This makes it OK to not have any listeners working. Specifically,
- We don't complain about an empty listener address
- We don't complain about not having anything to announce to global
discovery servers
- We don't send local discovery packets when there is nothing to
announce.
The last point also fixes a thing where the list of addresses for local
discovery was set at startup time and never refreshed.
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4517
This makes the device ID a real type that can be used in the protobuf
schema. That avoids the juggling back and forth from []byte in a bunch
of places and simplifies the code.
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3695
A random "instance ID" is generated on each start of the local discovery
service. The instance ID is included in the announcement. When we see a
new instance ID we treat is a new device and respond with an
announcement of our own. Hence devices get to know each other quickly on
restart.
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3385
