From bf65974835a99b0f8b913a131790600154b54a11 Mon Sep 17 00:00:00 2001
From: Patrick Rohr <prohr@google.com>
Date: Tue, 25 Feb 2025 09:20:40 -0800
Subject: [PATCH] Move client request validation to L2capNetworkSpecifier

Test: TH
Change-Id: Ied1af7edc60a0df01d820c2e81e16de980eb526f
---
 .../android/net/L2capNetworkSpecifier.java    | 23 +++++++++++++++++++
 .../android/server/L2capNetworkProvider.java  | 20 +---------------
 2 files changed, 24 insertions(+), 19 deletions(-)

diff --git a/framework/src/android/net/L2capNetworkSpecifier.java b/framework/src/android/net/L2capNetworkSpecifier.java
index cfc9ed9d14..d4a69f23c4 100644
--- a/framework/src/android/net/L2capNetworkSpecifier.java
+++ b/framework/src/android/net/L2capNetworkSpecifier.java
@@ -170,6 +170,29 @@ public final class L2capNetworkSpecifier extends NetworkSpecifier implements Par
         return mPsm;
     }
 
+    /**
+     * Checks whether the given L2capNetworkSpecifier is valid as part of a client network request.
+     *
+     * @hide
+     */
+    public boolean isValidClientRequestSpecifier() {
+        // The ROLE_CLIENT offer can be satisfied by a ROLE_ANY request.
+        if (mRole != ROLE_CLIENT) return false;
+
+        // HEADER_COMPRESSION_ANY is never valid in a request.
+        if (mHeaderCompression == HEADER_COMPRESSION_ANY) return false;
+
+        // Remote address must not be null for ROLE_CLIENT requests.
+        if (mRemoteAddress == null) return false;
+
+        // Client network requests require a PSM to be specified.
+        // Ensure the PSM is within the valid range of dynamic BLE L2CAP values.
+        if (mPsm < 0x80) return false;
+        if (mPsm > 0xFF) return false;
+
+        return true;
+    }
+
     /** A builder class for L2capNetworkSpecifier. */
     public static final class Builder {
         @Role
diff --git a/service/src/com/android/server/L2capNetworkProvider.java b/service/src/com/android/server/L2capNetworkProvider.java
index 9d070cd598..fdc66dd139 100644
--- a/service/src/com/android/server/L2capNetworkProvider.java
+++ b/service/src/com/android/server/L2capNetworkProvider.java
@@ -509,24 +509,6 @@ public class L2capNetworkProvider {
             return true;
         }
 
-        private boolean isValidL2capClientSpecifier(L2capNetworkSpecifier l2capSpec) {
-            // The ROLE_CLIENT offer can be satisfied by a ROLE_ANY request.
-            if (l2capSpec.getRole() != ROLE_CLIENT) return false;
-
-            // HEADER_COMPRESSION_ANY is never valid in a request.
-            if (l2capSpec.getHeaderCompression() == HEADER_COMPRESSION_ANY) return false;
-
-            // remoteAddr must not be null for ROLE_CLIENT requests.
-            if (l2capSpec.getRemoteAddress() == null) return false;
-
-            // Client network requests require a PSM to be specified.
-            // Ensure the PSM is within the valid range of dynamic BLE L2CAP values.
-            if (l2capSpec.getPsm() < 0x80) return false;
-            if (l2capSpec.getPsm() > 0xFF) return false;
-
-            return true;
-        }
-
         @Override
         public void onNetworkNeeded(NetworkRequest request) {
             // The NetworkSpecifier is guaranteed to be either null or an L2capNetworkSpecifier, so
@@ -534,7 +516,7 @@ public class L2capNetworkProvider {
             final L2capNetworkSpecifier requestSpecifier =
                     (L2capNetworkSpecifier) request.getNetworkSpecifier();
             if (requestSpecifier == null) return;
-            if (!isValidL2capClientSpecifier(requestSpecifier)) {
+            if (!requestSpecifier.isValidClientRequestSpecifier()) {
                 Log.i(TAG, "Ignoring invalid client request: " + request);
                 return;
             }