Re: [Qemu-devel] [PATCH V4 03/12] net/filter-mirror.c: Make filter_mirror_send support vnet support.

[Zhang Chen]

On 05/15/2017 11:28 AM, Jason Wang wrote:
> On 2017年05月12日 09:41, Zhang Chen wrote:
> > In this patch, if vnet_hdr=on 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 | 35 ++++++++++++++++++++++++++++++-----
> >   1 file changed, 30 insertions(+), 5 deletions(-)
> >
> > diff --git a/net/filter-mirror.c b/net/filter-mirror.c
> > index 3766414..64323fc 100644
> > --- a/net/filter-mirror.c
> > +++ b/net/filter-mirror.c
> > @@ -44,10 +44,11 @@ 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;
> >       uint32_t len = 0;
> > @@ -59,14 +60,38 @@ 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;
> >       }
> >   +    if (s->vnet_hdr) {
> > +        /*
> > +         * If vnet_hdr = on, we send vnet header len to make other
> > +         * module(like colo-compare) know how to parse net
> > +         * packet correctly.
> > +         */
> > +        ssize_t vnet_hdr_len;
> > +
> > +        if (nf->netdev->using_vnet_hdr) {
> > +            vnet_hdr_len = nf->netdev->vnet_hdr_len;
> > +        } else if (nf->netdev->peer->using_vnet_hdr) {
> > +            vnet_hdr_len = nf->netdev->peer->vnet_hdr_len;
>
> Still questionable here, may need a comment to explain.

OK, I will add comments in next version.

> > +        } else {
> > +            error_report("filter get vnet_hdr_len failed");
>
> Why need error here, could we just use zero?

Yes,we can.

Thanks
Zhang Chen

> Thanks
>
> > +            goto err;
> > +        }
> > +
> > +        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;
> > @@ -142,7 +167,7 @@ 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));
> >       }
> > @@ -165,7 +190,7 @@ 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));
> >           }
>
>
>
> .

--
Thanks
Zhang Chen