contrib/bind9/lib/dns/xfrin.c

   1 /*
   2  * Copyright (C) 2004-2006  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 1999-2003  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: xfrin.c,v 1.135.18.11 2006/07/19 00:58:01 marka Exp $ */
  19
  20 /*! \file */
  21
  22 #include <config.h>
  23
  24 #include <isc/mem.h>
  25 #include <isc/print.h>
  26 #include <isc/random.h>
  27 #include <isc/string.h>         /* Required for HP/UX (and others?) */
  28 #include <isc/task.h>
  29 #include <isc/timer.h>
  30 #include <isc/util.h>
  31
  32 #include <dns/db.h>
  33 #include <dns/diff.h>
  34 #include <dns/events.h>
  35 #include <dns/journal.h>
  36 #include <dns/log.h>
  37 #include <dns/message.h>
  38 #include <dns/rdataclass.h>
  39 #include <dns/rdatalist.h>
  40 #include <dns/rdataset.h>
  41 #include <dns/result.h>
  42 #include <dns/soa.h>
  43 #include <dns/tcpmsg.h>
  44 #include <dns/timer.h>
  45 #include <dns/tsig.h>
  46 #include <dns/view.h>
  47 #include <dns/xfrin.h>
  48 #include <dns/zone.h>
  49
  50 #include <dst/dst.h>
  51
  52 /*
  53  * Incoming AXFR and IXFR.
  54  */
  55
  56 /*%
  57  * It would be non-sensical (or at least obtuse) to use FAIL() with an
  58  * ISC_R_SUCCESS code, but the test is there to keep the Solaris compiler
  59  * from complaining about "end-of-loop code not reached".
  60  */
  61 #define FAIL(code) \
  62         do { result = (code);                                   \
  63                 if (result != ISC_R_SUCCESS) goto failure;      \
  64         } while (0)
  65
  66 #define CHECK(op) \
  67         do { result = (op);                                     \
  68                 if (result != ISC_R_SUCCESS) goto failure;      \
  69         } while (0)
  70
  71 /*%
  72  * The states of the *XFR state machine.  We handle both IXFR and AXFR
  73  * with a single integrated state machine because they cannot be distinguished
  74  * immediately - an AXFR response to an IXFR request can only be detected
  75  * when the first two (2) response RRs have already been received.
  76  */
  77 typedef enum {
  78         XFRST_SOAQUERY,
  79         XFRST_GOTSOA,
  80         XFRST_INITIALSOA,
  81         XFRST_FIRSTDATA,
  82         XFRST_IXFR_DELSOA,
  83         XFRST_IXFR_DEL,
  84         XFRST_IXFR_ADDSOA,
  85         XFRST_IXFR_ADD,
  86         XFRST_AXFR,
  87         XFRST_END
  88 } xfrin_state_t;
  89
  90 /*%
  91  * Incoming zone transfer context.
  92  */
  93
  94 struct dns_xfrin_ctx {
  95         unsigned int            magic;
  96         isc_mem_t               *mctx;
  97         dns_zone_t              *zone;
  98
  99         int                     refcount;
 100
 101         isc_task_t              *task;
 102         isc_timer_t             *timer;
 103         isc_socketmgr_t         *socketmgr;
 104
 105         int                     connects;       /*%< Connect in progress */
 106         int                     sends;          /*%< Send in progress */
 107         int                     recvs;          /*%< Receive in progress */
 108         isc_boolean_t           shuttingdown;
 109
 110         dns_name_t              name;           /*%< Name of zone to transfer */
 111         dns_rdataclass_t        rdclass;
 112
 113         isc_boolean_t           checkid;
 114         dns_messageid_t         id;
 115
 116         /*%
 117          * Requested transfer type (dns_rdatatype_axfr or
 118          * dns_rdatatype_ixfr).  The actual transfer type
 119          * may differ due to IXFR->AXFR fallback.
 120          */
 121         dns_rdatatype_t         reqtype;
 122
 123         isc_sockaddr_t          masteraddr;
 124         isc_sockaddr_t          sourceaddr;
 125         isc_socket_t            *socket;
 126
 127         /*% Buffer for IXFR/AXFR request message */
 128         isc_buffer_t            qbuffer;
 129         unsigned char           qbuffer_data[512];
 130
 131         /*% Incoming reply TCP message */
 132         dns_tcpmsg_t            tcpmsg;
 133         isc_boolean_t           tcpmsg_valid;
 134
 135         dns_db_t                *db;
 136         dns_dbversion_t         *ver;
 137         dns_diff_t              diff;           /*%< Pending database changes */
 138         int                     difflen;        /*%< Number of pending tuples */
 139
 140         xfrin_state_t           state;
 141         isc_uint32_t            end_serial;
 142         isc_boolean_t           is_ixfr;
 143
 144         unsigned int            nmsg;           /*%< Number of messages recvd */
 145
 146         dns_tsigkey_t           *tsigkey;       /*%< Key used to create TSIG */
 147         isc_buffer_t            *lasttsig;      /*%< The last TSIG */
 148         dst_context_t           *tsigctx;       /*%< TSIG verification context */
 149         unsigned int            sincetsig;      /*%< recvd since the last TSIG */
 150         dns_xfrindone_t         done;
 151
 152         /*%
 153          * AXFR- and IXFR-specific data.  Only one is used at a time
 154          * according to the is_ixfr flag, so this could be a union,
 155          * but keeping them separate makes it a bit simpler to clean
 156          * things up when destroying the context.
 157          */
 158         struct {
 159                 dns_addrdatasetfunc_t add_func;
 160                 dns_dbload_t          *add_private;
 161         } axfr;
 162
 163         struct {
 164                 isc_uint32_t    request_serial;
 165                 isc_uint32_t    current_serial;
 166                 dns_journal_t   *journal;
 167
 168         } ixfr;
 169 };
 170
 171 #define XFRIN_MAGIC               ISC_MAGIC('X', 'f', 'r', 'I')
 172 #define VALID_XFRIN(x)            ISC_MAGIC_VALID(x, XFRIN_MAGIC)
 173
 174 /**************************************************************************/
 175 /*
 176  * Forward declarations.
