/*
 * Note: this file originally auto-generated by mib2c using
 *        : mib2c.scalar.conf,v 1.9 2005/01/07 09:37:18 dts12 Exp $
 */

#include <net-snmp/net-snmp-config.h>
#include <net-snmp/net-snmp-includes.h>
#include <net-snmp/agent/net-snmp-agent-includes.h>
#include <net-snmp/agent/hardware/memory.h>
#include "memory.h"

#define DEFAULTMINIMUMSWAP 16000        /* kilobytes */
static int minimum_swap;

/** Initializes the memory module */
void
init_memory(void)
{
    const oid      memory_oid[] = { 1, 3, 6, 1, 4, 1, 2021, 4 };
    const oid      memSwapError_oid[]  = { 1, 3, 6, 1, 4, 1, 2021, 4, 100 };
    const oid      memSwapErrMsg_oid[] = { 1, 3, 6, 1, 4, 1, 2021, 4, 101 };

    DEBUGMSGTL(("memory", "Initializing\n"));

    netsnmp_register_scalar_group(
        netsnmp_create_handler_registration("memory", handle_memory,
                                 memory_oid, OID_LENGTH(memory_oid),
                                             HANDLER_CAN_RONLY),
                                 1, 17);
    netsnmp_register_scalar(
        netsnmp_create_handler_registration("memSwapError", handle_memory,
                           memSwapError_oid, OID_LENGTH(memSwapError_oid),
                                             HANDLER_CAN_RONLY));
    netsnmp_register_scalar(
        netsnmp_create_handler_registration("memSwapErrMsg", handle_memory,
                          memSwapErrMsg_oid, OID_LENGTH(memSwapErrMsg_oid),
                                             HANDLER_CAN_RONLY));

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

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

void
memory_free_config(void)
{
    minimum_swap = DEFAULTMINIMUMSWAP;
}

int
handle_memory(netsnmp_mib_handler *handler,
                netsnmp_handler_registration *reginfo,
                netsnmp_agent_request_info *reqinfo,
                netsnmp_request_info *requests)
{
    netsnmp_memory_info *mem_info;
    int val;
    char buf[1024];

    /*
     * We just need to handle valid GET requests, as invalid instances
     *   are rejected automatically, and (valid) GETNEXT requests are
     *   converted into the appropriate GET request.
     *
     * We also only ever receive one request at a time.
     */
    switch (reqinfo->mode) {
    case MODE_GET:
        netsnmp_memory_load();
        switch (requests->requestvb->name[ reginfo->rootoid_len - 2 ]) {
        case MEMORY_INDEX:
            val = 0;
            break;
        case MEMORY_ERRNAME:
            sprintf(buf, "swap");
            snmp_set_var_typed_value(requests->requestvb, ASN_OCTET_STR,
                                     (u_char *)buf, strlen(buf));
            return SNMP_ERR_NOERROR;
        case MEMORY_SWAP_TOTAL:
            mem_info = netsnmp_memory_get_byIdx( NETSNMP_MEM_TYPE_SWAP, 0 );
            if (!mem_info)
               goto NOSUCH;
            val  =  mem_info->size;     /* swaptotal */
            val *= (mem_info->units/1024);
            break;
        case MEMORY_SWAP_AVAIL:
            mem_info = netsnmp_memory_get_byIdx( NETSNMP_MEM_TYPE_SWAP, 0 );
            if (!mem_info)
               goto NOSUCH;
            val  =  mem_info->free;     /* swapfree */
            val *= (mem_info->units/1024);
            break;
        case MEMORY_REAL_TOTAL:
            mem_info = netsnmp_memory_get_byIdx( NETSNMP_MEM_TYPE_PHYSMEM, 0 );
            if (!mem_info)
               goto NOSUCH;
            val  =  mem_info->size;     /* memtotal */
            val *= (mem_info->units/1024);
            break;
        case MEMORY_REAL_AVAIL:
            mem_info = netsnmp_memory_get_byIdx( NETSNMP_MEM_TYPE_PHYSMEM, 0 );
            if (!mem_info)
               goto NOSUCH;
            val  =  mem_info->free;     /* memfree */
            val *= (mem_info->units/1024);
            break;
        case MEMORY_STXT_TOTAL:
            mem_info = netsnmp_memory_get_byIdx( NETSNMP_MEM_TYPE_STEXT, 0 );
            if (!mem_info)
               goto NOSUCH;
            val  =  mem_info->size;
            val *= (mem_info->units/1024);
            break;
        case MEMORY_STXT_AVAIL:    /* Deprecated */
        case MEMORY_STXT_USED:
            /*
             *   The original MIB description of memAvailSwapTXT
             * was inconsistent with that implied by the name.
             *   Retain the actual behaviour for the (sole)
             * implementation of this object, but deprecate it in
             * favour of a more consistently named replacement object.
             */
            mem_info = netsnmp_memory_get_byIdx( NETSNMP_MEM_TYPE_STEXT, 0 );
            if (!mem_info)
               goto NOSUCH;
            val  = (mem_info->size - mem_info->free);
            val *= (mem_info->units/1024);
            break;
        case MEMORY_RTXT_TOTAL:
            mem_info = netsnmp_memory_get_byIdx( NETSNMP_MEM_TYPE_RTEXT, 0 );
            if (!mem_info)
               goto NOSUCH;
            val  =  mem_info->size;
            val *= (mem_info->units/1024);
            break;
        case MEMORY_RTXT_AVAIL:    /* Deprecated */
        case MEMORY_RTXT_USED:
            /*
             *   The original MIB description of memAvailRealTXT
             * was inconsistent with that implied by the name.
             *   Retain the actual behaviour for the (sole)
             * implementation of this object, but deprecate it in
             * favour of a more consistently named replacement object.
             */
            mem_info = netsnmp_memory_get_byIdx( NETSNMP_MEM_TYPE_RTEXT, 0 );
            if (!mem_info)
               goto NOSUCH;
            val  = (mem_info->size - mem_info->free);
            val *= (mem_info->units/1024);
            break;
        case MEMORY_FREE:
            mem_info = netsnmp_memory_get_byIdx( NETSNMP_MEM_TYPE_VIRTMEM, 0 );
            if (!mem_info)
               goto NOSUCH;
            val  =  mem_info->free;     /* memfree + swapfree */
            val *= (mem_info->units/1024);
            break;
        case MEMORY_SWAP_MIN:
            val = minimum_swap;
            break;
        case MEMORY_SHARED:
            mem_info = netsnmp_memory_get_byIdx( NETSNMP_MEM_TYPE_SHARED, 0 );
            if (!mem_info)
               goto NOSUCH;
            val  =  mem_info->size;     /* memshared */
            val *= (mem_info->units/1024);
            break;
        case MEMORY_BUFFER:
            mem_info = netsnmp_memory_get_byIdx( NETSNMP_MEM_TYPE_MBUF, 0 );
            if (!mem_info || mem_info->size == -1)
               goto NOSUCH;
            val  = (mem_info->size - mem_info->free);      /* buffers */
            val *= (mem_info->units/1024);
            break;
        case MEMORY_CACHED:
            mem_info = netsnmp_memory_get_byIdx( NETSNMP_MEM_TYPE_CACHED, 0 );
            if (!mem_info || mem_info->size== -1)
               goto NOSUCH;
            val  = (mem_info->size - mem_info->free);      /* cached */
            val *= (mem_info->units/1024);
            break;
        case MEMORY_SWAP_ERROR:
            mem_info = netsnmp_memory_get_byIdx( NETSNMP_MEM_TYPE_SWAP, 0 );
            if (!mem_info)
               goto NOSUCH;
            val = ((mem_info->units / 1024) * mem_info->free > minimum_swap) ? 0 : 1;
            break;
        case MEMORY_SWAP_ERRMSG:
            mem_info = netsnmp_memory_get_byIdx( NETSNMP_MEM_TYPE_SWAP, 0 );
            if (!mem_info)
               goto NOSUCH;
            if ((mem_info->units / 1024) * mem_info->free > minimum_swap)
                buf[0] = 0;
            else
                sprintf(buf, "Running out of swap space (%ld)", mem_info->free);
            snmp_set_var_typed_value(requests->requestvb, ASN_OCTET_STR,
                                     (u_char *)buf, strlen(buf));
            return SNMP_ERR_NOERROR;
        default:
            snmp_log(LOG_ERR, "unknown object (%lu) in handle_memory\n",
                     requests->requestvb->name[ reginfo->rootoid_len - 2 ]);
NOSUCH:
            netsnmp_set_request_error( reqinfo, requests, SNMP_NOSUCHOBJECT );
            return SNMP_ERR_NOERROR;
        }
        /*
         * All non-integer objects (and errors) have already been
         * processed.  So return the integer value.
         */
        snmp_set_var_typed_value(requests->requestvb, ASN_INTEGER,
                                 (u_char *)&val, sizeof(val));
        break;

    default:
        /*
         * we should never get here, so this is a really bad error 
         */
        snmp_log(LOG_ERR, "unknown mode (%d) in handle_memory\n",
                 reqinfo->mode);
        return SNMP_ERR_GENERR;
    }

    return SNMP_ERR_NOERROR;
}