Lshal: support commands.

Support the following commands:
  lshal list
  lshal list -itrpc
  lshal help
  lshal help list
  lshal list -h
  lshal list --help

Test: run these commands
Bug: 37725279
Change-Id: I970fbc8d250d43f57e92f783229e0645d7e8df4e
diff --git a/cmds/lshal/ListCommand.cpp b/cmds/lshal/ListCommand.cpp
new file mode 100644
index 0000000..5696843
--- /dev/null
+++ b/cmds/lshal/ListCommand.cpp
@@ -0,0 +1,710 @@
+/*
+ * 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 <fstream>
+#include <iomanip>
+#include <iostream>
+#include <map>
+#include <sstream>
+#include <regex>
+
+#include <android-base/parseint.h>
+#include <android/hidl/manager/1.0/IServiceManager.h>
+#include <hidl/ServiceManagement.h>
+#include <hidl-util/FQName.h>
+#include <private/android_filesystem_config.h>
+#include <sys/stat.h>
+#include <vintf/HalManifest.h>
+#include <vintf/parse_xml.h>
+
+#include "Lshal.h"
+#include "PipeRelay.h"
+#include "Timeout.h"
+#include "utils.h"
+
+using ::android::hardware::hidl_string;
+using ::android::hidl::manager::V1_0::IServiceManager;
+
+namespace android {
+namespace lshal {
+
+ListCommand::ListCommand(Lshal &lshal) : mLshal(lshal), mErr(lshal.err()), mOut(lshal.out()) {
+}
+
+std::string getCmdline(pid_t pid) {
+    std::ifstream ifs("/proc/" + std::to_string(pid) + "/cmdline");
+    std::string cmdline;
+    if (!ifs.is_open()) {
+        return "";
+    }
+    ifs >> cmdline;
+    return cmdline;
+}
+
+const std::string &ListCommand::getCmdline(pid_t pid) {
+    auto pair = mCmdlines.find(pid);
+    if (pair != mCmdlines.end()) {
+        return pair->second;
+    }
+    mCmdlines[pid] = ::android::lshal::getCmdline(pid);
+    return mCmdlines[pid];
+}
+
+void ListCommand::removeDeadProcesses(Pids *pids) {
+    static const pid_t myPid = getpid();
+    std::remove_if(pids->begin(), pids->end(), [this](auto pid) {
+        return pid == myPid || this->getCmdline(pid).empty();
+    });
+}
+
+bool ListCommand::getReferencedPids(
+        pid_t serverPid, std::map<uint64_t, Pids> *objects) const {
+
+    std::ifstream ifs("/d/binder/proc/" + std::to_string(serverPid));
+    if (!ifs.is_open()) {
+        return false;
+    }
+
+    static const std::regex prefix("^\\s*node \\d+:\\s+u([0-9a-f]+)\\s+c([0-9a-f]+)\\s+");
+
+    std::string line;
+    std::smatch match;
+    while(getline(ifs, line)) {
+        if (!std::regex_search(line, match, prefix)) {
+            // the line doesn't start with the correct prefix
+            continue;
+        }
+        std::string ptrString = "0x" + match.str(2); // use number after c
+        uint64_t ptr;
+        if (!::android::base::ParseUint(ptrString.c_str(), &ptr)) {
+            // Should not reach here, but just be tolerant.
+            mErr << "Could not parse number " << ptrString << std::endl;
+            continue;
+        }
+        const std::string proc = " proc ";
+        auto pos = line.rfind(proc);
+        if (pos != std::string::npos) {
+            for (const std::string &pidStr : split(line.substr(pos + proc.size()), ' ')) {
+                int32_t pid;
+                if (!::android::base::ParseInt(pidStr, &pid)) {
+                    mErr << "Could not parse number " << pidStr << std::endl;
+                    continue;
+                }
+                (*objects)[ptr].push_back(pid);
+            }
+        }
+    }
+    return true;
+}
+
+// Must process hwbinder services first, then passthrough services.
+void ListCommand::forEachTable(const std::function<void(Table &)> &f) {
+    f(mServicesTable);
+    f(mPassthroughRefTable);
+    f(mImplementationsTable);
+}
+void ListCommand::forEachTable(const std::function<void(const Table &)> &f) const {
+    f(mServicesTable);
+    f(mPassthroughRefTable);
+    f(mImplementationsTable);
+}
+
+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));
+            }
+        }
+    });
+    // use a double for loop here because lshal doesn't care about efficiency.
