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1/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
2 *
3 * This program is free software; you can redistribute it and/or
4 * modify it under the terms of version 2 of the GNU General Public
5 * License as published by the Free Software Foundation.
6 *
7 * This program is distributed in the hope that it will be useful, but
8 * WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
10 * General Public License for more details.
11 */
12#include <linux/bpf.h>
13#include <linux/rcupdate.h>
14#include <linux/random.h>
15#include <linux/smp.h>
16#include <linux/ktime.h>
17#include <linux/sched.h>
18#include <linux/uidgid.h>
19
20/* If kernel subsystem is allowing eBPF programs to call this function,
21 * inside its own verifier_ops->get_func_proto() callback it should return
22 * bpf_map_lookup_elem_proto, so that verifier can properly check the arguments
23 *
24 * Different map implementations will rely on rcu in map methods
25 * lookup/update/delete, therefore eBPF programs must run under rcu lock
26 * if program is allowed to access maps, so check rcu_read_lock_held in
27 * all three functions.
28 */
29static u64 bpf_map_lookup_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
30{
31 /* verifier checked that R1 contains a valid pointer to bpf_map
32 * and R2 points to a program stack and map->key_size bytes were
33 * initialized
34 */
35 struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;
36 void *key = (void *) (unsigned long) r2;
37 void *value;
38
39 WARN_ON_ONCE(!rcu_read_lock_held());
40
41 value = map->ops->map_lookup_elem(map, key);
42
43 /* lookup() returns either pointer to element value or NULL
44 * which is the meaning of PTR_TO_MAP_VALUE_OR_NULL type
45 */
46 return (unsigned long) value;
47}
48
49const struct bpf_func_proto bpf_map_lookup_elem_proto = {
50 .func = bpf_map_lookup_elem,
51 .gpl_only = false,
52 .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
53 .arg1_type = ARG_CONST_MAP_PTR,
54 .arg2_type = ARG_PTR_TO_MAP_KEY,
55};
56
57static u64 bpf_map_update_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
58{
59 struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;
60 void *key = (void *) (unsigned long) r2;
61 void *value = (void *) (unsigned long) r3;
62
63 WARN_ON_ONCE(!rcu_read_lock_held());
64
65 return map->ops->map_update_elem(map, key, value, r4);
66}
67
68const struct bpf_func_proto bpf_map_update_elem_proto = {
69 .func = bpf_map_update_elem,
70 .gpl_only = false,
71 .ret_type = RET_INTEGER,
72 .arg1_type = ARG_CONST_MAP_PTR,
73 .arg2_type = ARG_PTR_TO_MAP_KEY,
74 .arg3_type = ARG_PTR_TO_MAP_VALUE,
75 .arg4_type = ARG_ANYTHING,
76};
77
78static u64 bpf_map_delete_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
79{
80 struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;
81 void *key = (void *) (unsigned long) r2;
82
83 WARN_ON_ONCE(!rcu_read_lock_held());
84
85 return map->ops->map_delete_elem(map, key);
86}
87
88const struct bpf_func_proto bpf_map_delete_elem_proto = {
89 .func = bpf_map_delete_elem,
90 .gpl_only = false,
91 .ret_type = RET_INTEGER,
92 .arg1_type = ARG_CONST_MAP_PTR,
93 .arg2_type = ARG_PTR_TO_MAP_KEY,
94};
95
96const struct bpf_func_proto bpf_get_prandom_u32_proto = {
