framework/jni/android_net_NetworkUtils.cpp - platform/packages/modules/Connectivity - Git at Google

 /*
  * Copyright 2020, The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #define LOG_TAG "NetworkUtils"

 #include <android/file_descriptor_jni.h>
 #include <android/multinetwork.h>
 #include <linux/filter.h>
 #include <linux/tcp.h>
 #include <netinet/in.h>
 #include <string.h>

 #include <DnsProxydProtocol.h> // NETID_USE_LOCAL_NAMESERVERS
 #include <nativehelper/JNIPlatformHelp.h>
 #include <utils/Log.h>

 #include "jni.h"

 #define NETUTILS_PKG_NAME "android/net/NetworkUtils"

 namespace android {

 constexpr int MAXPACKETSIZE = 8 * 1024;
 // FrameworkListener limits the size of commands to 4096 bytes.
 constexpr int MAXCMDSIZE = 4096;

 static volatile jclass class_Network = 0;
 static volatile jmethodID method_fromNetworkHandle = 0;

 static inline jclass FindClassOrDie(JNIEnv* env, const char* class_name) {
     jclass clazz = env->FindClass(class_name);
     LOG_ALWAYS_FATAL_IF(clazz == NULL, "Unable to find class %s", class_name);
     return clazz;
 }

 template <typename T>
 static inline T MakeGlobalRefOrDie(JNIEnv* env, T in) {
     jobject res = env->NewGlobalRef(in);
     LOG_ALWAYS_FATAL_IF(res == NULL, "Unable to create global reference.");
     return static_cast<T>(res);
 }

 static void android_net_utils_attachDropAllBPFFilter(JNIEnv *env, jobject clazz, jobject javaFd)
 {
     struct sock_filter filter_code[] = {
         // Reject all.
         BPF_STMT(BPF_RET | BPF_K, 0)
     };
     struct sock_fprog filter = {
         sizeof(filter_code) / sizeof(filter_code[0]),
         filter_code,
     };

     int fd = AFileDescriptor_getFd(env, javaFd);
     if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter)) != 0) {
         jniThrowExceptionFmt(env, "java/net/SocketException",
                 "setsockopt(SO_ATTACH_FILTER): %s", strerror(errno));
     }
 }

 static void android_net_utils_detachBPFFilter(JNIEnv *env, jobject clazz, jobject javaFd)
 {
     int optval_ignored = 0;
     int fd = AFileDescriptor_getFd(env, javaFd);
     if (setsockopt(fd, SOL_SOCKET, SO_DETACH_FILTER, &optval_ignored, sizeof(optval_ignored)) !=
         0) {
         jniThrowExceptionFmt(env, "java/net/SocketException",
                 "setsockopt(SO_DETACH_FILTER): %s", strerror(errno));
     }
 }

 static jboolean android_net_utils_bindProcessToNetworkHandle(JNIEnv *env, jobject thiz,
         jlong netHandle)
 {
     return (jboolean) !android_setprocnetwork(netHandle);
 }

 static jlong android_net_utils_getBoundNetworkHandleForProcess(JNIEnv *env, jobject thiz)
 {
     net_handle_t network;
     if (android_getprocnetwork(&network) != 0) {
         jniThrowExceptionFmt(env, "java/lang/IllegalStateException",
                 "android_getprocnetwork(): %s", strerror(errno));
         return NETWORK_UNSPECIFIED;
     }
     return (jlong) network;
 }

 static jboolean android_net_utils_bindProcessToNetworkForHostResolution(JNIEnv *env, jobject thiz,
         jint netId, jlong netHandle)
 {
     return (jboolean) !android_setprocdns(netHandle);
 }

 static jint android_net_utils_bindSocketToNetworkHandle(JNIEnv *env, jobject thiz, jobject javaFd,
                                                   jlong netHandle) {
     return android_setsocknetwork(netHandle, AFileDescriptor_getFd(env, javaFd));
 }

