contrib/bind-9.5.2/lib/dns/forward.c

   1 /*
   2  * Copyright (C) 2004, 2005, 2007  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 2000, 2001  Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and/or distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  10  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  11  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  13  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  14  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  15  * PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 /* $Id: forward.c,v 1.12 2007/06/19 23:47:16 tbox Exp $ */
  19
  20 /*! \file */
  21
  22 #include <config.h>
  23
  24 #include <isc/magic.h>
  25 #include <isc/mem.h>
  26 #include <isc/rwlock.h>
  27 #include <isc/sockaddr.h>
  28 #include <isc/util.h>
  29
  30 #include <dns/forward.h>
  31 #include <dns/rbt.h>
  32 #include <dns/result.h>
  33 #include <dns/types.h>
  34
  35 struct dns_fwdtable {
  36         /* Unlocked. */
  37         unsigned int            magic;
  38         isc_mem_t               *mctx;
  39         isc_rwlock_t            rwlock;
  40         /* Locked by lock. */
  41         dns_rbt_t               *table;
  42 };
  43
  44 #define FWDTABLEMAGIC           ISC_MAGIC('F', 'w', 'd', 'T')
  45 #define VALID_FWDTABLE(ft)      ISC_MAGIC_VALID(ft, FWDTABLEMAGIC)
  46
  47 static void
  48 auto_detach(void *, void *);
  49
  50 isc_result_t
  51 dns_fwdtable_create(isc_mem_t *mctx, dns_fwdtable_t **fwdtablep) {
  52         dns_fwdtable_t *fwdtable;
  53         isc_result_t result;
  54
  55         REQUIRE(fwdtablep != NULL && *fwdtablep == NULL);
  56
  57         fwdtable = isc_mem_get(mctx, sizeof(dns_fwdtable_t));
  58         if (fwdtable == NULL)
  59                 return (ISC_R_NOMEMORY);
  60
  61         fwdtable->table = NULL;
  62         result = dns_rbt_create(mctx, auto_detach, fwdtable, &fwdtable->table);
  63         if (result != ISC_R_SUCCESS)
  64                 goto cleanup_fwdtable;
  65
  66         result = isc_rwlock_init(&fwdtable->rwlock, 0, 0);
  67         if (result != ISC_R_SUCCESS)
  68                 goto cleanup_rbt;
  69
  70         fwdtable->mctx = NULL;
  71         isc_mem_attach(mctx, &fwdtable->mctx);
  72         fwdtable->magic = FWDTABLEMAGIC;
  73         *fwdtablep = fwdtable;
  74
  75         return (ISC_R_SUCCESS);
  76
  77    cleanup_rbt:
  78         dns_rbt_destroy(&fwdtable->table);
  79
  80    cleanup_fwdtable:
  81         isc_mem_put(mctx, fwdtable, sizeof(dns_fwdtable_t));
  82
  83         return (result);
  84 }
  85
  86 isc_result_t
  87 dns_fwdtable_add(dns_fwdtable_t *fwdtable, dns_name_t *name,
  88                  isc_sockaddrlist_t *addrs, dns_fwdpolicy_t fwdpolicy)
  89 {
  90         isc_result_t result;
  91         dns_forwarders_t *forwarders;
  92         isc_sockaddr_t *sa, *nsa;
  93
  94         REQUIRE(VALID_FWDTABLE(fwdtable));
  95
  96         forwarders = isc_mem_get(fwdtable->mctx, sizeof(dns_forwarders_t));
  97         if (forwarders == NULL)
  98                 return (ISC_R_NOMEMORY);
  99
 100         ISC_LIST_INIT(forwarders->addrs);
 101         for (sa = ISC_LIST_HEAD(*addrs);
 102              sa != NULL;
 103              sa = ISC_LIST_NEXT(sa, link))
 104         {
