Slow packet transfer using bonjour and nsnetservice - ios

I'm working on a local network based game. By this I mean that you can play it on different iphone on local network wifi or bluetooth. I did the implementation with NSStream with a tcp connection to transfer data. I have one server who listens the network :
service = [[NSNetService alloc] initWithDomain:#"local."// 4
type:CreateNSString(serviceType)
name:CreateNSString(serviceName)
port:80];
if(service)
{
service.includesPeerToPeer = YES;
[service setDelegate:delegatePublisherObject];// 5
[service publishWithOptions:NSNetServiceListenForConnections];
And clients who search for game sessions around :
serviceBrowser = [[NSNetServiceBrowser alloc] init];
serviceBrowser.includesPeerToPeer = YES;
[serviceBrowser setDelegate:delegateBrowserObject];
[serviceBrowser searchForServicesOfType: CreateNSString(service) inDomain:#"local"];
But i have an issue with the data transfer between them. What i did from now, is :
i queued the data i want to send. If i can write it directly in the output stream i do
dataWriteQueue insertObject:data atIndex:0];
if (flag_canSendDirectly)
[self _sendData];
...
- (void)_sendData {
NSData *data = [dataWriteQueue lastObject];
flag_canSendDirectly = NO;
if (data == nil)
{
flag_canSendDirectly = YES;
return;
}
bufferToSend = (uint8_t *)[data bytes];
NSInteger bytesWritten;
bytesWritten = [_outputStream write:bufferToSend maxLength:dataBufferLimit - currentDataOffset];
if the callback NSStreamEventHasSpaceAvailable is called i send the last pieces of data queued.
case NSStreamEventHasSpaceAvailable: {
if (stream == _outputStream)
{
//read a new chunk of data
[self _sendData];
}
} break;
I have stopped the browsing of devices when i transfer data between peers.
The transfer is done well. But my issue here is that the transfer is pretty fast in bluetooth. But slower in wifi. I don't understand this, it doesn't seems logical. Do you have any clues about this issue ? The browsing is shut down when the peers are connected.

