v1.16.9

ADDED: * netx.IsPub * encodingx/hexx Rest are mostly small corrections and docs
2026-06-22 18:51:13 -04:00
parent c6fc692f5e
commit 58556d7281
35 changed files with 5492 additions and 2486 deletions
@@ -455,6 +455,82 @@ func IsPrefixNet(s string) (isNet bool) {
 	return
 }

+/*
+IsPublic returns true if ALL of the following conditions are *true* for ip:
+
+	* [net/netip.Addr.IsGlobalUnicast]
+	* [net/netip.Addr.IsValid]
+	* (IPv4) Is not in 192.0.2.0/24, 198.51.100.0/24, or 203.0.113.0/24 ([RFC 5737])
+	* (IPv6) Is not in 2001:db8::/32 or 3fff::/20 ([RFC 3849], [RFC 9637])
+
+AND ALL of the following conditions are *false* for ip:
+
+	* [net/netip.Addr.IsLinkLocalMulticast]
+	* [net/netip.Addr.IsInterfaceLocalMulticast]
+	* [net/netip.Addr.IsLinkLocalUnicast]
+	* [net/netip.Addr.IsMulticast]
+	* [net/netip.Addr.IsLoopback]
+	* [net/netip.Addr.IsPrivate]
+	* [net/netip.Addr.IsUnspecified]
+
+4-in-6 addresses (::0:0/96, "IPv4-Compatible IPv6 Address" [RFC 4291 § 2.5.5.1] (Legacy/Obsolete);
+::ffff:0:0/96, "IPv4-Mapped IPv6" [RFC 4291 § 2.5.5.2]) will be internally
+"unwrapped" back to native IPv4 before performing conditional checks.
+
+[RFC 5737]: https://datatracker.ietf.org/doc/html/rfc5737
+[RFC 4291 § 2.5.5.1]: https://datatracker.ietf.org/doc/html/rfc4291#section-2.5.5.1
+[RFC 4291 § 2.5.5.2]: https://datatracker.ietf.org/doc/html/rfc4291#section-2.5.5.2
+[RFC 3849]: https://datatracker.ietf.org/doc/html/rfc3849
+[RFC 9637]: https://datatracker.ietf.org/doc/html/rfc9637
+*/
+func IsPublic(ip netip.Addr) (isPub bool) {
+
+	var err error
+	var v bool
+	var addr netip.Addr
+
+	// Clone to avoid modification to the passed in value.
+	if addr, err = netip.ParseAddr(ip.String()); err != nil {
+		return
+	}
+	addr = addr.Unmap()
+
+	// Short-circuit on invalid first to avoid any possible logic oddness.
+	if !addr.IsValid() {
+		return
+	}
+	// Following must be FALSE
+	for _, v = range []bool{
+		addr.IsLinkLocalMulticast(),
+		addr.IsInterfaceLocalMulticast(),
+		addr.IsLinkLocalUnicast(),
+		addr.IsMulticast(),
+		addr.IsLoopback(),
+		addr.IsPrivate(),
+		addr.IsUnspecified(),
+		// these are in the FALSE to keep syntax pattern but it's cleaner to doc as if it's a !<cond> in TRUE.
+		ip4In6Legacy.Contains(ip),
+		ip4In6Modern.Contains(ip),
+	} {
+		if v {
+			return
+		}
+	}
+	// Following must be TRUE
+	for _, v = range []bool{
+		addr.IsGlobalUnicast(),
+	} {
+		if !v {
+			return
+		}
+	}
+
+	// All conditions pass
+	isPub = true
+
+	return
+}
+
 /*
 Mask4ToCidr converts an IPv4 netmask *in bitmask form* to a CIDR prefix size/bit size/bit length.