verifier_mtu.c

 1// SPDX-License-Identifier: GPL-2.0
 2
 3#include "vmlinux.h"
 4#include <bpf/bpf_helpers.h>
 5#include "bpf_misc.h"
 6
 7SEC("tc/ingress")
 8__description("uninit/mtu: write rejected")
 9__success
10__caps_unpriv(CAP_BPF|CAP_NET_ADMIN)
11__failure_unpriv __msg_unpriv("invalid read from stack")
12int tc_uninit_mtu(struct __sk_buff *ctx)
13{
14	__u32 mtu;
15
16	bpf_check_mtu(ctx, 0, &mtu, 0, 0);
17	return TCX_PASS;
18}
19
20char LICENSE[] SEC("license") = "GPL";