第 4 章 コード例とテスト

この章では、API 関数の適切な使用方法を示すコード例を記載します。

この章は、次の節から構成されます。

• 一般的な API 関数

• dhcptab API 関数

• DHCP ネットワークコンテナの API 関数

• パブリックモジュールのテスト

コードのテンプレート

この節では、API 関数の「一般的な」使用方法を示すテンプレートを記載します。

Sun の Web サイトにある developer のページ (http://www.sun.com/developer) から Sun の ASCII ファイルデータ格納 (ds_SUNWfiles) 用のソースコードをダウンロードしてください。このモジュールのためのソースコードは、ユーザーが独自のモジュールを作成する上で役立ちます。

一般的な API 関数

このテンプレートでは、一般的な API 関数である status()、version()、mklocation() が使用されています。

例 4–1 general.c

* Copyright (c) 2000 by Sun Microsystems, Inc. /*
 * Copyright (c) 2000 by Sun Microsystems, Inc.
 * All rights reserved.
 */

#pragma	ident	"@(#)general.c	1.15	00/08/16 SMI"

/*
 * This module contains the public APIs for status, version, and mklocation.
 */

#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <dhcp_svc_public.h>

/*
 * This API function instructs the underlying datastore to return its 
 * general status. If the "location" argument is non-NULL, the function 
 * validates the location for the data store containers (is it formed 
 * correctly for the data store, and does it exist).
 */
int
status(const char *location)
{
	return (DSVC_UNSUPPORTED);
}

/*
 * Return the data store API version supported by this module.  This version
 * was implemented to support version 1 of the API.
 */
int
version(int *vp)
{
	*vp = DSVC_PUBLIC_VERSION;
	return (DSVC_SUCCESS);
}

/*
 * Create the datastore-specific "location" if it doesn't already exist.
 * Containers will ultimately be created there.
 */
int
mklocation(const char *location)
{
	return (DSVC_UNSUPPORTED);
}

dhcptab API 関数

このテンプレートでは、dhcptab コンテナとともに使用される関数が例示されています。

例 4–2 dhcptab.c

/*
 * Copyright (c) 1998-2000 by Sun Microsystems, Inc.
 * All rights reserved.
 */

#pragma	ident	"@(#)dhcptab.c	1.12	00/08/16 SMI"

/*
 * This module contains the public API functions for managing the dhcptab
 * container.
 */

#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <dhcp_svc_public.h>

/*
 * List the current number of dhcptab container objects located at
 * "location" in "listppp". Return number of list elements in "count".
 * If no objects exist, then "count" is set to 0 and DSVC_SUCCESS is 
 * returned.
 *
 * This function will block waiting for a result, if the underlying 
 * data store is busy.
 */
int
list_dt(const char *location, char ***listppp, uint32_t *count)
{
	return (DSVC_UNSUPPORTED);
}

/*
 * Creates or opens the dhcptab container in "location" and initializes
 * "handlep" to point to the instance handle. When creating a new dhcptab, 
 * the caller's identity is used for owner/permissions. Performs any 
 * initialization needed by data store.
 */
int
open_dt(void **handlep, const char *location, uint32_t flags)
{
	return (DSVC_UNSUPPORTED);
}

/*
 * Frees instance handle, cleans up per instance state.
 */
int
close_dt(void **handlep)
{
	return (DSVC_UNSUPPORTED);
}

/*
 * Remove dhcptab container in "location" from data store. If the underlying
 * data store is busy, this function will block.
 */
int
remove_dt(const char *location)
{
	return (DSVC_UNSUPPORTED);
}

/*
 * Searches the dhcptab container for instances that match the query
 * described by the combination of query and targetp.  If the partial
 * argument is true, then lookup operations that are unable to
 * complete entirely are allowed (and considered successful).  The
 * query argument consists of 2 fields, each 16 bits long.  The lower
 * 16 bits selects which fields {key, flags} of targetp are to be
 * considered in the query.  The upper 16 bits identifies whether a
 * particular field value must match (bit set) or not match (bit
 * clear).  Bits 2-15 in both 16 bit fields are currently unused, and
 * must be set to 0.  The count field specifies the maximum number of
 * matching records to return, or -1 if any number of records may be
 * returned.  The recordsp argument is set to point to the resulting
 * list of records; if recordsp is passed in as NULL then no records
 * are actually returned. Note that these records are dynamically
 * allocated, thus the caller is responsible for freeing them.  The
 * number of records found is returned in nrecordsp; a value of 0
 * means that no records matched the query.
 */
int
lookup_dt(void *handle, boolean_t partial, uint32_t query, int32_t count,
    const dt_rec_t *targetp, dt_rec_list_t **recordsp, uint32_t *nrecordsp)
{
	return (DSVC_UNSUPPORTED);
}

/*
 * Add the record pointed to by "addp" to from the dhcptab container 
 * referred to by the handle. The underlying public module will set 
 * "addp's" signature as part of the data store operation.
 */
int
add_dt(void *handle, dt_rec_t *addp)
{
	return (DSVC_UNSUPPORTED);
}

