cmds/lshal/ListCommand.cpp

/*
 * Copyright (C) 2017 The Android Open Source 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 "ListCommand.h"

#include <getopt.h>

#include <algorithm>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <regex>
#include <sstream>

#include <android-base/file.h>
#include <android-base/hex.h>
#include <android-base/logging.h>
#include <android/hidl/manager/1.0/IServiceManager.h>
#include <hidl-hash/Hash.h>
#include <hidl-util/FQName.h>
#include <private/android_filesystem_config.h>
#include <sys/stat.h>
#include <vintf/HalManifest.h>
#include <vintf/parse_string.h>
#include <vintf/parse_xml.h>

#include "Lshal.h"
#include "PipeRelay.h"
#include "Timeout.h"
#include "utils.h"

using ::android::hardware::hidl_array;
using ::android::hardware::hidl_string;
using ::android::hardware::hidl_vec;
using ::android::hidl::base::V1_0::DebugInfo;
using ::android::hidl::base::V1_0::IBase;
using ::android::hidl::manager::V1_0::IServiceManager;

namespace android {
namespace lshal {

vintf::SchemaType toSchemaType(Partition p) {
    return (p == Partition::SYSTEM) ? vintf::SchemaType::FRAMEWORK : vintf::SchemaType::DEVICE;
}

Partition toPartition(vintf::SchemaType t) {
    switch (t) {
        case vintf::SchemaType::FRAMEWORK: return Partition::SYSTEM;
        // TODO(b/71555570): Device manifest does not distinguish HALs from vendor or ODM.
        case vintf::SchemaType::DEVICE: return Partition::VENDOR;
    }
    return Partition::UNKNOWN;
}

std::string getPackageAndVersion(const std::string& fqInstance) {
    return splitFirst(fqInstance, ':').first;
}

NullableOStream<std::ostream> ListCommand::out() const {
    return mLshal.out();
}

NullableOStream<std::ostream> ListCommand::err() const {
    return mLshal.err();
}

std::string ListCommand::GetName() {
    return "list";
}
std::string ListCommand::getSimpleDescription() const {
    return "List HIDL HALs.";
}

std::string ListCommand::parseCmdline(pid_t pid) const {
    return android::procpartition::getCmdline(pid);
}

const std::string &ListCommand::getCmdline(pid_t pid) {
    static const std::string kEmptyString{};
    if (pid == NO_PID) return kEmptyString;
    auto pair = mCmdlines.find(pid);
    if (pair != mCmdlines.end()) {
        return pair->second;
    }
    mCmdlines[pid] = parseCmdline(pid);
    return mCmdlines[pid];
}

void ListCommand::removeDeadProcesses(Pids *pids) {
    static const pid_t myPid = getpid();
    pids->erase(std::remove_if(pids->begin(), pids->end(), [this](auto pid) {
        return pid == myPid || this->getCmdline(pid).empty();
    }), pids->end());
}

Partition ListCommand::getPartition(pid_t pid) {
    if (pid == NO_PID) return Partition::UNKNOWN;
    auto it = mPartitions.find(pid);
    if (it != mPartitions.end()) {
        return it->second;
    }
    Partition partition = android::procpartition::getPartition(pid);
    mPartitions.emplace(pid, partition);
    return partition;
}

// Give sensible defaults when nothing can be inferred from runtime.
// process: Partition inferred from executable location or cmdline.
Partition ListCommand::resolvePartition(Partition process, const FqInstance& fqInstance) const {
    if (fqInstance.inPackage("vendor") || fqInstance.inPackage("com")) {
        return Partition::VENDOR;
    }

    if (fqInstance.inPackage("android.frameworks") || fqInstance.inPackage("android.system") ||
        fqInstance.inPackage("android.hidl")) {
        return Partition::SYSTEM;
    }

    // Some android.hardware HALs are served from system. Check the value from executable
    // location / cmdline first.
    if (fqInstance.inPackage("android.hardware")) {
        if (process != Partition::UNKNOWN) {
            return process;
        }
        return Partition::VENDOR;
    }

    return process;
}

bool match(const vintf::ManifestInstance& instance, const FqInstance& fqInstance,
           vintf::TransportArch ta) {
    // For hwbinder libs, allow missing arch in manifest.
    // For passthrough libs, allow missing interface/instance in table.
    return (ta.transport == instance.transport()) &&
            (ta.transport == vintf::Transport::HWBINDER ||
             vintf::contains(instance.arch(), ta.arch)) &&
            (!fqInstance.hasInterface() || fqInstance.getInterface() == instance.interface()) &&
            (!fqInstance.hasInstance() || fqInstance.getInstance() == instance.instance());
}

bool match(const vintf::MatrixInstance& instance, const FqInstance& fqInstance,
           vintf::TransportArch /* ta */) {
    return (!fqInstance.hasInterface() || fqInstance.getInterface() == instance.interface()) &&
            (!fqInstance.hasInstance() || instance.matchInstance(fqInstance.getInstance()));
}

template <typename ObjectType>
VintfInfo getVintfInfo(const std::shared_ptr<const ObjectType>& object,
                       const FqInstance& fqInstance, vintf::TransportArch ta, VintfInfo value) {
    bool found = false;
    (void)object->forEachHidlInstanceOfVersion(fqInstance.getPackage(), fqInstance.getVersion(),
                                               [&](const auto& instance) {
                                                   found = match(instance, fqInstance, ta);
                                                   return !found; // continue if not found
                                               });
    return found ? value : VINTF_INFO_EMPTY;
}

std::shared_ptr<const vintf::HalManifest> ListCommand::getDeviceManifest() const {
    return vintf::VintfObject::GetDeviceHalManifest();
}

std::shared_ptr<const vintf::CompatibilityMatrix> ListCommand::getDeviceMatrix() const {
    return vintf::VintfObject::GetDeviceCompatibilityMatrix();
}

std::shared_ptr<const vintf::HalManifest> ListCommand::getFrameworkManifest() const {
    return vintf::VintfObject::GetFrameworkHalManifest();
}

std::shared_ptr<const vintf::CompatibilityMatrix> ListCommand::getFrameworkMatrix() const {
    return vintf::VintfObject::GetFrameworkCompatibilityMatrix();
}

