[PATCH 4/4] virtio_net: Add a MAC filter table

[Alex Williamson <alex.williamson@hp.com>]

Number of entries configurable via module param.

Signed-off-by: Alex Williamson <alex.williamson@hp.com
---

 drivers/net/virtio_net.c   |   71 +++++++++++++++++++++++++++++++++++++++++++-
 include/linux/virtio_net.h |    4 ++
 2 files changed, 73 insertions(+), 2 deletions(-)


diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index b18dd4c..1f021c4 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -32,6 +32,11 @@ static int csum = 1, gso = 1;
 module_param(csum, bool, 0444);
 module_param(gso, bool, 0444);
 
+static unsigned int mac_entries = 16;
+module_param(mac_entries, uint, 0444);
+MODULE_PARM_DESC(mac_entries,
+	"Number of entries in the MAC filter table.");
+
 /* FIXME: MTU in config. */
 #define MAX_PACKET_LEN (ETH_HLEN+ETH_DATA_LEN)
 #define GOOD_COPY_LEN	128
@@ -669,9 +674,61 @@ static void virtnet_set_rx_mode(struct net_device *dev)
 	struct virtnet_info *vi = netdev_priv(dev);
 	u8 promisc, allmulti;
 
-	promisc = ((dev->flags & IFF_PROMISC) != 0 || dev->uc_count > 0);
-	allmulti = ((dev->flags & IFF_ALLMULTI) != 0 || dev->mc_count > 0);
+	promisc = ((dev->flags & IFF_PROMISC) != 0);
+	allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
+
+	if (dev->uc_count > mac_entries) {
+		promisc = 1;
+		if (dev->mc_count > mac_entries)
+			allmulti = 1;
+	} else if (dev->uc_count + dev->mc_count > mac_entries)
+		allmulti = 1;
+
+	if (!promisc && (dev->uc_count || (dev->mc_count && !allmulti))) {
+		u8 *buf, *cur;
+		int count, i;
+		struct dev_addr_list *uc_ptr, *mc_ptr;
+
+		count = dev->uc_count + (allmulti ? 0 : dev->mc_count);
 
+		buf = kzalloc(count * ETH_ALEN, GFP_ATOMIC);
+		if (!buf) {
+			promisc = 1;
+			goto set_status;
+		}
+
+		cur = buf;
+		uc_ptr = dev->uc_list;
+		mc_ptr = dev->mc_list;
+
+		for (i = 0; i < dev->uc_count; i++) {
+			memcpy(cur, uc_ptr->da_addr, ETH_ALEN);
+			cur += ETH_ALEN;
+			uc_ptr = uc_ptr->next;
+		}
+		if (!allmulti) {
+			for (i = 0; i < dev->mc_count; i++) {
+				memcpy(cur, mc_ptr->da_addr, ETH_ALEN);
+				cur += ETH_ALEN;
+				mc_ptr = mc_ptr->next;
+			}
+		}
+		if (virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC_TABLE,
+					 VIRTIO_NET_CTRL_MAC_TABLE_SET,
+					 buf, count * ETH_ALEN)) {
+			printk(KERN_WARNING "%s: failed to program MAC filter "
+			       "table, running in promiscuous mode.\n",
+			       dev->name);
+			promisc = 1;
+		}
+		kfree(buf);
+	} else {
+		/* Set an empty MAC table - disabled */
+		virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC_TABLE,
+				     VIRTIO_NET_CTRL_MAC_TABLE_SET, NULL, 0);
+	}
+
+set_status:
 	virtnet_send_command(vi, VIRTIO_NET_CTRL_RX_MODE,
 			     VIRTIO_NET_CTRL_RX_MODE_PROMISC,
 			     &promisc, sizeof(promisc));
@@ -799,6 +856,16 @@ static int virtnet_probe(struct virtio_device *vdev)
 	vi->cvq = vdev->config->find_vq(vdev, 2, NULL);
 	if (IS_ERR(vi->cvq))
 		vi->cvq = NULL;
+	else {
+		unsigned int entries;
+
+		entries = mac_entries = min(mac_entries,
+					(unsigned int)(PAGE_SIZE / ETH_ALEN));
+		if (virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC_TABLE,
+					 VIRTIO_NET_CTRL_MAC_TABLE_ALLOC,
+					 &entries, sizeof(entries)))
+			mac_entries = 0;
+	}
 
 	/* Initialize our empty receive and send queues. */
 	skb_queue_head_init(&vi->recv);
diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
index 80cd7d3..31235a0 100644
--- a/include/linux/virtio_net.h
+++ b/include/linux/virtio_net.h
@@ -60,4 +60,8 @@ struct virtio_net_hdr_mrg_rxbuf {
  #define VIRTIO_NET_CTRL_RX_MODE_PROMISC      0
  #define VIRTIO_NET_CTRL_RX_MODE_ALLMULTI     1
 
+#define VIRTIO_NET_CTRL_MAC_TABLE  1
+ #define VIRTIO_NET_CTRL_MAC_TABLE_ALLOC      0
+ #define VIRTIO_NET_CTRL_MAC_TABLE_SET        1
+
 #endif /* _LINUX_VIRTIO_NET_H */