doc: big BOLT update to incorporate warnings language.

We do this (send warnings) in almost all cases anyway, so mainly this
is a textual update, but there are some changes:

1. Send ERROR not WARNING if they send a malformed commitment secret.
2. Send WARNING not ERROR if they get the shutdown_scriptpubkey wrong (vs upfront)
3. Send WARNING not ERROR if they send a bad shutdown_scriptpubkey (e.g. p2pkh in future)
4. Rename some vars 'err' to 'warn' to make it clear we send a warning.

This means test_option_upfront_shutdown_script can be made reliable, too,
and it now warns and doesn't automatically close channel.

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

Makefile

@@ -24,7 +24,7 @@ CCANDIR := ccan
 
 # Where we keep the BOLT RFCs
 BOLTDIR := ../lightning-rfc/
-DEFAULT_BOLTVERSION := c876dac2b5038f6499154d0a739240b6ff5db70d
+DEFAULT_BOLTVERSION := 93909f67f6a48ee3f155a6224c182e612dd5f187
 # Can be overridden on cmdline.
 BOLTVERSION := $(DEFAULT_BOLTVERSION)
 

channeld/channeld.c

@@ -728,7 +728,8 @@ static void handle_peer_feechange(struct peer *peer, const u8 *msg)
 	 * A receiving node:
 	 *...
 	 *  - if the sender is not responsible for paying the Bitcoin fee:
-	 *    - MUST fail the channel.
+	 *    - MUST send a `warning` and close the connection, or send an
+	 *      `error` and fail the channel.
 	 */
 	if (peer->channel->opener != REMOTE)
 		peer_failed_warn(peer->pps, &peer->channel_id,
@@ -742,7 +743,8 @@ static void handle_peer_feechange(struct peer *peer, const u8 *msg)
 	 * A receiving node:
 	 *   - if the `update_fee` is too low for timely processing, OR is
 	 *     unreasonably large:
-	 *     - SHOULD fail the channel.
+	 *     - MUST send a `warning` and close the connection, or send an
+	 *       `error` and fail the channel.
 	 */
 	if (!feerate_same_or_better(peer->channel, feerate,
 				    peer->feerate_min, peer->feerate_max))
@@ -757,7 +759,8 @@ static void handle_peer_feechange(struct peer *peer, const u8 *msg)
 	 *
 	 *  - if the sender cannot afford the new fee rate on the receiving
 	 *    node's current commitment transaction:
-	 *    - SHOULD fail the channel,
+	 *    - SHOULD send a `warning` and close the connection, or send an
+	 *      `error` and fail the channel.
 	 *      - but MAY delay this check until the `update_fee` is committed.
 	 */
 	if (!channel_update_feerate(peer->channel, feerate))
@@ -1627,7 +1630,8 @@ static void handle_peer_commit_sig(struct peer *peer, const u8 *msg)
 	 *  - once all pending updates are applied:
 	 *    - if `signature` is not valid for its local commitment transaction
 	 *      OR non-compliant with LOW-S-standard rule...:
-	 *      - MUST fail the channel.
+	 *      - MUST send a `warning` and close the connection, or send an
+	 *        `error` and fail the channel.
 	 */
 	if (!check_tx_sig(txs[0], 0, NULL, funding_wscript,
 			  &peer->channel->funding_pubkey[REMOTE], &commit_sig)) {
@@ -1651,7 +1655,8 @@ static void handle_peer_commit_sig(struct peer *peer, const u8 *msg)
 	 *...
 	 *    - if `num_htlcs` is not equal to the number of HTLC outputs in the
 	 * local commitment transaction:
-	 *      - MUST fail the channel.
+	 *     - MUST send a `warning` and close the connection, or send an
+	 *       `error` and fail the channel.
 	 */
 	if (tal_count(htlc_sigs) != tal_count(txs) - 1)
 		peer_failed_warn(peer->pps, &peer->channel_id,
@@ -1662,7 +1667,8 @@ static void handle_peer_commit_sig(struct peer *peer, const u8 *msg)
 	 *
 	 *   - if any `htlc_signature` is not valid for the corresponding HTLC
 	 *     transaction OR non-compliant with LOW-S-standard rule...:
-	 *     - MUST fail the channel.
+	 *     - MUST send a `warning` and close the connection, or send an
+	 *       `error` and fail the channel.
 	 */
 	for (i = 0; i < tal_count(htlc_sigs); i++) {
 		u8 *wscript;
@@ -1813,11 +1819,11 @@ static void handle_peer_revoke_and_ack(struct peer *peer, const u8 *msg)
 	 * A receiving node:
 	 *  - if `per_commitment_secret` is not a valid secret key or does not
 	 *    generate the previous `per_commitment_point`:
-	 *    - MUST fail the channel.
+	 *     - MUST send an `error` and fail the channel.
 	 */
 	memcpy(&privkey, &old_commit_secret, sizeof(privkey));
 	if (!pubkey_from_privkey(&privkey, &per_commit_point)) {
-		peer_failed_warn(peer->pps, &peer->channel_id,
+		peer_failed_err(peer->pps, &peer->channel_id,
 				"Bad privkey %s",
 				type_to_string(msg, struct privkey, &privkey));
 	}
@@ -1957,7 +1963,8 @@ static void handle_peer_fail_malformed_htlc(struct peer *peer, const u8 *msg)
 	 *
 	 *   - if the `BADONION` bit in `failure_code` is not set for
 	 *    `update_fail_malformed_htlc`:
-	 *      - MUST fail the channel.
+	 *      - MUST send a `warning` and close the connection, or send an
+	 *       `error` and fail the channel.
 	 */
 	if (!(failure_code & BADONION)) {
 		peer_failed_warn(peer->pps, &peer->channel_id,
@@ -2011,6 +2018,7 @@ static void handle_peer_shutdown(struct peer *peer, const u8 *shutdown)
 	 * feature, and the receiving node received a non-zero-length
 	 * `shutdown_scriptpubkey` in `open_channel` or `accept_channel`, and
 	 * that `shutdown_scriptpubkey` is not equal to `scriptpubkey`:
+	 *    - MAY send a `warning`.
 	 *    - MUST fail the connection.
 	 */
 	/* openingd only sets this if feature was negotiated at opening. */
@@ -2018,7 +2026,7 @@ static void handle_peer_shutdown(struct peer *peer, const u8 *shutdown)
 	    && !memeq(scriptpubkey, tal_count(scriptpubkey),
 		      peer->remote_upfront_shutdown_script,
 		      tal_count(peer->remote_upfront_shutdown_script)))
-		peer_failed_err(peer->pps, &peer->channel_id,
+		peer_failed_warn(peer->pps, &peer->channel_id,
 				 "scriptpubkey %s is not as agreed upfront (%s)",
 				 tal_hex(peer, scriptpubkey),
 				 tal_hex(peer, peer->remote_upfront_shutdown_script));
@@ -2528,12 +2536,12 @@ static void check_future_dataloss_fields(struct peer *peer,
  *    commitment transaction:
  * ...
  *  - if `your_last_per_commitment_secret` does not match the expected values:
- *     - SHOULD fail the channel.
+ *     - SHOULD send an `error` and fail the channel.
  *  - otherwise, if it supports `option_data_loss_protect`:
  *...
  *    - otherwise (`your_last_per_commitment_secret` or
  *     `my_current_per_commitment_point` do not match the expected values):
- *      - SHOULD fail the channel.
+ *      - SHOULD send an `error` and fail the channel.
  */
 static void check_current_dataloss_fields(struct peer *peer,
 			u64 next_revocation_number,
@@ -2950,10 +2958,10 @@ skip_tlvs:
 	 *    - if `next_revocation_number` is not equal to 1 greater
 	 *      than the commitment number of the last `revoke_and_ack` the
 	 *      receiving node has sent:
-	 *      - SHOULD fail the channel.
+	 *      - SHOULD send an `error` and fail the channel.
 	 *    - if it has not sent `revoke_and_ack`, AND
 	 *      `next_revocation_number` is not equal to 0:
-	 *      - SHOULD fail the channel.
+	 *      - SHOULD send an `error` and fail the channel.
 	 */
 	if (next_revocation_number == peer->next_index[LOCAL] - 2) {
 		/* Don't try to retransmit revocation index -1! */
@@ -3021,7 +3029,7 @@ skip_tlvs:
 	 *     - if `next_commitment_number` is not 1 greater than the
 	 *       commitment number of the last `commitment_signed` message the
 	 *       receiving node has sent:
-	 *       - SHOULD fail the channel.
+	 *       - SHOULD send an `error` and fail the channel.
 	 */
 	} else if (next_commitment_number != peer->next_index[REMOTE])
 		peer_failed_err(peer->pps,

