plugins: use json_scan.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

plugins/keysend.c

@@ -2,6 +2,7 @@
 #include <ccan/array_size/array_size.h>
 #include <ccan/tal/str/str.h>
 #include <common/gossmap.h>
+#include <common/type_to_string.h>
 #include <plugins/libplugin-pay.h>
 #include <plugins/libplugin.h>
 #include <wire/onion_wire.h>
@@ -244,13 +245,11 @@ static struct command_result *htlc_accepted_call(struct command *cmd,
 						 const char *buf,
 						 const jsmntok_t *params)
 {
-	const jsmntok_t *payloadt = json_delve(buf, params, ".onion.payload");
-	const jsmntok_t *payment_hash_tok = json_delve(buf, params, ".htlc.payment_hash");
 	const u8 *rawpayload;
+	struct sha256 payment_hash;
 	size_t max;
 	struct tlv_tlv_payload *payload;
 	struct tlv_field *preimage_field = NULL;
-	char *hexpreimage, *hexpaymenthash;
 	bigsize_t s;
 	bool unknown_even_type = false;
 	struct tlv_field *field;
@@ -258,10 +257,11 @@ static struct command_result *htlc_accepted_call(struct command *cmd,
 	struct out_req *req;
 	struct timeabs now = time_now();
 
-	if (!payloadt)
+	if (!json_scan(buf, params, "{onion:{payload:%},htlc:{payment_hash:%}}",
+		       JSON_SCAN_TAL(cmd, json_tok_bin_from_hex, &rawpayload),
+		       JSON_SCAN(json_to_sha256, &payment_hash)))
 		return htlc_accepted_continue(cmd, NULL);
 
-	rawpayload = json_tok_bin_from_hex(cmd, buf, payloadt);
 	max = tal_bytelen(rawpayload);
 	payload = tlv_tlv_payload_new(cmd);
 
@@ -272,7 +272,8 @@ static struct command_result *htlc_accepted_call(struct command *cmd,
 	if (!fromwire_tlv_payload(&rawpayload, &max, payload)) {
 		plugin_log(
 		    cmd->plugin, LOG_UNUSUAL, "Malformed TLV payload %.*s",
-		    payloadt->end - payloadt->start, buf + payloadt->start);
+		    json_tok_full_len(params),
+		    json_tok_full(buf, params));
 		return htlc_accepted_continue(cmd, NULL);
 	}
 
@@ -318,20 +319,18 @@ static struct command_result *htlc_accepted_call(struct command *cmd,
 	ki->payload = tal_steal(ki, payload);
 	ki->preimage_field = preimage_field;
 
-	hexpreimage = tal_hex(cmd, preimage_field->value);
-
 	/* If the preimage doesn't hash to the payment_hash we must continue,
 	 * maybe someone else knows how to handle these. */
 	sha256(&ki->payment_hash, preimage_field->value, preimage_field->length);
-	hexpaymenthash = tal_hexstr(cmd, &ki->payment_hash, sizeof(ki->payment_hash));
-	if (!json_tok_streq(buf, payment_hash_tok, hexpaymenthash)) {
+	if (!sha256_eq(&ki->payment_hash, &payment_hash)) {
 		plugin_log(
 		    cmd->plugin, LOG_UNUSUAL,
 		    "Preimage provided by the sender does not match the "
-		    "payment_hash: SHA256(%s)=%s != %.*s. Ignoring keysend.",
-		    hexpreimage, hexpaymenthash,
-		    payment_hash_tok->end - payment_hash_tok->start,
-		    buf + payment_hash_tok->start);
+		    "payment_hash: SHA256(%s)=%s != %s. Ignoring keysend.",
+		    tal_hexstr(tmpctx,
+			       preimage_field->value, preimage_field->length),
+		    type_to_string(tmpctx, struct sha256, &ki->payment_hash),
+		    type_to_string(tmpctx, struct sha256, &payment_hash));
 		tal_free(ki);
 		return htlc_accepted_continue(cmd, NULL);
 	}
@@ -348,7 +347,7 @@ static struct command_result *htlc_accepted_call(struct command *cmd,
 				    &htlc_accepted_invoice_created,
 				    ki);
 
