/*
 * memory_freebsd2.c
 */

#include <net-snmp/net-snmp-config.h>


/*
 * Ripped from /usr/scr/usr.bin/vmstat/vmstat.c (covering all bases) 
 */
#include <sys/param.h>
#include <sys/time.h>
#ifdef dragonfly
#include <sys/user.h>
#else
#include <sys/proc.h>
#include <sys/dkstat.h>
#endif
#ifdef freebsd5
#include <sys/bio.h>
#endif
#include <sys/buf.h>
#include <sys/uio.h>
#include <sys/namei.h>
#include <sys/malloc.h>
#include <sys/signal.h>
#include <sys/fcntl.h>
#include <sys/ioctl.h>
#include <sys/sysctl.h>
#include <sys/vmmeter.h>

#if HAVE_SYS_VMPARAM_H
#include <sys/vmparam.h>
#else
#include <vm/vm_param.h>
#endif

#include <time.h>
#include <nlist.h>
#include <kvm.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include <paths.h>
#include <limits.h>

#include <net-snmp/net-snmp-includes.h>
#include <net-snmp/agent/net-snmp-agent-includes.h>
#include <net-snmp/agent/auto_nlist.h>

#include "util_funcs.h"
#include "memory.h"
#include "memory_freebsd2.h"

/*
 * nlist symbols 
 */
#define SUM_SYMBOL      "cnt"
#ifndef openbsd2
#define BUFSPACE_SYMBOL "bufspace"
#endif

/*
 * Default swap warning limit (kb) 
 */
#define DEFAULTMINIMUMSWAP 16000

/*
 * Swap warning limit 
 */
long            minimumswap;

/*
 * Swap info 
 */
quad_t          swapTotal;
quad_t          swapUsed;
quad_t          swapFree;

static FindVarMethod var_extensible_mem;

void
init_memory_freebsd2(void)
{

    struct variable2 extensible_mem_variables[] = {
        {MIBINDEX, ASN_INTEGER, RONLY, var_extensible_mem, 1, {MIBINDEX}},
        {ERRORNAME, ASN_OCTET_STR, RONLY, var_extensible_mem, 1,
         {ERRORNAME}},
        {MEMTOTALSWAP, ASN_INTEGER, RONLY, var_extensible_mem, 1,
         {MEMTOTALSWAP}},
        {MEMAVAILSWAP, ASN_INTEGER, RONLY, var_extensible_mem, 1,
         {MEMAVAILSWAP}},
        {MEMTOTALREAL, ASN_INTEGER, RONLY, var_extensible_mem, 1,
         {MEMTOTALREAL}},
        {MEMAVAILREAL, ASN_INTEGER, RONLY, var_extensible_mem, 1,
         {MEMAVAILREAL}},
        {MEMTOTALSWAPTXT, ASN_INTEGER, RONLY, var_extensible_mem, 1,
         {MEMTOTALSWAPTXT}},
        {MEMUSEDSWAPTXT, ASN_INTEGER, RONLY, var_extensible_mem, 1,
         {MEMUSEDSWAPTXT}},
        {MEMTOTALREALTXT, ASN_INTEGER, RONLY, var_extensible_mem, 1,
         {MEMTOTALREALTXT}},
        {MEMUSEDREALTXT, ASN_INTEGER, RONLY, var_extensible_mem, 1,
         {MEMUSEDREALTXT}},
        {MEMTOTALFREE, ASN_INTEGER, RONLY, var_extensible_mem, 1,
         {MEMTOTALFREE}},
        {MEMSWAPMINIMUM, ASN_INTEGER, RONLY, var_extensible_mem, 1,
         {MEMSWAPMINIMUM}},
        {MEMSHARED, ASN_INTEGER, RONLY, var_extensible_mem, 1,
         {MEMSHARED}},
        {MEMBUFFER, ASN_INTEGER, RONLY, var_extensible_mem, 1,
         {MEMBUFFER}},
        {MEMCACHED, ASN_INTEGER, RONLY, var_extensible_mem, 1,
         {MEMCACHED}},
        {ERRORFLAG, ASN_INTEGER, RONLY, var_extensible_mem, 1,
         {ERRORFLAG}},
        {ERRORMSG, ASN_OCTET_STR, RONLY, var_extensible_mem, 1, {ERRORMSG}}
    };