channeld/full_channel.c

@@ -559,7 +559,8 @@ static enum channel_add_err add_htlc(struct channel *channel,
 	 *...
 	 *  - if sending node sets `cltv_expiry` to greater or equal to
 	 *    500000000:
-	 *    - SHOULD fail the channel.
+	 *    - 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;
@@ -584,7 +585,8 @@ static enum channel_add_err add_htlc(struct channel *channel,
 	 * A receiving node:
 	 *  - receiving an `amount_msat` equal to 0, OR less than its own
 	 *    `htlc_minimum_msat`:
-	 *    - SHOULD fail the channel.
+	 *        - SHOULD send a `warning` and close the connection, or send an
+	 *        `error` and fail the channel.
 	 */
 	if (amount_msat_eq(htlc->amount, AMOUNT_MSAT(0))) {
 		return CHANNEL_ERR_HTLC_BELOW_MINIMUM;
@@ -652,7 +654,8 @@ static enum channel_add_err add_htlc(struct channel *channel,
 	 *   - if a sending node... adds more than receiver
 	 *     `max_htlc_value_in_flight_msat` worth of offered HTLCs to its
 	 *     local commitment transaction:
-	 *     - SHOULD fail the channel.
+	 *     - SHOULD send a `warning` and close the connection, or send an
+	 *       `error` and fail the channel.
 	 */
 
