src/ios/CDVReachability.m

/*

 File: Reachability.m
 Abstract: Basic demonstration of how to use the SystemConfiguration Reachability APIs.
 Version: 2.2

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*/

#import <sys/socket.h>
#import <netinet/in.h>
#import <netinet6/in6.h>
#import <arpa/inet.h>
#import <ifaddrs.h>
#import <netdb.h>

#import <CoreFoundation/CoreFoundation.h>

#import "CDVReachability.h"

#define kShouldPrintReachabilityFlags 0

static void CDVPrintReachabilityFlags(SCNetworkReachabilityFlags flags, const char* comment)
{
#if kShouldPrintReachabilityFlags
        NSLog(@"Reachability Flag Status: %c%c %c%c%c%c%c%c%c %s\n",
            (flags & kSCNetworkReachabilityFlagsIsWWAN)               ? 'W' : '-',
            (flags & kSCNetworkReachabilityFlagsReachable)            ? 'R' : '-',

            (flags & kSCNetworkReachabilityFlagsTransientConnection)  ? 't' : '-',
            (flags & kSCNetworkReachabilityFlagsConnectionRequired)   ? 'c' : '-',
            (flags & kSCNetworkReachabilityFlagsConnectionOnTraffic)  ? 'C' : '-',
            (flags & kSCNetworkReachabilityFlagsInterventionRequired) ? 'i' : '-',
            (flags & kSCNetworkReachabilityFlagsConnectionOnDemand)   ? 'D' : '-',
            (flags & kSCNetworkReachabilityFlagsIsLocalAddress)       ? 'l' : '-',
            (flags & kSCNetworkReachabilityFlagsIsDirect)             ? 'd' : '-',
            comment
            );
#endif
}

@implementation CDVReachability

static void CDVReachabilityCallback(SCNetworkReachabilityRef target, SCNetworkReachabilityFlags flags, void* info)
{
#pragma unused (target, flags)
    //	NSCAssert(info != NULL, @"info was NULL in ReachabilityCallback");
    //	NSCAssert([(NSObject*) info isKindOfClass: [Reachability class]], @"info was wrong class in ReachabilityCallback");

    // Converted the asserts above to conditionals, with safe return from the function
    if (info == NULL) {
        NSLog(@"info was NULL in ReachabilityCallback");
        return;
    }

    if (![(__bridge NSObject*)info isKindOfClass :[CDVReachability class]]) {
        NSLog(@"info was wrong class in ReachabilityCallback");
        return;
    }

    // We're on the main RunLoop, so an NSAutoreleasePool is not necessary, but is added defensively
    // in case someon uses the Reachability object in a different thread.
    @autoreleasepool {
        CDVReachability* noteObject = (__bridge CDVReachability*)info;
        // Post a notification to notify the client that the network reachability changed.
        [[NSNotificationCenter defaultCenter] postNotificationName:kReachabilityChangedNotification object:noteObject];
    }
}

- (BOOL)startNotifier
{
    BOOL retVal = NO;
    SCNetworkReachabilityContext context = {0, (__bridge void*)(self), NULL, NULL, NULL};

    if (SCNetworkReachabilitySetCallback(reachabilityRef, CDVReachabilityCallback, &context)) {
        if (SCNetworkReachabilityScheduleWithRunLoop(reachabilityRef, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode)) {
            retVal = YES;
        }
    }
    return retVal;
}

- (void)stopNotifier
{
    if (reachabilityRef != NULL) {
        SCNetworkReachabilityUnscheduleFromRunLoop(reachabilityRef, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);
    }
}

- (void)dealloc
{
    [self stopNotifier];
    if (reachabilityRef != NULL) {
        CFRelease(reachabilityRef);
    }
}

+ (CDVReachability*)reachabilityWithHostName:(NSString*)hostName;
{
    CDVReachability* retVal = NULL;
    SCNetworkReachabilityRef reachability = SCNetworkReachabilityCreateWithName(NULL, [hostName UTF8String]);
    if (reachability != NULL) {
        retVal = [[self alloc] init];
        if (retVal != NULL) {
            retVal->reachabilityRef = reachability;
            retVal->localWiFiRef = NO;
        }
    }
    return retVal;
}

