util: add utility functions for retrieving Hotspot 2.0 specific IEs

Instead of using the parsed IEs maintained in NetworkDetail, the interested
party can use the newly added utility functions to retrieve the elements
that it is interested in.  This allows us to remove the NetworkDetail
dependencies from Passpoint code.

I think if we ever want to maintain a copy of parsed IEs, it should be
in ScanResult instead of NetworkDetail.

Bug: 35888100
Test: frameworks/opt/net/wifi/tests/wifitests/runtests.sh

Change-Id: I69849728c93d3e1f9b6c7bda1e5c21cfdb40689a

1 files changed, 66 insertions, 0 deletions

diff --git a/service/java/com/android/server/wifi/util/InformationElementUtil.java b/service/java/com/android/server/wifi/util/InformationElementUtil.java
index 9d7de241a..fdb1ca318 100644
--- a/service/java/com/android/server/wifi/util/InformationElementUtil.java
+++ b/service/java/com/android/server/wifi/util/InformationElementUtil.java
@@ -30,6 +30,7 @@ import java.util.ArrayList;
 import java.util.BitSet;
 
 public class InformationElementUtil {
+    private static final String TAG = "InformationElementUtil";
 
     public static InformationElement[] parseInformationElements(byte[] bytes) {
         if (bytes == null) {
@@ -63,6 +64,71 @@ public class InformationElementUtil {
         return infoElements.toArray(new InformationElement[infoElements.size()]);
     }
 
+    /**
+     * Parse and retrieve the Roaming Consortium Information Element from the list of IEs.
+     *
+     * @param ies List of IEs to retrieve from
+     * @return {@link RoamingConsortium}
+     */
+    public static RoamingConsortium getRoamingConsortiumIE(InformationElement[] ies) {
+        RoamingConsortium roamingConsortium = new RoamingConsortium();
+        if (ies != null) {
+            for (InformationElement ie : ies) {
+                if (ie.id == InformationElement.EID_ROAMING_CONSORTIUM) {
+                    try {
+                        roamingConsortium.from(ie);
+                    } catch (RuntimeException e) {
+                        Log.e(TAG, "Failed to parse Roaming Consortium IE: " + e.getMessage());
+                    }
+                }
+            }
+        }
+        return roamingConsortium;
+    }
+
+    /**
+     * Parse and retrieve the Hotspot 2.0 Vendor Specific Information Element from the list of IEs.
+     *
+     * @param ies List of IEs to retrieve from
+     * @return {@link Vsa}
+     */
+    public static Vsa getHS2VendorSpecificIE(InformationElement[] ies) {
+        Vsa vsa = new Vsa();
+        if (ies != null) {
+            for (InformationElement ie : ies) {
+                if (ie.id == InformationElement.EID_VSA) {
+                    try {
+                        vsa.from(ie);
+                    } catch (RuntimeException e) {
+                        Log.e(TAG, "Failed to parse Vendor Specific IE: " + e.getMessage());
+                    }
+                }
+            }
+        }
+        return vsa;
+    }
+
+    /**
+     * Parse and retrieve the Interworking information element from the list of IEs.
+     *
+     * @param ies List of IEs to retrieve from
+     * @return {@link Interworking}
+     */
+    public static Interworking getInterworkingIE(InformationElement[] ies) {
+        Interworking interworking = new Interworking();
+        if (ies != null) {
+            for (InformationElement ie : ies) {
+                if (ie.id == InformationElement.EID_INTERWORKING) {
+                    try {
+                        interworking.from(ie);
+                    } catch (RuntimeException e) {
+                        Log.e(TAG, "Failed to parse Interworking IE: " + e.getMessage());
+                    }
+                }
+            }
+        }
+        return interworking;
+    }
 
     public static class BssLoad {
         public int stationCount = 0;