    /*
     * Define the OID pointer to the top of the mib tree that we're
     * registering underneath 
     */
    oid             mem_variables_oid[] = { NETSNMP_UCDAVIS_MIB, NETSNMP_MEMMIBNUM };

    /*
     * register ourselves with the agent to handle our mib tree 
     */
    REGISTER_MIB("ucd-snmp/memory", extensible_mem_variables, variable2,
                 mem_variables_oid);

    snmpd_register_config_handler("swap", memory_parse_config,
                                  memory_free_config, "min-avail");
}


void
memory_parse_config(const char *token, char *cptr)
{
    minimumswap = atoi(cptr);
}

void
memory_free_config(void)
{
    minimumswap = DEFAULTMINIMUMSWAP;
}

#ifndef freebsd4
/*
 * Executes swapinfo and parses last line 
 */
/*
 * This is just way too ugly ;) 
 */

void
swapmode(void)
{
    struct extensible ext;
    int             fd;
    FILE           *file;

    strcpy(ext.command, "/usr/sbin/swapinfo -k");

    if ((fd = get_exec_output(&ext)) != -1) {
        file = fdopen(fd, "r");

        while (fgets(ext.output, sizeof(ext.output), file) != NULL);

        fclose(file);
        wait_on_exec(&ext);

        sscanf(ext.output, "%*s%*d%qd%qd", &swapUsed, &swapFree);

        swapTotal = swapUsed + swapFree;
    }
}
#else
/*
 * swapmode is based on a program called swapinfo written
 * by Kevin Lahey <kml@rokkaku.atl.ga.us>.
 */

#include <sys/conf.h>

void
swapmode(void)
{
    int             pagesize;
    int             i, n;
    static kvm_t   *kd = NULL;
    struct kvm_swap kswap[16];

    if (kd == NULL)
        kd = kvm_openfiles(NULL, NULL, NULL, O_RDONLY, NULL);

    n = kvm_getswapinfo(kd, kswap, sizeof(kswap) / sizeof(kswap[0]), 0);

    swapUsed = swapTotal = swapFree = 0;
    /*
     * Count up free swap space. 
     */
    for (i = 0; i < n; ++i)
        swapFree += kswap[i].ksw_total - kswap[i].ksw_used;

    /*
     * Count up total swap space 
     */
    for (i = 0; i < n; i++)
        swapTotal += kswap[i].ksw_total;

    /*
     * Calculate used swap space 
     */
    swapUsed = swapTotal - swapFree;

    /*
     * Convert to kb 
     */
    pagesize = getpagesize() / 1024;

    swapTotal *= pagesize;
    swapUsed *= pagesize;
    swapFree *= pagesize;
}
#endif


/*
 * var_extensible_mem(...
 * Arguments:
 * vp     IN      - pointer to variable entry that points here
 * name    IN/OUT  - IN/name requested, OUT/name found
 * length  IN/OUT  - length of IN/OUT oid's 
 * exact   IN      - TRUE if an exact match was requested
 * var_len OUT     - length of variable or 0 if function returned
 * write_method
 * 
 */

static unsigned char *
var_extensible_mem(struct variable *vp,
                   oid * name,
                   size_t * length,
                   int exact,
                   size_t * var_len, WriteMethod ** write_method)
{
    static long     long_ret;
    static char     errmsg[1024];

#ifdef dragonfly
    static struct vmstats mem;
    size_t        vmstats_size = sizeof(mem);
#endif
    static struct vmmeter mem;
#endif
    static struct vmtotal total;

    size_t          total_size = sizeof(total);
    int             total_mib[] = { CTL_VM, VM_METER };

    u_long          phys_mem;
    size_t          phys_mem_size = sizeof(phys_mem);
    int             phys_mem_mib[] = { CTL_HW, HW_PHYSMEM };

