commando: add support for parameters by array, parameter count.

Awkward to filter, but they're really practical for many commands.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

doc/lightning-commando-rune.7.md

@@ -33,7 +33,9 @@ being run:
 * time: the current UNIX time, e.g. "time<1656759180".
 * id: the node_id of the peer, e.g. "id=024b9a1fa8e006f1e3937f65f66c408e6da8e1ca728ea43222a7381df1cc449605".
 * method: the command being run, e.g. "method=withdraw".
+* pnum: the number of parameters. e.g. "pnum<2".
 * pnameX: the parameter named X. e.g. "pnamedestination=1RustyRX2oai4EYYDpQGWvEL62BBGqN9T".
+* parrN: the N'th parameter. e.g. "parr0=1RustyRX2oai4EYYDpQGWvEL62BBGqN9T".
 
 RESTRICTION FORMAT
 ------------------
@@ -56,11 +58,66 @@ a `\\`.
 * `!`: only passes if the *name* does *not* exist. e.g. `pnamedestination!`.
        Every other operator except `#` fails if *name* does not exist!
 
-For example, the "readonly" restriction is actually two restrictions:
+EXAMPLES
+--------
+
+This creates a fresh rune which can do anything:
+
+    $ lightning-cli commando-rune
+    {
+       "rune": "KUhZzNlECC7pYsz3QVbF1TqjIUYi3oyESTI7n60hLMs9MA==",
+       "unique_id": "0"
+    }
+
+We can add restrictions to that rune, like so:
+
+    $ lightning-cli commando-rune rune=KUhZzNlECC7pYsz3QVbF1TqjIUYi3oyESTI7n60hLMs9MA== restrictions=readonly
+    {
+       "rune": "NbL7KkXcPQsVseJ9TdJNjJK2KsPjnt_q4cE_wvc873I9MCZtZXRob2RebGlzdHxtZXRob2ReZ2V0fG1ldGhvZD1zdW1tYXJ5Jm1ldGhvZC9saXN0ZGF0YXN0b3Jl",
+       "unique_id": "0"
+    }
+
+The "readonly" restriction is a short-cut for two restrictions:
 
 1. `method^list|method^get|method=summary`: You may call list, get or summary.
 2. `method/listdatastore`: But not listdatastore: that contains sensitive stuff!
 
