General: Forums subtopic: App & System Services > Networking TN3151 Choosing the right networking API Networking Overview document — Despite the fact that this is in the archive, this is still really useful. TLS for App Developers forums post Choosing a Network Debugging Tool documentation WWDC 2019 Session 712 Advances in Networking, Part 1 — This explains the concept of constrained networking, which is Apple’s preferred solution to questions like How do I check whether I’m on Wi-Fi? TN3135 Low-level networking on watchOS TN3179 Understanding local network privacy Adapt to changing network conditions tech talk Understanding Also-Ran Connections forums post Extra-ordinary Networking forums post Foundation networking: Forums tags: Foundation, CFNetwork URL Loading System documentation — NSURLSession, or URLSession in Swift, is the recommended API for HTTP[S] on Apple platforms. Moving to Fewer, Larger Transfers forums post Testing Background Session Code forums post Network framework: Forums tag: Network Network framework documentation — Network framework is the recommended API for TCP, UDP, and QUIC on Apple platforms. Building a custom peer-to-peer protocol sample code (aka TicTacToe) Implementing netcat with Network Framework sample code (aka nwcat) Configuring a Wi-Fi accessory to join a network sample code Moving from Multipeer Connectivity to Network Framework forums post NWEndpoint History and Advice forums post Wi-Fi (general): How to modernize your captive network developer news post Wi-Fi Fundamentals forums post Filing a Wi-Fi Bug Report forums post Working with a Wi-Fi Accessory forums post — This is part of the Extra-ordinary Networking series. Wi-Fi (iOS): TN3111 iOS Wi-Fi API overview technote Wi-Fi Aware framework documentation WirelessInsights framework documentation iOS Network Signal Strength forums post Network Extension Resources Wi-Fi on macOS: Forums tag: Core WLAN Core WLAN framework documentation Secure networking: Forums tags: Security Apple Platform Security support document Preventing Insecure Network Connections documentation — This is all about App Transport Security (ATS). WWDC 2017 Session 701 Your Apps and Evolving Network Security Standards [1] — This is generally interesting, but the section starting at 17:40 is, AFAIK, the best information from Apple about how certificate revocation works on modern systems. Available trusted root certificates for Apple operating systems support article Requirements for trusted certificates in iOS 13 and macOS 10.15 support article About upcoming limits on trusted certificates support article Apple’s Certificate Transparency policy support article What’s new for enterprise in iOS 18 support article — This discusses new key usage requirements. Technote 2232 HTTPS Server Trust Evaluation Technote 2326 Creating Certificates for TLS Testing QA1948 HTTPS and Test Servers Miscellaneous: More network-related forums tags: 5G, QUIC, Bonjour On FTP forums post Using the Multicast Networking Additional Capability forums post Investigating Network Latency Problems forums post Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com" [1] This video is no longer available from Apple, but the URL should help you locate other sources of this info.

I am trying to activate an application which sends my serial number to a server. The send is being blocked. The app is signed but not sandboxed. I am running Sequoia on a recent iMac. My network firewall is off and I do not have any third party virus software. I have selected Allow Applications from App Store & Known Developers. My local network is wifi using the eero product. There is no firewall or virus scanning installed with this product. Under what circumstances will Mac OS block outgoing internet connections from a non-sandboxed app? How else could the outgoing connection be blocked?

Description: I'm noticing that when using the completion handler variant of URLSession.dataTask(with:), the delegate method urlSession(_:dataTask:didReceive:) is not called—even though a delegate is set when creating the session. Here's a minimal reproducible example: ✅ Case where delegate method is called: class CustomSessionDelegate: NSObject, URLSessionDataDelegate { func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive data: Data) { print("✅ Delegate method called: Data received") } } let delegate = CustomSessionDelegate() let session = URLSession(configuration: .default, delegate: delegate, delegateQueue: nil) let request = URLRequest(url: URL(string: "https://httpbin.org/get")!) let task = session.dataTask(with: request) // ✅ No completion handler task.resume() In this case, the delegate method didReceive is called as expected. ❌ Case where delegate method is NOT called: class CustomSessionDelegate: NSObject, URLSessionDataDelegate { func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive data: Data) { print("❌ Delegate method NOT called") } } let delegate = CustomSessionDelegate() let session = URLSession(configuration: .default, delegate: delegate, delegateQueue: nil) let request = URLRequest(url: URL(string: "https://httpbin.org/get")!) let task = session.dataTask(with: request) { data, response, error in print("Completion handler called") } task.resume() Here, the completion handler is executed, but the delegate method didReceive is never called. Notes: I’ve verified this behavior on iOS 16, 17, and 18. Other delegate methods such as urlSession(_:task:didFinishCollecting:) do get called with the completion handler API. This happens regardless of whether swizzling or instrumentation is involved — the issue is reproducible even with direct method implementations. Questions: Is this the expected behavior (i.e., delegate methods like didReceive are skipped when a completion handler is used)? If yes, is there any official documentation that explains this? Is there a recommended way to ensure delegate methods are invoked, even when using completion handler APIs? Thanks in advance!

