mfd-access-unsorted-external-defines.m2i

开发snmp的开发包有两个开放的SNMP开发库

#############################################################  -*- c -*-
## generic include for XXX. Do not use directly.
##
## $Id: mfd-access-unsorted-external-defines.m2i 11972 2005-03-02 19:35:44Z rstory $
########################################################################
##
@eval $mfd_aue_wrap_param = "wrap_ctx"@
@eval $mfd_aue_wrap_param_type = "${context}_interface_ctx *"@
@eval $mfd_aue_wrap_param_decl = "$mfd_aue_wrap_param_type $mfd_aue_wrap_param"@
##
@eval $mfd_aue_param = "${context}_reg"@
@eval $mfd_aue_param_type = "${context}_registration *"@
@eval $mfd_aue_param_decl = "$mfd_aue_param_type $mfd_aue_param"@
@eval $mfd_aue_param_cmt = "$mfd_aue_param Pointer to a $mfd_aue_param_type"
##
@if $m2c_mark_boundary == 1@
/** START code generated by $RCSfile$ $Revision: 11972 $ */
@end@
##//####################################################################
##//@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
##//@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@if $m2c_processing_type eq 'h'@
##
@if $m2c_include_examples == 1@
$example_start
/* *********************************************************************
 * Since we have no idea how you really access your data, we'll go with
 * a worst case example: a flat text file.
 @   if $m2c_data_transient != 2@
 @      print Example code is for fully transient data. Either turn off@
 @      print m2c_include_examples or set m2c_data_transient to 2.@
 @      exit@
 @   end@
 */
#define MAX_LINE_SIZE 256
$example_end

@end@
/**
 * loop context
 *
 * TODO:
 * define loop context structure
 *
 *  Since the actual loop is in the MFD handler, a loop contex parameter
 *  is provided to help you keep track of where you are in between calls
 *  to functions that you wrote and the master MFD handler calls. The
 *  structure of this context is user defineable, and is defined in the
 *  file ${table}_data_access.h.
 *
 *  E.G., if your data is stored in a linked list, the obvious thing you
 *  want to know from one function call to the next is your current
 *  position in the linked list.  Thus the easiest context to use is a
 *  pointer within the linked list.  For an array, the current index to
 *  that array would be easiest.
 *
 *  The funtion calls are actually passed a reference to the loop
 *  context, to allow the loop context to be allocated memory. Here are
 *  some simple examples definitions for various data formats. These
 *  definitions are used in examples later on.
 *
 */
typedef struct ${context}_loop_context_s {
    /*
     * temporary context used during iteration
     */
    ${context}_rowreq_ctx *rowreq_ctx;
@if $m2c_include_examples == 1@
    
    /*
     * this example code is based on a data source that is a
     * text file to be read and parsed.
     */
    FILE *filep;
    char line[MAX_LINE_SIZE];
@end@
} ${context}_loop_context;

/*
 * define a reference to the loop context
 *
 * NOTE: DO NOT ADD ITEMS TO THIS STRUCTURE!
 */
typedef struct ${context}_ref_loop_ctx_s {
    ${context}_loop_context *loop_ctx;
} ${context}_ref_loop_ctx;

int ${context}_loop_get_first( $mfd_aue_param_decl, ${context}_ref_loop_ctx *loop_ctx_ref,
                    ${context}_ref_rowreq_ctx *rowreq_ctx_ref);
int ${context}_loop_get_next( $mfd_aue_param_decl, ${context}_ref_loop_ctx *loop_ctx_ref,
                        ${context}_ref_rowreq_ctx *rowreq_ctx_ref);
int ${context}_loop_get_data( $mfd_aue_param_decl, ${context}_ref_loop_ctx *loop_ctx_ref,
                        ${context}_ref_rowreq_ctx *rowreq_ctx_ref);
int ${context}_loop_save_position($mfd_aue_param_decl,
                       ${context}_ref_loop_ctx *loop_ctx_ref,
                       ${context}_ref_loop_ctx *save_loop_ctx_ref, int reuse);
int ${context}_loop_cleanup_context( $mfd_aue_param_decl, ${context}_ref_loop_ctx *ref);

