// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

use prelude::v1::*;

use fmt;
use hash;
use io;
use libc::{self, socklen_t, sa_family_t};
use mem;
use net::{lookup_host, ntoh, hton, IpAddr, Ipv4Addr, Ipv6Addr};
use option;
use sys_common::{FromInner, AsInner, IntoInner};
use vec;

/// Representation of a socket address for networking applications.
///
/// A socket address can either represent the IPv4 or IPv6 protocol and is
/// paired with at least a port number as well. Each protocol may have more
/// specific information about the address available to it as well.
#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
#[stable(feature = "rust1", since = "1.0.0")]
pub enum SocketAddr {
    /// An IPv4 socket address which is a (ip, port) combination.
    #[stable(feature = "rust1", since = "1.0.0")]
    V4(SocketAddrV4),
    /// An IPv6 socket address
    #[stable(feature = "rust1", since = "1.0.0")]
    V6(SocketAddrV6),
}

/// An IPv4 socket address which is a (ip, port) combination.
#[derive(Copy)]
#[stable(feature = "rust1", since = "1.0.0")]
pub struct SocketAddrV4 { inner: libc::sockaddr_in }

/// An IPv6 socket address
#[derive(Copy)]
#[stable(feature = "rust1", since = "1.0.0")]
pub struct SocketAddrV6 { inner: libc::sockaddr_in6 }

impl SocketAddr {
    /// Creates a new socket address from the (ip, port) pair.
    #[unstable(feature = "ip_addr", reason = "recent addition")]
    pub fn new(ip: IpAddr, port: u16) -> SocketAddr {
        match ip {
            IpAddr::V4(a) => SocketAddr::V4(SocketAddrV4::new(a, port)),
            IpAddr::V6(a) => SocketAddr::V6(SocketAddrV6::new(a, port, 0, 0)),
        }
    }

    /// Gets the IP address associated with this socket address.
    #[unstable(feature = "ip_addr", reason = "recent addition")]
    pub fn ip(&self) -> IpAddr {
        match *self {
            SocketAddr::V4(ref a) => IpAddr::V4(*a.ip()),
            SocketAddr::V6(ref a) => IpAddr::V6(*a.ip()),
        }
    }

    /// Gets the port number associated with this socket address
    #[stable(feature = "rust1", since = "1.0.0")]
    pub fn port(&self) -> u16 {
        match *self {
            SocketAddr::V4(ref a) => a.port(),
            SocketAddr::V6(ref a) => a.port(),
        }
    }
}

impl SocketAddrV4 {
    /// Creates a new socket address from the (ip, port) pair.
    #[stable(feature = "rust1", since = "1.0.0")]
    pub fn new(ip: Ipv4Addr, port: u16) -> SocketAddrV4 {
        SocketAddrV4 {
            inner: libc::sockaddr_in {
                sin_family: libc::AF_INET as sa_family_t,
                sin_port: hton(port),
                sin_addr: *ip.as_inner(),
                .. unsafe { mem::zeroed() }
            },
        }
    }

    /// Gets the IP address associated with this socket address.
    #[stable(feature = "rust1", since = "1.0.0")]
    pub fn ip(&self) -> &Ipv4Addr {
        unsafe {
            &*(&self.inner.sin_addr as *const libc::in_addr as *const Ipv4Addr)
        }
    }

    /// Gets the port number associated with this socket address
    #[stable(feature = "rust1", since = "1.0.0")]
    pub fn port(&self) -> u16 { ntoh(self.inner.sin_port) }
}

impl SocketAddrV6 {
    /// Creates a new socket address from the ip/port/flowinfo/scope_id
    /// components.
    #[stable(feature = "rust1", since = "1.0.0")]
    pub fn new(ip: Ipv6Addr, port: u16, flowinfo: u32, scope_id: u32)
               -> SocketAddrV6 {
        SocketAddrV6 {
            inner: libc::sockaddr_in6 {
                sin6_family: libc::AF_INET6 as sa_family_t,
                sin6_port: hton(port),
                sin6_addr: *ip.as_inner(),
                sin6_flowinfo: hton(flowinfo),
                sin6_scope_id: hton(scope_id),
                .. unsafe { mem::zeroed() }
            },
        }
    }

