src/main.rs

// Copyright 2017 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

//! Runs a virtual machine under KVM

pub mod argument;
pub mod linux;
pub mod panic_hook;
#[cfg(feature = "plugin")]
pub mod plugin;

use std::collections::BTreeMap;
use std::fmt;
use std::fs::{File, OpenOptions};
use std::net;
use std::num::ParseIntError;
use std::os::unix::io::{FromRawFd, RawFd};
use std::path::{Path, PathBuf};
use std::string::String;
use std::thread::sleep;
use std::time::Duration;

use devices::{SerialParameters, SerialType};
use msg_socket::{MsgReceiver, MsgSender, MsgSocket};
use qcow::QcowFile;
use sys_util::{
    debug, error, getpid, info, kill_process_group, net::UnixSeqpacket, reap_child, syslog,
    validate_raw_fd, warn,
};
use vm_control::{
    BalloonControlCommand, DiskControlCommand, MaybeOwnedFd, UsbControlCommand, UsbControlResult,
    VmControlRequestSocket, VmRequest, VmResponse, USB_CONTROL_MAX_PORTS,
};

use crate::argument::{print_help, set_arguments, Argument};

static SECCOMP_POLICY_DIR: &'static str = "/usr/share/policy/crosvm";

struct DiskOption {
    path: PathBuf,
    read_only: bool,
}

#[allow(dead_code)]
struct BindMount {
    src: PathBuf,
    dst: PathBuf,
    writable: bool,
}

#[allow(dead_code)]
struct GidMap {
    inner: libc::gid_t,
    outer: libc::gid_t,
    count: u32,
}

const DEFAULT_TOUCH_DEVICE_WIDTH: u32 = 800;
const DEFAULT_TOUCH_DEVICE_HEIGHT: u32 = 1280;

struct TouchDeviceOption {
    path: PathBuf,
    width: u32,
    height: u32,
}

impl TouchDeviceOption {
    fn new(path: PathBuf) -> TouchDeviceOption {
        TouchDeviceOption {
            path,
            width: DEFAULT_TOUCH_DEVICE_WIDTH,
            height: DEFAULT_TOUCH_DEVICE_HEIGHT,
        }
    }
}

#[derive(Debug)]
pub enum Executable {
    Bios(PathBuf),
    Kernel(PathBuf),
    Plugin(PathBuf),
}

fn executable_is_plugin(executable: &Option<Executable>) -> bool {
    match executable {
        Some(Executable::Plugin(_)) => true,
        _ => false,
    }
}

pub struct Config {
    vcpu_count: Option<u32>,
    vcpu_affinity: Vec<usize>,
    memory: Option<usize>,
    executable_path: Option<Executable>,
    android_fstab: Option<PathBuf>,
    initrd_path: Option<PathBuf>,
    params: Vec<String>,
    socket_path: Option<PathBuf>,
    plugin_root: Option<PathBuf>,
    plugin_mounts: Vec<BindMount>,
    plugin_gid_maps: Vec<GidMap>,
    disks: Vec<DiskOption>,
    pmem_devices: Vec<DiskOption>,
    host_ip: Option<net::Ipv4Addr>,
    netmask: Option<net::Ipv4Addr>,
    mac_address: Option<net_util::MacAddress>,
    vhost_net: bool,
    tap_fd: Vec<RawFd>,
    cid: Option<u64>,
    wayland_socket_path: Option<PathBuf>,
    wayland_dmabuf: bool,
    shared_dirs: Vec<(PathBuf, String)>,
    sandbox: bool,
    seccomp_policy_dir: PathBuf,
    seccomp_log_failures: bool,
    gpu: bool,
    software_tpm: bool,
    cras_audio: bool,
    cras_capture: bool,
    null_audio: bool,
    serial_parameters: BTreeMap<u8, SerialParameters>,
    syslog_tag: Option<String>,
    virtio_single_touch: Option<TouchDeviceOption>,
    virtio_trackpad: Option<TouchDeviceOption>,
    virtio_mouse: Option<PathBuf>,
    virtio_keyboard: Option<PathBuf>,
    virtio_input_evdevs: Vec<PathBuf>,
    split_irqchip: bool,
}

impl Default for Config {
    fn default() -> Config {
        Config {
            vcpu_count: None,
            vcpu_affinity: Vec::new(),
            memory: None,
            executable_path: None,
            android_fstab: None,
            initrd_path: None,
            params: Vec::new(),
            socket_path: None,
            plugin_root: None,
            plugin_mounts: Vec::new(),
            plugin_gid_maps: Vec::new(),
            disks: Vec::new(),
            pmem_devices: Vec::new(),
            host_ip: None,
            netmask: None,
            mac_address: None,
            vhost_net: false,
            tap_fd: Vec::new(),
            cid: None,
            gpu: false,
            software_tpm: false,
            wayland_socket_path: None,
            wayland_dmabuf: false,
            shared_dirs: Vec::new(),
            sandbox: !cfg!(feature = "default-no-sandbox"),
            seccomp_policy_dir: PathBuf::from(SECCOMP_POLICY_DIR),
            seccomp_log_failures: false,
            cras_audio: false,
            cras_capture: false,
            null_audio: false,
            serial_parameters: BTreeMap::new(),
            syslog_tag: None,
            virtio_single_touch: None,
            virtio_trackpad: None,
            virtio_mouse: None,
            virtio_keyboard: None,
            virtio_input_evdevs: Vec::new(),
            split_irqchip: false,
        }
    }
}

// Wait for all children to exit. Return true if they have all exited, false
// otherwise.
fn wait_all_children() -> bool {
    const CHILD_WAIT_MAX_ITER: isize = 100;
    const CHILD_WAIT_MS: u64 = 10;
    for _ in 0..CHILD_WAIT_MAX_ITER {
        loop {
            match reap_child() {
                Ok(0) => break,
                // We expect ECHILD which indicates that there were no children left.
                Err(e) if e.errno() == libc::ECHILD => return true,
                Err(e) => {
                    warn!("error while waiting for children: {}", e);
                    return false;
                }
                // We reaped one child, so continue reaping.
                _ => {}
            }
        }
        // There's no timeout option for waitpid which reap_child calls internally, so our only
        // recourse is to sleep while waiting for the children to exit.
        sleep(Duration::from_millis(CHILD_WAIT_MS));
    }

    // If we've made it to this point, not all of the children have exited.
    false
}

