On Tue, Oct 31, 2017 at 7:32 PM, Jason Wang <jasow...@redhat.com> wrote: > This patch introduces an eBPF based queue selection method based on > the flow steering policy ops. Userspace could load an eBPF program > through TUNSETSTEERINGEBPF. This gives much more flexibility compare > to simple but hard coded policy in kernel. > > Signed-off-by: Jason Wang <jasow...@redhat.com> > --- > +static int tun_set_steering_ebpf(struct tun_struct *tun, void __user *data) > +{ > + struct bpf_prog *prog; > + u32 fd; > + > + if (copy_from_user(&fd, data, sizeof(fd))) > + return -EFAULT; > + > + prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
If the idea is to allow guests to pass BPF programs down to the host, you may want to define a new program type that is more restrictive than socket filter. The external functions allowed for socket filters (sk_filter_func_proto) are relatively few (compared to, say, clsact), but may still leak host information to a guest. More importantly, guest security considerations limits how we can extend socket filters later.