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6c8226d7d6
freebsd-skq/lib/dns/journal.c
dougb 6c8226d7d6 Vendor import of BIND 9.4.3
2008-12-23 18:35:21 +00:00

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/*
* Copyright (C) 2004, 2005, 2007, 2008 Internet Systems Consortium, Inc. ("ISC")
* Copyright (C) 1999-2002 Internet Software Consortium.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: journal.c,v 1.86.18.14 2008/09/25 04:01:36 tbox Exp $ */
#include <config.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <isc/file.h>
#include <isc/mem.h>
#include <isc/stdio.h>
#include <isc/string.h>
#include <isc/util.h>
#include <dns/compress.h>
#include <dns/db.h>
#include <dns/dbiterator.h>
#include <dns/diff.h>
#include <dns/fixedname.h>
#include <dns/journal.h>
#include <dns/log.h>
#include <dns/rdataset.h>
#include <dns/rdatasetiter.h>
#include <dns/result.h>
#include <dns/soa.h>
/*! \file
* \brief Journalling.
*
* A journal file consists of
*
* \li A fixed-size header of type journal_rawheader_t.
*
* \li The index. This is an unordered array of index entries
* of type journal_rawpos_t giving the locations
* of some arbitrary subset of the journal's addressable
* transactions. The index entries are used as hints to
* speed up the process of locating a transaction with a given
* serial number. Unused index entries have an "offset"
* field of zero. The size of the index can vary between
* journal files, but does not change during the lifetime
* of a file. The size can be zero.
*
* \li The journal data. This consists of one or more transactions.
* Each transaction begins with a transaction header of type
* journal_rawxhdr_t. The transaction header is followed by a
* sequence of RRs, similar in structure to an IXFR difference
* sequence (RFC1995). That is, the pre-transaction SOA,
* zero or more other deleted RRs, the post-transaction SOA,
* and zero or more other added RRs. Unlike in IXFR, each RR
* is prefixed with a 32-bit length.
*
* The journal data part grows as new transactions are
* appended to the file. Only those transactions
* whose serial number is current-(2^31-1) to current
* are considered "addressable" and may be pointed
* to from the header or index. They may be preceded
* by old transactions that are no longer addressable,
* and they may be followed by transactions that were
* appended to the journal but never committed by updating
* the "end" position in the header. The latter will
* be overwritten when new transactions are added.
*/
/*%
* When true, accept IXFR difference sequences where the
* SOA serial number does not change (BIND 8 sends such
* sequences).
*/
static isc_boolean_t bind8_compat = ISC_TRUE; /* XXX config */
/**************************************************************************/
/*
* Miscellaneous utilities.
*/
#define JOURNAL_COMMON_LOGARGS \
dns_lctx, DNS_LOGCATEGORY_GENERAL, DNS_LOGMODULE_JOURNAL
#define JOURNAL_DEBUG_LOGARGS(n) \
JOURNAL_COMMON_LOGARGS, ISC_LOG_DEBUG(n)
/*%
* It would be non-sensical (or at least obtuse) to use FAIL() with an
* ISC_R_SUCCESS code, but the test is there to keep the Solaris compiler
* from complaining about "end-of-loop code not reached".
*/
#define FAIL(code) \
do { result = (code); \
if (result != ISC_R_SUCCESS) goto failure; \
} while (0)
#define CHECK(op) \
do { result = (op); \
if (result != ISC_R_SUCCESS) goto failure; \
} while (0)
static isc_result_t index_to_disk(dns_journal_t *);
static inline isc_uint32_t
decode_uint32(unsigned char *p) {
return ((p[0] << 24) +
(p[1] << 16) +
(p[2] << 8) +
(p[3] << 0));
}
static inline void
encode_uint32(isc_uint32_t val, unsigned char *p) {
p[0] = (isc_uint8_t)(val >> 24);
p[1] = (isc_uint8_t)(val >> 16);
p[2] = (isc_uint8_t)(val >> 8);
p[3] = (isc_uint8_t)(val >> 0);
}
isc_result_t
dns_db_createsoatuple(dns_db_t *db, dns_dbversion_t *ver, isc_mem_t *mctx,
dns_diffop_t op, dns_difftuple_t **tp)
{
isc_result_t result;
dns_dbnode_t *node;
dns_rdataset_t rdataset;
dns_rdata_t rdata = DNS_RDATA_INIT;
dns_name_t *zonename;
zonename = dns_db_origin(db);
node = NULL;
result = dns_db_findnode(db, zonename, ISC_FALSE, &node);
if (result != ISC_R_SUCCESS)
goto nonode;
dns_rdataset_init(&rdataset);
result = dns_db_findrdataset(db, node, ver, dns_rdatatype_soa, 0,
(isc_stdtime_t)0, &rdataset, NULL);
if (result != ISC_R_SUCCESS)
goto freenode;
result = dns_rdataset_first(&rdataset);
if (result != ISC_R_SUCCESS)
goto freenode;
dns_rdataset_current(&rdataset, &rdata);
result = dns_difftuple_create(mctx, op, zonename, rdataset.ttl,
&rdata, tp);
dns_rdataset_disassociate(&rdataset);
dns_db_detachnode(db, &node);
return (ISC_R_SUCCESS);
freenode:
dns_db_detachnode(db, &node);
nonode:
UNEXPECTED_ERROR(__FILE__, __LINE__, "missing SOA");
return (result);
}
/* Journalling */
/*%
* On-disk representation of a "pointer" to a journal entry.
