jsonrpc: Add `mindepth` argument to fundchannel and multifundchannel

This will eventually enable us to specify 0 for zeroconf channels.

Changelog-Added: JSON-RPC: Added `mindepth` argument to specify the number of confirmations we require for `fundchannel` and `multifundchannel`

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

@@ -703,7 +703,8 @@ class LightningRpc(UnixDomainSocketRpc):
 
     def fundchannel(self, node_id, amount, feerate=None, announce=True,
                     minconf=None, utxos=None, push_msat=None, close_to=None,
-                    request_amt=None, compact_lease=None):
+                    request_amt=None, compact_lease=None,
+                    mindepth: Optional[int] = None):
         """
         Fund channel with {id} using {amount} satoshis with feerate
         of {feerate} (uses default feerate if unset).
@@ -728,11 +729,12 @@ class LightningRpc(UnixDomainSocketRpc):
             "close_to": close_to,
             "request_amt": request_amt,
             "compact_lease": compact_lease,
+            "mindepth": mindepth,
         }
         return self.call("fundchannel", payload)
 
     def fundchannel_start(self, node_id, amount, feerate=None, announce=True,
-                          close_to=None):
+                          close_to=None, mindepth: Optional[int] = None):
         """
         Start channel funding with {id} for {amount} satoshis
         with feerate of {feerate} (uses default feerate if unset).
@@ -748,6 +750,7 @@ class LightningRpc(UnixDomainSocketRpc):
             "feerate": feerate,
             "announce": announce,
             "close_to": close_to,
+            "mindepth": mindepth,
         }
         return self.call("fundchannel_start", payload)
 

doc/lightning-fundchannel.7.md

@@ -89,6 +89,7 @@ On success, an object is returned, containing:
 - **outnum** (u32): The 0-based output index showing which output funded the channel
 - **channel_id** (hex): The channel_id of the resulting channel (always 64 characters)
 - **close_to** (hex, optional): The raw scriptPubkey which mutual close will go to; only present if *close_to* parameter was specified and peer supports `option_upfront_shutdown_script`
+- **mindepth** (u32, optional): Number of confirmations before we consider the channel active.
 
 [comment]: # (GENERATE-FROM-SCHEMA-END)
 
@@ -113,4 +114,4 @@ RESOURCES
 
 Main web site: <https://github.com/ElementsProject/lightning>
 
-[comment]: # ( SHA256STAMP:4a8d7c524cfe257f961531929d14d3589efb6ecd182a33e92aade30af90406f8)
+[comment]: # ( SHA256STAMP:4bde4785d98f4fdb74ea2415b89ddc864fdf09bd9a30f8056a376aaa668a84b8)

doc/lightning-fundchannel_start.7.md

@@ -46,6 +46,7 @@ On success, an object is returned, containing:
 - **funding_address** (string): The address to send funding to for the channel. DO NOT SEND COINS TO THIS ADDRESS YET.
 - **scriptpubkey** (hex): The raw scriptPubkey for the address
 - **close_to** (hex, optional): The raw scriptPubkey which mutual close will go to; only present if *close_to* parameter was specified and peer supports `option_upfront_shutdown_script`
+- **mindepth** (u32, optional): Number of confirmations before we consider the channel active.
 
 The following warnings may also be returned:
 - **warning_usage**: A warning not to prematurely broadcast the funding transaction (always present!)
@@ -82,4 +83,4 @@ RESOURCES
 
 Main web site: <https://github.com/ElementsProject/lightning>
 
-[comment]: # ( SHA256STAMP:acbd9ffb07219bc10e06e8f8bc6772d12ec62650bd30b6ee1084a24f53da2ac2)
+[comment]: # ( SHA256STAMP:6dc3dd4d3d65baa617b285fd3f6e746d62e2806635a8f8852fd3a94ef6fe3e6a)

doc/schemas/fundchannel.schema.json

@@ -30,6 +30,10 @@
     "close_to": {
       "type": "hex",
       "description": "The raw scriptPubkey which mutual close will go to; only present if *close_to* parameter was specified and peer supports `option_upfront_shutdown_script`"
+    },
+    "mindepth": {
+      "type": "u32",
+      "description": "Number of confirmations before we consider the channel active."
     }
   }
 }

doc/schemas/fundchannel_start.schema.json

@@ -23,6 +23,10 @@
     "warning_usage": {
       "type": "string",
       "description": "A warning not to prematurely broadcast the funding transaction (always present!)"
+    },
+    "mindepth": {
+      "type": "u32",
+      "description": "Number of confirmations before we consider the channel active."
     }
   }
 }

lightningd/opening_common.c

@@ -53,6 +53,13 @@ new_uncommitted_channel(struct peer *peer)
 
 	uc->fc = NULL;
 	uc->our_config.id = 0;
+	/* BOLT #2:
+	 *
+	 * The sender:
+	 *   - SHOULD set `minimum_depth` to a number of blocks it considers
+	 *     reasonable to avoid double-spending of the funding transaction.
+	 */
+	uc->minimum_depth = ld->config.anchor_confirms;
 
 	memset(&uc->cid, 0xFF, sizeof(uc->cid));
 

lightningd/opening_control.c

@@ -891,13 +891,6 @@ bool peer_start_openingd(struct peer *peer, struct peer_fd *peer_fd)
 		       &max_to_self_delay,
 		       &min_effective_htlc_capacity);
 
