Re: [Qemu-devel] [PATCH V2 2/3] net/filter-redirector:Add filter-redirector

[Li Zhijian <lizhijian@cn.fujitsu.com>]

On 02/29/2016 08:23 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
>                           |
>                           |
>                           v
>                        filter------> guest
>
> usage:
>
> -netdev tap,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>
> ---
>   net/Makefile.objs       |   1 +
>   net/filter-redirector.c | 216 ++++++++++++++++++++++++++++++++++++++++++++++++
>   qemu-options.hx         |   8 ++
>   vl.c                    |   3 +-
>   4 files changed, 227 insertions(+), 1 deletion(-)
>   create mode 100644 net/filter-redirector.c
>
> diff --git a/net/Makefile.objs b/net/Makefile.objs
> index b7c22fd..8af9932 100644
> --- a/net/Makefile.objs
> +++ b/net/Makefile.objs
> @@ -16,3 +16,4 @@ common-obj-$(CONFIG_NETMAP) += netmap.o
>   common-obj-y += filter.o
>   common-obj-y += filter-buffer.o
>   common-obj-y += filter-mirror.o
> +common-obj-y += filter-redirector.o
> diff --git a/net/filter-redirector.c b/net/filter-redirector.c
> new file mode 100644
> index 0000000..d0eb76d
> --- /dev/null
> +++ b/net/filter-redirector.c
> @@ -0,0 +1,216 @@
> +/*
> + * 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-traffic.h"
> +
> +#define FILTER_REDIRECTOR(obj) \
> +    OBJECT_CHECK(TrafficState, (obj), TYPE_FILTER_REDIRECTOR)
> +
> +#define TYPE_FILTER_REDIRECTOR "filter-redirector"
> +#define REDIRECT_HEADER_LEN sizeof(uint32_t)
> +
> +static int filter_redirector_send(NetFilterState *nf,
> +                                   const struct iovec *iov,
> +                                   int iovcnt)
> +{
> +    return filter_traffic_send(nf, iov, iovcnt);
> +}
> +
> +static ssize_t filter_redirector_receive_iov(NetFilterState *nf,
> +                                         NetClientState *sender,
> +                                         unsigned flags,
> +                                         const struct iovec *iov,
> +                                         int iovcnt,
> +                                         NetPacketSent *sent_cb)
> +{
> +    TrafficState *s = FILTER_REDIRECTOR(nf);
> +    ssize_t ret = 0;
> +
> +    if (s->chr_out) {
> +        ret = filter_redirector_send(nf, iov, iovcnt);
> +        if (ret < 0) {
> +            error_report("filter_redirector_send failed");
> +        }
> +        return iov_size(iov, iovcnt);
> +    } else {
> +        return 0;
> +    }
> +}
> +
> +static void filter_redirector_cleanup(NetFilterState *nf)
> +{
> +    TrafficState *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 int redirector_chr_can_read(void *opaque)
> +{
> +    return REDIRECT_HEADER_LEN;
> +}
> +
> +static void redirector_chr_read(void *opaque, const uint8_t *buf, int size)
> +{
> +    NetFilterState *nf = opaque;
> +    TrafficState *s = FILTER_REDIRECTOR(nf);
> +    uint32_t len;
> +    int ret = 0;
> +    uint8_t *recv_buf;
> +    int offset = size;
> +
> +    while (offset < REDIRECT_HEADER_LEN) {
> +        ret = s->chr_in->chr_sync_read(s->chr_in, (uint8_t *)buf + offset,
> +                REDIRECT_HEADER_LEN - offset);
> +        if (ret == -1 && errno == EAGAIN) {
> +            g_usleep(100);
> +        }
> +        offset += ret;
if 'ret' is a nagative value, you will cut 'offset'.


> +    }
> +
> +    memcpy(&len, buf, sizeof(len));
> +    len = ntohl(len);
> +
> +    if (len > 0 && len < NET_BUFSIZE) {
> +        recv_buf = g_malloc(len);
> +        ret = qemu_chr_fe_read_all(s->chr_in, recv_buf, len);
> +        if (ret != len) {
> +            error_report("filter-redirector recv buf failed");
> +            g_free(recv_buf);
> +            return;
> +        }
> +
> +        ret = qemu_net_queue_send(s->incoming_queue, nf->netdev,
> +                            0, (const uint8_t *)recv_buf, len, NULL);
> +        g_free(recv_buf);
> +        if (ret < 0) {
> +            error_report("filter-redirector out to guest failed");
> +        }
> +    } else {
> +        error_report("filter-redirector recv len failed");
> +    }
> +}
> +
> +static void filter_redirector_setup(NetFilterState *nf, Error **errp)
> +{
> +    TrafficState *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) {
> +        error_setg(errp, "filter redirector needs 'indev' and "
> +                "'outdev'  are not same");
> +        return;
> +    }
> +
> +    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, NULL, 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);
> +    }
> +    s->incoming_queue = qemu_new_net_queue(qemu_netfilter_pass_to_next, nf);
Does just 'indev' need an incoming_queue ?

Best regards.
Li Zhijian

> +}
> +
> +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)
> +{
> +    TrafficState *s = FILTER_REDIRECTOR(obj);
> +
> +    return g_strdup(s->indev);
> +}
> +
> +static void
> +filter_redirector_set_indev(Object *obj, const char *value, Error **errp)
> +{
> +    TrafficState *s = FILTER_REDIRECTOR(obj);
> +
> +    g_free(s->indev);
> +    s->indev = g_strdup(value);
> +}
> +
> +static char *filter_redirector_get_outdev(Object *obj, Error **errp)
> +{
> +    TrafficState *s = FILTER_REDIRECTOR(obj);
> +
> +    return g_strdup(s->outdev);
> +}
> +
> +static void
> +filter_redirector_set_outdev(Object *obj, const char *value, Error **errp)
> +{
> +    TrafficState *s = FILTER_REDIRECTOR(obj);
> +
> +    g_free(s->outdev);
> +    s->outdev = g_strdup(value);
> +}
> +
> +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_redirector_fini(Object *obj)
> +{
> +    TrafficState *s = FILTER_REDIRECTOR(obj);
> +
> +    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(TrafficState),
> +};
> +
> +static void register_types(void)
> +{
> +    type_register_static(&filter_redirector_info);
> +}
> +
> +type_init(register_types);
> diff --git a/qemu-options.hx b/qemu-options.hx
> index ca27863..84584e3 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -3764,6 +3764,14 @@ 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 to be set.
> +
>   @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 d68533a..c389a3f 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -2799,7 +2799,8 @@ 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;
>       }
>
>