Function json_add_fallbacks

plugins/offers.c:1183–1233

Returns true if valid */

/* Returns true if valid */
static bool json_add_fallbacks(struct json_stream *js,
			       const struct bitcoin_blkid *chains,
			       struct fallback_address **fallbacks)
{
	const struct chainparams *chain;
	bool valid = true;

	/* Present address as first chain mentioned. */
	if (tal_count(chains) != 0)
		chain = chainparams_by_chainhash(&chains[0]);
	else
		chain = chainparams_for_network("bitcoin");

	json_array_start(js, "invoice_fallbacks");
	for (size_t i = 0; i < tal_count(fallbacks); i++) {
		size_t addrlen = tal_bytelen(fallbacks[i]->address);

		json_object_start(js, NULL);
		json_add_u32(js, "version", fallbacks[i]->version);
		json_add_hex_talarr(js, "hex", fallbacks[i]->address);

		/* BOLT #12:
		 * - for the bitcoin chain, if the invoice specifies `invoice_fallbacks`:
		 *   - MUST ignore any `fallback_address` for which `version` is
		 *     greater than 16.
		 * -  MUST ignore any `fallback_address` for which `address` is
		 *    less than 2 or greater than 40 bytes.
		 * - MUST ignore any `fallback_address` for which `address` does
		 *   not meet known requirements for the given `version`
		 */
		if (fallbacks[i]->version > 16) {
			json_add_string(js,
					"warning_invalid_invoice_fallbacks_version",
					"invoice fallback version > 16");
			valid = false;
		} else if (addrlen < 2 || addrlen > 40) {
			json_add_string(js,
					"warning_invalid_invoice_fallbacks_address",
					"invoice fallback address bad length");
			valid = false;
		} else if (chain) {
			valid &= json_add_fallback_address(js, chain,
							   fallbacks[i]->version,
							   fallbacks[i]->address);
		}
		json_object_end(js);
	}
	json_array_end(js);

	return valid;
}

static void json_add_invoice_request(struct command *cmd,
				     struct json_stream *js,