Networking

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Explore the networking protocols and technologies used by the device to connect to Wi-Fi networks, Bluetooth devices, and cellular data services.

Networking Documentation

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How to avoid my local server flows in Transparent App Proxy
I have written the Transparent App Proxy and can capture the network flow and send it to my local server. I want to avoid any processing on the traffic outgoing from my server and establish a connection with a remote server, but instead of connecting to the remote server, it again gets captured and sent back to my local server. I am not getting any clue on how to ignore these flows originating from my server. Any pointers, API, or mechanisms that will help me?
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165
Apr ’25
Wi-Fi Aware Sample doesn't build in Xcode 26.0 beta
Hello, I'm trying to build the sample app from Building peer-to-peer apps that demonstrates Wi-Fi Aware. Upon downloading the example source code, opening it in Xcode 26.0 beta, and building the app, the compiler fails with: DeviceDiscoveryPairingView.swift:8:8 No such module 'DeviceDiscoveryUI' Is this a known issue? I know that DeviceDiscoveryUI was previously only a tvOS capability. Thanks
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118
Jun ’25
Local Network permission prompt for daemon on macOS 15
Hi Team, OS is prompting for local network permission for our application which runs as root level daemon. As per the our analysis, it looks like it is prompting from our own library which is trying to get network info ' using /usr/sbin/system_profiler with "-xml -detailLevel basic SPNetworkDataType" and then trying to iterate to find DNS.ServerAddresses for each item. Then using [NSHost hostWithAddress:IPAddress];(When this library is not linked to the app then there is no prompt, so most likely this is the code that is resulting in the prompt). Is this expected ? . Is there any other way that we can get DNS host name without being prompted for local network permission on mac OS 15
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4.0k
Feb ’25
URLCache behavior for request with different header values
Greetings, I would like to understand this URLCache behavior for two different requests to the same end point but with a different header value. Here is a code with comment explaining the behavior. // Create a request to for a url. let url = URL(string: "https://<my url>?f=json")! var request = URLRequest(url: url) // Set custom header with a value. request.setValue("myvalue", forHTTPHeaderField: "CustomField") // Send request to get the response. let (data, response) = try await URLSession.shared.data(for: request) print("data: \(String(describing: String(data: data, encoding: .utf8)))") print("response: \(response)") // Create second request to the same url but with different value of custom header field. var request2 = URLRequest(url: url) request2.setValue("newvalue", forHTTPHeaderField: "CustomField") // Check the URL cache for second request and it returns the response // of the first request even though the second request has different header value. let cachedResponse = URLCache.shared.cachedResponse(for: request2) print("cachedResponse: \(cachedResponse?.response)") Is this a bug in URLCache that request headers are not matched while returning the response? Is this an expected behavior? If yes, why?
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1.5k
3w
Getting list of wifi networks nearby with a specific prefix
I'm building an app that helps manage my own wifi access points. Now, all my wifis emit SSIDs starting with the same prefix. Is it possible for me to list down all the SSIDs near me that start with that prefix, so that determine which of my wifis are near me? (Swift) Can NEHotspotHelper or NEHotspotConfigurationManager help in this regard?
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283
Feb ’25
Need help on MDM Profile for Transparent Proxy
We have an application which is written in Swift, which activates two network extensions (Content Filter, Transparent Proxy). We want to use MDM deployment for these network system extensions. For Content Filter, we already have Jamf Profile which has Web Content Filter payload and it works fine. Our Transparent Proxy module is a system extension, which is exposing an app proxy provider interface (We are using NETransparentProxyProvider class and in extension’s Info.plist we use com.apple.networkextension.app-proxy key.) We don’t have any remote server setup to forward the traffic, instead we open a connection with a certain localhost:port to redirect the traffic which is received in our transparent proxy. We have another module that listens to the particular localhost:port to process the traffic further. We are unable to find the appropriate payload in any of the Profile Editor applications like Apple Configurator, iMazing Profile Editor and Jamf Pro that correctly describes our setup. As per https://developer.apple.com/documentation/devicemanagement/vpn/transparentproxy documentation, we noticed that we can use the VPN payload with app-proxy as Provider Type for Transparent Proxy. Here are the list of issues encountered with different MDM solutions. **AppleConfigurator: ** We were able to install the profile created via Apple Configurator. However when we install our product (which has the above mentioned system extensions), the Transparent Proxy added by our product fails to map with the installed profile. User has to provide the credentials and follow the steps while installing the extension via the product. Attached the screenshot of "Network->Filters" screen and the profile for reference. Profile Created using Apple Configurator iMazing Profile Editor: Unable to install the profile created using iMazing Profile Editor. Attached the screenshot of error and the profile for reference: Profile Created Using iMazing Profile Editor Jamf Pro: We were able to install the profile created via Jamf Pro and also while in stalling our product the Transparent Proxy gets mapped with the one which is installed via profile. However after that the network is broken and hence unable to browse anything. Attached the profile for reference. Profile Created using Jamf Pro What should be the correct profile payload to use for our Transparent Proxy?
