rippled/src/libxrpl/tx/transactors/proposal/TransactionProposalCreate.cpp

#include <xrpl/tx/transactors/proposal/TransactionProposalCreate.h>

#include <xrpl/basics/Log.h>
#include <xrpl/core/ServiceRegistry.h>
#include <xrpl/ledger/ApplyView.h>
#include <xrpl/ledger/View.h>
#include <xrpl/ledger/helpers/AccountRootHelpers.h>
#include <xrpl/ledger/helpers/DirectoryHelpers.h>
#include <xrpl/ledger/helpers/ProposalHelpers.h>
#include <xrpl/ledger/helpers/SponsorHelpers.h>
#include <xrpl/protocol/AccountID.h>
#include <xrpl/protocol/Indexes.h>
#include <xrpl/protocol/Keylet.h>
#include <xrpl/protocol/SField.h>
#include <xrpl/protocol/STLedgerEntry.h>
#include <xrpl/protocol/STObject.h>
#include <xrpl/protocol/STTx.h>
#include <xrpl/protocol/SeqProxy.h>
#include <xrpl/protocol/TER.h>
#include <xrpl/protocol/XRPAmount.h>
#include <xrpl/tx/SignerEntries.h>
#include <xrpl/tx/Transactor.h>
#include <xrpl/tx/applySteps.h>

#include <algorithm>
#include <cstdint>
#include <exception>
#include <expected>
#include <memory>

namespace xrpl {

NotTEC
TransactionProposalCreate::preflight(PreflightContext const& ctx)
{
    if (ctx.tx[sfExpiration] == 0)
    {
        JLOG(ctx.j.debug()) << "TransactionProposalCreate: zero expiration.";
        return temBAD_EXPIRATION;
    }

    STObject const proposedTx = ctx.tx.getFieldObject(sfProposedTransaction);

    // The proposed transaction must pass its own static checks under the
    // current rules, so no statically-dead proposal can be stored. This also
    // guarantees every field common to all transactions (TransactionType,
    // Account, Fee, Sequence, ...) is present, since applyTemplate throws
    // otherwise; the checks below can therefore read those fields directly
    // without re-checking presence. TapDryRun accepts the unsigned canonical
    // form without a signature check; TapProposal additionally skips
    // signature-presence checks (e.g. Batch signer matching), which are
    // deferred to submission time (On-Chain Cosigner spec §5.3.1.2). A
    // proposedTx that fails here is rejected with its own type's preflight
    // code (or temMALFORMED if it isn't even a valid instance of that type),
    // ahead of the Cosigner-specific structural checks below.
    try
    {
        STTx const stx{STObject{proposedTx}};
        auto const inner =
            xrpl::preflight(ctx.registry, ctx.rules, stx, TapDryRun | TapProposal, ctx.j);
        if (!isTesSuccess(inner.ter))
        {
            JLOG(ctx.j.debug()) << "TransactionProposalCreate: proposed txn "
                                   "failed preflight: "
                                << transHuman(inner.ter);
            // Surface the proposed transaction type's own preflight code
            // rather than collapsing it to a generic error (On-Chain Cosigner
            // spec §5.3.1).
            return inner.ter;
        }
    }
    catch (std::exception const& e)
    {
        JLOG(ctx.j.debug()) << "TransactionProposalCreate: proposed txn is "
                               "malformed: "
                            << e.what();
        return temMALFORMED;
    }

    // The proposed transaction must be independently submittable through the
    // ordinary multi-sign path: no nested proposals, no pseudo-transactions,
    // no batch inner transactions — and, if it is a Batch, none of its own
    // inner transactions may be a nested proposal or a pseudo-transaction
    // either.
    if (!proposal::isValidProposal(proposedTx))
    {
        JLOG(ctx.j.debug()) << "TransactionProposalCreate: proposed txn is not "
                               "independently submittable.";
        return temINVALID;
    }

    // The proposed transaction is stored in its unsigned canonical form; the
    // ledger populates its signature fields as contributions arrive.
    if (proposal::hasSignatureField(proposedTx))
    {
        JLOG(ctx.j.debug()) << "TransactionProposalCreate: proposed txn "
                               "carries signature fields.";
        return temBAD_SIGNER;
    }

    if (!proposal::hasEmptySigningPubKey(proposedTx))
    {
        JLOG(ctx.j.debug()) << "TransactionProposalCreate: proposed txn "
                               "SigningPubKey must be present and empty.";
        return temBAD_SIGNER;
    }

    // The proposed transaction must be ticket-based: it must carry a
    // TicketSequence and must not use a live Sequence. Sequence is a required
    // common field, so "no Sequence" is expressed as a Sequence of 0 rather
    // than an absent field. A ticket decouples the proposal from the target
    // account's live sequence, so unrelated target-account activity cannot
    // invalidate it while signatures are collected (On-Chain Cosigner spec
    // §4.2.1).
    if (!proposedTx.isFieldPresent(sfTicketSequence) || proposedTx.getFieldU32(sfSequence) != 0)
        return temSEQ_AND_TICKET;

    // If this transaction itself is paying with a Ticket, and the proposed
    // transaction is targeting that same account and Ticket, then applying
    // this transaction consumes the very Ticket the proposal depends on
    // before the proposal is even stored: the proposal would be dead on
    // arrival, and its only recourse would be TransactionProposalCancel.
    if (ctx.tx.getSeqProxy().isTicket() &&
        proposedTx.getAccountID(sfAccount) == ctx.tx.getAccountID(sfAccount) &&
        proposedTx.getFieldU32(sfTicketSequence) == ctx.tx.getSeqProxy().value())
    {
        JLOG(ctx.j.debug()) << "TransactionProposalCreate: proposed txn "
                               "reuses the Ticket this transaction itself consumes.";
        return temMALFORMED;
    }

    return tesSUCCESS;
}

TER
TransactionProposalCreate::preclaim(PreclaimContext const& ctx)
{
    if (hasExpired(ctx.view, ctx.tx[~sfExpiration]))
    {
        JLOG(ctx.j.debug()) << "TransactionProposalCreate: already expired.";
        return tecEXPIRED;
    }

    auto const proposedTx = ctx.tx.getFieldObject(sfProposedTransaction);

    // Once the proposed transaction's own ledger bound has passed it can never
    // be applied, so the proposal is dead on arrival. The bound is the one the
    // ordinary path uses for tefMAX_LEDGER: the last ledger in which the
    // proposed transaction may still be submitted (On-Chain Cosigner spec
    // §4.5).
    if (proposedTx.isFieldPresent(sfLastLedgerSequence) &&
        proposedTx.getFieldU32(sfLastLedgerSequence) <= ctx.view.seq())
    {
        JLOG(ctx.j.debug()) << "TransactionProposalCreate: proposed txn "
                               "LastLedgerSequence has passed.";
        return tecEXPIRED;
    }

    AccountID const target = proposedTx.getAccountID(sfAccount);
    auto const sleTarget = ctx.view.read(keylet::account(target));
    if (!sleTarget)
    {
        JLOG(ctx.j.debug()) << "TransactionProposalCreate: target account "
                               "does not exist.";
        return tecNO_TARGET;
    }

    // A pseudo-account cannot authorize a transaction through a SignerList.
    if (isPseudoAccount(sleTarget))
        return tecNO_PERMISSION;

    // Only the target account itself, an account on its SignerList, or (if
    // the proposed transaction's own type has been delegated by the target,
    // Permission Delegation / XLS-75) that delegate or an account on the
    // delegate's own SignerList, may create a proposal against it. Otherwise
    // any account could spam or squat the target's Tickets with unwanted
    // proposals (On-Chain Cosigner V1 scope).
    if (AccountID const proposer = ctx.tx.getAccountID(sfAccount); proposer != target)
    {
        // Whether `proposer` is `account` itself or an entry on `account`'s
        // applicable SignerList.
        auto isAuthorizedFor = [&](AccountID const& account) -> std::expected<bool, TER> {
            if (proposer == account)
                return true;

            auto const sleSigners = ctx.view.read(keylet::signerList(account));
            if (!sleSigners)
                return false;

            // deserialize itself returns unexpected(temMALFORMED) when
            // sfSignerEntries is missing or an element is not an sfSignerEntry.
            // Those are the right codes for a transaction object. Here the object
            // is an on-ledger ltSIGNER_LIST (sfSignerEntries is SoeRequired;
            // each element is an sfSignerEntry). A corrupt SLE can still throw
            // from the STObject accessors deserialize calls: getFieldArray
            // ("Wrong field type") or getAccountID/getFieldU16 ("Field not
            // found") when an sfSignerEntry is missing required fields. Either
            // the expected<> error or a throw is unexpected ledger state, not a
            // malformed TransactionProposalCreate, so tefBAD_LEDGER (rather
            // than tefINTERNAL, which is reserved for truly unreachable code
            // paths) is the right code.
            try
            {
                auto const accountSigners =
                    SignerEntries::deserialize(*sleSigners, ctx.j, "ledger");
                if (!accountSigners)
                {
                    JLOG(ctx.j.fatal()) << "TransactionProposalCreate: unparseable SignerList: "
                                        << transToken(accountSigners.error());
                    return std::unexpected(tefBAD_LEDGER);
                }

                return std::ranges::any_of(
                    *accountSigners, [&](auto const& entry) { return entry.account == proposer; });
            }
            catch (std::exception const& e)
            {
                JLOG(ctx.j.fatal())
                    << "TransactionProposalCreate: unparseable SignerList: " << e.what();
                return std::unexpected(tefBAD_LEDGER);
            }
        };

        auto isSigner = isAuthorizedFor(target);
        if (!isSigner)
            return isSigner.error();