 	/* We don't enforce this for channel_force_htlcs: some might already
@@ -670,7 +673,8 @@ static enum channel_add_err add_htlc(struct channel *channel,
 	 *  - receiving an `amount_msat` that the sending node cannot afford at
 	 *    the current `feerate_per_kw` (while maintaining its channel
 	 *    reserve and any `to_local_anchor` and `to_remote_anchor` costs):
-	 *    - SHOULD fail the channel.
+	 *      - SHOULD send a `warning` and close the connection, or send an
+	 *       `error` and fail the channel.
 	 */
 	if (enforce_aggregate_limits) {
 		struct amount_msat remainder;
@@ -894,7 +898,8 @@ enum channel_remove_err channel_fulfill_htlc(struct channel *channel,
 	 *
 	 *  - if the `payment_preimage` value in `update_fulfill_htlc`
 	 *  doesn't SHA256 hash to the corresponding HTLC `payment_hash`:
-	 *    - MUST fail the channel.
+	 *     - MUST send a `warning` and close the connection, or send an
+	 *       `error` and fail the channel.
 	 */
 	if (!sha256_eq(&hash, &htlc->rhash))
 		return CHANNEL_ERR_BAD_PREIMAGE;
@@ -905,7 +910,8 @@ enum channel_remove_err channel_fulfill_htlc(struct channel *channel,
 	 *
 	 *  - if the `id` does not correspond to an HTLC in its current
 	 *    commitment transaction:
-	 *    - MUST fail the channel.
+	 *     - MUST send a `warning` and close the connection, or send an
+	 *       `error` and fail the channel.
 	 */
 	if (!htlc_has(htlc, HTLC_FLAG(!htlc_owner(htlc), HTLC_F_COMMITTED))) {
 		status_unusual("channel_fulfill_htlc: %"PRIu64" in state %s",
@@ -957,7 +963,8 @@ enum channel_remove_err channel_fail_htlc(struct channel *channel,
 	 * A receiving node:
 	 *   - if the `id` does not correspond to an HTLC in its current
 	 *     commitment transaction:
-	 *     - MUST fail the channel.
+	 *     - MUST send a `warning` and close the connection, or send an
+	 *       `error` and fail the channel.
 	 */
 	if (!htlc_has(htlc, HTLC_FLAG(!htlc_owner(htlc), HTLC_F_COMMITTED))) {
 		status_unusual("channel_fail_htlc: %"PRIu64" in state %s",
@@ -1145,7 +1152,8 @@ static int change_htlcs(struct channel *channel,
  *...
  *   - if the sender cannot afford the new fee rate on the receiving node's
  *     current commitment transaction:
- *      - SHOULD fail the channel,
+ *     - SHOULD send a `warning` and close the connection, or send an
+ *       `error` and fail the channel.
  */
 u32 approx_max_feerate(const struct channel *channel)
 {
@@ -1257,7 +1265,8 @@ bool can_opener_afford_feerate(const struct channel *channel, u32 feerate_per_kw
 	 *
 	 *   - if the sender cannot afford the new fee rate on the receiving
 	 *     node's current commitment transaction:
-	 *     - SHOULD fail the channel
+	 *     - SHOULD send a `warning` and close the connection, or send an
+	 *       `error` and fail the channel.
 	 */
 	/* Note: sender == opener */
 

closingd/closingd.c

@@ -291,7 +291,8 @@ receive_offer(struct per_peer_state *pps,
 	 *   - if the `signature` is not valid for either variant of closing transaction
 	 *   specified in [BOLT #3](03-transactions.md#closing-transaction)
 	 *   OR non-compliant with LOW-S-standard rule...:
-	 *     - MUST fail the connection.
+	 *     - MUST send a `warning` and close the connection, or send an
+	 *	 `error` and fail the channel.
 	 */
 	tx = close_tx(tmpctx, chainparams, pps, channel_id,
 		      local_wallet_index,

common/decode_array.c

@@ -33,10 +33,12 @@ struct short_channel_id *decode_short_ids(const tal_t *ctx, const u8 *encoded)
 	 * The receiver:
 	 *   - if the first byte of `encoded_short_ids` is not a known encoding
 	 *     type:
-	 *     - MAY fail the connection
+	 *     - MAY send a `warning`.
+	 *     - MAY close the connection.
 	 *   - if `encoded_short_ids` does not decode into a whole number of
 	 *     `short_channel_id`:
-	 *     - MAY fail the connection
+	 *     - MAY send a `warning`.
+	 *     - MAY close the connection.
 	 */
 	type = fromwire_u8(&encoded, &max);
 	switch (type) {
@@ -75,10 +77,12 @@ bigsize_t *decode_scid_query_flags(const tal_t *ctx,
 	 *...
 	 *  - if the incoming message includes `query_short_channel_ids_tlvs`:
 	 *    - if `encoding_type` is not a known encoding type:
-	 *      - MAY fail the connection
+	 *      - MAY send a `warning`.
+	 *      - MAY close the connection.
 	 *    - if `encoded_query_flags` does not decode to exactly one flag per
 	 *      `short_channel_id`:
-	 *      - MAY fail the connection.
+	 *      - MAY send a `warning`.
+	 *      - MAY close the connection.
 	 */
 	switch (qf->encoding_type) {
 	case ARR_ZLIB:

common/features.c

@@ -123,7 +123,8 @@ static const struct dependency feature_deps[] = {
 	 * `option_anchor_outputs` | ...      | ...      | `option_static_remotekey`
 	 */
 	{ OPT_ANCHOR_OUTPUTS, OPT_STATIC_REMOTEKEY },
-	/* BOLT #9:
+	/* FIXME: This dep was added later! */
+	/* BOLT-master #9:
 	 * Name                | Description  | Context  | Dependencies  |
 	 *...
 	 * `option_anchors_zero_fee_htlc_tx` | ...      | ...      | `option_static_remotekey`

common/ping.c

@@ -16,7 +16,6 @@ bool check_ping_make_pong(const tal_t *ctx, const u8 *ping, u8 **pong)
 	/* BOLT #1:
 	 *
 	 * A node receiving a `ping` message:
-	 *...
 	 *  - if `num_pong_bytes` is less than 65532:
 	 *    - MUST respond by sending a `pong` message, with `byteslen` equal
 	 *      to `num_pong_bytes`.

