mirror of https://github.com/D4-project/d4-core
112 lines
3.1 KiB
C
112 lines
3.1 KiB
C
/*
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* gen_uuid.c --- generate a DCE-compatible uuid
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*
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* Copyright (C) 1996, 1997, 1998, 1999 Theodore Ts'o.
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*
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* %Begin-Header%
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, and the entire permission notice in its entirety,
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* including the disclaimer of warranties.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote
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* products derived from this software without specific prior
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* written permission.
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*
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF
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* WHICH ARE HEREBY DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
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* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
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* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
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* USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH
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* DAMAGE.
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* %End-Header%
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <string.h>
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#include <fcntl.h>
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#include <errno.h>
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#include <limits.h>
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#include <sys/types.h>
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#include <sys/time.h>
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#include <sys/stat.h>
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#include "uuidP.h"
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#include "randutils.h"
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#ifdef HAVE_TLS
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#define THREAD_LOCAL static __thread
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#else
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#define THREAD_LOCAL static
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#endif
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/*
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* Try using the uuidd daemon to generate the UUID
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*
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* Returns 0 on success, non-zero on failure.
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*/
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void __uuid_generate_random(uuid_t out, int *num)
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{
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uuid_t buf;
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struct uuid uu;
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int i, n;
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if (!num || !*num)
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n = 1;
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else
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n = *num;
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for (i = 0; i < n; i++) {
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random_get_bytes(buf, sizeof(buf));
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uuid_unpack(buf, &uu);
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uu.clock_seq = (uu.clock_seq & 0x3FFF) | 0x8000;
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uu.time_hi_and_version = (uu.time_hi_and_version & 0x0FFF)
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| 0x4000;
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uuid_pack(&uu, out);
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out += sizeof(uuid_t);
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}
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}
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void uuid_generate_random(uuid_t out)
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{
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int num = 1;
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/* No real reason to use the daemon for random uuid's -- yet */
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__uuid_generate_random(out, &num);
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}
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/*
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* Check whether good random source (/dev/random or /dev/urandom)
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* is available.
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*/
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static int have_random_source(void)
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{
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return (access("/dev/random", R_OK) == 0 ||
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access("/dev/urandom", R_OK) == 0);
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}
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/*
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* This is the generic front-end to uuid_generate_random and
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* uuid_generate_time. It uses uuid_generate_random only if
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* /dev/urandom is available, since otherwise we won't have
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* high-quality randomness.
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*/
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void uuid_generate(uuid_t out)
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{
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if (have_random_source())
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uuid_generate_random(out);
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}
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