Add LoanBrokerCoverWithdraw transaction

- Untested

include/xrpl/protocol/Protocol.h

@@ -102,6 +102,11 @@ std::uint16_t constexpr maxFeeRate = 10'000;
 */
 std::uint32_t constexpr maxCoverRate = 100'000;
 
+/** Basis points (bps) represent 0.01% of a thing. Given a value X, to find the
+ * amount for B bps, use X * B / bpsPerOne
+ */
+std::uint32_t constexpr bpsPerOne = 10'000;
+
 /** The maximum length of a URI inside an NFT */
 std::size_t constexpr maxTokenURILength = 256;
 

include/xrpl/protocol/detail/transactions.macro

@@ -22,12 +22,12 @@
 #endif
 
 /**
- * TRANSACTION(tag, value, name, fields)
+ * TRANSACTION(tag, value, name, privileges, fields)
  *
  * You must define a transactor class in the `ripple` namespace named `name`,
  * and include its header in `src/xrpld/app/tx/detail/applySteps.cpp`.
  *
- * The fourth parameter of the TRANSACTION macro is a bitfield
+ * The `privileges` parameter of the TRANSACTION macro is a bitfield
  * defining which operations the transaction can perform.
  *
  * The values are only used in InvariantCheck.cpp
@@ -557,16 +557,16 @@ TRANSACTION(ttLOAN_BROKER_DELETE, 75, LoanBrokerDelete,
 /** This transaction deposits First Loss Capital into a Loan Broker */
 TRANSACTION(ttLOAN_BROKER_COVER_DEPOSIT, 76, LoanBrokerCoverDeposit, noPriv, ({
     {sfLoanBrokerID, soeREQUIRED},
-    {sfAmount, soeREQUIRED},
+    {sfAmount, soeREQUIRED, soeMPTSupported},
 }))
 
-#if 0
 /** This transaction withdraws First Loss Capital from a Loan Broker */
 TRANSACTION(ttLOAN_BROKER_COVER_WITHDRAW, 77, LoanBrokerCoverWithdraw, noPriv, ({
     {sfLoanBrokerID, soeREQUIRED},
-    {sfAmount, soeREQUIRED},
+    {sfAmount, soeREQUIRED, soeMPTSupported},
 }))
 
+#if 0
 /** This transaction creates a Loan */
 TRANSACTION(ttLOAN_SET, 78, LoanSet, noPriv, ({
     {sfLoanBrokerID, soeREQUIRED},
@@ -600,13 +600,13 @@ TRANSACTION(ttLOAN_MANAGE, 80, LoanManage, noPriv, ({
 /** The Borrower uses this transaction to draws funds from the Loan. */
 TRANSACTION(ttLOAN_DRAW, 81, LoanDraw, noPriv, ({
     {sfLoanID, soeREQUIRED},
-    {sfAmount, soeREQUIRED},
+    {sfAmount, soeREQUIRED, soeMPTSupported},
 }))
 
 /** The Borrower uses this transaction to make a Payment on the Loan. */
 TRANSACTION(ttLOAN_PAY, 82, LoanPay, noPriv, ({
     {sfLoanID, soeREQUIRED},
-    {sfAmount, soeREQUIRED},
+    {sfAmount, soeREQUIRED, soeMPTSupported},
 }))
 #endif
 

src/xrpld/app/tx/detail/LoanBrokerCoverDeposit.cpp

@@ -91,9 +91,18 @@ LoanBrokerCoverDeposit::preclaim(PreclaimContext const& ctx)
     if (amount.asset() != vaultAsset)
         return tecWRONG_ASSET;
 