Related

Not able to receive response of the sent UDP packets using GCDAsyncSocket

I am making an app to send UDP packets in order to switch on a LED bulb. I have been able to perform all the actions when I am connecting to the Ad-hoc created by the Wifi bridge.
Now, I want to configure the Wifi bridge so that it can connect to my main router. I have the AT command set to perform this procedure but somehow I am not able to receive the response form the Wifi bridge for the commands which I am sending to it.
The procedure is as follows:-
Step 1 : Send UDP message to the LAN broadcast IP address of "10.10.100.255" and port of 48899 => "Link_Wi-Fi"
All Wifi bridges on the LAN will respond with their details. Response is "10.10.100.254, ACCF232483E8"
Step 2 : (optional for changing settings on the wifi bridge): Then send "+ok" to the LimitlessLED Wifi Bridge. Send UDP message to the response IP address returned from step 1 "10.10.100.254" => "+ok"
Step 3 : (optional for changing settings on the wifi bridge): After that you may send AT commands (ending with \r\n) to the module.
The code for sending the UDP packets is as follows
-(void)configureWifi{
counter++;
NSString *host = #"10.10.100.255";
if ([host length] == 0)
{
[self logError:#"Address required"];
return;
}
int port = 48899; //[portField.text intValue];
if (port <= 0 || port > 65535)
{
[self logError:#"Valid port required"];
return;
}
NSString *msg = #"Link_Wi-Fi";
NSData *data = [msg dataUsingEncoding:NSUTF8StringEncoding];
NSLog(#"the message sent is %#", data);
[udpSocket sendData:data toHost:host port:port withTimeout:-1 tag:tag];
}
Now in order to setup the socket and to receive the data I am using these two delegate methods:
- (void)setupSocket
{
// Setup our socket.
// The socket will invoke our delegate methods using the usual delegate paradigm.
// However, it will invoke the delegate methods on a specified GCD delegate dispatch queue.
//
// Now we can configure the delegate dispatch queues however we want.
// We could simply use the main dispatc queue, so the delegate methods are invoked on the main thread.
// Or we could use a dedicated dispatch queue, which could be helpful if we were doing a lot of processing.
//
// The best approach for your application will depend upon convenience, requirements and performance.
//
// For this simple example, we're just going to use the main thread.
udpSocket = [[GCDAsyncUdpSocket alloc] initWithDelegate:self delegateQueue:dispatch_get_main_queue()];
NSError *error = nil;
if (![udpSocket bindToPort:0 error:&error])
{
[self logError:FORMAT(#"Error binding: %#", error)];
return;
}
if (![udpSocket beginReceiving:&error])
{
[self logError:FORMAT(#"Error receiving: %#", error)];
return;
}
[self logInfo:#"Ready"];
}
and to Receive data this is the method which is note getting called after sending the UDP packets. This is the delegate method of the GCDAsyncUdpSocket class which I have used in my project in order to send and receive the UDP packets.
- (void)udpSocket:(GCDAsyncUdpSocket *)sock didReceiveData:(NSData *)data
fromAddress:(NSData *)address
withFilterContext:(id)filterContext
{
NSString *msg = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
if (msg)
{
[self logMessage:FORMAT(#"RECV: %#", msg)];
}
else
{
NSString *host = nil;
uint16_t port = 0;
[GCDAsyncUdpSocket getHost:&host port:&port fromAddress:address];
[self logInfo:FORMAT(#"RECV: Unknown message from: %#:%hu", host, port)];
}
}
Once I am able to receive the response I will be able to send the next AT commands in order to configure the Bridge.
Thanks. Any help will be appreciated.
Here are the troubleshooting steps I recommend that you use :
