At some point, my apmode utility got dropped from Erica Utilities and a number of people, particularly my pal Pytey, asked if I could find some time to bring it back to life. Last night, I decided to see if I could put this together using 2.x technology after having put this off for far too long.

In its first iteration, apmode used dynamic linking to access functions in the public Preferences framework. With 2.0, Preferences had been moved to Private Frameworks and I assumed that it more or less offered the same functionality. This assumption was wrong.

In fact, Airport control was moved by Apple into a separate framework, another private framework called SpringBoardServices, which offers many features specific to SpringBoard operations. It handles watchdogs, the status bar, badging and more, bringing many features out of the SpringBoard application and into a more general library, presumably that can be accessed by other Apple applications.

After running nm to get a symbol dump, I found a reference to two different Airplane functions: SBEnableAirplaneMode and SBSetAirplaneModeEnabled. I'll spare you the reverse engineering details other than to say that you do in fact have to supply a mach port to the function as you normally do with UIKit calls in order for the function to work. In its past, Preferences-based life, the Airplane function just took a single argument, a boolean. The new version, takes both the port and the boolean instead.

So here's the final working code. It makes two dynamic links, first to UIKit to retrieve the port and second to the SpringBoardServices to set the Airplane mode to either off or on. When you test this, make sure you do some sort of "set it off, sleep, then turn it back on" command otherwise you'll lock yourself out of your ongoing secure shell session.

This is for you, Pytey.

#import <UIKit/UIKit.h>
#import <UIKit/UIApplication.h>
#include <dlfcn.h>
#include <stdio.h>

// Framework Paths
#define SBSERVPATH  "/System/Library/PrivateFrameworks/SpringBoardServices.framework/SpringBoardServices"
#define UIKITPATH "/System/Library/Framework/UIKit.framework/UIKit"

int main(int argc, char **argv)
{
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];

   //
   // For testing try issuing the following: 
   //         ap y; sleep 5; ./ap n
   //

   if (argc < 2)
   {
      printf("Usage: %s (y | n)\n", argv[0]);
      exit(-1);
   }

   // Argument used to switch airplane mode off or on
   BOOL yorn = [[[NSString stringWithCString:argv[1]] 
                    uppercaseString] hasPrefix:@"Y"];

   // Fetch the SpringBoard server port
   mach_port_t *p;
   void *uikit = dlopen(UIKITPATH, RTLD_LAZY);
   int (*SBSSpringBoardServerPort)() = 
         dlsym(uikit, "SBSSpringBoardServerPort");
   p = SBSSpringBoardServerPort(); 
   dlclose(uikit);

   // Link to SBSetAirplaneModeEnabled
   void *sbserv = dlopen(SBSERVPATH, RTLD_LAZY);
   int (*setAPMode)(mach_port_t* port, BOOL yorn) = 
         dlsym(sbserv, "SBSetAirplaneModeEnabled");
   setAPMode(p, yorn);
   dlclose(sbserv);

   [pool release];
}