device-util: introduce device_in_subsystem() and device_is_devtype() helper functions

src/libsystemd/sd-device/device-util.c

@@ -139,3 +139,21 @@ char** device_make_log_fields(sd_device *device) {
 
         return TAKE_PTR(strv);
 }
+
+bool device_in_subsystem(sd_device *device, const char *subsystem) {
+        const char *s = NULL;
+
+        assert(device);
+
+        (void) sd_device_get_subsystem(device, &s);
+        return streq_ptr(s, subsystem);
+}
+
+bool device_is_devtype(sd_device *device, const char *devtype) {
+        const char *s = NULL;
+
+        assert(device);
+
+        (void) sd_device_get_devtype(device, &s);
+        return streq_ptr(s, devtype);
+}

src/libsystemd/sd-device/device-util.h

@@ -102,3 +102,6 @@ static inline int devname_from_stat_rdev(const struct stat *st, char **ret) {
 int device_open_from_devnum(mode_t mode, dev_t devnum, int flags, char **ret);
 
 char** device_make_log_fields(sd_device *device);
+
+bool device_in_subsystem(sd_device *device, const char *subsystem);
+bool device_is_devtype(sd_device *device, const char *devtype);

src/libsystemd/sd-device/test-device-util.c

@@ -1,23 +1,91 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
 #include "device-util.h"
+#include "mountpoint-util.h"
 #include "tests.h"
 
 TEST(log_device_full) {
+        _cleanup_(sd_device_unrefp) sd_device *dev = NULL;
         int r;
 
-        for (int level = LOG_ERR; level <= LOG_DEBUG; level++) {
-                log_device_full(NULL, level, "test level=%d: %m", level);
+        (void) sd_device_new_from_subsystem_sysname(&dev, "net", "lo");
 
-                r = log_device_full_errno(NULL, level, EUCLEAN, "test level=%d errno=EUCLEAN: %m", level);
+        for (int level = LOG_ERR; level <= LOG_DEBUG; level++) {
+                log_device_full(dev, level, "test level=%d: %m", level);
+
+                r = log_device_full_errno(dev, level, EUCLEAN, "test level=%d errno=EUCLEAN: %m", level);
                 assert_se(r == -EUCLEAN);
 
-                r = log_device_full_errno(NULL, level, 0, "test level=%d errno=0: %m", level);
+                r = log_device_full_errno(dev, level, 0, "test level=%d errno=0: %m", level);
                 assert_se(r == 0);
 
-                r = log_device_full_errno(NULL, level, SYNTHETIC_ERRNO(ENODATA), "test level=%d errno=S(ENODATA): %m", level);
+                r = log_device_full_errno(dev, level, SYNTHETIC_ERRNO(ENODATA), "test level=%d errno=S(ENODATA): %m", level);
                 assert_se(r == -ENODATA);
         }
 }
 
-DEFINE_TEST_MAIN(LOG_INFO);
+TEST(device_in_subsystem) {
+        _cleanup_(sd_device_unrefp) sd_device *dev = NULL;
+        int r;
+
+        r = sd_device_new_from_subsystem_sysname(&dev, "net", "lo");
+        if (r == -ENODEV)
+                return (void) log_tests_skipped("net/lo does not exist");
+        assert_se(r >= 0);
+
+        assert_se(device_in_subsystem(dev, "net"));
+        assert_se(!device_in_subsystem(dev, "disk"));
+        assert_se(!device_in_subsystem(dev, "subsystem"));
+        assert_se(!device_in_subsystem(dev, ""));
+        assert_se(!device_in_subsystem(dev, NULL));
+
+        dev = sd_device_unref(dev);
+
+        assert_se(sd_device_new_from_syspath(&dev, "/sys/class/net") >= 0);
+        assert_se(!device_in_subsystem(dev, "net"));
+        assert_se(!device_in_subsystem(dev, "disk"));
+        assert_se(device_in_subsystem(dev, "subsystem"));
+        assert_se(!device_in_subsystem(dev, ""));
+        assert_se(!device_in_subsystem(dev, NULL));
+
+        dev = sd_device_unref(dev);
+
+        assert_se(sd_device_new_from_syspath(&dev, "/sys/class") >= 0);
+        assert_se(!device_in_subsystem(dev, "net"));
+        assert_se(!device_in_subsystem(dev, "disk"));
+        assert_se(!device_in_subsystem(dev, "subsystem"));
+        assert_se(!device_in_subsystem(dev, ""));
+        assert_se(device_in_subsystem(dev, NULL));
+}
+
+TEST(device_is_devtype) {
+        _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
+        _cleanup_(sd_device_unrefp) sd_device *dev = NULL;
+
+        assert_se(sd_device_enumerator_new(&e) >= 0);
+        assert_se(sd_device_enumerator_add_match_subsystem(e, "disk", true) >= 0);
+
+        FOREACH_DEVICE(e, d) {
+                const char *t;
+
+                assert_se(sd_device_get_devtype(d, &t) >= 0);
+                assert_se(device_is_devtype(d, t));
+                assert_se(!device_is_devtype(d, "hoge"));
+                assert_se(!device_is_devtype(d, ""));
+                assert_se(!device_is_devtype(d, NULL));
+        }
+
+        assert_se(sd_device_new_from_syspath(&dev, "/sys/class/net") >= 0);
+        assert_se(!device_is_devtype(dev, "hoge"));
+        assert_se(!device_is_devtype(dev, ""));
+        assert_se(device_is_devtype(dev, NULL));
+}
+
+static int intro(void) {
+        if (path_is_mount_point("/sys", NULL, 0) <= 0)
+                return log_tests_skipped("/sys is not mounted");
+
+        return EXIT_SUCCESS;
+}
+
+DEFINE_TEST_MAIN_WITH_INTRO(LOG_INFO, intro);