VintfInfo ListCommand::getVintfInfo(const std::string& fqInstanceName,
                                    vintf::TransportArch ta) const {
    FqInstance fqInstance;
    if (!fqInstance.setTo(fqInstanceName) &&
        // Ignore interface / instance for passthrough libs
        !fqInstance.setTo(getPackageAndVersion(fqInstanceName))) {
        err() << "Warning: Cannot parse '" << fqInstanceName << "'; no VINTF info." << std::endl;
        return VINTF_INFO_EMPTY;
    }

    return lshal::getVintfInfo(getDeviceManifest(), fqInstance, ta, DEVICE_MANIFEST) |
            lshal::getVintfInfo(getFrameworkManifest(), fqInstance, ta, FRAMEWORK_MANIFEST) |
            lshal::getVintfInfo(getDeviceMatrix(), fqInstance, ta, DEVICE_MATRIX) |
            lshal::getVintfInfo(getFrameworkMatrix(), fqInstance, ta, FRAMEWORK_MATRIX);
}

bool ListCommand::getPidInfo(
        pid_t serverPid, BinderPidInfo *pidInfo) const {
    const auto& status = getBinderPidInfo(BinderDebugContext::HWBINDER, serverPid, pidInfo);
    return status == OK;
}

const BinderPidInfo* ListCommand::getPidInfoCached(pid_t serverPid) {
    auto pair = mCachedPidInfos.insert({serverPid, BinderPidInfo{}});
    if (pair.second /* did insertion take place? */) {
        if (!getPidInfo(serverPid, &pair.first->second)) {
            return nullptr;
        }
    }
    return &pair.first->second;
}

bool ListCommand::shouldFetchHalType(const HalType &type) const {
    return (std::find(mFetchTypes.begin(), mFetchTypes.end(), type) != mFetchTypes.end());
}

Table* ListCommand::tableForType(HalType type) {
    switch (type) {
        case HalType::BINDERIZED_SERVICES:
            return &mServicesTable;
        case HalType::PASSTHROUGH_CLIENTS:
            return &mPassthroughRefTable;
        case HalType::PASSTHROUGH_LIBRARIES:
            return &mImplementationsTable;
        case HalType::VINTF_MANIFEST:
            return &mManifestHalsTable;
        case HalType::LAZY_HALS:
            return &mLazyHalsTable;
        default:
            LOG(FATAL) << "Unknown HAL type " << static_cast<int64_t>(type);
            return nullptr;
    }
}
const Table* ListCommand::tableForType(HalType type) const {
    return const_cast<ListCommand*>(this)->tableForType(type);
}

void ListCommand::forEachTable(const std::function<void(Table &)> &f) {
    for (const auto& type : mListTypes) {
        f(*tableForType(type));
    }
}
void ListCommand::forEachTable(const std::function<void(const Table &)> &f) const {
    for (const auto& type : mListTypes) {
        f(*tableForType(type));
    }
}

void ListCommand::postprocess() {
    forEachTable([this](Table &table) {
        if (mSortColumn) {
            std::sort(table.begin(), table.end(), mSortColumn);
        }
        for (TableEntry &entry : table) {
            entry.serverCmdline = getCmdline(entry.serverPid);
            removeDeadProcesses(&entry.clientPids);
            for (auto pid : entry.clientPids) {
                entry.clientCmdlines.push_back(this->getCmdline(pid));
            }
        }
        for (TableEntry& entry : table) {
            if (entry.partition == Partition::UNKNOWN) {
                entry.partition = getPartition(entry.serverPid);
            }
            entry.vintfInfo = getVintfInfo(entry.interfaceName, {entry.transport, entry.arch});
        }
    });
    // use a double for loop here because lshal doesn't care about efficiency.
    for (TableEntry &packageEntry : mImplementationsTable) {
        std::string packageName = packageEntry.interfaceName;
        FQName fqPackageName;
        if (!FQName::parse(packageName.substr(0, packageName.find("::")), &fqPackageName)) {
            continue;
        }
        for (TableEntry &interfaceEntry : mPassthroughRefTable) {
            if (interfaceEntry.arch != vintf::Arch::ARCH_EMPTY) {
                continue;
            }
            FQName interfaceName;
            if (!FQName::parse(splitFirst(interfaceEntry.interfaceName, '/').first, &interfaceName)) {
                continue;
            }
            if (interfaceName.getPackageAndVersion() == fqPackageName) {
                interfaceEntry.arch = packageEntry.arch;
            }
        }
    }

    mServicesTable.setDescription(
            "| All HIDL binderized services (registered with hwservicemanager)");
    mPassthroughRefTable.setDescription(
            "| All HIDL interfaces getService() has ever returned as a passthrough interface;\n"
            "| PIDs / processes shown below might be inaccurate because the process\n"
            "| might have relinquished the interface or might have died.\n"
            "| The Server / Server CMD column can be ignored.\n"
            "| The Clients / Clients CMD column shows all process that have ever dlopen'ed \n"
            "| the library and successfully fetched the passthrough implementation.");
    mImplementationsTable.setDescription(
            "| All available HIDL passthrough implementations (all -impl.so files).\n"
            "| These may return subclasses through their respective HIDL_FETCH_I* functions.");
    mManifestHalsTable.setDescription(
            "| All HIDL HALs that are in VINTF manifest.");
    mLazyHalsTable.setDescription(
            "| All HIDL HALs that are declared in VINTF manifest:\n"
            "|    - as hwbinder HALs but are not registered to hwservicemanager, and\n"
            "|    - as hwbinder/passthrough HALs with no implementation.");
}

bool ListCommand::addEntryWithInstance(const TableEntry& entry,
                                       vintf::HalManifest* manifest) const {
    FqInstance fqInstance;
    if (!fqInstance.setTo(entry.interfaceName)) {
        err() << "Warning: '" << entry.interfaceName << "' is not a valid FqInstance." << std::endl;
        return false;
    }

    if (fqInstance.getPackage() == "android.hidl.base") {
        return true; // always remove IBase from manifest
    }

