/*

     File: XPCService.m

 Abstract: The main object in the XPC service.

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#import "XPCService.h"

#import "Common.h"

#import "HelperTool.h"

#include <ServiceManagement/ServiceManagement.h>

@interface XPCService () <NSXPCListenerDelegate, XPCServiceProtocol>

@property (atomic, strong, readonly ) NSXPCListener *    listener;

@property (atomic, copy,   readonly ) NSData *           authorization;

@property (atomic, strong, readonly ) NSOperationQueue * queue;

@property (atomic, strong, readwrite) NSXPCConnection *  helperToolConnection;      // only accessed or modified by operations on self.queue

@end

@implementation XPCService {

    AuthorizationRef    _authRef;

}

- (id)init

{

    self = [super init];

    if (self != nil) {

        OSStatus                    err;

        AuthorizationExternalForm   extForm;

        self->_listener = [NSXPCListener serviceListener];

        assert(self->_listener != nil);     // this code must be run from an XPC service

        self->_listener.delegate = self;

        err = AuthorizationCreate(NULL, NULL, 0, &self->_authRef);

        if (err == errAuthorizationSuccess) {

            err = AuthorizationMakeExternalForm(self->_authRef, &extForm);

        }

        if (err == errAuthorizationSuccess) {

            self->_authorization = [[NSData alloc] initWithBytes:&extForm length:sizeof(extForm)];

        }

        assert(err == errAuthorizationSuccess);

        self->_queue = [[NSOperationQueue alloc] init];

        [self->_queue setMaxConcurrentOperationCount:1];

    }

    return self;

}

- (void)dealloc

{

    if (self->_authRef != NULL) {

        (void) AuthorizationFree(self->_authRef, 0);

    }

}

- (void)run

{

    [self.listener resume];     // never comes back

}

- (BOOL)listener:(NSXPCListener *)listener shouldAcceptNewConnection:(NSXPCConnection *)newConnection

    // Called by our XPC listener when a new connection comes in.  We configure the connection

    // with our protocol and ourselves as the main object.

{

    assert(listener == self.listener);

    #pragma unused(listener)

    assert(newConnection != nil);

    newConnection.exportedInterface = [NSXPCInterface interfaceWithProtocol:@protocol(XPCServiceProtocol)];

    newConnection.exportedObject = self;

    [newConnection resume];

    return YES;

}

- (void)installHelperToolWithReply:(void(^)(NSError * error))reply

    // Part of XPCServiceProtocol.  Called by the app to install the helper tool.

{

    Boolean             success;

    CFErrorRef          error;

    success = SMJobBless(

        kSMDomainSystemLaunchd,

        CFSTR("com.example.apple-samplecode.EBAS.HelperTool"),

        self->_authRef,

        &error

    );

    if (success) {

        reply(nil);

    } else {

        assert(error != NULL);

        reply((__bridge NSError *) error);

        CFRelease(error);

    }

}

- (void)setupAuthorizationRights

    // Part of XPCServiceProtocol.  Called by the app at startup time to set up our 

    // authorization rights in the authorization database.

{

    [Common setupAuthorizationRights:self->_authRef];

}

- (void)connectWithEndpointAndAuthorizationReply:(void(^)(NSXPCListenerEndpoint * endpoint, NSData * authorization))reply

    // Part of XPCServiceProtocol.  Called by the app to get an endpoint that's 

    // connected to the helper tool.  This a also returns the XPC service's authorization 

    // reference so that the app can pass that to the requests it sends to the helper tool.  

    // Without this authorization will fail because the app is sandboxed.

{

    // Because we access helperToolConnection, we have to run on the operation queue.

    [self.queue addOperationWithBlock:^{

        // Create our connection to the helper tool if it's not already in place.

        if (self.helperToolConnection == nil) {

            self.helperToolConnection = [[NSXPCConnection alloc] initWithMachServiceName:kHelperToolMachServiceName options:NSXPCConnectionPrivileged];

            self.helperToolConnection.remoteObjectInterface = [NSXPCInterface interfaceWithProtocol:@protocol(HelperToolProtocol)];

            #pragma clang diagnostic push

            #pragma clang diagnostic ignored "-Warc-retain-cycles"

            // We can ignore the retain cycle warning because a) the retain taken by the

            // invalidation handler block is released by us setting it to nil when the block 

            // actually runs, and b) the retain taken by the block passed to -addOperationWithBlock: 

            // will be released when that operation completes and the operation itself is deallocated 

            // (notably self does not have a reference to the NSBlockOperation).

            self.helperToolConnection.invalidationHandler = ^{

                // If the connection gets invalidated then, on our operation queue thread, nil out our

                // reference to it.  This ensures that we attempt to rebuild it the next time around.

                self.helperToolConnection.invalidationHandler = nil;

                [self.queue addOperationWithBlock:^{

                    self.helperToolConnection = nil;

                    NSLog(@"connection invalidated");

                }];

            };

            #pragma clang diagnostic pop

            [self.helperToolConnection resume];

        }

        // Call the helper tool to get the endpoint we need.

        [[self.helperToolConnection remoteObjectProxyWithErrorHandler:^(NSError * proxyError) {

            NSLog(@"connect failed: %@ / %d", [proxyError domain], (int) [proxyError code]);

            reply(nil, nil);

        }] connectWithEndpointReply:^(NSXPCListenerEndpoint *replyEndpoint) {

            reply(replyEndpoint, self.authorization);

        }];

    }];

}

@end