    /// Gets the IP address associated with this socket address.
    #[stable(feature = "rust1", since = "1.0.0")]
    pub fn ip(&self) -> &Ipv6Addr {
        unsafe {
            &*(&self.inner.sin6_addr as *const libc::in6_addr as *const Ipv6Addr)
        }
    }

    /// Gets the port number associated with this socket address
    #[stable(feature = "rust1", since = "1.0.0")]
    pub fn port(&self) -> u16 { ntoh(self.inner.sin6_port) }

    /// Gets scope ID associated with this address, corresponding to the
    /// `sin6_flowinfo` field in C.
    #[stable(feature = "rust1", since = "1.0.0")]
    pub fn flowinfo(&self) -> u32 { ntoh(self.inner.sin6_flowinfo) }

    /// Gets scope ID associated with this address, corresponding to the
    /// `sin6_scope_id` field in C.
    #[stable(feature = "rust1", since = "1.0.0")]
    pub fn scope_id(&self) -> u32 { ntoh(self.inner.sin6_scope_id) }
}

impl FromInner<libc::sockaddr_in> for SocketAddrV4 {
    fn from_inner(addr: libc::sockaddr_in) -> SocketAddrV4 {
        SocketAddrV4 { inner: addr }
    }
}

impl FromInner<libc::sockaddr_in6> for SocketAddrV6 {
    fn from_inner(addr: libc::sockaddr_in6) -> SocketAddrV6 {
        SocketAddrV6 { inner: addr }
    }
}

impl<'a> IntoInner<(*const libc::sockaddr, socklen_t)> for &'a SocketAddr {
    fn into_inner(self) -> (*const libc::sockaddr, socklen_t) {
        match *self {
            SocketAddr::V4(ref a) => {
                (a as *const _ as *const _, mem::size_of_val(a) as socklen_t)
            }
            SocketAddr::V6(ref a) => {
                (a as *const _ as *const _, mem::size_of_val(a) as socklen_t)
            }
        }
    }
}

#[stable(feature = "rust1", since = "1.0.0")]
impl fmt::Display for SocketAddr {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match *self {
            SocketAddr::V4(ref a) => a.fmt(f),
            SocketAddr::V6(ref a) => a.fmt(f),
        }
    }
}

#[stable(feature = "rust1", since = "1.0.0")]
impl fmt::Display for SocketAddrV4 {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{}:{}", self.ip(), self.port())
    }
}

#[stable(feature = "rust1", since = "1.0.0")]
impl fmt::Debug for SocketAddrV4 {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        fmt::Display::fmt(self, fmt)
    }
}

#[stable(feature = "rust1", since = "1.0.0")]
impl fmt::Display for SocketAddrV6 {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "[{}]:{}", self.ip(), self.port())
    }
}

#[stable(feature = "rust1", since = "1.0.0")]
impl fmt::Debug for SocketAddrV6 {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        fmt::Display::fmt(self, fmt)
    }
}

#[stable(feature = "rust1", since = "1.0.0")]
impl Clone for SocketAddrV4 {
    fn clone(&self) -> SocketAddrV4 { *self }
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Clone for SocketAddrV6 {
    fn clone(&self) -> SocketAddrV6 { *self }
}