 177  */
 178
 179 static isc_result_t
 180 xfrin_create(isc_mem_t *mctx,
 181              dns_zone_t *zone,
 182              dns_db_t *db,
 183              isc_task_t *task,
 184              isc_timermgr_t *timermgr,
 185              isc_socketmgr_t *socketmgr,
 186              dns_name_t *zonename,
 187              dns_rdataclass_t rdclass,
 188              dns_rdatatype_t reqtype,
 189              isc_sockaddr_t *masteraddr,
 190              isc_sockaddr_t *sourceaddr,
 191              dns_tsigkey_t *tsigkey,
 192              dns_xfrin_ctx_t **xfrp);
 193
 194 static isc_result_t axfr_init(dns_xfrin_ctx_t *xfr);
 195 static isc_result_t axfr_makedb(dns_xfrin_ctx_t *xfr, dns_db_t **dbp);
 196 static isc_result_t axfr_putdata(dns_xfrin_ctx_t *xfr, dns_diffop_t op,
 197                                    dns_name_t *name, dns_ttl_t ttl,
 198                                    dns_rdata_t *rdata);
 199 static isc_result_t axfr_apply(dns_xfrin_ctx_t *xfr);
 200 static isc_result_t axfr_commit(dns_xfrin_ctx_t *xfr);
 201
 202 static isc_result_t ixfr_init(dns_xfrin_ctx_t *xfr);
 203 static isc_result_t ixfr_apply(dns_xfrin_ctx_t *xfr);
 204 static isc_result_t ixfr_putdata(dns_xfrin_ctx_t *xfr, dns_diffop_t op,
 205                                  dns_name_t *name, dns_ttl_t ttl,
 206                                  dns_rdata_t *rdata);
 207 static isc_result_t ixfr_commit(dns_xfrin_ctx_t *xfr);
 208
 209 static isc_result_t xfr_rr(dns_xfrin_ctx_t *xfr, dns_name_t *name,
 210                            isc_uint32_t ttl, dns_rdata_t *rdata);
 211
 212 static isc_result_t xfrin_start(dns_xfrin_ctx_t *xfr);
 213
 214 static void xfrin_connect_done(isc_task_t *task, isc_event_t *event);
 215 static isc_result_t xfrin_send_request(dns_xfrin_ctx_t *xfr);
 216 static void xfrin_send_done(isc_task_t *task, isc_event_t *event);
 217 static void xfrin_sendlen_done(isc_task_t *task, isc_event_t *event);
 218 static void xfrin_recv_done(isc_task_t *task, isc_event_t *event);
 219 static void xfrin_timeout(isc_task_t *task, isc_event_t *event);
 220
 221 static void maybe_free(dns_xfrin_ctx_t *xfr);
 222
 223 static void
 224 xfrin_fail(dns_xfrin_ctx_t *xfr, isc_result_t result, const char *msg);
 225 static isc_result_t
 226 render(dns_message_t *msg, isc_mem_t *mctx, isc_buffer_t *buf);
 227
 228 static void
 229 xfrin_logv(int level, const char *zonetext, isc_sockaddr_t *masteraddr,
 230            const char *fmt, va_list ap)
 231      ISC_FORMAT_PRINTF(4, 0);
 232
 233 static void
 234 xfrin_log1(int level, const char *zonetext, isc_sockaddr_t *masteraddr,
 235            const char *fmt, ...)
 236      ISC_FORMAT_PRINTF(4, 5);
 237
 238 static void
 239 xfrin_log(dns_xfrin_ctx_t *xfr, int level, const char *fmt, ...)
 240      ISC_FORMAT_PRINTF(3, 4);
 241
 242 /**************************************************************************/
 243 /*
 244  * AXFR handling
 245  */
 246
 247 static isc_result_t
 248 axfr_init(dns_xfrin_ctx_t *xfr) {
 249         isc_result_t result;
 250
 251         xfr->is_ixfr = ISC_FALSE;
 252
 253         if (xfr->db != NULL)
 254                 dns_db_detach(&xfr->db);
 255
 256         CHECK(axfr_makedb(xfr, &xfr->db));
 257         CHECK(dns_db_beginload(xfr->db, &xfr->axfr.add_func,
 258                                &xfr->axfr.add_private));
 259         result = ISC_R_SUCCESS;
 260  failure:
 261         return (result);
 262 }
 263
 264 static isc_result_t
 265 axfr_makedb(dns_xfrin_ctx_t *xfr, dns_db_t **dbp) {
 266         return (dns_db_create(xfr->mctx, /* XXX */
 267                               "rbt", /* XXX guess */
 268                               &xfr->name,
 269                               dns_dbtype_zone,
 270                               xfr->rdclass,
 271                               0, NULL, /* XXX guess */
 272                               dbp));
 273 }
 274
 275 static isc_result_t
 276 axfr_putdata(dns_xfrin_ctx_t *xfr, dns_diffop_t op,
 277              dns_name_t *name, dns_ttl_t ttl, dns_rdata_t *rdata)
 278 {
 279         isc_result_t result;
 280
 281         dns_difftuple_t *tuple = NULL;
 282
 283         CHECK(dns_zone_checknames(xfr->zone, name, rdata));
 284         CHECK(dns_difftuple_create(xfr->diff.mctx, op,
 285                                    name, ttl, rdata, &tuple));
 286         dns_diff_append(&xfr->diff, &tuple);
 287         if (++xfr->difflen > 100)
 288                 CHECK(axfr_apply(xfr));
 289         result = ISC_R_SUCCESS;
 290  failure:
 291         return (result);
 292 }
 293
 294 /*
 295  * Store a set of AXFR RRs in the database.
 296  */
 297 static isc_result_t
 298 axfr_apply(dns_xfrin_ctx_t *xfr) {
 299         isc_result_t result;
 300
 301         CHECK(dns_diff_load(&xfr->diff,
 302                             xfr->axfr.add_func, xfr->axfr.add_private));
 303         xfr->difflen = 0;
 304         dns_diff_clear(&xfr->diff);
 305         result = ISC_R_SUCCESS;
 306  failure:
 307         return (result);
 308 }
 309
 310 static isc_result_t
 311 axfr_commit(dns_xfrin_ctx_t *xfr) {
 312         isc_result_t result;
 313
 314         CHECK(axfr_apply(xfr));
 315         CHECK(dns_db_endload(xfr->db, &xfr->axfr.add_private));
 316         CHECK(dns_zone_replacedb(xfr->zone, xfr->db, ISC_TRUE));
 317
 318         result = ISC_R_SUCCESS;
 319  failure:
 320         return (result);
 321 }
 322
 323 /**************************************************************************/
 324 /*
 325  * IXFR handling
 326  */
 327
 328 static isc_result_t
 329 ixfr_init(dns_xfrin_ctx_t *xfr) {
 330         isc_result_t result;
 331         char *journalfile;
 332
 333         if (xfr->reqtype != dns_rdatatype_ixfr) {
 334                 xfrin_log(xfr, ISC_LOG_ERROR,
 335                           "got incremental response to AXFR request");
 336                 return (DNS_R_FORMERR);
 337         }
 338
 339         xfr->is_ixfr = ISC_TRUE;
 340         INSIST(xfr->db != NULL);
 341         xfr->difflen = 0;
 342
 343         journalfile = dns_zone_getjournal(xfr->zone);
 344         if (journalfile != NULL)
 345                 CHECK(dns_journal_open(xfr->mctx, journalfile,
 346                                        ISC_TRUE, &xfr->ixfr.journal));
 347
 348         result = ISC_R_SUCCESS;
 349  failure:
 350         return (result);
 351 }
 352
 353 static isc_result_t
 354 ixfr_putdata(dns_xfrin_ctx_t *xfr, dns_diffop_t op,
 355              dns_name_t *name, dns_ttl_t ttl, dns_rdata_t *rdata)
 356 {
 357         isc_result_t result;
 358
 359         dns_difftuple_t *tuple = NULL;
 360         if (op == DNS_DIFFOP_ADD)
 361                 CHECK(dns_zone_checknames(xfr->zone, name, rdata));
 362         CHECK(dns_difftuple_create(xfr->diff.mctx, op,
 363                                    name, ttl, rdata, &tuple));
 364         dns_diff_append(&xfr->diff, &tuple);
 365         if (++xfr->difflen > 100)
 366                 CHECK(ixfr_apply(xfr));
 367         result = ISC_R_SUCCESS;
 368  failure:
 369         return (result);
 370 }
 371
 372 /*
 373  * Apply a set of IXFR changes to the database.
