path: root/src/sys/termios.rs

//! An interface for controlling asynchronous communication ports
//!
//! This interface provides a safe wrapper around the termios subsystem defined by POSIX. The
//! underlying types are all implemented in libc for most platforms and either wrapped in safer
//! types here or exported directly.
//!
//! If you are unfamiliar with the `termios` API, you should first read the
//! [API documentation](http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/termios.h.html) and
//! then come back to understand how `nix` safely wraps it.
//!
//! It should be noted that this API incurs some runtime overhead above the base `libc` definitions.
//! As this interface is not used with high-bandwidth information, this should be fine in most
//! cases. The primary cost when using this API is that the `Termios` datatype here duplicates the
//! standard fields of the underlying `termios` struct and uses safe type wrappers for those fields.
//! This means that when crossing the FFI interface to the underlying C library, data is first
//! copied into the underlying `termios` struct, then the operation is done, and the data is copied
//! back (with additional sanity checking) into the safe wrapper types. The `termios` struct is
//! relatively small across all platforms (on the order of 32-64 bytes).
//!
//! The following examples highlight some of the API use cases such that users coming from using C
//! or reading the standard documentation will understand how to use the safe API exposed here.
//!
//! Example disabling processing of the end-of-file control character:
//!
//! ```
//! # use self::nix::sys::termios::SpecialCharacterIndices::VEOF;
//! # use self::nix::sys::termios::{_POSIX_VDISABLE, Termios};
//! # let mut termios = unsafe { Termios::default_uninit() };
//! termios.control_chars[VEOF as usize] = _POSIX_VDISABLE;
//! ```
//!
//! The flags within `Termios` are defined as bitfields using the `bitflags` crate. This provides
//! an interface for working with bitfields that is similar to working with the raw unsigned
//! integer types but offers type safety because of the internal checking that values will always
//! be a valid combination of the defined flags.
//!
//! An example showing some of the basic operations for interacting with the control flags:
//!
//! ```
//! # use self::nix::sys::termios::{CS5, CSIZE, Termios};
//! # let mut termios = unsafe { Termios::default_uninit() };
//! termios.control_flags & CSIZE == CS5;
//! termios.control_flags |= CS5;
//! ```

use {Errno, Result};
use libc::{self, c_int, tcflag_t};
use std::cell::{Ref, RefCell};
use std::convert::From;
use std::mem;
use std::os::unix::io::RawFd;

use ::unistd::Pid;

/// Stores settings for the termios API
///
/// This is a wrapper around the `libc::termios` struct that provides a safe interface for the
/// standard fields. The only safe way to obtain an instance of this struct is to extract it from
/// an open port using `tcgetattr()`.
#[derive(Clone)]
pub struct Termios {
    inner: RefCell<libc::termios>,
    /// Input mode flags (see `termios.c_iflag` documentation)
    pub input_flags: InputFlags,
    /// Output mode flags (see `termios.c_oflag` documentation)
    pub output_flags: OutputFlags,
    /// Control mode flags (see `termios.c_cflag` documentation)
    pub control_flags: ControlFlags,
    /// Local mode flags (see `termios.c_lflag` documentation)
    pub local_flags: LocalFlags,
    /// Control characters (see `termios.c_cc` documentation)
    pub control_chars: [libc::cc_t; libc::NCCS],
}

impl Termios {
    /// Exposes an immutable reference to the underlying `libc::termios` data structure.
    ///
    /// This can be used for interfacing with other FFI functions like:
    ///
    /// ```rust
    /// # extern crate libc;
    /// # extern crate nix;
    /// # fn main() {
    /// # use nix::sys::termios::Termios;
    /// # let mut termios = unsafe { Termios::default_uninit() };
    /// let inner_termios = termios.get_libc_termios();
    /// unsafe { libc::cfgetispeed(&*inner_termios) };
    /// # }
    /// ```
    ///
    /// There is no public API exposed for functions that modify the underlying `libc::termios`
    /// data because it requires additional work to maintain type safety.
    // FIXME: Switch this over to use pub(crate)
    #[doc(hidden)]
    pub fn get_libc_termios(&self) -> Ref<libc::termios> {
        {
            let mut termios = self.inner.borrow_mut();
            termios.c_iflag = self.input_flags.bits();
            termios.c_oflag = self.output_flags.bits();
            termios.c_cflag = self.control_flags.bits();
            termios.c_lflag = self.local_flags.bits();
            termios.c_cc = self.control_chars;
        }
        self.inner.borrow()
    }

