bpf: make it easier to add new metadata kfunc

No functional changes.

Instead of having hand-crafted code in bpf_dev_bound_resolve_kfunc,
move kfunc <> xmo handler relationship into XDP_METADATA_KFUNC_xxx.
This way, any time new kfunc is added, we don't have to touch
bpf_dev_bound_resolve_kfunc.

Also document XDP_METADATA_KFUNC_xxx arguments since we now have
more than two and it might be confusing what is what.

Cc: netdev@vger.kernel.org
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230913171350.369987-2-sdf@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
This commit is contained in:
Stanislav Fomichev 2023-09-13 10:13:48 -07:00 committed by Martin KaFai Lau
parent d609f3d228
commit fc45c5b642
3 changed files with 19 additions and 10 deletions

View File

@ -383,14 +383,22 @@ void xdp_attachment_setup(struct xdp_attachment_info *info,
#define DEV_MAP_BULK_SIZE XDP_BULK_QUEUE_SIZE
/* Define the relationship between xdp-rx-metadata kfunc and
* various other entities:
* - xdp_rx_metadata enum
* - kfunc name
* - xdp_metadata_ops field
*/
#define XDP_METADATA_KFUNC_xxx \
XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_TIMESTAMP, \
bpf_xdp_metadata_rx_timestamp) \
bpf_xdp_metadata_rx_timestamp, \
xmo_rx_timestamp) \
XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_HASH, \
bpf_xdp_metadata_rx_hash) \
bpf_xdp_metadata_rx_hash, \
xmo_rx_hash) \
enum {
#define XDP_METADATA_KFUNC(name, _) name,
enum xdp_rx_metadata {
#define XDP_METADATA_KFUNC(name, _, __) name,
XDP_METADATA_KFUNC_xxx
#undef XDP_METADATA_KFUNC
MAX_XDP_METADATA_KFUNC,

View File

@ -845,10 +845,11 @@ void *bpf_dev_bound_resolve_kfunc(struct bpf_prog *prog, u32 func_id)
if (!ops)
goto out;
if (func_id == bpf_xdp_metadata_kfunc_id(XDP_METADATA_KFUNC_RX_TIMESTAMP))
p = ops->xmo_rx_timestamp;
else if (func_id == bpf_xdp_metadata_kfunc_id(XDP_METADATA_KFUNC_RX_HASH))
p = ops->xmo_rx_hash;
#define XDP_METADATA_KFUNC(name, _, xmo) \
if (func_id == bpf_xdp_metadata_kfunc_id(name)) p = ops->xmo;
XDP_METADATA_KFUNC_xxx
#undef XDP_METADATA_KFUNC
out:
up_read(&bpf_devs_lock);

View File

@ -741,7 +741,7 @@ __bpf_kfunc int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, u32 *hash,
__diag_pop();
BTF_SET8_START(xdp_metadata_kfunc_ids)
#define XDP_METADATA_KFUNC(_, name) BTF_ID_FLAGS(func, name, KF_TRUSTED_ARGS)
#define XDP_METADATA_KFUNC(_, name, __) BTF_ID_FLAGS(func, name, KF_TRUSTED_ARGS)
XDP_METADATA_KFUNC_xxx
#undef XDP_METADATA_KFUNC
BTF_SET8_END(xdp_metadata_kfunc_ids)
@ -752,7 +752,7 @@ static const struct btf_kfunc_id_set xdp_metadata_kfunc_set = {
};
BTF_ID_LIST(xdp_metadata_kfunc_ids_unsorted)
#define XDP_METADATA_KFUNC(name, str) BTF_ID(func, str)
#define XDP_METADATA_KFUNC(name, str, _) BTF_ID(func, str)
XDP_METADATA_KFUNC_xxx
#undef XDP_METADATA_KFUNC