 374  */
 375 static isc_result_t
 376 ixfr_apply(dns_xfrin_ctx_t *xfr) {
 377         isc_result_t result;
 378
 379         if (xfr->ver == NULL) {
 380                 CHECK(dns_db_newversion(xfr->db, &xfr->ver));
 381                 if (xfr->ixfr.journal != NULL)
 382                         CHECK(dns_journal_begin_transaction(xfr->ixfr.journal));
 383         }
 384         CHECK(dns_diff_apply(&xfr->diff, xfr->db, xfr->ver));
 385         if (xfr->ixfr.journal != NULL) {
 386                 result = dns_journal_writediff(xfr->ixfr.journal, &xfr->diff);
 387                 if (result != ISC_R_SUCCESS)
 388                         goto failure;
 389         }
 390         dns_diff_clear(&xfr->diff);
 391         xfr->difflen = 0;
 392         result = ISC_R_SUCCESS;
 393  failure:
 394         return (result);
 395 }
 396
 397 static isc_result_t
 398 ixfr_commit(dns_xfrin_ctx_t *xfr) {
 399         isc_result_t result;
 400
 401         CHECK(ixfr_apply(xfr));
 402         if (xfr->ver != NULL) {
 403                 /* XXX enter ready-to-commit state here */
 404                 if (xfr->ixfr.journal != NULL)
 405                         CHECK(dns_journal_commit(xfr->ixfr.journal));
 406                 dns_db_closeversion(xfr->db, &xfr->ver, ISC_TRUE);
 407                 dns_zone_markdirty(xfr->zone);
 408         }
 409         result = ISC_R_SUCCESS;
 410  failure:
 411         return (result);
 412 }
 413
 414 /**************************************************************************/
 415 /*
 416  * Common AXFR/IXFR protocol code
 417  */
 418
 419 /*
 420  * Handle a single incoming resource record according to the current
 421  * state.
 422  */
 423 static isc_result_t
 424 xfr_rr(dns_xfrin_ctx_t *xfr, dns_name_t *name, isc_uint32_t ttl,
 425        dns_rdata_t *rdata)
 426 {
 427         isc_result_t result;
 428
 429  redo:
 430         switch (xfr->state) {
 431         case XFRST_SOAQUERY:
 432                 if (rdata->type != dns_rdatatype_soa) {
 433                         xfrin_log(xfr, ISC_LOG_ERROR,
 434                                   "non-SOA response to SOA query");
 435                         FAIL(DNS_R_FORMERR);
 436                 }
 437                 xfr->end_serial = dns_soa_getserial(rdata);
 438                 if (!DNS_SERIAL_GT(xfr->end_serial, xfr->ixfr.request_serial) &&
 439                     !dns_zone_isforced(xfr->zone)) {
 440                         xfrin_log(xfr, ISC_LOG_DEBUG(3),
 441                                   "requested serial %u, "
 442                                   "master has %u, not updating",
 443                                   xfr->ixfr.request_serial, xfr->end_serial);
 444                         FAIL(DNS_R_UPTODATE);
 445                 }
 446                 xfr->state = XFRST_GOTSOA;
 447                 break;
 448
 449         case XFRST_GOTSOA:
 450                 /*
 451                  * Skip other records in the answer section.
 452                  */
 453                 break;
 454
 455         case XFRST_INITIALSOA:
 456                 if (rdata->type != dns_rdatatype_soa) {
 457                         xfrin_log(xfr, ISC_LOG_ERROR,
 458                                   "first RR in zone transfer must be SOA");
 459                         FAIL(DNS_R_FORMERR);
 460                 }
 461                 /*
 462                  * Remember the serial number in the initial SOA.
 463                  * We need it to recognize the end of an IXFR.
 464                  */
 465                 xfr->end_serial = dns_soa_getserial(rdata);
 466                 if (xfr->reqtype == dns_rdatatype_ixfr &&
 467                     ! DNS_SERIAL_GT(xfr->end_serial, xfr->ixfr.request_serial)
 468                     && !dns_zone_isforced(xfr->zone))
 469                 {
 470                         /*
 471                          * This must be the single SOA record that is
 472                          * sent when the current version on the master
 473                          * is not newer than the version in the request.
 474                          */
 475                         xfrin_log(xfr, ISC_LOG_DEBUG(3),
 476                                   "requested serial %u, "
 477                                   "master has %u, not updating",
 478                                   xfr->ixfr.request_serial, xfr->end_serial);
 479                         FAIL(DNS_R_UPTODATE);
 480                 }
 481                 if (xfr->reqtype == dns_rdatatype_axfr)
 482                         xfr->checkid = ISC_FALSE;
 483                 xfr->state = XFRST_FIRSTDATA;
 484                 break;
 485
 486         case XFRST_FIRSTDATA:
 487                 /*
 488                  * If the transfer begins with one SOA record, it is an AXFR,
 489                  * if it begins with two SOAs, it is an IXFR.
 490                  */
 491                 if (xfr->reqtype == dns_rdatatype_ixfr &&
 492                     rdata->type == dns_rdatatype_soa &&
 493                     xfr->ixfr.request_serial == dns_soa_getserial(rdata)) {
 494                         xfrin_log(xfr, ISC_LOG_DEBUG(3),
 495                                   "got incremental response");
 496                         CHECK(ixfr_init(xfr));
 497                         xfr->state = XFRST_IXFR_DELSOA;
 498                 } else {
 499                         xfrin_log(xfr, ISC_LOG_DEBUG(3),
 500                                   "got nonincremental response");
 501                         CHECK(axfr_init(xfr));
 502                         xfr->state = XFRST_AXFR;
 503                 }
 504                 goto redo;
 505
 506         case XFRST_IXFR_DELSOA:
 507                 INSIST(rdata->type == dns_rdatatype_soa);
 508                 CHECK(ixfr_putdata(xfr, DNS_DIFFOP_DEL, name, ttl, rdata));
 509                 xfr->state = XFRST_IXFR_DEL;
 510                 break;
 511
 512         case XFRST_IXFR_DEL:
 513                 if (rdata->type == dns_rdatatype_soa) {
 514                         isc_uint32_t soa_serial = dns_soa_getserial(rdata);
 515                         xfr->state = XFRST_IXFR_ADDSOA;
 516                         xfr->ixfr.current_serial = soa_serial;
 517                         goto redo;
 518                 }
 519                 CHECK(ixfr_putdata(xfr, DNS_DIFFOP_DEL, name, ttl, rdata));
 520                 break;
 521
 522         case XFRST_IXFR_ADDSOA:
 523                 INSIST(rdata->type == dns_rdatatype_soa);
 524                 CHECK(ixfr_putdata(xfr, DNS_DIFFOP_ADD, name, ttl, rdata));
 525                 xfr->state = XFRST_IXFR_ADD;
 526                 break;
 527
 528         case XFRST_IXFR_ADD:
 529                 if (rdata->type == dns_rdatatype_soa) {
 530                         isc_uint32_t soa_serial = dns_soa_getserial(rdata);
 531                         if (soa_serial == xfr->end_serial) {
 532                                 CHECK(ixfr_commit(xfr));
 533                                 xfr->state = XFRST_END;
 534                                 break;
 535                         } else if (soa_serial != xfr->ixfr.current_serial) {
 536                                 xfrin_log(xfr, ISC_LOG_ERROR,
 537                                           "IXFR out of sync: "
 538                                           "expected serial %u, got %u",
 539                                           xfr->ixfr.current_serial, soa_serial);
 540                                 FAIL(DNS_R_FORMERR);
 541                         } else {
 542                                 CHECK(ixfr_commit(xfr));
 543                                 xfr->state = XFRST_IXFR_DELSOA;
 544                                 goto redo;
 545                         }
 546                 }
 547                 if (rdata->type == dns_rdatatype_ns &&
 548                     dns_name_iswildcard(name))
 549                         FAIL(DNS_R_INVALIDNS);
 550                 CHECK(ixfr_putdata(xfr, DNS_DIFFOP_ADD, name, ttl, rdata));
 551                 break;
 552
 553         case XFRST_AXFR:
 554                 /*
 555                  * Old BINDs sent cross class A records for non IN classes.
