NetworkRequest: Embed requestor uid & packageName

Add the requestorUid & requestorPackageName fields to
NetworkCapabilities. This is populated by CS when
a new network request is received.
These 2 requestor fields are also optionally used for network
matching. All of the regular app initiated requests will have the
requestor uid and package name set by connectivity service. Network
agents can optionally set the requestorUid and requestorPackageName
to restrict the network created only to the app that requested the network.

This will help removing the necessity for the various specifiers to embed
the uid & package name info in the specifier for network matching.

Note: NetworkSpecifier.assertValidFromUid() is deprecated & removed in
favor of setting the uid/package name on the agent to restrict the
network to a certain app (useful for wifi peer to peer API & wifi aware).

Bug: 144102365
Test: Verified that wifi network request related CTS verifier tests
pass.
Test: Device boots up and connects to wifi networks
Change-Id: I207c446108afdac7ee2c25e6bbcbc37c4e3f6529
diff --git a/core/java/android/net/NetworkCapabilities.java b/core/java/android/net/NetworkCapabilities.java
index cf5f225..f8b51dd 100644
--- a/core/java/android/net/NetworkCapabilities.java
+++ b/core/java/android/net/NetworkCapabilities.java
@@ -27,6 +27,7 @@
 import android.os.Parcel;
 import android.os.Parcelable;
 import android.os.Process;
+import android.text.TextUtils;
 import android.util.ArraySet;
 import android.util.proto.ProtoOutputStream;
 
@@ -63,6 +64,16 @@
     // Set to true when private DNS is broken.
     private boolean mPrivateDnsBroken;
 
+    /**
+     * Uid of the app making the request.
+     */
+    private int mRequestorUid;
+
+    /**
+     * Package name of the app making the request.
+     */
+    private String mRequestorPackageName;
+
     public NetworkCapabilities() {
         clearAll();
         mNetworkCapabilities = DEFAULT_CAPABILITIES;
@@ -89,6 +100,8 @@
         mOwnerUid = Process.INVALID_UID;
         mSSID = null;
         mPrivateDnsBroken = false;
+        mRequestorUid = Process.INVALID_UID;
+        mRequestorPackageName = null;
     }
 
     /**
@@ -109,6 +122,8 @@
         mUnwantedNetworkCapabilities = nc.mUnwantedNetworkCapabilities;
         mSSID = nc.mSSID;
         mPrivateDnsBroken = nc.mPrivateDnsBroken;
+        mRequestorUid = nc.mRequestorUid;
+        mRequestorPackageName = nc.mRequestorPackageName;
     }
 
     /**
@@ -810,7 +825,7 @@
     }
 
     /**
-     * UID of the app that owns this network, or INVALID_UID if none/unknown.
+     * UID of the app that owns this network, or Process#INVALID_UID if none/unknown.
      *
      * <p>This field keeps track of the UID of the app that created this network and is in charge of
      * its lifecycle. This could be the UID of apps such as the Wifi network suggestor, the running
@@ -821,8 +836,9 @@
     /**
      * Set the UID of the owner app.
      */
-    public void setOwnerUid(final int uid) {
+    public @NonNull NetworkCapabilities setOwnerUid(final int uid) {
         mOwnerUid = uid;
+        return this;
     }
 
     /**
@@ -865,9 +881,11 @@
      * @hide
      */
     @SystemApi
-    public void setAdministratorUids(@NonNull final List<Integer> administratorUids) {
+    public @NonNull NetworkCapabilities setAdministratorUids(
+            @NonNull final List<Integer> administratorUids) {
         mAdministratorUids.clear();
         mAdministratorUids.addAll(administratorUids);
+        return this;
     }
 
     /**
@@ -1385,6 +1403,7 @@
         combineSignalStrength(nc);
         combineUids(nc);
         combineSSIDs(nc);
+        combineRequestor(nc);
     }
 
     /**
@@ -1404,7 +1423,8 @@
                 && satisfiedBySpecifier(nc)
                 && (onlyImmutable || satisfiedBySignalStrength(nc))
                 && (onlyImmutable || satisfiedByUids(nc))
-                && (onlyImmutable || satisfiedBySSID(nc)));
+                && (onlyImmutable || satisfiedBySSID(nc)))
+                && (onlyImmutable || satisfiedByRequestor(nc));
     }
 
     /**
@@ -1488,7 +1508,7 @@
     public boolean equals(@Nullable Object obj) {
         if (obj == null || (obj instanceof NetworkCapabilities == false)) return false;
         NetworkCapabilities that = (NetworkCapabilities) obj;
-        return (equalsNetCapabilities(that)
+        return equalsNetCapabilities(that)
                 && equalsTransportTypes(that)
                 && equalsLinkBandwidths(that)
                 && equalsSignalStrength(that)
@@ -1496,7 +1516,8 @@
                 && equalsTransportInfo(that)
                 && equalsUids(that)
                 && equalsSSID(that)
-                && equalsPrivateDnsBroken(that));
+                && equalsPrivateDnsBroken(that)
+                && equalsRequestor(that);
     }
 
     @Override
@@ -1514,7 +1535,9 @@
                 + Objects.hashCode(mUids) * 31
                 + Objects.hashCode(mSSID) * 37
                 + Objects.hashCode(mTransportInfo) * 41
-                + Objects.hashCode(mPrivateDnsBroken) * 43;
+                + Objects.hashCode(mPrivateDnsBroken) * 43
+                + Objects.hashCode(mRequestorUid) * 47
+                + Objects.hashCode(mRequestorPackageName) * 53;
     }
 
