diff options
Diffstat (limited to '')
| -rw-r--r-- | lib/dns/forward.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/lib/dns/forward.c b/lib/dns/forward.c new file mode 100644 index 0000000..e59f23c --- /dev/null +++ b/lib/dns/forward.c @@ -0,0 +1,227 @@ +/* + * Copyright (C) Internet Systems Consortium, Inc. ("ISC") + * + * SPDX-License-Identifier: MPL-2.0 + * + * 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 https://mozilla.org/MPL/2.0/. + * + * See the COPYRIGHT file distributed with this work for additional + * information regarding copyright ownership. + */ + +/*! \file */ + +#include <isc/magic.h> +#include <isc/mem.h> +#include <isc/rwlock.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(*fwdtable)); + + fwdtable->table = NULL; + result = dns_rbt_create(mctx, auto_detach, fwdtable, &fwdtable->table); + if (result != ISC_R_SUCCESS) { + goto cleanup_fwdtable; + } + + isc_rwlock_init(&fwdtable->rwlock, 0, 0); + fwdtable->mctx = NULL; + isc_mem_attach(mctx, &fwdtable->mctx); + fwdtable->magic = FWDTABLEMAGIC; + *fwdtablep = fwdtable; + + return (ISC_R_SUCCESS); + +cleanup_fwdtable: + isc_mem_put(mctx, fwdtable, sizeof(*fwdtable)); + + return (result); +} + +isc_result_t +dns_fwdtable_addfwd(dns_fwdtable_t *fwdtable, const dns_name_t *name, + dns_forwarderlist_t *fwdrs, dns_fwdpolicy_t fwdpolicy) { + isc_result_t result; + dns_forwarders_t *forwarders; + dns_forwarder_t *fwd, *nfwd; + + REQUIRE(VALID_FWDTABLE(fwdtable)); + + forwarders = isc_mem_get(fwdtable->mctx, sizeof(*forwarders)); + + ISC_LIST_INIT(forwarders->fwdrs); + for (fwd = ISC_LIST_HEAD(*fwdrs); fwd != NULL; + fwd = ISC_LIST_NEXT(fwd, link)) + { + nfwd = isc_mem_get(fwdtable->mctx, sizeof(*nfwd)); + *nfwd = *fwd; + ISC_LINK_INIT(nfwd, link); + ISC_LIST_APPEND(forwarders->fwdrs, nfwd, 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->fwdrs)) { + fwd = ISC_LIST_HEAD(forwarders->fwdrs); + ISC_LIST_UNLINK(forwarders->fwdrs, fwd, link); + isc_mem_put(fwdtable->mctx, fwd, sizeof(*fwd)); + } + isc_mem_put(fwdtable->mctx, forwarders, sizeof(*forwarders)); + return (result); +} + +isc_result_t +dns_fwdtable_add(dns_fwdtable_t *fwdtable, const dns_name_t *name, + isc_sockaddrlist_t *addrs, dns_fwdpolicy_t fwdpolicy) { + isc_result_t result; + dns_forwarders_t *forwarders; + dns_forwarder_t *fwd; + isc_sockaddr_t *sa; + + REQUIRE(VALID_FWDTABLE(fwdtable)); + + forwarders = isc_mem_get(fwdtable->mctx, sizeof(*forwarders)); + + ISC_LIST_INIT(forwarders->fwdrs); + for (sa = ISC_LIST_HEAD(*addrs); sa != NULL; + sa = ISC_LIST_NEXT(sa, link)) + { + fwd = isc_mem_get(fwdtable->mctx, sizeof(*fwd)); + fwd->addr = *sa; + fwd->dscp = -1; + ISC_LINK_INIT(fwd, link); + ISC_LIST_APPEND(forwarders->fwdrs, fwd, 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->fwdrs)) { + fwd = ISC_LIST_HEAD(forwarders->fwdrs); + ISC_LIST_UNLINK(forwarders->fwdrs, fwd, link); + isc_mem_put(fwdtable->mctx, fwd, sizeof(*fwd)); + } + isc_mem_put(fwdtable->mctx, forwarders, sizeof(*forwarders)); + return (result); +} + +isc_result_t +dns_fwdtable_delete(dns_fwdtable_t *fwdtable, const dns_name_t *name) { + isc_result_t result; + + REQUIRE(VALID_FWDTABLE(fwdtable)); + + RWLOCK(&fwdtable->rwlock, isc_rwlocktype_write); + result = dns_rbt_deletename(fwdtable->table, name, false); + RWUNLOCK(&fwdtable->rwlock, isc_rwlocktype_write); + + if (result == DNS_R_PARTIALMATCH) { + result = ISC_R_NOTFOUND; + } + + return (result); +} + +isc_result_t +dns_fwdtable_find(dns_fwdtable_t *fwdtable, const 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; + + REQUIRE(fwdtablep != NULL && VALID_FWDTABLE(*fwdtablep)); + + fwdtable = *fwdtablep; + *fwdtablep = NULL; + + dns_rbt_destroy(&fwdtable->table); + isc_rwlock_destroy(&fwdtable->rwlock); + fwdtable->magic = 0; + + isc_mem_putanddetach(&fwdtable->mctx, fwdtable, sizeof(*fwdtable)); +} + +/*** + *** Private + ***/ + +static void +auto_detach(void *data, void *arg) { + dns_forwarders_t *forwarders = data; + dns_fwdtable_t *fwdtable = arg; + dns_forwarder_t *fwd; + + UNUSED(arg); + + while (!ISC_LIST_EMPTY(forwarders->fwdrs)) { + fwd = ISC_LIST_HEAD(forwarders->fwdrs); + ISC_LIST_UNLINK(forwarders->fwdrs, fwd, link); + isc_mem_put(fwdtable->mctx, fwd, sizeof(*fwd)); + } + isc_mem_put(fwdtable->mctx, forwarders, sizeof(*forwarders)); +} |