offers: make find_best_peer take a feature bitmap.

This means we can ask for more than one required feature at a time.

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

plugins/offers.c

@@ -1,6 +1,7 @@
 /* This plugin covers both sending and receiving offers */
 #include "config.h"
 #include <ccan/array_size/array_size.h>
+#include <ccan/bitops/bitops.h>
 #include <ccan/rune/rune.h>
 #include <ccan/tal/str/str.h>
 #include <common/bech32.h>
@@ -314,7 +315,7 @@ struct find_best_peer_data {
 	struct command_result *(*cb)(struct command *,
 				     const struct chaninfo *,
 				     void *);
-	int needed_feature;
+	u64 needed_features;
 	void *arg;
 };
 
@@ -333,6 +334,7 @@ static struct command_result *listincoming_done(struct command *cmd,
 		struct chaninfo ci;
 		const jsmntok_t *pftok;
 		u8 *features;
+		u64 feature_bits;
 		const char *err;
 		struct amount_msat feebase;
 		bool enabled;
@@ -373,11 +375,20 @@ static struct command_result *listincoming_done(struct command *cmd,
 		if (!pftok)
 			continue;
 		features = json_tok_bin_from_hex(tmpctx, buf, pftok);
-		if (!feature_offered(features, data->needed_feature))
-			continue;
+
+		/* It must have all the features we need */
+		feature_bits = data->needed_features;
+		while (feature_bits) {
+			int feature = bitops_ls64(feature_bits);
+			if (!feature_offered(features, feature))
+				goto next;
+			feature_bits &= ~(1ULL << feature);
+		}
 
 		if (!best || amount_msat_greater(ci.capacity, best->capacity))
 			best = tal_dup(tmpctx, struct chaninfo, &ci);
+
+		next:;
 	}
 
 	/* Free data if they don't */
@@ -386,7 +397,7 @@ static struct command_result *listincoming_done(struct command *cmd,
 }
 
 struct command_result *find_best_peer_(struct command *cmd,
-				       int needed_feature,
+				       u64 needed_features,
 				       struct command_result *(*cb)(struct command *,
 								    const struct chaninfo *,
 								    void *),
@@ -396,7 +407,7 @@ struct command_result *find_best_peer_(struct command *cmd,
 	struct find_best_peer_data *data = tal(cmd, struct find_best_peer_data);
 	data->cb = cb;
 	data->arg = arg;
-	data->needed_feature = needed_feature;
+	data->needed_features = needed_features;
 	req = jsonrpc_request_start(cmd, "listincoming",
 				    listincoming_done, forward_error, data);
 	return send_outreq(req);

plugins/offers.h

@@ -78,14 +78,14 @@ struct chaninfo {
 
 /* Calls listpeerchannels, then cb with best peer (if any!) which has needed_feature */
 struct command_result *find_best_peer_(struct command *cmd,
-				       int needed_feature,
+				       u64 needed_features,
 				       struct command_result *(*cb)(struct command *,
 								    const struct chaninfo *,
 								    void *),
 				       void *arg);
 
-#define find_best_peer(cmd, needed_feature, cb, arg)			\
-	find_best_peer_((cmd), (needed_feature),			\
+#define find_best_peer(cmd, needed_features, cb, arg)			\
+	find_best_peer_((cmd), (needed_features),			\
 			typesafe_cb_preargs(struct command_result *, void *, \
 					    (cb), (arg),		\
 					    struct command *,		\

plugins/offers_invreq_hook.c

@@ -381,7 +381,7 @@ static struct command_result *add_blindedpaths(struct command *cmd,
 	if (!we_want_blinded_path(cmd->plugin, true))
 		return create_invoicereq(cmd, ir);
 
-	return find_best_peer(cmd, OPT_ROUTE_BLINDING,
+	return find_best_peer(cmd, 1ULL << OPT_ROUTE_BLINDING,
 			      found_best_peer, ir);
 }
 

plugins/offers_offer.c

@@ -303,7 +303,7 @@ static struct command_result *maybe_add_path(struct command *cmd,
 	 */
 	if (!offinfo->offer->offer_paths) {
 		if (we_want_blinded_path(cmd->plugin, false))
-			return find_best_peer(cmd, OPT_ONION_MESSAGES,
+			return find_best_peer(cmd, 1ULL << OPT_ONION_MESSAGES,
 					      found_best_peer, offinfo);
 	}
 	return create_offer(cmd, offinfo);
@@ -729,7 +729,7 @@ struct command_result *json_invoicerequest(struct command *cmd,
 		idata->invreq = invreq;
 		idata->single_use = *single_use;
 		idata->label = label;
-		return find_best_peer(cmd, OPT_ONION_MESSAGES,
+		return find_best_peer(cmd, 1ULL << OPT_ONION_MESSAGES,
 				      found_best_peer_invrequest, idata);
 	}