Getting IPV4 address as a String - ios

Question

Im using Bonjour to browse for available services from specific devices. I can successfully obtain and resolve the services returned from the browse, however I would like to take the service and retrieve it's IPV4 address in String form. To do this I am using the arpa/inet library to translate the NSdata object received by the NSNetService.addresses into a String. The code below works most of the time however occasionally the line below results in the crashing of the app.
NSString *ipString = [NSString stringWithFormat: #"%s",
inet_ntoa(socketAddress->sin_addr)];
The error: EXC_BAD_ACCESS
I am sure it has to do with the way I have declared this code, any ideas?
+ (NSString *)getStringFromAddressData:(NSData *)dataIn {
struct sockaddr_in *socketAddress = nil;
socketAddress = (struct sockaddr_in *)[dataIn bytes];
NSString *ipString = [NSString stringWithFormat: #"%s", inet_ntoa(socketAddress->sin_addr)];
return ipString;
}
Stack trace:
2015-08-13 08:23:45.860 Semiphores[4664:2119558] Stack trace : (
0 Semiphores 0x0000000100001c0b +[BonjourAddressHelper getStringFromAddressData:] + 107
1 Semiphores 0x0000000100007c8a _TFFC10Semiphores17BonjourController15resolveServicesFS0_FPSs9AnyObject_T_U_FT_T_ + 2682
2 Semiphores 0x0000000100007207 _TTRXFo__dT__XFdCb__dT__ + 39
3 libdispatch.dylib 0x00000001006852bb _dispatch_call_block_and_release + 12
4 libdispatch.dylib 0x000000010067fd43 _dispatch_client_callout + 8
5 libdispatch.dylib 0x0000000100683283 _dispatch_root_queue_drain + 1471
6 libdispatch.dylib 0x0000000100694cd0 _dispatch_worker_thread3 + 106
7 libsystem_pthread.dylib 0x00007fff86770637 _pthread_wqthread + 729
8 libsystem_pthread.dylib 0x00007fff8676e40d start_wqthread + 13
)

Answer 1

What would happen if someone passed in nil data?
+ (NSString *)getStringFromAddressData:(NSData *)dataIn {
if (dataIn != nil) {
struct sockaddr_in *socketAddress = nil;
socketAddress = (struct sockaddr_in *)[dataIn bytes];
NSString *ipString = [NSString stringWithFormat: #"%s", inet_ntoa(socketAddress->sin_addr)];
return ipString;
}
return #"";
}