1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
|
// Copyright (c) 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "device/hid/hid_connection_linux.h"
#include <errno.h>
#include <linux/hidraw.h>
#include <sys/ioctl.h>
#include <string>
#include "base/bind.h"
#include "base/files/file_path.h"
#include "base/message_loop/message_loop.h"
#include "base/message_loop/message_pump_libevent.h"
#include "base/posix/eintr_wrapper.h"
#include "base/thread_task_runner_handle.h"
#include "base/threading/thread_restrictions.h"
#include "components/device_event_log/device_event_log.h"
#include "device/hid/hid_service.h"
// These are already defined in newer versions of linux/hidraw.h.
#ifndef HIDIOCSFEATURE
#define HIDIOCSFEATURE(len) _IOC(_IOC_WRITE | _IOC_READ, 'H', 0x06, len)
#endif
#ifndef HIDIOCGFEATURE
#define HIDIOCGFEATURE(len) _IOC(_IOC_WRITE | _IOC_READ, 'H', 0x07, len)
#endif
namespace device {
class HidConnectionLinux::FileThreadHelper
: public base::MessagePumpLibevent::Watcher {
public:
FileThreadHelper(base::PlatformFile platform_file,
scoped_refptr<HidDeviceInfo> device_info,
base::WeakPtr<HidConnectionLinux> connection,
scoped_refptr<base::SingleThreadTaskRunner> task_runner)
: platform_file_(platform_file),
connection_(connection),
task_runner_(task_runner) {
// Report buffers must always have room for the report ID.
report_buffer_size_ = device_info->max_input_report_size() + 1;
has_report_id_ = device_info->has_report_id();
}
~FileThreadHelper() override {
DCHECK(thread_checker_.CalledOnValidThread());
}
// Starts the FileDescriptorWatcher that reads input events from the device.
// Must be called on a thread that has a base::MessageLoopForIO. The helper
// object is owned by the thread where it was started.
void Start() {
base::ThreadRestrictions::AssertIOAllowed();
thread_checker_.DetachFromThread();
if (!base::MessageLoopForIO::current()->WatchFileDescriptor(
platform_file_, true, base::MessageLoopForIO::WATCH_READ,
&file_watcher_, this)) {
HID_LOG(ERROR) << "Failed to start watching device file.";
}
}
private:
// base::MessagePumpLibevent::Watcher implementation.
void OnFileCanReadWithoutBlocking(int fd) override {
DCHECK(thread_checker_.CalledOnValidThread());
DCHECK_EQ(fd, platform_file_);
scoped_refptr<net::IOBuffer> buffer(new net::IOBuffer(report_buffer_size_));
char* data = buffer->data();
size_t length = report_buffer_size_;
if (!has_report_id_) {
// Linux will not prefix the buffer with a report ID if report IDs are not
// used by the device. Prefix the buffer with 0.
*data++ = 0;
length--;
}
ssize_t bytes_read = HANDLE_EINTR(read(platform_file_, data, length));
if (bytes_read < 0) {
if (errno != EAGAIN) {
HID_PLOG(EVENT) << "Read failed";
// This assumes that the error is unrecoverable and disables reading
// from the device until it has been re-opened.
// TODO(reillyg): Investigate starting and stopping the file descriptor
// watcher in response to pending read requests so that per-request
// errors can be returned to the client.
file_watcher_.StopWatchingFileDescriptor();
}
return;
}
if (!has_report_id_) {
// Behave as if the byte prefixed above as the the report ID was read.
bytes_read++;
}
task_runner_->PostTask(FROM_HERE,
base::Bind(&HidConnectionLinux::ProcessInputReport,
connection_, buffer, bytes_read));
}
void OnFileCanWriteWithoutBlocking(int fd) override {
NOTREACHED(); // Only listening for reads.
}
base::ThreadChecker thread_checker_;
base::PlatformFile platform_file_;
size_t report_buffer_size_;
bool has_report_id_;
base::WeakPtr<HidConnectionLinux> connection_;
scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
base::MessagePumpLibevent::FileDescriptorWatcher file_watcher_;
};
HidConnectionLinux::HidConnectionLinux(
scoped_refptr<HidDeviceInfo> device_info,
base::File device_file,
scoped_refptr<base::SingleThreadTaskRunner> file_task_runner)
: HidConnection(device_info),
file_task_runner_(file_task_runner),
weak_factory_(this) {
task_runner_ = base::ThreadTaskRunnerHandle::Get();
device_file_ = device_file.Pass();
// The helper is passed a weak pointer to this connection so that it can be
// cleaned up after the connection is closed.
helper_ = new FileThreadHelper(device_file_.GetPlatformFile(), device_info,
weak_factory_.GetWeakPtr(), task_runner_);
file_task_runner_->PostTask(FROM_HERE, base::Bind(&FileThreadHelper::Start,
base::Unretained(helper_)));
}
HidConnectionLinux::~HidConnectionLinux() {
DCHECK(helper_ == nullptr);
}
void HidConnectionLinux::PlatformClose() {
// By closing the device file on the FILE thread (1) the requirement that
// base::File::Close is called on a thread where I/O is allowed is satisfied
// and (2) any tasks posted to this task runner that refer to this file will
// complete before it is closed.
