, destructor, and operator-overloading is overkill and in fact would prove that a person doesn't know when object oriented programming is appropriate.

Another thing to note is that the function operates on an external API and thus needs to drop down to a flattened C programming level. At those times it often makes sense to not introduce C++ constructs which may add hidden overhead and data that could very well muck up the code.

oh, and hi trancexx

[trancexx]

Hi there mister, nice to see you around . I was thinking about you when posting here. I thought, ahh where is Ascend4nt now, he would have something to say.

Additional abstraction through usage of standard library features serves the purpose of simplification, but isn't a way for programmer to understand the essence of the language. That's why I was describing the "abstraction".

Let's see what D4RKON3 comes up with, and if the learning experience for him would be to a desired level.

[FaridAgl]

Well, I never thought I will learn this much from this thread, all the tips about the OOP and C++ were great, thank you all.

I start reading about OOP in C++ again (Remember something from the past, but never really tried), it's quite simple and understandable, gonna post the code as soon as It's done.

Thanks everyone.