Re: [Qemu-devel] [PATCH V2] net/traffic-mirror:Add traffic-mirror

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

On 2016/1/27 10:40, Zhang Chen wrote:
> From: ZhangChen <zhangchen.fnst@cn.fujitsu.com>
>
> Traffic-mirror is a netfilter plugin.
> It gives qemu the ability to copy and mirror guest's
> net packet. we output packet to chardev.
>
> usage:
>
> -netdev tap,id=hn0
> -chardev socket,id=mirror0,host=ip_primary,port=X,server,nowait
> -traffic-mirror,id=m0,netdev=hn0,queue=tx/rx/all,outdev=mirror0
>
> Signed-off-by: ZhangChen <zhangchen.fnst@cn.fujitsu.com>
> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
> Reviewed-by: Yang Hongyang <hongyang.yang@easystack.cn>
> ---
>   net/Makefile.objs    |   1 +
>   net/traffic-mirror.c | 173 +++++++++++++++++++++++++++++++++++++++++++++++++++
>   qemu-options.hx      |   5 ++
>   vl.c                 |   3 +-
>   4 files changed, 181 insertions(+), 1 deletion(-)
>   create mode 100644 net/traffic-mirror.c
>
> diff --git a/net/Makefile.objs b/net/Makefile.objs
> index 5fa2f97..de06ebe 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-mirror.o
> diff --git a/net/traffic-mirror.c b/net/traffic-mirror.c
> new file mode 100644
> index 0000000..bed915c
> --- /dev/null
> +++ b/net/traffic-mirror.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_MIRROR(obj) \
> +    OBJECT_CHECK(MirrorState, (obj), TYPE_FILTER_TRAFFIC_MIRROR)
> +
> +#define TYPE_FILTER_TRAFFIC_MIRROR "traffic-mirror"
> +
> +typedef struct MirrorState {
> +    NetFilterState parent_obj;
> +    char *outdev;
> +    CharDriverState *chr_out;
> +

Redundant space here. (Maybe it is no need
for another version if there is no other problem ;) ).
Other seems to be OK.

Reviewed-by: zhanghailiang <zhang.zhanghailiang@huawei.com>

> +} MirrorState;
> +




> +static ssize_t traffic_mirror_send(NetFilterState *nf,
> +                                   const struct iovec *iov,
> +                                   int iovcnt)
> +{
> +    MirrorState *s = FILTER_TRAFFIC_MIRROR(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_mirror_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_mirror_send(nf, iov, iovcnt);
> +    if (ret < 0) {
> +        error_report("traffic_mirror_send failed");
> +    }
> +
> +    return 0;
> +}
> +
> +static void traffic_mirror_cleanup(NetFilterState *nf)
> +{
> +    MirrorState *s = FILTER_TRAFFIC_MIRROR(nf);
> +
> +    if (s->chr_out) {
> +        qemu_chr_fe_release(s->chr_out);
> +    }
> +}
> +
> +static void traffic_mirror_setup(NetFilterState *nf, Error **errp)
> +{
> +    MirrorState *s = FILTER_TRAFFIC_MIRROR(nf);
> +
> +    if (!s->outdev) {
> +        error_setg(errp, "filter traffic mirror needs 'outdev' "
> +                "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_mirror_class_init(ObjectClass *oc, void *data)
> +{
> +    NetFilterClass *nfc = NETFILTER_CLASS(oc);
> +
> +    nfc->setup = traffic_mirror_setup;
> +    nfc->cleanup = traffic_mirror_cleanup;
> +    nfc->receive_iov = traffic_mirror_receive_iov;
> +}
> +
> +static char *traffic_mirror_get_outdev(Object *obj, Error **errp)
> +{
> +    MirrorState *s = FILTER_TRAFFIC_MIRROR(obj);
> +
> +    return g_strdup(s->outdev);
> +}
> +
> +static void
> +traffic_mirror_set_outdev(Object *obj, const char *value, Error **errp)
> +{
> +    MirrorState *s = FILTER_TRAFFIC_MIRROR(obj);
> +
> +    g_free(s->outdev);
> +    s->outdev = g_strdup(value);
> +    if (!s->outdev) {
> +        error_setg(errp, "filter traffic mirror needs 'outdev' "
> +                "property set!");
> +        return;
> +    }
> +}
> +
> +static void traffic_mirror_init(Object *obj)
> +{
> +    object_property_add_str(obj, "outdev", traffic_mirror_get_outdev,
> +                            traffic_mirror_set_outdev, NULL);
> +}
> +
> +static void traffic_mirror_fini(Object *obj)
> +{
> +    MirrorState *s = FILTER_TRAFFIC_MIRROR(obj);
> +
> +    g_free(s->outdev);
> +}
> +
> +static const TypeInfo traffic_mirror_info = {
> +    .name = TYPE_FILTER_TRAFFIC_MIRROR,
> +    .parent = TYPE_NETFILTER,
> +    .class_init = traffic_mirror_class_init,
> +    .instance_init = traffic_mirror_init,
> +    .instance_finalize = traffic_mirror_fini,
> +    .instance_size = sizeof(MirrorState),
> +};
> +
> +static void register_types(void)
> +{
> +    type_register_static(&traffic_mirror_info);
> +}
> +
> +type_init(register_types);
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 0eea4ee..6fd2d46 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-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid}[,queue=@var{all|rx|tx}]
> +
> +traffic-mirror on netdev @var{netdevid},mirror net packet to outdev.
> +queue @var{all|rx|tx} is an option that can be applied to traffic-mirror.
> +
>   @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..413d73a 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-mirror")) {
>           return false;
>       }
>
>