Files
epics-base/modules/ca/src/client/hostNameCache.cpp
2018-06-19 11:33:25 +02:00

93 lines
3.0 KiB
C++

/*************************************************************************\
* Copyright (c) 2002 The University of Chicago, as Operator of Argonne
* National Laboratory.
* Copyright (c) 2002 The Regents of the University of California, as
* Operator of Los Alamos National Laboratory.
* EPICS BASE Versions 3.13.7
* and higher are distributed subject to a Software License Agreement found
* in file LICENSE that is included with this distribution.
\*************************************************************************/
/*
*
*
* L O S A L A M O S
* Los Alamos National Laboratory
* Los Alamos, New Mexico 87545
*
* Copyright, 1986, The Regents of the University of California.
*
*
* Author Jeffrey O. Hill
* johill@lanl.gov
*/
#include <algorithm>
#include <cstring>
#define epicsAssertAuthor "Jeff Hill johill@lanl.gov"
#include "hostNameCache.h"
#include "epicsGuard.h"
hostNameCache::hostNameCache (
const osiSockAddr & addr, ipAddrToAsciiEngine & engine ) :
dnsTransaction ( engine.createTransaction() ), nameLength ( 0 )
{
sockAddrToDottedIP ( &addr.sa, hostNameBuf, sizeof ( hostNameBuf ) );
hostNameBuf[ sizeof ( hostNameBuf ) - 1 ] = '\0';
nameLength = strlen ( hostNameBuf );
this->dnsTransaction.ipAddrToAscii ( addr, *this );
}
void hostNameCache::destroy ()
{
delete this;
}
hostNameCache::~hostNameCache ()
{
this->dnsTransaction.release ();
}
void hostNameCache::transactionComplete ( const char * pHostNameIn )
{
epicsGuard < epicsMutex > guard ( this->mutex );
// a few legacy clients have a direct pointer to this buffer so we
// set the entrire string to nill terminators before we start copying
// in the name (this reduces the chance that another thread will see
// garbage characters).
size_t newNameLen = strlen ( pHostNameIn );
if ( newNameLen > sizeof ( this->hostNameBuf ) - 1u ) {
newNameLen = sizeof ( this->hostNameBuf ) - 1u;
}
strncpy ( this->hostNameBuf, "", sizeof ( this->hostNameBuf ) );
strncpy ( this->hostNameBuf, pHostNameIn, sizeof ( this->hostNameBuf ) - 1 );
this->nameLength = newNameLen;
}
unsigned hostNameCache::getName (
char * pBuf, unsigned bufSize ) const
{
if ( bufSize == 0u ) {
return 0u;
}
epicsGuard < epicsMutex > guard ( this->mutex );
if ( this->nameLength > 0u ) {
if ( this->nameLength < bufSize ) {
strcpy ( pBuf, this->hostNameBuf );
return this->nameLength;
}
else {
unsigned reducedSize = bufSize - 1u;
strncpy ( pBuf, this->hostNameBuf, reducedSize );
pBuf [ reducedSize ] = '\0';
return reducedSize;
}
}
else {
osiSockAddr tmpAddr = this->dnsTransaction.address ();
return sockAddrToDottedIP ( &tmpAddr.sa, pBuf, bufSize );
}
}