commit 9d11ddfd5c3872b7ced68ecdef76af8fc0183981
author Hungming Chen <nuccachen@google.com> Sat Dec 25 21:50:49 2021 +0800
committer Hungming Chen <nuccachen@google.com> Tue Jan 25 18:44:09 2022 +0800
tree 664aebf0ffeb98adb1f5c56c797a29ee70d71885
parent 9625caa8e59987abcef357e2328e34fc17738d7b

[CLATJ#22] ClatCoordinator: stop clatd

provide clatd stop function which stops clatd by pid.

Bug: 212345928
Test: flash and boot
Run "atest ClatCoordinatorTest" in a follow commit.

Change-Id: Icd9c4f9038bf75113fbc5608f213145e58a061d9

service/jni/com_android_server_connectivity_ClatCoordinator.cpp

diff --git a/service/jni/com_android_server_connectivity_ClatCoordinator.cpp b/service/jni/com_android_server_connectivity_ClatCoordinator.cpp
index 3c8fd0d..eeaad18 100644
--- a/service/jni/com_android_server_connectivity_ClatCoordinator.cpp
+++ b/service/jni/com_android_server_connectivity_ClatCoordinator.cpp
@@ -24,6 +24,7 @@
 #include <nativehelper/JNIHelp.h>
 #include <net/if.h>
 #include <spawn.h>
+#include <sys/wait.h>
 #include <string>
 
 #include <netjniutils/netjniutils.h>
@@ -425,16 +426,20 @@
     return pid;
 }
 
-// TODO: stop clatd and rename to .._stopClatd.
-static void com_android_server_connectivity_ClatCoordinator_maybeStopBpf(JNIEnv* env, jobject clazz,
-                                                                       jstring iface, jstring pfx96,
-                                                                       jstring v4, jstring v6,
-                                                                       jint pid /* unused */) {
+static void com_android_server_connectivity_ClatCoordinator_stopClatd(JNIEnv* env, jobject clazz,
+                                                                      jstring iface, jstring pfx96,
+                                                                      jstring v4, jstring v6,
+                                                                      jint pid) {
     ScopedUtfChars ifaceStr(env, iface);
     ScopedUtfChars pfx96Str(env, pfx96);
     ScopedUtfChars v4Str(env, v4);
     ScopedUtfChars v6Str(env, v6);
 
+    if (pid <= 0) {
+        jniThrowExceptionFmt(env, "java/io/IOException", "Invalid pid");
+        return;
+    }
+
     if (!net::clat::initMaps()) {
         net::clat::ClatdTracker tracker = {};
         if (!initTracker(ifaceStr.c_str(), pfx96Str.c_str(), v4Str.c_str(), v6Str.c_str(),
@@ -442,6 +447,9 @@
             net::clat::maybeStopBpf(tracker);
         }
     }
+
+    kill(pid, SIGTERM);
+    waitpid(pid, nullptr, 0);  // Should we block in JNI?
 }
 
 /*
@@ -470,9 +478,9 @@
          "(Ljava/io/FileDescriptor;Ljava/io/FileDescriptor;Ljava/io/FileDescriptor;Ljava/lang/"
          "String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)I",
          (void*)com_android_server_connectivity_ClatCoordinator_startClatd},
-        {"native_maybeStopBpf",
+        {"native_stopClatd",
          "(Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;I)V",
-          (void*)com_android_server_connectivity_ClatCoordinator_maybeStopBpf},
+         (void*)com_android_server_connectivity_ClatCoordinator_stopClatd},
 };
 
 int register_android_server_connectivity_ClatCoordinator(JNIEnv* env) {

service/src/com/android/server/connectivity/ClatCoordinator.java

diff --git a/service/src/com/android/server/connectivity/ClatCoordinator.java b/service/src/com/android/server/connectivity/ClatCoordinator.java
index 45e8125..9cdc086 100644
--- a/service/src/com/android/server/connectivity/ClatCoordinator.java
+++ b/service/src/com/android/server/connectivity/ClatCoordinator.java
@@ -179,11 +179,11 @@
         }
 
         /**
-         * Maybe stop bpf.
+         * Stop clatd.
          */
-        public void maybeStopBpf(String iface, String pfx96, String v4, String v6, int pid)
+        public void stopClatd(String iface, String pfx96, String v4, String v6, int pid)
                 throws IOException {
-            native_maybeStopBpf(iface, pfx96, v4, v6, pid);
+            native_stopClatd(iface, pfx96, v4, v6, pid);
         }
     }
 
@@ -349,8 +349,12 @@
      * Stop clatd
      */
     public void clatStop() throws IOException {
-        mDeps.maybeStopBpf(mIface, mNat64Prefix, mXlatLocalAddress4, mXlatLocalAddress6,
-                mPid /* unused */);
+        if (mPid == INVALID_PID) {
+            throw new IOException("Clatd has not started");
+        }
+        Log.i(TAG, "Stopping clatd pid=" + mPid + " on " + mIface);
+
+        mDeps.stopClatd(mIface, mNat64Prefix, mXlatLocalAddress4, mXlatLocalAddress6, mPid);
         // TODO: remove setIptablesDropRule
 
         Log.i(TAG, "clatd on " + mIface + " stopped");
@@ -359,6 +363,7 @@
         mNat64Prefix = null;
         mXlatLocalAddress4 = null;
         mXlatLocalAddress6 = null;
+        mPid = INVALID_PID;
     }
 
     private static native String native_selectIpv4Address(String v4addr, int prefixlen)
@@ -377,6 +382,6 @@
     private static native int native_startClatd(FileDescriptor tunfd, FileDescriptor readsock6,
             FileDescriptor writesock6, String iface, String pfx96, String v4, String v6)
             throws IOException;
-    private static native void native_maybeStopBpf(String iface, String pfx96, String v4,
-            String v6, int pid) throws IOException;
+    private static native void native_stopClatd(String iface, String pfx96, String v4, String v6,
+            int pid) throws IOException;
 }