1 files changed, 240 insertions, 0 deletions
diff --git a/Firebase/Utilities/Reachability/GULReachabilityChecker.m b/Firebase/Utilities/Reachability/GULReachabilityChecker.m
new file mode 100644
index 0000000..1ddacdf
--- /dev/null
+++ b/Firebase/Utilities/Reachability/GULReachabilityChecker.m
@@ -0,0 +1,240 @@
+// Copyright 2017 Google
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#import <Foundation/Foundation.h>
+
+#import "GULReachabilityChecker+Internal.h"
+#import "Private/GULReachabilityChecker.h"
+#import "Private/GULReachabilityMessageCode.h"
+
+#import <GoogleUtilities/GULLogger.h>
+#import <GoogleUtilities/GULReachabilityChecker.h>
+
+static GULLoggerService kGULLoggerReachability = @"[GULReachability]";
+
+static void ReachabilityCallback(SCNetworkReachabilityRef reachability,
+                                 SCNetworkReachabilityFlags flags,
+                                 void *info);
+
+static const struct GULReachabilityApi kGULDefaultReachabilityApi = {
+    SCNetworkReachabilityCreateWithName,
+    SCNetworkReachabilitySetCallback,
+    SCNetworkReachabilityScheduleWithRunLoop,
+    SCNetworkReachabilityUnscheduleFromRunLoop,
+    CFRelease,
+};
+
+static NSString *const kGULReachabilityUnknownStatus = @"Unknown";
+static NSString *const kGULReachabilityConnectedStatus = @"Connected";
+static NSString *const kGULReachabilityDisconnectedStatus = @"Disconnected";
+
+@interface GULReachabilityChecker ()
+
+@property(nonatomic, assign) const struct GULReachabilityApi *reachabilityApi;
+@property(nonatomic, assign) GULReachabilityStatus reachabilityStatus;
+@property(nonatomic, copy) NSString *host;
+@property(nonatomic, assign) SCNetworkReachabilityRef reachability;
+
+@end
+
+@implementation GULReachabilityChecker
+
+@synthesize reachabilityApi = reachabilityApi_;
+@synthesize reachability = reachability_;
+
+- (const struct GULReachabilityApi *)reachabilityApi {
+  return reachabilityApi_;
+}
+
+- (void)setReachabilityApi:(const struct GULReachabilityApi *)reachabilityApi {
+  if (reachability_) {
+    GULLogError(kGULLoggerReachability, NO,
+                [NSString stringWithFormat:@"I-REA%06ld", (long)kGULReachabilityMessageCode000],
+                @"Cannot change reachability API while reachability is running. "
+                @"Call stop first.");
+    return;
+  }
+  reachabilityApi_ = reachabilityApi;
+}
+
+@synthesize reachabilityStatus = reachabilityStatus_;
+@synthesize host = host_;
+@synthesize reachabilityDelegate = reachabilityDelegate_;
+
+- (BOOL)isActive {
+  return reachability_ != nil;
+}
+
+- (void)setReachabilityDelegate:(id<GULReachabilityDelegate>)reachabilityDelegate {
+  if (reachabilityDelegate &&
+      (![(NSObject *)reachabilityDelegate conformsToProtocol:@protocol(GULReachabilityDelegate)])) {
+    GULLogError(kGULLoggerReachability, NO,
+                [NSString stringWithFormat:@"I-NET%06ld", (long)kGULReachabilityMessageCode005],
+                @"Reachability delegate doesn't conform to Reachability protocol.");
+    return;
+  }
+  reachabilityDelegate_ = reachabilityDelegate;
+}
+
+- (instancetype)initWithReachabilityDelegate:(id<GULReachabilityDelegate>)reachabilityDelegate
+                                    withHost:(NSString *)host {
+  self = [super init];
+
+  if (!host || !host.length) {
+    GULLogError(kGULLoggerReachability, NO,
+                [NSString stringWithFormat:@"I-REA%06ld", (long)kGULReachabilityMessageCode001],
+                @"Invalid host specified");
+    return nil;
+  }
+  if (self) {
+    [self setReachabilityDelegate:reachabilityDelegate];
+    reachabilityApi_ = &kGULDefaultReachabilityApi;
+    reachabilityStatus_ = kGULReachabilityUnknown;
+    host_ = [host copy];
+    reachability_ = nil;
+  }
+  return self;
+}
+
+- (void)dealloc {
+  reachabilityDelegate_ = nil;
+  [self stop];
+}
+
+- (BOOL)start {
+  if (!reachability_) {
+    reachability_ = reachabilityApi_->createWithNameFn(kCFAllocatorDefault, [host_ UTF8String]);
+    if (!reachability_) {
+      return NO;
+    }
+    SCNetworkReachabilityContext context = {
+        0,                       /* version */
+        (__bridge void *)(self), /* info (passed as last parameter to reachability callback) */
+        NULL,                    /* retain */
+        NULL,                    /* release */
+        NULL                     /* copyDescription */
+    };
+    if (!reachabilityApi_->setCallbackFn(reachability_, ReachabilityCallback, &context) ||
+        !reachabilityApi_->scheduleWithRunLoopFn(reachability_, CFRunLoopGetMain(),
+                                                 kCFRunLoopCommonModes)) {
+      reachabilityApi_->releaseFn(reachability_);
+      reachability_ = nil;
+
+      GULLogError(kGULLoggerReachability, NO,
+                  [NSString stringWithFormat:@"I-REA%06ld", (long)kGULReachabilityMessageCode002],
+                  @"Failed to start reachability handle");
+      return NO;
+    }
+  }
+  GULLogDebug(kGULLoggerReachability, NO,
+              [NSString stringWithFormat:@"I-REA%06ld", (long)kGULReachabilityMessageCode003],
+              @"Monitoring the network status");
+  return YES;
+}
+
+- (void)stop {
+  if (reachability_) {
+    reachabilityStatus_ = kGULReachabilityUnknown;
+    reachabilityApi_->unscheduleFromRunLoopFn(reachability_, CFRunLoopGetMain(),
+                                              kCFRunLoopCommonModes);
+    reachabilityApi_->releaseFn(reachability_);
+    reachability_ = nil;
+  }
+}
+
+- (GULReachabilityStatus)statusForFlags:(SCNetworkReachabilityFlags)flags {
+  GULReachabilityStatus status = kGULReachabilityNotReachable;
+  // If the Reachable flag is not set, we definitely don't have connectivity.
