usb/1.3-dual_role_usb/Usb.cpp

/*
 * Copyright (C) 2016-2021 The Android Open Source Project
 * Copyright (C) 2018-2024 The LineageOS Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include <assert.h>
#include <dirent.h>
#include <pthread.h>
#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <fstream>
#include <iostream>

#include <cutils/uevent.h>
#include <sys/epoll.h>
#include <utils/Errors.h>
#include <utils/StrongPointer.h>

#include "Usb.h"

namespace android {
namespace hardware {
namespace usb {
namespace V1_3 {
namespace implementation {

Return<bool> Usb::enableUsbDataSignal(bool enable) {
    bool result = true;
    ALOGI("Userspace turn %s USB data signaling", enable ? "on" : "off");
    if (enable) {
        if (!WriteStringToFile("1", mDevicePath + USB_DATA_PATH)) {
            ALOGE("Not able to turn on usb connection notification");
            result = false;
        }
        if (!WriteStringToFile(mGadgetName, PULLUP_PATH)) {
            ALOGW("Gadget cannot be pulled up");
        }
    } else {
        if (!WriteStringToFile("1", mDevicePath + ID_PATH)) {
            ALOGW("Not able to turn off host mode");
        }
        if (!WriteStringToFile("0", mDevicePath + VBUS_PATH)) {
            ALOGW("Not able to set Vbus state");
        }
        if (!WriteStringToFile("0", mDevicePath + USB_DATA_PATH)) {
            ALOGE("Not able to turn off usb connection notification");
            result = false;
        }
        if (!WriteStringToFile("none", PULLUP_PATH)) {
            ALOGW("Gadget cannot be pulled down");
        }
    }
    return result;
}

// Set by the signal handler to destroy the thread
volatile bool destroyThread;

int32_t readFile(std::string filename, std::string& contents) {
    std::ifstream file(filename);

    if (file.is_open()) {
        getline(file, contents);
        file.close();
        return 0;
    }
    return -1;
}

std::string appendRoleNodeHelper(const std::string portName, PortRoleType type) {
    std::string node("/sys/class/dual_role_usb/" + portName);

    switch (type) {
        case PortRoleType::DATA_ROLE:
            return node + "/data_role";
        case PortRoleType::POWER_ROLE:
            return node + "/power_role";
        default:
            return node + "/mode";
    }
}

std::string convertRoletoString(PortRole role) {
    if (role.type == PortRoleType::POWER_ROLE) {
        if (role.role == static_cast<uint32_t>(PortPowerRole::SOURCE))
            return "source";
        else if (role.role == static_cast<uint32_t>(PortPowerRole::SINK))
            return "sink";
    } else if (role.type == PortRoleType::DATA_ROLE) {
        if (role.role == static_cast<uint32_t>(PortDataRole::HOST)) return "host";
        if (role.role == static_cast<uint32_t>(PortDataRole::DEVICE)) return "device";
    } else if (role.type == PortRoleType::MODE) {
        if (role.role == static_cast<uint32_t>(PortMode_1_1::UFP)) return "ufp";
        if (role.role == static_cast<uint32_t>(PortMode_1_1::DFP)) return "dfp";
    }
    return "none";
}

Return<void> Usb::switchRole(const hidl_string& portName, const PortRole& newRole) {
    std::string filename = appendRoleNodeHelper(std::string(portName.c_str()), newRole.type);
    std::ofstream file(filename);
    std::string written;
    bool roleSwitch = false;

    if (filename == "") {
        ALOGE("Fatal: invalid node type");
        return Void();
    }

    pthread_mutex_lock(&mRoleSwitchLock);

    ALOGI("filename write: %s role:%d", filename.c_str(), newRole.role);

    if (file.is_open()) {
        file << convertRoletoString(newRole).c_str();
        file.close();
        if (!readFile(filename, written)) {
            ALOGI("written: %s", written.c_str());
            if (written == convertRoletoString(newRole)) {
                ALOGI("Role switch successfull");
                Return<void> ret =
                        mCallback_1_0->notifyRoleSwitchStatus(portName, newRole, Status::SUCCESS);
                if (!ret.isOk()) ALOGE("RoleSwitchStatus error %s", ret.description().c_str());
            }
        }
    }

