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 "netutils/ifc.h"
39
40 #include "jni.h"
41 #include <android-base/stringprintf.h>
42 #include <android-base/unique_fd.h>
43 #include <nativehelper/JNIHelp.h>
44 #include <nativehelper/ScopedUtfChars.h>
45
46 namespace android {
47
48 //------------------------------------------------------------------------------
49
throwException(JNIEnv * env,int error,const char * action,const char * iface)50 static void throwException(JNIEnv* env, int error, const char* action, const char* iface) {
51 const std::string& msg =
52 android::base::StringPrintf("Error %s %s: %s", action, iface, strerror(error));
53
54 jniThrowException(env, "java/lang/IllegalStateException", msg.c_str());
55 }
56
createTunTapInterface(JNIEnv * env,bool isTun,const char * iface)57 static int createTunTapInterface(JNIEnv* env, bool isTun, const char* iface) {
58 base::unique_fd tun(open("/dev/tun", O_RDWR | O_NONBLOCK));
59 ifreq ifr{};
60
61 // Allocate interface.
62 ifr.ifr_flags = (isTun ? IFF_TUN : IFF_TAP) | IFF_NO_PI;
63 strlcpy(ifr.ifr_name, iface, IFNAMSIZ);
64 if (ioctl(tun.get(), TUNSETIFF, &ifr)) {
65 throwException(env, errno, "allocating", ifr.ifr_name);
66 return -1;
67 }
68
69 // Activate interface using an unconnected datagram socket.
70 base::unique_fd inet6CtrlSock(socket(AF_INET6, SOCK_DGRAM, 0));
71 ifr.ifr_flags = IFF_UP;
72
73 if (ioctl(inet6CtrlSock.get(), SIOCSIFFLAGS, &ifr)) {
74 throwException(env, errno, "activating", ifr.ifr_name);
75 return -1;
76 }
77
78 return tun.release();
79 }
80
81 //------------------------------------------------------------------------------
82
create(JNIEnv * env,jobject,jboolean isTun,jstring jIface)83 static jint create(JNIEnv* env, jobject /* thiz */, jboolean isTun, jstring jIface) {
84 ScopedUtfChars iface(env, jIface);
85 if (!iface.c_str()) {
86 jniThrowNullPointerException(env, "iface");
87 return -1;
88 }
89
90 int tun = createTunTapInterface(env, isTun, iface.c_str());
91
92 // Any exceptions will be thrown from the createTunTapInterface call
93 return tun;
94 }
95
96 //------------------------------------------------------------------------------
97
98 static const JNINativeMethod gMethods[] = {
99 {"jniCreateTunTap", "(ZLjava/lang/String;)I", (void*)create},
100 };
101
register_android_server_TestNetworkService(JNIEnv * env)102 int register_android_server_TestNetworkService(JNIEnv* env) {
103 return jniRegisterNativeMethods(env, "com/android/server/TestNetworkService", gMethods,
104 NELEM(gMethods));
105 }
106
107 }; // namespace android
108