Ignore fees per channel

.msggen.json

@@ -1002,6 +1002,7 @@
             "ListPeerChannels.channels[].funding_outnum": 11,
             "ListPeerChannels.channels[].funding_txid": 10,
             "ListPeerChannels.channels[].htlcs[]": 52,
+            "ListPeerChannels.channels[].ignore_fee_limits": 54,
             "ListPeerChannels.channels[].in_fulfilled_msat": 47,
             "ListPeerChannels.channels[].in_offered_msat": 45,
             "ListPeerChannels.channels[].in_payments_fulfilled": 46,
@@ -1401,6 +1402,7 @@
             "SetChannel.channels[].channel_id": 2,
             "SetChannel.channels[].fee_base_msat": 4,
             "SetChannel.channels[].fee_proportional_millionths": 5,
+            "SetChannel.channels[].ignore_fee_limits": 10,
             "SetChannel.channels[].maximum_htlc_out_msat": 8,
             "SetChannel.channels[].minimum_htlc_out_msat": 6,
             "SetChannel.channels[].peer_id": 1,
@@ -1414,7 +1416,8 @@
             "SetChannel.feeppm": 3,
             "SetChannel.htlcmax": 5,
             "SetChannel.htlcmin": 4,
-            "SetChannel.id": 1
+            "SetChannel.id": 1,
+            "SetChannel.ignorefeelimits": 7
         },
         "SetchannelResponse": {
             "SetChannel.channels[]": 1
@@ -3881,6 +3884,10 @@
             "added": "v23.02",
             "deprecated": false
         },
+        "ListPeerChannels.channels[].ignore_fee_limits": {
+            "added": "v23.08",
+            "deprecated": false
+        },
         "ListPeerChannels.channels[].in_fulfilled_msat": {
             "added": "v23.02",
             "deprecated": false
@@ -5013,6 +5020,10 @@
             "added": "pre-v0.10.1",
             "deprecated": false
         },
+        "SetChannel.channels[].ignore_fee_limits": {
+            "added": "v23.08",
+            "deprecated": false
+        },
         "SetChannel.channels[].maximum_htlc_out_msat": {
             "added": "pre-v0.10.1",
             "deprecated": false
@@ -5061,6 +5072,10 @@
             "added": "pre-v0.10.1",
             "deprecated": false
         },
+        "SetChannel.ignorefeelimits": {
+            "added": "v23.08",
+            "deprecated": false
+        },
         "SignInvoice": {
             "added": "v23.02",
             "deprecated": null

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

@@ -1321,7 +1321,7 @@ def sendonion(
         }
         return self.call("sendonion", payload)
 
-    def setchannel(self, id, feebase=None, feeppm=None, htlcmin=None, htlcmax=None, enforcedelay=None):
+    def setchannel(self, id, feebase=None, feeppm=None, htlcmin=None, htlcmax=None, enforcedelay=None, ignorefeelimits=None):
         """Set configuration a channel/peer {id} (or 'all').
 
         {feebase} is a value in millisatoshi that is added as base fee
@@ -1339,6 +1339,8 @@ def setchannel(self, id, feebase=None, feeppm=None, htlcmin=None, htlcmax=None,
         {enforcedelay} is the number of seconds before enforcing this
         change.
 
+        {ignorefeelimits} is a flag to indicate peer can set any feerate (dangerous!)
+
         """
         payload = {
             "id": id,
@@ -1347,6 +1349,7 @@ def setchannel(self, id, feebase=None, feeppm=None, htlcmin=None, htlcmax=None,
             "htlcmin": htlcmin,
             "htlcmax": htlcmax,
             "enforcedelay": enforcedelay,
+            "ignorefeelimits": ignorefeelimits,
         }
         return self.call("setchannel", payload)
 

