Oracle Module in Cross Chain of BNB chain

Oracle relayer

? Tại sao set key manager is nil? → keyword defer

Khá impact. có thể update db! Nhưng giả sử mình là 1 node trong đó thì sao? thao túng được tất cả hay không? có cơ chế nào tránh sự thao túng này không? ← check oracle module

Query seq:

• Gen key: prefix 1 byte, chain id 2 byte, channel id 1 byte
• ABCI query store: /store/sc/key + key

Claim cross chain package log:

• where oracle_sequence = ? and chain_id = ? and status = ?

Get prophecy:

• Gen key: GetClaimId(chainId, channelId, sequence)
• ABCI query: /store/oracle/key + key

append package

claim execute. → broadcast

Oracle module

• route.go

• handler.go

  handleClaimMsg:

  New claim include:

  • claim id (msg.chainid, channelID, msg.Sequence)
  • validator address
  • msg.payload

  Get seq ← key value store in keeper

  REQUIRE: msg.seq == seq

  ProccessClaim ← keeper.go

  fail → delete

  not success → return

  decode payload from string to packages[]

  handlePackage(ctx, oracleKeeper, chainID, &pack)

  ….

  handlePackage:

  executeClaim:

• keeper.go

  ProcessClaim:

  Check valid oracle validator

  REQUIRE: claim≠”” && len(claim.Payload)≠0

  GetProphecy(ctx, claim.ID) ← claim was controlled by oracle relayer

  • Prophecy is not found → create new Prophecy

  REQUIRE: prophecy status is pending

  Add claim (validator address, claim.payload)

  Proccess Completion ← important

  return Prophecy

  processCompletion:

  call highest claim ← highest claim, highest power, total claims power, total power

  why do highestConsensusRatio and highestPossibleConsensusRatio equal 0?

  (!) The precision-adjusted value of the quo() function is 8. Except when highestClaimPower is 0, the result is always 0.

  get consensusNeeded ← kv store

  if highestConsensusRatio ≥ consensusNeeded → set status success, set claim

  else highestPossibleConsensusRatio ≤ consensusNeeded → fail

  return prophecy

• prophecy.go

  Addclaim:

  Add claimPayload to map ValidatorClaims[valAddr]

  Add addr to map ClaimValidators[claimPayload][]

  FindHighestClaim:

  Get Power of oracle relayer

  for each validators of map claimValidators:

  • accure claim power of this claim to find highest claim
  • total all claims power

  total power ← all power of validators

  return highestClaim, highestClaimPower, totalClaimsPower, totalPower

Oracle module Flow