Hi,
We're receiving data via centralManager.centralManager.scanForPeripherals, with no options or filtering (for now), and in the func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber) callback, we get advertisementData for each bluetooth device found.
But, I know one of my BLE devices is sending an Eddystone TLM payload, which generally is received into the kCBAdvDataServiceData part of the advertisementData dictionary, but, it doesn't show up.
What is happening however (when comparing to other devices that do show that payload), is I've noticed the "isConnectable" part is false, and others have it true. Technically we're not "connecting" as such as we're simply reading passive advertisement data, but does that have any bearing on how CoreBluetooth decides to build up it's AdvertisementData response?
Example (with serviceData; and I know this has Eddystone TLM)
["kCBAdvDataLocalName": FSC-BP105N, "kCBAdvDataRxPrimaryPHY": 1, "kCBAdvDataServiceUUIDs": <__NSArrayM 0x300b71f80>(
FEAA,
FEF5
)
, "kCBAdvDataTimestamp": 773270526.26279, "kCBAdvDataServiceData": {
FFF0 = {length = 11, bytes = 0x36021892dc0d3015aeb164};
FEAA = {length = 14, bytes = 0x20000be680000339ffa229bbce8a};
}, "kCBAdvDataRxSecondaryPHY": 0, "kCBAdvDataIsConnectable": 1]
Vs
This also has Eddystone TLM configured
["kCBAdvDataLocalName": 100FA9FD-7000-1000, "kCBAdvDataIsConnectable": 0, "kCBAdvDataRxPrimaryPHY": 1, "kCBAdvDataRxSecondaryPHY": 0, "kCBAdvDataTimestamp": 773270918.97273]
Any insight would be great to understand if the presence of other flags drive the exposure of ServiceData or not...
Networking
RSS for tagExplore the networking protocols and technologies used by the device to connect to Wi-Fi networks, Bluetooth devices, and cellular data services.
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I'm using the NEHotspostConfigurationManager to join the WiFi network of a configured accessory.
While this is all nice and dandy, I wonder why I'm still connected to said WiFi when I (force-)close the app. Wouldn't it be more useful to reconnect to the last network before?
Topic:
App & System Services
SubTopic:
Networking
I am wondering wether iOS allow apps to detect users' proxy.
Topic:
App & System Services
SubTopic:
Networking
Hello, I'm working on a Transparent Proxy and when the proxy is being stopped, I'm stopping all the flows by calling
flow.closeWriteWithError(POSIXError(.ECANCELED))
flow.closeReadWithError(POSIXError(.ECANCELED))
Then all the flows are deallocated.
When deallocating the flow the crash occurs:
OS Version: macOS 14.1.2 (23B92)
Exception Type: EXC_BREAKPOINT (SIGTRAP)
Exception Codes: 0x0000000000000001, 0x000000018c2ef704
Termination Reason: Namespace SIGNAL, Code 5 Trace/BPT trap: 5
Terminating Process: exc handler [553]
Thread 32 Crashed:: Dispatch queue: <my dispatch queue>
0 CoreFoundation 0x18c2ef704 CF_IS_OBJC + 76
1 CoreFoundation 0x18c23f61c CFErrorGetDomain + 32
2 libnetworkextension.dylib 0x19fe56a00 flow_error_to_errno + 28
3 libnetworkextension.dylib 0x19fe56920 flow_handle_pending_write_requests + 216
4 libnetworkextension.dylib 0x19fe5667c __NEFlowDeallocate + 380
5 CoreFoundation 0x18c2efe28 _CFRelease + 292
6 NetworkExtension 0x19d208390 -[NEAppProxyFlow dealloc] + 36
Is there any way to debug what is happening and if it's related to closing the flow with POSIXError?
Thank you
sometimes app from background to foreground , then send a Http request will got network lost response,
and if you delay 0.1 seconds to send request, it's work fine. Does any one can explian this?
Hi!
We have created an app that communicates with devices over BLE, and it is currently out in Testflight. It works as expected for almost everyone, but for some users we get a strange behaviour.
We start by scanning for devices with
scanForPeripherals(withServices:options:),
then connect, and finally initiate pairing by subscribing and writing to a pair of characteristics, which both require encryption.
