* Trigger connection loop on config device addition (fixes#7600)
* Also check for device address equality
* Move EqualStrings from api_test to utils, and use in connections/service.go
* Make sure CommitConfiguration cannot block due on the deviceAddressesChanged channel
* Update lib/connections/service.go
Co-authored-by: Jakob Borg <jakob@kastelo.net>
This adds two new configuration options:
// The number of connections at which we stop trying to connect to more
// devices, zero meaning no limit. Does not affect incoming connections.
ConnectionLimitEnough int
// The maximum number of connections which we will allow in total, zero
// meaning no limit. Affects incoming connections and prevents
// attempting outgoing connections.
ConnectionLimitMax int
These can be used to limit the number of concurrent connections in
various ways.
This breaks out some methods from the connection loop to make it simpler
to manage and understand.
Some slight simplifications to remove the `seen` variable (we can filter
`nextDial` based on times are in the future or not, so we don't need to
track `seen`) and adding a minimum loop interval (5s) in case some
dialer goes haywire and requests a 0s redial interval or such.
Otherwise no significant behavioral changes.
This does two things:
- Exclude QUIC from go1.16 builds, automatically, for now, since it
doesn't work and just panics.
- Provide some fake listeners and dialers when QUIC is disabled.
These fake listeners and dialers indicate that they are disabled and
unsupported, which silences "Dialing $address: unknown address scheme:
quic" type of stuff which is not super helpful to the user.
Our authentication is based on device ID (certificate fingerprint) but
we also check the certificate name for ... historical extra security
reasons. (I don't think this adds anything but it is what it is.) Since
that check breaks in Go 1.15 this change does two things:
- Adds a manual check for the peer certificate CommonName, and if they
are equal we are happy and don't call the more advanced
VerifyHostname() function. This allows our old style certificates to
still pass the check.
- Adds the cert name "syncthing" as a DNS SAN when generating the
certificate. This is the correct way nowadays and makes VerifyHostname()
happy in Go 1.15 as well, even without the above patch.
- In the few places where we wrap errors, use the new Go 1.13 "%w"
construction instead of %s or %v.
- Where we create errors with constant strings, consistently use
errors.New and not fmt.Errorf.
- Remove capitalization from errors in the few places where we had that.
