[Qemu-devel] [PATCH RFC v2 3/5] net/filter: Introduce a helper to add a filter to the netdev

[zhanghailiang <zhang.zhanghailiang@huawei.com>]

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.zhanghailiang@huawei.com>
---
v2:
 -Re-implement netdev_add_filter() by re-using object_create()
  (Jason's suggestion)
---
 include/net/filter.h |  7 +++++
 net/filter.c         | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 87 insertions(+)

diff --git a/include/net/filter.h b/include/net/filter.h
index af3c53c..ee1c024 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;
     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 *id,
+                       bool is_default,
+                       Error **errp);
+
 #endif /* QEMU_NET_FILTER_H */
diff --git a/net/filter.c b/net/filter.c
index d08a2be..dc7aa9b 100644
--- a/net/filter.c
+++ b/net/filter.c
@@ -214,6 +214,86 @@ static void netfilter_complete(UserCreatable *uc, Error **errp)
     QTAILQ_INSERT_TAIL(&nf->netdev->filters, nf, next);
 }
 
+QemuOptsList qemu_filter_opts = {
+    .name = "default-filter",
+    .head = QTAILQ_HEAD_INITIALIZER(qemu_filter_opts.head),
+    .desc = {
+        {
+            .name = "qom-type",
+            .type = QEMU_OPT_STRING,
+        },{
+            .name = "id",
+            .type = QEMU_OPT_STRING,
+        },{
+            .name = "netdev",
+            .type = QEMU_OPT_STRING,
+        },{
+            .name = "status",
+            .type = QEMU_OPT_STRING,
+        },
+        { /* end of list */ }
+    },
+};
+
+static void filter_set_default_flag(const char *id,
+                                    bool is_default,
+                                    Error **errp)
+{
+    Object *obj, *container;
+    NetFilterState *nf;
+
+    container = object_get_objects_root();
+    obj = object_resolve_path_component(container, id);
+    if (!obj) {
+        error_setg(errp, "object id not found");
+        return;
+    }
+    nf = NETFILTER(obj);
+    nf->is_default = is_default;
+}
+
+void netdev_add_filter(const char *netdev_id,
+                       const char *filter_type,
+                       const char *id,
+                       bool is_default,
+                       Error **errp)
+{
+    NetClientState *nc = qemu_find_netdev(netdev_id);
+    char *optarg;
+    QemuOpts *opts = NULL;
+    Error *err = NULL;
+
+    /* FIXME: Not support multiple queues */
+    if (!nc || nc->queue_index > 1) {
+        return;
+    }
+    /* Not support vhost-net */
+    if (get_vhost_net(nc)) {
+        return;
+    }
+
+    optarg = g_strdup_printf("qom-type=%s,id=%s,netdev=%s,status=%s",
+            filter_type, id, netdev_id, is_default ? "disable" : "enable");
+    opts = qemu_opts_parse_noisily(&qemu_filter_opts,
+                                   optarg, false);
+    if (!opts) {
+        error_report("Failed to parse param '%s'", optarg);
+        exit(1);
+    }
+    g_free(optarg);
+    if (object_create(NULL, opts, &err) < 0) {
+        error_report("Failed to create object");
+        goto out_clean;
+    }
+    filter_set_default_flag(id, is_default, &err);
+
+out_clean:
+    qemu_opts_del(opts);
+    if (err) {
+        error_propagate(errp, err);
+    }
+}
+
 static void netfilter_finalize(Object *obj)
 {
     NetFilterState *nf = NETFILTER(obj);
-- 
1.8.3.1