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.
mark_pull_request_creation time requires an exclusive lock on gossip:
https://github.com/solana-labs/solana/blob/16944e218/core/src/cluster_info.rs#L1547-L1548
Current code is redundantly marking each peer once for each request.
There are at most only 2 unique peers, whereas there are hundreds of
requests per each. So the lock is acquired hundreds of time longer than
necessary.
ClusterInfo::process_packets handles incoming packets in a thread_pool:
https://github.com/solana-labs/solana/blob/87311cce7/core/src/cluster_info.rs#L2118-L2134
However, profiling runtime shows that threads are not well utilized and
a lot of the processing is done sequentially.
This commit redistributes the work done in parallel. Testing on a gce
cluster shows 20%+ improvement in processing gossip packets with much
smaller variations.
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).
* Filter push/pulls from spies
* Don't pull from peers with shred version == 0, don't push to people with shred_version == 0
Co-authored-by: Carl <carl@solana.com>
* 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