common/read_peer_msg.c

@@ -34,16 +34,23 @@ bool is_peer_error(const tal_t *ctx, const u8 *msg,
 	 * ...
 	 * The receiving node:
 	 *  - upon receiving `error`:
-	 *    - MUST fail the channel referred to by the error message, if that
+	 *     - if `channel_id` is all zero:
-	 *      channel is with the sending node.
+	 *       - MUST fail all channels with the sending node.
-	 *  - if no existing channel is referred to by the message:
+	 *     - otherwise:
+	 *       - MUST fail the channel referred to by `channel_id`, if that channel is with the sending node.
+	 *   - upon receiving `warning`:
+	 *     - SHOULD log the message for later diagnosis.
+	 *     - MAY disconnect.
+	 *     - MAY reconnect after some delay to retry.
+	 *     - MAY attempt `shutdown` if permitted at this point.
+	 *   - if no existing channel is referred to by `channel_id`:
 	 *     - MUST ignore the message.
 	 */
-	/* FIXME: The spec changed, so for *errors* all 0 is not special.
+
-	 * But old gossipd would send these, so we turn them into warnings */
+	/* FIXME: We don't actually free all channels at once, they'll
-	if (channel_id_is_all(&err_chanid))
+	 * have to error each in turn. */
-		*warning = true;
+	if (!channel_id_is_all(&err_chanid)
-	else if (!channel_id_eq(&err_chanid, channel_id))
+	    && !channel_id_eq(&err_chanid, channel_id))
 		*desc = tal_free(*desc);
 
 	return true;

common/wireaddr.h

@@ -26,10 +26,7 @@ struct sockaddr_un;
  *
  *   * `1`: ipv4; data = `[4:ipv4_addr][2:port]` (length 6)
  *   * `2`: ipv6; data = `[16:ipv6_addr][2:port]` (length 18)
- *   * `3`: Tor v2 onion service; data = `[10:onion_addr][2:port]` (length 12)
+ *   * `3`: Deprecated (length 12). Used to contain Tor v2 onion services.
- *       * version 2 onion service addresses; Encodes an 80-bit, truncated `SHA-1` hash
- *         of a 1024-bit `RSA` public key for the onion service (a.k.a. Tor
- *	   hidden service).
  *   * `4`: Tor v3 onion service; data = `[35:onion_addr][2:port]` (length 37)
  *       * version 3 ([prop224](https://gitweb.torproject.org/torspec.git/tree/proposals/224-rend-spec-ng.txt))
  *         onion service addresses; Encodes:

connectd/connectd.c

@@ -364,7 +364,7 @@ struct io_plan *peer_connected(struct io_conn *conn,
 	 *  - upon receiving unknown _odd_ feature bits that are non-zero:
 	 *    - MUST ignore the bit.
 	 *  - upon receiving unknown _even_ feature bits that are non-zero:
-	 *    - MUST fail the connection.
+	 *    - MUST close the connection.
 	 */
 	unsup = features_unsupported(daemon->our_features, their_features,
 				     INIT_FEATURE);

connectd/multiplex.c

@@ -1225,7 +1225,6 @@ void send_manual_ping(struct daemon *daemon, const u8 *msg)
 	/* BOLT #1:
 	 *
 	 * A node receiving a `ping` message:
-	 *...
 	 *  - if `num_pong_bytes` is less than 65532:
 	 *    - MUST respond by sending a `pong` message, with `byteslen` equal
 	 *      to `num_pong_bytes`.

connectd/peer_exchange_initmsg.c

@@ -75,7 +75,7 @@ static struct io_plan *peer_init_received(struct io_conn *conn,
 	 * The receiving node:
 	 * ...
 	 *  - upon receiving `networks` containing no common chains
-	 *    - MAY fail the connection.
+	 *    - MAY close the connection.
 	 */
 	if (tlvs->networks) {
 		if (!contains_common_chain(tlvs->networks)) {

gossipd/queries.c

@@ -258,7 +258,8 @@ const u8 *handle_query_short_channel_ids(struct peer *peer, const u8 *msg)
 		 *  - if the incoming message includes
 		 *    `query_short_channel_ids_tlvs`:
 		 *    - if `encoding_type` is not a known encoding type:
-		 *      - MAY fail the connection
+		 *      - MAY send a `warning`.
+		 *      - MAY close the connection.
 		 */
 		flags = decode_scid_query_flags(tmpctx, tlvs->query_flags);
 		if (!flags) {
@@ -288,7 +289,8 @@ const u8 *handle_query_short_channel_ids(struct peer *peer, const u8 *msg)
 	 * - if it has not sent `reply_short_channel_ids_end` to a
 	 *   previously received `query_short_channel_ids` from this
 	 *   sender:
-	 *    - MAY fail the connection.
+	 *    - MAY send a `warning`.
+	 *    - MAY close the connection.
 	 */
 	if (peer->scid_queries || peer->scid_query_nodes) {
 		return towire_warningfmt(peer, NULL,
@@ -308,7 +310,8 @@ const u8 *handle_query_short_channel_ids(struct peer *peer, const u8 *msg)
 	 *...
 	 *    - if `encoded_query_flags` does not decode to exactly one flag per
 	 *      `short_channel_id`:
-	 *      - MAY fail the connection.
+	 *     - MAY send a `warning`.
+	 *     - MAY close the connection.
 	 */
 	if (!flags) {
 		/* Pretend they asked for everything. */

gossipd/routing.c

@@ -886,7 +886,7 @@ u8 *handle_channel_announcement(struct routing_state *rstate,
 {
 	struct pending_cannouncement *pending;
 	struct bitcoin_blkid chain_hash;
-	u8 *features, *err;
+	u8 *features, *warn;
 	secp256k1_ecdsa_signature node_signature_1, node_signature_2;
 	secp256k1_ecdsa_signature bitcoin_signature_1, bitcoin_signature_2;
 	struct chan *chan;
@@ -911,7 +911,7 @@ u8 *handle_channel_announcement(struct routing_state *rstate,
 					   &pending->node_id_2,
 					   &pending->bitcoin_key_1,
 					   &pending->bitcoin_key_2)) {
-		err = towire_warningfmt(rstate, NULL,
+		warn = towire_warningfmt(rstate, NULL,
 					"Malformed channel_announcement %s",
 					tal_hex(pending, pending->announce));
 		goto malformed;
@@ -991,7 +991,7 @@ u8 *handle_channel_announcement(struct routing_state *rstate,
 	}
 