#[stable(feature = "rust1", since = "1.0.0")]
impl PartialEq for SocketAddrV4 {
    fn eq(&self, other: &SocketAddrV4) -> bool {
        self.inner.sin_port == other.inner.sin_port &&
            self.inner.sin_addr.s_addr == other.inner.sin_addr.s_addr
    }
}
#[stable(feature = "rust1", since = "1.0.0")]
impl PartialEq for SocketAddrV6 {
    fn eq(&self, other: &SocketAddrV6) -> bool {
        self.inner.sin6_port == other.inner.sin6_port &&
            self.inner.sin6_addr.s6_addr == other.inner.sin6_addr.s6_addr &&
            self.inner.sin6_flowinfo == other.inner.sin6_flowinfo &&
            self.inner.sin6_scope_id == other.inner.sin6_scope_id
    }
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Eq for SocketAddrV4 {}
#[stable(feature = "rust1", since = "1.0.0")]
impl Eq for SocketAddrV6 {}

#[stable(feature = "rust1", since = "1.0.0")]
impl hash::Hash for SocketAddrV4 {
    fn hash<H: hash::Hasher>(&self, s: &mut H) {
        (self.inner.sin_port, self.inner.sin_addr.s_addr).hash(s)
    }
}
#[stable(feature = "rust1", since = "1.0.0")]
impl hash::Hash for SocketAddrV6 {
    fn hash<H: hash::Hasher>(&self, s: &mut H) {
        (self.inner.sin6_port, &self.inner.sin6_addr.s6_addr,
         self.inner.sin6_flowinfo, self.inner.sin6_scope_id).hash(s)
    }
}

/// A trait for objects which can be converted or resolved to one or more
/// `SocketAddr` values.
///
/// This trait is used for generic address resolution when constructing network
/// objects.  By default it is implemented for the following types:
///
///  * `SocketAddr`, `SocketAddrV4`, `SocketAddrV6` - `to_socket_addrs` is
///    identity function.
///
///  * `(IpvNAddr, u16)` - `to_socket_addrs` constructs `SocketAddr` trivially.
///
///  * `(&str, u16)` - the string should be either a string representation of an
///    IP address expected by `FromStr` implementation for `IpvNAddr` or a host
///    name.
///
///  * `&str` - the string should be either a string representation of a
///    `SocketAddr` as expected by its `FromStr` implementation or a string like
///    `<host_name>:<port>` pair where `<port>` is a `u16` value.
///
/// This trait allows constructing network objects like `TcpStream` or
/// `UdpSocket` easily with values of various types for the bind/connection
/// address. It is needed because sometimes one type is more appropriate than
/// the other: for simple uses a string like `"localhost:12345"` is much nicer
/// than manual construction of the corresponding `SocketAddr`, but sometimes
/// `SocketAddr` value is *the* main source of the address, and converting it to
/// some other type (e.g. a string) just for it to be converted back to
/// `SocketAddr` in constructor methods is pointless.
///
/// Some examples:
///
/// ```no_run
/// # #![feature(net)]
/// use std::net::{SocketAddrV4, TcpStream, UdpSocket, TcpListener, Ipv4Addr};
///
/// fn main() {
///     let ip = Ipv4Addr::new(127, 0, 0, 1);
///     let port = 12345;
///
///     // The following lines are equivalent modulo possible "localhost" name
///     // resolution differences
///     let tcp_s = TcpStream::connect(SocketAddrV4::new(ip, port));
///     let tcp_s = TcpStream::connect((ip, port));
///     let tcp_s = TcpStream::connect(("127.0.0.1", port));
///     let tcp_s = TcpStream::connect(("localhost", port));
///     let tcp_s = TcpStream::connect("127.0.0.1:12345");
///     let tcp_s = TcpStream::connect("localhost:12345");
///
///     // TcpListener::bind(), UdpSocket::bind() and UdpSocket::send_to()
///     // behave similarly
///     let tcp_l = TcpListener::bind("localhost:12345");
///
///     let mut udp_s = UdpSocket::bind(("127.0.0.1", port)).unwrap();
///     udp_s.send_to(&[7], (ip, 23451));
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub trait ToSocketAddrs {
    /// Returned iterator over socket addresses which this type may correspond
    /// to.
    #[stable(feature = "rust1", since = "1.0.0")]
    type Iter: Iterator<Item=SocketAddr>;

