The extension paper S-Kademlia includes a proposal for lookups over
disjoint paths. Within vanilla Kademlia, queries keep track of the
closest nodes in a single bucket. Any adversary along the path can thus
influence all future paths, in case they can come up with the
next-closest (not overall closest) hops. S-Kademlia tries to solve the
attack above by querying over disjoint paths using multiple buckets.
To adjust the libp2p Kademlia implementation accordingly this change-set
introduces an additional peers iterator: `ClosestDisjointPeersIter`.
This new iterator wraps around a set of `ClosestPeersIter`
`ClosestDisjointPeersIter` enforces that each of the `ClosestPeersIter`
explore disjoint paths by having each peer instantly return that was
queried by a different iterator before.
* Fix broken links in rustdoc
This fixes all of the rustdoc warnings on nightly.
* Check documentation intra-link
* Fix config
* Fix bad indent
* Make nightly explicit
* More links fixes
* Fix link broken after master merge
Co-authored-by: Demi Obenour <48690212+DemiMarie-parity@users.noreply.github.com>
* Address some TODOs, refactor queries and public API.
The following left-over issues are addressed:
* The key for FIND_NODE requests is generalised to any Multihash,
instead of just peer IDs.
* All queries get a (configurable) timeout.
* Finishing queries as soon as enough results have been received is simplified
to avoid code duplication.
* No more panics in provider-API-related code paths. The provider API is
however still untested and (I think) still incomplete (e.g. expiration
of provider records).
* Numerous smaller TODOs encountered in the code.
The following public API changes / additions are made:
* Introduce a `KademliaConfig` with new configuration options for
the replication factor and query timeouts.
* Rename `find_node` to `get_closest_peers`.
* Rename `get_value` to `get_record` and `put_value` to `put_record`,
introducing a `Quorum` parameter for both functions, replacing the
existing `num_results` parameter with clearer semantics.
* Rename `add_providing` to `start_providing` and `remove_providing`
to `stop_providing`.
* Add a `bootstrap` function that implements a (almost) standard
Kademlia bootstrapping procedure.
* Rename `KademliaOut` to `KademliaEvent` with an updated list of
constructors (some renaming). All events that report query results
now report a `Result` to uniformly permit reporting of errors.
The following refactorings are made:
* Introduce some constants.
* Consolidate `query.rs` and `write.rs` behind a common query interface
to reduce duplication and facilitate better code reuse, introducing
the notion of a query peer iterator. `query/peers/closest.rs`
contains the code that was formerly in `query.rs`. `query/peers/fixed.rs` contains
a modified variant of `write.rs` (which is removed). The new `query.rs`
provides an interface for working with a collection of queries, taking
over some code from `behaviour.rs`.
* Reduce code duplication in tests and use the current_thread runtime for
polling swarms to avoid spurious errors in the test output due to aborted
connections when a test finishes prematurely (e.g. because a quorum of
results has been collected).
* Some additions / improvements to the existing tests.
* Fix test.
* Fix rebase.
* Tweak kad-ipfs example.
* Incorporate some feedback.
* Provide easy access and conversion to keys in error results.
