1// SPDX-License-Identifier: GPL-2.0
2
3/*
4 * Copyright 2020 Google LLC.
5 */
6
7#include "vmlinux.h"
8#include <errno.h>
9#include <bpf/bpf_core_read.h>
10#include <bpf/bpf_helpers.h>
11#include <bpf/bpf_tracing.h>
12#include "bpf_misc.h"
13
14struct {
15	__uint(type, BPF_MAP_TYPE_ARRAY);
16	__uint(max_entries, 1);
17	__type(key, __u32);
18	__type(value, __u64);
19} array SEC(".maps");
20
21struct {
22	__uint(type, BPF_MAP_TYPE_HASH);
23	__uint(max_entries, 1);
24	__type(key, __u32);
25	__type(value, __u64);
26} hash SEC(".maps");
27
28struct {
29	__uint(type, BPF_MAP_TYPE_LRU_HASH);
30	__uint(max_entries, 1);
31	__type(key, __u32);
32	__type(value, __u64);
33} lru_hash SEC(".maps");
34
35struct {
36	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
37	__uint(max_entries, 1);
38	__type(key, __u32);
39	__type(value, __u64);
40} percpu_array SEC(".maps");
41
42struct {
43	__uint(type, BPF_MAP_TYPE_PERCPU_HASH);
44	__uint(max_entries, 1);
45	__type(key, __u32);
46	__type(value, __u64);
47} percpu_hash SEC(".maps");
48
49struct {
50	__uint(type, BPF_MAP_TYPE_LRU_PERCPU_HASH);
51	__uint(max_entries, 1);
52	__type(key, __u32);
53	__type(value, __u64);
54} lru_percpu_hash SEC(".maps");
55
56struct inner_map {
57	__uint(type, BPF_MAP_TYPE_ARRAY);
58	__uint(max_entries, 1);
59	__type(key, int);
60	__type(value, __u64);
61} inner_map SEC(".maps");
62
63struct outer_arr {
64	__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
65	__uint(max_entries, 1);
66	__uint(key_size, sizeof(int));
67	__uint(value_size, sizeof(int));
68	__array(values, struct inner_map);
69} outer_arr SEC(".maps") = {
70	.values = { [0] = &inner_map },
71};
72
73struct outer_hash {
74	__uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
75	__uint(max_entries, 1);
76	__uint(key_size, sizeof(int));
77	__array(values, struct inner_map);
78} outer_hash SEC(".maps") = {
79	.values = { [0] = &inner_map },
80};
81
82char _license[] SEC("license") = "GPL";
83
84int monitored_pid = 0;
85int mprotect_count = 0;
86int bprm_count = 0;
87
88SEC("lsm/file_mprotect")
89int BPF_PROG(test_int_hook, struct vm_area_struct *vma,
90	     unsigned long reqprot, unsigned long prot, int ret)
91{
92	if (ret != 0)
93		return ret;
94
95	__s32 pid = bpf_get_current_pid_tgid() >> 32;
96	int is_stack = 0;
97
98	is_stack = (vma->vm_start <= vma->vm_mm->start_stack &&
99		    vma->vm_end >= vma->vm_mm->start_stack);
100
101	if (is_stack && monitored_pid == pid) {
102		mprotect_count++;
103		ret = -EPERM;
104	}
105
106	return ret;
107}
108
109SEC("lsm.s/bprm_committed_creds")
110int BPF_PROG(test_void_hook, struct linux_binprm *bprm)
111{
112	__u32 pid = bpf_get_current_pid_tgid() >> 32;
113	struct inner_map *inner_map;
114	char args[64];
115	__u32 key = 0;
116	__u64 *value;
117
118	if (monitored_pid == pid)
119		bprm_count++;
120
121	bpf_copy_from_user(args, sizeof(args), (void *)bprm->vma->vm_mm->arg_start);
122	bpf_copy_from_user(args, sizeof(args), (void *)bprm->mm->arg_start);
123
124	value = bpf_map_lookup_elem(&array, &key);
125	if (value)
126		*value = 0;
127	value = bpf_map_lookup_elem(&hash, &key);
128	if (value)
129		*value = 0;
130	value = bpf_map_lookup_elem(&lru_hash, &key);
131	if (value)
132		*value = 0;
133	value = bpf_map_lookup_elem(&percpu_array, &key);
134	if (value)
135		*value = 0;
136	value = bpf_map_lookup_elem(&percpu_hash, &key);
137	if (value)
138		*value = 0;
139	value = bpf_map_lookup_elem(&lru_percpu_hash, &key);
140	if (value)
141		*value = 0;
142	inner_map = bpf_map_lookup_elem(&outer_arr, &key);
143	if (inner_map) {
144		value = bpf_map_lookup_elem(inner_map, &key);
145		if (value)
146			*value = 0;
147	}
148	inner_map = bpf_map_lookup_elem(&outer_hash, &key);
149	if (inner_map) {
150		value = bpf_map_lookup_elem(inner_map, &key);
151		if (value)
152			*value = 0;
153	}
154
155	return 0;
156}
157SEC("lsm/task_free") /* lsm/ is ok, lsm.s/ fails */
158int BPF_PROG(test_task_free, struct task_struct *task)
159{
160	return 0;
161}
162
163int copy_test = 0;
164
165SEC("fentry.s/" SYS_PREFIX "sys_setdomainname")
166int BPF_PROG(test_sys_setdomainname, struct pt_regs *regs)
167{
168	void *ptr = (void *)PT_REGS_PARM1_SYSCALL(regs);
169	int len = PT_REGS_PARM2_SYSCALL(regs);
170	int buf = 0;
171	long ret;
172
173	ret = bpf_copy_from_user(&buf, sizeof(buf), ptr);
174	if (len == -2 && ret == 0 && buf == 1234)
175		copy_test++;
176	if (len == -3 && ret == -EFAULT)
177		copy_test++;
178	if (len == -4 && ret == -EFAULT)
179		copy_test++;
180	return 0;
181}
182