bcli: Refactor bcli plugin to synchronous execution

lightningd/bitcoind.c

@@ -111,6 +111,35 @@ static void bitcoin_plugin_error(struct bitcoind *bitcoind, const char *buf,
 	      toks->end - toks->start, buf + toks->start);
 }
 
+/* Check response for error (fatal if found) and return result token (fatal if not found). */
+static const jsmntok_t *get_bitcoin_result(struct bitcoind *bitcoind,
+					   const char *buf,
+					   const jsmntok_t *toks,
+					   const char *method)
+{
+	const jsmntok_t *err_tok, *msg_tok, *result_tok;
+
+	err_tok = json_get_member(buf, toks, "error");
+	if (err_tok) {
+		msg_tok = json_get_member(buf, err_tok, "message");
+		if (msg_tok)
+			bitcoin_plugin_error(bitcoind, buf, toks, method,
+					     "%.*s", json_tok_full_len(msg_tok),
+					     json_tok_full(buf, msg_tok));
+		else
+			bitcoin_plugin_error(bitcoind, buf, toks, method,
+					     "%.*s", json_tok_full_len(err_tok),
+					     json_tok_full(buf, err_tok));
+	}
+
+	result_tok = json_get_member(buf, toks, "result");
+	if (!result_tok)
+		bitcoin_plugin_error(bitcoind, buf, toks, method,
+				     "missing 'result' field");
+
+	return result_tok;
+}
+
 /* Send a request to the Bitcoin plugin which registered that method,
  * if it's still alive. */
 static void bitcoin_plugin_send(struct bitcoind *bitcoind,
@@ -287,11 +316,7 @@ static void estimatefees_callback(const char *buf, const jsmntok_t *toks,
 	struct feerate_est *feerates;
 	u32 floor;
 
-	resulttok = json_get_member(buf, toks, "result");
-	if (!resulttok)
-		bitcoin_plugin_error(call->bitcoind, buf, toks,
-				     "estimatefees",
-				     "bad 'result' field");
+	resulttok = get_bitcoin_result(call->bitcoind, buf, toks, "estimatefees");
 
 	/* Modern style has floor. */
 	floortok = json_get_member(buf, resulttok, "feerate_floor");
@@ -386,21 +411,24 @@ static void sendrawtx_callback(const char *buf, const jsmntok_t *toks,
 			       const jsmntok_t *idtok,
 			       struct sendrawtx_call *call)
 {
+	const jsmntok_t *resulttok;
 	const char *err;
 	const char *errmsg = NULL;
 	bool success = false;
 
-	err = json_scan(tmpctx, buf, toks, "{result:{success:%}}",
+	resulttok = get_bitcoin_result(call->bitcoind, buf, toks, "sendrawtransaction");
+
+	err = json_scan(tmpctx, buf, resulttok, "{success:%}",
 			JSON_SCAN(json_to_bool, &success));
 	if (err) {
-		bitcoin_plugin_error(call->bitcoind, buf, toks,
+		bitcoin_plugin_error(call->bitcoind, buf, resulttok,
 				     "sendrawtransaction",
 				     "bad 'result' field: %s", err);
 	} else if (!success) {
-		err = json_scan(tmpctx, buf, toks, "{result:{errmsg:%}}",
+		err = json_scan(tmpctx, buf, resulttok, "{errmsg:%}",
 				JSON_SCAN_TAL(tmpctx, json_strdup, &errmsg));
 		if (err)
-			bitcoin_plugin_error(call->bitcoind, buf, toks,
+			bitcoin_plugin_error(call->bitcoind, buf, resulttok,
 					     "sendrawtransaction",
 					     "bad 'errmsg' field: %s",
 					     err);
@@ -465,38 +493,41 @@ getrawblockbyheight_callback(const char *buf, const jsmntok_t *toks,
 			     const jsmntok_t *idtok,
 			     struct getrawblockbyheight_call *call)
 {
+	const jsmntok_t *resulttok;
 	const char *block_str, *err;
 	struct bitcoin_blkid blkid;
 	struct bitcoin_block *blk;
 	const tal_t *ctx;
 	trace_span_resume(call);
 	trace_span_end(call);
 
+	resulttok = get_bitcoin_result(call->bitcoind, buf, toks, "getrawblockbyheight");
+
 	/* Callback may free parent of call, so steal onto context to
 	 * free if it doesn't */
 	ctx = tal(NULL, char);
 	tal_steal(ctx, call);
 