 	/* Note that if node_id_1 or node_id_2 are malformed, it's caught here */
-	err = check_channel_announcement(rstate,
+	warn = check_channel_announcement(rstate,
 					 &pending->node_id_1,
 					 &pending->node_id_2,
 					 &pending->bitcoin_key_1,
@@ -1001,13 +1001,15 @@ u8 *handle_channel_announcement(struct routing_state *rstate,
 					 &bitcoin_signature_1,
 					 &bitcoin_signature_2,
 					 pending->announce);
-	if (err) {
+	if (warn) {
 		/* BOLT #7:
 		 *
 		 * - if `bitcoin_signature_1`, `bitcoin_signature_2`,
 		 *   `node_signature_1` OR `node_signature_2` are invalid OR NOT
 		 *    correct:
-		 *    - SHOULD fail the connection.
+		 *   - SHOULD send a `warning`.
+		 *   - MAY close the connection.
+		 *   - MUST ignore the message.
 		 */
 		goto malformed;
 	}
@@ -1049,7 +1051,7 @@ u8 *handle_channel_announcement(struct routing_state *rstate,
 malformed:
 	tal_free(pending);
 	*scid = NULL;
-	return err;
+	return warn;
 
 ignored:
 	tal_free(pending);
@@ -1458,7 +1460,7 @@ u8 *handle_channel_update(struct routing_state *rstate, const u8 *update TAKES,
 	struct bitcoin_blkid chain_hash;
 	u8 direction;
 	struct pending_cannouncement *pending;
-	u8 *err;
+	u8 *warn;
 
 	serialized = tal_dup_talarr(tmpctx, u8, update);
 	if (!fromwire_channel_update(serialized, &signature,
@@ -1467,10 +1469,10 @@ u8 *handle_channel_update(struct routing_state *rstate, const u8 *update TAKES,
 				     &channel_flags, &expiry,
 				     &htlc_minimum, &fee_base_msat,
 				     &fee_proportional_millionths)) {
-		err = towire_warningfmt(rstate, NULL,
+		warn = towire_warningfmt(rstate, NULL,
 					 "Malformed channel_update %s",
 					 tal_hex(tmpctx, serialized));
-		return err;
+		return warn;
 	}
 	direction = channel_flags & 0x1;
 
@@ -1523,18 +1525,18 @@ u8 *handle_channel_update(struct routing_state *rstate, const u8 *update TAKES,
 		return NULL;
 	}
 
-	err = check_channel_update(rstate, owner, &signature, serialized);
+	warn = check_channel_update(rstate, owner, &signature, serialized);
-	if (err) {
+	if (warn) {
 		/* BOLT #7:
 		 *
 		 * - if `signature` is not a valid signature, using `node_id`
 		 *  of the double-SHA256 of the entire message following the
 		 *  `signature` field (including unknown fields following
 		 *  `fee_proportional_millionths`):
+		 *    - SHOULD send a `warning` and close the connection.
 		 *    - MUST NOT process the message further.
-		 *    - SHOULD fail the connection.
 		 */
-		return err;
+		return warn;
 	}
 
 	routing_add_channel_update(rstate, take(serialized), 0, peer, force);
@@ -1712,13 +1714,14 @@ u8 *handle_node_announcement(struct routing_state *rstate, const u8 *node_ann,
 		/* BOLT #7:
 		 *
 		 *   - if `node_id` is NOT a valid compressed public key:
-		 *    - SHOULD fail the connection.
+		 *    - SHOULD send a `warning`.
+		 *    - MAY close the connection.
 		 *    - MUST NOT process the message further.
 		 */
-		u8 *err = towire_warningfmt(rstate, NULL,
+		u8 *warn = towire_warningfmt(rstate, NULL,
 					    "Malformed node_announcement %s",
 					    tal_hex(tmpctx, node_ann));
-		return err;
+		return warn;
 	}
 
 	sha256_double(&hash, serialized + 66, tal_count(serialized) - 66);
@@ -1731,10 +1734,10 @@ u8 *handle_node_announcement(struct routing_state *rstate, const u8 *node_ann,
                  *   message following the `signature` field
                  *   (including unknown fields following
                  *   `fee_proportional_millionths`):
+                 *     - SHOULD send a `warning` and close the connection.
                  *     - MUST NOT process the message further.
-		 *    - SHOULD fail the connection.
 		 */
-		u8 *err = towire_warningfmt(rstate, NULL,
+		u8 *warn = towire_warningfmt(rstate, NULL,
 					    "Bad signature for %s hash %s"
 					    " on node_announcement %s",
 					    type_to_string(tmpctx,
@@ -1744,7 +1747,7 @@ u8 *handle_node_announcement(struct routing_state *rstate, const u8 *node_ann,
 							   struct sha256_double,
 							   &hash),
 					    tal_hex(tmpctx, node_ann));
-		return err;
+		return warn;
 	}
 
 	wireaddrs = fromwire_wireaddr_array(tmpctx, addresses);
@@ -1753,13 +1756,14 @@ u8 *handle_node_announcement(struct routing_state *rstate, const u8 *node_ann,
 		 *
 		 * - if `addrlen` is insufficient to hold the address
 		 *  descriptors of the known types:
-		 *    - SHOULD fail the connection.
+		 *    - SHOULD send a `warning`.
+		 *    - MAY close the connection.
 		 */
-		u8 *err = towire_warningfmt(rstate, NULL,
+		u8 *warn = towire_warningfmt(rstate, NULL,
 					    "Malformed wireaddrs %s in %s.",
 					    tal_hex(tmpctx, wireaddrs),
 					    tal_hex(tmpctx, node_ann));
-		return err;
+		return warn;
 	}
 