 static bool checkLenAndCopy(JNIEnv* env, const jbyteArray& addr, int len, void* dst)
 {
     if (env->GetArrayLength(addr) != len) {
         return false;
     }
     env->GetByteArrayRegion(addr, 0, len, reinterpret_cast<jbyte*>(dst));
     return true;
 }

 static jobject android_net_utils_resNetworkQuery(JNIEnv *env, jobject thiz, jlong netHandle,
         jstring dname, jint ns_class, jint ns_type, jint flags) {
     const jsize javaCharsCount = env->GetStringLength(dname);
     const jsize byteCountUTF8 = env->GetStringUTFLength(dname);

     // Only allow dname which could be simply formatted to UTF8.
     // In native layer, res_mkquery would re-format the input char array to packet.
     char queryname[byteCountUTF8 + 1];
     memset(queryname, 0, (byteCountUTF8 + 1) * sizeof(char));

     env->GetStringUTFRegion(dname, 0, javaCharsCount, queryname);
     int fd = android_res_nquery(netHandle, queryname, ns_class, ns_type, flags);

     if (fd < 0) {
         jniThrowErrnoException(env, "resNetworkQuery", -fd);
         return nullptr;
     }

     return jniCreateFileDescriptor(env, fd);
 }

 static jobject android_net_utils_resNetworkSend(JNIEnv *env, jobject thiz, jlong netHandle,
         jbyteArray msg, jint msgLen, jint flags) {
     uint8_t data[MAXCMDSIZE];

     checkLenAndCopy(env, msg, msgLen, data);
     int fd = android_res_nsend(netHandle, data, msgLen, flags);

     if (fd < 0) {
         jniThrowErrnoException(env, "resNetworkSend", -fd);
         return nullptr;
     }

     return jniCreateFileDescriptor(env, fd);
 }

 static jobject android_net_utils_resNetworkResult(JNIEnv *env, jobject thiz, jobject javaFd) {
     int fd = AFileDescriptor_getFd(env, javaFd);
     int rcode;
     uint8_t buf[MAXPACKETSIZE] = {0};

     int res = android_res_nresult(fd, &rcode, buf, MAXPACKETSIZE);
     jniSetFileDescriptorOfFD(env, javaFd, -1);
     if (res < 0) {
         jniThrowErrnoException(env, "resNetworkResult", -res);
         return nullptr;
     }

     jbyteArray answer = env->NewByteArray(res);
     if (answer == nullptr) {
         jniThrowErrnoException(env, "resNetworkResult", ENOMEM);
         return nullptr;
     } else {
         env->SetByteArrayRegion(answer, 0, res, reinterpret_cast<jbyte*>(buf));
     }

     jclass class_DnsResponse = env->FindClass("android/net/DnsResolver$DnsResponse");
     jmethodID ctor = env->GetMethodID(class_DnsResponse, "<init>", "([BI)V");

     return env->NewObject(class_DnsResponse, ctor, answer, rcode);
 }

 static void android_net_utils_resNetworkCancel(JNIEnv *env, jobject thiz, jobject javaFd) {
     int fd = AFileDescriptor_getFd(env, javaFd);
     android_res_cancel(fd);
     jniSetFileDescriptorOfFD(env, javaFd, -1);
 }

 static jobject android_net_utils_getDnsNetwork(JNIEnv *env, jobject thiz) {
     net_handle_t dnsNetHandle = NETWORK_UNSPECIFIED;
     if (int res = android_getprocdns(&dnsNetHandle) < 0) {
         jniThrowErrnoException(env, "getDnsNetwork", -res);
         return nullptr;
     }

     if (method_fromNetworkHandle == 0) {
         // This may be called multiple times concurrently but that is fine
         class_Network = MakeGlobalRefOrDie(env, FindClassOrDie(env, "android/net/Network"));
         method_fromNetworkHandle = env->GetStaticMethodID(class_Network, "fromNetworkHandle",
                 "(J)Landroid/net/Network;");
     }
     return env->CallStaticObjectMethod(class_Network, method_fromNetworkHandle,
             static_cast<jlong>(dnsNetHandle));
 }

 static jobject android_net_utils_getTcpRepairWindow(JNIEnv *env, jobject thiz, jobject javaFd) {
     if (javaFd == NULL) {
         jniThrowNullPointerException(env, NULL);
         return NULL;
     }

     int fd = AFileDescriptor_getFd(env, javaFd);
     struct tcp_repair_window trw = {};
     socklen_t size = sizeof(trw);

