diff options
Diffstat (limited to 'lib/dns/forward.c')
| -rw-r--r-- | lib/dns/forward.c | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/lib/dns/forward.c b/lib/dns/forward.c new file mode 100644 index 0000000..39e2ef5 --- /dev/null +++ b/lib/dns/forward.c @@ -0,0 +1,199 @@ +/* + * 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)); +} |