[PATCH 5/7] qemu:virtio-net: Enable filtering based on MAC, promisc, broadcast and allmulti

Alex Williamson
2009-01-20T21:31:08Z

Make use of the new RX_MODE control virtqueue class by dropping
packets the guest doesn't want to see.

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

Updated to look past vnet_hdr where necessary.

qemu/hw/virtio-net.c | 28 ++++++++++++++++++++++++++++
1 files changed, 28 insertions(+), 0 deletions(-)

diff --git a/qemu/hw/virtio-net.c b/qemu/hw/virtio-net.c
index d34c299..18877b4 100644
--- a/qemu/hw/virtio-net.c
+++ b/qemu/hw/virtio-net.c
@@ -293,6 +293,31 @@ static int receive_header(VirtIONet *n, struct iovec *iov, int iovcnt,
return offset;
}

+static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
+{
+ static uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
+ uint8_t *ptr = (uint8_t *)buf;
+
+#ifdef TAP_VNET_HDR
+ if (tap_has_vnet_hdr(n->vc->vlan->first_client))
+ ptr += sizeof(struct virtio_net_hdr);
+#endif
+
+ if (n->promisc)
+ return 1;
+
+ if ((ptr[0] & 1) && n->allmulti)
+ return 1;
+
+ if (!memcmp(ptr, bcast, sizeof(bcast)))
+ return 1;
+
+ if (!memcmp(ptr, n->mac, ETH_ALEN))
+ return 1;
+
+ return 0;
+}
+
static void virtio_net_receive(void *opaque, const uint8_t *buf, int size)
{
VirtIONet *n = opaque;
@@ -302,6 +327,9 @@ static void virtio_net_receive(void *opaque, const uint8_t *buf, int size)
if (!do_virtio_net_can_receive(n, size))
return;

+ if (!receive_filter(n, buf, size))
+ return;
+
/* hdr_len refers to the header we supply to the guest */
hdr_len = n->mergeable_rx_bufs ?
sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr);