Re: [Qemu-devel] [PATCH V5 1/2] net/filter-mirror:Add filter-mirror

[Jason Wang]

On 02/23/2016 08:00 PM, Zhang Chen wrote:
> Filter-mirror is a netfilter plugin.
> It gives qemu the ability to mirror
> packets to a chardev.
>
> usage:
>
> -netdev tap,id=hn0
> -chardev socket,id=mirror0,host=ip_primary,port=X,server,nowait
> -filter-mirror,id=m0,netdev=hn0,queue=tx/rx/all,outdev=mirror0
>
> Signed-off-by: Zhang Chen <address@hidden>
> Signed-off-by: Wen Congyang <address@hidden>
> Reviewed-by: Yang Hongyang <address@hidden>
> Reviewed-by: zhanghailiang <address@hidden>
> ---
>  net/Makefile.objs   |   1 +
>  net/filter-mirror.c | 181 
> ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  qemu-options.hx     |   5 ++
>  vl.c                |   3 +-
>  4 files changed, 189 insertions(+), 1 deletion(-)
>  create mode 100644 net/filter-mirror.c
>
> diff --git a/net/Makefile.objs b/net/Makefile.objs
> index 5fa2f97..b7c22fd 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 += filter-mirror.o
> diff --git a/net/filter-mirror.c b/net/filter-mirror.c
> new file mode 100644
> index 0000000..ad722f7
> --- /dev/null
> +++ b/net/filter-mirror.c
> @@ -0,0 +1,181 @@
> +/*
> + * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
> + * Copyright (c) 2016 FUJITSU LIMITED
> + * Copyright (c) 2016 Intel Corporation
> + *
> + * Author: Zhang Chen <address@hidden>
> + *
> + * 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"
> +#include "qemu/sockets.h"
> +
> +#define FILTER_MIRROR(obj) \
> +    OBJECT_CHECK(MirrorState, (obj), TYPE_FILTER_MIRROR)
> +
> +#define TYPE_FILTER_MIRROR "filter-mirror"
> +
> +typedef struct MirrorState {
> +    NetFilterState parent_obj;
> +    char *outdev;
> +    CharDriverState *chr_out;
> +} MirrorState;
> +
> +static int filter_mirror_send(NetFilterState *nf,
> +                                   const struct iovec *iov,
> +                                   int iovcnt)
> +{
> +    MirrorState *s = FILTER_MIRROR(nf);
> +    int ret = 0;
> +    ssize_t size = 0;
> +    uint32_t len =  0;
> +    char *buf;
> +
> +    size = iov_size(iov, iovcnt);
> +    if (!size) {
> +        return 0;
> +    }
> +
> +    len = htonl(size);
> +    ret = qemu_chr_fe_write_all(s->chr_out, (uint8_t *)&len, sizeof(len));
> +    if (ret != sizeof(len)) {
> +        goto err;
> +    }
> +
> +    buf = g_malloc(size);
> +    iov_to_buf(iov, iovcnt, 0, buf, size);
> +    ret = qemu_chr_fe_write_all(s->chr_out, (uint8_t *)buf, size);
> +    g_free(buf);
> +    if (ret != size) {
> +        goto err;
> +    }
> +
> +    return 0;
> +
> +err:
> +      return ret < 0 ? ret : -EIO;

The indentation looks odd here.

Other looks good.

> +}
> +
> +static ssize_t filter_mirror_receive_iov(NetFilterState *nf,
> +                                         NetClientState *sender,
> +                                         unsigned flags,
> +                                         const struct iovec *iov,
> +                                         int iovcnt,
> +                                         NetPacketSent *sent_cb)
> +{
> +    int ret;
> +
> +    ret = filter_mirror_send(nf, iov, iovcnt);
> +    if (ret) {
> +        error_report("filter_mirror_send failed(%s)", strerror(-ret));
> +    }
> +
> +    /*
> +     * we don't hope this error interrupt the normal
> +     * path of net packet, so we always return zero.
> +     */
> +    return 0;
> +}
> +
> +static void filter_mirror_cleanup(NetFilterState *nf)
> +{
> +    MirrorState *s = FILTER_MIRROR(nf);
> +
> +    if (s->chr_out) {
> +        qemu_chr_fe_release(s->chr_out);
> +    }
> +}
> +
> +static void filter_mirror_setup(NetFilterState *nf, Error **errp)
> +{
> +    MirrorState *s = FILTER_MIRROR(nf);
> +
> +    if (!s->outdev) {
> +        error_setg(errp, "filter filter 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 filter_mirror_class_init(ObjectClass *oc, void *data)
> +{
> +    NetFilterClass *nfc = NETFILTER_CLASS(oc);
> +
> +    nfc->setup = filter_mirror_setup;
> +    nfc->cleanup = filter_mirror_cleanup;
> +    nfc->receive_iov = filter_mirror_receive_iov;
> +}
> +
> +static char *filter_mirror_get_outdev(Object *obj, Error **errp)
> +{
> +    MirrorState *s = FILTER_MIRROR(obj);
> +
> +    return g_strdup(s->outdev);
> +}
> +
> +static void
> +filter_mirror_set_outdev(Object *obj, const char *value, Error **errp)
> +{
> +    MirrorState *s = FILTER_MIRROR(obj);
> +
> +    g_free(s->outdev);
> +    s->outdev = g_strdup(value);
> +    if (!s->outdev) {
> +        error_setg(errp, "filter filter mirror needs 'outdev' "
> +                "property set");
> +        return;
> +    }
> +}
> +
> +static void filter_mirror_init(Object *obj)
> +{
> +    object_property_add_str(obj, "outdev", filter_mirror_get_outdev,
> +                            filter_mirror_set_outdev, NULL);
> +}
> +
> +static void filter_mirror_fini(Object *obj)
> +{
> +    MirrorState *s = FILTER_MIRROR(obj);
> +
> +    g_free(s->outdev);
> +}
> +
> +static const TypeInfo filter_mirror_info = {
> +    .name = TYPE_FILTER_MIRROR,
> +    .parent = TYPE_NETFILTER,
> +    .class_init = filter_mirror_class_init,
> +    .instance_init = filter_mirror_init,
> +    .instance_finalize = filter_mirror_fini,
> +    .instance_size = sizeof(MirrorState),
> +};
> +
> +static void register_types(void)
> +{
> +    type_register_static(&filter_mirror_info);
> +}
> +
> +type_init(register_types);
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 2f0465e..ca27863 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -3759,6 +3759,11 @@ 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.
>  
> address@hidden -object 
> filter-mirror,address@hidden,address@hidden,address@hidden,address@hidden|rx|tx}]
> +
> +filter-mirror on netdev @var{netdevid},mirror net packet to chardev
> address@hidden
> +
>  @item -object 
> filter-dump,address@hidden,address@hidden,address@hidden,address@hidden
>  
>  Dump the network traffic on netdev @var{dev} to the file specified by
> diff --git a/vl.c b/vl.c
> index 175ebcc..d68533a 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -2798,7 +2798,8 @@ 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, "filter-mirror")) {
>          return false;
>      }
>