ipaddresstable_data_access.c

开发snmp的开发包有两个开放的SNMP开发库

/*
 * Note: this file originally auto-generated by mib2c using
 *       version : 1.17 $ of : mfd-data-access.m2c,v $ 
 *
 * $Id: ipAddressTable_data_access.c 16381 2007-05-17 21:53:28Z hardaker $
 */
/*
 * standard Net-SNMP includes 
 */
#include <net-snmp/net-snmp-config.h>
#include <net-snmp/net-snmp-includes.h>
#include <net-snmp/agent/net-snmp-agent-includes.h>

/*
 * include our parent header 
 */
#include "ipAddressTable.h"


#include "ipAddressTable_data_access.h"

#include <sys/ioctl.h>
#include <errno.h>


/** @ingroup interface 
 * @addtogroup data_access data_access: Routines to access data
 *
 * These routines are used to locate the data used to satisfy
 * requests.
 * 
 * @{
 */
/**********************************************************************
 **********************************************************************
 ***
 *** Table ipAddressTable
 ***
 **********************************************************************
 **********************************************************************/
/*
 * IP-MIB::ipAddressTable is subid 34 of ip.
 * Its status is Current.
 * OID: .1.3.6.1.2.1.4.34, length: 8
 */

/**
 * initialization for ipAddressTable data access
 *
 * This function is called during startup to allow you to
 * allocate any resources you need for the data table.
 *
 * @param ipAddressTable_reg
 *        Pointer to ipAddressTable_registration
 *
 * @retval MFD_SUCCESS : success.
 * @retval MFD_ERROR   : unrecoverable error.
 */
int
ipAddressTable_init_data(ipAddressTable_registration * ipAddressTable_reg)
{
    DEBUGMSGTL(("verbose:ipAddressTable:ipAddressTable_init_data",
                "called\n"));

    /*
     * TODO:303:o: Initialize ipAddressTable data.
     */

    return MFD_SUCCESS;
}                               /* ipAddressTable_init_data */

/**
 * container overview
 *
 */
/**
 * check entry for update
 */
static void
_clear_times(ipAddressTable_rowreq_ctx * rowreq_ctx, void *magic)
{
    rowreq_ctx->ipAddressLastChanged = rowreq_ctx->ipAddressCreated = 0;
}

/**
 * container initialization
 *
 * @param container_ptr_ptr A pointer to a container pointer. If you
 *        create a custom container, use this parameter to return it
 *        to the MFD helper. If set to NULL, the MFD helper will
 *        allocate a container for you.
 * @param  cache A pointer to a cache structure. You can set the timeout
 *         and other cache flags using this pointer.
 *
 *  This function is called at startup to allow you to customize certain
 *  aspects of the access method. For the most part, it is for advanced
 *  users. The default code should suffice for most cases. If no custom
 *  container is allocated, the MFD code will create one for your.
 *
 *  This is also the place to set up cache behavior. The default, to
 *  simply set the cache timeout, will work well with the default
 *  container. If you are using a custom container, you may want to
 *  look at the cache helper documentation to see if there are any
 *  flags you want to set.
 *
 * @remark
 *  This would also be a good place to do any initialization needed
 *  for you data source. For example, opening a connection to another
 *  process that will supply the data, opening a database, etc.
 */
void
ipAddressTable_container_init(netsnmp_container **container_ptr_ptr,
                              netsnmp_cache * cache)
{
    DEBUGMSGTL(("verbose:ipAddressTable:ipAddressTable_container_init",
                "called\n"));

    if (NULL == container_ptr_ptr) {
        snmp_log(LOG_ERR,
                 "bad container param to ipAddressTable_container_init\n");
        return;
    }