    Partition partition = resolvePartition(entry.partition, fqInstance);

    if (partition == Partition::UNKNOWN) {
        err() << "Warning: Cannot guess the partition of FqInstance " << fqInstance.string()
              << std::endl;
        return false;
    }

    if (partition != mVintfPartition) {
        return true; // strip out instances that is in a different partition.
    }

    vintf::Arch arch;
    if (entry.transport == vintf::Transport::HWBINDER) {
        arch = vintf::Arch::ARCH_EMPTY; // no need to specify arch in manifest
    } else if (entry.transport == vintf::Transport::PASSTHROUGH) {
        if (entry.arch == vintf::Arch::ARCH_EMPTY) {
            err() << "Warning: '" << entry.interfaceName << "' doesn't have bitness info.";
            return false;
        }
        arch = entry.arch;
    } else {
        err() << "Warning: '" << entry.transport << "' is not a valid transport." << std::endl;
        return false;
    }

    auto vintfFqInstance = vintf::FqInstance::from(fqInstance.string());
    if (!vintfFqInstance.has_value()) {
        err() << "Unable to convert " << fqInstance.string() << " to vintf::FqInstance"
              << std::endl;
        return false;
    }

    std::string e;
    if (!manifest->insertInstance(*vintfFqInstance, entry.transport, arch, vintf::HalFormat::HIDL,
                                  &e)) {
        err() << "Warning: Cannot insert '" << fqInstance.string() << ": " << e << std::endl;
        return false;
    }
    return true;
}

bool ListCommand::addEntryWithoutInstance(const TableEntry& entry,
                                          const vintf::HalManifest* manifest) const {
    const auto& packageAndVersion = splitFirst(getPackageAndVersion(entry.interfaceName), '@');
    const auto& package = packageAndVersion.first;
    vintf::Version version;
    if (!vintf::parse(packageAndVersion.second, &version)) {
        err() << "Warning: Cannot parse version '" << packageAndVersion.second << "' for entry '"
              << entry.interfaceName << "'" << std::endl;
        return false;
    }

    bool found = false;
    (void)manifest->forEachHidlInstanceOfVersion(package, version, [&found](const auto&) {
        found = true;
        return false; // break
    });
    return found;
}

void ListCommand::dumpVintf(const NullableOStream<std::ostream>& out) const {
    using vintf::operator|=;
    using vintf::operator<<;
    using namespace std::placeholders;

    vintf::HalManifest manifest;
    manifest.setType(toSchemaType(mVintfPartition));

    std::vector<std::string> error;
    for (const TableEntry& entry : mServicesTable)
        if (!addEntryWithInstance(entry, &manifest)) error.push_back(entry.interfaceName);
    for (const TableEntry& entry : mPassthroughRefTable)
        if (!addEntryWithInstance(entry, &manifest)) error.push_back(entry.interfaceName);
    for (const TableEntry& entry : mManifestHalsTable)
        if (!addEntryWithInstance(entry, &manifest)) error.push_back(entry.interfaceName);

    std::vector<std::string> passthrough;
    for (const TableEntry& entry : mImplementationsTable)
        if (!addEntryWithoutInstance(entry, &manifest)) passthrough.push_back(entry.interfaceName);

    out << "<!-- " << std::endl
        << "    This is a skeleton " << manifest.type() << " manifest. Notes: " << std::endl
        << INIT_VINTF_NOTES;
    if (!error.empty()) {
        out << std::endl << "    The following HALs are not added; see warnings." << std::endl;
        for (const auto& e : error) {
            out << "        " << e << std::endl;
        }
    }
    if (!passthrough.empty()) {
        out << std::endl
            << "    The following HALs are passthrough and no interface or instance " << std::endl
            << "    names can be inferred." << std::endl;
        for (const auto& e : passthrough) {
            out << "        " << e << std::endl;
        }
    }
    out << "-->" << std::endl;
    out << vintf::toXml(manifest, vintf::SerializeFlags::HALS_ONLY);
}

std::string ListCommand::INIT_VINTF_NOTES{
    "    1. If a HAL is supported in both hwbinder and passthrough transport,\n"
    "       only hwbinder is shown.\n"
    "    2. It is likely that HALs in passthrough transport does not have\n"
    "       <interface> declared; users will have to write them by hand.\n"
    "    3. A HAL with lower minor version can be overridden by a HAL with\n"
    "       higher minor version if they have the same name and major version.\n"
    "    4. This output is intended for launch devices.\n"
    "       Upgrading devices should not use this tool to generate device\n"
    "       manifest and replace the existing manifest directly, but should\n"
    "       edit the existing manifest manually.\n"
    "       Specifically, devices which launched at Android O-MR1 or earlier\n"
    "       should not use the 'fqname' format for required HAL entries and\n"
    "       should instead use the legacy package, name, instance-name format\n"
    "       until they are updated.\n"
};

static vintf::Arch fromBaseArchitecture(::android::hidl::base::V1_0::DebugInfo::Architecture a) {
    switch (a) {
        case ::android::hidl::base::V1_0::DebugInfo::Architecture::IS_64BIT:
            return vintf::Arch::ARCH_64;
        case ::android::hidl::base::V1_0::DebugInfo::Architecture::IS_32BIT:
            return vintf::Arch::ARCH_32;
        case ::android::hidl::base::V1_0::DebugInfo::Architecture::UNKNOWN: // fallthrough
        default:
            return vintf::Arch::ARCH_EMPTY;
    }
}

void ListCommand::dumpTable(const NullableOStream<std::ostream>& out) const {
    if (mNeat) {
        std::vector<const Table*> tables;
        forEachTable([&tables](const Table &table) {
            tables.push_back(&table);
        });
        MergedTable(std::move(tables)).createTextTable().dump(out.buf());
        return;
    }

    forEachTable([this, &out](const Table &table) {

        // We're only interested in dumping debug info for already
        // instantiated services. There's little value in dumping the
        // debug info for a service we create on the fly, so we only operate
        // on the "mServicesTable".
        std::function<std::string(const std::string&)> emitDebugInfo = nullptr;
        if (mEmitDebugInfo && &table == &mServicesTable) {
            emitDebugInfo = [this](const auto& iName) {
                std::stringstream ss;
                auto pair = splitFirst(iName, '/');
                mLshal.emitDebugInfo(pair.first, pair.second, {},
                                     ParentDebugInfoLevel::FQNAME_ONLY, ss,
                                     NullableOStream<std::ostream>(nullptr));
                return ss.str();
            };
        }
        table.createTextTable(mNeat, emitDebugInfo).dump(out.buf());
        out << std::endl;
    });
}

