Having an ordinal index on crds values based on insert order allows to
efficiently filter values using a cursor. In particular
CrdsGossipPush::push_messages hash-map can be replaced with a cursor,
saving on the bookkeepings, purging, etc
IP addresses need to be validated before sending packets to them.
This commit, sends a ping packet to nodes before any pull requests.
Pull requests are then only sent to the nodes which have responded with
the correct hash of their respective ping packet.
It is crucial that VersionedCrdsValue::insert_timestamp does not go
backward in time:
https://github.com/solana-labs/solana/blob/ec37a843a/core/src/crds.rs#L67-L79
Otherwise methods such as get_votes and get_epoch_slots_since will
break, which will break their downstream flow, including vote-listener
and optimistic confirmation:
https://github.com/solana-labs/solana/blob/ec37a843a/core/src/cluster_info.rs#L1197-L1215https://github.com/solana-labs/solana/blob/ec37a843a/core/src/cluster_info.rs#L1274-L1298
For that, Crds::new_versioned is intended to be called "atomically" with
Crds::insert_verioned (as the comment already says so):
https://github.com/solana-labs/solana/blob/ec37a843a/core/src/crds.rs#L126-L129
However, currently this is violated in the code. For example,
filter_pull_responses creates VersionedCrdsValues (with the current
timestamp), then acquires an exclusive lock on gossip, then
process_pull_responses writes those values to the crds table:
https://github.com/solana-labs/solana/blob/ec37a843a/core/src/cluster_info.rs#L2375-L2392
Depending on the workload and lock contention, the insert_timestamps may
well be in the past when these values finally are inserted into gossip.
To avoid such scenarios, this commit:
* removes Crds::new_versioned and Crd::insert_versioned.
* makes VersionedCrdsValue constructor private, only invoked in
Crds::insert, so that insert_timestamp is populated right before
insert.
This will improve insert_timestamp monotonicity as long as Crds::insert
is not called with a stalled timestamp. Following commits may further
improve this by calling timestamp() inside Crds::insert, and/or
switching to std::time::Instant which guarantees monotonicity.
Crds values buffered when responding to pull-requests can be very large taking a lot of memory.
Added a limit for number of buffered crds values based on outbound data budget.
https://hackerone.com/reports/991106
> It’s possible to use UDP gossip protocol to amplify DDoS attacks. An attacker
> can spoof IP address in UDP packet when sending PullRequest to the node.
> There's no any validation if provided source IP address is not spoofed and
> the node can send much larger PullResponse to victim's IP. As I checked,
> PullRequest is about 290 bytes, while PullResponse is about 10 kB. It means
> that amplification is about 34x. This way an attacker can easily perform DDoS
> attack both on Solana node and third-party server.
>
> To prevent it, need for example to implement ping-pong mechanism similar as
> in Ethereum: Before accepting requests from remote client needs to validate
> his IP. Local node sends Ping packet to the remote node and it needs to reply
> with Pong packet that contains hash of matching Ping packet. Content of Ping
> packet is unpredictable. If hash from Pong packet matches, local node can
> remember IP where Ping packet was sent as correct and allow further
> communication.
>
> More info:
> https://github.com/ethereum/devp2p/blob/master/discv4.md#endpoint-proof
> https://github.com/ethereum/devp2p/blob/master/discv4.md#wire-protocol
The commit adds a PingCache, which maintains records of remote nodes
which have returned a valid response to a ping message, and on-the-fly
ping messages pending a pong response from the remote node.
When handling pull-requests, those from addresses which have not passed
the ping-pong check are filtered out, and additionally ping packets are
added for addresses which need to be (re)verified.
Based on run-time profiles, the majority time of new_pull_requests is
spent building bloom filters, in hashing and bit-vec ops.
This commit builds crds filters in parallel using rayon constructs. The
added benchmark shows ~5x speedup (4-core machine, 8 threads).
* Gossip benchmark
* Rayon tweaking
* push pulls
* fanout to max nodes
* fixup! fanout to max nodes
* fixup! fixup! fanout to max nodes
* update
* multi vote test
* fixup prune
* fast propagation
* fixups
* compute up to 95%
* test for specific tx
* stats
* stats
* fixed tests
* rename
* track a lagging view of which nodes have the local node in their active set in the local received_cache
* test fixups
* dups are old now
* dont prune your own origin
* send vote to tpu
* tests
* fixed tests
* fixed test
* update
* ignore scale
* lint
* fixup
* fixup
* fixup
* cleanup
Co-authored-by: Stephen Akridge <sakridge@gmail.com>
* Batch process pull responses
* Generate pull requests at 1/2 rate
* Do filtering work of process_pull_response in read lock
Only take write lock to insert if needed.
* filter messages that are likely to be pushed from the response
* tests
* tests
* wait to start filtering responses, and push stats to influx
* wait to start filtering responses, and push stats to influx
* reduce the timers to match the publish self timeout
* fmt
* fmt
* Add CrdsValue timeout checks on Pull Responses
* Allow older values to enter Crds as long as a ContactInfo exists
* Allow staked contact infos to be inserted into crds if they haven't expired
* Try and handle oveflows
* Fix test
* Some comments
* Fix compile
* fix test deadlock
* Add a test for processing timed out values received via pull response
* Remove the name "blob" from archivers
* Remove the name "blob" from broadcast
* Remove the name "blob" from Cluset Info
* Remove the name "blob" from Repair
* Remove the name "blob" from a bunch more places
* Remove the name "blob" from tests and book
* Coalesce gossip pull requests and serve them in batches
* batch all filters and immediately respond to messages in gossip
* Fix tests
* make download_from_replicator perform a greedy recv
* fixed bloom filter math
* Add split each pull request into multiple pulls with different filters
* Rework CrdsFilter to generate all possible masks to cover the keyspace
* Limit the bloom sizes such that each pull request is no larger than mtu
* Be able to create bank snapshots
* fix clippy
* load snapshot on start
* regenerate account index from the storage
* Remove rc feature dependency
* cleanup
* save snapshot for slot 0
* Add Epoch Slots to gossip
* Add new gossip structure to support Repair
* remove unnecessary clones
* Setup dummy fast repair in repair_service
* PR comments
behzad nouri
Michael Vines
sakridge
anatoly yakovenko
Sagar Dhawan
Justin Starry
Sathish
Rob Walker
carllin