The issue is that for these users, the following code:
func peripheral(
_ peripheral: CBPeripheral,
didDiscoverCharacteristicsFor service: CBService,
error: Error?
) {
guard error == nil else {
LogManager.shared.log(
"❌ Error discovering characteristics: \(error!)"
)
return
}
for characteristic in service.characteristics ?? [] {
if characteristic.uuid == controlPointUUID {
controlPointCharacteristic = characteristic
LogManager.shared.debugLog(
"Control Point characteristic found."
)
} else if characteristic.uuid == statusUUID {
statusCharacteristic = characteristic
LogManager.shared.debugLog("Notify characteristic found.")
}
}
if statusCharacteristic != nil {
LogManager.shared.debugLog("Call Set notify.")
peripheral.setNotifyValue(true, for: statusCharacteristic!)
}
}
func peripheral(
_ peripheral: CBPeripheral,
didUpdateNotificationStateFor characteristic: CBCharacteristic,
error: Error?
) {
if error != nil {
LogManager.shared.log(
"❌ Failed to subscribe to \(characteristic.uuid): \(error.debugDescription)"
)
produces this error:
> > [22:31:34.632] ❌ Failed to subscribe to F1D0FFF2-DEAA-ECEE-B42F-C9BA7ED623BB: Optional(Error Domain=CBATTErrorDomain Code=15 "Encryption is insufficient." UserInfo={NSLocalizedDescription=Encryption is insufficient.})
So in essence, we can't perform pairing and enable encryption, because we have insufficient encryption.
I know that the system caches some key material after pairing. When I do "Forget device" and then pair again, I don't need to put my device in pairing mode for the pairing pin to appear, which is not the case for devices that have not been paired before.
Given that I can't reproduce the problem locally, it's hard to debug using the console. What I've been trying to do is figure out how to reset Bluetooth, which should hopefully remove old keys and whatever else might be there.
The top hit when searching for 'clear corebluetooth cache macos' is on stackexchange, and writes:
Turn off Bluetooth
Delete com.apple.Bluetooth.plist from /Library/Preferences
Delete files named com.apple.Bluetooth.somehexuuidstuff.plist from ~/Library/Preferences/ByHost (note that this is the user preference folder, not the system one)
Turn on Bluetooth
The answer is from December 2013, so it's not surpising that things don't work out of the box, but anyways:
My ByHost folder does not contain any plist files with Bluetooth in them, and deleting the one in /Library/Preferences did not do anything, and judging from the content, it does not contain anything valuable.
I have tried "sudo grep -r 'Bluetooth' ." in both /Library/Preferences/ and ~/Library/Preferences/ and looked at the resulting hits, but I can't seem to find anything meaningful.
As a sidenote, does anyone know what is going on with Apple's entitlement service? We applied for an entitlement in August and have yet to receive a response.
Hello team,
Would this mean that content filters intended for all browsing can only be implemented for managed devices using MDM? My goal would be to create a content filtering app for all users, regardless of if their device is managed/supervised.
thanks.
Topic:
App & System Services
SubTopic:
Networking
We've received logs and have spuriously reproduced the following behavior:
calls to setTunnelNetworkSettings completing with NETunnelProviderError where the code is networkSettingsInvalid, and the error domain string is empty.
After subsequent calls to setTunnelNetworkSettings, the tunnel is stopped via the userInitiated stop reason within around 1 second from the first failure.
This happens after a number of successful calls to setTunnelNetworkSettings have been made in the lifetime of a given packet tunnel process.
We can confirm that no user ever initiates the disconnection. We can confirm that the only significant changes between the different calls to setTunnelNetworkSettings are that the parameters contain different private IPs for the tunnel settings - the routes and DNS settings remain the same.
In our limited testing, it seems that we can replicate the behavior we're observing by removing the VPN profile while the tunnel is up. However, we are certain the same behavior happens under other circumstances without any user interaction. Is this what memory starvation looks like?
Or is this something else?
Our main concern is that the tunnel is killed and it is not brought back up even though our profile is set to be on-demand. It's difficult to give any promises about leaks to our users if the tunnel can be killed at any point and not be brought back.
The spurious disconnections are a security issue for our app, we'd like to know if there's anything we can do differently so that this does not happen.