##
@end@ // m2c_processing_type eq 'h'
########################################################################
##//####################################################################
##//@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
##//@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@if $m2c_processing_type eq 'i'@
/**
 * @internal
 * wrapper around clean up a loop reference
 */
static int
_${context}_loop_cleanup_context( $mfd_aue_wrap_param_decl,
                            ${context}_ref_loop_ctx *ref)
{
   DEBUGMSGTL(("internal:${context}:_${context}_loop_cleanup_context","called\n"));

   return ${context}_loop_cleanup_context($mfd_aue_wrap_param->user_ctx, ref);
} /* _${context}_loop_cleanup_context */

/**
 * @internal
 * wrapper around save position
 */
static int
_${context}_loop_save_position( $mfd_aue_wrap_param_decl, ${context}_ref_loop_ctx *ref,
                         ${context}_ref_loop_ctx *ref_copy, int reuse)
{
   DEBUGMSGTL(("internal:${context}:_${context}_loop_save_position","called\n"));

   return ${context}_loop_save_position($mfd_aue_wrap_param->user_ctx, ref,
                                 ref_copy, reuse);
} /* _${context}_loop_save_position */

/**
 * @internal
 * wrapper around user get_first to setup the index oid
 */
static int
_${context}_loop_get_first_wrapper($mfd_aue_wrap_param_decl,
                           ${context}_ref_loop_ctx * loop_ctx_ref,
                           ${context}_ref_rowreq_ctx * rowreq_ctx_ref)
{
    int rc;
    DEBUGMSGTL(("internal:${context}:_${context}_loop_get_first_wrapper","called\n"));

    rc = ${context}_loop_get_first($mfd_aue_wrap_param->user_ctx, loop_ctx_ref,
                                 rowreq_ctx_ref);
    /*
     * convert index to OID
     */
    if(SNMPERR_SUCCESS == rc ) {
        netsnmp_assert((NULL != rowreq_ctx_ref) &&
                       (rowreq_ctx_ref->rowreq_ctx->oid_idx.oids == rowreq_ctx_ref->rowreq_ctx->oid_tmp));
        rowreq_ctx_ref->rowreq_ctx->oid_idx.len = sizeof(rowreq_ctx_ref->rowreq_ctx->oid_tmp);
        rc = ${context}_index_to_oid(&rowreq_ctx_ref->rowreq_ctx->oid_idx,
                                   &rowreq_ctx_ref->rowreq_ctx->tbl_idx);
        netsnmp_assert(rowreq_ctx_ref->rowreq_ctx->oid_idx.len !=
                       sizeof(rowreq_ctx_ref->rowreq_ctx->oid_tmp));
    }

    return rc;
} /* _${context}_loop_get_first_wrapper */

/**
 * @internal
 * wrapper around user get_next to setup the index oid
 */
static int
_${context}_loop_get_next_wrapper($mfd_aue_wrap_param_decl,
                          ${context}_ref_loop_ctx * loop_ctx_ref,
                          ${context}_ref_rowreq_ctx * rowreq_ctx_ref)
{
    int rc;
    DEBUGMSGTL(("internal:${context}:_${context}_loop_get_next_wrapper","called\n"));

    rc = ${context}_loop_get_next($mfd_aue_wrap_param->user_ctx, loop_ctx_ref,
                                rowreq_ctx_ref);
    /*
     * convert index to OID
     */
    if(SNMPERR_SUCCESS == rc ) {
        netsnmp_assert((NULL != rowreq_ctx_ref) &&
                       (rowreq_ctx_ref->rowreq_ctx->oid_idx.oids == rowreq_ctx_ref->rowreq_ctx->oid_tmp));
        rowreq_ctx_ref->rowreq_ctx->oid_idx.len = sizeof(rowreq_ctx_ref->rowreq_ctx->oid_tmp);
        rc = ${context}_index_to_oid(&rowreq_ctx_ref->rowreq_ctx->oid_idx,
                                   &rowreq_ctx_ref->rowreq_ctx->tbl_idx);
        netsnmp_assert(rowreq_ctx_ref->rowreq_ctx->oid_idx.len !=
                       sizeof(rowreq_ctx_ref->rowreq_ctx->oid_tmp));
    }