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586
Feb ’25
Qt C++ executable and Local network access issues on macOS Sequoia
Hello, I have a Qt c++ executable that accesses a server backend on my local network. After building the executable, I can run it either from within the Qt Creator IDE, OR I can run it from the command line. When I launch from within the Qt Creator IDE, the same executable cannot talk to the backend server on my local network. However, the same executable when launched from the command line works fine. This started only with macOS Sequoia and the new "Local Network" permission. How can I get my IDE launched executable to work? Otherwise I cannot continue my app development.
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651
Sep ’24
Does URLSession support ticket-based TLS session resumption
My company has a server that supports ticket-based TLS session resumption (per RFC 5077). We have done Wireshark captures that show that our iOS client app, which uses URLSession for REST and WebSocket connections to the server, is not sending the TLS "session_ticket" extension in the Client Hello package that necessary to enable ticket-based resumption with the server. Is it expected that URLSession does not support ticket-based TLS session resumption? If "yes", is there any way to tell URLSession to enable ticket-based session resumption? the lower-level API set_protocol_options_set_tls_tickets_enabled() hints that the overall TLS / HTTP stack on IOS does support ticket-based resumption, but I can't see how to use that low-level API with URLSession. I can provide (lots) more technical details if necessary, but hopefully this is enough context to determine whether ticket-based TLS resumption is supported with URLSession. Any tips / clarifications would be greatly appreciated.
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614
Aug ’25
Issue with Multicast Response via NWConnectionGroup Behind a Firewall
Hello Everyone, I’m working on a project that involves multicast communication between processes running on different devices within the same network. For all my Apple devices (macOS, iOS, etc.), I am using NWConnectionGroup, which listens on a multicast address "XX.XX.XX.XX" and a specific multicast port. The issue occurs when a requestor (such as a non-Apple process) sends a multicast request, and the server, which is a process running on an Apple device using NWConnectionGroup (the responder), attempts to reply. The problem is that the response is sent from a different ephemeral port rather than the port on which the multicast request was received. If the client is behind a firewall that blocks unsolicited traffic, the firewall only allows incoming packets on the same multicast port used for the initial request. Since the multicast response is sent from a different ephemeral port, the firewall blocks this response, preventing the requestor from receiving it. Questions: Is there a recommended approach within the NWConnectionGroup or Network.framework to ensure that responses to multicast requests are sent from the same port used for the request? Are there any best practices for handling multicast responses in scenarios where the requestor is behind a restrictive firewall? Any insights or suggestions on how to account for this behavior and ensure reliable multicast communication in such environments would be greatly appreciated. Thanks, Harshal
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552
May ’25
App does not wake up in the background when using AccessorySetupKit and Bluetooth background modes
I'm building a bluetooth device that is connected to my app. The device I'm building will be connected to the phone as much as possible, and when the user leaves the device's range and then comes back later, I expect the OS to wake the app up when it reconnects in the background using the CoreBluetooth willRestoreState wake up method. Using just CoreBluetooth for pairing, I've confirmed that the phone will reconnect to the device while in the background and the app gets woken up when that happens. I'm hoping to use ASK for pairing instead as it's a much nicer user experience. When I initiate and confirm pairing via ASK, I can see that it's connected and paired successfully and I see my device and app connected as I expect. But when the device goes away, and the app has been in the background, and then I come in range of the phone, the device never reconnects automatically in Bluetooth settings. When I manually tap the device in settings to connect, it does connect, but I don't think my app gets woken up and restored as I don't see the requests I expect happening when it's in the background. Does ASK support scanning for peripherals via CoreBluetooth while in the background, or automatic reconnection? I assumed that when my app is launched, I activate the ASAccessorySession session, and the .activated callback will fire, but I'm not seeing that happen.
