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/*
* DEBUG: section 47 Store Directory Routines
* AUTHOR: Duane Wessels
*
* SQUID Web Proxy Cache http://www.squid-cache.org/
* ----------------------------------------------------------
*
* Squid is the result of efforts by numerous individuals from
* the Internet community; see the CONTRIBUTORS file for full
* details. Many organizations have provided support for Squid's
* development; see the SPONSORS file for full details. Squid is
* Copyrighted (C) 2001 by the Regents of the University of
* California; see the COPYRIGHT file for full details. Squid
* incorporates software developed and/or copyrighted by other
* sources; see the CREDITS file for full details.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
*
*/
#include "squid.h"
#include "StoreSwapLogData.h"
#include "swap_log_op.h"
// Based on Internet Checksum (RFC 1071) algorithm but takes three 32bit ints.
// TODO: Consider Fletcher's checksum algorithm as a higher quality alternative
void
SwapChecksum24::set(uint32_t f1, uint32_t f2, uint32_t f3)
{
uint64_t sum = f1;
sum += f2;
sum += f3;
while (const uint64_t higherBits = sum >> 24)
sum = (sum & 0xFFFFFF) + higherBits;
sum = ~sum;
raw[0] = static_cast<uint8_t>(sum);
raw[1] = static_cast<uint8_t>(sum >> 8);
raw[2] = static_cast<uint8_t>(sum >> 16);
}
/// Same as 3-argument SwapChecksum24::set() but for int32_t and uint64_t
void
SwapChecksum24::set(int32_t f1, uint64_t f2)
{
// split the second 64bit word into two 32bit words
set(static_cast<uint32_t>(f1),
static_cast<uint32_t>(f2 >> 32),
static_cast<uint32_t>(f2 & 0xFFFFFFFF));
}
std::ostream &
SwapChecksum24::print(std::ostream &os) const
{
return os << raw[0] << '-' << raw[1] << '-' << raw[2];
}
StoreSwapLogData::StoreSwapLogData()
{
memset(this, 0, sizeof(*this));
}
bool
StoreSwapLogData::sane() const
{
SwapChecksum24 actualSum;
actualSum.set(swap_filen, swap_file_sz);
if (checksum != actualSum)
return false;
const time_t minTime = -2; // -1 is common; expires sometimes uses -2
// Check what we safely can; for some fields any value might be valid
return SWAP_LOG_NOP < op && op < SWAP_LOG_MAX &&
swap_filen >= 0 &&
timestamp >= minTime &&
lastref >= minTime &&
expires >= minTime &&
lastmod >= minTime &&
swap_file_sz > 0; // because swap headers ought to consume space
}
void
StoreSwapLogData::finalize()
{
checksum.set(swap_filen, swap_file_sz);
}
StoreSwapLogHeader::StoreSwapLogHeader(): op(SWAP_LOG_VERSION), version(2),
record_size(sizeof(StoreSwapLogData))
{
checksum.set(version, record_size, 0);
}
bool
StoreSwapLogHeader::sane() const
{
SwapChecksum24 actualSum;
actualSum.set(version, record_size, 0);
if (checksum != actualSum)
return false;
return op == SWAP_LOG_VERSION && version >= 2 && record_size > 0;
}
size_t
StoreSwapLogHeader::gapSize() const
{
assert(record_size > 0);
assert(static_cast<size_t>(record_size) > sizeof(*this));
return static_cast<size_t>(record_size) - sizeof(*this);
}
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