Status ListCommand::dump() {
    auto dump = mVintf ? &ListCommand::dumpVintf : &ListCommand::dumpTable;

    if (mFileOutputPath.empty()) {
        (*this.*dump)(out());
        return OK;
    }

    std::ofstream fileOutput(mFileOutputPath);
    if (!fileOutput.is_open()) {
        err() << "Could not open file '" << mFileOutputPath << "'." << std::endl;
        return IO_ERROR;
    }
    chown(mFileOutputPath.c_str(), AID_SHELL, AID_SHELL);

    (*this.*dump)(NullableOStream<std::ostream>(fileOutput));

    fileOutput.flush();
    fileOutput.close();
    return OK;
}

void ListCommand::putEntry(HalType type, TableEntry &&entry) {
    tableForType(type)->add(std::forward<TableEntry>(entry));
}

Status ListCommand::fetchAllLibraries(const sp<IServiceManager> &manager) {
    if (!shouldFetchHalType(HalType::PASSTHROUGH_LIBRARIES)) { return OK; }

    using namespace ::android::hardware;
    using namespace ::android::hidl::manager::V1_0;
    using namespace ::android::hidl::base::V1_0;

    // The lambda function may be executed asynchrounously because it is passed to timeoutIPC,
    // even though the interface function call is synchronous.
    // However, there's no need to lock because if ret.isOk(), the background thread has
    // already ended, so it is safe to dereference entries.
    auto entries = std::make_shared<std::map<std::string, TableEntry>>();
    auto ret =
            timeoutIPC(mLshal.getDebugDumpWait(), manager, &IServiceManager::debugDump,
                       [entries](const auto& infos) {
                           for (const auto& info : infos) {
                               std::string interfaceName = std::string{info.interfaceName.c_str()} +
                                       "/" + std::string{info.instanceName.c_str()};
                               entries->emplace(interfaceName,
                                                TableEntry{
                                                        .interfaceName = interfaceName,
                                                        .transport = vintf::Transport::PASSTHROUGH,
                                                        .clientPids = info.clientPids,
                                                })
                                       .first->second.arch |= fromBaseArchitecture(info.arch);
                           }
                       });
    if (!ret.isOk()) {
        err() << "Error: Failed to call list on getPassthroughServiceManager(): "
             << ret.description() << std::endl;
        return DUMP_ALL_LIBS_ERROR;
    }
    for (auto&& pair : *entries) {
        putEntry(HalType::PASSTHROUGH_LIBRARIES, std::move(pair.second));
    }
    return OK;
}

Status ListCommand::fetchPassthrough(const sp<IServiceManager> &manager) {
    if (!shouldFetchHalType(HalType::PASSTHROUGH_CLIENTS)) { return OK; }

    using namespace ::android::hardware;
    using namespace ::android::hardware::details;
    using namespace ::android::hidl::manager::V1_0;
    using namespace ::android::hidl::base::V1_0;

    // The lambda function may be executed asynchrounously because it is passed to timeoutIPC,
    // even though the interface function call is synchronous.
    // However, there's no need to lock because if ret.isOk(), the background thread has
    // already ended, so it is safe to dereference entries.
    auto entries = std::make_shared<std::vector<TableEntry>>();
    auto ret =
            timeoutIPC(mLshal.getIpcCallWait(), manager, &IServiceManager::debugDump,
                       [entries](const auto& infos) {
                           for (const auto& info : infos) {
                               if (info.clientPids.size() <= 0) {
                                   continue;
                               }
                               entries->emplace_back(
                                       TableEntry{.interfaceName =
                                                          std::string{info.interfaceName.c_str()} +
                                                          "/" +
                                                          std::string{info.instanceName.c_str()},
                                                  .transport = vintf::Transport::PASSTHROUGH,
                                                  .serverPid = info.clientPids.size() == 1
                                                          ? info.clientPids[0]
                                                          : NO_PID,
                                                  .clientPids = info.clientPids,
                                                  .arch = fromBaseArchitecture(info.arch)});
                           }
                       });
    if (!ret.isOk()) {
        err() << "Error: Failed to call debugDump on defaultServiceManager(): "
             << ret.description() << std::endl;
        return DUMP_PASSTHROUGH_ERROR;
    }
    for (auto&& entry : *entries) {
        putEntry(HalType::PASSTHROUGH_CLIENTS, std::move(entry));
    }
    return OK;
}

Status ListCommand::fetchBinderized(const sp<IServiceManager> &manager) {
    using vintf::operator<<;

    if (!shouldFetchHalType(HalType::BINDERIZED_SERVICES)) { return OK; }

    const vintf::Transport mode = vintf::Transport::HWBINDER;

    // The lambda function may be executed asynchrounously because it is passed to timeoutIPC,
    // even though the interface function call is synchronous.
    // However, there's no need to lock because if listRet.isOk(), the background thread has
    // already ended, so it is safe to dereference fqInstanceNames.
    auto fqInstanceNames = std::make_shared<hidl_vec<hidl_string>>();
    auto listRet = timeoutIPC(mLshal.getIpcCallWait(), manager, &IServiceManager::list,
                              [fqInstanceNames](const auto& names) { *fqInstanceNames = names; });
    if (!listRet.isOk()) {
        err() << "Error: Failed to list services for " << mode << ": "
             << listRet.description() << std::endl;
        return DUMP_BINDERIZED_ERROR;
    }

    Status status = OK;
    std::map<std::string, TableEntry> allTableEntries;
    for (const auto& fqInstanceName : *fqInstanceNames) {
        // create entry and default assign all fields.
        TableEntry& entry = allTableEntries[fqInstanceName];
        entry.interfaceName = fqInstanceName;
        entry.transport = mode;
        entry.serviceStatus = ServiceStatus::NON_RESPONSIVE;

        status |= fetchBinderizedEntry(manager, &entry);
    }

    for (auto& pair : allTableEntries) {
        putEntry(HalType::BINDERIZED_SERVICES, std::move(pair.second));
    }
    return status;
}

