cmds/dumpstate/utils.cpp

/*
 * Copyright (C) 2008 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 <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <libgen.h>
#include <limits.h>
#include <poll.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/capability.h>
#include <sys/inotify.h>
#include <sys/klog.h>
#include <sys/prctl.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>
#include <string>
#include <vector>

#define LOG_TAG "dumpstate"

#include <android-base/file.h>
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
#include <cutils/debugger.h>
#include <cutils/log.h>
#include <cutils/properties.h>
#include <cutils/sockets.h>
#include <private/android_filesystem_config.h>

#include <selinux/android.h>

#include "dumpstate.h"

#define SU_PATH "/system/xbin/su"

static const int64_t NANOS_PER_SEC = 1000000000;

static const int TRACE_DUMP_TIMEOUT_MS = 10000; // 10 seconds

// TODO: temporary variables and functions used during C++ refactoring
static Dumpstate& ds = Dumpstate::GetInstance();
static int RunCommand(const std::string& title, const std::vector<std::string>& full_command,
                      const CommandOptions& options = CommandOptions::DEFAULT) {
    return ds.RunCommand(title, full_command, options);
}
static bool IsDryRun() {
    return Dumpstate::GetInstance().IsDryRun();
}
static void UpdateProgress(int delta) {
    ds.UpdateProgress(delta);
}

/* list of native processes to include in the native dumps */
// This matches the /proc/pid/exe link instead of /proc/pid/cmdline.
static const char* native_processes_to_dump[] = {
        "/system/bin/audioserver",
        "/system/bin/cameraserver",
        "/system/bin/drmserver",
        "/system/bin/mediacodec",     // media.codec
        "/system/bin/mediadrmserver",
        "/system/bin/mediaextractor", // media.extractor
        "/system/bin/mediaserver",
        "/system/bin/sdcard",
        "/system/bin/surfaceflinger",
        "/system/bin/vehicle_network_service",
        NULL,
};

/* Most simple commands have 10 as timeout, so 5 is a good estimate */
static const int WEIGHT_FILE = 5;

CommandOptions CommandOptions::DEFAULT = CommandOptions::WithTimeout(10).Build();
CommandOptions CommandOptions::DEFAULT_DUMPSYS = CommandOptions::WithTimeout(30).Build();
CommandOptions CommandOptions::AS_ROOT_5 = CommandOptions::WithTimeout(5).AsRoot().Build();
CommandOptions CommandOptions::AS_ROOT_10 = CommandOptions::WithTimeout(10).AsRoot().Build();
CommandOptions CommandOptions::AS_ROOT_20 = CommandOptions::WithTimeout(20).AsRoot().Build();

CommandOptions::CommandOptionsBuilder::CommandOptionsBuilder(long timeout) : values(timeout) {
}

CommandOptions::CommandOptionsBuilder& CommandOptions::CommandOptionsBuilder::Always() {
    values.always_ = true;
    return *this;
}

CommandOptions::CommandOptionsBuilder& CommandOptions::CommandOptionsBuilder::AsRoot() {
    values.root_mode_ = SU_ROOT;
    return *this;
}

CommandOptions::CommandOptionsBuilder& CommandOptions::CommandOptionsBuilder::DropRoot() {
    values.root_mode_ = DROP_ROOT;
    return *this;
}

CommandOptions::CommandOptionsBuilder& CommandOptions::CommandOptionsBuilder::RedirectStderr() {
    values.stdout_mode_ = REDIRECT_TO_STDERR;
    return *this;
}

CommandOptions::CommandOptionsBuilder& CommandOptions::CommandOptionsBuilder::Log(
    const std::string& message) {
    values.logging_message_ = message;
    return *this;
}

CommandOptions CommandOptions::CommandOptionsBuilder::Build() {
    return CommandOptions(values);
}

CommandOptions::CommandOptionsValues::CommandOptionsValues(long timeout)
    : timeout_(timeout),
      always_(false),
      root_mode_(DONT_DROP_ROOT),
      stdout_mode_(NORMAL_STDOUT),
      logging_message_("") {
}

CommandOptions::CommandOptions(const CommandOptionsValues& values) : values(values) {
}

long CommandOptions::Timeout() const {
    return values.timeout_;
}

bool CommandOptions::Always() const {
    return values.always_;
}

RootMode CommandOptions::RootMode() const {
    return values.root_mode_;
}

StdoutMode CommandOptions::StdoutMode() const {
    return values.stdout_mode_;
}

std::string CommandOptions::LoggingMessage() const {
    return values.logging_message_;
}

CommandOptions::CommandOptionsBuilder CommandOptions::WithTimeout(long timeout) {
    return CommandOptions::CommandOptionsBuilder(timeout);
}

Dumpstate::Dumpstate(const std::string& version, bool dry_run, const std::string& build_type)
    : pid_(getpid()),
      version_(version),
      now_(time(nullptr)),
      dry_run_(dry_run),
      build_type_(build_type) {
}

Dumpstate& Dumpstate::GetInstance() {
    static Dumpstate singleton_(android::base::GetProperty("dumpstate.version", VERSION_CURRENT),
                                android::base::GetBoolProperty("dumpstate.dry_run", false),
                                android::base::GetProperty("ro.build.type", "(unknown)"));
    return singleton_;
}

DurationReporter::DurationReporter(const std::string& title) : DurationReporter(title, stdout) {
}

DurationReporter::DurationReporter(const std::string& title, FILE* out) : title_(title), out_(out) {
    if (!title_.empty()) {
        started_ = DurationReporter::Nanotime();
    }
}

DurationReporter::~DurationReporter() {
    if (!title_.empty()) {
        uint64_t elapsed = DurationReporter::Nanotime() - started_;
        // Use "Yoda grammar" to make it easier to grep|sort sections.
        if (out_ != nullptr) {
            fprintf(out_, "------ %.3fs was the duration of '%s' ------\n",
                    (float)elapsed / NANOS_PER_SEC, title_.c_str());
        } else {
            MYLOGD("Duration of '%s': %.3fs\n", title_.c_str(), (float)elapsed / NANOS_PER_SEC);
        }
    }
}

uint64_t DurationReporter::DurationReporter::Nanotime() {
    struct timespec ts;
    clock_gettime(CLOCK_MONOTONIC, &ts);
    return (uint64_t) ts.tv_sec * NANOS_PER_SEC + ts.tv_nsec;
}

bool Dumpstate::IsDryRun() const {
    return dry_run_;
}

bool Dumpstate::IsUserBuild() const {
    return "user" == build_type_;
}

bool Dumpstate::IsZipping() const {
    return zip_writer_ != nullptr;
}

std::string Dumpstate::GetPath(const std::string& suffix) const {
    return android::base::StringPrintf("%s/%s-%s%s", bugreport_dir_.c_str(), base_name_.c_str(),
                                       name_.c_str(), suffix.c_str());
}

void for_each_userid(void (*func)(int), const char *header) {
    if (IsDryRun()) return;

