tcplistenertable_interface.c

开发snmp的开发包有两个开放的SNMP开发库

    tcpListenerTable_rowreq_ctx *rowreq_ctx =
        netsnmp_container_table_row_extract(requests);

    DEBUGMSGTL(("internal:tcpListenerTable:_mfd_tcpListenerTable_object_lookup", "called\n"));

    /*
     * get our context from mfd
     * tcpListenerTable_interface_ctx *if_ctx =
     *             (tcpListenerTable_interface_ctx *)reginfo->my_reg_void;
     */

    if (NULL == rowreq_ctx) {
        rc = SNMP_ERR_NOCREATION;
    }

    if (MFD_SUCCESS != rc)
        netsnmp_request_set_error_all(requests, rc);
    else
        tcpListenerTable_row_prep(rowreq_ctx);

    return SNMP_VALIDATE_ERR(rc);
}                               /* _mfd_tcpListenerTable_object_lookup */

/***********************************************************************
 *
 * GET processing
 *
 ***********************************************************************/
/*
 * @internal
 * Retrieve the value for a particular column
 */
NETSNMP_STATIC_INLINE int
_tcpListenerTable_get_column(tcpListenerTable_rowreq_ctx * rowreq_ctx,
                             netsnmp_variable_list * var, int column)
{
    int             rc = SNMPERR_SUCCESS;

    DEBUGMSGTL(("internal:tcpListenerTable:_mfd_tcpListenerTable_get_column", "called for %d\n", column));


    netsnmp_assert(NULL != rowreq_ctx);

    switch (column) {

        /*
         * tcpListenerProcess(4)/UNSIGNED32/ASN_UNSIGNED/u_long(u_long)//l/A/w/e/r/d/h 
         */
    case COLUMN_TCPLISTENERPROCESS:
        var->val_len = sizeof(u_long);
        var->type = ASN_UNSIGNED;
        rc = tcpListenerProcess_get(rowreq_ctx,
                                    (u_long *) var->val.string);
        break;

    default:
        snmp_log(LOG_ERR,
                 "unknown column %d in _tcpListenerTable_get_column\n",
                 column);
        break;
    }

    return rc;
}                               /* _tcpListenerTable_get_column */

int
_mfd_tcpListenerTable_get_values(netsnmp_mib_handler *handler,
                                 netsnmp_handler_registration *reginfo,
                                 netsnmp_agent_request_info *agtreq_info,
                                 netsnmp_request_info *requests)
{
    tcpListenerTable_rowreq_ctx *rowreq_ctx =
        netsnmp_container_table_row_extract(requests);
    netsnmp_table_request_info *tri;
    u_char         *old_string;
    void            (*dataFreeHook) (void *);
    int             rc;

    DEBUGMSGTL(("internal:tcpListenerTable:_mfd_tcpListenerTable_get_values", "called\n"));

    netsnmp_assert(NULL != rowreq_ctx);

    for (; requests; requests = requests->next) {
        /*
         * save old pointer, so we can free it if replaced
         */
        old_string = requests->requestvb->val.string;
        dataFreeHook = requests->requestvb->dataFreeHook;
        if (NULL == requests->requestvb->val.string) {
            requests->requestvb->val.string = requests->requestvb->buf;
            requests->requestvb->val_len =
                sizeof(requests->requestvb->buf);
        } else if (requests->requestvb->buf ==
                   requests->requestvb->val.string) {
            if (requests->requestvb->val_len !=
                sizeof(requests->requestvb->buf))
                requests->requestvb->val_len =
                    sizeof(requests->requestvb->buf);
        }

        /*
         * get column data
         */
        tri = netsnmp_extract_table_info(requests);
        if (NULL == tri)
            continue;

        rc = _tcpListenerTable_get_column(rowreq_ctx, requests->requestvb,
                                          tri->colnum);
        if (rc) {
            if (MFD_SKIP == rc) {
                requests->requestvb->type = SNMP_NOSUCHINSTANCE;
                rc = SNMP_ERR_NOERROR;
            }
        } else if (NULL == requests->requestvb->val.string) {
            snmp_log(LOG_ERR, "NULL varbind data pointer!\n");
            rc = SNMP_ERR_GENERR;
        }
        if (rc)
            netsnmp_request_set_error(requests, SNMP_VALIDATE_ERR(rc));

        /*
         * if the buffer wasn't used previously for the old data (i.e. it
         * was allcoated memory)  and the get routine replaced the pointer,
         * we need to free the previous pointer.
         */
        if (old_string && (old_string != requests->requestvb->buf) &&
            (requests->requestvb->val.string != old_string)) {
            if (dataFreeHook)
                (*dataFreeHook) (old_string);
            else
                free(old_string);
        }
    }                           /* for results */

    return SNMP_ERR_NOERROR;
}                               /* _mfd_tcpListenerTable_get_values */


/***********************************************************************
 *
 * SET processing
 *
 ***********************************************************************/