 	/* May still fail, if we don't know the node. */

lightningd/channel_control.c

@@ -9,6 +9,7 @@
 #include <common/shutdown_scriptpubkey.h>
 #include <common/type_to_string.h>
 #include <common/wire_error.h>
+#include <connectd/connectd_wiregen.h>
 #include <errno.h>
 #include <hsmd/capabilities.h>
 #include <lightningd/chaintopology.h>
@@ -289,18 +290,32 @@ static void peer_got_shutdown(struct channel *channel, const u8 *msg)
 		return;
 	}
 
-	/* FIXME: Add to spec that we must allow repeated shutdown! */
+	/* BOLT #2:
-	tal_free(channel->shutdown_scriptpubkey[REMOTE]);
+	 * A receiving node:
-	channel->shutdown_scriptpubkey[REMOTE] = scriptpubkey;
+	 *...
-
+	 *   - if the `scriptpubkey` is not in one of the above forms:
+	 *     - SHOULD send a `warning`.
+	 */
 	if (!valid_shutdown_scriptpubkey(scriptpubkey, anysegwit, anchors)) {
-		channel_fail_permanent(channel,
+		u8 *warning = towire_warningfmt(NULL,
-				       REASON_PROTOCOL,
+						&channel->cid,
 						"Bad shutdown scriptpubkey %s",
 						tal_hex(tmpctx, scriptpubkey));
+
+		/* Get connectd to send warning, and then allow reconnect. */
+		subd_send_msg(ld->connectd,
+			      take(towire_connectd_peer_final_msg(NULL,
+								  &channel->peer->id,
+								  warning)));
+		channel_fail_reconnect(channel, "Bad shutdown scriptpubkey %s",
+				       tal_hex(tmpctx, scriptpubkey));
 		return;
 	}
 
+	/* FIXME: Add to spec that we must allow repeated shutdown! */
+	tal_free(channel->shutdown_scriptpubkey[REMOTE]);
+	channel->shutdown_scriptpubkey[REMOTE] = scriptpubkey;
+
 	/* If we weren't already shutting down, we are now */
 	if (channel->state != CHANNELD_SHUTTING_DOWN)
 		channel_set_state(channel,

lightningd/dual_open_control.c

@@ -15,6 +15,7 @@
 #include <common/psbt_open.h>
 #include <common/shutdown_scriptpubkey.h>
 #include <common/type_to_string.h>
+#include <common/wire_error.h>
 #include <connectd/connectd_wiregen.h>
 #include <errno.h>
 #include <hsmd/capabilities.h>
@@ -1324,13 +1325,21 @@ static void handle_peer_wants_to_close(struct subd *dualopend,
 	 * A receiving node:
 	 *...
 	 *  - if the `scriptpubkey` is not in one of the above forms:
-	 *    - SHOULD fail the connection.
+	 *    - SHOULD send a `warning`
 	 */
 	if (!valid_shutdown_scriptpubkey(scriptpubkey, anysegwit, anchors)) {
-		channel_fail_permanent(channel,
+		u8 *warning = towire_warningfmt(NULL,
-				       REASON_PROTOCOL,
+						&channel->cid,
 						"Bad shutdown scriptpubkey %s",
-				       tal_hex(channel, scriptpubkey));
+						tal_hex(tmpctx, scriptpubkey));
+
+		/* Get connectd to send warning, and then allow reconnect. */
+		subd_send_msg(ld->connectd,
+			      take(towire_connectd_peer_final_msg(NULL,
+								  &channel->peer->id,
+								  warning)));
+		channel_fail_reconnect(channel, "Bad shutdown scriptpubkey %s",
+				       tal_hex(tmpctx, scriptpubkey));
 		return;
 	}
 

lightningd/peer_control.c

@@ -329,24 +329,30 @@ void channel_errmsg(struct channel *channel,
 	 *
 	 * A sending node:
 	 *...
-	 *   - when `channel_id` is 0:
+	 *   - when sending `error`:
-	 *    - MUST fail all channels with the receiving node.
+	 *     - MUST fail the channel(s) referred to by the error message.
-	 *    - MUST close the connection.
+	 *     - MAY set `channel_id` to all zero to indicate all channels.
 	 */
 	/* FIXME: Close if it's an all-channels error sent or rcvd */
 
 	/* BOLT #1:
 	 *
 	 * A sending node:
+	 *...
 	 *  - when sending `error`:
-	 *    - MUST fail the channel referred to by the error message.
+	 *    - MUST fail the channel(s) referred to by the error message.
+	 *    - MAY set `channel_id` to all zero to indicate all channels.
 	 *...
 	 * The receiving node:
 	 *  - upon receiving `error`:
-	 *    - MUST fail the channel referred to by the error message,
+	 *    - if `channel_id` is all zero:
-	 *      if that channel is with the sending node.
+	 *       - MUST fail all channels with the sending node.
+	 *    - otherwise:
+	 *      - MUST fail the channel referred to by `channel_id`, if that channel is with the
+	 *        sending node.
 	 */
 