Status ListCommand::fetchBinderizedEntry(const sp<IServiceManager> &manager,
                                         TableEntry *entry) {
    Status status = OK;
    const auto handleError = [&](Status additionalError, const std::string& msg) {
        err() << "Warning: Skipping \"" << entry->interfaceName << "\": " << msg << std::endl;
        status |= DUMP_BINDERIZED_ERROR | additionalError;
    };

    const auto pair = splitFirst(entry->interfaceName, '/');
    const auto &serviceName = pair.first;
    const auto &instanceName = pair.second;
    auto getRet = timeoutIPC(mLshal.getIpcCallWait(), manager, &IServiceManager::get, serviceName,
                             instanceName);
    if (!getRet.isOk()) {
        handleError(TRANSACTION_ERROR,
                    "cannot be fetched from service manager:" + getRet.description());
        return status;
    }
    sp<IBase> service = getRet;
    if (service == nullptr) {
        handleError(NO_INTERFACE, "cannot be fetched from service manager (null)");
        return status;
    }

    // getDebugInfo
    do {
        // The lambda function may be executed asynchrounously because it is passed to timeoutIPC,
        // even though the interface function call is synchronous.
        // However, there's no need to lock because if debugRet.isOk(), the background thread has
        // already ended, so it is safe to dereference debugInfo.
        auto debugInfo = std::make_shared<DebugInfo>();
        auto debugRet = timeoutIPC(mLshal.getIpcCallWait(), service, &IBase::getDebugInfo,
                                   [debugInfo](const auto& received) { *debugInfo = received; });
        if (!debugRet.isOk()) {
            handleError(TRANSACTION_ERROR,
                        "debugging information cannot be retrieved: " + debugRet.description());
            break; // skip getPidInfo
        }

        entry->serverPid = debugInfo->pid;
        entry->serverObjectAddress = debugInfo->ptr;
        entry->arch = fromBaseArchitecture(debugInfo->arch);

        if (debugInfo->pid != NO_PID) {
            const BinderPidInfo* pidInfo = getPidInfoCached(debugInfo->pid);
            if (pidInfo == nullptr) {
                handleError(IO_ERROR,
                            "no information for PID " + std::to_string(debugInfo->pid) +
                                    ", are you root?");
                break;
            }
            if (debugInfo->ptr != NO_PTR) {
                auto it = pidInfo->refPids.find(debugInfo->ptr);
                if (it != pidInfo->refPids.end()) {
                    entry->clientPids = it->second;
                }
            }
            entry->threadUsage = pidInfo->threadUsage;
            entry->threadCount = pidInfo->threadCount;
        }
    } while (0);

    // hash
    do {
        // The lambda function may be executed asynchrounously because it is passed to timeoutIPC,
        // even though the interface function call is synchronous.
        auto hashIndexStore = std::make_shared<ssize_t>(-1);
        auto ifaceChainRet = timeoutIPC(mLshal.getIpcCallWait(), service, &IBase::interfaceChain,
                                        [hashIndexStore, serviceName](const auto& c) {
                                            for (size_t i = 0; i < c.size(); ++i) {
                                                if (serviceName == c[i]) {
                                                    *hashIndexStore = static_cast<ssize_t>(i);
                                                    break;
                                                }
                                            }
                                        });
        if (!ifaceChainRet.isOk()) {
            handleError(TRANSACTION_ERROR,
                        "interfaceChain fails: " + ifaceChainRet.description());
            break; // skip getHashChain
        }
        // if ifaceChainRet.isOk(), the background thread has already ended, so it is safe to
        // dereference hashIndex without any locking.
        auto hashIndex = *hashIndexStore;
        if (hashIndex < 0) {
            handleError(BAD_IMPL, "Interface name does not exist in interfaceChain.");
            break; // skip getHashChain
        }
        // See comments about hashIndex above.
        auto hashChain = std::make_shared<hidl_vec<hidl_array<uint8_t, 32>>>();
        auto hashRet = timeoutIPC(mLshal.getIpcCallWait(), service, &IBase::getHashChain,
                                  [hashChain](const auto& ret) { *hashChain = std::move(ret); });
        if (!hashRet.isOk()) {
            handleError(TRANSACTION_ERROR, "getHashChain failed: " + hashRet.description());
            break; // skip getHashChain
        }
        if (static_cast<size_t>(hashIndex) >= hashChain->size()) {
            handleError(BAD_IMPL,
                        "interfaceChain indicates position " + std::to_string(hashIndex) +
                                " but getHashChain returns " + std::to_string(hashChain->size()) +
                                " hashes");
            break; // skip getHashChain
        }
        auto&& hashArray = (*hashChain)[hashIndex];
        entry->hash = android::base::HexString(hashArray.data(), hashArray.size());
    } while (0);
    if (status == OK) {
        entry->serviceStatus = ServiceStatus::ALIVE;
    }
    return status;
}

Status ListCommand::fetchManifestHals() {
    if (!shouldFetchHalType(HalType::VINTF_MANIFEST)) { return OK; }
    Status status = OK;

    for (auto manifest : {getDeviceManifest(), getFrameworkManifest()}) {
        if (manifest == nullptr) {
            status |= VINTF_ERROR;
            continue;
        }

        std::map<std::string, TableEntry> entries;

        manifest->forEachHidlInstance([&] (const vintf::ManifestInstance& manifestInstance) {
            TableEntry entry{
                .interfaceName = manifestInstance.description(),
                .transport = manifestInstance.transport(),
                .arch = manifestInstance.arch(),
                // TODO(b/71555570): Device manifest does not distinguish HALs from vendor or ODM.
                .partition = toPartition(manifest->type()),
                .serviceStatus = ServiceStatus::DECLARED};
            std::string key = entry.interfaceName;
            entries.emplace(std::move(key), std::move(entry));
            return true;
        });

        for (auto&& pair : entries)
            mManifestHalsTable.add(std::move(pair.second));
    }
    return status;
}

