lib/dns/order.c

	order.c revision 0c27b3fe77ac1d5094ba3521e8142d9e7973133f
/*
 * Copyright (C) 2002, 2004, 2005, 2007, 2015, 2016  Internet Systems Consortium, Inc. ("ISC")
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

/* $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 (DNS_RDATASETATTR_RANDOMIZE);
}

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));
}