+    auto const pseudoAccountID = sleBroker->at(sfAccount);
+
     // Cannot transfer a frozen Asset
     if (isFrozen(ctx.view, account, vaultAsset))
         return vaultAsset.holds<Issue>() ? tecFROZEN : tecLOCKED;
+    if (vaultAsset.holds<Issue>())
+    {
+        auto const issue = vaultAsset.get<Issue>();
+        if (isDeepFrozen(
+                ctx.view, pseudoAccountID, issue.currency, issue.account))
+            return tecFROZEN;
+    }
 
     if (accountHolds(
             ctx.view,

src/xrpld/app/tx/detail/LoanBrokerCoverWithdraw.cpp

@@ -0,0 +1,162 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2025 Ripple Labs Inc.
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include <xrpld/app/tx/detail/LoanBrokerCoverWithdraw.h>
+#include <xrpld/app/tx/detail/LoanBrokerSet.h>
+#include <xrpld/ledger/ApplyView.h>
+#include <xrpld/ledger/View.h>
+
+#include <xrpl/basics/Log.h>
+#include <xrpl/basics/Number.h>
+#include <xrpl/basics/chrono.h>
+#include <xrpl/beast/utility/Journal.h>
+#include <xrpl/beast/utility/instrumentation.h>
+#include <xrpl/protocol/AccountID.h>
+#include <xrpl/protocol/Feature.h>
+#include <xrpl/protocol/Indexes.h>
+#include <xrpl/protocol/PublicKey.h>
+#include <xrpl/protocol/SField.h>
+#include <xrpl/protocol/STAmount.h>
+#include <xrpl/protocol/STNumber.h>
+#include <xrpl/protocol/STObject.h>
+#include <xrpl/protocol/TER.h>
+#include <xrpl/protocol/TxFlags.h>
+#include <xrpl/protocol/XRPAmount.h>
+
+namespace ripple {
+
+bool
+LoanBrokerCoverWithdraw::isEnabled(PreflightContext const& ctx)
+{
+    return lendingProtocolEnabled(ctx);
+}
+
+std::uint32_t
+LoanBrokerCoverWithdraw::getFlagsMask(PreflightContext const& ctx)
+{
+    return tfUniversalMask;
+}
+
+NotTEC
+LoanBrokerCoverWithdraw::doPreflight(PreflightContext const& ctx)
+{
+    if (ctx.tx[sfLoanBrokerID] == beast::zero)
+        return temINVALID;
+
+    if (ctx.tx[sfAmount] <= beast::zero)
+        return temBAD_AMOUNT;
+
+    return tesSUCCESS;
+}
+
+TER
+LoanBrokerCoverWithdraw::preclaim(PreclaimContext const& ctx)
+{
+    auto const& tx = ctx.tx;
+
+    auto const account = tx[sfAccount];
+    auto const brokerID = tx[sfLoanBrokerID];
+    auto const amount = tx[sfAmount];
+
+    auto const sleBroker = ctx.view.read(keylet::loanbroker(brokerID));
+    if (!sleBroker)
+    {
+        JLOG(ctx.j.warn()) << "LoanBroker does not exist.";
+        return tecNO_ENTRY;
+    }
+    if (account != sleBroker->at(sfOwner))
+    {
+        JLOG(ctx.j.warn()) << "Account is not the owner of the LoanBroker.";
+        return tecNO_PERMISSION;
+    }
+    auto const vault = ctx.view.read(keylet::vault(sleBroker->at(sfVaultID)));
+    auto const vaultAsset = vault->at(sfAsset);
+
+    if (amount.asset() != vaultAsset)
+        return tecWRONG_ASSET;
+
+    // Cannot transfer a frozen Asset
+    auto const pseudoAccountID = sleBroker->at(sfAccount);
+
+    // Cannot transfer a frozen Asset
+    /*
+    if (isFrozen(ctx.view, account, vaultAsset))
+        return vaultAsset.holds<Issue>() ? tecFROZEN : tecLOCKED;
+    */
+    if (isFrozen(ctx.view, pseudoAccountID, vaultAsset))
+        return vaultAsset.holds<Issue>() ? tecFROZEN : tecLOCKED;
+    if (vaultAsset.holds<Issue>())
+    {
+        auto const issue = vaultAsset.get<Issue>();
+        if (isDeepFrozen(ctx.view, account, issue.currency, issue.account))
+            return tecFROZEN;
+    }
+
+    auto const coverAvail = sleBroker->at(sfCoverAvailable);
+    // Cover Rate is in 1/10 bps units
+    auto const minimumCover = sleBroker->at(sfDebtTotal) *
+        sleBroker->at(sfCoverRateMinimum) / bpsPerOne / 10;
+    if (coverAvail < amount)
+        return tecINSUFFICIENT_FUNDS;
+    if ((coverAvail - amount) < minimumCover)
+        return tecINSUFFICIENT_FUNDS;
+
+    if (accountHolds(
+            ctx.view,
+            account,
+            vaultAsset,
+            FreezeHandling::fhZERO_IF_FROZEN,
+            AuthHandling::ahZERO_IF_UNAUTHORIZED,
+            ctx.j) < amount)
+        return tecINSUFFICIENT_FUNDS;
+
+    return tesSUCCESS;
+}
+
+TER
+LoanBrokerCoverWithdraw::doApply()
+{
+    auto const& tx = ctx_.tx;
+
+    auto const brokerID = tx[sfLoanBrokerID];
+    auto const amount = tx[sfAmount];
+
+    auto broker = view().peek(keylet::loanbroker(brokerID));
+
+    auto const brokerPseudoID = broker->at(sfAccount);
+
+    // Transfer assets from pseudo-account to depositor.
+    if (auto ter = accountSend(
+            view(),
+            brokerPseudoID,
+            account_,
+            amount,
+            j_,
+            WaiveTransferFee::Yes))
+        return ter;
+
+    // Increase the LoanBroker's CoverAvailable by Amount
+    broker->at(sfCoverAvailable) -= amount;
+
+    return tesSUCCESS;
+}
+
+//------------------------------------------------------------------------------
+
+}  // namespace ripple

