Implement matching semantics for L2capNetworkSpecifier

A server network is created by using ConnectivityManger#reserveNetwork,
in which the app passes a specifier that sets:

reservationRequest = {
    role = server
    headerCompression = 6lowpan
    remoteAddr = any (null)
    psm = any
}

This specifier must subsequently match the blanket reservation offer,
and the reserved offer that is generated as a response:

blanketOffer = {
    role = server
    headerCompression = any
    remoteAddr = any (null)
    psm = any
}

reservedOffer = {
    role = server
    headerCompression = 6lowpan
    remoteAddr = any (null)
    psm = 0x81
}

And not the client network offer or a client network:

clientOffer = {
    role = client
    headerCompression = any
    remoteAddr = any (null)
    psm = any
}

clientNetwork = {
    role = client
    headerCompression = 6lowpan
    remoteAddr = 01:02:03:04:05:06
    psm = 0x81
}

Similarly the client request must match both the clientOffer and
clientNetweork, but not the reservedOffer (and technically
blanketOffer):

clientRequest = {
    role = client
    headerCompression = 6lowpan
    remoteAddr = 01:02:03:04:05:06
    psm = 0x81
}

Note, a request for TRANSPORT_BLUETOOTH with no specifier matches *any*
specifier per specifier matching semantics in NetworkCapabilities.

Test: L2capNetworkSpecifierTest
Change-Id: Ia16926b463a54530ae6e88278466e92ed82bf852
diff --git a/framework/src/android/net/L2capNetworkSpecifier.java b/framework/src/android/net/L2capNetworkSpecifier.java
index 3331123..3c95dd0 100644
--- a/framework/src/android/net/L2capNetworkSpecifier.java
+++ b/framework/src/android/net/L2capNetworkSpecifier.java
@@ -251,8 +251,29 @@
     /** @hide */
     @Override
     public boolean canBeSatisfiedBy(NetworkSpecifier other) {
-        // TODO: implement matching semantics.
-        return false;
+        if (!(other instanceof L2capNetworkSpecifier)) return false;
+        final L2capNetworkSpecifier rhs = (L2capNetworkSpecifier) other;
+
+        // A network / offer cannot be ROLE_ANY, but it is added for consistency.
+        if (mRole != rhs.mRole && mRole != ROLE_ANY && rhs.mRole != ROLE_ANY) {
+            return false;
+        }
+
+        if (mHeaderCompression != rhs.mHeaderCompression
+                && mHeaderCompression != HEADER_COMPRESSION_ANY
+                && rhs.mHeaderCompression != HEADER_COMPRESSION_ANY) {
+            return false;
+        }
+
+        if (!Objects.equals(mRemoteAddress, rhs.mRemoteAddress)
+                && mRemoteAddress != null && rhs.mRemoteAddress != null) {
+            return false;
+        }
+
+        if (mPsm != rhs.mPsm && mPsm != PSM_ANY && rhs.mPsm != PSM_ANY) {
+            return false;
+        }
+        return true;
     }
 
     /** @hide */
diff --git a/tests/cts/net/src/android/net/cts/L2capNetworkSpecifierTest.kt b/tests/cts/net/src/android/net/cts/L2capNetworkSpecifierTest.kt
index 51ccdd5..484cce8 100644
--- a/tests/cts/net/src/android/net/cts/L2capNetworkSpecifierTest.kt
+++ b/tests/cts/net/src/android/net/cts/L2capNetworkSpecifierTest.kt
@@ -18,8 +18,11 @@
 
 import android.net.L2capNetworkSpecifier
 import android.net.L2capNetworkSpecifier.HEADER_COMPRESSION_6LOWPAN
+import android.net.L2capNetworkSpecifier.HEADER_COMPRESSION_ANY
 import android.net.L2capNetworkSpecifier.HEADER_COMPRESSION_NONE
+import android.net.L2capNetworkSpecifier.PSM_ANY
 import android.net.L2capNetworkSpecifier.ROLE_CLIENT
+import android.net.L2capNetworkSpecifier.ROLE_SERVER
 import android.net.MacAddress
 import android.os.Build
 import com.android.testutils.ConnectivityModuleTest
@@ -27,6 +30,8 @@
 import com.android.testutils.DevSdkIgnoreRunner
 import com.android.testutils.assertParcelingIsLossless
 import kotlin.test.assertEquals
+import kotlin.test.assertFalse
+import kotlin.test.assertTrue
 import org.junit.Test
 import org.junit.runner.RunWith
 
@@ -60,4 +65,53 @@
         assertEquals(123, specifier.getPsm())
         assertEquals(remoteMac, specifier.getRemoteAddress())
     }
+
+    @Test
+    fun testCanBeSatisfiedBy() {
+        val blanketOffer = L2capNetworkSpecifier.Builder()
+                .setRole(ROLE_SERVER)
+                .setHeaderCompression(HEADER_COMPRESSION_ANY)
+                .setPsm(PSM_ANY)
+                .build()
+
+        val reservedOffer = L2capNetworkSpecifier.Builder()
+                .setRole(ROLE_SERVER)
+                .setHeaderCompression(HEADER_COMPRESSION_6LOWPAN)
+                .setPsm(42)
+                .build()
+
+        val clientOffer = L2capNetworkSpecifier.Builder()
+                .setRole(ROLE_CLIENT)
+                .setHeaderCompression(HEADER_COMPRESSION_ANY)
+                .build()
+
+        val serverReservation = L2capNetworkSpecifier.Builder()
+                .setRole(ROLE_SERVER)
+                .setHeaderCompression(HEADER_COMPRESSION_6LOWPAN)
+                .build()
+
+        assertTrue(serverReservation.canBeSatisfiedBy(blanketOffer))
+        assertTrue(serverReservation.canBeSatisfiedBy(reservedOffer))
+        // Note: serverReservation can be filed using reserveNetwork, or it could be a regular
+        // request filed using requestNetwork.
+        assertFalse(serverReservation.canBeSatisfiedBy(clientOffer))
+
+        val clientRequest = L2capNetworkSpecifier.Builder()
+                .setRole(ROLE_CLIENT)
+                .setHeaderCompression(HEADER_COMPRESSION_6LOWPAN)
+                .setRemoteAddress(MacAddress.fromString("00:01:02:03:04:05"))
+                .setPsm(42)
+                .build()
+
+        assertTrue(clientRequest.canBeSatisfiedBy(clientOffer))
+        // Note: the BlanketOffer also includes a RES_ID_MATCH_ALL_RESERVATIONS. Since the
+        // clientRequest is not a reservation, it won't match that request to begin with.
+        assertFalse(clientRequest.canBeSatisfiedBy(blanketOffer))
+        assertFalse(clientRequest.canBeSatisfiedBy(reservedOffer))
+
+        val matchAny = L2capNetworkSpecifier.Builder().build()
+        assertTrue(matchAny.canBeSatisfiedBy(blanketOffer))
+        assertTrue(matchAny.canBeSatisfiedBy(reservedOffer))
+        assertTrue(matchAny.canBeSatisfiedBy(clientOffer))
+    }
 }