lib/dns/keytable.c

	keytable.c revision 41c82f935585b3b2b5c308d011ecc78b02cce545
/*
 * Copyright (C) 2000  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 <stddef.h>
#include <string.h>

#include <isc/assertions.h>
#include <isc/buffer.h>
#include <isc/magic.h>
#include <isc/rwlock.h>
#include <isc/result.h>
#include <isc/util.h>

#include <dns/keytable.h>
#include <dns/fixedname.h>
#include <dns/name.h>
#include <dns/rbt.h>

#include <dst/dst.h>

struct dns_keytable {
    /* Unlocked. */
        unsigned int        magic;
    isc_mem_t       *mctx;
    isc_mutex_t     lock;
    isc_rwlock_t        rwlock;
    /* Locked by lock. */
    isc_uint32_t        active_nodes;
    /* Locked by rwlock. */
    isc_uint32_t        references;
    dns_rbt_t       *table;
};

#define KEYTABLE_MAGIC          0x4b54626cU /* KTbl */
#define VALID_KEYTABLE(kt)      ISC_MAGIC_VALID(kt, KEYTABLE_MAGIC)

struct dns_keynode {
        unsigned int        magic;
    dst_key_t *     key;
    struct dns_keynode *    next;
};

#define KEYNODE_MAGIC           0x4b4e6f64U /* KNod */
#define VALID_KEYNODE(kn)       ISC_MAGIC_VALID(kn, KEYNODE_MAGIC)

static void
free_keynode(void *node, void *arg) {
    dns_keynode_t *keynode = node;
    isc_mem_t *mctx = arg;

    REQUIRE(VALID_KEYNODE(keynode));
    dst_key_free(keynode->key);
    isc_mem_put(mctx, keynode, sizeof(dns_keynode_t));
}

isc_result_t
dns_keytable_create(isc_mem_t *mctx, dns_keytable_t **keytablep) {
    dns_keytable_t *keytable;
    isc_result_t result;

    /*
     * Create a keytable.
     */

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

    keytable = isc_mem_get(mctx, sizeof *keytable);
    if (keytable == NULL)
        return (ISC_R_NOMEMORY);

    keytable->table = NULL;
    result = dns_rbt_create(mctx, free_keynode, mctx, &keytable->table);
    if (result != ISC_R_SUCCESS)
        goto cleanup_keytable;

    result = isc_mutex_init(&keytable->lock);
    if (result != ISC_R_SUCCESS) {
        UNEXPECTED_ERROR(__FILE__, __LINE__,
                 "isc_mutex_init() failed: %s",
                 isc_result_totext(result));
        result = ISC_R_UNEXPECTED;
        goto cleanup_rbt;
    }

    result = isc_rwlock_init(&keytable->rwlock, 0, 0);
    if (result != ISC_R_SUCCESS) {
        UNEXPECTED_ERROR(__FILE__, __LINE__,
                 "isc_rwlock_init() failed: %s",
                 isc_result_totext(result));
        result = ISC_R_UNEXPECTED;
        goto cleanup_lock;
    }

    keytable->mctx = mctx;
    keytable->active_nodes = 0;
    keytable->references = 1;
    keytable->magic = KEYTABLE_MAGIC;
    *keytablep = keytable;

    return (ISC_R_SUCCESS);

   cleanup_lock:
    isc_mutex_destroy(&keytable->lock);

   cleanup_rbt:
    dns_rbt_destroy(&keytable->table);

   cleanup_keytable:
    isc_mem_put(mctx, keytable, sizeof *keytable);

    return (result);
}


void
dns_keytable_attach(dns_keytable_t *source, dns_keytable_t **targetp) {

    /*
     * Attach *targetp to source.
     */

    REQUIRE(VALID_KEYTABLE(source));
    REQUIRE(targetp != NULL && *targetp == NULL);

    RWLOCK(&source->rwlock, isc_rwlocktype_write);

    INSIST(source->references > 0);
    source->references++;
    INSIST(source->references != 0);

    RWUNLOCK(&source->rwlock, isc_rwlocktype_write);

    *targetp = source;
}

void
dns_keytable_detach(dns_keytable_t **keytablep) {
    isc_boolean_t destroy = ISC_FALSE;
    dns_keytable_t *keytable;

    /*
     * Detach *keytablep from its keytable.
     */

    REQUIRE(keytablep != NULL && VALID_KEYTABLE(*keytablep));

    keytable = *keytablep;

    RWLOCK(&keytable->rwlock, isc_rwlocktype_write);

    INSIST(keytable->references > 0);
    keytable->references--;
    LOCK(&keytable->lock);
    if (keytable->references == 0 && keytable->active_nodes == 0)
        destroy = ISC_TRUE;
    UNLOCK(&keytable->lock);

    RWUNLOCK(&keytable->rwlock, isc_rwlocktype_write);

    if (destroy) {
        dns_rbt_destroy(&keytable->table);
        isc_rwlock_destroy(&keytable->rwlock);
        isc_mutex_destroy(&keytable->lock);
        keytable->magic = 0;
        isc_mem_put(keytable->mctx, keytable, sizeof *keytable);
    }

    *keytablep = NULL;
}

isc_result_t
dns_keytable_add(dns_keytable_t *keytable, dst_key_t **keyp) {
    isc_result_t result;
    dns_keynode_t *knode;
    dns_rbtnode_t *node;
    dns_fixedname_t fname;
    char *keyname;
    isc_buffer_t buffer;
    size_t len;

