8 files changed, 914 insertions, 0 deletions
diff --git a/third_party/rust/libudev/src/context.rs b/third_party/rust/libudev/src/context.rs
new file mode 100644
index 0000000000..95252611e4
--- /dev/null
+++ b/third_party/rust/libudev/src/context.rs
@@ -0,0 +1,47 @@
+use std::path::Path;
+
+use ::device::{Device};
+use ::handle::{Handle};
+
+/// A libudev context.
+pub struct Context {
+    udev: *mut ::ffi::udev
+}
+
+impl Drop for Context {
+    fn drop(&mut self) {
+        unsafe {
+            ::ffi::udev_unref(self.udev);
+        }
+    }
+}
+
+#[doc(hidden)]
+impl Handle<::ffi::udev> for Context {
+    fn as_ptr(&self) -> *mut ::ffi::udev {
+        self.udev
+    }
+}
+
+impl Context {
+    /// Creates a new context.
+    pub fn new() -> ::Result<Self> {
+        let ptr = try_alloc!(unsafe { ::ffi::udev_new() });
+
+        Ok(Context { udev: ptr })
+    }
+
+    /// Creates a device for a given syspath.
+    ///
+    /// The `syspath` parameter should be a path to the device file within the `sysfs` file system,
+    /// e.g., `/sys/devices/virtual/tty/tty0`.
+    pub fn device_from_syspath(&self, syspath: &Path) -> ::Result<Device> {
+        let syspath = try!(::util::os_str_to_cstring(syspath));
+
+        let ptr = try_alloc!(unsafe {
+            ::ffi::udev_device_new_from_syspath(self.udev, syspath.as_ptr())
+        });
+
+        Ok(::device::new(self, ptr))
+    }
+}
diff --git a/third_party/rust/libudev/src/device.rs b/third_party/rust/libudev/src/device.rs
new file mode 100644
index 0000000000..736e7b58ff
--- /dev/null
+++ b/third_party/rust/libudev/src/device.rs
@@ -0,0 +1,340 @@
+use std::str;
+
+use std::ffi::{CStr,OsStr};
+use std::path::Path;
+use std::str::FromStr;
+
+use libc::{c_char,dev_t};
+
+use ::context::Context;
+use ::handle::*;
+
+pub fn new(context: &Context, device: *mut ::ffi::udev_device) -> Device {
+    Device {
+        _context: context,
+        device: device,
+    }
+}
+
+/// A structure that provides access to sysfs/kernel devices.
+pub struct Device<'a> {
+    _context: &'a Context,
+    device: *mut ::ffi::udev_device,
+}
+
+impl<'a> Drop for Device<'a> {
+    fn drop(&mut self) {
+        unsafe {
+            ::ffi::udev_device_unref(self.device);
+        }
+    }
+}
+
+#[doc(hidden)]
+impl<'a> Handle<::ffi::udev_device> for Device<'a> {
+    fn as_ptr(&self) -> *mut ::ffi::udev_device {
+        self.device
+    }
+}
+
+impl<'a> Device<'a> {
+    /// Checks whether the device has already been handled by udev.
+    ///
+    /// When a new device is connected to the system, udev initializes the device by setting
+    /// permissions, renaming network devices, and possibly other initialization routines. This
+    /// method returns `true` if udev has performed all of its work to initialize this device.
+    ///
+    /// This method only applies to devices with device nodes or network interfaces. All other
+    /// devices return `true` by default.
+    pub fn is_initialized(&self) -> bool {
+        unsafe {
+            ::ffi::udev_device_get_is_initialized(self.device) > 0
+        }
+    }
+
+    /// Gets the device's major/minor number.
+    pub fn devnum(&self) -> Option<dev_t> {
+        match unsafe { ::ffi::udev_device_get_devnum(self.device) } {
+            0 => None,
+            n => Some(n)
+        }
+    }
+
+    /// Returns the syspath of the device.
+    ///
+    /// The path is an absolute path and includes the sys mount point. For example, the syspath for
+    /// `tty0` could be `/sys/devices/virtual/tty/tty0`, which includes the sys mount point,
+    /// `/sys`.
+    pub fn syspath(&self) -> &Path {
+        Path::new(unsafe {
+            ::util::ptr_to_os_str_unchecked(::ffi::udev_device_get_syspath(self.device))
+        })
+    }
+
+    /// Returns the kernel devpath value of the device.
+    ///
+    /// The path does not contain the sys mount point, but does start with a `/`. For example, the
+    /// devpath for `tty0` could be `/devices/virtual/tty/tty0`.
+    pub fn devpath(&self) -> &OsStr {
+        unsafe {
+            ::util::ptr_to_os_str_unchecked(::ffi::udev_device_get_devpath(self.device))
+        }
+    }
+
+    /// Returns the path to the device node belonging to the device.
+    ///
+    /// The path is an absolute path and starts with the device directory. For example, the device
+    /// node for `tty0` could be `/dev/tty0`.
+    pub fn devnode(&self) -> Option<&Path> {
+        ::util::ptr_to_os_str(unsafe { ::ffi::udev_device_get_devnode(self.device) }).map(|path| {
+            Path::new(path)
+        })
+    }
+
+    /// Returns the parent of the device.
+    pub fn parent(&self) -> Option<Device> {
+        let ptr = unsafe { ::ffi::udev_device_get_parent(self.device) };
+
+        if !ptr.is_null() {
+            unsafe {
+                ::ffi::udev_device_ref(ptr);
+            }
+
+            Some(Device {
+                _context: self._context,
+                device: ptr,
+            })
+        }
+        else {
+            None
+        }
+    }
+
+    /// Returns the subsystem name of the device.
+    ///
+    /// The subsystem name is a string that indicates which kernel subsystem the device belongs to.
+    /// Examples of subsystem names are `tty`, `vtconsole`, `block`, `scsi`, and `net`.
+    pub fn subsystem(&self) -> &OsStr {
+        unsafe {
+            ::util::ptr_to_os_str_unchecked(::ffi::udev_device_get_subsystem(self.device))
+        }
+    }
+
+    /// Returns the kernel device name for the device.
+    ///
+    /// The sysname is a string that differentiates the device from others in the same subsystem.
+    /// For example, `tty0` is the sysname for a TTY device that differentiates it from others,
+    /// such as `tty1`.
+    pub fn sysname(&self) -> &OsStr {
+        unsafe {
+            ::util::ptr_to_os_str_unchecked(::ffi::udev_device_get_sysname(self.device))
+        }
+    }
+
+    /// Returns the instance number of the device.
+    ///
+    /// The instance number is used to differentiate many devices of the same type. For example,
+    /// `/dev/tty0` and `/dev/tty1` are both TTY devices but have instance numbers of 0 and 1,
+    /// respectively.
+    ///
+    /// Some devices don't have instance numbers, such as `/dev/console`, in which case the method
+    /// returns `None`.
+    pub fn sysnum(&self) -> Option<usize> {
+        let ptr = unsafe { ::ffi::udev_device_get_sysnum(self.device) };
+
+        if !ptr.is_null() {
+            match str::from_utf8(unsafe { CStr::from_ptr(ptr) }.to_bytes()) {
+                Err(_) => None,
+                Ok(s) => FromStr::from_str(s).ok()
+            }
+        }
+        else {
+            None
+        }
+    }
+
+    /// Returns the devtype name of the device.
+    pub fn devtype(&self) -> Option<&OsStr> {
+        ::util::ptr_to_os_str(unsafe { ::ffi::udev_device_get_devtype(self.device) })
+    }
+
+    /// Returns the name of the kernel driver attached to the device.
+    pub fn driver(&self) -> Option<&OsStr> {
+        ::util::ptr_to_os_str(unsafe { ::ffi::udev_device_get_driver(self.device) })
+    }
+
+    /// Retreives the value of a device property.
+    pub fn property_value<T: AsRef<OsStr>>(&self, property: T) -> Option<&OsStr> {
+        let prop = match ::util::os_str_to_cstring(property) {
+            Ok(s) => s,
+            Err(_) => return None
+        };
+
+        ::util::ptr_to_os_str(unsafe {
+            ::ffi::udev_device_get_property_value(self.device, prop.as_ptr())
+        })
+    }
+
+    /// Retreives the value of a device attribute.
+    pub fn attribute_value<T: AsRef<OsStr>>(&self, attribute: T) -> Option<&OsStr> {
+        let attr = match ::util::os_str_to_cstring(attribute) {
+            Ok(s) => s,
+            Err(_) => return None
+        };
+
+        ::util::ptr_to_os_str(unsafe {
+            ::ffi::udev_device_get_sysattr_value(self.device, attr.as_ptr())
+        })
+    }
+
+    /// Sets the value of a device attribute.
+    pub fn set_attribute_value<T: AsRef<OsStr>, U: AsRef<OsStr>>(&mut self, attribute: T, value: U) -> ::Result<()> {
+        let attribute = try!(::util::os_str_to_cstring(attribute));
+        let value = try!(::util::os_str_to_cstring(value));
+
+        ::util::errno_to_result(unsafe {
+            ::ffi::udev_device_set_sysattr_value(self.device, attribute.as_ptr(), value.as_ptr() as *mut c_char)
+        })
+    }
+
+    /// Returns an iterator over the device's properties.
+    ///
+    /// ## Example
+    ///
+    /// This example prints out all of a device's properties:
+    ///
+    /// ```no_run
+    /// # use std::path::Path;
+    /// # let mut context = libudev::Context::new().unwrap();
+    /// # let device = context.device_from_syspath(Path::new("/sys/devices/virtual/tty/tty0")).unwrap();
+    /// for property in device.properties() {
+    ///     println!("{:?} = {:?}", property.name(), property.value());
+    /// }
+    /// ```
+    pub fn properties(&self) -> Properties {
+        Properties {
+            _device: self,
+            entry: unsafe { ::ffi::udev_device_get_properties_list_entry(self.device) }
+        }
+    }
+
+    /// Returns an iterator over the device's attributes.
+    ///
+    /// ## Example
+    ///
+    /// This example prints out all of a device's attributes:
+    ///
+    /// ```no_run
+    /// # use std::path::Path;
+    /// # let mut context = libudev::Context::new().unwrap();
+    /// # let device = context.device_from_syspath(Path::new("/sys/devices/virtual/tty/tty0")).unwrap();
+    /// for attribute in device.attributes() {
+    ///     println!("{:?} = {:?}", attribute.name(), attribute.value());
+    /// }
+    /// ```
+    pub fn attributes(&self) -> Attributes {
+        Attributes {
+            device: self,
+            entry: unsafe { ::ffi::udev_device_get_sysattr_list_entry(self.device) }
+        }
+    }
+}
+
+
+/// Iterator over a device's properties.
+pub struct Properties<'a> {
+    _device: &'a Device<'a>,
+    entry: *mut ::ffi::udev_list_entry
+}
+
+impl<'a> Iterator for Properties<'a> {
+    type Item = Property<'a>;
+
+    fn next(&mut self) -> Option<Property<'a>> {
+        if self.entry.is_null() {
+            None
+        }
+        else {
+            let name = unsafe { ::util::ptr_to_os_str_unchecked(::ffi::udev_list_entry_get_name(self.entry)) };
+            let value = unsafe { ::util::ptr_to_os_str_unchecked(::ffi::udev_list_entry_get_value(self.entry)) };
+
+            self.entry = unsafe { ::ffi::udev_list_entry_get_next(self.entry) };
+
+            Some(Property {
+                name: name,
+                value: value
+            })
+        }
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (0, None)
+    }
+}
+
+/// A device property.
+pub struct Property<'a> {
+    name: &'a OsStr,
+    value: &'a OsStr
+}
+
+impl<'a> Property<'a> {
+    /// Returns the property name.
+    pub fn name(&self) -> &OsStr {
+        self.name
+    }
+
+    /// Returns the property value.
+    pub fn value(&self) -> &OsStr {
+        self.value
+    }
+}
+
+
+/// Iterator over a device's attributes.
