chrome.hid: enrich model with report IDs

device/hid/hid_connection.cc

 // 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.h"
 
+#include <algorithm>
+
 namespace device {
 
+namespace {
+
+const uint8_t kNullReportId = 0x00;
+const uint8_t kAnyReportId = 0xFF;

[Ken Rockot(use gerrit already), 2014/06/27 14:50:22]

How about moving these constants to hid_connection_info.h so they can be shared
across modules? Seems like a reasonable place since HidConnectionInfo stores
report IDs.

[jracle (use Gerrit), 2014/06/27 20:07:06]

Makes sense.

On 2014/06/27 14:50:22, Ken Rockot wrote:

+
+struct CollectionHasReportId {

[Ken Rockot(use gerrit already), 2014/06/27 14:50:22]

Maybe a brief comment that this is a functor used to filter collections by
report ID.

[jracle (use Gerrit), 2014/06/27 20:07:06]

Sure.

On 2014/06/27 14:50:22, Ken Rockot wrote:

+  explicit CollectionHasReportId(const uint8_t report_id)
+      : report_id_(report_id) {}
+
+  bool operator()(const HidCollectionInfo& info) const {
+    if (info.report_ids.size() == 0 || report_id_ == kNullReportId)
+      return false;
+
+    if (report_id_ == kAnyReportId)
+      return true;
+
+    return std::find(info.report_ids.begin(),
+                     info.report_ids.end(),
+                     report_id_) != info.report_ids.end();
+  }
+
+ private:
+  const uint8_t report_id_;
+};
+
+struct CollectionIsProtected {

[Ken Rockot(use gerrit already), 2014/06/27 14:50:22]

Brief comment here as well.

[jracle (use Gerrit), 2014/06/27 20:07:06]

OK.

On 2014/06/27 14:50:22, Ken Rockot wrote:

+  bool operator()(const HidCollectionInfo& info) const {
+    return info.usage.IsProtected();
+  }
+};
+
+bool FindCollectionByReportId(const HidDeviceInfo& device_info,
+                              const uint8_t report_id,
+                              HidCollectionInfo* collection_info) {
+  std::vector<HidCollectionInfo>::const_iterator collection_iter =
+      std::find_if(device_info.collections.begin(),
+                   device_info.collections.end(),
+                   CollectionHasReportId(report_id));
+  if (collection_iter != device_info.collections.end()) {
+    if (collection_info) {
+      *collection_info = *collection_iter;
+    }
+    return true;
+  }
+
+  return false;
+}
+
+bool HasReportId(const HidDeviceInfo& device_info) {
+  return FindCollectionByReportId(device_info, kAnyReportId, NULL);
+}
+
+bool HasProtectedCollection(const HidDeviceInfo& device_info) {
+  return std::find_if(device_info.collections.begin(),
+                      device_info.collections.end(),
+                      CollectionIsProtected()) != device_info.collections.end();
+}
+
+}  // namespace
+
+HidConnection::HidConnection(const HidDeviceInfo& device_info)
+    : device_info_(device_info) {
+  DCHECK(thread_checker_.CalledOnValidThread());

[Ken Rockot(use gerrit already), 2014/06/27 14:50:22]

Actually I realize this was in the other implementations before, but there's
really no need for this DCHECK. The valid thread is by definition (by
construction of ThreadChecker) the thread on which the constructor is called.
This will always be true.

[jracle (use Gerrit), 2014/06/27 20:07:06]

Sorry, got it now..! Useless indeed

On 2014/06/27 14:50:22, Ken Rockot wrote:

+  has_protected_collection_ = HasProtectedCollection(device_info);
+  has_report_id_ = HasReportId(device_info);
+}
+
+HidConnection::~HidConnection() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
+
+void HidConnection::Read(scoped_refptr<net::IOBufferWithSize> buffer,
+                         const IOCallback& callback) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (device_info_.max_input_report_size == 0) {
+    // The device does not support input reports.
+    callback.Run(false, 0);
+    return;
+  }
+  int expected_buffer_size = device_info_.max_input_report_size;
+  if (!has_report_id()) {
+    expected_buffer_size--;
+  }
+  if (buffer->size() < expected_buffer_size) {
+    // Receive buffer is too small.
+    callback.Run(false, 0);
+    return;
+  }
+
+  PlatformRead(buffer, callback);
+}
+
+void HidConnection::Write(uint8_t report_id,
+                          scoped_refptr<net::IOBufferWithSize> buffer,
+                          const IOCallback& callback) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (device_info_.max_output_report_size == 0) {
+    // The device does not support output reports.
+    callback.Run(false, 0);
+    return;
+  }
+  if (IsReportIdProtected(report_id)) {
+    callback.Run(false, 0);
+    return;
+  }
+
+  PlatformWrite(report_id, buffer, callback);
+}
+
+void HidConnection::GetFeatureReport(
+    uint8_t report_id,
+    scoped_refptr<net::IOBufferWithSize> buffer,
+    const IOCallback& callback) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (device_info_.max_feature_report_size == 0) {
+    // The device does not support feature reports.
+    callback.Run(false, 0);
+    return;
+  }
+  if (IsReportIdProtected(report_id)) {
+    callback.Run(false, 0);
+    return;
+  }
+  int expected_buffer_size = device_info_.max_feature_report_size;
+  if (!has_report_id()) {
+    expected_buffer_size--;
+  }
+  if (buffer->size() < expected_buffer_size) {
+    // Receive buffer is too small.
+    callback.Run(false, 0);
+    return;
+  }
+
+  PlatformGetFeatureReport(report_id, buffer, callback);
+}
+
+void HidConnection::SendFeatureReport(
+    uint8_t report_id,
+    scoped_refptr<net::IOBufferWithSize> buffer,
+    const IOCallback& callback) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (device_info_.max_feature_report_size == 0) {
+    // The device does not support feature reports.
+    callback.Run(false, 0);
+    return;
+  }
+  if (IsReportIdProtected(report_id)) {
+    callback.Run(false, 0);
+    return;
+  }
+
+  PlatformSendFeatureReport(report_id, buffer, callback);
+}
+
+void HidConnection::CompleteRead(scoped_refptr<net::IOBufferWithSize> buffer,
+                                 const IOCallback& callback) {
+  if (FilterInputReport(buffer, callback)) {
+    return;
+  }
+
+  callback.Run(true, buffer->size());
+}
+
+bool HidConnection::FilterInputReport(
+    scoped_refptr<net::IOBufferWithSize> buffer,
+    const IOCallback& callback) {
+  if (buffer->size() == 0) {
+    return false;
+  }
+
+  if (IsReportIdProtected(buffer->data()[0])) {
+    callback.Run(true, 0);
+    return true;
+  }
+
+  return false;
+}
+
+bool HidConnection::IsReportIdProtected(const uint8_t report_id) {
+  HidCollectionInfo collection_info;
+  if (FindCollectionByReportId(device_info_, report_id, &collection_info)) {
+    return collection_info.usage.IsProtected();
+  }
+
+  return has_protected_collection();
+}
+
 PendingHidReport::PendingHidReport() {}
 
 PendingHidReport::~PendingHidReport() {}
 
 PendingHidRead::PendingHidRead() {}
 
 PendingHidRead::~PendingHidRead() {}
 
-HidConnection::HidConnection(const HidDeviceInfo& device_info)
-    : device_info_(device_info) {}
-
-HidConnection::~HidConnection() {}
-
 }  // namespace device