feat: config additions

doc/lightning-listconfigs.7.md

@@ -71,6 +71,8 @@ On success, an object is returned, containing:
 - **rescan** (integer, optional): `rescan` field from config or cmdline, or default
 - **fee-per-satoshi** (u32, optional): `fee-per-satoshi` field from config or cmdline, or default
 - **max-concurrent-htlcs** (u32, optional): `max-concurrent-htlcs` field from config or cmdline, or default
+- **htlc-minimum-msat** (msat, optional): `htlc-minimum-msat` field from config or cmdline, or default
+- **htlc-maximum-msat** (msat, optional): `htlc-maximum-msat` field from config or cmdline, or default
 - **max-dust-htlc-exposure-msat** (msat, optional): `max-dust-htlc-exposure-mast` field from config or cmdline, or default
 - **min-capacity-sat** (u64, optional): `min-capacity-sat` field from config or cmdline, or default
 - **addr** (string, optional): `addr` field from config or cmdline (can be more than one)
@@ -80,6 +82,7 @@ On success, an object is returned, containing:
 - **autolisten** (boolean, optional): `autolisten` field from config or cmdline, or default
 - **proxy** (string, optional): `proxy` field from config or cmdline, or default
 - **disable-dns** (boolean, optional): `true` if `disable-dns` was set in config or cmdline
+- **disable-ip-discovery** (boolean, optional): `true` if `disable-ip-discovery` was set in config or cmdline
 - **encrypted-hsm** (boolean, optional): `true` if `encrypted-hsm` was set in config or cmdline
 - **rpc-file-mode** (string, optional): `rpc-file-mode` field from config or cmdline, or default
 - **log-level** (string, optional): `log-level` field from config or cmdline, or default
@@ -208,4 +211,4 @@ RESOURCES
 ---------
 
 Main web site: <https://github.com/ElementsProject/lightning>
-[comment]: # ( SHA256STAMP:59b197ad256bd701744ed5aa9f663166e48ef6320cf3a1538af0bd855daa3186)
+[comment]: # ( SHA256STAMP:ebc37d1f9cb452d312285a8168d2bb6da2d1dba08db56bbb8d3d7f47b58d7fa4)

doc/lightningd-config.5.md

@@ -278,6 +278,23 @@ values), and the order is "opening", "mutual_close", "unilateral_close",
 You would usually put this option in the per-chain config file, to avoid
 setting it on Bitcoin mainnet!  e.g. `~rusty/.lightning/regtest/config`.
 
+ **htlc-minimum-msat**=*MILLISATOSHI*
+Default: 0. Sets the minimal allowed HTLC value for newly created channels.
+If you want to change the `htlc_minimum_msat` for existing channels, use the
+RPC call lightning-setchannel(7).
+
+ **htlc-maximum-msat**=*MILLISATOSHI*
+Default: unset (no limit). Sets the maximum allowed HTLC value for newly created
+channels. If you want to change the `htlc_maximum_msat` for existing channels,
+use the RPC call lightning-setchannel(7).
+
+ **disable-ip-discovery**
+Turn off public IP discovery to send `node_announcement` updates that contain
+the discovered IP with TCP port 9735 as announced address. If unset and you
+open TCP port 9735 on your router towords your node, your node will remain
+connectable on changing IP addresses.  Note: Will always be disabled if you use
+'always-use-proxy'.
+
 ### Lightning channel and HTLC options
 
  **large-channels**

doc/schemas/listconfigs.schema.json

@@ -187,6 +187,14 @@
       "type": "u32",
       "description": "`max-concurrent-htlcs` field from config or cmdline, or default"
     },
+    "htlc-minimum-msat": {
+      "type": "msat",
+      "description": "`htlc-minimum-msat` field from config or cmdline, or default"
+    },
+    "htlc-maximum-msat": {
+      "type": "msat",
+      "description": "`htlc-maximum-msat` field from config or cmdline, or default"
+    },
     "max-dust-htlc-exposure-msat": {
       "type": "msat",
       "description": "`max-dust-htlc-exposure-mast` field from config or cmdline, or default"
@@ -223,6 +231,10 @@
       "type": "boolean",
       "description": "`true` if `disable-dns` was set in config or cmdline"
     },
+    "disable-ip-discovery": {
+      "type": "boolean",
+      "description": "`true` if `disable-ip-discovery` was set in config or cmdline"
+    },
     "encrypted-hsm": {
       "type": "boolean",
       "description": "`true` if `encrypted-hsm` was set in config or cmdline"

lightningd/lightningd.h

@@ -33,6 +33,10 @@ struct config {
 	/* htlcs per channel */
 	u32 max_concurrent_htlcs;
 
