lib/dns/adb.c

	adb.c revision 11fcc67616fac1bc6a28b3d4fed24641137888e7
/*
 * Copyright (C) 1999  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

#include <config.h>

#include <isc/assertions.h>

#include <dns/address.h>

#define VCHECK(a,b)     (((a) != NULL) && ((a)->magic == (b)))

#define DNS_ADB_MAGIC           0x44616462  /* Dadb. */
#define DNS_ADB_VALID(x)        VCHECK(x, DNS_ADB_MAGIC)
#define DNS_ADBNAME_MAGIC       0x6164624e  /* adbN. */
#define DNS_ADBNAME_VALID(x)        VCHECK(x, DNS_ADBNAME_MAGIC)
#define DNS_ADBNAMEHOOK_MAGIC       0x61644e48  /* adNH. */
#define DNS_ADBNAMEHOOK_VALID(x)    VCHECK(x, DNS_ADBNAMEHOOK_MAGIC)
#define DNS_ADBZONEINFO_MAGIC       0x6164625a  /* adbZ. */
#define DNS_ADBZONEINFO_VALID(x)    VCHECK(x, DNS_ADBZONEINFO_MAGIC)
#define DNS_ADBENTRY_MAGIC      0x61646245  /* adbE. */
#define DNS_ADBENTRY_VALID(x)       VCHECK(x, DNS_ADBENTRY_MAGIC)
#define DNS_ADBHANDLE_MAGIC     0x61646248  /* adbH. */
#define DNS_ADBHANDLE_VALID(x)      VCHECK(x, DNS_ADBHANDLE_MAGIC)
#define DNS_ADBADDRINFO_MAGIC       0x61644149  /* adAI. */
#define DNS_ADBADDRINFO_VALID(x)    VCHECK(x, DNS_ADBADDRINFO_MAGIC)

typedef struct dns_adbname dns_adbname_t;
typedef struct dns_adbnamehook dns_adbnamehook_t;
typedef struct dns_adbzoneinfo dns_adbzoneinfo_t;

struct dns_adb {
    unsigned int            magic;

    isc_mutex_t         lock;
    isc_mem_t              *mctx;

    isc_mempool_t              *nmp;    /* dns_adbname_t */
    isc_mempool_t              *nhmp;   /* dns_adbnamehook_t */
    isc_mempool_t              *zimp;   /* dns_adbzoneinfo_t */
    isc_mempool_t              *emp;    /* dns_adbentry_t */
    isc_mempool_t              *ahmp;   /* dns_adbhandle_t */
    isc_mempool_t              *aimp;   /* dns_adbaddrinfo_t */

    ISC_LIST(dns_adbname_t)     names;
};

struct dns_adbname {
    unsigned int            magic;
    dns_name_t             *name;
    ISC_LIST(dns_adbnamehook_t) namehooks;
};

/*
 * dns_adbnamehook_t
 *
 * This is a small widget that dangles off a dns_adbname_t.  It contains a
 * pointer to the address information about this host, and a link to the next
 * namehook that will contain the next address this host has.
 */
struct dns_adbnamehook {
    unsigned int            magic;
    dns_adbentry_t             *address;
    ISC_LINK(dns_adbnamehook_t) link;
};

/*
 * dns_adbzoneinfo_t
 *
 * This is a small widget that holds zone-specific information about an
 * address.  Currently limited to lameness, but could just as easily be
 * extended to other types of information about zones.
 */
struct dns_adbzoneinfo {
    unsigned int            magic;

    dns_name_t             *zone;
    unsigned int            lame_timer;

    ISC_LINK(dns_adbzoneinfo_t) link;
};

/*
 * An address entry.  It holds quite a bit of information about addresses,
 * including edns state, rtt, and of course the address of the host.
 */
struct dns_adbentry {
    unsigned int            magic;

    unsigned int            lock_bucket;
    unsigned int            refcount;

    unsigned int            flags;
    int             goodness;   /* bad <= 0 < good */
    unsigned int            srtt;
    isc_sockaddr_t          sockaddr;

    ISC_LIST(dns_adbzoneinfo_t) zoneinfo;

    ISC_LINK(dns_adbentry_t)    link;
};

/*
 * dns_adbhandle_t
 *
 * This is returned to the user, and contains all the state we need to do
 * more fetches, return more information to the user, and to return the
 * address list itself.
 */
struct dns_adbhandle {
    unsigned int            magic;

    dns_adb_t              *adb;

    isc_task_t             *task;
    isc_taskaction_t           *taskaction;
    void                   *arg;
    dns_name_t             *zone;

    dns_adbaddrlist_t       addrlist;

    ISC_LINK(dns_adbhandle_t)   link;
};

/*
 * Internal functions.
 */

/*
 * Public functions.
 */

isc_result_t
dns_adb_create(isc_mem_t *mem, dns_adb_t **newadb)
{
    REQUIRE(mem != NULL);
    REQUIRE(newadb != NULL && *newadb == NULL);

    return (ISC_R_NOTIMPLEMENTED);
}

void
dns_adb_destroy(dns_adb_t **adb)
{
    REQUIRE(adb != NULL);
    REQUIRE(DNS_ADB_VALID(*adb));

    INSIST(1 == 0);
}

isc_result_t
dns_adb_lookup(dns_adb_t *adb, isc_task_t *task, isc_taskaction_t *action,
           void *arg, dns_rdataset_t *nsrdataset, dns_name_t *zone,
           dns_adbhandle_t **handle)
{
    REQUIRE(DNS_ADB_VALID(adb));
    if (task != NULL) {
        REQUIRE(action != NULL);
    }
    REQUIRE(nsrdataset != NULL);
    REQUIRE(zone != NULL);
    REQUIRE(handle != NULL && *handle == NULL);

    return (ISC_R_NOTIMPLEMENTED);
}

void
dns_adb_cancel(dns_adb_t *adb, dns_adbhandle_t **handle)
{
    REQUIRE(DNS_ADB_VALID(adb));
    REQUIRE(handle != NULL && DNS_ADBHANDLE_VALID(*handle));

    INSIST(1 == 0);
}

void
dns_adb_done(dns_adb_t *adb, dns_adbhandle_t **handle)
{
    REQUIRE(DNS_ADB_VALID(adb));
    REQUIRE(handle != NULL && DNS_ADBHANDLE_VALID(*handle));

    INSIST(1 == 0);
}