I have written a simple groovy program that uses the Jsch Library to establish an ssh tunnel and open a shell on the target server. The script connect fine and the shell opens. In IntelliJ I can enter input into the shell and get the subsequent output if I run the program. However if I attempt to do the same in the Terminal or in a cmd it connects fine but I cannot enter any input so can't run commands.
println "Opening connection to ${sshUser}#${sshHost}:${sshPort}"
Properties config = new Properties()
config.put("StrictHostKeyChecking", "no")
JSch jsch = new JSch()
Session sshSession = jsch.getSession(sshUser, sshHost, sshPort as int)
sshSession.setPassword(sshPass)
sshSession.setConfig(config)
sshSession.connect()
println "Connected"
println "Forwarding connection to ${targetHost}:${targetPort}"
def assignedPort = sshSession.setPortForwardingL(0, targetHost, targetPort as int)
println "Got port $assignedPort"
// Set the session to open as a Shell
Channel channel = targetSession.openChannel("shell")
// Set Input and Output streams
channel.setInputStream(System.in)
channel.setOutputStream(System.out);
// Connect
channel.connect()
UPDATE
After further reading it seems that to get this working there is a hack for the Windows prompt. However the code that JCraft provided has a number of issues that I'm struggling with:
channel.setInputStream(new FilterInputStream(System.in){
public int read(byte[] b, int off, int len)throws IOException{
return in.read(b, off, (len>1024?1024:len));
}
});
I get the very helpful error "Wrong Statement"
I've found a solution really simple in the end. The Windows Prompt hack does work but needs to be tweaked as follows:
return System.in.read(b, off, (len>1024?1024:len));
Thanks for your help anyway guys
Related
I'm using Jcraft JSch to ssh into a remote machine and execute a command. As it's a non-interactive shell it's not finding Java home. How do I set Java home while using jsch? looking like
((ChannelExec) channel).setEnv("LANG", "UTF-8");
((ChannelExec) channel).setEnv("JAVA_HOME", "/blah/java/J8.0_64/");
is deprecated?
public String sendCommand(String command) {
StringBuilder outputBuffer = new StringBuilder();
try {
Channel channel = sesConnection.openChannel("exec");
((ChannelExec) channel).setEnv("LANG", "UTF-8");
((ChannelExec) channel).setEnv("JAVA_HOME", "/blah/java/J8.0_64/");
((ChannelExec) channel).setCommand(command);
InputStream commandOutput = channel.getInputStream();
channel.connect();
int readByte = commandOutput.read();
while (readByte != 0xffffffff) {
outputBuffer.append((char) readByte);
readByte = commandOutput.read();
}
channel.disconnect();
} catch (IOException ioX) {
logWarning(ioX.getMessage());
return null;
} catch (JSchException jschX) {
logWarning(jschX.getMessage());
return null;
}
return outputBuffer.toString();
}
Error I'm getting while executing a command
JAVA_HOME not set and cannot find javac to deduce location, please set JAVA_HOME.
ChannelExec.setEnv on JSch side probably works. But assuming you are connecting to an OpenSSH server, the server must be explicitly configured to allow you to set the LANG and JAVA_HOME environment variables using the AcceptEnv directive. What it probably is not.
You can try the same using PuTTY (Connection > Data > Environment variables). You will probably get "Server refused to set environment variables" message back.
See also How can I set environment variables when I ssh login to my Unix box by passing custom arguments?
Anyway, the correct solution is to fix your server configuration to set the environment correctly even for non-interactive sessions.
Or as a dirty workaround you can set the variables directly in your command:
JAVA_HOME=/blah/java/J8.0_64/; java ...
See also Certain Unix commands fail with "... not found", when executed through Java using JSch.
This got me when I was trying to run maven using jsch exec.
Easy work-around is to use bash to run your command.
String command = "bash --login -c 'mvn --version'";
((ChannelExec) channel).setCommand(command);
or
((ChannelExec) channel).setCommand("bash --login -c '"+command+"'");
I have a piece of code which connects to a Unix server and executes commands.