     // Obtain the parameters of the TCP repair window.
     int rc = getsockopt(fd, IPPROTO_TCP, TCP_REPAIR_WINDOW, &trw, &size);
     if (rc == -1) {
         jniThrowErrnoException(env, "getsockopt : TCP_REPAIR_WINDOW", errno);
         return NULL;
     }

     struct tcp_info tcpinfo = {};
     socklen_t tcpinfo_size = sizeof(tcp_info);

     // Obtain the window scale from the tcp info structure. This contains a scale factor that
     // should be applied to the window size.
     rc = getsockopt(fd, IPPROTO_TCP, TCP_INFO, &tcpinfo, &tcpinfo_size);
     if (rc == -1) {
         jniThrowErrnoException(env, "getsockopt : TCP_INFO", errno);
         return NULL;
     }

     jclass class_TcpRepairWindow = env->FindClass("android/net/TcpRepairWindow");
     jmethodID ctor = env->GetMethodID(class_TcpRepairWindow, "<init>", "(IIIIII)V");

     return env->NewObject(class_TcpRepairWindow, ctor, trw.snd_wl1, trw.snd_wnd, trw.max_window,
             trw.rcv_wnd, trw.rcv_wup, tcpinfo.tcpi_rcv_wscale);
 }

 // ----------------------------------------------------------------------------

 /*
  * JNI registration.
  */
 // clang-format off
 static const JNINativeMethod gNetworkUtilMethods[] = {
     /* name, signature, funcPtr */
     { "bindProcessToNetworkHandle", "(J)Z", (void*) android_net_utils_bindProcessToNetworkHandle },
     { "getBoundNetworkHandleForProcess", "()J", (void*) android_net_utils_getBoundNetworkHandleForProcess },
     { "bindProcessToNetworkForHostResolution", "(I)Z", (void*) android_net_utils_bindProcessToNetworkForHostResolution },
     { "bindSocketToNetworkHandle", "(Ljava/io/FileDescriptor;J)I", (void*) android_net_utils_bindSocketToNetworkHandle },
     { "attachDropAllBPFFilter", "(Ljava/io/FileDescriptor;)V", (void*) android_net_utils_attachDropAllBPFFilter },
     { "detachBPFFilter", "(Ljava/io/FileDescriptor;)V", (void*) android_net_utils_detachBPFFilter },
     { "getTcpRepairWindow", "(Ljava/io/FileDescriptor;)Landroid/net/TcpRepairWindow;", (void*) android_net_utils_getTcpRepairWindow },
     { "resNetworkSend", "(J[BII)Ljava/io/FileDescriptor;", (void*) android_net_utils_resNetworkSend },
     { "resNetworkQuery", "(JLjava/lang/String;III)Ljava/io/FileDescriptor;", (void*) android_net_utils_resNetworkQuery },
     { "resNetworkResult", "(Ljava/io/FileDescriptor;)Landroid/net/DnsResolver$DnsResponse;", (void*) android_net_utils_resNetworkResult },
     { "resNetworkCancel", "(Ljava/io/FileDescriptor;)V", (void*) android_net_utils_resNetworkCancel },
     { "getDnsNetwork", "()Landroid/net/Network;", (void*) android_net_utils_getDnsNetwork },
 };
 // clang-format on

 int register_android_net_NetworkUtils(JNIEnv* env)
 {
     return jniRegisterNativeMethods(env, NETUTILS_PKG_NAME, gNetworkUtilMethods,
                                     NELEM(gNetworkUtilMethods));
 }