    /// Converts this object to an iterator of resolved `SocketAddr`s.
    ///
    /// The returned iterator may not actually yield any values depending on the
    /// outcome of any resolution performed.
    ///
    /// Note that this function may block the current thread while resolution is
    /// performed.
    ///
    /// # Errors
    ///
    /// Any errors encountered during resolution will be returned as an `Err`.
    #[stable(feature = "rust1", since = "1.0.0")]
    fn to_socket_addrs(&self) -> io::Result<Self::Iter>;
}

#[stable(feature = "rust1", since = "1.0.0")]
impl ToSocketAddrs for SocketAddr {
    type Iter = option::IntoIter<SocketAddr>;
    fn to_socket_addrs(&self) -> io::Result<option::IntoIter<SocketAddr>> {
        Ok(Some(*self).into_iter())
    }
}

#[stable(feature = "rust1", since = "1.0.0")]
impl ToSocketAddrs for SocketAddrV4 {
    type Iter = option::IntoIter<SocketAddr>;
    fn to_socket_addrs(&self) -> io::Result<option::IntoIter<SocketAddr>> {
        SocketAddr::V4(*self).to_socket_addrs()
    }
}

#[stable(feature = "rust1", since = "1.0.0")]
impl ToSocketAddrs for SocketAddrV6 {
    type Iter = option::IntoIter<SocketAddr>;
    fn to_socket_addrs(&self) -> io::Result<option::IntoIter<SocketAddr>> {
        SocketAddr::V6(*self).to_socket_addrs()
    }
}

#[stable(feature = "rust1", since = "1.0.0")]
impl ToSocketAddrs for (IpAddr, u16) {
    type Iter = option::IntoIter<SocketAddr>;
    fn to_socket_addrs(&self) -> io::Result<option::IntoIter<SocketAddr>> {
        let (ip, port) = *self;
        match ip {
            IpAddr::V4(ref a) => (*a, port).to_socket_addrs(),
            IpAddr::V6(ref a) => (*a, port).to_socket_addrs(),
        }
    }
}

#[stable(feature = "rust1", since = "1.0.0")]
impl ToSocketAddrs for (Ipv4Addr, u16) {
    type Iter = option::IntoIter<SocketAddr>;
    fn to_socket_addrs(&self) -> io::Result<option::IntoIter<SocketAddr>> {
        let (ip, port) = *self;
        SocketAddrV4::new(ip, port).to_socket_addrs()
    }
}

#[stable(feature = "rust1", since = "1.0.0")]
impl ToSocketAddrs for (Ipv6Addr, u16) {
    type Iter = option::IntoIter<SocketAddr>;
    fn to_socket_addrs(&self) -> io::Result<option::IntoIter<SocketAddr>> {
        let (ip, port) = *self;
        SocketAddrV6::new(ip, port, 0, 0).to_socket_addrs()
    }
}

fn resolve_socket_addr(s: &str, p: u16) -> io::Result<vec::IntoIter<SocketAddr>> {
    let ips = try!(lookup_host(s));
    let v: Vec<_> = try!(ips.map(|a| {
        a.map(|a| {
            match a {
                SocketAddr::V4(ref a) => {
                    SocketAddr::V4(SocketAddrV4::new(*a.ip(), p))
                }
                SocketAddr::V6(ref a) => {
                    SocketAddr::V6(SocketAddrV6::new(*a.ip(), p, a.flowinfo(),
                                                     a.scope_id()))
                }
            }
        })
    }).collect());
    Ok(v.into_iter())
}

#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> ToSocketAddrs for (&'a str, u16) {
    type Iter = vec::IntoIter<SocketAddr>;
    fn to_socket_addrs(&self) -> io::Result<vec::IntoIter<SocketAddr>> {
        let (host, port) = *self;