Hi folks, I'm building an iOS companion app to a local hosted server app (hosted on 0.0.0.0). The MacOS app locally connects to this server hosted, and I took the approach of advertising the server using a Daemon and BonjourwithTXT(for port) and then net service to resolve a local name. Unfortunately if there's not enough time given after the iPhone/iPad is plugged in (usb or ethernet), the app will cycle through attempts and disconnects many times before connecting and I'm trying to find a way to only connect when a viable en interface is available. I've run into a weird thing in which the en interface only becomes seen on the NWMonitor after multiple connection attempts have been made and failed. If I screen for en before connecting it simply never appears. Is there any way to handle this such that my app can intelligently wait for an en connection before trying to connect? Attaching my code although I have tried a few other setups but none has been perfect. func startMonitoringAndBrowse() { DebugLogger.shared.append("Starting Bonjour + Ethernet monitoring") if !browserStarted { let params = NWParameters.tcp params.includePeerToPeer = false params.requiredInterfaceType = .wiredEthernet browser = NWBrowser(for: .bonjourWithTXTRecord(type: "_mytcpapp._tcp", domain: nil), using: params) browser?.stateUpdateHandler = { state in if case .ready = state { DebugLogger.shared.append("Bonjour browser ready.") } } browser?.browseResultsChangedHandler = { results, _ in self.handleBrowseResults(results) } browser?.start(queue: .main) browserStarted = true } // Start monitoring for wired ethernet monitor = NWPathMonitor() monitor?.pathUpdateHandler = { path in let hasEthernet = path.availableInterfaces.contains { $0.type == .wiredEthernet } let ethernetInUse = path.usesInterfaceType(.wiredEthernet) DebugLogger.shared.append(""" NWPathMonitor: - Status: \(path.status) - Interfaces: \(path.availableInterfaces.map { "\($0.name)[\($0.type)]" }.joined(separator: ", ")) - Wired Ethernet: \(hasEthernet), In Use: \(ethernetInUse) """) self.tryToConnectIfReady() self.stopMonitoring() } monitor?.start(queue: monitorQueue) } // MARK: - Internal Logic private func handleBrowseResults(_ results: Set<NWBrowser.Result>) { guard !self.isResolving, !self.hasResolvedService else { return } for result in results { guard case let .bonjour(txtRecord) = result.metadata, let portString = txtRecord["actual_port"], let actualPort = Int(portString), case let .service(name, type, domain, _) = result.endpoint else { continue } DebugLogger.shared.append("Bonjour result — port: \(actualPort)") self.resolvedPort = actualPort self.isResolving = true self.resolveWithNetService(name: name, type: type, domain: domain) break } } private func resolveWithNetService(name: String, type: String, domain: String) { let netService = NetService(domain: domain, type: type, name: name) netService.delegate = self netService.includesPeerToPeer = false netService.resolve(withTimeout: 5.0) resolvingNetService = netService DebugLogger.shared.append("Resolving NetService: \(name).\(type)\(domain)") } private func tryToConnectIfReady() { guard hasResolvedService, let host = resolvedHost, let port = resolvedPort else { return } DebugLogger.shared.append("Attempting to connect: \(host):\(port)") discoveredIP = host discoveredPort = port connectionPublisher.send(.connecting(ip: host, port: port)) stopBrowsing() socketManager.connectToServer(ip: host, port: port) hasResolvedService = false } } // MARK: - NetServiceDelegate extension BonjourManager: NetServiceDelegate { func netServiceDidResolveAddress(_ sender: NetService) { guard let hostname = sender.hostName else { DebugLogger.shared.append("Resolved service with no hostname") return } DebugLogger.shared.append("Resolved NetService hostname: \(hostname)") resolvedHost = hostname isResolving = false hasResolvedService = true tryToConnectIfReady() } func netService(_ sender: NetService, didNotResolve errorDict: [String : NSNumber]) { DebugLogger.shared.append("NetService failed to resolve: \(errorDict)") } }

