Validate SipMessages have a correct Via branch parameter

SIP messages are required to have a transaction ID, which is based
on the Via header's unique branch parameter. For processing, we require
this parameter to be set in order to send state updates about the message.

Also, as per council guidelines in b/184151053, throw a NPE instaed of
IllegalArgumentException for null params.

Fixes: 181087377
Test: atest CtsTelephonyTestCases
Change-Id: Ic4a637e780d04e9ac5d8ba01d7ba6dfae92307b1

4 files changed, 13 insertions, 23 deletions

diff --git a/core/api/system-current.txt b/core/api/system-current.txt
index 3f11b722306a..e6624cdb865a 100644
--- a/core/api/system-current.txt
+++ b/core/api/system-current.txt
@@ -11988,7 +11988,7 @@ package android.telephony.ims {
     method @NonNull public byte[] getEncodedMessage();
     method @NonNull public String getHeaderSection();
     method @NonNull public String getStartLine();
-    method @Nullable public String getViaBranchParameter();
+    method @NonNull public String getViaBranchParameter();
     method public void writeToParcel(@NonNull android.os.Parcel, int);
     field @NonNull public static final android.os.Parcelable.Creator<android.telephony.ims.SipMessage> CREATOR;
   }
diff --git a/telephony/java/android/telephony/ims/SipMessage.java b/telephony/java/android/telephony/ims/SipMessage.java
index ad6d73c39962..b5295637d4dd 100644
--- a/telephony/java/android/telephony/ims/SipMessage.java
+++ b/telephony/java/android/telephony/ims/SipMessage.java
@@ -24,6 +24,7 @@ import android.annotation.SystemApi;
 import android.os.Build;
 import android.os.Parcel;
 import android.os.Parcelable;
+import android.text.TextUtils;
 
 import com.android.internal.telephony.SipMessageParsingUtils;
 
@@ -60,14 +61,19 @@ public final class SipMessage implements Parcelable {
      */
     public SipMessage(@NonNull String startLine, @NonNull String headerSection,
             @NonNull byte[] content) {
-        if (startLine == null || headerSection == null || content == null) {
-            throw new IllegalArgumentException("One or more null parameters entered");
-        }
+        Objects.requireNonNull(startLine, "Required parameter is null: startLine");
+        Objects.requireNonNull(headerSection, "Required parameter is null: headerSection");
+        Objects.requireNonNull(content, "Required parameter is null: content");
+
         mStartLine = startLine;
         mHeaderSection = headerSection;
         mContent = content;
 
         mViaBranchParam = SipMessageParsingUtils.getTransactionId(mHeaderSection);
+        if (TextUtils.isEmpty(mViaBranchParam)) {
+            throw new IllegalArgumentException("header section MUST contain a branch parameter "
+                    + "inside of the Via header.");
+        }
         mCallIdParam = SipMessageParsingUtils.getCallId(mHeaderSection);
     }
 
@@ -107,11 +113,9 @@ public final class SipMessage implements Parcelable {
 
     /**
      * @return the branch parameter enclosed in the Via header key's value. See RFC 3261 section
-     * 20.42 for more information on the Via header. If {@code null}, then there was either no
-     * Via parameter found in this SIP message's headers or no branch parameter found in the
-     * Via header.
+     * 20.42 for more information on the Via header.
      */
-    public @Nullable String getViaBranchParameter() {
+    public @NonNull String getViaBranchParameter() {
         return mViaBranchParam;
     }
 
diff --git a/telephony/java/android/telephony/ims/aidl/SipDelegateAidlWrapper.java b/telephony/java/android/telephony/ims/aidl/SipDelegateAidlWrapper.java
index 739946be2e5b..5c9ec53d713b 100644
--- a/telephony/java/android/telephony/ims/aidl/SipDelegateAidlWrapper.java
+++ b/telephony/java/android/telephony/ims/aidl/SipDelegateAidlWrapper.java
@@ -28,8 +28,6 @@ import android.telephony.ims.SipDelegateImsConfiguration;
 import android.telephony.ims.SipDelegateManager;
 import android.telephony.ims.SipMessage;
 import android.telephony.ims.stub.SipDelegate;
-import android.text.TextUtils;
-import android.util.Log;
 
 import java.util.ArrayList;
 import java.util.Set;
@@ -187,11 +185,6 @@ public class SipDelegateAidlWrapper implements DelegateStateCallback, DelegateMe
 
     private void notifyLocalMessageFailedToBeReceived(SipMessage m, int reason) {
         String transactionId = m.getViaBranchParameter();
-        if (TextUtils.isEmpty(transactionId)) {
-            Log.w(LOG_TAG, "failure to parse SipMessage.");
-            throw new IllegalArgumentException("Malformed SipMessage, can not determine "
-                    + "transaction ID.");
-        }
         SipDelegate d = mDelegate;
         if (d != null) {
             mExecutor.execute(() -> d.notifyMessageReceiveError(transactionId, reason));
diff --git a/telephony/java/android/telephony/ims/aidl/SipDelegateConnectionAidlWrapper.java b/telephony/java/android/telephony/ims/aidl/SipDelegateConnectionAidlWrapper.java
index 3cd27264295c..ad02fe55902f 100644
--- a/telephony/java/android/telephony/ims/aidl/SipDelegateConnectionAidlWrapper.java
+++ b/telephony/java/android/telephony/ims/aidl/SipDelegateConnectionAidlWrapper.java
@@ -28,7 +28,6 @@ import android.telephony.ims.SipMessage;
 import android.telephony.ims.stub.DelegateConnectionMessageCallback;
 import android.telephony.ims.stub.DelegateConnectionStateCallback;
 import android.telephony.ims.stub.SipDelegate;
-import android.text.TextUtils;
 import android.util.ArraySet;
 import android.util.Log;
 
@@ -267,12 +266,6 @@ public class SipDelegateConnectionAidlWrapper implements SipDelegateConnection,
 
     private void notifyLocalMessageFailedToSend(SipMessage m, int reason) {
         String transactionId = m.getViaBranchParameter();
-        if (TextUtils.isEmpty(transactionId)) {
-            Log.w(LOG_TAG, "sendMessage detected a malformed SipMessage and can not get a "
-                    + "transaction ID.");
-            throw new IllegalArgumentException("Could not send SipMessage due to malformed header");
-        }
-        mExecutor.execute(() ->
-                mMessageCallback.onMessageSendFailure(transactionId, reason));
+        mExecutor.execute(() -> mMessageCallback.onMessageSendFailure(transactionId, reason));
     }
 }