 }; // namespace android
	/*
	* Copyright 2020, The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#define LOG_TAG "NetworkUtils"

	#include <android/file_descriptor_jni.h>
	#include <android/multinetwork.h>
	#include <linux/filter.h>
	#include <linux/tcp.h>
	#include <netinet/in.h>
	#include <string.h>

	#include <DnsProxydProtocol.h> // NETID_USE_LOCAL_NAMESERVERS
	#include <nativehelper/JNIPlatformHelp.h>
	#include <utils/Log.h>

	#include "jni.h"

	#define NETUTILS_PKG_NAME "android/net/NetworkUtils"

	namespace android {

	constexpr int MAXPACKETSIZE = 8 * 1024;
	// FrameworkListener limits the size of commands to 4096 bytes.
	constexpr int MAXCMDSIZE = 4096;

	static volatile jclass class_Network = 0;
	static volatile jmethodID method_fromNetworkHandle = 0;

	static inline jclass FindClassOrDie(JNIEnv* env, const char* class_name) {
	jclass clazz = env->FindClass(class_name);
	LOG_ALWAYS_FATAL_IF(clazz == NULL, "Unable to find class %s", class_name);
	return clazz;
	}

	template <typename T>
	static inline T MakeGlobalRefOrDie(JNIEnv* env, T in) {
	jobject res = env->NewGlobalRef(in);
	LOG_ALWAYS_FATAL_IF(res == NULL, "Unable to create global reference.");
	return static_cast<T>(res);
	}

	static void android_net_utils_attachDropAllBPFFilter(JNIEnv *env, jobject clazz, jobject javaFd)
	{
	struct sock_filter filter_code[] = {
	// Reject all.
	BPF_STMT(BPF_RET \| BPF_K, 0)
	};
	struct sock_fprog filter = {
	sizeof(filter_code) / sizeof(filter_code[0]),
	filter_code,
	};

	int fd = AFileDescriptor_getFd(env, javaFd);
	if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter)) != 0) {
	jniThrowExceptionFmt(env, "java/net/SocketException",
	"setsockopt(SO_ATTACH_FILTER): %s", strerror(errno));
	}
	}

	static void android_net_utils_detachBPFFilter(JNIEnv *env, jobject clazz, jobject javaFd)
	{
	int optval_ignored = 0;
	int fd = AFileDescriptor_getFd(env, javaFd);
	if (setsockopt(fd, SOL_SOCKET, SO_DETACH_FILTER, &optval_ignored, sizeof(optval_ignored)) !=
	0) {
	jniThrowExceptionFmt(env, "java/net/SocketException",
	"setsockopt(SO_DETACH_FILTER): %s", strerror(errno));
	}
	}

	static jboolean android_net_utils_bindProcessToNetworkHandle(JNIEnv *env, jobject thiz,
	jlong netHandle)
	{
	return (jboolean) !android_setprocnetwork(netHandle);
	}

	static jlong android_net_utils_getBoundNetworkHandleForProcess(JNIEnv *env, jobject thiz)
	{
	net_handle_t network;
	if (android_getprocnetwork(&network) != 0) {
	jniThrowExceptionFmt(env, "java/lang/IllegalStateException",
	"android_getprocnetwork(): %s", strerror(errno));
	return NETWORK_UNSPECIFIED;
	}
	return (jlong) network;
	}

	static jboolean android_net_utils_bindProcessToNetworkForHostResolution(JNIEnv *env, jobject thiz,
	jint netId, jlong netHandle)
	{
	return (jboolean) !android_setprocdns(netHandle);
	}

	static jint android_net_utils_bindSocketToNetworkHandle(JNIEnv *env, jobject thiz, jobject javaFd,
	jlong netHandle) {
	return android_setsocknetwork(netHandle, AFileDescriptor_getFd(env, javaFd));
	}

	static bool checkLenAndCopy(JNIEnv* env, const jbyteArray& addr, int len, void* dst)
	{
	if (env->GetArrayLength(addr) != len) {
	return false;
	}
	env->GetByteArrayRegion(addr, 0, len, reinterpret_cast<jbyte*>(dst));
	return true;
	}

	static jobject android_net_utils_resNetworkQuery(JNIEnv *env, jobject thiz, jlong netHandle,
	jstring dname, jint ns_class, jint ns_type, jint flags) {
	const jsize javaCharsCount = env->GetStringLength(dname);
	const jsize byteCountUTF8 = env->GetStringUTFLength(dname);

