Fix empty value problem in the TextEntry
Now, the value in TextEntry would be a zero length byte array if
the text record response doesn't contain the value. The problem
is that the value could either be an empty string ("key="), or
there can be no value ("key"), as per rfc6763 6.4 "If there is
no '=' in a DNS-SD TXT record string, then it is a boolean
attribute, simply identified as being present, with no value.".
Bug: 254166302
Test: atest FramworksNetTests
Change-Id: I4eaa5e593ce9ddaa6b6cb2f069c1aef977910796
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsServiceInfo.java b/service/mdns/com/android/server/connectivity/mdns/MdnsServiceInfo.java
index f1b2def..9683bc9 100644
--- a/service/mdns/com/android/server/connectivity/mdns/MdnsServiceInfo.java
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsServiceInfo.java
@@ -270,7 +270,8 @@
public Map<String, String> getAttributes() {
Map<String, String> map = new HashMap<>(attributes.size());
for (Map.Entry<String, byte[]> kv : attributes.entrySet()) {
- map.put(kv.getKey(), new String(kv.getValue(), UTF_8));
+ final byte[] value = kv.getValue();
+ map.put(kv.getKey(), value == null ? null : new String(value, UTF_8));
}
return Collections.unmodifiableMap(map);
}
@@ -342,7 +343,7 @@
// 2. If there is no '=' in a DNS-SD TXT record string, then it is a
// boolean attribute, simply identified as being present, with no value.
if (delimitPos < 0) {
- return new TextEntry(new String(textBytes, US_ASCII), "");
+ return new TextEntry(new String(textBytes, US_ASCII), (byte[]) null);
} else if (delimitPos == 0) {
return null;
}
@@ -353,13 +354,13 @@
/** Creates a new {@link TextEntry} with given key and value of a UTF-8 string. */
public TextEntry(String key, String value) {
- this(key, value.getBytes(UTF_8));
+ this(key, value == null ? null : value.getBytes(UTF_8));
}
/** Creates a new {@link TextEntry} with given key and value of a byte array. */
public TextEntry(String key, byte[] value) {
this.key = key;
- this.value = value.clone();
+ this.value = value == null ? null : value.clone();
}
private TextEntry(Parcel in) {
@@ -372,17 +373,24 @@
}
public byte[] getValue() {
- return value.clone();
+ return value == null ? null : value.clone();
}
/** Converts this {@link TextEntry} instance to '=' separated byte array. */
public byte[] toBytes() {
- return ByteUtils.concat(key.getBytes(US_ASCII), new byte[]{'='}, value);
+ final byte[] keyBytes = key.getBytes(US_ASCII);
+ if (value == null) {
+ return keyBytes;
+ }
+ return ByteUtils.concat(keyBytes, new byte[]{'='}, value);
}
/** Converts this {@link TextEntry} instance to '=' separated string. */
@Override
public String toString() {
+ if (value == null) {
+ return key;
+ }
return key + "=" + new String(value, UTF_8);
}
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MdnsServiceInfoTest.java b/tests/unit/java/com/android/server/connectivity/mdns/MdnsServiceInfoTest.java
index d3934c2..ebdb73f 100644
--- a/tests/unit/java/com/android/server/connectivity/mdns/MdnsServiceInfoTest.java
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MdnsServiceInfoTest.java
@@ -164,7 +164,8 @@
List.of("vn=Alphabet Inc.", "mn=Google Nest Hub Max", "id=12345"),
List.of(
MdnsServiceInfo.TextEntry.fromString("vn=Google Inc."),
- MdnsServiceInfo.TextEntry.fromString("mn=Google Nest Hub Max")));
+ MdnsServiceInfo.TextEntry.fromString("mn=Google Nest Hub Max"),
+ MdnsServiceInfo.TextEntry.fromString("test=")));
beforeParcel.writeToParcel(parcel, 0);
parcel.setDataPosition(0);
@@ -208,11 +209,11 @@
}
@Test
- public void textEntry_fromStringWithoutAssignPunc_valueisEmpty() {
+ public void textEntry_fromStringWithoutAssignPunc_noValue() {
TextEntry entry = TextEntry.fromString("AA");
assertEquals("AA", entry.getKey());
- assertArrayEquals(new byte[] {}, entry.getValue());
+ assertNull(entry.getValue());
}
@Test
@@ -241,11 +242,11 @@
}
@Test
- public void textEntry_fromBytesWithoutAssignPunc_valueisEmpty() {
+ public void textEntry_fromBytesWithoutAssignPunc_noValue() {
TextEntry entry = TextEntry.fromBytes(new byte[] {'A', 'A'});
assertEquals("AA", entry.getKey());
- assertArrayEquals(new byte[] {}, entry.getValue());
+ assertNull(entry.getValue());
}
@Test
@@ -270,4 +271,12 @@
assertEquals(new TextEntry("BB", "xxyyzz"), new TextEntry("BB", "xxyyzz"));
assertEquals(new TextEntry("AA", "XXYYZZ"), new TextEntry("AA", "XXYYZZ"));
}
+
+ @Test
+ public void textEntry_fromString_valueIsEmpty() {
+ TextEntry entry = TextEntry.fromString("AA=");
+
+ assertEquals("AA", entry.getKey());
+ assertArrayEquals(new byte[] {}, entry.getValue());
+ }
}