        // try to parse the host as a regular IP address first
        if let Ok(addr) = host.parse::<Ipv4Addr>() {
            let addr = SocketAddrV4::new(addr, port);
            return Ok(vec![SocketAddr::V4(addr)].into_iter())
        }
        if let Ok(addr) = host.parse::<Ipv6Addr>() {
            let addr = SocketAddrV6::new(addr, port, 0, 0);
            return Ok(vec![SocketAddr::V6(addr)].into_iter())
        }

        resolve_socket_addr(host, port)
    }
}

// accepts strings like 'localhost:12345'
#[stable(feature = "rust1", since = "1.0.0")]
impl ToSocketAddrs for str {
    type Iter = vec::IntoIter<SocketAddr>;
    fn to_socket_addrs(&self) -> io::Result<vec::IntoIter<SocketAddr>> {
        // try to parse as a regular SocketAddr first
        match self.parse().ok() {
            Some(addr) => return Ok(vec![addr].into_iter()),
            None => {}
        }

        macro_rules! try_opt {
            ($e:expr, $msg:expr) => (
                match $e {
                    Some(r) => r,
                    None => return Err(io::Error::new(io::ErrorKind::InvalidInput,
                                                      $msg)),
                }
            )
        }

        // split the string by ':' and convert the second part to u16
        let mut parts_iter = self.rsplitn(2, ':');
        let port_str = try_opt!(parts_iter.next(), "invalid socket address");
        let host = try_opt!(parts_iter.next(), "invalid socket address");
        let port: u16 = try_opt!(port_str.parse().ok(), "invalid port value");
        resolve_socket_addr(host, port)
    }
}

impl<'a, T: ToSocketAddrs + ?Sized> ToSocketAddrs for &'a T {
    type Iter = T::Iter;
    fn to_socket_addrs(&self) -> io::Result<T::Iter> {
        (**self).to_socket_addrs()
    }
}

#[cfg(test)]
mod tests {
    use prelude::v1::*;
    use io;
    use net::*;
    use net::Ipv6MulticastScope::*;

    #[test]
    fn test_from_str_ipv4() {
        assert_eq!(Ok(Ipv4Addr::new(127, 0, 0, 1)), "127.0.0.1".parse());
        assert_eq!(Ok(Ipv4Addr::new(255, 255, 255, 255)), "255.255.255.255".parse());
        assert_eq!(Ok(Ipv4Addr::new(0, 0, 0, 0)), "0.0.0.0".parse());

        // out of range
        let none: Option<Ipv4Addr> = "256.0.0.1".parse().ok();
        assert_eq!(None, none);
        // too short
        let none: Option<Ipv4Addr> = "255.0.0".parse().ok();
        assert_eq!(None, none);
        // too long
        let none: Option<Ipv4Addr> = "255.0.0.1.2".parse().ok();
        assert_eq!(None, none);
        // no number between dots
        let none: Option<Ipv4Addr> = "255.0..1".parse().ok();
        assert_eq!(None, none);
    }

    #[test]
    fn test_from_str_ipv6() {
        assert_eq!(Ok(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 0)), "0:0:0:0:0:0:0:0".parse());
        assert_eq!(Ok(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1)), "0:0:0:0:0:0:0:1".parse());

        assert_eq!(Ok(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1)), "::1".parse());
        assert_eq!(Ok(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 0)), "::".parse());

        assert_eq!(Ok(Ipv6Addr::new(0x2a02, 0x6b8, 0, 0, 0, 0, 0x11, 0x11)),
                "2a02:6b8::11:11".parse());

        // too long group
        let none: Option<Ipv6Addr> = "::00000".parse().ok();
        assert_eq!(None, none);
        // too short
        let none: Option<Ipv6Addr> = "1:2:3:4:5:6:7".parse().ok();
        assert_eq!(None, none);
        // too long
        let none: Option<Ipv6Addr> = "1:2:3:4:5:6:7:8:9".parse().ok();
        assert_eq!(None, none);
        // triple colon
        let none: Option<Ipv6Addr> = "1:2:::6:7:8".parse().ok();
        assert_eq!(None, none);
        // two double colons
        let none: Option<Ipv6Addr> = "1:2::6::8".parse().ok();
        assert_eq!(None, none);
    }