	// Only allow dname which could be simply formatted to UTF8.
	// In native layer, res_mkquery would re-format the input char array to packet.
	char queryname[byteCountUTF8 + 1];
	memset(queryname, 0, (byteCountUTF8 + 1) * sizeof(char));

	env->GetStringUTFRegion(dname, 0, javaCharsCount, queryname);
	int fd = android_res_nquery(netHandle, queryname, ns_class, ns_type, flags);

	if (fd < 0) {
	jniThrowErrnoException(env, "resNetworkQuery", -fd);
	return nullptr;
	}

	return jniCreateFileDescriptor(env, fd);
	}

	static jobject android_net_utils_resNetworkSend(JNIEnv *env, jobject thiz, jlong netHandle,
	jbyteArray msg, jint msgLen, jint flags) {
	uint8_t data[MAXCMDSIZE];

	checkLenAndCopy(env, msg, msgLen, data);
	int fd = android_res_nsend(netHandle, data, msgLen, flags);

	if (fd < 0) {
	jniThrowErrnoException(env, "resNetworkSend", -fd);
	return nullptr;
	}

	return jniCreateFileDescriptor(env, fd);
	}

	static jobject android_net_utils_resNetworkResult(JNIEnv *env, jobject thiz, jobject javaFd) {
	int fd = AFileDescriptor_getFd(env, javaFd);
	int rcode;
	uint8_t buf[MAXPACKETSIZE] = {0};

	int res = android_res_nresult(fd, &rcode, buf, MAXPACKETSIZE);
	jniSetFileDescriptorOfFD(env, javaFd, -1);
	if (res < 0) {
	jniThrowErrnoException(env, "resNetworkResult", -res);
	return nullptr;
	}

	jbyteArray answer = env->NewByteArray(res);
	if (answer == nullptr) {
	jniThrowErrnoException(env, "resNetworkResult", ENOMEM);
	return nullptr;
	} else {
	env->SetByteArrayRegion(answer, 0, res, reinterpret_cast<jbyte*>(buf));
	}

	jclass class_DnsResponse = env->FindClass("android/net/DnsResolver$DnsResponse");
	jmethodID ctor = env->GetMethodID(class_DnsResponse, "<init>", "([BI)V");

	return env->NewObject(class_DnsResponse, ctor, answer, rcode);
	}

	static void android_net_utils_resNetworkCancel(JNIEnv *env, jobject thiz, jobject javaFd) {
	int fd = AFileDescriptor_getFd(env, javaFd);
	android_res_cancel(fd);
	jniSetFileDescriptorOfFD(env, javaFd, -1);
	}

	static jobject android_net_utils_getDnsNetwork(JNIEnv *env, jobject thiz) {
	net_handle_t dnsNetHandle = NETWORK_UNSPECIFIED;
	if (int res = android_getprocdns(&dnsNetHandle) < 0) {
	jniThrowErrnoException(env, "getDnsNetwork", -res);
	return nullptr;
	}

	if (method_fromNetworkHandle == 0) {
	// This may be called multiple times concurrently but that is fine
	class_Network = MakeGlobalRefOrDie(env, FindClassOrDie(env, "android/net/Network"));
	method_fromNetworkHandle = env->GetStaticMethodID(class_Network, "fromNetworkHandle",
	"(J)Landroid/net/Network;");
	}
	return env->CallStaticObjectMethod(class_Network, method_fromNetworkHandle,
	static_cast<jlong>(dnsNetHandle));
	}

	static jobject android_net_utils_getTcpRepairWindow(JNIEnv *env, jobject thiz, jobject javaFd) {
	if (javaFd == NULL) {
	jniThrowNullPointerException(env, NULL);
	return NULL;
	}

	int fd = AFileDescriptor_getFd(env, javaFd);
	struct tcp_repair_window trw = {};
	socklen_t size = sizeof(trw);