Status ListCommand::fetchLazyHals() {
    using vintf::operator<<;

    if (!shouldFetchHalType(HalType::LAZY_HALS)) { return OK; }
    Status status = OK;

    for (const TableEntry& manifestEntry : mManifestHalsTable) {
        if (manifestEntry.transport == vintf::Transport::HWBINDER) {
            if (!hasHwbinderEntry(manifestEntry)) {
                mLazyHalsTable.add(TableEntry(manifestEntry));
            }
            continue;
        }
        if (manifestEntry.transport == vintf::Transport::PASSTHROUGH) {
            if (!hasPassthroughEntry(manifestEntry)) {
                mLazyHalsTable.add(TableEntry(manifestEntry));
            }
            continue;
        }
        err() << "Warning: unrecognized transport in VINTF manifest: "
              << manifestEntry.transport;
        status |= VINTF_ERROR;
    }
    return status;
}

bool ListCommand::hasHwbinderEntry(const TableEntry& entry) const {
    for (const TableEntry& existing : mServicesTable) {
        if (existing.interfaceName == entry.interfaceName) {
            return true;
        }
    }
    return false;
}

bool ListCommand::hasPassthroughEntry(const TableEntry& entry) const {
    FqInstance entryFqInstance;
    if (!entryFqInstance.setTo(entry.interfaceName)) {
        return false; // cannot parse, so add it anyway.
    }
    for (const TableEntry& existing : mImplementationsTable) {
        FqInstance existingFqInstance;
        if (!existingFqInstance.setTo(getPackageAndVersion(existing.interfaceName))) {
            continue;
        }

        // For example, manifest may say graphics.mapper@2.1 but passthroughServiceManager
        // can only list graphics.mapper@2.0.
        if (entryFqInstance.getPackage() == existingFqInstance.getPackage() &&
            vintf::Version{entryFqInstance.getVersion()}
                .minorAtLeast(vintf::Version{existingFqInstance.getVersion()})) {
            return true;
        }
    }
    return false;
}

Status ListCommand::fetch() {
    Status status = OK;
    auto bManager = mLshal.serviceManager();
    if (bManager == nullptr) {
        err() << "Failed to get defaultServiceManager()!" << std::endl;
        status |= NO_BINDERIZED_MANAGER;
    } else {
        status |= fetchBinderized(bManager);
        // Passthrough PIDs are registered to the binderized manager as well.
        status |= fetchPassthrough(bManager);
    }

    auto pManager = mLshal.passthroughManager();
    if (pManager == nullptr) {
        err() << "Failed to get getPassthroughServiceManager()!" << std::endl;
        status |= NO_PASSTHROUGH_MANAGER;
    } else {
        status |= fetchAllLibraries(pManager);
    }
    status |= fetchManifestHals();
    status |= fetchLazyHals();
    return status;
}

void ListCommand::initFetchTypes() {
    // TODO: refactor to do polymorphism on each table (so that dependency graph is not hardcoded).
    static const std::map<HalType, std::set<HalType>> kDependencyGraph{
        {HalType::LAZY_HALS, {HalType::BINDERIZED_SERVICES,
                              HalType::PASSTHROUGH_LIBRARIES,
                              HalType::VINTF_MANIFEST}},
    };
    mFetchTypes.insert(mListTypes.begin(), mListTypes.end());
    for (HalType listType : mListTypes) {
        auto it = kDependencyGraph.find(listType);
        if (it != kDependencyGraph.end()) {
            mFetchTypes.insert(it->second.begin(), it->second.end());
        }
    }
}

// Get all values of enum type T, assuming the first value is 0 and the last value is T::LAST.
// T::LAST is not included in the returned list.
template <typename T>
std::vector<T> GetAllValues() {
    using BaseType = std::underlying_type_t<T>;
    std::vector<T> ret;
    for (BaseType i = 0; i < static_cast<BaseType>(T::LAST); ++i) {
        ret.push_back(static_cast<T>(i));
    }
    return ret;
}

void ListCommand::registerAllOptions() {
    int v = mOptions.size();
    // A list of acceptable command line options
    // key: value returned by getopt_long
    // long options with short alternatives
    mOptions.push_back({'h', "help", no_argument, v++, [](ListCommand*, const char*) {
        return USAGE;
    }, ""});
    mOptions.push_back({'i', "interface", no_argument, v++, [](ListCommand* thiz, const char*) {
        thiz->mSelectedColumns.push_back(TableColumnType::INTERFACE_NAME);
        return OK;
    }, "print the instance name column"});
    mOptions.push_back({'l', "released", no_argument, v++, [](ListCommand* thiz, const char*) {
        thiz->mSelectedColumns.push_back(TableColumnType::RELEASED);
        return OK;
    }, "print the 'is released?' column\n(Y=released, N=unreleased, ?=unknown)"});
    mOptions.push_back({'t', "transport", no_argument, v++, [](ListCommand* thiz, const char*) {
        thiz->mSelectedColumns.push_back(TableColumnType::TRANSPORT);
        return OK;
    }, "print the transport mode column"});
    mOptions.push_back({'r', "arch", no_argument, v++, [](ListCommand* thiz, const char*) {
        thiz->mSelectedColumns.push_back(TableColumnType::ARCH);
        return OK;
    }, "print the bitness column"});
    mOptions.push_back({'s', "hash", no_argument, v++, [](ListCommand* thiz, const char*) {
        thiz->mSelectedColumns.push_back(TableColumnType::HASH);
        return OK;
    }, "print hash of the interface"});
    mOptions.push_back({'p', "pid", no_argument, v++, [](ListCommand* thiz, const char*) {
        thiz->mSelectedColumns.push_back(TableColumnType::SERVER_PID);
        return OK;
    }, "print the server PID, or server cmdline if -m is set"});
    mOptions.push_back({'a', "address", no_argument, v++, [](ListCommand* thiz, const char*) {
        thiz->mSelectedColumns.push_back(TableColumnType::SERVER_ADDR);
        return OK;
    }, "print the server object address column"});
    mOptions.push_back({'c', "clients", no_argument, v++, [](ListCommand* thiz, const char*) {
        thiz->mSelectedColumns.push_back(TableColumnType::CLIENT_PIDS);
        return OK;
    }, "print the client PIDs, or client cmdlines if -m is set"});
    mOptions.push_back({'e', "threads", no_argument, v++, [](ListCommand* thiz, const char*) {
        thiz->mSelectedColumns.push_back(TableColumnType::THREADS);
        return OK;
    }, "print currently used/available threads\n(note, available threads created lazily)"});
    mOptions.push_back({'m', "cmdline", no_argument, v++, [](ListCommand* thiz, const char*) {
        thiz->mEnableCmdlines = true;
        return OK;
    }, "print cmdline instead of PIDs"});
    mOptions.push_back({'d', "debug", optional_argument, v++, [](ListCommand* thiz, const char* arg) {
        thiz->mEmitDebugInfo = true;
        if (arg) thiz->mFileOutputPath = arg;
        return OK;
    }, "Emit debug info from\nIBase::debug with empty options. Cannot be used with --neat.\n"
        "Writes to specified file if 'arg' is provided, otherwise stdout."});