+  if (flags & kSCNetworkReachabilityFlagsReachable) {
+    // Reachable flag is set. Check further flags.
+    if (!(flags & kSCNetworkReachabilityFlagsConnectionRequired)) {
+// Connection required flag is not set, so we have connectivity.
+#if TARGET_OS_IOS || TARGET_OS_TV
+      status = (flags & kSCNetworkReachabilityFlagsIsWWAN) ? kGULReachabilityViaCellular
+                                                           : kGULReachabilityViaWifi;
+#elif TARGET_OS_OSX
+      status = kGULReachabilityViaWifi;
+#endif
+    } else if ((flags & (kSCNetworkReachabilityFlagsConnectionOnDemand |
+                         kSCNetworkReachabilityFlagsConnectionOnTraffic)) &&
+               !(flags & kSCNetworkReachabilityFlagsInterventionRequired)) {
+// If the connection on demand or connection on traffic flag is set, and user intervention
+// is not required, we have connectivity.
+#if TARGET_OS_IOS || TARGET_OS_TV
+      status = (flags & kSCNetworkReachabilityFlagsIsWWAN) ? kGULReachabilityViaCellular
+                                                           : kGULReachabilityViaWifi;
+#elif TARGET_OS_OSX
+      status = kGULReachabilityViaWifi;
+#endif
+    }
+  }
+  return status;
+}
+
+- (void)reachabilityFlagsChanged:(SCNetworkReachabilityFlags)flags {
+  GULReachabilityStatus status = [self statusForFlags:flags];
+  if (reachabilityStatus_ != status) {
+    NSString *reachabilityStatusString;
+    if (status == kGULReachabilityUnknown) {
+      reachabilityStatusString = kGULReachabilityUnknownStatus;
+    } else {
+      reachabilityStatusString = (status == kGULReachabilityNotReachable)
+                                     ? kGULReachabilityDisconnectedStatus
+                                     : kGULReachabilityConnectedStatus;
+    }
+
+    GULLogDebug(kGULLoggerReachability, NO,
+                [NSString stringWithFormat:@"I-REA%06ld", (long)kGULReachabilityMessageCode004],
+                @"Network status has changed. Code:%@, status:%@", @(status),
+                reachabilityStatusString);
+    reachabilityStatus_ = status;
+    [reachabilityDelegate_ reachability:self statusChanged:reachabilityStatus_];
+  }
+}
+
+@end
+
+static void ReachabilityCallback(SCNetworkReachabilityRef reachability,
+                                 SCNetworkReachabilityFlags flags,
+                                 void *info) {
+  GULReachabilityChecker *checker = (__bridge GULReachabilityChecker *)info;
+  [checker reachabilityFlagsChanged:flags];
+}
+
+// This function used to be at the top of the file, but it was moved here
+// as a workaround for a suspected compiler bug. When compiled in Release mode
+// and run on an iOS device with WiFi disabled, the reachability code crashed
+// when calling SCNetworkReachabilityScheduleWithRunLoop, or shortly thereafter.
+// After unsuccessfully trying to diagnose the cause of the crash, it was
+// discovered that moving this function to the end of the file magically fixed
+// the crash. If you are going to edit this file, exercise caution and make sure
+// to test thoroughly with an iOS device under various network conditions.
+const NSString *GULReachabilityStatusString(GULReachabilityStatus status) {
+  switch (status) {
+    case kGULReachabilityUnknown:
+      return @"Reachability Unknown";
+
+    case kGULReachabilityNotReachable:
+      return @"Not reachable";
+
+    case kGULReachabilityViaWifi:
+      return @"Reachable via Wifi";
+
+    case kGULReachabilityViaCellular:
+      return @"Reachable via Cellular Data";
+
+    default:
+      return [NSString stringWithFormat:@"Invalid reachability status %d", (int)status];
+  }
+}