platform: add parameter to nm_platform_sysctl_get() to suppress logging error

In some cases, an error when reading the sysctl value can be expected.
In this case, we want to suppress the error message

Signed-off-by: Thomas Haller <thaller@redhat.com>

src/platform/nm-fake-platform.c

@@ -72,7 +72,7 @@ sysctl_set (NMPlatform *platform, const char *path, const char *value)
 }
 
 static char *
-sysctl_get (NMPlatform *platform, const char *path)
+sysctl_get (NMPlatform *platform, const char *path, gboolean silent_on_error)
 {
 	NMFakePlatformPrivate *priv = NM_FAKE_PLATFORM_GET_PRIVATE (platform);
 
@@ -566,7 +566,7 @@ master_get_option (NMPlatform *platform, int master, const char *option)
 {
 	auto_g_free char *path = g_strdup_printf ("master:%d:%s", master, option);
 
-	return sysctl_get (platform, path);
+	return sysctl_get (platform, path, FALSE);
 }
 
 static gboolean
@@ -582,7 +582,7 @@ slave_get_option (NMPlatform *platform, int slave, const char *option)
 {
 	auto_g_free char *path = g_strdup_printf ("slave:%d:%s", slave, option);
 
-	return sysctl_get (platform, path);
+	return sysctl_get (platform, path, FALSE);
 }
 
 static gboolean

src/platform/nm-linux-platform.c

@@ -1352,13 +1352,14 @@ sysctl_set (NMPlatform *platform, const char *path, const char *value)
 }
 
 static char *
-sysctl_get (NMPlatform *platform, const char *path)
+sysctl_get (NMPlatform *platform, const char *path, gboolean silent_on_error)
 {
 	GError *error = NULL;
 	char *contents;
 
 	if (!g_file_get_contents (path, &contents, NULL, &error)) {
-		error ("error reading %s: %s", path, error->message);
+		if (!silent_on_error)
+			error ("error reading %s: %s", path, error->message);
 		g_clear_error (&error);
 		return NULL;
 	}
@@ -1767,7 +1768,7 @@ link_get_physical_port_id (NMPlatform *platform, int ifindex)
 
 	path = g_strdup_printf ("/sys/class/net/%s/phys_port_id", ifname);
 	if (g_file_test (path, G_FILE_TEST_EXISTS))
-		id = sysctl_get (platform, path);
+		id = sysctl_get (platform, path, FALSE);
 	else
 		id = NULL;
 	g_free (path);
@@ -1888,7 +1889,7 @@ link_get_option (int master, const char *category, const char *option)
 {
 	auto_g_free char *path = link_option_path (master, category, option);
 
-	return path ? nm_platform_sysctl_get (path) : NULL;
+	return path ? nm_platform_sysctl_get (path, FALSE) : NULL;
 }
 
 static const char *
@@ -2012,7 +2013,7 @@ tun_get_properties (NMPlatform *platform, int ifindex, NMPlatformTunProperties *
 		return FALSE;
 
 	path = g_strdup_printf ("/sys/class/net/%s/owner", ifname);
-	val = nm_platform_sysctl_get (path);
+	val = nm_platform_sysctl_get (path, FALSE);
 	g_free (path);
 	if (!val)
 		return FALSE;
@@ -2020,7 +2021,7 @@ tun_get_properties (NMPlatform *platform, int ifindex, NMPlatformTunProperties *
 	g_free (val);
 
 	path = g_strdup_printf ("/sys/class/net/%s/group", ifname);
-	val = nm_platform_sysctl_get (path);
+	val = nm_platform_sysctl_get (path, FALSE);
 	g_free (path);
 	if (!val)
 		return FALSE;
@@ -2028,7 +2029,7 @@ tun_get_properties (NMPlatform *platform, int ifindex, NMPlatformTunProperties *
 	g_free (val);
 
 	path = g_strdup_printf ("/sys/class/net/%s/tun_flags", ifname);
-	val = nm_platform_sysctl_get (path);
+	val = nm_platform_sysctl_get (path, FALSE);
 	g_free (path);
 	if (!val)
 		return FALSE;

src/platform/nm-platform.c

@@ -230,18 +230,20 @@ nm_platform_sysctl_set (const char *path, const char *value)
 /**
  * nm_platform_sysctl_get:
  * @path: Absolute path to sysctl
+ * @silent_on_error: don't log an error message when the value
+ * could not be read.
  *
  * Returns: (transfer full): Contents of the virtual sysctl file.
  */
 char *
-nm_platform_sysctl_get (const char *path)
+nm_platform_sysctl_get (const char *path, gboolean silent_on_error)
 {
 	reset_error ();
 
 	g_return_val_if_fail (path, NULL);
 	g_return_val_if_fail (klass->sysctl_get, NULL);
 
-	return klass->sysctl_get (platform, path);
+	return klass->sysctl_get (platform, path, silent_on_error);
 }
 
 /**
@@ -263,7 +265,7 @@ nm_platform_sysctl_get_int32 (const char *path, gint32 fallback)
 	g_return_val_if_fail (path, fallback);
 
 	if (path)
-		value = nm_platform_sysctl_get (path);
+		value = nm_platform_sysctl_get (path, FALSE);
 
 	if (!value) {
 		errno = EINVAL;

src/platform/nm-platform.h

@@ -252,7 +252,7 @@ typedef struct {
 	gboolean (*setup) (NMPlatform *);
 
 	gboolean (*sysctl_set) (NMPlatform *, const char *path, const char *value);
-	char * (*sysctl_get) (NMPlatform *, const char *path);
+	char * (*sysctl_get) (NMPlatform *, const char *path, gboolean silent_on_error);
 
 	GArray *(*link_get_all) (NMPlatform *);
 	gboolean (*link_add) (NMPlatform *, const char *name, NMLinkType type);
@@ -369,7 +369,7 @@ const char *nm_platform_get_error_msg (void);
 void nm_platform_query_devices (void);
 
 gboolean nm_platform_sysctl_set (const char *path, const char *value);
-char *nm_platform_sysctl_get (const char *path);
+char *nm_platform_sysctl_get (const char *path, gboolean silent_on_error);
 gint32 nm_platform_sysctl_get_int32 (const char *path, gint32 fallback);
 
 GArray *nm_platform_link_get_all (void);

src/platform/tests/platform.c

@@ -47,7 +47,7 @@ do_sysctl_set (char **argv)
 static gboolean
 do_sysctl_get (char **argv)
 {
-	auto_g_free char *value = nm_platform_sysctl_get (argv[0]);
+	auto_g_free char *value = nm_platform_sysctl_get (argv[0], FALSE);
 
 	printf ("%s\n", value);