I have been trying with simple commands and they work fine.
I am able to login and get the output of the commands.
I need to run an Ab-initio graph through Java.
I am using the air sandbox run graph command for this.
It runs fine, when I login using SSH client and run the command. I am able to run the graph. However, when I try to run the command through Java it gives me a "air not found" error.
Is there any kind of limit on what kind of Unix commands JSch supports?
Any idea why I'm not able to run the command through my Java code?
Here's the code:
public static void connect(){
try{
JSch jsch=new JSch();
String host="*****";
String user="*****";
String config =
"Host foo\n"+
" User "+user+"\n"+
" Hostname "+host+"\n";
ConfigRepository configRepository =
com.jcraft.jsch.OpenSSHConfig.parse(config);
jsch.setConfigRepository(configRepository);
Session session=jsch.getSession("foo");
String passwd ="*****";
session.setPassword(passwd);
UserInfo ui = new MyUserInfo(){
public boolean promptYesNo(String message){
int foo = 0;
return foo==0;
}
};
session.setUserInfo(ui);
session.connect();
String command="air sandbox run <graph-path>";
Channel channel=session.openChannel("exec");
((ChannelExec)channel).setCommand(command);
channel.setInputStream(null);
((ChannelExec)channel).setErrStream(System.err);
InputStream in=channel.getInputStream();
channel.connect();
byte[] tmp=new byte[1024];
while(true){
while(in.available()>0){
int i=in.read(tmp, 0, 1024);
if(i<0)break;
page_message=new String(tmp, 0, i);
System.out.print(page_message);
}
if(channel.isClosed()){
if(in.available()>0) continue;
System.out.println("exit-status: "+channel.getExitStatus());
break;
}
try{Thread.sleep(1000);}catch(Exception ee){}
}
channel.disconnect();
session.disconnect();
}
catch(Exception e){
System.out.println(e);
}
}
public static void main(String arg[]){
connect();
}
public String return_message(){
String ret_message=page_message;
return ret_message;
}
public static abstract class MyUserInfo
implements UserInfo, UIKeyboardInteractive{
public String getPassword(){ return null; }
public boolean promptYesNo(String str){ return false; }
public String getPassphrase(){ return null; }
public boolean promptPassphrase(String message){ return false; }
public boolean promptPassword(String message){ return false; }
public void showMessage(String message){ }
public String[] promptKeyboardInteractive(String destination,
String name,
String instruction,
String[] prompt,
boolean[] echo){
return null;
}
}
The "exec" channel in the JSch (rightfully) does not allocate a pseudo terminal (PTY) for the session. As a consequence a different set of startup scripts is (might be) sourced (particularly for non-interactive sessions, .bash_profile is not sourced). And/or different branches in the scripts are taken, based on absence/presence of the TERM environment variable. So the environment might differ from the interactive session, you use with your SSH client.
So, in your case, the PATH is probably set differently; and consequently the air executable cannot be found.
To verify that this is the root cause, disable the pseudo terminal allocation in your SSH client. For example in PuTTY, it's Connection > SSH > TTY > Don't allocate a pseudo terminal. Then, go to Connection > SSH > Remote command and enter your air ... command. Check Session > Close window on exit > Never and open the session. You should get the same "air not found" error.
Ways to fix this, in preference order:
Fix the command not to rely on a specific environment. Use a full path to air in the command. E.g.:
/bin/air sandbox run <graph-path>
If you do not know the full path, on common *nix systems, you can use which air command in your interactive SSH session.
Fix your startup scripts to set the PATH the same for both interactive and non-interactive sessions.
