journal.c revision 174188
1/* 2 * Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC") 3 * Copyright (C) 1999-2002 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: journal.c,v 1.86.18.12 2007/09/07 05:21:41 marka Exp $ */ 19 20#include <config.h> 21 22#include <stdlib.h> 23#include <unistd.h> 24#include <errno.h> 25 26#include <isc/file.h> 27#include <isc/mem.h> 28#include <isc/stdio.h> 29#include <isc/string.h> 30#include <isc/util.h> 31 32#include <dns/compress.h> 33#include <dns/db.h> 34#include <dns/dbiterator.h> 35#include <dns/diff.h> 36#include <dns/fixedname.h> 37#include <dns/journal.h> 38#include <dns/log.h> 39#include <dns/rdataset.h> 40#include <dns/rdatasetiter.h> 41#include <dns/result.h> 42#include <dns/soa.h> 43 44/*! \file 45 * \brief Journalling. 46 * 47 * A journal file consists of 48 * 49 * \li A fixed-size header of type journal_rawheader_t. 50 * 51 * \li The index. This is an unordered array of index entries 52 * of type journal_rawpos_t giving the locations 53 * of some arbitrary subset of the journal's addressable 54 * transactions. The index entries are used as hints to 55 * speed up the process of locating a transaction with a given 56 * serial number. Unused index entries have an "offset" 57 * field of zero. The size of the index can vary between 58 * journal files, but does not change during the lifetime 59 * of a file. The size can be zero. 60 * 61 * \li The journal data. This consists of one or more transactions. 62 * Each transaction begins with a transaction header of type 63 * journal_rawxhdr_t. The transaction header is followed by a 64 * sequence of RRs, similar in structure to an IXFR difference 65 * sequence (RFC1995). That is, the pre-transaction SOA, 66 * zero or more other deleted RRs, the post-transaction SOA, 67 * and zero or more other added RRs. Unlike in IXFR, each RR 68 * is prefixed with a 32-bit length. 69 * 70 * The journal data part grows as new transactions are 71 * appended to the file. Only those transactions 72 * whose serial number is current-(2^31-1) to current 73 * are considered "addressable" and may be pointed 74 * to from the header or index. They may be preceded 75 * by old transactions that are no longer addressable, 76 * and they may be followed by transactions that were 77 * appended to the journal but never committed by updating 78 * the "end" position in the header. The latter will 79 * be overwritten when new transactions are added. 80 */ 81/*% 82 * When true, accept IXFR difference sequences where the 83 * SOA serial number does not change (BIND 8 sends such 84 * sequences). 85 */ 86static isc_boolean_t bind8_compat = ISC_TRUE; /* XXX config */ 87 88/**************************************************************************/ 89/* 90 * Miscellaneous utilities. 91 */ 92 93#define JOURNAL_COMMON_LOGARGS \ 94 dns_lctx, DNS_LOGCATEGORY_GENERAL, DNS_LOGMODULE_JOURNAL 95 96#define JOURNAL_DEBUG_LOGARGS(n) \ 97 JOURNAL_COMMON_LOGARGS, ISC_LOG_DEBUG(n) 98 99/*% 100 * It would be non-sensical (or at least obtuse) to use FAIL() with an 101 * ISC_R_SUCCESS code, but the test is there to keep the Solaris compiler 102 * from complaining about "end-of-loop code not reached". 103 */ 104#define FAIL(code) \ 105 do { result = (code); \ 106 if (result != ISC_R_SUCCESS) goto failure; \ 107 } while (0) 108 109#define CHECK(op) \ 110 do { result = (op); \ 111 if (result != ISC_R_SUCCESS) goto failure; \ 112 } while (0) 113 114static isc_result_t index_to_disk(dns_journal_t *); 115 116static inline isc_uint32_t 117decode_uint32(unsigned char *p) { 118 return ((p[0] << 24) + 119 (p[1] << 16) + 120 (p[2] << 8) + 121 (p[3] << 0)); 122} 123 124static inline void 125encode_uint32(isc_uint32_t val, unsigned char *p) { 126 p[0] = (isc_uint8_t)(val >> 24); 127 p[1] = (isc_uint8_t)(val >> 16); 128 p[2] = (isc_uint8_t)(val >> 8); 129 p[3] = (isc_uint8_t)(val >> 0); 130} 131 132isc_result_t 133dns_db_createsoatuple(dns_db_t *db, dns_dbversion_t *ver, isc_mem_t *mctx, 134 dns_diffop_t op, dns_difftuple_t **tp) 135{ 136 isc_result_t result; 137 dns_dbnode_t *node; 138 dns_rdataset_t rdataset; 139 dns_rdata_t rdata = DNS_RDATA_INIT; 140 dns_name_t *zonename; 141 142 zonename = dns_db_origin(db); 143 144 node = NULL; 145 result = dns_db_findnode(db, zonename, ISC_FALSE, &node); 146 if (result != ISC_R_SUCCESS) 147 goto nonode; 148 149 dns_rdataset_init(&rdataset); 150 result = dns_db_findrdataset(db, node, ver, dns_rdatatype_soa, 0, 151 (isc_stdtime_t)0, &rdataset, NULL); 152 if (result != ISC_R_SUCCESS) 153 goto freenode; 154 155 result = dns_rdataset_first(&rdataset); 156 if (result != ISC_R_SUCCESS) 157 goto freenode; 158 159 dns_rdataset_current(&rdataset, &rdata); 160 161 result = dns_difftuple_create(mctx, op, zonename, rdataset.ttl, 162 &rdata, tp); 163 164 dns_rdataset_disassociate(&rdataset); 165 dns_db_detachnode(db, &node); 166 return (ISC_R_SUCCESS); 167 168 freenode: 169 dns_db_detachnode(db, &node); 170 nonode: 171 UNEXPECTED_ERROR(__FILE__, __LINE__, "missing SOA"); 172 return (result); 173} 174 175/* Journalling */ 176 177/*% 178 * On-disk representation of a "pointer" to a journal entry. 179 * These are used in the journal header to locate the beginning 180 * and end of the journal, and in the journal index to locate 181 * other transactions. 182 */ 183typedef struct { 184 unsigned char serial[4]; /*%< SOA serial before update. */ 185 /* 186 * XXXRTH Should offset be 8 bytes? 187 * XXXDCL ... probably, since isc_offset_t is 8 bytes on many OSs. 188 * XXXAG ... but we will not be able to seek >2G anyway on many 189 * platforms as long as we are using fseek() rather 190 * than lseek(). 191 */ 192 unsigned char offset[4]; /*%< Offset from beginning of file. */ 193} journal_rawpos_t; 194 195 196/*% 197 * The header is of a fixed size, with some spare room for future 198 * extensions. 199 */ 200#define JOURNAL_HEADER_SIZE 64 /* Bytes. */ 201 202/*% 203 * The on-disk representation of the journal header. 204 * All numbers are stored in big-endian order. 205 */ 206typedef union { 207 struct { 208 /*% File format version ID. */ 209 unsigned char format[16]; 210 /*% Position of the first addressable transaction */ 211 journal_rawpos_t begin; 212 /*% Position of the next (yet nonexistent) transaction. */ 213 journal_rawpos_t end; 214 /*% Number of index entries following the header. */ 215 unsigned char index_size[4]; 216 } h; 217 /* Pad the header to a fixed size. */ 218 unsigned char pad[JOURNAL_HEADER_SIZE]; 219} journal_rawheader_t; 220 221/*% 222 * The on-disk representation of the transaction header. 223 * There is one of these at the beginning of each transaction. 224 */ 225typedef struct { 226 unsigned char size[4]; /*%< In bytes, excluding header. */ 227 unsigned char serial0[4]; /*%< SOA serial before update. */ 228 unsigned char serial1[4]; /*%< SOA serial after update. */ 229} journal_rawxhdr_t; 230 231/*% 232 * The on-disk representation of the RR header. 233 * There is one of these at the beginning of each RR. 234 */ 235typedef struct { 236 unsigned char size[4]; /*%< In bytes, excluding header. */ 237} journal_rawrrhdr_t; 238 239/*% 240 * The in-core representation of the journal header. 241 */ 242typedef struct { 243 isc_uint32_t serial; 244 isc_offset_t offset; 245} journal_pos_t; 246 247#define POS_VALID(pos) ((pos).offset != 0) 248#define POS_INVALIDATE(pos) ((pos).offset = 0, (pos).serial = 0) 249 250typedef struct { 251 unsigned char format[16]; 252 journal_pos_t begin; 253 journal_pos_t end; 254 isc_uint32_t index_size; 255} journal_header_t; 256 257/*% 258 * The in-core representation of the transaction header. 259 */ 260 261typedef struct { 262 isc_uint32_t size; 263 isc_uint32_t serial0; 264 isc_uint32_t serial1; 265} journal_xhdr_t; 266 267/*% 268 * The in-core representation of the RR header. 