We are implementing a connection between iPad and iPhone devices using LocalPushConnectivity, and have introduced SimplePushProvider into the project. We will have it switch between roles of Server and Client within a single project. ※ iPad will be Server and the iPhone will be Client. Communication between Server and Client is via TLS, with Server reading p12 file and Client setting public key. Currently, a TLS error code of "-9836" (invalid protocol version) is occurring when communicating from Client's SimplePushProvider to Server. I believe that Client is sending TLS1.3, and Server is set to accept TLS1.2 to 1.3. Therefore, I believe that the actual error is not due to TLS protocol version, but is an error that is related to security policy or TLS communication setting. Example: P12 file does not meet some requirement NWProtocolTLS.Options setting is insufficient etc... I'm not sure what the problem is, so please help. For reference, I will attach you implementation of TLS communication settings. P12 file is self-signed and was created by exporting it from Keychain Access. Test environment: iPad (OS: 16.6) iPhone (OS: 18.3.2) ConnectionOptions: TLS communication settings public enum ConnectionOptions { public enum TCP { public static var options: NWProtocolTCP.Options { let options = NWProtocolTCP.Options() options.noDelay = true options.enableFastOpen return options } } public enum TLS { public enum Error: Swift.Error { case invalidP12 case unableToExtractIdentity case unknown } public class Server { public let p12: URL public let passphrase: String public init(p12 url: URL, passphrase: String) { self.p12 = url self.passphrase = passphrase } public var options: NWProtocolTLS.Options? { guard let data = try? Data(contentsOf: p12) else { return nil } let pkcs12Options = [kSecImportExportPassphrase: passphrase] var importItems: CFArray? let status = SecPKCS12Import(data as CFData, pkcs12Options as CFDictionary, &importItems) guard status == errSecSuccess, let items = importItems as? [[String: Any]], let importItemIdentity = items.first?[kSecImportItemIdentity as String], let identity = sec_identity_create(importItemIdentity as! SecIdentity) else { return nil } let options = NWProtocolTLS.Options() sec_protocol_options_set_min_tls_protocol_version(options.securityProtocolOptions, .TLSv12) sec_protocol_options_set_max_tls_protocol_version(options.securityProtocolOptions, .TLSv13) sec_protocol_options_set_local_identity(options.securityProtocolOptions, identity) sec_protocol_options_append_tls_ciphersuite(options.securityProtocolOptions, tls_ciphersuite_t.RSA_WITH_AES_128_GCM_SHA256) return options } } public class Client { public let publicKeyHash: String private let dispatchQueue = DispatchQueue(label: "ConnectionParameters.TLS.Client.dispatchQueue") public init(publicKeyHash: String) { self.publicKeyHash = publicKeyHash } // Attempt to verify the pinned certificate. public var options: NWProtocolTLS.Options { let options = NWProtocolTLS.Options() sec_protocol_options_set_min_tls_protocol_version(options.securityProtocolOptions, .TLSv12) sec_protocol_options_set_max_tls_protocol_version(options.securityProtocolOptions, .TLSv13) sec_protocol_options_set_verify_block( options.securityProtocolOptions, verifyClosure, dispatchQueue ) return options } private func verifyClosure( secProtocolMetadata: sec_protocol_metadata_t, secTrust: sec_trust_t, secProtocolVerifyComplete: @escaping sec_protocol_verify_complete_t ) { let trust = sec_trust_copy_ref(secTrust).takeRetainedValue() guard let serverPublicKeyData = publicKey(from: trust) else { secProtocolVerifyComplete(false) return } let keyHash = cryptoKitSHA256(data: serverPublicKeyData) guard keyHash == publicKeyHash else { // Presented certificate doesn't match. secProtocolVerifyComplete(false) return } // Presented certificate matches the pinned cert. secProtocolVerifyComplete(true) } private func cryptoKitSHA256(data: Data) -> String { let rsa2048Asn1Header: [UInt8] = [ 0x30, 0x82, 0x01, 0x22, 0x30, 0x0d, 0x06, 0x09, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x01, 0x05, 0x00, 0x03, 0x82, 0x01, 0x0f, 0x00 ] let data = Data(rsa2048Asn1Header) + data let hash = SHA256.hash(data: data) return Data(hash).base64EncodedString() } private func publicKey(from trust: SecTrust) -> Data? { guard let certificateChain = SecTrustCopyCertificateChain(trust) as? [SecCertificate], let serverCertificate = certificateChain.first else { return nil } let publicKey = SecCertificateCopyKey(serverCertificate) return SecKeyCopyExternalRepresentation(publicKey!, nil)! as Data } } } }

For our outdoor power supply company that builds public WiFi networks at camping sites, we want to implement the following features in our app: Scan surrounding WiFi networks When detecting specific public WiFi SSIDs, provide users with corresponding passwords Automatically connect to those WiFi networks Regarding the NEHotspotHelper API permission application, when I clicked on https://developer.apple.com/contact/request/network-extension, it redirected me to https://developer.apple.com/unauthorized/. I'm not sure where to properly apply for this permission now.

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?

I've just watched Scott Herschel's WWDC 25 session "Use structured concurrency with Network framework" and I am more than overjoyed to see said framework offer these new features. However, the documentation has not yet been updated (or it's not where I expect to find it) .. Is there more that I can read about the enhancements to the framework? One specific question is whether the structured concurrency portion of the framework's enhancement is backward compatible to before "26"?

