blockdev_is_root.c

blockdev_is_root.c (text/plain), 1.02 KB, created by Matthias Schwarzott on 2007-04-19 17:28:54 UTC

// compare MAJOR/MINOR in environment with the device
// / is mounted on
//
// Author: Matthias Schwarzott <[e-mail]>

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

#include <stdio.h>
#include <stdlib.h>

// Getting major/minor
#include <sys/sysmacros.h>
int main(int argc, char **argv)
{
	struct stat stat_buf;
	unsigned int root_major=0, root_minor=0;
	unsigned int dev_major=0, dev_minor=0;
	char *t;

	t=getenv("MAJOR");
	if (!t)
		return EXIT_FAILURE;
	else
		dev_major=strtol(t, NULL, 10);

	t=getenv("MINOR");
	if (!t)
		return EXIT_FAILURE;
	else
		dev_minor=strtol(t, NULL, 10);
	

	if (stat("/", &stat_buf)<0)
		return EXIT_FAILURE;

	root_major=major(stat_buf.st_dev);
	root_minor=minor(stat_buf.st_dev);


	// printf("ROOT: %d / %d \n", root_major, root_minor);
	// printf("DEV:  %d / %d \n", dev_major, dev_minor);

	if (!root_major || !dev_major) {
		printf("MAJOR==0\n");
		return EXIT_FAILURE;
	}

	if ( (root_major==dev_major) && (root_minor==dev_minor))
		return EXIT_SUCCESS;

	return EXIT_FAILURE;
}