tor-android/src/org/torproject/android/service/TorServiceUtils.java

/* Copyright (c) 2009, Nathan Freitas, Orbot / The Guardian Project - http://openideals.com/guardian */
/* See LICENSE for licensing information */
package org.torproject.android.service;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.StringTokenizer;

import android.util.Log;

public class TorServiceUtils implements TorServiceConstants {

	/**
	 * Check if we have root access
	 * @return boolean true if we have root
	 */
	public static boolean checkRootAccess() {
	

		StringBuilder log = new StringBuilder();
		
		try {
			
			// Run an empty script just to check root access
			String[] cmd = {"exit 0"};
			int exitCode = TorServiceUtils.doShellCommand(cmd, log, true, true);
			if (exitCode == 0) {
				
				return true;
			}
			
		} catch (IOException e) {
			//this means that there is no root to be had (normally) so we won't log anything
		}
		catch (Exception e) {
			Log.w(TAG,"Error checking for root access: " + e.getMessage());
			//this means that there is no root to be had (normally)
		}
		
		logNotice("Could not acquire root permissions");
		return false;
	}
	
	
	private static void logNotice (String msg)
	{
		if (LOG_OUTPUT_TO_DEBUG)
			Log.d(TAG, msg);
	}
	
	public static int findProcessId(String command) 
	{
		int procId = -1;
		
		try
		{
			procId = findProcessIdWithPidOf(command);
			
			if (procId == -1)
				procId = findProcessIdWithPS(command);
		}
		catch (Exception e)
		{
			try
			{
				procId = findProcessIdWithPS(command);

			}
			catch (Exception e2)
			{
				Log.w(TAG,"Unable to get proc id for: " + command,e2);
			}
		}
		
		return procId;
	}
	
	//use 'pidof' command
	public static int findProcessIdWithPidOf(String command) throws Exception
	{
		
		int procId = -1;
		
		Runtime r = Runtime.getRuntime();
		    	
		Process procPs = null;
		
        procPs = r.exec(SHELL_CMD_PIDOF);
            
        BufferedReader reader = new BufferedReader(new InputStreamReader(procPs.getInputStream()));
        String line = null;
        

        while ((line = reader.readLine())!=null)
        {
        	if (line.indexOf(command)!=-1)
        	{

        		//this line should just be the process id
        		procId = Integer.parseInt(line.trim());

        		
        		break;
        	}
        }
            
       
        return procId;

	}
	
	//use 'ps' command
	public static int findProcessIdWithPS(String command) throws Exception
	{
		
		int procId = -1;
		
		Runtime r = Runtime.getRuntime();
		    	
		Process procPs = null;
		
        procPs = r.exec(SHELL_CMD_PS);
            
        BufferedReader reader = new BufferedReader(new InputStreamReader(procPs.getInputStream()));
        String line = null;
        
        while ((line = reader.readLine())!=null)
        {
        	if (line.indexOf(command)!=-1)
        	{
        		
        		StringTokenizer st = new StringTokenizer(line," ");
        		st.nextToken(); //proc owner
        		
        		procId = Integer.parseInt(st.nextToken().trim());
        		
        		break;
        	}
        }
        
       
        
        return procId;

	}
	
	
	public static int doShellCommand(String[] cmds, StringBuilder log, boolean runAsRoot, boolean waitFor) throws Exception
	{
		logNotice("executing shell cmds: " + cmds[0] + "; runAsRoot=" + runAsRoot);
		
		 	
		Process proc = null;
		int exitCode = -1;
		
            
        	if (runAsRoot)
        		proc = Runtime.getRuntime().exec("su");
        	else
        		proc = Runtime.getRuntime().exec("sh");
        	
        	
        	OutputStreamWriter out = new OutputStreamWriter(proc.getOutputStream());
            
            for (int i = 0; i < cmds.length; i++)
            {
            	out.write(cmds[i]);
            	out.write("\n");
            }
            
            out.flush();
			out.write("exit\n");
			out.flush();
		
			if (waitFor)
			{
				
				
				
				final char buf[] = new char[10];
				
				// Consume the "stdout"
				InputStreamReader reader = new InputStreamReader(proc.getInputStream());
				int read=0;
				while ((read=reader.read(buf)) != -1) {
					if (log != null) log.append(buf, 0, read);
				}
				
				// Consume the "stderr"
				reader = new InputStreamReader(proc.getErrorStream());
				read=0;
				while ((read=reader.read(buf)) != -1) {
					if (log != null) log.append(buf, 0, read);
				}
				
				exitCode = proc.waitFor();
				log.append("process exit code: ");
				log.append(exitCode);
				log.append("\n");
				
				logNotice("command process exit value: " + exitCode);
			}
        
        
        return exitCode;

	}
}