liquidity ad implementation

bitcoin/psbt.c

@@ -848,3 +848,27 @@ struct amount_sat psbt_compute_fee(const struct wally_psbt *psbt)
 
 	return fee;
 }
+
+size_t psbt_input_weight(const struct wally_psbt *psbt, size_t in)
+{
+	size_t weight;
+
+	/* txid + txout + sequence */
+	weight = (32 + 4 + 4) * 4;
+	weight +=
+		(psbt->inputs[in].redeem_script_len +
+			(varint_t) varint_size(psbt->inputs[in].redeem_script_len)) * 4;
+
+	/* BOLT-f53ca2301232db780843e894f55d95d512f297f9 #3:
+	 *
+	 * The minimum witness weight for an input is 110.
+	 */
+	weight += 110;
+	return weight;
+}
+
+size_t psbt_output_weight(const struct wally_psbt *psbt, size_t outnum)
+{
+	return (8 + psbt->tx->outputs[outnum].script_len +
+		varint_size(psbt->tx->outputs[outnum].script_len)) * 4;
+}

bitcoin/psbt.h

@@ -272,4 +272,8 @@ struct wally_psbt *psbt_from_bytes(const tal_t *ctx, const u8 *bytes,
 void towire_wally_psbt(u8 **pptr, const struct wally_psbt *psbt);
 struct wally_psbt *fromwire_wally_psbt(const tal_t *ctx,
 				       const u8 **cursor, size_t *max);
+
+/* Calculate the weight of a psbt input or output */
+size_t psbt_input_weight(const struct wally_psbt *psbt, size_t in);
+size_t psbt_output_weight(const struct wally_psbt *psbt, size_t outnum);
 #endif /* LIGHTNING_BITCOIN_PSBT_H */

bitcoin/script.c

@@ -14,6 +14,8 @@
 /* To push 0-75 bytes onto stack. */
 #define OP_PUSHBYTES(val) (val)
 
+#define max(a, b) ((a) > (b) ? (a) : (b))
+
 /* Bitcoin's OP_HASH160 is RIPEMD(SHA256()) */
 static void hash160(struct ripemd160 *redeemhash, const void *mem, size_t len)
 {
@@ -327,13 +329,24 @@ u8 *scriptpubkey_witness_raw(const tal_t *ctx, u8 version,
  * block csv lock.
  *    <remote_pubkey> OP_CHECKSIGVERIFY 1 OP_CHECKSEQUENCEVERIFY
  */
+/* BOLT- #3
+ * ##### Leased channel (`option_will_fund`)
+ *
+ * If a `lease` applies to the channel, the `to_remote` output
+ * of the `initiator` ensures the `leasor` funds are not
+ * spendable until the lease expires.
+ *
+ * <remote_pubkey> OP_CHECKSIGVERIFY MAX(1, lease_end - blockheight) OP_CHECKSEQUENCEVERIFY
+ */
+
 u8 *anchor_to_remote_redeem(const tal_t *ctx,
-			    const struct pubkey *remote_key)
+			    const struct pubkey *remote_key,
+			    u32 csv_lock)
 {
 	u8 *script = tal_arr(ctx, u8, 0);
 	add_push_key(&script, remote_key);
 	add_op(&script, OP_CHECKSIGVERIFY);
-	add_number(&script, 1);
+	add_number(&script, csv_lock);
 	add_op(&script, OP_CHECKSEQUENCEVERIFY);
 
 	assert(is_anchor_witness_script(script, tal_bytelen(script)));
@@ -342,15 +355,21 @@ u8 *anchor_to_remote_redeem(const tal_t *ctx,
 
