Add support for parsing --classic switch

This patch adds the necessary logic to parse the --classic switch. All
of the unit tests are adjusted to check that it is parsed correctly.

Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@canonical.com>

src/snap-confine-args-test.c

@@ -93,6 +93,37 @@ static void test_sc_nonfatal_parse_args__typical()
 	// Check supported switches and arguments
 	g_assert_cmpstr(sc_args_security_tag(args), ==, "snap.app");
 	g_assert_cmpint(sc_args_is_version_query(args), ==, false);
+	g_assert_cmpint(sc_args_is_classic_confinement(args), ==, false);
+
+	// Check remaining arguments
+	g_assert_cmpint(argc, ==, 3);
+	g_assert_cmpstr(argv[0], ==, "/usr/lib/snapd/snap-confine");
+	g_assert_cmpstr(argv[1], ==, "--option");
+	g_assert_cmpstr(argv[2], ==, "arg");
+	g_assert_null(argv[3]);
+}
+
+static void test_sc_nonfatal_parse_args__typical_classic()
+{
+	// Test that typical invocation of snap-confine is parsed correctly.
+	struct sc_error *err __attribute__ ((cleanup(sc_cleanup_error))) = NULL;
+	struct sc_args *args;
+
+	int argc;
+	char **argv;
+	test_argc_argv(&argc, &argv,
+		       "/usr/lib/snapd/snap-confine", "--classic", "snap.app",
+		       "--option", "arg", NULL);
+
+	args = sc_nonfatal_parse_args(&argc, &argv, &err);
+	g_test_queue_destroy((GDestroyNotify) sc_args_free, args);
+	g_assert_null(err);
+	g_assert_nonnull(args);
+
+	// Check supported switches and arguments
+	g_assert_cmpstr(sc_args_security_tag(args), ==, "snap.app");
+	g_assert_cmpint(sc_args_is_version_query(args), ==, false);
+	g_assert_cmpint(sc_args_is_classic_confinement(args), ==, true);
 
 	// Check remaining arguments
 	g_assert_cmpint(argc, ==, 3);
@@ -124,6 +155,7 @@ static void test_sc_nonfatal_parse_args__ubuntu_core_launcher()
 	// Check supported switches and arguments
 	g_assert_cmpstr(sc_args_security_tag(args), ==, "snap.app");
 	g_assert_cmpint(sc_args_is_version_query(args), ==, false);
+	g_assert_cmpint(sc_args_is_classic_confinement(args), ==, false);
 
 	// Check remaining arguments
 	g_assert_cmpint(argc, ==, 3);
@@ -153,6 +185,7 @@ static void test_sc_nonfatal_parse_args__version()
 	// Check supported switches and arguments
 	g_assert_null(sc_args_security_tag(args));
 	g_assert_cmpint(sc_args_is_version_query(args), ==, true);
+	g_assert_cmpint(sc_args_is_classic_confinement(args), ==, false);
 
 	// Check remaining arguments
 	g_assert_cmpint(argc, ==, 3);
@@ -247,6 +280,8 @@ static void __attribute__ ((constructor)) init()
 	g_test_add_func("/args/test_argc_argv", test_test_argc_argv);
 	g_test_add_func("/args/sc_nonfatal_parse_args/typical",
 			test_sc_nonfatal_parse_args__typical);
+	g_test_add_func("/args/sc_nonfatal_parse_args/typical_classic",
+			test_sc_nonfatal_parse_args__typical_classic);
 	g_test_add_func("/args/sc_nonfatal_parse_args/ubuntu_core_launcher",
 			test_sc_nonfatal_parse_args__ubuntu_core_launcher);
 	g_test_add_func("/args/sc_nonfatal_parse_args/version",

src/snap-confine-args.c

@@ -35,6 +35,8 @@ struct sc_args {
 
 	// Flag indicating that --version was passed on command line.
 	bool is_version_query;
+	// Flag indicating that --classic was passed on command line.
+	bool is_classic_confinement;
 };
 
 struct sc_args *sc_nonfatal_parse_args(int *argcp, char ***argvp,
@@ -85,6 +87,9 @@ struct sc_args *sc_nonfatal_parse_args(int *argcp, char ***argvp,
 				args->is_version_query = true;
 				// NOTE: --version short-circuits the parser to finish
 				break;
+			} else if (strcmp(argv[optind], "--classic") == 0) {
+				args->is_classic_confinement = true;
+				continue;
 			}
 			// Report unhandled option switches
 			err = sc_error_init(SC_ARGS_DOMAIN, 0,
@@ -149,6 +154,14 @@ bool sc_args_is_version_query(struct sc_args *args)
 	return args->is_version_query;
 }
 
+bool sc_args_is_classic_confinement(struct sc_args * args)
+{
+	if (args == NULL) {
+		die("cannot obtain classic confinement flag from NULL argument parser");
+	}
+	return args->is_classic_confinement;
+}
+
 const char *sc_args_security_tag(struct sc_args *args)
 {
 	if (args == NULL) {

src/snap-confine-args.h

@@ -65,6 +65,11 @@ void sc_args_free(struct sc_args *args);
  **/
 bool sc_args_is_version_query(struct sc_args *args);
 
+/**
+ * Check if snap-confine was invoked with the --classic switch.
+ **/
+bool sc_args_is_classic_confinement(struct sc_args *args);
+
 /**
  * Get the security tag passed to snap-confine.
  *