    pthread_mutex_lock(&mLock);
    if (mCallback_1_0 != NULL) {
        Return<void> ret = mCallback_1_0->notifyRoleSwitchStatus(
                portName, newRole, roleSwitch ? Status::SUCCESS : Status::ERROR);
        if (!ret.isOk()) ALOGE("RoleSwitchStatus error %s", ret.description().c_str());
    } else {
        ALOGE("Not notifying the userspace. Callback is not set");
    }
    pthread_mutex_unlock(&mLock);
    pthread_mutex_unlock(&mRoleSwitchLock);

    return Void();
}

Status getCurrentRoleHelper(const std::string& portName, PortRoleType type, uint32_t& currentRole) {
    std::string filename;
    std::string roleName;

    if (type == PortRoleType::POWER_ROLE) {
        filename = "/sys/class/dual_role_usb/" + portName + "/power_role";
        currentRole = static_cast<uint32_t>(PortPowerRole::NONE);
    } else if (type == PortRoleType::DATA_ROLE) {
        filename = "/sys/class/dual_role_usb/" + portName + "/data_role";
        currentRole = static_cast<uint32_t>(PortDataRole::NONE);
    } else if (type == PortRoleType::MODE) {
        filename = "/sys/class/dual_role_usb/" + portName + "/mode";
        currentRole = static_cast<uint32_t>(PortMode_1_1::NONE);
    }

    if (readFile(filename, roleName)) {
        ALOGE("getCurrentRole: Failed to open filesystem node");
        return Status::ERROR;
    }

    if (roleName == "dfp")
        currentRole = static_cast<uint32_t>(PortMode_1_1::DFP);
    else if (roleName == "ufp")
        currentRole = static_cast<uint32_t>(PortMode_1_1::UFP);
    else if (roleName == "source")
        currentRole = static_cast<uint32_t>(PortPowerRole::SOURCE);
    else if (roleName == "sink")
        currentRole = static_cast<uint32_t>(PortPowerRole::SINK);
    else if (roleName == "host")
        currentRole = static_cast<uint32_t>(PortDataRole::HOST);
    else if (roleName == "device")
        currentRole = static_cast<uint32_t>(PortDataRole::DEVICE);
    else if (roleName != "none") {
        /* case for none has already been addressed.
         * so we check if the role isnt none.
         */
        return Status::UNRECOGNIZED_ROLE;
    }
    return Status::SUCCESS;
}

Status getTypeCPortNamesHelper(std::vector<std::string>& names) {
    DIR* dp;

    dp = opendir("/sys/class/dual_role_usb");
    if (dp != NULL) {
    rescan:
        int32_t ports = 0;
        int32_t current = 0;
        struct dirent* ep;

        while ((ep = readdir(dp))) {
            if (ep->d_type == DT_LNK) {
                ports++;
            }
        }

        if (ports == 0) {
            closedir(dp);
            return Status::SUCCESS;
        }

        names.resize(ports);
        rewinddir(dp);

        while ((ep = readdir(dp))) {
            if (ep->d_type == DT_LNK) {
                /* Check to see if new ports were added since the first pass. */
                if (current >= ports) {
                    rewinddir(dp);
                    goto rescan;
                }
                names[current++] = ep->d_name;
            }
        }

        closedir(dp);
        return Status::SUCCESS;
    }

    ALOGE("Failed to open /sys/class/dual_role_usb");
    return Status::ERROR;
}

bool canSwitchRoleHelper(const std::string& portName, PortRoleType type) {
    std::string filename = appendRoleNodeHelper(portName, type);
    std::ofstream file(filename);

    if (file.is_open()) {
        file.close();
        return true;
    }
    return false;
}

Status getPortModeHelper(const std::string portName, V1_0::PortMode& portMode) {
    std::string filename =
            "/sys/class/dual_role_usb/" + std::string(portName.c_str()) + "/supported_modes";
    std::string modes;

    if (readFile(filename, modes)) {
        ALOGE("getSupportedRoles: Failed to open filesystem node");
        return Status::ERROR;
    }

    if (modes == "ufp dfp")
        portMode = V1_0::PortMode::DRP;
    else if (modes == "ufp")
        portMode = V1_0::PortMode::UFP;
    else if (modes == "dfp")
        portMode = V1_0::PortMode::DFP;
    else
        return Status::UNRECOGNIZED_ROLE;

