feat: support IPv6 in exclude-private-IPs and DNS routing so dual-stack tunnels can exclude local ranges

tunnel/src/main/java/org/amnezia/awg/config/InetEndpoint.java

@@ -54,13 +54,19 @@ public final class InetEndpoint {
         }
         if (uri.getPort() < 0 || uri.getPort() > 65535)
             throw new ParseException(InetEndpoint.class, endpoint, "Missing/invalid port number");
+        String host = uri.getHost();
+        if (host == null)
+            throw new ParseException(InetEndpoint.class, endpoint, "Missing host");
+        // URI.getHost() wraps IPv6 literals in brackets; strip them so the numeric parser accepts it.
+        if (host.length() > 1 && host.charAt(0) == '[' && host.charAt(host.length() - 1) == ']')
+            host = host.substring(1, host.length() - 1);
         try {
-            InetAddresses.parse(uri.getHost());
+            InetAddresses.parse(host);
             // Parsing ths host as a numeric address worked, so we don't need to do DNS lookups.
-            return new InetEndpoint(uri.getHost(), true, uri.getPort());
+            return new InetEndpoint(host, true, uri.getPort());
         } catch (final ParseException ignored) {
             // Failed to parse the host as a numeric address, so it must be a DNS hostname/FQDN.
-            return new InetEndpoint(uri.getHost(), false, uri.getPort());
+            return new InetEndpoint(host, false, uri.getPort());
         }
     }
 

tunnel/src/test/java/org/amnezia/awg/config/InetEndpointTest.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright © 2017-2023 WireGuard LLC. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.amnezia.awg.config;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+public class InetEndpointTest {
+
+    @Test
+    public void ipv6_literal_is_parsed_as_canonical_numeric_host() throws ParseException {
+        final InetEndpoint endpoint = InetEndpoint.parse("[2001:db8::1]:51820");
+        // URI.getHost() yields the bracketed form; the stored host must be the bare, canonical one.
+        assertEquals("Host is stored without brackets", "2001:db8::1", endpoint.getHost());
+        assertEquals("Port is parsed", 51820, endpoint.getPort());
+        // toString() must re-add brackets so the userspace string is valid for amneziawg-go.
+        assertEquals("toString re-brackets the literal", "[2001:db8::1]:51820", endpoint.toString());
+    }
+
+    @Test
+    public void ipv4_endpoint_is_unchanged() throws ParseException {
+        final InetEndpoint endpoint = InetEndpoint.parse("192.0.2.1:51820");
+        assertEquals("192.0.2.1", endpoint.getHost());
+        assertEquals(51820, endpoint.getPort());
+        assertEquals("192.0.2.1:51820", endpoint.toString());
+    }
+
+    @Test
+    public void hostname_endpoint_is_preserved() throws ParseException {
+        final InetEndpoint endpoint = InetEndpoint.parse("vpn.example.com:51820");
+        assertEquals("vpn.example.com", endpoint.getHost());
+        assertEquals(51820, endpoint.getPort());
+    }
+
+    @Test
+    public void ipv6_endpoint_round_trips_to_userspace_string() throws BadConfigException {
+        final Peer peer = new Peer.Builder()
+                .parsePublicKey("vBN7qyUTb5lJtWYJ8LhbPio1Z4RcyBPGnqFBGn6O6Qg=")
+                .parseEndpoint("[2001:db8::1]:51820")
+                .build();
+        assertTrue(
+                "Userspace string keeps the bracketed IPv6 endpoint",
+                peer.toAwgUserspaceString().contains("endpoint=[2001:db8::1]:51820")
+        );
+    }
+}

ui/src/main/java/org/amnezia/awg/viewmodel/PeerProxy.kt

@@ -63,11 +63,11 @@ class PeerProxy : BaseObservable, Parcelable {
 
     @get:Bindable
     val isAbleToExcludePrivateIps: Boolean
-        get() = allowedIpsState == AllowedIpsState.CONTAINS_IPV4_PUBLIC_NETWORKS || allowedIpsState == AllowedIpsState.CONTAINS_IPV4_WILDCARD
+        get() = allowedIpsState == AllowedIpsState.CONTAINS_PUBLIC_NETWORKS || allowedIpsState == AllowedIpsState.CONTAINS_WILDCARD
 
     @get:Bindable
     val isExcludingPrivateIps: Boolean
-        get() = allowedIpsState == AllowedIpsState.CONTAINS_IPV4_PUBLIC_NETWORKS
+        get() = allowedIpsState == AllowedIpsState.CONTAINS_PUBLIC_NETWORKS
 
     private constructor(parcel: Parcel) {
         allowedIps = parcel.readString() ?: ""
@@ -106,12 +106,11 @@ class PeerProxy : BaseObservable, Parcelable {
             // the above sets of (valid) *networks*. We are not checking for a superset based on
             // the individual addresses in each set.
             val networkStrings: Collection<String> = getAllowedIpsSet()
-            // If allowedIps contains both the wildcard and the public networks, then private
-            // networks aren't excluded!
-            if (networkStrings.containsAll(IPV4_WILDCARD))
-                AllowedIpsState.CONTAINS_IPV4_WILDCARD
-            else if (networkStrings.containsAll(IPV4_PUBLIC_NETWORKS))
-                AllowedIpsState.CONTAINS_IPV4_PUBLIC_NETWORKS
+            // A wildcard in either family means private IPs can still be excluded.
+            if (networkStrings.containsAll(IPV4_WILDCARD) || networkStrings.containsAll(IPV6_WILDCARD))
+                AllowedIpsState.CONTAINS_WILDCARD
+            else if (networkStrings.containsAll(IPV4_PUBLIC_NETWORKS) || networkStrings.containsAll(IPV6_PUBLIC_NETWORKS))
+                AllowedIpsState.CONTAINS_PUBLIC_NETWORKS
             else
                 AllowedIpsState.OTHER
         } else {
@@ -128,31 +127,29 @@ class PeerProxy : BaseObservable, Parcelable {
 
     private fun getAllowedIpsSet() = setOf(*Attribute.split(allowedIps))
 
