Protocol: make var_onion, payment_secret and basic_mpp non-EXPERIMENTAL.

Thanks to @t-bast, who made this possible by interop testing with Eclair!

Changelog-Added: Protocol: can now send and receive TLV-style onion messages.
Changelog-Added: Protocol: can now send and receive BOLT11 payment_secrets.
Changelog-Added: Protocol: can now receive basic multi-part payments.
Changelog-Added: RPC: low-level commands sendpay and waitsendpay can now be used to manually send multi-part payments.

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

channeld/channeld.c

@@ -960,11 +960,9 @@ static u8 *make_failmsg(const tal_t *ctx,
 		/* FIXME: wire this into tlv parser somehow. */
 		msg = towire_invalid_onion_payload(ctx, 0, 0);
 		goto done;
-#if EXPERIMENTAL_FEATURES
 	case WIRE_MPP_TIMEOUT:
 		msg = towire_mpp_timeout(ctx);
 		goto done;
-#endif /* EXPERIMENTAL_FEATURES */
 	}
 	status_failed(STATUS_FAIL_INTERNAL_ERROR,
 		      "Asked to create failmsg %u (%s)",

common/features.c

@@ -8,11 +8,9 @@ static const u32 our_features[] = {
 	OPTIONAL_FEATURE(OPT_DATA_LOSS_PROTECT),
 	OPTIONAL_FEATURE(OPT_UPFRONT_SHUTDOWN_SCRIPT),
 	OPTIONAL_FEATURE(OPT_GOSSIP_QUERIES),
-#if EXPERIMENTAL_FEATURES
 	OPTIONAL_FEATURE(OPT_VAR_ONION),
 	OPTIONAL_FEATURE(OPT_PAYMENT_SECRET),
 	OPTIONAL_FEATURE(OPT_BASIC_MPP),
-#endif
 	OPTIONAL_FEATURE(OPT_GOSSIP_QUERIES_EX),
 	OPTIONAL_FEATURE(OPT_STATIC_REMOTEKEY),
 };

common/onion.c

@@ -101,9 +101,7 @@ u8 *onion_final_hop(const tal_t *ctx,
 		struct tlv_tlv_payload *tlv = tlv_tlv_payload_new(tmpctx);
 		struct tlv_tlv_payload_amt_to_forward tlv_amt;
 		struct tlv_tlv_payload_outgoing_cltv_value tlv_cltv;
-#if EXPERIMENTAL_FEATURES
 		struct tlv_tlv_payload_payment_data tlv_pdata;
-#endif
 
 		/* BOLT #4:
 		 *
@@ -118,17 +116,11 @@ u8 *onion_final_hop(const tal_t *ctx,
 		tlv->amt_to_forward = &tlv_amt;
 		tlv->outgoing_cltv_value = &tlv_cltv;
 
-#if EXPERIMENTAL_FEATURES
 		if (payment_secret) {
 			tlv_pdata.payment_secret = *payment_secret;
 			tlv_pdata.total_msat = total_msat.millisatoshis; /* Raw: TLV convert */
 			tlv->payment_data = &tlv_pdata;
 		}
-#else
-		/* Wihtout EXPERIMENTAL_FEATURES, we can't send payment_secret */
-		if (payment_secret)
-			return NULL;
-#endif
 		return make_tlv_hop(ctx, tlv);
 	} else {
 		static struct short_channel_id all_zero_scid;
@@ -170,10 +162,6 @@ static bool pull_payload_length(const u8 **cursor,
 		return true;
 	}
 
-#if !EXPERIMENTAL_FEATURES
-	/* Only handle legacy format */
-	return false;
-#else
 	/* BOLT #4:
 	 * - `tlv_payload` format, identified by any length over `1`. In this
 	 *   case the `hop_payload_length` is equal to the numeric value of
@@ -191,7 +179,6 @@ static bool pull_payload_length(const u8 **cursor,
 	}
 
 	return false;
-#endif /* EXPERIMENTAL_FEATURES */
 }
 
 size_t onion_payload_length(const u8 *raw_payload, size_t len,
@@ -289,7 +276,6 @@ struct onion_payload *onion_decode(const tal_t *ctx,
 
 		p->payment_secret = NULL;
 
