(self.segments()[0] & 0xff00) == 0xff00
}
+ /// Converts this address to an [IPv4 address] if it's an "IPv4-mapped IPv6 address"
+ /// defined in [IETF RFC 4291 section 2.5.5.2], otherwise returns [`None`].
+ ///
+ /// `::ffff:a.b.c.d` becomes `a.b.c.d`.
+ /// All addresses *not* starting with `::ffff` will return `None`.
+ ///
+ /// [IPv4 address]: ../../std/net/struct.Ipv4Addr.html
+ /// [`None`]: ../../std/option/enum.Option.html#variant.None
+ /// [IETF RFC 4291 section 2.5.5.2]: https://tools.ietf.org/html/rfc4291#section-2.5.5.2
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// #![feature(ip)]
+ ///
+ /// use std::net::{Ipv4Addr, Ipv6Addr};
+ ///
+ /// assert_eq!(Ipv6Addr::new(0xff00, 0, 0, 0, 0, 0, 0, 0).to_ipv4_mapped(), None);
+ /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0xc00a, 0x2ff).to_ipv4_mapped(),
+ /// Some(Ipv4Addr::new(192, 10, 2, 255)));
+ /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1).to_ipv4_mapped(), None);
+ /// ```
+ pub fn to_ipv4_mapped(&self) -> Option<Ipv4Addr> {
+ match self.octets() {
+ [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff, a, b, c, d] => {
+ Some(Ipv4Addr::new(a, b, c, d))
+ }
+ _ => None,
+ }
+ }
+
/// Converts this address to an [IPv4 address]. Returns [`None`] if this address is
/// neither IPv4-compatible or IPv4-mapped.
///
);
}
+ #[test]
+ fn ipv6_to_ipv4_mapped() {
+ assert_eq!(
+ Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0x1234, 0x5678).to_ipv4_mapped(),
+ Some(Ipv4Addr::new(0x12, 0x34, 0x56, 0x78))
+ );
+ assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0x1234, 0x5678).to_ipv4_mapped(), None);
+ }
+
#[test]
fn ipv6_to_ipv4() {
assert_eq!(