+	/* FIXME: We don't close all channels */
 	/* We should immediately forget the channel if we receive error during
 	 * CHANNELD_AWAITING_LOCKIN if we are fundee. */
 	if (!err_for_them && channel->opener == REMOTE

lightningd/peer_htlcs.c

@@ -1945,7 +1945,8 @@ static bool channel_added_their_htlc(struct channel *channel,
 	/* BOLT #2:
 	 *
 	 *  - receiving an `amount_msat` equal to 0, OR less than its own `htlc_minimum_msat`:
-	 *    - SHOULD fail the channel.
+	 *     - SHOULD send a `warning` and close the connection, or send an
+	 *       `error` and fail the channel.
 	 */
 	if (amount_msat_eq(added->amount, AMOUNT_MSAT(0))
 	    || amount_msat_less(added->amount, channel->our_config.htlc_minimum)) {
@@ -2280,7 +2281,8 @@ void peer_got_revoke(struct channel *channel, const u8 *msg)
 	 *
 	 *   - if the `per_commitment_secret` was not generated by the protocol
 	 *     in [BOLT #3](03-transactions.md#per-commitment-secret-requirements):
-	 *     - MAY fail the channel.
+	 *     - MAY send a `warning` and close the connection, or send an
+	 *       `error` and fail the channel.
 	 */
 	if (!wallet_shachain_add_hash(ld->wallet,
 				      &channel->their_shachain,
@@ -2488,6 +2490,7 @@ void htlcs_notify_new_block(struct lightningd *ld, u32 height)
 	 *
 	 *   - if an HTLC which it offered is in either node's current
 	 *   commitment transaction, AND is past this timeout deadline:
+	 *     - SHOULD send an `error` to the receiving peer (if connected).
 	 *     - MUST fail the channel.
 	 */
 	/* FIXME: use db to look this up in one go (earliest deadline per-peer) */
@@ -2532,6 +2535,7 @@ void htlcs_notify_new_block(struct lightningd *ld, u32 height)
 	 *...
 	 *   - if an HTLC it has fulfilled is in either node's current commitment
 	 *   transaction, AND is past this fulfillment deadline:
+	 *     - SHOULD send an `error` to the offering peer (if connected).
 	 *     - MUST fail the channel.
 	 */
 	do {

openingd/dualopend.c

@@ -1202,8 +1202,7 @@ static u8 *opening_negotiate_msg(const tal_t *ctx, struct state *state)
 				  &err, &warning)) {
 			/* BOLT #1:
 			 *
-			 *  - if no existing channel is referred to by the
+			 *  - if no existing channel is referred to by `channel_id`:
-			 *    message:
 			 *    - MUST ignore the message.
 			 */
 			/* In this case, is_peer_error returns true, but sets
@@ -1850,13 +1849,14 @@ static u8 *accepter_commits(struct state *state,
 	 * The recipient:
 	 *   - if `signature` is incorrect OR non-compliant with LOW-S-standard
 	 *       rule...:
-	 *     - MUST fail the channel.
+	 *     - MUST send a `warning` and close the connection, or send an
+	 *       `error` and fail the channel.
 	 */
 	if (!check_tx_sig(local_commit, 0, NULL, wscript,
 			  &state->their_funding_pubkey, &remote_sig)) {
 		/* BOLT #1:
 		 *
-		 * ### The `error` Message
+		 * ### The `error` and `warning` Messages
 		 *...
 		 * - when failure was caused by an invalid signature check:
 		 *    - SHOULD include the raw, hex-encoded transaction in reply
@@ -2575,14 +2575,15 @@ static u8 *opener_commits(struct state *state,
 	 * The recipient:
 	 *   - if `signature` is incorrect OR non-compliant with LOW-S-standard
 	 *     rule...:
-	 *     - MUST fail the channel.
+	 *     - MUST send a `warning` and close the connection, or send an
+	 *       `error` and fail the channel.
 	 */
 	if (!check_tx_sig(local_commit, 0, NULL, wscript,
 			  &state->their_funding_pubkey,
 			  &remote_sig)) {
 		/* BOLT #1:
 		 *
-		 * ### The `error` Message
+		 * ### The `error` and `warning` Messages
 		 *...
 		 * - when failure was caused by an invalid signature check:
 		 *    - SHOULD include the raw, hex-encoded transaction in reply
@@ -3588,7 +3589,7 @@ static void do_reconnect_dance(struct state *state)
 	/* BOLT #2:
 	 *    - if it has not sent `revoke_and_ack`, AND
 	 *      `next_revocation_number` is not equal to 0:
-	 *      - SHOULD fail the channel.
+	 *      - SHOULD send an `error` and fail the channel.
 	 */
 	/* It's possible that we've opened an outdated copy of the
 	 * database, and the peer is very much ahead of us.