269 */ 270typedef struct { 271 isc_uint32_t size; 272} journal_rrhdr_t; 273 274 275/*% 276 * Initial contents to store in the header of a newly created 277 * journal file. 278 * 279 * The header starts with the magic string ";BIND LOG V9\n" 280 * to identify the file as a BIND 9 journal file. An ASCII 281 * identification string is used rather than a binary magic 282 * number to be consistent with BIND 8 (BIND 8 journal files 283 * are ASCII text files). 284 */ 285 286static journal_header_t 287initial_journal_header = { ";BIND LOG V9\n", { 0, 0 }, { 0, 0 }, 0 }; 288 289#define JOURNAL_EMPTY(h) ((h)->begin.offset == (h)->end.offset) 290 291typedef enum { 292 JOURNAL_STATE_INVALID, 293 JOURNAL_STATE_READ, 294 JOURNAL_STATE_WRITE, 295 JOURNAL_STATE_TRANSACTION 296} journal_state_t; 297 298struct dns_journal { 299 unsigned int magic; /*%< JOUR */ 300 isc_mem_t *mctx; /*%< Memory context */ 301 journal_state_t state; 302 const char *filename; /*%< Journal file name */ 303 FILE * fp; /*%< File handle */ 304 isc_offset_t offset; /*%< Current file offset */ 305 journal_header_t header; /*%< In-core journal header */ 306 unsigned char *rawindex; /*%< In-core buffer for journal index in on-disk format */ 307 journal_pos_t *index; /*%< In-core journal index */ 308 309 /*% Current transaction state (when writing). */ 310 struct { 311 unsigned int n_soa; /*%< Number of SOAs seen */ 312 journal_pos_t pos[2]; /*%< Begin/end position */ 313 } x; 314 315 /*% Iteration state (when reading). */ 316 struct { 317 /* These define the part of the journal we iterate over. */ 318 journal_pos_t bpos; /*%< Position before first, */ 319 journal_pos_t epos; /*%< and after last transaction */ 320 /* The rest is iterator state. */ 321 isc_uint32_t current_serial; /*%< Current SOA serial */ 322 isc_buffer_t source; /*%< Data from disk */ 323 isc_buffer_t target; /*%< Data from _fromwire check */ 324 dns_decompress_t dctx; /*%< Dummy decompression ctx */ 325 dns_name_t name; /*%< Current domain name */ 326 dns_rdata_t rdata; /*%< Current rdata */ 327 isc_uint32_t ttl; /*%< Current TTL */ 328 unsigned int xsize; /*%< Size of transaction data */ 329 unsigned int xpos; /*%< Current position in it */ 330 isc_result_t result; /*%< Result of last call */ 331 } it; 332}; 333 334#define DNS_JOURNAL_MAGIC ISC_MAGIC('J', 'O', 'U', 'R') 335#define DNS_JOURNAL_VALID(t) ISC_MAGIC_VALID(t, DNS_JOURNAL_MAGIC) 336 337static void 338journal_pos_decode(journal_rawpos_t *raw, journal_pos_t *cooked) { 339 cooked->serial = decode_uint32(raw->serial); 340 cooked->offset = decode_uint32(raw->offset); 341} 342 343static void 344journal_pos_encode(journal_rawpos_t *raw, journal_pos_t *cooked) { 345 encode_uint32(cooked->serial, raw->serial); 346 encode_uint32(cooked->offset, raw->offset); 347} 348 349static void 350journal_header_decode(journal_rawheader_t *raw, journal_header_t *cooked) { 351 INSIST(sizeof(cooked->format) == sizeof(raw->h.format)); 352 memcpy(cooked->format, raw->h.format, sizeof(cooked->format)); 353 journal_pos_decode(&raw->h.begin, &cooked->begin); 354 journal_pos_decode(&raw->h.end, &cooked->end); 355 cooked->index_size = decode_uint32(raw->h.index_size); 356} 357 358static void 359journal_header_encode(journal_header_t *cooked, journal_rawheader_t *raw) { 360 INSIST(sizeof(cooked->format) == sizeof(raw->h.format)); 361 memset(raw->pad, 0, sizeof(raw->pad)); 362 memcpy(raw->h.format, cooked->format, sizeof(raw->h.format)); 363 journal_pos_encode(&raw->h.begin, &cooked->begin); 364 journal_pos_encode(&raw->h.end, &cooked->end); 365 encode_uint32(cooked->index_size, raw->h.index_size); 366} 367 368/* 369 * Journal file I/O subroutines, with error checking and reporting. 370 */ 371static isc_result_t 372journal_seek(dns_journal_t *j, isc_uint32_t offset) { 373 isc_result_t result; 374 result = isc_stdio_seek(j->fp, (long)offset, SEEK_SET); 375 if (result != ISC_R_SUCCESS) { 376 isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR, 377 "%s: seek: %s", j->filename, 378 isc_result_totext(result)); 379 return (ISC_R_UNEXPECTED); 380 } 381 j->offset = offset; 382 return (ISC_R_SUCCESS); 383} 384 385static isc_result_t 386journal_read(dns_journal_t *j, void *mem, size_t nbytes) { 387 isc_result_t result; 388 389 result = isc_stdio_read(mem, 1, nbytes, j->fp, NULL); 390 if (result != ISC_R_SUCCESS) { 391 if (result == ISC_R_EOF) 392 return (ISC_R_NOMORE); 393 isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR, 394 "%s: read: %s", 395 j->filename, isc_result_totext(result)); 396 return (ISC_R_UNEXPECTED); 397 } 398 j->offset += nbytes; 399 return (ISC_R_SUCCESS); 400} 401 402static isc_result_t 403journal_write(dns_journal_t *j, void *mem, size_t nbytes) { 404 isc_result_t result; 405 406 result = isc_stdio_write(mem, 1, nbytes, j->fp, NULL); 407 if (result != ISC_R_SUCCESS) { 408 isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR, 409 "%s: write: %s", 410 j->filename, isc_result_totext(result)); 411 return (ISC_R_UNEXPECTED); 412 } 413 j->offset += nbytes; 414 return (ISC_R_SUCCESS); 415} 416 417static isc_result_t 418journal_fsync(dns_journal_t *j) { 419 isc_result_t result; 420 result = isc_stdio_flush(j->fp); 421 if (result != ISC_R_SUCCESS) { 422 isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR, 423 "%s: flush: %s", 424 j->filename, isc_result_totext(result)); 425 return (ISC_R_UNEXPECTED); 426 } 427 result = isc_stdio_sync(j->fp); 428 if (result != ISC_R_SUCCESS) { 429 isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR, 430 "%s: fsync: %s", 431 j->filename, isc_result_totext(result)); 432 return (ISC_R_UNEXPECTED); 433 } 434 return (ISC_R_SUCCESS); 435} 436 437/* 438 * Read/write a transaction header at the current file position. 439 */ 440 441static isc_result_t 442journal_read_xhdr(dns_journal_t *j, journal_xhdr_t *xhdr) { 443 journal_rawxhdr_t raw; 444 isc_result_t result; 445 result = journal_read(j, &raw, sizeof(raw)); 446 if (result != ISC_R_SUCCESS) 447 return (result); 448 xhdr->size = decode_uint32(raw.size); 449 xhdr->serial0 = decode_uint32(raw.serial0); 450 xhdr->serial1 = decode_uint32(raw.serial1); 451 return (ISC_R_SUCCESS); 452} 453 454static isc_result_t 455journal_write_xhdr(dns_journal_t *j, isc_uint32_t size, 456 isc_uint32_t serial0, isc_uint32_t serial1) 457{ 458 journal_rawxhdr_t raw; 459 encode_uint32(size, raw.size); 460 encode_uint32(serial0, raw.serial0); 461 encode_uint32(serial1, raw.serial1); 462 return (journal_write(j, &raw, sizeof(raw))); 463} 464 465 466/* 467 * Read an RR header at the current file position. 468 */ 469 470static isc_result_t 471journal_read_rrhdr(dns_journal_t *j, journal_rrhdr_t *rrhdr) { 472 journal_rawrrhdr_t raw; 473 isc_result_t result; 474 result = journal_read(j, &raw, sizeof(raw)); 475 if (result != ISC_R_SUCCESS) 476 return (result); 477 rrhdr->size = decode_uint32(raw.size); 478 return (ISC_R_SUCCESS); 479} 480 481static isc_result_t 482journal_file_create(isc_mem_t *mctx, const char *filename) { 483 FILE *fp = NULL; 484 isc_result_t result; 485 journal_header_t header; 486 journal_rawheader_t rawheader; 487 int index_size = 56; /* XXX configurable */ 488 int size; 489 void *mem; /* Memory for temporary index image. */ 490 491 INSIST(sizeof(journal_rawheader_t) == JOURNAL_HEADER_SIZE); 492 493 result = isc_stdio_open(filename, "wb", &fp); 494 if (result != ISC_R_SUCCESS) { 495 isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR, 496 "%s: create: %s", 497 filename, isc_result_totext(result)); 498 return (ISC_R_UNEXPECTED); 499 } 500 501 header = initial_journal_header; 502 header.index_size = index_size; 503 journal_header_encode(&header, &rawheader); 504 505 size = sizeof(journal_rawheader_t) + 506 index_size * sizeof(journal_rawpos_t); 507 508 mem = isc_mem_get(mctx, size); 509 if (mem == NULL) { 510 (void)isc_stdio_close(fp); 511 (void)isc_file_remove(filename); 512 return (ISC_R_NOMEMORY); 513 } 514 memset(mem, 0, size); 515 memcpy(mem, &rawheader, sizeof(rawheader)); 516 517 result = isc_stdio_write(mem, 1, (size_t) size, fp, NULL); 518 if (result != ISC_R_SUCCESS) { 