lightningd: make option_data_loss_protect compulsory.

As suggested in lightning/bolts#1092.

Signed-off-by: Rusty Russell <[email protected]>
Changelog-Changed: Protocol: `option_data_loss_protect` is now required (advertized by all but 11 nodes)

Author: rustyrussell

lightningd/lightningd.c

@@ -869,9 +869,16 @@ static struct io_plan *sigchld_rfd_in(struct io_conn *conn,
  * features later, or adding them when supplied by plugins. */
 static struct feature_set *default_features(const tal_t *ctx)
 {
+	/* BOLT PR https://github.com/lightning/bolts/pull/1092
+	 * suggests making the following compulsory:
+	 *     var_onion_optin (all but 6 nodes)
+	 *     gossip_queries (all but 11 nodes)
+	 *     option_data_loss_protect (all but 11 nodes)
+	 *     option_static_remotekey (all but 16 nodes)
+	 */
 	struct feature_set *ret = NULL;
 	static const u32 features[] = {
-		OPTIONAL_FEATURE(OPT_DATA_LOSS_PROTECT),
+		COMPULSORY_FEATURE(OPT_DATA_LOSS_PROTECT),
 		OPTIONAL_FEATURE(OPT_UPFRONT_SHUTDOWN_SCRIPT),
 		OPTIONAL_FEATURE(OPT_GOSSIP_QUERIES),
 		COMPULSORY_FEATURE(OPT_VAR_ONION),

tests/test_connection.py

@@ -3577,9 +3577,9 @@ def test_nonstatic_channel(node_factory, bitcoind):
     """Smoke test for a channel without option_static_remotekey"""
     l1, l2 = node_factory.line_graph(2,
                                      opts=[{},
-                                           # needs at least 15 to connect
+                                           # needs at least 1 and 15 to connect
                                            # (and 9 is a dependent)
-                                           {'dev-force-features': '9,15////////'}])
+                                           {'dev-force-features': '1,9,15////////'}])
     chan = only_one(l1.rpc.listpeerchannels()['channels'])
     assert 'option_static_remotekey' not in chan['features']
     assert 'option_anchor' not in chan['features']

tests/test_misc.py

@@ -2243,7 +2243,7 @@ def test_dev_demux(node_factory):
 def test_list_features_only(node_factory):
     features = subprocess.check_output(['lightningd/lightningd',
                                         '--list-features-only']).decode('utf-8').splitlines()
-    expected = ['option_data_loss_protect/odd',
+    expected = ['option_data_loss_protect/even',
                 'option_upfront_shutdown_script/odd',
                 'option_gossip_queries/odd',
                 'option_var_onion_optin/even',

tests/utils.py

@@ -36,7 +36,7 @@ def hex_bits(features):
 
 def expected_peer_features(extra=[]):
     """Return the expected peer features hexstring for this configuration"""
-    features = [1, 5, 7, 8, 11, 13, 14, 17, 19, 25, 27, 45, 47, 51]
+    features = [0, 5, 7, 8, 11, 13, 14, 17, 19, 25, 27, 45, 47, 51]
     if EXPERIMENTAL_DUAL_FUND:
         # option_dual_fund
         features += [29]
@@ -50,7 +50,7 @@ def expected_peer_features(extra=[]):
 # features for the 'node' and the 'peer' feature sets
 def expected_node_features(extra=[]):
     """Return the expected node features hexstring for this configuration"""
-    features = [1, 5, 7, 8, 11, 13, 14, 17, 19, 25, 27, 45, 47, 51, 55]
+    features = [0, 5, 7, 8, 11, 13, 14, 17, 19, 25, 27, 45, 47, 51, 55]
     if EXPERIMENTAL_DUAL_FUND:
         # option_dual_fund
         features += [29]