xen-netback: add support for multicast control

[cascardo/linux.git] / drivers / net / xen-netback / netback.c

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 3f44b52..42569b9 100644 (file)
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -1157,6 +1157,80 @@ static bool tx_credit_exceeded(struct xenvif_queue *queue, unsigned size)
        return false;
 }
 
+/* No locking is required in xenvif_mcast_add/del() as they are
+ * only ever invoked from NAPI poll. An RCU list is used because
+ * xenvif_mcast_match() is called asynchronously, during start_xmit.
+ */
+
+static int xenvif_mcast_add(struct xenvif *vif, const u8 *addr)
+{
+       struct xenvif_mcast_addr *mcast;
+
+       if (vif->fe_mcast_count == XEN_NETBK_MCAST_MAX) {
+               if (net_ratelimit())
+                       netdev_err(vif->dev,
+                                  "Too many multicast addresses\n");
+               return -ENOSPC;
+       }
+
+       mcast = kzalloc(sizeof(*mcast), GFP_ATOMIC);
+       if (!mcast)
+               return -ENOMEM;
+
+       ether_addr_copy(mcast->addr, addr);
+       list_add_tail_rcu(&mcast->entry, &vif->fe_mcast_addr);
+       vif->fe_mcast_count++;
+
+       return 0;
+}
+
+static void xenvif_mcast_del(struct xenvif *vif, const u8 *addr)
+{
+       struct xenvif_mcast_addr *mcast;
+
+       list_for_each_entry_rcu(mcast, &vif->fe_mcast_addr, entry) {
+               if (ether_addr_equal(addr, mcast->addr)) {
+                       --vif->fe_mcast_count;
+                       list_del_rcu(&mcast->entry);
+                       kfree_rcu(mcast, rcu);
+                       break;
+               }
+       }
+}
+
+bool xenvif_mcast_match(struct xenvif *vif, const u8 *addr)
+{
+       struct xenvif_mcast_addr *mcast;
+
+       rcu_read_lock();
+       list_for_each_entry_rcu(mcast, &vif->fe_mcast_addr, entry) {
+               if (ether_addr_equal(addr, mcast->addr)) {
+                       rcu_read_unlock();
+                       return true;
+               }
+       }
+       rcu_read_unlock();
+
+       return false;
+}
+
+void xenvif_mcast_addr_list_free(struct xenvif *vif)
+{
+       /* No need for locking or RCU here. NAPI poll and TX queue
+        * are stopped.
+        */
+       while (!list_empty(&vif->fe_mcast_addr)) {
+               struct xenvif_mcast_addr *mcast;
+
+               mcast = list_first_entry(&vif->fe_mcast_addr,
+                                        struct xenvif_mcast_addr,
+                                        entry);
+               --vif->fe_mcast_count;
+               list_del(&mcast->entry);
+               kfree(mcast);
+       }
+}
+
 static void xenvif_tx_build_gops(struct xenvif_queue *queue,
                                     int budget,
                                     unsigned *copy_ops,
@@ -1215,6 +1289,31 @@ static void xenvif_tx_build_gops(struct xenvif_queue *queue,
                                break;
                }
 
+               if (extras[XEN_NETIF_EXTRA_TYPE_MCAST_ADD - 1].type) {
+                       struct xen_netif_extra_info *extra;
+
+                       extra = &extras[XEN_NETIF_EXTRA_TYPE_MCAST_ADD - 1];
+                       ret = xenvif_mcast_add(queue->vif, extra->u.mcast.addr);
+
+                       make_tx_response(queue, &txreq,
+                                        (ret == 0) ?
+                                        XEN_NETIF_RSP_OKAY :
+                                        XEN_NETIF_RSP_ERROR);
+                       push_tx_responses(queue);
+                       continue;
+               }
+
+               if (extras[XEN_NETIF_EXTRA_TYPE_MCAST_DEL - 1].type) {
+                       struct xen_netif_extra_info *extra;
+
+                       extra = &extras[XEN_NETIF_EXTRA_TYPE_MCAST_DEL - 1];
+                       xenvif_mcast_del(queue->vif, extra->u.mcast.addr);
+
+                       make_tx_response(queue, &txreq, XEN_NETIF_RSP_OKAY);
+                       push_tx_responses(queue);
+                       continue;
+               }
+
                ret = xenvif_count_requests(queue, &txreq, txfrags, work_to_do);
                if (unlikely(ret < 0))
                        break;