Re: [Qemu-devel] [PATCH v3 2/4] net/filter: Introduce a helper to add a filter to the netdev

[Hailiang Zhang]

On 2016/2/2 11:14, Yang Hongyang wrote:

On 02/01/2016 08:01 PM, zhanghailiang wrote:

We add a new helper function netdev_add_filter(), this function
can help adding a filter object to a netdev.
Besides, we add a is_default member for struct NetFilterState
to indicate whether the filter is default or not.

Signed-off-by: zhanghailiang <zhang.zhanghaili...@huawei.com>
---
v3:
  - Use object_new_with_props() instead of object_create()
   (Daniel's suggestion)
v2:
  - Re-implement netdev_add_filter() by re-using object_create()
   (Jason's suggestion)
---
  include/net/filter.h |  7 +++++++
  net/filter.c         | 34 ++++++++++++++++++++++++++++++++++
  2 files changed, 41 insertions(+)

diff --git a/include/net/filter.h b/include/net/filter.h
index af3c53c..661abef 100644
--- a/include/net/filter.h
+++ b/include/net/filter.h
@@ -55,6 +55,7 @@ struct NetFilterState {
      char *netdev_id;
      NetClientState *netdev;
      NetFilterDirection direction;
+    bool is_default;

You added a member, but seems did not initialize it. although the
default behavior of a struct init is 0, a explicit is_defuault=false
is better IMO.

OK, i will fix it in next version.

      bool enabled;
      QTAILQ_ENTRY(NetFilterState) next;
  };
@@ -74,4 +75,10 @@ ssize_t qemu_netfilter_pass_to_next(NetClientState *sender,
                                      int iovcnt,
                                      void *opaque);

+void netdev_add_filter(const char *netdev_id,
+                       const char *filter_type,
+                       const char *filter_id,
+                       bool is_default,
+                       Error **errp);
+
  #endif /* QEMU_NET_FILTER_H */
diff --git a/net/filter.c b/net/filter.c
index d08a2be..7f9df57 100644
--- a/net/filter.c
+++ b/net/filter.c
@@ -214,6 +214,40 @@ static void netfilter_complete(UserCreatable *uc, Error 
**errp)
      QTAILQ_INSERT_TAIL(&nf->netdev->filters, nf, next);
  }

+void netdev_add_filter(const char *netdev_id,
+                       const char *filter_type,
+                       const char *filter_id,
+                       bool is_default,
+                       Error **errp)

We could assume all calls to this API is adding default filter.
so is_default is useness.

Make sense, i will rename this API to netdev_add_default_filter()
and drop the is_default parameter.

Thanks,
Hailiang

+{
+    NetClientState *nc = qemu_find_netdev(netdev_id);
+    Object *filter;
+    NetFilterState *nf;
+    Error *local_err = NULL;
+
+    /* FIXME: Not support multiple queues */
+    if (!nc || nc->queue_index > 1) {
+        return;
+    }
+    /* Not support vhost-net */
+    if (get_vhost_net(nc)) {
+        return;
+    }
+    filter = object_new_with_props(filter_type,
+                        object_get_objects_root(),
+                        filter_id,
+                        &local_err,
+                        "netdev", netdev_id,
+                        "status", is_default ? "disable" : "enable",
+                        NULL);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+    nf = NETFILTER(filter);
+    nf->is_default = is_default;
+}
+
  static void netfilter_finalize(Object *obj)
  {
      NetFilterState *nf = NETFILTER(obj);