I have been polishing an app that connects and communicates between a tvOS app I created and a iPadOS app that I also created. Connection works fantastic! However, for some reason when the user selects the button to open the DevicePicker provided by this API and then selects a iPad device the notification that comes across the the iPad reads, "Connect your Apple TV to "AppName" on this iPhone. Is this a bug or am I missing some configuration in maybe Info.plist or a modifier I need to add the DevicePicker for it to communicate the proper device identification? I have everything setup in both app Info.plist files to connect and work fine, but the notification saying iPhone on an iPad is sadly a small detail I would love to change. So...not sure if I found a bug or if I am missing something.

Recently, we have observed that after upgrading to OS 15.4.1, some devices are experiencing network issues. We are using a Network Extension with a transparent app proxy in our product. The user encounters this issue while using our client, but the issue persists even after stopping the client app. This appears to be an OS issue. Below is the sytem logs. In the system logs, it says [C669.1 Hostname#546597df:443 failed transform (unsatisfied (No network route), flow divert agg: 2)] event: transform:children_failed @0.001s In scutil --dns, it says not reachble. DNS configuration resolver #1 flags : reach : 0x00000000 (Not Reachable) resolver #2 domain : local options : mdns timeout : 5 flags : reach : 0x00000000 (Not Reachable) order : 300000 resolver #3 domain : 254.169.in-addr.arpa options : mdns timeout : 5 flags : reach : 0x00000000 (Not Reachable) order : 300200 resolver #4 domain : 8.e.f.ip6.arpa options : mdns timeout : 5 flags : reach : 0x00000000 (Not Reachable) order : 300400 resolver #5 domain : 9.e.f.ip6.arpa options : mdns timeout : 5 flags : reach : 0x00000000 (Not Reachable) order : 300600 resolver #6 domain : a.e.f.ip6.arpa options : mdns timeout : 5 flags : reach : 0x00000000 (Not Reachable) order : 300800 resolver #7 domain : b.e.f.ip6.arpa options : mdns timeout : 5 flags : reach : 0x00000000 (Not Reachable) order : 301000 We need to restart the system to recover from the issue.

I'm trying to invoke a 3rd party command line tool from a launch agent to connect to a server on my LAN. It seems impossible. I have a little shell script that does what I need, and it works fine invoked in Terminal.app. The first time I run it that way I get permission prompts and I agree to them all. Subsequent invocations work. Now I put a launch agent in ~/Library/Launch Agents. It does nothing more than invoke my shell script at some specific time daily. launchd launches it, but it fails to access the LAN, with a 'no route to host' error message. The command line tool I'm trying to use is not a macOS-provided one, but one from MacPorts/HomeBrew (I tried both). It doesn't even matter which tool I'm using, I tried a very simple case of just using nc/netcat. If I use the macOS-provided nc, then I can access my LAN. If I install nc from MacPorts /HomeBrew, that nc cannot access my LAN. This I've reproed on a literally brand new Mac, then updated to newest Sequoia (15.3.2), then done all I've described above. I've ruled out DNS by working with raw IP addresses. I've disabled gatekeeper with sudo spctl --master-disable. I've tried using cron instead of launch agents, same results. I've tried codesigning with codesign -dvvv /opt/homebrew/bin/nc, no help. I've read TN3179 Understanding local network privacy. In summary: Terminal.app -> script -> macOS/brew nc -> internet/LAN = works launchagent -> script -> macOS nc -> internet = works launchagent -> script -> macOS nc -> LAN = works launchagent -> script -> brew nc -> internet = works launchagent -> script -> brew nc -> LAN = fails How can I make that last case work?

Question 1: After NetworkExtension is installed, when the software receives a pushed uninstall command, it needs to download the entire software but fails to uninstall this NetworkExtension. Are there any solutions? Question 2: How can residual, uninstalled NetworkExtensions be cleaned up when SIP (System Integrity Protection) is enabled?