    mOptions.push_back({'V', "vintf", no_argument, v++, [](ListCommand* thiz, const char*) {
        thiz->mSelectedColumns.push_back(TableColumnType::VINTF);
        return OK;
    }, "print VINTF info. This column contains a comma-separated list of:\n"
       "    - DM: if the HIDL HAL is in the device manifest\n"
       "    - DC: if the HIDL HAL is in the device compatibility matrix\n"
       "    - FM: if the HIDL HAL is in the framework manifest\n"
       "    - FC: if the HIDL HAL is in the framework compatibility matrix\n"
       "    - X: if the HIDL HAL is in none of the above lists"});
    mOptions.push_back({'S', "service-status", no_argument, v++, [](ListCommand* thiz, const char*) {
        thiz->mSelectedColumns.push_back(TableColumnType::SERVICE_STATUS);
        return OK;
    }, "print service status column. Possible values are:\n"
       "    - alive: alive and running hwbinder service;\n"
       "    - registered;dead: registered to hwservicemanager but is not responsive;\n"
       "    - declared: only declared in VINTF manifest but is not registered to hwservicemanager;\n"
       "    - N/A: no information for passthrough HALs."});

    mOptions.push_back({'A', "all", no_argument, v++,
                        [](ListCommand* thiz, const char*) {
                            auto allColumns = GetAllValues<TableColumnType>();
                            thiz->mSelectedColumns.insert(thiz->mSelectedColumns.end(),
                                                          allColumns.begin(), allColumns.end());
                            return OK;
                        },
                        "print all columns"});

    // long options without short alternatives
    mOptions.push_back({'\0', "init-vintf", no_argument, v++, [](ListCommand* thiz, const char* arg) {
        thiz->mVintf = true;
        if (thiz->mVintfPartition == Partition::UNKNOWN)
            thiz->mVintfPartition = Partition::VENDOR;
        if (arg) thiz->mFileOutputPath = arg;
        return OK;
    }, "form a skeleton HAL manifest to specified file,\nor stdout if no file specified."});
    mOptions.push_back({'\0', "init-vintf-partition", required_argument, v++, [](ListCommand* thiz, const char* arg) {
        if (!arg) return USAGE;
        thiz->mVintfPartition = android::procpartition::parsePartition(arg);
        if (thiz->mVintfPartition == Partition::UNKNOWN) return USAGE;
        return OK;
    }, "Specify the partition of the HAL manifest\ngenerated by --init-vintf.\n"
       "Valid values are 'system', 'vendor', and 'odm'. Default is 'vendor'."});
    mOptions.push_back({'\0', "sort", required_argument, v++, [](ListCommand* thiz, const char* arg) {
        if (strcmp(arg, "interface") == 0 || strcmp(arg, "i") == 0) {
            thiz->mSortColumn = TableEntry::sortByInterfaceName;
        } else if (strcmp(arg, "pid") == 0 || strcmp(arg, "p") == 0) {
            thiz->mSortColumn = TableEntry::sortByServerPid;
        } else {
            thiz->err() << "Unrecognized sorting column: " << arg << std::endl;
            return USAGE;
        }
        return OK;
    }, "sort by a column. 'arg' can be (i|interface) or (p|pid)."});
    mOptions.push_back({'\0', "neat", no_argument, v++, [](ListCommand* thiz, const char*) {
        thiz->mNeat = true;
        return OK;
    }, "output is machine parsable (no explanatory text).\nCannot be used with --debug."});
    mOptions.push_back(
            {'\0', "types", required_argument, v++,
             [](ListCommand* thiz, const char* arg) {
                 if (!arg) {
                     return USAGE;
                 }

                 static const std::map<std::string, std::vector<HalType>> kHalTypeMap{
                         {"binderized", {HalType::BINDERIZED_SERVICES}},
                         {"b", {HalType::BINDERIZED_SERVICES}},
                         {"passthrough_clients", {HalType::PASSTHROUGH_CLIENTS}},
                         {"c", {HalType::PASSTHROUGH_CLIENTS}},
                         {"passthrough_libs", {HalType::PASSTHROUGH_LIBRARIES}},
                         {"l", {HalType::PASSTHROUGH_LIBRARIES}},
                         {"vintf", {HalType::VINTF_MANIFEST}},
                         {"v", {HalType::VINTF_MANIFEST}},
                         {"lazy", {HalType::LAZY_HALS}},
                         {"z", {HalType::LAZY_HALS}},
                         {"all", GetAllValues<HalType>()},
                         {"a", GetAllValues<HalType>()},
                 };

                 std::vector<std::string> halTypesArgs = split(std::string(arg), ',');
                 for (const auto& halTypeArg : halTypesArgs) {
                     if (halTypeArg.empty()) continue;

                     const auto& halTypeIter = kHalTypeMap.find(halTypeArg);
                     if (halTypeIter == kHalTypeMap.end()) {
                         thiz->err() << "Unrecognized HAL type: " << halTypeArg << std::endl;
                         return USAGE;
                     }