We tried to get DTS, but given that we have no way to reproduce this issue with a minimal project. But we can reproduce the behavior (kill the tunnel by removing it's profile) from a minimal Xcode project, is that considered good enough for a reproduction?
What is the best way to detect if the Wifi is being used for Wireless Carplay or is just a normal network interface?
Hello,
I’m reviewing the open-source mDNSResponder repository and have a question regarding licensing/provenance in mDNSCore/DNSDigest.c file.
That file contains an embedded notice stating that parts of the MD5/digest implementation were derived from older OpenSSL sources and therefore include the legacy OpenSSL/SSLeay license text, even though OpenSSL itself is now Apache-2.0 starting from version 3.0.
The legacy OpenSSL/SSLeay license is widely understood to impose additional attribution and notice requirements compared to Apache-2.0, and some downstream projects prefer to avoid it when a permissively licensed alternative is available.
Repository: https://github.com/apple-oss-distributions/mDNSResponder
File: https://github.com/apple-oss-distributions/mDNSResponder/blob/main/mDNSCore/DNSDigest.c#L66
I’d like to clarify a few points:
Is the MD5/digest code in DNSDigest.c still based on pre–OpenSSL-3.0 sources, such that retaining the legacy OpenSSL/SSLeay license block is intentional and required?
If the goal were to simplify licensing (Apache-2.0 only), would Apple consider replacing this MD5 implementation with an Apache-2.0–licensed alternative (for example, code derived from OpenSSL 3.x or another permissive implementation)?
Are there any technical or policy reasons (compatibility, crypto policy, platform APIs) that make such a replacement undesirable?
Since GitHub issues and PRs are restricted for this repository, I’m asking here for guidance. If maintainers agree that such an update would be useful, I’d be happy to help by preparing a PR for review.
I've also created a feedback report for this topic, the reference ID is FB21269078.
Thanks for any clarification.
Transport Layer Security (TLS) is the most important security protocol on the Internet today. Most notably, TLS puts the S into HTTPS, adding security to the otherwise insecure HTTP protocol.
IMPORTANT TLS is the successor to the Secure Sockets Layer (SSL) protocol. SSL is no longer considered secure and it’s now rarely used in practice, although many folks still say SSL when they mean TLS.
TLS is a complex protocol. Much of that complexity is hidden from app developers but there are places where it’s important to understand specific details of the protocol in order to meet your requirements. This post explains the fundamentals of TLS, concentrating on the issues that most often confuse app developers.
Note The focus of this is TLS-PKI, where PKI stands for public key infrastructure. This is the standard TLS as deployed on the wider Internet. There’s another flavour of TLS, TLS-PSK, where PSK stands for pre-shared key. This has a variety of uses, but an Apple platforms we most commonly see it with local traffic, for example, to talk to a Wi-Fi based accessory. For more on how to use TLS, both TLS-PKI and TLS-PSK, in a local context, see TLS For Accessory Developers.
Server Certificates
For standard TLS to work the server must have a digital identity, that is, the combination of a certificate and the private key matching the public key embedded in that certificate. TLS Crypto Magic™ ensures that:
The client gets a copy of the server’s certificate.
The client knows that the server holds the private key matching the public key in that certificate.
In a typical TLS handshake the server passes the client a list of certificates, where item 0 is the server’s certificate (the leaf certificate), item N is (optionally) the certificate of the certificate authority that ultimately issued that certificate (the root certificate), and items 1 through N-1 are any intermediate certificates required to build a cryptographic chain of trust from 0 to N.
Note The cryptographic chain of trust is established by means of digital signatures. Certificate X in the chain is issued by certificate X+1. The owner of certificate X+1 uses their private key to digitally sign certificate X. The client verifies this signature using the public key embedded in certificate X+1. Eventually this chain terminates in a trusted anchor, that is, a certificate that the client trusts by default. Typically this anchor is a self-signed root certificate from a certificate authority.
Note Item N is optional for reasons I’ll explain below. Also, the list of intermediate certificates may be empty (in the case where the root certificate directly issued the leaf certificate) but that’s uncommon for servers in the real world.
Once the client gets the server’s certificate, it evaluates trust on that certificate to confirm that it’s talking to the right server. There are three levels of trust evaluation here:
Basic X.509 trust evaluation checks that there’s a cryptographic chain of trust from the leaf through the intermediates to a trusted root certificate. The client has a set of trusted root certificates built in (these are from well-known certificate authorities, or CAs), and a site admin can add more via a configuration profile.