+pub struct Attributes<'a> {
+    device: &'a Device<'a>,
+    entry: *mut ::ffi::udev_list_entry
+}
+
+impl<'a> Iterator for Attributes<'a> {
+    type Item = Attribute<'a>;
+
+    fn next(&mut self) -> Option<Attribute<'a>> {
+        if !self.entry.is_null() {
+            let name = unsafe { ::util::ptr_to_os_str_unchecked(::ffi::udev_list_entry_get_name(self.entry)) };
+
+            self.entry = unsafe { ::ffi::udev_list_entry_get_next(self.entry) };
+
+            Some(Attribute {
+                device: self.device,
+                name: name
+            })
+        }
+        else {
+            None
+        }
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (0, None)
+    }
+}
+
+/// A device attribute.
+pub struct Attribute<'a> {
+    device: &'a Device<'a>,
+    name: &'a OsStr
+}
+
+impl<'a> Attribute<'a> {
+    /// Returns the attribute name.
+    pub fn name(&self) -> &OsStr {
+        self.name
+    }
+
+    /// Returns the attribute value.
+    pub fn value(&self) -> Option<&OsStr> {
+        self.device.attribute_value(self.name)
+    }
+}
diff --git a/third_party/rust/libudev/src/enumerator.rs b/third_party/rust/libudev/src/enumerator.rs
new file mode 100644
index 0000000000..641d68a2c1
--- /dev/null
+++ b/third_party/rust/libudev/src/enumerator.rs
@@ -0,0 +1,171 @@
+use std::ffi::{OsStr};
+use std::path::Path;
+
+use ::handle::prelude::*;
+
+pub use context::{Context};
+pub use device::{Device};
+
+
+/// An enumeration context.
+///
+/// An Enumerator scans `/sys` for devices matching its filters. Filters are added to an Enumerator
+/// by calling its `match_*` and `nomatch_*` methods. After the filters are setup, the
+/// `scan_devices()` method finds devices in `/sys` that match the filters.
+pub struct Enumerator<'a> {
+    context: &'a Context,
+    enumerator: *mut ::ffi::udev_enumerate
+}
+
+impl<'a> Drop for Enumerator<'a> {
+    fn drop(&mut self) {
+        unsafe { ::ffi::udev_enumerate_unref(self.enumerator) };
+    }
+}
+
+impl<'a> Enumerator<'a> {
+    /// Creates a new Enumerator.
+    pub fn new(context: &'a Context) -> ::Result<Self> {
+        let ptr = try_alloc!(unsafe { ::ffi::udev_enumerate_new(context.as_ptr()) });
+
+        Ok(Enumerator {
+            context: context,
+            enumerator: ptr
+        })
+    }
+
+    /// Adds a filter that matches only initialized devices.
+    pub fn match_is_initialized(&mut self) -> ::Result<()> {
+        ::util::errno_to_result(unsafe {
+            ::ffi::udev_enumerate_add_match_is_initialized(self.enumerator)
+        })
+    }
+
+    /// Adds a filter that matches only devices that belong to the given kernel subsystem.
+    pub fn match_subsystem<T: AsRef<OsStr>>(&mut self, subsystem: T) -> ::Result<()> {
+        let subsystem = try!(::util::os_str_to_cstring(subsystem));
+
+        ::util::errno_to_result(unsafe {
+            ::ffi::udev_enumerate_add_match_subsystem(self.enumerator, subsystem.as_ptr())
+        })
+    }
+
+    /// Adds a filter that matches only devices with the given attribute value.
+    pub fn match_attribute<T: AsRef<OsStr>, U: AsRef<OsStr>>(&mut self, attribute: T, value: U) -> ::Result<()> {
+        let attribute = try!(::util::os_str_to_cstring(attribute));
+        let value = try!(::util::os_str_to_cstring(value));
+
+        ::util::errno_to_result(unsafe {
+            ::ffi::udev_enumerate_add_match_sysattr(self.enumerator, attribute.as_ptr(), value.as_ptr())
+        })
+    }
+
+    /// Adds a filter that matches only devices with the given kernel device name.
+    pub fn match_sysname<T: AsRef<OsStr>>(&mut self, sysname: T) -> ::Result<()> {
+        let sysname = try!(::util::os_str_to_cstring(sysname));
+
+        ::util::errno_to_result(unsafe {
+            ::ffi::udev_enumerate_add_match_sysname(self.enumerator, sysname.as_ptr())
+        })
+    }
+
+    /// Adds a filter that matches only devices with the given property value.
