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6#include <linux/bpf.h>
7#include <linux/filter.h>
8#include <linux/bpf_lirc.h>
9#include "rc-core-priv.h"
10
11
12
13
14const struct bpf_prog_ops lirc_mode2_prog_ops = {
15};
16
17BPF_CALL_1(bpf_rc_repeat, u32*, sample)
18{
19 struct ir_raw_event_ctrl *ctrl;
20
21 ctrl = container_of(sample, struct ir_raw_event_ctrl, bpf_sample);
22
23 rc_repeat(ctrl->dev);
24
25 return 0;
26}
27
28static const struct bpf_func_proto rc_repeat_proto = {
29 .func = bpf_rc_repeat,
30 .gpl_only = true,
31 .ret_type = RET_INTEGER,
32 .arg1_type = ARG_PTR_TO_CTX,
33};
34
35
36
37
38
39
40BPF_CALL_4(bpf_rc_keydown, u32*, sample, u32, protocol, u64, scancode,
41 u32, toggle)
42{
43 struct ir_raw_event_ctrl *ctrl;
44
45 ctrl = container_of(sample, struct ir_raw_event_ctrl, bpf_sample);
46
47 rc_keydown(ctrl->dev, protocol, scancode, toggle != 0);
48
49 return 0;
50}
51
52static const struct bpf_func_proto rc_keydown_proto = {
53 .func = bpf_rc_keydown,
54 .gpl_only = true,
55 .ret_type = RET_INTEGER,
56 .arg1_type = ARG_PTR_TO_CTX,
57 .arg2_type = ARG_ANYTHING,
58 .arg3_type = ARG_ANYTHING,
59 .arg4_type = ARG_ANYTHING,
60};
61
62static const struct bpf_func_proto *
63lirc_mode2_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
64{
65 switch (func_id) {
66 case BPF_FUNC_rc_repeat:
67 return &rc_repeat_proto;
68 case BPF_FUNC_rc_keydown:
69 return &rc_keydown_proto;
70 case BPF_FUNC_map_lookup_elem:
71 return &bpf_map_lookup_elem_proto;
72 case BPF_FUNC_map_update_elem:
73 return &bpf_map_update_elem_proto;
74 case BPF_FUNC_map_delete_elem:
75 return &bpf_map_delete_elem_proto;
76 case BPF_FUNC_ktime_get_ns:
77 return &bpf_ktime_get_ns_proto;
78 case BPF_FUNC_tail_call:
79 return &bpf_tail_call_proto;
80 case BPF_FUNC_get_prandom_u32:
81 return &bpf_get_prandom_u32_proto;
82 case BPF_FUNC_trace_printk:
83 if (capable(CAP_SYS_ADMIN))
84 return bpf_get_trace_printk_proto();
85
86 default:
87 return NULL;
88 }
89}
90
91static bool lirc_mode2_is_valid_access(int off, int size,
92 enum bpf_access_type type,
93 const struct bpf_prog *prog,
94 struct bpf_insn_access_aux *info)
95{
96
97 return type == BPF_READ && off == 0 && size == sizeof(u32);
98}
99
100const struct bpf_verifier_ops lirc_mode2_verifier_ops = {
101 .get_func_proto = lirc_mode2_func_proto,
102 .is_valid_access = lirc_mode2_is_valid_access
103};
104
105#define BPF_MAX_PROGS 64
106
107static int lirc_bpf_attach(struct rc_dev *rcdev, struct bpf_prog *prog)
108{
109 struct bpf_prog_array __rcu *old_array;
110 struct bpf_prog_array *new_array;
111 struct ir_raw_event_ctrl *raw;
112 int ret;
113
114 if (rcdev->driver_type != RC_DRIVER_IR_RAW)
115 return -EINVAL;
116
117 ret = mutex_lock_interruptible(&ir_raw_handler_lock);
118 if (ret)
119 return ret;
120
121 raw = rcdev->raw;
122 if (!raw) {
123 ret = -ENODEV;
124 goto unlock;
125 }
126
127 if (raw->progs && bpf_prog_array_length(raw->progs) >= BPF_MAX_PROGS) {
128 ret = -E2BIG;
129 goto unlock;
130 }
131
132 old_array = raw->progs;
133 ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array);
134 if (ret < 0)
135 goto unlock;
136
137 rcu_assign_pointer(raw->progs, new_array);
138 bpf_prog_array_free(old_array);
139
140unlock:
141 mutex_unlock(&ir_raw_handler_lock);
142 return ret;
143}
144
145static int lirc_bpf_detach(struct rc_dev *rcdev, struct bpf_prog *prog)