    #[test]
    fn test_from_str_ipv4_in_ipv6() {
        assert_eq!(Ok(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 49152, 545)),
                "::192.0.2.33".parse());
        assert_eq!(Ok(Ipv6Addr::new(0, 0, 0, 0, 0, 0xFFFF, 49152, 545)),
                "::FFFF:192.0.2.33".parse());
        assert_eq!(Ok(Ipv6Addr::new(0x64, 0xff9b, 0, 0, 0, 0, 49152, 545)),
                "64:ff9b::192.0.2.33".parse());
        assert_eq!(Ok(Ipv6Addr::new(0x2001, 0xdb8, 0x122, 0xc000, 0x2, 0x2100, 49152, 545)),
                "2001:db8:122:c000:2:2100:192.0.2.33".parse());

        // colon after v4
        let none: Option<Ipv4Addr> = "::127.0.0.1:".parse().ok();
        assert_eq!(None, none);
        // not enough groups
        let none: Option<Ipv6Addr> = "1.2.3.4.5:127.0.0.1".parse().ok();
        assert_eq!(None, none);
        // too many groups
        let none: Option<Ipv6Addr> = "1.2.3.4.5:6:7:127.0.0.1".parse().ok();
        assert_eq!(None, none);
    }

    #[test]
    fn test_from_str_socket_addr() {
        assert_eq!(Ok(sa4(Ipv4Addr::new(77, 88, 21, 11), 80)),
                   "77.88.21.11:80".parse());
        assert_eq!(Ok(sa6(Ipv6Addr::new(0x2a02, 0x6b8, 0, 1, 0, 0, 0, 1), 53)),
                   "[2a02:6b8:0:1::1]:53".parse());
        assert_eq!(Ok(sa6(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0x7F00, 1), 22)),
                   "[::127.0.0.1]:22".parse());

        // without port
        let none: Option<SocketAddr> = "127.0.0.1".parse().ok();
        assert_eq!(None, none);
        // without port
        let none: Option<SocketAddr> = "127.0.0.1:".parse().ok();
        assert_eq!(None, none);
        // wrong brackets around v4
        let none: Option<SocketAddr> = "[127.0.0.1]:22".parse().ok();
        assert_eq!(None, none);
        // port out of range
        let none: Option<SocketAddr> = "127.0.0.1:123456".parse().ok();
        assert_eq!(None, none);
    }

    #[test]
    fn ipv6_addr_to_string() {
        // ipv4-mapped address
        let a1 = Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0xc000, 0x280);
        assert_eq!(a1.to_string(), "::ffff:192.0.2.128");

        // ipv4-compatible address
        let a1 = Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0xc000, 0x280);
        assert_eq!(a1.to_string(), "::192.0.2.128");

        // v6 address with no zero segments
        assert_eq!(Ipv6Addr::new(8, 9, 10, 11, 12, 13, 14, 15).to_string(),
                   "8:9:a:b:c:d:e:f");

        // reduce a single run of zeros
        assert_eq!("ae::ffff:102:304",
                   Ipv6Addr::new(0xae, 0, 0, 0, 0, 0xffff, 0x0102, 0x0304).to_string());

        // don't reduce just a single zero segment
        assert_eq!("1:2:3:4:5:6:0:8",
                   Ipv6Addr::new(1, 2, 3, 4, 5, 6, 0, 8).to_string());

        // 'any' address
        assert_eq!("::", Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 0).to_string());

        // loopback address
        assert_eq!("::1", Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1).to_string());

        // ends in zeros
        assert_eq!("1::", Ipv6Addr::new(1, 0, 0, 0, 0, 0, 0, 0).to_string());