     @Override
@@ -1537,6 +1560,8 @@
         dest.writeBoolean(mPrivateDnsBroken);
         dest.writeList(mAdministratorUids);
         dest.writeInt(mOwnerUid);
+        dest.writeInt(mRequestorUid);
+        dest.writeString(mRequestorPackageName);
     }
 
     public static final @android.annotation.NonNull Creator<NetworkCapabilities> CREATOR =
@@ -1559,6 +1584,8 @@
                 netCap.mPrivateDnsBroken = in.readBoolean();
                 netCap.setAdministratorUids(in.readArrayList(null));
                 netCap.mOwnerUid = in.readInt();
+                netCap.mRequestorUid = in.readInt();
+                netCap.mRequestorPackageName = in.readString();
                 return netCap;
             }
             @Override
@@ -1624,6 +1651,9 @@
             sb.append(" Private DNS is broken");
         }
 
+        sb.append(" RequestorUid: ").append(mRequestorUid);
+        sb.append(" RequestorPackageName: ").append(mRequestorPackageName);
+
         sb.append("]");
         return sb.toString();
     }
@@ -1632,6 +1662,7 @@
     private interface NameOf {
         String nameOf(int value);
     }
+
     /**
      * @hide
      */
@@ -1799,4 +1830,120 @@
     private boolean equalsPrivateDnsBroken(NetworkCapabilities nc) {
         return mPrivateDnsBroken == nc.mPrivateDnsBroken;
     }
+
+    /**
+     * Set the uid of the app making the request.
+     *
+     * Note: This works only for {@link NetworkAgent} instances. Any capabilities passed in
+     * via the public {@link ConnectivityManager} API's will have this field overwritten.
+     *
+     * @param uid UID of the app.
+     * @hide
+     */
+    @SystemApi
+    public @NonNull NetworkCapabilities setRequestorUid(int uid) {
+        mRequestorUid = uid;
+        return this;
+    }
+
+    /**
+     * @return the uid of the app making the request.
+     *
+     * Note: This could return {@link Process#INVALID_UID} if the {@link NetworkRequest}
+     * object was not obtained from {@link ConnectivityManager}.
+     * @hide
+     */
+    public int getRequestorUid() {
+        return mRequestorUid;
+    }
+
+    /**
+     * Set the package name of the app making the request.
+     *
+     * Note: This works only for {@link NetworkAgent} instances. Any capabilities passed in
+     * via the public {@link ConnectivityManager} API's will have this field overwritten.
+     *
+     * @param packageName package name of the app.
+     * @hide
+     */
+    @SystemApi
+    public @NonNull NetworkCapabilities setRequestorPackageName(@NonNull String packageName) {
+        mRequestorPackageName = packageName;
+        return this;
+    }
+
+    /**
+     * @return the package name of the app making the request.
+     *
+     * Note: This could return {@code null} if the {@link NetworkRequest} object was not obtained
+     * from {@link ConnectivityManager}.
+     * @hide
+     */
+    @Nullable
+    public String getRequestorPackageName() {
+        return mRequestorPackageName;
+    }
+
+    /**
+     * Set the uid and package name of the app making the request.
+     *
+     * Note: This is intended to be only invoked from within connectivitiy service.
+     *
+     * @param uid UID of the app.
+     * @param packageName package name of the app.
+     * @hide
+     */
+    public @NonNull NetworkCapabilities setRequestorUidAndPackageName(
+            int uid, @NonNull String packageName) {
+        return setRequestorUid(uid).setRequestorPackageName(packageName);
+    }
+
+    /**
+     * Test whether the passed NetworkCapabilities satisfies the requestor restrictions of this
+     * capabilities.
+     *
+     * This method is called on the NetworkCapabilities embedded in a request with the
+     * capabilities of an available network. If the available network, sets a specific
+     * requestor (by uid and optionally package name), then this will only match a request from the
+     * same app. If either of the capabilities have an unset uid or package name, then it matches
+     * everything.
+     * <p>
+     * nc is assumed nonnull. Else, NPE.
+     */
+    private boolean satisfiedByRequestor(NetworkCapabilities nc) {
+        // No uid set, matches everything.
+        if (mRequestorUid == Process.INVALID_UID || nc.mRequestorUid == Process.INVALID_UID) {
+            return true;
+        }
+        // uids don't match.
+        if (mRequestorUid != nc.mRequestorUid) return false;
+        // No package names set, matches everything
+        if (null == nc.mRequestorPackageName || null == mRequestorPackageName) return true;
+        // check for package name match.
+        return TextUtils.equals(mRequestorPackageName, nc.mRequestorPackageName);
+    }
+
+    /**
+     * Combine requestor info of the capabilities.
+     * <p>
+     * This is only legal if either the requestor info of this object is reset, or both info are
+     * equal.
+     * nc is assumed nonnull.
+     */
+    private void combineRequestor(@NonNull NetworkCapabilities nc) {
+        if (mRequestorUid != Process.INVALID_UID && mRequestorUid != nc.mOwnerUid) {
+            throw new IllegalStateException("Can't combine two uids");
+        }
+        if (mRequestorPackageName != null
+                && !mRequestorPackageName.equals(nc.mRequestorPackageName)) {
+            throw new IllegalStateException("Can't combine two package names");
+        }
+        setRequestorUid(nc.mRequestorUid);
+        setRequestorPackageName(nc.mRequestorPackageName);
+    }
+
+    private boolean equalsRequestor(NetworkCapabilities nc) {
+        return mRequestorUid == nc.mRequestorUid
+                && TextUtils.equals(mRequestorPackageName, nc.mRequestorPackageName);
+    }
 }