This step also checks that none of the certificates have expired, and various other more technical criteria (like the Basic Constraints extension).
Note This explains why the server does not have to include the root certificate in the list of certificates it passes to the client; the client has to have the root certificate installed if trust evaluation is to succeed.
In addition, TLS trust evaluation (per RFC 2818) checks that the DNS name that you connected to matches the DNS name in the certificate. Specifically, the DNS name must be listed in the Subject Alternative Name extension.
Note The Subject Alternative Name extension can also contain IP addresses, although that’s a much less well-trodden path. Also, historically it was common to accept DNS names in the Common Name element of the Subject but that is no longer the case on Apple platforms.
App Transport Security (ATS) adds its own security checks.
Basic X.509 and TLS trust evaluation are done for all TLS connections. ATS is only done on TLS connections made by URLSession and things layered on top URLSession (like WKWebView). In many situations you can override trust evaluation; for details, see Technote 2232 HTTPS Server Trust Evaluation). Such overrides can either tighten or loosen security. For example:
You might tighten security by checking that the server certificate was issued by a specific CA. That way, if someone manages to convince a poorly-managed CA to issue them a certificate for your server, you can detect that and fail.
You might loosen security by adding your own CA’s root certificate as a trusted anchor.
IMPORTANT If you rely on loosened security you have to disable ATS. If you leave ATS enabled, it requires that the default server trust evaluation succeeds regardless of any customisations you do.
Mutual TLS
The previous section discusses server trust evaluation, which is required for all standard TLS connections. That process describes how the client decides whether to trust the server. Mutual TLS (mTLS) is the opposite of that, that is, it’s the process by which the server decides whether to trust the client.
Note mTLS is commonly called client certificate authentication. I avoid that term because of the ongoing industry-wide confusion between certificates and digital identities. While it’s true that, in mTLS, the server authenticates the client certificate, to set this up on the client you need a digital identity, not a certificate.
mTLS authentication is optional. The server must request a certificate from the client and the client may choose to supply one or not (although if the server requests a certificate and the client doesn’t supply one it’s likely that the server will then fail the connection).
At the TLS protocol level this works much like it does with the server certificate. For the client to provide this certificate it must apply a digital identity, known as the client identity, to the connection. TLS Crypto Magic™ assures the server that, if it gets a certificate from the client, the client holds the private key associated with that certificate.
Where things diverge is in trust evaluation. Trust evaluation of the client certificate is done on the server, and the server uses its own rules to decided whether to trust a specific client certificate. For example:
Some servers do basic X.509 trust evaluation and then check that the chain of trust leads to one specific root certificate; that is, a client is trusted if it holds a digital identity whose certificate was issued by a specific CA.
Some servers just check the certificate against a list of known trusted client certificates.
When the client sends its certificate to the server it actually sends a list of certificates, much as I’ve described above for the server’s certificates. In many cases the client only needs to send item 0, that is, its leaf certificate. That’s because:
The server already has the intermediate certificates required to build a chain of trust from that leaf to its root.
There’s no point sending the root, as I discussed above in the context of server trust evaluation.
However, there are no hard and fast rules here; the server does its client trust evaluation using its own internal logic, and it’s possible that this logic might require the client to present intermediates, or indeed present the root certificate even though it’s typically redundant. If you have problems with this, you’ll have to ask the folks running the server to explain its requirements.
Note If you need to send additional certificates to the server, pass them to the certificates parameter of the method you use to create your URLCredential (typically init(identity:certificates:persistence:)).
One thing that bears repeating is that trust evaluation of the client certificate is done on the server, not the client. The client doesn’t care whether the client certificate is trusted or not. Rather, it simply passes that certificate the server and it’s up to the server to make that decision.
When a server requests a certificate from the client, it may supply a list of acceptable certificate authorities [1]. Safari uses this to filter the list of client identities it presents to the user. If you are building an HTTPS server and find that Safari doesn’t show the expected client identity, make sure you have this configured correctly. If you’re building an iOS app and want to implement a filter like Safari’s, get this list using:
The distinguishedNames property, if you’re using URLSession
The sec_protocol_metadata_access_distinguished_names routine, if you’re using Network framework
[1] See the certificate_authorities field in Section 7.4.4 of RFC 5246, and equivalent features in other TLS versions.
