forked from Minki/linux
0367d0a294
adding selftests for bpf_xdp_adjust_tail helper. in this synthetic test we are testing that 1) if data_end < data helper will return EINVAL 2) for normal use case packet's length would be reduced. Signed-off-by: Nikita V. Shirokov <tehnerd@tehnerd.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
31 lines
731 B
C
31 lines
731 B
C
/* SPDX-License-Identifier: GPL-2.0
|
|
* Copyright (c) 2018 Facebook
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of version 2 of the GNU General Public
|
|
* License as published by the Free Software Foundation.
|
|
*/
|
|
#include <linux/bpf.h>
|
|
#include <linux/if_ether.h>
|
|
#include "bpf_helpers.h"
|
|
|
|
int _version SEC("version") = 1;
|
|
|
|
SEC("xdp_adjust_tail")
|
|
int _xdp_adjust_tail(struct xdp_md *xdp)
|
|
{
|
|
void *data_end = (void *)(long)xdp->data_end;
|
|
void *data = (void *)(long)xdp->data;
|
|
int offset = 0;
|
|
|
|
if (data_end - data == 54)
|
|
offset = 256;
|
|
else
|
|
offset = 20;
|
|
if (bpf_xdp_adjust_tail(xdp, 0 - offset))
|
|
return XDP_DROP;
|
|
return XDP_TX;
|
|
}
|
|
|
|
char _license[] SEC("license") = "GPL";
|