* Marc-André Lureau (marcandre.lur...@gmail.com) wrote:
> Hi
>
> On Thu, Aug 24, 2017 at 12:27 PM, Dr. David Alan Gilbert (git)
> <dgilb...@redhat.com> wrote:
> > From: "Dr. David Alan Gilbert" <dgilb...@redhat.com>
> >
> > Allow replies with fds (for postcopy)
> >
> > Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> > ---
> > contrib/libvhost-user/libvhost-user.c | 29 ++++++++++++++++++++++++++++-
> > 1 file changed, 28 insertions(+), 1 deletion(-)
> >
> > diff --git a/contrib/libvhost-user/libvhost-user.c
> > b/contrib/libvhost-user/libvhost-user.c
> > index 8bbdf5fb40..47884c0a15 100644
> > --- a/contrib/libvhost-user/libvhost-user.c
> > +++ b/contrib/libvhost-user/libvhost-user.c
> > @@ -213,6 +213,30 @@ vu_message_write(VuDev *dev, int conn_fd, VhostUserMsg
> > *vmsg)
> > {
> > int rc;
> > uint8_t *p = (uint8_t *)vmsg;
> > + char control[CMSG_SPACE(VHOST_MEMORY_MAX_NREGIONS * sizeof(int))] = {
> > };
> > + struct iovec iov = {
> > + .iov_base = (char *)vmsg,
> > + .iov_len = VHOST_USER_HDR_SIZE,
> > + };
> > + struct msghdr msg = {
> > + .msg_iov = &iov,
> > + .msg_iovlen = 1,
> > + .msg_control = control,
> > + };
> > + struct cmsghdr *cmsg;
> > +
> > + memset(control, 0, sizeof(control));
> > + if (vmsg->fds) {
>
> This is going to be always true, right? Check vmsg->fd_num > 0 instead?
Ah yes, thanks.
> I would also add check or assert(vmsg->fd_num <= VHOST_MEMORY_MAX_NREGIONS)
- if (vmsg->fds) {
+ assert(vmsg->fd_num <= VHOST_MEMORY_MAX_NREGIONS);
+ if (vmsg->fd_num > 0) {
>
> > + size_t fdsize = vmsg->fd_num * sizeof(int);
> > + msg.msg_controllen = CMSG_SPACE(fdsize);
> > + cmsg = CMSG_FIRSTHDR(&msg);
> > + cmsg->cmsg_len = CMSG_LEN(fdsize);
> > + cmsg->cmsg_level = SOL_SOCKET;
> > + cmsg->cmsg_type = SCM_RIGHTS;
> > + memcpy(CMSG_DATA(cmsg), vmsg->fds, fdsize);
> > + } else {
> > + msg.msg_controllen = 0;
> > + }
> >
> > /* Set the version in the flags when sending the reply */
> > vmsg->flags &= ~VHOST_USER_VERSION_MASK;
> > @@ -220,7 +244,7 @@ vu_message_write(VuDev *dev, int conn_fd, VhostUserMsg
> > *vmsg)
> > vmsg->flags |= VHOST_USER_REPLY_MASK;
> >
> > do {
> > - rc = write(conn_fd, p, VHOST_USER_HDR_SIZE);
> > + rc = sendmsg(conn_fd, &msg, 0);
> > } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
> >
> > do {
> > @@ -313,6 +337,7 @@ vu_get_features_exec(VuDev *dev, VhostUserMsg *vmsg)
> > }
> >
> > vmsg->size = sizeof(vmsg->payload.u64);
> > + vmsg->fd_num = 0;
> >
> > DPRINT("Sending back to guest u64: 0x%016"PRIx64"\n",
> > vmsg->payload.u64);
> >
> > @@ -454,6 +479,7 @@ vu_set_log_base_exec(VuDev *dev, VhostUserMsg *vmsg)
> > dev->log_size = log_mmap_size;
> >
> > vmsg->size = sizeof(vmsg->payload.u64);
> > + vmsg->fd_num = 0;
> >
> > return true;
> > }
> > @@ -698,6 +724,7 @@ vu_get_protocol_features_exec(VuDev *dev, VhostUserMsg
> > *vmsg)
> >
> > vmsg->payload.u64 = features;
> > vmsg->size = sizeof(vmsg->payload.u64);
> > + vmsg->fd_num = 0;
> >
> > return true;
> > }
> > --
> > 2.13.5
> >
> >
>
> other than that
> Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com>
Thanks.
Dave
>
>
> --
> Marc-André Lureau
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
