/*
 * blockdev.c --- Do various simple block device ioctls from the command line
 * aeb, 991028
 */

#include "blockdata.h"

int getsize(int fd, long long *sectors) {
	int err;
	long sz;
	long long b;

	err = ioctl (fd, BLKGETSIZE, &sz);
	if (err)
		return err;
	err = ioctl(fd, BLKGETSIZE64, &b);
	if (err || b == 0 || b == sz)
		*sectors = sz;
	else
		*sectors = (b >> 9);
	return 0;
}

int get_device_data(char *device, int *blocksize, int *startsector) {
	int fd;
	int sizesect, blksize;
	long long bytes;
	struct hd_geometry g;

	fd = open(device, O_RDONLY | O_NONBLOCK);
	if (fd < 0) {
		fprintf(stderr, "ERROR: cannot open device '%s'\n", device);
		return -1;
	}

	sizesect = blksize = 0;
	g.start = 0;

	int get_geometry = ioctl (fd, HDIO_GETGEO, &g);

	// FIXME fail silently; valid behavior?
	if( get_geometry != 0 ) {
		//fprintf(stderr, "ioctl error on device %s; probably loopback? error=%d\n", device, get_geometry);
		//do nothing
	}

	int ret = -1;

	if( ioctl (fd, BLKBSZGET, &blksize) == 0 && getsize (fd, &bytes) == 0) {
		*startsector = g.start;
		*blocksize = blksize;
		ret = 0;
	} else {
		*startsector = g.start;
		*blocksize = blksize;
		ret = -1;
	}

	if(fd > 0)
		close(fd);
	
	return ret;
}
/*
 * Guillaume Cottenceau (gc@mandrakesoft.com)
 *
 * Copyright 2000 Mandrakesoft
 *
 * This software may be freely redistributed under the terms of the GNU
 * public license.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

/*
 * Portions from Erik Troan (ewt@redhat.com)
 *
 * Copyright 1996 Red Hat Software 
 *
 */

int seek_and_compare(int fd, struct partition_detection_anchor anch) {

	char buf[500];
	size_t count;
	if (lseek(fd, anch.offset, SEEK_SET) == (off_t)-1) {
		fprintf(stderr, "seek failed");
		return -1;
	}
	count = read(fd, buf, strlen(anch.anchor));
	if (count != strlen(anch.anchor)) {
		fprintf(stderr, "read failed");
		return -1;
	}
	buf[count] = '\0';
	if (strcmp(anch.anchor, buf))
		return 1;
	return 0;
}

char * detect_partition_type(char * dev) {

	struct partition_detection_info {
		const char * name;
		struct partition_detection_anchor anchor0;
		struct partition_detection_anchor anchor1;
		struct partition_detection_anchor anchor2;
	};
	struct partition_detection_info partitions_signatures[] = { 
		{ "Linux Swap", { 4086, "SWAP-SPACE" }, { 0, NULL }, { 0, NULL } },
		{ "Linux Swap", { 4086, "SWAPSPACE2" }, { 0, NULL }, { 0, NULL } },
		{ "Ext3", { 0x45c, "\x0000004" }, { 0, NULL }, { 0, NULL } },
		{ "Ext2", { 0x438, "\x53\xEF" }, { 0, NULL }, { 0, NULL } },
		{ "ReiserFS", { 0x10034, "ReIsErFs" }, { 0, NULL }, { 0, NULL } },
		{ "ReiserFS", { 0x10034, "ReIsEr2Fs" }, { 0, NULL }, { 0, NULL } },
		{ "XFS", { 0, "XFSB" }, { 0x200, "XAGF" }, { 0x400, "XAGI" } },
		{ "JFS", { 0x8000, "JFS1" }, { 0, NULL }, { 0, NULL } },
		{ "NTFS", { 0x1FE, "\x55\xAA" }, { 0x3, "NTFS" }, { 0, NULL } },
		{ "FAT32", { 0x1FE, "\x55\xAA" }, { 0x52, "FAT32" }, { 0, NULL } },
		{ "FAT", { 0x1FE, "\x55\xAA" }, { 0x36, "FAT" }, { 0, NULL } },
		{ "x86 boot sector", {  0x1FE, "\x55\xAA" }, { 0, NULL }, { 0, NULL } },
		{ "Linux LVM", { 0, "HM\1\0" }, { 0, NULL }, { 0, NULL } }
	};
	int partitions_signatures_nb = sizeof(partitions_signatures) / sizeof(struct partition_detection_info);
	int i;
	int fd;
        char *part_type = NULL;

	//check it exists
	/*struct stat     statbuf;
	if (!stat(dev, &statbuf)){
		fprintf(stderr, "device does not exist\n");
		return NULL;
	}*/

	if ((fd = open(dev, O_RDONLY, 0)) < 0) {
		fprintf(stderr, "device open failed\n");
		return NULL;
	}
	
	for (i=0; i<partitions_signatures_nb; i++) {
		int results = seek_and_compare(fd, partitions_signatures[i].anchor0);
		if (results == -1)
			goto detect_partition_type_end;
		if (results == 1)
			continue;
		if (!partitions_signatures[i].anchor1.anchor)
			goto detect_partition_found_it;

		results = seek_and_compare(fd, partitions_signatures[i].anchor1);
		if (results == -1)
			goto detect_partition_type_end;
		if (results == 1)
			continue;
		if (!partitions_signatures[i].anchor2.anchor)
			goto detect_partition_found_it;

		results = seek_and_compare(fd, partitions_signatures[i].anchor2);
		if (results == -1)
			goto detect_partition_type_end;
		if (results == 1)
			continue;

	detect_partition_found_it:
		part_type = strdup(partitions_signatures[i].name);
                break;
	}

 detect_partition_type_end:
	close(fd);
	return part_type;
}