    /// Exposes the inner `libc::termios` datastore within `Termios`.
    ///
    /// This is unsafe because if this is used to modify the inner libc::termios struct, it will not
    /// automatically update the safe wrapper type around it. Therefore we disable docs to
    /// effectively limit its use to nix internals. In this case it should also be paired with a
    /// call to `update_wrapper()` so that the wrapper-type and internal representation stay
    /// consistent.
    unsafe fn get_libc_termios_mut(&mut self) -> *mut libc::termios {
        {
            let mut termios = self.inner.borrow_mut();
            termios.c_iflag = self.input_flags.bits();
            termios.c_oflag = self.output_flags.bits();
            termios.c_cflag = self.control_flags.bits();
            termios.c_lflag = self.local_flags.bits();
            termios.c_cc = self.control_chars;
        }
        self.inner.as_ptr()
    }

    /// Allows for easily creating new Termios structs that will be overwritten with real data.
    ///
    /// This should only be used when the inner libc::termios struct will be overwritten before it's
    /// read.
    // FIXME: Switch this over to use pub(crate)
    #[doc(hidden)]
    pub unsafe fn default_uninit() -> Self {
        Termios {
            inner: RefCell::new(mem::uninitialized()),
            input_flags: InputFlags::empty(),
            output_flags: OutputFlags::empty(),
            control_flags: ControlFlags::empty(),
            local_flags: LocalFlags::empty(),
            control_chars: [0 as libc::cc_t; NCCS],
        }
    }

    /// Updates the wrapper values from the internal `libc::termios` data structure.
    #[doc(hidden)]
    pub fn update_wrapper(&mut self) {
        let termios = *self.inner.borrow_mut();
        self.input_flags = InputFlags::from_bits_truncate(termios.c_iflag);
        self.output_flags = OutputFlags::from_bits_truncate(termios.c_oflag);
        self.control_flags = ControlFlags::from_bits_truncate(termios.c_cflag);
        self.local_flags = LocalFlags::from_bits_truncate(termios.c_lflag);
        self.control_chars = termios.c_cc;
    }
}

impl From<libc::termios> for Termios {
    fn from(termios: libc::termios) -> Self {
        Termios {
            inner: RefCell::new(termios),
            input_flags: InputFlags::from_bits_truncate(termios.c_iflag),
            output_flags: OutputFlags::from_bits_truncate(termios.c_oflag),
            control_flags: ControlFlags::from_bits_truncate(termios.c_cflag),
            local_flags: LocalFlags::from_bits_truncate(termios.c_lflag),
            control_chars: termios.c_cc,
        }
    }
}

impl From<Termios> for libc::termios {
    fn from(termios: Termios) -> Self {
        termios.inner.into_inner()
    }
}

libc_enum!{
    /// Baud rates supported by the system
    ///
    /// B0 is special and will disable the port.
    #[cfg_attr(all(any(target_os = "ios", target_os = "macos"), target_pointer_width = "64"), repr(u64))]
    #[cfg_attr(not(all(any(target_os = "ios", target_os = "macos"), target_pointer_width = "64")), repr(u32))]
    pub enum BaudRate {
        B0,
        B50,
        B75,
        B110,
        B134,
        B150,
        B200,
        B300,
        B600,
        B1200,
        B1800,
        B2400,
        B4800,
        #[cfg(any(target_os = "dragonfly",
                target_os = "freebsd",
                target_os = "macos",
                target_os = "netbsd",
                target_os = "openbsd"))]
        B7200,
        B9600,
        #[cfg(any(target_os = "dragonfly",
                target_os = "freebsd",
                target_os = "macos",
                target_os = "netbsd",
                target_os = "openbsd"))]
        B14400,
        B19200,
        #[cfg(any(target_os = "dragonfly",
                target_os = "freebsd",
                target_os = "macos",
                target_os = "netbsd",
                target_os = "openbsd"))]
        B28800,
        B38400,
        B57600,
        #[cfg(any(target_os = "dragonfly",
                target_os = "freebsd",
                target_os = "macos",
                target_os = "netbsd",
                target_os = "openbsd"))]
        B76800,
        B115200,
        B230400,
        #[cfg(any(target_os = "android",
                target_os = "freebsd",
                target_os = "linux",
                taget_os = "netbsd"))]
        B460800,
        #[cfg(any(target_os = "android", target_os = "linux"))]
        B500000,
        #[cfg(any(target_os = "android", target_os = "linux"))]
        B576000,
        #[cfg(any(target_os = "android",
                target_os = "freebsd",
                target_os = "linux",
                taget_os = "netbsd"))]
        B921600,
        #[cfg(any(target_os = "android", target_os = "linux"))]
        B1000000,
        #[cfg(any(target_os = "android", target_os = "linux"))]
        B1152000,
        #[cfg(any(target_os = "android", target_os = "linux"))]
        B1500000,
        #[cfg(any(target_os = "android", target_os = "linux"))]
        B2000000,
        #[cfg(any(target_os = "android", target_os = "linux"))]
        B2500000,
        #[cfg(any(target_os = "android", target_os = "linux"))]
        B3000000,
        #[cfg(any(target_os = "android", target_os = "linux"))]
        B3500000,
        #[cfg(any(target_os = "android", target_os = "linux"))]
        B4000000,
    }
}

impl From<libc::speed_t> for BaudRate {
    fn from(s: libc::speed_t) -> BaudRate {

        use libc::{B0, B50, B75, B110, B134, B150, B200, B300, B600, B1200, B1800, B2400, B4800,
                   B9600, B19200, B38400, B57600, B115200, B230400};
        #[cfg(any(target_os = "android", target_os = "linux"))]
        use libc::{B500000, B576000, B1000000, B1152000, B1500000, B2000000, B2500000, B3000000,
                   B3500000, B4000000};
        #[cfg(any(target_os = "dragonfly",
                  target_os = "freebsd",
                  target_os = "macos",
                  target_os = "netbsd",
                  target_os = "openbsd"))]
        use libc::{B7200, B14400, B28800, B76800};
        #[cfg(any(target_os = "android",
                  target_os = "freebsd",
                  target_os = "linux",
                  target_os = "netbsd"))]
        use libc::{B460800, B921600};

        match s {
            B0 => BaudRate::B0,
            B50 => BaudRate::B50,
            B75 => BaudRate::B75,
            B110 => BaudRate::B110,
            B134 => BaudRate::B134,
            B150 => BaudRate::B150,
            B200 => BaudRate::B200,
            B300 => BaudRate::B300,
            B600 => BaudRate::B600,
            B1200 => BaudRate::B1200,
            B1800 => BaudRate::B1800,
            B2400 => BaudRate::B2400,
            B4800 => BaudRate::B4800,
            #[cfg(any(target_os = "dragonfly",
                      target_os = "freebsd",
                      target_os = "macos",
                      target_os = "netbsd",
                      target_os = "openbsd"))]
            B7200 => BaudRate::B7200,
            B9600 => BaudRate::B9600,
            #[cfg(any(target_os = "dragonfly",
                      target_os = "freebsd",
                      target_os = "macos",
                      target_os = "netbsd",
                      target_os = "openbsd"))]
            B14400 => BaudRate::B14400,
            B19200 => BaudRate::B19200,
            #[cfg(any(target_os = "dragonfly",
                      target_os = "freebsd",
                      target_os = "macos",
                      target_os = "netbsd",
                      target_os = "openbsd"))]
            B28800 => BaudRate::B28800,
            B38400 => BaudRate::B38400,
            B57600 => BaudRate::B57600,
            #[cfg(any(target_os = "dragonfly",
                      target_os = "freebsd",
                      target_os = "macos",
                      target_os = "netbsd",
                      target_os = "openbsd"))]
            B76800 => BaudRate::B76800,
            B115200 => BaudRate::B115200,
            B230400 => BaudRate::B230400,
            #[cfg(any(target_os = "android",
                      target_os = "freebsd",
                      target_os = "linux",
                      taget_os = "netbsd"))]
            B460800 => BaudRate::B460800,
            #[cfg(any(target_os = "android", target_os = "linux"))]
            B500000 => BaudRate::B500000,
            #[cfg(any(target_os = "android", target_os = "linux"))]
            B576000 => BaudRate::B576000,
            #[cfg(any(target_os = "android",
                      target_os = "freebsd",
                      target_os = "linux",
                      taget_os = "netbsd"))]
            B921600 => BaudRate::B921600,
            #[cfg(any(target_os = "android", target_os = "linux"))]
            B1000000 => BaudRate::B1000000,
            #[cfg(any(target_os = "android", target_os = "linux"))]
            B1152000 => BaudRate::B1152000,
            #[cfg(any(target_os = "android", target_os = "linux"))]
            B1500000 => BaudRate::B1500000,
            #[cfg(any(target_os = "android", target_os = "linux"))]
            B2000000 => BaudRate::B2000000,
            #[cfg(any(target_os = "android", target_os = "linux"))]
            B2500000 => BaudRate::B2500000,
            #[cfg(any(target_os = "android", target_os = "linux"))]
            B3000000 => BaudRate::B3000000,
            #[cfg(any(target_os = "android", target_os = "linux"))]
            B3500000 => BaudRate::B3500000,
            #[cfg(any(target_os = "android", target_os = "linux"))]
            B4000000 => BaudRate::B4000000,
            b @ _ => unreachable!("Invalid baud constant: {}", b),
        }
    }
}

// TODO: Add TCSASOFT, which will require treating this as a bitfield.
libc_enum! {
    /// Specify when a port configuration change should occur.
    ///
    /// Used as an argument to `tcsetattr()`
    #[repr(i32)]
    pub enum SetArg {
        /// The change will occur immediately
        TCSANOW,
        /// The change occurs after all output has been written
        TCSADRAIN,
        /// Same as `TCSADRAIN`, but will also flush the input buffer
        TCSAFLUSH,
    }
}

libc_enum! {
    /// Specify a combination of the input and output buffers to flush
    ///
    /// Used as an argument to `tcflush()`.
    #[repr(i32)]
    pub enum FlushArg {
        /// Flush data that was received but not read
        TCIFLUSH,
        /// Flush data written but not transmitted
        TCOFLUSH,
        /// Flush both received data not read and written data not transmitted
        TCIOFLUSH,
    }
}

libc_enum! {
    /// Specify how transmission flow should be altered
    ///
    /// Used as an argument to `tcflow()`.
    #[repr(i32)]
    pub enum FlowArg {
        /// Suspend transmission
        TCOOFF,
        /// Resume transmission
        TCOON,
        /// Transmit a STOP character, which should disable a connected terminal device
        TCIOFF,
        /// Transmit a START character, which should re-enable a connected terminal device
        TCION,
    }
}

// TODO: Make this usable directly as a slice index.
libc_enum! {
    /// Indices into the `termios.c_cc` array for special characters.
    #[repr(usize)]
    pub enum SpecialCharacterIndices {
        VDISCARD,
        #[cfg(any(target_os = "dragonfly",
                target_os = "freebsd",
                target_os = "macos",
                target_os = "netbsd",
                target_os = "openbsd"))]
        VDSUSP,
        VEOF,
        VEOL,
        VEOL2,
        VERASE,
        #[cfg(any(target_os = "dragonfly", target_os = "freebsd"))]
        VERASE2,
        VINTR,
        VKILL,
        VLNEXT,
        VMIN,
        VQUIT,
        VREPRINT,
        VSTART,
        #[cfg(any(target_os = "dragonfly",
                target_os = "freebsd",
                target_os = "macos",
                target_os = "netbsd",
                target_os = "openbsd"))]
        VSTATUS,
        VSTOP,
        VSUSP,
        #[cfg(target_os = "linux")]
        VSWTC,
        #[cfg(target_os = "haiku")]
        VSWTCH,
        VTIME,
        VWERASE,
        #[cfg(target_os = "dragonfly")]
        VCHECKPT,
    }
}

pub use libc::NCCS;
#[cfg(any(target_os = "dragonfly",
          target_os = "freebsd",
          target_os = "linux",
          target_os = "macos",
          target_os = "netbsd",
          target_os = "openbsd"))]
pub use libc::_POSIX_VDISABLE;

libc_bitflags! {
    /// Flags for configuring the input mode of a terminal
    pub flags InputFlags: tcflag_t {
        IGNBRK,
        BRKINT,
        IGNPAR,
        PARMRK,
        INPCK,
        ISTRIP,
        INLCR,
        IGNCR,
        ICRNL,
        IXON,
        IXOFF,
        IXANY,
        IMAXBEL,
        #[cfg(any(target_os = "android", target_os = "linux", target_os = "macos"))]
        IUTF8,
    }
}

libc_bitflags! {
    /// Flags for configuring the output mode of a terminal
    pub flags OutputFlags: tcflag_t {
        OPOST,
        #[cfg(any(target_os = "android",
                  target_os = "haiku",
                  target_os = "linux",
                  target_os = "openbsd"))]
        OLCUC,
        ONLCR,
        OCRNL as tcflag_t,
        ONOCR as tcflag_t,
        ONLRET as tcflag_t,
        #[cfg(any(target_os = "android",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        OFILL as tcflag_t,
        #[cfg(any(target_os = "android",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        OFDEL as tcflag_t,
        #[cfg(any(target_os = "android",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        NL0 as tcflag_t,
        #[cfg(any(target_os = "android",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        NL1 as tcflag_t,
        #[cfg(any(target_os = "android",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        CR0 as tcflag_t,
        #[cfg(any(target_os = "android",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        CR1 as tcflag_t,
        #[cfg(any(target_os = "android",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        CR2 as tcflag_t,
        #[cfg(any(target_os = "android",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        CR3 as tcflag_t,
        #[cfg(any(target_os = "android",
                  target_os = "freebsd",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        TAB0 as tcflag_t,
        #[cfg(any(target_os = "android",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        TAB1 as tcflag_t,
        #[cfg(any(target_os = "android",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        TAB2 as tcflag_t,
        #[cfg(any(target_os = "android",
                  target_os = "freebsd",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        TAB3 as tcflag_t,
        #[cfg(any(target_os = "android", target_os = "linux"))]
        XTABS,
        #[cfg(any(target_os = "android",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        BS0 as tcflag_t,
        #[cfg(any(target_os = "android",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        BS1 as tcflag_t,
        #[cfg(any(target_os = "android",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        VT0 as tcflag_t,
        #[cfg(any(target_os = "android",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        VT1 as tcflag_t,
        #[cfg(any(target_os = "android",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        FF0 as tcflag_t,
        #[cfg(any(target_os = "android",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        FF1 as tcflag_t,
        #[cfg(any(target_os = "freebsd",
                  target_os = "dragonfly",
                  target_os = "ios",
                  target_os = "macos",
                  target_os = "netbsd",
                  target_os = "openbsd"))]
        OXTABS,
        #[cfg(any(target_os = "freebsd",
                  target_os = "dragonfly",
                  target_os = "macos",
                  target_os = "netbsd",
                  target_os = "openbsd"))]
        ONOEOT as tcflag_t,

        // Bitmasks for use with OutputFlags to select specific settings
        // These should be moved to be a mask once https://github.com/rust-lang-nursery/bitflags/issues/110
        // is resolved.

        #[cfg(any(target_os = "android",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        NLDLY as tcflag_t, // FIXME: Datatype needs to be corrected in libc for mac
        #[cfg(any(target_os = "android",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        CRDLY as tcflag_t,
        #[cfg(any(target_os = "android",
                  target_os = "freebsd",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        TABDLY as tcflag_t,
        #[cfg(any(target_os = "android",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        BSDLY as tcflag_t,
        #[cfg(any(target_os = "android",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        VTDLY as tcflag_t,
        #[cfg(any(target_os = "android",
                  target_os = "haiku",
                  target_os = "ios",
                  target_os = "linux",
                  target_os = "macos"))]
        FFDLY as tcflag_t,
    }
}

libc_bitflags! {
    /// Flags for setting the control mode of a terminal
    pub flags ControlFlags: tcflag_t {
        #[cfg(any(target_os = "dragonfly",
                  target_os = "freebsd",
                  target_os = "ios",
                  target_os = "macos",
                  target_os = "netbsd",
                  target_os = "openbsd"))]
        CIGNORE,
        CS5,
        CS6,
        CS7,
        CS8,
        CSTOPB,
        CREAD,
        PARENB,
        PARODD,
        HUPCL,
        CLOCAL,
        CRTSCTS,
        #[cfg(any(target_os = "android", target_os = "linux"))]
        CBAUD,
        #[cfg(any(target_os = "android", all(target_os = "linux", not(target_arch = "mips"))))]
        CMSPAR,
        #[cfg(any(target_os = "android",
                  all(target_os = "linux",
                      not(any(target_arch = "powerpc", target_arch = "powerpc64")))))]
        CIBAUD,
        #[cfg(any(target_os = "android", target_os = "linux"))]
        CBAUDEX,
        #[cfg(any(target_os = "dragonfly",
                  target_os = "freebsd",
                  target_os = "macos",
                  target_os = "netbsd",
                  target_os = "openbsd"))]
        MDMBUF,
        #[cfg(any(target_os = "netbsd", target_os = "openbsd"))]
        CHWFLOW,
        #[cfg(any(target_os = "dragonfly",
                  target_os = "freebsd",
                  target_os = "netbsd",
                  target_os = "openbsd"))]
        CCTS_OFLOW,
        #[cfg(any(target_os = "dragonfly",
                  target_os = "freebsd",
                  target_os = "netbsd",
                  target_os = "openbsd"))]
        CRTS_IFLOW,
        #[cfg(any(target_os = "dragonfly",
                  target_os = "freebsd"))]
        CDTR_IFLOW,
        #[cfg(any(target_os = "dragonfly",
                  target_os = "freebsd"))]
        CDSR_OFLOW,
        #[cfg(any(target_os = "dragonfly",
                  target_os = "freebsd"))]
        CCAR_OFLOW,

        // Bitmasks for use with ControlFlags to select specific settings
        // These should be moved to be a mask once https://github.com/rust-lang-nursery/bitflags/issues/110
        // is resolved.

        CSIZE,
    }
}

libc_bitflags! {
    /// Flags for setting any local modes
    pub flags LocalFlags: tcflag_t {
        ECHOKE,
        ECHOE,
        ECHOK,
        ECHO,
        ECHONL,
        ECHOPRT,
        ECHOCTL,
        ISIG,
        ICANON,
        #[cfg(any(target_os = "freebsd",
                  target_os = "dragonfly",
                  target_os = "ios",
                  target_os = "macos",
                  target_os = "netbsd",
                  target_os = "openbsd"))]
        ALTWERASE,
        IEXTEN,
        EXTPROC,
        TOSTOP,
        FLUSHO,
        #[cfg(any(target_os = "freebsd",
                  target_os = "dragonfly",
                  target_os = "ios",
                  target_os = "macos",
                  target_os = "netbsd",
                  target_os = "openbsd"))]
        NOKERNINFO,
        PENDIN,
        NOFLSH,
    }
}

/// Get input baud rate (see
/// [cfgetispeed(3p)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/cfgetispeed.html)).
///
/// `cfgetispeed()` extracts the input baud rate from the given Termios structure.
pub fn cfgetispeed(termios: &Termios) -> BaudRate {
    let inner_termios = termios.get_libc_termios();
    unsafe { libc::cfgetispeed(&*inner_termios) }.into()
}

/// Get output baud rate (see
/// [cfgetospeed(3p)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/cfgetospeed.html)).
///
/// `cfgetospeed()` extracts the output baud rate from the given Termios structure.
pub fn cfgetospeed(termios: &Termios) -> BaudRate {
    let inner_termios = termios.get_libc_termios();
    unsafe { libc::cfgetospeed(&*inner_termios) }.into()
}

/// Configures the port to something like the "raw" mode of the old Version 7 terminal driver (see
/// [termios(3)](http://man7.org/linux/man-pages/man3/termios.3.html)).
///
/// `cfmakeraw()` configures the termios structure such that input is available character-by-
/// character, echoing is disabled, and all special input and output processing is disabled. Note
/// that this is a non-standard function, but is available on Linux and BSDs.
pub fn cfmakeraw(termios: &mut Termios) {
    let inner_termios = unsafe { termios.get_libc_termios_mut() };
    unsafe {
        libc::cfmakeraw(inner_termios);
    }
    termios.update_wrapper();
}

/// Set input baud rate (see
/// [cfsetispeed(3p)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/cfsetispeed.html)).
///
/// `cfsetispeed()` sets the intput baud rate in the given Termios structure.
pub fn cfsetispeed(termios: &mut Termios, baud: BaudRate) -> Result<()> {
    let inner_termios = unsafe { termios.get_libc_termios_mut() };
    let res = unsafe { libc::cfsetispeed(inner_termios, baud as libc::speed_t) };
    termios.update_wrapper();
    Errno::result(res).map(drop)
}

