//

// SKNetworkConnection.m

// SensingKit

//

// Copyright (c) 2014. Kleomenis Katevas

// Kleomenis Katevas, minos.kat@gmail.com

//

// This file is part of SensingKit-iOS library.

// For more information, please visit https://www.sensingkit.org

//

// SensingKit-iOS is free software: you can redistribute it and/or modify

// it under the terms of the GNU Lesser General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// SensingKit-iOS is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

// GNU Lesser General Public License for more details.

//

// You should have received a copy of the GNU Lesser General Public License

// along with SensingKit-iOS. If not, see <http://www.gnu.org/licenses/>.

//

#import "SKNetworkConnection.h"

#import "SKNetworkConnectionData.h"

#include <net/if.h>

#include <ifaddrs.h>

@interface SKNetworkConnection ()

@property (nonatomic, strong) NSTimer *timer;

@property (nonatomic) SKNetworkDataActivity totalNetworkDataActivity;

@end

@implementation SKNetworkConnection

- (instancetype)initWithConfiguration:(SKNetworkConnectionConfiguration *)configuration

{

if (self = [super init])

{

self.configuration = configuration;

self.totalNetworkDataActivity = (SKNetworkDataActivity){0, 0, 0, 0};

}

return self;

}

#pragma mark Configuration

- (void)setConfiguration:(SKConfiguration *)configuration

{

super.configuration = configuration;

// Cast the configuration instance

// SKNetworkConnectionConfiguration *networkConnectionConfiguration = (SKNetworkConnectionConfiguration *)configuration;

// Make the required updates on the sensor

//

}

#pragma mark Sensing

+ (BOOL)isSensorAvailable

{

// Always available

return YES;

}

- (BOOL)startSensing:(NSError **)error

{

if (![super startSensing:error]) {

return NO;

}

if (![SKNetworkConnection isSensorAvailable])

{

if (error) {

NSDictionary *userInfo = @{

NSLocalizedDescriptionKey: NSLocalizedString(@"Network Connection sensor is not available.", nil),

};

*error = [NSError errorWithDomain:SKErrorDomain

code:SKSensorNotAvailableError

userInfo:userInfo];

}

return NO;

}

// Save offset

SKNetworkDataActivity startSensingOffset = [self getNetworkDataSinceDeviceBoot];

// Start sensor

SKNetworkConnectionConfiguration *networkConnectionConfiguration = (SKNetworkConnectionConfiguration *)self.configuration;

NSTimeInterval interval = 1 / networkConnectionConfiguration.sampleRate;

__weak typeof(self) weakSelf = self;

self.timer = [NSTimer scheduledTimerWithTimeInterval:interval repeats:YES block:^(NSTimer * _Nonnull timer) {

__strong typeof(weakSelf) strongSelf = weakSelf;

if (!strongSelf) { return; }

// get actual data consumed (since start sensing)

SKNetworkDataActivity currentDataActivity = [strongSelf getNetworkDataWithOffset:startSensingOffset];

// accumulate data

SKNetworkDataActivity totalNetworkDataActivity = strongSelf.totalNetworkDataActivity;

totalNetworkDataActivity.wifiSent += currentDataActivity.wifiSent;

totalNetworkDataActivity.wifiReceived += currentDataActivity.wifiReceived;

totalNetworkDataActivity.cellularSent += currentDataActivity.cellularSent;

totalNetworkDataActivity.cellularReceived += currentDataActivity.cellularReceived;

strongSelf.totalNetworkDataActivity = totalNetworkDataActivity;

SKNetworkConnectionData *data = [[SKNetworkConnectionData alloc] initWithNetworkDataActivity:totalNetworkDataActivity];

[strongSelf submitSensorData:data error:NULL];

}];

return YES;

}

- (BOOL)stopSensing:(NSError **)error

{

[self.timer invalidate];

self.timer = nil;

return [super stopSensing:error];

}

- (SKNetworkDataActivity)getNetworkDataWithOffset:(SKNetworkDataActivity)offset

{

SKNetworkDataActivity networkDataActivity = [self getNetworkDataSinceDeviceBoot];

// apply offset

networkDataActivity.wifiSent -= offset.wifiSent;

networkDataActivity.wifiReceived -= offset.wifiReceived;

networkDataActivity.cellularSent -= offset.cellularSent;

networkDataActivity.cellularReceived -= offset.cellularReceived;

return networkDataActivity;

}

// thanks to:

// https://stackoverflow.com/questions/7946699/iphone-data-usage-tracking-monitoring

- (SKNetworkDataActivity)getNetworkDataSinceDeviceBoot

{

SKNetworkDataActivity networkDataActivity = (SKNetworkDataActivity){0, 0, 0, 0};

struct ifaddrs *addrs;

if (getifaddrs(&addrs) == 0)

{

const struct ifaddrs *cursor = addrs;

while (cursor != NULL)

{

if (cursor->ifa_addr->sa_family == AF_LINK)

{

NSString *name = @(cursor->ifa_name);

if ([name hasPrefix:@"en"]) // WiFi

{

[self accumulateBytesForIfAddress:cursor

intoSent:&networkDataActivity.wifiSent

andReceived:&networkDataActivity.wifiReceived];

}

else if ([name hasPrefix:@"pdp_ip"]) // Cellular

{

[self accumulateBytesForIfAddress:cursor

intoSent:&networkDataActivity.cellularSent

andReceived:&networkDataActivity.cellularReceived];

}

// else, not interested. Ignore.

}

cursor = cursor->ifa_next;

}

freeifaddrs(addrs);

}

return networkDataActivity;

}

- (void)accumulateBytesForIfAddress:(const struct ifaddrs *)ifaddrs

intoSent:(uint64_t *)sent

andReceived:(uint64_t *)received

{

const struct if_data *ifa_data = (struct if_data *)ifaddrs->ifa_data;

if (ifa_data != NULL)

{

*sent += ifa_data->ifi_obytes;

*received += ifa_data->ifi_ibytes;

}

}

@end