+    for (TableEntry &packageEntry : mImplementationsTable) {
+        std::string packageName = packageEntry.interfaceName;
+        FQName fqPackageName{packageName.substr(0, packageName.find("::"))};
+        if (!fqPackageName.isValid()) {
+            continue;
+        }
+        for (TableEntry &interfaceEntry : mPassthroughRefTable) {
+            if (interfaceEntry.arch != ARCH_UNKNOWN) {
+                continue;
+            }
+            FQName interfaceName{splitFirst(interfaceEntry.interfaceName, '/').first};
+            if (!interfaceName.isValid()) {
+                continue;
+            }
+            if (interfaceName.getPackageAndVersion() == fqPackageName) {
+                interfaceEntry.arch = packageEntry.arch;
+            }
+        }
+    }
+}
+
+void ListCommand::printLine(
+        const std::string &interfaceName,
+        const std::string &transport,
+        const std::string &arch,
+        const std::string &server,
+        const std::string &serverCmdline,
+        const std::string &address, const std::string &clients,
+        const std::string &clientCmdlines) const {
+    if (mSelectedColumns & ENABLE_INTERFACE_NAME)
+        mOut << std::setw(80) << interfaceName << "\t";
+    if (mSelectedColumns & ENABLE_TRANSPORT)
+        mOut << std::setw(10) << transport << "\t";
+    if (mSelectedColumns & ENABLE_ARCH)
+        mOut << std::setw(5) << arch << "\t";
+    if (mSelectedColumns & ENABLE_SERVER_PID) {
+        if (mEnableCmdlines) {
+            mOut << std::setw(15) << serverCmdline << "\t";
+        } else {
+            mOut << std::setw(5)  << server << "\t";
+        }
+    }
+    if (mSelectedColumns & ENABLE_SERVER_ADDR)
+        mOut << std::setw(16) << address << "\t";
+    if (mSelectedColumns & ENABLE_CLIENT_PIDS) {
+        if (mEnableCmdlines) {
+            mOut << std::setw(0)  << clientCmdlines;
+        } else {
+            mOut << std::setw(0)  << clients;
+        }
+    }
+    mOut << std::endl;
+}
+
+void ListCommand::dumpVintf() const {
+    mOut << "<!-- " << std::endl
+         << "    This is a skeleton device manifest. Notes: " << std::endl
+         << "    1. android.hidl.*, android.frameworks.*, android.system.* are not included." << std::endl
+         << "    2. If a HAL is supported in both hwbinder and passthrough transport, " << std::endl
+         << "       only hwbinder is shown." << std::endl
+         << "    3. It is likely that HALs in passthrough transport does not have" << std::endl
+         << "       <interface> declared; users will have to write them by hand." << std::endl
+         << "    4. sepolicy version is set to 0.0. It is recommended that the entry" << std::endl
+         << "       is removed from the manifest file and written by assemble_vintf" << std::endl
+         << "       at build time." << std::endl
+         << "-->" << std::endl;
+
+    vintf::HalManifest manifest;
+    forEachTable([this, &manifest] (const Table &table) {
+        for (const TableEntry &entry : table) {
+
+            std::string fqInstanceName = entry.interfaceName;
+
+            if (&table == &mImplementationsTable) {
+                // Quick hack to work around *'s
+                replaceAll(&fqInstanceName, '*', 'D');
+            }
+            auto splittedFqInstanceName = splitFirst(fqInstanceName, '/');
+            FQName fqName(splittedFqInstanceName.first);
+            if (!fqName.isValid()) {
+                mErr << "Warning: '" << splittedFqInstanceName.first
+                     << "' is not a valid FQName." << std::endl;
+                continue;
+            }
+            // Strip out system libs.