+    pub fn match_property<T: AsRef<OsStr>, U: AsRef<OsStr>>(&mut self, property: T, value: U) -> ::Result<()> {
+        let property = try!(::util::os_str_to_cstring(property));
+        let value = try!(::util::os_str_to_cstring(value));
+
+        ::util::errno_to_result(unsafe {
+            ::ffi::udev_enumerate_add_match_property(self.enumerator, property.as_ptr(), value.as_ptr())
+        })
+    }
+
+    /// Adds a filter that matches only devices with the given tag.
+    pub fn match_tag<T: AsRef<OsStr>>(&mut self, tag: T) -> ::Result<()> {
+        let tag = try!(::util::os_str_to_cstring(tag));
+
+        ::util::errno_to_result(unsafe {
+            ::ffi::udev_enumerate_add_match_tag(self.enumerator, tag.as_ptr())
+        })
+    }
+
+    /// Includes the parent device and all devices in the subtree of the parent device.
+    pub fn match_parent(&mut self, parent: &Device) -> ::Result<()> {
+        ::util::errno_to_result(unsafe {
+            ::ffi::udev_enumerate_add_match_parent(self.enumerator, parent.as_ptr())
+        })
+    }
+
+    /// Adds a filter that matches only devices that don't belong to the given kernel subsystem.
+    pub fn nomatch_subsystem<T: AsRef<OsStr>>(&mut self, subsystem: T) -> ::Result<()> {
+        let subsystem = try!(::util::os_str_to_cstring(subsystem));
+
+        ::util::errno_to_result(unsafe {
+            ::ffi::udev_enumerate_add_nomatch_subsystem(self.enumerator, subsystem.as_ptr())
+        })
+    }
+
+    /// Adds a filter that matches only devices that don't have the the given attribute value.
+    pub fn nomatch_attribute<T: AsRef<OsStr>, U: AsRef<OsStr>>(&mut self, attribute: T, value: U) -> ::Result<()> {
+        let attribute = try!(::util::os_str_to_cstring(attribute));
+        let value = try!(::util::os_str_to_cstring(value));
+
+        ::util::errno_to_result(unsafe {
+            ::ffi::udev_enumerate_add_nomatch_sysattr(self.enumerator, attribute.as_ptr(), value.as_ptr())
+        })
+    }
+
+    /// Includes the device with the given syspath.
+    pub fn add_syspath(&mut self, syspath: &Path) -> ::Result<()> {
+        let syspath = try!(::util::os_str_to_cstring(syspath));
+
+        ::util::errno_to_result(unsafe {
+            ::ffi::udev_enumerate_add_syspath(self.enumerator, syspath.as_ptr())
+        })
+    }
+
+    /// Scans `/sys` for devices matching the attached filters.
+    ///
+    /// The devices will be sorted in dependency order.
+    pub fn scan_devices(&mut self) -> ::Result<Devices> {
+        try!(::util::errno_to_result(unsafe {
+            ::ffi::udev_enumerate_scan_devices(self.enumerator)
+        }));
+
+        Ok(Devices {
+            enumerator: self,
+            entry: unsafe { ::ffi::udev_enumerate_get_list_entry(self.enumerator) }
+        })
+    }
+}
+
+
+/// Iterator over devices.
+pub struct Devices<'a> {
+    enumerator: &'a Enumerator<'a>,
+    entry: *mut ::ffi::udev_list_entry
+}
+
+impl<'a> Iterator for Devices<'a> {
+    type Item = Device<'a>;
+
+    fn next(&mut self) -> Option<Device<'a>> {
+        while !self.entry.is_null() {
+            let syspath = Path::new(unsafe {
+                ::util::ptr_to_os_str_unchecked(::ffi::udev_list_entry_get_name(self.entry))
+            });
+
+            self.entry = unsafe { ::ffi::udev_list_entry_get_next(self.entry) };
+
+            match self.enumerator.context.device_from_syspath(syspath) {
+                Ok(d) => return Some(d),
+                Err(_) => continue
+            };
+        }
+
+        None
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (0, None)
+    }
+}
diff --git a/third_party/rust/libudev/src/error.rs b/third_party/rust/libudev/src/error.rs
new file mode 100644
index 0000000000..2c503149c8
--- /dev/null
+++ b/third_party/rust/libudev/src/error.rs
@@ -0,0 +1,76 @@
+use std::ffi::CStr;
+use std::fmt;
+use std::io;
+use std::str;
+
+use std::error::Error as StdError;
+use std::result::Result as StdResult;
+
+use ::libc::c_int;
+
+/// A `Result` type for libudev operations.
