Skip to content

Add Ipv6Addr::is_ipv4_mapped #86490

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 1 commit into from
Closed

Add Ipv6Addr::is_ipv4_mapped #86490

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
22 changes: 22 additions & 0 deletions library/std/src/net/ip.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1468,6 +1468,28 @@ impl Ipv6Addr {
(self.segments()[0] & 0xff00) == 0xff00
}

/// Returns [`true`] if the address is an IPv4-mapped address (`::ffff:0:0/96`).
///
/// IPv4-mapped addresses can be converted to their canonical IPv4 address with [`to_ipv4`](Ipv6Addr::to_ipv4).
///
/// # Examples
/// ```
/// #![feature(ip)]
///
/// use std::net::{Ipv4Addr, Ipv6Addr};
///
/// let ipv4_mapped = Ipv4Addr::new(192, 0, 2, 255).to_ipv6_mapped();
/// assert_eq!(ipv4_mapped.is_ipv4_mapped(), true);
/// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0xc000, 0x2ff).is_ipv4_mapped(), true);
///
/// assert_eq!(Ipv6Addr::new(0x2001, 0xdb8, 0, 0, 0, 0, 0, 0).is_ipv4_mapped(), false);
/// ```
#[unstable(feature = "ip", issue = "27709")]
#[inline]
pub const fn is_ipv4_mapped(&self) -> bool {
matches!(self.segments(), [0, 0, 0, 0, 0, 0xffff, _, _])
}

/// 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`].
///
Expand Down
74 changes: 45 additions & 29 deletions library/std/src/net/ip/tests.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -475,27 +475,28 @@ fn ipv6_properties() {
assert_eq!(&ip!($s).octets(), octets);
assert_eq!(Ipv6Addr::from(*octets), ip!($s));

let unspecified: u16 = 1 << 0;
let loopback: u16 = 1 << 1;
let unique_local: u16 = 1 << 2;
let global: u16 = 1 << 3;
let unicast_link_local: u16 = 1 << 4;
let unicast_global: u16 = 1 << 7;
let documentation: u16 = 1 << 8;
let multicast_interface_local: u16 = 1 << 9;
let multicast_link_local: u16 = 1 << 10;
let multicast_realm_local: u16 = 1 << 11;
let multicast_admin_local: u16 = 1 << 12;
let multicast_site_local: u16 = 1 << 13;
let multicast_organization_local: u16 = 1 << 14;
let multicast_global: u16 = 1 << 15;
let multicast: u16 = multicast_interface_local
let unspecified: u32 = 1 << 0;
let loopback: u32 = 1 << 1;
let unique_local: u32 = 1 << 2;
let global: u32 = 1 << 3;
let unicast_link_local: u32 = 1 << 4;
let unicast_global: u32 = 1 << 7;
let documentation: u32 = 1 << 8;
let multicast_interface_local: u32 = 1 << 9;
let multicast_link_local: u32 = 1 << 10;
let multicast_realm_local: u32 = 1 << 11;
let multicast_admin_local: u32 = 1 << 12;
let multicast_site_local: u32 = 1 << 13;
let multicast_organization_local: u32 = 1 << 14;
let multicast_global: u32 = 1 << 15;
let multicast: u32 = multicast_interface_local
| multicast_admin_local
| multicast_global
| multicast_link_local
| multicast_realm_local
| multicast_site_local
| multicast_organization_local;
let ipv4_mapped = 1 << 17;
Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I assigned ipv4_mapped to 1 << 17, as I already assigned 1 << 16 to benchmarking in the related PR #86434. (the actual values don't really matter, only that they are distinct)


if ($mask & unspecified) == unspecified {
assert!(ip!($s).is_unspecified());
Expand Down Expand Up @@ -567,23 +568,29 @@ fn ipv6_properties() {
assert_eq!(ip!($s).multicast_scope().unwrap(),
Ipv6MulticastScope::Global);
}
if ($mask & ipv4_mapped) == ipv4_mapped {
assert!(ip!($s).is_ipv4_mapped());
} else {
assert!(!ip!($s).is_ipv4_mapped());
}
}
}

let unspecified: u16 = 1 << 0;
let loopback: u16 = 1 << 1;
let unique_local: u16 = 1 << 2;
let global: u16 = 1 << 3;
let unicast_link_local: u16 = 1 << 4;
let unicast_global: u16 = 1 << 7;
let documentation: u16 = 1 << 8;
let multicast_interface_local: u16 = 1 << 9;
let multicast_link_local: u16 = 1 << 10;
let multicast_realm_local: u16 = 1 << 11;
let multicast_admin_local: u16 = 1 << 12;
let multicast_site_local: u16 = 1 << 13;
let multicast_organization_local: u16 = 1 << 14;
let multicast_global: u16 = 1 << 15;
let unspecified: u32 = 1 << 0;
let loopback: u32 = 1 << 1;
let unique_local: u32 = 1 << 2;
let global: u32 = 1 << 3;
let unicast_link_local: u32 = 1 << 4;
let unicast_global: u32 = 1 << 7;
let documentation: u32 = 1 << 8;
let multicast_interface_local: u32 = 1 << 9;
let multicast_link_local: u32 = 1 << 10;
let multicast_realm_local: u32 = 1 << 11;
let multicast_admin_local: u32 = 1 << 12;
let multicast_site_local: u32 = 1 << 13;
let multicast_organization_local: u32 = 1 << 14;
let multicast_global: u32 = 1 << 15;
let ipv4_mapped: u32 = 1 << 17;

check!("::", &[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], unspecified);

Expand All @@ -593,6 +600,12 @@ fn ipv6_properties() {

check!("1::", &[0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], global | unicast_global);

check!(
"::ffff:127.0.0.1",
&[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff, 0x7f, 0, 0, 1],
global | unicast_global | ipv4_mapped
Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

According to the IANA IPv6 Special Address Registry IPv4-mapped addresses are not globally reachable. However due to the current simplistic implementation of Ipv6Addr::is_global compared to Ipv4Addr::is_global, Rust currently considers these addresses global. I plan to address this in a future PR reworking is_global.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

The rework of Ipv6Addr::is_global has been submitted (#86634).

);

check!("fc00::", &[0xfc, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], unique_local);

check!(
Expand Down Expand Up @@ -894,6 +907,9 @@ fn ipv6_const() {
const IS_MULTICAST: bool = IP_ADDRESS.is_multicast();
assert!(!IS_MULTICAST);

const IS_IPV4_MAPPED: bool = IP_ADDRESS.is_ipv4_mapped();
assert!(!IS_IPV4_MAPPED);

const IP_V4: Option<Ipv4Addr> = IP_ADDRESS.to_ipv4();
assert_eq!(IP_V4.unwrap(), Ipv4Addr::new(0, 0, 0, 1));
}
Expand Down