canbus: honor shutdown mode

Makefile.am

@@ -74,11 +74,15 @@ ecutuned_SOURCES = $(SRC_FILES) src/ecutuned.c
 ecutuned_CFLAGS = -DUSESSL -DTHREADED $(INCLUDE_ALL_DIRS) $(COMPILER_FLAGS) $(LOG_FLAGS)
 ecutuned_LDFLAGS = $(LD_FLAG) $(EXTERNAL_LIBS)
 
-TESTS = check_j2534
-check_PROGRAMS = check_j2534
+TESTS = check_j2534 check_canbus_shutdown
+check_PROGRAMS = check_j2534 check_canbus_shutdown
 check_j2534_SOURCES = $(ECUTOOLS_TEST_FILES)
 check_j2534_LDFLAGS = $(LD_FLAG) -lcheck -lj2534
 
+check_canbus_shutdown_SOURCES = tests/check_canbus_shutdown.c src/canbus.c
+check_canbus_shutdown_LDFLAGS = -Wl,--wrap=shutdown
+check_canbus_shutdown_LDADD = -lcheck -lsubunit
+
 bundle-install:
 	cd bindings/ruby && bundle install && cd -
 	cd cli && bundle install && cd -

src/canbus.c

@@ -190,7 +190,7 @@ int canbus_filter(canbus_client *canbus, struct can_filter *filters, unsigned in
 
 void canbus_shutdown(canbus_client *canbus, int how) {
   if(canbus->socket != NULL) {
-    if(shutdown(canbus->socket, SHUT_RD) != 0) {
+    if(shutdown(canbus->socket, how) != 0) {
       syslog(LOG_ERR, "canbus_shutdown: unable to shutdown socket");
     }
   }

tests/check_canbus_shutdown.c

@@ -0,0 +1,48 @@
+#include <stdlib.h>
+#include <check.h>
+
+#include "canbus.h"
+
+static int shutdown_fd;
+static int shutdown_how;
+
+int __wrap_shutdown(int fd, int how)
+{
+  shutdown_fd = fd;
+  shutdown_how = how;
+  return 0;
+}
+
+START_TEST(test_canbus_shutdown_forwards_how)
+{
+  canbus_client client = {
+    .socket = 42
+  };
+
+  shutdown_fd = -1;
+  shutdown_how = -1;
+
+  canbus_shutdown(&client, SHUT_WR);
+
+  ck_assert_int_eq(shutdown_fd, 42);
+  ck_assert_int_eq(shutdown_how, SHUT_WR);
+}
+END_TEST
+
+int main(void)
+{
+  int failed;
+  Suite *suite = suite_create("canbus_shutdown");
+  TCase *core = tcase_create("core");
+  SRunner *runner;
+
+  tcase_add_test(core, test_canbus_shutdown_forwards_how);
+  suite_add_tcase(suite, core);
+
+  runner = srunner_create(suite);
+  srunner_run_all(runner, CK_NORMAL);
+  failed = srunner_ntests_failed(runner);
+  srunner_free(runner);
+
+  return failed == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
+}