diff --git a/cmds/dumpstate/DumpstateUtil.cpp b/cmds/dumpstate/DumpstateUtil.cpp
new file mode 100644
index 0000000..9faa63e
--- /dev/null
+++ b/cmds/dumpstate/DumpstateUtil.cpp
@@ -0,0 +1,344 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+
+#define LOG_TAG "dumpstate"
+
+#include "DumpstateUtil.h"
+
+#include <fcntl.h>
+#include <sys/prctl.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include <vector>
+
+#include <android-base/properties.h>
+#include <cutils/log.h>
+
+#include "DumpstateInternal.h"
+
+// TODO: move to unnamed namespace
+static constexpr const char* kSuPath = "/system/xbin/su";
+
+// TODO: move to unnamed namespace
+static 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;
+    }
+
+    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;
+}
+
+CommandOptions CommandOptions::DEFAULT = CommandOptions::WithTimeout(10).Build();
+CommandOptions CommandOptions::AS_ROOT = CommandOptions::WithTimeout(10).AsRoot().Build();
+CommandOptions CommandOptions::AS_ROOT_5 = CommandOptions::WithTimeout(5).AsRoot().Build();
+
+CommandOptions::CommandOptionsBuilder::CommandOptionsBuilder(int64_t timeout) : values(timeout) {
+}
+
+CommandOptions::CommandOptionsBuilder& CommandOptions::CommandOptionsBuilder::Always() {
+    values.always_ = true;
+    return *this;
+}
+
+CommandOptions::CommandOptionsBuilder& CommandOptions::CommandOptionsBuilder::AsRoot() {
+    values.account_mode_ = SU_ROOT;
+    return *this;
+}
+
+CommandOptions::CommandOptionsBuilder& CommandOptions::CommandOptionsBuilder::DropRoot() {
+    values.account_mode_ = DROP_ROOT;
+    return *this;
+}
+
+CommandOptions::CommandOptionsBuilder& CommandOptions::CommandOptionsBuilder::RedirectStderr() {
+    values.output_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(int64_t timeout)
+    : timeout_(timeout),
+      always_(false),
+      account_mode_(DONT_DROP_ROOT),
+      output_mode_(NORMAL_OUTPUT),
+      logging_message_("") {
+}
+
+CommandOptions::CommandOptions(const CommandOptionsValues& values) : values(values) {
+}
+
+int64_t CommandOptions::Timeout() const {
+    return values.timeout_;
+}
+
+bool CommandOptions::Always() const {
+    return values.always_;
+}
+
+PrivilegeMode CommandOptions::PrivilegeMode() const {
+    return values.account_mode_;
+}
+
+OutputMode CommandOptions::OutputMode() const {
+    return values.output_mode_;
+}
+
+std::string CommandOptions::LoggingMessage() const {
+    return values.logging_message_;
+}
+
+CommandOptions::CommandOptionsBuilder CommandOptions::WithTimeout(int64_t timeout) {
+    return CommandOptions::CommandOptionsBuilder(timeout);
+}
+
+std::string PropertiesHelper::build_type_ = "";
+int PropertiesHelper::dry_run_ = -1;
+
+bool PropertiesHelper::IsUserBuild() {
+    if (build_type_.empty()) {
+        build_type_ = android::base::GetProperty("ro.build.type", "user");
+    }
+    return "user" == build_type_;
+}
+
+bool PropertiesHelper::IsDryRun() {
+    if (dry_run_ == -1) {
+        dry_run_ = android::base::GetBoolProperty("dumpstate.dry_run", false) ? 1 : 0;
+    }
+    return dry_run_ == 1;
+}
+
+int DumpFileToFd(int out_fd, const std::string& title, const std::string& path) {
+    int fd = TEMP_FAILURE_RETRY(open(path.c_str(), O_RDONLY | O_NONBLOCK | O_CLOEXEC));
+    if (fd < 0) {
+        int err = errno;
+        if (title.empty()) {
+            dprintf(out_fd, "*** Error dumping %s: %s\n", path.c_str(), strerror(err));
+        } else {
+            dprintf(out_fd, "*** Error dumping %s (%s): %s\n", path.c_str(), title.c_str(),
+                    strerror(err));
+        }
+        fsync(out_fd);
+        return -1;
+    }
+    return DumpFileFromFdToFd(title, path, fd, out_fd, PropertiesHelper::IsDryRun());
+}
+
+int RunCommandToFd(int fd, const std::string& title, const std::vector<std::string>& full_command,
+                   const CommandOptions& options) {
+    if (full_command.empty()) {
+        MYLOGE("No arguments on RunCommandToFd(%s)\n", title.c_str());
+        return -1;
+    }
+