+            if (fqName.inPackage("android.hidl") ||
+                fqName.inPackage("android.frameworks") ||
+                fqName.inPackage("android.system")) {
+                continue;
+            }
+            std::string interfaceName =
+                    &table == &mImplementationsTable ? "" : fqName.name();
+            std::string instanceName =
+                    &table == &mImplementationsTable ? "" : splittedFqInstanceName.second;
+
+            vintf::Version version{fqName.getPackageMajorVersion(),
+                                   fqName.getPackageMinorVersion()};
+            vintf::Transport transport;
+            vintf::Arch arch;
+            if (entry.transport == "hwbinder") {
+                transport = vintf::Transport::HWBINDER;
+                arch = vintf::Arch::ARCH_EMPTY;
+            } else if (entry.transport == "passthrough") {
+                transport = vintf::Transport::PASSTHROUGH;
+                switch (entry.arch) {
+                    case lshal::ARCH32:
+                        arch = vintf::Arch::ARCH_32;    break;
+                    case lshal::ARCH64:
+                        arch = vintf::Arch::ARCH_64;    break;
+                    case lshal::ARCH_BOTH:
+                        arch = vintf::Arch::ARCH_32_64; break;
+                    case lshal::ARCH_UNKNOWN: // fallthrough
+                    default:
+                        mErr << "Warning: '" << fqName.package()
+                             << "' doesn't have bitness info, assuming 32+64." << std::endl;
+                        arch = vintf::Arch::ARCH_32_64;
+                }
+            } else {
+                mErr << "Warning: '" << entry.transport << "' is not a valid transport." << std::endl;
+                continue;
+            }
+
+            bool done = false;
+            for (vintf::ManifestHal *hal : manifest.getHals(fqName.package())) {
+                if (hal->transport() != transport) {
+                    if (transport != vintf::Transport::PASSTHROUGH) {
+                        mErr << "Fatal: should not reach here. Generated result may be wrong."
+                             << std::endl;
+                    }
+                    done = true;
+                    break;
+                }
+                if (hal->hasVersion(version)) {
+                    if (&table != &mImplementationsTable) {
+                        hal->interfaces[interfaceName].name = interfaceName;
+                        hal->interfaces[interfaceName].instances.insert(instanceName);
+                    }
+                    done = true;
+                    break;
+                }
+            }
+            if (done) {
+                continue; // to next TableEntry
+            }
+            decltype(vintf::ManifestHal::interfaces) interfaces;
+            if (&table != &mImplementationsTable) {
+                interfaces[interfaceName].name = interfaceName;
+                interfaces[interfaceName].instances.insert(instanceName);
+            }
+            if (!manifest.add(vintf::ManifestHal{
+                    .format = vintf::HalFormat::HIDL,
+                    .name = fqName.package(),
+                    .versions = {version},
+                    .transportArch = {transport, arch},
+                    .interfaces = interfaces})) {
+                mErr << "Warning: cannot add hal '" << fqInstanceName << "'" << std::endl;
+            }
+        }
+    });
+    mOut << vintf::gHalManifestConverter(manifest);
+}
+
+static const std::string &getArchString(Architecture arch) {
+    static const std::string sStr64 = "64";
+    static const std::string sStr32 = "32";
+    static const std::string sStrBoth = "32+64";
+    static const std::string sStrUnknown = "";
+    switch (arch) {
+        case ARCH64:
+            return sStr64;
+        case ARCH32:
+            return sStr32;
+        case ARCH_BOTH:
+            return sStrBoth;
+        case ARCH_UNKNOWN: // fall through
+        default:
+            return sStrUnknown;
+    }
+}
+
+static Architecture fromBaseArchitecture(::android::hidl::base::V1_0::DebugInfo::Architecture a) {
+    switch (a) {
+        case ::android::hidl::base::V1_0::DebugInfo::Architecture::IS_64BIT:
+            return ARCH64;
+        case ::android::hidl::base::V1_0::DebugInfo::Architecture::IS_32BIT:
+            return ARCH32;
+        case ::android::hidl::base::V1_0::DebugInfo::Architecture::UNKNOWN: // fallthrough
+        default:
+            return ARCH_UNKNOWN;
+    }
+}
+
+void ListCommand::dumpTable() {
+    mServicesTable.description =
+            "All binderized services (registered services through hwservicemanager)";
+    mPassthroughRefTable.description =
+            "All interfaces that getService() has ever return 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.description =
+            "All available passthrough implementations (all -impl.so files)";
+    forEachTable([this] (const Table &table) {
+        mOut << table.description << std::endl;
+        mOut << std::left;
+        printLine("Interface", "Transport", "Arch", "Server", "Server CMD",
+                  "PTR", "Clients", "Clients CMD");
+
+        // 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".
