Add support for NLM_F_DUMP request in StructNLMsgHdr

Test: atest NetworkStaticLibTests:com.android.net.moduletests.util.netlink.StructNlMsgHdrTest
Change-Id: I395560fb1edfb1c806b2ed4c74a7a3081c7b2515
diff --git a/staticlibs/device/com/android/net/module/util/netlink/NetlinkMessage.java b/staticlibs/device/com/android/net/module/util/netlink/NetlinkMessage.java
index 111e0ba..781a04e 100644
--- a/staticlibs/device/com/android/net/module/util/netlink/NetlinkMessage.java
+++ b/staticlibs/device/com/android/net/module/util/netlink/NetlinkMessage.java
@@ -142,6 +142,7 @@
                 return (NetlinkMessage) RtNetlinkAddressMessage.parse(nlmsghdr, byteBuffer);
             case NetlinkConstants.RTM_NEWROUTE:
             case NetlinkConstants.RTM_DELROUTE:
+            case NetlinkConstants.RTM_GETROUTE:
                 return (NetlinkMessage) RtNetlinkRouteMessage.parse(nlmsghdr, byteBuffer);
             case NetlinkConstants.RTM_NEWNEIGH:
             case NetlinkConstants.RTM_DELNEIGH:
diff --git a/staticlibs/device/com/android/net/module/util/netlink/StructNlMsgHdr.java b/staticlibs/device/com/android/net/module/util/netlink/StructNlMsgHdr.java
index ff37639..5272366 100644
--- a/staticlibs/device/com/android/net/module/util/netlink/StructNlMsgHdr.java
+++ b/staticlibs/device/com/android/net/module/util/netlink/StructNlMsgHdr.java
@@ -71,13 +71,17 @@
             }
             sb.append("NLM_F_ECHO");
         }
-        if ((flags & NLM_F_ROOT) != 0) {
+        if ((flags & NLM_F_DUMP) == NLM_F_DUMP) {
+            if (sb.length() > 0) {
+                sb.append("|");
+            }
+            sb.append("NLM_F_DUMP");
+        } else if ((flags & NLM_F_ROOT) != 0) { // NLM_F_DUMP = NLM_F_ROOT | NLM_F_MATCH
             if (sb.length() > 0) {
                 sb.append("|");
             }
             sb.append("NLM_F_ROOT");
-        }
-        if ((flags & NLM_F_MATCH) != 0) {
+        } else if ((flags & NLM_F_MATCH) != 0) {
             if (sb.length() > 0) {
                 sb.append("|");
             }
diff --git a/staticlibs/tests/unit/src/com/android/net/module/util/netlink/StructNlMsgHdrTest.java b/staticlibs/tests/unit/src/com/android/net/module/util/netlink/StructNlMsgHdrTest.java
index b7f68c6..a0d8b8c 100644
--- a/staticlibs/tests/unit/src/com/android/net/module/util/netlink/StructNlMsgHdrTest.java
+++ b/staticlibs/tests/unit/src/com/android/net/module/util/netlink/StructNlMsgHdrTest.java
@@ -16,6 +16,7 @@
 
 package com.android.net.module.util.netlink;
 
+import static com.android.net.module.util.netlink.StructNlMsgHdr.NLM_F_DUMP;
 import static org.junit.Assert.fail;
 
 import android.system.OsConstants;
@@ -48,10 +49,14 @@
     public static final String TEST_NLMSG_PID_STR = "nlmsg_pid{5678}";
 
     private StructNlMsgHdr makeStructNlMsgHdr(short type) {
+        return makeStructNlMsgHdr(type, TEST_NLMSG_FLAGS);
+    }
+
+    private StructNlMsgHdr makeStructNlMsgHdr(short type, short flags) {
         final StructNlMsgHdr struct = new StructNlMsgHdr();
         struct.nlmsg_len = TEST_NLMSG_LEN;
         struct.nlmsg_type = type;
-        struct.nlmsg_flags = TEST_NLMSG_FLAGS;
+        struct.nlmsg_flags = flags;
         struct.nlmsg_seq = TEST_NLMSG_SEQ;
         struct.nlmsg_pid = TEST_NLMSG_PID;
         return struct;
@@ -62,6 +67,11 @@
         fail("\"" + actualValue + "\" does not contain \"" + expectedSubstring + "\"");
     }
 
+    private static void assertNotContains(String actualValue, String unexpectedSubstring) {
+        if (!actualValue.contains(unexpectedSubstring)) return;
+        fail("\"" + actualValue + "\" contains \"" + unexpectedSubstring + "\"");
+    }
+
     @Test
     public void testToString() {
         StructNlMsgHdr struct = makeStructNlMsgHdr(NetlinkConstants.RTM_NEWADDR);
@@ -99,4 +109,31 @@
         assertContains(s, TEST_NLMSG_PID_STR);
         assertContains(s, "nlmsg_type{20(SOCK_DIAG_BY_FAMILY)}");
     }
+
+    @Test
+    public void testToString_flags_dumpRequest() {
+        final short flags = StructNlMsgHdr.NLM_F_REQUEST | StructNlMsgHdr.NLM_F_DUMP;
+        StructNlMsgHdr struct = makeStructNlMsgHdr(NetlinkConstants.RTM_GETROUTE, flags);
+
+        String s = struct.toString(OsConstants.NETLINK_ROUTE);
+
+        assertContains(s, "RTM_GETROUTE");
+        assertContains(s, "NLM_F_REQUEST");
+        assertContains(s, "NLM_F_DUMP");
+        // NLM_F_DUMP = NLM_F_ROOT | NLM_F_MATCH;
+        assertNotContains(s, "NLM_F_MATCH");
+        assertNotContains(s, "NLM_F_ROOT");
+    }
+
+    @Test
+    public void testToString_flags_root() {
+        final short flags = StructNlMsgHdr.NLM_F_ROOT;
+        StructNlMsgHdr struct = makeStructNlMsgHdr(NetlinkConstants.RTM_GETROUTE, flags);
+
+        String s = struct.toString(OsConstants.NETLINK_ROUTE);
+
+        assertContains(s, "NLM_F_ROOT");
+        // NLM_F_DUMP = NLM_F_ROOT | NLM_F_MATCH;
+        assertNotContains(s, "NLM_F_DUMP");
+    }
 }