[V6,1/2] net/filter-mirror: implement filter-redirector

Filter-redirector is a netfilter plugin.
It gives qemu the ability to redirect net packet.
redirector can redirect filter's net packet to outdev.
and redirect indev's packet to filter.

                      filter
                        +
            redirector  |
               +--------------+
               |        |     |
  indev +-----------+   +---------->  outdev
               |    |         |
               +--------------+
                    |
                    v
                  filter

usage:

-netdev user,id=hn0
-chardev socket,id=s0,host=ip_primary,port=X,server,nowait
-chardev socket,id=s1,host=ip_primary,port=Y,server,nowait
-filter-redirector,id=r0,netdev=hn0,queue=tx/rx/all,indev=s0,outdev=s1

Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
---
 net/filter-mirror.c | 244 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 qemu-options.hx     |   9 ++
 vl.c                |   3 +-
 3 files changed, 255 insertions(+), 1 deletion(-)

On 03/17/2016 03:32 PM, Zhang Chen wrote:
> Filter-redirector is a netfilter plugin.
> It gives qemu the ability to redirect net packet.
> redirector can redirect filter's net packet to outdev.
> and redirect indev's packet to filter.
>
>                        filter
>                          +
>              redirector  |
>                 +--------------+
>                 |        |     |
>    indev +-----------+   +---------->  outdev
>                 |    |         |
>                 +--------------+
>                      |
>                      v
>                    filter
>
> usage:
>
> -netdev user,id=hn0
> -chardev socket,id=s0,host=ip_primary,port=X,server,nowait
> -chardev socket,id=s1,host=ip_primary,port=Y,server,nowait
> -filter-redirector,id=r0,netdev=hn0,queue=tx/rx/all,indev=s0,outdev=s1
>
> Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
> ---
>   net/filter-mirror.c | 244 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>   qemu-options.hx     |   9 ++
>   vl.c                |   3 +-
>   3 files changed, 255 insertions(+), 1 deletion(-)
>
> diff --git a/net/filter-mirror.c b/net/filter-mirror.c
> index 1b1ec16..6335511 100644
> --- a/net/filter-mirror.c
> +++ b/net/filter-mirror.c
> @@ -26,12 +26,23 @@
>   #define FILTER_MIRROR(obj) \
>       OBJECT_CHECK(MirrorState, (obj), TYPE_FILTER_MIRROR)
>
> +#define FILTER_REDIRECTOR(obj) \
> +    OBJECT_CHECK(MirrorState, (obj), TYPE_FILTER_REDIRECTOR)
> +
>   #define TYPE_FILTER_MIRROR "filter-mirror"
> +#define TYPE_FILTER_REDIRECTOR "filter-redirector"
> +#define REDIRECTOR_MAX_LEN NET_BUFSIZE
>
>   typedef struct MirrorState {
>       NetFilterState parent_obj;
> +    char *indev;
>       char *outdev;
> +    CharDriverState *chr_in;
>       CharDriverState *chr_out;
> +    int state; /* 0 = getting length, 1 = getting data */
> +    unsigned int index;
> +    unsigned int packet_len;
> +    uint8_t buf[REDIRECTOR_MAX_LEN];
>   } MirrorState;
>
>   static int filter_mirror_send(CharDriverState *chr_out,
> @@ -68,6 +79,96 @@ err:
>       return ret < 0 ? ret : -EIO;
>   }
>
> +static void
> +redirector_to_filter(NetFilterState *nf, const uint8_t *buf, int len)
> +{
> +    struct iovec iov = {
> +        .iov_base = (void *)buf,
> +        .iov_len = len,
> +    };
> +
> +    if (nf->direction == NET_FILTER_DIRECTION_ALL ||
> +        nf->direction == NET_FILTER_DIRECTION_TX) {
> +        qemu_netfilter_pass_to_next(nf->netdev, 0, &iov, 1, nf);
> +    }
> +
> +    if (nf->direction == NET_FILTER_DIRECTION_ALL ||
> +        nf->direction == NET_FILTER_DIRECTION_RX) {
> +        qemu_netfilter_pass_to_next(nf->netdev->peer, 0, &iov, 1, nf);
> +     }
> +}
> +
> +static int redirector_chr_can_read(void *opaque)
> +{
> +    return REDIRECTOR_MAX_LEN;
> +}
> +
> +static void redirector_chr_read(void *opaque, const uint8_t *buf, int size)
> +{
> +    NetFilterState *nf = opaque;
> +    MirrorState *s = FILTER_REDIRECTOR(nf);
> +    unsigned int l;
> +
> +    while (size > 0) {
> +        /* reassemble a packet from the network */
> +        switch (s->state) { /* 0 = getting length, 1 = getting data */
> +        case 0:
> +            l = 4 - s->index;
> +            if (l > size) {
> +                l = size;
> +            }
> +            memcpy(s->buf + s->index, buf, l);
> +            buf += l;
> +            size -= l;
> +            s->index += l;
> +            if (s->index == 4) {
> +                /* got length */
> +                s->packet_len = ntohl(*(uint32_t *)s->buf);
> +                s->index = 0;
> +                s->state = 1;
> +            }
> +            break;
> +        case 1:
> +            l = s->packet_len - s->index;
> +            if (l > size) {
> +                l = size;
> +            }
> +            if (s->index + l <= sizeof(s->buf)) {
> +                memcpy(s->buf + s->index, buf, l);
> +            } else {
> +                error_report("serious error: oversized packet received.");
> +                s->index = s->state = 0;
> +                qemu_chr_add_handlers(s->chr_in, NULL, NULL, NULL, NULL);
> +                return;
> +            }
> +
> +            s->index += l;
> +            buf += l;
> +            size -= l;
> +            if (s->index >= s->packet_len) {
> +                s->index = 0;
> +                s->state = 0;
> +                redirector_to_filter(nf, s->buf, s->packet_len);
> +            }
> +            break;
> +        }
> +    }
> +}
> +
> +static void redirector_chr_event(void *opaque, int event)
> +{
> +    NetFilterState *nf = opaque;
> +    MirrorState *s = FILTER_REDIRECTOR(nf);
