From f7d8805a47f9b670403b43f056a96d3d4cc4fdc6 Mon Sep 17 00:00:00 2001 From: Christiaan Dirkx Date: Fri, 25 Jun 2021 14:35:51 +0200 Subject: [PATCH] Fix `Ipv6Addr::is_global` to check for global reachability rather than global scope --- library/std/src/net/ip.rs | 91 ++++++++++++++++++++++++----- library/std/src/net/ip/tests.rs | 100 ++++++++++++++++++++++++++++---- 2 files changed, 166 insertions(+), 25 deletions(-) diff --git a/library/std/src/net/ip.rs b/library/std/src/net/ip.rs index 438bae01b60..0b141efbc18 100644 --- a/library/std/src/net/ip.rs +++ b/library/std/src/net/ip.rs @@ -1349,13 +1349,33 @@ impl Ipv6Addr { u128::from_be_bytes(self.octets()) == u128::from_be_bytes(Ipv6Addr::LOCALHOST.octets()) } - /// Returns [`true`] if the address appears to be globally routable. + /// Returns [`true`] if the address appears to be globally reachable + /// as specified by the [IANA IPv6 Special-Purpose Address Registry]. + /// Whether or not an address is practically reachable will depend on your network configuration. /// - /// The following return [`false`]: + /// Most IPv6 addresses are globally reachable; + /// unless they are specifically defined as *not* globally reachable. /// - /// - the loopback address - /// - link-local and unique local unicast addresses - /// - interface-, link-, realm-, admin- and site-local multicast addresses + /// Non-exhaustive list of notable addresses that are not globally reachable: + /// - The [unspecified address] ([`is_unspecified`](Ipv6Addr::is_unspecified)) + /// - The [loopback address] ([`is_loopback`](Ipv6Addr::is_loopback)) + /// - IPv4-mapped addresses + /// - Addresses reserved for benchmarking + /// - Addresses reserved for documentation ([`is_documentation`](Ipv6Addr::is_documentation)) + /// - Unique local addresses ([`is_unique_local`](Ipv6Addr::is_unique_local)) + /// - Unicast addresses with link-local scope ([`is_unicast_link_local`](Ipv6Addr::is_unicast_link_local)) + /// + /// For the complete overview of which addresses are globally reachable, see the table at the [IANA IPv6 Special-Purpose Address Registry]. + /// + /// Note that an address having global scope is not the same as being globally reachable, + /// and there is no direct relation between the two concepts: There exist addresses with global scope + /// that are not globally reachable (for example unique local addresses), + /// and addresses that are globally reachable without having global scope + /// (multicast addresses with non-global scope). + /// + /// [IANA IPv6 Special-Purpose Address Registry]: https://www.iana.org/assignments/iana-ipv6-special-registry/iana-ipv6-special-registry.xhtml + /// [unspecified address]: Ipv6Addr::UNSPECIFIED + /// [loopback address]: Ipv6Addr::LOCALHOST /// /// # Examples /// @@ -1364,20 +1384,65 @@ impl Ipv6Addr { /// /// use std::net::Ipv6Addr; /// - /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0xc00a, 0x2ff).is_global(), true); - /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 0x1).is_global(), false); - /// assert_eq!(Ipv6Addr::new(0, 0, 0x1c9, 0, 0, 0xafc8, 0, 0x1).is_global(), true); + /// // Most IPv6 addresses are globally reachable: + /// assert_eq!(Ipv6Addr::new(0x26, 0, 0x1c9, 0, 0, 0xafc8, 0x10, 0x1).is_global(), true); + /// + /// // However some addresses have been assigned a special meaning + /// // that makes them not globally reachable. Some examples are: + /// + /// // The unspecified address (`::`) + /// assert_eq!(Ipv6Addr::UNSPECIFIED.is_global(), false); + /// + /// // The loopback address (`::1`) + /// assert_eq!(Ipv6Addr::LOCALHOST.is_global(), false); + /// + /// // IPv4-mapped addresses (`::ffff:0:0/96`) + /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0xc00a, 0x2ff).is_global(), false); + /// + /// // Addresses reserved for benchmarking (`2001:2::/48`) + /// assert_eq!(Ipv6Addr::new(0x2001, 2, 0, 0, 0, 0, 0, 1,).is_global(), false); + /// + /// // Addresses reserved for documentation (`2001:db8::/32`) + /// assert_eq!(Ipv6Addr::new(0x2001, 0xdb8, 0, 0, 0, 0, 0, 1).is_global(), false); + /// + /// // Unique local addresses (`fc00::/7`) + /// assert_eq!(Ipv6Addr::new(0xfc02, 0, 0, 0, 0, 0, 0, 1).is_global(), false); + /// + /// // Unicast addresses with link-local scope (`fe80::/10`) + /// assert_eq!(Ipv6Addr::new(0xfe81, 0, 0, 0, 0, 0, 0, 1).is_global(), false); + /// + /// // For a complete overview see the IANA IPv6 Special-Purpose Address Registry. /// ``` #[rustc_const_unstable(feature = "const_ipv6", issue = "76205")] #[unstable(feature = "ip", issue = "27709")] #[must_use] #[inline] pub const fn is_global(&self) -> bool { - match self.multicast_scope() { - Some(Ipv6MulticastScope::Global) => true, - None => self.is_unicast_global(), - _ => false, - } + !(self.is_unspecified() + || self.is_loopback() + // IPv4-mapped Address (`::ffff:0:0/96`) + || matches!(self.segments(), [0, 0, 0, 0, 0, 0xffff, _, _]) + // IPv4-IPv6 Translat. (`64:ff9b:1::/48`) + || matches!