Reachability.m 6.42 KB
Newer Older
Han Ruisong's avatar
Han Ruisong committed
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
/*
 Copyright (C) 2016 Apple Inc. All Rights Reserved.
 See LICENSE.txt for this sample’s licensing information
 
 Abstract:
 Basic demonstration of how to use the SystemConfiguration Reachablity APIs.
 */

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

#import <CoreFoundation/CoreFoundation.h>

#import "Reachability.h"

#pragma mark IPv6 Support
//Reachability fully support IPv6.  For full details, see ReadMe.md.


NSString *kReachabilityChangedNotification = @"kNetworkReachabilityChangedNotification";


#pragma mark - Supporting functions

#define kShouldPrintReachabilityFlags 1

static void PrintReachabilityFlags(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
}


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

    Reachability* noteObject = (__bridge Reachability *)info;
    // Post a notification to notify the client that the network reachability changed.
    [[NSNotificationCenter defaultCenter] postNotificationName: kReachabilityChangedNotification object: noteObject];
}


#pragma mark - Reachability implementation

@implementation Reachability
{
	SCNetworkReachabilityRef _reachabilityRef;
}

+ (instancetype)reachabilityWithHostName:(NSString *)hostName
{
	Reachability* returnValue = NULL;
	SCNetworkReachabilityRef reachability = SCNetworkReachabilityCreateWithName(NULL, [hostName UTF8String]);
	if (reachability != NULL)
	{
		returnValue= [[self alloc] init];
		if (returnValue != NULL)
		{
			returnValue->_reachabilityRef = reachability;
		}
        else {
            CFRelease(reachability);
        }
	}
	return returnValue;
}


+ (instancetype)reachabilityWithAddress:(const struct sockaddr *)hostAddress
{
	SCNetworkReachabilityRef reachability = SCNetworkReachabilityCreateWithAddress(kCFAllocatorDefault, hostAddress);

	Reachability* returnValue = NULL;

	if (reachability != NULL)
	{
		returnValue = [[self alloc] init];
		if (returnValue != NULL)
		{
			returnValue->_reachabilityRef = reachability;
		}
        else {
            CFRelease(reachability);
        }
	}
	return returnValue;
}


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

#pragma mark reachabilityForLocalWiFi
//reachabilityForLocalWiFi has been removed from the sample.  See ReadMe.md for more information.
//+ (instancetype)reachabilityForLocalWiFi



#pragma mark - Start and stop notifier

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

	if (SCNetworkReachabilitySetCallback(_reachabilityRef, ReachabilityCallback, &context))
	{
		if (SCNetworkReachabilityScheduleWithRunLoop(_reachabilityRef, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode))
		{
			returnValue = YES;
		}
	}
    
	return returnValue;
}


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


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


#pragma mark - Network Flag Handling

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

    NetworkStatus returnValue = NotReachable;

	if ((flags & kSCNetworkReachabilityFlagsConnectionRequired) == 0)
	{
		/*
         If the target host is reachable and no connection is required then we'll assume (for now) that you're on Wi-Fi...
         */
		returnValue = 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...
             */
            returnValue = ReachableViaWiFi;
        }
    }

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


- (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 SCNetworkReachabilityRef");
	NetworkStatus returnValue = NotReachable;
	SCNetworkReachabilityFlags flags;
    
	if (SCNetworkReachabilityGetFlags(_reachabilityRef, &flags))
	{
        returnValue = [self networkStatusForFlags:flags];
	}
    
	return returnValue;
}


@end