feat(code/consensus): Add support for full nodes

[hoank101]

Closes: #742

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PR author checklist

For all contributors

• Reference GitHub issue
• Ensure PR title follows the conventional commits spec

For external contributors

• Maintainers of Malachite are allowed to push changes to the branch

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 75.54%. Comparing base (3e977d1) to head (a6c29b2).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #750      +/-   ##
==========================================
+ Coverage   75.51%   75.54%   +0.03%     
==========================================
  Files         165      165              
  Lines       14301    14329      +28     
==========================================
+ Hits        10799    10824      +25     
- Misses       3502     3505       +3     

Flag	Coverage Δ
integration	75.54% <ø> (+0.03%)	⬆️

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[romac]

Great work! 🚀

[ancazamfir]

Not sure about the proposal filtering, seems we are trying to defend against a bug where get_proposer() returns a non-validator/ full node address...but in this case the is_validator() should also fail.

[romac]

Yes it's just defensive coding. Maybe we can change the check to do a debug_assert or even an assert in order to ensure this code path is never hit.

[ancazamfir]

Can we start a full node from command line?

[ancazamfir]

Wondering if we should send VoteSetRequest to a non-validator, or accept VoteSetResponse from a non-validator.

[ancazamfir]

So for the receive side, verify_signed_vote() and verify_signed_proposal() handle the case where a full node sends messages and we will see warning messages of the form: Received vote/proposal from unknown validator. Maybe non-validator would be better but really minor.

[romac]

Wondering if we should send VoteSetRequest to a non-validator, or accept VoteSetResponse from a non-validator.

Good question, perhaps there is a higher chance that non-validators might be byzantine and in that case we should restrict those queries to validators only?

[romac]

Can we start a full node from command line?

Not at the moment, you have to remove the full node address from the validator set in the genesis of all validator nodes.

[ancazamfir]

Wondering if we should send VoteSetRequest to a non-validator, or accept VoteSetResponse from a non-validator.

Good question, perhaps there is a higher chance that non-validators might be byzantine and in that case we should restrict those queries to validators only?

Not sure myself, let's discuss next time we meet. On a side note, we should allow vote sync when blocksync is disabled (iirc this is not the case today)