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

[Zhang Chen <zhangchen.fnst@cn.fujitsu.com>]

Filter-rewriter is a part of COLO project.
It will rewrite some of secondary packet to make
secondary guest's connection established successfully.

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.fnst@cn.fujitsu.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
---
 net/Makefile.objs     |   1 +
 net/filter-rewriter.c | 112 ++++++++++++++++++++++++++++++++++++++++++++++++++
 qemu-options.hx       |  10 +++++
 vl.c                  |   3 +-
 4 files changed, 125 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..08b015d
--- /dev/null
+++ b/net/filter-rewriter.c
@@ -0,0 +1,112 @@
+/*
+ * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
+ * Copyright (c) 2016 FUJITSU LIMITED
+ * Copyright (c) 2016 Intel Corporation
+ *
+ * Author: Zhang Chen <zhangchen.fnst@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;
+    NetQueue *incoming_queue;
+    /* to protect conn_list */
+    QemuMutex conn_list_lock;
+    /* hashtable to save connection */
+    GHashTable *connection_track_table;
+    /* to save unprocessed_connections */
+    GQueue unprocessed_connections;
+    /* 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);
+
+    qemu_mutex_destroy(&s->conn_list_lock);
+    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);
+    qemu_mutex_init(&s->conn_list_lock);
+    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..d7ab165 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -3859,6 +3859,16 @@ 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 some of secondary packet.
+
+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;
     }
 
-- 
2.7.4