+        sp<IServiceManager> serviceManager;
+        if (mEmitDebugInfo && &table == &mServicesTable) {
+            serviceManager = ::android::hardware::defaultServiceManager();
+        }
+
+        for (const auto &entry : table) {
+            printLine(entry.interfaceName,
+                    entry.transport,
+                    getArchString(entry.arch),
+                    entry.serverPid == NO_PID ? "N/A" : std::to_string(entry.serverPid),
+                    entry.serverCmdline,
+                    entry.serverObjectAddress == NO_PTR ? "N/A" : toHexString(entry.serverObjectAddress),
+                    join(entry.clientPids, " "),
+                    join(entry.clientCmdlines, ";"));
+
+            if (serviceManager != nullptr) {
+                auto pair = splitFirst(entry.interfaceName, '/');
+                mLshal.emitDebugInfo(serviceManager, pair.first, pair.second, {}, mOut.buf());
+            }
+        }
+        mOut << std::endl;
+    });
+
+}
+
+void ListCommand::dump() {
+    if (mVintf) {
+        dumpVintf();
+        if (!!mFileOutput) {
+            mFileOutput.buf().close();
+            delete &mFileOutput.buf();
+            mFileOutput = nullptr;
+        }
+        mOut = std::cout;
+    } else {
+        dumpTable();
+    }
+}
+
+void ListCommand::putEntry(TableEntrySource source, TableEntry &&entry) {
+    Table *table = nullptr;
+    switch (source) {
+        case HWSERVICEMANAGER_LIST :
+            table = &mServicesTable; break;
+        case PTSERVICEMANAGER_REG_CLIENT :
+            table = &mPassthroughRefTable; break;
+        case LIST_DLLIB :
+            table = &mImplementationsTable; break;
+        default:
+            mErr << "Error: Unknown source of entry " << source << std::endl;
+    }
+    if (table) {
+        table->entries.push_back(std::forward<TableEntry>(entry));
+    }
+}
+
+Status ListCommand::fetchAllLibraries(const sp<IServiceManager> &manager) {
+    using namespace ::android::hardware;
+    using namespace ::android::hidl::manager::V1_0;
+    using namespace ::android::hidl::base::V1_0;
+    auto ret = timeoutIPC(manager, &IServiceManager::debugDump, [&] (const auto &infos) {
+        std::map<std::string, TableEntry> entries;
+        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 = "passthrough",
+                .serverPid = NO_PID,
+                .serverObjectAddress = NO_PTR,
+                .clientPids = {},
+                .arch = ARCH_UNKNOWN
+            }).first->second.arch |= fromBaseArchitecture(info.arch);
+        }
+        for (auto &&pair : entries) {
+            putEntry(LIST_DLLIB, std::move(pair.second));
+        }
+    });
+    if (!ret.isOk()) {
+        mErr << "Error: Failed to call list on getPassthroughServiceManager(): "
+             << ret.description() << std::endl;
+        return DUMP_ALL_LIBS_ERROR;
+    }
+    return OK;
+}
+
+Status ListCommand::fetchPassthrough(const sp<IServiceManager> &manager) {
+    using namespace ::android::hardware;
+    using namespace ::android::hardware::details;
+    using namespace ::android::hidl::manager::V1_0;
+    using namespace ::android::hidl::base::V1_0;
+    auto ret = timeoutIPC(manager, &IServiceManager::debugDump, [&] (const auto &infos) {
+        for (const auto &info : infos) {
+            if (info.clientPids.size() <= 0) {
+                continue;
+            }
+            putEntry(PTSERVICEMANAGER_REG_CLIENT, {
+                .interfaceName =
+                        std::string{info.interfaceName.c_str()} + "/" +
+                        std::string{info.instanceName.c_str()},
+                .transport = "passthrough",
+                .serverPid = info.clientPids.size() == 1 ? info.clientPids[0] : NO_PID,
+                .serverObjectAddress = NO_PTR,
+                .clientPids = info.clientPids,
+                .arch = fromBaseArchitecture(info.arch)
+            });
+        }
+    });
+    if (!ret.isOk()) {
+        mErr << "Error: Failed to call debugDump on defaultServiceManager(): "
+             << ret.description() << std::endl;
+        return DUMP_PASSTHROUGH_ERROR;
+    }
+    return OK;
+}
+
