platform: add nm_platform_link_get_by_address()

src/platform/nm-fake-platform.c

@@ -167,6 +167,28 @@ _nm_platform_link_get (NMPlatform *platform, int ifindex, NMPlatformLink *l)
 	return !!device;
 }
 
+static gboolean
+_nm_platform_link_get_by_address (NMPlatform *platform,
+                                  gconstpointer address,
+                                  size_t length,
+                                  NMPlatformLink *l)
+{
+	NMFakePlatformPrivate *priv = NM_FAKE_PLATFORM_GET_PRIVATE (platform);
+	guint i;
+
+	for (i = 0; i < priv->links->len; i++) {
+		NMFakePlatformLink *device = &g_array_index (priv->links, NMFakePlatformLink, i);
+
+		if (   device->address
+		    && g_bytes_get_size (device->address) == length
+		    && memcmp (g_bytes_get_data (device->address, NULL), address, length) == 0) {
+			*l = device->link;
+			return TRUE;
+		}
+	}
+	return FALSE;
+}
+
 static gboolean
 link_add (NMPlatform *platform,
           const char *name,
@@ -1370,6 +1392,7 @@ nm_fake_platform_class_init (NMFakePlatformClass *klass)
 	platform_class->sysctl_get = sysctl_get;
 
 	platform_class->link_get = _nm_platform_link_get;
+	platform_class->link_get_by_address = _nm_platform_link_get_by_address;
 	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

@@ -2318,6 +2318,30 @@ _nm_platform_link_get (NMPlatform *platform, int ifindex, NMPlatformLink *l)
 	return (rtnllink && init_link (platform, l ? l : &tmp, rtnllink));
 }
 
+static gboolean
+_nm_platform_link_get_by_address (NMPlatform *platform,
+                                  gconstpointer address,
+                                  size_t length,
+                                  NMPlatformLink *l)
+{
+	NMLinuxPlatformPrivate *priv = NM_LINUX_PLATFORM_GET_PRIVATE (platform);
+	struct nl_object *object;
+
+	for (object = nl_cache_get_first (priv->link_cache); object; object = nl_cache_get_next (object)) {
+		struct rtnl_link *rtnl_link = (struct rtnl_link *) object;
+		struct nl_addr *nladdr;
+		gconstpointer hwaddr;
+
+		nladdr = rtnl_link_get_addr (rtnl_link);
+		if (nladdr && (nl_addr_get_len (nladdr) == length)) {
+			hwaddr = nl_addr_get_binary_addr (nladdr);
+			if (hwaddr && memcmp (hwaddr, address, length) == 0)
+				return init_link (platform, l, rtnl_link);
+		}
+	}
+	return FALSE;
+}
+
 static struct nl_object *
 build_rtnl_link (int ifindex, const char *name, NMLinkType type)
 {
@@ -4705,6 +4729,7 @@ nm_linux_platform_class_init (NMLinuxPlatformClass *klass)
 	platform_class->sysctl_get = sysctl_get;
 
 	platform_class->link_get = _nm_platform_link_get;
+	platform_class->link_get_by_address = _nm_platform_link_get_by_address;
 	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

@@ -541,6 +541,35 @@ nm_platform_link_get (NMPlatform *self, int ifindex, NMPlatformLink *link)
 	return !!klass->link_get (self, ifindex, link);
 }
 
+/**
+ * nm_platform_link_get_by_address:
+ * @self: platform instance
+ * @address: a pointer to the binary hardware address
+ * @length: the size of @address in bytes
+ * @link: (out): output NMPlatformLink structure.
+ *
+ * If a link with given @address 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_by_address (NMPlatform *self,
+                                 gconstpointer address,
+                                 size_t length,
+                                 NMPlatformLink *link)
+{
+	_CHECK_SELF (self, klass, FALSE);
+
+	g_return_val_if_fail (address != NULL, FALSE);
+	g_return_val_if_fail (length > 0, FALSE);
+	g_return_val_if_fail (link, FALSE);
+
+	g_return_val_if_fail (klass->link_get_by_address, FALSE);
+	return !!klass->link_get_by_address (self, address, length, link);
+}
+
 /**
  * nm_platform_link_add:
  * @self: platform instance

src/platform/nm-platform.h

@@ -374,6 +374,7 @@ typedef struct {
 	char * (*sysctl_get) (NMPlatform *, const char *path);
 
 	gboolean (*link_get) (NMPlatform *platform, int ifindex, NMPlatformLink *link);
+	gboolean (*link_get_by_address) (NMPlatform *platform, gconstpointer address, size_t length, NMPlatformLink *link);
 	GArray *(*link_get_all) (NMPlatform *);
 	gboolean (*link_add) (NMPlatform *,
 	                      const char *name,
@@ -531,6 +532,7 @@ gboolean nm_platform_sysctl_set_ip6_hop_limit_safe (NMPlatform *self, const char
 
 gboolean nm_platform_link_get (NMPlatform *self, int ifindex, NMPlatformLink *link);
 GArray *nm_platform_link_get_all (NMPlatform *self);
+gboolean nm_platform_link_get_by_address (NMPlatform *self, gconstpointer address, size_t length, NMPlatformLink *link);
 gboolean nm_platform_dummy_add (NMPlatform *self, const char *name, NMPlatformLink *out_link);
 gboolean nm_platform_bridge_add (NMPlatform *self, const char *name, const void *address, size_t address_len, NMPlatformLink *out_link);
 gboolean nm_platform_bond_add (NMPlatform *self, const char *name, NMPlatformLink *out_link);