Merge pull request #1215 from angeloc/master

src/context: get current bootslot on custom bootloader

Makefile.am

@@ -219,14 +219,16 @@ EXTRA_DIST += tap-t \
 	      test/sharness.sh \
 	      test/system.conf \
 	      test/test.conf \
+	      test/test-custom.conf \
 	      test/test-global.conf \
 	      test/test-datadir.conf \
 	      test/test-dummy-handler.conf \
 	      test/get-coverity.sh \
 	      test/openssl-ca-create.sh \
 	      test/openssl-ca-check.sh \
 	      test/openssl-enc-create.sh \
-	      test/run-coverity.sh
+	      test/run-coverity.sh \
+	      test/custom-state-current
 
 librauctest_la_SOURCES = \
 	test/common.c \

configure.ac

@@ -273,9 +273,11 @@ AC_CONFIG_LINKS([test/rauc.t:test/rauc.t])
 AC_CONFIG_LINKS([test/rootfs.raucs:test/rootfs.raucs])
 AC_CONFIG_LINKS([test/sharness.sh:test/sharness.sh])
 AC_CONFIG_LINKS([test/test.conf:test/test.conf])
+AC_CONFIG_LINKS([test/test-custom.conf:test/test-custom.conf])
 AC_CONFIG_LINKS([test/test-global.conf:test/test-global.conf])
 AC_CONFIG_LINKS([test/test-datadir.conf:test/test-datadir.conf])
 AC_CONFIG_LINKS([test/test-dummy-handler.conf:test/test-dummy-handler.conf])
+AC_CONFIG_LINKS([test/custom-state-current:test/custom-state-current])
 
 AC_CONFIG_FILES([
         Makefile

docs/integration.rst

@@ -485,6 +485,16 @@ See the `systemd-veritysetup-generator documentation
 <https://www.freedesktop.org/software/systemd/man/systemd-veritysetup-generator.html#systemd.verity_root_data=>`_
 for details.
 
