table_data.c

开发snmp的开发包有两个开放的SNMP开发库

        return NULL;
}

/** inserts a newly created table_data row into a request */
NETSNMP_INLINE void
netsnmp_insert_table_row(netsnmp_request_info *request,
                         netsnmp_table_row *row)
{
    netsnmp_request_info       *req;
    netsnmp_table_request_info *table_info = NULL;
    netsnmp_variable_list      *this_index = NULL;
    netsnmp_variable_list      *that_index = NULL;
    oid      base_oid[] = {0, 0};	/* Make sure index OIDs are legal! */
    oid      this_oid[MAX_OID_LEN];
    oid      that_oid[MAX_OID_LEN];
    size_t   this_oid_len, that_oid_len;

    if (!request)
        return;

    /*
     * We'll add the new row information to any request
     * structure with the same index values as the request
     * passed in (which includes that one!).
     *
     * So construct an OID based on these index values.
     */

    table_info = netsnmp_extract_table_info(request);
    this_index = table_info->indexes;
    build_oid_noalloc(this_oid, MAX_OID_LEN, &this_oid_len,
                      base_oid, 2, this_index);

    /*
     * We need to look through the whole of the request list
     * (as received by the current handler), as there's no
     * guarantee that this routine will be called by the first
     * varbind that refers to this row.
     *   In particular, a RowStatus controlled row creation
     * may easily occur later in the variable list.
     *
     * So first, we rewind to the head of the list....
     */
    for (req=request; req->prev; req=req->prev)
        ;

    /*
     * ... and then start looking for matching indexes
     * (by constructing OIDs from these index values)
     */
    for (; req; req=req->next) {
        table_info = netsnmp_extract_table_info(req);
        that_index = table_info->indexes;
        build_oid_noalloc(that_oid, MAX_OID_LEN, &that_oid_len,
                          base_oid, 2, that_index);
      
        /*
         * This request has the same index values,
         * so add the newly-created row information.
         */
        if (snmp_oid_compare(this_oid, this_oid_len,
                             that_oid, that_oid_len) == 0) {
            netsnmp_request_add_list_data(req,
                netsnmp_create_data_list(TABLE_DATA_ROW, row, NULL));
        }
    }
}

/* builds a result given a row, a varbind to set and the data */
int
netsnmp_table_data_build_result(netsnmp_handler_registration *reginfo,
                                netsnmp_agent_request_info *reqinfo,
                                netsnmp_request_info *request,
                                netsnmp_table_row *row,
                                int column,
                                u_char type,
                                u_char * result_data,
                                size_t result_data_len)
{
    oid             build_space[MAX_OID_LEN];

    if (!reginfo || !reqinfo || !request)
        return SNMPERR_GENERR;

    if (reqinfo->mode == MODE_GETNEXT || reqinfo->mode == MODE_GETBULK) {
        /*
         * only need to do this for getnext type cases where oid is changing 
         */
        memcpy(build_space, reginfo->rootoid,   /* registered oid */
               reginfo->rootoid_len * sizeof(oid));
        build_space[reginfo->rootoid_len] = 1;  /* entry */
        build_space[reginfo->rootoid_len + 1] = column; /* column */
        memcpy(build_space + reginfo->rootoid_len + 2,  /* index data */
               row->index_oid, row->index_oid_len * sizeof(oid));
        snmp_set_var_objid(request->requestvb, build_space,
                           reginfo->rootoid_len + 2 + row->index_oid_len);
    }
    snmp_set_var_typed_value(request->requestvb, type,
                             result_data, result_data_len);
    return SNMPERR_SUCCESS;     /* WWWXXX: check for bounds */
}


/* ==================================
 *
 * Table Data API: Row operations
 *     (table-independent rows)
 *
 * ================================== */

/** returns the first row in the table */
netsnmp_table_row *
netsnmp_table_data_get_first_row(netsnmp_table_data *table)
{
    if (!table)
        return NULL;
    return table->first_row;
}

/** returns the next row in the table */
netsnmp_table_row *
netsnmp_table_data_get_next_row(netsnmp_table_data *table,
                                netsnmp_table_row  *row)
{
    if (!row)
        return NULL;
    return row->next;
}

/** finds the data in "datalist" stored at "indexes" */
netsnmp_table_row *
netsnmp_table_data_get(netsnmp_table_data *table,
                       netsnmp_variable_list * indexes)
{
    oid             searchfor[MAX_OID_LEN];
    size_t          searchfor_len = MAX_OID_LEN;

    build_oid_noalloc(searchfor, MAX_OID_LEN, &searchfor_len, NULL, 0,
                      indexes);
    return netsnmp_table_data_get_from_oid(table, searchfor,
                                           searchfor_len);
}

