/* Copyright (C) 2007-2013 Open Information Security Foundation
 *
 * You can copy, redistribute or modify this Program under the terms of
 * the GNU General Public License version 2 as published by the Free
 * Software Foundation.
 *
 * 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
 * version 2 along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

/**
 * \file
 *
 * \author Pablo Rincon Crespo <pablo.rincon.crespo@gmail.com>
 *
 * Retrieve CPU information (configured CPUs, online CPUs)
 */

#include "suricata-common.h"
#include "util-error.h"
#include "util-debug.h"
#include "util-cpu.h"

/**
 * Ok, if they should use sysconf, check that they have the macro's
 * (syscalls) defined;
 *
 * Note: For windows it's different; Check the following:
 *      SYSTEM_INFO info;
 *      GetSystemInfo(&info);
 *      -> info.dwNumberOfProcessors;
 */
#ifdef _SC_NPROCESSORS_CONF
#define SYSCONF_NPROCESSORS_CONF_COMPAT
#endif

#ifdef _SC_NPROCESSORS_ONLN
#define SYSCONF_NPROCESSORS_ONLN_COMPAT
#endif

/* This one is available on Solaris 10 */
#ifdef _SC_NPROCESSORS_MAX
#define SYSCONF_NPROCESSORS_MAX_COMPAT
#endif

/**
 * \brief Get the number of cpus configured in the system
 * \retval 0 if the syscall is not available or we have an error;
 *           otherwise it will return the number of cpus configured
 */
uint16_t UtilCpuGetNumProcessorsConfigured(void)
{
#ifdef SYSCONF_NPROCESSORS_CONF_COMPAT
	long nprocs = -1;
    nprocs = sysconf(_SC_NPROCESSORS_CONF);
    if (nprocs < 1) {
        SCLogError(SC_ERR_SYSCALL, "Couldn't retrieve the number of cpus "
                   "configured (%s)", strerror(errno));
        return 0;
    }

    if (nprocs > UINT16_MAX) {
        SCLogDebug("It seems that there are more than %d CPUs "
                   "configured on this system. You can modify util-cpu.{c,h} "
                   "to use uint32_t to support it", UINT16_MAX);
        return UINT16_MAX;
    }

    return (uint16_t)nprocs;
#elif OS_WIN32
	long nprocs = -1;
	const char* envvar = getenv("NUMBER_OF_PROCESSORS");
	nprocs = (NULL != envvar) ? atoi(envvar) : 0;
    if (nprocs < 1) {
        SCLogError(SC_ERR_SYSCALL, "Couldn't retrieve the number of cpus "
                   "configured from the NUMBER_OF_PROCESSORS environment variable");
        return 0;
    }
    return (uint16_t)nprocs;
#else
    SCLogError(SC_ERR_SYSCONF, "Couldn't retrieve the number of cpus "
               "configured, sysconf macro unavailable");
    return 0;
#endif
}

/**
 * \brief Get the number of cpus online in the system
 * \retval 0 if the syscall is not available or we have an error;
 *           otherwise it will return the number of cpus online
 */
uint16_t UtilCpuGetNumProcessorsOnline(void)
{
#ifdef SYSCONF_NPROCESSORS_ONLN_COMPAT
    long nprocs = -1;
    nprocs = sysconf(_SC_NPROCESSORS_ONLN);
    if (nprocs < 1) {
        SCLogError(SC_ERR_SYSCALL, "Couldn't retrieve the number of cpus "
                   "online (%s)", strerror(errno));
        return 0;
    }

    if (nprocs > UINT16_MAX) {
        SCLogDebug("It seems that there are more than %d CPUs online. "
                   "You can modify util-cpu.{c,h} to use uint32_t to "
                   "support it", UINT16_MAX);
        return UINT16_MAX;
    }

    return nprocs;
#elif OS_WIN32
	return UtilCpuGetNumProcessorsConfigured();
#else
    SCLogError(SC_ERR_SYSCONF, "Couldn't retrieve the number of cpus online, "
               "synconf macro unavailable");
    return 0;
#endif
}

