contrib/bind/lib/dns/byaddr.c

   1 /*
   2  * Copyright (C) 2004, 2005, 2007  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 2000-2003  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: byaddr.c,v 1.39 2007/06/19 23:47:16 tbox Exp $ */
  19
  20 /*! \file */
  21
  22 #include <config.h>
  23
  24 #include <isc/mem.h>
  25 #include <isc/netaddr.h>
  26 #include <isc/print.h>
  27 #include <isc/string.h>         /* Required for HP/UX (and others?) */
  28 #include <isc/task.h>
  29 #include <isc/util.h>
  30
  31 #include <dns/byaddr.h>
  32 #include <dns/db.h>
  33 #include <dns/events.h>
  34 #include <dns/lookup.h>
  35 #include <dns/rdata.h>
  36 #include <dns/rdataset.h>
  37 #include <dns/rdatastruct.h>
  38 #include <dns/resolver.h>
  39 #include <dns/result.h>
  40 #include <dns/view.h>
  41
  42 /*
  43  * XXXRTH  We could use a static event...
  44  */
  45
  46 struct dns_byaddr {
  47         /* Unlocked. */
  48         unsigned int            magic;
  49         isc_mem_t *             mctx;
  50         isc_mutex_t             lock;
  51         dns_fixedname_t         name;
  52         /* Locked by lock. */
  53         unsigned int            options;
  54         dns_lookup_t *          lookup;
  55         isc_task_t *            task;
  56         dns_byaddrevent_t *     event;
  57         isc_boolean_t           canceled;
  58 };
  59
  60 #define BYADDR_MAGIC                    ISC_MAGIC('B', 'y', 'A', 'd')
  61 #define VALID_BYADDR(b)                 ISC_MAGIC_VALID(b, BYADDR_MAGIC)
  62
  63 #define MAX_RESTARTS 16
  64
  65 static char hex_digits[] = {
  66         '0', '1', '2', '3', '4', '5', '6', '7',
  67         '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
  68 };
  69
  70 isc_result_t
  71 dns_byaddr_createptrname(isc_netaddr_t *address, isc_boolean_t nibble,
  72                          dns_name_t *name)
  73 {
  74         /*
  75          * We dropped bitstring labels, so all lookups will use nibbles.
  76          */
  77         UNUSED(nibble);
  78
  79         return (dns_byaddr_createptrname2(address,
  80                                           DNS_BYADDROPT_IPV6INT, name));
  81 }
  82
  83 isc_result_t
  84 dns_byaddr_createptrname2(isc_netaddr_t *address, unsigned int options,
  85                           dns_name_t *name)
  86 {
  87         char textname[128];
  88         unsigned char *bytes;
  89         int i;
  90         char *cp;
  91         isc_buffer_t buffer;
  92         unsigned int len;
  93
  94         REQUIRE(address != NULL);
  95
  96         /*
  97          * We create the text representation and then convert to a
  98          * dns_name_t.  This is not maximally efficient, but it keeps all
  99          * of the knowledge of wire format in the dns_name_ routines.
 100          */
 101
 102         bytes = (unsigned char *)(&address->type);
 103         if (address->family == AF_INET) {
 104                 (void)snprintf(textname, sizeof(textname),
 105                                "%u.%u.%u.%u.in-addr.arpa.",
 106                                (bytes[3] & 0xff),
 107                                (bytes[2] & 0xff),
 108                                (bytes[1] & 0xff),
 109                                (bytes[0] & 0xff));
 110         } else if (address->family == AF_INET6) {
 111                 cp = textname;
 112                 for (i = 15; i >= 0; i--) {
 113                         *cp++ = hex_digits[bytes[i] & 0x0f];
 114                         *cp++ = '.';
 115                         *cp++ = hex_digits[(bytes[i] >> 4) & 0x0f];
 116                         *cp++ = '.';
 117                 }
 118                 if ((options & DNS_BYADDROPT_IPV6INT) != 0)
 119                         strcpy(cp, "ip6.int.");
 120                 else
 121                         strcpy(cp, "ip6.arpa.");
 122         } else
 123                 return (ISC_R_NOTIMPLEMENTED);
 124
 125         len = (unsigned int)strlen(textname);
 126         isc_buffer_init(&buffer, textname, len);
 127         isc_buffer_add(&buffer, len);
 128         return (dns_name_fromtext(name, &buffer, dns_rootname,
 129                                   ISC_FALSE, NULL));
 130 }
 131
 132 static inline isc_result_t
 133 copy_ptr_targets(dns_byaddr_t *byaddr, dns_rdataset_t *rdataset) {
 134         isc_result_t result;
 135         dns_name_t *name;
 136         dns_rdata_t rdata = DNS_RDATA_INIT;
 137
 138         /*
 139          * The caller must be holding the byaddr's lock.
