Packet::from_data is ignoring serialization errors:
https://github.com/solana-labs/solana/blob/d08c3232e/sdk/src/packet.rs#L42-L48
This is likely never useful as the packet will be sent over the wire
taking bandwidth but at the receiving end will either fail to
deserialize or it will be invalid.
This commit will propagate the errors out of the function to the
call-site, allowing the call-site to handle the error.
* Fix tower/blockstore unsync due to external causes
* Add and clean up long comments
* Clean up test
* Comment about warped_slot_history
* Run test_future_tower with master-only/master-slave
* Update comments about false leader condition
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.
* Follow up to persistent tower
* Ignore for now...
* Hard-code validator identities for easy reasoning
* Add a test for opt. conf violation without tower
* Fix compile with rust < 1.47
* Remove unused method
* More move of assert tweak to the asser pr
* Add comments
* Clean up
* Clean the test addressing various review comments
* Clean up a bit