+Status ListCommand::fetchBinderized(const sp<IServiceManager> &manager) {
+    using namespace ::std;
+    using namespace ::android::hardware;
+    using namespace ::android::hidl::manager::V1_0;
+    using namespace ::android::hidl::base::V1_0;
+    const std::string mode = "hwbinder";
+
+    hidl_vec<hidl_string> fqInstanceNames;
+    // copying out for timeoutIPC
+    auto listRet = timeoutIPC(manager, &IServiceManager::list, [&] (const auto &names) {
+        fqInstanceNames = names;
+    });
+    if (!listRet.isOk()) {
+        mErr << "Error: Failed to list services for " << mode << ": "
+             << listRet.description() << std::endl;
+        return DUMP_BINDERIZED_ERROR;
+    }
+
+    Status status = OK;
+    // server pid, .ptr value of binder object, child pids
+    std::map<std::string, DebugInfo> allDebugInfos;
+    std::map<pid_t, std::map<uint64_t, Pids>> allPids;
+    for (const auto &fqInstanceName : fqInstanceNames) {
+        const auto pair = splitFirst(fqInstanceName, '/');
+        const auto &serviceName = pair.first;
+        const auto &instanceName = pair.second;
+        auto getRet = timeoutIPC(manager, &IServiceManager::get, serviceName, instanceName);
+        if (!getRet.isOk()) {
+            mErr << "Warning: Skipping \"" << fqInstanceName << "\": "
+                 << "cannot be fetched from service manager:"
+                 << getRet.description() << std::endl;
+            status |= DUMP_BINDERIZED_ERROR;
+            continue;
+        }
+        sp<IBase> service = getRet;
+        if (service == nullptr) {
+            mErr << "Warning: Skipping \"" << fqInstanceName << "\": "
+                 << "cannot be fetched from service manager (null)"
+                 << std::endl;
+            status |= DUMP_BINDERIZED_ERROR;
+            continue;
+        }
+        auto debugRet = timeoutIPC(service, &IBase::getDebugInfo, [&] (const auto &debugInfo) {
+            allDebugInfos[fqInstanceName] = debugInfo;
+            if (debugInfo.pid >= 0) {
+                allPids[static_cast<pid_t>(debugInfo.pid)].clear();
+            }
+        });
+        if (!debugRet.isOk()) {
+            mErr << "Warning: Skipping \"" << fqInstanceName << "\": "
+                 << "debugging information cannot be retrieved:"
+                 << debugRet.description() << std::endl;
+            status |= DUMP_BINDERIZED_ERROR;
+        }
+    }
+    for (auto &pair : allPids) {
+        pid_t serverPid = pair.first;
+        if (!getReferencedPids(serverPid, &allPids[serverPid])) {
+            mErr << "Warning: no information for PID " << serverPid
+                      << ", are you root?" << std::endl;
+            status |= DUMP_BINDERIZED_ERROR;
+        }
+    }
+    for (const auto &fqInstanceName : fqInstanceNames) {
+        auto it = allDebugInfos.find(fqInstanceName);
+        if (it == allDebugInfos.end()) {
+            putEntry(HWSERVICEMANAGER_LIST, {
+                .interfaceName = fqInstanceName,
+                .transport = mode,
+                .serverPid = NO_PID,
+                .serverObjectAddress = NO_PTR,
+                .clientPids = {},
+                .arch = ARCH_UNKNOWN
+            });
+            continue;
+        }
+        const DebugInfo &info = it->second;
+        putEntry(HWSERVICEMANAGER_LIST, {
+            .interfaceName = fqInstanceName,
+            .transport = mode,
+            .serverPid = info.pid,
+            .serverObjectAddress = info.ptr,
+            .clientPids = info.pid == NO_PID || info.ptr == NO_PTR
+                    ? Pids{} : allPids[info.pid][info.ptr],
+            .arch = fromBaseArchitecture(info.arch),
+        });
+    }
+    return status;
+}
+
+Status ListCommand::fetch() {
+    Status status = OK;
+    auto bManager = ::android::hardware::defaultServiceManager();
+    if (bManager == nullptr) {
+        mErr << "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 = ::android::hardware::getPassthroughServiceManager();
+    if (pManager == nullptr) {
+        mErr << "Failed to get getPassthroughServiceManager()!" << std::endl;
+        status |= NO_PASSTHROUGH_MANAGER;
+    } else {
