On Mon, Mar 11, 2019 at 7:52 AM Magnus Karlsson
<magnus.karls...@intel.com> 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 <magnus.karls...@intel.com>
> ---
> 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?
Also, what about bind_flags and xdp_flags? For those we are deferring
to underlying systems to check extra flags?
> 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
>
