1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
3
4 #include "vmlinux.h"
5 #include <bpf/bpf_helpers.h>
6 #include <bpf/bpf_tracing.h>
7 #include "bpf_kfuncs.h"
8
9 char _license[] SEC("license") = "GPL";
10
11 __u32 monitored_pid;
12 __u32 found_xattr;
13
14 static const char expected_value[] = "hello";
15 char value[32];
16
17 SEC("lsm.s/file_open")
18 int BPF_PROG(test_file_open, struct file *f)
19 {
20 struct bpf_dynptr value_ptr;
21 __u32 pid;
22 int ret;
23
24 pid = bpf_get_current_pid_tgid() >> 32;
25 if (pid != monitored_pid)
26 return 0;
27
28 bpf_dynptr_from_mem(value, sizeof(value), 0, &value_ptr);
29
30 ret = bpf_get_file_xattr(f, "user.kfuncs", &value_ptr);
31 if (ret != sizeof(expected_value))
32 return 0;
33 if (bpf_strncmp(value, ret, expected_value))
34 return 0;
35 found_xattr = 1;
36 return 0;
37 }
38
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.