/// Parse a comma-separated list of CPU numbers and ranges and convert it to a Vec of CPU numbers.
fn parse_cpu_set(s: &str) -> argument::Result<Vec<usize>> {
    let mut cpuset = Vec::new();
    for part in s.split(',') {
        let range: Vec<&str> = part.split('-').collect();
        if range.len() == 0 || range.len() > 2 {
            return Err(argument::Error::InvalidValue {
                value: part.to_owned(),
                expected: "invalid list syntax",
            });
        }
        let first_cpu: usize = range[0]
            .parse()
            .map_err(|_| argument::Error::InvalidValue {
                value: part.to_owned(),
                expected: "CPU index must be a non-negative integer",
            })?;
        let last_cpu: usize = if range.len() == 2 {
            range[1]
                .parse()
                .map_err(|_| argument::Error::InvalidValue {
                    value: part.to_owned(),
                    expected: "CPU index must be a non-negative integer",
                })?
        } else {
            first_cpu
        };

        if last_cpu < first_cpu {
            return Err(argument::Error::InvalidValue {
                value: part.to_owned(),
                expected: "CPU ranges must be from low to high",
            });
        }

        for cpu in first_cpu..=last_cpu {
            cpuset.push(cpu);
        }
    }
    Ok(cpuset)
}

fn parse_serial_options(s: &str) -> argument::Result<SerialParameters> {
    let mut serial_setting = SerialParameters {
        type_: SerialType::Sink,
        path: None,
        num: 1,
        console: false,
        stdin: false,
    };

    let opts = s
        .split(",")
        .map(|frag| frag.split("="))
        .map(|mut kv| (kv.next().unwrap_or(""), kv.next().unwrap_or("")));

    for (k, v) in opts {
        match k {
            "type" => {
                serial_setting.type_ = v
                    .parse::<SerialType>()
                    .map_err(|e| argument::Error::UnknownArgument(format!("{}", e)))?
            }
            "num" => {
                let num = v.parse::<u8>().map_err(|e| {
                    argument::Error::Syntax(format!("serial device number is not parsable: {}", e))
                })?;
                if num < 1 || num > 4 {
                    return Err(argument::Error::InvalidValue {
                        value: num.to_string(),
                        expected: "Serial port num must be between 1 - 4",
                    });
                }
                serial_setting.num = num;
            }
            "console" => {
                serial_setting.console = v.parse::<bool>().map_err(|e| {
                    argument::Error::Syntax(format!(
                        "serial device console is not parseable: {}",
                        e
                    ))
                })?
            }
            "stdin" => {
                serial_setting.stdin = v.parse::<bool>().map_err(|e| {
                    argument::Error::Syntax(format!("serial device stdin is not parseable: {}", e))
                })?
            }
            "path" => serial_setting.path = Some(PathBuf::from(v)),
            _ => {
                return Err(argument::Error::UnknownArgument(format!(
                    "serial parameter {}",
                    k
                )));
            }
        }
    }

    Ok(serial_setting)
}

fn set_argument(cfg: &mut Config, name: &str, value: Option<&str>) -> argument::Result<()> {
    match name {
        "" => {
            if cfg.executable_path.is_some() {
                return Err(argument::Error::TooManyArguments(format!(
                    "A VM executable was already specified: {:?}",
                    cfg.executable_path
                )));
            }
            let kernel_path = PathBuf::from(value.unwrap());
            if !kernel_path.exists() {
                return Err(argument::Error::InvalidValue {
                    value: value.unwrap().to_owned(),
                    expected: "this kernel path does not exist",
                });
            }
            cfg.executable_path = Some(Executable::Kernel(kernel_path));
        }
        "android-fstab" => {
            if cfg.android_fstab.is_some()
                && !cfg.android_fstab.as_ref().unwrap().as_os_str().is_empty()
            {
                return Err(argument::Error::TooManyArguments(
                    "expected exactly one android fstab path".to_owned(),
                ));
            } else {
                let android_fstab = PathBuf::from(value.unwrap());
                if !android_fstab.exists() {
                    return Err(argument::Error::InvalidValue {
                        value: value.unwrap().to_owned(),
                        expected: "this android fstab path does not exist",
                    });
                }
                cfg.android_fstab = Some(android_fstab);
            }
        }
        "params" => {
            cfg.params.push(value.unwrap().to_owned());
        }
        "cpus" => {
            if cfg.vcpu_count.is_some() {
                return Err(argument::Error::TooManyArguments(
                    "`cpus` already given".to_owned(),
                ));
            }
            cfg.vcpu_count =
                Some(
                    value
                        .unwrap()
                        .parse()
                        .map_err(|_| argument::Error::InvalidValue {
                            value: value.unwrap().to_owned(),
                            expected: "this value for `cpus` needs to be integer",
                        })?,
                )
        }
        "cpu-affinity" => {
            if cfg.vcpu_affinity.len() != 0 {
                return Err(argument::Error::TooManyArguments(
                    "`cpu-affinity` already given".to_owned(),
                ));
            }
            cfg.vcpu_affinity = parse_cpu_set(value.unwrap())?;
        }
        "mem" => {
            if cfg.memory.is_some() {
                return Err(argument::Error::TooManyArguments(
                    "`mem` already given".to_owned(),
                ));
            }
            cfg.memory =
                Some(
                    value
                        .unwrap()
                        .parse()
                        .map_err(|_| argument::Error::InvalidValue {
                            value: value.unwrap().to_owned(),
                            expected: "this value for `mem` needs to be integer",
                        })?,
                )
        }
        "cras-audio" => {
            cfg.cras_audio = true;
        }
        "cras-capture" => {
            cfg.cras_capture = true;
        }
        "null-audio" => {
            cfg.null_audio = true;
        }
        "serial" => {
            let serial_params = parse_serial_options(value.unwrap())?;
            let num = serial_params.num;
            if cfg.serial_parameters.contains_key(&num) {
                return Err(argument::Error::TooManyArguments(format!(
                    "serial num {}",
                    num
                )));
            }

            if serial_params.console {
                for params in cfg.serial_parameters.values() {
                    if params.console {
                        return Err(argument::Error::TooManyArguments(format!(
                            "serial device {} already set as console",
                            params.num
                        )));
                    }
                }
            }

            if serial_params.stdin {
                if let Some(previous_stdin) = cfg.serial_parameters.values().find(|sp| sp.stdin) {
                    return Err(argument::Error::TooManyArguments(format!(
                        "serial device {} already connected to standard input",
                        previous_stdin.num
                    )));
                }
            }

            cfg.serial_parameters.insert(num, serial_params);
        }
        "syslog-tag" => {
            if cfg.syslog_tag.is_some() {
                return Err(argument::Error::TooManyArguments(
                    "`syslog-tag` already given".to_owned(),
                ));
            }
            syslog::set_proc_name(value.unwrap());
            cfg.syslog_tag = Some(value.unwrap().to_owned());
        }
        "root" | "rwroot" | "disk" | "rwdisk" | "qcow" | "rwqcow" => {
            let read_only = !name.starts_with("rw");
            let disk_path = PathBuf::from(value.unwrap());
            if !disk_path.exists() {
                return Err(argument::Error::InvalidValue {
                    value: value.unwrap().to_owned(),
                    expected: "this disk path does not exist",
                });
            }
            if name.ends_with("root") {
                if cfg.disks.len() >= 26 {
                    return Err(argument::Error::TooManyArguments(
                        "ran out of letters for to assign to root disk".to_owned(),
                    ));
                }
                cfg.params.push(format!(
                    "root=/dev/vd{} {}",
                    char::from(b'a' + cfg.disks.len() as u8),
                    if read_only { "ro" } else { "rw" }
                ));
            }
            cfg.disks.push(DiskOption {
                path: disk_path,
                read_only,
            });
        }
        "pmem-device" | "rw-pmem-device" => {
            let disk_path = PathBuf::from(value.unwrap());
            if !disk_path.exists() {
                return Err(argument::Error::InvalidValue {
                    value: value.unwrap().to_owned(),
                    expected: "this disk path does not exist",
                });
            }

            cfg.pmem_devices.push(DiskOption {
                path: disk_path,
                read_only: !name.starts_with("rw"),
            });
        }
        "host_ip" => {
            if cfg.host_ip.is_some() {
                return Err(argument::Error::TooManyArguments(
                    "`host_ip` already given".to_owned(),
                ));
            }
            cfg.host_ip =
                Some(
                    value
                        .unwrap()
                        .parse()
                        .map_err(|_| argument::Error::InvalidValue {
                            value: value.unwrap().to_owned(),
                            expected: "`host_ip` needs to be in the form \"x.x.x.x\"",
                        })?,
                )
        }
        "netmask" => {
            if cfg.netmask.is_some() {
                return Err(argument::Error::TooManyArguments(
                    "`netmask` already given".to_owned(),
                ));
            }
            cfg.netmask =
                Some(
                    value
                        .unwrap()
                        .parse()
                        .map_err(|_| argument::Error::InvalidValue {
                            value: value.unwrap().to_owned(),
                            expected: "`netmask` needs to be in the form \"x.x.x.x\"",
                        })?,
                )
        }
        "mac" => {
            if cfg.mac_address.is_some() {
                return Err(argument::Error::TooManyArguments(
                    "`mac` already given".to_owned(),
                ));
            }
            cfg.mac_address =
                Some(
                    value
                        .unwrap()
                        .parse()
                        .map_err(|_| argument::Error::InvalidValue {
                            value: value.unwrap().to_owned(),
                            expected: "`mac` needs to be in the form \"XX:XX:XX:XX:XX:XX\"",
                        })?,
                )
        }
        "wayland-sock" => {
            if cfg.wayland_socket_path.is_some() {
                return Err(argument::Error::TooManyArguments(
                    "`wayland-sock` already given".to_owned(),
                ));
            }
            let wayland_socket_path = PathBuf::from(value.unwrap());
            if !wayland_socket_path.exists() {
                return Err(argument::Error::InvalidValue {
                    value: value.unwrap().to_string(),
                    expected: "Wayland socket does not exist",
                });
            }
            cfg.wayland_socket_path = Some(wayland_socket_path);
        }
        #[cfg(feature = "wl-dmabuf")]
        "wayland-dmabuf" => cfg.wayland_dmabuf = true,
        "socket" => {
            if cfg.socket_path.is_some() {
                return Err(argument::Error::TooManyArguments(
                    "`socket` already given".to_owned(),
                ));
            }
            let mut socket_path = PathBuf::from(value.unwrap());
            if socket_path.is_dir() {
                socket_path.push(format!("crosvm-{}.sock", getpid()));
            }
            if socket_path.exists() {
                return Err(argument::Error::InvalidValue {
                    value: socket_path.to_string_lossy().into_owned(),
                    expected: "this socket path already exists",
                });
            }
            cfg.socket_path = Some(socket_path);
        }
        "disable-sandbox" => {
            cfg.sandbox = false;
        }
        "cid" => {
            if cfg.cid.is_some() {
                return Err(argument::Error::TooManyArguments(
                    "`cid` alread given".to_owned(),
                ));
            }
            cfg.cid = Some(
                value
                    .unwrap()
                    .parse()
                    .map_err(|_| argument::Error::InvalidValue {
                        value: value.unwrap().to_owned(),
                        expected: "this value for `cid` must be an unsigned integer",
                    })?,
            );
        }
        "shared-dir" => {
            // Formatted as <src:tag>.
            let param = value.unwrap();
            let mut components = param.splitn(2, ':');
            let src =
                PathBuf::from(
                    components
                        .next()
                        .ok_or_else(|| argument::Error::InvalidValue {
                            value: param.to_owned(),
                            expected: "missing source path for `shared-dir`",
                        })?,
                );
            let tag = components
                .next()
                .ok_or_else(|| argument::Error::InvalidValue {
                    value: param.to_owned(),
                    expected: "missing tag for `shared-dir`",
                })?
                .to_owned();

            if !src.is_dir() {
                return Err(argument::Error::InvalidValue {
                    value: param.to_owned(),
                    expected: "source path for `shared-dir` must be a directory",
                });
            }

            cfg.shared_dirs.push((src, tag));
        }
        "seccomp-policy-dir" => {
            // `value` is Some because we are in this match so it's safe to unwrap.
            cfg.seccomp_policy_dir = PathBuf::from(value.unwrap());
        }
        "seccomp-log-failures" => {
            cfg.seccomp_log_failures = true;
        }
        "plugin" => {
            if cfg.executable_path.is_some() {
                return Err(argument::Error::TooManyArguments(format!(
                    "A VM executable was already specified: {:?}",
                    cfg.executable_path
                )));
            }
            let plugin = PathBuf::from(value.unwrap().to_owned());
            if plugin.is_relative() {
                return Err(argument::Error::InvalidValue {
                    value: plugin.to_string_lossy().into_owned(),
                    expected: "the plugin path must be an absolute path",
                });
            }
            cfg.executable_path = Some(Executable::Plugin(plugin));
        }
        "plugin-root" => {
            cfg.plugin_root = Some(PathBuf::from(value.unwrap().to_owned()));
        }
        "plugin-mount" => {
            let components: Vec<&str> = value.unwrap().split(":").collect();
            if components.len() != 3 {
                return Err(argument::Error::InvalidValue {
                    value: value.unwrap().to_owned(),
                    expected:
                        "`plugin-mount` must have exactly 3 components: <src>:<dst>:<writable>",
                });
            }

            let src = PathBuf::from(components[0]);
            if src.is_relative() {
                return Err(argument::Error::InvalidValue {
                    value: components[0].to_owned(),
                    expected: "the source path for `plugin-mount` must be absolute",
                });
            }
            if !src.exists() {
                return Err(argument::Error::InvalidValue {
                    value: components[0].to_owned(),
                    expected: "the source path for `plugin-mount` does not exist",
                });
            }

            let dst = PathBuf::from(components[1]);
            if dst.is_relative() {
                return Err(argument::Error::InvalidValue {
                    value: components[1].to_owned(),
                    expected: "the destination path for `plugin-mount` must be absolute",
                });
            }

            let writable: bool =
                components[2]
                    .parse()
                    .map_err(|_| argument::Error::InvalidValue {
                        value: components[2].to_owned(),
                        expected: "the <writable> component for `plugin-mount` is not valid bool",
                    })?;

            cfg.plugin_mounts.push(BindMount { src, dst, writable });
        }
        "plugin-gid-map" => {
            let components: Vec<&str> = value.unwrap().split(":").collect();
            if components.len() != 3 {
                return Err(argument::Error::InvalidValue {
                    value: value.unwrap().to_owned(),
                    expected:
                        "`plugin-gid-map` must have exactly 3 components: <inner>:<outer>:<count>",
                });
            }

            let inner: libc::gid_t =
                components[0]
                    .parse()
                    .map_err(|_| argument::Error::InvalidValue {
                        value: components[0].to_owned(),
                        expected: "the <inner> component for `plugin-gid-map` is not valid gid",
                    })?;

            let outer: libc::gid_t =
                components[1]
                    .parse()
                    .map_err(|_| argument::Error::InvalidValue {
                        value: components[1].to_owned(),
                        expected: "the <outer> component for `plugin-gid-map` is not valid gid",
                    })?;

            let count: u32 = components[2]
                .parse()
                .map_err(|_| argument::Error::InvalidValue {
                    value: components[2].to_owned(),
                    expected: "the <count> component for `plugin-gid-map` is not valid number",
                })?;

            cfg.plugin_gid_maps.push(GidMap {
                inner,
                outer,
                count,
            });
        }
        "vhost-net" => cfg.vhost_net = true,
        "tap-fd" => {
            cfg.tap_fd.push(
                value
                    .unwrap()
                    .parse()
                    .map_err(|_| argument::Error::InvalidValue {
                        value: value.unwrap().to_owned(),
                        expected: "this value for `tap-fd` must be an unsigned integer",
                    })?,
            );
        }
        "gpu" => {
            cfg.gpu = true;
        }
        "software-tpm" => {
            cfg.software_tpm = true;
        }
        "single-touch" => {
            if cfg.virtio_single_touch.is_some() {
                return Err(argument::Error::TooManyArguments(
                    "`single-touch` already given".to_owned(),
                ));
            }
            let mut it = value.unwrap().split(":");

            let mut single_touch_spec =
                TouchDeviceOption::new(PathBuf::from(it.next().unwrap().to_owned()));
            if let Some(width) = it.next() {
                single_touch_spec.width = width.trim().parse().unwrap();
            }
            if let Some(height) = it.next() {
                single_touch_spec.height = height.trim().parse().unwrap();
            }

            cfg.virtio_single_touch = Some(single_touch_spec);
        }
        "trackpad" => {
            if cfg.virtio_trackpad.is_some() {
                return Err(argument::Error::TooManyArguments(
                    "`trackpad` already given".to_owned(),
                ));
            }
            let mut it = value.unwrap().split(":");

            let mut trackpad_spec =
                TouchDeviceOption::new(PathBuf::from(it.next().unwrap().to_owned()));
            if let Some(width) = it.next() {
                trackpad_spec.width = width.trim().parse().unwrap();
            }
            if let Some(height) = it.next() {
                trackpad_spec.height = height.trim().parse().unwrap();
            }

            cfg.virtio_trackpad = Some(trackpad_spec);
        }
        "mouse" => {
            if cfg.virtio_mouse.is_some() {
                return Err(argument::Error::TooManyArguments(
                    "`mouse` already given".to_owned(),
                ));
            }
            cfg.virtio_mouse = Some(PathBuf::from(value.unwrap().to_owned()));
        }
        "keyboard" => {
            if cfg.virtio_keyboard.is_some() {
                return Err(argument::Error::TooManyArguments(
                    "`keyboard` already given".to_owned(),
                ));
            }
            cfg.virtio_keyboard = Some(PathBuf::from(value.unwrap().to_owned()));
        }
        "evdev" => {
            let dev_path = PathBuf::from(value.unwrap());
            if !dev_path.exists() {
                return Err(argument::Error::InvalidValue {
                    value: value.unwrap().to_owned(),
                    expected: "this input device path does not exist",
                });
            }
            cfg.virtio_input_evdevs.push(dev_path);
        }
        "split-irqchip" => {
            cfg.split_irqchip = true;
        }
        "initrd" => {
            cfg.initrd_path = Some(PathBuf::from(value.unwrap().to_owned()));
        }
        "bios" => {
            if cfg.executable_path.is_some() {
                return Err(argument::Error::TooManyArguments(format!(
                    "A VM executable was already specified: {:?}",
                    cfg.executable_path
                )));
            }
            cfg.executable_path = Some(Executable::Bios(PathBuf::from(value.unwrap().to_owned())));
        }
        "help" => return Err(argument::Error::PrintHelp),
        _ => unreachable!(),
    }
    Ok(())
}

fn run_vm(args: std::env::Args) -> std::result::Result<(), ()> {
    let arguments =
        &[Argument::positional("KERNEL", "bzImage of kernel to run"),
          Argument::value("android-fstab", "PATH", "Path to Android fstab"),
          Argument::short_value('i', "initrd", "PATH", "Initial ramdisk to load."),
          Argument::short_value('p',
                                "params",
                                "PARAMS",
                                "Extra kernel or plugin command line arguments. Can be given more than once."),
          Argument::short_value('c', "cpus", "N", "Number of VCPUs. (default: 1)"),
          Argument::value("cpu-affinity", "CPUSET", "Comma-separated list of CPUs or CPU ranges to run VCPUs on. (e.g. 0,1-3,5) (default: no mask)"),
          Argument::short_value('m',
                                "mem",
                                "N",
                                "Amount of guest memory in MiB. (default: 256)"),
          Argument::short_value('r',
                                "root",
                                "PATH",
                                "Path to a root disk image. Like `--disk` but adds appropriate kernel command line option."),
          Argument::value("rwroot", "PATH", "Path to a writable root disk image."),
          Argument::short_value('d', "disk", "PATH", "Path to a disk image."),
          Argument::value("qcow", "PATH", "Path to a qcow2 disk image. (Deprecated; use --disk instead.)"),
          Argument::value("rwdisk", "PATH", "Path to a writable disk image."),
          Argument::value("rwqcow", "PATH", "Path to a writable qcow2 disk image. (Deprecated; use --rwdisk instead.)"),
          Argument::value("rw-pmem-device", "PATH", "Path to a writable disk image."),
          Argument::value("pmem-device", "PATH", "Path to a disk image."),
          Argument::value("host_ip",
                          "IP",
                          "IP address to assign to host tap interface."),
          Argument::value("netmask", "NETMASK", "Netmask for VM subnet."),
          Argument::value("mac", "MAC", "MAC address for VM."),
          Argument::flag("cras-audio", "Add an audio device to the VM that plays samples through CRAS server"),
          Argument::flag("cras-capture", "Enable capturing audio from CRAS server to the cras-audio device"),
          Argument::flag("null-audio", "Add an audio device to the VM that plays samples to /dev/null"),
          Argument::value("serial",
                          "type=TYPE,[num=NUM,path=PATH,console,stdin]",
                          "Comma seperated key=value pairs for setting up serial devices. Can be given more than once.
                          Possible key values:
                          type=(stdout,syslog,sink,file) - Where to route the serial device
                          num=(1,2,3,4) - Serial Device Number. If not provided, num will default to 1.
                          path=PATH - The path to the file to write to when type=file
                          console - Use this serial device as the guest console. Can only be given once. Will default to first serial port if not provided.
                          stdin - Direct standard input to this serial device. Can only be given once. Will default to first serial port if not provided.
                          "),
          Argument::value("syslog-tag", "TAG", "When logging to syslog, use the provided tag."),
          Argument::value("wayland-sock", "PATH", "Path to the Wayland socket to use."),
          #[cfg(feature = "wl-dmabuf")]
          Argument::flag("wayland-dmabuf", "Enable support for DMABufs in Wayland device."),
          Argument::short_value('s',
                                "socket",
                                "PATH",
                                "Path to put the control socket. If PATH is a directory, a name will be generated."),
          Argument::flag("disable-sandbox", "Run all devices in one, non-sandboxed process."),
          Argument::value("cid", "CID", "Context ID for virtual sockets."),
          Argument::value("shared-dir", "PATH:TAG",
                          "Directory to be shared with a VM as a source:tag pair. Can be given more than once."),
          Argument::value("seccomp-policy-dir", "PATH", "Path to seccomp .policy files."),
          Argument::flag("seccomp-log-failures", "Instead of seccomp filter failures being fatal, they will be logged instead."),
          #[cfg(feature = "plugin")]
          Argument::value("plugin", "PATH", "Absolute path to plugin process to run under crosvm."),
          #[cfg(feature = "plugin")]
          Argument::value("plugin-root", "PATH", "Absolute path to a directory that will become root filesystem for the plugin process."),
          #[cfg(feature = "plugin")]
          Argument::value("plugin-mount", "PATH:PATH:BOOL", "Path to be mounted into the plugin's root filesystem.  Can be given more than once."),
          #[cfg(feature = "plugin")]
          Argument::value("plugin-gid-map", "GID:GID:INT", "Supplemental GIDs that should be mapped in plugin jail.  Can be given more than once."),
          Argument::flag("vhost-net", "Use vhost for networking."),
          Argument::value("tap-fd",
                          "fd",
                          "File descriptor for configured tap device. A different virtual network card will be added each time this argument is given."),
          #[cfg(feature = "gpu")]
          Argument::flag("gpu", "(EXPERIMENTAL) enable virtio-gpu device"),
          #[cfg(feature = "tpm")]
          Argument::flag("software-tpm", "enable a software emulated trusted platform module device"),
          Argument::value("evdev", "PATH", "Path to an event device node. The device will be grabbed (unusable from the host) and made available to the guest with the same configuration it shows on the host"),
          Argument::value("single-touch", "PATH:WIDTH:HEIGHT", "Path to a socket from where to read single touch input events (such as those from a touchscreen) and write status updates to, optionally followed by width and height (defaults to 800x1280)."),
          Argument::value("trackpad", "PATH:WIDTH:HEIGHT", "Path to a socket from where to read trackpad input events and write status updates to, optionally followed by screen width and height (defaults to 800x1280)."),
          Argument::value("mouse", "PATH", "Path to a socket from where to read mouse input events and write status updates to."),
          Argument::value("keyboard", "PATH", "Path to a socket from where to read keyboard input events and write status updates to."),
          #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
          Argument::flag("split-irqchip", "(EXPERIMENTAL) enable split-irqchip support"),
          Argument::value("bios", "PATH", "Path to BIOS/firmware ROM"),
          Argument::short_flag('h', "help", "Print help message.")];

    let mut cfg = Config::default();
    let match_res = set_arguments(args, &arguments[..], |name, value| {
        set_argument(&mut cfg, name, value)
    })
    .and_then(|_| {
        if cfg.executable_path.is_none() {
            return Err(argument::Error::ExpectedArgument("`KERNEL`".to_owned()));
        }
        if cfg.host_ip.is_some() || cfg.netmask.is_some() || cfg.mac_address.is_some() {
            if cfg.host_ip.is_none() {
                return Err(argument::Error::ExpectedArgument(
                    "`host_ip` missing from network config".to_owned(),
                ));
            }
            if cfg.netmask.is_none() {
                return Err(argument::Error::ExpectedArgument(
                    "`netmask` missing from network config".to_owned(),
                ));
            }
            if cfg.mac_address.is_none() {
                return Err(argument::Error::ExpectedArgument(
                    "`mac` missing from network config".to_owned(),
                ));
            }
        }
        if cfg.plugin_root.is_some() && !executable_is_plugin(&cfg.executable_path) {
            return Err(argument::Error::ExpectedArgument(
                "`plugin-root` requires `plugin`".to_owned(),
            ));
        }
        Ok(())
    });

    match match_res {
        #[cfg(feature = "plugin")]
        Ok(()) if executable_is_plugin(&cfg.executable_path) => match plugin::run_config(cfg) {
            Ok(_) => {
                info!("crosvm and plugin have exited normally");
                Ok(())
            }
            Err(e) => {
                error!("{}", e);
                Err(())
            }
        },
        Ok(()) => match linux::run_config(cfg) {
            Ok(_) => {
                info!("crosvm has exited normally");
                Ok(())
            }
            Err(e) => {
                error!("{}", e);
                Err(())
            }
        },
        Err(argument::Error::PrintHelp) => {
            print_help("crosvm run", "KERNEL", &arguments[..]);
            Ok(())
        }
        Err(e) => {
            println!("{}", e);
            Err(())
        }
    }
}

fn handle_request(
    request: &VmRequest,
    args: std::env::Args,
) -> std::result::Result<VmResponse, ()> {
    let mut return_result = Err(());
    for socket_path in args {
        match UnixSeqpacket::connect(&socket_path) {
            Ok(s) => {
                let socket: VmControlRequestSocket = MsgSocket::new(s);
                if let Err(e) = socket.send(request) {
                    error!(
                        "failed to send request to socket at '{}': {}",
                        socket_path, e
                    );
                    return_result = Err(());
                    continue;
                }
                match socket.recv() {
                    Ok(response) => return_result = Ok(response),
                    Err(e) => {
                        error!(
                            "failed to send request to socket at2 '{}': {}",
                            socket_path, e
                        );
                        return_result = Err(());
                        continue;
                    }
                }
            }
            Err(e) => {
                error!("failed to connect to socket at '{}': {}", socket_path, e);
                return_result = Err(());
            }
        }
    }

    return_result
}

fn vms_request(request: &VmRequest, args: std::env::Args) -> std::result::Result<(), ()> {
    let response = handle_request(request, args)?;
    info!("request response was {}", response);
    Ok(())
}

fn stop_vms(args: std::env::Args) -> std::result::Result<(), ()> {
    if args.len() == 0 {
        print_help("crosvm stop", "VM_SOCKET...", &[]);
        println!("Stops the crosvm instance listening on each `VM_SOCKET` given.");
        return Err(());
    }
    vms_request(&VmRequest::Exit, args)
}

fn suspend_vms(args: std::env::Args) -> std::result::Result<(), ()> {
    if args.len() == 0 {
        print_help("crosvm suspend", "VM_SOCKET...", &[]);
        println!("Suspends the crosvm instance listening on each `VM_SOCKET` given.");
        return Err(());
    }
    vms_request(&VmRequest::Suspend, args)
}

fn resume_vms(args: std::env::Args) -> std::result::Result<(), ()> {
    if args.len() == 0 {
        print_help("crosvm resume", "VM_SOCKET...", &[]);
        println!("Resumes the crosvm instance listening on each `VM_SOCKET` given.");
        return Err(());
    }
    vms_request(&VmRequest::Resume, args)
}

fn balloon_vms(mut args: std::env::Args) -> std::result::Result<(), ()> {
    if args.len() < 2 {
        print_help("crosvm balloon", "SIZE VM_SOCKET...", &[]);
        println!("Set the ballon size of the crosvm instance to `SIZE` bytes.");
        return Err(());
    }
    let num_bytes = match args.nth(0).unwrap().parse::<u64>() {
        Ok(n) => n,
        Err(_) => {
            error!("Failed to parse number of bytes");
            return Err(());
        }
    };

    let command = BalloonControlCommand::Adjust { num_bytes };
    vms_request(&VmRequest::BalloonCommand(command), args)
}

fn create_qcow2(mut args: std::env::Args) -> std::result::Result<(), ()> {
    if args.len() != 2 {
        print_help("crosvm create_qcow2", "PATH SIZE", &[]);
        println!("Create a new QCOW2 image at `PATH` of the specified `SIZE` in bytes.");
        return Err(());
    }
    let file_path = args.nth(0).unwrap();
    let size: u64 = match args.nth(0).unwrap().parse::<u64>() {
        Ok(n) => n,
        Err(_) => {
            error!("Failed to parse size of the disk.");
            return Err(());
        }
    };

    let file = OpenOptions::new()
        .create(true)
        .read(true)
        .write(true)
        .open(&file_path)
        .map_err(|e| {
            error!("Failed opening qcow file at '{}': {}", file_path, e);
        })?;

    QcowFile::new(file, size).map_err(|e| {
        error!("Failed to create qcow file at '{}': {}", file_path, e);
    })?;

    Ok(())
}

fn disk_cmd(mut args: std::env::Args) -> std::result::Result<(), ()> {
    if args.len() < 2 {
        print_help("crosvm disk", "SUBCOMMAND VM_SOCKET...", &[]);
        println!("Manage attached virtual disk devices.");
        println!("Subcommands:");
        println!("  resize DISK_INDEX NEW_SIZE VM_SOCKET");
        return Err(());
    }
    let subcommand: &str = &args.nth(0).unwrap();

    let request = match subcommand {
        "resize" => {
            let disk_index = match args.nth(0).unwrap().parse::<usize>() {
                Ok(n) => n,
                Err(_) => {
                    error!("Failed to parse disk index");
                    return Err(());
                }
            };

            let new_size = match args.nth(0).unwrap().parse::<u64>() {
                Ok(n) => n,
                Err(_) => {
                    error!("Failed to parse disk size");
                    return Err(());
                }
            };

