In-Provider Networking
Network APIs for use by all types of NetworkExtension providers and by hotspot helpers.
Overview
NetworkExtension providers and hotspot helpers run in an unusual network environment that can cause problems for general-purpose networking APIs. For example, URLSession typically sends requests via the default route, which is inappropriate for a hotspot helper that must always use the Wi-Fi interface. The NetworkExtension framework includes a number of APIs that are useful in such situations.
These APIs have the following key characteristics:
They aren’t general-purpose APIs; they can only be used in the context of a NetworkExtension provider or hotspot helper.
In many cases, you don’t need to use them. For example, it’s possible for a packet tunnel provider to use a general-purpose networking API, like BSD Sockets, for its tunnel connection.
The recommended general-purpose networking APIs are the URL Loading System for HTTP and the Network framework for TCP and UDP.