report_rom: add 'verbose' config attribute

repos/os/src/server/report_rom/README

@@ -22,3 +22,6 @@ client obtains the data from the report client with the label specified in the
 'report' attribute. In the example above, the nitpicker GUI server sends
 reports about the pointer position to the report-ROM service. Those reports
 are handed out to a window decorator (labeled "decorator") as ROM module.
+
+The component can be configured to write all incoming reports to the LOG
+output by setting the 'verbose' attribute of the '<config>' node to "yes".

repos/os/src/server/report_rom/main.cc

@@ -50,7 +50,16 @@ struct Server::Main
 
 	Xml_node rom_config = _rom_config_node();
 
-	Report::Root report_root = { ep, sliced_heap, rom_registry };
+	bool _verbose_config()
+	{
+		char const *attr = "verbose";
+		return Genode::config()->xml_node().has_attribute(attr)
+		    && Genode::config()->xml_node().attribute(attr).has_value("yes");
+	}
+
+	bool verbose = _verbose_config();
+
+	Report::Root report_root = { ep, sliced_heap, rom_registry, verbose };
 	Rom   ::Root    rom_root = { ep, sliced_heap, rom_registry, rom_config};
 
 	Main(Entrypoint &ep) : ep(ep)

repos/os/src/server/report_rom/report_service.h

@@ -39,14 +39,29 @@ struct Report::Session_component : Genode::Rpc_object<Session>, Rom::Writer
 
 		Rom::Module &_module;
 
+		bool &_verbose;
+
+		size_t const _str_line_end(char const * const str, size_t const len)
+		{
+			size_t i = 0;
+			for (; str[i] && i < len && str[i] != '\n'; i++);
+
+			/* the newline character belongs to the line */
+			if (str[i] == '\n')
+				i++;
+
+			return i;
+		}
+
 	public:
 
 		Session_component(Rom::Module::Name const &name, size_t buffer_size,
-		                  Rom::Registry_for_writer &registry)
+		                  Rom::Registry_for_writer &registry, bool &verbose)
 		:
 			_registry(registry),
 			_ds(Genode::env()->ram_session(), buffer_size),
-			_module(_registry.lookup(*this, name))
+			_module(_registry.lookup(*this, name)),
+			_verbose(verbose)
 		{ }
 
 		/**
@@ -62,10 +77,49 @@ struct Report::Session_component : Genode::Rpc_object<Session>, Rom::Writer
 
 		Dataspace_capability dataspace() override { return _ds.cap(); }
 
-		void submit(size_t const length) override
+		void submit(size_t length) override
 		{
-			_module.write_content(_ds.local_addr<char>(),
-			                      Genode::min(length, _ds.size()));
+			length = Genode::min(length, _ds.size());
+
+			if (_verbose) {
+
+				PLOG("report '%s'", _module.name().string());
+
+				/*
+				 * We cannot simply print the content of the report dataspace
+				 * as one string because we cannot expect the client to null-
+				 * terminate the content properly. Therefore, we output the
+				 * report line by line while keeping track of the dataspace
+				 * size.
+				 */
+
+				/* pointer and length of remaining string */
+				char const *str = _ds.local_addr<char>();
+				size_t      len = length;
+
+				while (*str && len) {
+
+					size_t const line_len = _str_line_end(str, len);
+
+					if (!line_len)
+						break;
+
+					/*
+					 * Copy line from (untrusted) report dataspace to local
+					 * line buffer,
+					 */
+					char line_buf[200];
+					Genode::strncpy(line_buf, str, Genode::min(line_len, sizeof(line_buf)));
+					PLOG("  %s", line_buf);
+
+					str += line_len;
+					len -= line_len;
+				}
+
+				PLOG("\n");
+			}
+
+			_module.write_content(_ds.local_addr<char>(), length);
 		}
 
 		void response_sigh(Genode::Signal_context_capability) override { }
@@ -79,6 +133,7 @@ struct Report::Root : Genode::Root_component<Session_component>
 	private:
 
 		Rom::Registry_for_writer &_rom_registry;
+		bool                     &_verbose;
 
 	protected:
 
@@ -96,17 +151,18 @@ struct Report::Root : Genode::Root_component<Session_component>
 
 			return new (md_alloc())
 				Session_component(Rom::Module::Name(label), buffer_size,
-				                  _rom_registry);
+				                  _rom_registry, _verbose);
 		}
 
 	public:
 
 		Root(Server::Entrypoint       &ep,
 		     Genode::Allocator        &md_alloc,
-		     Rom::Registry_for_writer &rom_registry)
+		     Rom::Registry_for_writer &rom_registry,
+		     bool                     &verbose)
 		:
 			Genode::Root_component<Session_component>(&ep.rpc_ep(), &md_alloc),
-			_rom_registry(rom_registry)
+			_rom_registry(rom_registry), _verbose(verbose)
 		{ }
 };
 

repos/os/src/server/report_rom/rom_module.h

@@ -192,6 +192,8 @@ struct Rom::Module : Module_list::Element
 		}
 
 		size_t size() const { return _size; }
+
+		Name name() const { return _name; }
 };
 
 #endif /* _ROM_MODULE_ */