1- I'm assuming you are using ARC so make sure that your udpSocket variable has a strong reference throughout the asynchronous communication. If it is being freed, then that could explain the absence of a callback.
2- Make sure the communication is really happening the way you think it is. Use a software such as Wireshark to capture the packets being exchanged on the network. This should allow you to confirm that your packets do get sent upon calling sendData: and it will also allow you to confirm whether or not you are getting a reply back.
3- Make sure you are using the GCDAsyncUdpSocket properly. Considering you want to broadcast a message, you shouldn't be calling bindToPort:error: in your setupSocket method. Instead you should be calling enableBroadcast:error:. Considering you also want to receive packets after broadcasting, you should use the connectToHost:onPort:error: method to change the state of the socket to allow for bidirectional communication. After that is done, you can replace your usage of sendData:toHost:port:withTimeout:tag: by sendData:withTimeout:tag:. Finally, you can call beginReceiving: so that the delegate gets called for any incoming packets.
4- If this still doesn't get you through it, I recommend that you read throughly the documentation of the GCDAsyncUdpSocket which is very well documented.
You can trouble shoot the problem using Wireshark or any network capture tool.
We use to work in similar kind of project where we used Wireshark extensively.
If packet has reached device(Z-Wave ) it will send out some sort of Ack.
this will help to make sure packets are getting out.

SocketRocket scan network and connect

I'm new to SocketRocket and what I want to do is to scan the network 192.168.1.x and when it finds the server connect to it.
this is my code:
NSString *seg=#"ws://192.168.1.";
NSString *puerto=#":5000";
self.socketReady = NO;
for (int i=0; i<255; i++) {
NSMutableString *ip =[[NSMutableString alloc]init];
[ip appendString:seg];
[ip appendString:[#(i) stringValue]];
[ip appendString:puerto];
self.serverSocket = [[SRWebSocket alloc] initWithURL:[[NSURL alloc] initWithString:ip]];
self.serverSocket.delegate = self;
[self.serverSocket open];
}
I know that [self.serverSocket open] can only be done once, but I don't know how to scan and then connect to the server.
[self.serverSocket open] is an asynchronous call - that is, it will immediately return, with your delegate method webSocketDidOpen: being called when/if the socket successfully connects or didFailWithError: if it doesn't.
You could change you loop so that it used a local variable rather than your property -
NSString *seg=#"ws://192.168.1.";
int puerto=5000;
for (int i=0; i<255; i++) {
NSString *ip =[NSString stringWithFormat:#"%#%d:%d",seg,i,puerto];
SRWebSocket *newSocket = [[SRWebSocket alloc] initWithURL:[[NSURL alloc] initWithString:ip]];
newSocket.delegate = self;
[newSocket open];
}
and then in the delegate method you would need to store the socket that connected successfully -
- (void)webSocketDidOpen:(SRWebSocket *)webSocket
{
self.serverSocket=webSocket;
//TO DO start processing data on the socket...
}
BUT this is a pretty ugly way of locating and connecting to a service:
It 'spams' the local network with multiple connection requests
It wastes a considerable amount of resources on your local device
It doesn't handle the case where there are multiple services/servers running on your port on different devices
What if the local network isn't 192.168.1.x ?
You should investigate other options for identifying your servers address such as Bonjour or even a simple application preference to set the server address

