Filter out txs that are too big for swap-in (#580)

There is a 65000 bytes limit for transactions, because they must fit in Lightning messages during interactive-tx negotiation.
ACINQ · Jan 8, 2024 · 4768ba6 · 4768ba6
1 parent 82c6b82
commit 4768ba6
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Showing 2 changed files with 4 additions and 2 deletions.
diff --git a/src/commonMain/kotlin/fr/acinq/lightning/blockchain/electrum/SwapInManager.kt b/src/commonMain/kotlin/fr/acinq/lightning/blockchain/electrum/SwapInManager.kt
@@ -1,9 +1,11 @@
 package fr.acinq.lightning.blockchain.electrum
 
 import fr.acinq.bitcoin.OutPoint
+import fr.acinq.bitcoin.Transaction
 import fr.acinq.bitcoin.TxId
 import fr.acinq.lightning.Lightning
 import fr.acinq.lightning.SwapInParams
+import fr.acinq.lightning.channel.FundingContributions.Companion.stripInputWitnesses
 import fr.acinq.lightning.channel.LocalFundingStatus
 import fr.acinq.lightning.channel.RbfStatus
 import fr.acinq.lightning.channel.SignedSharedTransaction
@@ -38,7 +40,7 @@ class SwapInManager(private var reservedUtxos: Set<OutPoint>, private val logger
             val utxos = buildSet {
                 // some utxos may be used for swap-in even if they are not confirmed, for example when migrating from the legacy phoenix android app
                 addAll(availableWallet.all.filter { cmd.trustedTxs.contains(it.outPoint.txid) })
-                addAll(availableWallet.deeplyConfirmed)
+                addAll(availableWallet.deeplyConfirmed.filter { Transaction.write(it.previousTx.stripInputWitnesses()).size < 65_000 })
             }.toList()
             if (utxos.balance > 0.sat) {
                 logger.info { "swap-in wallet: requesting channel using ${utxos.size} utxos with balance=${utxos.balance}" }

diff --git a/src/commonMain/kotlin/fr/acinq/lightning/channel/InteractiveTx.kt b/src/commonMain/kotlin/fr/acinq/lightning/channel/InteractiveTx.kt
@@ -255,7 +255,7 @@ data class FundingContributions(val inputs: List<InteractiveTxInput.Outgoing>, v
         }
 
         /** Strip input witnesses to save space (there is a max size on txs due to lightning message limits). */
-        private fun Transaction.stripInputWitnesses(): Transaction = copy(txIn = txIn.map { it.updateWitness(ScriptWitness.empty) })
+        fun Transaction.stripInputWitnesses(): Transaction = copy(txIn = txIn.map { it.updateWitness(ScriptWitness.empty) })
 
         /** Compute the weight we need to pay on-chain fees for. */
         private fun computeWeightPaid(isInitiator: Boolean, sharedInput: SharedFundingInput?, sharedOutputScript: ByteVector, walletInputs: List<WalletState.Utxo>, localOutputs: List<TxOut>): Int {