1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2023 Facebook */
3 #include "vmlinux.h"
4 #include "bpf_tracing_net.h"
5 #include <bpf/bpf_helpers.h>
6 #include <bpf/bpf_tracing.h>
7 #include <bpf/bpf_core_read.h>
8
9 void *local_storage_ptr = NULL;
10 void *sk_ptr = NULL;
11 int cookie_found = 0;
12 __u64 cookie = 0;
13 __u32 omem = 0;
14
15 struct {
16 __uint(type, BPF_MAP_TYPE_SK_STORAGE);
17 __uint(map_flags, BPF_F_NO_PREALLOC);
18 __type(key, int);
19 __type(value, int);
20 } sk_storage SEC(".maps");
21
22 SEC("fexit/bpf_local_storage_destroy")
BPF_PROG(bpf_local_storage_destroy,struct bpf_local_storage * local_storage)23 int BPF_PROG(bpf_local_storage_destroy, struct bpf_local_storage *local_storage)
24 {
25 struct sock *sk;
26
27 if (local_storage_ptr != local_storage)
28 return 0;
29
30 sk = bpf_core_cast(sk_ptr, struct sock);
31 if (sk->sk_cookie.counter != cookie)
32 return 0;
33
34 cookie_found++;
35 omem = sk->sk_omem_alloc.counter;
36 local_storage_ptr = NULL;
37
38 return 0;
39 }
40
41 SEC("fentry/inet6_sock_destruct")
BPF_PROG(inet6_sock_destruct,struct sock * sk)42 int BPF_PROG(inet6_sock_destruct, struct sock *sk)
43 {
44 int *value;
45
46 if (!cookie || sk->sk_cookie.counter != cookie)
47 return 0;
48
49 value = bpf_sk_storage_get(&sk_storage, sk, 0, 0);
50 if (value && *value == 0xdeadbeef) {
51 cookie_found++;
52 sk_ptr = sk;
53 local_storage_ptr = sk->sk_bpf_storage;
54 }
55
56 return 0;
57 }
58
59 char _license[] SEC("license") = "GPL";
60