/* Simple test to check that device nodes are correctly created and visible */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>

#define TEST_MINOR 120
#define TEST_MAJOR 25

void usage(char *prog)
{
	fprintf(stderr, "usage: %s <filename>\n", prog);
	exit(1);
}

/* 
 * this stuff inlined here instead of using appropriate header 
 * to avoid linking to symbols which is not present in newer libc.
 * Currently this is the case, as UML image contains RedHat 9 and 
 * developers use something newer (Fedora, etc.) --umka
 */
inline unsigned int
__gnu_dev_major (unsigned long long int __dev)
{
	return ((__dev >> 8) & 0xfff) | ((unsigned int) (__dev >> 32) & ~0xfff);
}

inline unsigned int
__gnu_dev_minor (unsigned long long int __dev)
{
	return (__dev & 0xff) | ((unsigned int) (__dev >> 12) & ~0xff);
}

inline unsigned long long int
__gnu_dev_makedev (unsigned int __major, unsigned int __minor)
{
	return ((__minor & 0xff) | ((__major & 0xfff) << 8)
		| (((unsigned long long int) (__minor & ~0xff)) << 12)
		| (((unsigned long long int) (__major & ~0xfff)) << 32));
}

#define __minor(dev) __gnu_dev_minor(dev)
#define __major(dev) __gnu_dev_major(dev)
#define __makedev(maj, min) __gnu_dev_makedev(maj, min)

int main( int argc, char **argv)
{
	char *prog = argv[0];
	char *filename = argv[1];

	struct stat st;
	int rq_rdev;
	int rc;

	if (argc != 2) 
		usage(prog);

	unlink(filename);
	
	/* first try block devices */
	rq_rdev = __makedev(TEST_MAJOR, TEST_MINOR);
	rc = mknod(filename, 0700 | S_IFBLK, rq_rdev);
	if (rc < 0) {
		fprintf(stderr, "%s: mknod(%s) failed: rc %d: %s\n",
			prog, filename, errno, strerror(errno));
		return 2;
	}

	rc = stat(filename, &st);
	if (rc < 0) {
		fprintf(stderr, "%s: stat(%s) failed: rc %d: %s\n",
			prog, filename, errno, strerror(errno));
		return 3;
	}

	if (st.st_rdev != rq_rdev) {
		fprintf(stderr, "%s: created device other than requested: (%u,%u) instead of (%u,%u)\n", 
			prog, __major(st.st_rdev),__minor(st.st_rdev),__major(rq_rdev),__minor(rq_rdev));
		return 4;
	}
	if (!S_ISBLK(st.st_mode)) {
		fprintf(stderr, "%s: created device of different type. Requested block device, got mode %o\n", prog, st.st_mode);
		return 5;
	}

	rc = unlink(filename);
	if ( rc < 0 ) {
		fprintf(stderr, "%s: Cannot unlink created device %s, rc %d: %s\n",
			prog, filename, errno, strerror(errno));
		return 6;
	}

	/* Second try char devices */
	rc = mknod(filename, 0700 | S_IFCHR, rq_rdev);
	if ( rc < 0 ) {
		fprintf(stderr, "%s: mknod(%s) failed: rc %d: %s\n",
			prog, filename, errno, strerror(errno));
		return 7;
	}

	rc = stat(filename, &st);
	if ( rc < 0 ) {
		fprintf(stderr, "%s: stat(%s) failed: rc %d: %s\n",
			prog, filename, errno, strerror(errno));
		return 8;
	}
	if (st.st_rdev != rq_rdev) {
		fprintf(stderr, "%s: created device other than requested: (%u,%u) instead of (%u,%u)\n", 
			prog, __major(st.st_rdev),__minor(st.st_rdev),__major(rq_rdev),__minor(rq_rdev));
		return 9;
	}
	if (!S_ISCHR(st.st_mode)) {
		fprintf(stderr, "%s: created device of different type. Requested char device, got mode %o\n", prog, st.st_mode);
		return 10;
	}

	rc = unlink(filename);
	if ( rc < 0 ) {
		fprintf(stderr, "%s: Cannot unlink created device %s, rc %d: %s\n",
			prog, filename, errno, strerror(errno));
		return 11;
	}

	printf("%s: device nodes created correctly\n", prog);

	return 0;
}