[Qemu-devel] [PATCH COLO-Frame v15 31/38] net/filter: Add a 'status' property for filter object

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

With this property, users can control if this filter is 'enable'
or 'disable'. The default behavior for filter is enabled.

We will skip the disabled filter when delivering packets in net layer.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Yang Hongyang <hongyang.yang@easystack.cn>
---
v15:
- Rename qemu_need_skip_netfilter to qemu_netfilter_can_skip (Jason)
- Remove some useless comment (Jason)
---
 include/net/filter.h |  1 +
 net/filter.c         | 40 ++++++++++++++++++++++++++++++++++++++++
 qemu-options.hx      |  4 +++-
 3 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/include/net/filter.h b/include/net/filter.h
index 5639976..af3c53c 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 enabled;
     QTAILQ_ENTRY(NetFilterState) next;
 };
 
diff --git a/net/filter.c b/net/filter.c
index d2a514e..f114dfb 100644
--- a/net/filter.c
+++ b/net/filter.c
@@ -17,6 +17,11 @@
 #include "qom/object_interfaces.h"
 #include "qemu/iov.h"
 
+static inline bool qemu_can_skip_netfilter(NetFilterState *nf)
+{
+    return nf->enabled ? false : true;
+}
+
 ssize_t qemu_netfilter_receive(NetFilterState *nf,
                                NetFilterDirection direction,
                                NetClientState *sender,
@@ -25,6 +30,9 @@ ssize_t qemu_netfilter_receive(NetFilterState *nf,
                                int iovcnt,
                                NetPacketSent *sent_cb)
 {
+    if (qemu_can_skip_netfilter(nf)) {
+        return 0;
+    }
     if (nf->direction == direction ||
         nf->direction == NET_FILTER_DIRECTION_ALL) {
         return NETFILTER_GET_CLASS(OBJECT(nf))->receive_iov(
@@ -134,8 +142,37 @@ static void netfilter_set_direction(Object *obj, int direction, Error **errp)
     nf->direction = direction;
 }
 
+static char *netfilter_get_status(Object *obj, Error **errp)
+{
+    NetFilterState *nf = NETFILTER(obj);
+
+    if (nf->enabled) {
+        return g_strdup("enable");
+    } else {
+        return g_strdup("disable");
+    }
+}
+
+static void netfilter_set_status(Object *obj, const char *str, Error **errp)
+{
+    NetFilterState *nf = NETFILTER(obj);
+
+    if (!strcmp(str, "enable")) {
+        nf->enabled = true;
+    } else if (!strcmp(str, "disable")) {
+        nf->enabled = false;
+    } else {
+        error_setg(errp, "Invalid value for netfilter status, "
+                         "should be 'enable' or 'disable'");
+    }
+}
+
 static void netfilter_init(Object *obj)
 {
+    NetFilterState *nf = NETFILTER(obj);
+
+    nf->enabled = true;
+
     object_property_add_str(obj, "netdev",
                             netfilter_get_netdev_id, netfilter_set_netdev_id,
                             NULL);
@@ -143,6 +180,9 @@ static void netfilter_init(Object *obj)
                              NetFilterDirection_lookup,
                              netfilter_get_direction, netfilter_set_direction,
                              NULL);
+    object_property_add_str(obj, "status",
+                            netfilter_get_status, netfilter_set_status,
+                            NULL);
 }
 
 static void netfilter_complete(UserCreatable *uc, Error **errp)
diff --git a/qemu-options.hx b/qemu-options.hx
index 2f0465e..6f302e6 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -3742,11 +3742,13 @@ version by providing the @var{passwordid} parameter. This provides
 the ID of a previously created @code{secret} object containing the
 password for decryption.
 
-@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}]
+@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{enable|disable}]
 
 Interval @var{t} can't be 0, this filter batches the packet delivery: all
 packets arriving in a given interval on netdev @var{netdevid} are delayed
 until the end of the interval. Interval is in microseconds.
+@option{status} is optional that indicate whether the netfilter is enabled
+or disabled, the default status for netfilter will be enabled.
 
 queue @var{all|rx|tx} is an option that can be applied to any netfilter.
 
-- 
1.8.3.1