refactor: TetherIngress becomes TetherDownstream6 (and friends)

Generated via:
  #!/bin/bash

  do_replace() {
    pushd "$1" >/dev/null
    shift
    git grep "$1" | cut -d: -f1 | sort -u | while read f; do
      sed -i -r "s@$1@$2@g" "${f}"
      git add "${f}"
    done
    popd >/dev/null
  }

  replace() {
    do_replace packages/modules/Connectivity/Tethering "$@"
    do_replace system/netd "$@"
  }

  do_reset() {
    pushd "$1" >/dev/null
    git rhh
    popd >/dev/null
  }

  main() {
    do_reset packages/modules/Connectivity/Tethering
    do_reset system/netd

    replace TetherIngressKey TetherDownstream6Key
    replace TetherIngressValue TetherDownstream6Value

    pushd packages/modules/Connectivity/Tethering/src/com/android/networkstack/tethering >/dev/null
    git mv TetherIngressKey.java TetherDownstream6Key.java
    git mv TetherIngressValue.java TetherDownstream6Value.java
    popd >/dev/null

    replace TETHER_INGRESS_PROG TETHER_DOWNSTREAM6_TC_PROG
    replace ingress_tether tether_downstream6
    replace ingress/tether_ tether_downstream6_
    replace TETHER_INGRESS_MAP TETHER_DOWNSTREAM6_MAP
    replace tether_ingress_map tether_downstream6_map

    replace getTetherIngressMapFd getTetherDownstream6MapFd
    replace getTetherIngressProgFd getTetherDownstream6TcProgFd

    replace mBpfIngressMap mBpfDownstream6Map
    replace bpfIngressMap bpfDownstream6Map
    replace printIngressMap printDownstream6Map
    replace 'BPF ingress map' 'BPF downstream ipv6 map'
  }

  main "$@"; exit

Followed by:
  cd system/netd
  # change regexp in tests/binder_test.cpp:3374
  git add tests/binder_test.cpp

(and whitespace adjustments to prevent lines from going over 100 characters)

Afterwards we have:
  $ adbz shell ls /sys/fs/bpf/tethering
  map_offload_tether_downstream6_map
  map_offload_tether_limit_map
  map_offload_tether_stats_map
  map_test_tether_downstream6_map
  prog_offload_schedcls_tether_downstream6_ether
  prog_offload_schedcls_tether_downstream6_rawip
  prog_test_xdp_drop_ipv4_udp_ether

Test: atest, TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Ib04dc0c6e3d034461f3f84e09f6fa93a862e1bb2

Tethering/apishim/31/com/android/networkstack/tethering/apishim/api31/BpfCoordinatorShimImpl.java

@@ -30,8 +30,8 @@ import androidx.annotation.Nullable;
 import com.android.networkstack.tethering.BpfCoordinator.Dependencies;
 import com.android.networkstack.tethering.BpfCoordinator.Ipv6ForwardingRule;
 import com.android.networkstack.tethering.BpfMap;
-import com.android.networkstack.tethering.TetherIngressKey;
-import com.android.networkstack.tethering.TetherIngressValue;
+import com.android.networkstack.tethering.TetherDownstream6Key;
+import com.android.networkstack.tethering.TetherDownstream6Value;
 import com.android.networkstack.tethering.TetherLimitKey;
 import com.android.networkstack.tethering.TetherLimitValue;
 import com.android.networkstack.tethering.TetherStatsKey;
@@ -57,7 +57,7 @@ public class BpfCoordinatorShimImpl
     // BPF map of ingress queueing discipline which pre-processes the packets by the IPv6
     // forwarding rules.
     @Nullable
-    private final BpfMap<TetherIngressKey, TetherIngressValue> mBpfIngressMap;
+    private final BpfMap<TetherDownstream6Key, TetherDownstream6Value> mBpfDownstream6Map;
 
     // BPF map of tethering statistics of the upstream interface since tethering startup.
     @Nullable
@@ -69,25 +69,25 @@ public class BpfCoordinatorShimImpl
 
     public BpfCoordinatorShimImpl(@NonNull final Dependencies deps) {
         mLog = deps.getSharedLog().forSubComponent(TAG);
-        mBpfIngressMap = deps.getBpfIngressMap();
+        mBpfDownstream6Map = deps.getBpfIngressMap();
         mBpfStatsMap = deps.getBpfStatsMap();
         mBpfLimitMap = deps.getBpfLimitMap();
     }
 
     @Override
     public boolean isInitialized() {
-        return mBpfIngressMap != null && mBpfStatsMap != null  && mBpfLimitMap != null;
+        return mBpfDownstream6Map != null && mBpfStatsMap != null  && mBpfLimitMap != null;
     }
 
     @Override
     public boolean tetherOffloadRuleAdd(@NonNull final Ipv6ForwardingRule rule) {
         if (!isInitialized()) return false;
 
-        final TetherIngressKey key = rule.makeTetherIngressKey();
-        final TetherIngressValue value = rule.makeTetherIngressValue();
+        final TetherDownstream6Key key = rule.makeTetherDownstream6Key();
+        final TetherDownstream6Value value = rule.makeTetherDownstream6Value();
 
         try {
-            mBpfIngressMap.updateEntry(key, value);
+            mBpfDownstream6Map.updateEntry(key, value);
         } catch (ErrnoException e) {
             mLog.e("Could not update entry: ", e);
             return false;
@@ -101,7 +101,7 @@ public class BpfCoordinatorShimImpl
         if (!isInitialized()) return false;
 
         try {
-            mBpfIngressMap.deleteEntry(rule.makeTetherIngressKey());
+            mBpfDownstream6Map.deleteEntry(rule.makeTetherDownstream6Key());
         } catch (ErrnoException e) {
             // Silent if the rule did not exist.
             if (e.errno != OsConstants.ENOENT) {
@@ -234,8 +234,8 @@ public class BpfCoordinatorShimImpl
 
     @Override
     public String toString() {
-        return "mBpfIngressMap{"
-                + (mBpfIngressMap != null ? "initialized" : "not initialized") + "}, "
+        return "mBpfDownstream6Map{"
+                + (mBpfDownstream6Map != null ? "initialized" : "not initialized") + "}, "
                 + "mBpfStatsMap{"
                 + (mBpfStatsMap != null ? "initialized" : "not initialized") + "}, "
                 + "mBpfLimitMap{"