    return rc;
} /* _${context}_loop_get_next_wrapper */

@if $m2c_data_transient != 0@ # 
/**
 * @internal
 * get data wrapper to allocate context for the user
 */
static int
_${context}_loop_get_data_wrapper($mfd_aue_wrap_param_decl,
                           ${context}_ref_loop_ctx * loop_ctx_ref,
                           ${context}_ref_rowreq_ctx * rowreq_ctx_ref)
{
//    ${context}_rowreq_ctx *orig_ctx = rowreq_ctx_ref->rowreq_ctx;

    DEBUGMSGTL(("internal:${context}:_${context}_loop_get_data_wrapper","called\n"));

    return ${context}_loop_get_data($mfd_aue_wrap_param->user_ctx, loop_ctx_ref, rowreq_ctx_ref);
} /* _${context}_loop_get_data_wrapper */

@end@ // transient != 0
/**
 * @internal
 * initialize the iterator container with functions or wrappers
 */
void
_${context}_container_init(${context}_interface_ctx *if_ctx)
{
    DEBUGMSGTL(("internal:${context}:_${context}_container_init","called\n"));
    
    if_ctx->container = netsnmp_container_iterator_get(/** registration */
        if_ctx,
        /** compare */
        NULL,
        /** get_first */
        (Netsnmp_Iterator_Loop_Key*)_${context}_loop_get_first_wrapper,
        /** get_next */
        (Netsnmp_Iterator_Loop_Key*)_${context}_loop_get_next_wrapper,
        /** get_data */
@if $m2c_data_transient != 0@ # 
        (Netsnmp_Iterator_Loop_Data*)_${context}_loop_get_data_wrapper,
@else@
        NULL,
@end@
        /** save_pos */
        (Netsnmp_Iterator_Ctx_Dup*)_${context}_loop_save_position,
        /** init_context */
        (Netsnmp_Iterator_Ctx*)NULL,
        /** cleanup_context */
        (Netsnmp_Iterator_Ctx*)_${context}_loop_cleanup_context,
        /** free_user_ctx */
        NULL,
        /** sorted */
        0);
} /* _${context}_container_init */

##
@end@ // m2c_processing_type eq 'i'
########################################################################
##//####################################################################
##//@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
##//@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@if $m2c_processing_type eq 'c'@
/**
 * unsorted-external overview
 *
 * The unsorted external data access code works by calling a few simple
 * functions to get the index value for each row. Once the agent determines
 * which row is needed to process an incoming request, another function
 * is called to retrieve the data for that row.
 *
 * A simplified version of the pseudo-code looks like this:
 *
 *    ${context}_loop_get_first(loop,data)
 *    while( no_error ) {
 *       if( best_match(data, key)
 *          ${context}_loop_save_position(loop,pos);
 *       ${context}_loop_get_next(loop,data)
 *    }
 *    ${context}_loop_get_data(pos,data)
 *    ${context}_loop_cleanup_context(loop)
 */

/***********************************************************************
 *
 * ITERATION
 *
 ***********************************************************************/