I'm using NERelayManager to set Relay configuration which all works perfectly fine. I then do a curl with the included domain and while I see QUIC connection succeeds with relay server and H3 request goes to the server, the connection gets abruptly closed by the client with "Software caused connection abort". Console has this information: default 09:43:04.459517-0700 curl nw_flow_connected [C1.1.1 192.168.4.197:4433 in_progress socket-flow (satisfied (Path is satisfied), viable, interface: en0[802.11], ipv4, ipv6, dns, uses wifi)] Transport protocol connected (quic) default 09:43:04.459901-0700 curl [C1.1.1 192.168.4.197:4433 in_progress socket-flow (satisfied (Path is satisfied), viable, interface: en0[802.11], ipv4, ipv6, dns, uses wifi)] event: flow:finish_transport @0.131s default 09:43:04.460745-0700 curl nw_flow_connected [C1.1.1 192.168.4.197:4433 in_progress socket-flow (satisfied (Path is satisfied), viable, interface: en0[802.11], ipv4, ipv6, dns, uses wifi)] Joined protocol connected (http3) default 09:43:04.461049-0700 curl [C1.1.1 192.168.4.197:4433 in_progress socket-flow (satisfied (Path is satisfied), viable, interface: en0[802.11], ipv4, ipv6, dns, uses wifi)] event: flow:finish_transport @0.133s default 09:43:04.465115-0700 curl [C2 E47A3A0C-7275-4F6B-AEDF-59077ABAE34B 192.168.4.197:4433 quic, multipath service: 1, tls, definite, attribution: developer] cancel default 09:43:04.465238-0700 curl [C2 E47A3A0C-7275-4F6B-AEDF-59077ABAE34B 192.168.4.197:4433 quic, multipath service: 1, tls, definite, attribution: developer] cancelled [C2 FCB1CFD1-4BF9-4E37-810E-81265D141087 192.168.4.139:53898<->192.168.4.197:4433] Connected Path: satisfied (Path is satisfied), viable, interface: en0[802.11], ipv4, ipv6, dns, uses wifi Duration: 0.121s, QUIC @0.000s took 0.000s, TLS 1.3 took 0.111s bytes in/out: 2880/4322, packets in/out: 4/8, rtt: 0.074s, retransmitted bytes: 0, out-of-order bytes: 0 ecn packets sent/acked/marked/lost: 3/1/0/0 default 09:43:04.465975-0700 curl nw_flow_disconnected [C2 192.168.4.197:4433 cancelled multipath-socket-flow ((null))] Output protocol disconnected default 09:43:04.469189-0700 curl nw_endpoint_proxy_receive_report [C1.1 IPv4#124bdc4d:80 in_progress proxy (satisfied (Path is satisfied), interface: en0[802.11], ipv4, ipv6, dns, proxy, uses wifi)] Privacy proxy failed with error 53 ([C1.1.1] masque Proxy: http://192.168.4.197:4433) default 09:43:04.469289-0700 curl [C1.1.1 192.168.4.197:4433 failed socket-flow (satisfied (Path is satisfied), viable, interface: en0[802.11], ipv4, ipv6, dns, uses wifi)] event: flow:failed_connect @0.141s, error Software caused connection abort Relay server otherwise works fine with our QUIC MASQUE clients but not with built-in macOS MASQUE client. Anything I'm missing?

Hey there! I’ve got some exciting news about Apple’s virtio_net_hdr implementation on macOS 15.4. It’s making communication a lot smoother, with a noticeable improvement! Now, I’d love to hear your thoughts on a couple of things. First, how do you think we can validate the populated values? And secondly, should we consider reusing populated values for the other endpoint, like the ‘flags’ field? Your insights would be invaluable!

There are multiple report of crashes on URLConnectionLoader::loadWithWhatToDo. The crashed thread in the stack traces pointing to calls inside CFNetwork which seems to be internal library in iOS. The crash has happened quite a while already (but we cannot detect when the crash started to occur) and impacted multiple iOS versions recorded from iOS 15.4 to 18.4.1 that was recorded in Xcode crash report organizer so far. Unfortunately, we have no idea on how to reproduce it yet but the crash keeps on increasing and affect more on iOS 18 users (which makes sense because many people updated their iOS to the newer version) and we haven’t found any clue on what actually happened and how to fix it on the crash reports. What we understand is it seems to come from a network request that happened to trigger the crash but we need more information on what (condition) actually cause it and how to solve it. Hereby, I attach sample crash report for both iOS 15 and 18. I also have submitted a report (that include more crash reports) with number: FB17775979. Will appreciate any insight regarding this issue and any resolution that we can do to avoid it. iOS 15.crash iOS 18.crash

Hello, I am writing a NetworkExtension VPN using custom protocol and our client would like to able to use 5G network slice on the VPN, is this possible at all? From Apple's documentation, I found the following statement: If both network slicing and VPN are configured for an app or device, the VPN connection takes precedence over the network slice, rendering the network slice unused. Is it possible to assign a network slice on a NetworkExtension-based VPN and let the VPN traffic uses the assign network slice? Many thanks