contrib/pyln-testing/pyln/testing/grpc2py.py

@@ -790,6 +790,7 @@ def listpeerchannels_channels2py(m):
         "peer_connected": m.peer_connected,  # PrimitiveField in generate_composite
         "state": str(m.state),  # EnumField in generate_composite
         "scratch_txid": hexlify(m.scratch_txid),  # PrimitiveField in generate_composite
+        "ignore_fee_limits": m.ignore_fee_limits,  # PrimitiveField in generate_composite
         "owner": m.owner,  # PrimitiveField in generate_composite
         "short_channel_id": m.short_channel_id,  # PrimitiveField in generate_composite
         "channel_id": hexlify(m.channel_id),  # PrimitiveField in generate_composite
@@ -1297,6 +1298,7 @@ def setchannel_channels2py(m):
         "short_channel_id": m.short_channel_id,  # PrimitiveField in generate_composite
         "fee_base_msat": amount2msat(m.fee_base_msat),  # PrimitiveField in generate_composite
         "fee_proportional_millionths": m.fee_proportional_millionths,  # PrimitiveField in generate_composite
+        "ignore_fee_limits": m.ignore_fee_limits,  # PrimitiveField in generate_composite
         "minimum_htlc_out_msat": amount2msat(m.minimum_htlc_out_msat),  # PrimitiveField in generate_composite
         "warning_htlcmin_too_low": m.warning_htlcmin_too_low,  # PrimitiveField in generate_composite
         "maximum_htlc_out_msat": amount2msat(m.maximum_htlc_out_msat),  # PrimitiveField in generate_composite

doc/lightning-listpeerchannels.7.md

@@ -36,6 +36,7 @@ On success, an object containing **channels** is returned.  It is an array of ob
     - Bit number
   - **names** (array of strings): Feature name for each bit set in this channel\_type:
     - Name of feature bit (one of "static\_remotekey/even", "anchor\_outputs/even", "anchors\_zero\_fee\_htlc\_tx/even", "scid\_alias/even", "zeroconf/even")
+- **ignore\_fee\_limits** (boolean, optional): set if we allow this peer to set fees to anything they want *(added v23.08)*
 - **feerate** (object, optional): Feerates for the current tx:
   - **perkw** (u32): Feerate per 1000 weight (i.e kSipa)
   - **perkb** (u32): Feerate per 1000 virtual bytes
@@ -194,4 +195,4 @@ Main web site: <https://github.com/ElementsProject/lightning> Lightning
 RFC site (BOLT \#9):
 <https://github.com/lightningnetwork/lightning-rfc/blob/master/09-features.md>
 
-[comment]: # ( SHA256STAMP:f5103dae3b20a7d2a4112a368e753f1dd0518a269bd34c2fd17657c9f90596d7)
+[comment]: # ( SHA256STAMP:c530e39c9144b5fbef0f6474170865095bd7b4c48e6378fdb7f9a7697b909473)

doc/lightning-setchannel.7.md

@@ -4,7 +4,7 @@ lightning-setchannel -- Command for configuring fees / htlc range advertized for
 SYNOPSIS
 --------
 
-**setchannel** *id* [*feebase*] [*feeppm*] [*htlcmin*] [*htlcmax*] [*enforcedelay*]
+**setchannel** *id* [*feebase*] [*feeppm*] [*htlcmin*] [*htlcmax*] [*enforcedelay*] [*ignorefeelimits*]
 
 DESCRIPTION
 -----------
@@ -62,6 +62,13 @@ only applied to a single rate increase per channel (we don't remember
 an arbitrary number of prior feerates) and if the node is restarted
 the updated configuration is enforced immediately.
 
