C / C++ / MFC

Re: Winsock2 and getting IP address of a CONNECTING entity

27-Feb-05 10:29

Try ::WSAAccept().
It allows you to specify a callback function that determines if the accept should succeed or fail.
The callback receives information about the connecting entity.

[EDIT]
I also found this article:
http://www.windowsitpro.com/Articles/Print.cfm?ArticleID=9632[^]
[/EDIT]

...cmk

Save the whales - collect the whole set

Theburninator1-Mar-05 10:05

Theburninator

1-Mar-05 10:05

Thanks a big fat ton! So, now my issue is specifying that callback function, would you happen to know how to do this...when it says use this prototype, I try making the function body, but get syntax errors etc...But I'll keep tinkering with it, if you have any pointers let me know! (get it pointers...)

Re: Winsock2 and getting IP address of a CONNECTING entity

cmk1-Mar-05 10:37

Re: Winsock2 and getting IP address of a CONNECTING entity

1-Mar-05 10:37

What errors ?

I've never used it - i generall use AcceptEx with IOCP.
Without the ability to use it in an overlapped manner you will be limiting the scaleability of your server app.

I do find it interesting though, i'm going to add it as an option to my server code.
I'll let you know how it goes.

...cmk

Save the whales - collect the whole set

TheBurninator1-Mar-05 10:59

TheBurninator

1-Mar-05 10:59

I'm actually fairly green in terms of Programming with winsock, and using intermediate programming steps such as these. Basically, I'm not rightly sure how to set up the callback function, or ANY callback function....

I'm thinking I'm getting a little warmer, do I just add:

int CALLBACK EXPORT WSAAccept()::ConditionFunc(IN LPWSABUF lpCallerId,
IN LPWSABUF lpCallerData,
IN OUT LPQOS lpSQOS,
IN OUT LPQOS lpGQOS,
IN LPWSABUF lpCalleeId,
OUT LPWSABUF lpCalleeData,
OUT GROUP FAR *g,
IN DWORD_PTR dwCallbackData)
{
//condition code
}

And that should work? I basically add this just like a normal function right now...to the tail end of my code getting a few syntax errors:

error C2061: syntax error : identifier 'WSAAccept'
error C2059: syntax error : ';'
error C2059: syntax error : ':'

Again, Callback functions are a fairly new concept for me, as is about everything to do with winsock Sniff | :^)

Re: Winsock2 and getting IP address of a CONNECTING entity

cmk1-Mar-05 11:13

Re: Winsock2 and getting IP address of a CONNECTING entity

1-Mar-05 11:13

You're a little off there.
More like:

int CALLBACK ConditionFunc(
IN LPWSABUF lpCallerId,
IN LPWSABUF lpCallerData,
IN OUT LPQOS lpSQOS,
IN OUT LPQOS lpGQOS,
IN LPWSABUF lpCalleeId,
OUT LPWSABUF lpCalleeData,
OUT GROUP FAR *g,
IN DWORD_PTR dwCallbackData
) {
// condition code
}

...
SOCKET sockListen,
sockClient;
SOCKADDR_STORAGE addrClient;
int addrLen = sizeof(addrClient);
...
// MyData may be a structure or could be 'this' is called within a class
// it is passed unmodified as dwCallbackData in ConditionFunc
sockClient = WSAAccept(sockListen, &addrClient, &addrLen, ConditionFunc, &MyData);
...

...cmk

Save the whales - collect the whole set

TheBurninator1-Mar-05 11:57

TheBurninator

1-Mar-05 11:57

Thanks again, I'm stumbling through this, though now I'm getting some very disconcerting warnings:

warning C4113: 'int (__stdcall *)(struct _WSABUF *,struct _WSABUF *,struct _QualityOfService *,struct _QualityOfService *,struct _WSABUF *,struct _WSABUF *,unsigned int *)' differs in paramet
er lists from 'int (__stdcall *)(struct _WSABUF *,struct _WSABUF *,struct _QualityOfService *,struct _QualityOfService *,struct _WSABUF *,struct _WSABUF *,unsigned int *,unsigned long )'
warning C4047: 'function' : 'unsigned long ' differs in levels of indirection from 'void *'
warning C4024: 'WSAAccept' : different types for formal and actual parameter 5

And my WSAAccept call is
socketClient = WSAAccept(listenSocket, (LPSOCKADDR)&SockAddr, &nLen,ConditionFunc,NULL);

Don't really care about the data at the moment, but it does build and link, so I'm not sure of the implications on the execution yet

oh and the
IN DWORD_PTR dwCallbackData
Had to be removed from the parameter listfor some strange reason otherwise I would get....
error C2146: syntax error : missing ')' before identifier 'dwCallbackData'
error C2081: 'DWORD_PTR' : name in formal parameter list illegal
error C2061: syntax error : identifier 'dwCallbackData'
error C2059: syntax error : ';'
error C2059: syntax error : ')'
error C2449: found '{' at file scope (missing function header?)
error C2059: syntax error : '}'

Thanks a lot, I really appreciate your effort...

Re: Winsock2 and getting IP address of a CONNECTING entity

TheBurninator1-Mar-05 12:19

TheBurninator

1-Mar-05 12:19

FYI, get an unhandled exception trying to write memory 0 referenced from somewhere's else...heh dunno if you have a similar issue...

