我正在通过TCP连接从Android 4.4.4客户端向使用java.net.socket和javax.net.ssl.SSLSocket的服务器传输1Mb到100Mb的文件。如果没有OpenVPN，它会按预期工作，但是随着它的运行，java.net.socket TCP连接会在每次结束时锁定，而javax.net.ssl.SSLSocket有时会锁定。 我目前解决这个问题的方法是在客户端将“缓冲区大小”更改为10个字节（请参阅代码）。 我已经尝试在OpenVPN配置文件中更改MTU，MSSFIX和FRAGMENT值。
我使用兼容WiFi的路由器建立了本地网络。路由器未连接到Internet。我的Android客户端通过WiFi连接。我有一个eth连接到我的计算机，我正在运行我的java服务器和Xubuntu在virtualbox上使用openvpn。 Virtualbox与桥接适配器连接。 Android客户端可以连接到openvpn服务器，并可以ping网络上的其他客户端。所有机器上的当前MTU为1500（默认值）。
我正在测试OpenVPN对纯文本和安全套接字连接的时间影响。
protected void nonsecure_transfer(String ip, int port, int fileno) {
Socket sock;
try {
sock = new Socket(ip, port);
// sendfile
final InputStream is;
switch (fileno){
case 0:
is = getResources().openRawResource(R.raw.test1mb);
break;
case 1:
is = getResources().openRawResource(R.raw.test10mb);
break;
case 2:
is = getResources().openRawResource(R.raw.test100mb);
break;
default: is = getResources().openRawResource(R.raw.test1mb);
break;
}
BufferedOutputStream os = new BufferedOutputStream(sock.getOutputStream());
int buffer_size = Integer.parseInt(buffersize.getText().toString());
byte buffer[] = new byte[buffer_size];
int count = 0;
while ((count = is.read(buffer)) > 0) {
os.write(buffer, 0, count);
}
os.flush();
sock.close();
} catch (UnknownHostException e) {
log.append("Error \n" + e);
} catch (IOException e) {
log.append("Error \n" + e);
}
protected void handleConnection(Socket server) throws Exception {
InputStream is = server.getInputStream();
FileOutputStream fos = new FileOutputStream(...);
BufferedOutputStream bos = new BufferedOutputStream(fos);
byte buffer[] = new byte[8129];
int count = 0;
int size = 0;
while ((count = is.read(buffer)) > 0)
{
bos.write(buffer, 0, count);
}
bos.flush();
bos.close();
is.close();
}
protected void secure_transfer(String ip, int port, int fileno) throws IOException, CertificateException, NoSuchAlgorithmException, UnrecoverableKeyException, KeyStoreException, KeyManagementException {
String passphrase = "test123";
KeyStore ks = KeyStore.getInstance("BKS");
InputStream keyin = getResources().openRawResource(R.raw.server_keystore);
ks.load(keyin, "test123".toCharArray());
TrustManagerFactory tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
tmf.init(ks);
KeyStore clientKeyStore = KeyStore.getInstance("BKS");
clientKeyStore.load(getResources().openRawResource(R.raw.client_keystore), passphrase.toCharArray());
KeyManagerFactory kmf = KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());
kmf.init(clientKeyStore, passphrase.toCharArray());
SSLContext sslContext = SSLContext.getInstance("TLS");
sslContext.init(kmf.getKeyManagers(), tmf.getTrustManagers(), new SecureRandom());
SSLSocketFactory socketFactory = sslContext.getSocketFactory();
SSLSocket socket = (SSLSocket)
socketFactory.createSocket(new Socket(ip, port), ip, port, false);
socket.startHandshake();
try {
// sendfile
final InputStream is;
switch (fileno){
case 0:
is = getResources().openRawResource(R.raw.test1mb);
break;
case 1:
is = getResources().openRawResource(R.raw.test10mb);
break;
case 2:
is = getResources().openRawResource(R.raw.test100mb);
break;
default: is = getResources().openRawResource(R.raw.test1mb);
break;
}
BufferedOutputStream os = new BufferedOutputStream(socket.getOutputStream());
int buffer_size = Integer.parseInt(buffersize.getText().toString());
byte buffer[] = new byte[buffer_size];
int count = 0;
while ((count = is.read(buffer)) > 0) {
os.write(buffer, 0, count);
}
os.flush();
socket.close();
} catch (UnknownHostException e) {
log.append("Error \n" + e);
} catch (IOException e) {
log.append("Error \n" + e);
}
}
public void listen() throws Exception {
try {
String passphrase = "test123";
KeyStore ks = KeyStore.getInstance("JKS");
ks.load(new FileInputStream("server_keystore.jks"),"test123".toCharArray());
KeyManagerFactory kmf =
KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());
kmf.init(ks, "test123".toCharArray());
SSLContext sslcontext =
SSLContext.getInstance("TLS");
sslcontext.init(kmf.getKeyManagers(), null, null);
ServerSocketFactory ssf =
sslcontext.getServerSocketFactory();
SSLServerSocket serverSocket = (SSLServerSocket)
ssf.createServerSocket(9999);
while (true) {
SSLSocket s = (SSLSocket) serverSocket.accept();
handleConnection(s);
s.close();
}
} catch (IOException ioe) {
System.out.println("IOException: " + ioe);
ioe.printStackTrace();
System.exit(1);
} catch (GeneralSecurityException e) {
System.out.println("GeneralSecurityException: " + e);
e.printStackTrace();
System.exit(1);
}
}
int packet = 0;
protected void handleConnection(Socket server) throws Exception {
InputStream is = server.getInputStream();
FileOutputStream fos = new FileOutputStream(...);
BufferedOutputStream bos = new BufferedOutputStream(fos);
byte buffer[] = new byte[8129];
int count = 0;
int size = 0;
while ((count = is.read(buffer)) > 0)
{
bos.write(buffer, 0, count);
}
bos.flush();
bos.close();
is.close();
}
port 1194
proto udp
dev tun
ca ca.crt
cert server.crt
key server.key # This file should be kept secret
dh dh2048.pem
push "redirect-gateway def1 bypass-dhcp"
push "dhcp-option DNS 208.67.222.222"
push "dhcp-option DNS 208.67.220.220"
;client-to-client
;duplicate-cn
keepalive 10 120
tls-auth ta.key 0 # This file is secret
key-direction 0
cipher AES-128-CBC # AES
auth SHA256
;comp-lzo
persist-key
persist-tun
mssfix 1500
enp0s3 Link encap:Ethernet HWaddr 08:00:27:19:55:dc
inet addr:192.168.1.216 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fdbb:8432:3a7c:0:3290:af79:3a93:dcfd/64 Scope:Global
inet6 addr: fe80::c133:9666:4062:e40f/64 Scope:Link
inet6 addr: fdbb:8432:3a7c::52c/128 Scope:Global
inet6 addr: fdbb:8432:3a7c:0:f8b3:90c2:1d8f:f21e/64 Scope:Global
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:162659 errors:0 dropped:0 overruns:0 frame:0
TX packets:63868 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:214361110 (214.3 MB) TX bytes:18496915 (18.4 MB)
tun0 Link encap:UNSPEC HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
inet addr:10.8.0.1 P-t-P:10.8.0.2 Mask:255.255.255.255
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1500 Metric:1
RX packets:9932 errors:0 dropped:0 overruns:0 frame:0
TX packets:7518 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:13666203 (13.6 MB) TX bytes:423228 (423.2 KB)
en1: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
ether 00:26:08:e8:d3:36
inet 192.168.1.194 netmask 0xffffff00 broadcast 192.168.1.255
media: autoselect
status: active