+        status |= fetchAllLibraries(pManager);
+    }
+    return status;
+}
+
+Status ListCommand::parseArgs(const std::string &command, const Arg &arg) {
+    static struct option longOptions[] = {
+        // long options with short alternatives
+        {"help",      no_argument,       0, 'h' },
+        {"interface", no_argument,       0, 'i' },
+        {"transport", no_argument,       0, 't' },
+        {"arch",      no_argument,       0, 'r' },
+        {"pid",       no_argument,       0, 'p' },
+        {"address",   no_argument,       0, 'a' },
+        {"clients",   no_argument,       0, 'c' },
+        {"cmdline",   no_argument,       0, 'm' },
+        {"debug",     optional_argument, 0, 'd' },
+
+        // long options without short alternatives
+        {"sort",      required_argument, 0, 's' },
+        {"init-vintf",optional_argument, 0, 'v' },
+        { 0,          0,                 0,  0  }
+    };
+
+    int optionIndex;
+    int c;
+    // Lshal::parseArgs has set optind to the next option to parse
+    for (;;) {
+        // using getopt_long in case we want to add other options in the future
+        c = getopt_long(arg.argc, arg.argv,
+                "hitrpacmd", longOptions, &optionIndex);
+        if (c == -1) {
+            break;
+        }
+        switch (c) {
+        case 's': {
+            if (strcmp(optarg, "interface") == 0 || strcmp(optarg, "i") == 0) {
+                mSortColumn = TableEntry::sortByInterfaceName;
+            } else if (strcmp(optarg, "pid") == 0 || strcmp(optarg, "p") == 0) {
+                mSortColumn = TableEntry::sortByServerPid;
+            } else {
+                mErr << "Unrecognized sorting column: " << optarg << std::endl;
+                mLshal.usage(command);
+                return USAGE;
+            }
+            break;
+        }
+        case 'v': {
+            if (optarg) {
+                mFileOutput = new std::ofstream{optarg};
+                mOut = mFileOutput;
+                if (!mFileOutput.buf().is_open()) {
+                    mErr << "Could not open file '" << optarg << "'." << std::endl;
+                    return IO_ERROR;
+                }
+            }
+            mVintf = true;
+        }
+        case 'i': {
+            mSelectedColumns |= ENABLE_INTERFACE_NAME;
+            break;
+        }
+        case 't': {
+            mSelectedColumns |= ENABLE_TRANSPORT;
+            break;
+        }
+        case 'r': {
+            mSelectedColumns |= ENABLE_ARCH;
+            break;
+        }
+        case 'p': {
+            mSelectedColumns |= ENABLE_SERVER_PID;
+            break;
+        }
+        case 'a': {
+            mSelectedColumns |= ENABLE_SERVER_ADDR;
+            break;
+        }
+        case 'c': {
+            mSelectedColumns |= ENABLE_CLIENT_PIDS;
+            break;
+        }
+        case 'm': {
+            mEnableCmdlines = true;
+            break;
+        }
+        case 'd': {
+            mEmitDebugInfo = true;
+
+            if (optarg) {
+                mFileOutput = new std::ofstream{optarg};
+                mOut = mFileOutput;
+                if (!mFileOutput.buf().is_open()) {
+                    mErr << "Could not open file '" << optarg << "'." << std::endl;
+                    return IO_ERROR;
+                }
+                chown(optarg, AID_SHELL, AID_SHELL);
+            }
+            break;
+        }
+        case 'h': // falls through
+        default: // see unrecognized options
+            mLshal.usage(command);
+            return USAGE;
+        }
+    }
+    if (optind < arg.argc) {
+        // see non option
+        mErr << "Unrecognized option `" << arg.argv[optind] << "`" << std::endl;
+    }
+
+    if (mSelectedColumns == 0) {
+        mSelectedColumns = ENABLE_INTERFACE_NAME | ENABLE_SERVER_PID | ENABLE_CLIENT_PIDS;
+    }
+    return OK;
+}
+
+Status ListCommand::main(const std::string &command, const Arg &arg) {
+    Status status = parseArgs(command, arg);
+    if (status != OK) {
+        return status;
+    }
+    status = fetch();
+    postprocess();
+    dump();
+    return status;
+}
+
+}  // namespace lshal
+}  // namespace android
+