Makefile: bolt version b38156b9510c0562cf50f8758a64602cc0315c19

"Allow nodes to overshoot final htlc amount and expiry (ElementsProject#1032)"

Note that this also renamed `min_final_cltv_expiry` to the more-correct
`min_final_cltv_expiry_delta`.

Signed-off-by: Rusty Russell <[email protected]>

Makefile

@@ -23,7 +23,7 @@ CCANDIR := ccan
 
 # Where we keep the BOLT RFCs
 BOLTDIR := ../bolts/
-DEFAULT_BOLTVERSION := fc40879995ebc61cc50dfd729512f17afb15b355
+DEFAULT_BOLTVERSION := b38156b9510c0562cf50f8758a64602cc0315c19
 # Can be overridden on cmdline.
 BOLTVERSION := $(DEFAULT_BOLTVERSION)
 

common/bolt11.c

@@ -284,7 +284,7 @@ static const char *decode_x(struct bolt11 *b11,
 
 /* BOLT #11:
  *
- * `c` (24): `data_length` variable.  `min_final_cltv_expiry` to use for the
+ * `c` (24): `data_length` variable. `min_final_cltv_expiry_delta` to use for the
  * last HTLC in the route. Default is 18 if not specified.
  */
 static const char *decode_c(struct bolt11 *b11,
@@ -594,7 +594,7 @@ struct bolt11 *new_bolt11(const tal_t *ctx,
 	b11->expiry = DEFAULT_X;
 	b11->features = tal_arr(b11, u8, 0);
 	/* BOLT #11:
-	 *   - if the `c` field (`min_final_cltv_expiry`) is not provided:
+	 *   - if the `c` field (`min_final_cltv_expiry_delta`) is not provided:
 	 *     - MUST use an expiry delta of at least 18 when making the payment
 	 */
 	b11->min_final_cltv_expiry = 18;
@@ -1009,7 +1009,7 @@ static void push_field(u5 **data, char type, const void *src, size_t nbits)
  *
  * - if `x` is included:
  *   - SHOULD use the minimum `data_length` possible.
- * - MUST include one `c` field (`min_final_cltv_expiry`).
+ * - MUST include one `c` field (`min_final_cltv_expiry_delta`).
  *...
  *   - SHOULD use the minimum `data_length` possible.
  */
@@ -1278,7 +1278,7 @@ char *bolt11_encode_(const tal_t *ctx,
 		encode_x(&data, b11->expiry);
 
 	/* BOLT #11:
-	 *   - MUST include one `c` field (`min_final_cltv_expiry`).
+	 *   - MUST include one `c` field (`min_final_cltv_expiry_delta`).
 	 */
 	encode_c(&data, b11->min_final_cltv_expiry);
 

common/bolt11.h

@@ -13,7 +13,7 @@
 
 /* BOLT #11:
  * * `c` (24): `data_length` variable.
- *    `min_final_cltv_expiry` to use for the last HTLC in the route.
+ *    `min_final_cltv_expiry_delta` to use for the last HTLC in the route.
  *    Default is 18 if not specified.
  */
 #define DEFAULT_FINAL_CLTV_DELTA 18

common/test/run-bolt11.c

@@ -527,9 +527,9 @@ int main(int argc, char *argv[])
 	 * * `x`: expiry time
 	 *   * `qy`: `data_length` (`q` = 0, `y` = 2; 0 * 32 + 4 == 4)
 	 *   * `jw5q`: 604800 seconds (`j` = 18, `w` = 14, `5` = 20, `q` = 0; 18 * 32^3 + 14 * 32^2 + 20 * 32 + 0 == 604800)
-	 * * `c`: `min_final_cltv_expiry`
+	 * * `c`: `min_final_cltv_expiry_delta`
 	 *   * `qp`: `data_length` (`q` = 0, `p` = 1; 0 * 32 + 1 == 1)
-	 *   * `2`: min_final_cltv_expiry = 10
+	 *   * `2`: min_final_cltv_expiry_delta = 10
 	 * * `r`: tagged field: route information
 	 *   * `zj`: `data_length` (`z` = 2, `j` = 18; 2 * 32 + 18 == 82)
 	 *   * `q0gxwkzc8w6323m55m4jyxcjwmy7stt9hwkwe2qxmy8zpsgg7jcuwz87fcqqeuqqqyqqqqlgqqqqn3qq9q`:

lightningd/peer_htlcs.c

@@ -311,6 +311,11 @@ static bool check_fwd_amount(struct htlc_in *hin,
  *     - MUST return an error if:
  * ...
  *        - `cltv_expiry` - `cltv_expiry_delta` < `outgoing_cltv_value`
+ *   - if it is the final node:
+ *...
+ *     - MUST return an error if:
+ *...
+ *       - incoming `cltv_expiry` < `outgoing_cltv_value`.
  */
 static bool check_cltv(struct htlc_in *hin,
 		       u32 cltv_expiry, u32 outgoing_cltv_value, u32 delta)
@@ -381,9 +386,9 @@ static void handle_localpay(struct htlc_in *hin,
 	 *     - MUST treat `total_msat` as if it were equal to `amt_to_forward` if it
 	 *       is not present.
 	 *     - MUST return an error if:
-	 *        - incoming `amount_msat` != `amt_to_forward`.
+	 *        - incoming `amount_msat` < `amt_to_forward`.
 	 */
-	if (!amount_msat_eq(amt_to_forward, hin->msat)) {
+	if (amount_msat_less(hin->msat, amt_to_forward)) {
 		log_debug(hin->key.channel->log,
 			  "HTLC %"PRIu64" final incorrect amount:"
 			  " %s in, %s expected",
@@ -408,7 +413,7 @@ static void handle_localpay(struct htlc_in *hin,
 	 *       is not present.
 	 *     - MUST return an error if:
 	 *...
-	 *        - incoming `cltv_expiry` != `cltv_expiry_delta`.
+	 *        - incoming `cltv_expiry` < `outgoing_cltv_value`.
 	 */
 	if (!check_cltv(hin, hin->cltv_expiry, outgoing_cltv_value, 0)) {
 		/* BOLT #4:
@@ -426,10 +431,7 @@ static void handle_localpay(struct htlc_in *hin,
 
 	/* BOLT #4:
 	 *
-	 *   - if the `cltv_expiry` value is unreasonably near the present:
-	 *     - MUST fail the HTLC.
-	 *     - MUST return an `incorrect_or_unknown_payment_details` error.
-	 */
+	 *   incoming `cltv_expiry` < `current_block_height` + `min_final_cltv_expiry_delta`.	 */
 	if (get_block_height(ld->topology) + ld->config.cltv_final
 	    > hin->cltv_expiry) {
 		log_debug(hin->key.channel->log,