Self-Signed Certificates
Self-signed certificates are an ongoing source of problems with TLS. There’s only one unequivocally correct place to use a self-signed certificate: the trusted anchor provided by a certificate authority.
One place where a self-signed certificate might make sense is in a local environment, that is, securing a connection between peers without any centralised infrastructure. However, depending on the specific circumstances there may be a better option. TLS For Accessory Developers discusses this topic in detail.
Finally, it’s common for folks to use self-signed certificates for testing. I’m not a fan of that approach. Rather, I recommend the approach described in QA1948 HTTPS and Test Servers. For advice on how to set that up using just your Mac, see TN2326 Creating Certificates for TLS Testing.
TLS Standards
RFC 6101 The Secure Sockets Layer (SSL) Protocol Version 3.0 (historic)
RFC 2246 The TLS Protocol Version 1.0
RFC 4346 The Transport Layer Security (TLS) Protocol Version 1.1
RFC 5246 The Transport Layer Security (TLS) Protocol Version 1.2
RFC 8446 The Transport Layer Security (TLS) Protocol Version 1.3
RFC 4347 Datagram Transport Layer Security
RFC 6347 Datagram Transport Layer Security Version 1.2
RFC 9147 The Datagram Transport Layer Security (DTLS) Protocol Version 1.3
Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"
Revision History:
2025-11-21 Clearly defined the terms TLS-PKI and TLS-PSK.
2024-03-19 Adopted the term mutual TLS in preference to client certificate authentication throughout, because the latter feeds into the ongoing certificate versus digital identity confusion. Defined the term client identity. Added the Self-Signed Certificates section. Made other minor editorial changes.
2023-02-28 Added an explanation mTLS acceptable certificate authorities.
2022-12-02 Added links to the DTLS RFCs.
2022-08-24 Added links to the TLS RFCs. Made other minor editorial changes.
2022-06-03 Added a link to TLS For Accessory Developers.
2021-02-26 Fixed the formatting. Clarified that ATS only applies to URLSession. Minor editorial changes.
2020-04-17 Updated the discussion of Subject Alternative Name to account for changes in the 2019 OS releases. Minor editorial updates.
2018-10-29 Minor editorial updates.
2016-11-11 First posted.
This issue has cropped up many times here on DevForums. Someone recently opened a DTS tech support incident about it, and I used that as an opportunity to post a definitive response here.
If you have questions or comments about this, start a new thread and tag it with Network so that I see it.
Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"
iOS Network Signal Strength
The iOS SDK has no general-purpose API that returns Wi-Fi or cellular signal strength in real time. Given that this has been the case for more than 10 years, it’s safe to assume that it’s not an accidental omission but a deliberate design choice.
For information about the Wi-Fi APIs that are available on iOS, see TN3111 iOS Wi-Fi API overview.
Network performance
Most folks who ask about this are trying to use the signal strength to estimate network performance. This is a technique that I specifically recommend against. That’s because it produces both false positives and false negatives:
The network signal might be weak and yet your app has excellent connectivity. For example, an iOS device on stage at WWDC might have terrible WWAN and Wi-Fi signal but that doesn’t matter because it’s connected to the Ethernet.
The network signal might be strong and yet your app has very poor connectivity. For example, if you’re on a train, Wi-Fi signal might be strong in each carriage but the overall connection to the Internet is poor because it’s provided by a single over-stretched WWAN.
The only good way to determine whether connectivity is good is to run a network request and see how it performs. If you’re issuing a lot of requests, use the performance of those requests to build a running estimate of how well the network is doing. Indeed, Apple practices what we preach here: This is exactly how HTTP Live Streaming works.
Remember that network performance can change from moment to moment. The user’s train might enter or leave a tunnel, the user might step into a lift, and so on. If you build code to estimate the network performance, make sure it reacts to such changes.
Keeping all of the above in mind, iOS 26 beta has two new APIs related to this issue:
Network framework now offers a linkQuality property. See this post for my take on how to use this effectively.
The WirelessInsights framework can notify you of anticipated WWAN condition changes.
But what about this code I found on the ’net?
Over the years various folks have used various unsupported techniques to get around this limitation. If you find code on the ’net that, say, uses KVC to read undocumented properties, or grovels through system logs, or walks the view hierarchy of the status bar, don’t use it. Such techniques are unsupported and, assuming they haven’t broken yet, are likely to break in the future.
But what about Hotspot Helper?
Hotspot Helper does have an API to read Wi-Fi signal strength, namely, the signalStrength property. However, this is not a general-purpose API. Like the rest of Hotspot Helper, this is tied to the specific use case for which it was designed. This value only updates in real time for networks that your hotspot helper is managing, as indicated by the isChosenHelper property.
But what about MetricKit?
MetricKit is so cool. Amongst other things, it supports the MXCellularConditionMetric payload, which holds a summary of the cellular conditions while your app was running. However, this is not a real-time signal strength value.
But what if I’m working for a carrier?
This post is about APIs in the iOS SDK. If you’re working for a carrier, discuss your requirements with your carrier’s contact at Apple.
Revision History
2025-07-02 Updated to cover new features in the iOS 16 beta. Made other minor editorial changes.
2022-12-01 First posted.
I am currently developing a custom-protocol VPN application for iOS using PacketTunnelProvider. I have also integrated an HTTP proxy service, which is launched via a dylib.
The overall flow is as follows:
App -> VPN TUN -> Local HTTP Proxy -> External Network
I have a question:
I am capturing all traffic, and normally, requests sent out by the HTTP proxy are also captured again by the VPN. However, when I send requests using createUdpSession in my code, they are not being captured by the virtual interface (TUN).
What could be the reason for this?
override func startTunnel(options: [String : NSObject]?, completionHandler: @escaping (Error?) -> Void) {
let tunnelNetworkSettings = NEPacketTunnelNetworkSettings(tunnelRemoteAddress: "192.168.18.0")
tunnelNetworkSettings.mtu=1400
let ipv4Settings = NEIPv4Settings(addresses: ["192.169.10.10"], subnetMasks: ["255.255.255.0"])
ipv4Settings.includedRoutes=[NEIPv4Route.default()]
ipv4Settings.excludedRoutes = [NEIPv4Route(destinationAddress: "10.0.0.0", subnetMask: "255.0.0.0"),
NEIPv4Route(destinationAddress: "172.16.0.0", subnetMask: "255.240.0.0"),
NEIPv4Route(destinationAddress: "192.168.0.0", subnetMask: "255.255.0.0"),
NEIPv4Route(destinationAddress:"127.0.0.0", subnetMask: "255.0.0.0"),
]
tunnelNetworkSettings.ipv4Settings = ipv4Settings
// Configure proxy settings
let proxySettings = NEProxySettings()
proxySettings.httpEnabled = true
proxySettings.httpServer = NEProxyServer(address: "127.0.0.1", port: 7890)
proxySettings.httpsEnabled = true
proxySettings.httpsServer = NEProxyServer(address: "127.0.0.1", port: 7890)
proxySettings.excludeSimpleHostnames = true
proxySettings.exceptionList=["localhost","127.0.0.1"]
tunnelNetworkSettings.proxySettings = proxySettings
setTunnelNetworkSettings(tunnelNetworkSettings) { [weak self] error in
if error != nil {
completionHandler(error)
return
}
completionHandler(nil)
let stack = TUNInterface(packetFlow: self!.packetFlow)
RawScoketFactory.TunnelProvider=self
stack.register(stack: UDPDirectStack())
stack.register(stack: TCPDirectStack())
stack.start()
}
}
NWUdpSession.swift
//
// NWUDPSocket.swift
// supervpn
//
// Created by TobbyQuinn on 2025/2/3.
