Commit 441a3303 authored Nov 20, 2017 by Jakub Kicinski Committed by Daniel Borkmann Nov 21, 2017

net: xdp: don't allow device-bound programs in driver mode



Currently device-bound programs are not able to run on the host
to save resources (host JIT is not invoked).  Don't allow XDP
programs to be attached without the HW_MODE flag.  In theory
if program is already translated for device offload the driver
should choose to offload it instead of loading it in the driver.
However, offloading translated program may still fail resulting
in device-bound program being run on the host.

Prevent this by refusing to attach device bound programs if
XDP_FLAGS_HW_MODE is not set.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

parent 288b3de5

net/core/dev.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -7143,6 +7143,13 @@ int dev_change_xdp_fd(struct net_device dev, struct netlink_ext_ack extack,
		bpf_op == ops->ndo_bpf);
		if (IS_ERR(prog))
		return PTR_ERR(prog);

		if (!(flags & XDP_FLAGS_HW_MODE) &&
		bpf_prog_is_dev_bound(prog->aux)) {
		NL_SET_ERR_MSG(extack, "using device-bound program without HW_MODE flag is not supported");
		bpf_prog_put(prog);
		return -EINVAL;
		}
		}

		err = dev_xdp_install(dev, bpf_op, extack, flags, prog);