Try running the script explicitly via login shell (use --login switch with common *nix shells):
bash --login -c "air sandbox run sandbox run <graph-path>"
If the command itself relies on a specific environment setup and you cannot fix the startup scripts, you can change the environment in the command itself. Syntax for that depends on the remote system and/or the shell. In common *nix systems, this works:
String command="PATH=\"$PATH;/path/to/air\" && air sandbox run <graph-path>";
Another (not recommended) approach is to force the pseudo terminal allocation for the "exec" channel using the .setPty method:
Channel channel = session.openChannel("exec");
((ChannelExec)channel).setPty(true);
Using the pseudo terminal to automate a command execution can bring you nasty side effects. See for example Is there a simple way to get rid of junk values that come when you SSH using Python's Paramiko library and fetch output from CLI of a remote machine?
For a similar issues, see
Certain Unix commands fail with "... not found", when executed through Java using JSch even with setPty enabled
Commands executed using JSch behaves differently than in SSH terminal (bypasses confirm prompt message of "yes/"no")
JSch: Is there a way to expose user environment variables to "exec" channel?
Command (.4gl) executed with SSH.NET SshClient.RunCommand fails with "No such file or directory"
you could try to find out where "air" resides with
whereis air
and then use this outcome.
something like
/usr/bin/air sandbox run graph
You can use an ~/.ssh/environment file to set your AB_HOME and PATH variables.
I have a piece of code which connects to a Unix server and executes commands.
I have been trying with simple commands and they work fine.
I am able to login and get the output of the commands.
I need to run an Ab-initio graph through Java.
I am using the air sandbox run graph command for this.
It runs fine, when I login using SSH client and run the command. I am able to run the graph. However, when I try to run the command through Java it gives me a "air not found" error.
Is there any kind of limit on what kind of Unix commands JSch supports?
Any idea why I'm not able to run the command through my Java code?
Here's the code:
public static void connect(){
try{
JSch jsch=new JSch();
String host="*****";
String user="*****";
String config =
"Host foo\n"+
" User "+user+"\n"+
" Hostname "+host+"\n";
ConfigRepository configRepository =
com.jcraft.jsch.OpenSSHConfig.parse(config);
jsch.setConfigRepository(configRepository);
Session session=jsch.getSession("foo");
String passwd ="*****";
session.setPassword(passwd);
UserInfo ui = new MyUserInfo(){
public boolean promptYesNo(String message){
int foo = 0;
return foo==0;
}
};
session.setUserInfo(ui);
session.connect();
String command="air sandbox run <graph-path>";
Channel channel=session.openChannel("exec");
((ChannelExec)channel).setCommand(command);
channel.setInputStream(null);
((ChannelExec)channel).setErrStream(System.err);
InputStream in=channel.getInputStream();
channel.connect();
byte[] tmp=new byte[1024];
while(true){
while(in.available()>0){
int i=in.read(tmp, 0, 1024);
if(i<0)break;
page_message=new String(tmp, 0, i);
System.out.print(page_message);
}
if(channel.isClosed()){
if(in.available()>0) continue;
System.out.println("exit-status: "+channel.getExitStatus());
break;
}
try{Thread.sleep(1000);}catch(Exception ee){}
}
channel.disconnect();
session.disconnect();
}
catch(Exception e){
System.out.println(e);
}
}
public static void main(String arg[]){
connect();
}
public String return_message(){
String ret_message=page_message;
return ret_message;
}
public static abstract class MyUserInfo
implements UserInfo, UIKeyboardInteractive{
public String getPassword(){ return null; }
public boolean promptYesNo(String str){ return false; }
public String getPassphrase(){ return null; }
public boolean promptPassphrase(String message){ return false; }
public boolean promptPassword(String message){ return false; }
public void showMessage(String message){ }
public String[] promptKeyboardInteractive(String destination,
String name,
String instruction,
String[] prompt,
boolean[] echo){
return null;
}
}
The "exec" channel in the JSch (rightfully) does not allocate a pseudo terminal (PTY) for the session. As a consequence a different set of startup scripts is (might be) sourced (particularly for non-interactive sessions, .bash_profile is not sourced). And/or different branches in the scripts are taken, based on absence/presence of the TERM environment variable. So the environment might differ from the interactive session, you use with your SSH client.