 140          */
 141
 142         result = dns_rdataset_first(rdataset);
 143         while (result == ISC_R_SUCCESS) {
 144                 dns_rdata_ptr_t ptr;
 145                 dns_rdataset_current(rdataset, &rdata);
 146                 result = dns_rdata_tostruct(&rdata, &ptr, NULL);
 147                 if (result != ISC_R_SUCCESS)
 148                         return (result);
 149                 name = isc_mem_get(byaddr->mctx, sizeof(*name));
 150                 if (name == NULL) {
 151                         dns_rdata_freestruct(&ptr);
 152                         return (ISC_R_NOMEMORY);
 153                 }
 154                 dns_name_init(name, NULL);
 155                 result = dns_name_dup(&ptr.ptr, byaddr->mctx, name);
 156                 dns_rdata_freestruct(&ptr);
 157                 if (result != ISC_R_SUCCESS) {
 158                         isc_mem_put(byaddr->mctx, name, sizeof(*name));
 159                         return (ISC_R_NOMEMORY);
 160                 }
 161                 ISC_LIST_APPEND(byaddr->event->names, name, link);
 162                 dns_rdata_reset(&rdata);
 163                 result = dns_rdataset_next(rdataset);
 164         }
 165         if (result == ISC_R_NOMORE)
 166                 result = ISC_R_SUCCESS;
 167
 168         return (result);
 169 }
 170
 171 static void
 172 lookup_done(isc_task_t *task, isc_event_t *event) {
 173         dns_byaddr_t *byaddr = event->ev_arg;
 174         dns_lookupevent_t *levent;
 175         isc_result_t result;
 176
 177         REQUIRE(event->ev_type == DNS_EVENT_LOOKUPDONE);
 178         REQUIRE(VALID_BYADDR(byaddr));
 179         REQUIRE(byaddr->task == task);
 180
 181         UNUSED(task);
 182
 183         levent = (dns_lookupevent_t *)event;
 184
 185         if (levent->result == ISC_R_SUCCESS) {
 186                 result = copy_ptr_targets(byaddr, levent->rdataset);
 187                 byaddr->event->result = result;
 188         } else
 189                 byaddr->event->result = levent->result;
 190         isc_event_free(&event);
 191         isc_task_sendanddetach(&byaddr->task, (isc_event_t **)&byaddr->event);
 192 }
 193
 194 static void
 195 bevent_destroy(isc_event_t *event) {
 196         dns_byaddrevent_t *bevent;
 197         dns_name_t *name, *next_name;
 198         isc_mem_t *mctx;
 199
 200         REQUIRE(event->ev_type == DNS_EVENT_BYADDRDONE);
 201         mctx = event->ev_destroy_arg;
 202         bevent = (dns_byaddrevent_t *)event;
 203
 204         for (name = ISC_LIST_HEAD(bevent->names);
 205              name != NULL;
 206              name = next_name) {
 207                 next_name = ISC_LIST_NEXT(name, link);
 208                 ISC_LIST_UNLINK(bevent->names, name, link);
 209                 dns_name_free(name, mctx);
 210                 isc_mem_put(mctx, name, sizeof(*name));
 211         }
 212         isc_mem_put(mctx, event, event->ev_size);
 213 }
 214
 215 isc_result_t
 216 dns_byaddr_create(isc_mem_t *mctx, isc_netaddr_t *address, dns_view_t *view,
 217                   unsigned int options, isc_task_t *task,
 218                   isc_taskaction_t action, void *arg, dns_byaddr_t **byaddrp)
 219 {
