#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <linux/fs.h>

#include "isys.h"

#if defined(__s390__) || defined(__s390x__)
#define u8 __u8
#define u16 __u16
#define u32 __u32
#define u64 __u64
#include <asm/vtoc.h>
#include <asm/dasd.h>
typedef struct vtoc_volume_label volume_label_t;
#endif


#if defined(__s390__) || defined(__s390x__)
/* s390 stuff to detect DASDs */
static int read_volume_label (int fd, unsigned long vlabel_start,
		volume_label_t *vlabel) {
	int rc;
	if (lseek(fd, vlabel_start, SEEK_SET) < 0) {
		/* fprintf(stderr, "Could not read volume label.\n"); */
		return 2;
	}
	rc = read(fd, vlabel, sizeof(volume_label_t));
	if (rc != sizeof(volume_label_t)) {
		/* fprintf(stderr, "Could not read volume label, DASD is probably unformatted\n"); */
		return 1;
	}
	return 0;
}

static int read_vlabel(dasd_information_t *dasd_info, int fd, int blksize, volume_label_t *vlabel) {
	unsigned long  pos;

	pos = dasd_info->label_block * blksize;

	memset(vlabel, 0, sizeof(volume_label_t));
	return read_volume_label(fd, pos, vlabel);
}
#endif

int isUsableDasd(char *device) {
#if !defined(__s390__) && !defined(__s390x__)
    return 0;
#else
	char devname[16];
	char label[5], v4_hex[9];
	char l4ebcdic_hex[] = "d3d5e7f1";  /* LNX1 */
	char cms1_hex[] = "c3d4e2f1";      /* CMS1 */
	int f, ret, blksize;
	dasd_information_t dasd_info;
	volume_label_t vlabel;
	memset(&dasd_info, 0, sizeof(dasd_info));
	strcpy(devname, "/dev/");
	strcat(devname, device);
	devMakeInode(device, devname);
	if((f = open(devname, O_RDONLY)) == -1) {
		return 0;
	}
	if (ioctl(f, BLKSSZGET, &blksize) != 0) {
		close(f);
		/* fprintf(stderr, "Could not retrieve blocksize information!\n"); */
		return 0;
	}
	if (ioctl(f, BIODASDINFO, &dasd_info) != 0) {
		close(f);
		/* fprintf(stderr, "Could not retrieve disk information!\n"); */
		return 0;
	}
	ret = read_vlabel(&dasd_info, f, blksize, &vlabel);
        close(f);

	if (ret == 2) {
		return 0;
	} else if (ret == 1) { /* probably unformatted DASD */
		/* fprintf(stderr, "Found a usable device: %s\n", devname); */
		return 1;
	}
	memset(label, 0, 5);
	memset(v4_hex, 0, 9);
	strncpy(label, vlabel.volkey, 4);
	sprintf(v4_hex, "%02x%02x%02x%02x", label[0], label[1], label[2], label[3]);
        
	if(!strncmp(v4_hex, cms1_hex, 9)) {
		return 0;
	}
	if(!strncmp(v4_hex, l4ebcdic_hex, 9)) {
		return 2;
	}
        return 1;
#endif
}

int isLdlDasd(char * device) {
   return (isUsableDasd(device) == 2);
}

char *getDasdPorts() {
#if !defined(__s390__) && !defined(__s390x__)
    return 0;
#else
        char * line, *ports = NULL;
	char devname[7];
        char port[10];
        FILE *fd;
	int ret;
        fd = fopen ("/proc/dasd/devices", "r");
        if(!fd) {
                return NULL;
        }
        line = (char *)malloc(100*sizeof(char));
        while (fgets (line, 100, fd) != NULL) {
                if ((strstr(line, "unknown") != NULL)) {
                        continue;
                }
                ret = sscanf (line, "%[A-Za-z.0-9](ECKD) at ( %*d: %*d) is %s : %*s", port, devname);
		if (ret == 2) {
			if(!ports) {
				ports = (char *)malloc(strlen(port) + 1);
				strcpy(ports, port);
			} else {
				ports = (char *)realloc(ports, strlen(ports) + strlen(port) + 2);
				strcat(ports, ",");
				strcat(ports, port);
			}
                }
        }
        if (fd) fclose(fd);
        return ports;
#endif
}