519 isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR, 520 "%s: write: %s", 521 filename, isc_result_totext(result)); 522 (void)isc_stdio_close(fp); 523 (void)isc_file_remove(filename); 524 isc_mem_put(mctx, mem, size); 525 return (ISC_R_UNEXPECTED); 526 } 527 isc_mem_put(mctx, mem, size); 528 529 result = isc_stdio_close(fp); 530 if (result != ISC_R_SUCCESS) { 531 isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR, 532 "%s: close: %s", 533 filename, isc_result_totext(result)); 534 (void)isc_file_remove(filename); 535 return (ISC_R_UNEXPECTED); 536 } 537 538 return (ISC_R_SUCCESS); 539} 540 541static isc_result_t 542journal_open(isc_mem_t *mctx, const char *filename, isc_boolean_t write, 543 isc_boolean_t create, dns_journal_t **journalp) { 544 FILE *fp = NULL; 545 isc_result_t result; 546 journal_rawheader_t rawheader; 547 dns_journal_t *j; 548 549 INSIST(journalp != NULL && *journalp == NULL); 550 j = isc_mem_get(mctx, sizeof(*j)); 551 if (j == NULL) 552 return (ISC_R_NOMEMORY); 553 554 j->mctx = mctx; 555 j->state = JOURNAL_STATE_INVALID; 556 j->fp = NULL; 557 j->filename = filename; 558 j->index = NULL; 559 j->rawindex = NULL; 560 561 result = isc_stdio_open(j->filename, write ? "rb+" : "rb", &fp); 562 563 if (result == ISC_R_FILENOTFOUND) { 564 if (create) { 565 isc_log_write(JOURNAL_COMMON_LOGARGS, 566 ISC_LOG_INFO, 567 "journal file %s does not exist, " 568 "creating it", 569 j->filename); 570 CHECK(journal_file_create(mctx, filename)); 571 /* 572 * Retry. 573 */ 574 result = isc_stdio_open(j->filename, "rb+", &fp); 575 } else { 576 FAIL(ISC_R_NOTFOUND); 577 } 578 } 579 if (result != ISC_R_SUCCESS) { 580 isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR, 581 "%s: open: %s", 582 j->filename, isc_result_totext(result)); 583 FAIL(ISC_R_UNEXPECTED); 584 } 585 586 j->fp = fp; 587 588 /* 589 * Set magic early so that seek/read can succeed. 590 */ 591 j->magic = DNS_JOURNAL_MAGIC; 592 593 CHECK(journal_seek(j, 0)); 594 CHECK(journal_read(j, &rawheader, sizeof(rawheader))); 595 596 if (memcmp(rawheader.h.format, initial_journal_header.format, 597 sizeof(initial_journal_header.format)) != 0) { 598 isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR, 599 "%s: journal format not recognized", 600 j->filename); 601 FAIL(ISC_R_UNEXPECTED); 602 } 603 journal_header_decode(&rawheader, &j->header); 604 605 /* 606 * If there is an index, read the raw index into a dynamically 607 * allocated buffer and then convert it into a cooked index. 608 */ 609 if (j->header.index_size != 0) { 610 unsigned int i; 611 unsigned int rawbytes; 612 unsigned char *p; 613 614 rawbytes = j->header.index_size * sizeof(journal_rawpos_t); 615 j->rawindex = isc_mem_get(mctx, rawbytes); 616 if (j->rawindex == NULL) 617 FAIL(ISC_R_NOMEMORY); 618 619 CHECK(journal_read(j, j->rawindex, rawbytes)); 620 621 j->index = isc_mem_get(mctx, j->header.index_size * 622 sizeof(journal_pos_t)); 623 if (j->index == NULL) 624 FAIL(ISC_R_NOMEMORY); 625 626 p = j->rawindex; 627 for (i = 0; i < j->header.index_size; i++) { 628 j->index[i].serial = decode_uint32(p); 629 p += 4; 630 j->index[i].offset = decode_uint32(p); 631 p += 4; 632 } 633 INSIST(p == j->rawindex + rawbytes); 634 } 635 j->offset = -1; /* Invalid, must seek explicitly. */ 636 637 /* 638 * Initialize the iterator. 639 */ 640 dns_name_init(&j->it.name, NULL); 641 dns_rdata_init(&j->it.rdata); 642 643 /* 644 * Set up empty initial buffers for uncheched and checked 645 * wire format RR data. They will be reallocated 646 * later. 647 */ 648 isc_buffer_init(&j->it.source, NULL, 0); 649 isc_buffer_init(&j->it.target, NULL, 0); 650 dns_decompress_init(&j->it.dctx, -1, DNS_DECOMPRESS_NONE); 651 652 j->state = 653 write ? JOURNAL_STATE_WRITE : JOURNAL_STATE_READ; 654 655 *journalp = j; 656 return (ISC_R_SUCCESS); 657 658 failure: 659 j->magic = 0; 660 if (j->index != NULL) { 661 isc_mem_put(j->mctx, j->index, j->header.index_size * 662 sizeof(journal_rawpos_t)); 663 j->index = NULL; 664 } 665 if (j->fp != NULL) 666 (void)isc_stdio_close(j->fp); 667 isc_mem_put(j->mctx, j, sizeof(*j)); 668 return (result); 669} 670 671isc_result_t 672dns_journal_open(isc_mem_t *mctx, const char *filename, isc_boolean_t write, 673 dns_journal_t **journalp) { 674 isc_result_t result; 675 int namelen; 676 char backup[1024]; 677 678 result = journal_open(mctx, filename, write, write, journalp); 679 if (result == ISC_R_NOTFOUND) { 680 namelen = strlen(filename); 681 if (namelen > 4 && strcmp(filename + namelen - 4, ".jnl") == 0) 682 namelen -= 4; 683 684 result = isc_string_printf(backup, sizeof(backup), "%.*s.jbk", 685 namelen, filename); 686 if (result != ISC_R_SUCCESS) 687 return (result); 688 result = journal_open(mctx, backup, write, write, journalp); 689 } 690 return (result); 691} 692 693/* 694 * A comparison function defining the sorting order for 695 * entries in the IXFR-style journal file. 696 * 697 * The IXFR format requires that deletions are sorted before 698 * additions, and within either one, SOA records are sorted 699 * before others. 700 * 701 * Also sort the non-SOA records by type as a courtesy to the 702 * server receiving the IXFR - it may help reduce the amount of 703 * rdataset merging it has to do. 704 */ 705static int 706ixfr_order(const void *av, const void *bv) { 707 dns_difftuple_t const * const *ap = av; 708 dns_difftuple_t const * const *bp = bv; 709 dns_difftuple_t const *a = *ap; 710 dns_difftuple_t const *b = *bp; 711 int r; 712 713 r = (b->op == DNS_DIFFOP_DEL) - (a->op == DNS_DIFFOP_DEL); 714 if (r != 0) 715 return (r); 716 717 r = (b->rdata.type == dns_rdatatype_soa) - 718 (a->rdata.type == dns_rdatatype_soa); 719 if (r != 0) 720 return (r); 721 722 r = (a->rdata.type - b->rdata.type); 723 return (r); 724} 725 726/* 727 * Advance '*pos' to the next journal transaction. 728 * 729 * Requires: 730 * *pos refers to a valid journal transaction. 731 * 732 * Ensures: 733 * When ISC_R_SUCCESS is returned, 734 * *pos refers to the next journal transaction. 735 * 736 * Returns one of: 737 * 738 * ISC_R_SUCCESS 739 * ISC_R_NOMORE *pos pointed at the last transaction 740 * Other results due to file errors are possible. 741 */ 742static isc_result_t 743journal_next(dns_journal_t *j, journal_pos_t *pos) { 744 isc_result_t result; 745 journal_xhdr_t xhdr; 746 REQUIRE(DNS_JOURNAL_VALID(j)); 747 748 result = journal_seek(j, pos->offset); 749 if (result != ISC_R_SUCCESS) 750 return (result); 751 752 if (pos->serial == j->header.end.serial) 753 return (ISC_R_NOMORE); 754 /* 755 * Read the header of the current transaction. 756 * This will return ISC_R_NOMORE if we are at EOF. 757 */ 758 result = journal_read_xhdr(j, &xhdr); 759 if (result != ISC_R_SUCCESS) 760 return (result); 761 762 /* 763 * Check serial number consistency. 764 */ 765 if (xhdr.serial0 != pos->serial) { 766 isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR, 767 "%s: journal file corrupt: " 768 "expected serial %u, got %u", 769 j->filename, pos->serial, xhdr.serial0); 770 return (ISC_R_UNEXPECTED); 771 } 772 773 /* 774 * Check for offset wraparound. 775 */ 776 if ((isc_offset_t)(pos->offset + sizeof(journal_rawxhdr_t) + xhdr.size) 777 < pos->offset) { 778 isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR, 779 "%s: offset too large", j->filename); 780 return (ISC_R_UNEXPECTED); 781 } 782 783 pos->offset += sizeof(journal_rawxhdr_t) + xhdr.size; 784 pos->serial = xhdr.serial1; 785 return (ISC_R_SUCCESS); 786} 787 788/* 789 * If the index of the journal 'j' contains an entry "better" 790 * than '*best_guess', replace '*best_guess' with it. 791 * 792 * "Better" means having a serial number closer to 'serial' 793 * but not greater than 'serial'. 