Function send_payment

lightningd/pay.c:1131–1219

}

static struct command_result *
send_payment(struct lightningd *ld,
	     struct command *cmd,
	     const struct sha256 *rhash,
	     u64 partid,
	     u64 group,
	     const struct route_hop *route,
	     struct amount_msat msat,
	     struct amount_msat total_msat,
	     const char *label TAKES,
	     const char *invstring TAKES,
	     const char *description TAKES,
	     const struct sha256 *local_offer_id,
	     const struct secret *payment_secret,
	     const u8 *payment_metadata)
{
	unsigned int base_expiry;
	struct onionpacket *packet;
	struct secret *path_secrets;
	size_t i, n_hops = tal_count(route);
	struct node_id *ids = tal_arr(tmpctx, struct node_id, n_hops);
	struct short_channel_id *channels;
	struct sphinx_path *path;
	struct pubkey pubkey;
	bool ret;
	u8 *onion;

	/* Expiry for HTLCs is absolute.  And add one to give some margin. */
	base_expiry = get_block_height(ld->topology) + 1;

	path = sphinx_path_new(tmpctx, rhash->u.u8);
	/* Extract IDs for each hop: create_onionpacket wants array. */
	for (i = 0; i < n_hops; i++)
		ids[i] = route[i].node_id;

	/* Create sphinx path */
	for (i = 0; i < n_hops - 1; i++) {
		ret = pubkey_from_node_id(&pubkey, &ids[i]);
		assert(ret);

		sphinx_add_hop_has_length(path, &pubkey,
			       take(onion_nonfinal_hop(NULL,
					&route[i + 1].scid,
					route[i + 1].amount,
					base_expiry + route[i + 1].delay,
					route[i].blinding,
					route[i].enctlv)));
	}

	/* And finally set the final hop to the special values in
	 * BOLT04 */
	ret = pubkey_from_node_id(&pubkey, &ids[i]);
	assert(ret);

	/* BOLT #4:
	 * - Unless `node_announcement`, `init` message or the
	 *   [BOLT #11](11-payment-encoding.md#tagged-fields) offers feature
	 *   `var_onion_optin`: