/*
 * uuid: emulation of e2fsprogs interface if implementation lacking.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Original uuid implementation: copyright (C) Theodore Ts'o
 *
 * This importation into heartbeat:
 *	Copyright (C) 2004 David Lee <t.d.lee@durham.ac.uk>
 *
 */

#include <config.h>
#include <stdio.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#include <string.h>
#include <ctype.h>

#include <replace_uuid.h>

/*
 * Local "replace" implementation of uuid functions.
 */


#include <sys/types.h>
#include <sys/time.h>
#include <time.h>

/* UUID Variant definitions */
#define UUID_VARIANT_NCS	0
#define UUID_VARIANT_DCE	1
#define UUID_VARIANT_MICROSOFT	2
#define UUID_VARIANT_OTHER	3

/* UUID Type definitions */  
#define UUID_TYPE_DCE_TIME	1
#define UUID_TYPE_DCE_RANDOM	4



/* For uuid_compare() */
#define UUCMP(u1,u2) if (u1 != u2) return((u1 < u2) ? -1 : 1);

/************************************
 * Private types
 ************************************/

#define longlong long long

/*
 * Offset between 15-Oct-1582 and 1-Jan-70
 */
#define TIME_OFFSET_HIGH 0x01B21DD2
#define TIME_OFFSET_LOW  0x13814000

#if (SIZEOF_INT == 4)
typedef	unsigned int	__u32;
#elif (SIZEOF_LONG == 4)
typedef	unsigned long	__u32;
#endif

#if (SIZEOF_INT == 2)
typedef	int		__s16;
typedef	unsigned int	__u16;
#elif (SIZEOF_SHORT == 2)
typedef	short		__s16;
typedef	unsigned short	__u16;
#endif

typedef unsigned char __u8;

struct uuid {
	__u32	time_low;
	__u16	time_mid;
	__u16	time_hi_and_version;
	__u16	clock_seq;
	__u8	node[6];
};

/************************************
 * internal routines
 ************************************/
static void uuid_pack(const struct uuid *uu, uuid_t ptr)
{
	__u32	tmp;
	unsigned char	*out = ptr;

	tmp = uu->time_low;
	out[3] = (unsigned char) tmp;
	tmp >>= 8;
	out[2] = (unsigned char) tmp;
	tmp >>= 8;
	out[1] = (unsigned char) tmp;
	tmp >>= 8;
	out[0] = (unsigned char) tmp;
	
	tmp = uu->time_mid;
	out[5] = (unsigned char) tmp;
	tmp >>= 8;
	out[4] = (unsigned char) tmp;

	tmp = uu->time_hi_and_version;
	out[7] = (unsigned char) tmp;
	tmp >>= 8;
	out[6] = (unsigned char) tmp;

	tmp = uu->clock_seq;
	out[9] = (unsigned char) tmp;
	tmp >>= 8;
	out[8] = (unsigned char) tmp;

	memcpy(out+10, uu->node, 6);
}

static void uuid_unpack(const uuid_t in, struct uuid *uu)
{
	const __u8	*ptr = in;
	__u32		tmp;

	tmp = *ptr++;
	tmp = (tmp << 8) | *ptr++;
	tmp = (tmp << 8) | *ptr++;
	tmp = (tmp << 8) | *ptr++;
	uu->time_low = tmp;

	tmp = *ptr++;
	tmp = (tmp << 8) | *ptr++;
	uu->time_mid = tmp;
	
	tmp = *ptr++;
	tmp = (tmp << 8) | *ptr++;
	uu->time_hi_and_version = tmp;

	tmp = *ptr++;
	tmp = (tmp << 8) | *ptr++;
	uu->clock_seq = tmp;

	memcpy(uu->node, ptr, 6);
}

/************************************
 * Main routines, except uuid_generate*()
 ************************************/
void
uuid_clear(uuid_t uu)
{
	memset(uu, 0, 16);
}

int
uuid_compare(const uuid_t uu1, const uuid_t uu2)
{
	struct uuid	uuid1, uuid2;

	uuid_unpack(uu1, &uuid1);
	uuid_unpack(uu2, &uuid2);

	UUCMP(uuid1.time_low, uuid2.time_low);
	UUCMP(uuid1.time_mid, uuid2.time_mid);
	UUCMP(uuid1.time_hi_and_version, uuid2.time_hi_and_version);
	UUCMP(uuid1.clock_seq, uuid2.clock_seq);
	return memcmp(uuid1.node, uuid2.node, 6);
}

void
uuid_copy(uuid_t dst, const uuid_t src)
{
	unsigned char		*cp1;
	const unsigned char	*cp2;
	int			i;

	for (i=0, cp1 = dst, cp2 = src; i < 16; i++)
		*cp1++ = *cp2++;
}

/* if uu is the null uuid, return 1 else 0 */
int
uuid_is_null(const uuid_t uu)
{
	const unsigned char 	*cp;
	int			i;

	for (i=0, cp = uu; i < 16; i++)
		if (*cp++)
			return 0;
	return 1;
}

/* 36byte-string=>uuid */
int
uuid_parse(const char *in, uuid_t uu)
{
	struct uuid	uuid;
	int 		i;
	const char	*cp;
	char		buf[3];

	if (strlen(in) != 36)
		return -1;
	for (i=0, cp = in; i <= 36; i++,cp++) {
		if ((i == 8) || (i == 13) || (i == 18) ||
		    (i == 23)) {
			if (*cp == '-')
				continue;
			else
				return -1;
		}
		if (i== 36)
			if (*cp == 0)
				continue;
		if (!isxdigit((int) *cp))
			return -1;
	}
	uuid.time_low = strtoul(in, NULL, 16);
	uuid.time_mid = strtoul(in+9, NULL, 16);
	uuid.time_hi_and_version = strtoul(in+14, NULL, 16);
	uuid.clock_seq = strtoul(in+19, NULL, 16);
	cp = in+24;
	buf[2] = 0;
	for (i=0; i < 6; i++) {
		buf[0] = *cp++;
		buf[1] = *cp++;
		uuid.node[i] = strtoul(buf, NULL, 16);
	}
	
	uuid_pack(&uuid, uu);
	return 0;
}

/* uuid=>36byte-string-with-null */
void
uuid_unparse(const uuid_t uu, char *out)
{
	struct uuid uuid;

	uuid_unpack(uu, &uuid);
	sprintf(out,
		"%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x",
		uuid.time_low, uuid.time_mid, uuid.time_hi_and_version,
		uuid.clock_seq >> 8, uuid.clock_seq & 0xFF,
		uuid.node[0], uuid.node[1], uuid.node[2],
		uuid.node[3], uuid.node[4], uuid.node[5]);
}


/************************************
 * Main routines: uuid_generate*()
 ************************************/

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

#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_SYS_SOCKIO_H
#include <sys/sockio.h>
#endif
#ifdef HAVE_NET_IF_H
#include <net/if.h>
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif

#ifdef HAVE_SRANDOM
#define srand(x) 	srandom(x)
#define rand() 		random()
#endif

static int get_random_fd(void)
{
	struct timeval	tv;
	static int	fd = -2;
	int		i;

	if (fd == -2) {
		gettimeofday(&tv, 0);
		fd = open("/dev/urandom", O_RDONLY);
		if (fd == -1)
			fd = open("/dev/random", O_RDONLY | O_NONBLOCK);
		srand((getpid() << 16) ^ getuid() ^ tv.tv_sec ^ tv.tv_usec);
	}
	/* Crank the random number generator a few times */
	gettimeofday(&tv, 0);
	for (i = (tv.tv_sec ^ tv.tv_usec) & 0x1F; i > 0; i--)
		rand();
	return fd;
}

/*
 * Generate a series of random bytes.  Use /dev/urandom if possible,
 * and if not, use srandom/random.
 */
static void get_random_bytes(void *buf, int nbytes)
{
	int i, n = nbytes, fd = get_random_fd();
	int lose_counter = 0;
	unsigned char *cp = (unsigned char *) buf;

	if (fd >= 0) {
		while (n > 0) {
			i = read(fd, cp, n);
			if (i <= 0) {
				if (lose_counter++ > 16)
					break;
				continue;
			}
			n -= i;
			cp += i;
			lose_counter = 0;
		}
	}
	
	/*
	 * We do this all the time, but this is the only source of
	 * randomness if /dev/random/urandom is out to lunch.
	 */
	for (cp = buf, i = 0; i < nbytes; i++)
		*cp++ ^= (rand() >> 7) & 0xFF;
	return;
}

/*
 * Get the ethernet hardware address, if we can find it...
 */
static int get_node_id(unsigned char *node_id)
{
#ifdef HAVE_NET_IF_H
	int 		sd;
	struct ifreq 	ifr, *ifrp;
	struct ifconf 	ifc;
	char buf[1024];
	int		n, i;
	unsigned char 	*a;
	
