New GetMaxMajorProtocolVersion shelley query

Author: jasagredo

ouroboros-consensus-cardano/changelog.d/20250616_122911_javier.sagredo_query_max_major_prot_ver.md

@@ -0,0 +1,23 @@
+<!--
+A new scriv changelog fragment.
+
+Uncomment the section that is right (remove the HTML comment wrapper).
+-->
+
+<!--
+### Patch
+
+- A bullet item for the Patch category.
+
+-->
+<!--
+### Non-Breaking
+
+- A bullet item for the Non-Breaking category.
+
+-->
+
+### Breaking
+
+- Expose new query `GetMaxMajorProtocolVersion` as a Shelley query, for getting
+  the max known protocol version for a node.

ouroboros-consensus-cardano/src/shelley/Ouroboros/Consensus/Shelley/Ledger/Query.hs

@@ -96,6 +96,7 @@ import Ouroboros.Consensus.Ledger.Query
 import Ouroboros.Consensus.Ledger.SupportsPeerSelection
 import Ouroboros.Consensus.Ledger.SupportsProtocol
 import Ouroboros.Consensus.Protocol.Abstract (ChainDepState)
+import Ouroboros.Consensus.Protocol.Praos.Common
 import qualified Ouroboros.Consensus.Shelley.Eras as SE
 import Ouroboros.Consensus.Shelley.Ledger.Block
 import Ouroboros.Consensus.Shelley.Ledger.Config
@@ -360,6 +361,8 @@ data instance BlockQuery (ShelleyBlock proto era) fp result where
   -- pools, in an extensible fashion.
   GetStakeDistribution2 ::
     BlockQuery (ShelleyBlock proto era) QFNoTables SL.PoolDistr
+  GetMaxMajorProtocolVersion ::
+    BlockQuery (ShelleyBlock proto era) QFNoTables MaxMajorProtVer
 
 -- WARNING: please add new queries to the end of the list and stick to this
 -- order in all other pattern matches on queries. This helps in particular
@@ -534,6 +537,11 @@ instance
          in SL.calculatePoolDistr' (maybe (const True) (flip Set.member) mPoolIds) stakeSet
       GetStakeDistribution2 ->
         SL.poolsByTotalStakeFraction globals st
+      GetMaxMajorProtocolVersion ->
+        protoMaxMajorPV
+          . configConsensus
+          . getExtLedgerCfg
+          $ cfg
    where
     lcfg = configLedger $ getExtLedgerCfg cfg
     globals = shelleyLedgerGlobals lcfg
@@ -592,6 +600,7 @@ instance
     QueryStakePoolDefaultVote{} -> (>= v12)
     GetPoolDistr2{} -> (>= v13)
     GetStakeDistribution2{} -> (>= v13)
+    GetMaxMajorProtocolVersion -> (>= v13)
    where
     -- WARNING: when adding a new query, a new @ShelleyNodeToClientVersionX@
     -- must be added. See #2830 for a template on how to do this.
@@ -759,6 +768,8 @@ instance SameDepIndex2 (BlockQuery (ShelleyBlock proto era)) where
   sameDepIndex2 GetPoolDistr2{} _ = Nothing
   sameDepIndex2 GetStakeDistribution2{} GetStakeDistribution2{} = Just Refl
   sameDepIndex2 GetStakeDistribution2{} _ = Nothing
+  sameDepIndex2 GetMaxMajorProtocolVersion{} GetMaxMajorProtocolVersion{} = Just Refl
+  sameDepIndex2 GetMaxMajorProtocolVersion{} _ = Nothing
 
 deriving instance Eq (BlockQuery (ShelleyBlock proto era) fp result)
 deriving instance Show (BlockQuery (ShelleyBlock proto era) fp result)
@@ -803,6 +814,7 @@ instance ShelleyCompatible proto era => ShowQuery (BlockQuery (ShelleyBlock prot
     QueryStakePoolDefaultVote{} -> show
     GetPoolDistr2{} -> show
     GetStakeDistribution2{} -> show
+    GetMaxMajorProtocolVersion{} -> show
 
 {-------------------------------------------------------------------------------
   Auxiliary
@@ -929,6 +941,8 @@ encodeShelleyQuery query = case query of
     CBOR.encodeListLen 2 <> CBOR.encodeWord8 36 <> toCBOR poolids
   GetStakeDistribution2 ->
     CBOR.encodeListLen 1 <> CBOR.encodeWord8 37
+  GetMaxMajorProtocolVersion ->
+    CBOR.encodeListLen 1 <> CBOR.encodeWord8 38
 
 decodeShelleyQuery ::
   forall era proto.
@@ -1002,6 +1016,7 @@ decodeShelleyQuery = do
     (2, 35) -> requireCG $ SomeBlockQuery . QueryStakePoolDefaultVote <$> LC.fromEraCBOR @era
     (2, 36) -> SomeBlockQuery . GetPoolDistr2 <$> fromCBOR
     (1, 37) -> return $ SomeBlockQuery GetStakeDistribution2
+    (1, 38) -> return $ SomeBlockQuery GetMaxMajorProtocolVersion
     _ -> failmsg "invalid"
 
 encodeShelleyResult ::
@@ -1050,6 +1065,7 @@ encodeShelleyResult v query = case query of
   QueryStakePoolDefaultVote{} -> toCBOR
   GetPoolDistr2{} -> LC.toEraCBOR @era
   GetStakeDistribution2{} -> LC.toEraCBOR @era
+  GetMaxMajorProtocolVersion -> toCBOR
 
 decodeShelleyResult ::
   forall proto era fp result.
@@ -1097,6 +1113,7 @@ decodeShelleyResult v query = case query of
   QueryStakePoolDefaultVote{} -> fromCBOR
   GetPoolDistr2{} -> LC.fromEraCBOR @era
   GetStakeDistribution2 -> LC.fromEraCBOR @era
+  GetMaxMajorProtocolVersion -> fromCBOR
 
 currentPParamsEnDecoding ::
   forall era s.

ouroboros-consensus-cardano/src/shelley/Ouroboros/Consensus/Shelley/Protocol/Abstract.hs

@@ -60,6 +60,7 @@ import Ouroboros.Consensus.Protocol.Abstract
   , ValidateView
   )
 import Ouroboros.Consensus.Protocol.Ledger.HotKey (HotKey)
+import Ouroboros.Consensus.Protocol.Praos.Common (HasMaxMajorProtVer)
 import Ouroboros.Consensus.Protocol.Signed (SignedHeader)
 import Ouroboros.Consensus.Util.Condense (Condense (..))
 
@@ -201,5 +202,6 @@ class
   , ProtocolHeaderSupportsLedger proto
   , Serialise (ChainDepState proto)
   , SignedHeader (ShelleyProtocolHeader proto)
+  , HasMaxMajorProtVer proto
   ) =>
   ShelleyProtocol proto

ouroboros-consensus-protocol/changelog.d/20250616_122906_javier.sagredo_query_max_major_prot_ver.md

@@ -0,0 +1,21 @@
+<!--
+A new scriv changelog fragment.
+
+Uncomment the section that is right (remove the HTML comment wrapper).
+-->
+
+<!--
+### Patch
+
+- A bullet item for the Patch category.
+
+-->
+<!--
+### Non-Breaking
+
+- A bullet item for the Non-Breaking category.
+
+-->
+### Breaking
+
+- Add new `HasMaxMajorProtVer` class for consensus protocols.

ouroboros-consensus-protocol/src/ouroboros-consensus-protocol/Ouroboros/Consensus/Protocol/Praos.hs

@@ -260,6 +260,9 @@ instance PraosCrypto c => NoThunks (ConsensusConfig (Praos c))
 
 type PraosValidateView c = Views.HeaderView c
 
+instance HasMaxMajorProtVer (Praos c) where
+  protoMaxMajorPV = praosMaxMajorPV . praosParams
+
 {-------------------------------------------------------------------------------
   ConsensusProtocol
 -------------------------------------------------------------------------------}

ouroboros-consensus-protocol/src/ouroboros-consensus-protocol/Ouroboros/Consensus/Protocol/Praos/Common.hs

@@ -9,6 +9,7 @@
 -- | Various things common to iterations of the Praos protocol.
 module Ouroboros.Consensus.Protocol.Praos.Common
   ( MaxMajorProtVer (..)
+  , HasMaxMajorProtVer (..)
   , PraosCanBeLeader (..)
   , PraosChainSelectView (..)
   , VRFTiebreakerFlavor (..)
@@ -21,6 +22,7 @@ module Ouroboros.Consensus.Protocol.Praos.Common
 import qualified Cardano.Crypto.VRF as VRF
 import Cardano.Ledger.BaseTypes (Nonce)
 import qualified Cardano.Ledger.BaseTypes as SL
+import Cardano.Ledger.Binary (FromCBOR, ToCBOR)
 import Cardano.Ledger.Keys (KeyHash, KeyRole (BlockIssuer))
 import qualified Cardano.Ledger.Shelley.API as SL
 import Cardano.Protocol.Crypto (Crypto, VRF)
@@ -59,7 +61,10 @@ newtype MaxMajorProtVer = MaxMajorProtVer
   { getMaxMajorProtVer :: SL.Version
   }
   deriving (Eq, Show, Generic)
-  deriving newtype NoThunks
+  deriving newtype (NoThunks, ToCBOR, FromCBOR)
+
+class HasMaxMajorProtVer proto where
+  protoMaxMajorPV :: ConsensusConfig proto -> MaxMajorProtVer
 
 -- | View of the tip of a header fragment for chain selection.
 data PraosChainSelectView c = PraosChainSelectView

ouroboros-consensus-protocol/src/ouroboros-consensus-protocol/Ouroboros/Consensus/Protocol/TPraos.hs

@@ -257,6 +257,9 @@ data instance ConsensusConfig (TPraos c) = TPraosConfig
 
 instance SL.PraosCrypto c => NoThunks (ConsensusConfig (TPraos c))
 
+instance HasMaxMajorProtVer (TPraos c) where
+  protoMaxMajorPV = tpraosMaxMajorPV . tpraosParams
+
 -- | Transitional Praos consensus state.
 --
 -- In addition to the 'ChainDepState' provided by the ledger, we track the slot