Sending multiple UDP packets with CocoaAsyncSocket

I have a lot of switches in my network which I try to check if they are online. I do this with a small UDP packet to which they respond with an UDP packet of their own to tell me that they are there. In fact it is only one switch simulating 200 hundred for testing but this is not important.
Since I do not like to work low level if I don't have to I use https://github.com/robbiehanson/CocoaAsyncSocket for the UDP thing.
It works... almost. When I ping for example 10 switches repeatedly (I ping them at the same time and then wait for all the responses) it seems to work for the first cycles but then after a few it gets out of hand and almost all seem to not be responding. It is completely random which are and which not. It gets worse when I add more switches (meaning it does not work from the first cycle). With cycles I man: I send pings for all switches an then wait for all the answers (or timeouts) and then send the pings again.
When I check my network traffic with a packet sniffer I see that for the "wrong" switches (meaning they are shown as offline == timeout, but are actually online) there are three possible cases for each switch:
The packet from the iPhone is never send so no answer is received.
The iPhone send the packet but the switch did not respond.
The answer packet is received but the iPhone didn't read it.
It's completely random and they are mixed in one cycle.
When all the switches are actually online the problem is minimized (takes more cycles to appear) but still there .
Since the code is asynchronous there is a high potential for bugs and I think there must be some kind of race condition or something.
I will post my ping class here. It is not very complicated. I stared at this for hours but could not find a bug.
The usage is the following:
You create an instance with:
- (id)initWithTimeout:(NSTimeInterval)timeout delegate:(id<NMASwitchPingerDelegate>)delegate;
Than you just call the following method for every ipAddress you want to ping. The method returns immediately. This means the pings are processed concurrently:
- (void)sendPingToAddress:(NSString*)address;
I added it to a paste bin for your convenience: http://pastebin.com/0LuiXsXY
#import "NMASwitchPinger.h"
/**
* Private interface.
*/
#interface NMASwitchPinger () {
/**
* The delegate of this class.
*/
__weak id<NMASwitchPingerDelegate> delegate;
/**
* The timeout after which the pinger stops waiting for a response.
*/
NSTimeInterval timeout;
/**
* The socket which is used to send the ping.
*/
GCDAsyncUdpSocket *socket;
/**
* List of pings which are awaiting a response.
*/
NSMutableDictionary *pendingPings;
/**
* Dispatch queue which serializes access to the pendingPings dictionary.
*/
dispatch_queue_t pendingPingsAccessQueue;
/**
* The queue on which the delegate methods of the socket are executed.
*/
dispatch_queue_t socketDelegateQueue;
/**
* Is set to true when the SwitchPinger started receiving responses (after first send)
*/
bool receiving;
}
#end
#implementation NMASwitchPinger
#pragma mark - Initialization
- (id)initWithTimeout:(NSTimeInterval)newTimeout delegate:(id<NMASwitchPingerDelegate>)newDelegate {
self = [super init];
if (self) {
// setting passed values
timeout = newTimeout;
delegate = newDelegate;
// init data structures
pendingPings = [[NSMutableDictionary alloc] init];
pendingPingsAccessQueue = dispatch_queue_create("de.nexans-ans.pingerPendingAccess", DISPATCH_QUEUE_SERIAL);
// create the socket for udp sending
socketDelegateQueue = dispatch_queue_create("de.nexans-ans.pingerDelegate", DISPATCH_QUEUE_CONCURRENT);
socket = [[GCDAsyncUdpSocket alloc] initWithDelegate:self delegateQueue:socketDelegateQueue];
}
return self;
}
- (id)init {
NSAssert(NO, #"Use the designated initializer");
return nil;
}
#pragma mark - Sending a ping
- (void)sendPingToAddress:(NSString *)address {
// we allow only one ping at a time to the same ip
__block BOOL alreadyInList = NO;
dispatch_sync(pendingPingsAccessQueue, ^{
if (pendingPings[address]) {
alreadyInList = YES;
} else {
pendingPings[address] = [[NSDate alloc] init];
}
});
// don't send a second ping to the same address
if (alreadyInList) {
NSLog(#"SimplePinger: did not send ping because already a ping pending to this addres: %#", address);
return;
}
// create a minimal packet (3 bytes)
NSMutableData *packet = [[NSMutableData alloc] initWithCapacity:3];
uint16_t vendor_value = CFSwapInt16HostToBig(266);
uint8_t request_type = 1;
[packet appendBytes:&vendor_value length:sizeof(vendor_value)];
[packet appendBytes:&request_type length:sizeof(request_type)];
// send over the wire
[socket sendData:packet toHost:address port:50266 withTimeout:timeout tag:0];
// schedule timeout handler
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(timeout * NSEC_PER_SEC));
dispatch_after(popTime, pendingPingsAccessQueue, ^(void){
[self removeTimedOutPingWithAddress:address];
});
// start receiving when not already receiving
if (!receiving) {
bool recvGood = [socket beginReceiving:nil];
NSAssert(recvGood, #"SimplePinger: could not start receiving");
receiving = YES;
}
}
#pragma mark - GCDAsyncSocket delegate
- (void)udpSocket:(GCDAsyncUdpSocket *)sock didReceiveData:(NSData *)data fromAddress:(NSData *)address withFilterContext:(id)filterContext {
NSString *ipAddress = [GCDAsyncUdpSocket hostFromAddress:address];
__block BOOL pingStillPending = NO;
dispatch_sync(pendingPingsAccessQueue, ^{
NSDate *sendDate = pendingPings[ipAddress];
if (sendDate) {
[pendingPings removeObjectForKey:ipAddress];
pingStillPending = YES;
}
});
if (pingStillPending) {
dispatch_async(dispatch_get_main_queue(), ^{
[delegate switchPinger:self didReceiveResponse:data fromAddress:ipAddress];
});
}
}
- (void)udpSocket:(GCDAsyncUdpSocket *)sock didNotSendDataWithTag:(long)tag dueToError:(NSError *)error {
NSLog(#"didnt send data");
}
- (void)udpSocket:(GCDAsyncUdpSocket *)sock didSendDataWithTag:(long)tag {
NSLog(#"did send");
}
#pragma mark - Private methods
/**
* Removes a timed out ping. A call of this function gets scheduled when a ping is send.
*
* #param address The address of the ping which should be removed.
*/
- (void)removeTimedOutPingWithAddress:(NSString*)address {
NSDate *sendDate = pendingPings[address];
if (sendDate) {
NSLog(#"timeout: %#", address);
NSAssert(fabs([sendDate timeIntervalSinceNow]) >= timeout, #"SimplePing: removed ping before timout");
[pendingPings removeObjectForKey:address];
dispatch_async(dispatch_get_main_queue(), ^{
[delegate switchPinger:self didReceiveTimeoutFromAddress:address];
});
}
}
#end

Problems with GKSession and sendDataToAllPeers:withDataMode:error:

Alright, this involves a lot of network coding from this part of a multiplayer tutorial.
Basically, I'm trying to implement a multiplayer game using GameKit as per the tutorial linked above. I put in all of the necessary network coding and more or less understand it, however I've hit a snag somewhere along the line of method calls. Basically, the setup that I have is that one device acts as the host and the rest act as the clients. I have two separate UIViewcontrollers for the host and clients respectively where the connection is established.
Now the thing is, the connection gets established, but it's only the host that recognizes the connection, not the client. The problem is here:
- (void)sendPacketToAllClients:(Packet *)packet
{
[_players enumerateKeysAndObjectsUsingBlock:^(id key, Player *obj, BOOL *stop)
{
obj.receivedResponse = [_session.peerID isEqualToString:obj.peerID];
}];
GKSendDataMode dataMode = GKSendDataReliable;
NSData *data = [packet data];
NSError *error;
if (![_session sendDataToAllPeers:data withDataMode:dataMode error:&error])
{
NSLog(#"Error sending data to clients: %#", error);
}
}
This is implemented in GameMultiplayer, where the actual game will be implemented. What this method is supposed to be doing is sending data packets to each of the clients saying that the host received the connection request and is able to connect with them. After [_session sendDataToAllPeers:data withDataMode:dataMode error:&error] is called (the method in the if statement), this method is supposed to be triggered:
- (void)receiveData:(NSData *)data fromPeer:(NSString *)peerID inSession:(GKSession *)session context:(void *)context
{
#ifdef DEBUG
NSLog(#"Game: receive data from peer: %#, data: %#, length: %d", peerID, data, [data length]);
#endif
Packet *packet = [Packet packetWithData:data];
if (packet == nil)
{
NSLog(#"Invalid packet: %#", data);
return;
}
Player *player = [self playerWithPeerID:peerID];
if (player != nil)
{
player.receivedResponse = YES; // this is the new bit
}
if (self.isServer)
[self serverReceivedPacket:packet fromPlayer:player];
else
[self clientReceivedPacket:packet];
}
This method is in the next part of the tutorial I linked above (which is here) and is supposed to receive the packets that the host sends to all clients and implement the next methods in this networking chain. However, the method never gets called. No debug breakpoints are triggered and I get nothing in the console.
I understand if I need to provide more source material, but there is a lot of network coding already implemented, so I want to keep it down to what people need to see. Also, [_session setDataReceiveHandler:self withContext:nil] and _session.delegate = self are written in another method that is called in GameMultiplayer, so that's not the problem. Does anyone know what I need to fix?
EDIT: As requested, here's where GKSession is initialized:
#property (nonatomic, strong, readonly) GKSession *session; //This is done in the header file
#synthesize session = _session; //This is done in the main file
- (void)startAcceptingConnectionsForSessionID:(NSString *)sessionID
{
if (_serverState == ServerStateIdle)
{
_serverState = ServerStateAcceptingConnections;
_connectedClients = [NSMutableArray arrayWithCapacity:self.maxClients];
_session = [[GKSession alloc] initWithSessionID:sessionID displayName:nil sessionMode:GKSessionModeServer];
_session.delegate = self;
_session.available = YES;
}
}
The session is initialized in MatchmakingServer, which is used in the host view controller. The session is then passed on to the main view controller of the app, which then initializes GameMultiplayer and sends the GKSession to it. Here's where the host view controller sends it to the main view controller:
- (IBAction)startAction:(id)sender
{
if (_matchmakingServer != nil && [_matchmakingServer connectedClientCount] > 0)
{
NSString *name = [self.nameTextField.text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
if ([name length] == 0)
name = _matchmakingServer.session.displayName;
[_matchmakingServer stopAcceptingConnections];
[self.delegate hostViewController:self startGameWithSession:_matchmakingServer.session playerName:name clients:_matchmakingServer.connectedClients];
}
}
and then the main view controller handles that method call here:
- (void)hostViewController:(MatchmakerHost *)controller startGameWithSession:(GKSession *)session playerName:(NSString *)name clients:(NSArray *)clients
{
[self dismissViewControllerAnimated:NO completion:^
{
[self startGameWithBlock:^(GameMultiplayer *aGame)
{
[aGame startServerGameWithSession:session playerName:name clients:clients];
}];
}];
}
and finally, this is where that method call is implemented in GameMultiplayer:
- (void)startServerGameWithSession:(GKSession *)session playerName:(NSString *)name clients:(NSArray *)clients
{
_clients = clients;
const char* className = class_getName([[_clients objectAtIndex:0] class]);
NSLog(#"yourObject is a: %s", className);
self.isServer = YES;
_session = session;
_session.available = NO;
_session.delegate = self;
[_session setDataReceiveHandler:self withContext:nil];
_state = GameStateWaitingForSignIn;
[self.delegate gameWaitingForClientsReady:self];
// Create the Player object for the server.
Player *player = [[Player alloc] init];
player.name = name;
player.peerID = _session.peerID;
player.position = PlayerPositionBottom;
[_players setObject:player forKey:player.peerID];
// Add a Player object for each client.
int index = 0;
for (NSString *peerID in clients)
{
Player *player = [[Player alloc] init];
player.peerID = peerID;
[_players setObject:player forKey:player.peerID];
if (index == 0)
player.position = ([clients count] == 1) ? PlayerPositionTop : PlayerPositionLeft;
else if (index == 1)
player.position = PlayerPositionTop;
else
player.position = PlayerPositionRight;
index++;
}
NSLog(#"Players:");
Packet *packet = [Packet packetWithType:PacketTypeSignInRequest];
[self sendPacketToAllClients:packet];
// for (int i = 0; i < [_players count]; i++) {
// NSLog([NSString stringWithFormat:#"%#", [clients objectAtIndex:i]]);
// }
}
I think you are calling send to fast. When server realize about connection it will send confirmation to client to really establish connection - so client knows about it succeed.
If you are sending packets before that happens - it will be lost.
Just do this:
[self performSelector:#selector(sendPacketToAllClients) withObject:nil afterDelay:1.0];
instead of:
[self sendPacketToAllClients];
I had the same problem that connection is established in different moment with small delay on client. The best is to send first packet from client that he is ready to receive packets from server - and than proceed normally from there.
Also try debugging:
- (void)session:(GKSession *)session peer:(NSString *)peerID didChangeState:(GKPeerConnectionState)state
On both devices (server and client).
I have also had my troubles with GKSession. I was interested to learn (on this site) today that GKSession is being deprecated in favor of using the Multipeer Connectivity Framework. With luck, Wenderlich et al. will do a tutorial using the new technology. :)
The system has some similarities to GKSession, so is not too hard to wrap your head around.
Apple's doc link.

