Make is_global/is_unicast_global special address handling complete

IANA explicitly documents 192.0.0.9/32, 192.0.0.9/32 and 2001:30::/28 as
globally reachable[1][2] and the is_global implementations declare
following IANA so let's make this happen.

In case of 2002::/16 IANA says N/A so I think it's safe to say we
shouldn't return true from is_global and is_unicast_global either for
addresses in that block.

[1] https://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml
[2] https://www.iana.org/assignments/iana-ipv6-special-registry/iana-ipv6-special-registry.xhtml

Author: jstasiak

library/core/src/net/ip_addr.rs

@@ -771,7 +771,11 @@ impl Ipv4Addr {
             || self.is_loopback()
             || self.is_link_local()
             // addresses reserved for future protocols (`192.0.0.0/24`)
-            ||(self.octets()[0] == 192 && self.octets()[1] == 0 && self.octets()[2] == 0)
+            // .9 and .10 are documented as globally reachable so they're excluded
+            || (
+                self.octets()[0] == 192 && self.octets()[1] == 0 && self.octets()[2] == 0
+                && self.octets()[3] != 9 && self.octets()[3] != 10
+            )
             || self.is_documentation()
             || self.is_benchmarking()
             || self.is_reserved()
@@ -1515,8 +1519,12 @@ impl Ipv6Addr {
                     // 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)
+                    // Drone Remote ID Protocol Entity Tags (DETs) Prefix (`2001:30::/28`)`
+                    || matches!(self.segments(), [0x2001, b, _, _, _, _, _, _] if b >= 0x20 && b <= 0x3F)
                 ))
+            // 6to4 (`2002::/16`) – it's not explicitly documented as globally reachable,
+            // IANA says N/A.
+            || matches!(self.segments(), [0x2002, _, _, _, _, _, _, _])
             || self.is_documentation()
             || self.is_unique_local()
             || self.is_unicast_link_local())
@@ -1684,6 +1692,7 @@ impl Ipv6Addr {
     /// - unique local addresses
     /// - the unspecified address
     /// - the address range reserved for documentation
+    /// - 6to4 addresses
     ///
     /// This method returns [`true`] for site-local addresses as per [RFC 4291 section 2.5.7]
     ///
@@ -1717,6 +1726,8 @@ impl Ipv6Addr {
             && !self.is_unspecified()
             && !self.is_documentation()
             && !self.is_benchmarking()
+            // 6to4 (`2002::/16`), not documented as globally reachable by IANA
+            && self.segments()[0] != 0x2002
     }
 
     /// Returns the address's multicast scope if the address is multicast.

library/core/tests/net/ip_addr.rs

@@ -461,6 +461,9 @@ fn ipv4_properties() {
     check!("198.18.54.2", benchmarking);
     check!("198.19.255.255", benchmarking);
     check!("192.0.0.0");
+    check!("192.0.0.8");
+    check!("192.0.0.9", global);
+    check!("192.0.0.10", global);
     check!("192.0.0.255");
     check!("192.0.0.100");
     check!("240.0.0.0", reserved);
@@ -480,6 +483,10 @@ fn ipv6_properties() {
     }
 
     macro_rules! check {
+        ($s:expr, &[$($octet:expr),*]) => {
+            check!($s, &[$($octet),*], 0);
+        };
+
         ($s:expr, &[$($octet:expr),*], $mask:expr) => {
             assert_eq!($s, ip!($s).to_string());
             let octets = &[$($octet),*];
@@ -657,14 +664,16 @@ fn ipv6_properties() {
         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!("2001:30::", &[0x20, 1, 0, 0x30, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], global | 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!("2002::", &[0x20, 0x02, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]);
+
     check!("fc00::", &[0xfc, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], unique_local);
 
     check!(