+pub type Result<T> = StdResult<T,Error>;
+
+/// Types of errors that occur in libudev.
+#[derive(Debug,Clone,Copy,PartialEq,Eq)]
+pub enum ErrorKind {
+    NoMem,
+    InvalidInput,
+    Io(io::ErrorKind)
+}
+
+/// The error type for libudev operations.
+#[derive(Debug)]
+pub struct Error {
+    errno: c_int,
+}
+
+impl Error {
+    fn strerror(&self) -> &str {
+        unsafe {
+            str::from_utf8_unchecked(CStr::from_ptr(::libc::strerror(self.errno)).to_bytes())
+        }
+    }
+
+    /// Returns the corresponding `ErrorKind` for this error.
+    pub fn kind(&self) -> ErrorKind {
+        match self.errno {
+            ::libc::ENOMEM => ErrorKind::NoMem,
+            ::libc::EINVAL => ErrorKind::InvalidInput,
+            errno => ErrorKind::Io(io::Error::from_raw_os_error(errno).kind()),
+        }
+    }
+
+    /// Returns a description of the error.
+    pub fn description(&self) -> &str {
+        self.strerror()
+    }
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> StdResult<(),fmt::Error> {
+        fmt.write_str(self.strerror())
+    }
+}
+
+impl StdError for Error {
+    fn description(&self) -> &str {
+        self.strerror()
+    }
+}
+
+impl From<Error> for io::Error {
+    fn from(error: Error) -> io::Error {
+        let io_error_kind = match error.kind() {
+            ErrorKind::Io(kind) => kind,
+            ErrorKind::InvalidInput => io::ErrorKind::InvalidInput,
+            ErrorKind::NoMem => io::ErrorKind::Other,
+        };
+
+        io::Error::new(io_error_kind, error.strerror())
+    }
+}
+
+pub fn from_errno(errno: c_int) -> Error {
+    Error { errno: -errno }
+}
diff --git a/third_party/rust/libudev/src/handle.rs b/third_party/rust/libudev/src/handle.rs
new file mode 100644
index 0000000000..3cfd943a00
--- /dev/null
+++ b/third_party/rust/libudev/src/handle.rs
@@ -0,0 +1,7 @@
+pub mod prelude {
+    pub use super::Handle;
+}
+
+pub trait Handle<T> {
+    fn as_ptr(&self) -> *mut T;
+}
diff --git a/third_party/rust/libudev/src/lib.rs b/third_party/rust/libudev/src/lib.rs
new file mode 100644
index 0000000000..ac6be5c169
--- /dev/null
+++ b/third_party/rust/libudev/src/lib.rs
@@ -0,0 +1,29 @@
+extern crate libudev_sys as ffi;
+extern crate libc;
+
+pub use context::{Context};
+pub use device::{Device,Properties,Property,Attributes,Attribute};
+pub use enumerator::{Enumerator,Devices};
+pub use error::{Result,Error,ErrorKind};
+pub use monitor::{Monitor,MonitorSocket,EventType,Event};
+
+macro_rules! try_alloc {
+    ($exp:expr) => {{
+        let ptr = $exp;
+
+        if ptr.is_null() {
+            return Err(::error::from_errno(::libc::ENOMEM));
+        }
+
+        ptr
+    }}
+}
+
+mod context;
+mod device;
+mod enumerator;
+mod error;
+mod monitor;
+
+mod handle;
+mod util;
diff --git a/third_party/rust/libudev/src/monitor.rs b/third_party/rust/libudev/src/monitor.rs
new file mode 100644
index 0000000000..836a8736ce
--- /dev/null
+++ b/third_party/rust/libudev/src/monitor.rs
@@ -0,0 +1,211 @@
+use std::fmt;
+use std::ptr;
+
+use std::ffi::{CString,OsStr};
+use std::ops::Deref;
+use std::os::unix::io::{RawFd,AsRawFd};
+
+use ::context::{Context};
+use ::device::{Device};
+use ::handle::prelude::*;
+
+
+/// Monitors for device events.