src/xrpld/app/tx/detail/LoanBrokerCoverWithdraw.h

@@ -0,0 +1,56 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2025 Ripple Labs Inc.
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef RIPPLE_TX_LOANBROKERCOVERWITHDRAW_H_INCLUDED
+#define RIPPLE_TX_LOANBROKERCOVERWITHDRAW_H_INCLUDED
+
+#include <xrpld/app/tx/detail/Transactor.h>
+
+namespace ripple {
+
+class LoanBrokerCoverWithdraw : public Transactor
+{
+public:
+    static constexpr ConsequencesFactoryType ConsequencesFactory{Normal};
+
+    explicit LoanBrokerCoverWithdraw(ApplyContext& ctx) : Transactor(ctx)
+    {
+    }
+
+    static bool
+    isEnabled(PreflightContext const& ctx);
+
+    static std::uint32_t
+    getFlagsMask(PreflightContext const& ctx);
+
+    static NotTEC
+    doPreflight(PreflightContext const& ctx);
+
+    static TER
+    preclaim(PreclaimContext const& ctx);
+
+    TER
+    doApply() override;
+};
+
+//------------------------------------------------------------------------------
+
+}  // namespace ripple
+
+#endif

src/xrpld/app/tx/detail/applySteps.cpp

@@ -42,6 +42,7 @@
 #include <xrpld/app/tx/detail/Escrow.h>
 #include <xrpld/app/tx/detail/LedgerStateFix.h>
 #include <xrpld/app/tx/detail/LoanBrokerCoverDeposit.h>
+#include <xrpld/app/tx/detail/LoanBrokerCoverWithdraw.h>
 #include <xrpld/app/tx/detail/LoanBrokerDelete.h>
 #include <xrpld/app/tx/detail/LoanBrokerSet.h>
 #include <xrpld/app/tx/detail/MPTokenAuthorize.h>

src/xrpld/ledger/detail/View.cpp

@@ -618,8 +618,8 @@ xrpLiquid(
     std::uint32_t const ownerCount = confineOwnerCount(
         view.ownerCountHook(id, sle->getFieldU32(sfOwnerCount)), ownerCountAdj);
 
-    // AMMs have no reserve requirement
+    // Pseudo-accounts have no reserve requirement
-    auto const reserve = sle->isFieldPresent(sfAMMID)
+    auto const reserve = isPseudoAccount(sle)
         ? XRPAmount{0}
         : view.fees().accountReserve(ownerCount);