Re: Winsock2 and getting IP address of a CONNECTING entity

TheBurninator1-Mar-05 12:31

TheBurninator

1-Mar-05 12:31

HEHEHE, I'm stumped by this, but that last arguement APPEARS to be a DWORD not a DWORD_PTR either that or there is something I'm missing to declare a DWORD_PTR, wouldn't it just be DWORD * ptrname?

Re: Winsock2 and getting IP address of a CONNECTING entity

cmk1-Mar-05 17:05

Help! how to alter the ScrollBar control's color

1-Mar-05 17:05

Ok, the warnings are because you removed IN DWORD_PTR dwCallbackData from the callback function.
You can't just remove it, the function has to match what is specified.
Focus on finding why DWORD_PTR isn't valid.

I just tested:

int CALLBACK ConditionFunc(
LPWSABUF lpCallerId,
LPWSABUF lpCallerData,
LPQOS lpSQOS,
LPQOS lpGQOS,
LPWSABUF lpCalleeId,
LPWSABUF lpCalleeData,
GROUP FAR *g,
DWORD_PTR dwCallbackData
) {
return(CF_ACCEPT); // or, CF_REJECT, or CF_DEFER
}

// called within one of my socket class methods,
// so 'this' is pointer to my socket class instance.
// int len = 0;
// SOCKADDR *sa = ...;

SOCKET s = ::WSAAccept(sockHnd, sa, &len, ConditionFunc, (DWORD)this);

I compiled without warnings or errors.

...cmk

Save the whales - collect the whole set

kcynic25-Feb-05 15:09

kcynic

25-Feb-05 15:09

somebody would tell me how to change the CScrollBar control's color?
Thanks!

Re: Help! how to alter the ScrollBar control's color

Branislav25-Feb-05 21:48

Branislav

25-Feb-05 21:48

http://msdn.microsoft.com/msdnmag/issues/01/11/c/
or custom draw:
http://www.codeproject.com/miscctrl/XScrollBar.asp

Re: Help! how to alter the ScrollBar control's color

kcynic28-Feb-05 14:29

kcynic

28-Feb-05 14:29

i had resolved it following ur guidance.
thanks very much!

A little unicode question.

Member 1219625225-Feb-05 14:02

Member 12196252

25-Feb-05 14:02

Hi!

I'm storing a certain path in a CAtlString class. The function i need to pass this path to however only likes char pointers. How do i get a char pointer from a Unicode CAtlString?

Re: A little unicode question.

PJ Arends25-Feb-05 14:16

PJ Arends

25-Feb-05 14:16

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vclib/html/_atl_string_conversion_macros.asp
[^]

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Re: A little unicode question.

Member 1219625226-Feb-05 0:36

Member 12196252

26-Feb-05 0:36

Thanks

This solved all of my coding problems. Never knew the conversions where this easy Wink | ;-)

c++ bool variable

tnvols25-Feb-05 12:46

25-Feb-05 12:46

Could someone point me to a good website that gives me some sample code on using bool variables in c++? Thanks.

Thanks!

Maximilien25-Feb-05 14:50

Maximilien

25-Feb-05 14:50

huh ?

bool bIDontUnderstand;
bIDontUnderstand = true;

Maximilien Lincourt
Your Head A Splode - Strong Bad

tnvols25-Feb-05 16:04

25-Feb-05 16:04

I'm trying to understand the advantage of declaring a variable type bool? I'm a beginner, For example: How do I use a bool variable?

#include <iostream>
using namespace std;

int main()
{
bool a;
int b,c;

if(b == c)
cout << "huh";

return 0;
}

Thanks!

Ravi Bhavnani25-Feb-05 16:10

Ravi Bhavnani

25-Feb-05 16:10

A bool is used when you want to store the (true/false) value of a condition, for later reference. For example:

// Check if the system is OK - this may take several
// seconds to execute
bool bSystemWasOK = checkIfSystemIsOK();
...
if (bSystemWasOK)
   doSomething();
...
if (bSystemWasOK)
   doSomethingElse();

Storing the value of the check in bSystemWasOK saves you the effort of calling checkIfSystemIsOK() repeatedly. This example assumes that the system state continues to be OK throughout the execution of the code fragment.

Hope this helps.

/ravi

My new year's resolution: 2048 x 1536
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tnvols25-Feb-05 16:32

25-Feb-05 16:32

I'm starting to see. The problem I'm working on is a magic square program.

r1 1 6 8
r2 5 7 3
r3 9 2 4

I'm comparing row totals to column totals to test for equality between rowsum[] and colsum[] arrays and storing the result in a bool variable. I'm having a hard time seeing how to loop through the comparisons and using the bool variable at the same time.

Thanks!

rbid25-Feb-05 20:01

rbid

25-Feb-05 20:01

Magic/Diabolic squares... mmmm... that seems to be known here in CodeProject.. Take a look on this article: Magic Square[^].

Just wanted to help.

Have a nice day.

-- Ricky Marek (AKA: rbid)
-- "Things are only impossible until they are not" --- Jean-Luc Picard

My articles

tnvols25-Feb-05 23:04

25-Feb-05 23:04

Your link to the magic square example was exactly what I needed! You are a life saver. Smile | :)

Thanks!