da4ab3aa26
integer. Presently, our implementation employs an approach that converts the value to int64_t, then back to int, unfortunately, this approach can be problematic when the the difference between the two time_low is larger than 0x7fffffff, as the value is then truncated to int. To quote the test case from the original PR, the following is true with the current implementation: 865e1a56-b9d9-11d9-ba27-0003476f2e88 < 062ac45c-b9d9-11d9-ba27-0003476f2e88 However, according to the DCE specification, the expected result should be: 865e1a56-b9d9-11d9-ba27-0003476f2e88 > 062ac45c-b9d9-11d9-ba27-0003476f2e88 This commit adds a new intermediate variable which uses int64_t to store the result of subtraction between the two time_low values, which would not introduce different semantic of the MSB found in time_low value. PR: 83107 Submitted by: Steve Sears <sjs at acm dot org> MFC After: 1 month
89 lines
2.9 KiB
C
89 lines
2.9 KiB
C
/*-
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* Copyright (c) 2002,2005 Marcel Moolenaar
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* Copyright (c) 2002 Hiten Mahesh Pandya
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* All rights reserved.
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*
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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, this list of conditions and the following disclaimer.
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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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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#include <string.h>
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#include <uuid.h>
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/*
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* uuid_compare() - compare two UUIDs.
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* See also:
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* http://www.opengroup.org/onlinepubs/009629399/uuid_compare.htm
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*
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* NOTE: Either UUID can be NULL, meaning a nil UUID. nil UUIDs are smaller
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* than any non-nil UUID.
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*/
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int32_t
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uuid_compare(const uuid_t *a, const uuid_t *b, uint32_t *status)
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{
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int res;
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int64_t res64;
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if (status != NULL)
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*status = uuid_s_ok;
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/* Deal with NULL or equal pointers. */
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if (a == b)
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return (0);
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if (a == NULL)
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return ((uuid_is_nil(b, NULL)) ? 0 : -1);
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if (b == NULL)
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return ((uuid_is_nil(a, NULL)) ? 0 : 1);
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/*
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* We have to compare the hard way.
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*
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* Note that time_low is defined as unsigned 32-bit
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* integer, therefore, with a significantly large
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* a->time_low and a small b->time_low, we will end
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* up with a value which is larger than 0x7fffffff
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* which is negative if casted to signed 32-bit
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* integer.
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*/
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res64 = (int64_t)a->time_low - (int64_t)b->time_low;
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if (res64)
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return ((res64 < 0) ? -1 : 1);
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res = (int)a->time_mid - (int)b->time_mid;
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if (res)
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return ((res < 0) ? -1 : 1);
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res = (int)a->time_hi_and_version - (int)b->time_hi_and_version;
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if (res)
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return ((res < 0) ? -1 : 1);
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res = (int)a->clock_seq_hi_and_reserved -
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(int)b->clock_seq_hi_and_reserved;
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if (res)
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return ((res < 0) ? -1 : 1);
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res = (int)a->clock_seq_low - (int)b->clock_seq_low;
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if (res)
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return ((res < 0) ? -1 : 1);
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res = memcmp(a->node, b->node, sizeof(a->node));
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if (res)
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return ((res < 0) ? -1 : 1);
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return (0);
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}
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