+ (CDVReachability*)reachabilityWithAddress:(const struct sockaddr_in*)hostAddress;
{
    SCNetworkReachabilityRef reachability = SCNetworkReachabilityCreateWithAddress(kCFAllocatorDefault, (const struct sockaddr*)hostAddress);
    CDVReachability* retVal = NULL;
    if (reachability != NULL) {
        retVal = [[self alloc] init];
        if (retVal != NULL) {
            retVal->reachabilityRef = reachability;
            retVal->localWiFiRef = NO;
        }
    }
    return retVal;
}

+ (CDVReachability*)reachabilityForInternetConnection;
{
    struct sockaddr_in zeroAddress;
    bzero(&zeroAddress, sizeof(zeroAddress));
    zeroAddress.sin_len = sizeof(zeroAddress);
    zeroAddress.sin_family = AF_INET;
    return [self reachabilityWithAddress:&zeroAddress];
}

+ (CDVReachability*)reachabilityForLocalWiFi;
{
    struct sockaddr_in localWifiAddress;
    bzero(&localWifiAddress, sizeof(localWifiAddress));
    localWifiAddress.sin_len = sizeof(localWifiAddress);
    localWifiAddress.sin_family = AF_INET;
    // IN_LINKLOCALNETNUM is defined in <netinet/in.h> as 169.254.0.0
    localWifiAddress.sin_addr.s_addr = htonl(IN_LINKLOCALNETNUM);
    CDVReachability* retVal = [self reachabilityWithAddress:&localWifiAddress];
    if (retVal != NULL) {
        retVal->localWiFiRef = YES;
    }
    return retVal;
}

#pragma mark Network Flag Handling

- (NetworkStatus)localWiFiStatusForFlags:(SCNetworkReachabilityFlags)flags
{
    CDVPrintReachabilityFlags(flags, "localWiFiStatusForFlags");

    BOOL retVal = NotReachable;
    if ((flags & kSCNetworkReachabilityFlagsReachable) && (flags & kSCNetworkReachabilityFlagsIsDirect)) {
        retVal = ReachableViaWiFi;
    }
    return retVal;
}

- (NetworkStatus)networkStatusForFlags:(SCNetworkReachabilityFlags)flags
{
    CDVPrintReachabilityFlags(flags, "networkStatusForFlags");
    if ((flags & kSCNetworkReachabilityFlagsReachable) == 0) {
        // if target host is not reachable
        return NotReachable;
    }

    BOOL retVal = NotReachable;

    if ((flags & kSCNetworkReachabilityFlagsConnectionRequired) == 0) {
        // if target host is reachable and no connection is required
        //  then we'll assume (for now) that your on Wi-Fi
        retVal = ReachableViaWiFi;
    }

    if ((((flags & kSCNetworkReachabilityFlagsConnectionOnDemand) != 0) ||
        ((flags & kSCNetworkReachabilityFlagsConnectionOnTraffic) != 0))) {
        // ... and the connection is on-demand (or on-traffic) if the
        //     calling application is using the CFSocketStream or higher APIs

        if ((flags & kSCNetworkReachabilityFlagsInterventionRequired) == 0) {
            // ... and no [user] intervention is needed
            retVal = ReachableViaWiFi;
        }
    }

    if ((flags & kSCNetworkReachabilityFlagsIsWWAN) == kSCNetworkReachabilityFlagsIsWWAN) {
        // ... but WWAN connections are OK if the calling application
        //     is using the CFNetwork (CFSocketStream?) APIs.
        retVal = ReachableViaWWAN;
    }
    return retVal;
}

- (BOOL)connectionRequired;
{
    NSAssert(reachabilityRef != NULL, @"connectionRequired called with NULL reachabilityRef");
    SCNetworkReachabilityFlags flags;
    if (SCNetworkReachabilityGetFlags(reachabilityRef, &flags)) {
        return flags & kSCNetworkReachabilityFlagsConnectionRequired;
    }
    return NO;
}

- (NetworkStatus)currentReachabilityStatus
{
    NSAssert(reachabilityRef != NULL, @"currentNetworkStatus called with NULL reachabilityRef");
    NetworkStatus retVal = NotReachable;
    SCNetworkReachabilityFlags flags;
    if (SCNetworkReachabilityGetFlags(reachabilityRef, &flags)) {
        if (localWiFiRef) {
            retVal = [self localWiFiStatusForFlags:flags];
        } else {
            retVal = [self networkStatusForFlags:flags];
        }
    }
    return retVal;
}

@end