-	plugin_log(cmd->plugin, LOG_INFORM, "Inserting a new invoice for keysend with payment_hash %s", hexpaymenthash);
+	plugin_log(cmd->plugin, LOG_INFORM, "Inserting a new invoice for keysend with payment_hash %s", type_to_string(tmpctx, struct sha256, &payment_hash));
 	json_add_string(req->js, "msatoshi", "any");
 	json_add_string(req->js, "label", ki->label);
 	json_add_string(req->js, "description", "Spontaneous incoming payment through keysend");

plugins/libplugin.c

@@ -802,34 +802,36 @@ static struct command_result *handle_init(struct command *cmd,
 					  const char *buf,
 					  const jsmntok_t *params)
 {
-	const jsmntok_t *configtok, *rpctok, *dirtok, *opttok, *nettok, *fsettok,
-		*t;
+	const jsmntok_t *configtok, *opttok, *t;
 	struct sockaddr_un addr;
 	size_t i;
 	char *dir, *network;
 	struct plugin *p = cmd->plugin;
 	bool with_rpc = p->rpc_conn != NULL;
 
-	configtok = json_delve(buf, params, ".configuration");
+	configtok = json_get_member(buf, params, "configuration");
+	if (!json_scan(buf, configtok,
+		       "{lightning-dir:%"
+		       ",network:%"
+		       ",feature_set:%"
+		       ",rpc-file:%}",
+		       JSON_SCAN_TAL(tmpctx, json_strdup, &dir),
+		       JSON_SCAN_TAL(tmpctx, json_strdup, &network),
+		       JSON_SCAN_TAL(p, json_to_feature_set, &p->our_features),
+		       JSON_SCAN_TAL(p, json_strdup, &p->rpc_location)))
+		plugin_err(p, "cannot scan init params: %.*s",
+			   json_tok_full_len(params),
+			   json_tok_full(buf, params));
 
 	/* Move into lightning directory: other files are relative */
-	dirtok = json_delve(buf, configtok, ".lightning-dir");
-	dir = json_strdup(tmpctx, buf, dirtok);
 	if (chdir(dir) != 0)
 		plugin_err(p, "chdir to %s: %s", dir, strerror(errno));
 
-	nettok = json_delve(buf, configtok, ".network");
-	network = json_strdup(tmpctx, buf, nettok);
 	chainparams = chainparams_for_network(network);
 
-	fsettok = json_delve(buf, configtok, ".feature_set");
-	p->our_features = json_to_feature_set(p, buf, fsettok);
-
 	/* Only attempt to connect if the plugin has configured the rpc_conn
 	 * already, if that's not the case we were told to run without an RPC
 	 * connection, so don't even log an error. */
-	rpctok = json_delve(buf, configtok, ".rpc-file");
-	p->rpc_location = json_strdup(p, buf, rpctok);
 	/* FIXME: Move this to its own function so we can initialize at a
 	 * later point in time. */
 	if (p->rpc_conn != NULL) {
@@ -837,9 +839,7 @@ static struct command_result *handle_init(struct command *cmd,
 		if (strlen(p->rpc_location) + 1 > sizeof(addr.sun_path))
 			plugin_err(p, "rpc filename '%s' too long",
 				   p->rpc_location);
-		memcpy(addr.sun_path, buf + rpctok->start,
-		       rpctok->end - rpctok->start);
-		addr.sun_path[rpctok->end - rpctok->start] = '\0';
+		strcpy(addr.sun_path, p->rpc_location);
 		addr.sun_family = AF_UNIX;
 
 		if (connect(p->rpc_conn->fd, (struct sockaddr *)&addr,

plugins/pay.c

@@ -394,20 +394,14 @@ execute_waitblockheight(struct command *cmd,
 static u32
 get_remote_block_height(const char *buf, const jsmntok_t *error)
 {
-	const jsmntok_t *raw_message_tok;
 	const u8 *raw_message;
 	size_t raw_message_len;
 	u16 type;
 
 	/* Is there even a raw_message?  */
-	raw_message_tok = json_delve(buf, error, ".data.raw_message");
-	if (!raw_message_tok)
-		return 0;
-	if (raw_message_tok->type != JSMN_STRING)
-		return 0;
-
-	raw_message = json_tok_bin_from_hex(tmpctx, buf, raw_message_tok);
-	if (!raw_message)
+	if (!json_scan(buf, error, "{data:{raw_message:%}}",
+		       JSON_SCAN_TAL(tmpctx, json_tok_bin_from_hex,
+				     &raw_message)))
 		return 0;
 