So, in your case, the PATH is probably set differently; and consequently the air executable cannot be found.
To verify that this is the root cause, disable the pseudo terminal allocation in your SSH client. For example in PuTTY, it's Connection > SSH > TTY > Don't allocate a pseudo terminal. Then, go to Connection > SSH > Remote command and enter your air ... command. Check Session > Close window on exit > Never and open the session. You should get the same "air not found" error.
Ways to fix this, in preference order:
Fix the command not to rely on a specific environment. Use a full path to air in the command. E.g.:
/bin/air sandbox run <graph-path>
If you do not know the full path, on common *nix systems, you can use which air command in your interactive SSH session.
Fix your startup scripts to set the PATH the same for both interactive and non-interactive sessions.
Try running the script explicitly via login shell (use --login switch with common *nix shells):
bash --login -c "air sandbox run sandbox run <graph-path>"
If the command itself relies on a specific environment setup and you cannot fix the startup scripts, you can change the environment in the command itself. Syntax for that depends on the remote system and/or the shell. In common *nix systems, this works:
String command="PATH=\"$PATH;/path/to/air\" && air sandbox run <graph-path>";
Another (not recommended) approach is to force the pseudo terminal allocation for the "exec" channel using the .setPty method:
Channel channel = session.openChannel("exec");
((ChannelExec)channel).setPty(true);
Using the pseudo terminal to automate a command execution can bring you nasty side effects. See for example Is there a simple way to get rid of junk values that come when you SSH using Python's Paramiko library and fetch output from CLI of a remote machine?
For a similar issues, see
Certain Unix commands fail with "... not found", when executed through Java using JSch even with setPty enabled
Commands executed using JSch behaves differently than in SSH terminal (bypasses confirm prompt message of "yes/"no")
JSch: Is there a way to expose user environment variables to "exec" channel?
Command (.4gl) executed with SSH.NET SshClient.RunCommand fails with "No such file or directory"
you could try to find out where "air" resides with
whereis air
and then use this outcome.
something like
/usr/bin/air sandbox run graph
You can use an ~/.ssh/environment file to set your AB_HOME and PATH variables.
I have a piece of code which connects to a Unix server and executes commands.
I have been trying with simple commands and they work fine.
I am able to login and get the output of the commands.
I need to run an Ab-initio graph through Java.
I am using the air sandbox run graph command for this.
It runs fine, when I login using SSH client and run the command. I am able to run the graph. However, when I try to run the command through Java it gives me a "air not found" error.
Is there any kind of limit on what kind of Unix commands JSch supports?
Any idea why I'm not able to run the command through my Java code?
Here's the code:
public static void connect(){
try{
JSch jsch=new JSch();
String host="*****";
String user="*****";
String config =
"Host foo\n"+
" User "+user+"\n"+
" Hostname "+host+"\n";
ConfigRepository configRepository =
com.jcraft.jsch.OpenSSHConfig.parse(config);
jsch.setConfigRepository(configRepository);
Session session=jsch.getSession("foo");
String passwd ="*****";
session.setPassword(passwd);
UserInfo ui = new MyUserInfo(){
public boolean promptYesNo(String message){
int foo = 0;
return foo==0;
}
};
session.setUserInfo(ui);
session.connect();
String command="air sandbox run <graph-path>";
Channel channel=session.openChannel("exec");
((ChannelExec)channel).setCommand(command);
channel.setInputStream(null);
((ChannelExec)channel).setErrStream(System.err);
InputStream in=channel.getInputStream();
channel.connect();
byte[] tmp=new byte[1024];
while(true){
while(in.available()>0){
int i=in.read(tmp, 0, 1024);
if(i<0)break;
page_message=new String(tmp, 0, i);
System.out.print(page_message);
}
if(channel.isClosed()){
if(in.available()>0) continue;
System.out.println("exit-status: "+channel.getExitStatus());
break;
}
try{Thread.sleep(1000);}catch(Exception ee){}
}
channel.disconnect();
session.disconnect();
}
catch(Exception e){
System.out.println(e);
}
}
public static void main(String arg[]){
connect();
}
public String return_message(){
String ret_message=page_message;
return ret_message;
}
public static abstract class MyUserInfo
implements UserInfo, UIKeyboardInteractive{
public String getPassword(){ return null; }
public boolean promptYesNo(String str){ return false; }
public String getPassphrase(){ return null; }
public boolean promptPassphrase(String message){ return false; }
public boolean promptPassword(String message){ return false; }
public void showMessage(String message){ }
public String[] promptKeyboardInteractive(String destination,
String name,
String instruction,
String[] prompt,
boolean[] echo){
return null;
}
}
The "exec" channel in the JSch (rightfully) does not allocate a pseudo terminal (PTY) for the session. As a consequence a different set of startup scripts is (might be) sourced (particularly for non-interactive sessions, .bash_profile is not sourced). And/or different branches in the scripts are taken, based on absence/presence of the TERM environment variable. So the environment might differ from the interactive session, you use with your SSH client.
