Permission issue?

svenh · 09-02-2014, 11:46 AM

I have written an application that is accessing a "dongle" in the USB port.
The dongle came with a library (.so) for Linux.
If I start the program with sudo, everything works fine.
Without sudo the program works but the dongle can't be accessed.
LoadLibrary works but calls to the library returns error codes.

Both my program and the library has all permissions and are both root.

-rwxrwxrwx 1 root root

I'm using Mint 17 64 bit on a VM on a MacBook Pro.

Thankful for any help.

evo2 · 09-02-2014, 07:49 PM

Hi,

presumably the dongle shows up as a device under /dev. Presumably the user running the program will need at least read permissions for that device. So what are the owner and group of the device and what are the permissions?

Evo2.

svenh · 09-03-2014, 12:06 PM

Should not a program with root and all permissions be able to access everything?
What is the difference between running a program with sudo and running the program as root with all permissions?
It does not look to me as a hardware permission issue.

Smokey_justme · 09-03-2014, 12:24 PM

Don't confuse running permissions with file permissions ... Unless the SUID bit is specified (and please don't) the file will always run with the user that is running the actual command... Ofcourse, when sudoing that user is root..

See what permissions the device has and add the user you wish to have access there to that group... Or, search and configure udev rules so that the device will have different permissions...

evo2 · 09-03-2014, 05:43 PM

Hi,

Quote:

Originally Posted by svenh

Should not a program with root and all permissions be able to access everything?

If by "all" you mean rwx, then no.

Quote:

What is the difference between running a program with sudo and running the program as root with all permissions?

The user running the program and the owner of the program are two completely different things.

Quote:

It does not look to me as a hardware permission issue.

Sorry, but your understanding of this is off. Please check the ownership and permissions of the device as I requested in my previous post.

Evo2.