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 <[email protected]> Reviewed-by: Quentin Monnet <[email protected]> Acked-by: Alexei Starovoitov <[email protected]> Acked-by: Daniel Borkmann <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]>
opendata26 · Nov 20, 2017 · 441a330 · 441a330
1 parent 288b3de
commit 441a330
Showing 1 changed file with 7 additions and 0 deletions.
diff --git a/net/core/dev.c b/net/core/dev.c
@@ -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);