Re: [Qemu-devel] [PATCH V3 04/10] net/filter-mirror.c: Add filter-mirror and filter-redirector vnet support.

[Zhang Chen]

On 05/02/2017 12:47 PM, Jason Wang wrote:
> On 2017年04月28日 17:47, Zhang Chen wrote:
> > In this patch, we change the send packet format from
> > struct {int size; const uint8_t buf[];} to {int size; int 
> > vnet_hdr_len; const uint8_t buf[];}.
> > make other module(like colo-compare) know how to parse net packet 
> > correctly.
> >
> > Signed-off-by: Zhang Chen <address@hidden>
> > ---
> >   net/filter-mirror.c | 28 +++++++++++++++++++++++-----
> >   1 file changed, 23 insertions(+), 5 deletions(-)
> >
> > diff --git a/net/filter-mirror.c b/net/filter-mirror.c
> > index 72fa7c2..bb9ecf3 100644
> > --- a/net/filter-mirror.c
> > +++ b/net/filter-mirror.c
> > @@ -43,12 +43,14 @@ typedef struct MirrorState {
> >       SocketReadState rs;
> >   } MirrorState;
> >   -static int filter_mirror_send(CharBackend *chr_out,
> > +static int filter_mirror_send(MirrorState *s,
> >                                 const struct iovec *iov,
> >                                 int iovcnt)
> >   {
> > +    NetFilterState *nf = NETFILTER(s);
> >       int ret = 0;
> >       ssize_t size = 0;
> > +    ssize_t vnet_hdr_len;
> >       uint32_t len = 0;
> >       char *buf;
> >   @@ -58,14 +60,30 @@ static int filter_mirror_send(CharBackend 
> > *chr_out,
> >       }
> >         len = htonl(size);
> > -    ret = qemu_chr_fe_write_all(chr_out, (uint8_t *)&len, sizeof(len));
> > +    ret = qemu_chr_fe_write_all(&s->chr_out, (uint8_t *)&len, 
> > sizeof(len));
> > +    if (ret != sizeof(len)) {
> > +        goto err;
> > +    }
> > +
> > +    /*
> > +     * We send vnet header len make other module(like colo-compare)
> > +     * know how to parse net packet correctly.
> > +     */
> > +    if (qemu_get_using_vnet_hdr(nf->netdev)) {
> > +        vnet_hdr_len = qemu_get_vnet_hdr_len(nf->netdev);
> > +    } else {
> > +        vnet_hdr_len = qemu_get_vnet_hdr_len(nf->netdev->peer);
> > +    }
>
> Any reason to query peer here?

That's depend on using NetClientState, If we using nf->netdev that need 
to query,
Otherwise we query nf->netdev->peer, then we can get the real 
vnet_hdr_len in my test.

Thanks
Zhang Chen

> > +
> > +    len = htonl(vnet_hdr_len);
> > +    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(chr_out, (uint8_t *)buf, size);
> > +    ret = qemu_chr_fe_write_all(&s->chr_out, (uint8_t *)buf, size);
> >       g_free(buf);
> >       if (ret != size) {
> >           goto err;
> > @@ -141,7 +159,7 @@ static ssize_t 
> > filter_mirror_receive_iov(NetFilterState *nf,
> >       MirrorState *s = FILTER_MIRROR(nf);
> >       int ret;
> >   -    ret = filter_mirror_send(&s->chr_out, iov, iovcnt);
> > +    ret = filter_mirror_send(s, iov, iovcnt);
> >       if (ret) {
> >           error_report("filter_mirror_send failed(%s)", strerror(-ret));
> >       }
> > @@ -164,7 +182,7 @@ static ssize_t 
> > filter_redirector_receive_iov(NetFilterState *nf,
> >       int ret;
> >         if (qemu_chr_fe_get_driver(&s->chr_out)) {
> > -        ret = filter_mirror_send(&s->chr_out, iov, iovcnt);
> > +        ret = filter_mirror_send(s, iov, iovcnt);
> >           if (ret) {
> >               error_report("filter_mirror_send failed(%s)", 
> > strerror(-ret));
> >           }
>
> Do we need to strip vnet_hdr_len in redirector_to_filter() ?
>
> Thanks
>
>
>
> .

--
Thanks
Zhang Chen