/// Set output baud rate (see
/// [cfsetospeed(3p)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/cfsetospeed.html)).
///
/// `cfsetospeed()` sets the output baud rate in the given termios structure.
pub fn cfsetospeed(termios: &mut Termios, baud: BaudRate) -> Result<()> {
    let inner_termios = unsafe { termios.get_libc_termios_mut() };
    let res = unsafe { libc::cfsetospeed(inner_termios, baud as libc::speed_t) };
    termios.update_wrapper();
    Errno::result(res).map(drop)
}

/// Set both the input and output baud rates (see
/// [termios(3)](http://man7.org/linux/man-pages/man3/termios.3.html)).
///
/// `cfsetspeed()` sets the input and output baud rate in the given termios structure. Note that
/// this is part of the 4.4BSD standard and not part of POSIX.
pub fn cfsetspeed(termios: &mut Termios, baud: BaudRate) -> Result<()> {
    let inner_termios = unsafe { termios.get_libc_termios_mut() };
    let res = unsafe { libc::cfsetspeed(inner_termios, baud as libc::speed_t) };
    termios.update_wrapper();
    Errno::result(res).map(drop)
}

/// Return the configuration of a port
/// [tcgetattr(3p)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/tcgetattr.html)).
///
/// `tcgetattr()` returns a Termios structure with the current configuration for a port. Modifying
/// this structure *will not* reconfigure the port, instead the modifications should be done to
/// the `Termios` structure and then the port should be reconfigured using `tcsetattr()`.
pub fn tcgetattr(fd: RawFd) -> Result<Termios> {
    let mut termios: libc::termios = unsafe { mem::uninitialized() };

    let res = unsafe { libc::tcgetattr(fd, &mut termios) };

    try!(Errno::result(res));

    Ok(termios.into())
}

/// Set the configuration for a terminal (see
/// [tcsetattr(3p)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/tcsetattr.html)).
///
/// `tcsetattr()` reconfigures the given port based on a given `Termios` structure. This change
/// takes affect at a time specified by `actions`. Note that this function may return success if
/// *any* of the parameters were successfully set, not only if all were set successfully.
pub fn tcsetattr(fd: RawFd, actions: SetArg, termios: &Termios) -> Result<()> {
    let inner_termios = termios.get_libc_termios();
    Errno::result(unsafe { libc::tcsetattr(fd, actions as c_int, &*inner_termios) }).map(drop)
}

/// Block until all output data is written (see
/// [tcdrain(3p)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/tcdrain.html)).
pub fn tcdrain(fd: RawFd) -> Result<()> {
    Errno::result(unsafe { libc::tcdrain(fd) }).map(drop)
}

/// Suspend or resume the transmission or reception of data (see
/// [tcflow(3p)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/tcflow.html)).
///
/// `tcflow()` suspends of resumes the transmission or reception of data for the given port
/// depending on the value of `action`.
pub fn tcflow(fd: RawFd, action: FlowArg) -> Result<()> {
    Errno::result(unsafe { libc::tcflow(fd, action as c_int) }).map(drop)
}

/// Discard data in the output or input queue (see
/// [tcflush(3p)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/tcflush.html)).
///
/// `tcflush()` will discard data for a terminal port in the input queue, output queue, or both
/// depending on the value of `action`.
pub fn tcflush(fd: RawFd, action: FlushArg) -> Result<()> {
    Errno::result(unsafe { libc::tcflush(fd, action as c_int) }).map(drop)
}

/// Send a break for a specific duration (see
/// [tcsendbreak(3p)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/tcsendbreak.html)).
///
/// When using asynchronous data transmission `tcsendbreak()` will transmit a continuous stream
/// of zero-valued bits for an implementation-defined duration.
pub fn tcsendbreak(fd: RawFd, duration: c_int) -> Result<()> {
    Errno::result(unsafe { libc::tcsendbreak(fd, duration) }).map(drop)
}

/// Get the session controlled by the given terminal (see
/// [tcgetsid(3)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/tcgetsid.html)).
pub fn tcgetsid(fd: RawFd) -> Result<Pid> {
    let res = unsafe { libc::tcgetsid(fd) };

    Errno::result(res).map(Pid::from_raw)
}