-	/* BOLT #2:
-	 *
-	 * The sender:
-	 *   - SHOULD set `minimum_depth` to a number of blocks it considers
-	 *     reasonable to avoid double-spending of the funding transaction.
-	 */
-	uc->minimum_depth = peer->ld->config.anchor_confirms;
 
 	msg = towire_openingd_init(NULL,
 				  chainparams,
@@ -1057,7 +1050,7 @@ static struct command_result *json_fundchannel_start(struct command *cmd,
 	struct node_id *id;
 	struct peer *peer;
 	bool *announce_channel;
-	u32 *feerate_per_kw;
+	u32 *feerate_per_kw, *mindepth;
 
 	struct amount_sat *amount;
 	struct amount_msat *push_msat;
@@ -1077,6 +1070,7 @@ static struct command_result *json_fundchannel_start(struct command *cmd,
 		   p_opt_def("announce", param_bool, &announce_channel, true),
 		   p_opt("close_to", param_bitcoin_address, &fc->our_upfront_shutdown_script),
 		   p_opt("push_msat", param_msat, &push_msat),
+		   p_opt_def("mindepth", param_u32, &mindepth, cmd->ld->config.anchor_confirms),
 		   NULL))
 		return command_param_failed();
 
@@ -1167,6 +1161,15 @@ static struct command_result *json_fundchannel_start(struct command *cmd,
 	peer->uncommitted_channel->fc = tal_steal(peer->uncommitted_channel, fc);
 	fc->uc = peer->uncommitted_channel;
 
+	/* BOLT #2:
+	 *
+	 * The sender:
+	 *   - SHOULD set `minimum_depth` to a number of blocks it considers
+	 *     reasonable to avoid double-spending of the funding transaction.
+	 */
+	assert(mindepth != NULL);
+	fc->uc->minimum_depth = *mindepth;
+
 	/* Needs to be stolen away from cmd */
 	if (fc->our_upfront_shutdown_script)
 		fc->our_upfront_shutdown_script

plugins/spender/fundchannel.c

@@ -44,6 +44,7 @@ json_fundchannel(struct command *cmd,
 	const jsmntok_t *close_to;
 	const jsmntok_t *request_amt;
 	const jsmntok_t *compact_lease;
+	const jsmntok_t *mindepth;
 
 	struct out_req *req;
 
@@ -58,6 +59,7 @@ json_fundchannel(struct command *cmd,
 		   p_opt("close_to", param_tok, &close_to),
 		   p_opt("request_amt", param_tok, &request_amt),
 		   p_opt("compact_lease", param_tok, &compact_lease),
+		   p_opt("mindepth", param_tok, &mindepth),
 		   NULL))
 		return command_param_failed();
 
@@ -84,6 +86,10 @@ json_fundchannel(struct command *cmd,
 		json_add_tok(req->js, "request_amt", request_amt, buf);
 		json_add_tok(req->js, "compact_lease", compact_lease, buf);
 	}
+
+	if (mindepth)
+		json_add_tok(req->js, "mindepth", mindepth, buf);
+
 	json_object_end(req->js);
 	json_array_end(req->js);
 	if (feerate)

plugins/spender/multifundchannel.c

@@ -1113,12 +1113,16 @@ fundchannel_start_dest(struct multifundchannel_destination *dest)
 		json_add_string(req->js, "feerate", mfc->cmtmt_feerate_str);
 	else if (mfc->feerate_str)
 		json_add_string(req->js, "feerate", mfc->feerate_str);
+
 	json_add_bool(req->js, "announce", dest->announce);
 	json_add_string(req->js, "push_msat",
 			fmt_amount_msat(tmpctx, dest->push_msat));
 	if (dest->close_to_str)
 		json_add_string(req->js, "close_to", dest->close_to_str);
 
+	if (dest->mindepth)
+		json_add_u32(req->js, "mindepth", *dest->mindepth);
+
 	send_outreq(cmd->plugin, req);
 }
 
@@ -1890,6 +1894,7 @@ param_destinations_array(struct command *cmd, const char *name,
 			   p_opt_def("request_amt", param_sat, &request_amt,
 				     AMOUNT_SAT(0)),
 			   p_opt("compact_lease", param_lease_hex, &rates),
+			   p_opt("mindepth", param_u32, &dest->mindepth),
 			   NULL))
 			return command_param_failed();
 

plugins/spender/multifundchannel.h

@@ -149,6 +149,9 @@ struct multifundchannel_destination {
 
 	/* Channel lease rates that we expect the peer to respond with */
 	struct lease_rates *rates;
+
+	/* Number of blocks to wait before sending `channel_ready`. */
+	u32 *mindepth;
 };