Required jsonrpc inside the method request.

As the json rpc specification tell, the "jsonrpc": "2.0" MUST be required.

Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>

lightningd/jsonrpc.c

@@ -700,7 +700,7 @@ static void replace_command(struct rpc_command_hook_payload *p,
 			    const char *buffer,
 			    const jsmntok_t *replacetok)
 {
-	const jsmntok_t *method = NULL, *params = NULL;
+	const jsmntok_t *method = NULL, *params = NULL, *jsonrpc = NULL;
 	const char *bad;
 
 	/* Must contain "method", "params" and "id" */
@@ -732,6 +732,12 @@ static void replace_command(struct rpc_command_hook_payload *p,
 		goto fail;
 	}
 
+	jsonrpc = json_get_member(buffer, replacetok, "jsonrpc");
+	if (!jsonrpc || jsonrpc->type != JSMN_STRING || !json_tok_streq(buffer, jsonrpc, "2.0")) {
+		bad = "jsonrpc: \"2.0\" must be specified in the request";
+		goto fail;
+	}
+
 	was_pending(command_exec(p->cmd->jcon, p->cmd, buffer, replacetok,
 				 params));
 	return;
@@ -864,7 +870,7 @@ REGISTER_PLUGIN_HOOK(rpc_command,
 static struct command_result *
 parse_request(struct json_connection *jcon, const jsmntok_t tok[])
 {
-	const jsmntok_t *method, *id, *params;
+	const jsmntok_t *method, *id, *params, *jsonrpc;
 	struct command *c;
 	struct rpc_command_hook_payload *rpc_hook;
 	bool completed;
@@ -878,17 +884,24 @@ parse_request(struct json_connection *jcon, const jsmntok_t tok[])
 	method = json_get_member(jcon->buffer, tok, "method");
 	params = json_get_member(jcon->buffer, tok, "params");
 	id = json_get_member(jcon->buffer, tok, "id");
+	jsonrpc = json_get_member(jcon->buffer, tok, "jsonrpc");
 
 	if (!id) {
 		json_command_malformed(jcon, "null", "No id");
 		return NULL;
 	}
+
 	if (id->type != JSMN_STRING && id->type != JSMN_PRIMITIVE) {
 		json_command_malformed(jcon, "null",
 				       "Expected string/primitive for id");
 		return NULL;
 	}
 
+        if (!jsonrpc || jsonrpc->type != JSMN_STRING || !json_tok_streq(jcon->buffer, jsonrpc, "2.0")) {
+		json_command_malformed(jcon, "null", "jsonrpc: \"2.0\" must be specified in the request");
+		return NULL;
+	}
+
 	/* Allocate the command off of the `jsonrpc` object and not
 	 * the connection since the command may outlive `conn`. */
 	c = tal(jcon->ld->jsonrpc, struct command);