xdp: factor out common program/flags handling from drivers

Basic operations drivers perform during xdp setup and query can
be moved to helpers in the core.  Encapsulate program and flags
into a structure and add helpers.  Note that the structure is
intended as the "main" program information source in the driver.
Most drivers will additionally place the program pointer in their
fast path or ring structures.

The helpers don't have a huge impact now, but they will
decrease the code duplication when programs can be installed
in HW and driver at the same time.  Encapsulating the basic
operations in helpers will hopefully also reduce the number
of changes to drivers which adopt them.

Helpers could really be static inline, but they depend on
definition of struct netdev_bpf which means they'd have
to be placed in netdevice.h, an already 4500 line header.

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

1 files changed, 13 insertions, 0 deletions

diff --git a/include/net/xdp.h b/include/net/xdp.h
index 2deea7166a34..fcb033f51d8c 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -144,4 +144,17 @@ xdp_data_meta_unsupported(const struct xdp_buff *xdp)
 	return unlikely(xdp->data_meta > xdp->data);
 }
 
+struct xdp_attachment_info {
+	struct bpf_prog *prog;
+	u32 flags;
+};
+
+struct netdev_bpf;
+int xdp_attachment_query(struct xdp_attachment_info *info,
+			 struct netdev_bpf *bpf);
+bool xdp_attachment_flags_ok(struct xdp_attachment_info *info,
+			     struct netdev_bpf *bpf);
+void xdp_attachment_setup(struct xdp_attachment_info *info,
+			  struct netdev_bpf *bpf);
+
 #endif /* __LINUX_NET_XDP_H__ */