    DIR *d;
    struct dirent *de;

    if (header) printf("\n------ %s ------\n", header);
    func(0);

    if (!(d = opendir("/data/system/users"))) {
        printf("Failed to open /data/system/users (%s)\n", strerror(errno));
        return;
    }

    while ((de = readdir(d))) {
        int userid;
        if (de->d_type != DT_DIR || !(userid = atoi(de->d_name))) {
            continue;
        }
        func(userid);
    }

    closedir(d);
}

static void __for_each_pid(void (*helper)(int, const char *, void *), const char *header, void *arg) {
    DIR *d;
    struct dirent *de;

    if (!(d = opendir("/proc"))) {
        printf("Failed to open /proc (%s)\n", strerror(errno));
        return;
    }

    if (header) printf("\n------ %s ------\n", header);
    while ((de = readdir(d))) {
        int pid;
        int fd;
        char cmdpath[255];
        char cmdline[255];

        if (!(pid = atoi(de->d_name))) {
            continue;
        }

        memset(cmdline, 0, sizeof(cmdline));

        snprintf(cmdpath, sizeof(cmdpath), "/proc/%d/cmdline", pid);
        if ((fd = TEMP_FAILURE_RETRY(open(cmdpath, O_RDONLY | O_CLOEXEC))) >= 0) {
            TEMP_FAILURE_RETRY(read(fd, cmdline, sizeof(cmdline) - 2));
            close(fd);
            if (cmdline[0]) {
                helper(pid, cmdline, arg);
                continue;
            }
        }

        // if no cmdline, a kernel thread has comm
        snprintf(cmdpath, sizeof(cmdpath), "/proc/%d/comm", pid);
        if ((fd = TEMP_FAILURE_RETRY(open(cmdpath, O_RDONLY | O_CLOEXEC))) >= 0) {
            TEMP_FAILURE_RETRY(read(fd, cmdline + 1, sizeof(cmdline) - 4));
            close(fd);
            if (cmdline[1]) {
                cmdline[0] = '[';
                size_t len = strcspn(cmdline, "\f\b\r\n");
                cmdline[len] = ']';
                cmdline[len+1] = '\0';
            }
        }
        if (!cmdline[0]) {
            strcpy(cmdline, "N/A");
        }
        helper(pid, cmdline, arg);
    }

    closedir(d);
}

static void for_each_pid_helper(int pid, const char *cmdline, void *arg) {
    for_each_pid_func *func = (for_each_pid_func*) arg;
    func(pid, cmdline);
}

void for_each_pid(for_each_pid_func func, const char *header) {
    if (IsDryRun()) return;

    __for_each_pid(for_each_pid_helper, header, (void *) func);
}

static void for_each_tid_helper(int pid, const char *cmdline, void *arg) {
    DIR *d;
    struct dirent *de;
    char taskpath[255];
    for_each_tid_func *func = (for_each_tid_func *) arg;

    snprintf(taskpath, sizeof(taskpath), "/proc/%d/task", pid);

    if (!(d = opendir(taskpath))) {
        printf("Failed to open %s (%s)\n", taskpath, strerror(errno));
        return;
    }

    func(pid, pid, cmdline);

    while ((de = readdir(d))) {
        int tid;
        int fd;
        char commpath[255];
        char comm[255];

        if (!(tid = atoi(de->d_name))) {
            continue;
        }

        if (tid == pid)
            continue;

        snprintf(commpath, sizeof(commpath), "/proc/%d/comm", tid);
        memset(comm, 0, sizeof(comm));
        if ((fd = TEMP_FAILURE_RETRY(open(commpath, O_RDONLY | O_CLOEXEC))) < 0) {
            strcpy(comm, "N/A");
        } else {
            char *c;
            TEMP_FAILURE_RETRY(read(fd, comm, sizeof(comm) - 2));
            close(fd);

            c = strrchr(comm, '\n');
            if (c) {
                *c = '\0';
            }
        }
        func(pid, tid, comm);
    }

    closedir(d);
}

void for_each_tid(for_each_tid_func func, const char *header) {
    if (IsDryRun()) return;

    __for_each_pid(for_each_tid_helper, header, (void *) func);
}

void show_wchan(int pid, int tid, const char *name) {
    if (IsDryRun()) return;

    char path[255];
    char buffer[255];
    int fd, ret, save_errno;
    char name_buffer[255];

    memset(buffer, 0, sizeof(buffer));

    snprintf(path, sizeof(path), "/proc/%d/wchan", tid);
    if ((fd = TEMP_FAILURE_RETRY(open(path, O_RDONLY | O_CLOEXEC))) < 0) {
        printf("Failed to open '%s' (%s)\n", path, strerror(errno));
        return;
    }

    ret = TEMP_FAILURE_RETRY(read(fd, buffer, sizeof(buffer)));
    save_errno = errno;
    close(fd);

    if (ret < 0) {
        printf("Failed to read '%s' (%s)\n", path, strerror(save_errno));
        return;
    }

    snprintf(name_buffer, sizeof(name_buffer), "%*s%s",
             pid == tid ? 0 : 3, "", name);

    printf("%-7d %-32s %s\n", tid, name_buffer, buffer);

    return;
}

// print time in centiseconds
static void snprcent(char *buffer, size_t len, size_t spc,
                     unsigned long long time) {
    static long hz; // cache discovered hz

    if (hz <= 0) {
        hz = sysconf(_SC_CLK_TCK);
        if (hz <= 0) {
            hz = 1000;
        }
    }

    // convert to centiseconds
    time = (time * 100 + (hz / 2)) / hz;

    char str[16];

    snprintf(str, sizeof(str), " %llu.%02u",
             time / 100, (unsigned)(time % 100));
    size_t offset = strlen(buffer);
    snprintf(buffer + offset, (len > offset) ? len - offset : 0,
             "%*s", (spc > offset) ? (int)(spc - offset) : 0, str);
}

// print permille as a percent
static void snprdec(char *buffer, size_t len, size_t spc, unsigned permille) {
    char str[16];

    snprintf(str, sizeof(str), " %u.%u%%", permille / 10, permille % 10);
    size_t offset = strlen(buffer);
    snprintf(buffer + offset, (len > offset) ? len - offset : 0,
             "%*s", (spc > offset) ? (int)(spc - offset) : 0, str);
}

void show_showtime(int pid, const char *name) {
    if (IsDryRun()) return;

    char path[255];
    char buffer[1023];
    int fd, ret, save_errno;

    memset(buffer, 0, sizeof(buffer));

    snprintf(path, sizeof(path), "/proc/%d/stat", pid);
    if ((fd = TEMP_FAILURE_RETRY(open(path, O_RDONLY | O_CLOEXEC))) < 0) {
        printf("Failed to open '%s' (%s)\n", path, strerror(errno));
        return;
    }

    ret = TEMP_FAILURE_RETRY(read(fd, buffer, sizeof(buffer)));
    save_errno = errno;
    close(fd);

    if (ret < 0) {
        printf("Failed to read '%s' (%s)\n", path, strerror(save_errno));
        return;
    }

