You can grab it here.

For any remarks, contact me

See ya !

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#ifdef DEBUG
#define DLog(fmt, ...) NSLog((@"%s [Line %d] " fmt), __PRETTY_FUNCTION__, __LINE__, ##__VA_ARGS__);
#else
#define DLog(...)
#endif
#define ALog(fmt, ...) NSLog((@"%s [Line %d] " fmt), __PRETTY_FUNCTION__, __LINE__, ##__VA_ARGS__);

Place this code in the [PROJECT_NAME]_Prefix.pch file, and it’s almost done

The macro DLog() works exaclty like NSLog(), so you can pass arguments etc… the advantage is that the line and the function name will be printed thanks to __PRETTY_FUNCTION__ & __LINE__ macros.
As for the macro ALog(), it remplaces NSLog() and will always produce an output.

The last thing you have to do is to define the DEBUG macro. In XCode go to project information, chose Debug configuration and in the Preprocessing part look for the line Preprocessor Macros and add it :

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DEBUG=1

See ya!

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#import <Foundation/Foundation.h>
#import <DiskArbitration/DiskArbitration.h>
 
DADissenterRef diskDidMount(DADiskRef dsk, void* context)
{
    DADissenterRef ref = DADissenterCreate(kCFAllocatorDefault, kDAReturnNotPermitted, NULL);
    return ref;
}
 
int main(int argc, const char* argv[])
{
    NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
    DASessionRef session = DASessionCreate(kCFAllocatorDefault);
    DARegisterDiskMountApprovalCallback(session, NULL, diskDidMount, NULL);
    DASessionScheduleWithRunLoop(session, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);
    CFRunLoopRun();	
    [pool drain];
    return 0;
}

First, there are some things that you need to know, OS X is an UNIX system but since Mac OS X 10.4 the daemons aren’t handled like the traditionals *BSD systems.
Since this release, daemons are managed by launchd. OS X have 2 kind of programs that run in background :
- Daemons : Their owner is the system, there are launched even when nobody is logged and a very important thing, they don’t have to launch any kind of GUI.
- Agents : Their owner is a normal user, there are only launched when an user is logged and can display a GUI.
In order to make a difference betwneen them, there are 2 distincts folders : /Library/LaunchDaemons and /Library/LaunchAgents

So let’s get working now, there is noting hard, first we will take a look at the Apple doc, here and here.
The second link is important because it shows what frameworks are daemons safe, and you can see that DiskArbitration is daemon safe, so we can adapt our program to run as a daemon.

Now look at the first link, it’s the man for launchd.plist, the first section that you must read is the EXPECTATIONS one, it tells you what you can do, what you can’t and what you must.
If you read correctly, you know that you need 2 fields at least in your plist :
- Label
- Program or ProgramArguments
You can take a look to the others flags too, some are interesting, like RunAtLoad which indicates that the program will run at login.
Here is our finalized plist :

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<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>Label</key>
	<string>fr.whine.diskblocker</string>
	<key>RunAtLoad</key>
	<true/>
	<key>Program</key>
	<string>/tmp/DiskBlocker</string>
	<key>UserName</key>
	<string>Nyxouf</string>
</dict>
</plist>

The name of the file must follow this scheme : [Label].plist, in my case I name it fr.whine.diskblocker.plist.
Let’s put the file in /Library/LaunchDaemons and you are done with the config file.
Now we need to add some code in our program to adapt it to run as a daemon. If you correctly read the doc, you know that you must catch the SIGTERM signal in order to terminate properly the daemon (free the memory etc..)
There is nothing complicated, to do that we use the functions in signal.h, we first create an handler function :

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void SIGTERM_handler(const int sigid)
{
    if (SIGTERM == sigid)
    {
        CFRunLoopStop(CFRunLoopGetCurrent());
    }
}

In the main function before the runloop, we call the signal function :

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signal(SIGTERM, (sig_t)SIGTERM_handler);

Once the signal received, the runloop will stop, so we could properly end the program :

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DASessionUnscheduleFromRunLoop(session, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);
CFRelease(session);
[pool drain];
return 0;

Now, let’s compile

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gcc DiskBlocker.m -o /tmp/DiskBlocker -framework DiskArbitration -framework Foundation

In the man, it’s written that the system daemon owner must be root, so need to do a chown :

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sudo chown root:wheel /tmp/DiskBlocker

Last thing, launch the daemon, to do that we use launchctl

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launchctl load /Library/LaunchDaemons/fr.whine.diskblocker.plist

If like me, you specified the RunAtLoad flag, you can try to reboot to se if the daemon is launched

You can get all the source code here

see ya!

Que dire, j’ai lutté pour garder les yeux ouverts devant ce film soit disant si terrifiant, il ne se passe rien pendant 1H20, et les seuls effets de surprise qui auraient pu être bien ne sont pas exploités.
Les spectateurs qui étaient dans la salle n’ont pas eu l’air plus terrifiés que moi, même les femmes n’ont pas crié, ce qui est rassurant, ça prouve que ça ne vient pas de moi
Faudra donc qu’on m’explique les vidéos sur lesquelles on peut voir des gens terrifiés dans les salles de cinéma (Fake peut-être?), pourquoi Spielberg a SOI-DISANT eu aussi peur ?
La conclusion est simple, la seule chose paranormale c’est d’arriver à faire un film aussi médiocre et chiant.

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#import <DiskArbitration/DiskArbitration.h>

Now, we need a DASessionRef object that we initialiaze like this :

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DASessionRef session = DASessionCreate(kCFAllocatorDefault);

At this point, it becomes really interesting to read the header we just imported.
By traversing it, we can see a function that could correspond as what we are looking for :

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extern void DARegisterDiskMountApprovalCallback(DAApprovalSessionRef session, CFDictionaryRef match, DADiskMountApprovalCallback callback, void* context);

As I said before, all the comments are very explicit, the most important parameter is the third, it’s a pointer to the function which will be called when a disk will want to mount, its definition is just above.

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typedef DADissenterRef (*DADiskMountApprovalCallback)(DADiskRef disk, void* context);

So, we need to create an handler function, name it diskDidMount.

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DADissenterRef diskDidMount(DADiskRef dsk, void* context)
{
	DADissenterRef ref = DADissenterCreate(kCFAllocatorDefault, kDAReturnNotPermitted, NULL);
	return ref;
}

For what we want to do, all the parameters are useless, we just have to create a DADissenterRef object which is the return value of the function. The interesting parameter here is the second, whicj is a flah that indicates the action to do. The flag list is available in the documentation.

All we have to do now, is create a loop to let the program run. The best would be to make this program a daemon, whicj if the object of a futur post

Here is the full code :

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#import <Foundation/Foundation.h>
#import <DiskArbitration/DiskArbitration.h>
 
DADissenterRef diskDidMount(DADiskRef dsk, void* context)
{
	DADissenterRef ref = DADissenterCreate(kCFAllocatorDefault, kDAReturnNotPermitted, NULL);
	return ref;
}
 
int main(int argc, const char* argv[])
{
    NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
    DASessionRef session = DASessionCreate(kCFAllocatorDefault);
    DARegisterDiskMountApprovalCallback(session, NULL, diskDidMount, NULL);
    DASessionScheduleWithRunLoop(session, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);
    CFRunLoopRun();	
    [pool drain];
    return 0;
}

see ya !