virtio-net: add vlan receive state to RxFilterInfo

Stefan Fritsch just fixed a virtio-net driver bug [1], virtio-net won't
filter out VLAN-tagged packets if VIRTIO_NET_F_CTRL_VLAN isn't negotiated.

This patch added a new field to @RxFilterInfo to indicate vlan receive
state ('normal', 'none', 'all'). If VIRTIO_NET_F_CTRL_VLAN isn't
negotiated, vlan receive state will be 'all', then all VLAN-tagged packets
will be received by guest.

This patch also fixed a boundary issue in visiting vlan table.

[1] http://lists.nongnu.org/archive/html/qemu-devel/2014-02/msg02604.htmlSigned-off-by: NAmos Kong <akong@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

hw/net/virtio-net.c

@@ -222,13 +222,33 @@ static char *mac_strdup_printf(const uint8_t *mac)
                             mac[1], mac[2], mac[3], mac[4], mac[5]);
 }
 
+static intList *get_vlan_table(VirtIONet *n)
+{
+    intList *list, *entry;
+    int i, j;
+
+    list = NULL;
+    for (i = 0; i < MAX_VLAN >> 5; i++) {
+        for (j = 0; n->vlans[i] && j <= 0x1f; j++) {
+            if (n->vlans[i] & (1U << j)) {
+                entry = g_malloc0(sizeof(*entry));
+                entry->value = (i << 5) + j;
+                entry->next = list;
+                list = entry;
+            }
+        }
+    }
+
+    return list;
+}
+
 static RxFilterInfo *virtio_net_query_rxfilter(NetClientState *nc)
 {
     VirtIONet *n = qemu_get_nic_opaque(nc);
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
     RxFilterInfo *info;
     strList *str_list, *entry;
-    intList *int_list, *int_entry;
-    int i, j;
+    int i;
 
     info = g_malloc0(sizeof(*info));
     info->name = g_strdup(nc->name);
@@ -273,19 +293,15 @@ static RxFilterInfo *virtio_net_query_rxfilter(NetClientState *nc)
         str_list = entry;
     }
     info->multicast_table = str_list;
+    info->vlan_table = get_vlan_table(n);
 
-    int_list = NULL;
-    for (i = 0; i < MAX_VLAN >> 5; i++) {
-        for (j = 0; n->vlans[i] && j < 0x1f; j++) {
-            if (n->vlans[i] & (1U << j)) {
-                int_entry = g_malloc0(sizeof(*int_entry));
-                int_entry->value = (i << 5) + j;
-                int_entry->next = int_list;
-                int_list = int_entry;
-            }
-        }
+    if (!((1 << VIRTIO_NET_F_CTRL_VLAN) & vdev->guest_features)) {
+        info->vlan = RX_STATE_ALL;
+    } else if (!info->vlan_table) {
+        info->vlan = RX_STATE_NONE;
+    } else {
+        info->vlan = RX_STATE_NORMAL;
     }
-    info->vlan_table = int_list;
 
     /* enable event notification after query */
     nc->rxfilter_notify_enabled = 1;

qapi-schema.json

@@ -4184,6 +4184,8 @@
 #
 # @unicast: unicast receive state
 #
+# @vlan: vlan receive state (Since 2.0)
+#
 # @broadcast-allowed: whether to receive broadcast
 #
 # @multicast-overflow: multicast table is overflowed or not
@@ -4207,6 +4209,7 @@
     'promiscuous':        'bool',
     'multicast':          'RxState',
     'unicast':            'RxState',
+    'vlan':               'RxState',
     'broadcast-allowed':  'bool',
     'multicast-overflow': 'bool',
     'unicast-overflow':   'bool',

qmp-commands.hx

@@ -3407,6 +3407,7 @@ Each array entry contains the following:
 - "promiscuous": promiscuous mode is enabled (json-bool)
 - "multicast": multicast receive state (one of 'normal', 'none', 'all')
 - "unicast": unicast receive state  (one of 'normal', 'none', 'all')
+- "vlan": vlan receive state (one of 'normal', 'none', 'all') (Since 2.0)
 - "broadcast-allowed": allow to receive broadcast (json-bool)
 - "multicast-overflow": multicast table is overflowed (json-bool)
 - "unicast-overflow": unicast table is overflowed (json-bool)
@@ -3424,6 +3425,7 @@ Example:
             "name": "vnet0",
             "main-mac": "52:54:00:12:34:56",
             "unicast": "normal",
+            "vlan": "normal",
             "vlan-table": [
                 4,
                 0