…h means do not abort the query early

…ient.

…we have heard about (in a given path) has been found

…ally. Concurrency option now sets alpha. DisjointPaths option now sets d. Default number of disjoint paths is now bucketSize/2.

* feat: consume identify events to evaluate routing table addition
* fix: routing table no longer gets an update just because new messages have arrived or been sent
* fix: add already connected peers into the routing table before listening to events

Co-authored-by: Raúl Kripalani <raul.kripalani@gmail.com>
Co-authored-by: Aarsh Shah <aarshkshah1992@gmail.com>

1. Continue to best-effort provide, but still return an error when we fail to
send provider records to the _best_ peers.
2. Continue returning the best peer's we've found in GetClosestPeers, but also
return an error to indicate that we didn't find the closest ones.

And fix the hang test.

* created Mode(ModeOpt) option for choosing between auto/client/server modes
* Auto mode internally switches the DHT between client and server modes based on the EvtLocalReachabilityChanged event emitted on the event bus (e.g. by AutoNAT)
* routing table management of peers that switch between client and server mode while we are connected to them (i.e. are in auto mode)
* removed Client(bool) option, becoming a DHT client is specified using Mode(ModeClient) instead

* feat: move options to main package and make internals private

Rationale:

1. This allows us to make private options for testing.
2. This removes an import for DHT users.
3. This makes options much easier to discover.
4. This makes it possible to make the config/options internals private.

We originally put them in a sub-package to avoid poluting the root namespace,
but that isn't really necessary.

This keeps the old package (for now) to avoid breaking too much.

* upgraded the protocol id to version 2 (i.e. /kad/2.0.0) and made it so v2 peers running in server mode respond to queries from v1 peers. Note: v2 peers will only send queries using the v2 protocol, will only add v2 peers to their routing tables, and will only tell v1 peers about v2 peers.
* to run a forked network we now use network specific protocol prefixes instead of manually setting protocol IDs. Use the ProtocolPrefix option instead of the Protocols option.
* emit errors during initialization if the user misuses the default protocol prefix by setting parameters inconsistent with the default protocol's network specification
* since the Client option has been deprecated it's been removed from the dht's options. While deprecated it is still available in the dht options package. Setting `Client(false)` now puts the node into ModeAuto.

* kpeerset refactoring
* query code cleanup

… Windows

…faulting to zero

…he query

* feat(query): fully async implementation of Kademlia lookup. peers returned from the lookup are not guaranteed to be alive (i.e. we're only guaranteed to have dialed the closest beta peers to the target), but given stable and correct routing tables the expectation that most of the peers returned are alive is high.
* feat(query): add wrapper lookup followup function to followup after the lookup is completed and ensure that the closest k returned peers from a lookup have been queried even for beta < k
* refactor(query) modified the structure returned from lookups to be a useful subset of the full query state instead of the entire query state
* feat(options): beta parameter exposed as the Resiliency parameter
* feat(routing): do not mark the routing table as updated after a FindPeer query
* feat(routing): FindPeer can return addresses even if not Connected as long as it was either recently connected (CanConnect) or was discovered during the lookup
* feat(bootstrap): bootstrap logic now uses GetClosestPeers instead of FindPeer
* refactor(dht): stopFn no longer takes any state
* fix(test): changed GetClosestPeers test to only assume beta instead of k peers since that is now more appropriate given the query logic changes and that the routing tables in that test are bad, i.e. a ring network with arbitrary peerIDs

Co-authored-by: Petar Maymounkov <petarm@gmail.com>
Co-authored-by: Aarsh Shah <aarshkshah1992@gmail.com>

* remove disjoint queries
* remove globally queried check
* removed dht rng field and mutex
* removed the Disjoint option

Co-authored-by: Adin Schmahmann <adin.schmahmann@gmail.com>

… DHT routing tables before running. TestFindPeerQuery no longer runs with the race detector because it uses too many goroutines.

Allows specifying peer filter functions on query and on adding peers to the routing table. This patch also includes some reasonable default functions for a public-only and private-only DHT.

Co-authored-by: Will Scott <will@cypherpunk.email>
Co-authored-by: Steven Allen <steven@stebalien.com>

This should stop us from waiting on unresponsive peers. This only kicks in when
we've already _sent_ a request so this:

* Shouldn't be blocked on other requests we're planning on making.
* Shouldn't be blocked on dialing.

* Add Kademlia async lookup implementation (replaces prior implementation)
* Add lookup events that allow full lookup reconstruction from logs
* Introduce lookup stopping condition, based on parameter "beta"

Co-authored-by: Adin Schmahmann <adin.schmahmann@gmail.com>

Previously, we'd only return the target peer if we were connected to them.
However, this makes it difficult to impossible to find peers that are mostly
disconnected from the network.

This change also changes `p` to `from` in several places as `p` is _very_
confusing. We should probably switch away from using `p` everywhere.

* new RT management policy

* fix Low Peers and Cleanup

…rs (#536)

* record valuable peers algorithm only takes into account latency of seed peers

…ns an error instead of hanging

Except deprecated warn calls

* Remove deprecated events.
* Fix warning -> warn.
* Use structured logging (some places).

The querying node _is_ allowed to reset and go away.

fixes #431

When this option is passed, the DHT node will listen on and query _only_ using
the old DHT protocol. Importantly, the node won't even pretend to be a new DHT
node because it's routing table includes V1 peers.

We no longer need this now that we explicitly support v1 compatibility mode.

…nd refresh routing tables for orphaned nodes