 220         isc_result_t result;
 221         dns_byaddr_t *byaddr;
 222         isc_event_t *ievent;
 223
 224         byaddr = isc_mem_get(mctx, sizeof(*byaddr));
 225         if (byaddr == NULL)
 226                 return (ISC_R_NOMEMORY);
 227         byaddr->mctx = mctx;
 228         byaddr->options = options;
 229
 230         byaddr->event = isc_mem_get(mctx, sizeof(*byaddr->event));
 231         if (byaddr->event == NULL) {
 232                 result = ISC_R_NOMEMORY;
 233                 goto cleanup_byaddr;
 234         }
 235         ISC_EVENT_INIT(byaddr->event, sizeof(*byaddr->event), 0, NULL,
 236                        DNS_EVENT_BYADDRDONE, action, arg, byaddr,
 237                        bevent_destroy, mctx);
 238         byaddr->event->result = ISC_R_FAILURE;
 239         ISC_LIST_INIT(byaddr->event->names);
 240
 241         byaddr->task = NULL;
 242         isc_task_attach(task, &byaddr->task);
 243
 244         result = isc_mutex_init(&byaddr->lock);
 245         if (result != ISC_R_SUCCESS)
 246                 goto cleanup_event;
 247
 248         dns_fixedname_init(&byaddr->name);
 249
 250         result = dns_byaddr_createptrname2(address, options,
 251                                            dns_fixedname_name(&byaddr->name));
 252         if (result != ISC_R_SUCCESS)
 253                 goto cleanup_lock;
 254
 255         byaddr->lookup = NULL;
 256         result = dns_lookup_create(mctx, dns_fixedname_name(&byaddr->name),
 257                                    dns_rdatatype_ptr, view, 0, task,
 258                                    lookup_done, byaddr, &byaddr->lookup);
 259         if (result != ISC_R_SUCCESS)
 260                 goto cleanup_lock;
 261
 262         byaddr->canceled = ISC_FALSE;
 263         byaddr->magic = BYADDR_MAGIC;
 264
 265         *byaddrp = byaddr;
 266
 267         return (ISC_R_SUCCESS);
 268
 269  cleanup_lock:
 270         DESTROYLOCK(&byaddr->lock);
 271
 272  cleanup_event:
 273         ievent = (isc_event_t *)byaddr->event;
 274         isc_event_free(&ievent);
 275         byaddr->event = NULL;
 276
 277         isc_task_detach(&byaddr->task);
 278
 279  cleanup_byaddr:
 280         isc_mem_put(mctx, byaddr, sizeof(*byaddr));
 281
 282         return (result);
 283 }
 284
 285 void
 286 dns_byaddr_cancel(dns_byaddr_t *byaddr) {
 287         REQUIRE(VALID_BYADDR(byaddr));
 288
 289         LOCK(&byaddr->lock);
 290
 291         if (!byaddr->canceled) {
 292                 byaddr->canceled = ISC_TRUE;
 293                 if (byaddr->lookup != NULL)
 294                         dns_lookup_cancel(byaddr->lookup);
 295         }
 296
 297         UNLOCK(&byaddr->lock);
 298 }
 299
 300 void
 301 dns_byaddr_destroy(dns_byaddr_t **byaddrp) {
 302         dns_byaddr_t *byaddr;
 303
 304         REQUIRE(byaddrp != NULL);
 305         byaddr = *byaddrp;
 306         REQUIRE(VALID_BYADDR(byaddr));
 307         REQUIRE(byaddr->event == NULL);
 308         REQUIRE(byaddr->task == NULL);
 309         dns_lookup_destroy(&byaddr->lookup);
 310
 311         DESTROYLOCK(&byaddr->lock);
 312         byaddr->magic = 0;
 313         isc_mem_put(byaddr->mctx, byaddr, sizeof(*byaddr));
 314
 315         *byaddrp = NULL;
 316 }