So, in your case, the PATH is probably set differently; and consequently the air executable cannot be found.
To verify that this is the root cause, disable the pseudo terminal allocation in your SSH client. For example in PuTTY, it's Connection > SSH > TTY > Don't allocate a pseudo terminal. Then, go to Connection > SSH > Remote command and enter your air ... command. Check Session > Close window on exit > Never and open the session. You should get the same "air not found" error.
Ways to fix this, in preference order:
Fix the command not to rely on a specific environment. Use a full path to air in the command. E.g.:
/bin/air sandbox run <graph-path>
If you do not know the full path, on common *nix systems, you can use which air command in your interactive SSH session.
Fix your startup scripts to set the PATH the same for both interactive and non-interactive sessions.
Try running the script explicitly via login shell (use --login switch with common *nix shells):
bash --login -c "air sandbox run sandbox run <graph-path>"
If the command itself relies on a specific environment setup and you cannot fix the startup scripts, you can change the environment in the command itself. Syntax for that depends on the remote system and/or the shell. In common *nix systems, this works:
String command="PATH=\"$PATH;/path/to/air\" && air sandbox run <graph-path>";
Another (not recommended) approach is to force the pseudo terminal allocation for the "exec" channel using the .setPty method:
Channel channel = session.openChannel("exec");
((ChannelExec)channel).setPty(true);
Using the pseudo terminal to automate a command execution can bring you nasty side effects. See for example Is there a simple way to get rid of junk values that come when you SSH using Python's Paramiko library and fetch output from CLI of a remote machine?
For a similar issues, see
Certain Unix commands fail with "... not found", when executed through Java using JSch even with setPty enabled
Commands executed using JSch behaves differently than in SSH terminal (bypasses confirm prompt message of "yes/"no")
JSch: Is there a way to expose user environment variables to "exec" channel?
Command (.4gl) executed with SSH.NET SshClient.RunCommand fails with "No such file or directory"
you could try to find out where "air" resides with
whereis air
and then use this outcome.
something like
/usr/bin/air sandbox run graph
You can use an ~/.ssh/environment file to set your AB_HOME and PATH variables.
I have a datacard ZTE MF190. I want to use AT commands to register in 2G or 3G and access internet via datacard. Found this article about how to make data call:
AT+cgatt=1
AT+CGDCONT=1,”IP”,”epc.tmobile.com” //I used my operator PDP context
AT+CGACT=1,1
But ping from OS terminal shows 100% package loss.
I've tried on Ubuntu 14 and Windows 7.
How can I connect internet with AT commands using datacard on Ubuntu?
UPDATE
I gave bounty to #tripleee's answer because it's more full than first one and answered all my questions. But I'm not satisfied with answers, so I'll answer my own question in a week.
In my answer I'll show how to handle this process with Java. So, please do not move this question to other Stack Exchange websites.
