1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2020 Google LLC. */
3 #include "bpf_iter.h"
4 #include <bpf/bpf_helpers.h>
5 #include <bpf/bpf_tracing.h>
6 
7 char _license[] SEC("license") = "GPL";
8 
9 struct {
10 	__uint(type, BPF_MAP_TYPE_SK_STORAGE);
11 	__uint(map_flags, BPF_F_NO_PREALLOC);
12 	__type(key, int);
13 	__type(value, int);
14 } sk_stg_map SEC(".maps");
15 
16 SEC("iter/bpf_sk_storage_map")
17 int delete_bpf_sk_storage_map(struct bpf_iter__bpf_sk_storage_map *ctx)
18 {
19 	if (ctx->sk)
20 		bpf_sk_storage_delete(&sk_stg_map, ctx->sk);
21 
22 	return 0;
23 }
24 
25 SEC("iter/task_file")
26 int fill_socket_owner(struct bpf_iter__task_file *ctx)
27 {
28 	struct task_struct *task = ctx->task;
29 	struct file *file = ctx->file;
30 	struct socket *sock;
31 	int *sock_tgid;
32 
33 	if (!task || !file)
34 		return 0;
35 
36 	sock = bpf_sock_from_file(file);
37 	if (!sock)
38 		return 0;
39 
40 	sock_tgid = bpf_sk_storage_get(&sk_stg_map, sock->sk, 0, 0);
41 	if (!sock_tgid)
42 		return 0;
43 
44 	*sock_tgid = task->tgid;
45 
46 	return 0;
47 }
48 
49 SEC("iter/tcp")
50 int negate_socket_local_storage(struct bpf_iter__tcp *ctx)
51 {
52 	struct sock_common *sk_common = ctx->sk_common;
53 	int *sock_tgid;
54 
55 	if (!sk_common)
56 		return 0;
57 
58 	sock_tgid = bpf_sk_storage_get(&sk_stg_map, sk_common, 0, 0);
59 	if (!sock_tgid)
60 		return 0;
61 
62 	*sock_tgid = -*sock_tgid;
63 
64 	return 0;
65 }
66