JSON-RPC: getinfo, add field our_features

All build flags and (experimental) options make it hard to find
out what features are supported or enabled.

And the undocumented `--list-features-only`, does not account for all
our featurebits, for example bit 55 (keysend).

Changelog-Added: JSON-RPC: `getinfo` result now includes `our_features` (bits) for various Bolt #9 contexts

Author: Simon Vrouwe

bitcoin/test/run-tx-bitcoin_tx_2of2_input_witness_weight.c

@@ -24,9 +24,6 @@ struct amount_sat amount_asset_to_sat(struct amount_asset *asset UNNEEDED)
 				       struct amount_sat a UNNEEDED,
 				       struct amount_sat b UNNEEDED)
 { fprintf(stderr, "amount_sat_add called!\n"); abort(); }
-/* Generated stub for amount_sat_eq */
-bool amount_sat_eq(struct amount_sat a UNNEEDED, struct amount_sat b UNNEEDED)
-{ fprintf(stderr, "amount_sat_eq called!\n"); abort(); }
 /* Generated stub for amount_sat_greater_eq */
 bool amount_sat_greater_eq(struct amount_sat a UNNEEDED, struct amount_sat b UNNEEDED)
 { fprintf(stderr, "amount_sat_greater_eq called!\n"); abort(); }

doc/lightning-getinfo.7.md

@@ -39,6 +39,11 @@ On success, an object is returned, containing:
 - **blockheight** (u32): The highest block height we've learned
 - **network** (string): represents the type of network on the node are working (e.g: `bitcoin`, `testnet`, or `regtest`)
 - **fees_collected_msat** (msat): Total routing fees collected by this node
+- **our_features** (object, optional): Our BOLT #9 feature bits (as hexstring) for various contexts:
+  - **init** (hex): features (incl. globalfeatures) in our init message, these also restrict what we offer in open_channel or accept in accept_channel
+  - **node** (hex): features in our node_announcement message
+  - **channel** (hex): negotiated channel features we — as channel initiator — publish in the channel_announcement message
+  - **invoice** (hex): features in our BOLT11 invoices
 - **address** (array of objects, optional): The addresses we announce to the world:
   - **type** (string): Type of connection (one of "dns", "ipv4", "ipv6", "torv2", "torv3", "websocket")
   - **port** (u16): port number
@@ -91,12 +96,18 @@ EXAMPLE JSON RESPONSE
          "port": 9736
       }
    ],
-   "version": "0.9.0",
-   "blockheight": 644297,
+   "version": "v0.10.2",
+   "blockheight": 724302,
    "network": "bitcoin",
    "msatoshi_fees_collected": 0,
    "fees_collected_msat": "0msat",
    "lightning-dir": "/media/vincent/Maxtor/C-lightning/node/bitcoin"
+   "our_features": {
+      "init": "8828226aa2",
+      "node": "80008828226aa2",
+      "channel": "",
+      "invoice": "20024200"
+   }
 }
 
 ```
@@ -117,4 +128,4 @@ RESOURCES
 ---------
 
 Main web site: <https://github.com/ElementsProject/lightning>
-[comment]: # ( SHA256STAMP:90a3bacb6cb4456119afee8e60677c29bf5f46c4cd950e660a9f9c8e0433b473)
+[comment]: # ( SHA256STAMP:041768347542d7cf4260739ad8934c77d52682d089d9fe07499e22f7331b53f5)

doc/schemas/getinfo.schema.json

@@ -56,6 +56,35 @@
       "type": "string",
       "description": "Identifies where you can find the configuration and other related files"
     },
+    "our_features": {
+      "type": "object",
+      "description": "Our BOLT #9 feature bits (as hexstring) for various contexts",
+      "additionalProperties": true,
+      "required": [
+        "init",
+        "node",
+        "channel",
+        "invoice"
+      ],
+      "properties": {
+        "init": {
+          "type": "hex",
+          "description": "features (incl. globalfeatures) in our init message, these also restrict what we offer in open_channel or accept in accept_channel"
+        },
+        "node": {
+          "type": "hex",
+          "description": "features in our node_announcement message"
+        },
+        "channel": {
+          "type": "hex",
+          "description": "negotiated channel features we — as channel initiator — publish in the channel_announcement message"
+        },
+        "invoice": {
+          "type": "hex",
+          "description": "features in our BOLT11 invoices"
+        }
+      }
+    },
     "blockheight": {
       "type": "u32",
       "description": "The highest block height we've learned"

lightningd/peer_control.c

@@ -1747,6 +1747,15 @@ static struct command_result *json_getinfo(struct command *cmd,
 	    json_add_string(response, "warning_lightningd_sync",
 			    "Still loading latest blocks from bitcoind.");
 
+    u8 **bits = cmd->ld->our_features->bits;
+    json_object_start(response, "our_features");
+    json_add_hex_talarr(response, "init",
+			featurebits_or(cmd, bits[INIT_FEATURE], bits[GLOBAL_INIT_FEATURE]));
+    json_add_hex_talarr(response, "node", bits[NODE_ANNOUNCE_FEATURE]);
+    json_add_hex_talarr(response, "channel", bits[CHANNEL_FEATURE]);
+    json_add_hex_talarr(response, "invoice", bits[BOLT11_FEATURE]);
+    json_object_end(response);
+
     return command_success(cmd, response);
 }
 

lightningd/test/run-invoice-select-inchan.c

@@ -184,6 +184,9 @@ bool feature_is_set(const u8 *features UNNEEDED, size_t bit UNNEEDED)
 bool feature_negotiated(const struct feature_set *our_features UNNEEDED,
 			const u8 *their_features UNNEEDED, size_t f UNNEEDED)
 { fprintf(stderr, "feature_negotiated called!\n"); abort(); }
+/* Generated stub for featurebits_or */
+u8 *featurebits_or(const tal_t *ctx UNNEEDED, const u8 *f1 TAKES UNNEEDED, const u8 *f2 TAKES UNNEEDED)
+{ fprintf(stderr, "featurebits_or called!\n"); abort(); }
 /* Generated stub for find_plugin_for_command */
 struct plugin *find_plugin_for_command(struct lightningd *ld UNNEEDED,
 				       const char *cmd_name UNNEEDED)