Creating a connection between the card and your provider is not sufficient. You need some mechanism for creating a network interface out of this connection, and set up your network stack to route packets over this interface.
Traditionally, the pppd daemon has been a popular choice for this task. You would create a "chat script" with the commands for establishing a data call (these days, pppd might come packaged with a suitable canned script) and the daemon would handle the entire process of placing the call, authenticating, setting up a network interface over the circuit, and configuring the system to route packets over it, as well as configuring DNS etc to use it for resolver queries, etc.
I tried to sniff USB port but on this case dashboard can not connect because of busy port
It is certainly possible. See this question
Found this article about how to make data call
What that article is about is how to set up the call, not how to make it.
After you made correct setup, connect to internet with this command:
ATD*99***1#
UPDATE1: After a bit of research I believe that article was written only to promote their software and has no practical use. In reality dialing is made with pppd or wvdial
UPDATE2: We discussed ways to solve the problem in a chat room (in Russian). It turned out cnetworkmanager will be the way to go
As far as I know wvdial uses ppp daemon to connect to the internet using modem. wvdial is preinstalled on desktop version of Ubuntu.
wvdial uses a config file located /etc/wvdial.conf. Let's edit this file. Type in your terminal
sudo nano /etc/wvdial.conf
and you will see something like this
[Dialer Defaults]
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2
Stupid Mode = yes
ISDN = 0
Modem Type = Analog Modem
New PPPD = yes
Phone = *99#
Modem = /dev/ttyUSB2
Username = ''
Password = ''
Baud = 9600
Dial Timeout = 30
Dial Attempts = 3
Explanation of all keys you can find in wvdial.conf(5) - Linux man page. If you need to change your provider dial number, username, password or any other information about connection and device you can change file content and save it.
There are 3 serial ports for ZTE MF190. Normally it's ttyUSB0, ttyUSB1 and ttyUSB2. And in my case ttyUSB2 is for internet connection. It would not work on other ports. So you need to find the right serial port for your modem.
There is an automatic configurator which edits wvdial.conf file, sets serial port baud rate etc. Since it is not always configure correctly I would not recommend to use it:
sudo wvdialconf /etc/wvdial.conf
It would be better if you configure wvdial manually.
Now, when your device connected and wvdial configured to work with device, you can execute this line from terminal:
wvdial
You will see a lot of lines. But if you see those lines - you have succeeded.
local IP address XX.XX.XX.XX
remote IP address XX.XX.XX.XX
primary DNS address XX.XX.XX.XX
secondary DNS address XX.XX.XX.XX
Now, how we can use it in programming? I'll provide some code to work with it on Java. You can use this code to dial.
public int dialer() {
// status for debug. If status == 4 then you connected successfully
int status;
// create process of wvdial
ProcessBuilder builder = new ProcessBuilder("wvdial");
try {
// start wvdial
final Process process = builder.start();
// wvdial listener thread
final Thread ioThread = new Thread() {
#Override
public void run() {
try {
final BufferedReader reader = new BufferedReader(
new InputStreamReader(process.getErrorStream()));
// wvdial output line
String line;
while ((line = reader.readLine()) != null) {
// if "local IP address" line detected set status 1
if (line.contains("local IP address")) {
status = 1;
}
if (line.contains("remote IP address")) {
status = 2;
}
if (line.contains("primary DNS address")) {
status = 3;
}
if (line.contains("secondary DNS address")) {
status = 4;
}
}
reader.close();
} catch (final Exception e) {
}
}
};
// start listener
ioThread.start();
// wait 6 secs and return status. Some kind of timeout
Thread.sleep(6000);
} catch (Exception e) {
}
return status;
}
And here is a disconnector method. All you need is to kill wvdial process and thread will be destroyed:
public boolean disconnect() {
ProcessBuilder builder = new ProcessBuilder("pkill", "wvdial");
try {
builder.start();
return true;
} catch (IOException e) {
return false;
}
}