From a75872039401df8bdd14b060da27c0eb151e591a Mon Sep 17 00:00:00 2001
From: Remi NGUYEN VAN <reminv@google.com>
Date: Thu, 23 Aug 2018 18:01:46 +0900
Subject: [PATCH] Add varargs methods to build DhcpServingParams

In common use-cases, only one gateway or DNS server may be set, so the
added methods make it easier for clients to build the parameters.

Bug: b/109584964
Test: runtest --no-hidden-api-checks frameworks-net
Change-Id: Ib54bc60a54ad4ef0605baea62d87b9f14caf8aa7
---
 .../android/net/dhcp/DhcpServingParams.java   | 50 +++++++++++++++++++
 .../net/dhcp/DhcpServingParamsTest.java       |  5 +-
 2 files changed, 52 insertions(+), 3 deletions(-)

diff --git a/services/net/java/android/net/dhcp/DhcpServingParams.java b/services/net/java/android/net/dhcp/DhcpServingParams.java
index ba9d116d0bd51..6d58bc63a5f23 100644
--- a/services/net/java/android/net/dhcp/DhcpServingParams.java
+++ b/services/net/java/android/net/dhcp/DhcpServingParams.java
@@ -28,6 +28,8 @@ import android.net.IpPrefix;
 import android.net.LinkAddress;
 import android.net.NetworkUtils;
 
+import com.google.android.collect.Sets;
+
 import java.net.Inet4Address;
 import java.util.Collections;
 import java.util.HashSet;
@@ -154,6 +156,25 @@ public class DhcpServingParams {
             return this;
         }
 
+        /**
+         * Set the default routers to be advertised to DHCP clients.
+         *
+         * <p>Each router must be inside the served prefix. This may be an empty list of routers,
+         * but it must always be set explicitly before building the {@link DhcpServingParams}.
+         */
+        public Builder setDefaultRouters(@NonNull Inet4Address... defaultRouters) {
+            return setDefaultRouters(Sets.newArraySet(defaultRouters));
+        }
+
+        /**
+         * Convenience method to build the parameters with no default router.
+         *
+         * <p>Equivalent to calling {@link #setDefaultRouters(Inet4Address...)} with no address.
+         */
+        public Builder withNoDefaultRouter() {
+            return setDefaultRouters();
+        }
+
         /**
          * Set the DNS servers to be advertised to DHCP clients.
          *
@@ -165,6 +186,25 @@ public class DhcpServingParams {
             return this;
         }
 
+        /**
+         * Set the DNS servers to be advertised to DHCP clients.
+         *
+         * <p>This may be an empty list of servers, but it must always be set explicitly before
+         * building the {@link DhcpServingParams}.
+         */
+        public Builder setDnsServers(@NonNull Inet4Address... dnsServers) {
+            return setDnsServers(Sets.newArraySet(dnsServers));
+        }
+
+        /**
+         * Convenience method to build the parameters with no DNS server.
+         *
+         * <p>Equivalent to calling {@link #setDnsServers(Inet4Address...)} with no address.
+         */
+        public Builder withNoDnsServer() {
+            return setDnsServers();
+        }
+
         /**
          * Set excluded addresses that the DHCP server is not allowed to assign to clients.
          *
@@ -176,6 +216,16 @@ public class DhcpServingParams {
             return this;
         }
 
+        /**
+         * Set excluded addresses that the DHCP server is not allowed to assign to clients.
+         *
+         * <p>This parameter is optional. DNS servers and default routers are always excluded
+         * and do not need to be set here.
+         */
+        public Builder setExcludedAddrs(@NonNull Inet4Address... excludedAddrs) {
+            return setExcludedAddrs(Sets.newArraySet(excludedAddrs));
+        }
+
         /**
          * Set the lease time for leases assigned by the DHCP server.
          *
diff --git a/tests/net/java/android/net/dhcp/DhcpServingParamsTest.java b/tests/net/java/android/net/dhcp/DhcpServingParamsTest.java
index dfa09a9f205c6..b6a4073a64da9 100644
--- a/tests/net/java/android/net/dhcp/DhcpServingParamsTest.java
+++ b/tests/net/java/android/net/dhcp/DhcpServingParamsTest.java
@@ -37,7 +37,6 @@ import org.junit.runner.RunWith;
 
 import java.net.Inet4Address;
 import java.util.Arrays;
-import java.util.Collections;
 import java.util.HashSet;
 import java.util.Set;
 
@@ -150,14 +149,14 @@ public class DhcpServingParamsTest {
 
     @Test(expected = InvalidParameterException.class)
     public void testBuild_PrefixTooSmall() throws InvalidParameterException {
-        mBuilder.setDefaultRouters(Collections.singleton(parseAddr("192.168.0.254")))
+        mBuilder.setDefaultRouters(parseAddr("192.168.0.254"))
                 .setServerAddr(new LinkAddress(TEST_SERVER_ADDR, 31))
                 .build();
     }
 
     @Test(expected = InvalidParameterException.class)
     public void testBuild_RouterNotInPrefix() throws InvalidParameterException {
-        mBuilder.setDefaultRouters(Collections.singleton(parseAddr("192.168.254.254"))).build();
+        mBuilder.setDefaultRouters(parseAddr("192.168.254.254")).build();
     }
 
     private static <T> void assertContains(@NonNull Set<T> set, @NonNull Set<T> subset) {