qemu

FORK: QEMU emulator
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uuid.c (3157B)

      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 
     20 void 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 
     40 int qemu_uuid_is_null(const QemuUUID *uu)
     41 {
     42     static QemuUUID null_uuid;
     43     return qemu_uuid_is_equal(uu, &null_uuid);
     44 }
     45 
     46 int qemu_uuid_is_equal(const QemuUUID *lhv, const QemuUUID *rhv)
     47 {
     48     return memcmp(lhv, rhv, sizeof(QemuUUID)) == 0;
     49 }
     50 
     51 void 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 
     59 char *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 
     68 static 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 
     90 int 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  */
    112 QemuUUID 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 }