resource.c revision dafcb997e390efa4423883dafd100c975c4095d6
/*
* Copyright (C) 2004 Internet Systems Consortium, Inc. ("ISC")
* Copyright (C) 2000, 2001 Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: resource.c,v 1.12 2004/03/05 05:11:46 marka Exp $ */
#include <config.h>
#include <sys/types.h>
#include <sys/time.h> /* Required on some systems for <sys/resource.h>. */
#include <sys/resource.h>
#include <isc/platform.h>
#include <isc/resource.h>
#include <isc/result.h>
#include <isc/util.h>
#include "errno2result.h"
static isc_result_t
resource2rlim(isc_resource_t resource, int *rlim_resource) {
isc_result_t result = ISC_R_SUCCESS;
switch (resource) {
case isc_resource_coresize:
*rlim_resource = RLIMIT_CORE;
break;
case isc_resource_cputime:
*rlim_resource = RLIMIT_CPU;
break;
case isc_resource_datasize:
*rlim_resource = RLIMIT_DATA;
break;
case isc_resource_filesize:
*rlim_resource = RLIMIT_FSIZE;
break;
case isc_resource_lockedmemory:
#ifdef RLIMIT_MEMLOCK
*rlim_resource = RLIMIT_MEMLOCK;
#else
result = ISC_R_NOTIMPLEMENTED;
#endif
break;
case isc_resource_openfiles:
#ifdef RLIMIT_NOFILE
*rlim_resource = RLIMIT_NOFILE;
#else
result = ISC_R_NOTIMPLEMENTED;
#endif
break;
case isc_resource_processes:
#ifdef RLIMIT_NPROC
*rlim_resource = RLIMIT_NPROC;
#else
result = ISC_R_NOTIMPLEMENTED;
#endif
break;
case isc_resource_residentsize:
#ifdef RLIMIT_RSS
*rlim_resource = RLIMIT_RSS;
#else
result = ISC_R_NOTIMPLEMENTED;
#endif
break;
case isc_resource_stacksize:
*rlim_resource = RLIMIT_STACK;
break;
default:
/*
* This test is not very robust if isc_resource_t
* changes, but generates a clear assertion message.
*/
REQUIRE(resource >= isc_resource_coresize &&
resource <= isc_resource_stacksize);
result = ISC_R_RANGE;
break;
}
return (result);
}
isc_result_t
isc_resource_setlimit(isc_resource_t resource, isc_resourcevalue_t value) {
struct rlimit rl;
ISC_PLATFORM_RLIMITTYPE rlim_value;
int unixresult;
int unixresource;
isc_result_t result;
result = resource2rlim(resource, &unixresource);
if (result != ISC_R_SUCCESS)
return (result);
if (value == ISC_RESOURCE_UNLIMITED)
rlim_value = RLIM_INFINITY;
else {
/*
* isc_resourcevalue_t was chosen as an unsigned 64 bit
* integer so that it could contain the maximum range of
* reasonable values. Unfortunately, this exceeds the typical
* range on Unix systems. Ensure the range of
* ISC_PLATFORM_RLIMITTYPE is not overflowed.
*/
isc_resourcevalue_t rlim_max;
isc_boolean_t rlim_t_is_signed =
ISC_TF(((double)(ISC_PLATFORM_RLIMITTYPE)-1) < 0);
if (rlim_t_is_signed)
rlim_max = ~((ISC_PLATFORM_RLIMITTYPE)1 <<
(sizeof(ISC_PLATFORM_RLIMITTYPE) * 8 - 1));
else
rlim_max = (ISC_PLATFORM_RLIMITTYPE)-1;
if (value > rlim_max)
value = rlim_max;
rlim_value = value;
}
/*
* The BIND 8 documentation reports:
*
* Note: on some operating systems the server cannot set an
* unlimited value and cannot determine the maximum number of
* open files the kernel can support. On such systems, choosing
* unlimited will cause the server to use the larger of the
* rlim_max for RLIMIT_NOFILE and the value returned by
* sysconf(_SC_OPEN_MAX). If the actual kernel limit is larger
* than this value, use limit files to specify the limit
* explicitly.
*
* The CHANGES for 8.1.2-T3A also mention:
*
* 352. [bug] Because of problems with setting an infinite
* rlim_max for RLIMIT_NOFILE on some systems, previous versions
* of the server implemented "limit files unlimited" by setting
* the limit to the value returned by sysconf(_SC_OPEN_MAX). The
* server will now use RLIM_INFINITY on systems which allow it.
*
* At some point the BIND 8 server stopped using SC_OPEN_MAX for this
* purpose at all, but it isn't clear to me when or why, as my access
* to the CVS archive is limited at the time of this writing. What
* BIND 8 *does* do is to set RLIMIT_NOFILE to either RLIMIT_INFINITY
* on a half dozen operating systems or to FD_SETSIZE on the rest,
* the latter of which is probably fewer than the real limit. (Note
* that libisc's socket module will have problems with any fd over
* FD_SETSIZE. This should be fixed in the socket module, not a
* limitation here. BIND 8's eventlib also has a problem, making
* its RLIMIT_INFINITY setting useless, because it closes and ignores
* any fd over FD_SETSIZE.)
*
* More troubling is the reference to some operating systems not being
* able to set an unlimited value for the number of open files. I'd
* hate to put in code that is really only there to support archaic
* systems that the rest of libisc won't work on anyway. So what this
* extremely verbose comment is here to say is the following:
*
* I'm aware there might be an issue with not limiting the value
* for RLIMIT_NOFILE on some systems, but since I don't know yet
* what those systems are and what the best workaround is (use
* sysconf()? rlim_max from getrlimit()? FD_SETSIZE?) so nothing
* is currently being done to clamp the value for open files.
*/
rl.rlim_cur = rl.rlim_max = rlim_value;
unixresult = setrlimit(unixresource, &rl);
if (unixresult == 0)
return (ISC_R_SUCCESS);
else
return (isc__errno2result(errno));
}
isc_result_t
isc_resource_getlimit(isc_resource_t resource, isc_resourcevalue_t *value) {
int unixresult;
int unixresource;
struct rlimit rl;
isc_result_t result;
result = resource2rlim(resource, &unixresource);
if (result == ISC_R_SUCCESS) {
unixresult = getrlimit(unixresource, &rl);
INSIST(unixresult == 0);
*value = rl.rlim_max;
}
return (result);
}