#ifdef BUFSPACE_SYMBOL
    long            bufspace;
#endif

    if (header_generic(vp, name, length, exact, var_len, write_method))
        return (NULL);

    /*
     * Memory info 
     */
#ifdef dragonfly
    sysctlbyname("vm.vmstats", &vmstats, &vmstats_size, NULL, 0);
#else
    auto_nlist(SUM_SYMBOL, (char *) &mem, sizeof(mem));
#endif
    sysctl(total_mib, 2, &total, &total_size, NULL, 0);

    /*
     * Swap info 
     */
    swapmode();
    /*
     * getSwap(); 
     */

    /*
     * Physical memory 
     */
    sysctl(phys_mem_mib, 2, &phys_mem, &phys_mem_size, NULL, 0);

#ifdef BUFSPACE_SYMBOL
    /*
     * Buffer space 
     */
    auto_nlist(BUFSPACE_SYMBOL, (char *) &bufspace, sizeof(bufspace));
#endif

    long_ret = 0;               /* set to 0 as default */

    /*
     * Page-to-kb macro 
     */
#define ptok(p) ((p) * (mem.v_page_size >> 10))

    switch (vp->magic) {
    case MIBINDEX:
        long_ret = 0;
        return ((u_char *) (&long_ret));
    case ERRORNAME:            /* dummy name */
        sprintf(errmsg, "swap");
        *var_len = strlen(errmsg);
        return ((u_char *) (errmsg));
    case MEMTOTALSWAP:
        long_ret = swapTotal;
        return ((u_char *) (&long_ret));
    case MEMAVAILSWAP:         /* FREE swap memory */
        long_ret = swapFree;
        return ((u_char *) (&long_ret));
    case MEMTOTALREAL:
        long_ret = phys_mem >> 10;
        return ((u_char *) (&long_ret));
    case MEMAVAILREAL:         /* FREE real memory */
        long_ret = ptok(mem.v_free_count);
        return ((u_char *) (&long_ret));

        /*
         * these are not implemented 
         */
    case MEMTOTALSWAPTXT:
    case MEMUSEDSWAPTXT:
    case MEMTOTALREALTXT:
    case MEMUSEDREALTXT:
#if NETSNMP_NO_DUMMY_VALUES
        return NULL;
#endif
        long_ret = -1;
        return ((u_char *) (&long_ret));

    case MEMTOTALFREE:
        long_ret = ptok((int) total.t_free);
        return ((u_char *) (&long_ret));
    case MEMSWAPMINIMUM:
        long_ret = minimumswap;
        return ((u_char *) (&long_ret));
    case MEMSHARED:
        long_ret = ptok(total.t_vmshr +
                        total.t_avmshr + total.t_rmshr + total.t_armshr);
        return ((u_char *) (&long_ret));
#ifdef BUFSPACE_SYMBOL
    case MEMBUFFER:
        long_ret = bufspace >> 10;
        return ((u_char *) (&long_ret));
#endif
#ifndef openbsd2
    case MEMCACHED:
#ifdef darwin
        long_ret = ptok(mem.v_lookups);
#elif  defined(dragonfly)
        long_ret = ptok(mem.v_cache_count);
#else
        long_ret = ptok(mem.v_cache_count) + ptok(mem.v_inactive_count);
#endif
        return ((u_char *) (&long_ret));
#endif
    case ERRORFLAG:
        long_ret = (swapFree > minimumswap) ? 0 : 1;
        return ((u_char *) (&long_ret));
    case ERRORMSG:
        if (swapFree < minimumswap)
            sprintf(errmsg, "Running out of swap space (%qd)", swapFree);
        else
            errmsg[0] = 0;
        *var_len = strlen(errmsg);
        return ((u_char *) (errmsg));
    }
    return NULL;
}