    // field 14 is utime
    // field 15 is stime
    // field 42 is iotime
    unsigned long long utime = 0, stime = 0, iotime = 0;
    if (sscanf(buffer,
               "%*u %*s %*s %*d %*d %*d %*d %*d %*d %*d %*d "
               "%*d %*d %llu %llu %*d %*d %*d %*d %*d %*d "
               "%*d %*d %*d %*d %*d %*d %*d %*d %*d %*d "
               "%*d %*d %*d %*d %*d %*d %*d %*d %*d %llu ",
               &utime, &stime, &iotime) != 3) {
        return;
    }

    unsigned long long total = utime + stime;
    if (!total) {
        return;
    }

    unsigned permille = (iotime * 1000 + (total / 2)) / total;
    if (permille > 1000) {
        permille = 1000;
    }

    // try to beautify and stabilize columns at <80 characters
    snprintf(buffer, sizeof(buffer), "%-6d%s", pid, name);
    if ((name[0] != '[') || utime) {
        snprcent(buffer, sizeof(buffer), 57, utime);
    }
    snprcent(buffer, sizeof(buffer), 65, stime);
    if ((name[0] != '[') || iotime) {
        snprcent(buffer, sizeof(buffer), 73, iotime);
    }
    if (iotime) {
        snprdec(buffer, sizeof(buffer), 79, permille);
    }
    puts(buffer); // adds a trailing newline

    return;
}

void do_dmesg() {
    const char *title = "KERNEL LOG (dmesg)";
    DurationReporter duration_reporter(title);
    printf("------ %s ------\n", title);

    if (IsDryRun()) return;

    /* Get size of kernel buffer */
    int size = klogctl(KLOG_SIZE_BUFFER, NULL, 0);
    if (size <= 0) {
        printf("Unexpected klogctl return value: %d\n\n", size);
        return;
    }
    char *buf = (char *) malloc(size + 1);
    if (buf == NULL) {
        printf("memory allocation failed\n\n");
        return;
    }
    int retval = klogctl(KLOG_READ_ALL, buf, size);
    if (retval < 0) {
        printf("klogctl failure\n\n");
        free(buf);
        return;
    }
    buf[retval] = '\0';
    printf("%s\n\n", buf);
    free(buf);
    return;
}

void do_showmap(int pid, const char *name) {
    char title[255];
    char arg[255];

    snprintf(title, sizeof(title), "SHOW MAP %d (%s)", pid, name);
    snprintf(arg, sizeof(arg), "%d", pid);
    RunCommand(title, {"showmap", "-q", arg}, CommandOptions::AS_ROOT_10);
}

// TODO: when converted to a Dumpstate function, it should be const
static int _dump_file_from_fd(const std::string& title, const char* path, int fd) {
    if (!title.empty()) {
        printf("------ %s (%s", title.c_str(), path);

        struct stat st;
        // Only show the modification time of non-device files.
        size_t path_len = strlen(path);
        if ((path_len < 6 || memcmp(path, "/proc/", 6)) &&
                (path_len < 5 || memcmp(path, "/sys/", 5)) &&
                (path_len < 3 || memcmp(path, "/d/", 3)) &&
                !fstat(fd, &st)) {
            char stamp[80];
            time_t mtime = st.st_mtime;
            strftime(stamp, sizeof(stamp), "%Y-%m-%d %H:%M:%S", localtime(&mtime));
            printf(": %s", stamp);
        }
        printf(") ------\n");
    }

    bool newline = false;
    fd_set read_set;
    struct timeval tm;
    while (1) {
        FD_ZERO(&read_set);
        FD_SET(fd, &read_set);
        /* Timeout if no data is read for 30 seconds. */
        tm.tv_sec = 30;
        tm.tv_usec = 0;
        uint64_t elapsed = DurationReporter::Nanotime();
        int ret = TEMP_FAILURE_RETRY(select(fd + 1, &read_set, NULL, NULL, &tm));
        if (ret == -1) {
            printf("*** %s: select failed: %s\n", path, strerror(errno));
            newline = true;
            break;
        } else if (ret == 0) {
            elapsed = DurationReporter::Nanotime() - elapsed;
            printf("*** %s: Timed out after %.3fs\n", path,
                   (float) elapsed / NANOS_PER_SEC);
            newline = true;
            break;
        } else {
            char buffer[65536];
            ssize_t bytes_read = TEMP_FAILURE_RETRY(read(fd, buffer, sizeof(buffer)));
            if (bytes_read > 0) {
                fwrite(buffer, bytes_read, 1, stdout);
                newline = (buffer[bytes_read-1] == '\n');
            } else {
                if (bytes_read == -1) {
                    printf("*** %s: Failed to read from fd: %s", path, strerror(errno));
                    newline = true;
                }
                break;
            }
        }
    }
    UpdateProgress(WEIGHT_FILE);
    close(fd);

    if (!newline) printf("\n");
    if (!title.empty()) printf("\n");
    return 0;
}

int Dumpstate::DumpFile(const std::string& title, const std::string& path) {
    DurationReporter duration_reporter(title);
    if (IsDryRun()) {
        if (!title.empty()) {
            printf("------ %s (%s) ------\n", title.c_str(), path.c_str());
            printf("\t(skipped on dry run)\n");
        }
        UpdateProgress(WEIGHT_FILE);
        return 0;
    }
    return JustDumpFile(title, path);
}

int Dumpstate::JustDumpFile(const std::string& title, const std::string& path) const {
    int fd = TEMP_FAILURE_RETRY(open(path.c_str(), O_RDONLY | O_NONBLOCK | O_CLOEXEC));
    if (fd < 0) {
        int err = errno;
        if (title.empty()) {
            printf("*** Error dumping %s: %s\n", path.c_str(), strerror(err));
        } else {
            printf("*** Error dumping %s (%s): %s\n", path.c_str(), title.c_str(), strerror(err));
        }
        return -1;
    }
    return _dump_file_from_fd(title, path.c_str(), fd);
}

int read_file_as_long(const char *path, long int *output) {
    int fd = TEMP_FAILURE_RETRY(open(path, O_RDONLY | O_NONBLOCK | O_CLOEXEC));
    if (fd < 0) {
        int err = errno;
        MYLOGE("Error opening file descriptor for %s: %s\n", path, strerror(err));
        return -1;
    }
    char buffer[50];
    ssize_t bytes_read = TEMP_FAILURE_RETRY(read(fd, buffer, sizeof(buffer)));
    if (bytes_read == -1) {
        MYLOGE("Error reading file %s: %s\n", path, strerror(errno));
        return -2;
    }
    if (bytes_read == 0) {
        MYLOGE("File %s is empty\n", path);
        return -3;
    }
    *output = atoi(buffer);
    return 0;
}