    /*
     * Add '*keyp' to 'keytable'.
     */

    REQUIRE(VALID_KEYTABLE(keytable));
    REQUIRE(keyp != NULL);

    keyname = dst_key_name(*keyp);
    INSIST(keyname != NULL);
    len = strlen(keyname);
    isc_buffer_init(&buffer, keyname, len, ISC_BUFFERTYPE_TEXT);
    isc_buffer_add(&buffer, len);
    dns_fixedname_init(&fname);
    result = dns_name_fromtext(dns_fixedname_name(&fname), &buffer,
                   dns_rootname, ISC_FALSE, NULL);
    if (result != ISC_R_SUCCESS)
        return (result);

    knode = isc_mem_get(keytable->mctx, sizeof *knode);
    if (knode == NULL)
        return (ISC_R_NOMEMORY);

    RWLOCK(&keytable->rwlock, isc_rwlocktype_write);

    node = NULL;
    result = dns_rbt_addnode(keytable->table, dns_fixedname_name(&fname),
                 &node);

    if (result == ISC_R_SUCCESS || result == ISC_R_EXISTS) {
        knode->magic = KEYNODE_MAGIC;
        knode->key = *keyp;
        knode->next = node->data;
        node->data = knode;
        *keyp = NULL;
        knode = NULL;
    }

    RWUNLOCK(&keytable->rwlock, isc_rwlocktype_write);

    if (knode != NULL)
        isc_mem_put(keytable->mctx, knode, sizeof *knode);

    return (result);
}

isc_result_t
dns_keytable_findkeynode(dns_keytable_t *keytable, dns_name_t *name,
             dns_secalg_t algorithm, dns_keytag_t tag,
             dns_keynode_t **keynodep)
{
    isc_result_t result;
    dns_keynode_t *knode;
    void *data;

    /*
     * Search for a key named 'name', matching 'algorithm' and 'tag' in
     * 'keytable'.
     */

    REQUIRE(VALID_KEYTABLE(keytable));
    REQUIRE(dns_name_isabsolute(name));
    REQUIRE(keynodep != NULL && *keynodep == NULL);

    RWLOCK(&keytable->rwlock, isc_rwlocktype_read);

    knode = NULL;
    data = NULL;
    result = dns_rbt_findname(keytable->table, name, 0, NULL, &data);

    if (result == ISC_R_SUCCESS) {
        INSIST(data != NULL);
        for (knode = data; knode != NULL; knode = knode->next) {
            if (algorithm == (dns_secalg_t)dst_key_alg(knode->key)
                && tag == (dns_keytag_t)dst_key_id(knode->key))
                break;
        }
        if (knode != NULL) {
            LOCK(&keytable->lock);
            keytable->active_nodes++;
            UNLOCK(&keytable->lock);
            *keynodep = knode;
        } else
            result = ISC_R_NOTFOUND;
    } else if (result == DNS_R_PARTIALMATCH)
        result = ISC_R_NOTFOUND;

    RWUNLOCK(&keytable->rwlock, isc_rwlocktype_read);

    return (result);
}

isc_result_t
dns_keytable_finddeepestmatch(dns_keytable_t *keytable, dns_name_t *name,
                  dns_name_t *foundname)
{
    isc_result_t result;
    dns_keynode_t *knode;
    void *data;

    /*
     * Search for the deepest match in 'keytable'.
     */

    REQUIRE(VALID_KEYTABLE(keytable));
    REQUIRE(dns_name_isabsolute(name));
    REQUIRE(foundname != NULL);

    RWLOCK(&keytable->rwlock, isc_rwlocktype_read);

    knode = NULL;
    data = NULL;
    result = dns_rbt_findname(keytable->table, name, 0, foundname, &data);

    if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH)
        result = ISC_R_SUCCESS;

    RWUNLOCK(&keytable->rwlock, isc_rwlocktype_read);

    return (result);
}

void
dns_keytable_detachkeynode(dns_keytable_t *keytable,
               dns_keynode_t **keynodep)
{
    /*
     * Give back a keynode found via dns_keytable_findkeynode().
     */

    REQUIRE(VALID_KEYTABLE(keytable));
    REQUIRE(keynodep != NULL && VALID_KEYNODE(*keynodep));

    LOCK(&keytable->lock);
    INSIST(keytable->active_nodes > 0);
    keytable->active_nodes--;
    UNLOCK(&keytable->lock);

    *keynodep = NULL;
}

isc_result_t
dns_keytable_issecuredomain(dns_keytable_t *keytable, dns_name_t *name,
                isc_boolean_t *wantdnssecp)
{
    isc_result_t result;
    void *data;

    /*
     * Is 'name' at or beneath a trusted key?
     */

    REQUIRE(VALID_KEYTABLE(keytable));
    REQUIRE(dns_name_isabsolute(name));
    REQUIRE(wantdnssecp != NULL);

    RWLOCK(&keytable->rwlock, isc_rwlocktype_read);

    data = NULL;
    result = dns_rbt_findname(keytable->table, name, 0, NULL, &data);

    if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH) {
        INSIST(data != NULL);
        *wantdnssecp = ISC_TRUE;
        result = ISC_R_SUCCESS;
    } else if (result == ISC_R_NOTFOUND) {
        *wantdnssecp = ISC_FALSE;
        result = ISC_R_SUCCESS;
    }

    RWUNLOCK(&keytable->rwlock, isc_rwlocktype_read);

    return (result);
}

dst_key_t *
dns_keynode_key(dns_keynode_t *keynode) {

    /*
     * Get the DST key associated with keynode.
     */

    REQUIRE(VALID_KEYNODE(keynode));

    return (keynode->key);
}