Use jniThrowErrnoException from JNIHelp

Use the jniThrowErrnoException that is available in JNIHelp, instead of
reimplementing in NetworkUtils.

Bug: 179229316
Test: device boots and has connectivity
Change-Id: I257a9d55ce1f5a7c588e209b4a89d3e7a3e09994
diff --git a/framework/jni/android_net_NetworkUtils.cpp b/framework/jni/android_net_NetworkUtils.cpp
index 19ffe77..c5b1ff8 100644
--- a/framework/jni/android_net_NetworkUtils.cpp
+++ b/framework/jni/android_net_NetworkUtils.cpp
@@ -30,6 +30,7 @@
 
 #include <DnsProxydProtocol.h> // NETID_USE_LOCAL_NAMESERVERS
 #include <cutils/properties.h>
+#include <nativehelper/JNIHelp.h>
 #include <nativehelper/JNIPlatformHelp.h>
 #include <nativehelper/ScopedLocalRef.h>
 #include <utils/Log.h>
@@ -57,14 +58,6 @@
     return clazz;
 }
 
-static inline jmethodID GetMethodIDOrDie(JNIEnv* env, jclass clazz, const char* method_name,
-                                         const char* method_signature) {
-    jmethodID res = env->GetMethodID(clazz, method_name, method_signature);
-    LOG_ALWAYS_FATAL_IF(res == NULL, "Unable to find method %s with signature %s", method_name,
-                        method_signature);
-    return res;
-}
-
 template <typename T>
 static inline T MakeGlobalRefOrDie(JNIEnv* env, T in) {
     jobject res = env->NewGlobalRef(in);
@@ -72,27 +65,6 @@
     return static_cast<T>(res);
 }
 
-static void throwErrnoException(JNIEnv* env, const char* functionName, int error) {
-    ScopedLocalRef<jstring> detailMessage(env, env->NewStringUTF(functionName));
-    if (detailMessage.get() == NULL) {
-        // Not really much we can do here. We're probably dead in the water,
-        // but let's try to stumble on...
-        env->ExceptionClear();
-    }
-    static jclass errnoExceptionClass =
-            MakeGlobalRefOrDie(env, FindClassOrDie(env, "android/system/ErrnoException"));
-
-    static jmethodID errnoExceptionCtor =
-            GetMethodIDOrDie(env, errnoExceptionClass,
-            "<init>", "(Ljava/lang/String;I)V");
-
-    jobject exception = env->NewObject(errnoExceptionClass,
-                                       errnoExceptionCtor,
-                                       detailMessage.get(),
-                                       error);
-    env->Throw(reinterpret_cast<jthrowable>(exception));
-}
-
 static void android_net_utils_attachDropAllBPFFilter(JNIEnv *env, jobject clazz, jobject javaFd)
 {
     struct sock_filter filter_code[] = {
@@ -170,7 +142,7 @@
     int fd = resNetworkQuery(netId, queryname.data(), ns_class, ns_type, flags);
 
     if (fd < 0) {
-        throwErrnoException(env, "resNetworkQuery", -fd);
+        jniThrowErrnoException(env, "resNetworkQuery", -fd);
         return nullptr;
     }
 
@@ -185,7 +157,7 @@
     int fd = resNetworkSend(netId, data, msgLen, flags);
 
     if (fd < 0) {
-        throwErrnoException(env, "resNetworkSend", -fd);
+        jniThrowErrnoException(env, "resNetworkSend", -fd);
         return nullptr;
     }
 
@@ -200,13 +172,13 @@
     int res = resNetworkResult(fd, &rcode, buf.data(), MAXPACKETSIZE);
     jniSetFileDescriptorOfFD(env, javaFd, -1);
     if (res < 0) {
-        throwErrnoException(env, "resNetworkResult", -res);
+        jniThrowErrnoException(env, "resNetworkResult", -res);
         return nullptr;
     }
 
     jbyteArray answer = env->NewByteArray(res);
     if (answer == nullptr) {
-        throwErrnoException(env, "resNetworkResult", ENOMEM);
+        jniThrowErrnoException(env, "resNetworkResult", ENOMEM);
         return nullptr;
     } else {
         env->SetByteArrayRegion(answer, 0, res,
@@ -228,7 +200,7 @@
 static jobject android_net_utils_getDnsNetwork(JNIEnv *env, jobject thiz) {
     unsigned dnsNetId = 0;
     if (int res = getNetworkForDns(&dnsNetId) < 0) {
-        throwErrnoException(env, "getDnsNetId", -res);
+        jniThrowErrnoException(env, "getDnsNetId", -res);
         return nullptr;
     }
     bool privateDnsBypass = dnsNetId & NETID_USE_LOCAL_NAMESERVERS;
@@ -253,7 +225,7 @@
     // Obtain the parameters of the TCP repair window.
     int rc = getsockopt(fd, IPPROTO_TCP, TCP_REPAIR_WINDOW, &trw, &size);
     if (rc == -1) {
-        throwErrnoException(env, "getsockopt : TCP_REPAIR_WINDOW", errno);
+        jniThrowErrnoException(env, "getsockopt : TCP_REPAIR_WINDOW", errno);
         return NULL;
     }
 
@@ -264,7 +236,7 @@
     // should be applied to the window size.
     rc = getsockopt(fd, IPPROTO_TCP, TCP_INFO, &tcpinfo, &tcpinfo_size);
     if (rc == -1) {
-        throwErrnoException(env, "getsockopt : TCP_INFO", errno);
+        jniThrowErrnoException(env, "getsockopt : TCP_INFO", errno);
         return NULL;
     }