KVSKeychainSyncingProxy/XPCNotificationDispatcher.m

   1 //
   2 //  XPCNotificationDispatcher.m
   3 //  Security
   4 //
   5 //  Created by Mitch Adler on 11/1/16.
   6 //
   7 //
   8
   9 #import "XPCNotificationDispatcher.h"
  10 #include <dispatch/dispatch.h>
  11
  12 #include <utilities/debugging.h>
  13
  14 #include <xpc/xpc.h>
  15
  16 //
  17 // PointerArray helpers
  18
  19 @interface NSPointerArray (Removal)
  20 - (void) removePointer: (nullable void *)pointer;
  21 @end
  22
  23 @implementation NSPointerArray (Removal)
  24 - (void) removePointer: (nullable void *)pointer {
  25     NSUInteger pos = 0;
  26     while(pos < [self count]) {
  27         if (pointer == [self pointerAtIndex:pos]) {
  28             [self removePointerAtIndex:pos];
  29         } else {
  30             pos += 1;
  31         }
  32     }
  33 }
  34 @end
  35
  36 //
  37 //
  38
  39 static const char *kXPCNotificationStreamName = "com.apple.notifyd.matching";
  40 static const char *kXPCNotificationNameKey = "Notification";
  41
  42 @interface XPCNotificationDispatcher ()
  43 @property dispatch_queue_t queue;
  44 @property NSPointerArray* listeners;
  45
  46 - (void) notification: (const char *) value;
  47
  48 @end
  49
  50
  51 @implementation XPCNotificationDispatcher
  52
  53 + (instancetype) dispatcher {
  54     static dispatch_once_t onceToken;
  55     static XPCNotificationDispatcher* sDispactcher;
  56     dispatch_once(&onceToken, ^{
  57         sDispactcher = [[XPCNotificationDispatcher alloc] init];
  58     });
  59
  60     return sDispactcher;
  61 }
  62
  63 - (instancetype) init {
  64     if ((self = [super init])) {
  65         self.queue = dispatch_queue_create("XPC Notification Dispatch", DISPATCH_QUEUE_SERIAL);
  66         self.listeners = [NSPointerArray weakObjectsPointerArray];
  67         __weak typeof(self) weakSelf = self;
  68
  69         xpc_set_event_stream_handler(kXPCNotificationStreamName, self.queue, ^(xpc_object_t event){
  70             const char *notificationName = xpc_dictionary_get_string(event, kXPCNotificationNameKey);
  71             if (notificationName) {
  72                 [weakSelf notification:notificationName];
  73             }
  74         });
  75     }
  76
  77     return self;
  78 }
  79
  80 - (void) notification:(const char *)name {
  81     [self.listeners compact];
  82     [[self.listeners allObjects] enumerateObjectsUsingBlock:^(id  _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
  83         [obj handleNotification: name];
  84     }];
  85
  86 }
  87
  88 - (void) addListener: (NSObject<XPCNotificationListener>*) newHandler {
  89     dispatch_sync(self.queue, ^{
  90         [self.listeners compact];
  91         [self.listeners addPointer:(__bridge void * _Nullable)(newHandler)];
  92     });
  93 }
  94
  95 - (void) removeListener: (NSObject<XPCNotificationListener>*) existingHandler {
  96     dispatch_sync(self.queue, ^{
  97         [self.listeners removePointer:(__bridge void * _Nullable)existingHandler];
  98     });
  99 }
 100
 101 @end