> +
> +    switch (event) {
> +    case CHR_EVENT_CLOSED:
> +        qemu_chr_add_handlers(s->chr_in, NULL, NULL, NULL, NULL);
> +        break;
> +    default:
> +        break;
> +    }
> +}
> +
>   static ssize_t filter_mirror_receive_iov(NetFilterState *nf,
>                                            NetClientState *sender,
>                                            unsigned flags,
> @@ -90,6 +191,27 @@ static ssize_t filter_mirror_receive_iov(NetFilterState *nf,
>       return 0;
>   }
>
> +static ssize_t filter_redirector_receive_iov(NetFilterState *nf,
> +                                             NetClientState *sender,
> +                                             unsigned flags,
> +                                             const struct iovec *iov,
> +                                             int iovcnt,
> +                                             NetPacketSent *sent_cb)
> +{
> +    MirrorState *s = FILTER_REDIRECTOR(nf);
> +    int ret;
> +
> +    if (s->chr_out) {
> +        ret = filter_mirror_send(s->chr_out, iov, iovcnt);
> +        if (ret) {
> +            error_report("filter_mirror_send failed(%s)", strerror(-ret));
> +        }
> +        return iov_size(iov, iovcnt);
> +    } else {
> +        return 0;
> +    }
> +}
> +
>   static void filter_mirror_cleanup(NetFilterState *nf)
>   {
>       MirrorState *s = FILTER_MIRROR(nf);
> @@ -99,6 +221,18 @@ static void filter_mirror_cleanup(NetFilterState *nf)
>       }
>   }
>
> +static void filter_redirector_cleanup(NetFilterState *nf)
> +{
> +    MirrorState *s = FILTER_REDIRECTOR(nf);
> +
> +    if (s->chr_in) {
> +        qemu_chr_fe_release(s->chr_in);
> +    }
> +    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);
> @@ -122,6 +256,48 @@ static void filter_mirror_setup(NetFilterState *nf, Error **errp)
>       }
>   }
>
> +static void filter_redirector_setup(NetFilterState *nf, Error **errp)
> +{
> +    MirrorState *s = FILTER_REDIRECTOR(nf);
> +
> +    if (!s->indev && !s->outdev) {
> +        error_setg(errp, "filter redirector needs 'indev' or "
> +                   "'outdev' at least one property set");
> +        return;
> +    } else if (s->indev && s->outdev) {
> +        if (!strcmp(s->indev, s->outdev)) {
> +            error_setg(errp, "'indev' and 'outdev' could not be same "
> +                       "for filter redirector");
> +            return;
> +        }
> +    }
> +
> +    s->state = s->index = 0;
> +
> +    if (s->indev) {
> +        s->chr_in = qemu_chr_find(s->indev);
> +        if (s->chr_in == NULL) {
> +            error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
> +                      "IN Device '%s' not found", s->indev);
> +            return;
> +        }
> +
> +        qemu_chr_fe_claim_no_fail(s->chr_in);
> +        qemu_chr_add_handlers(s->chr_in, redirector_chr_can_read,
> +                              redirector_chr_read, redirector_chr_event, nf);
> +    }
> +
> +    if (s->outdev) {
> +        s->chr_out = qemu_chr_find(s->outdev);
> +        if (s->chr_out == NULL) {
> +            error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
> +                      "OUT Device '%s' not found", s->outdev);
> +            return;
> +        }
> +        qemu_chr_fe_claim_no_fail(s->chr_out);
> +    }
> +}
> +
>   static void filter_mirror_class_init(ObjectClass *oc, void *data)
>   {
>       NetFilterClass *nfc = NETFILTER_CLASS(oc);
> @@ -131,6 +307,31 @@ static void filter_mirror_class_init(ObjectClass *oc, void *data)
>       nfc->receive_iov = filter_mirror_receive_iov;
>   }
>
> +static void filter_redirector_class_init(ObjectClass *oc, void *data)
> +{
> +    NetFilterClass *nfc = NETFILTER_CLASS(oc);
> +
> +    nfc->setup = filter_redirector_setup;
> +    nfc->cleanup = filter_redirector_cleanup;
> +    nfc->receive_iov = filter_redirector_receive_iov;
> +}
> +
> +static char *filter_redirector_get_indev(Object *obj, Error **errp)
> +{
> +    MirrorState *s = FILTER_REDIRECTOR(obj);
> +
> +    return g_strdup(s->indev);
> +}
> +
> +static void
> +filter_redirector_set_indev(Object *obj, const char *value, Error **errp)
> +{
> +    MirrorState *s = FILTER_REDIRECTOR(obj);
> +
> +    g_free(s->indev);
> +    s->indev = g_strdup(value);
> +}
> +
>   static char *filter_mirror_get_outdev(Object *obj, Error **errp)
>   {
>       MirrorState *s = FILTER_MIRROR(obj);
> @@ -152,12 +353,36 @@ filter_mirror_set_outdev(Object *obj, const char *value, Error **errp)
>       }
>   }
>
> +static char *filter_redirector_get_outdev(Object *obj, Error **errp)
> +{
> +    MirrorState *s = FILTER_REDIRECTOR(obj);
> +
> +    return g_strdup(s->outdev);
> +}
> +
> +static void
> +filter_redirector_set_outdev(Object *obj, const char *value, Error **errp)
> +{
> +    MirrorState *s = FILTER_REDIRECTOR(obj);
> +
> +    g_free(s->outdev);
> +    s->outdev = g_strdup(value);
> +}
> +
>   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_redirector_init(Object *obj)
> +{
> +    object_property_add_str(obj, "indev", filter_redirector_get_indev,
> +                            filter_redirector_set_indev, NULL);
> +    object_property_add_str(obj, "outdev", filter_redirector_get_outdev,
> +                            filter_redirector_set_outdev, NULL);
> +}
> +
>   static void filter_mirror_fini(Object *obj)
>   {
>       MirrorState *s = FILTER_MIRROR(obj);
> @@ -165,6 +390,24 @@ static void filter_mirror_fini(Object *obj)
>       g_free(s->outdev);
>   }
>
> +static void filter_redirector_fini(Object *obj)
> +{
> +    MirrorState *s = FILTER_REDIRECTOR(obj);
> +
> +    qemu_chr_add_handlers(s->chr_in, NULL, NULL, NULL, NULL);

hi, Jason
Do we reset the chardev handler here is reasonable ?
filter_redirector_fini() is destruction of filter_redirector_init() which we
don't register handler.

So, I think move the handler reset to filter_redirector_cleanup() would be better.

Thanks
Li

> +    g_free(s->indev);
> +    g_free(s->outdev);
> +}
> +
> +static const TypeInfo filter_redirector_info = {
> +    .name = TYPE_FILTER_REDIRECTOR,
> +    .parent = TYPE_NETFILTER,
> +    .class_init = filter_redirector_class_init,
> +    .instance_init = filter_redirector_init,
> +    .instance_finalize = filter_redirector_fini,
> +    .instance_size = sizeof(MirrorState),
> +};
> +
>   static const TypeInfo filter_mirror_info = {
>       .name = TYPE_FILTER_MIRROR,
>       .parent = TYPE_NETFILTER,
> @@ -177,6 +420,7 @@ static const TypeInfo filter_mirror_info = {
>   static void register_types(void)
>   {
>       type_register_static(&filter_mirror_info);
> +    type_register_static(&filter_redirector_info);
>   }
>
>   type_init(register_types);
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 5379cb5..796d053 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -3821,6 +3821,15 @@ queue @var{all|rx|tx} is an option that can be applied to any netfilter.
>   filter-mirror on netdev @var{netdevid},mirror net packet to chardev
>   @var{chardevid}
>
> +@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},
> +outdev=@var{chardevid}[,queue=@var{all|rx|tx}]
> +
> +filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev
> +@var{chardevid},and redirect indev's packet to filter.
> +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-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 79bb11a..dc6e63a 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -2841,7 +2841,8 @@ static bool object_create_initial(const char *type)
>        */
>       if (g_str_equal(type, "filter-buffer") ||
>           g_str_equal(type, "filter-dump") ||
> -        g_str_equal(type, "filter-mirror")) {
> +        g_str_equal(type, "filter-mirror") ||
> +        g_str_equal(type, "filter-redirector")) {
>           return false;
>       }
>
>

On 03/17/2016 03:50 PM, Li Zhijian wrote:
>>
>> +static void filter_redirector_fini(Object *obj)
>> +{
>> +    MirrorState *s = FILTER_REDIRECTOR(obj);
>> +
>> +    qemu_chr_add_handlers(s->chr_in, NULL, NULL, NULL, NULL);
>
> hi, Jason
> Do we reset the chardev handler here is reasonable ?
> filter_redirector_fini() is destruction of filter_redirector_init()
> which we
> don't register handler.
>
> So, I think move the handler reset to filter_redirector_cleanup()
> would be better.
>
> Thanks
> Li 

Yes, please.

Thanks