(self.segments(), [0x64, 0xff9b, 1, _, _, _, _, _]) + // Discard-Only Address Block (`100::/64`) + || matches!(self.segments(), [0x100, 0, 0, 0, _, _, _, _]) + // IETF Protocol Assignments (`2001::/23`) + || (matches!(self.segments(), [0x2001, b, _, _, _, _, _, _] if b < 0x200) + && !( + // Port Control Protocol Anycast (`2001:1::1`) + u128::from_be_bytes(self.octets()) == 0x2001_0001_0000_0000_0000_0000_0000_0001 + // Traversal Using Relays around NAT Anycast (`2001:1::2`) + || u128::from_be_bytes(self.octets()) == 0x2001_0001_0000_0000_0000_0000_0000_0002 + // AMT (`2001:3::/32`) + || matches!(self.segments(), [0x2001, 3, _, _, _, _, _, _]) + // AS112-v6 (`2001:4:112::/48`) + || matches!(self.segments(), [0x2001, 4, 0x112, _, _, _, _, _]) + // ORCHIDv2 (`2001:20::/28`) + || matches!(self.segments(), [0x2001, b, _, _, _, _, _, _] if b >= 0x20 && b <= 0x2F) + )) + || self.is_documentation() + || self.is_unique_local() + || self.is_unicast_link_local()) } /// Returns [`true`] if this is a unique local address (`fc00::/7`). diff --git a/library/std/src/net/ip/tests.rs b/library/std/src/net/ip/tests.rs index 7956c6a25e4..0311efa8625 100644 --- a/library/std/src/net/ip/tests.rs +++ b/library/std/src/net/ip/tests.rs @@ -321,12 +321,12 @@ fn ip_properties() { check!("fe80:ffff::"); check!("febf:ffff::"); check!("fec0::", global); - check!("ff01::", multicast); - check!("ff02::", multicast); - check!("ff03::", multicast); - check!("ff04::", multicast); - check!("ff05::", multicast); - check!("ff08::", multicast); + check!("ff01::", global | multicast); + check!("ff02::", global | multicast); + check!("ff03::", global | multicast); + check!("ff04::", global | multicast); + check!("ff05::", global | multicast); + check!("ff08::", global | multicast); check!("ff0e::", global | multicast); check!("2001:db8:85a3::8a2e:370:7334", doc); check!("2001:2::ac32:23ff:21", global | benchmarking); @@ -609,6 +609,60 @@ 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], + unicast_global + ); + + check!( + "64:ff9b:1::", + &[0, 0x64, 0xff, 0x9b, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], + unicast_global + ); + + check!("100::", &[0x01, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], unicast_global); + + check!("2001::", &[0x20, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], unicast_global); + + check!( + "2001:1::1", + &[0x20, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1], + global | unicast_global + ); + + check!( + "2001:1::2", + &[0x20, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2], + global | unicast_global + ); + + check!( + "2001:3::", + &[0x20, 1, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], + global | unicast_global + ); + + check!( + "2001:4:112::", + &[0x20, 1, 0, 4, 1, 0x12, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], + global | unicast_global + ); + + check!( + "2001:20::", + &[0x20, 1, 0, 0x20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], + global | unicast_global + ); + + check!("2001:30::", &[0x20, 1, 0, 0x30, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], unicast_global); + + check!( + "2001:200::", + &[0x20, 1, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], + global | unicast_global + ); + check!("fc00::", &[0xfc, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], unique_local); check!( @@ -666,21 +720,37 @@ fn ipv6_properties() { check!( "ff01::", &[0xff, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], - multicast_interface_local + multicast_interface_local | global ); - check!("ff02::", &[0xff, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], multicast_link_local); + check!( + "ff02::", + &[0xff, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], + multicast_link_local | global + ); - check!("ff03::", &[0xff, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], multicast_realm_local); + check!( + "ff03::", + &[0xff, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], + multicast_realm_local | global + ); - check!("ff04::", &[0xff, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], multicast_admin_local); + check!( + "ff04::", + &[0xff, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], + multicast_admin_local | global + ); - check!("ff05::", &[0xff, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], multicast_site_local); + check!( + "ff05::", + &[0xff, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], + multicast_site_local | global + ); check!( "ff08::", &[0xff, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], - multicast_organization_local + multicast_organization_local | global ); check!( @@ -689,6 +759,12 @@ fn ipv6_properties() { multicast_global | global ); + check!( + "2001:2::ac32:23ff:21", + &[0x20, 1, 0, 2, 0, 0, 0, 0, 0, 0, 0xac, 0x32, 0x23, 0xff, 0, 0x21], + unicast_global + ); + check!( "2001:db8:85a3::8a2e:370:7334", &[0x20, 1, 0xd, 0xb8, 0x85, 0xa3, 0, 0, 0, 0, 0x8a, 0x2e, 3, 0x70, 0x73, 0x34],