Function add_htlc

channeld/full_channel.c:518–843

}

static enum channel_add_err add_htlc(struct channel *channel,
				     enum htlc_state state,
				     u64 id,
				     struct amount_msat amount,
				     u32 cltv_expiry,
				     const struct sha256 *payment_hash,
				     const u8 routing[TOTAL_PACKET_SIZE(ROUTING_INFO_SIZE)],
				     const struct pubkey *blinding TAKES,
				     struct htlc **htlcp,
				     bool enforce_aggregate_limits,
				     struct amount_sat *htlc_fee,
				     bool err_immediate_failures)
{
	struct htlc *htlc, *old;
	struct amount_msat msat_in_htlcs, committed_msat,
			   adding_msat, removing_msat, htlc_dust_amt;
	enum side sender = htlc_state_owner(state), recipient = !sender;
	const struct htlc **committed, **adding, **removing;
	const struct channel_view *view;
	size_t htlc_count;
	bool option_anchor_outputs = channel_has(channel, OPT_ANCHOR_OUTPUTS);
	u32 feerate, feerate_ceil;

	htlc = tal(tmpctx, struct htlc);

	htlc->id = id;
	htlc->amount = amount;
	htlc->state = state;
	htlc->fail_immediate = false;

	htlc->rhash = *payment_hash;
	htlc->blinding = tal_dup_or_null(htlc, struct pubkey, blinding);
	htlc->failed = NULL;
	htlc->r = NULL;
	htlc->routing = tal_dup_arr(htlc, u8, routing, TOTAL_PACKET_SIZE(ROUTING_INFO_SIZE), 0);

	/* FIXME: Change expiry to simple u32 */

	/* BOLT #2:
	 *
	 * A receiving node:
	 *...
	 *  - if sending node sets `cltv_expiry` to greater or equal to
	 *    500000000:
	 *    - SHOULD send a `warning` and close the connection, or send an
	 *      `error` and fail the channel.
	 */
	if (!blocks_to_abs_locktime(cltv_expiry, &htlc->expiry)) {
		return CHANNEL_ERR_INVALID_EXPIRY;
	}

	old = htlc_get(channel->htlcs, htlc->id, htlc_owner(htlc));
	if (old) {
		if (old->state != htlc->state
		    || !amount_msat_eq(old->amount, htlc->amount)
		    || old->expiry.locktime != htlc->expiry.locktime
		    || !sha256_eq(&old->rhash, &htlc->rhash))
			return CHANNEL_ERR_DUPLICATE_ID_DIFFERENT;