 556                  */
 557                 if (rdata->type == dns_rdatatype_a &&
 558                     rdata->rdclass != xfr->rdclass &&
 559                     xfr->rdclass != dns_rdataclass_in)
 560                         break;
 561                 CHECK(axfr_putdata(xfr, DNS_DIFFOP_ADD, name, ttl, rdata));
 562                 if (rdata->type == dns_rdatatype_soa) {
 563                         CHECK(axfr_commit(xfr));
 564                         xfr->state = XFRST_END;
 565                         break;
 566                 }
 567                 break;
 568         case XFRST_END:
 569                 FAIL(DNS_R_EXTRADATA);
 570         default:
 571                 INSIST(0);
 572                 break;
 573         }
 574         result = ISC_R_SUCCESS;
 575  failure:
 576         return (result);
 577 }
 578
 579 isc_result_t
 580 dns_xfrin_create(dns_zone_t *zone, dns_rdatatype_t xfrtype,
 581                  isc_sockaddr_t *masteraddr, dns_tsigkey_t *tsigkey,
 582                  isc_mem_t *mctx, isc_timermgr_t *timermgr,
 583                  isc_socketmgr_t *socketmgr, isc_task_t *task,
 584                  dns_xfrindone_t done, dns_xfrin_ctx_t **xfrp)
 585 {
 586         isc_sockaddr_t sourceaddr;
 587
 588         switch (isc_sockaddr_pf(masteraddr)) {
 589         case PF_INET:
 590                 sourceaddr = *dns_zone_getxfrsource4(zone);
 591                 break;
 592         case PF_INET6:
 593                 sourceaddr = *dns_zone_getxfrsource6(zone);
 594                 break;
 595         default:
 596                 INSIST(0);
 597         }
 598
 599         return(dns_xfrin_create2(zone, xfrtype, masteraddr, &sourceaddr,
 600                                  tsigkey, mctx, timermgr, socketmgr,
 601                                  task, done, xfrp));
 602 }
 603
 604 isc_result_t
 605 dns_xfrin_create2(dns_zone_t *zone, dns_rdatatype_t xfrtype,
 606                   isc_sockaddr_t *masteraddr, isc_sockaddr_t *sourceaddr,
 607                   dns_tsigkey_t *tsigkey, isc_mem_t *mctx,
 608                   isc_timermgr_t *timermgr, isc_socketmgr_t *socketmgr,
 609                   isc_task_t *task, dns_xfrindone_t done, dns_xfrin_ctx_t **xfrp)
 610 {
 611         dns_name_t *zonename = dns_zone_getorigin(zone);
 612         dns_xfrin_ctx_t *xfr = NULL;
 613         isc_result_t result;
 614         dns_db_t *db = NULL;
 615
 616         REQUIRE(xfrp != NULL && *xfrp == NULL);
 617
 618         (void)dns_zone_getdb(zone, &db);
 619
 620         if (xfrtype == dns_rdatatype_soa || xfrtype == dns_rdatatype_ixfr)
 621                 REQUIRE(db != NULL);
 622
 623         CHECK(xfrin_create(mctx, zone, db, task, timermgr, socketmgr, zonename,
 624                            dns_zone_getclass(zone), xfrtype, masteraddr,
 625                            sourceaddr, tsigkey, &xfr));
 626
 627         CHECK(xfrin_start(xfr));
 628
 629         xfr->done = done;
 630         xfr->refcount++;
 631         *xfrp = xfr;
 632
 633  failure:
 634         if (db != NULL)
 635                 dns_db_detach(&db);
 636         if (result != ISC_R_SUCCESS) {
 637                 char zonetext[DNS_NAME_MAXTEXT+32];
 638                 dns_zone_name(zone, zonetext, sizeof(zonetext));
 639                 xfrin_log1(ISC_LOG_ERROR, zonetext, masteraddr,
 640                            "zone transfer setup failed");
 641         }
 642         return (result);
 643 }
 644
 645 void
 646 dns_xfrin_shutdown(dns_xfrin_ctx_t *xfr) {
 647         if (! xfr->shuttingdown)
 648                 xfrin_fail(xfr, ISC_R_CANCELED, "shut down");
 649 }
 650
 651 void
 652 dns_xfrin_attach(dns_xfrin_ctx_t *source, dns_xfrin_ctx_t **target) {
 653         REQUIRE(target != NULL && *target == NULL);
 654         source->refcount++;
 655         *target = source;
 656 }
 657
 658 void
 659 dns_xfrin_detach(dns_xfrin_ctx_t **xfrp) {
 660         dns_xfrin_ctx_t *xfr = *xfrp;
 661         INSIST(xfr->refcount > 0);
 662         xfr->refcount--;
 663         maybe_free(xfr);
 664         *xfrp = NULL;
 665 }
 666
 667 static void
 668 xfrin_cancelio(dns_xfrin_ctx_t *xfr) {
 669         if (xfr->connects > 0) {
 670                 isc_socket_cancel(xfr->socket, xfr->task,
 671                                   ISC_SOCKCANCEL_CONNECT);
 672         } else if (xfr->recvs > 0) {
 673                 dns_tcpmsg_cancelread(&xfr->tcpmsg);
 674         } else if (xfr->sends > 0) {
 675                 isc_socket_cancel(xfr->socket, xfr->task,
 676                                   ISC_SOCKCANCEL_SEND);
 677         }
 678 }
 679
 680 static void
 681 xfrin_reset(dns_xfrin_ctx_t *xfr) {
 682         REQUIRE(VALID_XFRIN(xfr));
 683
 684         xfrin_log(xfr, ISC_LOG_INFO, "resetting");
 685
 686         xfrin_cancelio(xfr);
 687
 688         if (xfr->socket != NULL)
 689                 isc_socket_detach(&xfr->socket);
 690
 691         if (xfr->lasttsig != NULL)
 692                 isc_buffer_free(&xfr->lasttsig);
 693
 694         dns_diff_clear(&xfr->diff);
 695         xfr->difflen = 0;
 696
 697         if (xfr->ixfr.journal != NULL)
 698                 dns_journal_destroy(&xfr->ixfr.journal);
 699
 700         if (xfr->axfr.add_private != NULL) {
 701                 (void)dns_db_endload(xfr->db, &xfr->axfr.add_private);
 702                 xfr->axfr.add_func = NULL;
 703         }
 704
 705         if (xfr->tcpmsg_valid) {
 706                 dns_tcpmsg_invalidate(&xfr->tcpmsg);
 707                 xfr->tcpmsg_valid = ISC_FALSE;
 708         }
 709
 710         if (xfr->ver != NULL)
 711                 dns_db_closeversion(xfr->db, &xfr->ver, ISC_FALSE);
 712 }
 713
 714
 715 static void
 716 xfrin_fail(dns_xfrin_ctx_t *xfr, isc_result_t result, const char *msg) {
 717         if (result != DNS_R_UPTODATE) {
 718                 xfrin_log(xfr, ISC_LOG_ERROR, "%s: %s",
 719                           msg, isc_result_totext(result));
 720                 if (xfr->is_ixfr)
 721                         /* Pass special result code to force AXFR retry */
 722                         result = DNS_R_BADIXFR;
 723         }
 724         xfrin_cancelio(xfr);
 725         if (xfr->done != NULL) {
 726                 (xfr->done)(xfr->zone, result);
 727                 xfr->done = NULL;
 728         }
 729         xfr->shuttingdown = ISC_TRUE;
 730         maybe_free(xfr);
 731 }
 732
 733 static isc_result_t
 734 xfrin_create(isc_mem_t *mctx,
 735              dns_zone_t *zone,
 736              dns_db_t *db,
 737              isc_task_t *task,
 738              isc_timermgr_t *timermgr,
 739              isc_socketmgr_t *socketmgr,
 740              dns_name_t *zonename,
 741              dns_rdataclass_t rdclass,
 742              dns_rdatatype_t reqtype,
 743              isc_sockaddr_t *masteraddr,
 744              isc_sockaddr_t *sourceaddr,
 745              dns_tsigkey_t *tsigkey,
 746              dns_xfrin_ctx_t **xfrp)
 747 {
 748         dns_xfrin_ctx_t *xfr = NULL;
 749         isc_result_t result;
 750         isc_uint32_t tmp;
 751
 752         xfr = isc_mem_get(mctx, sizeof(*xfr));
 753         if (xfr == NULL)
 754                 return (ISC_R_NOMEMORY);
 755         xfr->mctx = mctx;
 756         xfr->refcount = 0;
 757         xfr->zone = NULL;
 758         dns_zone_iattach(zone, &xfr->zone);
 759         xfr->task = NULL;
 760         isc_task_attach(task, &xfr->task);
 761         xfr->timer = NULL;
 762         xfr->socketmgr = socketmgr;
 763         xfr->done = NULL;
 764
 765         xfr->connects = 0;
 766         xfr->sends = 0;
 767         xfr->recvs = 0;
 768         xfr->shuttingdown = ISC_FALSE;
 769
 770         dns_name_init(&xfr->name, NULL);
 771         xfr->rdclass = rdclass;
 772         isc_random_get(&tmp);
 773         xfr->checkid = ISC_TRUE;
 774         xfr->id = (isc_uint16_t)(tmp & 0xffff);
 775         xfr->reqtype = reqtype;
 776
 777         /* sockaddr */
 778         xfr->socket = NULL;
 779         /* qbuffer */
 780         /* qbuffer_data */
 781         /* tcpmsg */
 782         xfr->tcpmsg_valid = ISC_FALSE;
 783
 784         xfr->db = NULL;
 785         if (db != NULL)
 786                 dns_db_attach(db, &xfr->db);
 787         xfr->ver = NULL;
 788         dns_diff_init(xfr->mctx, &xfr->diff);
 789         xfr->difflen = 0;
 790
 791         if (reqtype == dns_rdatatype_soa)
 792                 xfr->state = XFRST_SOAQUERY;
 793         else
 794                 xfr->state = XFRST_INITIALSOA;
 795         /* end_serial */
 796
 797         xfr->nmsg = 0;
 798
 799         xfr->tsigkey = NULL;
 800         if (tsigkey != NULL)
 801                 dns_tsigkey_attach(tsigkey, &xfr->tsigkey);
 802         xfr->lasttsig = NULL;
 803         xfr->tsigctx = NULL;
 804         xfr->sincetsig = 0;
 805         xfr->is_ixfr = ISC_FALSE;
 806
 807         /* ixfr.request_serial */
 808         /* ixfr.current_serial */
 809         xfr->ixfr.journal = NULL;
 810
 811         xfr->axfr.add_func = NULL;
 812         xfr->axfr.add_private = NULL;
 813
 814         CHECK(dns_name_dup(zonename, mctx, &xfr->name));
 815
 816         CHECK(isc_timer_create(timermgr, isc_timertype_inactive, NULL, NULL,
 817                                task, xfrin_timeout, xfr, &xfr->timer));
 818         CHECK(dns_timer_setidle(xfr->timer,
 819                                 dns_zone_getmaxxfrin(xfr->zone),
 820                                 dns_zone_getidlein(xfr->zone),
 821                                 ISC_FALSE));
 822
 823         xfr->masteraddr = *masteraddr;
 824
 825         INSIST(isc_sockaddr_pf(masteraddr) == isc_sockaddr_pf(sourceaddr));
 826         xfr->sourceaddr = *sourceaddr;
 827         isc_sockaddr_setport(&xfr->sourceaddr, 0);
 828
 829         isc_buffer_init(&xfr->qbuffer, xfr->qbuffer_data,
 830                         sizeof(xfr->qbuffer_data));
 831
 832         xfr->magic = XFRIN_MAGIC;
 833         *xfrp = xfr;
 834         return (ISC_R_SUCCESS);
 835
 836  failure:
 837         if (xfr->timer != NULL)
 838                 isc_timer_detach(&xfr->timer);
 839         if (dns_name_dynamic(&xfr->name))
 840                 dns_name_free(&xfr->name, xfr->mctx);
 841         if (xfr->tsigkey != NULL)
 842                 dns_tsigkey_detach(&xfr->tsigkey);
 843         if (xfr->db != NULL)
 844                 dns_db_detach(&xfr->db);
 845         isc_task_detach(&xfr->task);
 846         dns_zone_idetach(&xfr->zone);
 847         isc_mem_put(mctx, xfr, sizeof(*xfr));
 848
 849         return (result);
 850 }
 851
 852 static isc_result_t
 853 xfrin_start(dns_xfrin_ctx_t *xfr) {
 854         isc_result_t result;
 855         CHECK(isc_socket_create(xfr->socketmgr,
 856                                 isc_sockaddr_pf(&xfr->sourceaddr),
 857                                 isc_sockettype_tcp,
 858                                 &xfr->socket));
 859 #ifndef BROKEN_TCP_BIND_BEFORE_CONNECT
 860         CHECK(isc_socket_bind(xfr->socket, &xfr->sourceaddr));
 861 #endif
 862         CHECK(isc_socket_connect(xfr->socket, &xfr->masteraddr, xfr->task,
 863                                  xfrin_connect_done, xfr));
 864         xfr->connects++;
 865         return (ISC_R_SUCCESS);
 866  failure:
 867         xfrin_fail(xfr, result, "failed setting up socket");
 868         return (result);
 869 }
 870
 871 /* XXX the resolver could use this, too */
 872
 873 static isc_result_t
 874 render(dns_message_t *msg, isc_mem_t *mctx, isc_buffer_t *buf) {
 875         dns_compress_t cctx;
 876         isc_boolean_t cleanup_cctx = ISC_FALSE;
 877         isc_result_t result;
 878
 879         CHECK(dns_compress_init(&cctx, -1, mctx));
 880         cleanup_cctx = ISC_TRUE;
 881         CHECK(dns_message_renderbegin(msg, &cctx, buf));
 882         CHECK(dns_message_rendersection(msg, DNS_SECTION_QUESTION, 0));
 883         CHECK(dns_message_rendersection(msg, DNS_SECTION_ANSWER, 0));
 884         CHECK(dns_message_rendersection(msg, DNS_SECTION_AUTHORITY, 0));
 885         CHECK(dns_message_rendersection(msg, DNS_SECTION_ADDITIONAL, 0));
 886         CHECK(dns_message_renderend(msg));
 887         result = ISC_R_SUCCESS;
 888  failure:
 889         if (cleanup_cctx)
 890                 dns_compress_invalidate(&cctx);
 891         return (result);
 892 }
 893
 894 /*
 895  * A connection has been established.
 896  */
 897 static void
 898 xfrin_connect_done(isc_task_t *task, isc_event_t *event) {
 899         isc_socket_connev_t *cev = (isc_socket_connev_t *) event;
 900         dns_xfrin_ctx_t *xfr = (dns_xfrin_ctx_t *) event->ev_arg;
 901         isc_result_t evresult = cev->result;
 902         isc_result_t result;
 903         char sourcetext[ISC_SOCKADDR_FORMATSIZE];
 904         isc_sockaddr_t sockaddr;
 905
 906         REQUIRE(VALID_XFRIN(xfr));
 907
 908         UNUSED(task);
 909
 910         INSIST(event->ev_type == ISC_SOCKEVENT_CONNECT);
 911         isc_event_free(&event);
 912
 913         xfr->connects--;
 914         if (xfr->shuttingdown) {
 915                 maybe_free(xfr);
 916                 return;
 917         }
 918
 919         CHECK(evresult);
 920         result = isc_socket_getsockname(xfr->socket, &sockaddr);
 921         if (result == ISC_R_SUCCESS) {
 922                 isc_sockaddr_format(&sockaddr, sourcetext, sizeof(sourcetext));
 923         } else
 924                 strcpy(sourcetext, "<UNKNOWN>");
 925         xfrin_log(xfr, ISC_LOG_INFO, "connected using %s", sourcetext);
 926
 927         dns_tcpmsg_init(xfr->mctx, xfr->socket, &xfr->tcpmsg);
 928         xfr->tcpmsg_valid = ISC_TRUE;
 929
 930         CHECK(xfrin_send_request(xfr));
 931  failure:
 932         if (result != ISC_R_SUCCESS)
 933                 xfrin_fail(xfr, result, "failed to connect");
 934 }
 935
 936 /*
 937  * Convert a tuple into a dns_name_t suitable for inserting
 938  * into the given dns_message_t.
 939  */
 940 static isc_result_t
 941 tuple2msgname(dns_difftuple_t *tuple, dns_message_t *msg, dns_name_t **target)
 942 {
 943         isc_result_t result;
 944         dns_rdata_t *rdata = NULL;
 945         dns_rdatalist_t *rdl = NULL;
 946         dns_rdataset_t *rds = NULL;
 947         dns_name_t *name = NULL;
 948
 949         REQUIRE(target != NULL && *target == NULL);
 950
 951         CHECK(dns_message_gettemprdata(msg, &rdata));
 952         dns_rdata_init(rdata);
 953         dns_rdata_clone(&tuple->rdata, rdata);
 954
 955         CHECK(dns_message_gettemprdatalist(msg, &rdl));
 956         dns_rdatalist_init(rdl);
 957         rdl->type = tuple->rdata.type;
 958         rdl->rdclass = tuple->rdata.rdclass;
 959         rdl->ttl = tuple->ttl;
 960         ISC_LIST_APPEND(rdl->rdata, rdata, link);
 961
 962         CHECK(dns_message_gettemprdataset(msg, &rds));
 963         dns_rdataset_init(rds);
 964         CHECK(dns_rdatalist_tordataset(rdl, rds));
 965
 966         CHECK(dns_message_gettempname(msg, &name));
 967         dns_name_init(name, NULL);
 968         dns_name_clone(&tuple->name, name);
 969         ISC_LIST_APPEND(name->list, rds, link);
 970
 971         *target = name;
 972         return (ISC_R_SUCCESS);
 973
 974  failure:
 975
 976         if (rds != NULL) {
 977                 dns_rdataset_disassociate(rds);
 978                 dns_message_puttemprdataset(msg, &rds);
 979         }
 980         if (rdl != NULL) {
 981                 ISC_LIST_UNLINK(rdl->rdata, rdata, link);
 982                 dns_message_puttemprdatalist(msg, &rdl);
 983         }
 984         if (rdata != NULL)
 985                 dns_message_puttemprdata(msg, &rdata);
 986
 987         return (result);
 988 }
 989
 990
 991 /*
 992  * Build an *XFR request and send its length prefix.
 993  */
 994 static isc_result_t
 995 xfrin_send_request(dns_xfrin_ctx_t *xfr) {
 996         isc_result_t result;
 997         isc_region_t region;
 998         isc_region_t lregion;
 999         dns_rdataset_t *qrdataset = NULL;
1000         dns_message_t *msg = NULL;
1001         unsigned char length[2];
1002         dns_difftuple_t *soatuple = NULL;
1003         dns_name_t *qname = NULL;
1004         dns_dbversion_t *ver = NULL;
1005         dns_name_t *msgsoaname = NULL;
1006
1007         /* Create the request message */
1008         CHECK(dns_message_create(xfr->mctx, DNS_MESSAGE_INTENTRENDER, &msg));
1009         CHECK(dns_message_settsigkey(msg, xfr->tsigkey));
1010
1011         /* Create a name for the question section. */
1012         CHECK(dns_message_gettempname(msg, &qname));
1013         dns_name_init(qname, NULL);
1014         dns_name_clone(&xfr->name, qname);
1015
1016         /* Formulate the question and attach it to the question name. */
1017         CHECK(dns_message_gettemprdataset(msg, &qrdataset));
1018         dns_rdataset_init(qrdataset);
1019         dns_rdataset_makequestion(qrdataset, xfr->rdclass, xfr->reqtype);
1020         ISC_LIST_APPEND(qname->list, qrdataset, link);
1021         qrdataset = NULL;
1022
1023         dns_message_addname(msg, qname, DNS_SECTION_QUESTION);
1024         qname = NULL;
1025
1026         if (xfr->reqtype == dns_rdatatype_ixfr) {
1027                 /* Get the SOA and add it to the authority section. */
1028                 /* XXX is using the current version the right thing? */
1029                 dns_db_currentversion(xfr->db, &ver);
1030                 CHECK(dns_db_createsoatuple(xfr->db, ver, xfr->mctx,
1031                                             DNS_DIFFOP_EXISTS, &soatuple));
1032                 xfr->ixfr.request_serial = dns_soa_getserial(&soatuple->rdata);
1033                 xfr->ixfr.current_serial = xfr->ixfr.request_serial;
1034                 xfrin_log(xfr, ISC_LOG_DEBUG(3),
1035                           "requesting IXFR for serial %u",
1036                           xfr->ixfr.request_serial);
1037
1038                 CHECK(tuple2msgname(soatuple, msg, &msgsoaname));
1039                 dns_message_addname(msg, msgsoaname, DNS_SECTION_AUTHORITY);
1040         } else if (xfr->reqtype == dns_rdatatype_soa)
1041                 CHECK(dns_db_getsoaserial(xfr->db, NULL,
1042                                           &xfr->ixfr.request_serial));
1043
1044         xfr->checkid = ISC_TRUE;
1045         xfr->id++;
1046         msg->id = xfr->id;
1047
1048         CHECK(render(msg, xfr->mctx, &xfr->qbuffer));
1049
1050         /*
1051          * Free the last tsig, if there is one.
1052          */
1053         if (xfr->lasttsig != NULL)
1054                 isc_buffer_free(&xfr->lasttsig);
1055
1056         /*
1057          * Save the query TSIG and don't let message_destroy free it.