794 */ 795static void 796index_find(dns_journal_t *j, isc_uint32_t serial, journal_pos_t *best_guess) { 797 unsigned int i; 798 if (j->index == NULL) 799 return; 800 for (i = 0; i < j->header.index_size; i++) { 801 if (POS_VALID(j->index[i]) && 802 DNS_SERIAL_GE(serial, j->index[i].serial) && 803 DNS_SERIAL_GT(j->index[i].serial, best_guess->serial)) 804 *best_guess = j->index[i]; 805 } 806} 807 808/* 809 * Add a new index entry. If there is no room, make room by removing 810 * the odd-numbered entries and compacting the others into the first 811 * half of the index. This decimates old index entries exponentially 812 * over time, so that the index always contains a much larger fraction 813 * of recent serial numbers than of old ones. This is deliberate - 814 * most index searches are for outgoing IXFR, and IXFR tends to request 815 * recent versions more often than old ones. 816 */ 817static void 818index_add(dns_journal_t *j, journal_pos_t *pos) { 819 unsigned int i; 820 if (j->index == NULL) 821 return; 822 /* 823 * Search for a vacant position. 824 */ 825 for (i = 0; i < j->header.index_size; i++) { 826 if (! POS_VALID(j->index[i])) 827 break; 828 } 829 if (i == j->header.index_size) { 830 unsigned int k = 0; 831 /* 832 * Found no vacant position. Make some room. 833 */ 834 for (i = 0; i < j->header.index_size; i += 2) { 835 j->index[k++] = j->index[i]; 836 } 837 i = k; /* 'i' identifies the first vacant position. */ 838 while (k < j->header.index_size) { 839 POS_INVALIDATE(j->index[k]); 840 k++; 841 } 842 } 843 INSIST(i < j->header.index_size); 844 INSIST(! POS_VALID(j->index[i])); 845 846 /* 847 * Store the new index entry. 848 */ 849 j->index[i] = *pos; 850} 851 852/* 853 * Invalidate any existing index entries that could become 854 * ambiguous when a new transaction with number 'serial' is added. 855 */ 856static void 857index_invalidate(dns_journal_t *j, isc_uint32_t serial) { 858 unsigned int i; 859 if (j->index == NULL) 860 return; 861 for (i = 0; i < j->header.index_size; i++) { 862 if (! DNS_SERIAL_GT(serial, j->index[i].serial)) 863 POS_INVALIDATE(j->index[i]); 864 } 865} 866 867/* 868 * Try to find a transaction with initial serial number 'serial' 869 * in the journal 'j'. 870 * 871 * If found, store its position at '*pos' and return ISC_R_SUCCESS. 872 * 873 * If 'serial' is current (= the ending serial number of the 874 * last transaction in the journal), set '*pos' to 875 * the position immediately following the last transaction and 876 * return ISC_R_SUCCESS. 877 * 878 * If 'serial' is within the range of addressable serial numbers 879 * covered by the journal but that particular serial number is missing 880 * (from the journal, not just from the index), return ISC_R_NOTFOUND. 881 * 882 * If 'serial' is outside the range of addressable serial numbers 883 * covered by the journal, return ISC_R_RANGE. 884 * 885 */ 886static isc_result_t 887journal_find(dns_journal_t *j, isc_uint32_t serial, journal_pos_t *pos) { 888 isc_result_t result; 889 journal_pos_t current_pos; 890 REQUIRE(DNS_JOURNAL_VALID(j)); 891 892 if (DNS_SERIAL_GT(j->header.begin.serial, serial)) 893 return (ISC_R_RANGE); 894 if (DNS_SERIAL_GT(serial, j->header.end.serial)) 895 return (ISC_R_RANGE); 896 if (serial == j->header.end.serial) { 897 *pos = j->header.end; 898 return (ISC_R_SUCCESS); 899 } 900 901 current_pos = j->header.begin; 902 index_find(j, serial, ¤t_pos); 903 904 while (current_pos.serial != serial) { 905 if (DNS_SERIAL_GT(current_pos.serial, serial)) 906 return (ISC_R_NOTFOUND); 907 result = journal_next(j, ¤t_pos); 908 if (result != ISC_R_SUCCESS) 909 return (result); 910 } 911 *pos = current_pos; 912 return (ISC_R_SUCCESS); 913} 914 915isc_result_t 916dns_journal_begin_transaction(dns_journal_t *j) { 917 isc_uint32_t offset; 918 isc_result_t result; 919 journal_rawxhdr_t hdr; 920 921 REQUIRE(DNS_JOURNAL_VALID(j)); 922 REQUIRE(j->state == JOURNAL_STATE_WRITE); 923 924 /* 925 * Find the file offset where the new transaction should 926 * be written, and seek there. 927 */ 928 if (JOURNAL_EMPTY(&j->header)) { 929 offset = sizeof(journal_rawheader_t) + 930 j->header.index_size * sizeof(journal_rawpos_t); 931 } else { 932 offset = j->header.end.offset; 933 } 934 j->x.pos[0].offset = offset; 935 j->x.pos[1].offset = offset; /* Initial value, will be incremented. */ 936 j->x.n_soa = 0; 937 938 CHECK(journal_seek(j, offset)); 939 940 /* 941 * Write a dummy transaction header of all zeroes to reserve 942 * space. It will be filled in when the transaction is 943 * finished. 944 */ 945 memset(&hdr, 0, sizeof(hdr)); 946 CHECK(journal_write(j, &hdr, sizeof(hdr))); 947 j->x.pos[1].offset = j->offset; 948 949 j->state = JOURNAL_STATE_TRANSACTION; 950 result = ISC_R_SUCCESS; 951 failure: 952 return (result); 953} 954 955isc_result_t 956dns_journal_writediff(dns_journal_t *j, dns_diff_t *diff) { 957 dns_difftuple_t *t; 958 isc_buffer_t buffer; 959 void *mem = NULL; 960 unsigned int size; 961 isc_result_t result; 962 isc_region_t used; 963 964 REQUIRE(DNS_DIFF_VALID(diff)); 965 REQUIRE(j->state == JOURNAL_STATE_TRANSACTION); 966 967 isc_log_write(JOURNAL_DEBUG_LOGARGS(3), "writing to journal"); 968 (void)dns_diff_print(diff, NULL); 969 970 /* 971 * Pass 1: determine the buffer size needed, and 972 * keep track of SOA serial numbers. 973 */ 974 size = 0; 975 for (t = ISC_LIST_HEAD(diff->tuples); t != NULL; 976 t = ISC_LIST_NEXT(t, link)) 977 { 978 if (t->rdata.type == dns_rdatatype_soa) { 979 if (j->x.n_soa < 2) 980 j->x.pos[j->x.n_soa].serial = 981 dns_soa_getserial(&t->rdata); 982 j->x.n_soa++; 983 } 984 size += sizeof(journal_rawrrhdr_t); 985 size += t->name.length; /* XXX should have access macro? */ 986 size += 10; 987 size += t->rdata.length; 988 } 989 990 mem = isc_mem_get(j->mctx, size); 991 if (mem == NULL) 992 return (ISC_R_NOMEMORY); 993 994 isc_buffer_init(&buffer, mem, size); 995 996 /* 997 * Pass 2. Write RRs to buffer. 998 */ 999 for (t = ISC_LIST_HEAD(diff->tuples); t != NULL; 1000 t = ISC_LIST_NEXT(t, link)) 1001 { 1002 /* 1003 * Write the RR header. 1004 */ 1005 isc_buffer_putuint32(&buffer, t->name.length + 10 + 1006 t->rdata.length); 1007 /* 1008 * Write the owner name, RR header, and RR data. 1009 */ 1010 isc_buffer_putmem(&buffer, t->name.ndata, t->name.length); 1011 isc_buffer_putuint16(&buffer, t->rdata.type); 1012 isc_buffer_putuint16(&buffer, t->rdata.rdclass); 1013 isc_buffer_putuint32(&buffer, t->ttl); 1014 INSIST(t->rdata.length < 65536); 1015 isc_buffer_putuint16(&buffer, (isc_uint16_t)t->rdata.length); 1016 INSIST(isc_buffer_availablelength(&buffer) >= t->rdata.length); 1017 isc_buffer_putmem(&buffer, t->rdata.data, t->rdata.length); 1018 } 1019 1020 isc_buffer_usedregion(&buffer, &used); 1021 INSIST(used.length == size); 1022 1023 j->x.pos[1].offset += used.length; 1024 1025 /* 1026 * Write the buffer contents to the journal file. 1027 */ 1028 CHECK(journal_write(j, used.base, used.length)); 1029 1030 result = ISC_R_SUCCESS; 1031 1032 failure: 1033 if (mem != NULL) 1034 isc_mem_put(j->mctx, mem, size); 1035 return (result); 1036 1037} 1038 1039isc_result_t 1040dns_journal_commit(dns_journal_t *j) { 1041 isc_result_t result; 1042 journal_rawheader_t rawheader; 1043 1044 REQUIRE(DNS_JOURNAL_VALID(j)); 1045 REQUIRE(j->state == JOURNAL_STATE_TRANSACTION); 1046 1047 /* 1048 * Perform some basic consistency checks. 1049 */ 1050 if (j->x.n_soa != 2) { 1051 isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR, 1052 "%s: malformed transaction: %d SOAs", 1053 j->filename, j->x.n_soa); 1054 return (ISC_R_UNEXPECTED); 1055 } 1056 if (! (DNS_SERIAL_GT(j->x.pos[1].serial, j->x.pos[0].serial) || 1057 (bind8_compat && 1058 j->x.pos[1].serial == j->x.pos[0].serial))) 1059 { 1060 isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR, 1061 "%s: malformed transaction: serial number " 1062 "would decrease", j->filename); 1063 return (ISC_R_UNEXPECTED); 1064 } 1065 if (! JOURNAL_EMPTY(&j->header)) { 1066 if (j->x.pos[0].serial != j->header.end.serial) { 1067 isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR, 1068 "malformed transaction: " 1069 "%s last serial %u != " 1070 "transaction first serial %u", 1071 j->filename, 1072 j->header.end.serial, 1073 j->x.pos[0].serial); 1074 return (ISC_R_UNEXPECTED); 1075 } 1076 } 1077 1078 /* 1079 * Some old journal entries may become non-addressable 1080 * when we increment the current serial number. Purge them 1081 * by stepping header.begin forward to the first addressable 1082 * transaction. Also purge them from the index. 