Re: [Qemu-devel] [PATCH] net/traffic-mirrorer:Add traffic-mirroer

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Yang Hongyang (hongyang.yang@easystack.cn) wrote:
> 
> 
> On 01/26/2016 04:59 PM, Zhang Chen wrote:
> >From: ZhangChen <zhangchen.fnst@cn.fujitsu.com>
> >
> >Traffic-mirrorer is a plugin of netfilter.
> 
> netfilter plugin
> 
> >It make qemu has ability to copy and mirror guest's
> 
> s/make/makes/    has the ability

Not quite.
  'It gives qemu the ability to...'

(Sorry, I can't explain why!).

> >net packet. we output packet to chardev.
> 
> there seems no 'mirrorer' in english, I think the plugin name
> 'traffic-mirror' is enough.

Agreed.

Dave

> 
> >
> >usage:
> >
> >-netdev tap,id=hn0
> >-chardev socket,id=mirrorer0,host=ip_primary,port=X,server,nowait
> >-traffic-mirrorer,id=m0,netdev=hn0,queue=tx,outdev=mirrorer0
> >
> >Signed-off-by: ZhangChen <zhangchen.fnst@cn.fujitsu.com>
> >Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
> 
> The code looks good overall, so:
> Reviewed-by: Yang Hongyang <hongyang.yang@easystack.cn>
> 
> >---
> >  net/Makefile.objs      |   1 +
> >  net/traffic-mirrorer.c | 173 +++++++++++++++++++++++++++++++++++++++++++++++++
> >  qemu-options.hx        |   5 ++
> >  vl.c                   |   3 +-
> >  4 files changed, 181 insertions(+), 1 deletion(-)
> >  create mode 100644 net/traffic-mirrorer.c
> >
> >diff --git a/net/Makefile.objs b/net/Makefile.objs
> >index 5fa2f97..6466764 100644
> >--- a/net/Makefile.objs
> >+++ b/net/Makefile.objs
> >@@ -15,3 +15,4 @@ common-obj-$(CONFIG_VDE) += vde.o
> >  common-obj-$(CONFIG_NETMAP) += netmap.o
> >  common-obj-y += filter.o
> >  common-obj-y += filter-buffer.o
> >+common-obj-y += traffic-mirrorer.o
> >diff --git a/net/traffic-mirrorer.c b/net/traffic-mirrorer.c
> >new file mode 100644
> >index 0000000..3b0da82
> >--- /dev/null
> >+++ b/net/traffic-mirrorer.c
> >@@ -0,0 +1,173 @@
> >+/*
> >+ * 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 "net/filter.h"
> >+#include "net/net.h"
> >+#include "qemu-common.h"
> >+#include "qapi/qmp/qerror.h"
> >+#include "qapi-visit.h"
> >+#include "qom/object.h"
> >+#include "qemu/main-loop.h"
> >+#include "qemu/error-report.h"
> >+#include "trace.h"
> >+#include "sysemu/char.h"
> >+#include "qemu/iov.h"
> >+
> >+#define FILTER_TRAFFIC_MIRRORER(obj) \
> >+    OBJECT_CHECK(MirrorerState, (obj), TYPE_FILTER_TRAFFIC_MIRRORER)
> >+
> >+#define TYPE_FILTER_TRAFFIC_MIRRORER "traffic-mirrorer"
> >+
> >+typedef struct MirrorerState {
> >+    NetFilterState parent_obj;
> >+    char *outdev;
> >+    CharDriverState *chr_out;
> >+
> >+} MirrorerState;
> >+
> >+static ssize_t traffic_mirrorer_send(NetFilterState *nf,
> >+                                         const struct iovec *iov,
> >+                                         int iovcnt)
> >+{
> >+    MirrorerState *s = FILTER_TRAFFIC_MIRRORER(nf);
> >+    ssize_t ret = 0;
> >+    ssize_t size = 0;
> >+    char *buf;
> >+
> >+    size = iov_size(iov, iovcnt);
> >+    if (!size) {
> >+        return 0;
> >+    }
> >+
> >+    buf = g_malloc0(size);
> >+    iov_to_buf(iov, iovcnt, 0, buf, size);
> >+    ret = qemu_chr_fe_write(s->chr_out, (uint8_t *)&size, sizeof(size));
> >+    if (ret < 0) {
> >+        g_free(buf);
> >+        return ret;
> >+    }
> >+
> >+    ret = qemu_chr_fe_write(s->chr_out, (uint8_t *)buf, size);
> >+    g_free(buf);
> >+    return ret;
> >+}
> >+
> >+static ssize_t traffic_mirrorer_receive_iov(NetFilterState *nf,
> >+                                         NetClientState *sender,
> >+                                         unsigned flags,
> >+                                         const struct iovec *iov,
> >+                                         int iovcnt,
> >+                                         NetPacketSent *sent_cb)
> >+{
> >+    /*
> >+     * We copy and mirror packet to outdev,
> >+     * then put back the packet.
> >+     */
> >+    ssize_t ret = 0;
> >+
> >+    ret = traffic_mirrorer_send(nf, iov, iovcnt);
> >+    if (ret < 0) {
