attestation consensus stuff. compiling not tested

src/ripple/app/tx/impl/Attest.cpp

@@ -71,6 +71,7 @@ Attest::preclaim(PreclaimContext const& ctx)
     else if (!exists && isDelete)
         return tecNO_ENTRY;
 
+
     return tesSUCCESS;
 }
 
@@ -83,6 +84,19 @@ Attest::doApply()
     if (!sle)
         return tefINTERNAL;
 
+    // check for sufficient reserves
+    {
+        STAmount const reserve{
+            view().fees().accountReserve(sle->getFieldU32(sfOwnerCount) + 1)};
+
+        STAmount const afterFee =
+            mPriorBalance - ctx_.tx.getFieldAmount(sfFee).xrp();
+
+        if (afterFee > mPriorBalance || afterFee < reserve)
+            return tecINSUFFICIENT_RESERVE;
+    }
+
+
     Keylet kl =
         keylet::attestation(account_, ctx_.tx.getFieldH256(sfAttestedTxnID));
 

src/ripple/app/tx/impl/Transactor.cpp

@@ -85,6 +85,41 @@ preflight0(PreflightContext const& ctx)
         return temINVALID;
     }
 
+    // don't allow attestations unless enabled
+    if (ctx.tx.isFieldPresent(sfAttesters))
+    {
+        if (!ctx.rules.enabled(featureAttestations))
+            return temDISABLED;
+
+        // make sure they can't spam millions of attesters
+        auto const& attesters = ctx.tx.getFieldArray(sfAttesters);
+        if (attesters.empty() || attesters.size() > 32)
+        {
+            JLOG(ctx.j.warn())
+                << "applyTransaction: attesters array too big (max 32) or empty.";
+            return temMALFORMED;
+        }
+  
+        // sanity check entries
+        std::set<AccountID> used; 
+        for (auto const& attester: attesters)
+        {
+            if (attester.getFName() != sfAttesterEntry)
+            {
+                JLOG(ctx.j.warn())
+                    << "applyTransaction: attesters array contained non AttesterEntry object.";
+                return temMALFORMED;
+            }
+
+            if (used.find(attester.getAccountID(sfAccount)) != used.end())
+            {
+                JLOG(ctx.j.warn())
+                    << "applyTransaction: attesters array contained duplicate attester ID.";
+                return temMALFORMED;
+            }
+        }
+    }
+
     return tesSUCCESS;
 }
 
@@ -1928,6 +1963,54 @@ Transactor::operator()()
         }
     }
 
+    if (applied && ctx_.tx.isFieldPresent(sfAttesters) && view().rules().enabled(featureAttestations))
+    {
+        // delete used attestation objects 
+        
+        auto const& attesters = ctx_.tx.getFieldArray(sfAttesters);
+        auto const txid = ctx_.tx.getTransactionID();
+
+        auto const& j = ctx_.app.journal("View");
+
+        for (auto const& attester : attesters)
+        {
+            Keylet kl = keylet::attestation(attester.getAccountID(sfAccount), txid);
+            if (!view().exists(kl))
+            {
+                JLOG(j.warn())
+                    << "Transactor: Warning!!! Attestation does not exist at end of attested txn "
+                    << txid;
+                continue;
+            }
+
+            // remove from dir
+            auto sleA = view().peek(kl);
+
+            AccountID owner = sleA->getAccountID(sfOwner);
+            auto sle = view().peek(keylet::account(owner));
+
+            if (!sle)
+            {
+                JLOG(j.warn()) 
+                    << "Transactor: Warning!!! Attester account does not exist at the end of attested txn "
+                    << txid;
+                continue;
+            }
+
+            auto const page = (*sleA)[sfOwnerNode];
+            if (!view().dirRemove(
+                    keylet::ownerDir(owner), page, kl.key, true))
+            {
+                JLOG(j.warn())
+                    << "Could not remove Attestation from owner directory";
+                continue;
+            }
+
+            view().erase(sleA);
+            adjustOwnerCount(view(), sle, -1, j);
+        }
+    }
+
     // Post-application (Weak TSH/AAW) Hooks are executed here.
     // These TSH do not have the ability to rollback.
     // The callback, if any, is also executed here.