/* calls skip to gate calling dump_from_fd recursively
 * in the specified directory. dump_from_fd defaults to
 * dump_file_from_fd above when set to NULL. skip defaults
 * to false when set to NULL. dump_from_fd will always be
 * called with title NULL.
 */
int dump_files(const std::string& title, const char* dir, bool (*skip)(const char* path),
               int (*dump_from_fd)(const char* title, const char* path, int fd)) {
    DurationReporter duration_reporter(title);
    DIR *dirp;
    struct dirent *d;
    char *newpath = NULL;
    const char *slash = "/";
    int fd, retval = 0;

    if (!title.empty()) {
        printf("------ %s (%s) ------\n", title.c_str(), dir);
    }
    if (IsDryRun()) return 0;

    if (dir[strlen(dir) - 1] == '/') {
        ++slash;
    }
    dirp = opendir(dir);
    if (dirp == NULL) {
        retval = -errno;
        MYLOGE("%s: %s\n", dir, strerror(errno));
        return retval;
    }

    if (!dump_from_fd) {
        dump_from_fd = dump_file_from_fd;
    }
    for (; ((d = readdir(dirp))); free(newpath), newpath = NULL) {
        if ((d->d_name[0] == '.')
         && (((d->d_name[1] == '.') && (d->d_name[2] == '\0'))
          || (d->d_name[1] == '\0'))) {
            continue;
        }
        asprintf(&newpath, "%s%s%s%s", dir, slash, d->d_name,
                 (d->d_type == DT_DIR) ? "/" : "");
        if (!newpath) {
            retval = -errno;
            continue;
        }
        if (skip && (*skip)(newpath)) {
            continue;
        }
        if (d->d_type == DT_DIR) {
            int ret = dump_files("", newpath, skip, dump_from_fd);
            if (ret < 0) {
                retval = ret;
            }
            continue;
        }
        fd = TEMP_FAILURE_RETRY(open(newpath, O_RDONLY | O_NONBLOCK | O_CLOEXEC));
        if (fd < 0) {
            retval = fd;
            printf("*** %s: %s\n", newpath, strerror(errno));
            continue;
        }
        (*dump_from_fd)(NULL, newpath, fd);
    }
    closedir(dirp);
    if (!title.empty()) {
        printf("\n");
    }
    return retval;
}

/* fd must have been opened with the flag O_NONBLOCK. With this flag set,
 * it's possible to avoid issues where opening the file itself can get
 * stuck.
 */
int dump_file_from_fd(const char *title, const char *path, int fd) {
    if (IsDryRun()) return 0;

    int flags = fcntl(fd, F_GETFL);
    if (flags == -1) {
        printf("*** %s: failed to get flags on fd %d: %s\n", path, fd, strerror(errno));
        close(fd);
        return -1;
    } else if (!(flags & O_NONBLOCK)) {
        printf("*** %s: fd must have O_NONBLOCK set.\n", path);
        close(fd);
        return -1;
    }
    return _dump_file_from_fd(title, path, fd);
}

bool waitpid_with_timeout(pid_t pid, int timeout_seconds, int* status) {
    sigset_t child_mask, old_mask;
    sigemptyset(&child_mask);
    sigaddset(&child_mask, SIGCHLD);

    if (sigprocmask(SIG_BLOCK, &child_mask, &old_mask) == -1) {
        printf("*** sigprocmask failed: %s\n", strerror(errno));
        return false;
    }

    struct timespec ts;
    ts.tv_sec = timeout_seconds;
    ts.tv_nsec = 0;
    int ret = TEMP_FAILURE_RETRY(sigtimedwait(&child_mask, NULL, &ts));
    int saved_errno = errno;
    // Set the signals back the way they were.
    if (sigprocmask(SIG_SETMASK, &old_mask, NULL) == -1) {
        printf("*** sigprocmask failed: %s\n", strerror(errno));
        if (ret == 0) {
            return false;
        }
    }
    if (ret == -1) {
        errno = saved_errno;
        if (errno == EAGAIN) {
            errno = ETIMEDOUT;
        } else {
            printf("*** sigtimedwait failed: %s\n", strerror(errno));
        }
        return false;
    }

    pid_t child_pid = waitpid(pid, status, WNOHANG);
    if (child_pid != pid) {
        if (child_pid != -1) {
            printf("*** Waiting for pid %d, got pid %d instead\n", pid, child_pid);
        } else {
            printf("*** waitpid failed: %s\n", strerror(errno));
        }
        return false;
    }
    return true;
}

int Dumpstate::RunCommand(const std::string& title, const std::vector<std::string>& full_command,
                          const CommandOptions& options) {
    if (full_command.empty()) {
        MYLOGE("No arguments on command '%s'\n", title.c_str());
        return -1;
    }

    int size = full_command.size() + 1;  // null terminated
    int starting_index = 0;
    if (options.RootMode() == SU_ROOT) {
        starting_index = 2;  // "su" "root"
        size += starting_index;
    }

    std::vector<const char*> args;
    args.resize(size);

    std::string command_string;
    if (options.RootMode() == SU_ROOT) {
        args[0] = SU_PATH;
        command_string += SU_PATH;
        args[1] = "root";
        command_string += " root ";
    }
    int i = starting_index;
    for (auto arg = full_command.begin(); arg != full_command.end(); ++arg) {
        args[i++] = arg->c_str();
        command_string += arg->c_str();
        if (arg != full_command.end() - 1) {
            command_string += " ";
        }
    }
    args[i] = nullptr;
    const char* path = args[0];
    const char* command = command_string.c_str();

    if (options.RootMode() == SU_ROOT && ds.IsUserBuild()) {
        printf("Skipping '%s' on user build.\n", command);
        return 0;
    }

    if (!title.empty()) {
        printf("------ %s (%s) ------\n", title.c_str(), command);
    }

    fflush(stdout);
    DurationReporter duration_reporter(title);

    const std::string& logging_message = options.LoggingMessage();
    if (!logging_message.empty()) {
        MYLOGI(logging_message.c_str(), command_string.c_str());
    }

    if (IsDryRun() && !options.Always()) {
        if (!title.empty()) {
            printf("\t(skipped on dry run)\n");
        }
        UpdateProgress(options.Timeout());
        return 0;
    }

    int status = JustRunCommand(command, path, args, options);

