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     self = [super init];
  65
  66     if (self) {
  67         self.queue = dispatch_queue_create("XPC Notification Dispatch", DISPATCH_QUEUE_SERIAL);
  68         self.listeners = [NSPointerArray weakObjectsPointerArray];
  69         __weak typeof(self) weakSelf = self;
  70
  71         xpc_set_event_stream_handler(kXPCNotificationStreamName, self.queue, ^(xpc_object_t event){
  72             const char *notificationName = xpc_dictionary_get_string(event, kXPCNotificationNameKey);
  73             if (notificationName) {
  74                 [weakSelf notification:notificationName];
  75             }
  76         });
  77     }
  78
  79     return self;
  80 }
  81
  82 - (void) notification:(const char *)name {
  83     [self.listeners compact];
  84     [[self.listeners allObjects] enumerateObjectsUsingBlock:^(id  _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
  85         [obj handleNotification: name];
  86     }];
  87
  88 }
  89
  90 - (void) addListener: (NSObject<XPCNotificationListener>*) newHandler {
  91     dispatch_sync(self.queue, ^{
  92         [self.listeners compact];
  93         [self.listeners addPointer:(__bridge void * _Nullable)(newHandler)];
  94     });
  95 }
  96
  97 - (void) removeListener: (NSObject<XPCNotificationListener>*) existingHandler {
  98     dispatch_sync(self.queue, ^{
  99         [self.listeners removePointer:(__bridge void * _Nullable)existingHandler];
 100     });
 101 }
 102
 103 @end