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-rw-r--r--net/core/dev_mcast.c75
1 files changed, 75 insertions, 0 deletions
diff --git a/net/core/dev_mcast.c b/net/core/dev_mcast.c
index aa38100601f..235a2a8a0d0 100644
--- a/net/core/dev_mcast.c
+++ b/net/core/dev_mcast.c
@@ -102,6 +102,81 @@ int dev_mc_add(struct net_device *dev, void *addr, int alen, int glbl)
return err;
}
+/**
+ * dev_mc_sync - Synchronize device's multicast list to another device
+ * @to: destination device
+ * @from: source device
+ *
+ * Add newly added addresses to the destination device and release
+ * addresses that have no users left. The source device must be
+ * locked by netif_tx_lock_bh.
+ *
+ * This function is intended to be called from the dev->set_multicast_list
+ * function of layered software devices.
+ */
+int dev_mc_sync(struct net_device *to, struct net_device *from)
+{
+ struct dev_addr_list *da;
+ int err = 0;
+
+ netif_tx_lock_bh(to);
+ for (da = from->mc_list; da != NULL; da = da->next) {
+ if (!da->da_synced) {
+ err = __dev_addr_add(&to->mc_list, &to->mc_count,
+ da->da_addr, da->da_addrlen, 0);
+ if (err < 0)
+ break;
+ da->da_synced = 1;
+ da->da_users++;
+ } else if (da->da_users == 1) {
+ __dev_addr_delete(&to->mc_list, &to->mc_count,
+ da->da_addr, da->da_addrlen, 0);
+ __dev_addr_delete(&from->mc_list, &from->mc_count,
+ da->da_addr, da->da_addrlen, 0);
+ }
+ }
+ if (!err)
+ __dev_set_rx_mode(to);
+ netif_tx_unlock_bh(to);
+
+ return err;
+}
+EXPORT_SYMBOL(dev_mc_sync);
+
+
+/**
+ * dev_mc_unsync - Remove synchronized addresses from the destination
+ * device
+ * @to: destination device
+ * @from: source device
+ *
+ * Remove all addresses that were added to the destination device by
+ * dev_mc_sync(). This function is intended to be called from the
+ * dev->stop function of layered software devices.
+ */
+void dev_mc_unsync(struct net_device *to, struct net_device *from)
+{
+ struct dev_addr_list *da;
+
+ netif_tx_lock_bh(from);
+ netif_tx_lock_bh(to);
+
+ for (da = from->mc_list; da != NULL; da = da->next) {
+ if (!da->da_synced)
+ continue;
+ __dev_addr_delete(&to->mc_list, &to->mc_count,
+ da->da_addr, da->da_addrlen, 0);
+ da->da_synced = 0;
+ __dev_addr_delete(&from->mc_list, &from->mc_count,
+ da->da_addr, da->da_addrlen, 0);
+ }
+ __dev_set_rx_mode(to);
+
+ netif_tx_unlock_bh(to);
+ netif_tx_unlock_bh(from);
+}
+EXPORT_SYMBOL(dev_mc_unsync);
+
/*
* Discard multicast list when a device is downed
*/