+Identification via custom backend
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+When using the custom bootloader backend and the information about the
+currently booted slot cannot be derived from the kernel command line,
+RAUC will try to query the custom bootloader backend to get this information.
+
+See the :ref:`sec-custom-bootloader-backend` bootloader section on how
+to implement a custom bootloader handler.
+
 Barebox
 ~~~~~~~
 
@@ -1114,6 +1124,7 @@ RAUC to trigger the following actions:
 * set the primary slot
 * get the boot state
 * set the boot state
+* get the current booted slot (optional)
 
 To get the primary slot, the handler is called with the argument ``get-primary``.
 The handler must output the current primary slot's bootname on the `stdout`,
@@ -1147,6 +1158,12 @@ The ``<state>`` argument corresponds to one of the following values:
 The return value must be ``0`` if the boot state was set successfully,
 or non-zero if an error occurred.
 
+To get the current running slot, the handler must be called with the argument
+``get-current``. The handler must output the current running slot's bootname on
+the `stdout`, and return ``0`` on exit, if no error occurred. Implementing this
+is only needed when the /proc/cmdline is not providing information about current
+booted slot.
+
 Init System and Service Startup
 -------------------------------
 

src/config_file.c

@@ -906,5 +906,6 @@ void free_config(RaucConfig *config)
 	g_free(config->encryption_key);
 	g_free(config->encryption_cert);
 	g_clear_pointer(&config->slots, g_hash_table_destroy);
+	g_free(config->custom_bootloader_backend);
 	g_free(config);
 }

src/context.c

@@ -140,6 +140,57 @@ static gchar* get_cmdline_bootname(void)
 	return bootname;
 }
 
+static gchar* get_custom_bootname(void)
+{
+	g_autoptr(GSubprocessLauncher) launcher = NULL;
+	g_autoptr(GSubprocess) handle = NULL;
+	g_autoptr(GDataInputStream) datainstream = NULL;
+	g_autoptr(GPtrArray) args_array = NULL;
+	g_autofree gchar *outline = NULL;
+	GError *ierror = NULL;
+	GInputStream *instream;
+	int res;
+
+	args_array = g_ptr_array_new();
+	g_ptr_array_add(args_array, context->config->custom_bootloader_backend);
+	g_ptr_array_add(args_array, (gchar *)("get-current"));
+	g_ptr_array_add(args_array, NULL);
+
+	launcher = g_subprocess_launcher_new(G_SUBPROCESS_FLAGS_STDOUT_PIPE);
+	handle = r_subprocess_launcher_spawnv(launcher, args_array, NULL);
+
+	if (handle == NULL) {
+		g_message("Failed to run custom backend '%s'",
+				context->config->custom_bootloader_backend);
+		return NULL;
+	}
+
+	instream = g_subprocess_get_stdout_pipe(handle);
+	datainstream = g_data_input_stream_new(instream);
+
+	outline = g_data_input_stream_read_line(datainstream, NULL, NULL, &ierror);
+
+	if (ierror) {
+		g_message("Failed to read custom backend output");
+		return NULL;
+	}
+
+	res = g_subprocess_wait_check(handle, NULL, NULL);
+	if (!res) {
+		g_message("Failed to get custom backend output");
+		return NULL;
+	}
+
+	if (!outline) {
+		g_message("Failed to get custom backend bootname: no output");
+		return NULL;
+	}
+
+	g_debug("Resolved custom backend bootname to %s", outline);
+
+	return g_steal_pointer(&outline);
+}
+
 /**
  * Launches a handler and obtains variables from output by looking for
  * 'RAUC_<SOMETHING>=value' lines to put them into a key/value store (GHashTable).
@@ -362,6 +413,10 @@ static gboolean r_context_configure_target(GError **error)
 		context->bootslot = get_cmdline_bootname();
 	}
 
+	if (context->bootslot == NULL && (g_strcmp0(context->config->system_bootloader, "custom") == 0)) {
+		context->bootslot = get_custom_bootname();
+	}
+
 	g_clear_pointer(&context->boot_id, g_free);
 	g_clear_pointer(&context->machine_id, g_free);
 

test/bin/custom-bootloader-script

@@ -33,6 +33,12 @@ function custom_set_primary ()
 	sed -i "s/\(PRIMARY=\).*/\1${bootname}/" "${CUSTOM_STATE_PATH}"
 }
 
+function custom_get_current ()
+{
+	echo $(grep CURRENT "$CUSTOM_STATE_PATH" | sed 's/.*=\(.*\)/\1/')
+}
+
+
 if [ "$1" = "get-state" ]; then
     shift
     custom_get_state "$@"
@@ -45,4 +51,7 @@ elif [ "$1" = "get-primary" ]; then
 elif [ "$1" = "set-primary" ]; then
     shift
     custom_set_primary "$@"
+elif [ "$1" = "get-current" ]; then
+    shift
+    custom_get_current "$@"
 fi

test/context.c

@@ -66,6 +66,19 @@ static void test_bootslot_no_bootslot(void)
 	r_context_clean();
 }
 
+static void test_bootslot_custom_bootloader(void)
+{
+	r_context_conf()->configpath = g_strdup("test/test-custom.conf");
+	r_context_conf()->configmode = R_CONTEXT_CONFIG_MODE_REQUIRED;
+	g_assert_true(g_setenv("CUSTOM_STATE_PATH", "test/custom-state-current", TRUE));
+	r_context_conf()->mock.proc_cmdline = "quiet";
+	g_clear_pointer(&r_context_conf()->bootslot, g_free);
+
+	g_assert_cmpstr(r_context()->bootslot, ==, "A");
+
+	r_context_clean();
+}
+
 
 /* Tests that the infos provided by the configured system-info handler make it
  * into RAUC's system information.
@@ -125,6 +138,8 @@ int main(int argc, char *argv[])
 
 	g_test_add_func("/context/bootslot/no-bootslot", test_bootslot_no_bootslot);
 
+	g_test_add_func("/context/bootslot/custom-bootslot", test_bootslot_custom_bootloader);
+
 	g_test_add_func("/context/system-info", test_context_system_info);
 
 	g_test_add_func("/context/system-info-dummy", test_context_system_info_dummy);

test/custom-state-current

@@ -0,0 +1 @@
+CURRENT=A

test/test-custom.conf

@@ -0,0 +1,23 @@
+# testsuite system configuration
+
+[system]
+compatible=Test Config
+bootloader=custom
+variant-name=Default Variant
+
+[handlers]
+bootloader-custom-backend=bin/custom-bootloader-script
+
+[keyring]
+path=openssl-ca/dev-ca.pem
+check-crl=true
+
+[slot.rootfs.0]
+device=images/rootfs-0
+type=raw
+bootname=system0
+
+[slot.rootfs.1]
+device=images/rootfs-1
+type=raw
+bootname=system1