 105                 nsa = isc_mem_get(fwdtable->mctx, sizeof(isc_sockaddr_t));
 106                 if (nsa == NULL) {
 107                         result = ISC_R_NOMEMORY;
 108                         goto cleanup;
 109                 }
 110                 *nsa = *sa;
 111                 ISC_LINK_INIT(nsa, link);
 112                 ISC_LIST_APPEND(forwarders->addrs, nsa, link);
 113         }
 114         forwarders->fwdpolicy = fwdpolicy;
 115
 116         RWLOCK(&fwdtable->rwlock, isc_rwlocktype_write);
 117         result = dns_rbt_addname(fwdtable->table, name, forwarders);
 118         RWUNLOCK(&fwdtable->rwlock, isc_rwlocktype_write);
 119
 120         if (result != ISC_R_SUCCESS)
 121                 goto cleanup;
 122
 123         return (ISC_R_SUCCESS);
 124
 125  cleanup:
 126         while (!ISC_LIST_EMPTY(forwarders->addrs)) {
 127                 sa = ISC_LIST_HEAD(forwarders->addrs);
 128                 ISC_LIST_UNLINK(forwarders->addrs, sa, link);
 129                 isc_mem_put(fwdtable->mctx, sa, sizeof(isc_sockaddr_t));
 130         }
 131         isc_mem_put(fwdtable->mctx, forwarders, sizeof(dns_forwarders_t));
 132         return (result);
 133 }
 134
 135 isc_result_t
 136 dns_fwdtable_find(dns_fwdtable_t *fwdtable, dns_name_t *name,
 137                   dns_forwarders_t **forwardersp)
 138 {
 139         return (dns_fwdtable_find2(fwdtable, name, NULL, forwardersp));
 140 }
 141
 142 isc_result_t
 143 dns_fwdtable_find2(dns_fwdtable_t *fwdtable, dns_name_t *name,
 144                    dns_name_t *foundname, dns_forwarders_t **forwardersp)
 145 {
 146         isc_result_t result;
 147
 148         REQUIRE(VALID_FWDTABLE(fwdtable));
 149
 150         RWLOCK(&fwdtable->rwlock, isc_rwlocktype_read);
 151
 152         result = dns_rbt_findname(fwdtable->table, name, 0, foundname,
 153                                   (void **)forwardersp);
 154         if (result == DNS_R_PARTIALMATCH)
 155                 result = ISC_R_SUCCESS;
 156
 157         RWUNLOCK(&fwdtable->rwlock, isc_rwlocktype_read);
 158
 159         return (result);
 160 }
 161
 162 void
 163 dns_fwdtable_destroy(dns_fwdtable_t **fwdtablep) {
 164         dns_fwdtable_t *fwdtable;
 165         isc_mem_t *mctx;
 166
 167         REQUIRE(fwdtablep != NULL && VALID_FWDTABLE(*fwdtablep));
 168
 169         fwdtable = *fwdtablep;
 170
 171         dns_rbt_destroy(&fwdtable->table);
 172         isc_rwlock_destroy(&fwdtable->rwlock);
 173         fwdtable->magic = 0;
 174         mctx = fwdtable->mctx;
 175         isc_mem_put(mctx, fwdtable, sizeof(dns_fwdtable_t));
 176         isc_mem_detach(&mctx);
 177
 178         *fwdtablep = NULL;
 179 }
 180
 181 /***
 182  *** Private
 183  ***/
 184
 185 static void
 186 auto_detach(void *data, void *arg) {
 187         dns_forwarders_t *forwarders = data;
 188         dns_fwdtable_t *fwdtable = arg;
 189         isc_sockaddr_t *sa;
 190
 191         UNUSED(arg);
 192
 193         while (!ISC_LIST_EMPTY(forwarders->addrs)) {
 194                 sa = ISC_LIST_HEAD(forwarders->addrs);
 195                 ISC_LIST_UNLINK(forwarders->addrs, sa, link);
 196                 isc_mem_put(fwdtable->mctx, sa, sizeof(isc_sockaddr_t));
 197         }
 198         isc_mem_put(fwdtable->mctx, forwarders, sizeof(dns_forwarders_t));
 199 }