1083 */ 1084 if (! JOURNAL_EMPTY(&j->header)) { 1085 while (! DNS_SERIAL_GT(j->x.pos[1].serial, 1086 j->header.begin.serial)) { 1087 CHECK(journal_next(j, &j->header.begin)); 1088 } 1089 index_invalidate(j, j->x.pos[1].serial); 1090 } 1091#ifdef notyet 1092 if (DNS_SERIAL_GT(last_dumped_serial, j->x.pos[1].serial)) { 1093 force_dump(...); 1094 } 1095#endif 1096 1097 /* 1098 * Commit the transaction data to stable storage. 1099 */ 1100 CHECK(journal_fsync(j)); 1101 1102 /* 1103 * Update the transaction header. 1104 */ 1105 CHECK(journal_seek(j, j->x.pos[0].offset)); 1106 CHECK(journal_write_xhdr(j, (j->x.pos[1].offset - j->x.pos[0].offset) - 1107 sizeof(journal_rawxhdr_t), 1108 j->x.pos[0].serial, j->x.pos[1].serial)); 1109 1110 /* 1111 * Update the journal header. 1112 */ 1113 if (JOURNAL_EMPTY(&j->header)) { 1114 j->header.begin = j->x.pos[0]; 1115 } 1116 j->header.end = j->x.pos[1]; 1117 journal_header_encode(&j->header, &rawheader); 1118 CHECK(journal_seek(j, 0)); 1119 CHECK(journal_write(j, &rawheader, sizeof(rawheader))); 1120 1121 /* 1122 * Update the index. 1123 */ 1124 index_add(j, &j->x.pos[0]); 1125 1126 /* 1127 * Convert the index into on-disk format and write 1128 * it to disk. 1129 */ 1130 CHECK(index_to_disk(j)); 1131 1132 /* 1133 * Commit the header to stable storage. 1134 */ 1135 CHECK(journal_fsync(j)); 1136 1137 /* 1138 * We no longer have a transaction open. 1139 */ 1140 j->state = JOURNAL_STATE_WRITE; 1141 1142 result = ISC_R_SUCCESS; 1143 1144 failure: 1145 return (result); 1146} 1147 1148isc_result_t 1149dns_journal_write_transaction(dns_journal_t *j, dns_diff_t *diff) { 1150 isc_result_t result; 1151 CHECK(dns_diff_sort(diff, ixfr_order)); 1152 CHECK(dns_journal_begin_transaction(j)); 1153 CHECK(dns_journal_writediff(j, diff)); 1154 CHECK(dns_journal_commit(j)); 1155 result = ISC_R_SUCCESS; 1156 failure: 1157 return (result); 1158} 1159 1160void 1161dns_journal_destroy(dns_journal_t **journalp) { 1162 dns_journal_t *j = *journalp; 1163 REQUIRE(DNS_JOURNAL_VALID(j)); 1164 1165 j->it.result = ISC_R_FAILURE; 1166 dns_name_invalidate(&j->it.name); 1167 dns_decompress_invalidate(&j->it.dctx); 1168 if (j->rawindex != NULL) 1169 isc_mem_put(j->mctx, j->rawindex, j->header.index_size * 1170 sizeof(journal_rawpos_t)); 1171 if (j->index != NULL) 1172 isc_mem_put(j->mctx, j->index, j->header.index_size * 1173 sizeof(journal_pos_t)); 1174 if (j->it.target.base != NULL) 1175 isc_mem_put(j->mctx, j->it.target.base, j->it.target.length); 1176 if (j->it.source.base != NULL) 1177 isc_mem_put(j->mctx, j->it.source.base, j->it.source.length); 1178 1179 if (j->fp != NULL) 1180 (void)isc_stdio_close(j->fp); 1181 j->magic = 0; 1182 isc_mem_put(j->mctx, j, sizeof(*j)); 1183 *journalp = NULL; 1184} 1185 1186/* 1187 * Roll the open journal 'j' into the database 'db'. 1188 * A new database version will be created. 1189 */ 1190 1191/* XXX Share code with incoming IXFR? */ 1192 1193static isc_result_t 1194roll_forward(dns_journal_t *j, dns_db_t *db) { 1195 isc_buffer_t source; /* Transaction data from disk */ 1196 isc_buffer_t target; /* Ditto after _fromwire check */ 1197 isc_uint32_t db_serial; /* Database SOA serial */ 1198 isc_uint32_t end_serial; /* Last journal SOA serial */ 1199 isc_result_t result; 1200 dns_dbversion_t *ver = NULL; 1201 journal_pos_t pos; 1202 dns_diff_t diff; 1203 unsigned int n_soa = 0; 1204 unsigned int n_put = 0; 1205 1206 REQUIRE(DNS_JOURNAL_VALID(j)); 1207 REQUIRE(DNS_DB_VALID(db)); 1208 1209 dns_diff_init(j->mctx, &diff); 1210 1211 /* 1212 * Set up empty initial buffers for uncheched and checked 1213 * wire format transaction data. They will be reallocated 1214 * later. 1215 */ 1216 isc_buffer_init(&source, NULL, 0); 1217 isc_buffer_init(&target, NULL, 0); 1218 1219 /* 1220 * Create the new database version. 1221 */ 1222 CHECK(dns_db_newversion(db, &ver)); 1223 1224 /* 1225 * Get the current database SOA serial number. 1226 */ 1227 CHECK(dns_db_getsoaserial(db, ver, &db_serial)); 1228 1229 /* 1230 * Locate a journal entry for the current database serial. 1231 */ 1232 CHECK(journal_find(j, db_serial, &pos)); 1233 /* 1234 * XXX do more drastic things, like marking zone stale, 1235 * if this fails? 1236 */ 1237 /* 1238 * XXXRTH The zone code should probably mark the zone as bad and 1239 * scream loudly into the log if this is a dynamic update 1240 * log reply that failed. 1241 */ 1242 1243 end_serial = dns_journal_last_serial(j); 1244 if (db_serial == end_serial) 1245 CHECK(DNS_R_UPTODATE); 1246 1247 CHECK(dns_journal_iter_init(j, db_serial, end_serial)); 1248 1249 for (result = dns_journal_first_rr(j); 1250 result == ISC_R_SUCCESS; 1251 result = dns_journal_next_rr(j)) 1252 { 1253 dns_name_t *name; 1254 isc_uint32_t ttl; 1255 dns_rdata_t *rdata; 1256 dns_difftuple_t *tuple = NULL; 1257 1258 name = NULL; 1259 rdata = NULL; 1260 dns_journal_current_rr(j, &name, &ttl, &rdata); 1261 1262 if (rdata->type == dns_rdatatype_soa) { 1263 n_soa++; 1264 if (n_soa == 2) 1265 db_serial = j->it.current_serial; 1266 } 1267 1268 if (n_soa == 3) 1269 n_soa = 1; 1270 if (n_soa == 0) { 1271 isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR, 1272 "%s: journal file corrupt: missing " 1273 "initial SOA", j->filename); 1274 FAIL(ISC_R_UNEXPECTED); 1275 } 1276 CHECK(dns_difftuple_create(diff.mctx, n_soa == 1 ? 1277 DNS_DIFFOP_DEL : DNS_DIFFOP_ADD, 1278 name, ttl, rdata, &tuple)); 1279 dns_diff_append(&diff, &tuple); 1280 1281 if (++n_put > 100) { 1282 isc_log_write(JOURNAL_DEBUG_LOGARGS(3), 1283 "%s: applying diff to database (%u)", 1284 j->filename, db_serial); 1285 (void)dns_diff_print(&diff, NULL); 1286 CHECK(dns_diff_apply(&diff, db, ver)); 1287 dns_diff_clear(&diff); 1288 n_put = 0; 1289 } 1290 } 1291 if (result == ISC_R_NOMORE) 1292 result = ISC_R_SUCCESS; 1293 CHECK(result); 1294 1295 if (n_put != 0) { 1296 isc_log_write(JOURNAL_DEBUG_LOGARGS(3), 1297 "%s: applying final diff to database (%u)", 1298 j->filename, db_serial); 1299 (void)dns_diff_print(&diff, NULL); 1300 CHECK(dns_diff_apply(&diff, db, ver)); 1301 dns_diff_clear(&diff); 1302 } 1303 1304 failure: 1305 if (ver != NULL) 1306 dns_db_closeversion(db, &ver, result == ISC_R_SUCCESS ? 1307 ISC_TRUE : ISC_FALSE); 1308 1309 if (source.base != NULL) 1310 isc_mem_put(j->mctx, source.base, source.length); 1311 if (target.base != NULL) 1312 isc_mem_put(j->mctx, target.base, target.length); 1313 1314 dns_diff_clear(&diff); 1315 1316 return (result); 1317} 1318 1319isc_result_t 1320dns_journal_rollforward(isc_mem_t *mctx, dns_db_t *db, const char *filename) { 1321 dns_journal_t *j; 1322 isc_result_t result; 1323 1324 REQUIRE(DNS_DB_VALID(db)); 1325 REQUIRE(filename != NULL); 1326 1327 j = NULL; 1328 result = dns_journal_open(mctx, filename, ISC_FALSE, &j); 1329 if (result == ISC_R_NOTFOUND) { 1330 isc_log_write(JOURNAL_DEBUG_LOGARGS(3), 1331 "no journal file, but that's OK"); 1332 return (DNS_R_NOJOURNAL); 1333 } 1334 if (result != ISC_R_SUCCESS) 1335 return (result); 1336 if (JOURNAL_EMPTY(&j->header)) 1337 result = DNS_R_UPTODATE; 1338 else 1339 result = roll_forward(j, db); 1340 1341 dns_journal_destroy(&j); 1342 1343 return (result); 1344} 1345 1346isc_result_t 1347dns_journal_print(isc_mem_t *mctx, const char *filename, FILE *file) { 1348 dns_journal_t *j; 1349 isc_buffer_t source; /* Transaction data from disk */ 1350 isc_buffer_t target; /* Ditto after _fromwire check */ 1351 isc_uint32_t start_serial; /* Database SOA serial */ 1352 isc_uint32_t end_serial; /* Last journal SOA serial */ 1353 isc_result_t result; 1354 dns_diff_t diff; 1355 unsigned int n_soa = 0; 1356 unsigned int n_put = 0; 1357 1358 REQUIRE(filename != NULL); 1359 1360 j = NULL; 1361 result = dns_journal_open(mctx, filename, ISC_FALSE, &j); 1362 if (result == ISC_R_NOTFOUND) { 1363 isc_log_write(JOURNAL_DEBUG_LOGARGS(3), "no journal file"); 1364 return (DNS_R_NOJOURNAL); 1365 } 1366 1367 if (result != ISC_R_SUCCESS) { 1368 isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR, 1369 "journal open failure: %s: %s", 1370 isc_result_totext(result), j->filename); 1371 return (result); 1372 } 1373 1374 dns_diff_init(j->mctx, &diff); 1375 1376 /* 1377 * Set up empty initial buffers for uncheched and checked 1378 * wire format transaction data. They will be reallocated 1379 * later. 