> >+        error_report("traffic_mirrorer_send failed");
> >+    }
> >+
> >+    return 0;
> >+}
> >+
> >+static void traffic_mirrorer_cleanup(NetFilterState *nf)
> >+{
> >+    MirrorerState *s = FILTER_TRAFFIC_MIRRORER(nf);
> >+
> >+    if (s->chr_out) {
> >+        qemu_chr_fe_release(s->chr_out);
> >+    }
> >+}
> >+
> >+static void traffic_mirrorer_setup(NetFilterState *nf, Error **errp)
> >+{
> >+    MirrorerState *s = FILTER_TRAFFIC_MIRRORER(nf);
> >+
> >+    if (!s->outdev) {
> >+        error_setg(errp, "filter traffic mirrorer needs 'outdev' property set!"
> >+                "property set!");
> >+        return;
> >+    }
> >+
> >+    s->chr_out = qemu_chr_find(s->outdev);
> >+    if (s->chr_out == NULL) {
> >+        error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
> >+                  "Device '%s' not found", s->outdev);
> >+        return;
> >+    }
> >+
> >+    if (qemu_chr_fe_claim(s->chr_out) != 0) {
> >+        error_setg(errp, QERR_DEVICE_IN_USE, s->outdev);
> >+        return;
> >+    }
> >+}
> >+
> >+static void traffic_mirrorer_class_init(ObjectClass *oc, void *data)
> >+{
> >+    NetFilterClass *nfc = NETFILTER_CLASS(oc);
> >+
> >+    nfc->setup = traffic_mirrorer_setup;
> >+    nfc->cleanup = traffic_mirrorer_cleanup;
> >+    nfc->receive_iov = traffic_mirrorer_receive_iov;
> >+}
> >+
> >+static char *traffic_mirrorer_get_outdev(Object *obj, Error **errp)
> >+{
> >+    MirrorerState *s = FILTER_TRAFFIC_MIRRORER(obj);
> >+
> >+    return g_strdup(s->outdev);
> >+}
> >+
> >+static void
> >+traffic_mirrorer_set_outdev(Object *obj, const char *value, Error **errp)
> >+{
> >+    MirrorerState *s = FILTER_TRAFFIC_MIRRORER(obj);
> >+
> >+    g_free(s->outdev);
> >+    s->outdev = g_strdup(value);
> >+    if (!s->outdev) {
> >+        error_setg(errp, "filter traffic mirrorer needs 'outdev' "
> >+                "property set!");
> >+        return;
> >+    }
> >+}
> >+
> >+static void traffic_mirrorer_init(Object *obj)
> >+{
> >+    object_property_add_str(obj, "outdev", traffic_mirrorer_get_outdev,
> >+                            traffic_mirrorer_set_outdev, NULL);
> >+}
> >+
> >+static void traffic_mirrorer_fini(Object *obj)
> >+{
> >+    MirrorerState *s = FILTER_TRAFFIC_MIRRORER(obj);
> >+
> >+    g_free(s->outdev);
> >+}
> >+
> >+static const TypeInfo traffic_mirrorer_info = {
> >+    .name = TYPE_FILTER_TRAFFIC_MIRRORER,
> >+    .parent = TYPE_NETFILTER,
> >+    .class_init = traffic_mirrorer_class_init,
> >+    .instance_init = traffic_mirrorer_init,
> >+    .instance_finalize = traffic_mirrorer_fini,
> >+    .instance_size = sizeof(MirrorerState),
> >+};
> >+
> >+static void register_types(void)
> >+{
> >+    type_register_static(&traffic_mirrorer_info);
> >+}
> >+
> >+type_init(register_types);
> >diff --git a/qemu-options.hx b/qemu-options.hx
> >index 0eea4ee..ecfa297 100644
> >--- a/qemu-options.hx
> >+++ b/qemu-options.hx
> >@@ -3670,6 +3670,11 @@ queue @var{all|rx|tx} is an option that can be applied to any netfilter.
> >  @option{tx}: the filter is attached to the transmit queue of the netdev,
> >               where it will receive packets sent by the netdev.
> >
> >+@item -object traffic-mirrorer,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid}[,queue=@var{all|rx|tx}]
> >+
> >+traffic-mirrorer on netdev @var{netdevid},mirror net packet to outdev.
> >+queue @var{all|rx|tx} is an option that can be applied to traffic-mirrorer.
> >+
> >  @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 8dc34ce..4fe01bc 100644
> >--- a/vl.c
> >+++ b/vl.c
> >@@ -2838,7 +2838,8 @@ static bool object_create_initial(const char *type)
> >       * they depend on netdevs already existing
> >       */
> >      if (g_str_equal(type, "filter-buffer") ||
> >-        g_str_equal(type, "filter-dump")) {
> >+        g_str_equal(type, "filter-dump") ||
> >+        g_str_equal(type, "traffic-mirrorer")) {
> >          return false;
> >      }
> >
> >
> 
> -- 
> Thanks,
> Yang
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK