platform: add nm_platform_link_get()

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

src/platform/nm-fake-platform.c

@@ -184,6 +184,16 @@ link_added_emit (gpointer user_data)
 	return FALSE;
 }
 
+static gboolean
+_nm_platform_link_get (NMPlatform *platform, int ifindex, NMPlatformLink *link)
+{
+	NMFakePlatformLink *device = link_get (platform, ifindex);
+
+	if (device)
+		*link = device->link;
+	return !!device;
+}
+
 static gboolean
 link_add (NMPlatform *platform, const char *name, NMLinkType type, const void *address, size_t address_len)
 {
@@ -1288,6 +1298,7 @@ nm_fake_platform_class_init (NMFakePlatformClass *klass)
 	platform_class->sysctl_set = sysctl_set;
 	platform_class->sysctl_get = sysctl_get;
 
+	platform_class->link_get = _nm_platform_link_get;
 	platform_class->link_get_all = link_get_all;
 	platform_class->link_add = link_add;
 	platform_class->link_delete = link_delete;

src/platform/nm-linux-platform.c

@@ -1877,6 +1877,22 @@ link_get_all (NMPlatform *platform)
 	return links;
 }
 
+static gboolean
+_nm_platform_link_get (NMPlatform *platform, int ifindex, NMPlatformLink *link)
+{
+	NMLinuxPlatformPrivate *priv = NM_LINUX_PLATFORM_GET_PRIVATE (platform);
+	auto_nl_object struct rtnl_link *rtnllink;
+
+	rtnllink = rtnl_link_get (priv->link_cache, ifindex);
+	if (rtnllink) {
+		if (link_is_announceable (platform, rtnllink)) {
+			if (init_link (platform, link, rtnllink))
+				return TRUE;
+		}
+	}
+	return FALSE;
+}
+
 static struct nl_object *
 build_rtnl_link (int ifindex, const char *name, NMLinkType type)
 {
@@ -3804,6 +3820,7 @@ nm_linux_platform_class_init (NMLinuxPlatformClass *klass)
 	platform_class->sysctl_set = sysctl_set;
 	platform_class->sysctl_get = sysctl_get;
 
+	platform_class->link_get = _nm_platform_link_get;
 	platform_class->link_get_all = link_get_all;
 	platform_class->link_add = link_add;
 	platform_class->link_delete = link_delete;

src/platform/nm-platform.c

@@ -439,6 +439,27 @@ nm_platform_link_get_all (void)
 	return result;
 }
 
+/**
+ * nm_platform_link_get:
+ * @ifindex: ifindex of the link
+ * @link: (out): output NMPlatformLink structure.
+ *
+ * If a link with given @ifindex exists, fill the given NMPlatformLink
+ * structure.
+ *
+ * Returns: %TRUE, if such a link exists, %FALSE otherwise.
+ * If the link does not exist, the content of @link is undefined.
+ **/
+gboolean
+nm_platform_link_get (int ifindex, NMPlatformLink *link)
+{
+	g_return_val_if_fail (ifindex > 0, FALSE);
+	g_return_val_if_fail (link, FALSE);
+
+	g_return_val_if_fail (klass->link_get, FALSE);
+	return !!klass->link_get (platform, ifindex, link);
+}
+
 /**
  * nm_platform_link_add:
  * @name: Interface name

src/platform/nm-platform.h

@@ -346,6 +346,7 @@ typedef struct {
 	gboolean (*sysctl_set) (NMPlatform *, const char *path, const char *value);
 	char * (*sysctl_get) (NMPlatform *, const char *path);
 
+	gboolean (*link_get) (NMPlatform *platform, int ifindex, NMPlatformLink *link);
 	GArray *(*link_get_all) (NMPlatform *);
 	gboolean (*link_add) (NMPlatform *, const char *name, NMLinkType type, const void *address, size_t address_len);
 	gboolean (*link_delete) (NMPlatform *, int ifindex);
@@ -477,6 +478,7 @@ char *nm_platform_sysctl_get (const char *path);
 gint32 nm_platform_sysctl_get_int32 (const char *path, gint32 fallback);
 gint64 nm_platform_sysctl_get_int_checked (const char *path, guint base, gint64 min, gint64 max, gint64 fallback);
 
+gboolean nm_platform_link_get (int ifindex, NMPlatformLink *link);
 GArray *nm_platform_link_get_all (void);
 gboolean nm_platform_dummy_add (const char *name);
 gboolean nm_platform_bridge_add (const char *name, const void *address, size_t address_len);