                     // Append unique (non-repeated) HAL types to the reporting list
                     for (auto halType : halTypeIter->second) {
                         if (std::find(thiz->mListTypes.begin(), thiz->mListTypes.end(), halType) ==
                             thiz->mListTypes.end()) {
                             thiz->mListTypes.push_back(halType);
                         }
                     }
                 }

                 if (thiz->mListTypes.empty()) {
                     return USAGE;
                 }
                 return OK;
             },
             "comma-separated list of one or more sections.\nThe output is restricted to the "
             "selected section(s). Valid options\nare: (b|binderized), (c|passthrough_clients), (l|"
             "passthrough_libs), (v|vintf), (z|lazy), and (a|all).\nDefault is `b,c,l`."});
}

// Create 'longopts' argument to getopt_long. Caller is responsible for maintaining
// the lifetime of "options" during the usage of the returned array.
static std::unique_ptr<struct option[]> getLongOptions(
        const ListCommand::RegisteredOptions& options,
        int* longOptFlag) {
    std::unique_ptr<struct option[]> ret{new struct option[options.size() + 1]};
    int i = 0;
    for (const auto& e : options) {
        ret[i].name = e.longOption.c_str();
        ret[i].has_arg = e.hasArg;
        ret[i].flag = longOptFlag;
        ret[i].val = e.val;

        i++;
    }
    // getopt_long last option has all zeros
    ret[i].name = nullptr;
    ret[i].has_arg = 0;
    ret[i].flag = nullptr;
    ret[i].val = 0;

    return ret;
}

// Create 'optstring' argument to getopt_long.
static std::string getShortOptions(const ListCommand::RegisteredOptions& options) {
    std::stringstream ss;
    for (const auto& e : options) {
        if (e.shortOption != '\0') {
            ss << e.shortOption;
        }
    }
    return ss.str();
}

Status ListCommand::parseArgs(const Arg &arg) {
    mListTypes.clear();

    if (mOptions.empty()) {
        registerAllOptions();
    }
    int longOptFlag;
    std::unique_ptr<struct option[]> longOptions = getLongOptions(mOptions, &longOptFlag);
    std::string shortOptions = getShortOptions(mOptions);

    // suppress output to std::err for unknown options
    opterr = 0;

    int optionIndex;
    int c;
    // Lshal::parseArgs has set optind to the next option to parse
    for (;;) {
        c = getopt_long(arg.argc, arg.argv,
                shortOptions.c_str(), longOptions.get(), &optionIndex);
        if (c == -1) {
            break;
        }
        const RegisteredOption* found = nullptr;
        if (c == 0) {
            // see long option
            for (const auto& e : mOptions) {
                if (longOptFlag == e.val) found = &e;
            }
        } else {
            // see short option
            for (const auto& e : mOptions) {
                if (c == e.shortOption) found = &e;
            }
        }

        if (found == nullptr) {
            // see unrecognized options
            err() << "unrecognized option `" << arg.argv[optind - 1] << "'" << std::endl;
            return USAGE;
        }

        Status status = found->op(this, optarg);
        if (status != OK) {
            return status;
        }
    }
    if (optind < arg.argc) {
        // see non option
        err() << "unrecognized option `" << arg.argv[optind] << "'" << std::endl;
        return USAGE;
    }

    if (mNeat && mEmitDebugInfo) {
        err() << "Error: --neat should not be used with --debug." << std::endl;
        return USAGE;
    }

    if (mSelectedColumns.empty()) {
        mSelectedColumns = {TableColumnType::VINTF, TableColumnType::RELEASED,
                            TableColumnType::INTERFACE_NAME, TableColumnType::THREADS,
                            TableColumnType::SERVER_PID, TableColumnType::CLIENT_PIDS};
    }

    if (mEnableCmdlines) {
        for (size_t i = 0; i < mSelectedColumns.size(); ++i) {
            if (mSelectedColumns[i] == TableColumnType::SERVER_PID) {
                mSelectedColumns[i] = TableColumnType::SERVER_CMD;
            }
            if (mSelectedColumns[i] == TableColumnType::CLIENT_PIDS) {
                mSelectedColumns[i] = TableColumnType::CLIENT_CMDS;
            }
        }
    }

    // By default, list all HAL types
    if (mListTypes.empty()) {
        mListTypes = {HalType::BINDERIZED_SERVICES, HalType::PASSTHROUGH_CLIENTS,
                      HalType::PASSTHROUGH_LIBRARIES};
    }
    initFetchTypes();

    forEachTable([this] (Table& table) {
        table.setSelectedColumns(this->mSelectedColumns);
    });

    return OK;
}

Status ListCommand::main(const Arg &arg) {
    Status status = parseArgs(arg);
    if (status != OK) {
        return status;
    }
    status = fetch();
    postprocess();
    status |= dump();
    return status;
}

const std::string& ListCommand::RegisteredOption::getHelpMessageForArgument() const {
    static const std::string empty{};
    static const std::string optional{"[=<arg>]"};
    static const std::string required{"=<arg>"};

    if (hasArg == optional_argument) {
        return optional;
    }
    if (hasArg == required_argument) {
        return required;
    }
    return empty;
}

void ListCommand::usage() const {

    err() << "list:" << std::endl
          << "    lshal" << std::endl
          << "    lshal list" << std::endl
          << "        List all hals with default ordering and columns (`lshal list -Vliepc`)" << std::endl
          << "    lshal list [-h|--help]" << std::endl
          << "        -h, --help: Print help message for list (`lshal help list`)" << std::endl
          << "    lshal [list] [OPTIONS...]" << std::endl;
    for (const auto& e : mOptions) {
        if (e.help.empty()) {
            continue;
        }
        err() << "        ";
        if (e.shortOption != '\0')
            err() << "-" << e.shortOption << e.getHelpMessageForArgument();
        if (e.shortOption != '\0' && !e.longOption.empty())
            err() << ", ";
        if (!e.longOption.empty())
            err() << "--" << e.longOption << e.getHelpMessageForArgument();
        err() << ": ";
        std::vector<std::string> lines = split(e.help, '\n');
        for (const auto& line : lines) {
            if (&line != &lines.front())
                err() << "            ";
            err() << line << std::endl;
        }
    }
}

}  // namespace lshal
}  // namespace android