diff mbox series

[net,v2,05/10] net: xdp: don't allow device-bound programs in driver mode

Message ID 20171120232200.14846-6-jakub.kicinski@netronome.com
State Accepted, archived
Delegated to: BPF Maintainers
Headers show
Series bpf: offload: check netdev pointer in the drivers and namespace trouble | expand

Commit Message

Jakub Kicinski Nov. 20, 2017, 11:21 p.m. UTC 
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>
---
 net/core/dev.c | 7 +++++++
 1 file changed, 7 insertions(+)
diff mbox series

Patch

diff --git a/net/core/dev.c b/net/core/dev.c
index 09525a27319c..5e2ba133fba7 100644
--- 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);