 	/* If block hash is `null`, this means not found! Call the callback
 	 * with NULL values. */
-	err = json_scan(tmpctx, buf, toks, "{result:{blockhash:null}}");
+	err = json_scan(tmpctx, buf, resulttok, "{blockhash:null}");
 	if (!err) {
 		call->cb(call->bitcoind, call->height, NULL, NULL, call->cb_arg);
 		goto clean;
 	}
 
-	err = json_scan(tmpctx, buf, toks, "{result:{blockhash:%,block:%}}",
+	err = json_scan(tmpctx, buf, resulttok, "{blockhash:%,block:%}",
 			JSON_SCAN(json_to_sha256, &blkid.shad.sha),
 			JSON_SCAN_TAL(tmpctx, json_strdup, &block_str));
 	if (err)
-		bitcoin_plugin_error(call->bitcoind, buf, toks,
+		bitcoin_plugin_error(call->bitcoind, buf, resulttok,
 				     "getrawblockbyheight",
 				     "bad 'result' field: %s", err);
 
 	blk = bitcoin_block_from_hex(tmpctx, chainparams, block_str,
 				     strlen(block_str));
 	if (!blk)
-		bitcoin_plugin_error(call->bitcoind, buf, toks,
+		bitcoin_plugin_error(call->bitcoind, buf, resulttok,
 				     "getrawblockbyheight",
 				     "bad block");
 
@@ -565,18 +596,21 @@ static void getchaininfo_callback(const char *buf, const jsmntok_t *toks,
 				  const jsmntok_t *idtok,
 				  struct getchaininfo_call *call)
 {
+	const jsmntok_t *resulttok;
 	const char *err, *chain;
 	u32 headers, blocks;
 	bool ibd;
 
-	err = json_scan(tmpctx, buf, toks,
-			"{result:{chain:%,headercount:%,blockcount:%,ibd:%}}",
+	resulttok = get_bitcoin_result(call->bitcoind, buf, toks, "getchaininfo");
+
+	err = json_scan(tmpctx, buf, resulttok,
+			"{chain:%,headercount:%,blockcount:%,ibd:%}",
 			JSON_SCAN_TAL(tmpctx, json_strdup, &chain),
 			JSON_SCAN(json_to_number, &headers),
 			JSON_SCAN(json_to_number, &blocks),
 			JSON_SCAN(json_to_bool, &ibd));
 	if (err)
-		bitcoin_plugin_error(call->bitcoind, buf, toks, "getchaininfo",
+		bitcoin_plugin_error(call->bitcoind, buf, resulttok, "getchaininfo",
 				     "bad 'result' field: %s", err);
 
 	call->cb(call->bitcoind, chain, headers, blocks, ibd,
@@ -636,24 +670,27 @@ static void getutxout_callback(const char *buf, const jsmntok_t *toks,
 			      const jsmntok_t *idtok,
 			      struct getutxout_call *call)
 {
+	const jsmntok_t *resulttok;
 	const char *err;
 	struct bitcoin_tx_output txout;
 
 	/* Whatever happens, we want to free this. */
 	tal_steal(tmpctx, call);
 
-	err = json_scan(tmpctx, buf, toks, "{result:{script:null}}");
+	resulttok = get_bitcoin_result(call->bitcoind, buf, toks, "getutxout");
+
+	err = json_scan(tmpctx, buf, resulttok, "{script:null}");
 	if (!err) {
 		call->cb(call->bitcoind, NULL, call->cb_arg);
 		return;
 	}
 
-	err = json_scan(tmpctx, buf, toks, "{result:{script:%,amount:%}}",
+	err = json_scan(tmpctx, buf, resulttok, "{script:%,amount:%}",
 			JSON_SCAN_TAL(tmpctx, json_tok_bin_from_hex,
 				      &txout.script),
 			JSON_SCAN(json_to_sat, &txout.amount));
 	if (err)
-		bitcoin_plugin_error(call->bitcoind, buf, toks, "getutxout",
+		bitcoin_plugin_error(call->bitcoind, buf, resulttok, "getutxout",
 				     "bad 'result' field: %s", err);
 
 	call->cb(call->bitcoind, &txout, call->cb_arg);