146{
147 struct bpf_prog_array __rcu *old_array;
148 struct bpf_prog_array *new_array;
149 struct ir_raw_event_ctrl *raw;
150 int ret;
151
152 if (rcdev->driver_type != RC_DRIVER_IR_RAW)
153 return -EINVAL;
154
155 ret = mutex_lock_interruptible(&ir_raw_handler_lock);
156 if (ret)
157 return ret;
158
159 raw = rcdev->raw;
160 if (!raw) {
161 ret = -ENODEV;
162 goto unlock;
163 }
164
165 old_array = raw->progs;
166 ret = bpf_prog_array_copy(old_array, prog, NULL, &new_array);
167
168
169
170
171
172 if (ret)
173 goto unlock;
174
175 rcu_assign_pointer(raw->progs, new_array);
176 bpf_prog_array_free(old_array);
177 bpf_prog_put(prog);
178unlock:
179 mutex_unlock(&ir_raw_handler_lock);
180 return ret;
181}
182
183void lirc_bpf_run(struct rc_dev *rcdev, u32 sample)
184{
185 struct ir_raw_event_ctrl *raw = rcdev->raw;
186
187 raw->bpf_sample = sample;
188
189 if (raw->progs)
190 BPF_PROG_RUN_ARRAY(raw->progs, &raw->bpf_sample, BPF_PROG_RUN);
191}
192
193
194
195
196
197void lirc_bpf_free(struct rc_dev *rcdev)
198{
199 struct bpf_prog **progs;
200
201 if (!rcdev->raw->progs)
202 return;
203
204 progs = rcu_dereference(rcdev->raw->progs)->progs;
205 while (*progs)
206 bpf_prog_put(*progs++);
207
208 bpf_prog_array_free(rcdev->raw->progs);
209}
210
211int lirc_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog)
212{
213 struct rc_dev *rcdev;
214 int ret;
215
216 if (attr->attach_flags)
217 return -EINVAL;
218
219 rcdev = rc_dev_get_from_fd(attr->target_fd);
220 if (IS_ERR(rcdev))
221 return PTR_ERR(rcdev);
222
223 ret = lirc_bpf_attach(rcdev, prog);
224
225 put_device(&rcdev->dev);
226
227 return ret;
228}
229
230int lirc_prog_detach(const union bpf_attr *attr)
231{
232 struct bpf_prog *prog;
233 struct rc_dev *rcdev;
234 int ret;
235
236 if (attr->attach_flags)
237 return -EINVAL;
238
239 prog = bpf_prog_get_type(attr->attach_bpf_fd,
240 BPF_PROG_TYPE_LIRC_MODE2);
241 if (IS_ERR(prog))
242 return PTR_ERR(prog);
243
244 rcdev = rc_dev_get_from_fd(attr->target_fd);
245 if (IS_ERR(rcdev)) {
246 bpf_prog_put(prog);
247 return PTR_ERR(rcdev);
248 }
249
250 ret = lirc_bpf_detach(rcdev, prog);
251
252 bpf_prog_put(prog);
253 put_device(&rcdev->dev);
254
255 return ret;
256}
257
258int lirc_prog_query(const union bpf_attr *attr, union bpf_attr __user *uattr)
259{
260 __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids);
261 struct bpf_prog_array __rcu *progs;
262 struct rc_dev *rcdev;
263 u32 cnt, flags = 0;
264 int ret;
265
266 if (attr->query.query_flags)
267 return -EINVAL;
268
269 rcdev = rc_dev_get_from_fd(attr->query.target_fd);
270 if (IS_ERR(rcdev))
271 return PTR_ERR(rcdev);
272
273 if (rcdev->driver_type != RC_DRIVER_IR_RAW) {
274 ret = -EINVAL;
275 goto put;
276 }
277
278 ret = mutex_lock_interruptible(&ir_raw_handler_lock);
279 if (ret)
280 goto put;
281
282 progs = rcdev->raw->progs;
283 cnt = progs ? bpf_prog_array_length(progs) : 0;
284
285 if (copy_to_user(&uattr->query.prog_cnt, &cnt, sizeof(cnt))) {
286 ret = -EFAULT;
287 goto unlock;
288 }
289
290 if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags))) {
291 ret = -EFAULT;
292 goto unlock;
293 }
294
295 if (attr->query.prog_cnt != 0 && prog_ids && cnt)
296 ret = bpf_prog_array_copy_to_user(progs, prog_ids, cnt);
297
298unlock:
299 mutex_unlock(&ir_raw_handler_lock);
300put:
301 put_device(&rcdev->dev);
302
303 return ret;
304}
305