1380 */ 1381 isc_buffer_init(&source, NULL, 0); 1382 isc_buffer_init(&target, NULL, 0); 1383 1384 start_serial = dns_journal_first_serial(j); 1385 end_serial = dns_journal_last_serial(j); 1386 1387 CHECK(dns_journal_iter_init(j, start_serial, end_serial)); 1388 1389 for (result = dns_journal_first_rr(j); 1390 result == ISC_R_SUCCESS; 1391 result = dns_journal_next_rr(j)) 1392 { 1393 dns_name_t *name; 1394 isc_uint32_t ttl; 1395 dns_rdata_t *rdata; 1396 dns_difftuple_t *tuple = NULL; 1397 1398 name = NULL; 1399 rdata = NULL; 1400 dns_journal_current_rr(j, &name, &ttl, &rdata); 1401 1402 if (rdata->type == dns_rdatatype_soa) 1403 n_soa++; 1404 1405 if (n_soa == 3) 1406 n_soa = 1; 1407 if (n_soa == 0) { 1408 isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR, 1409 "%s: journal file corrupt: missing " 1410 "initial SOA", j->filename); 1411 FAIL(ISC_R_UNEXPECTED); 1412 } 1413 CHECK(dns_difftuple_create(diff.mctx, n_soa == 1 ? 1414 DNS_DIFFOP_DEL : DNS_DIFFOP_ADD, 1415 name, ttl, rdata, &tuple)); 1416 dns_diff_append(&diff, &tuple); 1417 1418 if (++n_put > 100) { 1419 result = dns_diff_print(&diff, file); 1420 dns_diff_clear(&diff); 1421 n_put = 0; 1422 if (result != ISC_R_SUCCESS) 1423 break; 1424 } 1425 } 1426 if (result == ISC_R_NOMORE) 1427 result = ISC_R_SUCCESS; 1428 CHECK(result); 1429 1430 if (n_put != 0) { 1431 result = dns_diff_print(&diff, file); 1432 dns_diff_clear(&diff); 1433 } 1434 goto cleanup; 1435 1436 failure: 1437 isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR, 1438 "%s: cannot print: journal file corrupt", j->filename); 1439 1440 cleanup: 1441 if (source.base != NULL) 1442 isc_mem_put(j->mctx, source.base, source.length); 1443 if (target.base != NULL) 1444 isc_mem_put(j->mctx, target.base, target.length); 1445 1446 dns_diff_clear(&diff); 1447 dns_journal_destroy(&j); 1448 1449 return (result); 1450} 1451 1452/**************************************************************************/ 1453/* 1454 * Miscellaneous accessors. 1455 */ 1456isc_uint32_t dns_journal_first_serial(dns_journal_t *j) { 1457 return (j->header.begin.serial); 1458} 1459 1460isc_uint32_t dns_journal_last_serial(dns_journal_t *j) { 1461 return (j->header.end.serial); 1462} 1463 1464/**************************************************************************/ 1465/* 1466 * Iteration support. 1467 * 1468 * When serving an outgoing IXFR, we transmit a part the journal starting 1469 * at the serial number in the IXFR request and ending at the serial 1470 * number that is current when the IXFR request arrives. The ending 1471 * serial number is not necessarily at the end of the journal: 1472 * the journal may grow while the IXFR is in progress, but we stop 1473 * when we reach the serial number that was current when the IXFR started. 1474 */ 1475 1476static isc_result_t read_one_rr(dns_journal_t *j); 1477 1478/* 1479 * Make sure the buffer 'b' is has at least 'size' bytes 1480 * allocated, and clear it. 1481 * 1482 * Requires: 1483 * Either b->base is NULL, or it points to b->length bytes of memory 1484 * previously allocated by isc_mem_get(). 1485 */ 1486 1487static isc_result_t 1488size_buffer(isc_mem_t *mctx, isc_buffer_t *b, unsigned size) { 1489 if (b->length < size) { 1490 void *mem = isc_mem_get(mctx, size); 1491 if (mem == NULL) 1492 return (ISC_R_NOMEMORY); 1493 if (b->base != NULL) 1494 isc_mem_put(mctx, b->base, b->length); 1495 b->base = mem; 1496 b->length = size; 1497 } 1498 isc_buffer_clear(b); 1499 return (ISC_R_SUCCESS); 1500} 1501 1502isc_result_t 1503dns_journal_iter_init(dns_journal_t *j, 1504 isc_uint32_t begin_serial, isc_uint32_t end_serial) 1505{ 1506 isc_result_t result; 1507 1508 CHECK(journal_find(j, begin_serial, &j->it.bpos)); 1509 INSIST(j->it.bpos.serial == begin_serial); 1510 1511 CHECK(journal_find(j, end_serial, &j->it.epos)); 1512 INSIST(j->it.epos.serial == end_serial); 1513 1514 result = ISC_R_SUCCESS; 1515 failure: 1516 j->it.result = result; 1517 return (j->it.result); 1518} 1519 1520 1521isc_result_t 1522dns_journal_first_rr(dns_journal_t *j) { 1523 isc_result_t result; 1524 1525 /* 1526 * Seek to the beginning of the first transaction we are 1527 * interested in. 1528 */ 1529 CHECK(journal_seek(j, j->it.bpos.offset)); 1530 j->it.current_serial = j->it.bpos.serial; 1531 1532 j->it.xsize = 0; /* We have no transaction data yet... */ 1533 j->it.xpos = 0; /* ...and haven't used any of it. */ 1534 1535 return (read_one_rr(j)); 1536 1537 failure: 1538 return (result); 1539} 1540 1541static isc_result_t 1542read_one_rr(dns_journal_t *j) { 1543 isc_result_t result; 1544 1545 dns_rdatatype_t rdtype; 1546 dns_rdataclass_t rdclass; 1547 unsigned int rdlen; 1548 isc_uint32_t ttl; 1549 journal_xhdr_t xhdr; 1550 journal_rrhdr_t rrhdr; 1551 1552 INSIST(j->offset <= j->it.epos.offset); 1553 if (j->offset == j->it.epos.offset) 1554 return (ISC_R_NOMORE); 1555 if (j->it.xpos == j->it.xsize) { 1556 /* 1557 * We are at a transaction boundary. 1558 * Read another transaction header. 1559 */ 1560 CHECK(journal_read_xhdr(j, &xhdr)); 1561 if (xhdr.size == 0) { 1562 isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR, 1563 "%s: journal corrupt: empty transaction", 1564 j->filename); 1565 FAIL(ISC_R_UNEXPECTED); 1566 } 1567 if (xhdr.serial0 != j->it.current_serial) { 1568 isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR, 1569 "%s: journal file corrupt: " 1570 "expected serial %u, got %u", 1571 j->filename, 1572 j->it.current_serial, xhdr.serial0); 1573 FAIL(ISC_R_UNEXPECTED); 1574 } 1575 j->it.xsize = xhdr.size; 1576 j->it.xpos = 0; 1577 } 1578 /* 1579 * Read an RR. 1580 */ 1581 CHECK(journal_read_rrhdr(j, &rrhdr)); 1582 /* 1583 * Perform a sanity check on the journal RR size. 1584 * The smallest possible RR has a 1-byte owner name 1585 * and a 10-byte header. The largest possible 1586 * RR has 65535 bytes of data, a header, and a maximum- 1587 * size owner name, well below 70 k total. 1588 */ 1589 if (rrhdr.size < 1+10 || rrhdr.size > 70000) { 1590 isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR, 1591 "%s: journal corrupt: impossible RR size " 1592 "(%d bytes)", j->filename, rrhdr.size); 1593 FAIL(ISC_R_UNEXPECTED); 1594 } 1595 1596 CHECK(size_buffer(j->mctx, &j->it.source, rrhdr.size)); 1597 CHECK(journal_read(j, j->it.source.base, rrhdr.size)); 1598 isc_buffer_add(&j->it.source, rrhdr.size); 1599 1600 /* 1601 * The target buffer is made the same size 1602 * as the source buffer, with the assumption that when 1603 * no compression in present, the output of dns_*_fromwire() 1604 * is no larger than the input. 1605 */ 1606 CHECK(size_buffer(j->mctx, &j->it.target, rrhdr.size)); 1607 1608 /* 1609 * Parse the owner name. We don't know where it 1610 * ends yet, so we make the entire "remaining" 1611 * part of the buffer "active". 1612 */ 1613 isc_buffer_setactive(&j->it.source, 1614 j->it.source.used - j->it.source.current); 1615 CHECK(dns_name_fromwire(&j->it.name, &j->it.source, 1616 &j->it.dctx, 0, &j->it.target)); 1617 1618 /* 1619 * Check that the RR header is there, and parse it. 1620 */ 1621 if (isc_buffer_remaininglength(&j->it.source) < 10) 1622 FAIL(DNS_R_FORMERR); 1623 1624 rdtype = isc_buffer_getuint16(&j->it.source); 1625 rdclass = isc_buffer_getuint16(&j->it.source); 1626 ttl = isc_buffer_getuint32(&j->it.source); 1627 rdlen = isc_buffer_getuint16(&j->it.source); 1628 1629 /* 1630 * Parse the rdata. 