* These are used in the journal header to locate the beginning
* and end of the journal, and in the journal index to locate
* other transactions.
*/
typedef struct {
unsigned char serial[4]; /*%< SOA serial before update. */
/*
* XXXRTH Should offset be 8 bytes?
* XXXDCL ... probably, since isc_offset_t is 8 bytes on many OSs.
* XXXAG ... but we will not be able to seek >2G anyway on many
* platforms as long as we are using fseek() rather
* than lseek().
*/
unsigned char offset[4]; /*%< Offset from beginning of file. */
} journal_rawpos_t;
/*%
* The header is of a fixed size, with some spare room for future
* extensions.
*/
#define JOURNAL_HEADER_SIZE 64 /* Bytes. */
/*%
* The on-disk representation of the journal header.
* All numbers are stored in big-endian order.
*/
typedef union {
struct {
/*% File format version ID. */
unsigned char format[16];
/*% Position of the first addressable transaction */
journal_rawpos_t begin;
/*% Position of the next (yet nonexistent) transaction. */
journal_rawpos_t end;
/*% Number of index entries following the header. */
unsigned char index_size[4];
} h;
/* Pad the header to a fixed size. */
unsigned char pad[JOURNAL_HEADER_SIZE];
} journal_rawheader_t;
/*%
* The on-disk representation of the transaction header.
* There is one of these at the beginning of each transaction.
*/
typedef struct {
unsigned char size[4]; /*%< In bytes, excluding header. */
unsigned char serial0[4]; /*%< SOA serial before update. */
unsigned char serial1[4]; /*%< SOA serial after update. */
} journal_rawxhdr_t;
/*%
* The on-disk representation of the RR header.
* There is one of these at the beginning of each RR.
*/
typedef struct {
unsigned char size[4]; /*%< In bytes, excluding header. */
} journal_rawrrhdr_t;
/*%
* The in-core representation of the journal header.
*/
typedef struct {
isc_uint32_t serial;
isc_offset_t offset;
} journal_pos_t;
#define POS_VALID(pos) ((pos).offset != 0)
#define POS_INVALIDATE(pos) ((pos).offset = 0, (pos).serial = 0)
typedef struct {
unsigned char format[16];
journal_pos_t begin;
journal_pos_t end;
isc_uint32_t index_size;
} journal_header_t;
/*%
* The in-core representation of the transaction header.
*/
typedef struct {
isc_uint32_t size;
isc_uint32_t serial0;
isc_uint32_t serial1;
} journal_xhdr_t;
/*%
* The in-core representation of the RR header.
*/
typedef struct {
isc_uint32_t size;
} journal_rrhdr_t;
/*%
* Initial contents to store in the header of a newly created
* journal file.
*
* The header starts with the magic string ";BIND LOG V9\n"
* to identify the file as a BIND 9 journal file. An ASCII
* identification string is used rather than a binary magic
* number to be consistent with BIND 8 (BIND 8 journal files
* are ASCII text files).