+	/* htlc min/max values */
+	struct amount_msat htlc_minimum_msat;
+	struct amount_msat htlc_maximum_msat;
+
 	/* Max amount of dust allowed per channel */
 	struct amount_msat max_dust_htlc_exposure_msat;
 
@@ -52,6 +56,9 @@ struct config {
 	/* Are we allowed to use DNS lookup for peers. */
 	bool use_dns;
 
+	/* Turn off IP address announcement discovered via peer `remote_addr` */
+	bool disable_ip_discovery;
+
 	/* Minimal amount of effective funding_satoshis for accepting channels */
 	u64 min_capacity_sat;
 

lightningd/opening_common.c

@@ -147,7 +147,7 @@ void channel_config(struct lightningd *ld,
 		= ld->config.max_dust_htlc_exposure_msat;
 
 	/* Don't care */
-	ours->htlc_minimum = AMOUNT_MSAT(0);
+	ours->htlc_minimum = ld->config.htlc_minimum_msat;
 
 	/* BOLT #2:
 	 *

lightningd/opening_control.c

@@ -211,8 +211,8 @@ wallet_commit_channel(struct lightningd *ld,
 			      take(new_height_states(NULL, uc->fc ? LOCAL : REMOTE,
 						     &lease_start_blockheight)),
 			      0, NULL, 0, 0, /* No leases on v1s */
-			      AMOUNT_MSAT(0), /* No htlc_minimum_msat */
-			      AMOUNT_MSAT(-1ULL)); /* No htlc_maximum_msat */
+			      ld->config.htlc_minimum_msat,
+			      ld->config.htlc_maximum_msat);
 
 	/* Now we finally put it in the database. */
 	wallet_channel_insert(ld->wallet, channel);

lightningd/options.c

@@ -757,6 +757,10 @@ static const struct config testnet_config = {
 	/* Testnet blockspace is free. */
 	.max_concurrent_htlcs = 483,
 
+	/* channel defaults for htlc min/max values */
+	.htlc_minimum_msat = AMOUNT_MSAT(0),
+	.htlc_maximum_msat = AMOUNT_MSAT(-1ULL),  /* no limit */
+
 	/* Max amount of dust allowed per channel (50ksat) */
 	.max_dust_htlc_exposure_msat = AMOUNT_MSAT(50000000),
 
@@ -780,6 +784,9 @@ static const struct config testnet_config = {
 
 	.use_dns = true,
 
+	/* Turn off IP address announcement discovered via peer `remote_addr` */
+	.disable_ip_discovery = false,
+
 	/* Sets min_effective_htlc_capacity - at 1000$/BTC this is 10ct */
 	.min_capacity_sat = 10000,
 
@@ -806,6 +813,10 @@ static const struct config mainnet_config = {
 	/* While up to 483 htlcs are possible we do 30 by default (as eclair does) to save blockspace */
 	.max_concurrent_htlcs = 30,
 
+	/* defaults for htlc min/max values */
+	.htlc_minimum_msat = AMOUNT_MSAT(0),
+	.htlc_maximum_msat = AMOUNT_MSAT(-1ULL),  /* no limit */
+
 	/* Max amount of dust allowed per channel (50ksat) */
 	.max_dust_htlc_exposure_msat = AMOUNT_MSAT(50000000),
 
@@ -839,6 +850,9 @@ static const struct config mainnet_config = {
 
 	.use_dns = true,
 
+	/* Turn off IP address announcement discovered via peer `remote_addr` */
+	.disable_ip_discovery = false,
+
 	/* Sets min_effective_htlc_capacity - at 1000$/BTC this is 10ct */
 	.min_capacity_sat = 10000,
 
@@ -1102,6 +1116,12 @@ static void register_opts(struct lightningd *ld)
 	opt_register_arg("--fee-per-satoshi", opt_set_u32, opt_show_u32,
 			 &ld->config.fee_per_satoshi,
 			 "Microsatoshi fee for every satoshi in HTLC");
+	opt_register_arg("--htlc-minimum-msat", opt_set_msat, NULL,
+			 &ld->config.htlc_minimum_msat,
+			 "The default minimal value an HTLC must carry in order to be forwardable for new channels");
+	opt_register_arg("--htlc-maximum-msat", opt_set_msat, NULL,
+			 &ld->config.htlc_maximum_msat,
+			 "The default maximal value an HTLC must carry in order to be forwardable for new channel");
 	opt_register_arg("--max-concurrent-htlcs", opt_set_u32, opt_show_u32,
 			 &ld->config.max_concurrent_htlcs,
 			 "Number of HTLCs one channel can handle concurrently. Should be between 1 and 483");
@@ -1120,6 +1140,9 @@ static void register_opts(struct lightningd *ld)
 	opt_register_arg("--announce-addr", opt_add_announce_addr, NULL,
 			 ld,
 			 "Set an IP address (v4 or v6) or .onion v3 to announce, but not listen on");
+	opt_register_noarg("--disable-ip-discovery", opt_set_bool,
+			 &ld->config.disable_ip_discovery,
+			 "Turn off announcement of discovered public IPs");
 
