iOS implementing NETunnelProviderProtocol with no remote server

问题

I'm trying to implement a packet sniffer similar to Charles for iOS using iOS's NetworkExtension framework.

Objective

So, that's a big goal and I'm breaking it down into a tiny piece right now: I want to see the os_log from my NEPacketTunnelProvider (bottom box in diagram)

What I have done so far

1. I have created a NetworkExtension target on type PacketTunnel. This is the code snippet in the 3rd box in the diagram titled "NEPacketTunnelProvider".
2. I have included the "app groups", "personal VPN", and "Network extension" capabilities from within XCode.

Question

I am looking in the Console.app to see the output from os_log("STARTING TUNNEL!!!!"). When I load the configuration and make the call to startVPNTunnel(), why is my TunnelProvider code never called?

I have verified that startVPNTunnel() is being called by placing a breakpoint in my code.

回答1:

There are a good number of reasons why your network extension process may not be starting:

1. I would put a breakpoint on the os_log("STARTING TUNNEL!!!!") and attach to your network extension process in Xcode via Debug -> Attach to Process by PID or Name... before you attempt to start the VPN
2. The network extension must extend the bundle id of the containing app. E.g. if the containing app is com.example.vpn then the network extension might be com.example.vpn.tunnel.
3. Ensure that your Network Extension Info.plist contains the NSExtension dictionary with NSExtensionPointIdentifier and NSExtensionPrincipalClass containing com.apple.networkextension.packet-tunnel and your NEPacketTunnelProvider class (e.g. $(PRODUCT_MODULE_NAME).PacketTunnelProvider) respectively.
4. Is the Packet Tunnel Provider Network Extension entitlement applied to both the containing application and the network extension?
5. If you are implementing a Packet Tunnel Provider, you do not want to enable the Personal VPN entitlement.

回答2:

in startVPNTunnel func ,you should call setTunnelNetworkSettings,then the tunnel will started, after that ,you can read/write packet.

setTunnelNetworkSettings(nil) {  error in
            pendingStartCompletion(error)
            
 }

来源：https://stackoverflow.com/questions/56619465/ios-implementing-netunnelproviderprotocol-with-no-remote-server