I am learning how to use DNS-SD from swift and have created a basic CLI app, however I am not getting callback results. I can get results from cli. Something I am doing wrong here? dns-sd -G v6 adet.local 10:06:08.423 Add 40000002 22 adet.local. FE80:0000... dns-sd -B _adt._udp. 11:19:10.696 Add 2 22 local. _adt._udp. adet import Foundation import dnssd var reference: DNSServiceRef? func dnsServiceGetAddrInfoReply(ref: DNSServiceRef?, flags: DNSServiceFlags, interfaceIndex: UInt32, errorCode: DNSServiceErrorType, hostname: UnsafePointer&lt;CChar&gt;?, address: UnsafePointer&lt;sockaddr&gt;?, ttl: UInt32, context: UnsafeMutableRawPointer?) { print("GetAddr'd") print(hostname.debugDescription.utf8CString) print(address.debugDescription.utf8CString) } var error = DNSServiceGetAddrInfo(&amp;reference, 0, 0, DNSServiceProtocol(kDNSServiceProtocol_IPv6), "adet.local", dnsServiceGetAddrInfoReply, nil) print("GetAddr: \(error)") func dnsServiceBrowseReply(ref: DNSServiceRef?, flags: DNSServiceFlags, interfaceIndex: UInt32, errorCode: DNSServiceErrorType, serviceName: UnsafePointer&lt;CChar&gt;?, regType: UnsafePointer&lt;CChar&gt;?, replyDomain: UnsafePointer&lt;CChar&gt;?, context: UnsafeMutableRawPointer?) { print("Browsed") print(serviceName.debugDescription.utf8CString) print(replyDomain.debugDescription.utf8CString) } error = DNSServiceBrowse(&amp;reference, 0, 0, "_adt._udp", nil, dnsServiceBrowseReply, nil) print("Browse: \(error)") Foundation.RunLoop.main.run() Info.plist &lt;?xml version="1.0" encoding="UTF-8"?&gt; &lt;!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"&gt; &lt;plist version="1.0"&gt; &lt;dict&gt; &lt;key&gt;NSLocalNetworkUsageDescription&lt;/key&gt; &lt;string&gt;By the Hammer of Grabthor&lt;/string&gt; &lt;key&gt;NSBonjourServices&lt;/key&gt; &lt;array&gt; &lt;string&gt;_adt._udp.&lt;/string&gt; &lt;string&gt;_http._tcp.&lt;/string&gt; &lt;string&gt;_http._tcp&lt;/string&gt; &lt;string&gt;_adt._udp&lt;/string&gt; &lt;/array&gt; &lt;/dict&gt; &lt;/plist&gt;

Hi~ I implemented network filtering on iOS using NEFilterControlProvider and NEFilterDataProvider. However, I found that their usage is restricted when distributing in the App Store. Does ADEP-based distribution allow the use of NEFilterControlProvider and NEFilterDataProvider? In TN3134, it states that NEPacketTunnelProvider requires MDM. Should I assume that NEFilterControlProvider and NEFilterDataProvider also require MDM in the same way? thanks.

Hi, i have a crash received in my Firebase Crashlytics. I couldn't figure out the root cause of the issue. Could anyone please help me with it. Crashed: com.apple.CFNetwork.Connection 0 libobjc.A.dylib 0x20b8 objc_retain_x19 + 16 1 CFNetwork 0x47398 HTTP3Fields::appendField(NSString*, NSString*) + 72 2 CFNetwork 0x41250 invocation function for block in HTTP3Stream::_buildRequestHeaders() + 240 3 CoreFoundation 0x249f0 __NSDICTIONARY_IS_CALLING_OUT_TO_A_BLOCK__ + 24 4 CoreFoundation 0x565dc ____NSDictionaryEnumerate_block_invoke_2 + 56 5 CoreFoundation 0x55b10 CFBasicHashApply + 148 6 CoreFoundation 0x8abfc __NSDictionaryEnumerate + 520 7 CFNetwork 0x793d4 HTTP3Stream::scheduleAndOpenWithHandler(CoreSchedulingSet const*, void (__CFHTTPMessage*, NSObject<OS_dispatch_data>*, CFStreamError const*) block_pointer, void (unsigned char) block_pointer) + 1120 8 CFNetwork 0x1665c HTTPProtocol::useNetStreamInfoForRequest(MetaNetStreamInfo*, HTTPRequestMessage const*, unsigned char) + 4044 9 CFNetwork 0x80c80 HTTP3ConnectionCacheEntry::enqueueRequestForProtocol(MetaConnectionCacheClient*, HTTPRequestMessage const*, MetaConnectionOptions) + 2540 10 CFNetwork 0x7fab8 HTTP3ConnectionCacheWrapper::ingestTube(Tube*, bool) + 2924 11 CFNetwork 0x257dc TubeManager::newTubeReady(Tube*, CFStreamError) + 4284 12 CFNetwork 0x57b64 invocation function for block in TubeManager::_onqueue_createNewTube(HTTPConnectionCacheKey*) + 72 13 CFNetwork 0x2fe30 Tube::_onqueue_invokeCB(CFStreamError) + 360 14 CFNetwork 0x2fc20 NWIOConnection::_signalEstablished() + 652 15 CFNetwork 0x4ba1c invocation function for block in NWIOConnection::_handleEvent_ReadyFinish() + 748 16 CFNetwork 0x4b5b0 invocation function for block in Tube::postConnectConfiguration(NSObject<OS_tcp_connection>*, NSObject<OS_nw_parameters>*, void () block_pointer) + 860 17 CFNetwork 0x4b220 BlockHolderVar<std::__1::shared_ptr<NetworkProxy>, bool, CFStreamError>::invoke_normal(std::__1::shared_ptr<NetworkProxy>, bool, CFStreamError) + 64 18 CFNetwork 0x32f2c ProxyConnectionEstablishment::postProxyConnectionConfiguration(__CFAllocator const*, std::__1::shared_ptr<TransportConnection>, NSObject<OS_nw_parameters>*, __CFHTTPMessage*, HTTPConnectionCacheKey*, std::__1::shared_ptr<MetaAuthClient>, SmartBlockWithArgs<std::__1::shared_ptr<NetworkProxy>, bool, CFStreamError>) + 664 19 CFNetwork 0x32bbc Tube::postConnectConfiguration(NSObject<OS_tcp_connection>*, NSObject<OS_nw_parameters>*, void () block_pointer) + 744 20 CFNetwork 0xc19b0 invocation function for block in NWIOConnection::_setupConnectionEvents() + 2360 21 libdispatch.dylib 0x132e8 _dispatch_block_async_invoke2 + 148 22 libdispatch.dylib 0x40d0 _dispatch_client_callout + 20 23 libdispatch.dylib 0xb6d8 _dispatch_lane_serial_drain + 744 24 libdispatch.dylib 0xc214 _dispatch_lane_invoke + 432 25 libdispatch.dylib 0xd670 _dispatch_workloop_invoke + 1732 26 libdispatch.dylib 0x17258 _dispatch_root_queue_drain_deferred_wlh + 288 27 libdispatch.dylib 0x16aa4 _dispatch_workloop_worker_thread + 540 28 libsystem_pthread.dylib 0x4c7c _pthread_wqthread + 288 29 libsystem_pthread.dylib 0x1488 start_wqthread + 8 [Here is the complete crash report.](https://developer.apple.com/forums/content/attachment/58b5bb7d-7c90-4eec-906c-4fb76861d44b)

