test_d_path.c

 1// SPDX-License-Identifier: GPL-2.0
 2
 3#include "vmlinux.h"
 4#include <bpf/bpf_helpers.h>
 5#include <bpf/bpf_tracing.h>
 6
 7#define MAX_PATH_LEN		128
 8#define MAX_FILES		7
 9
10pid_t my_pid = 0;
11__u32 cnt_stat = 0;
12__u32 cnt_close = 0;
13char paths_stat[MAX_FILES][MAX_PATH_LEN] = {};
14char paths_close[MAX_FILES][MAX_PATH_LEN] = {};
15int rets_stat[MAX_FILES] = {};
16int rets_close[MAX_FILES] = {};
17
18int called_stat = 0;
19int called_close = 0;
20int path_match_fallocate = 0;
21
22SEC("fentry/security_inode_getattr")
23int BPF_PROG(prog_stat, struct path *path, struct kstat *stat,
24	     __u32 request_mask, unsigned int query_flags)
25{
26	pid_t pid = bpf_get_current_pid_tgid() >> 32;
27	__u32 cnt = cnt_stat;
28	int ret;
29
30	called_stat = 1;
31
32	if (pid != my_pid)
33		return 0;
34
35	if (cnt >= MAX_FILES)
36		return 0;
37	ret = bpf_d_path(path, paths_stat[cnt], MAX_PATH_LEN);
38
39	rets_stat[cnt] = ret;
40	cnt_stat++;
41	return 0;
42}
43
44SEC("fentry/filp_close")
45int BPF_PROG(prog_close, struct file *file, void *id)
46{
47	pid_t pid = bpf_get_current_pid_tgid() >> 32;
48	__u32 cnt = cnt_close;
49	int ret;
50
51	called_close = 1;
52
53	if (pid != my_pid)
54		return 0;
55
56	if (cnt >= MAX_FILES)
57		return 0;
58	ret = bpf_d_path(&file->f_path,
59			 paths_close[cnt], MAX_PATH_LEN);
60
61	rets_close[cnt] = ret;
62	cnt_close++;
63	return 0;
64}
65
66SEC("fentry/vfs_fallocate")
67int BPF_PROG(prog_fallocate, struct file *file, int mode, loff_t offset, loff_t len)
68{
69	pid_t pid = bpf_get_current_pid_tgid() >> 32;
70	int ret = 0;
71	char path_fallocate[MAX_PATH_LEN] = {};
72
73	if (pid != my_pid)
74		return 0;
75
76	ret = bpf_d_path(&file->f_path,
77			 path_fallocate, MAX_PATH_LEN);
78	if (ret < 0)
79		return 0;
80
81	if (!path_fallocate[0])
82		return 0;
83
84	path_match_fallocate = 1;
85	return 0;
86}
87
88char _license[] SEC("license") = "GPL";