1631 */ 1632 if (isc_buffer_remaininglength(&j->it.source) != rdlen) 1633 FAIL(DNS_R_FORMERR); 1634 isc_buffer_setactive(&j->it.source, rdlen); 1635 dns_rdata_reset(&j->it.rdata); 1636 CHECK(dns_rdata_fromwire(&j->it.rdata, rdclass, 1637 rdtype, &j->it.source, &j->it.dctx, 1638 0, &j->it.target)); 1639 j->it.ttl = ttl; 1640 1641 j->it.xpos += sizeof(journal_rawrrhdr_t) + rrhdr.size; 1642 if (rdtype == dns_rdatatype_soa) { 1643 /* XXX could do additional consistency checks here */ 1644 j->it.current_serial = dns_soa_getserial(&j->it.rdata); 1645 } 1646 1647 result = ISC_R_SUCCESS; 1648 1649 failure: 1650 j->it.result = result; 1651 return (result); 1652} 1653 1654isc_result_t 1655dns_journal_next_rr(dns_journal_t *j) { 1656 j->it.result = read_one_rr(j); 1657 return (j->it.result); 1658} 1659 1660void 1661dns_journal_current_rr(dns_journal_t *j, dns_name_t **name, isc_uint32_t *ttl, 1662 dns_rdata_t **rdata) 1663{ 1664 REQUIRE(j->it.result == ISC_R_SUCCESS); 1665 *name = &j->it.name; 1666 *ttl = j->it.ttl; 1667 *rdata = &j->it.rdata; 1668} 1669 1670/**************************************************************************/ 1671/* 1672 * Generating diffs from databases 1673 */ 1674 1675/* 1676 * Construct a diff containing all the RRs at the current name of the 1677 * database iterator 'dbit' in database 'db', version 'ver'. 1678 * Set '*name' to the current name, and append the diff to 'diff'. 1679 * All new tuples will have the operation 'op'. 1680 * 1681 * Requires: 'name' must have buffer large enough to hold the name. 1682 * Typically, a dns_fixedname_t would be used. 1683 */ 1684static isc_result_t 1685get_name_diff(dns_db_t *db, dns_dbversion_t *ver, isc_stdtime_t now, 1686 dns_dbiterator_t *dbit, dns_name_t *name, dns_diffop_t op, 1687 dns_diff_t *diff) 1688{ 1689 isc_result_t result; 1690 dns_dbnode_t *node = NULL; 1691 dns_rdatasetiter_t *rdsiter = NULL; 1692 dns_difftuple_t *tuple = NULL; 1693 1694 result = dns_dbiterator_current(dbit, &node, name); 1695 if (result != ISC_R_SUCCESS) 1696 return (result); 1697 1698 result = dns_db_allrdatasets(db, node, ver, now, &rdsiter); 1699 if (result != ISC_R_SUCCESS) 1700 goto cleanup_node; 1701 1702 for (result = dns_rdatasetiter_first(rdsiter); 1703 result == ISC_R_SUCCESS; 1704 result = dns_rdatasetiter_next(rdsiter)) 1705 { 1706 dns_rdataset_t rdataset; 1707 1708 dns_rdataset_init(&rdataset); 1709 dns_rdatasetiter_current(rdsiter, &rdataset); 1710 1711 for (result = dns_rdataset_first(&rdataset); 1712 result == ISC_R_SUCCESS; 1713 result = dns_rdataset_next(&rdataset)) 1714 { 1715 dns_rdata_t rdata = DNS_RDATA_INIT; 1716 dns_rdataset_current(&rdataset, &rdata); 1717 result = dns_difftuple_create(diff->mctx, op, name, 1718 rdataset.ttl, &rdata, 1719 &tuple); 1720 if (result != ISC_R_SUCCESS) { 1721 dns_rdataset_disassociate(&rdataset); 1722 goto cleanup_iterator; 1723 } 1724 dns_diff_append(diff, &tuple); 1725 } 1726 dns_rdataset_disassociate(&rdataset); 1727 if (result != ISC_R_NOMORE) 1728 goto cleanup_iterator; 1729 } 1730 if (result != ISC_R_NOMORE) 1731 goto cleanup_iterator; 1732 1733 result = ISC_R_SUCCESS; 1734 1735 cleanup_iterator: 1736 dns_rdatasetiter_destroy(&rdsiter); 1737 1738 cleanup_node: 1739 dns_db_detachnode(db, &node); 1740 1741 return (result); 1742} 1743 1744/* 1745 * Comparison function for use by dns_diff_subtract when sorting 1746 * the diffs to be subtracted. The sort keys are the rdata type 1747 * and the rdata itself. The owner name is ignored, because 1748 * it is known to be the same for all tuples. 1749 */ 1750static int 1751rdata_order(const void *av, const void *bv) { 1752 dns_difftuple_t const * const *ap = av; 1753 dns_difftuple_t const * const *bp = bv; 1754 dns_difftuple_t const *a = *ap; 1755 dns_difftuple_t const *b = *bp; 1756 int r; 1757 r = (b->rdata.type - a->rdata.type); 1758 if (r != 0) 1759 return (r); 1760 r = dns_rdata_compare(&a->rdata, &b->rdata); 1761 return (r); 1762} 1763 1764static isc_result_t 1765dns_diff_subtract(dns_diff_t diff[2], dns_diff_t *r) { 1766 isc_result_t result; 1767 dns_difftuple_t *p[2]; 1768 int i, t; 1769 isc_boolean_t append; 1770 1771 CHECK(dns_diff_sort(&diff[0], rdata_order)); 1772 CHECK(dns_diff_sort(&diff[1], rdata_order)); 1773 1774 for (;;) { 1775 p[0] = ISC_LIST_HEAD(diff[0].tuples); 1776 p[1] = ISC_LIST_HEAD(diff[1].tuples); 1777 if (p[0] == NULL && p[1] == NULL) 1778 break; 1779 1780 for (i = 0; i < 2; i++) 1781 if (p[!i] == NULL) { 1782 ISC_LIST_UNLINK(diff[i].tuples, p[i], link); 1783 ISC_LIST_APPEND(r->tuples, p[i], link); 1784 goto next; 1785 } 1786 t = rdata_order(&p[0], &p[1]); 1787 if (t < 0) { 1788 ISC_LIST_UNLINK(diff[0].tuples, p[0], link); 1789 ISC_LIST_APPEND(r->tuples, p[0], link); 1790 goto next; 1791 } 1792 if (t > 0) { 1793 ISC_LIST_UNLINK(diff[1].tuples, p[1], link); 1794 ISC_LIST_APPEND(r->tuples, p[1], link); 1795 goto next; 1796 } 1797 INSIST(t == 0); 1798 /* 1799 * Identical RRs in both databases; skip them both 1800 * if the ttl differs. 1801 */ 1802 append = ISC_TF(p[0]->ttl != p[1]->ttl); 1803 for (i = 0; i < 2; i++) { 1804 ISC_LIST_UNLINK(diff[i].tuples, p[i], link); 1805 if (append) { 1806 ISC_LIST_APPEND(r->tuples, p[i], link); 1807 } else { 1808 dns_difftuple_free(&p[i]); 1809 } 1810 } 1811 next: ; 1812 } 1813 result = ISC_R_SUCCESS; 1814 failure: 1815 return (result); 1816} 1817 1818/* 1819 * Compare the databases 'dba' and 'dbb' and generate a journal 1820 * entry containing the changes to make 'dba' from 'dbb' (note 1821 * the order). This journal entry will consist of a single, 1822 * possibly very large transaction. 1823 */ 1824 1825isc_result_t 1826dns_db_diff(isc_mem_t *mctx, 1827 dns_db_t *dba, dns_dbversion_t *dbvera, 1828 dns_db_t *dbb, dns_dbversion_t *dbverb, 1829 const char *journal_filename) 1830{ 1831 dns_db_t *db[2]; 1832 dns_dbversion_t *ver[2]; 1833 dns_dbiterator_t *dbit[2] = { NULL, NULL }; 1834 isc_boolean_t have[2] = { ISC_FALSE, ISC_FALSE }; 1835 dns_fixedname_t fixname[2]; 1836 isc_result_t result, itresult[2]; 1837 dns_diff_t diff[2], resultdiff; 1838 int i, t; 1839 dns_journal_t *journal = NULL; 1840 1841 db[0] = dba, db[1] = dbb; 1842 ver[0] = dbvera, ver[1] = dbverb; 1843 1844 dns_diff_init(mctx, &diff[0]); 1845 dns_diff_init(mctx, &diff[1]); 1846 dns_diff_init(mctx, &resultdiff); 1847 1848 dns_fixedname_init(&fixname[0]); 1849 dns_fixedname_init(&fixname[1]); 1850 1851 result = dns_journal_open(mctx, journal_filename, ISC_TRUE, &journal); 1852 if (result != ISC_R_SUCCESS) 1853 return (result); 1854 1855 result = dns_db_createiterator(db[0], ISC_FALSE, &dbit[0]); 1856 if (result != ISC_R_SUCCESS) 1857 goto cleanup_journal; 1858 result = dns_db_createiterator(db[1], ISC_FALSE, &dbit[1]); 1859 if (result != ISC_R_SUCCESS) 1860 goto cleanup_interator0; 1861 1862 itresult[0] = dns_dbiterator_first(dbit[0]); 1863 itresult[1] = dns_dbiterator_first(dbit[1]); 1864 1865 for (;;) { 1866 for (i = 0; i < 2; i++) { 1867 if (! have[i] && itresult[i] == ISC_R_SUCCESS) { 1868 CHECK(get_name_diff(db[i], ver[i], 0, dbit[i], 1869 dns_fixedname_name(&fixname[i]), 1870 i == 0 ? 