/*
 * Atomically modify the record "origp" with the record "newp" in the
 * dhcptab container referred to by the handle.  "newp's" signature will
 * be set by the underlying public module.  If an update collision
 * occurs, either because "origp's" signature in the data store has changed
 * or "newp" would overwrite an existing record, DSVC_COLLISION is
 * returned and no update of the data store occurs.
 */
int
modify_dt(void *handle, const dt_rec_t *origp, dt_rec_t *newp)
{
	return (DSVC_UNSUPPORTED);
}

/*
 * Delete the record referred to by dtp from the dhcptab container
 * referred to by the handle. If "dtp's" signature is zero, the
 * caller is not interested in checking for collisions, and the record
 * should simply be deleted if it exists. If the signature is non-zero,
 * and the signature of the data store version of this record do not match,
 * an update collision occurs, no deletion of matching record in data store
 * is done, and DSVC_COLLISION is returned.
 */
int
delete_dt(void *handle, const dt_rec_t *dtp)
{
	return (DSVC_UNSUPPORTED);
}

DHCP ネットワークコンテナの API 関数

このテンプレートでは、DHCP ネットワークコンテナとともに使用される関数が例示されています。

例 4–3 dhcp_network.c

/*
 * Copyright (c) 1998-2000 by Sun Microsystems, Inc.
 * All rights reserved.
 */

#pragma	ident	"@(#)dhcp_network.c	1.12	00/08/16 SMI"

/*
 * This module contains public API functions for managing dhcp network
 * containers.
 */

#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <dhcp_svc_public.h>

/*
 * List the current number of dhcp network container objects located at
 * "location" in "listppp". Return number of list elements in "count".
 * If no objects exist, then "count" is set to 0 and DSVC_SUCCESS is 
 * returned.
 *
 * This function will block if the underlying data service is busy or is
 * otherwise unvailable.
 */
int
list_dn(const char *location, char ***listppp, uint32_t *count)
{
	return (DSVC_UNSUPPORTED);
}

/*
 * Creates or opens the dhcp network container "netp" (host order) in
 * "location" and initializes "handlep" to point to the instance handle.
 * Performs any initialization needed by data store. New containers are
 * created with the identity of the caller.
 */
int
open_dn(void **handlep, const char *location, uint32_t flags,
    const struct in_addr *netp)
{
	return (DSVC_UNSUPPORTED);
}

/*
 * Frees instance handle, cleans up per instance state.
 */
int
close_dn(void **handlep)
{
	return (DSVC_UNSUPPORTED);
}

/*
 * Remove DHCP network container "netp" (host order) in location.
 * This function will block if the underlying data service is busy or
 * otherwise unavailable.
 */
int
remove_dn(const char *location, const struct in_addr *netp)
{
	return (DSVC_UNSUPPORTED);
}

/*
 * Searches DHCP network container for instances that match the query
 * described by the combination of query and targetp.  If the partial
 * argument is true, then lookup operations that are unable to
 * complete entirely are allowed (and considered successful).  The
 * query argument consists of 2 fields, each 16 bits long.  The lower
 * 16 bits selects which fields {client_id, flags, client_ip,
 * server_ip, expiration, macro, or comment} of targetp are to be
 * considered in the query.  The upper 16 bits identifies whether a
 * particular field value must match (bit set) or not match (bit
 * clear).  Bits 7-15 in both 16 bit fields are currently unused, and
 * must be set to 0.  The count field specifies the maximum number of
 * matching records to return, or -1 if any number of records may be
 * returned.  The recordsp argument is set to point to the resulting
 * list of records; if recordsp is passed in as NULL then no records
 * are actually returned. Note that these records are dynamically
 * allocated, thus the caller is responsible for freeing them.  The
 * number of records found is returned in nrecordsp; a value of 0 means
 * that no records matched the query.
 */
int
lookup_dn(void *handle, boolean_t partial, uint32_t query, int32_t count,
    const dn_rec_t *targetp, dn_rec_list_t **recordsp, uint32_t *nrecordsp)
{
	return (DSVC_UNSUPPORTED);
}

/*
 * Add the record pointed to by "addp" to from the dhcp network container
 * referred to by the handle.  The underlying public module will set 
 * "addp's" signature as part of the data store operation.
 */
int
add_dn(void *handle, dn_rec_t *addp)
{
	return (DSVC_UNSUPPORTED);
}

/*
 * Atomically modify the record "origp" with the record "newp" in the dhcp
 * network container referred to by the handle.  "newp's" signature will
 * be set by the underlying public module.  If an update collision
 * occurs, either because "origp's" signature in the data store has changed
 * or "newp" would overwrite an preexisting record, DSVC_COLLISION is
 * returned and no update of the data store occurs.
 */
int
modify_dn(void *handle, const dn_rec_t *origp, dn_rec_t *newp)
{
	return (DSVC_UNSUPPORTED);
}

/*
 * Delete the record pointed to by "pnp" from the dhcp network container
 * referred to by the handle. If "pnp's" signature is zero, the caller
 * is not interested in checking for collisions, and the record should 
 * simply be deleted if it exists. If the signature is non-zero, and the 
 * signature of the data store version of this record do not match, an 
 * update collision occurs, no deletion of any record is done, and 
 * DSVC_COLLISION is returned.
 */
int
delete_dn(void *handle, const dn_rec_t *pnp)
{
	return (DSVC_UNSUPPORTED);
}

パブリックモジュールのテスト

パブリックモジュールをテストする上で助けになるテストセットのダウンロードについては、http://www.sun.com/developer を参照してください。