+///
+/// A monitor communicates with the kernel over a socket. Filtering events is performed efficiently
+/// in the kernel, and only events that match the filters are received by the socket. Filters must
+/// be setup before listening for events.
+pub struct Monitor<'a> {
+    context: &'a Context,
+    monitor: *mut ::ffi::udev_monitor
+}
+
+impl<'a> Drop for Monitor<'a> {
+    fn drop(&mut self) {
+        unsafe {
+            ::ffi::udev_monitor_unref(self.monitor);
+        }
+    }
+}
+
+impl<'a> Monitor<'a> {
+    /// Creates a new `Monitor`.
+    pub fn new(context: &'a Context) -> ::Result<Self> {
+        let name = CString::new("udev").unwrap();
+
+        let ptr = try_alloc!(unsafe {
+            ::ffi::udev_monitor_new_from_netlink(context.as_ptr(), name.as_ptr())
+        });
+
+        Ok(Monitor {
+            context: context,
+            monitor: ptr
+        })
+    }
+
+    /// Adds a filter that matches events for devices with the given subsystem.
+    pub fn match_subsystem<T: AsRef<OsStr>>(&mut self, subsystem: T) -> ::Result<()> {
+        let subsystem = try!(::util::os_str_to_cstring(subsystem));
+
+        ::util::errno_to_result(unsafe {
+            ::ffi::udev_monitor_filter_add_match_subsystem_devtype(self.monitor, subsystem.as_ptr(), ptr::null())
+        })
+    }
+
+    /// Adds a filter that matches events for devices with the given subsystem and device type.
+    pub fn match_subsystem_devtype<T: AsRef<OsStr>, U: AsRef<OsStr>>(&mut self, subsystem: T, devtype: U) -> ::Result<()> {
+        let subsystem = try!(::util::os_str_to_cstring(subsystem));
+        let devtype = try!(::util::os_str_to_cstring(devtype));
+
+        ::util::errno_to_result(unsafe {
+            ::ffi::udev_monitor_filter_add_match_subsystem_devtype(self.monitor, subsystem.as_ptr(), devtype.as_ptr())
+        })
+    }
+
+    /// Adds a filter that matches events for devices with the given tag.
+    pub fn match_tag<T: AsRef<OsStr>>(&mut self, tag: T) -> ::Result<()> {
+        let tag = try!(::util::os_str_to_cstring(tag));
+
+        ::util::errno_to_result(unsafe {
+            ::ffi::udev_monitor_filter_add_match_tag(self.monitor, tag.as_ptr())
+        })
+    }
+
+    /// Removes all filters currently set on the monitor.
+    pub fn clear_filters(&mut self) -> ::Result<()> {
+        ::util::errno_to_result(unsafe {
+            ::ffi::udev_monitor_filter_remove(self.monitor)
+        })
+    }
+
+    /// Listens for events matching the current filters.
+    ///
+    /// This method consumes the `Monitor`.
+    pub fn listen(self) -> ::Result<MonitorSocket<'a>> {
+        try!(::util::errno_to_result(unsafe {
+            ::ffi::udev_monitor_enable_receiving(self.monitor)
+        }));
+
+        Ok(MonitorSocket { inner: self })
+    }
+}
+
+
+/// An active monitor that can receive events.
+///
+/// The events received by a `MonitorSocket` match the filters setup by the `Monitor` that created
+/// the socket.
+///
+/// Monitors are initially setup to receive events from the kernel via a nonblocking socket. A
+/// variant of `poll()` should be used on the file descriptor returned by the `AsRawFd` trait to
+/// wait for new events.
+pub struct MonitorSocket<'a> {
+    inner: Monitor<'a>
+}
+
+/// Provides raw access to the monitor's socket.
+impl<'a> AsRawFd for MonitorSocket<'a> {
+    /// Returns the file descriptor of the monitor's socket.