GKSession - kill and renew session

In order to read a new display name of a peer I need to kill and renew the GKSession. Setting it to nil and initiate it anew does not work. In the code below, the NSLog in the for-loop to show the available peers is not called (there's no error message):
-(IBAction) btnRefresh:(id) sender {
self.currentSession = nil;
self.currentSession = [[GKSession alloc] initWithSessionID:#"anything" displayName:name sessionMode:GKSessionModePeer];
self.currentSession.delegate = self;
self.currentSession.available = YES;
self.currentSession.disconnectTimeout = 0;
[self.currentSession setDataReceiveHandler:self withContext:nil];
peerListAvailable = [[NSMutableArray alloc] initWithArray:[currentSession peersWithConnectionState:GKPeerStateAvailable]];
for (NSString *peer in peerListAvailable) {
NSLog(#"found available peer; checking name and ID... %#, %#",[currentSession displayNameForPeer:peer], peer);
}
What is wrong with setting the currentSession to nil and initiate it anew?
Maybe you know of another way to renew a GKSession?
Thanks very much in advance.
The following methods illustrate GKSession setup and teardown:
- (void)setupSession
{
gkSession = [[GKSession alloc] initWithSessionID:nil displayName:nil sessionMode:GKSessionModePeer];
gkSession.delegate = self;
gkSession.disconnectTimeout = 5;
gkSession.available = YES;
}
- (void)teardownSession
{
gkSession.available = NO;
[gkSession disconnectFromAllPeers];
}
If you're interested in delving deeper, take a look at GKSessionP2P, a demo app that illustrates the ad-hoc networking features of GKSession. The app both advertises itself on the local network and automatically connects to available peers, establishing a peer-to-peer network.

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