// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2023 Facebook */
#include "vmlinux.h"
#include "bpf_tracing_net.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_core_read.h>

void *sk_ptr = NULL;
int cookie_found = 0;
__u64 cookie = 0;
__u32 omem = 0;

struct {
        __uint(type, BPF_MAP_TYPE_SK_STORAGE);
        __uint(map_flags, BPF_F_NO_PREALLOC);
        __type(key, int);
        __type(value, int);
} sk_storage SEC(".maps");

SEC("fexit/bpf_sk_storage_free")
int BPF_PROG(bpf_sk_storage_free, struct sock *sk)
{
        if (sk_ptr != sk)
                return 0;

        if (sk->sk_cookie.counter != cookie)
                return 0;

        cookie_found++;
        omem = sk->sk_omem_alloc.counter;

        return 0;
}

SEC("fentry/inet6_sock_destruct")
int BPF_PROG(inet6_sock_destruct, struct sock *sk)
{
        int *value;

        if (!cookie || sk->sk_cookie.counter != cookie)
                return 0;

        value = bpf_sk_storage_get(&sk_storage, sk, 0, 0);
        if (value && *value == 0xdeadbeef) {
                cookie_found++;
                sk_ptr = sk;
        }

        return 0;
}

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