    /* TODO: for now we're simplifying the progress calculation by using the
     * timeout as the weight. It's a good approximation for most cases, except when calling dumpsys,
     * where its weight should be much higher proportionally to its timeout.
     * Ideally, it should use a options.EstimatedDuration() instead...*/
    int weight = options.Timeout();

    if (weight > 0) {
        UpdateProgress(weight);
    }

    return status;
}

int Dumpstate::JustRunCommand(const char* command, const char* path, std::vector<const char*>& args,
                              const CommandOptions& options) const {
    bool silent = (options.StdoutMode() == REDIRECT_TO_STDERR);

    uint64_t start = DurationReporter::Nanotime();
    pid_t pid = fork();

    /* handle error case */
    if (pid < 0) {
        if (!silent) printf("*** fork: %s\n", strerror(errno));
        MYLOGE("*** fork: %s\n", strerror(errno));
        return pid;
    }

    /* handle child case */
    if (pid == 0) {
        if (options.RootMode() == DROP_ROOT && !drop_root_user()) {
            if (!silent)
                printf("*** failed to drop root before running %s: %s\n", command, strerror(errno));
            MYLOGE("*** could not drop root before running %s: %s\n", command, strerror(errno));
            return -1;
        }

        if (silent) {
            // Redirect stderr to stdout
            dup2(STDERR_FILENO, STDOUT_FILENO);
        }

        /* make sure the child dies when dumpstate dies */
        prctl(PR_SET_PDEATHSIG, SIGKILL);

        /* just ignore SIGPIPE, will go down with parent's */
        struct sigaction sigact;
        memset(&sigact, 0, sizeof(sigact));
        sigact.sa_handler = SIG_IGN;
        sigaction(SIGPIPE, &sigact, NULL);

        execvp(path, (char**)args.data());
        // execvp's result will be handled after waitpid_with_timeout() below, but
        // if it failed, it's safer to exit dumpstate.
        MYLOGD("execvp on command '%s' failed (error: %s)\n", command, strerror(errno));
        fflush(stdout);
        // Must call _exit (instead of exit), otherwise it will corrupt the zip
        // file.
        _exit(EXIT_FAILURE);
    }

    /* handle parent case */
    int status;
    bool ret = waitpid_with_timeout(pid, options.Timeout(), &status);
    uint64_t elapsed = DurationReporter::Nanotime() - start;
    if (!ret) {
        if (errno == ETIMEDOUT) {
            if (!silent)
                printf("*** command '%s' timed out after %.3fs (killing pid %d)\n", command,
                       (float)elapsed / NANOS_PER_SEC, pid);
            MYLOGE("*** command '%s' timed out after %.3fs (killing pid %d)\n", command,
                   (float)elapsed / NANOS_PER_SEC, pid);
        } else {
            if (!silent)
                printf("*** command '%s': Error after %.4fs (killing pid %d)\n", command,
                       (float)elapsed / NANOS_PER_SEC, pid);
            MYLOGE("command '%s': Error after %.4fs (killing pid %d)\n", command,
                   (float)elapsed / NANOS_PER_SEC, pid);
        }
        kill(pid, SIGTERM);
        if (!waitpid_with_timeout(pid, 5, nullptr)) {
            kill(pid, SIGKILL);
            if (!waitpid_with_timeout(pid, 5, nullptr)) {
                if (!silent)
                    printf("could not kill command '%s' (pid %d) even with SIGKILL.\n", command,
                           pid);
                MYLOGE("could not kill command '%s' (pid %d) even with SIGKILL.\n", command, pid);
            }
        }
        return -1;
    }

    if (WIFSIGNALED(status)) {
        if (!silent)
            printf("*** command '%s' failed: killed by signal %d\n", command, WTERMSIG(status));
        MYLOGE("*** command '%s' failed: killed by signal %d\n", command, WTERMSIG(status));
    } else if (WIFEXITED(status) && WEXITSTATUS(status) > 0) {
        status = WEXITSTATUS(status);
        if (!silent) printf("*** command '%s' failed: exit code %d\n", command, status);
        MYLOGE("*** command '%s' failed: exit code %d\n", command, status);
    }

    return status;
}

void Dumpstate::RunDumpsys(const std::string& title, const std::vector<std::string>& dumpsys_args,
                           const CommandOptions& options, long dumpsysTimeout) {
    long timeout = dumpsysTimeout > 0 ? dumpsysTimeout : options.Timeout();
    std::vector<std::string> dumpsys = {"/system/bin/dumpsys", "-t", std::to_string(timeout)};
    dumpsys.insert(dumpsys.end(), dumpsys_args.begin(), dumpsys_args.end());
    RunCommand(title, dumpsys, options);
}

bool drop_root_user() {
    if (getgid() == AID_SHELL && getuid() == AID_SHELL) {
        MYLOGD("drop_root_user(): already running as Shell\n");
        return true;
    }
    /* ensure we will keep capabilities when we drop root */
    if (prctl(PR_SET_KEEPCAPS, 1) < 0) {
        MYLOGE("prctl(PR_SET_KEEPCAPS) failed: %s\n", strerror(errno));
        return false;
    }

    gid_t groups[] = { AID_LOG, AID_SDCARD_R, AID_SDCARD_RW,
            AID_MOUNT, AID_INET, AID_NET_BW_STATS, AID_READPROC, AID_WAKELOCK,
            AID_BLUETOOTH };
    if (setgroups(sizeof(groups)/sizeof(groups[0]), groups) != 0) {
        MYLOGE("Unable to setgroups, aborting: %s\n", strerror(errno));
        return false;
    }
    if (setgid(AID_SHELL) != 0) {
        MYLOGE("Unable to setgid, aborting: %s\n", strerror(errno));
        return false;
    }
    if (setuid(AID_SHELL) != 0) {
        MYLOGE("Unable to setuid, aborting: %s\n", strerror(errno));
        return false;
    }

    struct __user_cap_header_struct capheader;
    struct __user_cap_data_struct capdata[2];
    memset(&capheader, 0, sizeof(capheader));
    memset(&capdata, 0, sizeof(capdata));
    capheader.version = _LINUX_CAPABILITY_VERSION_3;
    capheader.pid = 0;

    capdata[CAP_TO_INDEX(CAP_SYSLOG)].permitted =
            (CAP_TO_MASK(CAP_SYSLOG) | CAP_TO_MASK(CAP_BLOCK_SUSPEND));
    capdata[CAP_TO_INDEX(CAP_SYSLOG)].effective =
            (CAP_TO_MASK(CAP_SYSLOG) | CAP_TO_MASK(CAP_BLOCK_SUSPEND));
    capdata[0].inheritable = 0;
    capdata[1].inheritable = 0;

    if (capset(&capheader, &capdata[0]) < 0) {
        MYLOGE("capset failed: %s\n", strerror(errno));
        return false;
    }

    return true;
}

void send_broadcast(const std::string& action, const std::vector<std::string>& args) {
    std::vector<std::string> am = {"/system/bin/am", "broadcast", "--user", "0", "-a", action};

    am.insert(am.end(), args.begin(), args.end());