/**
 * get the first data index
 *
 * Summary
 * -------
 *  This function is called to initialize the iterator loop context for a
 *  new iteration loop and return the index(es) for the first
 *  ${context}_data in the data set.
 *
 *  Note that during the loop, 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 should limit yourself to setting the indexes. Extracting the
 *  can be put off until the desired row is found. See the notes on
 *  ${context}_loop_get_data().
 *
 *  Note that this function does not correspond to a SNMP GET pdu, and
 *  you should return data items in whatever order they are already in.
 *  (In fact, if your data is already ordered in the same order as the
 *  SNMP indexes, you shouldn't be using the unsorted-access code).
 *
 *  This function should update the table index (rowreq_ctx_ref->rowreq_ctx->tbl_idx)
 *  values for the raw data (rowreq_ctx_ref->rowreq_ctx->data).
 *
 * More Details
 * ------------
 *  If there is currently no data available, return MFD_END_OF_DATA.
 *  Otherwise, you should set rowreq_ctx_ref->rowreq_ctx and its indexes.
 *
 *  rowreq_ctx_ref->rowreq_ctx will be NULL. You should allocate a new context
 *  for this loop. [Alternatively, you could allocate one in
 *  ${context}_loop_init_context, save it in your
 *  ${context}_ref_loop_ctx, and use it here.]
 *
 *  Once you have your context pointer, you should set the index (or indexes)
 *  in rowreq_ctx_ref->rowreq_ctx->tbl_idx to the appropriate value for this row. [If you
 *  use your loop_ctx_ref cleverly, you might be able to put this work in
 *  ${context}_loop_get_next, and simply call that function.]
 *
 * @param $mfd_aue_param_cmt
 * @param loop_ctx_ref  Pointer to your loop reference.
 * @param rowreq_ctx_ref  Pointer to a context reference.
 *
 * @retval MFD_SUCCESS     : success.
 * @retval MFD_END_OF_DATA : no data available
 * @retval MFD_ERROR       : error.
 */
int
${context}_loop_get_first( $mfd_aue_param_decl, ${context}_ref_loop_ctx *loop_ctx_ref,
                    ${context}_ref_rowreq_ctx *rowreq_ctx_ref)
{
    DEBUGMSGTL(("verbose:${context}:${context}_loop_get_first","called\n"));

    netsnmp_assert(rowreq_ctx_ref);
    netsnmp_assert(loop_ctx_ref);
    
    /*
     * allocate memory for new structure
     */
    loop_ctx_ref->loop_ctx = SNMP_MALLOC_TYPEDEF(${context}_loop_context);
    if(NULL == loop_ctx_ref->loop_ctx)
        return MFD_ERROR;

    /*
     * allocate a temporary context to use during iteration
     */
@   eval $m2c_tmp = ""@
@   if ($m2c_data_allocate == 1) || ($m2c_data_init == 1)@
@      eval $m2c_tmp = "NULL"@
@      if ($m2c_data_allocate == 1) && ($m2c_data_init == 1)@
@         eval $m2c_tmp = "$m2c_tmp, NULL"@
@      @end@
@   end@
    loop_ctx_ref->loop_ctx->rowreq_ctx = ${context}_allocate_rowreq_ctx($m2c_tmp);
    if(NULL == loop_ctx_ref->loop_ctx->rowreq_ctx) {
        SNMP_FREE(loop_ctx_ref->loop_ctx);
        return MFD_RESOURCE_UNAVAILABLE;
    }

    /*
     * TODO:
     * set up loop context
     */
@if $m2c_include_examples == 1@
$example_start
    /*
     * open our data file.
     */
    loop_ctx_ref->loop_ctx->filep = fopen("/etc/dummy.conf", "r");
    if(NULL ==  loop_ctx_ref->loop_ctx->filep) {
        return MFD_RESOURCE_UNAVAILABLE;
    }

$example_end
@end@

@ifconf ${table}_update_idx.m2i@
@   include ${table}_update_idx.m2i@
@else@
@   if $m2c_include_examples == 1@
$example_start
    /*
     * in this example, after opening the file, get next does the same thing
     * as get first, we let's just call get next...
     */
    return ${context}_loop_get_next($mfd_aue_param, loop_ctx_ref, rowreq_ctx_ref);
$example_end
@   else@
    /*
     * we just need the index for now. Reuse the one in the loop context's
     * temporary row request context. (rowreq_ctx_ref->rowreq_ctx->tbl_idx)
     */
    rowreq_ctx_ref->rowreq_ctx = loop_ctx_ref->loop_ctx->rowreq_ctx;

    /*
     * TODO:
     * set local vars for index from loop_ctx_ref->loop_ctx
     *  this can be done in one of two ways:
     */