	// Obtain the parameters of the TCP repair window.
	int rc = getsockopt(fd, IPPROTO_TCP, TCP_REPAIR_WINDOW, &trw, &size);
	if (rc == -1) {
	jniThrowErrnoException(env, "getsockopt : TCP_REPAIR_WINDOW", errno);
	return NULL;
	}

	struct tcp_info tcpinfo = {};
	socklen_t tcpinfo_size = sizeof(tcp_info);

	// Obtain the window scale from the tcp info structure. This contains a scale factor that
	// should be applied to the window size.
	rc = getsockopt(fd, IPPROTO_TCP, TCP_INFO, &tcpinfo, &tcpinfo_size);
	if (rc == -1) {
	jniThrowErrnoException(env, "getsockopt : TCP_INFO", errno);
	return NULL;
	}

	jclass class_TcpRepairWindow = env->FindClass("android/net/TcpRepairWindow");
	jmethodID ctor = env->GetMethodID(class_TcpRepairWindow, "<init>", "(IIIIII)V");

	return env->NewObject(class_TcpRepairWindow, ctor, trw.snd_wl1, trw.snd_wnd, trw.max_window,
	trw.rcv_wnd, trw.rcv_wup, tcpinfo.tcpi_rcv_wscale);
	}

	// ----------------------------------------------------------------------------

	/*
	* JNI registration.
	*/
	// clang-format off
	static const JNINativeMethod gNetworkUtilMethods[] = {
	/* name, signature, funcPtr */
	{ "bindProcessToNetworkHandle", "(J)Z", (void*) android_net_utils_bindProcessToNetworkHandle },
	{ "getBoundNetworkHandleForProcess", "()J", (void*) android_net_utils_getBoundNetworkHandleForProcess },
	{ "bindProcessToNetworkForHostResolution", "(I)Z", (void*) android_net_utils_bindProcessToNetworkForHostResolution },
	{ "bindSocketToNetworkHandle", "(Ljava/io/FileDescriptor;J)I", (void*) android_net_utils_bindSocketToNetworkHandle },
	{ "attachDropAllBPFFilter", "(Ljava/io/FileDescriptor;)V", (void*) android_net_utils_attachDropAllBPFFilter },
	{ "detachBPFFilter", "(Ljava/io/FileDescriptor;)V", (void*) android_net_utils_detachBPFFilter },
	{ "getTcpRepairWindow", "(Ljava/io/FileDescriptor;)Landroid/net/TcpRepairWindow;", (void*) android_net_utils_getTcpRepairWindow },
	{ "resNetworkSend", "(J[BII)Ljava/io/FileDescriptor;", (void*) android_net_utils_resNetworkSend },
	{ "resNetworkQuery", "(JLjava/lang/String;III)Ljava/io/FileDescriptor;", (void*) android_net_utils_resNetworkQuery },
	{ "resNetworkResult", "(Ljava/io/FileDescriptor;)Landroid/net/DnsResolver$DnsResponse;", (void*) android_net_utils_resNetworkResult },
	{ "resNetworkCancel", "(Ljava/io/FileDescriptor;)V", (void*) android_net_utils_resNetworkCancel },
	{ "getDnsNetwork", "()Landroid/net/Network;", (void*) android_net_utils_getDnsNetwork },
	};
	// clang-format on

	int register_android_net_NetworkUtils(JNIEnv* env)
	{
	return jniRegisterNativeMethods(env, NETUTILS_PKG_NAME, gNetworkUtilMethods,
	NELEM(gNetworkUtilMethods));
	}

	}; // namespace android