*/
static journal_header_t
initial_journal_header = { ";BIND LOG V9\n", { 0, 0 }, { 0, 0 }, 0 };
#define JOURNAL_EMPTY(h) ((h)->begin.offset == (h)->end.offset)
typedef enum {
JOURNAL_STATE_INVALID,
JOURNAL_STATE_READ,
JOURNAL_STATE_WRITE,
JOURNAL_STATE_TRANSACTION
} journal_state_t;
struct dns_journal {
unsigned int magic; /*%< JOUR */
isc_mem_t *mctx; /*%< Memory context */
journal_state_t state;
const char *filename; /*%< Journal file name */
FILE * fp; /*%< File handle */
isc_offset_t offset; /*%< Current file offset */
journal_header_t header; /*%< In-core journal header */
unsigned char *rawindex; /*%< In-core buffer for journal index in on-disk format */
journal_pos_t *index; /*%< In-core journal index */
/*% Current transaction state (when writing). */
struct {
unsigned int n_soa; /*%< Number of SOAs seen */
journal_pos_t pos[2]; /*%< Begin/end position */
} x;
/*% Iteration state (when reading). */
struct {
/* These define the part of the journal we iterate over. */
journal_pos_t bpos; /*%< Position before first, */
journal_pos_t epos; /*%< and after last transaction */
/* The rest is iterator state. */
isc_uint32_t current_serial; /*%< Current SOA serial */
isc_buffer_t source; /*%< Data from disk */
isc_buffer_t target; /*%< Data from _fromwire check */
dns_decompress_t dctx; /*%< Dummy decompression ctx */
dns_name_t name; /*%< Current domain name */
dns_rdata_t rdata; /*%< Current rdata */
isc_uint32_t ttl; /*%< Current TTL */
unsigned int xsize; /*%< Size of transaction data */
unsigned int xpos; /*%< Current position in it */
isc_result_t result; /*%< Result of last call */
} it;
};
#define DNS_JOURNAL_MAGIC ISC_MAGIC('J', 'O', 'U', 'R')
#define DNS_JOURNAL_VALID(t) ISC_MAGIC_VALID(t, DNS_JOURNAL_MAGIC)
static void
journal_pos_decode(journal_rawpos_t *raw, journal_pos_t *cooked) {
cooked->serial = decode_uint32(raw->serial);
cooked->offset = decode_uint32(raw->offset);
}
static void
journal_pos_encode(journal_rawpos_t *raw, journal_pos_t *cooked) {
encode_uint32(cooked->serial, raw->serial);
encode_uint32(cooked->offset, raw->offset);
}
static void
journal_header_decode(journal_rawheader_t *raw, journal_header_t *cooked) {
INSIST(sizeof(cooked->format) == sizeof(raw->h.format));
memcpy(cooked->format, raw->h.format, sizeof(cooked->format));
journal_pos_decode(&raw->h.begin, &cooked->begin);
journal_pos_decode(&raw->h.end, &cooked->end);
cooked->index_size = decode_uint32(raw->h.index_size);
}
static void
journal_header_encode(journal_header_t *cooked, journal_rawheader_t *raw) {
INSIST(sizeof(cooked->format) == sizeof(raw->h.format));
memset(raw->pad, 0, sizeof(raw->pad));
memcpy(raw->h.format, cooked->format, sizeof(raw->h.format));
journal_pos_encode(&raw->h.begin, &cooked->begin);
journal_pos_encode(&raw->h.end, &cooked->end);
encode_uint32(cooked->index_size, raw->h.index_size);
}
/*
* Journal file I/O subroutines, with error checking and reporting.
*/
static isc_result_t
journal_seek(dns_journal_t *j, isc_uint32_t offset) {
isc_result_t result;
result = isc_stdio_seek(j->fp, (long)offset, SEEK_SET);
if (result != ISC_R_SUCCESS) {
isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR,
"%s: seek: %s", j->filename,
isc_result_totext(result));
return (ISC_R_UNEXPECTED);
}
j->offset = offset;
return (ISC_R_SUCCESS);
}
static isc_result_t
journal_read(dns_journal_t *j, void *mem, size_t nbytes) {
isc_result_t result;
result = isc_stdio_read(mem, 1, nbytes, j->fp, NULL);
if (result != ISC_R_SUCCESS) {
if (result == ISC_R_EOF)
return (ISC_R_NOMORE);
isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR,
"%s: read: %s",
j->filename, isc_result_totext(result));
return (ISC_R_UNEXPECTED);
}
j->offset += nbytes;
return (ISC_R_SUCCESS);
}
static isc_result_t
journal_write(dns_journal_t *j, void *mem, size_t nbytes) {
isc_result_t result;
result = isc_stdio_write(mem, 1, nbytes, j->fp, NULL);
if (result != ISC_R_SUCCESS) {
isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR,
"%s: write: %s",
j->filename, isc_result_totext(result));
return (ISC_R_UNEXPECTED);
}
j->offset += nbytes;
return (ISC_R_SUCCESS);
}
static isc_result_t
journal_fsync(dns_journal_t *j) {
isc_result_t result;
result = isc_stdio_flush(j->fp);
if (result != ISC_R_SUCCESS) {
isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR,
"%s: flush: %s",
j->filename, isc_result_totext(result));
return (ISC_R_UNEXPECTED);
}
result = isc_stdio_sync(j->fp);
if (result != ISC_R_SUCCESS) {
isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR,
"%s: fsync: %s",
j->filename, isc_result_totext(result));
return (ISC_R_UNEXPECTED);
}
return (ISC_R_SUCCESS);
}
/*
* Read/write a transaction header at the current file position.