//
import Foundation
import NetworkExtension
import CocoaLumberjack
public protocol NWUDPSocketDelegate: AnyObject{
func didReceive(data:Data,from:NWUDPSocket)
func didCancel(socket:NWUDPSocket)
}
public class NWUDPSocket:NSObject{
private let session:NWUDPSession
private let timeout:Int
private var pendingWriteData: [Data] = []
private var writing = false
private let queue:DispatchQueue=QueueFactory.getQueue()
public weak var delegate:NWUDPSocketDelegate?
public init?(host:String,port:UInt16,timeout:Int=Opt.UDPSocketActiveTimeout){
guard let udpSession = RawScoketFactory.TunnelProvider?.createUDPSession(to: NWHostEndpoint(hostname: host, port: "\(port)"), from: nil) else{
return nil
}
session = udpSession
self.timeout=timeout
super.init()
session.addObserver(self, forKeyPath: #keyPath(NWUDPSession.state),options: [.new], context: nil)
session.setReadHandler({ dataArray, error in
self.queueCall{
guard error == nil, let dataArray = dataArray else {
print("Error when reading from remote server or connection reset")
return
}
for data in dataArray{
self.delegate?.didReceive(data: data, from: self)
}
}
}, maxDatagrams: 32)
}
/**
Send data to remote.
- parameter data: The data to send.
*/
public func write(data: Data) {
pendingWriteData.append(data)
checkWrite()
}
public func disconnect() {
session.cancel()
}
public override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
guard keyPath == "state" else {
return
}
switch session.state {
case .cancelled:
queueCall {
self.delegate?.didCancel(socket: self)
}
case .ready:
checkWrite()
default:
break
}
}
private func checkWrite() {
guard session.state == .ready else {
return
}
guard !writing else {
return
}
guard pendingWriteData.count > 0 else {
return
}
writing = true
session.writeMultipleDatagrams(self.pendingWriteData) {_ in
self.queueCall {
self.writing = false
self.checkWrite()
}
}
self.pendingWriteData.removeAll(keepingCapacity: true)
}
private func queueCall(block:@escaping ()->Void){
queue.async {
block()
}
}
deinit{
session.removeObserver(self, forKeyPath: #keyPath(NWUDPSession.state))
}
}
Hi,
I'm experiencing intermittent delays with URLSession where requests take 3-4 seconds to be sent, even though the actual server processing is fast. This happens randomly, maybe 10-20% of requests.
The pattern I've noticed is
I create my request
I send off my request using try await urlSession.data(for: request)
My middleware ends up receiving this request 4-7s after its been fired from the client-side
The round trip ends up taking 4-7s!
This hasn't been reproducible consistently at all on my end. I've also tried ephemeral URLSessions (so recreating the session instead of using .shared so no dead connections, but this doesn't seem to help at all)
Completely lost on what to do. Please help!
Hello,
How long does it usually take for a URL Filter request to be reviewed?
It's been 2.5 weeks since we submitted the request form but we haven't received any feedback yet.
Just in case, the request ID is D3633USVZZ
I develop a Network Extension with NEFilterDataProvider and want to understand how to stop or disable it on exit of the base app without deactivating NE from OS and leave ability to start it again without requiring a password from the user.
It starts normally, but when I try to disable it:
NEFilterManager.sharedManager.enabled = NO;
[NEFilterManager.sharedManager saveToPreferencesWithCompletionHandler:^(NSError * _Nullable error) {
// never called
}];
the completion handler has never called.
But stopFilterWithReason inside the NE code called by the framework where I only replay with required completionHandler();. Then NE process keeps alive.
I also tried to call remove, which should disable NE:
[NEFilterManager.sharedManager removeFromPreferencesWithCompletionHandler:^(NSError * _Nullable error) {
// never called
}];
with same result - I freeze forever on waiting completion handler.
So what is the correct way to disable NE without explicit deactivation it by [OSSystemExtensionRequest deactivationRequestForExtension:...]?
Esim activation. Assuming I already have card data, I use the universal link https://esimsetup.apple.com/esim_qrcode_provisioning?carddata= to install it.
However, it always ends up in the system Settings app.
The flow: 1. Click the link -> 2. Redirect to Settings -> 3. Show activation dialog.
Is there anyway to make the activation flow stay within the app? I couldn't find any documentation for that.
This is an example from Revolut app, where the whole flow above happens without leaving the app.
When running my app with Xcode16.4, it crashed with the error:
dyld[1045]: Symbol not found: ___res_9_state
Referenced from: <8B329554-5BEF-38D0-BFCD-1731FA6120CB> /private/var/containers/Bundle/Application/00C941BA-E397-4D0B-B280-E75583FF2890/xxx.app/xxx.debug.dylib
Expected in: <7D74C679-8F55-3A01-9AA2-C205A4A19D3E> /usr/lib/libresolv.9.dylib
The ___res_9_state related code in my app is:
let state = __res_9_state()
res_9_ninit(state)
var servers = [res_9_sockaddr_union](repeating: res_9_sockaddr_union(), count: Int(MAXNS))
let found = Int(res_9_getservers(state, &servers, Int32(MAXNS)))
res_9_nclose(state)
if found > 0 {
return Array(servers[0..<found]).filter() { $0.sin.sin_len > 0 }
} else {
return []
}
Previously, __res_9_state() could run normally in Xcode 16.1
How to fix this problem?
