Fund all (#1249)

* Funding channel with "all"
* Added test for fund all

lightningd/opening_control.c

@@ -816,51 +816,76 @@ static void gossip_peer_released(struct subd *gossip,
 			   fds[0], fds[1]);
 }
 
+/**
+ * json_fund_channel - Entrypoint for funding a channel
+ */
 static void json_fund_channel(struct command *cmd,
 			      const char *buffer, const jsmntok_t *params)
 {
-	jsmntok_t *peertok, *satoshitok;
+	jsmntok_t *desttok, *sattok;
-	struct funding_channel *fc = tal(cmd, struct funding_channel);
+	bool all_funds = false;
+	struct funding_channel * fc;
+	u32 feerate_per_kw = get_feerate(cmd->ld->topology, FEERATE_NORMAL);
+    u64 fee_estimate;
 	u8 *msg;
 
 	if (!json_get_params(cmd, buffer, params,
-			     "id", &peertok,
+			     "id", &desttok,
-			     "satoshi", &satoshitok,
+			     "satoshi", &sattok,
 			     NULL)) {
 		return;
 	}
 
+	fc = tal(cmd, struct funding_channel);
 	fc->cmd = cmd;
+	fc->change_keyindex = 0;
+	fc->funding_satoshi = 0;
 
-	if (!pubkey_from_hexstr(buffer + peertok->start,
+	if (json_tok_streq(buffer, sattok, "all")) {
-				peertok->end - peertok->start, &fc->peerid)) {
+		all_funds = true;
-		command_fail(cmd, "Could not parse id");
-		return;
-	}
 
-	if (!json_tok_u64(buffer, satoshitok, &fc->funding_satoshi)) {
+	} else if (!json_tok_u64(buffer, sattok, &fc->funding_satoshi)) {
 		command_fail(cmd, "Invalid satoshis");
 		return;
 	}
 
-	if (fc->funding_satoshi > MAX_FUNDING_SATOSHI) {
+	if (!pubkey_from_hexstr(buffer + desttok->start,
-		command_fail(cmd, "Funding satoshi must be <= %d",
+				desttok->end - desttok->start, &fc->peerid)) {
-			     MAX_FUNDING_SATOSHI);
+		command_fail(cmd, "Could not parse id");
 		return;
 	}
-
 	/* FIXME: Support push_msat? */
 	fc->push_msat = 0;
 	fc->channel_flags = OUR_CHANNEL_FLAGS;
 
 	/* Try to do this now, so we know if insufficient funds. */
 	/* FIXME: dustlimit */
-	fc->utxomap = build_utxos(fc, cmd->ld, fc->funding_satoshi,
+    if (all_funds) {
-				  get_feerate(cmd->ld->topology, FEERATE_NORMAL),
+		fc->utxomap = wallet_select_all(cmd, cmd->ld->wallet,
-				  600, BITCOIN_SCRIPTPUBKEY_P2WSH_LEN,
+			feerate_per_kw,
-				  &fc->change, &fc->change_keyindex);
+			BITCOIN_SCRIPTPUBKEY_P2WSH_LEN,
-	if (!fc->utxomap) {
+			&fc->funding_satoshi,
-		command_fail(cmd, "Cannot afford funding transaction");
+			&fee_estimate);
+		if (!fc->utxomap || fc->funding_satoshi < 546) {
+			command_fail(cmd, "Cannot afford fee %"PRIu64,
+				     fee_estimate);
+			return;
+		}
+		fc->change = 0;
+	} else {
+		fc->utxomap = build_utxos(fc, cmd->ld, fc->funding_satoshi,
+			feerate_per_kw,
+			600, BITCOIN_SCRIPTPUBKEY_P2WSH_LEN,
+			&fc->change, &fc->change_keyindex);
+		if (!fc->utxomap) {
+			command_fail(cmd, "Cannot afford funding transaction");
+			return;
+		}
+	}
+
+	if (fc->funding_satoshi > MAX_FUNDING_SATOSHI) {
+		command_fail(cmd, "Funding satoshi must be <= %d",
+			     MAX_FUNDING_SATOSHI);
 		return;
 	}
 

tests/test_lightningd.py

@@ -3121,6 +3121,21 @@ class LightningDTests(BaseLightningDTests):
         assert outputs[0] > 8990000
         assert outputs[2] == 10000000
 
+    def test_funding_all(self):
+        """Add some funds, fund a channel using all funds, make sure no funds remain
+        """
+        l1, l2 = self.connect()
+
+        self.give_funds(l1, 0.1 * 10**8)
+
+        outputs = l1.db_query('SELECT value FROM outputs WHERE status=0;')
+        assert len(outputs) == 1 and outputs[0]['value'] == 10000000
+
+        l1.rpc.fundchannel(l2.info['id'], "all")
+
+        outputs = l1.db_query('SELECT value FROM outputs WHERE status=0;')
+        assert len(outputs) == 0
+
     def test_funding_fail(self):
         """Add some funds, fund a channel without enough funds"""
         # Previous runs with same bitcoind can leave funds!

wallet/walletrpc.c

@@ -91,7 +91,7 @@ static void json_withdraw(struct command *cmd,
 	u32 feerate_per_kw = get_feerate(cmd->ld->topology, FEERATE_NORMAL);
 	u64 fee_estimate;
 	struct bitcoin_tx *tx;
-	bool withdraw_all = false;
+	bool all_funds = false;
 	enum address_parse_result addr_parse;
 
 	if (!json_get_params(cmd, buffer, params,
@@ -105,7 +105,7 @@ static void json_withdraw(struct command *cmd,
 	withdraw->cmd = cmd;
 
 	if (json_tok_streq(buffer, sattok, "all"))
-		withdraw_all = true;
+		all_funds = true;
 	else if (!json_tok_u64(buffer, sattok, &withdraw->amount)) {
 		command_fail(cmd, "Invalid satoshis");
 		return;
@@ -132,7 +132,7 @@ static void json_withdraw(struct command *cmd,
 	}
 
 	/* Select the coins */
-	if (withdraw_all) {
+	if (all_funds) {
 		withdraw->utxos = wallet_select_all(cmd, cmd->ld->wallet,
 						    feerate_per_kw,
 						    tal_len(withdraw->destination),