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370
Dec ’24
First update to NWBrowser is always ready, irrespective of Local Networking privacy status
I'm trying to detect the state of Local Network privacy on macOS Sequoia via NWBrowser, as recommended in https://developer.apple.com/documentation/technotes/tn3179-understanding-local-network-privacy Regardless of the state of Local Network privacy - undetermined, allowed or denied, NWBrowser receives an update indicating that its in the ready state. Scanning does not seem to trigger the Local Network privacy alert for me - I have to use the other recommended method to trigger the prompt. Enabling or disabling Local Network privacy does not seem to send any updates for NWBrowser. https://developer.apple.com/forums/thread/666431 seems related, and implies that they did receive further updates to NWBrowser. Filed as FB16077972
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741
Jan ’25
NWConnection is crashed on iOS 15 and 16, but it works well on 17
Hello 👋 I need to implement a logic for searching for devices with our own service type using Bonjour. Using the NWBrowser, I can receive a list of all devices and connect to them. I need to utilize a WebSocket connection. By the property endpoint of NWBrowser.Result objects I can create NWConnection. Below is my implementation which works fine on iOS 17: let params = NWParameters.tcp let webSocketOptions = NWProtocolWebSocket.Options() params.defaultProtocolStack.applicationProtocols.insert(webSocketOptions, at: 0) // The `endpoint` is from `browseResultsChangedHandler` of NWBrowser let connection = NWConnection(to: endpoint, using: params) However, it doesn't work on iOS 15 and 16 because of the crash: 2024-06-01 16:07:18.136068+0300 MyApp[591:16845549] [] nw_endpoint_get_url called with null endpoint 2024-06-01 16:07:18.136932+0300 MyApp[591:16845549] [] nw_endpoint_get_url called with null endpoint, dumping backtrace: [arm64] libnetcore-3100.102.1 0 Network 0x000000018530e174 __nw_create_backtrace_string + 188 1 Network 0x000000018538ba20 nw_endpoint_get_url + 852 2 Network 0x0000000185310020 nw_ws_create_client_request + 84 3 Network 0x0000000184f4b3cc __nw_ws_create_state_block_invoke + 416 4 Network 0x000000018504bc68 nw_protocol_options_access_handle + 92 5 Network 0x0000000184f41e98 nw_ws_create_state + 204 6 Network 0x0000000184f41aec __nw_protocol_copy_ws_definition_block_invoke_2 + 176 7 Network 0x0000000184f69188 nw_framer_protocol_connected + 348 8 Network 0x00000001854a6638 _ZL29nw_socket_handle_socket_eventP9nw_socket + 1560 9 libdispatch.dylib 0x0000000126b89d50 _dispatch_client_callout + 16 10 libdispatch.dylib 0x0000000126b8d208 _dispatch_continuation_pop + 756 11 libdispatch.dylib 0x0000000126ba48d4 _dispatch_source_invoke + 1676 12 libdispatch.dylib 0x0000000126b94398 _dispatch_workloop_invoke + 2428 13 libdispatch.dylib 0x0000000126ba0b74 _dispatch_workloop_worker_thread + 1716 14 libsystem_pthread.dylib 0x000000012371f814 _pthread_wqthread + 284 15 libsystem_pthread.dylib 0x000000012371e5d4 start_wqthread + 8 Also, there is the stack trace of bt-command in the debug console: * thread #20, queue = 'com.apple.network.connections', stop reason = EXC_BAD_ACCESS (code=1, address=0x0) * frame #0: 0x0000000123078c24 libsystem_platform.dylib`_platform_strlen + 4 frame #1: 0x00000001803c538c CoreFoundation`CFStringCreateWithCString + 40 frame #2: 0x0000000185310030 Network`nw_ws_create_client_request + 100 frame #3: 0x0000000184f4b3cc Network`__nw_ws_create_state_block_invoke + 416 frame #4: 0x000000018504bc68 Network`nw_protocol_options_access_handle + 92 frame #5: 0x0000000184f41e98 Network`nw_ws_create_state + 204 frame #6: 0x0000000184f41aec Network`__nw_protocol_copy_ws_definition_block_invoke_2 + 176 frame #7: 0x0000000184f69188 Network`nw_framer_protocol_connected + 348 frame #8: 0x00000001854a6638 Network`nw_socket_handle_socket_event(nw_socket*) + 1560 frame #9: 0x0000000126b89d50 libdispatch.dylib`_dispatch_client_callout + 16 frame #10: 0x0000000126b8d208 libdispatch.dylib`_dispatch_continuation_pop + 756 frame #11: 0x0000000126ba48d4 libdispatch.dylib`_dispatch_source_invoke + 1676 frame #12: 0x0000000126b94398 libdispatch.dylib`_dispatch_workloop_invoke + 2428 frame #13: 0x0000000126ba0b74 libdispatch.dylib`_dispatch_workloop_worker_thread + 1716 frame #14: 0x000000012371f814 libsystem_pthread.dylib`_pthread_wqthread + 284 I have found out a couple things: There are no crashes if I initialize the NWConnection object with using, for instance, the NWEndpoint.url(_:). initializer: let urlHost = URL(string: "ws://10.20.30.40:5060")! let endpoint = NWEndpoint.url(urlHost) let params = NWParameters.tcp let webSocketOptions = NWProtocolWebSocket.Options() params.defaultProtocolStack.applicationProtocols.insert(webSocketOptions, at: 0) let connection = NWConnection(to: endpoint, using: params) self.connection = connection But, in this case, I must extract IP-addresses 🙇‍♂️ Meanwhile, there is a topic such as Don’t Try to Get the Device’s IP Address.. I have tried to find anything that could help me move forward in this problem and run into some odd behaviour. There is a property skipHandshake of NWProtocolWebSocket.Options object. If I set the property value to true, there are no crashes as well as no connection to a device.
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1
964
Oct ’24
No internet connection on wireguard per-app vpn in ios
I am integrating per-app VPN functionality into an iOS app using Wireguard. Chrome is designated as a per-app application for this purpose. However, upon opening Chrome, the VPN icon appears in the notification bar, but there is no internet connection within the Chrome browser. I have verified this behavior with OpenVPN, and it works correctly. While I am familiar with the MDM payload and how to implement per-app VPN, my primary concern is understanding why per-app VPN functionality is not functioning as expected with WireGuard. An observation we made in the server-side logs is the message: "wireguard: wg0: Packet has incorrect size from peer 1"
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1
1.1k
Feb ’25
Crash within com.apple.CFNetwork.Connection , specifically due to EXC_BAD_ACCESS KERN_INVALID_ADDRESS.
Crash within com.apple.CFNetwork.Connection , specifically due to EXC_BAD_ACCESS KERN_INVALID_ADDRESS. The crash occurred within the nghttp2_session_del() function indicating a problem with the nghttp2 library, which is commonly used for HTTP/2 communication. This points towards a memory management issue. EXC_BAD_ACCESS generally signifies that the application attempted to access memory it didn't have permission to access, often caused by using a pointer after it has been freed or pointing to an invalid memory address. ** Crashed: com.apple.CFNetwork.Connection 0 libapple_nghttp2.dylib 0xa6ec nghttp2_session_del + 124 1 CFNetwork 0xace4c + 428 2 CFNetwork 0xacc80 + 36 3 libdispatch.dylib 0x2370 _dispatch_call_block_and_release + 32 4 libdispatch.dylib 0x40d0 _dispatch_client_callout + 20 5 libdispatch.dylib 0xb6d8 _dispatch_lane_serial_drain + 744 6 libdispatch.dylib 0xc214 _dispatch_lane_invoke + 432 7 libdispatch.dylib 0xd670 _dispatch_workloop_invoke + 1732 8 libdispatch.dylib 0x17258 _dispatch_root_queue_drain_deferred_wlh + 288 9 libdispatch.dylib 0x16aa4 _dispatch_workloop_worker_thread + 540 10 libsystem_pthread.dylib 0x4c7c _pthread_wqthread + 288 11 libsystem_pthread.dylib 0x1488 start_wqthread + 8 ** The stack trace does not point to any code within our product codebase, hence making it difficult to pinpoint the root cause of the issue as there are multiple network calls running concurrently during the app's runtime.