/** finds the data in "datalist" stored at the searchfor oid */
netsnmp_table_row *
netsnmp_table_data_get_from_oid(netsnmp_table_data *table,
                                oid * searchfor, size_t searchfor_len)
{
    netsnmp_table_row *row;
    if (!table)
        return NULL;

    for (row = table->first_row; row != NULL; row = row->next) {
        if (row->index_oid &&
            snmp_oid_compare(searchfor, searchfor_len,
                             row->index_oid, row->index_oid_len) == 0)
            return row;
    }
    return NULL;
}

int
netsnmp_table_data_num_rows(netsnmp_table_data *table)
{
    int i=0;
    netsnmp_table_row *row;
    if (!table)
        return 0;
    for (row = table->first_row; row; row = row->next) {
        i++;
    }
    return i;
}

    /* =====================================
     * Generic API - mostly renamed wrappers
     * ===================================== */

netsnmp_table_row *
netsnmp_table_data_row_first(netsnmp_table_data *table)
{
    return netsnmp_table_data_get_first_row(table);
}

netsnmp_table_row *
netsnmp_table_data_row_get(  netsnmp_table_data *table,
                             netsnmp_table_row  *row)
{
    if (!table || !row)
        return NULL;
    return netsnmp_table_data_get_from_oid(table, row->index_oid,
                                                  row->index_oid_len);
}

netsnmp_table_row *
netsnmp_table_data_row_next( netsnmp_table_data *table,
                             netsnmp_table_row  *row)
{
    return netsnmp_table_data_get_next_row(table, row);
}

netsnmp_table_row *
netsnmp_table_data_row_get_byoid( netsnmp_table_data *table,
                                  oid *instance, size_t len)
{
    return netsnmp_table_data_get_from_oid(table, instance, len);
}

netsnmp_table_row *
netsnmp_table_data_row_next_byoid(netsnmp_table_data *table,
                                  oid *instance, size_t len)
{
    netsnmp_table_row *row;

    if (!table || !instance)
        return NULL;
    
    for (row = table->first_row; row; row = row->next) {
        if (snmp_oid_compare(row->index_oid,
                             row->index_oid_len,
                             instance, len) > 0)
            return row;
    }
    return NULL;
}

netsnmp_table_row *
netsnmp_table_data_row_get_byidx( netsnmp_table_data    *table,
                                  netsnmp_variable_list *indexes)
{
    return netsnmp_table_data_get(table, indexes);
}

netsnmp_table_row *
netsnmp_table_data_row_next_byidx(netsnmp_table_data    *table,
                                  netsnmp_variable_list *indexes)
{
    oid    instance[MAX_OID_LEN];
    size_t len    = MAX_OID_LEN;

    if (!table || !indexes)
        return NULL;

    build_oid_noalloc(instance, MAX_OID_LEN, &len, NULL, 0, indexes);
    return netsnmp_table_data_row_next_byoid(table, instance, len);
}

int
netsnmp_table_data_row_count(netsnmp_table_data *table)
{
    return netsnmp_table_data_num_rows(table);
}


/* ==================================
 *
 * Table Data API: Row operations
 *     (table-specific rows)
 *
 * ================================== */

void *
netsnmp_table_data_entry_first(netsnmp_table_data *table)
{
    netsnmp_table_row *row =
        netsnmp_table_data_get_first_row(table);
    return (row ? row->data : NULL );
}

void *
netsnmp_table_data_entry_get(  netsnmp_table_data *table,
                               netsnmp_table_row  *row)
{
    return (row ? row->data : NULL );
}

void *
netsnmp_table_data_entry_next( netsnmp_table_data *table,
                               netsnmp_table_row  *row)
{
    row =
        netsnmp_table_data_row_next(table, row);
    return (row ? row->data : NULL );
}

void *
netsnmp_table_data_entry_get_byidx( netsnmp_table_data    *table,
                                    netsnmp_variable_list *indexes)
{
    netsnmp_table_row *row =
        netsnmp_table_data_row_get_byidx(table, indexes);
    return (row ? row->data : NULL );
}

void *
netsnmp_table_data_entry_next_byidx(netsnmp_table_data    *table,
                                    netsnmp_variable_list *indexes)
{
    netsnmp_table_row *row =
        netsnmp_table_data_row_next_byidx(table, indexes);
    return (row ? row->data : NULL );
}

void *
netsnmp_table_data_entry_get_byoid( netsnmp_table_data *table,
                                    oid *instance, size_t len)
{
    netsnmp_table_row *row =
        netsnmp_table_data_row_get_byoid(table, instance, len);
    return (row ? row->data : NULL );
}

void *
netsnmp_table_data_entry_next_byoid(netsnmp_table_data *table,
                                    oid *instance, size_t len)
{
    netsnmp_table_row *row =
        netsnmp_table_data_row_next_byoid(table, instance, len);
    return (row ? row->data : NULL );
}

    /* =====================================
     * Generic API - mostly renamed wrappers
     * ===================================== */

/* ==================================
 *
 * Table Data API: Index operations
 *
 * ================================== */

/** @} 
 */