how to use execv system call to launch remote application on redhat 5?

Linuxfan0001 · 11-07-2009, 04:21 AM

Hi
I am trying to use system call execv to launch an application on remote machine.
code snippet:
:
:
char* cmd[] = {"usepwdutility", (char*)0};
ret = execv("/xyz/root/pwdcheck/usepwdutility", cmd);
:
:
where xyz is remote machine name. i also tried substituting ipaddress of the machine in place of machine name. Error it gives is ENOENT

Please let me know in case of any info on this..

Thanks

raskin · 11-09-2009, 12:38 AM

You cannot just simply run applications on remote computers. If what you tried worked, you could put any name there and execute arbitrary code on arbitrary Internet-connected computers.. a clear security problem.

Probably execvp("ssh", "ssh", "user@host", "command to run");. It is supposed to be ru in terminal; ssh will ask password from user. This, of course, implies that you know a login name of the user on the remote host.

raskin · 11-09-2009, 12:38 AM

[deleted duplicate]

Linuxfan0001 · 11-10-2009, 12:52 AM

is there any other method to launch application on remote machine?
the scenario is:
Therez an application running on m/c 'A'which tells a deamon process on m/c 'B' to run a program. Now this program and parameters required by it are passed by the application on m/c 'A' to the deamon process running on m/c 'B'. the deamon process waits for the program to complete and sends back the exxit value of the program to the application running on m/c 'A'.
Please let me know the approach to implement above mentioned functionality.
Let me know in case of any clarification required.
Thanks

raskin · 11-10-2009, 01:02 AM

SSH still meets your needs.

Code:

$ ssh -i ~/.ssh/id_dsa example.com "exit 17" ;
$ echo $?
17

-i allows you to specify "identity" - a secret key. If corresponding public key is added to ~/.ssh/authorize_keys of target user on target computer, and identity file is not protected by password, no password entering is required. Also, SSH returns exit code of remote process as own exit code.

Read "man ssh" and "man sshd".

What you need to keep in mind, though, is that the daemon in your design needs a way to be sure that the application is your nice application, not some spammer trying to send spam using your bandwidth. For ssh thi means that you want to protect your identity files well.

Linuxfan0001 · 11-10-2009, 02:09 AM

i want to achieve mentioned functionality programatically. suppose i have remoteapplicationlauncher named out file. using this application i want to programatically send program name and its parameters thati want to run on remote machine.
suppose the application i want to run on remote m/c is usepwdcheckutility and parameters it take is const char* and int. with examples mentioned let me know the code snippet that will be used to achieve the requirement.
Thanks

Linuxfan0001 · 11-10-2009, 02:10 AM

execvp("ssh", "ssh", "user@host", "command to run"); does not work...

raskin · 11-10-2009, 02:19 AM

What happens when you do

Code:

execvp("ssh", "ssh", "user@host", "ls");

? Maybe I was wrong with argument count - then you need

Code:

execvp("ssh", "user@host", "ls");

You are supposed to run the test program in a terminal, by the way. It will be able to run without user interaction when you configure identities.