    RunCommand("", am, CommandOptions::WithTimeout(20)
                           .Log("Sending broadcast: '%s'\n")
                           .Always()
                           .DropRoot()
                           .RedirectStderr()
                           .Build());
}

size_t num_props = 0;
static char* props[2000];

static void print_prop(const char *key, const char *name, void *user) {
    (void) user;
    if (num_props < sizeof(props) / sizeof(props[0])) {
        char buf[PROPERTY_KEY_MAX + PROPERTY_VALUE_MAX + 10];
        snprintf(buf, sizeof(buf), "[%s]: [%s]\n", key, name);
        props[num_props++] = strdup(buf);
    }
}

static int compare_prop(const void *a, const void *b) {
    return strcmp(*(char * const *) a, *(char * const *) b);
}

/* prints all the system properties */
void print_properties() {
    const char* title = "SYSTEM PROPERTIES";
    DurationReporter duration_reporter(title);
    printf("------ %s ------\n", title);
    if (IsDryRun()) return;
    size_t i;
    num_props = 0;
    property_list(print_prop, NULL);
    qsort(&props, num_props, sizeof(props[0]), compare_prop);

    for (i = 0; i < num_props; ++i) {
        fputs(props[i], stdout);
        free(props[i]);
    }
    printf("\n");
}

int open_socket(const char *service) {
    int s = android_get_control_socket(service);
    if (s < 0) {
        MYLOGE("android_get_control_socket(%s): %s\n", service, strerror(errno));
        exit(1);
    }
    fcntl(s, F_SETFD, FD_CLOEXEC);
    if (listen(s, 4) < 0) {
        MYLOGE("listen(control socket): %s\n", strerror(errno));
        exit(1);
    }

    struct sockaddr addr;
    socklen_t alen = sizeof(addr);
    int fd = accept(s, &addr, &alen);
    if (fd < 0) {
        MYLOGE("accept(control socket): %s\n", strerror(errno));
        exit(1);
    }

    return fd;
}

/* redirect output to a service control socket */
void redirect_to_socket(FILE *redirect, const char *service) {
    int fd = open_socket(service);
    fflush(redirect);
    dup2(fd, fileno(redirect));
    close(fd);
}

// TODO: should call is_valid_output_file and/or be merged into it.
void create_parent_dirs(const char *path) {
    char *chp = const_cast<char *> (path);

    /* skip initial slash */
    if (chp[0] == '/')
        chp++;

    /* create leading directories, if necessary */
    struct stat dir_stat;
    while (chp && chp[0]) {
        chp = strchr(chp, '/');
        if (chp) {
            *chp = 0;
            if (stat(path, &dir_stat) == -1 || !S_ISDIR(dir_stat.st_mode)) {
                MYLOGI("Creating directory %s\n", path);
                if (mkdir(path, 0770)) { /* drwxrwx--- */
                    MYLOGE("Unable to create directory %s: %s\n", path, strerror(errno));
                } else if (chown(path, AID_SHELL, AID_SHELL)) {
                    MYLOGE("Unable to change ownership of dir %s: %s\n", path, strerror(errno));
                }
            }
            *chp++ = '/';
        }
    }
}

void _redirect_to_file(FILE *redirect, char *path, int truncate_flag) {
    create_parent_dirs(path);

    int fd = TEMP_FAILURE_RETRY(open(path,
                                     O_WRONLY | O_CREAT | truncate_flag | O_CLOEXEC | O_NOFOLLOW,
                                     S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH));
    if (fd < 0) {
        MYLOGE("%s: %s\n", path, strerror(errno));
        exit(1);
    }

    TEMP_FAILURE_RETRY(dup2(fd, fileno(redirect)));
    close(fd);
}

void redirect_to_file(FILE *redirect, char *path) {
    _redirect_to_file(redirect, path, O_TRUNC);
}

void redirect_to_existing_file(FILE *redirect, char *path) {
    _redirect_to_file(redirect, path, O_APPEND);
}

static bool should_dump_native_traces(const char* path) {
    for (const char** p = native_processes_to_dump; *p; p++) {
        if (!strcmp(*p, path)) {
            return true;
        }
    }
    return false;
}

/* dump Dalvik and native stack traces, return the trace file location (NULL if none) */
const char *dump_traces() {
    DurationReporter duration_reporter("DUMP TRACES");

    const char* result = nullptr;

    std::string traces_path = android::base::GetProperty("dalvik.vm.stack-trace-file", "");
    if (traces_path.empty()) return nullptr;

    /* move the old traces.txt (if any) out of the way temporarily */
    std::string anrtraces_path = traces_path + ".anr";
    if (rename(traces_path.c_str(), anrtraces_path.c_str()) && errno != ENOENT) {
        MYLOGE("rename(%s, %s): %s\n", traces_path.c_str(), anrtraces_path.c_str(), strerror(errno));
        return nullptr;  // Can't rename old traces.txt -- no permission? -- leave it alone instead
    }

    /* create a new, empty traces.txt file to receive stack dumps */
    int fd = TEMP_FAILURE_RETRY(open(traces_path.c_str(),
                                     O_CREAT | O_WRONLY | O_TRUNC | O_NOFOLLOW | O_CLOEXEC,
                                     0666)); /* -rw-rw-rw- */
    if (fd < 0) {
        MYLOGE("%s: %s\n", traces_path.c_str(), strerror(errno));
        return nullptr;
    }
    int chmod_ret = fchmod(fd, 0666);
    if (chmod_ret < 0) {
        MYLOGE("fchmod on %s failed: %s\n", traces_path.c_str(), strerror(errno));
        close(fd);
        return nullptr;
    }

    /* Variables below must be initialized before 'goto' statements */
    int dalvik_found = 0;
    int ifd, wfd = -1;

    /* walk /proc and kill -QUIT all Dalvik processes */
    DIR *proc = opendir("/proc");
    if (proc == NULL) {
        MYLOGE("/proc: %s\n", strerror(errno));
        goto error_close_fd;
    }

