forward.c revision 70e5a7403f0e0a3bd292b8287c5fed5772c15270
/*
* Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC")
* Copyright (C) 2000, 2001 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: forward.c,v 1.12 2007/06/19 23:47:16 tbox Exp $ */
/*! \file */
#include <config.h>
#include <isc/magic.h>
#include <isc/mem.h>
#include <isc/rwlock.h>
#include <isc/sockaddr.h>
#include <isc/util.h>
#include <dns/forward.h>
#include <dns/rbt.h>
#include <dns/result.h>
#include <dns/types.h>
struct dns_fwdtable {
/* Unlocked. */
unsigned int magic;
isc_mem_t *mctx;
isc_rwlock_t rwlock;
/* Locked by lock. */
dns_rbt_t *table;
};
#define FWDTABLEMAGIC ISC_MAGIC('F', 'w', 'd', 'T')
#define VALID_FWDTABLE(ft) ISC_MAGIC_VALID(ft, FWDTABLEMAGIC)
static void
auto_detach(void *, void *);
isc_result_t
dns_fwdtable_create(isc_mem_t *mctx, dns_fwdtable_t **fwdtablep) {
dns_fwdtable_t *fwdtable;
isc_result_t result;
REQUIRE(fwdtablep != NULL && *fwdtablep == NULL);
fwdtable = isc_mem_get(mctx, sizeof(dns_fwdtable_t));
if (fwdtable == NULL)
return (ISC_R_NOMEMORY);
fwdtable->table = NULL;
result = dns_rbt_create(mctx, auto_detach, fwdtable, &fwdtable->table);
if (result != ISC_R_SUCCESS)
goto cleanup_fwdtable;
result = isc_rwlock_init(&fwdtable->rwlock, 0, 0);
if (result != ISC_R_SUCCESS)
goto cleanup_rbt;
fwdtable->mctx = NULL;
isc_mem_attach(mctx, &fwdtable->mctx);
fwdtable->magic = FWDTABLEMAGIC;
*fwdtablep = fwdtable;
return (ISC_R_SUCCESS);
cleanup_rbt:
dns_rbt_destroy(&fwdtable->table);
cleanup_fwdtable:
isc_mem_put(mctx, fwdtable, sizeof(dns_fwdtable_t));
return (result);
}
isc_result_t
dns_fwdtable_add(dns_fwdtable_t *fwdtable, dns_name_t *name,
isc_sockaddrlist_t *addrs, dns_fwdpolicy_t fwdpolicy)
{
isc_result_t result;
dns_forwarders_t *forwarders;
isc_sockaddr_t *sa, *nsa;
REQUIRE(VALID_FWDTABLE(fwdtable));
forwarders = isc_mem_get(fwdtable->mctx, sizeof(dns_forwarders_t));
if (forwarders == NULL)
return (ISC_R_NOMEMORY);
ISC_LIST_INIT(forwarders->addrs);
for (sa = ISC_LIST_HEAD(*addrs);
sa != NULL;
sa = ISC_LIST_NEXT(sa, link))
{
nsa = isc_mem_get(fwdtable->mctx, sizeof(isc_sockaddr_t));
if (nsa == NULL) {
result = ISC_R_NOMEMORY;
goto cleanup;
}
*nsa = *sa;
ISC_LINK_INIT(nsa, link);
ISC_LIST_APPEND(forwarders->addrs, nsa, link);
}
forwarders->fwdpolicy = fwdpolicy;
RWLOCK(&fwdtable->rwlock, isc_rwlocktype_write);
result = dns_rbt_addname(fwdtable->table, name, forwarders);
RWUNLOCK(&fwdtable->rwlock, isc_rwlocktype_write);
if (result != ISC_R_SUCCESS)
goto cleanup;
return (ISC_R_SUCCESS);
cleanup:
while (!ISC_LIST_EMPTY(forwarders->addrs)) {
sa = ISC_LIST_HEAD(forwarders->addrs);
ISC_LIST_UNLINK(forwarders->addrs, sa, link);
isc_mem_put(fwdtable->mctx, sa, sizeof(isc_sockaddr_t));
}
isc_mem_put(fwdtable->mctx, forwarders, sizeof(dns_forwarders_t));
return (result);
}
isc_result_t
dns_fwdtable_find(dns_fwdtable_t *fwdtable, dns_name_t *name,
dns_forwarders_t **forwardersp)
{
return (dns_fwdtable_find2(fwdtable, name, NULL, forwardersp));
}
isc_result_t
dns_fwdtable_find2(dns_fwdtable_t *fwdtable, dns_name_t *name,
dns_name_t *foundname, dns_forwarders_t **forwardersp)
{
isc_result_t result;
REQUIRE(VALID_FWDTABLE(fwdtable));
RWLOCK(&fwdtable->rwlock, isc_rwlocktype_read);
result = dns_rbt_findname(fwdtable->table, name, 0, foundname,
(void **)forwardersp);
if (result == DNS_R_PARTIALMATCH)
result = ISC_R_SUCCESS;
RWUNLOCK(&fwdtable->rwlock, isc_rwlocktype_read);
return (result);
}
void
dns_fwdtable_destroy(dns_fwdtable_t **fwdtablep) {
dns_fwdtable_t *fwdtable;
isc_mem_t *mctx;
REQUIRE(fwdtablep != NULL && VALID_FWDTABLE(*fwdtablep));
fwdtable = *fwdtablep;
dns_rbt_destroy(&fwdtable->table);
isc_rwlock_destroy(&fwdtable->rwlock);
fwdtable->magic = 0;
mctx = fwdtable->mctx;
isc_mem_put(mctx, fwdtable, sizeof(dns_fwdtable_t));
isc_mem_detach(&mctx);
*fwdtablep = NULL;
}
/***
*** Private
***/
static void
auto_detach(void *data, void *arg) {
dns_forwarders_t *forwarders = data;
dns_fwdtable_t *fwdtable = arg;
isc_sockaddr_t *sa;
UNUSED(arg);
while (!ISC_LIST_EMPTY(forwarders->addrs)) {
sa = ISC_LIST_HEAD(forwarders->addrs);
ISC_LIST_UNLINK(forwarders->addrs, sa, link);
isc_mem_put(fwdtable->mctx, sa, sizeof(isc_sockaddr_t));
}
isc_mem_put(fwdtable->mctx, forwarders, sizeof(dns_forwarders_t));
}