Most apps perform ordinary network operations, like fetching an HTTP resource with URLSession and opening a TCP connection to a mail server with Network framework. These operations are not without their challenges, but they’re the well-trodden path. If your app performs ordinary networking, see TN3151 Choosing the right networking API for recommendations as to where to start. Some apps have extra-ordinary networking requirements. For example, apps that: Help the user configure a Wi-Fi accessory Require a connection to run over a specific interface Listen for incoming connections Building such an app is tricky because: Networking is hard in general. Apple devices support very dynamic networking, and your app has to work well in whatever environment it’s running in. Documentation for the APIs you need is tucked away in man pages and doc comments. In many cases you have to assemble these APIs in creative ways. If you’re developing an app with extra-ordinary networking requirements, this post is for you. Note If you have questions or comments about any of the topics discussed here, put them in a new thread here on DevForums. Make sure I see it by putting it in the App & System Services > Networking area. And feel free to add tags appropriate to the specific technology you’re using, like Foundation, CFNetwork, Network, or Network Extension. Links, Links, and More Links Each topic is covered in a separate post: The iOS Wi-Fi Lifecycle describes how iOS joins and leaves Wi-Fi networks. Understanding this is especially important if you’re building an app that works with a Wi-Fi accessory. Network Interface Concepts explains how Apple platforms manage network interfaces. If you’ve got this far, you definitely want to read this. Network Interface Techniques offers a high-level overview of some of the more common techniques you need when working with network interfaces. Network Interface APIs describes APIs and core techniques for working with network interfaces. It’s referenced by many other posts. Running an HTTP Request over WWAN explains why most apps should not force an HTTP request to run over WWAN, what they should do instead, and what to do if you really need that behaviour. If you’re building an iOS app with an embedded network server, see Showing Connection Information in an iOS Server for details on how to get the information to show to your user so they can connect to your server. Many folks run into trouble when they try to find the device’s IP address, or other seemingly simple things, like the name of the Wi-Fi interface. Don’t Try to Get the Device’s IP Address explains why these problems are hard, and offers alternative approaches that function correctly in all network environments. Similarly, folks also run into trouble when trying to get the host name. On Host Names explains why that’s more complex than you might think. If you’re working with broadcasts or multicasts, see Broadcasts and Multicasts, Hints and Tips. If you’re building an app that works with a Wi-Fi accessory, see Working with a Wi-Fi Accessory. If you’re trying to gather network interface statistics, see Network Interface Statistics. There are also some posts that are not part of this series but likely to be of interest if you’re working in this space: TN3179 Understanding local network privacy discusses the local network privacy feature. Calling BSD Sockets from Swift does what it says on the tin, that is, explains how to call BSD Sockets from Swift. When doing weird things with the network, you often find yourself having to use BSD Sockets, and that API is not easy to call from Swift. The code therein is primarily for the benefit of test projects, oh, and DevForums posts like these. TN3111 iOS Wi-Fi API overview is a critical resource if you’re doing Wi-Fi specific stuff on iOS. TLS For Accessory Developers tackles the tricky topic of how to communicate securely with a network-based accessory. A Peek Behind the NECP Curtain discusses NECP, a subsystem that control which programs have access to which network interfaces. Networking Resources has links to many other useful resources. Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com" Revision History 2025-07-31 Added a link to A Peek Behind the NECP Curtain. 2025-03-28 Added a link to On Host Names. 2025-01-16 Added a link to Broadcasts and Multicasts, Hints and Tips. Updated the local network privacy link to point to TN3179. Made other minor editorial changes. 2024-04-30 Added a link to Network Interface Statistics. 2023-09-14 Added a link to TLS For Accessory Developers. 2023-07-23 First posted.