 	/* BOLT #4:
@@ -435,21 +429,19 @@ static struct command_result *waitsendpay_error(struct command *cmd,
 						struct pay_command *pc)
 {
 	struct pay_attempt *attempt = current_attempt(pc);
-	const jsmntok_t *codetok, *failcodetok, *nodeidtok, *scidtok, *dirtok;
 	errcode_t code;
 	int failcode;
-	bool node_err = false;
 
 	attempt_failed_tok(pc, "waitsendpay", buf, error);
 
-	codetok = json_get_member(buf, error, "code");
-	if (!json_to_errcode(buf, codetok, &code))
+	if (!json_scan(buf, error, "{code:%}",
+		       JSON_SCAN(json_to_errcode, &code)))
 		plugin_err(cmd->plugin, "waitsendpay error gave no 'code'? '%.*s'",
 			   error->end - error->start, buf + error->start);
 
 	if (code != PAY_UNPARSEABLE_ONION) {
-		failcodetok = json_delve(buf, error, ".data.failcode");
-		if (!json_to_int(buf, failcodetok, &failcode))
+		if (!json_scan(buf, error, "{data:{failcode:%}}",
+			       JSON_SCAN(json_to_int, &failcode)))
 			plugin_err(cmd->plugin, "waitsendpay error gave no 'failcode'? '%.*s'",
 				   error->end - error->start, buf + error->start);
 	}
@@ -512,57 +504,54 @@ static struct command_result *waitsendpay_error(struct command *cmd,
 		return forward_error(cmd, buf, error, pc);
 	}
 
-	if (failcode & NODE) {
-		nodeidtok = json_delve(buf, error, ".data.erring_node");
-		if (!nodeidtok)
-			plugin_err(cmd->plugin, "waitsendpay error no erring_node '%.*s'",
-				   error->end - error->start, buf + error->start);
-		node_err = true;
-	} else {
-		scidtok = json_delve(buf, error, ".data.erring_channel");
-		if (!scidtok)
-			plugin_err(cmd->plugin, "waitsendpay error no erring_channel '%.*s'",
-				   error->end - error->start, buf + error->start);
-		dirtok = json_delve(buf, error, ".data.erring_direction");
-		if (!dirtok)
-			plugin_err(cmd->plugin, "waitsendpay error no erring_direction '%.*s'",
-				   error->end - error->start, buf + error->start);
-	}
-
 	if (time_after(time_now(), pc->stoptime)) {
 		return waitsendpay_expired(cmd, pc);
 	}
 
-	if (node_err) {
+	if (failcode & NODE) {
+		struct node_id id;
+		const char *idstr;
+
+		if (!json_scan(buf, error, "{data:{erring_node:%}}",
+			       JSON_SCAN(json_to_node_id, &id)))
+			plugin_err(cmd->plugin, "waitsendpay error no erring_node '%.*s'",
+				   error->end - error->start, buf + error->start);
+
+		/* FIXME: Keep as node_id, don't use strings. */
+		idstr = node_id_to_hexstr(tmpctx, &id);
+
 		/* If failure is in routehint part, try next one */
 		if (node_or_channel_in_routehint(pc->plugin, pc->current_routehint,
-						 buf + nodeidtok->start,
-						 nodeidtok->end - nodeidtok->start))
+						 idstr, strlen(idstr)))
 			return next_routehint(cmd, pc);
 
 		/* Otherwise, add erring channel to exclusion list. */
-		tal_arr_expand(&pc->excludes,
-			       tal_fmt(pc->excludes, "%.*s",
-			       nodeidtok->end - nodeidtok->start,
-			       buf + nodeidtok->start));
+		tal_arr_expand(&pc->excludes, tal_steal(pc->excludes, idstr));
 	} else {
+		struct short_channel_id scid;
+		u32 dir;
+		const char *scidstr;
+
+		if (!json_scan(buf, error, "{data:{erring_channel:%,erring_direction:%}}",
+			       JSON_SCAN(json_to_short_channel_id, &scid),
+			       JSON_SCAN(json_to_number, &dir)))
+			plugin_err(cmd->plugin, "waitsendpay error no erring_channel/direction '%.*s'",
+				   error->end - error->start, buf + error->start);
+
+		scidstr = short_channel_id_to_str(tmpctx, &scid);
 		/* If failure is in routehint part, try next one */
 		if (node_or_channel_in_routehint(pc->plugin, pc->current_routehint,
-						 buf + scidtok->start,
-						 scidtok->end - scidtok->start))
+						 scidstr, strlen(scidstr)))
 			return next_routehint(cmd, pc);
 
