order.c

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/*
 * Copyright (C) 2004, 2005, 2007  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 2002  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and/or 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 ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC 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.
 */

/* $Id: order.c,v 1.10 2007/06/19 23:47:16 tbox Exp $ */

/*! \file */

#include <config.h>

#include <isc/magic.h>
#include <isc/mem.h>
#include <isc/types.h>
#include <isc/util.h>
#include <isc/refcount.h>

#include <dns/fixedname.h>
#include <dns/name.h>
#include <dns/order.h>
#include <dns/rdataset.h>
#include <dns/types.h>

typedef struct dns_order_ent dns_order_ent_t;
struct dns_order_ent {
        dns_fixedname_t                 name;
        dns_rdataclass_t                rdclass;
        dns_rdatatype_t                 rdtype;
        unsigned int                    mode;
        ISC_LINK(dns_order_ent_t)       link;
};

struct dns_order {
        unsigned int                    magic;
        isc_refcount_t                  references;
        ISC_LIST(dns_order_ent_t)       ents;
        isc_mem_t                       *mctx;
};
        
#define DNS_ORDER_MAGIC ISC_MAGIC('O','r','d','r')
#define DNS_ORDER_VALID(order)  ISC_MAGIC_VALID(order, DNS_ORDER_MAGIC)

isc_result_t
dns_order_create(isc_mem_t *mctx, dns_order_t **orderp) {
        dns_order_t *order;
        isc_result_t result;

        REQUIRE(orderp != NULL && *orderp == NULL);

        order = isc_mem_get(mctx, sizeof(*order));
        if (order == NULL)
                return (ISC_R_NOMEMORY);
        
        ISC_LIST_INIT(order->ents);

        /* Implicit attach. */
        result = isc_refcount_init(&order->references, 1);
        if (result != ISC_R_SUCCESS) {
                isc_mem_put(mctx, order, sizeof(*order));
                return (result);
        }

        order->mctx = NULL;
        isc_mem_attach(mctx, &order->mctx);
        order->magic = DNS_ORDER_MAGIC;
        *orderp = order;
        return (ISC_R_SUCCESS);
}

isc_result_t
dns_order_add(dns_order_t *order, dns_name_t *name,
              dns_rdatatype_t rdtype, dns_rdataclass_t rdclass,
              unsigned int mode)
{
        dns_order_ent_t *ent;

        REQUIRE(DNS_ORDER_VALID(order));
        REQUIRE(mode == DNS_RDATASETATTR_RANDOMIZE ||
                mode == DNS_RDATASETATTR_FIXEDORDER ||
                mode == 0 /* DNS_RDATASETATTR_CYCLIC */ );

        ent = isc_mem_get(order->mctx, sizeof(*ent));
        if (ent == NULL)
                return (ISC_R_NOMEMORY);

        dns_fixedname_init(&ent->name);
        RUNTIME_CHECK(dns_name_copy(name, dns_fixedname_name(&ent->name), NULL)
                      == ISC_R_SUCCESS);
        ent->rdtype = rdtype;
        ent->rdclass = rdclass;
        ent->mode = mode;
        ISC_LINK_INIT(ent, link);
        ISC_LIST_INITANDAPPEND(order->ents, ent, link);
        return (ISC_R_SUCCESS);
}

static inline isc_boolean_t
match(dns_name_t *name1, dns_name_t *name2) {
        
        if (dns_name_iswildcard(name2))
                return(dns_name_matcheswildcard(name1, name2));
        return (dns_name_equal(name1, name2));
}

unsigned int
dns_order_find(dns_order_t *order, dns_name_t *name,
               dns_rdatatype_t rdtype, dns_rdataclass_t rdclass)
{
        dns_order_ent_t *ent;
        REQUIRE(DNS_ORDER_VALID(order));

        for (ent = ISC_LIST_HEAD(order->ents);
             ent != NULL;
             ent = ISC_LIST_NEXT(ent, link)) {
                if (ent->rdtype != rdtype && ent->rdtype != dns_rdatatype_any)
                        continue;
                if (ent->rdclass != rdclass &&
                    ent->rdclass != dns_rdataclass_any)
                        continue;
                if (match(name, dns_fixedname_name(&ent->name)))
                        return (ent->mode);
        }
        return (0);
}

void
dns_order_attach(dns_order_t *source, dns_order_t **target) {
        REQUIRE(DNS_ORDER_VALID(source));
        REQUIRE(target != NULL && *target == NULL);
        isc_refcount_increment(&source->references, NULL);
        *target = source;
}

void
dns_order_detach(dns_order_t **orderp) {
        dns_order_t *order;
        dns_order_ent_t *ent;
        unsigned int references;

        REQUIRE(orderp != NULL);
        order = *orderp;
        REQUIRE(DNS_ORDER_VALID(order));
        isc_refcount_decrement(&order->references, &references);
        *orderp = NULL;
        if (references != 0)
                return;

        order->magic = 0;
        while ((ent = ISC_LIST_HEAD(order->ents)) != NULL) {
                ISC_LIST_UNLINK(order->ents, ent, link);
                isc_mem_put(order->mctx, ent, sizeof(*ent));
        }
        isc_refcount_destroy(&order->references);
        isc_mem_putanddetach(&order->mctx, order, sizeof(*order));
}

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