97 .func = bpf_user_rnd_u32,
98 .gpl_only = false,
99 .ret_type = RET_INTEGER,
100};
101
102static u64 bpf_get_smp_processor_id(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
103{
104 return raw_smp_processor_id();
105}
106
107const struct bpf_func_proto bpf_get_smp_processor_id_proto = {
108 .func = bpf_get_smp_processor_id,
109 .gpl_only = false,
110 .ret_type = RET_INTEGER,
111};
112
113static u64 bpf_ktime_get_ns(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
114{
115 /* NMI safe access to clock monotonic */
116 return ktime_get_mono_fast_ns();
117}
118
119const struct bpf_func_proto bpf_ktime_get_ns_proto = {
120 .func = bpf_ktime_get_ns,
121 .gpl_only = true,
122 .ret_type = RET_INTEGER,
123};
124
125static u64 bpf_get_current_pid_tgid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
126{
127 struct task_struct *task = current;
128
129 if (!task)
130 return -EINVAL;
131
132 return (u64) task->tgid << 32 | task->pid;
133}
134
135const struct bpf_func_proto bpf_get_current_pid_tgid_proto = {
136 .func = bpf_get_current_pid_tgid,
137 .gpl_only = false,
138 .ret_type = RET_INTEGER,
139};
140
141static u64 bpf_get_current_uid_gid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
142{
143 struct task_struct *task = current;
144 kuid_t uid;
145 kgid_t gid;
146
147 if (!task)
148 return -EINVAL;
149
150 current_uid_gid(&uid, &gid);
151 return (u64) from_kgid(&init_user_ns, gid) << 32 |
152 from_kuid(&init_user_ns, uid);
153}
154
155const struct bpf_func_proto bpf_get_current_uid_gid_proto = {
156 .func = bpf_get_current_uid_gid,
157 .gpl_only = false,
158 .ret_type = RET_INTEGER,
159};
160
161static u64 bpf_get_current_comm(u64 r1, u64 size, u64 r3, u64 r4, u64 r5)
162{
163 struct task_struct *task = current;
164 char *buf = (char *) (long) r1;
165
166 if (!task)
167 return -EINVAL;
168
169 strlcpy(buf, task->comm, min_t(size_t, size, sizeof(task->comm)));
170 return 0;
171}
172
173const struct bpf_func_proto bpf_get_current_comm_proto = {
174 .func = bpf_get_current_comm,
175 .gpl_only = false,
176 .ret_type = RET_INTEGER,
177 .arg1_type = ARG_PTR_TO_STACK,
178 .arg2_type = ARG_CONST_STACK_SIZE,
179};
1/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
2 *
3 * This program is free software; you can redistribute it and/or
4 * modify it under the terms of version 2 of the GNU General Public
5 * License as published by the Free Software Foundation.
6 *
7 * This program is distributed in the hope that it will be useful, but
8 * WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
10 * General Public License for more details.
11 */
12#include <linux/bpf.h>
13#include <linux/rcupdate.h>
14#include <linux/random.h>
15#include <linux/smp.h>
16#include <linux/ktime.h>
17#include <linux/sched.h>
18#include <linux/uidgid.h>
19
20/* If kernel subsystem is allowing eBPF programs to call this function,
21 * inside its own verifier_ops->get_func_proto() callback it should return
22 * bpf_map_lookup_elem_proto, so that verifier can properly check the arguments
23 *
24 * Different map implementations will rely on rcu in map methods
25 * lookup/update/delete, therefore eBPF programs must run under rcu lock
26 * if program is allowed to access maps, so check rcu_read_lock_held in
27 * all three functions.