            VmRequest::DiskCommand {
                disk_index,
                command: DiskControlCommand::Resize { new_size },
            }
        }
        _ => {
            error!("Unknown disk subcommand '{}'", subcommand);
            return Err(());
        }
    };

    vms_request(&request, args)
}

enum ModifyUsbError {
    ArgMissing(&'static str),
    ArgParse(&'static str, String),
    ArgParseInt(&'static str, String, ParseIntError),
    FailedFdValidate(sys_util::Error),
    PathDoesNotExist(PathBuf),
    SocketFailed,
    UnexpectedResponse(VmResponse),
    UnknownCommand(String),
    UsbControl(UsbControlResult),
}

impl fmt::Display for ModifyUsbError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        use self::ModifyUsbError::*;

        match self {
            ArgMissing(a) => write!(f, "argument missing: {}", a),
            ArgParse(name, value) => {
                write!(f, "failed to parse argument {} value `{}`", name, value)
            }
            ArgParseInt(name, value, e) => write!(
                f,
                "failed to parse integer argument {} value `{}`: {}",
                name, value, e
            ),
            FailedFdValidate(e) => write!(f, "failed to validate file descriptor: {}", e),
            PathDoesNotExist(p) => write!(f, "path `{}` does not exist", p.display()),
            SocketFailed => write!(f, "socket failed"),
            UnexpectedResponse(r) => write!(f, "unexpected response: {}", r),
            UnknownCommand(c) => write!(f, "unknown command: `{}`", c),
            UsbControl(e) => write!(f, "{}", e),
        }
    }
}

type ModifyUsbResult<T> = std::result::Result<T, ModifyUsbError>;

fn parse_bus_id_addr(v: &str) -> ModifyUsbResult<(u8, u8, u16, u16)> {
    debug!("parse_bus_id_addr: {}", v);
    let mut ids = v.split(":");
    match (ids.next(), ids.next(), ids.next(), ids.next()) {
        (Some(bus_id), Some(addr), Some(vid), Some(pid)) => {
            let bus_id = bus_id
                .parse::<u8>()
                .map_err(|e| ModifyUsbError::ArgParseInt("bus_id", bus_id.to_owned(), e))?;
            let addr = addr
                .parse::<u8>()
                .map_err(|e| ModifyUsbError::ArgParseInt("addr", addr.to_owned(), e))?;
            let vid = u16::from_str_radix(&vid, 16)
                .map_err(|e| ModifyUsbError::ArgParseInt("vid", vid.to_owned(), e))?;
            let pid = u16::from_str_radix(&pid, 16)
                .map_err(|e| ModifyUsbError::ArgParseInt("pid", pid.to_owned(), e))?;
            Ok((bus_id, addr, vid, pid))
        }
        _ => Err(ModifyUsbError::ArgParse(
            "BUS_ID_ADDR_BUS_NUM_DEV_NUM",
            v.to_owned(),
        )),
    }
}

fn raw_fd_from_path(path: &Path) -> ModifyUsbResult<RawFd> {
    if !path.exists() {
        return Err(ModifyUsbError::PathDoesNotExist(path.to_owned()));
    }
    let raw_fd = path
        .file_name()
        .and_then(|fd_osstr| fd_osstr.to_str())
        .map_or(
            Err(ModifyUsbError::ArgParse(
                "USB_DEVICE_PATH",
                path.to_string_lossy().into_owned(),
            )),
            |fd_str| {
                fd_str.parse::<libc::c_int>().map_err(|e| {
                    ModifyUsbError::ArgParseInt("USB_DEVICE_PATH", fd_str.to_owned(), e)
                })
            },
        )?;
    validate_raw_fd(raw_fd).map_err(ModifyUsbError::FailedFdValidate)
}

fn usb_attach(mut args: std::env::Args) -> ModifyUsbResult<UsbControlResult> {
    let val = args
        .next()
        .ok_or(ModifyUsbError::ArgMissing("BUS_ID_ADDR_BUS_NUM_DEV_NUM"))?;
    let (bus, addr, vid, pid) = parse_bus_id_addr(&val)?;
    let dev_path = PathBuf::from(
        args.next()
            .ok_or(ModifyUsbError::ArgMissing("usb device path"))?,
    );
    let usb_file: Option<File> = if dev_path == Path::new("-") {
        None
    } else if dev_path.parent() == Some(Path::new("/proc/self/fd")) {
        // Special case '/proc/self/fd/*' paths. The FD is already open, just use it.
        // Safe because we will validate |raw_fd|.
        Some(unsafe { File::from_raw_fd(raw_fd_from_path(&dev_path)?) })
    } else {
        Some(
            OpenOptions::new()
                .read(true)
                .write(true)
                .open(&dev_path)
                .map_err(|_| ModifyUsbError::UsbControl(UsbControlResult::FailedToOpenDevice))?,
        )
    };

    let request = VmRequest::UsbCommand(UsbControlCommand::AttachDevice {
        bus,
        addr,
        vid,
        pid,
        fd: usb_file.map(MaybeOwnedFd::Owned),
    });
    let response = handle_request(&request, args).map_err(|_| ModifyUsbError::SocketFailed)?;
    match response {
        VmResponse::UsbResponse(usb_resp) => Ok(usb_resp),
        r => Err(ModifyUsbError::UnexpectedResponse(r)),
    }
}

fn usb_detach(mut args: std::env::Args) -> ModifyUsbResult<UsbControlResult> {
    let port: u8 = args
        .next()
        .map_or(Err(ModifyUsbError::ArgMissing("PORT")), |p| {
            p.parse::<u8>()
                .map_err(|e| ModifyUsbError::ArgParseInt("PORT", p.to_owned(), e))
        })?;
    let request = VmRequest::UsbCommand(UsbControlCommand::DetachDevice { port });
    let response = handle_request(&request, args).map_err(|_| ModifyUsbError::SocketFailed)?;
    match response {
        VmResponse::UsbResponse(usb_resp) => Ok(usb_resp),
        r => Err(ModifyUsbError::UnexpectedResponse(r)),
    }
}

fn usb_list(args: std::env::Args) -> ModifyUsbResult<UsbControlResult> {
    let mut ports: [u8; USB_CONTROL_MAX_PORTS] = Default::default();
    for (index, port) in ports.iter_mut().enumerate() {
        *port = index as u8
    }
    let request = VmRequest::UsbCommand(UsbControlCommand::ListDevice { ports });
    let response = handle_request(&request, args).map_err(|_| ModifyUsbError::SocketFailed)?;
    match response {
        VmResponse::UsbResponse(usb_resp) => Ok(usb_resp),
        r => Err(ModifyUsbError::UnexpectedResponse(r)),
    }
}

fn modify_usb(mut args: std::env::Args) -> std::result::Result<(), ()> {
    if args.len() < 2 {
        print_help("crosvm usb",
                   "[attach BUS_ID:ADDR:VENDOR_ID:PRODUCT_ID [USB_DEVICE_PATH|-] | detach PORT | list] VM_SOCKET...", &[]);
        return Err(());
    }

