root/tools/testing/selftests/bpf/progs/test_skb_ctx.c
// SPDX-License-Identifier: GPL-2.0

#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>

#include "bpf_compiler.h"

char _license[] SEC("license") = "GPL";

SEC("tc")
int process(struct __sk_buff *skb)
{
        __pragma_loop_unroll_full
        for (int i = 0; i < 5; i++) {
                if (skb->cb[i] != i + 1)
                        return 1;
                skb->cb[i]++;
        }
        skb->priority++;
        skb->tstamp++;
        skb->mark++;

        if (skb->wire_len != 100)
                return 1;
        if (skb->gso_segs != 8)
                return 1;
        if (skb->gso_size != 10)
                return 1;
        if (skb->ingress_ifindex != 11)
                return 1;
        if (skb->ifindex != 1)
                return 1;
        if (skb->hwtstamp != 11)
                return 1;

        return 0;
}