*/
static isc_result_t
journal_read_xhdr(dns_journal_t *j, journal_xhdr_t *xhdr) {
journal_rawxhdr_t raw;
isc_result_t result;
result = journal_read(j, &raw, sizeof(raw));
if (result != ISC_R_SUCCESS)
return (result);
xhdr->size = decode_uint32(raw.size);
xhdr->serial0 = decode_uint32(raw.serial0);
xhdr->serial1 = decode_uint32(raw.serial1);
return (ISC_R_SUCCESS);
}
static isc_result_t
journal_write_xhdr(dns_journal_t *j, isc_uint32_t size,
isc_uint32_t serial0, isc_uint32_t serial1)
{
journal_rawxhdr_t raw;
encode_uint32(size, raw.size);
encode_uint32(serial0, raw.serial0);
encode_uint32(serial1, raw.serial1);
return (journal_write(j, &raw, sizeof(raw)));
}
/*
* Read an RR header at the current file position.
*/
static isc_result_t
journal_read_rrhdr(dns_journal_t *j, journal_rrhdr_t *rrhdr) {
journal_rawrrhdr_t raw;
isc_result_t result;
result = journal_read(j, &raw, sizeof(raw));
if (result != ISC_R_SUCCESS)
return (result);
rrhdr->size = decode_uint32(raw.size);
return (ISC_R_SUCCESS);
}
static isc_result_t
journal_file_create(isc_mem_t *mctx, const char *filename) {
FILE *fp = NULL;
isc_result_t result;
journal_header_t header;
journal_rawheader_t rawheader;
int index_size = 56; /* XXX configurable */
int size;
void *mem; /* Memory for temporary index image. */
INSIST(sizeof(journal_rawheader_t) == JOURNAL_HEADER_SIZE);
result = isc_stdio_open(filename, "wb", &fp);
if (result != ISC_R_SUCCESS) {
isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR,
"%s: create: %s",
filename, isc_result_totext(result));
return (ISC_R_UNEXPECTED);
}
header = initial_journal_header;
header.index_size = index_size;
journal_header_encode(&header, &rawheader);
size = sizeof(journal_rawheader_t) +
index_size * sizeof(journal_rawpos_t);
mem = isc_mem_get(mctx, size);
if (mem == NULL) {
(void)isc_stdio_close(fp);
(void)isc_file_remove(filename);
return (ISC_R_NOMEMORY);
}
memset(mem, 0, size);
memcpy(mem, &rawheader, sizeof(rawheader));
result = isc_stdio_write(mem, 1, (size_t) size, fp, NULL);
if (result != ISC_R_SUCCESS) {
isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR,
"%s: write: %s",
filename, isc_result_totext(result));
(void)isc_stdio_close(fp);
(void)isc_file_remove(filename);
isc_mem_put(mctx, mem, size);
return (ISC_R_UNEXPECTED);
}
isc_mem_put(mctx, mem, size);
result = isc_stdio_close(fp);
if (result != ISC_R_SUCCESS) {
isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR,
"%s: close: %s",
filename, isc_result_totext(result));
(void)isc_file_remove(filename);
return (ISC_R_UNEXPECTED);
}
return (ISC_R_SUCCESS);
}
static isc_result_t
journal_open(isc_mem_t *mctx, const char *filename, isc_boolean_t write,
isc_boolean_t create, dns_journal_t **journalp) {
FILE *fp = NULL;
isc_result_t result;
journal_rawheader_t rawheader;
dns_journal_t *j;
INSIST(journalp != NULL && *journalp == NULL);
j = isc_mem_get(mctx, sizeof(*j));
if (j == NULL)
return (ISC_R_NOMEMORY);
j->mctx = mctx;
j->state = JOURNAL_STATE_INVALID;
j->fp = NULL;
j->filename = filename;
j->index = NULL;
j->rawindex = NULL;
result = isc_stdio_open(j->filename, write ? "rb+" : "rb", &fp);
if (result == ISC_R_FILENOTFOUND) {
if (create) {
isc_log_write(JOURNAL_COMMON_LOGARGS,
ISC_LOG_INFO,
"journal file %s does not exist, "
"creating it",
j->filename);
CHECK(journal_file_create(mctx, filename));
/*
* Retry.
