Initial commit after restructure

network/netutils/ip.go

@@ -0,0 +1,98 @@
+// Copyright Safing ICS Technologies GmbH. Use of this source code is governed by the AGPL license that can be found in the LICENSE file.
+
+package netutils
+
+import "net"
+
+// IP types
+const (
+	hostLocal int8 = iota
+	linkLocal
+	siteLocal
+	global
+	localMulticast
+	globalMulticast
+	invalid
+)
+
+func classifyAddress(ip net.IP) int8 {
+	if ip4 := ip.To4(); ip4 != nil {
+		// IPv4
+		switch {
+		case ip4[0] == 127:
+			// 127.0.0.0/8
+			return hostLocal
+		case ip4[0] == 169 && ip4[1] == 254:
+			// 169.254.0.0/16
+			return linkLocal
+		case ip4[0] == 10:
+			// 10.0.0.0/8
+			return siteLocal
+		case ip4[0] == 172 && ip4[1]&0xf0 == 16:
+			// 172.16.0.0/12
+			return siteLocal
+		case ip4[0] == 192 && ip4[1] == 168:
+			// 192.168.0.0/16
+			return siteLocal
+		case ip4[0] == 224:
+			// 224.0.0.0/8
+			return localMulticast
+		case ip4[0] >= 225 && ip4[0] <= 239:
+			// 225.0.0.0/8 - 239.0.0.0/8
+			return globalMulticast
+		case ip4[0] >= 240:
+			// 240.0.0.0/8 - 255.0.0.0/8
+			return invalid
+		default:
+			return global
+		}
+	} else if len(ip) == net.IPv6len {
+		// IPv6
+		switch {
+		case ip.Equal(net.IPv6loopback):
+			return hostLocal
+		case ip[0]&0xfe == 0xfc:
+			// fc00::/7
+			return siteLocal
+		case ip[0] == 0xfe && ip[1]&0xc0 == 0x80:
+			// fe80::/10
+			return linkLocal
+		case ip[0] == 0xff && ip[1] <= 0x05:
+			// ff00::/16 - ff05::/16
+			return localMulticast
+		case ip[0] == 0xff:
+			// other ff00::/8
+			return globalMulticast
+		default:
+			return global
+		}
+	}
+	return invalid
+}
+
+// IPIsLocal returns true if the given IP is a site-local or link-local address
+func IPIsLocal(ip net.IP) bool {
+	switch classifyAddress(ip) {
+	case siteLocal:
+		return true
+	case linkLocal:
+		return true
+	default:
+		return false
+	}
+}
+
+// IPIsGlobal returns true if the given IP is a global address
+func IPIsGlobal(ip net.IP) bool {
+	return classifyAddress(ip) == global
+}
+
+// IPIsLinkLocal returns true if the given IP is a link-local address
+func IPIsLinkLocal(ip net.IP) bool {
+	return classifyAddress(ip) == linkLocal
+}
+
+// IPIsSiteLocal returns true if the given IP is a site-local address
+func IPIsSiteLocal(ip net.IP) bool {
+	return classifyAddress(ip) == siteLocal
+}