-    // Replace the first instance of the wildcard with the public network list, or vice versa.
-    // DNS servers only need to handled specially when we're excluding private IPs.
+    // For each family, replace the first instance of the wildcard with its public network list, or vice versa.
     fun setExcludingPrivateIps(excludingPrivateIps: Boolean) {
         if (!isAbleToExcludePrivateIps || isExcludingPrivateIps == excludingPrivateIps) return
-        val oldNetworks = if (excludingPrivateIps) IPV4_WILDCARD else IPV4_PUBLIC_NETWORKS
-        val newNetworks = if (excludingPrivateIps) IPV4_PUBLIC_NETWORKS else IPV4_WILDCARD
+        val replacements = listOf(IPV4_WILDCARD to IPV4_PUBLIC_NETWORKS, IPV6_WILDCARD to IPV6_PUBLIC_NETWORKS)
+            .map { (wildcard, public) -> if (excludingPrivateIps) wildcard to public else public to wildcard }
         val input: Collection<String> = getAllowedIpsSet()
-        val outputSize = input.size - oldNetworks.size + newNetworks.size
-        val output: MutableCollection<String?> = LinkedHashSet(outputSize)
-        var replaced = false
-        // Replace the first instance of the wildcard with the public network list, or vice versa.
+        val output: MutableCollection<String?> = LinkedHashSet(input.size)
+        val replaced = BooleanArray(replacements.size)
         for (network in input) {
-            if (oldNetworks.contains(network)) {
-                if (!replaced) {
-                    for (replacement in newNetworks) if (!output.contains(replacement)) output.add(replacement)
-                    replaced = true
+            val family = replacements.indexOfFirst { it.first.contains(network) }
+            if (family >= 0) {
+                if (!replaced[family]) {
+                    for (replacement in replacements[family].second) if (!output.contains(replacement)) output.add(replacement)
+                    replaced[family] = true
                 }
             } else if (!output.contains(network)) {
                 output.add(network)
             }
         }
-        // DNS servers only need to handled specially when we're excluding private IPs.
+        // DNS servers only need to be handled specially when we're excluding private IPs.
         if (excludingPrivateIps) output.addAll(dnsRoutes) else output.removeAll(dnsRoutes)
         allowedIps = Attribute.join(output)
-        allowedIpsState = if (excludingPrivateIps) AllowedIpsState.CONTAINS_IPV4_PUBLIC_NETWORKS else AllowedIpsState.CONTAINS_IPV4_WILDCARD
+        allowedIpsState = if (excludingPrivateIps) AllowedIpsState.CONTAINS_PUBLIC_NETWORKS else AllowedIpsState.CONTAINS_WILDCARD
         notifyPropertyChanged(BR.allowedIps)
         notifyPropertyChanged(BR.excludingPrivateIps)
     }
@@ -169,8 +166,10 @@ class PeerProxy : BaseObservable, Parcelable {
     }
 
     private fun setInterfaceDns(dnsServers: CharSequence) {
-        val newDnsRoutes = Attribute.split(dnsServers).filter { !it.contains(":") }.map { "$it/32" }
-        if (allowedIpsState == AllowedIpsState.CONTAINS_IPV4_PUBLIC_NETWORKS) {
+        val newDnsRoutes = Attribute.split(dnsServers)
+            .filter { it.contains(":") || it.matches(Regex("""^\d{1,3}(\.\d{1,3}){3}$""")) }
+            .map { if (it.contains(":")) "$it/128" else "$it/32" }
+        if (allowedIpsState == AllowedIpsState.CONTAINS_PUBLIC_NETWORKS) {
             val input = getAllowedIpsSet()
             // Yes, this is quadratic in the number of DNS servers, but most users have 1 or 2.
             val output = input.filter { !dnsRoutes.contains(it) || newDnsRoutes.contains(it) }.plus(newDnsRoutes).distinct()
@@ -209,7 +208,7 @@ class PeerProxy : BaseObservable, Parcelable {
     }
 
     private enum class AllowedIpsState {
-        CONTAINS_IPV4_PUBLIC_NETWORKS, CONTAINS_IPV4_WILDCARD, INVALID, OTHER
+        CONTAINS_PUBLIC_NETWORKS, CONTAINS_WILDCARD, INVALID, OTHER
     }
 
     private class InterfaceDnsListener constructor(peerProxy: PeerProxy) : OnPropertyChangedCallback() {
@@ -290,5 +289,11 @@ class PeerProxy : BaseObservable, Parcelable {
             "193.0.0.0/8", "194.0.0.0/7", "196.0.0.0/6", "200.0.0.0/5", "208.0.0.0/4"
         )
         private val IPV4_WILDCARD = setOf("0.0.0.0/0")
+        // ::/0 minus the private ranges fc00::/7 (unique local) and fe80::/10 (link-local).
+        private val IPV6_PUBLIC_NETWORKS = setOf(
+            "::/1", "8000::/2", "c000::/3", "e000::/4", "f000::/5", "f800::/6",
+            "fe00::/9", "fec0::/10", "ff00::/8"
+        )
+        private val IPV6_WILDCARD = setOf("::/0")
     }
 }