/**
 * \brief Get the maximum number of cpus allowed in the system
 *        This syscall is present on Solaris, but it's not on linux
 *        or macosx. Maybe you should look at UtilCpuGetNumProcessorsConfigured()
 * \retval 0 if the syscall is not available or we have an error;
 *           otherwise it will return the number of cpus allowed
 */
uint16_t UtilCpuGetNumProcessorsMax(void)
{
#ifdef SYSCONF_NPROCESSORS_MAX_COMPAT
    long nprocs = -1;
    nprocs = sysconf(_SC_NPROCESSORS_MAX);
    if (nprocs < 1) {
        SCLogError(SC_ERR_SYSCALL, "Couldn't retrieve the maximum number of cpus "
                   "allowed by the system (%s)", strerror(errno));
        return 0;
    }

    if (nprocs > UINT16_MAX) {
        SCLogDebug("It seems that the system support more that %"PRIu16" CPUs. You "
                   "can modify util-cpu.{c,h} to use uint32_t to support it", UINT16_MAX);
        return UINT16_MAX;
    }

    return (uint16_t)nprocs;
#else
    SCLogError(SC_ERR_SYSCONF, "Couldn't retrieve the maximum number of cpus allowed by "
               "the system, synconf macro unavailable");
    return 0;
#endif
}

/**
 * \brief Print a summary of CPUs detected (configured and online)
 */
void UtilCpuPrintSummary(void)
{
    uint16_t cpus_conf = UtilCpuGetNumProcessorsConfigured();
    uint16_t cpus_online = UtilCpuGetNumProcessorsOnline();

    SCLogDebug("CPUs Summary: ");
    if (cpus_conf > 0)
        SCLogDebug("CPUs configured: %"PRIu16, cpus_conf);
    if (cpus_online > 0)
        SCLogInfo("CPUs/cores online: %"PRIu16, cpus_online);
    if (cpus_online == 0 && cpus_conf == 0)
        SCLogInfo("Couldn't retireve any information of CPU's, please, send your operating "
                  "system info and check util-cpu.{c,h}");
}

/**
 * Get the current number of ticks from the CPU.
 *
 * \todo We'll have to deal with removig ticks from the extra cpuids inbetween
 *       2 calls.
 */
uint64_t UtilCpuGetTicks(void)
{
    uint64_t val;
#if defined(__GNUC__) && (defined(__x86_64) || defined(_X86_64_) || defined(ia_64) || defined(__i386__))
#if defined(__x86_64) || defined(_X86_64_) || defined(ia_64)
    __asm__ __volatile__ (
    "xorl %%eax,%%eax\n\t"
    "cpuid\n\t"
    ::: "%rax", "%rbx", "%rcx", "%rdx");
#else
    __asm__ __volatile__ (
    "xorl %%eax,%%eax\n\t"
    "pushl %%ebx\n\t"
    "cpuid\n\t"
    "popl %%ebx\n\t"
    ::: "%eax", "%ecx", "%edx");
#endif
    uint32_t a, d;
    __asm__ __volatile__ ("rdtsc" : "=a" (a), "=d" (d));
    val = ((uint64_t)a) | (((uint64_t)d) << 32);
#if defined(__x86_64) || defined(_X86_64_) || defined(ia_64)
    __asm__ __volatile__ (
    "xorl %%eax,%%eax\n\t"
    "cpuid\n\t"
    ::: "%rax", "%rbx", "%rcx", "%rdx");
#else
    __asm__ __volatile__ (
    "xorl %%eax,%%eax\n\t"
    "pushl %%ebx\n\t"
    "cpuid\n\t"
    "popl %%ebx\n\t"
    ::: "%eax", "%ecx", "%edx");
#endif

#else /* #if defined(__GNU__) */
//#warning Using inferior version of UtilCpuGetTicks
    struct timeval now;
    gettimeofday(&now, NULL);
    val = (now.tv_sec * 1000000) + now.tv_usec;
#endif
    return val;
}