 bool is_anchor_witness_script(const u8 *script, size_t script_len)
 {
-	if (script_len != 34 + 1 + 1 + 1)
+	size_t len = 34 + 1 + 1 + 1;
+	/* With option_will_fund, the pushbytes can be up to 2 bytes more
+	 *
+	 * <remote_pubkey> OP_CHECKSIGVERIFY
+	 * 		MAX(1, lease_end - blockheight)
+	 * 		OP_CHECKSEQUENCEVERIFY
+	 */
+	if (script_len < len || script_len > len + 2)
 		return false;
 	if (script[0] != OP_PUSHBYTES(33))
 		return false;
 	if (script[34] != OP_CHECKSIGVERIFY)
 		return false;
-	if (script[35] != 0x51)
-		return false;
-	if (script[36] != OP_CHECKSEQUENCEVERIFY)
+	/* FIXME: check for push value */
+	if (script[script_len - 1] != OP_CHECKSEQUENCEVERIFY)
 		return false;
 	return true;
 }
@@ -510,15 +529,35 @@ u8 **bitcoin_witness_sig_and_element(const tal_t *ctx,
  *     OP_ENDIF
  *     OP_CHECKSIG
  */
-u8 *bitcoin_wscript_to_local(const tal_t *ctx, u16 to_self_delay,
+/* BOLT- #3
+ * ##### Leased channel (`option_will_fund`)
+ * If a `lease` applies to the channel, the `to_local` output of the `accepter`
+ * ensures the `leasor` funds are not spendable until the lease expires.
+ *
+ * In a leased channel, the `to_local` output that pays the `accepter` node
+ * is modified so that its CSV is equal to the greater of the
+ * `to_self_delay` or the `lease_end` - `blockheight`.
+ *
+ *  OP_IF
+ *      # Penalty transaction
+ *      <revocationpubkey>
+ *  OP_ELSE
+ *      MAX(`to_self_delay`, `lease_end` - `blockheight`)
+ *      OP_CHECKSEQUENCEVERIFY
+ *      OP_DROP
+ *      <local_delayedpubkey>
+ *  OP_ENDIF
+ *  OP_CHECKSIG
+ */
+u8 *bitcoin_wscript_to_local(const tal_t *ctx, u16 to_self_delay, u32 csv,
 			     const struct pubkey *revocation_pubkey,
 			     const struct pubkey *local_delayedkey)
 {
 	u8 *script = tal_arr(ctx, u8, 0);
 	add_op(&script, OP_IF);
 	add_push_key(&script, revocation_pubkey);
 	add_op(&script, OP_ELSE);
-	add_number(&script, to_self_delay);
+	add_number(&script, max(csv, to_self_delay));
 	add_op(&script, OP_CHECKSEQUENCEVERIFY);
 	add_op(&script, OP_DROP);
 	add_push_key(&script, local_delayedkey);

bitcoin/script.h

@@ -67,9 +67,10 @@ u8 *scriptpubkey_p2wpkh_derkey(const tal_t *ctx, const u8 der[33]);
 u8 *scriptpubkey_witness_raw(const tal_t *ctx, u8 version,
 			     const u8 *wprog, size_t wprog_size);
 
-/* To-remotekey with csv 1 delay. */
+/* To-remotekey with csv max(lease_expiry - blockheight, 1) delay. */
 u8 *anchor_to_remote_redeem(const tal_t *ctx,
-			    const struct pubkey *remote_key);
+			    const struct pubkey *remote_key,
+			    u32 csv_lock);
 
 /* Create a witness which spends the 2of2. */
 u8 **bitcoin_witness_2of2(const tal_t *ctx,
@@ -90,8 +91,7 @@ u8 **bitcoin_witness_sig_and_element(const tal_t *ctx,
 				     const u8 *witnessscript);
 
 /* BOLT #3 to-local output */
-u8 *bitcoin_wscript_to_local(const tal_t *ctx,
-			     u16 to_self_delay,
+u8 *bitcoin_wscript_to_local(const tal_t *ctx, u16 to_self_delay, u32 csv,
 			     const struct pubkey *revocation_pubkey,
 			     const struct pubkey *local_delayedkey);
 

channeld/Makefile

@@ -35,6 +35,7 @@ CHANNELD_COMMON_OBJS :=				\
 	common/billboard.o			\
 	common/bip32.o				\
 	common/blinding.o			\
+	common/blockheight_states.o		\
 	common/channel_config.o			\
 	common/channel_id.o			\
 	common/crypto_state.o			\