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403
Jan ’25
Add "local network access" permission for macOS 15 runners
Hi, We have an issue (https://github.com/actions/runner-images/issues/10924) raised by a user requesting to add 'local network access' permission for macOS 15 and macOS 15-arm64 image runners. Apple introduced a new LNP policy with macOS Sequoia that is not controlled by TCC or MDM. Could you please guide us on how to add 'local network access' permission for macOS 15 and macOS 15-arm64 image runners? Thanks.
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1
1.3k
Mar ’25
BSSID: Right way to retrieve it taking into account new security concerns
Hi everybody! With latest updates on Ventura around 13.9.X, Sonoma 14.5 and upper, and most probably Sequoia, we notice a change on how to retrieve BSSID. We know Airport is discontinue, but also other commands are impacted by new security policies. Now, to make any command work in the proper way we need to ask for Location Permission. But here is where we are finding some issues to make it compatible with the new requirements. We have a web desktop app (Built with Electronjs) that use an mach-o executable (built on C++). This executable runs IOREG to retrieve the BSSID. One of the tries we did is to request the Location Permission on the parent/GUI app, but by doing this, IOREG was not able to retrieve the BSSID. Then, we try to look for a way to make a little test only with our executable. But in the attempt to, we do not found a way to trigger the location permission request, either manually or by a command. Is there a way to prompt the user from a terminal executable or the right way is to prompt from the GUI? Do we need to stop using Mach-o executable in c++ and move to a native mach-o executable in swift to be able to prompt from it (This executable runs in the machine frequently, several times per minute)? We are open to change the command if need it.
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827
Sep ’24
Interpreting kernel/iOSAppProxyProvider logs
Hi, I'm troubleshooting an iOS network connectivity issue when my app is running 'in' a per-app VPN and would like some clarification about the ordering of some of the logging generated after installing various debugging profiles on the device (VPN (Network Extension), Network Diagnostics, mDNSResponder). Context The connectivity issue is between two vendors my app is involved with. One supplies an app proxy provider extension to provide per-app VPN capability for my app. The other vendor provides an SDK framework that's attempting to make network connections which normally work when the VPN is not involved. We have confirmed with the VPN vendor that it is not a configuration (whitelisting, etc) type issue. I am trying to understand from the logs what component caused/initiated the network connection termination. Was it the kernel, was it the App Proxy Provider Network Extension code or was it the app (SDK framework) code ? Log entries I've attached a short log file and number the lines for reference, and have redacted a few commercially sensitive parts. NetworkLogExcerpt.txt Questions Can this log help determine who caused the network connection failure, and if not, is there any more instrumentation I could enable that might help? Do the log entries (and their timestamps) reflect the actual order/timing of events reported on, or is there some jumbling occurring due to my app, the kernel and iOSAppProxyProvider running in different processes/threads? After the app initiates the network connection (line 1), it appears that the kernel flow diversion code in netinet/flow_divert.c establishes the flow and closes it (lines 2 - 6) before iOSAppProxyProvider even starts to establish the flow (lines 7 - 10). Then the app somehow seems to detects a network error (line 8), before the iOSAppProxyProvider has even matched the VPN extension (line 12) to it and then finally the iOSAppProxyProvider closes the flow (lines 13-17). I'd have expected an interleaving of kernel and iOSAppProxyProvider log entries, with the app's own logging just occurring at the start and end, bracketing the whole interaction... I am new to this area of iOS, so apologies if I am missing some important foundational concepts about how these components all work together. Thanks in advance, Rob
0
1
349
Oct ’24
iOS18 UDP failed to send data
iOS18 UDP fails to send data, iOS other systems fine Device discovery by broadcasting over UDP Failed to send data to the discovered device using UDP communication This problem only occurs on iOS18, other iOS versions work fine I read the official forum of Apple, it is recommended to use BSD socket to send data, and it cannot be sent on iOS18. I suspect that the device privacy permission is found locally, which is invalid on iOS18
6
1
875
Sep ’24