    /* use inotify to find when processes are done dumping */
    ifd = inotify_init();
    if (ifd < 0) {
        MYLOGE("inotify_init: %s\n", strerror(errno));
        goto error_close_fd;
    }

    wfd = inotify_add_watch(ifd, traces_path.c_str(), IN_CLOSE_WRITE);
    if (wfd < 0) {
        MYLOGE("inotify_add_watch(%s): %s\n", traces_path.c_str(), strerror(errno));
        goto error_close_ifd;
    }

    struct dirent *d;
    while ((d = readdir(proc))) {
        int pid = atoi(d->d_name);
        if (pid <= 0) continue;

        char path[PATH_MAX];
        char data[PATH_MAX];
        snprintf(path, sizeof(path), "/proc/%d/exe", pid);
        ssize_t len = readlink(path, data, sizeof(data) - 1);
        if (len <= 0) {
            continue;
        }
        data[len] = '\0';

        if (!strncmp(data, "/system/bin/app_process", strlen("/system/bin/app_process"))) {
            /* skip zygote -- it won't dump its stack anyway */
            snprintf(path, sizeof(path), "/proc/%d/cmdline", pid);
            int cfd = TEMP_FAILURE_RETRY(open(path, O_RDONLY | O_CLOEXEC));
            len = read(cfd, data, sizeof(data) - 1);
            close(cfd);
            if (len <= 0) {
                continue;
            }
            data[len] = '\0';
            if (!strncmp(data, "zygote", strlen("zygote"))) {
                continue;
            }

            ++dalvik_found;
            uint64_t start = DurationReporter::Nanotime();
            if (kill(pid, SIGQUIT)) {
                MYLOGE("kill(%d, SIGQUIT): %s\n", pid, strerror(errno));
                continue;
            }

            /* wait for the writable-close notification from inotify */
            struct pollfd pfd = { ifd, POLLIN, 0 };
            int ret = poll(&pfd, 1, TRACE_DUMP_TIMEOUT_MS);
            if (ret < 0) {
                MYLOGE("poll: %s\n", strerror(errno));
            } else if (ret == 0) {
                MYLOGE("warning: timed out dumping pid %d\n", pid);
            } else {
                struct inotify_event ie;
                read(ifd, &ie, sizeof(ie));
            }

            if (lseek(fd, 0, SEEK_END) < 0) {
                MYLOGE("lseek: %s\n", strerror(errno));
            } else {
                dprintf(fd, "[dump dalvik stack %d: %.3fs elapsed]\n", pid,
                        (float)(DurationReporter::Nanotime() - start) / NANOS_PER_SEC);
            }
        } else if (should_dump_native_traces(data)) {
            /* dump native process if appropriate */
            if (lseek(fd, 0, SEEK_END) < 0) {
                MYLOGE("lseek: %s\n", strerror(errno));
            } else {
                static uint16_t timeout_failures = 0;
                uint64_t start = DurationReporter::Nanotime();

                /* If 3 backtrace dumps fail in a row, consider debuggerd dead. */
                if (timeout_failures == 3) {
                    dprintf(fd, "too many stack dump failures, skipping...\n");
                } else if (dump_backtrace_to_file_timeout(pid, fd, 20) == -1) {
                    dprintf(fd, "dumping failed, likely due to a timeout\n");
                    timeout_failures++;
                } else {
                    timeout_failures = 0;
                }
                dprintf(fd, "[dump native stack %d: %.3fs elapsed]\n", pid,
                        (float)(DurationReporter::Nanotime() - start) / NANOS_PER_SEC);
            }
        }
    }

    if (dalvik_found == 0) {
        MYLOGE("Warning: no Dalvik processes found to dump stacks\n");
    }

    static std::string dumptraces_path = android::base::StringPrintf(
        "%s/bugreport-%s", dirname(traces_path.c_str()), basename(traces_path.c_str()));
    if (rename(traces_path.c_str(), dumptraces_path.c_str())) {
        MYLOGE("rename(%s, %s): %s\n", traces_path.c_str(), dumptraces_path.c_str(),
               strerror(errno));
        goto error_close_ifd;
    }
    result = dumptraces_path.c_str();

    /* replace the saved [ANR] traces.txt file */
    rename(anrtraces_path.c_str(), traces_path.c_str());

error_close_ifd:
    close(ifd);
error_close_fd:
    close(fd);
    return result;
}

void dump_route_tables() {
    DurationReporter duration_reporter("DUMP ROUTE TABLES");
    if (IsDryRun()) return;
    const char* const RT_TABLES_PATH = "/data/misc/net/rt_tables";
    ds.DumpFile("RT_TABLES", RT_TABLES_PATH);
    FILE* fp = fopen(RT_TABLES_PATH, "re");
    if (!fp) {
        printf("*** %s: %s\n", RT_TABLES_PATH, strerror(errno));
        return;
    }
    char table[16];
    // Each line has an integer (the table number), a space, and a string (the table name). We only
    // need the table number. It's a 32-bit unsigned number, so max 10 chars. Skip the table name.
    // Add a fixed max limit so this doesn't go awry.
    for (int i = 0; i < 64 && fscanf(fp, " %10s %*s", table) == 1; ++i) {
        RunCommand("ROUTE TABLE IPv4", {"ip", "-4", "route", "show", "table", table});
        RunCommand("ROUTE TABLE IPv6", {"ip", "-6", "route", "show", "table", table});
    }
    fclose(fp);
}

// TODO: make this function thread safe if sections are generated in parallel.
void Dumpstate::UpdateProgress(int delta) {
    if (!update_progress_) return;

    progress_ += delta;

    // TODO: remove property support once Shell uses IDumpstateListener
    char key[PROPERTY_KEY_MAX];
    char value[PROPERTY_VALUE_MAX];

    // adjusts max on the fly
    if (progress_ > weight_total_) {
        int new_total = weight_total_ * 1.2;
        MYLOGD("Adjusting total weight from %d to %d\n", weight_total_, new_total);
        weight_total_ = new_total;

        if (listener_ != nullptr) {
            listener_->onMaxProgressUpdated(weight_total_);
        } else {
            snprintf(key, sizeof(key), "dumpstate.%d.max", pid_);
            snprintf(value, sizeof(value), "%d", weight_total_);
            int status = property_set(key, value);
            if (status != 0) {
                MYLOGE("Could not update max weight by setting system property %s to %s: %d\n", key,
                       value, status);
            }
        }
    }

    if (control_socket_fd_ >= 0) {
        dprintf(control_socket_fd_, "PROGRESS:%d/%d\n", progress_, weight_total_);
        fsync(control_socket_fd_);
    }

