blob: 03b9793ccba8be473cf255fb9ae450738a6c3493 [file] [log] [blame]
/*
* Copyright 2008, 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 "NetUtils"
#include <vector>
#include <arpa/inet.h>
#include <linux/filter.h>
#include <linux/if_arp.h>
#include <linux/tcp.h>
#include <net/if.h>
#include <netinet/ether.h>
#include <netinet/ip.h>
#include <netinet/udp.h>
#include <DnsProxydProtocol.h> // NETID_USE_LOCAL_NAMESERVERS
#include <android_runtime/AndroidRuntime.h>
#include <cutils/properties.h>
#include <nativehelper/JNIHelp.h>
#include <nativehelper/ScopedLocalRef.h>
#include <utils/Log.h>
#include <utils/misc.h>
#include "NetdClient.h"
#include "core_jni_helpers.h"
#include "jni.h"
extern "C" {
int ifc_enable(const char *ifname);
int ifc_disable(const char *ifname);
}
#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 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[] = {
// Reject all.
BPF_STMT(BPF_RET | BPF_K, 0)
};
struct sock_fprog filter = {
sizeof(filter_code) / sizeof(filter_code[0]),
filter_code,
};
int fd = jniGetFDFromFileDescriptor(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 dummy = 0;
int fd = jniGetFDFromFileDescriptor(env, javaFd);
if (setsockopt(fd, SOL_SOCKET, SO_DETACH_FILTER, &dummy, sizeof(dummy)) != 0) {
jniThrowExceptionFmt(env, "java/net/SocketException",
"setsockopt(SO_DETACH_FILTER): %s", strerror(errno));
}
}
static jboolean android_net_utils_bindProcessToNetwork(JNIEnv *env, jobject thiz, jint netId)
{
return (jboolean) !setNetworkForProcess(netId);
}
static jint android_net_utils_getBoundNetworkForProcess(JNIEnv *env, jobject thiz)
{
return getNetworkForProcess();
}
static jboolean android_net_utils_bindProcessToNetworkForHostResolution(JNIEnv *env, jobject thiz,
jint netId)
{
return (jboolean) !setNetworkForResolv(netId);
}
static jint android_net_utils_bindSocketToNetwork(JNIEnv *env, jobject thiz, jint socket,
jint netId)
{
return setNetworkForSocket(netId, socket);
}
static jboolean android_net_utils_protectFromVpn(JNIEnv *env, jobject thiz, jint socket)
{
return (jboolean) !protectFromVpn(socket);
}
static jboolean android_net_utils_queryUserAccess(JNIEnv *env, jobject thiz, jint uid, jint netId)
{
return (jboolean) !queryUserAccess(uid, netId);
}
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, jint netId,
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.
std::vector<char> queryname(byteCountUTF8 + 1, 0);
env->GetStringUTFRegion(dname, 0, javaCharsCount, queryname.data());
int fd = resNetworkQuery(netId, queryname.data(), ns_class, ns_type, flags);
if (fd < 0) {
throwErrnoException(env, "resNetworkQuery", -fd);
return nullptr;
}
return jniCreateFileDescriptor(env, fd);
}
static jobject android_net_utils_resNetworkSend(JNIEnv *env, jobject thiz, jint netId,
jbyteArray msg, jint msgLen, jint flags) {
uint8_t data[MAXCMDSIZE];
checkLenAndCopy(env, msg, msgLen, data);
int fd = resNetworkSend(netId, data, msgLen, flags);
if (fd < 0) {
throwErrnoException(env, "resNetworkSend", -fd);
return nullptr;
}
return jniCreateFileDescriptor(env, fd);
}
static jobject android_net_utils_resNetworkResult(JNIEnv *env, jobject thiz, jobject javaFd) {
int fd = jniGetFDFromFileDescriptor(env, javaFd);
int rcode;
std::vector<uint8_t> buf(MAXPACKETSIZE, 0);
int res = resNetworkResult(fd, &rcode, buf.data(), MAXPACKETSIZE);
jniSetFileDescriptorOfFD(env, javaFd, -1);
if (res < 0) {
throwErrnoException(env, "resNetworkResult", -res);
return nullptr;
}
jbyteArray answer = env->NewByteArray(res);
if (answer == nullptr) {
throwErrnoException(env, "resNetworkResult", ENOMEM);
return nullptr;
} else {
env->SetByteArrayRegion(answer, 0, res,
reinterpret_cast<jbyte*>(buf.data()));
}
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 = jniGetFDFromFileDescriptor(env, javaFd);
resNetworkCancel(fd);
jniSetFileDescriptorOfFD(env, javaFd, -1);
}
static jobject android_net_utils_getDnsNetwork(JNIEnv *env, jobject thiz) {
unsigned dnsNetId = 0;
if (int res = getNetworkForDns(&dnsNetId) < 0) {
throwErrnoException(env, "getDnsNetId", -res);
return nullptr;
}
bool privateDnsBypass = dnsNetId & NETID_USE_LOCAL_NAMESERVERS;
static jclass class_Network = MakeGlobalRefOrDie(
env, FindClassOrDie(env, "android/net/Network"));
static jmethodID ctor = env->GetMethodID(class_Network, "<init>", "(IZ)V");
return env->NewObject(
class_Network, ctor, dnsNetId & ~NETID_USE_LOCAL_NAMESERVERS, privateDnsBypass);
}
static jobject android_net_utils_getTcpRepairWindow(JNIEnv *env, jobject thiz, jobject javaFd) {
if (javaFd == NULL) {
jniThrowNullPointerException(env, NULL);
return NULL;
}
int fd = jniGetFDFromFileDescriptor(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) {
throwErrnoException(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) {
throwErrnoException(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.
*/
static const JNINativeMethod gNetworkUtilMethods[] = {
/* name, signature, funcPtr */
{ "bindProcessToNetwork", "(I)Z", (void*) android_net_utils_bindProcessToNetwork },
{ "getBoundNetworkForProcess", "()I", (void*) android_net_utils_getBoundNetworkForProcess },
{ "bindProcessToNetworkForHostResolution", "(I)Z", (void*) android_net_utils_bindProcessToNetworkForHostResolution },
{ "bindSocketToNetwork", "(II)I", (void*) android_net_utils_bindSocketToNetwork },
{ "protectFromVpn", "(I)Z", (void*)android_net_utils_protectFromVpn },
{ "queryUserAccess", "(II)Z", (void*)android_net_utils_queryUserAccess },
{ "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", "(I[BII)Ljava/io/FileDescriptor;", (void*) android_net_utils_resNetworkSend },
{ "resNetworkQuery", "(ILjava/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 },
};
int register_android_net_NetworkUtils(JNIEnv* env)
{
return RegisterMethodsOrDie(env, NETUTILS_PKG_NAME, gNetworkUtilMethods,
NELEM(gNetworkUtilMethods));
}
}; // namespace android