    return Status::SUCCESS;
}

Status getPortMode_1_1Helper(const std::string portName, PortMode_1_1& portMode) {
    std::string filename =
            "/sys/class/dual_role_usb/" + std::string(portName.c_str()) + "/supported_modes";
    std::string modes;

    if (readFile(filename, modes)) {
        ALOGE("getSupportedRoles: Failed to open filesystem node");
        return Status::ERROR;
    }

    if (modes == "ufp dfp")
        portMode = PortMode_1_1::DRP;
    else if (modes == "ufp")
        portMode = PortMode_1_1::UFP;
    else if (modes == "dfp")
        portMode = PortMode_1_1::DFP;
    else
        return Status::UNRECOGNIZED_ROLE;

    return Status::SUCCESS;
}

/*
 * The caller of this method would reconstruct the V1_0::PortStatus
 * object if required.
 */
Status getPortStatusHelper(hidl_vec<PortStatus>* currentPortStatus_1_2, bool V1_0) {
    std::vector<std::string> names;
    Status result = getTypeCPortNamesHelper(names);

    if (result == Status::SUCCESS) {
        currentPortStatus_1_2->resize(names.size());
        for (std::vector<std::string>::size_type i = 0; i < names.size(); i++) {
            ALOGI("%s", names[i].c_str());
            (*currentPortStatus_1_2)[i].status_1_1.status.portName = names[i];

            uint32_t currentRole;
            if (getCurrentRoleHelper(names[i], PortRoleType::POWER_ROLE, currentRole) ==
                Status::SUCCESS) {
                (*currentPortStatus_1_2)[i].status_1_1.status.currentPowerRole =
                        static_cast<PortPowerRole>(currentRole);
            } else {
                ALOGE("Error while retreiving portNames");
                goto done;
            }

            if (getCurrentRoleHelper(names[i], PortRoleType::DATA_ROLE, currentRole) ==
                Status::SUCCESS) {
                (*currentPortStatus_1_2)[i].status_1_1.status.currentDataRole =
                        static_cast<PortDataRole>(currentRole);
            } else {
                ALOGE("Error while retreiving current port role");
                goto done;
            }

            if (getCurrentRoleHelper(names[i], PortRoleType::MODE, currentRole) ==
                Status::SUCCESS) {
                (*currentPortStatus_1_2)[i].status_1_1.currentMode =
                        static_cast<PortMode_1_1>(currentRole);
                (*currentPortStatus_1_2)[i].status_1_1.status.currentMode =
                        static_cast<V1_0::PortMode>(currentRole);
            } else {
                ALOGE("Error while retreiving current data role");
                goto done;
            }

            (*currentPortStatus_1_2)[i].status_1_1.status.canChangeMode =
                    canSwitchRoleHelper(names[i], PortRoleType::MODE);
            (*currentPortStatus_1_2)[i].status_1_1.status.canChangeDataRole =
                    canSwitchRoleHelper(names[i], PortRoleType::DATA_ROLE);
            (*currentPortStatus_1_2)[i].status_1_1.status.canChangePowerRole =
                    canSwitchRoleHelper(names[i], PortRoleType::POWER_ROLE);

            ALOGI("canChangeMode: %d canChagedata: %d canChangePower:%d",
                  (*currentPortStatus_1_2)[i].status_1_1.status.canChangeMode,
                  (*currentPortStatus_1_2)[i].status_1_1.status.canChangeDataRole,
                  (*currentPortStatus_1_2)[i].status_1_1.status.canChangePowerRole);

            if (V1_0) {
                if (getPortModeHelper(
                            names[i],
                            (*currentPortStatus_1_2)[i].status_1_1.status.supportedModes) !=
                    Status::SUCCESS) {
                    ALOGE("Error while retrieving port modes");
                    goto done;
                }
            } else {
                (*currentPortStatus_1_2)[i].status_1_1.supportedModes =
                        PortMode_1_1::UFP | PortMode_1_1::DFP;
                (*currentPortStatus_1_2)[i].status_1_1.status.supportedModes = V1_0::PortMode::NONE;
                (*currentPortStatus_1_2)[i].status_1_1.status.currentMode = V1_0::PortMode::NONE;