/*
 * BSD 4.4 defines the size of an ifreq to be
 * max(sizeof(ifreq), sizeof(ifreq.ifr_name)+ifreq.ifr_addr.sa_len
 * However, under earlier systems, sa_len isn't present, so the size is 
 * just sizeof(struct ifreq)
 */
#ifdef HAVE_SA_LEN
#ifndef max
#define max(a,b) ((a) > (b) ? (a) : (b))
#endif
#define ifreq_size(i) max(sizeof(struct ifreq),\
     sizeof((i).ifr_name)+(i).ifr_addr.sa_len)
#else
#define ifreq_size(i) sizeof(struct ifreq)
#endif /* HAVE_SA_LEN*/

	sd = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);
	if (sd < 0) {
		return -1;
	}
	memset(buf, 0, sizeof(buf));
	ifc.ifc_len = sizeof(buf);
	ifc.ifc_buf = buf;
	if (ioctl (sd, SIOCGIFCONF, (char *)&ifc) < 0) {
		close(sd);
		return -1;
	}
	n = ifc.ifc_len;
	for (i = 0; i < n; i+= ifreq_size(*ifr) ) {
		ifrp = (struct ifreq *)((char *) ifc.ifc_buf+i);
		strncpy(ifr.ifr_name, ifrp->ifr_name, IFNAMSIZ);
#ifdef SIOCGIFHWADDR
		if (ioctl(sd, SIOCGIFHWADDR, &ifr) < 0)
			continue;
		a = (unsigned char *) &ifr.ifr_hwaddr.sa_data;
#else
#ifdef SIOCGENADDR
		if (ioctl(sd, SIOCGENADDR, &ifr) < 0)
			continue;
		a = (unsigned char *) ifr.ifr_enaddr;
#else
		/*
		 * XXX we don't have a way of getting the hardware
		 * address
		 */
		close(sd);
		return 0;
#endif /* SIOCGENADDR */
#endif /* SIOCGIFHWADDR */
		if (!a[0] && !a[1] && !a[2] && !a[3] && !a[4] && !a[5])
			continue;
		if (node_id) {
			memcpy(node_id, a, 6);
			close(sd);
			return 1;
		}
	}
	close(sd);
#endif
	return 0;
}

/* Assume that the gettimeofday() has microsecond granularity */
#define MAX_ADJUSTMENT 10

static int
get_clock(__u32 *clock_high, __u32 *clock_low, __u16 *ret_clock_seq)
{
	static int			adjustment = 0;
	static struct timeval		last = {0, 0};
	static __u16			clock_seq;
	struct timeval 			tv;
	unsigned longlong		clock_reg;
	
try_again:
	gettimeofday(&tv, 0);
	if ((last.tv_sec == 0) && (last.tv_usec == 0)) {
		get_random_bytes(&clock_seq, sizeof(clock_seq));
		clock_seq &= 0x1FFF;
		last = tv;
		last.tv_sec--;
	}
	if ((tv.tv_sec < last.tv_sec) ||
	    ((tv.tv_sec == last.tv_sec) &&
	     (tv.tv_usec < last.tv_usec))) {
		clock_seq = (clock_seq+1) & 0x1FFF;
		adjustment = 0;
		last = tv;
	} else if ((tv.tv_sec == last.tv_sec) &&
	    (tv.tv_usec == last.tv_usec)) {
		if (adjustment >= MAX_ADJUSTMENT)
			goto try_again;
		adjustment++;
	} else {
		adjustment = 0;
		last = tv;
	}
		
	clock_reg = tv.tv_usec*10 + adjustment;
	clock_reg += ((unsigned longlong) tv.tv_sec)*10000000;
	clock_reg += (((unsigned longlong) 0x01B21DD2) << 32) + 0x13814000;

	*clock_high = clock_reg >> 32;
	*clock_low = clock_reg;
	*ret_clock_seq = clock_seq;
	return 0;
}

/* create a new uuid, based on randomness */
void
uuid_generate_random(uuid_t out)
{
	uuid_t	buf;
	struct uuid uu;

	get_random_bytes(buf, sizeof(buf));
	uuid_unpack(buf, &uu);

	uu.clock_seq = (uu.clock_seq & 0x3FFF) | 0x8000;
	uu.time_hi_and_version = (uu.time_hi_and_version & 0x0FFF) | 0x4000;
	uuid_pack(&uu, out);
}

/* create a new uuid, based on time */
static void
uuid_generate_time(uuid_t out)
{
	static unsigned char node_id[6];
	static int has_init = 0;
	struct uuid uu;
	__u32	clock_mid;

	if (!has_init) {
		if (get_node_id(node_id) <= 0) {
			get_random_bytes(node_id, 6);
			/*
			 * Set multicast bit, to prevent conflicts
			 * with IEEE 802 addresses obtained from
			 * network cards
			 */
			node_id[0] |= 0x80;
		}
		has_init = 1;
	}
	get_clock(&clock_mid, &uu.time_low, &uu.clock_seq);
	uu.clock_seq |= 0x8000;
	uu.time_mid = (__u16) clock_mid;
	uu.time_hi_and_version = (clock_mid >> 16) | 0x1000;
	memcpy(uu.node, node_id, 6);
	uuid_pack(&uu, out);
}

void
uuid_generate(uuid_t out)
{
	if (get_random_fd() >= 0) {
		uuid_generate_random(out);
	}else{
		uuid_generate_time(out);
	}
}