    if (listener_ != nullptr) {
        if (progress_ % 100 == 0) {
            // We don't want to spam logcat, so only log multiples of 100.
            MYLOGD("Setting progress (%s): %d/%d\n", listener_name_.c_str(), progress_,
                   weight_total_);
        } else {
            // stderr is ignored on normal invocations, but useful when calling
            // /system/bin/dumpstate directly for debuggging.
            fprintf(stderr, "Setting progress (%s): %d/%d\n", listener_name_.c_str(), progress_,
                    weight_total_);
        }
        listener_->onProgressUpdated(progress_);
    } else {
        snprintf(key, sizeof(key), "dumpstate.%d.progress", pid_);
        snprintf(value, sizeof(value), "%d", progress_);

        if (progress_ % 100 == 0) {
            // We don't want to spam logcat, so only log multiples of 100.
            MYLOGD("Setting progress (%s): %s/%d\n", key, value, weight_total_);
        } else {
            // stderr is ignored on normal invocations, but useful when calling
            // /system/bin/dumpstate directly for debuggging.
            fprintf(stderr, "Setting progress (%s): %s/%d\n", key, value, weight_total_);
        }

        int status = property_set(key, value);
        if (status) {
            MYLOGE("Could not update progress by setting system property %s to %s: %d\n", key,
                   value, status);
        }
    }
}

void Dumpstate::TakeScreenshot(const std::string& path) {
    const std::string& real_path = path.empty() ? screenshot_path_ : path;
    int status =
        RunCommand("", {"/system/bin/screencap", "-p", real_path},
                   CommandOptions::WithTimeout(10).Always().DropRoot().RedirectStderr().Build());
    if (status == 0) {
        MYLOGD("Screenshot saved on %s\n", real_path.c_str());
    } else {
        MYLOGE("Failed to take screenshot on %s\n", real_path.c_str());
    }
}

void vibrate(FILE* vibrator, int ms) {
    fprintf(vibrator, "%d\n", ms);
    fflush(vibrator);
}

bool is_dir(const char* pathname) {
    struct stat info;
    if (stat(pathname, &info) == -1) {
        return false;
    }
    return S_ISDIR(info.st_mode);
}

time_t get_mtime(int fd, time_t default_mtime) {
    struct stat info;
    if (fstat(fd, &info) == -1) {
        return default_mtime;
    }
    return info.st_mtime;
}

void dump_emmc_ecsd(const char *ext_csd_path) {
    // List of interesting offsets
    struct hex {
        char str[2];
    };
    static const size_t EXT_CSD_REV = 192 * sizeof(hex);
    static const size_t EXT_PRE_EOL_INFO = 267 * sizeof(hex);
    static const size_t EXT_DEVICE_LIFE_TIME_EST_TYP_A = 268 * sizeof(hex);
    static const size_t EXT_DEVICE_LIFE_TIME_EST_TYP_B = 269 * sizeof(hex);

    std::string buffer;
    if (!android::base::ReadFileToString(ext_csd_path, &buffer)) {
        return;
    }

    printf("------ %s Extended CSD ------\n", ext_csd_path);

    if (buffer.length() < (EXT_CSD_REV + sizeof(hex))) {
        printf("*** %s: truncated content %zu\n\n", ext_csd_path, buffer.length());
        return;
    }

    int ext_csd_rev = 0;
    std::string sub = buffer.substr(EXT_CSD_REV, sizeof(hex));
    if (sscanf(sub.c_str(), "%2x", &ext_csd_rev) != 1) {
        printf("*** %s: EXT_CSD_REV parse error \"%s\"\n\n",
               ext_csd_path, sub.c_str());
        return;
    }

    static const char *ver_str[] = {
        "4.0", "4.1", "4.2", "4.3", "Obsolete", "4.41", "4.5", "5.0"
    };
    printf("rev 1.%d (MMC %s)\n",
           ext_csd_rev,
           (ext_csd_rev < (int)(sizeof(ver_str) / sizeof(ver_str[0]))) ?
               ver_str[ext_csd_rev] :
               "Unknown");
    if (ext_csd_rev < 7) {
        printf("\n");
        return;
    }

    if (buffer.length() < (EXT_PRE_EOL_INFO + sizeof(hex))) {
        printf("*** %s: truncated content %zu\n\n", ext_csd_path, buffer.length());
        return;
    }

    int ext_pre_eol_info = 0;
    sub = buffer.substr(EXT_PRE_EOL_INFO, sizeof(hex));
    if (sscanf(sub.c_str(), "%2x", &ext_pre_eol_info) != 1) {
        printf("*** %s: PRE_EOL_INFO parse error \"%s\"\n\n",
               ext_csd_path, sub.c_str());
        return;
    }

    static const char *eol_str[] = {
        "Undefined",
        "Normal",
        "Warning (consumed 80% of reserve)",
        "Urgent (consumed 90% of reserve)"
    };
    printf("PRE_EOL_INFO %d (MMC %s)\n",
           ext_pre_eol_info,
           eol_str[(ext_pre_eol_info < (int)
                       (sizeof(eol_str) / sizeof(eol_str[0]))) ?
                           ext_pre_eol_info : 0]);

    for (size_t lifetime = EXT_DEVICE_LIFE_TIME_EST_TYP_A;
            lifetime <= EXT_DEVICE_LIFE_TIME_EST_TYP_B;
            lifetime += sizeof(hex)) {
        int ext_device_life_time_est;
        static const char *est_str[] = {
            "Undefined",
            "0-10% of device lifetime used",
            "10-20% of device lifetime used",
            "20-30% of device lifetime used",
            "30-40% of device lifetime used",
            "40-50% of device lifetime used",
            "50-60% of device lifetime used",
            "60-70% of device lifetime used",
            "70-80% of device lifetime used",
            "80-90% of device lifetime used",
            "90-100% of device lifetime used",
            "Exceeded the maximum estimated device lifetime",
        };

        if (buffer.length() < (lifetime + sizeof(hex))) {
            printf("*** %s: truncated content %zu\n", ext_csd_path, buffer.length());
            break;
        }

        ext_device_life_time_est = 0;
        sub = buffer.substr(lifetime, sizeof(hex));
        if (sscanf(sub.c_str(), "%2x", &ext_device_life_time_est) != 1) {
            printf("*** %s: DEVICE_LIFE_TIME_EST_TYP_%c parse error \"%s\"\n",
                   ext_csd_path,
                   (unsigned)((lifetime - EXT_DEVICE_LIFE_TIME_EST_TYP_A) /
                              sizeof(hex)) + 'A',
                   sub.c_str());
            continue;
        }
        printf("DEVICE_LIFE_TIME_EST_TYP_%c %d (MMC %s)\n",
               (unsigned)((lifetime - EXT_DEVICE_LIFE_TIME_EST_TYP_A) /
                          sizeof(hex)) + 'A',
               ext_device_life_time_est,
               est_str[(ext_device_life_time_est < (int)
                           (sizeof(est_str) / sizeof(est_str[0]))) ?
                               ext_device_life_time_est : 0]);
    }

    printf("\n");
}