+    int size = full_command.size() + 1;  // null terminated
+    int starting_index = 0;
+    if (options.PrivilegeMode() == SU_ROOT) {
+        starting_index = 2;  // "su" "root"
+        size += starting_index;
+    }
+
+    std::vector<const char*> args;
+    args.resize(size);
+
+    std::string command_string;
+    if (options.PrivilegeMode() == SU_ROOT) {
+        args[0] = kSuPath;
+        command_string += kSuPath;
+        args[1] = "root";
+        command_string += " root ";
+    }
+    for (size_t i = 0; i < full_command.size(); i++) {
+        args[i + starting_index] = full_command[i].data();
+        command_string += args[i + starting_index];
+        if (i != full_command.size() - 1) {
+            command_string += " ";
+        }
+    }
+    args[size - 1] = nullptr;
+
+    const char* command = command_string.c_str();
+
+    if (options.PrivilegeMode() == SU_ROOT && PropertiesHelper::IsUserBuild()) {
+        dprintf(fd, "Skipping '%s' on user build.\n", command);
+        return 0;
+    }
+
+    if (!title.empty()) {
+        dprintf(fd, "------ %s (%s) ------\n", title.c_str(), command);
+        fsync(fd);
+    }
+
+    const std::string& logging_message = options.LoggingMessage();
+    if (!logging_message.empty()) {
+        MYLOGI(logging_message.c_str(), command_string.c_str());
+    }
+
+    bool silent = (options.OutputMode() == REDIRECT_TO_STDERR);
+    bool redirecting_to_fd = STDOUT_FILENO != fd;
+
+    if (PropertiesHelper::IsDryRun() && !options.Always()) {
+        if (!title.empty()) {
+            dprintf(fd, "\t(skipped on dry run)\n");
+        } else if (redirecting_to_fd) {
+            // There is no title, but we should still print a dry-run message
+            dprintf(fd, "%s: skipped on dry run\n", command_string.c_str());
+        }
+        fsync(fd);
+        return 0;
+    }
+
+    const char* path = args[0];
+
+    uint64_t start = Nanotime();
+    pid_t pid = fork();
+
+    /* handle error case */
+    if (pid < 0) {
+        if (!silent) dprintf(fd, "*** fork: %s\n", strerror(errno));
+        MYLOGE("*** fork: %s\n", strerror(errno));
+        return pid;
+    }
+
+    /* handle child case */
+    if (pid == 0) {
+        if (options.PrivilegeMode() == DROP_ROOT && !DropRootUser()) {
+            if (!silent) {
+                dprintf(fd, "*** 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) {
+            // Redirects stdout to stderr
+            TEMP_FAILURE_RETRY(dup2(STDERR_FILENO, STDOUT_FILENO));
+        } else if (redirecting_to_fd) {
+            // Redirect stdout to fd
+            TEMP_FAILURE_RETRY(dup2(fd, STDOUT_FILENO));
+            close(fd);
+        }
+
+        /* 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));
+        // 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);
+    fsync(fd);
+
+    uint64_t elapsed = Nanotime() - start;
+    if (!ret) {
+        if (errno == ETIMEDOUT) {
+            if (!silent)
+                dprintf(fd, "*** command '%s' timed out after %.3fs (killing pid %d)\n", command,
+                        static_cast<float>(elapsed) / NANOS_PER_SEC, pid);
+            MYLOGE("*** command '%s' timed out after %.3fs (killing pid %d)\n", command,
+                   static_cast<float>(elapsed) / NANOS_PER_SEC, pid);
+        } else {
+            if (!silent)
+                dprintf(fd, "*** command '%s': Error after %.4fs (killing pid %d)\n", command,
+                        static_cast<float>(elapsed) / NANOS_PER_SEC, pid);
+            MYLOGE("command '%s': Error after %.4fs (killing pid %d)\n", command,
+                   static_cast<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)
+                    dprintf(fd, "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)
+            dprintf(fd, "*** 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) dprintf(fd, "*** command '%s' failed: exit code %d\n", command, status);
+        MYLOGE("*** command '%s' failed: exit code %d\n", command, status);
+    }
+
+    return status;
+}