Re: [Qemu-devel] [RFC PATCH V3 1/3] filter-rewriter: introduce filter-rewriter initialization

[Zhang Chen]

On 07/27/2016 03:02 PM, Jason Wang wrote:


On 2016年07月05日 18:29, Zhang Chen wrote:
Filter-rewriter is a part of COLO project.
It will rewrite some of secondary packet to make
secondary guest's tcp connection established successfully.
In this module we will rewrite tcp packet's ack to the secondary
from primary,and rewrite tcp packet's seq to the primary from
secondary.

usage:

colo secondary:
-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
-object filter-rewriter,id=rew0,netdev=hn0,queue=all

Signed-off-by: Zhang Chen <zhangchen.f...@cn.fujitsu.com>
Signed-off-by: Li Zhijian <lizhij...@cn.fujitsu.com>
Signed-off-by: Wen Congyang <we...@cn.fujitsu.com>
---
  net/Makefile.objs     |   1 +
  net/filter-rewriter.c | 108 
++++++++++++++++++++++++++++++++++++++++++++++++++
  qemu-options.hx       |  13 ++++++
  vl.c                  |   3 +-
  4 files changed, 124 insertions(+), 1 deletion(-)
  create mode 100644 net/filter-rewriter.c

diff --git a/net/Makefile.objs b/net/Makefile.objs
index 119589f..645bd10 100644
--- a/net/Makefile.objs
+++ b/net/Makefile.objs
@@ -18,3 +18,4 @@ common-obj-y += filter-buffer.o
  common-obj-y += filter-mirror.o
  common-obj-y += colo-compare.o
  common-obj-y += colo-base.o
+common-obj-y += filter-rewriter.o
diff --git a/net/filter-rewriter.c b/net/filter-rewriter.c
new file mode 100644
index 0000000..c4f2739
--- /dev/null
+++ b/net/filter-rewriter.c
@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
+ * Copyright (c) 2016 FUJITSU LIMITED
+ * Copyright (c) 2016 Intel Corporation
+ *
+ * Author: Zhang Chen <zhangchen.f...@cn.fujitsu.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * later.  See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "net/colo-base.h"
+#include "net/filter.h"
+#include "net/net.h"
+#include "qemu-common.h"
+#include "qapi/error.h"
+#include "qapi/qmp/qerror.h"
+#include "qapi-visit.h"
+#include "qom/object.h"
+#include "qemu/main-loop.h"
+#include "qemu/iov.h"
+#include "net/checksum.h"
+
+#define FILTER_COLO_REWRITER(obj) \
+    OBJECT_CHECK(RewriterState, (obj), TYPE_FILTER_REWRITER)
+
+#define TYPE_FILTER_REWRITER "filter-rewriter"
+
+enum {
+    PRIMARY = 0,
+    SECONDARY,
+};
+
+typedef struct RewriterState {
+    NetFilterState parent_obj;
+    /* connection list: the connections belonged to this NIC could 
be found
+     * in this list.
+     * element type: Connection
+     */
+    GQueue conn_list;

The connection were either in conntection_track_table or 
unprocessed_connections, why still need this list?

I will remove it in next version,filter-rewriter needn't flush packet 
before checkpoint.


+    NetQueue *incoming_queue;
+    /* hashtable to save connection */
+    GHashTable *connection_track_table;
+    /* to save unprocessed_connections */
+    GQueue unprocessed_connections;

Unused in this series.

Yes,I will remove it.

Thanks
Zhang Chen


+    /* current hash size */
+    uint32_t hashtable_size;
+} RewriterState;
+
+static ssize_t colo_rewriter_receive_iov(NetFilterState *nf,
+                                         NetClientState *sender,
+                                         unsigned flags,
+                                         const struct iovec *iov,
+                                         int iovcnt,
+                                         NetPacketSent *sent_cb)
+{
+    /*
+     * if we get tcp packet
+     * we will rewrite it to make secondary guest's
+     * connection established successfully
+     */
+    return 0;
+}
+
+static void colo_rewriter_cleanup(NetFilterState *nf)
+{
+    RewriterState *s = FILTER_COLO_REWRITER(nf);
+
+    g_queue_free(&s->conn_list);
+}
+
+static void colo_rewriter_setup(NetFilterState *nf, Error **errp)
+{
+    RewriterState *s = FILTER_COLO_REWRITER(nf);
+
+    g_queue_init(&s->conn_list);
+    s->hashtable_size = 0;
+
+    s->connection_track_table = 
g_hash_table_new_full(connection_key_hash,
+ connection_key_equal,
+                                                      g_free,
+ connection_destroy);
+    s->incoming_queue = 
qemu_new_net_queue(qemu_netfilter_pass_to_next, nf);
+}
+
+static void colo_rewriter_class_init(ObjectClass *oc, void *data)
+{
+    NetFilterClass *nfc = NETFILTER_CLASS(oc);
+
+    nfc->setup = colo_rewriter_setup;
+    nfc->cleanup = colo_rewriter_cleanup;
+    nfc->receive_iov = colo_rewriter_receive_iov;
+}
+
+static const TypeInfo colo_rewriter_info = {
+    .name = TYPE_FILTER_REWRITER,
+    .parent = TYPE_NETFILTER,
+    .class_init = colo_rewriter_class_init,
+    .instance_size = sizeof(RewriterState),
+};
+
+static void register_types(void)
+{
+    type_register_static(&colo_rewriter_info);
+}
+
+type_init(register_types);
diff --git a/qemu-options.hx b/qemu-options.hx
index 14bade5..4afd511 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -3859,6 +3859,19 @@ Create a filter-redirector we need to differ 
outdev id from indev id, id can not
  be the same. we can just use indev or outdev, but at least one of 
indev or outdev
  need to be specified.
  +@item -object 
filter-rewriter,id=@var{id},netdev=@var{netdevid},rewriter-mode=@var{mode}[,queue=@var{all|rx|tx}]
+
+Filter-rewriter is a part of COLO project.It will rewrite tcp packet to
+secondary from primary to keep secondary tcp connection,and rewrite
+tcp packet to primary from secondary make tcp packet can be handled by
+client.
+
+usage:
+colo secondary:
+-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
+-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
+-object filter-rewriter,id=rew0,netdev=hn0,queue=all
+
  @item -object 
filter-dump,id=@var{id},netdev=@var{dev},file=@var{filename}][,maxlen=@var{len}]
    Dump the network traffic on netdev @var{dev} to the file 
specified by
diff --git a/vl.c b/vl.c
index c6b9a6f..b47be6a 100644
--- a/vl.c
+++ b/vl.c
@@ -2866,7 +2866,8 @@ static bool object_create_initial(const char 
*type)
          g_str_equal(type, "filter-dump") ||
          g_str_equal(type, "filter-mirror") ||
          g_str_equal(type, "filter-redirector") ||
-        g_str_equal(type, "colo-compare")) {
+        g_str_equal(type, "colo-compare") ||
+        g_str_equal(type, "filter-rewriter")) {
          return false;
      }



.


--
Thanks
zhangchen