28 */
29static u64 bpf_map_lookup_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
30{
31 /* verifier checked that R1 contains a valid pointer to bpf_map
32 * and R2 points to a program stack and map->key_size bytes were
33 * initialized
34 */
35 struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;
36 void *key = (void *) (unsigned long) r2;
37 void *value;
38
39 WARN_ON_ONCE(!rcu_read_lock_held());
40
41 value = map->ops->map_lookup_elem(map, key);
42
43 /* lookup() returns either pointer to element value or NULL
44 * which is the meaning of PTR_TO_MAP_VALUE_OR_NULL type
45 */
46 return (unsigned long) value;
47}
48
49const struct bpf_func_proto bpf_map_lookup_elem_proto = {
50 .func = bpf_map_lookup_elem,
51 .gpl_only = false,
52 .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
53 .arg1_type = ARG_CONST_MAP_PTR,
54 .arg2_type = ARG_PTR_TO_MAP_KEY,
55};
56
57static u64 bpf_map_update_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
58{
59 struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;
60 void *key = (void *) (unsigned long) r2;
61 void *value = (void *) (unsigned long) r3;
62
63 WARN_ON_ONCE(!rcu_read_lock_held());
64
65 return map->ops->map_update_elem(map, key, value, r4);
66}
67
68const struct bpf_func_proto bpf_map_update_elem_proto = {
69 .func = bpf_map_update_elem,
70 .gpl_only = false,
71 .ret_type = RET_INTEGER,
72 .arg1_type = ARG_CONST_MAP_PTR,
73 .arg2_type = ARG_PTR_TO_MAP_KEY,
74 .arg3_type = ARG_PTR_TO_MAP_VALUE,
75 .arg4_type = ARG_ANYTHING,
76};
77
78static u64 bpf_map_delete_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
79{
80 struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;
81 void *key = (void *) (unsigned long) r2;
82
83 WARN_ON_ONCE(!rcu_read_lock_held());
84
85 return map->ops->map_delete_elem(map, key);
86}
87
88const struct bpf_func_proto bpf_map_delete_elem_proto = {
89 .func = bpf_map_delete_elem,
90 .gpl_only = false,
91 .ret_type = RET_INTEGER,
92 .arg1_type = ARG_CONST_MAP_PTR,
93 .arg2_type = ARG_PTR_TO_MAP_KEY,
94};
95
96const struct bpf_func_proto bpf_get_prandom_u32_proto = {
97 .func = bpf_user_rnd_u32,
98 .gpl_only = false,
99 .ret_type = RET_INTEGER,
100};
101
102static u64 bpf_get_smp_processor_id(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
103{
104 return raw_smp_processor_id();
105}
106
107const struct bpf_func_proto bpf_get_smp_processor_id_proto = {
108 .func = bpf_get_smp_processor_id,
109 .gpl_only = false,
110 .ret_type = RET_INTEGER,
111};
112
113static u64 bpf_ktime_get_ns(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
114{
115 /* NMI safe access to clock monotonic */
116 return ktime_get_mono_fast_ns();
117}
118
119const struct bpf_func_proto bpf_ktime_get_ns_proto = {
120 .func = bpf_ktime_get_ns,
121 .gpl_only = true,
122 .ret_type = RET_INTEGER,
123};
124
125static u64 bpf_get_current_pid_tgid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
126{
127 struct task_struct *task = current;
128
129 if (!task)
130 return -EINVAL;
131
132 return (u64) task->tgid << 32 | task->pid;
133}
134
135const struct bpf_func_proto bpf_get_current_pid_tgid_proto = {
136 .func = bpf_get_current_pid_tgid,
137 .gpl_only = false,
138 .ret_type = RET_INTEGER,
139};
140
141static u64 bpf_get_current_uid_gid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
142{
143 struct task_struct *task = current;
144 kuid_t uid;
145 kgid_t gid;
146
147 if (!task)
148 return -EINVAL;
149
150 current_uid_gid(&uid, &gid);
151 return (u64) from_kgid(&init_user_ns, gid) << 32 |
152 from_kuid(&init_user_ns, uid);
153}
154
155const struct bpf_func_proto bpf_get_current_uid_gid_proto = {
156 .func = bpf_get_current_uid_gid,
157 .gpl_only = false,
158 .ret_type = RET_INTEGER,
159};
160
161static u64 bpf_get_current_comm(u64 r1, u64 size, u64 r3, u64 r4, u64 r5)
162{
163 struct task_struct *task = current;
164 char *buf = (char *) (long) r1;
165
166 if (!task)
167 return -EINVAL;
168
169 strlcpy(buf, task->comm, min_t(size_t, size, sizeof(task->comm)));
170 return 0;
171}
172
173const struct bpf_func_proto bpf_get_current_comm_proto = {
174 .func = bpf_get_current_comm,
175 .gpl_only = false,
176 .ret_type = RET_INTEGER,
177 .arg1_type = ARG_PTR_TO_STACK,
178 .arg2_type = ARG_CONST_STACK_SIZE,
179};