openingd/openingd.c

@@ -192,8 +192,7 @@ static u8 *opening_negotiate_msg(const tal_t *ctx, struct state *state,
 				  &err, &warning)) {
 			/* BOLT #1:
 			 *
-			 *  - if no existing channel is referred to by the
+			 *  - if no existing channel is referred to by `channel_id`:
-			 *    message:
 			 *    - MUST ignore the message.
 			 */
 			/* In this case, is_peer_error returns true, but sets
@@ -1107,7 +1106,8 @@ static u8 *fundee_channel(struct state *state, const u8 *open_channel_msg)
 	 * The recipient:
 	 *   - if `signature` is incorrect OR non-compliant with LOW-S-standard
 	 *     rule...:
-	 *     - MUST fail the channel.
+	 *     - MUST send a `warning` and close the connection, or send an
+	 *       `error` and fail the channel.
 	 */
 	local_commit = initial_channel_tx(state, &wscript, state->channel,
 					  &state->first_per_commitment_point[LOCAL],
@@ -1125,7 +1125,7 @@ static u8 *fundee_channel(struct state *state, const u8 *open_channel_msg)
 			  &theirsig)) {
 		/* BOLT #1:
 		 *
-		 * ### The `error` Message
+		 * ### The `error` and `warning` Messages
 		 *...
 		 * - when failure was caused by an invalid signature check:
 		 *    - SHOULD include the raw, hex-encoded transaction in reply

tests/test_closing.py

@@ -1,5 +1,4 @@
 from fixtures import *  # noqa: F401,F403
-from flaky import flaky
 from pyln.client import RpcError, Millisatoshi
 from shutil import copyfile
 from pyln.testing.utils import SLOW_MACHINE
@@ -3186,31 +3185,27 @@ def test_shutdown(node_factory):
     l1.rpc.stop()
 
 
-@flaky
 @pytest.mark.developer("needs to set upfront_shutdown_script")
 def test_option_upfront_shutdown_script(node_factory, bitcoind, executor):
-    # There's a workaround in channeld, that it treats incoming errors
-    # before both sides are locked in as warnings; this happens in
-    # this test, so l1 reports the error as a warning!
     l1 = node_factory.get_node(start=False, allow_warning=True)
     # Insist on upfront script we're not going to match.
     # '0014' + l1.rpc.call('dev-listaddrs', [10])['addresses'][-1]['bech32_redeemscript']
     l1.daemon.env["DEV_OPENINGD_UPFRONT_SHUTDOWN_SCRIPT"] = "00143d43d226bcc27019ade52d7a3dc52a7ac1be28b8"
     l1.start()
 
-    l2 = node_factory.get_node()
+    l2 = node_factory.get_node(allow_warning=True)
     l1.rpc.connect(l2.info['id'], 'localhost', l2.port)
     l1.fundchannel(l2, 1000000, False)
 
-    # This will block, as l12 will send an error but l2 will retry.
+    # This will block, as l1 will send a warning but l2 will retry.
     fut = executor.submit(l1.rpc.close, l2.info['id'])
 
-    # l2 will close unilaterally when it dislikes shutdown script.
+    # l2 will send a warning when it dislikes shutdown script.
-    l1.daemon.wait_for_log(r'scriptpubkey .* is not as agreed upfront \(00143d43d226bcc27019ade52d7a3dc52a7ac1be28b8\)')
+    l1.daemon.wait_for_log(r'WARNING.*scriptpubkey .* is not as agreed upfront \(00143d43d226bcc27019ade52d7a3dc52a7ac1be28b8\)')
 
-    # Clear channel.
+    # Close from l2's side and clear channel.
-    wait_for(lambda: len(bitcoind.rpc.getrawmempool()) != 0)
+    l2.rpc.close(l1.info['id'], unilateraltimeout=1)
-    bitcoind.generate_block(1)
+    bitcoind.generate_block(1, wait_for_mempool=1)
     fut.result(TIMEOUT)
     wait_for(lambda: [c['state'] for c in only_one(l1.rpc.listpeers()['peers'])['channels']] == ['ONCHAIN'])
     wait_for(lambda: [c['state'] for c in only_one(l2.rpc.listpeers()['peers'])['channels']] == ['ONCHAIN'])
@@ -3219,14 +3214,12 @@ def test_option_upfront_shutdown_script(node_factory, bitcoind, executor):
     l1.rpc.connect(l2.info['id'], 'localhost', l2.port)
     l1.fundchannel(l2, 1000000, False)
 
-    l2.rpc.close(l1.info['id'])
+    l2.rpc.close(l1.info['id'], unilateraltimeout=5)
 
-    # l2 will close unilaterally when it dislikes shutdown script.
+    # l2 will send warning unilaterally when it dislikes shutdown script.
-    l1.daemon.wait_for_log(r'scriptpubkey .* is not as agreed upfront \(00143d43d226bcc27019ade52d7a3dc52a7ac1be28b8\)')
+    l1.daemon.wait_for_log(r'WARNING.*scriptpubkey .* is not as agreed upfront \(00143d43d226bcc27019ade52d7a3dc52a7ac1be28b8\)')
 
-    # Clear channel.
+    bitcoind.generate_block(1, wait_for_mempool=1)
-    wait_for(lambda: len(bitcoind.rpc.getrawmempool()) != 0)
-    bitcoind.generate_block(1)
     wait_for(lambda: [c['state'] for c in only_one(l1.rpc.listpeers()['peers'])['channels']] == ['ONCHAIN', 'ONCHAIN'])
     wait_for(lambda: [c['state'] for c in only_one(l2.rpc.listpeers()['peers'])['channels']] == ['ONCHAIN', 'ONCHAIN'])
 

wire/extracted_peer_02_warning.patch

@@ -1,13 +0,0 @@
---- wire/peer_exp_wire.csv	2021-01-14 11:00:27.526336550 +1030
-+++ -	2021-01-21 15:31:37.071118999 +1030
-@@ -10,6 +10,10 @@
- msgdata,error,channel_id,channel_id,
- msgdata,error,len,u16,
- msgdata,error,data,byte,len
-+msgtype,warning,1
-+msgdata,warning,channel_id,channel_id,
-+msgdata,warning,len,u16,
-+msgdata,warning,data,byte,len
- msgtype,ping,18
- msgdata,ping,num_pong_bytes,u16,
- msgdata,ping,byteslen,u16,