On Mon, Mar 11, 2019 at 5:54 PM Andrii Nakryiko
<[email protected]> wrote:
>
> On Mon, Mar 11, 2019 at 7:52 AM Magnus Karlsson
> <[email protected]> wrote:
> >
> > In xsk_socket__create(), the libbpf_flags field was not checked for
> > setting currently unused/unknown flags. This patch fixes that by returning
> > -EINVAL if the user has set any flag that is not in use at this point
> > in time.
> >
> > Fixes: 1cad07884239 ("libbpf: add support for using AF_XDP sockets")
> > Signed-off-by: Magnus Karlsson <[email protected]>
> > ---
> > tools/lib/bpf/xsk.c | 15 +++++++++++----
> > 1 file changed, 11 insertions(+), 4 deletions(-)
> >
> > diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c
> > index f98ac82..912f942 100644
> > --- a/tools/lib/bpf/xsk.c
> > +++ b/tools/lib/bpf/xsk.c
> > @@ -126,8 +126,8 @@ static void xsk_set_umem_config(struct xsk_umem_config
> > *cfg,
> > cfg->frame_headroom = usr_cfg->frame_headroom;
> > }
> >
> > -static void xsk_set_xdp_socket_config(struct xsk_socket_config *cfg,
> > - const struct xsk_socket_config
> > *usr_cfg)
> > +static int xsk_set_xdp_socket_config(struct xsk_socket_config *cfg,
> > + const struct xsk_socket_config
> > *usr_cfg)
> > {
> > if (!usr_cfg) {
> > cfg->rx_size = XSK_RING_CONS__DEFAULT_NUM_DESCS;
> > @@ -135,14 +135,19 @@ static void xsk_set_xdp_socket_config(struct
> > xsk_socket_config *cfg,
> > cfg->libbpf_flags = 0;
> > cfg->xdp_flags = 0;
> > cfg->bind_flags = 0;
> > - return;
> > + return 0;
> > }
> >
> > + if (cfg->libbpf_flags & ~XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD)
> > + return -EINVAL;
> > +
>
> Shouldn't this be checking usr_cfg->libbpf_flags instead?
Arrghh! Yes you are of course right. Thanks for catching this. Will spin a v2.
> Also, what about bind_flags and xdp_flags? For those we are deferring
> to underlying systems to check extra flags?
I defer that to the underlying calls so I do not have to keep this
code up to date with changes to those flags.
Thanks: Magnus
>
> > cfg->rx_size = usr_cfg->rx_size;
> > cfg->tx_size = usr_cfg->tx_size;
> > cfg->libbpf_flags = usr_cfg->libbpf_flags;
> > cfg->xdp_flags = usr_cfg->xdp_flags;
> > cfg->bind_flags = usr_cfg->bind_flags;
> > +
> > + return 0;
> > }
> >
> > int xsk_umem__create(struct xsk_umem **umem_ptr, void *umem_area, __u64
> > size,
> > @@ -557,7 +562,9 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr,
> > const char *ifname,
> > }
> > strncpy(xsk->ifname, ifname, IFNAMSIZ);
> >
> > - xsk_set_xdp_socket_config(&xsk->config, usr_config);
> > + err = xsk_set_xdp_socket_config(&xsk->config, usr_config);
> > + if (err)
> > + goto out_socket;
> >
> > if (rx) {
> > err = setsockopt(xsk->fd, SOL_XDP, XDP_RX_RING,
> > --
> > 2.7.4
> >