Topic:
App & System Services
SubTopic:
Networking
I'm looking for help with a network extension filtering issue. Specifically, we have a subclass of NEFilterDataProvider that is used to filter flows based upon a set of rules, including source IP and destination IP. We've run into an issue where the source IP is frequently 0.0.0.0 (or the IPv6 equivalent) on outgoing flows. This has made it so rules based upon source IP don't work. This is also an issue as we report these connections, but we're lacking critical data. We were able to work around the issue somewhat by keeping a list of flows that we allow that we periodically check to see if the source IP is available, and then report after it becomes available.
We also considered doing a "peekBytes" to allow a bit of data to flow and then recheck the flow, but we don't want to allow data leakage on connections that should be blocked because of the source IP.
Is there a way to force the operating system or network extension frameworks to determine the source IP for an outbound flow without allowing any bytes to flow to the network?
STEPS TO REPRODUCE
Create a network filtering extension for filtering flows using NEFilterDataProvider
See that when handleNewFlow: is called, the outgoing flow lacks the source IP (is 0.0.0.0) in most cases
There is this post that is discussing a similar question, though for a slightly different reason. I imagine the answer to this and the other post will be related, at least as far as NEFilterDataProvider:handleNewFlow not having source IP is considered.
Thanks!
I’m developing an app designed for hospital environments, where public internet access may not be available. The app includes two components: the main app and a Local Connectivity Extension. Both rely on persistent TCP socket connections to communicate with a local server.
We’re observing a recurring issue where the extension’s socket becomes unresponsive every 1–3 hours, but only when the device is on the lock screen, even if the main app remains in the foreground.
When the screen is not locked, the connection is stable and no disconnections occur.
❗ Issue Details:
• What’s going on: The extension sends a keep-alive ping packet every second, and the server replies with a pong and a system time packet.
• The bug: The server stops receiving keep alive packets from the extension.
• On the server, we detect about 30 second gap on the server, a gap that shows no packets were received by the extension. This was confirmed via server logs and Wireshark).
• On the extension, from our logs there was no gap in sending packets. From it’s perspective, all packets were sent with no error.
• Because no packet are being received by the server, no packets will be sent to the extension. Eventually the server closes the connection due to keep-alive timeout.
• FYI we log when the NEAppPushProvider subclass sleeps and it did NOT go to sleep while we were debugging.
🧾 Example Logs:
Extension log:
2025-03-24 18:34:48.808 sendKeepAliveRequest()
2025-03-24 18:34:49.717 sendKeepAliveRequest()
2025-03-24 18:34:50.692 sendKeepAliveRequest()
... // continuous sending of the ping packet to the server, no problems here
2025-03-24 18:35:55.063 sendKeepAliveRequest()
2025-03-24 18:35:55.063 keepAliveTimer IS TIME OUT... in CoreService. // this is triggered because we did not receive any packets from the server
2025-03-24 18:34:16.298 No keep-alive received for 16 seconds... connection ID=95b3... // this shows that there has been no packets being received by the extension
...
2025-03-24 18:34:30.298 Connection timed out on keep-alive. connection ID=95b3... // eventually closes due to no packets being received
2025-03-24 18:34:30.298 Remote Subsystem Disconnected {name=iPhone|Replica-Ext|...}
✅ Observations:
• The extension process continues running and logging keep-alive attempts.
• However, network traffic stops reaching the server, and no inbound packets are received by the extension.
• It looks like the socket becomes silently suspended or frozen, without being properly closed or throwing an error.
❓Questions:
• Do you know why this might happen within a Local Connectivity Extension, especially under foreground conditions and locked ?
• Is there any known system behavior that might cause the socket to be suspended or blocked in this way after running for a few hours?
Any insights or recommendations would be greatly appreciated.
Thank you!