                (*currentPortStatus_1_2)[i].supportedContaminantProtectionModes =
                        ContaminantProtectionMode::NONE | ContaminantProtectionMode::NONE;
                (*currentPortStatus_1_2)[i].supportsEnableContaminantPresenceProtection = false;
                (*currentPortStatus_1_2)[i].supportsEnableContaminantPresenceDetection = false;
                (*currentPortStatus_1_2)[i].contaminantProtectionStatus =
                        ContaminantProtectionStatus::NONE;
            }
        }
        return Status::SUCCESS;
    }
done:
    return Status::ERROR;
}

Return<void> Usb::queryPortStatus() {
    hidl_vec<PortStatus> currentPortStatus_1_2;
    hidl_vec<V1_1::PortStatus_1_1> currentPortStatus_1_1;
    hidl_vec<V1_0::PortStatus> currentPortStatus;
    Status status;
    sp<IUsbCallback> callback_V1_2 = IUsbCallback::castFrom(mCallback_1_0);
    sp<V1_1::IUsbCallback> callback_V1_1 = V1_1::IUsbCallback::castFrom(mCallback_1_0);

    pthread_mutex_lock(&mLock);
    if (mCallback_1_0 != NULL) {
        if (callback_V1_1 != NULL) {      // 1.1 or 1.2
            if (callback_V1_2 == NULL) {  // 1.1 only
                status = getPortStatusHelper(&currentPortStatus_1_2, false);
                currentPortStatus_1_1.resize(currentPortStatus_1_2.size());
                for (unsigned long i = 0; i < currentPortStatus_1_2.size(); i++)
                    currentPortStatus_1_1[i].status = currentPortStatus_1_2[i].status_1_1.status;
            } else  // 1.2 only
                status = getPortStatusHelper(&currentPortStatus_1_2, false);
        } else {  // 1.0 only
            status = getPortStatusHelper(&currentPortStatus_1_2, true);
            currentPortStatus.resize(currentPortStatus_1_2.size());
            for (unsigned long i = 0; i < currentPortStatus_1_2.size(); i++)
                currentPortStatus[i] = currentPortStatus_1_2[i].status_1_1.status;
        }

        Return<void> ret;

        if (callback_V1_2 != NULL)
            ret = callback_V1_2->notifyPortStatusChange_1_2(currentPortStatus_1_2, status);
        else if (callback_V1_1 != NULL)
            ret = callback_V1_1->notifyPortStatusChange_1_1(currentPortStatus_1_1, status);
        else
            ret = mCallback_1_0->notifyPortStatusChange(currentPortStatus, status);

        if (!ret.isOk()) ALOGE("queryPortStatus_1_1 error %s", ret.description().c_str());
    } else {
        ALOGI("Notifying userspace skipped. Callback is NULL");
    }
    pthread_mutex_unlock(&mLock);
    return Void();
}

struct data {
    int uevent_fd;
    android::hardware::usb::V1_3::implementation::Usb* usb;
};

Return<void> Usb::enableContaminantPresenceDetection(const hidl_string& portName __unused,
                                                     bool enable __unused) {
    ALOGI("Contaminant Presence Detection is not supported");
    return Void();
}

Return<void> Usb::enableContaminantPresenceProtection(const hidl_string& portName __unused,
                                                      bool enable __unused) {
    ALOGI("Contaminant Presence Protection is not supported");
    return Void();
}

static void uevent_event(uint32_t /*epevents*/, struct data* payload) {
    char msg[UEVENT_MSG_LEN + 2];
    char* cp;
    int n;

    n = uevent_kernel_multicast_recv(payload->uevent_fd, msg, UEVENT_MSG_LEN);
    if (n <= 0) return;
    if (n >= UEVENT_MSG_LEN) /* overflow -- discard */
        return;

    msg[n] = '\0';
    msg[n + 1] = '\0';
    cp = msg;

    while (*cp) {
        sp<IUsbCallback> callback_V1_2 = IUsbCallback::castFrom(payload->usb->mCallback_1_0);
        sp<V1_1::IUsbCallback> callback_V1_1 =
                V1_1::IUsbCallback::castFrom(payload->usb->mCallback_1_0);
        hidl_vec<PortStatus> currentPortStatus_1_2;
        Return<void> ret;
        if (!strcmp(cp, "SUBSYSTEM=dual_role_usb")) {
            ALOGE("uevent received %s", cp);
            ret = payload->usb->queryPortStatus();
            break;
        }
        /* advance to after the next \0 */
        while (*cp++)
            ;
    }
}

void* work(void* param) {
    int epoll_fd, uevent_fd;
    struct epoll_event ev;
    int nevents = 0;
    struct data payload;

