Make UPnP more robust
- Once a random port was mapped, we try to stick to it even if a UPnP
refresh fails. Previously we were immediately moving back to try the
default port, leading to frequent ENR changes.
- We were deleting port mappings before refresh as a possible
workaround. This created issues in some UPnP servers. The UPnP (and PMP)
specification is explicit about the refresh requirements, and delete is
clearly not needed (see
https://github.com/ethereum/go-ethereum/pull/30265#issuecomment-2766987859).
From now on we only delete when closing.
- We were trying to add port mappings only once, and then moved on to
random ports. Now we insist a bit more, so that a simple failed request
won't lead to ENR changes.
Fixes https://github.com/ethereum/go-ethereum/issues/31418
---------
Signed-off-by: Csaba Kiraly <csaba.kiraly@gmail.com>
Co-authored-by: Felix Lange <fjl@twurst.com>
Here we are modifying the port mapping logic so that existing port
mappings will only be removed when they were previously created by geth.
The AddAnyPortMapping functionality has been adapted to work consistently
between the IGDv1 and IGDv2 backends.
This changes the port mapping procedure such that, when the requested port is unavailable
an alternative port suggested by the router is used instead.
We now also repeatedly request the external IP from the router in order to catch any IP changes.
Co-authored-by: Felix Lange <fjl@twurst.com>