1058          */
1059         CHECK(dns_message_getquerytsig(msg, xfr->mctx, &xfr->lasttsig));
1060
1061         isc_buffer_usedregion(&xfr->qbuffer, &region);
1062         INSIST(region.length <= 65535);
1063
1064         length[0] = region.length >> 8;
1065         length[1] = region.length & 0xFF;
1066         lregion.base = length;
1067         lregion.length = 2;
1068         CHECK(isc_socket_send(xfr->socket, &lregion, xfr->task,
1069                               xfrin_sendlen_done, xfr));
1070         xfr->sends++;
1071
1072  failure:
1073         if (qname != NULL)
1074                 dns_message_puttempname(msg, &qname);
1075         if (qrdataset != NULL)
1076                 dns_message_puttemprdataset(msg, &qrdataset);
1077         if (msg != NULL)
1078                 dns_message_destroy(&msg);
1079         if (soatuple != NULL)
1080                 dns_difftuple_free(&soatuple);
1081         if (ver != NULL)
1082                 dns_db_closeversion(xfr->db, &ver, ISC_FALSE);
1083         return (result);
1084 }
1085
1086 /* XXX there should be library support for sending DNS TCP messages */
1087
1088 static void
1089 xfrin_sendlen_done(isc_task_t *task, isc_event_t *event) {
1090         isc_socketevent_t *sev = (isc_socketevent_t *) event;
1091         dns_xfrin_ctx_t *xfr = (dns_xfrin_ctx_t *) event->ev_arg;
1092         isc_result_t evresult = sev->result;
1093         isc_result_t result;
1094         isc_region_t region;
1095
1096         REQUIRE(VALID_XFRIN(xfr));
1097
1098         UNUSED(task);
1099
1100         INSIST(event->ev_type == ISC_SOCKEVENT_SENDDONE);
1101         isc_event_free(&event);
1102
1103         xfr->sends--;
1104         if (xfr->shuttingdown) {
1105                 maybe_free(xfr);
1106                 return;
1107         }
1108
1109         xfrin_log(xfr, ISC_LOG_DEBUG(3), "sent request length prefix");
1110         CHECK(evresult);
1111
1112         isc_buffer_usedregion(&xfr->qbuffer, &region);
1113         CHECK(isc_socket_send(xfr->socket, &region, xfr->task,
1114                               xfrin_send_done, xfr));
1115         xfr->sends++;
1116  failure:
1117         if (result != ISC_R_SUCCESS)
1118                 xfrin_fail(xfr, result, "failed sending request length prefix");
1119 }
1120
1121
1122 static void
1123 xfrin_send_done(isc_task_t *task, isc_event_t *event) {
1124         isc_socketevent_t *sev = (isc_socketevent_t *) event;
1125         dns_xfrin_ctx_t *xfr = (dns_xfrin_ctx_t *) event->ev_arg;
1126         isc_result_t result;
1127
1128         REQUIRE(VALID_XFRIN(xfr));
1129
1130         UNUSED(task);
1131
1132         INSIST(event->ev_type == ISC_SOCKEVENT_SENDDONE);
1133
1134         xfr->sends--;
1135         xfrin_log(xfr, ISC_LOG_DEBUG(3), "sent request data");
1136         CHECK(sev->result);
1137
1138         CHECK(dns_tcpmsg_readmessage(&xfr->tcpmsg, xfr->task,
1139                                      xfrin_recv_done, xfr));
1140         xfr->recvs++;
1141  failure:
1142         isc_event_free(&event);
1143         if (result != ISC_R_SUCCESS)
1144                 xfrin_fail(xfr, result, "failed sending request data");
1145 }
1146
1147
1148 static void
1149 xfrin_recv_done(isc_task_t *task, isc_event_t *ev) {
1150         dns_xfrin_ctx_t *xfr = (dns_xfrin_ctx_t *) ev->ev_arg;
1151         isc_result_t result;
1152         dns_message_t *msg = NULL;
1153         dns_name_t *name;
1154         dns_tcpmsg_t *tcpmsg;
1155         dns_name_t *tsigowner = NULL;
1156
1157         REQUIRE(VALID_XFRIN(xfr));
1158
1159         UNUSED(task);
1160
1161         INSIST(ev->ev_type == DNS_EVENT_TCPMSG);
1162         tcpmsg = ev->ev_sender;
1163         isc_event_free(&ev);
1164
1165         xfr->recvs--;
1166         if (xfr->shuttingdown) {
1167                 maybe_free(xfr);
1168                 return;
1169         }
1170
1171         CHECK(tcpmsg->result);
1172
1173         xfrin_log(xfr, ISC_LOG_DEBUG(7), "received %u bytes",
1174                   tcpmsg->buffer.used);
1175
1176         CHECK(isc_timer_touch(xfr->timer));
1177
1178         CHECK(dns_message_create(xfr->mctx, DNS_MESSAGE_INTENTPARSE, &msg));
1179
1180         CHECK(dns_message_settsigkey(msg, xfr->tsigkey));
1181         CHECK(dns_message_setquerytsig(msg, xfr->lasttsig));
1182         msg->tsigctx = xfr->tsigctx;
1183         if (xfr->nmsg > 0)
1184                 msg->tcp_continuation = 1;
1185
1186         result = dns_message_parse(msg, &tcpmsg->buffer,
1187                                    DNS_MESSAGEPARSE_PRESERVEORDER);
1188
1189         if (result != ISC_R_SUCCESS || msg->rcode != dns_rcode_noerror ||
1190             (xfr->checkid && msg->id != xfr->id)) {
1191                 if (result == ISC_R_SUCCESS)
1192                         result = ISC_RESULTCLASS_DNSRCODE + msg->rcode; /*XXX*/
1193                 if (result == ISC_R_SUCCESS || result == DNS_R_NOERROR)
1194                         result = DNS_R_UNEXPECTEDID;
1195                 if (xfr->reqtype == dns_rdatatype_axfr ||
1196                     xfr->reqtype == dns_rdatatype_soa)
1197                         FAIL(result);
1198                 xfrin_log(xfr, ISC_LOG_DEBUG(3), "got %s, retrying with AXFR",
1199                        isc_result_totext(result));
1200  try_axfr:
1201                 dns_message_destroy(&msg);
1202                 xfrin_reset(xfr);
1203                 xfr->reqtype = dns_rdatatype_soa;
1204                 xfr->state = XFRST_SOAQUERY;
1205                 (void)xfrin_start(xfr);
1206                 return;
1207         }
1208
1209         /*
1210          * Does the server know about IXFR?  If it doesn't we will get
1211          * a message with a empty answer section or a potentially a CNAME /
1212          * DNAME, the later is handled by xfr_rr() which will return FORMERR
1213          * if the first RR in the answer section is not a SOA record.
1214          */
1215         if (xfr->reqtype == dns_rdatatype_ixfr &&
1216             xfr->state == XFRST_INITIALSOA &&
1217             msg->counts[DNS_SECTION_ANSWER] == 0) {
1218                 xfrin_log(xfr, ISC_LOG_DEBUG(3),
1219                           "empty answer section, retrying with AXFR");
1220                 goto try_axfr;
1221         }
1222
1223         if (xfr->reqtype == dns_rdatatype_soa &&
1224             (msg->flags & DNS_MESSAGEFLAG_AA) == 0) {
1225                 FAIL(DNS_R_NOTAUTHORITATIVE);
1226         }
1227
1228
1229         result = dns_message_checksig(msg, dns_zone_getview(xfr->zone));
1230         if (result != ISC_R_SUCCESS) {
1231                 xfrin_log(xfr, ISC_LOG_DEBUG(3), "TSIG check failed: %s",
1232                        isc_result_totext(result));
1233                 FAIL(result);
1234         }
1235
1236         for (result = dns_message_firstname(msg, DNS_SECTION_ANSWER);
1237              result == ISC_R_SUCCESS;
1238              result = dns_message_nextname(msg, DNS_SECTION_ANSWER))
1239         {
1240                 dns_rdataset_t *rds;
1241
1242                 name = NULL;
1243                 dns_message_currentname(msg, DNS_SECTION_ANSWER, &name);
1244                 for (rds = ISC_LIST_HEAD(name->list);
1245                      rds != NULL;
1246                      rds = ISC_LIST_NEXT(rds, link))
1247                 {
1248                         for (result = dns_rdataset_first(rds);
1249                              result == ISC_R_SUCCESS;
1250                              result = dns_rdataset_next(rds))
1251                         {
1252                                 dns_rdata_t rdata = DNS_RDATA_INIT;
1253                                 dns_rdataset_current(rds, &rdata);
1254                                 CHECK(xfr_rr(xfr, name, rds->ttl, &rdata));
1255                         }
1256                 }
1257         }
1258         if (result != ISC_R_NOMORE)
1259                 goto failure;
1260
1261         if (dns_message_gettsig(msg, &tsigowner) != NULL) {
1262                 /*
1263                  * Reset the counter.
