Commit 7445cf31 authored by Zvi Effron's avatar Zvi Effron Committed by Alexei Starovoitov
Browse files

bpf: Add function for XDP meta data length check 



This commit prepares to use the XDP meta data length check in multiple
places by making it into a static inline function instead of a literal.

Co-developed-by: default avatarCody Haas <chaas@riotgames.com>
Co-developed-by: default avatarLisa Watanabe <lwatanabe@riotgames.com>
Signed-off-by: default avatarCody Haas <chaas@riotgames.com>
Signed-off-by: default avatarLisa Watanabe <lwatanabe@riotgames.com>
Signed-off-by: default avatarZvi Effron <zeffron@riotgames.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210707221657.3985075-2-zeffron@riotgames.com
parent 5e437416

include/net/xdp.h

+5 −0
Original line number Diff line number Diff line
@@ -276,6 +276,11 @@ xdp_data_meta_unsupported(const struct xdp_buff *xdp) 
	return unlikely(xdp->data_meta > xdp->data);

}



static inline bool xdp_metalen_invalid(unsigned long metalen)

{

	return (metalen & (sizeof(__u32) - 1)) || (metalen > 32);

}



struct xdp_attachment_info {

	struct bpf_prog *prog;

	u32 flags;

net/core/filter.c

+2 −2
Original line number Diff line number Diff line
@@ -77,6 +77,7 @@ 
#include <net/transp_v6.h>

#include <linux/btf_ids.h>

#include <net/tls.h>

#include <net/xdp.h>



static const struct bpf_func_proto *

bpf_sk_base_func_proto(enum bpf_func_id func_id);
@@ -3880,8 +3881,7 @@ BPF_CALL_2(bpf_xdp_adjust_meta, struct xdp_buff *, xdp, int, offset) 
	if (unlikely(meta < xdp_frame_end ||

		     meta > xdp->data))

		return -EINVAL;

	if (unlikely((metalen & (sizeof(__u32) - 1)) ||

		     (metalen > 32)))

	if (unlikely(xdp_metalen_invalid(metalen)))

		return -EACCES;



	xdp->data_meta = meta;