 	opt_register_noarg("--offline", opt_set_offline, ld,
 			   "Start in offline-mode (do not automatically reconnect and do not accept incoming connections)");

lightningd/peer_control.c

@@ -1070,7 +1070,7 @@ static void update_remote_addr(struct lightningd *ld,
 			       const struct node_id peer_id)
 {
 	/* failsafe to prevent privacy leakage. */
-	if (ld->always_use_proxy)
+	if (ld->always_use_proxy || ld->config.disable_ip_discovery)
 		return;
 
 	switch (remote_addr->type) {

tests/test_connection.py

@@ -120,6 +120,38 @@ def test_remote_addr(node_factory, bitcoind):
     assert address['port'] == 9735
 
 
+@pytest.mark.developer("needs DEVELOPER=1 for having localhost remote_addr and fast gossip")
+def test_remote_addr_disabled(node_factory, bitcoind):
+    """Simply tests that IP address discovery annoucements can be turned off
+    """
+    opts = {'announce-addr': [], 'disable-ip-discovery': None, 'may_reconnect': True}
+    l1, l2, l3 = node_factory.get_nodes(3, opts=opts)
+
+    # l1->l2
+    l2.rpc.connect(l1.info['id'], 'localhost', l1.port)
+    l2.daemon.wait_for_log("Peer says it sees our address as: 127.0.0.1:[0-9]{5}")
+    l1.fundchannel(l2)
+    bitcoind.generate_block(5)
+    l1.daemon.wait_for_log(f"Received node_announcement for node {l2.info['id']}")
+    # l2->l3
+    l2.rpc.connect(l3.info['id'], 'localhost', l3.port)
+    l2.daemon.wait_for_log("Peer says it sees our address as: 127.0.0.1:[0-9]{5}")
+    l2.fundchannel(l3)
+    bitcoind.generate_block(5)
+
+    # restart both and wait for channels to be ready
+    l1.restart()
+    l2.rpc.connect(l1.info['id'], 'localhost', l1.port)
+    l2.daemon.wait_for_log("Already have funding locked in")
+    l3.restart()
+    l2.rpc.connect(l3.info['id'], 'localhost', l3.port)
+    l2.daemon.wait_for_log("Already have funding locked in")
+
+    # if ip discovery would have been enabled, we would have send an updated
+    # node_annoucement by now. Check we didn't...
+    assert not l2.daemon.is_in_log("Update our node_announcement for discovered address")
+
+
 def test_connect_standard_addr(node_factory):
     """Test standard node@host:port address
     """

tests/test_pay.py

@@ -2376,6 +2376,29 @@ def test_setchannel_all(node_factory, bitcoind):
     assert result['channels'][1]['maximum_htlc_out_msat'] == 0xCAFE
 
 
+@pytest.mark.developer("updates are delayed without --dev-fast-gossip")
+def test_setchannel_startup_opts(node_factory, bitcoind):
+    """Tests that custom config/cmdline options are applied correctly when set
+    """
+    opts = {
+        'fee-base': 2,
+        'fee-per-satoshi': 3,
+        'htlc-minimum-msat': '4msat',
+        'htlc-maximum-msat': '5msat'
+    }
+    l1, l2 = node_factory.line_graph(2, opts=opts, wait_for_announce=True)
+
+    result = l2.rpc.listchannels()['channels']
+    assert result[0]['base_fee_millisatoshi'] == 2
+    assert result[0]['fee_per_millionth'] == 3
+    assert result[0]['htlc_minimum_msat'] == Millisatoshi(4)
+    assert result[0]['htlc_maximum_msat'] == Millisatoshi(5)
+    assert result[1]['base_fee_millisatoshi'] == 2
+    assert result[1]['fee_per_millionth'] == 3
+    assert result[1]['htlc_minimum_msat'] == Millisatoshi(4)
+    assert result[1]['htlc_maximum_msat'] == Millisatoshi(5)
+
+
 @pytest.mark.developer("gossip without DEVELOPER=1 is slow")
 def test_channel_spendable(node_factory, bitcoind):
     """Test that spendable_msat is accurate"""