I have an application which consists of the native part and higher
layer.
Therefore, it needs to be granted the root privilege to run some
native functions.
As the article I post before, I added a piece of code taken from Bluez
Utils(hidd.c).
if (bind(sk, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
close(sk);
return -1;
}
The code has been built to be a .so by NDK.
Unfortunately, It keeps returning -1 and errno is 13 which means
Permission Denied.
Some experienced developers(Thank you here) mentioned about that the
error happens because this application doesnt have enough permission.
It "SHOULD NOT" be something like
Process process = Runtime.getRuntime().exec("su");
I think this means you possess a system permission but your
application doesnt.
(Let me know if I am wrong)
Is there any way to grant the app for having the root privilege?
Any reply/clue/hint will be highly appreciated.
Regards-
Sam
I think i can help you with this.
Here we gooo...
void gainRoot()
{
Process chperm;
try {
chperm=Runtime.getRuntime().exec("su");
DataOutputStream os =
new DataOutputStream(chperm.getOutputStream());
os.writeBytes("chmod 777 /dev/video0\n");
os.flush();
os.writeBytes("exit\n");
os.flush();
chperm.waitFor();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
This is a function i normally use to change the permissions of root files.
When you do su, a new process will be created with root privileges. So using this Process you can do any root operations. There is some specific syntax that needs to be followed. Which is shown in the above example.
so one thing what you can do is build the bind part of the code as a separate executable and place it inside system/bin or at that place where normally executables are kept. Suppose the name of the executable is bind123 then instead of
os.writeBytes("chmod 777 /dev/video0\n");
os.flush();
replace it with
os.writeBytes("bind123\n");
os.flush();
in the above code.
This should work. Probably once this is working we can try integrating it with the application without any dependency on the executable. I hope i am not confusing you. If atall some clarity is neede, let me knowww.... ALL the best...
You don't need root to bind to port >=1024. You only need INTERNET permission in your ApplicationManifest.xml file.
Related
I develop an app and want update itself and want following fetures, device have been rooted :
1 automatic check can update every start (I can do)
2 download the apk file to local (I can do)
3 update with custom dialog, or update silently (I dont know )
edit：
My app run on TV with remote, the default dialog which can control but perfect , so I want use my dialog if there must a dialog.Its best if need not a dialog.
First declare this variables, then call function wherever you want. Then grant superuser, on your superuser application, check the option to always grant, for non user interaction.
#Override
public void onCreate() {
super.onCreate();
//some code...
final String libs = "LD_LIBRARY_PATH=/vendor/lib:/system/lib ";
final String commands = libs + "pm install -r " + "your apk directory"+ "app.apk";
instalarApk(commands);
}
private void instalarApk( String commands ) {
try {
Process p = Runtime.getRuntime().exec( "su" );
InputStream es = p.getErrorStream();
DataOutputStream os = new DataOutputStream(p.getOutputStream());
os.writeBytes(commands + "\n");
os.writeBytes("exit\n");
os.flush();
int read;
byte[] buffer = new byte[4096];
String output = new String();
while ((read = es.read(buffer)) > 0) {
output += new String(buffer, 0, read);
}
p.waitFor();
} catch (IOException e) {
Log.v(Debug.TAG, e.toString());
} catch (InterruptedException e) {
Log.v(Debug.TAG, e.toString());
}
}
The regular way (without root and a default installer dialog) is described in another question, and should be used in most cases imho, as I dislike requesting root privileges for a update feature.
There is no difference in providing a custom dialog and installing an apk silently, as both technically are silent installs (e.g. not made by the install activity). With root privileges, you could use a root shell and either replace the apk (as in the open-source keybord manager app) or invoke the package manager from shell. I'd suggest you go for the second way, I linked the keybord manager app source mainly for the root shell creation stuff.
The Android Framework make it defficult to update silently, on custom devices you must call system install service for your apk file, and it will show the install dialog for the user, but if the device is rooted, I think you can make that silently.
I am developing an Android-App with "Aide".Aide is an app for developing android apps with android devices. When i start the app, i have created, i get an error like "the app has aborted unfortunately". how can i resolve what happened wrong ? is there a log-file where i can see the stack trace ? is ist possible that everytime an error happens a dialog apperas with the stack trace instead of the message "the app has aborted" ? thanks for everybody who can help me.
Greets
Arne
If you want to observe the stack trace, all you need is a LogCat reader, like CatLog, for instance. Note that if your device is Jelly Bean of higher, you'll need root permissions to read the logs.
EDIT:
Further research indicates that there is a LogCat reader built into AIDE. The root permission issue still applies.
I have never used Aide, but the concept will be the same. You need to be able to debug your app on your phone via your IDE. As an example in Eclipse I would connect my phone via usb and in Eclipse it then shows up as an Android Device in AVD. I then run my App in Debug mode on my phone and all your error output will be in Logcat. Otherwise you will have to code debug logic into your app so that it writes it's own logging onto your fs on you phone.
If you have the Android SDK installed (I guess it's the case), then you can use the adb utility to access the log :
adb logcat
This will show you stacktrace in case of error, and many very other useful informations.
You got 3 options:
Upgrade into a stable Pro version to use the working LogCat on AIDE
Use USB debugging as mentioned by apesa
Use following function to log to local file:
public void appendLog(String text)
// https://stackoverflow.com/a/6209739/8800831
{
File logFile = new File("sdcard/log.file");
if (!logFile.exists())
{
try
{
logFile.createNewFile();
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
try
{
//BufferedWriter for performance, true to set append to file flag
BufferedWriter buf = new BufferedWriter(new FileWriter(logFile, true));
buf.append(text);
buf.newLine();
buf. flush();
buf.close();
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
Use it like this:
try{
// your code goes here
}catch (Exception e){
appendLog(e);
}
You need to add permission for writing_external_storage in Manifest.
To clarify, I use this code to get superuser permission for my app so I can access root and whatnot:
public String runProcess(String[] functs) {
DataOutputStream dos;
DataInputStream dis;
StringBuffer contents = new StringBuffer("");
String tempInput;
Process process;
try {
process = Runtime.getRuntime().exec(functs);
dos = new DataOutputStream(process.getOutputStream());
dis = new DataInputStream(process.getInputStream());
for (String command : functs) {
dos.writeBytes(command + "\n");
dos.flush();
while ((tempInput = dis.readLine()) != null)
contents.append(tempInput + "\n");
}
dos.writeBytes("exit\n");
dos.flush();
process.waitFor();
} catch (Exception e) {
e.printStackTrace();
}
return contents.toString();
}
And although it works just fine, whenever I call runProcess(new String[] { "su", "-c", "some other command" }); it always asks for superuser permission. I see a lot of root apps on the market who just have to gain superuser permission once at each startup of the app, but I don't think I'd need to ask the user for superuser permission every single time the app calls an function that requires SU. So my question would be, how would I prompt the user to give me SU permission once at the startup of an app without having to continually ask for it for every SU-related action?
EDIT: I know I could run my method/the Runtime.getRuntime().exec() method without typing "su" in it every time but that only works with non-su related actions (i.e. exec("ps") or exec("ls"). Any ideas?
You can use my Library which does this.
https://code.google.com/p/roottools/
Also, if you don't want to use the library the source is available so you can just rip out my code and use it in your application.
Here is a link to the source:
https://code.google.com/p/roottools/source/browse/#svn%2Ftrunk%2FStable%2FRootTools-sdk3-generic%2Fsrc%2Fcom%2Fstericson%2FRootTools
If you are just looking for the permission from a "superUser" app which is already running in your device, you just need the following code in your main java file.
try {
process p= Runtime.getRuntime().exec(su);
}
catch (IOException e) {
e.printStackTrace();
}
Yes, no need to mention that the device has to be already rooted!!!
Every time you open a console asking for root access, i.e. start it with su, the corresponding super user app will either prompt you or allow/deny it, if you checked something like "Don't ask me again" on the previous prompt.
If you only want to have ask (the super user app) once, you will have to keep your root console open, by not calling dos.writeBytes("exit\n");.
Then keep this session in a background thread and use it when necessary.
So either make sure the user checks "Don't ask me again" on the first prompt or keep the session open.
I was curious if there is any library to work with the capacitive buttons of Samsung phones??
I mean to light them up when an event occurs, or blink them, stuffs like that...
Thanks,
rohitkg
There is nothing in the Android SDK for this, as there is no assumption that such buttons exist, have backlights, etc. You are welcome to contact device manufacturers to see if they have a documented and supported means of doing this for their specific devices.
Here's a code snippet I grabbed from samsung-moment-notifications.
Process process = null;
DataOutputStream os = null;
try {
// get root
process = Runtime.getRuntime().exec("su");
os = new DataOutputStream(process.getOutputStream());
// write the command
os.writeBytes("echo 100 > /sys/class/leds/button-backlight/brightness\n");
os.writeBytes("exit\n");
// clear the buffer
os.flush();
Toast.makeText(NotificationLights.this, "Lights are on", Toast.LENGTH_SHORT).show();
// wait for complete
process.waitFor();
// won't catch an error with root, but it has to have an exception catcher to execute
} catch (Exception e) {
Toast.makeText(NotificationLights.this, "Couldn't get SU, are you rooted?", Toast.LENGTH_SHORT).show();
return;
}
1- You must have a rooted device.
2- You must know the location of the script which turns the lights on/off for each device.
/sys/class/leds/button-backlight/brightness is specific to the Samsung Moment.
If you were to try it on another device it wouldn't work.
I have taken Code Aurora's FM Radio code and merged with my Android Gingerbread codebase.
The FM app framework tries to access the fm radio device ( /dev/radio ) using JNI which is implemented in a file by name android_hardware_fm.cpp . There is a function in this file which tries to acquire a file descriptor to the device node using open() in the read/write mode. However, the call fails with error code -13 : Permission denied.
I also made a small C executable which tries to open the /dev/radio file ( in RDWR mode), prints its fd and closes it. It runs from /system/bin in the target system and displays a valid fd.
Btw, the JNI implementation is part of the android core library. It is located in frameworks/base/core/jni and is compiled as part of libandroid_runtime.so
Any ideas/solutions? Thanks in advance.
Clearly you donot have permissions to open the device from user space. In the second case when you are running the executable from terminal, you are having permissions probably because you have done su before running the executable.
For your problem here, two things can be done.
1) Change the permissions of the node from terimnal.
Steps involved:
Open the terminal (adb shell)
Do su(In order to do this your device must be rooted)
Do chmod 777 /dev/radio in the terminal
Once this is done, your radio node is having proper permissions for the user to read and write. So you can now do open() call and it will work.
2) Programmatically you can achieve this (assuming your device is rooted and su is running on your device) by calling the below function - changePerm(). This is a small function I have written which will change the permissions of the device nodes or rather any system file that does not have user access. Once you have permissions, you can open it from user space. open() call will work properly after this.
void changePerm()
{
Process chperm;
try {
chperm=Runtime.getRuntime().exec("su");
DataOutputStream os =
new DataOutputStream(chperm.getOutputStream());
os.writeBytes("chmod 777 /dev/radio\n");
os.flush();
os.writeBytes("exit\n");
os.flush();
chperm.waitFor();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
I have tested this for other nodes. So it should also work for radio aswell. Let me know in case yo are facing any difficulty. Thanks