+*ignorefeelimits* set to True means to allow the peer to set the commitment
+transaction fees (or closing transaction fees) to any value they want.  This is dangerous: they could
+set an exorbitant fee (so HTLCs are unenforcable), or a tiny fee (so that
+commitment transactions cannot be relayed), but avoids channel breakage
+in case of feerate disagreements.  (Note: the global `ignore_fee_limits`
+setting overrides this).
+
 RETURN VALUE
 ------------
 
@@ -72,6 +79,7 @@ On success, an object containing **channels** is returned.  It is an array of ob
 - **channel\_id** (hex): The channel\_id of the channel (always 64 characters)
 - **fee\_base\_msat** (msat): The resulting feebase (this is the BOLT #7 name)
 - **fee\_proportional\_millionths** (u32): The resulting feeppm (this is the BOLT #7 name)
+- **ignore\_fee\_limits** (boolean): If we are now allowing peer to set feerate on commitment transaction without restriction *(added v23.08)*
 - **minimum\_htlc\_out\_msat** (msat): The resulting htlcmin we will advertize (the BOLT #7 name is htlc\_minimum\_msat)
 - **maximum\_htlc\_out\_msat** (msat): The resulting htlcmax we will advertize (the BOLT #7 name is htlc\_maximum\_msat)
 - **short\_channel\_id** (short\_channel\_id, optional): the short\_channel\_id (if locked in)
@@ -107,4 +115,4 @@ RESOURCES
 
 Main web site: <https://github.com/ElementsProject/lightning>
 
-[comment]: # ( SHA256STAMP:0175aaf74aa6d75640d0b79f68b552b1b700f93ad7576465c73de93af04d71e6)
+[comment]: # ( SHA256STAMP:5209ba4d4bbe2d897d9824f95a97fa48d968e83ffec2e4cfbd87df6fd90c48f0)

doc/lightning-sql.7.md

@@ -250,6 +250,7 @@ The following tables are currently supported:
     - `row` (reference to `peerchannels_channel_type.rowid`, sqltype `INTEGER`)
     - `arrindex` (index within array, sqltype `INTEGER`)
     - `names` (type `string`, sqltype `TEXT`)
+  - `ignore_fee_limits` (type `boolean`, sqltype `INTEGER`)
   - `feerate_perkw` (type `u32`, sqltype `INTEGER`, from JSON object `feerate`)
   - `feerate_perkb` (type `u32`, sqltype `INTEGER`, from JSON object `feerate`)
   - `owner` (type `string`, sqltype `TEXT`)
@@ -510,4 +511,4 @@ RESOURCES
 ---------
 
 Main web site: <https://github.com/ElementsProject/lightning>
-[comment]: # ( SHA256STAMP:68c72c66bdc8b0515c6d5dddd5ffd14aa0342bd00f17a44929177c48c36a213f)
+[comment]: # ( SHA256STAMP:4cfeeb2855f92a12d6a52d912a58df7573fc34f1f17a190bba26e46695f54de6)

doc/lightningd-config.5.md

@@ -332,7 +332,8 @@ falls below this.
   Allow nodes which establish channels to us to set any fee they want.
 This may result in a channel which cannot be closed, should fees
 increase, but make channels far more reliable since we never close it
-due to unreasonable fees.
+due to unreasonable fees.  Note that this can be set on a per-channel
+basis with lightning-setchannel(7).
 
 * **commit-time**=*MILLISECONDS*
 

doc/schemas/listpeerchannels.schema.json

@@ -84,6 +84,11 @@
               }
             }
           },
+          "ignore_fee_limits": {
+            "type": "boolean",
+            "added": "v23.08",
+            "description": "set if we allow this peer to set fees to anything they want"
+          },
           "feerate": {
             "type": "object",
             "description": "Feerates for the current tx",
@@ -609,6 +614,7 @@
                 "scratch_txid": {},
                 "channel_type": {},
                 "feerate": {},
+                "ignore_fee_limits": {},
                 "owner": {},
                 "short_channel_id": {},
                 "channel_id": {},
@@ -699,6 +705,7 @@
                 "scratch_txid": {},
                 "channel_type": {},
                 "feerate": {},
+                "ignore_fee_limits": {},
                 "owner": {},
                 "short_channel_id": {},
                 "channel_id": {},
@@ -788,6 +795,7 @@
                 "scratch_txid": {},
                 "channel_type": {},
                 "feerate": {},
+                "ignore_fee_limits": {},
                 "owner": {},
                 "short_channel_id": {},
                 "channel_id": {},
@@ -878,6 +886,7 @@
                 "scratch_txid": {},
                 "channel_type": {},
                 "feerate": {},
+                "ignore_fee_limits": {},
                 "owner": {},
                 "alias": {},
                 "short_channel_id": {},

