CODEWITHSUNDEEP
iossockets
David Douglas
David Douglas

Reputation: 10503

Can you setup listener socket on localhost with iOS?

I'm trying to setup a listenerSocket on localhost using GCDAsyncSocket for iOS device.

In the socketDidDisconnect delegate I either get error Code=49 for trying with port 0 (which I'm hoping would find the first available free port). Or if I use a port no then I get error Code=61 for trying to connect with localhost.

- (IBAction)start:(id)sender {
    asyncSocket = [[GCDAsyncSocket alloc] initWithDelegate:self delegateQueue:dispatch_get_main_queue()];
    NSError *err = nil;
    if(![asyncSocket connectToHost:@"localhost" onPort:0 error:&err])
    {
        NSLog(@"Connect Error: %@", err);
    }
}

#pragma mark – delegate

-(void)socketDidDisconnect:(GCDAsyncSocket *)sock withError:(NSError *)err
{
    NSLog(@"socketDidDisconnect");
    if (err) {
        NSLog(@"Socket Error: %@", err);
        // Error in connect function:
        // NSPOSIXErrorDomain Code=49 "Can't assign requested address" - onPort:0
        // NSPOSIXErrorDomain Code=61 "Connection refused" - connectToHost:@"localhost"
    }
}

Upvotes: 2

Views: 1042

Answers (1)

trojanfoe
trojanfoe

Reputation: 122391

connectToHost will act as the client-side of the connection. You want to read the Writing a server section of the help page:

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

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

- (void)socket:(GCDAsyncSocket *)sender didAcceptNewSocket:(GCDAsyncSocket *)newSocket
{
    // The "sender" parameter is the listenSocket we created.
    // The "newSocket" is a new instance of GCDAsyncSocket.
    // It represents the accepted incoming client connection.

    // Do server stuff with newSocket...
}

However you need to know the port to use (if you let the system decide what port to use then how is a client supposed to know how to connect to the server?). Also the port will almost certainly need to be > 1024 (out of the reserved port range). However I haven't ever tried to create a Server on iOS.

Upvotes: 1

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