Merge "Remove dependency on legacy jniGetFDFromFileDescriptor" am: 7f03c09497 (7f380d39) · Commits · e / os / android_packages_modules_NetworkStack

jni/network_stack_utils_jni.cpp

+65 −5

Original line number	Diff line number	Diff line
		@@ -16,6 +16,7 @@

		#define LOG_TAG "NetworkStackUtils-JNI"

		#include <dlfcn.h>
		#include <errno.h>
		#include <jni.h>
		#include <linux/filter.h>
		@@ -27,11 +28,11 @@
		#include <netinet/ip6.h>
		#include <netinet/udp.h>
		#include <stdlib.h>
		#include <sys/system_properties.h>

		#include <string>

		#include <nativehelper/JNIHelp.h>
		#include <nativehelper/JNIHelpCompat.h>

		#include <android/log.h>

		@@ -57,6 +58,65 @@ static bool checkLenAndCopy(JNIEnv* env, const jbyteArray& addr, int len, void*
		return true;
		}

		static int getNativeFileDescriptorWithoutNdk(JNIEnv* env, jobject javaFd) {
		// Prior to Android S, we need to find the descriptor field in the FileDescriptor class. The
		// symbol name has been stable in libcore, but is a private implementation detail.
		static jfieldID descriptorFieldID = nullptr;
		if (descriptorFieldID == nullptr) {
		jclass fileDescriptorClass = env->FindClass("java/io/FileDescriptor");
		descriptorFieldID = env->GetFieldID(fileDescriptorClass, "descriptor", "I");
		env->DeleteLocalRef(fileDescriptorClass);
		if (descriptorFieldID == nullptr) {
		__android_log_print(ANDROID_LOG_ERROR, LOG_TAG, "Failed to get descriptor field.");
		return -1;
		}
		}
		return javaFd != nullptr ? env->GetIntField(javaFd, descriptorFieldID) : -1;
		}

		static int getNativeFileDescriptorWithNdk(JNIEnv* env, jobject javaFd) {
		// Since Android S, there is an NDK API to get a file descriptor present in libnativehelper.so.
		// libnativehelper is loaded into all processes by the zygote since the zygote uses it
		// to load the Android Runtime and is also a public library (because of the NDK API).
		static int (ndkGetFD)(JNIEnv, jobject) = nullptr;
		if (ndkGetFD == nullptr) {
		void* handle = dlopen("libnativehelper.so", RTLD_NOLOAD \| RTLD_NODELETE);
		ndkGetFD = reinterpret_cast<decltype(ndkGetFD)>(dlsym(handle, "AFileDescriptor_getFD"));
		if (ndkGetFD == nullptr) {
		__android_log_print(ANDROID_LOG_ERROR, LOG_TAG,
		"Failed to dlsym(AFileDescriptor_getFD): %s", dlerror());
		dlclose(handle);
		return -1;
		}
		dlclose(handle);
		}
		return javaFd != nullptr ? ndkGetFD(env, javaFd) : -1;
		}

		static int getNativeFileDescriptor(JNIEnv* env, jobject javaFd) {
		static bool preferNdkFileDescriptorApi = false;
		static bool probeNdkFileDescriptorApi = true;

		if (probeNdkFileDescriptorApi) {
		// Check if we should use the NDK File Descriptor API introduced in S.
		preferNdkFileDescriptorApi = (android_get_device_api_level() >= __ANDROID_API_S__);
		if (!preferNdkFileDescriptorApi) {
		// Check if this is a device with Android S dogfood build.
		static constexpr const char* kCodenameProperty = "ro.build.version.codename";
		char codename[PROP_VALUE_MAX] = { 0 };
		preferNdkFileDescriptorApi = (__system_property_get(kCodenameProperty, codename) > 0 &&
		strncmp(codename, "S", 2) == 0);
		}
		probeNdkFileDescriptorApi = false;
		}

		if (preferNdkFileDescriptorApi) {
		return getNativeFileDescriptorWithNdk(env, javaFd);
		} else {
		return getNativeFileDescriptorWithoutNdk(env, javaFd);
		}
		}

		static void network_stack_utils_addArpEntry(JNIEnv *env, jobject thiz, jbyteArray ethAddr,
		jbyteArray ipv4Addr, jstring ifname, jobject javaFd) {
		arpreq req = {};
		@@ -84,7 +144,7 @@ static void network_stack_utils_addArpEntry(JNIEnv *env, jobject thiz, jbyteArra
		env->GetStringUTFRegion(ifname, 0, ifLen, req.arp_dev);

		req.arp_flags = ATF_COM; // Completed entry (ha valid)
		int fd = jniGetFDFromFileDescriptor(env, javaFd);
		int fd = getNativeFileDescriptor(env, javaFd);
		if (fd < 0) {
		jniThrowExceptionFmt(env, "java/io/IOException", "Invalid file descriptor");
		return;
		@@ -122,7 +182,7 @@ static void network_stack_utils_attachDhcpFilter(JNIEnv *env, jobject clazz, job
		filter_code,
		};

		int fd = jniGetFDFromFileDescriptor(env, javaFd);
		int fd = getNativeFileDescriptor(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));
		@@ -155,7 +215,7 @@ static void network_stack_utils_attachRaFilter(JNIEnv *env, jobject clazz, jobje
		filter_code,
		};

		int fd = jniGetFDFromFileDescriptor(env, javaFd);
		int fd = getNativeFileDescriptor(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));
		@@ -230,7 +290,7 @@ static void network_stack_utils_attachControlPacketFilter(
		filter_code,
		};

		int fd = jniGetFDFromFileDescriptor(env, javaFd);
		int fd = getNativeFileDescriptor(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));