diff options
| author | Aleksander Lobakin <aleksander.lobakin@intel.com> | 2023-12-06 21:59:19 +0100 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2023-12-11 16:09:36 +0100 |
| commit | 2ebe81c814355d000fe49d9c4213983844dcb32b (patch) | |
| tree | 695a116c8cea02abc891dd2e3181e11adc48ba57 /include/net | |
| parent | 15c79c6507c0eab5ec0d4cd402ac52d42735a43e (diff) | |
net, xdp: Allow metadata > 32
32 bytes may be not enough for some custom metadata. Relax the restriction,
allow metadata larger than 32 bytes and make __skb_metadata_differs() work
with bigger lengths.
Now size of metadata is only limited by the fact it is stored as u8 in
skb_shared_info, so maximum possible value is 255. Size still has to be
aligned to 4, so the actual upper limit becomes 252. Most driver
implementations will offer less, none can offer more.
Other important conditions, such as having enough space for xdp_frame
building, are already checked in bpf_xdp_adjust_meta().
Signed-off-by: Aleksander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/eb87653c-8ff8-447d-a7a1-25961f60518a@kernel.org
Link: https://lore.kernel.org/bpf/20231206205919.404415-3-larysa.zaremba@intel.com
Diffstat (limited to 'include/net')
| -rw-r--r-- | include/net/xdp.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/include/net/xdp.h b/include/net/xdp.h index 349c36fb5fd8..5d3673afc037 100644 --- a/include/net/xdp.h +++ b/include/net/xdp.h @@ -369,7 +369,12 @@ xdp_data_meta_unsupported(const struct xdp_buff *xdp) static inline bool xdp_metalen_invalid(unsigned long metalen) { - return (metalen & (sizeof(__u32) - 1)) || (metalen > 32); + unsigned long meta_max; + + meta_max = type_max(typeof_member(struct skb_shared_info, meta_len)); + BUILD_BUG_ON(!__builtin_constant_p(meta_max)); + + return !IS_ALIGNED(metalen, sizeof(u32)) || metalen > meta_max; } struct xdp_attachment_info { |