    ALOGE("creating thread");

    uevent_fd = uevent_open_socket(64 * 1024, true);

    if (uevent_fd < 0) {
        ALOGE("uevent_init: uevent_open_socket failed\n");
        return NULL;
    }

    payload.uevent_fd = uevent_fd;
    payload.usb = (android::hardware::usb::V1_3::implementation::Usb*)param;

    fcntl(uevent_fd, F_SETFL, O_NONBLOCK);

    ev.events = EPOLLIN;
    ev.data.ptr = (void*)uevent_event;

    epoll_fd = epoll_create(64);
    if (epoll_fd == -1) {
        ALOGE("epoll_create failed; errno=%d", errno);
        goto error;
    }

    if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, uevent_fd, &ev) == -1) {
        ALOGE("epoll_ctl failed; errno=%d", errno);
        goto error;
    }

    while (!destroyThread) {
        struct epoll_event events[64];

        nevents = epoll_wait(epoll_fd, events, 64, -1);
        if (nevents == -1) {
            if (errno == EINTR) continue;
            ALOGE("usb epoll_wait failed; errno=%d", errno);
            break;
        }

        for (int n = 0; n < nevents; ++n) {
            if (events[n].data.ptr)
                (*(void (*)(int, struct data* payload))events[n].data.ptr)(events[n].events,
                                                                           &payload);
        }
    }

    ALOGI("exiting worker thread");
error:
    close(uevent_fd);

    if (epoll_fd >= 0) close(epoll_fd);

    return NULL;
}

void sighandler(int sig) {
    if (sig == SIGUSR1) {
        destroyThread = true;
        ALOGI("destroy set");
        return;
    }
    signal(SIGUSR1, sighandler);
}

Return<void> Usb::setCallback(const sp<V1_0::IUsbCallback>& callback) {
    sp<V1_1::IUsbCallback> callback_V1_1 = V1_1::IUsbCallback::castFrom(callback);
    sp<IUsbCallback> callback_V1_2 = IUsbCallback::castFrom(callback);

    if (callback != NULL)
        if (callback_V1_1 == NULL) ALOGI("Registering 1.0 callback");

    pthread_mutex_lock(&mLock);
    /*
     * When both the old callback and new callback values are NULL,
     * there is no need to spin off the worker thread.
     * When both the values are not NULL, we would already have a
     * worker thread running, so updating the callback object would
     * be suffice.
     */
    if ((mCallback_1_0 == NULL && callback == NULL) ||
        (mCallback_1_0 != NULL && callback != NULL)) {
        /*
         * Always store as V1_0 callback object. Type cast to V1_1
         * when the callback is actually invoked.
         */
        mCallback_1_0 = callback;
        pthread_mutex_unlock(&mLock);
        return Void();
    }

    mCallback_1_0 = callback;
    ALOGI("registering callback");

    // Kill the worker thread if the new callback is NULL.
    if (mCallback_1_0 == NULL) {
        pthread_mutex_unlock(&mLock);
        if (!pthread_kill(mPoll, SIGUSR1)) {
            pthread_join(mPoll, NULL);
            ALOGI("pthread destroyed");
        }
        return Void();
    }

    destroyThread = false;
    signal(SIGUSR1, sighandler);

    /*
     * Create a background thread if the old callback value is NULL
     * and being updated with a new value.
     */
    if (pthread_create(&mPoll, NULL, work, this)) {
        ALOGE("pthread creation failed %d", errno);
        mCallback_1_0 = NULL;
    }

    pthread_mutex_unlock(&mLock);
    return Void();
}

// Protects *usb assignment
pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
Usb* usb;

Usb::Usb(std::string deviceName, std::string gadgetName)
    : mGadgetName(gadgetName) {
    if (access(SOC_PLATFORM_PATH, F_OK) == 0) {
        mDevicePath = SOC_PLATFORM_PATH + deviceName + "/";
    } else if (access(SOC_PATH, F_OK) == 0) {
        mDevicePath = SOC_PATH + deviceName + "/";
    }

    pthread_mutex_lock(&lock);
    // Make this a singleton class
    assert(usb == NULL);
    usb = this;
    pthread_mutex_unlock(&lock);
}

}  // namespace implementation
}  // namespace V1_3
}  // namespace usb
}  // namespace hardware
}  // namespace android