1264                  */
1265                 xfr->sincetsig = 0;
1266
1267                 /*
1268                  * Free the last tsig, if there is one.
1269                  */
1270                 if (xfr->lasttsig != NULL)
1271                         isc_buffer_free(&xfr->lasttsig);
1272
1273                 /*
1274                  * Update the last tsig pointer.
1275                  */
1276                 CHECK(dns_message_getquerytsig(msg, xfr->mctx,
1277                                                &xfr->lasttsig));
1278
1279         } else if (dns_message_gettsigkey(msg) != NULL) {
1280                 xfr->sincetsig++;
1281                 if (xfr->sincetsig > 100 ||
1282                     xfr->nmsg == 0 || xfr->state == XFRST_END)
1283                 {
1284                         result = DNS_R_EXPECTEDTSIG;
1285                         goto failure;
1286                 }
1287         }
1288
1289         /*
1290          * Update the number of messages received.
1291          */
1292         xfr->nmsg++;
1293
1294         /*
1295          * Copy the context back.
1296          */
1297         xfr->tsigctx = msg->tsigctx;
1298
1299         dns_message_destroy(&msg);
1300
1301         if (xfr->state == XFRST_GOTSOA) {
1302                 xfr->reqtype = dns_rdatatype_axfr;
1303                 xfr->state = XFRST_INITIALSOA;
1304                 CHECK(xfrin_send_request(xfr));
1305         } else if (xfr->state == XFRST_END) {
1306                 /*
1307                  * Inform the caller we succeeded.
1308                  */
1309                 if (xfr->done != NULL) {
1310                         (xfr->done)(xfr->zone, ISC_R_SUCCESS);
1311                         xfr->done = NULL;
1312                 }
1313                 /*
1314                  * We should have no outstanding events at this
1315                  * point, thus maybe_free() should succeed.
1316                  */
1317                 xfr->shuttingdown = ISC_TRUE;
1318                 maybe_free(xfr);
1319         } else {
1320                 /*
1321                  * Read the next message.
1322                  */
1323                 CHECK(dns_tcpmsg_readmessage(&xfr->tcpmsg, xfr->task,
1324                                              xfrin_recv_done, xfr));
1325                 xfr->recvs++;
1326         }
1327         return;
1328
1329  failure:
1330         if (msg != NULL)
1331                 dns_message_destroy(&msg);
1332         if (result != ISC_R_SUCCESS)
1333                 xfrin_fail(xfr, result, "failed while receiving responses");
1334 }
1335
1336 static void
1337 xfrin_timeout(isc_task_t *task, isc_event_t *event) {
1338         dns_xfrin_ctx_t *xfr = (dns_xfrin_ctx_t *) event->ev_arg;
1339
1340         REQUIRE(VALID_XFRIN(xfr));
1341
1342         UNUSED(task);
1343
1344         isc_event_free(&event);
1345         /*
1346          * This will log "giving up: timeout".
1347          */
1348         xfrin_fail(xfr, ISC_R_TIMEDOUT, "giving up");
1349 }
1350
1351 static void
1352 maybe_free(dns_xfrin_ctx_t *xfr) {
1353         REQUIRE(VALID_XFRIN(xfr));
1354
1355         if (! xfr->shuttingdown || xfr->refcount != 0 ||
1356             xfr->connects != 0 || xfr->sends != 0 ||
1357             xfr->recvs != 0)
1358                 return;
1359
1360         xfrin_log(xfr, ISC_LOG_INFO, "end of transfer");
1361
1362         if (xfr->socket != NULL)
1363                 isc_socket_detach(&xfr->socket);
1364
1365         if (xfr->timer != NULL)
1366                 isc_timer_detach(&xfr->timer);
1367
1368         if (xfr->task != NULL)
1369                 isc_task_detach(&xfr->task);
1370
1371         if (xfr->tsigkey != NULL)
1372                 dns_tsigkey_detach(&xfr->tsigkey);
1373
1374         if (xfr->lasttsig != NULL)
1375                 isc_buffer_free(&xfr->lasttsig);
1376
1377         dns_diff_clear(&xfr->diff);
1378
1379         if (xfr->ixfr.journal != NULL)
1380                 dns_journal_destroy(&xfr->ixfr.journal);
1381
1382         if (xfr->axfr.add_private != NULL)
1383                 (void)dns_db_endload(xfr->db, &xfr->axfr.add_private);
1384
1385         if (xfr->tcpmsg_valid)
1386                 dns_tcpmsg_invalidate(&xfr->tcpmsg);
1387
1388         if ((xfr->name.attributes & DNS_NAMEATTR_DYNAMIC) != 0)
1389                 dns_name_free(&xfr->name, xfr->mctx);
1390
1391         if (xfr->ver != NULL)
1392                 dns_db_closeversion(xfr->db, &xfr->ver, ISC_FALSE);
1393
1394         if (xfr->db != NULL)
1395                 dns_db_detach(&xfr->db);
1396
1397         if (xfr->zone != NULL)
1398                 dns_zone_idetach(&xfr->zone);
1399
1400         isc_mem_put(xfr->mctx, xfr, sizeof(*xfr));
1401 }
1402
1403 /*
1404  * Log incoming zone transfer messages in a format like
1405  * transfer of <zone> from <address>: <message>
1406  */
1407 static void
1408 xfrin_logv(int level, const char *zonetext, isc_sockaddr_t *masteraddr,
1409            const char *fmt, va_list ap)
1410 {
1411         char mastertext[ISC_SOCKADDR_FORMATSIZE];
1412         char msgtext[2048];
1413
1414         isc_sockaddr_format(masteraddr, mastertext, sizeof(mastertext));
1415         vsnprintf(msgtext, sizeof(msgtext), fmt, ap);
1416
1417         isc_log_write(dns_lctx, DNS_LOGCATEGORY_XFER_IN,
1418                       DNS_LOGMODULE_XFER_IN, level,
1419                       "transfer of '%s' from %s: %s",
1420                       zonetext, mastertext, msgtext);
1421 }
1422
1423 /*
1424  * Logging function for use when a xfrin_ctx_t has not yet been created.
1425  */
1426
1427 static void
1428 xfrin_log1(int level, const char *zonetext, isc_sockaddr_t *masteraddr,
1429            const char *fmt, ...)
1430 {
1431         va_list ap;
1432
1433         if (isc_log_wouldlog(dns_lctx, level) == ISC_FALSE)
1434                 return;
1435
1436         va_start(ap, fmt);
1437         xfrin_logv(level, zonetext, masteraddr, fmt, ap);
1438         va_end(ap);
1439 }
1440
1441 /*
1442  * Logging function for use when there is a xfrin_ctx_t.
1443  */
1444
1445 static void
1446 xfrin_log(dns_xfrin_ctx_t *xfr, int level, const char *fmt, ...)
1447 {
1448         va_list ap;
1449         char zonetext[DNS_NAME_MAXTEXT+32];
1450
1451         if (isc_log_wouldlog(dns_lctx, level) == ISC_FALSE)
1452                 return;
1453
1454         dns_zone_name(xfr->zone, zonetext, sizeof(zonetext));
1455
1456         va_start(ap, fmt);
1457         xfrin_logv(level, zonetext, &xfr->masteraddr, fmt, ap);
1458         va_end(ap);
1459 }