 		/* Otherwise, add erring channel to exclusion list. */
 		tal_arr_expand(&pc->excludes,
-			       tal_fmt(pc->excludes, "%.*s/%c",
-			       scidtok->end - scidtok->start,
-			       buf + scidtok->start,
-			       buf[dirtok->start]));
+			       tal_fmt(pc->excludes, "%s/%u", scidstr, dir));
 	}
 
 	/* Try again. */
 	return start_pay_attempt(cmd, pc, "Excluded %s %s",
-				 node_err ? "node" : "channel",
+				 failcode & NODE ? "node" : "channel",
 				 pc->excludes[tal_count(pc->excludes)-1]);
 }
 
@@ -765,16 +754,10 @@ static struct command_result *getroute_done(struct command *cmd,
 	} else
 		attempt->route = json_strdup(pc->ps->attempts, buf, t);
 
-	if (!json_to_msat(buf, json_delve(buf, t, "[0].msatoshi"), &fee))
-		plugin_err(cmd->plugin, "getroute with invalid msatoshi? %.*s",
-			   result->end - result->start, buf);
-	if (!amount_msat_sub(&fee, fee, pc->msat))
-		plugin_err(cmd->plugin, "final amount %s less than paid %s",
-			   type_to_string(tmpctx, struct amount_msat, &fee),
-			   type_to_string(tmpctx, struct amount_msat, &pc->msat));
-
-	if (!json_to_number(buf, json_delve(buf, t, "[0].delay"), &delay))
-		plugin_err(cmd->plugin, "getroute with invalid delay? %.*s",
+	if (!json_scan(buf, t, "[0:{msatoshi:%,delay:%}]",
+		       JSON_SCAN(json_to_msat, &fee),
+		       JSON_SCAN(json_to_number, &delay)))
+		plugin_err(cmd->plugin, "getroute with invalid msatoshi/delay? %.*s",
 			   result->end - result->start, buf);
 
 	if (pc->maxfee_pct_millionths / 100 > UINT32_MAX)

plugins/spender/openchannel.c

@@ -544,38 +544,17 @@ static void json_peer_sigs(struct command *cmd,
 			   const char *buf,
 			   const jsmntok_t *params)
 {
-	const jsmntok_t *cid_tok, *psbt_tok;
 	struct channel_id cid;
 	const struct wally_psbt *psbt;
 	struct multifundchannel_destination *dest;
 
-	cid_tok = json_delve(buf, params, ".openchannel_peer_sigs.channel_id");
-	if (!cid_tok)
+	if (!json_scan(buf, params,
+		       "{openchannel_peer_sigs:"
+		       "{channel_id:%,signed_psbt:%}}",
+		       JSON_SCAN(json_to_channel_id, &cid),
+		       JSON_SCAN_TAL(cmd, json_to_psbt, &psbt)))
 		plugin_err(cmd->plugin,
-			   "`openchannel_peer_sigs` notification did not "
-			   "send 'channel_id'? %.*s",
-			   json_tok_full_len(params),
-			   json_tok_full(buf, params));
-	if (!json_to_channel_id(buf, cid_tok, &cid))
-		plugin_err(cmd->plugin,
-			   "Unable to parse openchannel_peer_sigs.channel_id "
-			   "%.*s",
-			   json_tok_full_len(params),
-			   json_tok_full(buf, params));
-
-	psbt_tok= json_delve(buf, params, ".openchannel_peer_sigs.signed_psbt");
-	if (!psbt_tok)
-		plugin_err(cmd->plugin,
-			   "`openchannel_peer_sigs` notification did not "
-			   "include 'signed_psbt'? %.*s",
-			   json_tok_full_len(params),
-			   json_tok_full(buf, params));
-
-	psbt = json_to_psbt(cmd, buf, psbt_tok);
-	if (!psbt)
-		plugin_err(cmd->plugin,
-			   "Unable to parse openchannel_peer_sigs.signed_psbt "
-			   "%.*s",
+			   "`openchannel_peer_sigs` did not scan",
 			   json_tok_full_len(params),
 			   json_tok_full(buf, params));