keychain/ckks/CKKSReachabilityTracker.m

   1 /*
   2  * Copyright (c) 2017 Apple Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #if OCTAGON
  25
  26 #import <Foundation/Foundation.h>
  27 #import <CloudKit/CloudKit.h>
  28
  29 #import <dispatch/dispatch.h>
  30 #import <sys/types.h>
  31 #import <sys/socket.h>
  32 #import <netinet/in.h>
  33
  34 #import <nw/private.h>
  35
  36 #import "keychain/ckks/CKKS.h"
  37 #import "keychain/ckks/CKKSGroupOperation.h"
  38 #import "keychain/ckks/CKKSResultOperation.h"
  39 #import "keychain/ckks/CKKSReachabilityTracker.h"
  40 #import "keychain/ckks/CKKSAnalytics.h"
  41 #import "keychain/ot/ObjCImprovements.h"
  42
  43 // force reachability timeout every now and then
  44 #define REACHABILITY_TIMEOUT (12 * 3600 * NSEC_PER_SEC)
  45
  46 @interface CKKSReachabilityTracker ()
  47 @property bool haveNetwork;
  48 @property dispatch_queue_t queue;
  49 @property NSOperationQueue* operationQueue;
  50 @property nw_path_monitor_t networkMonitor;
  51 @property dispatch_source_t timer;
  52 @end
  53
  54 @implementation CKKSReachabilityTracker
  55
  56 - (instancetype)init {
  57     if((self = [super init])) {
  58         _queue = dispatch_queue_create("reachabiltity-tracker", DISPATCH_QUEUE_SERIAL_WITH_AUTORELEASE_POOL);
  59         _operationQueue = [[NSOperationQueue alloc] init];
  60
  61         dispatch_sync(_queue, ^{
  62             [self _onQueueResetReachabilityDependency];
  63         });
  64
  65         WEAKIFY(self);
  66
  67         if(!SecCKKSTestsEnabled()) {
  68             _networkMonitor = nw_path_monitor_create();
  69             nw_path_monitor_set_queue(self.networkMonitor, _queue);
  70             nw_path_monitor_set_update_handler(self.networkMonitor, ^(nw_path_t  _Nonnull path) {
  71                 STRONGIFY(self);
  72                 bool networkAvailable = (nw_path_get_status(path) == nw_path_status_satisfied);
  73
  74                 ckksinfo_global("ckksnetwork", "nw_path update: network is %@", networkAvailable ? @"available" : @"unavailable");
  75                 [self _onqueueSetNetworkReachability:networkAvailable];
  76             });
  77             nw_path_monitor_start(self.networkMonitor);
  78         }
  79     }
  80     return self;
  81 }
  82
  83 - (NSString*)description {
  84     return [NSString stringWithFormat: @"<CKKSReachabilityTracker: %@>", self.haveNetwork ? @"online" : @"offline"];
  85 }
  86
  87 - (bool)currentReachability {
  88     __block bool currentReachability = false;
  89     dispatch_sync(self.queue, ^{
  90         currentReachability = self.haveNetwork;
  91     });
  92     return currentReachability;
  93 }
  94
  95 - (void)_onQueueRunReachabilityDependency
  96 {
  97     dispatch_assert_queue(self.queue);
  98     // We have network now, or the timer expired. Either way, execute dependency
  99     if (self.reachabilityDependency) {
 100         [self.operationQueue addOperation: self.reachabilityDependency];
 101         self.reachabilityDependency = nil;
 102     }
 103     if (self.timer) {
 104         dispatch_source_cancel(self.timer);
 105         self.timer = nil;
 106     }
 107 }
 108
 109 - (void)_onQueueResetReachabilityDependency {
 110     dispatch_assert_queue(self.queue);
 111
 112     if(self.reachabilityDependency == nil || ![self.reachabilityDependency isPending]) {
 113         WEAKIFY(self);
 114
 115         ckksnotice_global("network", "Network unavailable");
 116         self.reachabilityDependency = [CKKSResultOperation named:@"network-available-dependency" withBlock: ^{
 117             STRONGIFY(self);
 118             if (self.haveNetwork) {
 119                 ckksnotice_global("network", "Network available");
 120             } else {
 121                 ckksnotice_global("network", "Network still not available, retrying after waiting %2.1f hours",
 122                                   ((float)(REACHABILITY_TIMEOUT/NSEC_PER_SEC)) / 3600);
 123             }
 124         }];
 125
 126         /*
 127          * Make sure we are not stuck forever and retry every REACHABILITY_TIMEOUT
 128          */
 129         self.timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER,
 130                                             0,
 131                                             (dispatch_source_timer_flags_t)0,
 132                                             self.queue);
 133         dispatch_source_set_event_handler(self.timer, ^{
 134             STRONGIFY(self);
 135             if (self == nil) {
 136                 return;
 137             }
 138             if (self.timer) {
 139                 [[CKKSAnalytics logger] noteEvent:CKKSEventReachabilityTimerExpired];
 140                 [self _onQueueRunReachabilityDependency];
 141             }
 142         });
 143
 144         dispatch_source_set_timer(self.timer,
 145                                   dispatch_time(DISPATCH_TIME_NOW, REACHABILITY_TIMEOUT),
 146                                   DISPATCH_TIME_FOREVER, //one-shot
 147                                   30 * NSEC_PER_SEC);
 148         dispatch_resume(self.timer);
 149     }
 150 }
 151
 152 - (void)_onqueueSetNetworkReachability:(bool)haveNetwork {
 153     dispatch_assert_queue(self.queue);
 154
 155     bool hadNetwork = self.haveNetwork;
 156     self.haveNetwork = !!(haveNetwork);
 157
 158     if(hadNetwork != self.haveNetwork) {
 159         if(self.haveNetwork) {
 160             // We're have network now
 161             [self _onQueueRunReachabilityDependency];
 162         } else {
 163             [self _onQueueResetReachabilityDependency];
 164         }
 165     }
 166 }
 167
 168 - (void)setNetworkReachability:(bool)reachable
 169 {
 170     dispatch_sync(self.queue, ^{
 171         [self _onqueueSetNetworkReachability:reachable];
 172     });
 173 }
 174
 175 - (bool)isNetworkError:(NSError *)error {
 176     return [CKKSReachabilityTracker isNetworkError:error];
 177 }
 178
 179 + (bool)isNetworkError:(NSError *)error {
 180     if (error == nil) {
 181         return false;
 182     }
 183
 184     if([CKKSReachabilityTracker isNetworkFailureError:error]) {
 185         return true;
 186     }
 187
 188     if ([error.domain isEqualToString:CKErrorDomain] &&
 189             (error.code == CKErrorNetworkUnavailable)) {
 190         return true;
 191     }
 192
 193     if ([error.domain isEqualToString:NSURLErrorDomain] &&
 194         error.code == NSURLErrorTimedOut) {
 195         return true;
 196     }
 197
 198     return false;
 199 }
 200
 201 + (bool)isNetworkFailureError:(NSError *)error
 202 {
 203     if (error == nil) {
 204         return false;
 205     }
 206     if ([error.domain isEqualToString:CKErrorDomain] && error.code == CKErrorNetworkFailure) {
 207         return true;
 208     }
 209
 210     return false;
 211 }
 212
 213 @end
 214
 215 #endif // OCTAGON
 216