doc/schemas/setchannel.request.json

@@ -23,6 +23,10 @@
     },
     "enforcedelay": {
       "type": "u32"
+    },
+    "ignorefeelimits": {
+      "added": "v23.08",
+      "type": "boolean"
     }
   }
 }

doc/schemas/setchannel.schema.json

@@ -18,7 +18,8 @@
           "fee_base_msat",
           "fee_proportional_millionths",
           "minimum_htlc_out_msat",
-          "maximum_htlc_out_msat"
+          "maximum_htlc_out_msat",
+          "ignore_fee_limits"
         ],
         "properties": {
           "peer_id": {
@@ -43,6 +44,11 @@
             "type": "u32",
             "description": "The resulting feeppm (this is the BOLT #7 name)"
           },
+          "ignore_fee_limits": {
+            "type": "boolean",
+            "added": "v23.08",
+            "description": "If we are now allowing peer to set feerate on commitment transaction without restriction"
+          },
           "minimum_htlc_out_msat": {
             "type": "msat",
             "description": "The resulting htlcmin we will advertize (the BOLT #7 name is htlc_minimum_msat)"

lightningd/chaintopology.c

@@ -1142,30 +1142,25 @@ u32 feerate_min(struct lightningd *ld, bool *unknown)
 	 *
 	 * [1] https://github.com/ElementsProject/lightning/issues/6362
 	 * */
-	if (ld->config.ignore_fee_limits)
-		min = 1;
-	else {
-		min = 0xFFFFFFFF;
-		for (size_t i = 0; i < ARRAY_SIZE(topo->feerates); i++) {
-			for (size_t j = 0; j < tal_count(topo->feerates[i]); j++) {
-				if (topo->feerates[i][j].rate < min)
-					min = topo->feerates[i][j].rate;
-			}
-		}
-		if (min == 0xFFFFFFFF) {
-			if (unknown)
-				*unknown = true;
-			min = 0;
+	min = 0xFFFFFFFF;
+	for (size_t i = 0; i < ARRAY_SIZE(topo->feerates); i++) {
+		for (size_t j = 0; j < tal_count(topo->feerates[i]); j++) {
+			if (topo->feerates[i][j].rate < min)
+				min = topo->feerates[i][j].rate;
 		}
-
-		/* FIXME: This is what bcli used to do: halve the slow feerate! */
-		min /= 2;
-
-		/* We can't allow less than feerate_floor, since that won't relay */
-		if (min < get_feerate_floor(topo))
-			return get_feerate_floor(topo);
 	}
+	if (min == 0xFFFFFFFF) {
+		if (unknown)
+			*unknown = true;
+		min = 0;
+	}
+
+	/* FIXME: This is what bcli used to do: halve the slow feerate! */
+	min /= 2;
 
+	/* We can't allow less than feerate_floor, since that won't relay */
+	if (min < get_feerate_floor(topo))
+		return get_feerate_floor(topo);
 	return min;
 }
 
@@ -1177,9 +1172,6 @@ u32 feerate_max(struct lightningd *ld, bool *unknown)
 	if (unknown)
 		*unknown = false;
 
-	if (ld->config.ignore_fee_limits)
-		return UINT_MAX;
-
 	for (size_t i = 0; i < ARRAY_SIZE(topo->feerates); i++) {
 		for (size_t j = 0; j < tal_count(topo->feerates[i]); j++) {
 			if (topo->feerates[i][j].rate > max)