+    fn as_raw_fd(&self) -> RawFd {
+        unsafe {
+            ::ffi::udev_monitor_get_fd(self.inner.monitor)
+        }
+    }
+}
+
+impl<'a> MonitorSocket<'a> {
+    /// Receives the next available event from the monitor.
+    ///
+    /// This method does not block. If no events are available, it returns `None` immediately.
+    pub fn receive_event<'b>(&'b mut self) -> Option<Event<'a>> {
+        let device = unsafe {
+            ::ffi::udev_monitor_receive_device(self.inner.monitor)
+        };
+
+        if device.is_null() {
+            None
+        }
+        else {
+            let device = ::device::new(self.inner.context, device);
+
+            Some(Event { device: device })
+        }
+    }
+}
+
+/// Types of events that can be received from udev.
+#[derive(Debug,Clone,Copy,PartialEq,Eq)]
+pub enum EventType {
+    /// A device was added.
+    Add,
+
+    /// A device changed.
+    Change,
+
+    /// A device was removed.
+    Remove,
+
+    /// An unknown event occurred.
+    Unknown,
+}
+
+impl Default for EventType {
+    fn default() -> EventType {
+        EventType::Unknown
+    }
+}
+
+impl fmt::Display for EventType {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.write_str(match self {
+            &EventType::Add => "add",
+            &EventType::Change => "change",
+            &EventType::Remove => "remove",
+            &EventType::Unknown => "unknown",
+        })
+    }
+}
+
+
+/// An event that indicates a change in device state.
+pub struct Event<'a> {
+    device: Device<'a>
+}
+
+/// Provides access to the device associated with the event.
+impl<'a> Deref for Event<'a> {
+    type Target = Device<'a>;
+
+    fn deref(&self) -> &Device<'a> {
+        &self.device
+    }
+}
+
+impl<'a> Event<'a> {
+    /// Returns the `EventType` corresponding to this event.
+    pub fn event_type(&self) -> EventType {
+        let value = match self.device.property_value("ACTION") {
+            Some(s) => s.to_str(),
+            None => None
+        };
+
+        match value {
+            Some("add") => EventType::Add,
+            Some("change") => EventType::Change,
+            Some("remove") => EventType::Remove,
+            _ => EventType::Unknown
+        }
+    }
+
+    /// Returns the event's sequence number.
+    pub fn sequence_number(&self) -> u64 {
+        unsafe {
+            ::ffi::udev_device_get_seqnum(self.device.as_ptr()) as u64
+        }
+    }
+
+    /// Returns the device associated with this event.
+    pub fn device(&self) -> &Device {
+        &self.device
+    }
+}
diff --git a/third_party/rust/libudev/src/util.rs b/third_party/rust/libudev/src/util.rs
new file mode 100644
index 0000000000..6831d2e14a
--- /dev/null
+++ b/third_party/rust/libudev/src/util.rs
@@ -0,0 +1,33 @@
+use std::slice;
+use std::ffi::{CString,OsStr};
+
+use ::libc::{c_int,c_char};
+
+use std::os::unix::prelude::*;
+
+pub fn ptr_to_os_str<'a>(ptr: *const c_char) -> Option<&'a OsStr> {
+    if !ptr.is_null() {
+        Some(unsafe { ptr_to_os_str_unchecked(ptr) })
+    }
+    else {
+        None
+    }
+}
+
+pub unsafe fn ptr_to_os_str_unchecked<'a>(ptr: *const c_char) -> &'a OsStr {
+    OsStr::from_bytes(slice::from_raw_parts(ptr as *const u8, ::libc::strlen(ptr) as usize))
+}
+
+pub fn os_str_to_cstring<T: AsRef<OsStr>>(s: T) -> ::Result<CString> {
+    match CString::new(s.as_ref().as_bytes()) {
+        Ok(s) => Ok(s),
+        Err(_) => return Err(::error::from_errno(::libc::EINVAL))
+    }
+}
+
+pub fn errno_to_result(errno: c_int) -> ::Result<()> {
+    match errno {
+        0 => Ok(()),
+        e => Err(::error::from_errno(e))
+    }
+}