linux_dsm_epyc7002/tools/testing/selftests/bpf/test_adjust_tail.c
Nikita V. Shirokov 0367d0a294 bpf: adding tests for bpf_xdp_adjust_tail
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>
2018-04-18 23:34:17 +02:00

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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";