        // two runs of zeros, second one is longer
        assert_eq!("1:0:0:4::8", Ipv6Addr::new(1, 0, 0, 4, 0, 0, 0, 8).to_string());

        // two runs of zeros, equal length
        assert_eq!("1::4:5:0:0:8", Ipv6Addr::new(1, 0, 0, 4, 5, 0, 0, 8).to_string());
    }

    #[test]
    fn ipv4_to_ipv6() {
        assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0x1234, 0x5678),
                   Ipv4Addr::new(0x12, 0x34, 0x56, 0x78).to_ipv6_mapped());
        assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0x1234, 0x5678),
                   Ipv4Addr::new(0x12, 0x34, 0x56, 0x78).to_ipv6_compatible());
    }

    #[test]
    fn ipv6_to_ipv4() {
        assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0x1234, 0x5678).to_ipv4(),
                   Some(Ipv4Addr::new(0x12, 0x34, 0x56, 0x78)));
        assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0x1234, 0x5678).to_ipv4(),
                   Some(Ipv4Addr::new(0x12, 0x34, 0x56, 0x78)));
        assert_eq!(Ipv6Addr::new(0, 0, 1, 0, 0, 0, 0x1234, 0x5678).to_ipv4(),
                   None);
    }

    #[test]
    fn ipv4_properties() {
        fn check(octets: &[u8; 4], unspec: bool, loopback: bool,
                 private: bool, link_local: bool, global: bool,
                 multicast: bool) {
            let ip = Ipv4Addr::new(octets[0], octets[1], octets[2], octets[3]);
            assert_eq!(octets, &ip.octets());

            assert_eq!(ip.is_unspecified(), unspec);
            assert_eq!(ip.is_loopback(), loopback);
            assert_eq!(ip.is_private(), private);
            assert_eq!(ip.is_link_local(), link_local);
            assert_eq!(ip.is_global(), global);
            assert_eq!(ip.is_multicast(), multicast);
        }

        //    address                unspec loopbk privt  linloc global multicast
        check(&[0, 0, 0, 0],         true,  false, false, false, true,  false);
        check(&[0, 0, 0, 1],         false, false, false, false, true,  false);
        check(&[1, 0, 0, 0],         false, false, false, false, true,  false);
        check(&[10, 9, 8, 7],        false, false, true,  false, false, false);
        check(&[127, 1, 2, 3],       false, true,  false, false, false, false);
        check(&[172, 31, 254, 253],  false, false, true,  false, false,  false);
        check(&[169, 254, 253, 242], false, false, false, true,  false, false);
        check(&[192, 168, 254, 253], false, false, true,  false, false, false);
        check(&[224, 0, 0, 0],       false, false, false, false, true,  true);
        check(&[239, 255, 255, 255], false, false, false, false, true,  true);
        check(&[255, 255, 255, 255], false, false, false, false, true,  false);
    }

    #[test]
    fn ipv6_properties() {
        fn check(str_addr: &str, unspec: bool, loopback: bool,
                 unique_local: bool, global: bool,
                 u_link_local: bool, u_site_local: bool, u_global: bool,
                 m_scope: Option<Ipv6MulticastScope>) {
            let ip: Ipv6Addr = str_addr.parse().unwrap();
            assert_eq!(str_addr, ip.to_string());

            assert_eq!(ip.is_unspecified(), unspec);
            assert_eq!(ip.is_loopback(), loopback);
            assert_eq!(ip.is_unique_local(), unique_local);
            assert_eq!(ip.is_global(), global);
            assert_eq!(ip.is_unicast_link_local(), u_link_local);
            assert_eq!(ip.is_unicast_site_local(), u_site_local);
            assert_eq!(ip.is_unicast_global(), u_global);
            assert_eq!(ip.multicast_scope(), m_scope);
            assert_eq!(ip.is_multicast(), m_scope.is_some());
        }