file_task_runner_->DeleteSoon(FROM_HERE, helper_);
helper_ = nullptr;
file_task_runner_->PostTask(FROM_HERE,
base::Bind(&HidConnectionLinux::CloseDevice,
base::Passed(&device_file_)));
while (!pending_reads_.empty()) {
pending_reads_.front().callback.Run(false, NULL, 0);
pending_reads_.pop();
}
}
void HidConnectionLinux::PlatformRead(const ReadCallback& callback) {
PendingHidRead pending_read;
pending_read.callback = callback;
pending_reads_.push(pending_read);
ProcessReadQueue();
}
void HidConnectionLinux::PlatformWrite(scoped_refptr<net::IOBuffer> buffer,
size_t size,
const WriteCallback& callback) {
// Linux expects the first byte of the buffer to always be a report ID so the
// buffer can be used directly.
file_task_runner_->PostTask(
FROM_HERE,
base::Bind(&HidConnectionLinux::BlockingWrite,
device_file_.GetPlatformFile(), buffer, size,
base::Bind(&HidConnectionLinux::FinishWrite,
weak_factory_.GetWeakPtr(), size, callback),
task_runner_));
}
void HidConnectionLinux::PlatformGetFeatureReport(
uint8_t report_id,
const ReadCallback& callback) {
// The first byte of the destination buffer is the report ID being requested
// and is overwritten by the feature report.
DCHECK_GT(device_info()->max_feature_report_size(), 0u);
scoped_refptr<net::IOBufferWithSize> buffer(
new net::IOBufferWithSize(device_info()->max_feature_report_size() + 1));
buffer->data()[0] = report_id;
file_task_runner_->PostTask(
FROM_HERE,
base::Bind(
&HidConnectionLinux::BlockingIoctl, device_file_.GetPlatformFile(),
HIDIOCGFEATURE(buffer->size()), buffer,
base::Bind(&HidConnectionLinux::FinishGetFeatureReport,
weak_factory_.GetWeakPtr(), report_id, buffer, callback),
task_runner_));
}
void HidConnectionLinux::PlatformSendFeatureReport(
scoped_refptr<net::IOBuffer> buffer,
size_t size,
const WriteCallback& callback) {
// Linux expects the first byte of the buffer to always be a report ID so the
// buffer can be used directly.
file_task_runner_->PostTask(
FROM_HERE,
base::Bind(&HidConnectionLinux::BlockingIoctl,
device_file_.GetPlatformFile(), HIDIOCSFEATURE(size), buffer,
base::Bind(&HidConnectionLinux::FinishSendFeatureReport,
weak_factory_.GetWeakPtr(), callback),
task_runner_));
}
void HidConnectionLinux::FinishWrite(size_t expected_size,
const WriteCallback& callback,
ssize_t result) {
if (result < 0) {
HID_PLOG(EVENT) << "Write failed";
callback.Run(false);
} else {
if (static_cast<size_t>(result) != expected_size) {
HID_LOG(EVENT) << "Incomplete HID write: " << result
<< " != " << expected_size;
}
callback.Run(true);
}
}
void HidConnectionLinux::FinishGetFeatureReport(
uint8_t report_id,
scoped_refptr<net::IOBuffer> buffer,
const ReadCallback& callback,
int result) {
if (result < 0) {
HID_PLOG(EVENT) << "Failed to get feature report";
callback.Run(false, NULL, 0);
} else if (result == 0) {
HID_LOG(EVENT) << "Get feature result too short.";
callback.Run(false, NULL, 0);
} else if (report_id == 0) {
// Linux adds a 0 to the beginning of the data received from the device.
scoped_refptr<net::IOBuffer> copied_buffer(new net::IOBuffer(result - 1));
memcpy(copied_buffer->data(), buffer->data() + 1, result - 1);
callback.Run(true, copied_buffer, result - 1);
} else {
callback.Run(true, buffer, result);
}
}
void HidConnectionLinux::FinishSendFeatureReport(const WriteCallback& callback,
int result) {
if (result < 0) {
HID_PLOG(EVENT) << "Failed to send feature report";
callback.Run(false);
} else {
callback.Run(true);
}
}
// static
void HidConnectionLinux::BlockingWrite(
base::PlatformFile platform_file,
scoped_refptr<net::IOBuffer> buffer,
size_t size,
const InternalWriteCallback& callback,
scoped_refptr<base::SingleThreadTaskRunner> task_runner) {
base::ThreadRestrictions::AssertIOAllowed();
ssize_t result = HANDLE_EINTR(write(platform_file, buffer->data(), size));
task_runner->PostTask(FROM_HERE, base::Bind(callback, result));
}
// static
void HidConnectionLinux::BlockingIoctl(
base::PlatformFile platform_file,
int request,
scoped_refptr<net::IOBuffer> buffer,
const IoctlCallback& callback,
scoped_refptr<base::SingleThreadTaskRunner> task_runner) {
base::ThreadRestrictions::AssertIOAllowed();
int result = ioctl(platform_file, request, buffer->data());
task_runner->PostTask(FROM_HERE, base::Bind(callback, result));
}
// static
void HidConnectionLinux::CloseDevice(base::File device_file) {
device_file.Close();
}
void HidConnectionLinux::ProcessInputReport(scoped_refptr<net::IOBuffer> buffer,
size_t size) {
DCHECK(thread_checker().CalledOnValidThread());
PendingHidReport report;
report.buffer = buffer;
report.size = size;
pending_reports_.push(report);
ProcessReadQueue();
}
void HidConnectionLinux::ProcessReadQueue() {
DCHECK(thread_checker().CalledOnValidThread());
while (pending_reads_.size() && pending_reports_.size()) {
PendingHidRead read = pending_reads_.front();
PendingHidReport report = pending_reports_.front();
pending_reports_.pop();
if (CompleteRead(report.buffer, report.size, read.callback)) {
pending_reads_.pop();
}
}
}
} // namespace device
|