src/ripple/app/tx/impl/Transactor.h

@@ -160,6 +160,20 @@ public:
     {
         // Most transactors do nothing
         // after checkSeq/Fee/Sign.
+        
+        if (ctx.tx.isFieldPresent(sfAttesters) && ctx.view.rules().enabled(featureAttestations))
+        {
+            // check if the required attestations are present on ledger
+            auto const& attesters = ctx.tx.getFieldArray(sfAttesters);
+
+            auto const txid = ctx.tx.getTransactionID();
+
+            // each required attestation must exist on the ledger to allow the txn through
+            // otherwise it gets marked retry
+            for (auto const& attester : attesters)
+                if (!ctx.view.exists(keylet::attestation(attester.getAccountID(sfAccount), txid)))
+                    return terRETRY;
+        }
         return tesSUCCESS;
     }
     /////////////////////////////////////////////////////

src/ripple/protocol/SField.h

@@ -591,6 +591,7 @@ extern SField const sfHookGrant;
 extern SField const sfActiveValidator;
 extern SField const sfImportVLKey;
 extern SField const sfHookEmission;
+extern SField const sfAttesterEntry;
 
 // array of objects (common)
 // ARRAY/1 is reserved for end of array
@@ -618,6 +619,7 @@ extern SField const sfGenesisMints;
 extern SField const sfActiveValidators;
 extern SField const sfImportVLKeys;
 extern SField const sfHookEmissions;
+extern SField const sfAttesters;
 
 //------------------------------------------------------------------------------
 

src/ripple/protocol/impl/InnerObjectFormats.cpp

@@ -141,6 +141,13 @@ InnerObjectFormats::InnerObjectFormats()
             {sfPublicKey, soeREQUIRED},
             {sfAccount, soeOPTIONAL},
         });
+
+    add(sfAttesterEntry.jsonName.c_str(),
+        sfAttesterEntry.getCode(),
+        {
+            {sfAccount, soeREQUIRED},
+            {sfFlags,   soeREQUIRED},
+        });
 }
 
 InnerObjectFormats const&

src/ripple/protocol/impl/SField.cpp

@@ -347,6 +347,7 @@ CONSTRUCT_UNTYPED_SFIELD(sfGenesisMint,         "GenesisMint",          OBJECT,
 CONSTRUCT_UNTYPED_SFIELD(sfActiveValidator,     "ActiveValidator",      OBJECT,    95);
 CONSTRUCT_UNTYPED_SFIELD(sfImportVLKey,         "ImportVLKey",          OBJECT,    94);
 CONSTRUCT_UNTYPED_SFIELD(sfHookEmission,        "HookEmission",         OBJECT,    93);
+CONSTRUCT_UNTYPED_SFIELD(sfAttesterEntry,       "AttesterEntry",        OBJECT,    90);
 
 // array of objects
 //                                                                            ARRAY/1 is reserved for end of array
@@ -371,6 +372,7 @@ CONSTRUCT_UNTYPED_SFIELD(sfGenesisMints,        "GenesisMints",         ARRAY,
 CONSTRUCT_UNTYPED_SFIELD(sfActiveValidators,    "ActiveValidators",     ARRAY,     95);
 CONSTRUCT_UNTYPED_SFIELD(sfImportVLKeys,        "ImportVLKeys",         ARRAY,     94);
 CONSTRUCT_UNTYPED_SFIELD(sfHookEmissions,       "HookEmissions",        ARRAY,     93);
+CONSTRUCT_UNTYPED_SFIELD(sfAttesters,           "Attesters",            ARRAY,     91);
 
 // clang-format on
 

src/ripple/protocol/impl/TxFormats.cpp

@@ -44,6 +44,7 @@ TxFormats::TxFormats()
         {sfNetworkID, soeOPTIONAL},
         {sfHookParameters, soeOPTIONAL},
         {sfOperationLimit, soeOPTIONAL},
+        {sfAttesters, soeOPTIONAL},
     };
 
     add(jss::AccountSet,

src/ripple/protocol/jss.h

@@ -51,6 +51,7 @@ JSS(Amendments);     // ledger type.
 JSS(Amount);         // in: TransactionSign; field.
 JSS(Authorize);      // field
 JSS(Attest);
+JSS(AttesterEntry);
 JSS(Attestation);
 JSS(Blob);
 JSS(Check);              // ledger type.