Parse params needed for SipDelegate routing

Add getViaBranchParameter and getCallId parameter to SipMessage
API in order to allow the SipDelegate to quickly route SipMessages
without requiring the app to peak into the headers.

Bug: 181591815
Test: atest CtsTelephonyTestCases
Change-Id: Iac94f73335ac5caa634b31c10a675aaf91c13af7

4 files changed, 47 insertions, 6 deletions

diff --git a/telephony/common/com/android/internal/telephony/SipMessageParsingUtils.java b/telephony/common/com/android/internal/telephony/SipMessageParsingUtils.java
index c7e7cd5ec64e..179248dd2cf9 100644
--- a/telephony/common/com/android/internal/telephony/SipMessageParsingUtils.java
+++ b/telephony/common/com/android/internal/telephony/SipMessageParsingUtils.java
@@ -65,6 +65,11 @@ public class SipMessageParsingUtils {
     // compact form of the via header key
     private static final String VIA_SIP_HEADER_KEY_COMPACT = "v";
 
+    // call-id header key
+    private static final String CALL_ID_SIP_HEADER_KEY = "call-id";
+    // compact form of the call-id header key
+    private static final String CALL_ID_SIP_HEADER_KEY_COMPACT = "i";
+
     /**
      * @return true if the SIP message start line is considered a request (based on known request
      * methods).
@@ -124,6 +129,17 @@ public class SipMessageParsingUtils {
         return null;
     }
 
+    /**
+     * Return the call-id header key's associated value.
+     * @param headerString The string containing the headers of the SIP message.
+     */
+    public static String getCallId(String headerString) {
+        // search for the call-Id header, there should only be one in the header.
+        List<Pair<String, String>> headers = parseHeaders(headerString, true,
+                CALL_ID_SIP_HEADER_KEY, CALL_ID_SIP_HEADER_KEY_COMPACT);
+        return !headers.isEmpty() ? headers.get(0).second : null;
+    }
+
     private static String[] splitStartLineAndVerify(String startLine) {
         String[] splitLine = startLine.split(" ");
         if (isStartLineMalformed(splitLine)) return null;
diff --git a/telephony/java/android/telephony/ims/SipMessage.java b/telephony/java/android/telephony/ims/SipMessage.java
index 9cfa640fce18..ad6d73c39962 100644
--- a/telephony/java/android/telephony/ims/SipMessage.java
+++ b/telephony/java/android/telephony/ims/SipMessage.java
@@ -19,6 +19,7 @@ package android.telephony.ims;
 import static java.nio.charset.StandardCharsets.UTF_8;
 
 import android.annotation.NonNull;
+import android.annotation.Nullable;
 import android.annotation.SystemApi;
 import android.os.Build;
 import android.os.Parcel;
@@ -46,6 +47,8 @@ public final class SipMessage implements Parcelable {
     private final String mStartLine;
     private final String mHeaderSection;
     private final byte[] mContent;
+    private final String mViaBranchParam;
+    private final String mCallIdParam;
 
     /**
      * Represents a partially encoded SIP message.
@@ -63,6 +66,9 @@ public final class SipMessage implements Parcelable {
         mStartLine = startLine;
         mHeaderSection = headerSection;
         mContent = content;
+
+        mViaBranchParam = SipMessageParsingUtils.getTransactionId(mHeaderSection);
+        mCallIdParam = SipMessageParsingUtils.getCallId(mHeaderSection);
     }
 
     /**
@@ -73,6 +79,8 @@ public final class SipMessage implements Parcelable {
         mHeaderSection = source.readString();
         mContent = new byte[source.readInt()];
         source.readByteArray(mContent);
+        mViaBranchParam = source.readString();
+        mCallIdParam = source.readString();
     }
 
     /**
@@ -97,6 +105,25 @@ public final class SipMessage implements Parcelable {
         return mContent;
     }
 
+    /**
+     * @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.
+     */
+    public @Nullable String getViaBranchParameter() {
+        return mViaBranchParam;
+    }
+
+    /**
+     * @return the value associated with the call-id header of this SIP message. See RFC 3261
+     * section 20.8 for more information on the call-id header. If {@code null}, then there was no
+     * call-id header found in this SIP message's headers.
+     */
+    public @Nullable String getCallIdParameter() {
+        return mCallIdParam;
+    }
+
     @Override
     public int describeContents() {
         return 0;
@@ -108,6 +135,8 @@ public final class SipMessage implements Parcelable {
         dest.writeString(mHeaderSection);
         dest.writeInt(mContent.length);
         dest.writeByteArray(mContent);
+        dest.writeString(mViaBranchParam);
+        dest.writeString(mCallIdParam);
     }
 
     public static final @NonNull Creator<SipMessage> CREATOR = new Creator<SipMessage>() {
diff --git a/telephony/java/android/telephony/ims/aidl/SipDelegateAidlWrapper.java b/telephony/java/android/telephony/ims/aidl/SipDelegateAidlWrapper.java
index 9d919015087d..739946be2e5b 100644
--- a/telephony/java/android/telephony/ims/aidl/SipDelegateAidlWrapper.java
+++ b/telephony/java/android/telephony/ims/aidl/SipDelegateAidlWrapper.java
@@ -31,8 +31,6 @@ import android.telephony.ims.stub.SipDelegate;
 import android.text.TextUtils;
 import android.util.Log;
 
-import com.android.internal.telephony.SipMessageParsingUtils;
-
 import java.util.ArrayList;
 import java.util.Set;
 import java.util.concurrent.Executor;
@@ -188,7 +186,7 @@ public class SipDelegateAidlWrapper implements DelegateStateCallback, DelegateMe
     }
 
     private void notifyLocalMessageFailedToBeReceived(SipMessage m, int reason) {
-        String transactionId = SipMessageParsingUtils.getTransactionId(m.getHeaderSection());
+        String transactionId = m.getViaBranchParameter();
         if (TextUtils.isEmpty(transactionId)) {
             Log.w(LOG_TAG, "failure to parse SipMessage.");
             throw new IllegalArgumentException("Malformed SipMessage, can not determine "
diff --git a/telephony/java/android/telephony/ims/aidl/SipDelegateConnectionAidlWrapper.java b/telephony/java/android/telephony/ims/aidl/SipDelegateConnectionAidlWrapper.java
index c877aca8ba96..3cd27264295c 100644
--- a/telephony/java/android/telephony/ims/aidl/SipDelegateConnectionAidlWrapper.java
+++ b/telephony/java/android/telephony/ims/aidl/SipDelegateConnectionAidlWrapper.java
@@ -32,8 +32,6 @@ import android.text.TextUtils;
 import android.util.ArraySet;
 import android.util.Log;
 
-import com.android.internal.telephony.SipMessageParsingUtils;
-
 import java.util.List;
 import java.util.NoSuchElementException;
 import java.util.concurrent.Executor;
@@ -268,7 +266,7 @@ public class SipDelegateConnectionAidlWrapper implements SipDelegateConnection,
     }
 
     private void notifyLocalMessageFailedToSend(SipMessage m, int reason) {
-        String transactionId = SipMessageParsingUtils.getTransactionId(m.getHeaderSection());
+        String transactionId = m.getViaBranchParameter();
         if (TextUtils.isEmpty(transactionId)) {
             Log.w(LOG_TAG, "sendMessage detected a malformed SipMessage and can not get a "
                     + "transaction ID.");