contrib/bind-9.2.4rc7/lib/dns/nxt.c

   1 /*
   2  * Copyright (C) 2004  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 1999-2001, 2003  Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and 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: nxt.c,v 1.26.2.3 2004/03/09 06:11:04 marka Exp $ */
  19
  20 #include <config.h>
  21
  22 #include <isc/string.h>
  23 #include <isc/util.h>
  24
  25 #include <dns/db.h>
  26 #include <dns/nxt.h>
  27 #include <dns/rdata.h>
  28 #include <dns/rdatalist.h>
  29 #include <dns/rdataset.h>
  30 #include <dns/rdatasetiter.h>
  31 #include <dns/rdatastruct.h>
  32 #include <dns/result.h>
  33
  34 #define RETERR(x) do { \
  35         result = (x); \
  36         if (result != ISC_R_SUCCESS) \
  37                 goto failure; \
  38         } while (0)
  39
  40 static void
  41 set_bit(unsigned char *array, unsigned int index, unsigned int bit) {
  42         unsigned int shift, mask;
  43
  44         shift = 7 - (index % 8);
  45         mask = 1 << shift;
  46
  47         if (bit != 0)
  48                 array[index / 8] |= mask;
  49         else
  50                 array[index / 8] &= (~mask & 0xFF);
  51 }
  52
  53 static unsigned int
  54 bit_isset(unsigned char *array, unsigned int index) {
  55         unsigned int byte, shift, mask;
  56
  57         byte = array[index / 8];
  58         shift = 7 - (index % 8);
  59         mask = 1 << shift;
  60
  61         return ((byte & mask) != 0);
  62 }
  63
  64 isc_result_t
  65 dns_nxt_buildrdata(dns_db_t *db, dns_dbversion_t *version,
  66                    dns_dbnode_t *node, dns_name_t *target,
  67                    unsigned char *buffer, dns_rdata_t *rdata)
  68 {
  69         isc_result_t result;
  70         dns_rdataset_t rdataset;
  71         isc_region_t r;
  72         int i;
  73
  74         unsigned char *nxt_bits;
  75         unsigned int max_type;
  76         dns_rdatasetiter_t *rdsiter;
  77
  78         memset(buffer, 0, DNS_NXT_BUFFERSIZE);
  79         dns_name_toregion(target, &r);
  80         memcpy(buffer, r.base, r.length);
  81         r.base = buffer;
  82         nxt_bits = r.base + r.length;
  83         set_bit(nxt_bits, dns_rdatatype_nxt, 1);
  84         max_type = dns_rdatatype_nxt;
  85         dns_rdataset_init(&rdataset);
  86         rdsiter = NULL;
  87         result = dns_db_allrdatasets(db, node, version, 0, &rdsiter);
  88         if (result != ISC_R_SUCCESS)
  89                 return (result);
  90         for (result = dns_rdatasetiter_first(rdsiter);
  91              result == ISC_R_SUCCESS;
  92              result = dns_rdatasetiter_next(rdsiter))
  93         {
  94                 dns_rdatasetiter_current(rdsiter, &rdataset);
  95                 if (rdataset.type > 127)
  96                         /* XXX "rdataset type too large" */
  97                         return (ISC_R_RANGE);
  98                 if (rdataset.type != dns_rdatatype_nxt) {
  99                         if (rdataset.type > max_type)
 100                                 max_type = rdataset.type;
 101                         set_bit(nxt_bits, rdataset.type, 1);
 102                 }
 103                 dns_rdataset_disassociate(&rdataset);
 104         }
 105
 106         /*
 107          * At zone cuts, deny the existence of glue in the parent zone.
 108          */
 109         if (bit_isset(nxt_bits, dns_rdatatype_ns) &&
 110             ! bit_isset(nxt_bits, dns_rdatatype_soa)) {
 111                 for (i = 0; i < 128; i++) {
 112                         if (bit_isset(nxt_bits, i) &&
 113                             ! dns_rdatatype_iszonecutauth((dns_rdatatype_t)i))
 114                                 set_bit(nxt_bits, i, 0);
 115                 }
 116         }
 117
 118         dns_rdatasetiter_destroy(&rdsiter);
 119         if (result != ISC_R_NOMORE)
 120                 return (result);
 121
 122         r.length += max_type / 8 + 1;
 123         INSIST(r.length <= DNS_NXT_BUFFERSIZE);
 124         dns_rdata_fromregion(rdata,
 125                              dns_db_class(db),
 126                              dns_rdatatype_nxt,
 127                              &r);
 128
 129         return (ISC_R_SUCCESS);
 130 }
 131
 132
 133 isc_result_t
 134 dns_nxt_build(dns_db_t *db, dns_dbversion_t *version, dns_dbnode_t *node,
 135               dns_name_t *target, dns_ttl_t ttl)
 136 {
 137         isc_result_t result;
 138         dns_rdata_t rdata = DNS_RDATA_INIT;
 139         unsigned char data[DNS_NXT_BUFFERSIZE];
 140         dns_rdatalist_t rdatalist;
 141         dns_rdataset_t rdataset;
 142
 143         dns_rdataset_init(&rdataset);
 144         dns_rdata_init(&rdata);
 145
 146         RETERR(dns_nxt_buildrdata(db, version, node, target, data, &rdata));
 147
 148         rdatalist.rdclass = dns_db_class(db);
 149         rdatalist.type = dns_rdatatype_nxt;
 150         rdatalist.covers = 0;
 151         rdatalist.ttl = ttl;
 152         ISC_LIST_INIT(rdatalist.rdata);
 153         ISC_LIST_APPEND(rdatalist.rdata, &rdata, link);
 154         RETERR(dns_rdatalist_tordataset(&rdatalist, &rdataset));
 155         result = dns_db_addrdataset(db, node, version, 0, &rdataset,
 156                                     0, NULL);
 157         if (result == DNS_R_UNCHANGED)
 158                 result = ISC_R_SUCCESS;
 159         RETERR(result);
 160  failure:
 161         if (dns_rdataset_isassociated(&rdataset))
 162                 dns_rdataset_disassociate(&rdataset);
 163         return (result);
 164 }
 165
 166 isc_boolean_t
 167 dns_nxt_typepresent(dns_rdata_t *nxt, dns_rdatatype_t type) {
 168         dns_rdata_nxt_t nxtstruct;
 169         isc_result_t result;
 170         isc_boolean_t present;
 171
 172         REQUIRE(nxt != NULL);
 173         REQUIRE(nxt->type == dns_rdatatype_nxt);
 174         REQUIRE(type < 128);
 175
 176         /* This should never fail */
 177         result = dns_rdata_tostruct(nxt, &nxtstruct, NULL);
 178         INSIST(result == ISC_R_SUCCESS);
 179
 180         if (type >= nxtstruct.len * 8)
 181                 present = ISC_FALSE;
 182         else
 183                 present = ISC_TF(bit_isset(nxtstruct.typebits, type));
 184         dns_rdata_freestruct(&nxt);
 185         return (present);
 186 }