I implemented a Network Extension in the macOS, use NETransparentProxyProvider. After installing and enabling it, I implemented a UDP client to test its. I found that the UDP client failed to send the data successfully (via sendto, and it returned a success), and when using Wireshark to capture the network data packet, I still couldn't see this UDP data packet. The code for Network Extension is like this: @interface MyTransparentProxyProvider : NETransparentProxyProvider @end @implementation MyTransparentProxyProvider - (void)startProxyWithOptions:(NSDictionary *)options completionHandler:(void (^)(NSError *))completionHandler { NETransparentProxyNetworkSettings *objSettings = [[NETransparentProxyNetworkSettings alloc] initWithTunnelRemoteAddress:@"127.0.0.1"]; // included rules NENetworkRule *objIncludedNetworkRule = [[NENetworkRule alloc] initWithRemoteNetwork:nil remotePrefix:0 localNetwork:nil localPrefix:0 protocol:NENetworkRuleProtocolAny direction:NETrafficDirectionOutbound]; NSMutableArray<NENetworkRule *> *arrIncludedNetworkRules = [NSMutableArray array]; [arrIncludedNetworkRules addObject:objIncludedNetworkRule]; objSettings.includedNetworkRules = arrIncludedNetworkRules; // apply [self setTunnelNetworkSettings:objSettings completionHandler: ^(NSError * _Nullable error) { // TODO } ]; if (completionHandler != nil) completionHandler(nil); } - (BOOL)handleNewFlow:(NEAppProxyFlow *)flow { if (flow == nil) return NO; char szProcPath[PROC_PIDPATHINFO_MAXSIZE] = {0}; audit_token_t *lpAuditToken = (audit_token_t*)flow.metaData.sourceAppAuditToken.bytes; if (lpAuditToken != NULL) { proc_pidpath_audittoken(lpAuditToken, szProcPath, sizeof(szProcPath)); } if ([flow isKindOfClass:[NEAppProxyTCPFlow class]]) { NWHostEndpoint *objRemoteEndpoint = (NWHostEndpoint *)((NEAppProxyTCPFlow *)flow).remoteEndpoint; LOG("-MyTransparentProxyProvider handleNewFlow:] TCP flow! Process: (%d)%s, %s Remote: %s:%s, %s", lpAuditToken != NULL ? audit_token_to_pid(*lpAuditToken) : -1, flow.metaData.sourceAppSigningIdentifier != nil ? [flow.metaData.sourceAppSigningIdentifier UTF8String] : "", szProcPath, objRemoteEndpoint != nil ? (objRemoteEndpoint.hostname != nil ? [objRemoteEndpoint.hostname UTF8String] : "") : "", objRemoteEndpoint != nil ? (objRemoteEndpoint.port != nil ? [objRemoteEndpoint.port UTF8String] : "") : "", ((NEAppProxyTCPFlow *)flow).remoteHostname != nil ? [((NEAppProxyTCPFlow *)flow).remoteHostname UTF8String] : "" ); } else if ([flow isKindOfClass:[NEAppProxyUDPFlow class]]) { NSString *strLocalEndpoint = [NSString stringWithFormat:@"%@", ((NEAppProxyUDPFlow *)flow).localEndpoint]; LOG("-[MyTransparentProxyProvider handleNewFlow:] UDP flow! Process: (%d)%s, %s LocalEndpoint: %s", lpAuditToken != NULL ? audit_token_to_pid(*lpAuditToken) : -1, flow.metaData.sourceAppSigningIdentifier != nil ? [flow.metaData.sourceAppSigningIdentifier UTF8String] : "", szProcPath, strLocalEndpoint != nil ? [strLocalEndpoint UTF8String] : "" ); } else { LOG("-[MyTransparentProxyProvider handleNewFlow:] Unknown flow! Process: (%d)%s, %s", lpAuditToken != NULL ? audit_token_to_pid(*lpAuditToken) : -1, flow.metaData.sourceAppSigningIdentifier != nil ? [flow.metaData.sourceAppSigningIdentifier UTF8String] : "", szProcPath ); } return NO; } @end The following methods can all enable UDP data packets to be successfully sent to the UDP server: 1.In -[MyTransparentProxyProvider startProxyWithOptions:completionHandler:], add the exclusion rule "The IP and port of the UDP server, the protocol is UDP"; 2.In -[MyTransparentProxyProvider startProxyWithOptions:completionHandler:], add the exclusion rule "All IPs and ports, protocol is UDP"; 3.In -[MyTransparentProxyProvider handleNewFlow:] or -[MyTransparentProxyProvider handleNewUDPFlow:initialRemoteEndpoint:], process the UDP Flow and return YES. Did I do anything wrong?