        // A delegate that the target has granted permission over the
        // proposed transaction — or one of that delegate's own signers — is
        // equally authorized: it will need to help complete the proposed
        // transaction's own authorization anyway once the proposal is
        // submitted. xrpl::invokeCheckPermission is the type-erased
        // submission hierarchy (not checkTxPermission alone, which would
        // reject a matching granular grant). Qualify xrpl:: so the inherited
        // Transactor template is not chosen; it cannot deduce T here. A
        // failed grant is still "not authorized" and becomes
        // tecNO_PERMISSION below — Create is already signed, so do not leak
        // the pre-sign terNO_DELEGATE_PERMISSION.
        if (!*isSigner && proposedTx.isFieldPresent(sfDelegate))
        {
            AccountID const delegateAccount = proposedTx.getAccountID(sfDelegate);
            STTx const proposedStTx{STObject{proposedTx}};
            if (isTesSuccess(xrpl::invokeCheckPermission(ctx.view, proposedStTx)))
            {
                // A grant cannot exist without a funded authorize (DelegateSet
                // uses tecNO_TARGET; AccountDelete of the delegatee removes the
                // Delegate SLE). Do not treat a missing account as a Create-time
                // user error — that would extra-validate the proposed tx. If
                // permission passed anyway, the ledger is corrupt.
                if (!ctx.view.exists(keylet::account(delegateAccount)))
                    return tefINTERNAL;  // LCOV_EXCL_LINE
                isSigner = isAuthorizedFor(delegateAccount);
                if (!isSigner)
                    return isSigner.error();
            }
        }

        if (!*isSigner)
        {
            JLOG(ctx.j.debug()) << "TransactionProposalCreate: proposer is "
                                   "not the target account, one of its "
                                   "signers, or an authorized delegate.";
            return tecNO_PERMISSION;
        }
    }

    std::uint32_t const ticketSequence = proposedTx.getFieldU32(sfTicketSequence);

    // The proposal reserves the ticket for as long as it exists (On-Chain
    // Cosigner spec §4.2.1, §5.3.2): a ticket that doesn't exist yet can't be
    // reserved.
    if (!ctx.view.exists(keylet::ticket(target, SeqProxy::rawTicket(ticketSequence))))
    {
        JLOG(ctx.j.debug()) << "TransactionProposalCreate: target ticket "
                               "does not exist.";
        return tefNO_TICKET;
    }

    if (ctx.view.exists(keylet::txProposal(target, ticketSequence)))
    {
        JLOG(ctx.j.debug()) << "TransactionProposalCreate: duplicate proposal.";
        return tecDUPLICATE;
    }

    return tesSUCCESS;
}

TER
TransactionProposalCreate::doApply()
{
    auto const sle = view().peek(keylet::account(accountID_));
    if (!sle)
        return tefINTERNAL;  // LCOV_EXCL_LINE

    auto const proposedTx = ctx_.tx.getFieldObject(sfProposedTransaction);
    std::uint32_t const ownerCount = proposal::proposalOwnerCount(proposedTx);

    // The proposal holds a full transaction plus its collected signatures, so
    // it reserves more than a typical ledger entry (5 increments; 10 for a
    // proposed Batch).
    if (auto const ret = checkReserve(
            ctx_.getApplyViewContext(),
            sle,
            preFeeBalance_,
            {.ownerCountDelta = static_cast<int>(ownerCount)},
            ctx_.journal);
        !isTesSuccess(ret))
        return ret;

    AccountID const target = proposedTx.getAccountID(sfAccount);
    std::uint32_t const ticketSequence = proposedTx.getFieldU32(sfTicketSequence);

    Keylet const proposalKeylet = keylet::txProposal(target, ticketSequence);
    auto sleProposal = std::make_shared<SLE>(proposalKeylet);
    sleProposal->setAccountID(sfOwner, accountID_);
    sleProposal->setFieldObject(sfProposedTransaction, proposedTx);
    sleProposal->setFieldU32(sfExpiration, ctx_.tx[sfExpiration]);

    view().insert(sleProposal);

    auto viewJ = ctx_.registry.get().getJournal("View");
    {
        auto const page = view().dirInsert(
            keylet::ownerDir(accountID_), proposalKeylet, describeOwnerDir(accountID_));
        if (!page)
            return tecDIR_FULL;  // LCOV_EXCL_LINE
        sleProposal->setFieldU64(sfOwnerNode, *page);
    }

    increaseOwnerCount(ctx_.getApplyViewContext(), sle, ownerCount, viewJ);
    addSponsorToLedgerEntry(ctx_.getApplyViewContext(), sleProposal);
    return tesSUCCESS;
}

void
TransactionProposalCreate::visitInvariantEntry(bool, SLE::const_ref, SLE::const_ref)
{
    // No transaction-specific invariants yet (future work). Object-level
    // invariants for the TransactionProposal ledger entry (unsigned canonical
    // form, non-zero Expiration, correct ProposalID key, sorted/unique signer
    // arrays) belong in a protocol-level ValidTransactionProposal check.
}

bool
TransactionProposalCreate::finalizeInvariants(
    STTx const&,
    TER,
    XRPAmount,
    ReadView const&,
    beast::Journal const&)
{
    // No transaction-specific invariants yet (future work).
    return true;
}

}  // namespace xrpl