-#if EXPERIMENTAL_FEATURES
 		if (tlv->payment_data) {
 			p->payment_secret = tal_dup(p, struct secret,
 						    &tlv->payment_data->payment_secret);
@@ -298,7 +284,6 @@ struct onion_payload *onion_decode(const tal_t *ctx,
 			p->total_msat->millisatoshis /* Raw: tu64 on wire */
 				= tlv->payment_data->total_msat;
 		}
-#endif
 		tal_free(tlv);
 		return p;
 	}

common/sphinx.c

@@ -498,11 +498,6 @@ struct route_step *process_onionpacket(
 
 	payload_size = onion_payload_length(paddedheader, ROUTING_INFO_SIZE,
 					    &valid, NULL);
-#if !EXPERIMENTAL_FEATURES
-	/* We don't even attempt to handle non-legacy or malformed payloads */
-	if (!valid)
-		return tal_free(step);
-#endif
 
 	/* Can't decode?  Treat it as terminal. */
 	if (!valid) {

contrib/pyln-client/pyln/client/lightning.py

@@ -886,12 +886,15 @@ def sendpay(self, route, payment_hash, *args, **kwargs):
         if 'description' in kwargs:
             return self._deprecated_sendpay(route, payment_hash, *args, **kwargs)
 
-        def _sendpay(route, payment_hash, label=None, msatoshi=None):
+        def _sendpay(route, payment_hash, label=None, msatoshi=None, bolt11=None, payment_secret=None, partid=None):
             payload = {
                 "route": route,
                 "payment_hash": payment_hash,
                 "label": label,
                 "msatoshi": msatoshi,
+                "bolt11": bolt11,
+                "payment_secret": payment_secret,
+                "partid": partid,
             }
             return self.call("sendpay", payload)
 
@@ -935,13 +938,14 @@ def waitinvoice(self, label):
         }
         return self.call("waitinvoice", payload)
 
-    def waitsendpay(self, payment_hash, timeout=None):
+    def waitsendpay(self, payment_hash, timeout=None, partid=None):
         """
         Wait for payment for preimage of {payment_hash} to complete
         """
         payload = {
             "payment_hash": payment_hash,
-            "timeout": timeout
+            "timeout": timeout,
+            "partid": partid,
         }
         return self.call("waitsendpay", payload)
 

doc/lightning-sendpay.7.md

@@ -5,7 +5,7 @@ SYNOPSIS
 --------
 
 **sendpay** *route* *payment\_hash* \[*label*\] \[*msatoshi*\]
-\[*bolt11*\]
+\[*bolt11*\] \[*partid*\]
 
 DESCRIPTION
 -----------
@@ -29,20 +29,21 @@ The *label* and *bolt11* parameters, if provided, will be returned in
 
 The *msatoshi* amount, if provided, is the amount that will be recorded
 as the target payment value. If not specified, it will be the final
-amount to the destination. If specified, then the final amount at the
-destination must be from the specified *msatoshi* to twice the specified
-*msatoshi*, inclusive. This is intended to obscure payments by
-overpaying slightly at the destination; the actual target payment is
-what should be specified as the *msatoshi* argument. *msatoshi* is in
-millisatoshi precision; it can be a whole number, or a whole number
+amount to the destination. By default it is in millisatoshi precision; it can be a whole number, or a whole number
 ending in *msat* or *sat*, or a number with three decimal places ending
 in *sat*, or a number with 1 to 11 decimal places ending in *btc*.
 
+The *partid* value, if provided and non-zero, allows for multiple parallel
+partial payments with the same *payment_hash*.  The *msatoshi* amount
+(which must be provided) for each **sendpay** with matching
+*payment_hash* must be equal, and **sendpay** will fail if there are
+already *msatoshi* worth of payments pending.
+
 Once a payment has succeeded, calls to **sendpay** with the same
 *payment\_hash* but a different *msatoshi* or destination will fail;
 this prevents accidental multiple payments. Calls to **sendpay** with
 the same *payment\_hash*, *msatoshi*, and destination as a previous
-successful payment (even if a different route) will return immediately
+successful payment (even if a different route or *partid*) will return immediately
 with success.
 
 RETURN VALUE

doc/lightning-waitsendpay.7.md

@@ -4,7 +4,7 @@ lightning-waitsendpay -- Command for sending a payment via a route
 SYNOPSIS
 --------
 
-**waitsendpay** *payment\_hash* \[*timeout*\]
+**waitsendpay** *payment\_hash* \[*timeout*\] \[*partid*\]
 
 DESCRIPTION
 -----------
@@ -13,6 +13,8 @@ The **waitsendpay** RPC command polls or waits for the status of an
 outgoing payment that was initiated by a previous **sendpay**
 invocation.
 
+The *partid* argument must match that of the **sendpay** command.
+
 Optionally the client may provide a *timeout*, an integer in seconds,
 for this RPC command to return. If the *timeout* is provided and the
 given amount of time passes without the payment definitely succeeding or