gw_uuid.c

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/*
 * clear.c -- Clear a UUID
 * 
 * Copyright (C) 1996, 1997 Theodore Ts'o.
 *
 * %Begin-Header%
 * This file may be redistributed under the terms of the GNU 
 * Library General Public License.
 * %End-Header%
 */

/*
 * Force inclusion of SVID stuff since we need it if we're compiling in
 * gcc-wall wall mode
 */
#ifndef _SVID_SOURCE
#define _SVID_SOURCE
#endif

#include "gw-config.h"

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#include <string.h>
#include <ctype.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/file.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
#include <stdio.h>

#include "gwlib/gw_uuid_types.h"
#include "gwlib/gw_uuid.h"

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

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


/*
 * prototypes
 */
static void uuid_pack(const struct uuid *uu, uuid_t ptr);
static void uuid_unpack(const uuid_t in, struct uuid *uu);
static int get_random_fd(void);


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



void uuid_init(void)
{
    /* 
     * open random device if any.
     * We should do it here because otherwise it's
     * possible that we open device twice.
     */
    get_random_fd();
}


void uuid_shutdown(void)
{
    int fd = get_random_fd();

    if (fd > 0)
        close(fd);
}

void uuid_clear(uuid_t uu)
{
    memset(uu, 0, 16);
}

/*
 * compare.c --- compare whether or not two UUID's are the same
 *
 * Returns an integer less than, equal to, or greater than zero if
 * uu1 respectively, to be less than, to match, or be greater than
 * uu2.
 * 
 * Copyright (C) 1996, 1997 Theodore Ts'o.
 *
 * %Begin-Header%
 * This file may be redistributed under the terms of the GNU 
 * Library General Public License.
 * %End-Header%
 */
#define UUCMP(u1,u2) if (u1 != u2) return((u1 < u2) ? -1 : 1);

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);
}

/*
 * copy.c --- copy UUIDs
 * 
 * Copyright (C) 1996, 1997 Theodore Ts'o.
 *
 * %Begin-Header%
 * This file may be redistributed under the terms of the GNU 
 * Library General Public License.
 * %End-Header%
 */
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++;
}


/*
 * gen_uuid.c --- generate a DCE-compatible uuid
 *
 * Copyright (C) 1996, 1997, 1998, 1999 Theodore Ts'o.
 *
 * %Begin-Header%
 * This file may be redistributed under the terms of the GNU 
 * Library General Public License.
 * %End-Header%
 */
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 long long      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 long long) tv.tv_sec)*10000000;
    clock_reg += (((unsigned long long) 0x01B21DD2) << 32) + 0x13814000;

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

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_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);
}

/*
 * This is the generic front-end to uuid_generate_random and
 * uuid_generate_time.  It uses uuid_generate_random only if
 * /dev/urandom is available, since otherwise we won't have
 * high-quality randomness.
 */
void uuid_generate(uuid_t out)
{
    if (get_random_fd() >= 0) {
        uuid_generate_random(out);
    }
    else
        uuid_generate_time(out);
}

/*
 * isnull.c --- Check whether or not the UUID is null
 * 
 * Copyright (C) 1996, 1997 Theodore Ts'o.
 *
 * %Begin-Header%
 * This file may be redistributed under the terms of the GNU 
 * Library General Public License.
 * %End-Header%
 */
/* Returns 1 if the uuid is the NULL uuid */
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;
}

/*
 * Internal routine for packing UUID's
 * 
 * Copyright (C) 1996, 1997 Theodore Ts'o.
 *
 * %Begin-Header%
 * This file may be redistributed under the terms of the GNU 
 * Library General Public License.
 * %End-Header%
 */
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);
}

/*
 * parse.c --- UUID parsing
 * 
 * Copyright (C) 1996, 1997 Theodore Ts'o.
 *
 * %Begin-Header%
 * This file may be redistributed under the terms of the GNU 
 * Library General Public License.
 * %End-Header%
 */
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(*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;
}
    

/*
 * Internal routine for unpacking UUID
 * 
 * Copyright (C) 1996, 1997 Theodore Ts'o.
 *
 * %Begin-Header%
 * This file may be redistributed under the terms of the GNU 
 * Library General Public License.
 * %End-Header%
 */
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);
}

/*
 * unparse.c -- convert a UUID to string
 * 
 * Copyright (C) 1996, 1997 Theodore Ts'o.
 *
 * %Begin-Header%
 * This file may be redistributed under the terms of the GNU 
 * Library General Public License.
 * %End-Header%
 */
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]);
}

/*
 * uuid_time.c --- Interpret the time field from a uuid.  This program
 *  violates the UUID abstraction barrier by reaching into the guts
 *  of a UUID and interpreting it.
 * 
 * Copyright (C) 1998, 1999 Theodore Ts'o.
 *
 * %Begin-Header%
 * This file may be redistributed under the terms of the GNU 
 * Library General Public License.
 * %End-Header%
 */
time_t uuid_time(const uuid_t uu, struct timeval *ret_tv)
{
    struct uuid     uuid;
    __u32           high;
    struct timeval      tv;
    unsigned long long  clock_reg;

    uuid_unpack(uu, &uuid);
    
    high = uuid.time_mid | ((uuid.time_hi_and_version & 0xFFF) << 16);
    clock_reg = uuid.time_low | ((unsigned long long) high << 32);

    clock_reg -= (((unsigned long long) 0x01B21DD2) << 32) + 0x13814000;
    tv.tv_sec = clock_reg / 10000000;
    tv.tv_usec = (clock_reg % 10000000) / 10;

    if (ret_tv)
        *ret_tv = tv;

    return tv.tv_sec;
}

int uuid_type(const uuid_t uu)
{
    struct uuid     uuid;

    uuid_unpack(uu, &uuid); 
    return ((uuid.time_hi_and_version >> 12) & 0xF);
}

int uuid_variant(const uuid_t uu)
{
    struct uuid     uuid;
    int         var;

    uuid_unpack(uu, &uuid); 
    var = uuid.clock_seq;

    if ((var & 0x8000) == 0)
        return UUID_VARIANT_NCS;
    if ((var & 0x4000) == 0)
        return UUID_VARIANT_DCE;
    if ((var & 0x2000) == 0)
        return UUID_VARIANT_MICROSOFT;
    return UUID_VARIANT_OTHER;
}

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