1 /*
2 * Copyright (C) 2018 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #define LOG_NDEBUG 0
18
19 #define LOG_TAG "TestNetworkServiceJni"
20
21 #include <arpa/inet.h>
22 #include <errno.h>
23 #include <fcntl.h>
24 #include <linux/if.h>
25 #include <linux/if_tun.h>
26 #include <linux/ipv6_route.h>
27 #include <linux/route.h>
28 #include <netinet/in.h>
29 #include <stdio.h>
30 #include <string.h>
31 #include <sys/ioctl.h>
32 #include <sys/socket.h>
33 #include <sys/stat.h>
34 #include <sys/types.h>
35
36 #include <log/log.h>
37
38 #include "jni.h"
39 #include <android-base/stringprintf.h>
40 #include <android-base/unique_fd.h>
41 #include <nativehelper/JNIHelp.h>
42 #include <nativehelper/ScopedUtfChars.h>
43
44 namespace android {
45
46 //------------------------------------------------------------------------------
47
throwException(JNIEnv * env,int error,const char * action,const char * iface)48 static void throwException(JNIEnv* env, int error, const char* action, const char* iface) {
49 const std::string& msg = "Error: " + std::string(action) + " " + std::string(iface) + ": "
50 + std::string(strerror(error));
51 jniThrowException(env, "java/lang/IllegalStateException", msg.c_str());
52 }
53
createTunTapInterface(JNIEnv * env,bool isTun,const char * iface)54 static int createTunTapInterface(JNIEnv* env, bool isTun, const char* iface) {
55 base::unique_fd tun(open("/dev/tun", O_RDWR | O_NONBLOCK));
56 ifreq ifr{};
57
58 // Allocate interface.
59 ifr.ifr_flags = (isTun ? IFF_TUN : IFF_TAP) | IFF_NO_PI;
60 strlcpy(ifr.ifr_name, iface, IFNAMSIZ);
61 if (ioctl(tun.get(), TUNSETIFF, &ifr)) {
62 throwException(env, errno, "allocating", ifr.ifr_name);
63 return -1;
64 }
65
66 // Activate interface using an unconnected datagram socket.
67 base::unique_fd inet6CtrlSock(socket(AF_INET6, SOCK_DGRAM, 0));
68 ifr.ifr_flags = IFF_UP;
69
70 if (ioctl(inet6CtrlSock.get(), SIOCSIFFLAGS, &ifr)) {
71 throwException(env, errno, "activating", ifr.ifr_name);
72 return -1;
73 }
74
75 return tun.release();
76 }
77
78 //------------------------------------------------------------------------------
79
create(JNIEnv * env,jobject,jboolean isTun,jstring jIface)80 static jint create(JNIEnv* env, jobject /* thiz */, jboolean isTun, jstring jIface) {
81 ScopedUtfChars iface(env, jIface);
82 if (!iface.c_str()) {
83 jniThrowNullPointerException(env, "iface");
84 return -1;
85 }
86
87 int tun = createTunTapInterface(env, isTun, iface.c_str());
88
89 // Any exceptions will be thrown from the createTunTapInterface call
90 return tun;
91 }
92
93 //------------------------------------------------------------------------------
94
95 static const JNINativeMethod gMethods[] = {
96 {"jniCreateTunTap", "(ZLjava/lang/String;)I", (void*)create},
97 };
98
register_android_server_TestNetworkService(JNIEnv * env)99 int register_android_server_TestNetworkService(JNIEnv* env) {
100 return jniRegisterNativeMethods(env, "com/android/server/TestNetworkService", gMethods,
101 NELEM(gMethods));
102 }
103
104 }; // namespace android
105