+We can do the same manually, like so:
+
+    $ lightning-cli commando-rune rune=KUhZzNlECC7pYsz3QVbF1TqjIUYi3oyESTI7n60hLMs9MA== restrictions='["method^list|method^get|method=summary","method/listdatastore"]'
+    {
+       "rune": "NbL7KkXcPQsVseJ9TdJNjJK2KsPjnt_q4cE_wvc873I9MCZtZXRob2RebGlzdHxtZXRob2ReZ2V0fG1ldGhvZD1zdW1tYXJ5Jm1ldGhvZC9saXN0ZGF0YXN0b3Jl",
+       "unique_id": "0"
+    }
+
+Let's create a rune which lets a specific peer
+(024b9a1fa8e006f1e3937f65f66c408e6da8e1ca728ea43222a7381df1cc449605)
+run "listpeers" on themselves:
+
+    $ lightning-cli commando-rune restrictions='["id=024b9a1fa8e006f1e3937f65f66c408e6da8e1ca728ea43222a7381df1cc449605","method=listpeers","pnum=1","pnameid=024b9a1fa8e006f1e3937f65f66c408e6da8e1ca728ea43222a7381df1cc449605|parr0=024b9a1fa8e006f1e3937f65f66c408e6da8e1ca728ea43222a7381df1cc449605"]'
+    {
+       "rune": "FE8GHiGVvxcFqCQcClVRRiNE_XEeLYQzyG2jmqto4jM9MiZpZD0wMjRiOWExZmE4ZTAwNmYxZTM5MzdmNjVmNjZjNDA4ZTZkYThlMWNhNzI4ZWE0MzIyMmE3MzgxZGYxY2M0NDk2MDUmbWV0aG9kPWxpc3RwZWVycyZwbnVtPTEmcG5hbWVpZD0wMjRiOWExZmE4ZTAwNmYxZTM5MzdmNjVmNjZjNDA4ZTZkYThlMWNhNzI4ZWE0MzIyMmE3MzgxZGYxY2M0NDk2MDV8cGFycjA9MDI0YjlhMWZhOGUwMDZmMWUzOTM3ZjY1ZjY2YzQwOGU2ZGE4ZTFjYTcyOGVhNDMyMjJhNzM4MWRmMWNjNDQ5NjA1",
+       "unique_id": "2"
+    }
+
+This allows `listpeers` with 1 argument (`pnum=1`), which is either by name (`pnameid`), or position (`parr0`).  We could shorten this in several ways: either allowing only positional or named parameters, or by testing the start of the parameters only.  Here's an example which only checks the first 9 bytes of the `listpeers` parameter:
+
+    $ lightning-cli commando-rune restrictions='["id=024b9a1fa8e006f1e3937f65f66c408e6da8e1ca728ea43222a7381df1cc449605","method=listpeers","pnum=1","pnameid^024b9a1fa8e006f1e393|parr0^024b9a1fa8e006f1e393"]'
+     {
+       "rune": "fTQnfL05coEbiBO8SS0cvQwCcPLxE9c02pZCC6HRVEY9MyZpZD0wMjRiOWExZmE4ZTAwNmYxZTM5MzdmNjVmNjZjNDA4ZTZkYThlMWNhNzI4ZWE0MzIyMmE3MzgxZGYxY2M0NDk2MDUmbWV0aG9kPWxpc3RwZWVycyZwbnVtPTEmcG5hbWVpZF4wMjRiOWExZmE4ZTAwNmYxZTM5M3xwYXJyMF4wMjRiOWExZmE4ZTAwNmYxZTM5Mw==",
+       "unique_id": "3"
+    }
+
+Before we give this to our peer, let's add another restriction: that
+it only be usable for 24 hours from now.  `date +%s` can give us the
+current time in seconds:
+
+    $ lightning-cli commando-rune rune=fTQnfL05coEbiBO8SS0cvQwCcPLxE9c02pZCC6HRVEY9MyZpZD0wMjRiOWExZmE4ZTAwNmYxZTM5MzdmNjVmNjZjNDA4ZTZkYThlMWNhNzI4ZWE0MzIyMmE3MzgxZGYxY2M0NDk2MDUmbWV0aG9kPWxpc3RwZWVycyZwbnVtPTEmcG5hbWVpZF4wMjRiOWExZmE4ZTAwNmYxZTM5M3xwYXJyMF4wMjRiOWExZmE4ZTAwNmYxZTM5Mw== restrictions="t<$(($(date +%s) + 24*60*60))"
+    {
+       "rune": "Sh-jGdfO9UGByLvah2AHgc_VwgoNujckPNkxTx54ugg9MyZpZD0wMjRiOWExZmE4ZTAwNmYxZTM5MzdmNjVmNjZjNDA4ZTZkYThlMWNhNzI4ZWE0MzIyMmE3MzgxZGYxY2M0NDk2MDUmbWV0aG9kPWxpc3RwZWVycyZwbnVtPTEmcG5hbWVpZF4wMjRiOWExZmE4ZTAwNmYxZTM5M3xwYXJyMF4wMjRiOWExZmE4ZTAwNmYxZTM5MyZ0PDE2NTY4OTc5MjU=",
+       "unique_id": "3"
+    }
+
 SHARING RUNES
 -------------
 

doc/schemas/commando.request.json

@@ -16,8 +16,16 @@
       "description": "method to invoke on peer"
     },
     "params": {
+      "oneOf": [
+        {
+          "type": "array",
+          "description": "array of positional parameters"
+        },
+        {
           "type": "object",
           "description": "parameters for method"
+        }
+      ]
     },
     "rune": {
       "type": "string",

plugins/commando.c

@@ -201,14 +201,16 @@ static const char *check_condition(const tal_t *ctx,
 		return rune_alt_single_str(ctx, alt,
 					   cinfo->buf + cinfo->method->start,
 					   cinfo->method->end - cinfo->method->start);
+	} else if (streq(alt->fieldname, "pnum")) {
+		return rune_alt_single_int(ctx, alt, cinfo->params->size);
 	}
 
 	/* Rest are params looksup: generate this once! */
-	if (cinfo->params) {
+	if (strmap_empty(&cinfo->cached_params)) {
-		/* Note: we require that params be an obj! */
 		const jsmntok_t *t;
 		size_t i;
 
+		if (cinfo->params->type == JSMN_OBJECT) {
 			json_for_each_obj(i, t, cinfo->params) {
 				char *pmemname = tal_fmt(tmpctx,
 							 "pname%.*s",
@@ -224,7 +226,12 @@ static const char *check_condition(const tal_t *ctx,
 				pmemname[off++] = '\0';
 				strmap_add(&cinfo->cached_params, pmemname, t+1);
 			}
-		cinfo->params = NULL;
+		} else if (cinfo->params->type == JSMN_ARRAY) {
+			json_for_each_arr(i, t, cinfo->params) {
+				char *pmemname = tal_fmt(tmpctx, "parr%zu", i);
+				strmap_add(&cinfo->cached_params, pmemname, t);
+			}
+		}
 	}
 
 	ptok = strmap_get(&cinfo->cached_params, alt->fieldname);
@@ -300,9 +307,9 @@ static void try_command(struct node_id *peer,
 		return;
 	}
 	params = json_get_member(buf, toks, "params");
-	if (params && params->type != JSMN_OBJECT) {
+	if (!params || (params->type != JSMN_OBJECT && params->type != JSMN_ARRAY)) {
 		commando_error(incoming, COMMANDO_ERROR_REMOTE,
-			       "Params must be object");
+			       "Params must be object or array");
 		return;
 	}
 	rune = json_get_member(buf, toks, "rune");
@@ -323,8 +330,9 @@ static void try_command(struct node_id *peer,
 		size_t i;
 		const jsmntok_t *t;
 