/*
 * SET PROCESSING NOT APPLICABLE (per MIB or user setting)
 */
/***********************************************************************
 *
 * DATA ACCESS
 *
 ***********************************************************************/
static void     _container_free(netsnmp_container *container);

/**
 * @internal
 */
static int
_cache_load(netsnmp_cache * cache, void *vmagic)
{
    DEBUGMSGTL(("internal:tcpListenerTable:_cache_load", "called\n"));

    if ((NULL == cache) || (NULL == cache->magic)) {
        snmp_log(LOG_ERR,
                 "invalid cache for tcpListenerTable_cache_load\n");
        return -1;
    }

    /** should only be called for an invalid or expired cache */
    netsnmp_assert((0 == cache->valid) || (1 == cache->expired));

    /*
     * call user code
     */
    return tcpListenerTable_container_load((netsnmp_container *) cache->
                                           magic);
}                               /* _cache_load */

/**
 * @internal
 */
static void
_cache_free(netsnmp_cache * cache, void *magic)
{
    netsnmp_container *container;

    DEBUGMSGTL(("internal:tcpListenerTable:_cache_free", "called\n"));

    if ((NULL == cache) || (NULL == cache->magic)) {
        snmp_log(LOG_ERR,
                 "invalid cache in tcpListenerTable_cache_free\n");
        return;
    }

    container = (netsnmp_container *) cache->magic;

    _container_free(container);
}                               /* _cache_free */

/**
 * @internal
 */
static void
_container_item_free(tcpListenerTable_rowreq_ctx * rowreq_ctx,
                     void *context)
{
    DEBUGMSGTL(("internal:tcpListenerTable:_container_item_free",
                "called\n"));

    if (NULL == rowreq_ctx)
        return;

    tcpListenerTable_release_rowreq_ctx(rowreq_ctx);
}                               /* _container_item_free */

/**
 * @internal
 */
static void
_container_free(netsnmp_container *container)
{
    DEBUGMSGTL(("internal:tcpListenerTable:_container_free", "called\n"));

    if (NULL == container) {
        snmp_log(LOG_ERR,
                 "invalid container in tcpListenerTable_container_free\n");
        return;
    }

    /*
     * call user code
     */
    tcpListenerTable_container_free(container);

    /*
     * free all items. inefficient, but easy.
     */
    CONTAINER_CLEAR(container,
                    (netsnmp_container_obj_func *) _container_item_free,
                    NULL);
}                               /* _container_free */

/**
 * @internal
 * initialize the container with functions or wrappers
 */
void
_tcpListenerTable_container_init(tcpListenerTable_interface_ctx * if_ctx)
{
    DEBUGMSGTL(("internal:tcpListenerTable:_tcpListenerTable_container_init", "called\n"));

    /*
     * cache init
     */
    if_ctx->cache = netsnmp_cache_create(30,    /* timeout in seconds */
                                         _cache_load, _cache_free,
                                         tcpListenerTable_oid,
                                         tcpListenerTable_oid_size);

    if (NULL == if_ctx->cache) {
        snmp_log(LOG_ERR, "error creating cache for tcpListenerTable\n");
        return;
    }

    if_ctx->cache->flags = NETSNMP_CACHE_DONT_INVALIDATE_ON_SET;

    tcpListenerTable_container_init(&if_ctx->container, if_ctx->cache);
    if (NULL == if_ctx->container)
        if_ctx->container =
            netsnmp_container_find("tcpListenerTable:table_container");
    if (NULL == if_ctx->container) {
        snmp_log(LOG_ERR, "error creating container in "
                 "tcpListenerTable_container_init\n");
        return;
    }

    if (NULL != if_ctx->cache)
        if_ctx->cache->magic = (void *) if_ctx->container;
}                               /* _tcpListenerTable_container_init */

/**
 * @internal
 * shutdown the container with functions or wrappers
 */
void
_tcpListenerTable_container_shutdown(tcpListenerTable_interface_ctx *
                                     if_ctx)
{
    DEBUGMSGTL(("internal:tcpListenerTable:_tcpListenerTable_container_shutdown", "called\n"));

    tcpListenerTable_container_shutdown(if_ctx->container);

    _container_free(if_ctx->container);

}                               /* _tcpListenerTable_container_shutdown */


tcpListenerTable_rowreq_ctx *
tcpListenerTable_row_find_by_mib_index(tcpListenerTable_mib_index *
                                       mib_idx)
{
    tcpListenerTable_rowreq_ctx *rowreq_ctx;
    oid             oid_tmp[MAX_OID_LEN];
    netsnmp_index   oid_idx;
    int             rc;

    /*
     * set up storage for OID
     */
    oid_idx.oids = oid_tmp;
    oid_idx.len = sizeof(oid_tmp) / sizeof(oid);

    /*
     * convert
     */
    rc = tcpListenerTable_index_to_oid(&oid_idx, mib_idx);
    if (MFD_SUCCESS != rc)
        return NULL;

    rowreq_ctx =
        CONTAINER_FIND(tcpListenerTable_if_ctx.container, &oid_idx);

    return rowreq_ctx;
}