1871 DNS_DIFFOP_ADD : 1872 DNS_DIFFOP_DEL, 1873 &diff[i])); 1874 itresult[i] = dns_dbiterator_next(dbit[i]); 1875 have[i] = ISC_TRUE; 1876 } 1877 } 1878 1879 if (! have[0] && ! have[1]) { 1880 INSIST(ISC_LIST_EMPTY(diff[0].tuples)); 1881 INSIST(ISC_LIST_EMPTY(diff[1].tuples)); 1882 break; 1883 } 1884 1885 for (i = 0; i < 2; i++) { 1886 if (! have[!i]) { 1887 ISC_LIST_APPENDLIST(resultdiff.tuples, 1888 diff[i].tuples, link); 1889 INSIST(ISC_LIST_EMPTY(diff[i].tuples)); 1890 have[i] = ISC_FALSE; 1891 goto next; 1892 } 1893 } 1894 1895 t = dns_name_compare(dns_fixedname_name(&fixname[0]), 1896 dns_fixedname_name(&fixname[1])); 1897 if (t < 0) { 1898 ISC_LIST_APPENDLIST(resultdiff.tuples, 1899 diff[0].tuples, link); 1900 INSIST(ISC_LIST_EMPTY(diff[0].tuples)); 1901 have[0] = ISC_FALSE; 1902 continue; 1903 } 1904 if (t > 0) { 1905 ISC_LIST_APPENDLIST(resultdiff.tuples, 1906 diff[1].tuples, link); 1907 INSIST(ISC_LIST_EMPTY(diff[1].tuples)); 1908 have[1] = ISC_FALSE; 1909 continue; 1910 } 1911 INSIST(t == 0); 1912 CHECK(dns_diff_subtract(diff, &resultdiff)); 1913 INSIST(ISC_LIST_EMPTY(diff[0].tuples)); 1914 INSIST(ISC_LIST_EMPTY(diff[1].tuples)); 1915 have[0] = have[1] = ISC_FALSE; 1916 next: ; 1917 } 1918 if (itresult[0] != ISC_R_NOMORE) 1919 FAIL(itresult[0]); 1920 if (itresult[1] != ISC_R_NOMORE) 1921 FAIL(itresult[1]); 1922 1923 if (ISC_LIST_EMPTY(resultdiff.tuples)) { 1924 isc_log_write(JOURNAL_DEBUG_LOGARGS(3), "no changes"); 1925 } else { 1926 CHECK(dns_journal_write_transaction(journal, &resultdiff)); 1927 } 1928 INSIST(ISC_LIST_EMPTY(diff[0].tuples)); 1929 INSIST(ISC_LIST_EMPTY(diff[1].tuples)); 1930 1931 failure: 1932 dns_diff_clear(&resultdiff); 1933 dns_dbiterator_destroy(&dbit[1]); 1934 cleanup_interator0: 1935 dns_dbiterator_destroy(&dbit[0]); 1936 cleanup_journal: 1937 dns_journal_destroy(&journal); 1938 return (result); 1939} 1940 1941isc_result_t 1942dns_journal_compact(isc_mem_t *mctx, char *filename, isc_uint32_t serial, 1943 isc_uint32_t target_size) 1944{ 1945 unsigned int i; 1946 journal_pos_t best_guess; 1947 journal_pos_t current_pos; 1948 dns_journal_t *j = NULL; 1949 dns_journal_t *new = NULL; 1950 journal_rawheader_t rawheader; 1951 unsigned int copy_length; 1952 int namelen; 1953 char *buf = NULL; 1954 unsigned int size = 0; 1955 isc_result_t result; 1956 unsigned int indexend; 1957 char newname[1024]; 1958 char backup[1024]; 1959 isc_boolean_t is_backup = ISC_FALSE; 1960 1961 namelen = strlen(filename); 1962 if (namelen > 4 && strcmp(filename + namelen - 4, ".jnl") == 0) 1963 namelen -= 4; 1964 1965 result = isc_string_printf(newname, sizeof(newname), "%.*s.jnw", 1966 namelen, filename); 1967 if (result != ISC_R_SUCCESS) 1968 return (result); 1969 1970 result = isc_string_printf(backup, sizeof(backup), "%.*s.jbk", 1971 namelen, filename); 1972 if (result != ISC_R_SUCCESS) 1973 return (result); 1974 1975 result = journal_open(mctx, filename, ISC_FALSE, ISC_FALSE, &j); 1976 if (result == ISC_R_NOTFOUND) { 1977 is_backup = ISC_TRUE; 1978 result = journal_open(mctx, backup, ISC_FALSE, ISC_FALSE, &j); 1979 } 1980 if (result != ISC_R_SUCCESS) 1981 return (result); 1982 1983 if (JOURNAL_EMPTY(&j->header)) { 1984 dns_journal_destroy(&j); 1985 return (ISC_R_SUCCESS); 1986 } 1987 1988 if (DNS_SERIAL_GT(j->header.begin.serial, serial) || 1989 DNS_SERIAL_GT(serial, j->header.end.serial)) { 1990 dns_journal_destroy(&j); 1991 return (ISC_R_RANGE); 1992 } 1993 1994 /* 1995 * Cope with very small target sizes. 1996 */ 1997 indexend = sizeof(journal_rawheader_t) + 1998 j->header.index_size * sizeof(journal_rawpos_t); 1999 if (target_size < indexend * 2) 2000 target_size = target_size/2 + indexend; 2001 2002 /* 2003 * See if there is any work to do. 2004 */ 2005 if ((isc_uint32_t) j->header.end.offset < target_size) { 2006 dns_journal_destroy(&j); 2007 return (ISC_R_SUCCESS); 2008 } 2009 2010 CHECK(journal_open(mctx, newname, ISC_TRUE, ISC_TRUE, &new)); 2011 2012 /* 2013 * Remove overhead so space test below can succeed. 2014 */ 2015 if (target_size >= indexend) 2016 target_size -= indexend; 2017 2018 /* 2019 * Find if we can create enough free space. 2020 */ 2021 best_guess = j->header.begin; 2022 for (i = 0; i < j->header.index_size; i++) { 2023 if (POS_VALID(j->index[i]) && 2024 DNS_SERIAL_GE(serial, j->index[i].serial) && 2025 ((isc_uint32_t)(j->header.end.offset - j->index[i].offset) 2026 >= target_size / 2) && 2027 j->index[i].offset > best_guess.offset) 2028 best_guess = j->index[i]; 2029 } 2030 2031 current_pos = best_guess; 2032 while (current_pos.serial != serial) { 2033 CHECK(journal_next(j, ¤t_pos)); 2034 if (current_pos.serial == j->header.end.serial) 2035 break; 2036 2037 if (DNS_SERIAL_GE(serial, current_pos.serial) && 2038 ((isc_uint32_t)(j->header.end.offset - current_pos.offset) 2039 >= (target_size / 2)) && 2040 current_pos.offset > best_guess.offset) 2041 best_guess = current_pos; 2042 else 2043 break; 2044 } 2045 2046 INSIST(best_guess.serial != j->header.end.serial); 2047 if (best_guess.serial != serial) 2048 CHECK(journal_next(j, &best_guess)); 2049 2050 /* 2051 * We should now be roughly half target_size provided 2052 * we did not reach 'serial'. If not we will just copy 2053 * all uncommitted deltas regardless of the size. 2054 */ 2055 copy_length = j->header.end.offset - best_guess.offset; 2056 2057 if (copy_length != 0) { 2058 /* 2059 * Copy best_guess to end into space just freed. 2060 */ 2061 size = 64*1024; 2062 if (copy_length < size) 2063 size = copy_length; 2064 buf = isc_mem_get(mctx, size); 2065 if (buf == NULL) { 2066 result = ISC_R_NOMEMORY; 2067 goto failure; 2068 } 2069 2070 CHECK(journal_seek(j, best_guess.offset)); 2071 CHECK(journal_seek(new, indexend)); 2072 for (i = 0; i < copy_length; i += size) { 2073 unsigned int len = (copy_length - i) > size ? size : 2074 (copy_length - i); 2075 CHECK(journal_read(j, buf, len)); 2076 CHECK(journal_write(new, buf, len)); 2077 } 2078 2079 CHECK(journal_fsync(new)); 2080 2081 /* 2082 * Compute new header. 2083 */ 2084 new->header.begin.serial = best_guess.serial; 2085 new->header.begin.offset = indexend; 2086 new->header.end.serial = j->header.end.serial; 2087 new->header.end.offset = indexend + copy_length; 2088 2089 /* 2090 * Update the journal header. 2091 */ 2092 journal_header_encode(&new->header, &rawheader); 2093 CHECK(journal_seek(new, 0)); 2094 CHECK(journal_write(new, &rawheader, sizeof(rawheader))); 2095 CHECK(journal_fsync(new)); 2096 2097 /* 2098 * Build new index. 2099 */ 2100 current_pos = new->header.begin; 2101 while (current_pos.serial != new->header.end.serial) { 2102 index_add(new, ¤t_pos); 2103 CHECK(journal_next(new, ¤t_pos)); 2104 } 2105 2106 /* 2107 * Write index. 2108 */ 2109 CHECK(index_to_disk(new)); 2110 CHECK(journal_fsync(new)); 2111 2112 indexend = new->header.end.offset; 2113 } 2114 dns_journal_destroy(&new); 2115 2116 /* 2117 * With a UFS file system this should just succeed and be atomic. 2118 * Any IXFR outs will just continue and the old journal will be 2119 * removed on final close. 2120 * 2121 * With MSDOS / NTFS we need to do a two stage rename triggered 2122 * bu EEXISTS. Hopefully all IXFR's that were active at the last 2123 * rename are now complete. 2124 */ 2125 if (rename(newname, filename) == -1) { 2126 if (errno == EACCES && !is_backup) { 2127 result = isc_file_remove(backup); 2128 if (result != ISC_R_SUCCESS && 2129 result != ISC_R_FILENOTFOUND) 2130 goto failure; 2131 if (rename(filename, backup) == -1) 2132 goto maperrno; 2133 if (rename(newname, filename) == -1) 2134 goto maperrno; 2135 (void)isc_file_remove(backup); 2136 } else { 2137 maperrno: 2138 result = ISC_R_FAILURE; 2139 goto failure; 2140 } 2141 } 2142 2143 dns_journal_destroy(&j); 2144 result = ISC_R_SUCCESS; 2145 2146 failure: 2147 (void)isc_file_remove(newname); 2148 if (buf != NULL) 2149 isc_mem_put(mctx, buf, size); 2150 if (j != NULL) 2151 dns_journal_destroy(&j); 2152 if (new != NULL) 2153 dns_journal_destroy(&new); 2154 return (result); 2155} 2156 2157static isc_result_t 2158index_to_disk(dns_journal_t *j) { 2159 isc_result_t result = ISC_R_SUCCESS; 2160 2161 if (j->header.index_size != 0) { 2162 unsigned int i; 2163 unsigned char *p; 2164 unsigned int rawbytes; 2165 2166 rawbytes = j->header.index_size * sizeof(journal_rawpos_t); 2167 2168 p = j->rawindex; 2169 for (i = 0; i < j->header.index_size; i++) { 2170 encode_uint32(j->index[i].serial, p); 2171 p += 4; 2172 encode_uint32(j->index[i].offset, p); 2173 p += 4; 2174 } 2175 INSIST(p == j->rawindex + rawbytes); 2176 2177 CHECK(journal_seek(j, sizeof(journal_rawheader_t))); 2178 CHECK(journal_write(j, j->rawindex, rawbytes)); 2179 } 2180failure: 2181 return (result); 2182} 2183