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1 /*
2  * Copyright (C) 2023 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #pragma once
18 
19 #include <aidl/android/hardware/usb/ComplianceWarning.h>
20 #include <aidl/android/hardware/usb/PortDataRole.h>
21 #include <android-base/chrono_utils.h>
22 #include <android-base/unique_fd.h>
23 
24 #include <set>
25 #include <string>
26 #include <vector>
27 
28 namespace android {
29 namespace hardware {
30 namespace google {
31 namespace pixel {
32 namespace usb {
33 
34 using ::aidl::android::hardware::usb::ComplianceWarning;
35 using ::aidl::android::hardware::usb::PortDataRole;
36 using ::android::base::boot_clock;
37 using ::android::base::unique_fd;
38 
39 /*
40  * UsbDataSessionMonitor monitors the usb device state sysfs of 3 different usb devices
41  * including device mode (udc), host mode high-speed port and host mode super-speed port. It
42  * reports Suez metrics for each data session and also provides API to query the compliance
43  * warnings detected in the current usb data session.
44  */
45 class UsbDataSessionMonitor {
46   public:
47     /*
48      * The host mode high-speed port and super-speed port can be assigned to either host1 or
49      * host2 without affecting functionality.
50      *
51      * UeventRegex: name regex of the device that's being monitored. The regex is matched against
52      *              uevent to detect dynamic creation/deletion/change of the device.
53      * StatePath: usb device state sysfs path of the device, monitored by epoll.
54      * dataRolePath: path to the usb data role sysfs, monitored by epoll.
55      * updatePortStatusCb: the callback is invoked when the compliance warings changes.
56      */
57     UsbDataSessionMonitor(const std::string &deviceUeventRegex, const std::string &deviceStatePath,
58                           const std::string &host1UeventRegex, const std::string &host1StatePath,
59                           const std::string &host2UeventRegex, const std::string &host2StatePath,
60                           const std::string &dataRolePath,
61                           std::function<void()> updatePortStatusCb);
62     ~UsbDataSessionMonitor();
63     // Returns the compliance warnings detected in the current data session.
64     void getComplianceWarnings(const PortDataRole &role, std::vector<ComplianceWarning> *warnings);
65 
66   private:
67     struct usbDeviceState {
68         // The name of the usb device, e.g. udc, host1, host2.
69         std::string name;
70         unique_fd fd;
71         std::string filePath;
72         std::string ueventRegex;
73         bool delayEpoll;
74         // Usb device states reported by state sysfs
75         std::vector<std::string> states;
76         // Timestamps of when the usb device states were captured
77         std::vector<boot_clock::time_point> timestamps;
78     };
79 
80     static void *monitorThread(void *param);
81     void handleUevent();
82     void handleTimerEvent();
83     void handleDataRoleEvent();
84     void handleDeviceStateEvent(struct usbDeviceState *deviceState);
85     void clearDeviceStateEvents(struct usbDeviceState *deviceState);
86     void setupNewSession();
87     void reportUsbDataSessionMetrics();
88     void evaluateComplianceWarning();
89     void notifyComplianceWarning();
90     void updateUdcBindStatus(const std::string &devname);
91 
92     pthread_t mMonitor;
93     unique_fd mPipefd0;
94     unique_fd mPipefd1;
95     unique_fd mEpollFd;
96     unique_fd mUeventFd;
97     unique_fd mTimerFd;
98     unique_fd mDataRoleFd;
99     struct usbDeviceState mDeviceState;
100     struct usbDeviceState mHost1State;
101     struct usbDeviceState mHost2State;
102     std::set<ComplianceWarning> mWarningSet;
103     // Callback function to notify the caller when there's a change in compliance warnings.
104     std::function<void()> mUpdatePortStatusCb;
105     /*
106      * Cache relevant info for a USB data session when one starts, including
107      * the data role and the time when the session starts.
108      */
109     PortDataRole mDataRole;
110     boot_clock::time_point mDataSessionStart;
111     /*
112      * In gadget mode: this indicates whether the udc device is bound to the configfs driver, which
113      * is done by userspace writing the udc device name to /config/usb_gadget/g1/UDC. When unbound,
114      * the gadget is in soft pulldown state and is expected not to enumerate. During gadget
115      * function switch, the udc device usually go through unbind and bind.
116      */
117     bool mUdcBind;
118 };
119 
120 }  // namespace usb
121 }  // namespace pixel
122 }  // namespace google
123 }  // namespace hardware
124 }  // namespace android
125