    /*
     * For advanced users, you can use a custom container. If you
     * do not create one, one will be created for you.
     */
    /*
     * We create a custom container here so we can pre-load it, which
     * will result in all new entries with last changed values. we need
     * to clear those...  We also need to make sure ifIndexes have been
     * assigned...
     */
    *container_ptr_ptr =
        netsnmp_container_find("ipAddressTable:table_container");
    if (NULL != *container_ptr_ptr) {
        ipAddressTable_container_load(*container_ptr_ptr);
        CONTAINER_FOR_EACH(*container_ptr_ptr,
                           (netsnmp_container_obj_func *) _clear_times,
                           NULL);
    }

    if (NULL == cache) {
        snmp_log(LOG_ERR,
                 "bad cache param to ipAddressTable_container_init\n");
        return;
    }

    /*
     * TODO:345:A: Set up ipAddressTable cache properties.
     *
     * Also for advanced users, you can set parameters for the
     * cache. Do not change the magic pointer, as it is used
     * by the MFD helper. To completely disable caching, set
     * cache->enabled to 0.
     */

    /*
     * basically, turn off all automatic cache handling except autoload.
     */
    cache->flags |=
        (NETSNMP_CACHE_DONT_AUTO_RELEASE | NETSNMP_CACHE_DONT_FREE_EXPIRED
         | NETSNMP_CACHE_DONT_FREE_BEFORE_LOAD | NETSNMP_CACHE_AUTO_RELOAD
         | NETSNMP_CACHE_DONT_INVALIDATE_ON_SET);
}                               /* ipAddressTable_container_init */

/**
 * container shutdown
 *
 * @param container_ptr A pointer to the container.
 *
 *  This function is called at shutdown to allow you to customize certain
 *  aspects of the access method. For the most part, it is for advanced
 *  users. The default code should suffice for most cases.
 *
 *  This function is called before ipAddressTable_container_free().
 *
 * @remark
 *  This would also be a good place to do any cleanup needed
 *  for you data source. For example, closing a connection to another
 *  process that supplied the data, closing a database, etc.
 */
void
ipAddressTable_container_shutdown(netsnmp_container *container_ptr)
{
    DEBUGMSGTL(("verbose:ipAddressTable:ipAddressTable_container_shutdown",
                "called\n"));

    if (NULL == container_ptr) {
        snmp_log(LOG_ERR,
                 "bad params to ipAddressTable_container_shutdown\n");
        return;
    }

}                               /* ipAddressTable_container_shutdown */

/**
 * check entry for update
 */
static void
_check_entry_for_updates(ipAddressTable_rowreq_ctx * rowreq_ctx,
                         void **magic)
{
    netsnmp_container *ipaddress_container = magic[0];
    netsnmp_container *to_delete = (netsnmp_container *) magic[1];

    /*
     * check for matching entry using secondary index.
     */
    netsnmp_ipaddress_entry *ipaddress_entry =
        CONTAINER_FIND(ipaddress_container, rowreq_ctx->data);
    if (NULL == ipaddress_entry) {
        DEBUGMSGTL(("ipAddressTable:access", "removing missing entry\n"));

        if (NULL == to_delete) {
            magic[1] = to_delete = netsnmp_container_find("lifo");
            if (NULL == to_delete)
                snmp_log(LOG_ERR, "couldn't create delete container\n");
        }
        if (NULL != to_delete)
            CONTAINER_INSERT(to_delete, rowreq_ctx);
    } else {
        DEBUGMSGTL(("ipAddressTable:access", "updating existing entry\n"));

        /*
         * Check for changes & update
         */
        if (netsnmp_access_ipaddress_entry_update(rowreq_ctx->data,
                                                  ipaddress_entry) > 0)
            rowreq_ctx->ipAddressLastChanged = netsnmp_get_agent_uptime();

        /*
         * remove entry from ifcontainer
         */
        CONTAINER_REMOVE(ipaddress_container, ipaddress_entry);
        netsnmp_access_ipaddress_entry_free(ipaddress_entry);
    }
}

/**
 * add new entry
 */
static void
_add_new_entry(netsnmp_ipaddress_entry *ipaddress_entry,
               netsnmp_container *container)
{
    ipAddressTable_rowreq_ctx *rowreq_ctx;

    DEBUGMSGTL(("ipAddressTable:access", "creating new entry\n"));

    netsnmp_assert(NULL != ipaddress_entry);
    netsnmp_assert(NULL != container);

    /*
     * allocate an row context and set the index(es)
     */
    rowreq_ctx = ipAddressTable_allocate_rowreq_ctx(ipaddress_entry, NULL);
    if ((NULL != rowreq_ctx) &&
        (MFD_SUCCESS ==
         ipAddressTable_indexes_set(rowreq_ctx,
                                    ipaddress_entry->ia_address_len,
                                    ipaddress_entry->ia_address,
                                    ipaddress_entry->ia_address_len))) {
        if (CONTAINER_INSERT(container, rowreq_ctx) < 0) {
            DEBUGMSGTL (("ipAddressTable:access","container insert failed for new entry\n"));
            ipAddressTable_release_rowreq_ctx(rowreq_ctx);
            return;
        }
        rowreq_ctx->ipAddressLastChanged =
            rowreq_ctx->ipAddressCreated = netsnmp_get_agent_uptime();
    } else {
        if (NULL != rowreq_ctx) {
            snmp_log(LOG_ERR, "error setting index while loading "
                     "ipAddressTable cache.\n");
            ipAddressTable_release_rowreq_ctx(rowreq_ctx);
        } else {
            snmp_log(LOG_ERR, "memory allocation failed while loading "
                     "ipAddressTable cache.\n");
            netsnmp_access_ipaddress_entry_free(ipaddress_entry);
        }

        return;
    }

    /*-------------------------------------------------------------------
     * handle data that isn't part of the data_access ipaddress structure
     */
    rowreq_ctx->ipAddressRowStatus = ROWSTATUS_ACTIVE;
}

/**
 * load initial data
 *
 * TODO:350:M: Implement ipAddressTable data load
 * This function will also be called by the cache helper to load
 * the container again (after the container free function has been
 * called to free the previous contents).
 *
 * @param container container to which items should be inserted
 *
 * @retval MFD_SUCCESS              : success.
 * @retval MFD_RESOURCE_UNAVAILABLE : Can't access data source
 * @retval MFD_ERROR                : other error.
 *
 *  This function is called to load the index(es) (and data, optionally)
 *  for the every row in the data set.
 *
 * @remark
 *  While loading the data, the only important thing is the indexes.
 *  If access to your data is cheap/fast (e.g. you have a pointer to a
 *  structure in memory), it would make sense to update the data here.
 *  If, however, the accessing the data invovles more work (e.g. parsing
 *  some other existing data, or peforming calculations to derive the data),
 *  then you can limit yourself to setting the indexes and saving any
 *  information you will need later. Then use the saved information in
 *  ipAddressTable_row_prep() for populating data.
 *
 * @note
 *  If you need consistency between rows (like you want statistics
 *  for each row to be from the same time frame), you should set all
 *  data here.
 *
 */
int
ipAddressTable_container_load(netsnmp_container *container)
{
    netsnmp_container *ipaddress_container;
    void           *tmp_ptr[2];

    DEBUGMSGTL(("verbose:ipAddressTable:ipAddressTable_cache_load",
                "called\n"));

    /*
     * TODO:351:M: |-> Load/update data in the ipAddressTable container.
     * loop over your ipAddressTable data, allocate a rowreq context,
     * set the index(es) [and data, optionally] and insert into
     * the container.
     */
    ipaddress_container =
        netsnmp_access_ipaddress_container_load(NULL,
                                                NETSNMP_ACCESS_IPADDRESS_LOAD_ADDL_IDX_BY_ADDR);
    /*
     * we just got a fresh copy of interface data. compare it to
     * what we've already got, and make any adjustments, saving
     * missing addresses to be deleted.
     */
    tmp_ptr[0] = ipaddress_container->next;
    tmp_ptr[1] = NULL;
    CONTAINER_FOR_EACH(container, (netsnmp_container_obj_func *)
                       _check_entry_for_updates, tmp_ptr);

    /*
     * now add any new interfaces
     */
    CONTAINER_FOR_EACH(ipaddress_container,