diff mbox

[RFC,3/4] virtio-net: Limit the num of uni/multicast mac addresses

Message ID 20100927125109.12060.19145.stgit@dhcp-91-7.nay.redhat.com.englab.nay.redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Jason Wang Sept. 27, 2010, 12:51 p.m. UTC
None
diff mbox

Patch

diff --git a/hw/virtio-net.c b/hw/virtio-net.c
index 0a9cae2..79afb65 100644
--- a/hw/virtio-net.c
+++ b/hw/virtio-net.c
@@ -291,7 +291,9 @@  static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
                mac_data.entries * ETH_ALEN);
         n->mac_table.in_use += mac_data.entries;
     } else {
-        n->mac_table.uni_overflow = 1;
+        /* Gratuitous packet could not be built properly in overflow mode, so we
+         * never allow uni_overflow here. */
+        return VIRTIO_NET_ERR;
     }
 
     n->mac_table.first_multi = n->mac_table.in_use;
@@ -309,7 +311,9 @@  static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
                    mac_data.entries * ETH_ALEN);
             n->mac_table.in_use += mac_data.entries;
         } else {
-            n->mac_table.multi_overflow = 1;
+            /* Gratuitous packet could not be built properly in overflow mode,
+             * so we never allow multi_overflow here. */
+            return VIRTIO_NET_ERR;
         }
     }
 
@@ -844,9 +848,8 @@  static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
             qemu_get_buffer(f, n->mac_table.macs,
                             n->mac_table.in_use * ETH_ALEN);
         } else if (n->mac_table.in_use) {
-            qemu_fseek(f, n->mac_table.in_use * ETH_ALEN, SEEK_CUR);
-            n->mac_table.multi_overflow = n->mac_table.uni_overflow = 1;
-            n->mac_table.in_use = 0;
+            error_report("virtio-net: Overflow was not permitted.");
+            return -EINVAL;
         }
     }
  
@@ -873,6 +876,10 @@  static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
     if (version_id >= 9) {
         n->mac_table.multi_overflow = qemu_get_byte(f);
         n->mac_table.uni_overflow = qemu_get_byte(f);
+        if (n->mac_table.multi_overflow || n->mac_table.uni_overflow) {
+            error_report("virtio-net: Overflow was not permitted");
+            return -EINVAL;
+        }
     }
 
     if (version_id >= 10) {