/*

 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")

 *

 * This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/.

 *

 * See the COPYRIGHT file distributed with this work for additional

 * information regarding copyright ownership.

 */

#include <config.h>

#include <inttypes.h>

#include <stdbool.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>

#ifdef __linux__

#include <linux/fs.h>	/* To get the large NR_OPEN. */

#endif

#if defined(__hpux) && defined(HAVE_SYS_DYNTUNE_H)

#include <sys/dyntune.h>

#endif

#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;

		bool rlim_t_is_signed =

			(((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;

	}

	rl.rlim_cur = rl.rlim_max = rlim_value;

	unixresult = setrlimit(unixresource, &rl);

	if (unixresult == 0)

		return (ISC_R_SUCCESS);

#if defined(OPEN_MAX) && defined(__APPLE__)

	/*

	 * The Darwin kernel doesn't accept RLIM_INFINITY for rlim_cur; the

	 * maximum possible value is OPEN_MAX.  BIND8 used to use

	 * sysconf(_SC_OPEN_MAX) for such a case, but this value is much

	 * smaller than OPEN_MAX and is not really effective.

	 */

	if (resource == isc_resource_openfiles && rlim_value == RLIM_INFINITY) {

		rl.rlim_cur = OPEN_MAX;

		unixresult = setrlimit(unixresource, &rl);

		if (unixresult == 0)

			return (ISC_R_SUCCESS);

	}

#elif defined(__linux__)

#ifndef NR_OPEN

#define NR_OPEN (1024*1024)

#endif

	/*

	 * Some Linux kernels don't accept RLIM_INFINIT; the maximum

	 * possible value is the NR_OPEN defined in linux/fs.h.

	 */

	if (resource == isc_resource_openfiles && rlim_value == RLIM_INFINITY) {

		rl.rlim_cur = rl.rlim_max = NR_OPEN;

		unixresult = setrlimit(unixresource, &rl);

		if (unixresult == 0)

			return (ISC_R_SUCCESS);

	}

#elif defined(__hpux) && defined(HAVE_SYS_DYNTUNE_H)

	if (resource == isc_resource_openfiles && rlim_value == RLIM_INFINITY) {

		uint64_t maxfiles;

		if (gettune("maxfiles_lim", &maxfiles) == 0) {

			rl.rlim_cur = rl.rlim_max = maxfiles;

			unixresult = setrlimit(unixresource, &rl);

			if (unixresult == 0)

				return (ISC_R_SUCCESS);

		}

	}

#endif

	if (resource == isc_resource_openfiles && rlim_value == RLIM_INFINITY) {

		if (getrlimit(unixresource, &rl) == 0) {

			rl.rlim_cur = rl.rlim_max;

			unixresult = setrlimit(unixresource, &rl);

			if (unixresult == 0)

				return (ISC_R_SUCCESS);

		}

	}

	return (isc__errno2result(errno));

}

isc_result_t

isc_resource_getlimit(isc_resource_t resource, isc_resourcevalue_t *value) {

	int unixresource;

	struct rlimit rl;

	isc_result_t result;

	result = resource2rlim(resource, &unixresource);

	if (result != ISC_R_SUCCESS) {

		return (result);

	}

	if (getrlimit(unixresource, &rl) != 0) {

		return (isc__errno2result(errno));

	}

	*value = rl.rlim_max;

	return (ISC_R_SUCCESS);

}

isc_result_t

isc_resource_getcurlimit(isc_resource_t resource, isc_resourcevalue_t *value) {

	int unixresource;

	struct rlimit rl;

	isc_result_t result;

	result = resource2rlim(resource, &unixresource);

	if (result != ISC_R_SUCCESS) {

		return (result);

	}

	if (getrlimit(unixresource, &rl) != 0) {

		return (isc__errno2result(errno));

	}

	*value = rl.rlim_cur;

	return (ISC_R_SUCCESS);

}