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 {
+
+// Functor used to filter collections by report ID.
+struct CollectionHasReportId {
+  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_ == HidConnection::kNullReportId)
+      return false;
+
+    if (report_id_ == HidConnection::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_;
+};
+
+// Functor returning true if collection has a protected usage.
+struct CollectionIsProtected {
+  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, HidConnection::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) {
+  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);
+}
+
+bool HidConnection::CompleteRead(scoped_refptr<net::IOBufferWithSize> buffer,
+                                 const IOCallback& callback) {
+  if (buffer->size() == 0 || IsReportIdProtected(buffer->data()[0])) {
+    return false;
+  }
+
+  callback.Run(true, buffer->size());
+  return true;
+}
+
+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