Merge branch 'fix-poll-behaviour-for-tcp-based-tunnel-protocols'

Merge branch 'fix-poll-behaviour-for-tcp-based-tunnel-protocols'

Ralf Lici says:

====================
fix poll behaviour for TCP-based tunnel protocols

This patch series introduces a polling function for datagram-style
sockets that operates on custom skb queues, and updates ovpn (the
OpenVPN data-channel offload module) and espintcp (the TCP Encapsulation
of IKE and IPsec Packets implementation) to use it accordingly.

Protocols like the aforementioned one decapsulate packets received over
TCP and deliver userspace-bound data through a separate skb queue, not
the standard sk_receive_queue. Previously, both relied on
datagram_poll(), which would signal readiness based on non-userspace
packets, leading to misleading poll results and unnecessary recv
attempts in userspace.

Patch 1 introduces datagram_poll_queue(), a variant of datagram_poll()
that accepts an explicit receive queue. This builds on the approach
introduced in commit b50b058, which extended other skb-related functions
to support custom queues. Patch 2 and 3 update espintcp_poll() and
ovpn_tcp_poll() respectively to use this helper, ensuring readiness is
only signaled when userspace data is available.

Each patch is self-contained and the ovpn one includes rationale and
lifecycle enforcement where appropriate.
====================

Link: https://patch.msgid.link/20251021100942.195010-1-ralf@mandelbit.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>