LXR qemu/util/uuid.c

   1/*
   2 *  QEMU UUID functions
   3 *
   4 *  Copyright 2016 Red Hat, Inc.
   5 *
   6 *  Authors:
   7 *   Fam Zheng <famz@redhat.com>
   8 *
   9 * This program is free software; you can redistribute it and/or modify it
  10 * under the terms of the GNU General Public License as published by the Free
  11 * Software Foundation; either version 2 of the License, or (at your option)
  12 * any later version.
  13 *
  14 */
  15
  16#include "qemu/osdep.h"
  17#include "qemu/uuid.h"
  18#include "qemu/bswap.h"
  19
  20void qemu_uuid_generate(QemuUUID *uuid)
  21{
  22    int i;
  23    uint32_t tmp[4];
  24
  25    QEMU_BUILD_BUG_ON(sizeof(QemuUUID) != 16);
  26
  27    for (i = 0; i < 4; ++i) {
  28        tmp[i] = g_random_int();
  29    }
  30    memcpy(uuid, tmp, sizeof(tmp));
  31    /* Set the two most significant bits (bits 6 and 7) of the
  32      clock_seq_hi_and_reserved to zero and one, respectively. */
  33    uuid->data[8] = (uuid->data[8] & 0x3f) | 0x80;
  34    /* Set the four most significant bits (bits 12 through 15) of the
  35      time_hi_and_version field to the 4-bit version number.
  36      */
  37    uuid->data[6] = (uuid->data[6] & 0xf) | 0x40;
  38}
  39
  40int qemu_uuid_is_null(const QemuUUID *uu)
  41{
  42    static QemuUUID null_uuid;
  43    return qemu_uuid_is_equal(uu, &null_uuid);
  44}
  45
  46int qemu_uuid_is_equal(const QemuUUID *lhv, const QemuUUID *rhv)
  47{
  48    return memcmp(lhv, rhv, sizeof(QemuUUID)) == 0;
  49}
  50
  51void qemu_uuid_unparse(const QemuUUID *uuid, char *out)
  52{
  53    const unsigned char *uu = &uuid->data[0];
  54    snprintf(out, UUID_FMT_LEN + 1, UUID_FMT,
  55             uu[0], uu[1], uu[2], uu[3], uu[4], uu[5], uu[6], uu[7],
  56             uu[8], uu[9], uu[10], uu[11], uu[12], uu[13], uu[14], uu[15]);
  57}
  58
  59char *qemu_uuid_unparse_strdup(const QemuUUID *uuid)
  60{
  61    const unsigned char *uu = &uuid->data[0];
  62    return g_strdup_printf(UUID_FMT,
  63                           uu[0], uu[1], uu[2], uu[3], uu[4], uu[5], uu[6],
  64                           uu[7], uu[8], uu[9], uu[10], uu[11], uu[12],
  65                           uu[13], uu[14], uu[15]);
  66}
  67
  68static bool qemu_uuid_is_valid(const char *str)
  69{
  70    int i;
  71
  72    for (i = 0; i < strlen(str); i++) {
  73        const char c = str[i];
  74        if (i == 8 || i == 13 || i == 18 || i == 23) {
  75            if (str[i] != '-') {
  76                return false;
  77            }
  78        } else {
  79            if ((c >= '0' && c <= '9') ||
  80                (c >= 'A' && c <= 'F') ||
  81                (c >= 'a' && c <= 'f')) {
  82                continue;
  83            }
  84            return false;
  85        }
  86    }
  87    return i == 36;
  88}
  89
  90int qemu_uuid_parse(const char *str, QemuUUID *uuid)
  91{
  92    unsigned char *uu = &uuid->data[0];
  93    int ret;
  94
  95    if (!qemu_uuid_is_valid(str)) {
  96        return -1;
  97    }
  98
  99    ret = sscanf(str, UUID_FMT, &uu[0], &uu[1], &uu[2], &uu[3],
 100                 &uu[4], &uu[5], &uu[6], &uu[7], &uu[8], &uu[9],
 101                 &uu[10], &uu[11], &uu[12], &uu[13], &uu[14],
 102                 &uu[15]);
 103
 104    if (ret != 16) {
 105        return -1;
 106    }
 107    return 0;
 108}
 109
 110/* Swap from UUID format endian (BE) to the opposite or vice versa.
 111 */
 112QemuUUID qemu_uuid_bswap(QemuUUID uuid)
 113{
 114    bswap32s(&uuid.fields.time_low);
 115    bswap16s(&uuid.fields.time_mid);
 116    bswap16s(&uuid.fields.time_high_and_version);
 117    return uuid;
 118}
 119