        //    unspec loopbk uniqlo global unill  unisl  uniglo mscope
        check("::",
              true,  false, false, true,  false, false, true,  None);
        check("::1",
              false, true,  false, false, false, false, false, None);
        check("::0.0.0.2",
              false, false, false, true,  false, false, true,  None);
        check("1::",
              false, false, false, true,  false, false, true,  None);
        check("fc00::",
              false, false, true,  false, false, false, false, None);
        check("fdff:ffff::",
              false, false, true,  false, false, false, false, None);
        check("fe80:ffff::",
              false, false, false, false, true,  false, false, None);
        check("febf:ffff::",
              false, false, false, false, true,  false, false, None);
        check("fec0::",
              false, false, false, false, false, true,  false, None);
        check("ff01::",
              false, false, false, false, false, false, false, Some(InterfaceLocal));
        check("ff02::",
              false, false, false, false, false, false, false, Some(LinkLocal));
        check("ff03::",
              false, false, false, false, false, false, false, Some(RealmLocal));
        check("ff04::",
              false, false, false, false, false, false, false, Some(AdminLocal));
        check("ff05::",
              false, false, false, false, false, false, false, Some(SiteLocal));
        check("ff08::",
              false, false, false, false, false, false, false, Some(OrganizationLocal));
        check("ff0e::",
              false, false, false, true,  false, false, false, Some(Global));
    }

    fn tsa<A: ToSocketAddrs>(a: A) -> Result<Vec<SocketAddr>, String> {
        match a.to_socket_addrs() {
            Ok(a) => Ok(a.collect()),
            Err(e) => Err(e.to_string()),
        }
    }

    #[test]
    fn to_socket_addr_socketaddr() {
        let a = sa4(Ipv4Addr::new(77, 88, 21, 11), 12345);
        assert_eq!(Ok(vec![a]), tsa(a));
    }

    fn sa4(a: Ipv4Addr, p: u16) -> SocketAddr {
        SocketAddr::V4(SocketAddrV4::new(a, p))
    }

    fn sa6(a: Ipv6Addr, p: u16) -> SocketAddr {
        SocketAddr::V6(SocketAddrV6::new(a, p, 0, 0))
    }

    #[test]
    fn to_socket_addr_ipaddr_u16() {
        let a = Ipv4Addr::new(77, 88, 21, 11);
        let p = 12345;
        let e = SocketAddr::V4(SocketAddrV4::new(a, p));
        assert_eq!(Ok(vec![e]), tsa((a, p)));
    }

    #[test]
    fn to_socket_addr_str_u16() {
        let a = sa4(Ipv4Addr::new(77, 88, 21, 11), 24352);
        assert_eq!(Ok(vec![a]), tsa(("77.88.21.11", 24352)));

        let a = sa6(Ipv6Addr::new(0x2a02, 0x6b8, 0, 1, 0, 0, 0, 1), 53);
        assert_eq!(Ok(vec![a]), tsa(("2a02:6b8:0:1::1", 53)));

        let a = sa4(Ipv4Addr::new(127, 0, 0, 1), 23924);
        assert!(tsa(("localhost", 23924)).unwrap().contains(&a));
    }

    #[test]
    fn to_socket_addr_str() {
        let a = sa4(Ipv4Addr::new(77, 88, 21, 11), 24352);
        assert_eq!(Ok(vec![a]), tsa("77.88.21.11:24352"));

        let a = sa6(Ipv6Addr::new(0x2a02, 0x6b8, 0, 1, 0, 0, 0, 1), 53);
        assert_eq!(Ok(vec![a]), tsa("[2a02:6b8:0:1::1]:53"));

        let a = sa4(Ipv4Addr::new(127, 0, 0, 1), 23924);
        assert!(tsa("localhost:23924").unwrap().contains(&a));
    }

    #[test]
    #[cfg(not(windows))]
    fn to_socket_addr_str_bad() {
        assert!(tsa("1200::AB00:1234::2552:7777:1313:34300").is_err());
    }
}
