Re: [Qemu-devel] [PATCH V3 1/2] net/filter-mirror:Add filter-mirror

[Zhang Chen]

On 02/15/2016 01:23 PM, Jason Wang wrote:
> On 02/04/2016 05:00 PM, Zhang Chen wrote:
> > On 02/04/2016 03:43 PM, Zhang Chen wrote:
> > > From: ZhangChen <address@hidden>
> > >
> > > Filter-mirror is a netfilter plugin.
> > > It gives qemu the ability to copy and mirror guest's
> > > net packet. we output packet to chardev.
> To make it compact, how about "It gives qemu the ability to mirror
> packets to a chardev."?

OK, will fix it in next version.

> > > 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
> An issue with mirror (and dump) is that it can not work correctly with
> the netdev that has a vnet header. Need to fix this, a possible solution
> is to checksum the buffer and strip the header before passing it to a
> chardev.

Thanks, I don't consider about vnet, we will fix it in next version.

> > > Signed-off-by: ZhangChen <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 | 171
> > > ++++++++++++++++++++++++++++++++++++++++++++++++++++
> > >    qemu-options.hx     |   5 ++
> > >    vl.c                |   3 +-
> > >    4 files changed, 179 insertions(+), 1 deletion(-)
> > >    create mode 100644 net/filter-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
> > s/traffic-mirror.o/filter-mirror.o/     rebase error....
> >
> > > diff --git a/net/filter-mirror.c b/net/filter-mirror.c
> > > new file mode 100644
> > > index 0000000..87ccaf5
> > > --- /dev/null
> > > +++ b/net/filter-mirror.c
> > > @@ -0,0 +1,171 @@
> > > +/*
> > > + * 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 ssize_t filter_mirror_send(NetFilterState *nf,
> > > +                                   const struct iovec *iov,
> > > +                                   int iovcnt)
> > > +{
> > > +    MirrorState *s = FILTER_MIRROR(nf);
> > > +    ssize_t ret = 0;
> > > +    ssize_t size = 0;
> > > +    uint32_t len =  0;
> > > +    char *buf;
> > > +
> > > +    size = iov_size(iov, iovcnt);
> > > +    len = htonl(size);
> > > +    if (!size) {
> > > +        return 0;
> > > +    }
> > > +
> > > +    buf = g_malloc0(size);
> > > +    iov_to_buf(iov, iovcnt, 0, buf, size);
> > > +    ret = qemu_chr_fe_write_all(s->chr_out, (uint8_t *)&len,
> > > sizeof(len));
> > > +    if (ret < 0) {
> I believe we should also fail when ret < sizeof(len) and modify the
> caller check in filter_mirror_iov(). To make this a little bit easier,
> there's no need to return ssize_t here (otherwise, caller need to call
> iov_size() before checking the return value), just return 0 for success
> and -EFXXX for failure.

OK, will fix it in next version

Thanks
zhangchen

> Other looks good.
>
>
>
> .

--
Thanks
zhangchen