Creating p2p connection iOS

Question

Okay. So I have been trying to connect devices p2p with streams for a week. Still no result and i am getting crazy and desperate. Please Don't send me to Ray Wenderlich tutorial and GCD wiki or to CFStream Guide as i have surfed it to the holes.

So 1) Variant Here i

1. Get Ip Of My device
2. Manually input ip in text field of other device
3. Init network communication on one device.

4. Error - connecting to host.

    + (NSString *)getIPAddress {
   
    NSString *address = @"error";
    struct ifaddrs *interfaces = NULL;
   struct ifaddrs *temp_addr = NULL;
   int success = 0;
   // retrieve the current interfaces - returns 0 on success
    success = getifaddrs(&interfaces);
    if (success == 0) {
    // Loop through linked list of interfaces
    temp_addr = interfaces;
     while(temp_addr != NULL) {
       if(temp_addr->ifa_addr->sa_family == AF_INET) {
       // Check if interface is en0 which is the wifi connection on the iPhone
          if([[NSString stringWithUTF8String:temp_addr->ifa_name] isEqualToString:@"en0"]) {
               // Get NSString from C String
               address = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_addr)->sin_addr)];
   
           }
   
       }
   
       temp_addr = temp_addr->ifa_next;
   }
    }
    // Free memory
   freeifaddrs(interfaces);
   return address;
   
   }
   

   • (void) initNetworkCommunication:(NSString*)ipToConnect { NSString *urlStr = ipToConnect; if (![urlStr isEqualToString:@""]) { NSURL *website = [NSURL URLWithString:urlStr]; if (!website) { NSLog(@"%@ is not a valid URL"); return; } CFReadStreamRef readStream; CFWriteStreamRef writeStream; CFStreamCreatePairWithSocketToHost(NULL, (__bridge CFStringRef)[website host], 80, &readStream, &writeStream);

   NSInputStream *inputStream = (__bridge_transfer NSInputStream *)readStream; NSOutputStream *outputStream = (__bridge_transfer NSOutputStream *)writeStream; [inputStream setDelegate:self]; [outputStream setDelegate:self]; [inputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode]; [outputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode]; [inputStream open]; [outputStream open];

   }

   • (void)stream:(NSStream *)theStream handleEvent:(NSStreamEvent)streamEvent {

   NSLog(@"stream event %lu", streamEvent);

   switch (streamEvent) {

   case NSStreamEventOpenCompleted:
       NSLog(@"Stream opened");
       break;
   case NSStreamEventHasBytesAvailable:
   
       if (theStream == inputStream) {
   
           uint8_t buffer[1024];
           int len;
   
           while ([inputStream hasBytesAvailable]) {
               len = [inputStream read:buffer maxLength:sizeof(buffer)];
               if (len > 0) {
   
                   NSString *output = [[NSString alloc] initWithBytes:buffer length:len encoding:NSASCIIStringEncoding];
   
                   if (nil != output) {
   
                       NSLog(@"server said: %@", output);
                       //[self messageReceived:output];
   
                   }
               }
           }
       }
       break;
   
   
   case NSStreamEventErrorOccurred:
   
       NSLog(@"Can not connect to the host!");
       break;
   
   case NSStreamEventEndEncountered:
   
       [theStream close];
       [theStream removeFromRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
    //   [theStream release];
       theStream = nil;
   
       break;
   default:
       NSLog(@"Unknown event");
   

   }

   }

Variant 2 with GCD. 1. Same 2. Set both devices to listen to input

+(void)listenSocket:(GCDAsyncSocket*)listenSocket
{

listenSocket = [[GCDAsyncSocket alloc] initWithDelegate:self delegateQueue:dispatch_get_main_queue()];

NSError *error = nil;
if (![listenSocket acceptOnPort:80 error:&error])
{
    NSLog(@"I goofed: %@", error);
}

}

3) Tried to connect with manually inputting IP

 +(void)connectToDeviceWithIp:(NSString*)deviceIp andSend:(HSUserCard*)tempCard andSocket:(GCDAsyncSocket*)tempSocket
{

tempSocket = [[GCDAsyncSocket alloc] initWithDelegate:self delegateQueue:dispatch_get_main_queue()];
NSError *err = nil;
if (![tempSocket connectToHost:deviceIp onPort:80 error:&err])
    NSLog(@"I goofed: %@", err);



[tempSocket writeData:[NSKeyedArchiver archivedDataWithRootObject:tempCard] withTimeout:-1 tag:1];
}

4) Result nothing - i did put several breaks on every delegate function =NOTHING.

Omg - i solved this task on Android in 20 minutes! But here it just drives crazy. Tried in several networks. Thrue 3g, home wifi. Please someone help!

Answer 1

The problem I can see from all of your various attempts is that you are storing the socket in a local variable - this means that once the method exits it will be released and no communications will be possible on that socket.

You need to store your socket references in strong properties.

I have created an example application using CocoaAsyncSocket that demonstrates listening for connections and making a connection along with tracking the connection state through properties holding the sockets.

It is available here https://github.com/paulw11/SocketDemo