    // This unwrap will not panic because of the above length check.
    let command = args.next().unwrap();
    let result = match command.as_ref() {
        "attach" => usb_attach(args),
        "detach" => usb_detach(args),
        "list" => usb_list(args),
        other => Err(ModifyUsbError::UnknownCommand(other.to_owned())),
    };
    match result {
        Ok(response) => {
            println!("{}", response);
            Ok(())
        }
        Err(e) => {
            println!("error {}", e);
            Err(())
        }
    }
}

fn print_usage() {
    print_help("crosvm", "[stop|run]", &[]);
    println!("Commands:");
    println!("    stop - Stops crosvm instances via their control sockets.");
    println!("    run  - Start a new crosvm instance.");
    println!("    create_qcow2  - Create a new qcow2 disk image file.");
    println!("    disk - Manage attached virtual disk devices.");
    println!("    usb - Manage attached virtual USB devices.");
}

fn crosvm_main() -> std::result::Result<(), ()> {
    if let Err(e) = syslog::init() {
        println!("failed to initialize syslog: {}", e);
        return Err(());
    }

    panic_hook::set_panic_hook();

    let mut args = std::env::args();
    if args.next().is_none() {
        error!("expected executable name");
        return Err(());
    }

    // Past this point, usage of exit is in danger of leaking zombie processes.
    let ret = match args.next().as_ref().map(|a| a.as_ref()) {
        None => {
            print_usage();
            Ok(())
        }
        Some("stop") => stop_vms(args),
        Some("suspend") => suspend_vms(args),
        Some("resume") => resume_vms(args),
        Some("run") => run_vm(args),
        Some("balloon") => balloon_vms(args),
        Some("create_qcow2") => create_qcow2(args),
        Some("disk") => disk_cmd(args),
        Some("usb") => modify_usb(args),
        Some(c) => {
            println!("invalid subcommand: {:?}", c);
            print_usage();
            Err(())
        }
    };

    // Reap exit status from any child device processes. At this point, all devices should have been
    // dropped in the main process and told to shutdown. Try over a period of 100ms, since it may
    // take some time for the processes to shut down.
    if !wait_all_children() {
        // We gave them a chance, and it's too late.
        warn!("not all child processes have exited; sending SIGKILL");
        if let Err(e) = kill_process_group() {
            // We're now at the mercy of the OS to clean up after us.
            warn!("unable to kill all child processes: {}", e);
        }
    }

    // WARNING: Any code added after this point is not guaranteed to run
    // since we may forcibly kill this process (and its children) above.
    ret
}

fn main() {
    std::process::exit(if crosvm_main().is_ok() { 0 } else { 1 });
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn parse_cpu_set_single() {
        assert_eq!(parse_cpu_set("123").expect("parse failed"), vec![123]);
    }

    #[test]
    fn parse_cpu_set_list() {
        assert_eq!(
            parse_cpu_set("0,1,2,3").expect("parse failed"),
            vec![0, 1, 2, 3]
        );
    }

    #[test]
    fn parse_cpu_set_range() {
        assert_eq!(
            parse_cpu_set("0-3").expect("parse failed"),
            vec![0, 1, 2, 3]
        );
    }

    #[test]
    fn parse_cpu_set_list_of_ranges() {
        assert_eq!(
            parse_cpu_set("3-4,7-9,18").expect("parse failed"),
            vec![3, 4, 7, 8, 9, 18]
        );
    }

    #[test]
    fn parse_cpu_set_repeated() {
        // For now, allow duplicates - they will be handled gracefully by the vec to cpu_set_t conversion.
        assert_eq!(parse_cpu_set("1,1,1").expect("parse failed"), vec![1, 1, 1]);
    }

    #[test]
    fn parse_cpu_set_negative() {
        // Negative CPU numbers are not allowed.
        parse_cpu_set("-3").expect_err("parse should have failed");
    }

    #[test]
    fn parse_cpu_set_reverse_range() {
        // Ranges must be from low to high.
        parse_cpu_set("5-2").expect_err("parse should have failed");
    }

    #[test]
    fn parse_cpu_set_open_range() {
        parse_cpu_set("3-").expect_err("parse should have failed");
    }

    #[test]
    fn parse_cpu_set_extra_comma() {
        parse_cpu_set("0,1,2,").expect_err("parse should have failed");
    }

    #[test]
    fn parse_serial_vaild() {
        parse_serial_options("type=syslog,num=1,console=true,stdin=true")
            .expect("parse should have succeded");
    }

    #[test]
    fn parse_serial_valid_no_num() {
        parse_serial_options("type=syslog").expect("parse should have succeded");
    }

    #[test]
    fn parse_serial_invalid_type() {
        parse_serial_options("type=wormhole,num=1").expect_err("parse should have failed");
    }

    #[test]
    fn parse_serial_invalid_num_upper() {
        parse_serial_options("type=syslog,num=5").expect_err("parse should have failed");
    }

    #[test]
    fn parse_serial_invalid_num_lower() {
        parse_serial_options("type=syslog,num=0").expect_err("parse should have failed");
    }

    #[test]
    fn parse_serial_invalid_num_string() {
        parse_serial_options("type=syslog,num=number3").expect_err("parse should have failed");
    }

    #[test]
    fn parse_serial_invalid_option() {
        parse_serial_options("type=syslog,speed=lightspeed").expect_err("parse should have failed");
    }

    #[test]
    fn parse_serial_invalid_two_stdin() {
        let mut config = Config::default();
        set_argument(&mut config, "serial", Some("num=1,type=stdout,stdin=true"))
            .expect("should parse the first serial argument");
        set_argument(&mut config, "serial", Some("num=2,type=stdout,stdin=true"))
            .expect_err("should fail to parse a second serial port connected to stdin");
    }
}