-		json_object_start(req->js, "params");
 		/* FIXME: This is ugly! */
+		if (params->type == JSMN_OBJECT) {
+			json_object_start(req->js, "params");
 			json_for_each_obj(i, t, params) {
 				json_add_jsonstr(req->js,
 						 json_strdup(tmpctx, buf, t),
@@ -332,6 +340,17 @@ static void try_command(struct node_id *peer,
 						 json_tok_full_len(t+1));
 			}
 			json_object_end(req->js);
+		} else {
+			assert(params->type == JSMN_ARRAY);
+			json_array_start(req->js, "params");
+			json_for_each_arr(i, t, params) {
+				json_add_jsonstr(req->js,
+						 NULL,
+						 json_tok_full(buf, t),
+						 json_tok_full_len(t));
+			}
+			json_array_end(req->js);
+		}
 	} else {
 		json_object_start(req->js, "params");
 		json_object_end(req->js);

tests/test_plugin.py

@@ -2660,6 +2660,12 @@ def test_commando_rune(node_factory):
     rune5 = l1.rpc.commando_rune(rune4['rune'], "pnamelevel!|pnamelevel/io")
     assert rune5['rune'] == 'Dw2tzGCoUojAyT0JUw7fkYJYqExpEpaDRNTkyvWKoJY9MyZpZF4wMjJkMjIzNjIwYTM1OWE0N2ZmNyZtZXRob2Q9bGlzdHBlZXJzJnBuYW1lbGV2ZWwhfHBuYW1lbGV2ZWwvaW8='
     assert rune5['unique_id'] == '3'
+    rune6 = l1.rpc.commando_rune(rune5['rune'], "parr1!|parr1/io")
+    assert rune6['rune'] == '2Wh6F4R51D3esZzp-7WWG51OhzhfcYKaaI8qiIonaHE9MyZpZF4wMjJkMjIzNjIwYTM1OWE0N2ZmNyZtZXRob2Q9bGlzdHBlZXJzJnBuYW1lbGV2ZWwhfHBuYW1lbGV2ZWwvaW8mcGFycjEhfHBhcnIxL2lv'
+    assert rune6['unique_id'] == '3'
+    rune7 = l1.rpc.commando_rune(restrictions="pnum=0")
+    assert rune7['rune'] == 'QJonN6ySDFw-P5VnilZxlOGRs_tST1ejtd-bAYuZfjk9NCZwbnVtPTA='
+    assert rune7['unique_id'] == '4'
 
     # Replace rune3 with a more useful timestamp!
     expiry = int(time.time()) + 15
@@ -2671,12 +2677,19 @@ def test_commando_rune(node_factory):
                  (rune3, "getinfo", {}),
                  (rune4, "listpeers", {}),
                  (rune5, "listpeers", {'id': l2.info['id']}),
-                 (rune5, "listpeers", {'id': l2.info['id'], 'level': 'broken'}))
+                 (rune5, "listpeers", {'id': l2.info['id'], 'level': 'broken'}),
+                 (rune6, "listpeers", [l2.info['id'], 'broken']),
+                 (rune6, "listpeers", [l2.info['id']]),
+                 (rune7, "listpeers", []),
+                 (rune7, "getinfo", {}))
     failures = ((rune2, "withdraw", {}),
                 (rune2, "plugin", {'subcommand': 'list'}),
                 (rune3, "getinfo", {}),
                 (rune4, "listnodes", {}),
-                (rune5, "listpeers", {'id': l2.info['id'], 'level': 'io'}))
+                (rune5, "listpeers", {'id': l2.info['id'], 'level': 'io'}),
+                (rune6, "listpeers", [l2.info['id'], 'io']),
+                (rune7, "listpeers", [l2.info['id']]),
+                (rune7, "listpeers", {'id': l2.info['id']}))
 
     for rune, cmd, params in successes:
         l2.rpc.call(method='commando',
@@ -2708,14 +2721,3 @@ def test_commando_rune(node_factory):
                              'method': "listpeers",
                              'params': {}})
     assert exc_info.value.error['code'] == 0x4c51
-        
-    # Remote doesn't allow array parameters.
-    l2.rpc.check_request_schemas = False
-    with pytest.raises(RpcError, match='Params must be object') as exc_info:
-            l2.rpc.call(method='commando',
-                        payload={'peer_id': l1.info['id'],
-                                 'rune': rune5['rune'],
-                                 'method': "listpeers",
-                                 'params': [l2.info['id'], 'io']})
-    assert exc_info.value.error['code'] == 0x4c50
-    l2.rpc.check_request_schemas = True