*/
result = isc_stdio_open(j->filename, "rb+", &fp);
} else {
FAIL(ISC_R_NOTFOUND);
}
}
if (result != ISC_R_SUCCESS) {
isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR,
"%s: open: %s",
j->filename, isc_result_totext(result));
FAIL(ISC_R_UNEXPECTED);
}
j->fp = fp;
/*
* Set magic early so that seek/read can succeed.
*/
j->magic = DNS_JOURNAL_MAGIC;
CHECK(journal_seek(j, 0));
CHECK(journal_read(j, &rawheader, sizeof(rawheader)));
if (memcmp(rawheader.h.format, initial_journal_header.format,
sizeof(initial_journal_header.format)) != 0) {
isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR,
"%s: journal format not recognized",
j->filename);
FAIL(ISC_R_UNEXPECTED);
}
journal_header_decode(&rawheader, &j->header);
/*
* If there is an index, read the raw index into a dynamically
* allocated buffer and then convert it into a cooked index.
*/
if (j->header.index_size != 0) {
unsigned int i;
unsigned int rawbytes;
unsigned char *p;
rawbytes = j->header.index_size * sizeof(journal_rawpos_t);
j->rawindex = isc_mem_get(mctx, rawbytes);
if (j->rawindex == NULL)
FAIL(ISC_R_NOMEMORY);
CHECK(journal_read(j, j->rawindex, rawbytes));
j->index = isc_mem_get(mctx, j->header.index_size *
sizeof(journal_pos_t));
if (j->index == NULL)
FAIL(ISC_R_NOMEMORY);
p = j->rawindex;
for (i = 0; i < j->header.index_size; i++) {
j->index[i].serial = decode_uint32(p);
p += 4;
j->index[i].offset = decode_uint32(p);
p += 4;
}
INSIST(p == j->rawindex + rawbytes);
}
j->offset = -1; /* Invalid, must seek explicitly. */
/*
* Initialize the iterator.
*/
dns_name_init(&j->it.name, NULL);
dns_rdata_init(&j->it.rdata);
/*
* Set up empty initial buffers for uncheched and checked
* wire format RR data. They will be reallocated
* later.
*/
isc_buffer_init(&j->it.source, NULL, 0);
isc_buffer_init(&j->it.target, NULL, 0);
dns_decompress_init(&j->it.dctx, -1, DNS_DECOMPRESS_NONE);
j->state =
write ? JOURNAL_STATE_WRITE : JOURNAL_STATE_READ;
*journalp = j;
return (ISC_R_SUCCESS);
failure:
j->magic = 0;
if (j->index != NULL) {
isc_mem_put(j->mctx, j->index, j->header.index_size *
sizeof(journal_rawpos_t));
j->index = NULL;
}
if (j->fp != NULL)
(void)isc_stdio_close(j->fp);
isc_mem_put(j->mctx, j, sizeof(*j));
return (result);
}
isc_result_t
dns_journal_open(isc_mem_t *mctx, const char *filename, isc_boolean_t write,
dns_journal_t **journalp) {
isc_result_t result;
int namelen;
char backup[1024];
result = journal_open(mctx, filename, write, write, journalp);
if (result == ISC_R_NOTFOUND) {
namelen = strlen(filename);
if (namelen > 4 && strcmp(filename + namelen - 4, ".jnl") == 0)
namelen -= 4;
result = isc_string_printf(backup, sizeof(backup), "%.*s.jbk",
namelen, filename);
if (result != ISC_R_SUCCESS)
return (result);
result = journal_open(mctx, backup, write, write, journalp);
}
return (result);
}
/*
* A comparison function defining the sorting order for
* entries in the IXFR-style journal file.
*
* The IXFR format requires that deletions are sorted before
* additions, and within either one, SOA records are sorted
* before others.
*
* Also sort the non-SOA records by type as a courtesy to the
* server receiving the IXFR - it may help reduce the amount of
* rdataset merging it has to do.
*/
static int
ixfr_order(const void *av, const void *bv) {
dns_difftuple_t const * const *ap = av;
dns_difftuple_t const * const *bp = bv;
dns_difftuple_t const *a = *ap;
dns_difftuple_t const *b = *bp;
int r;
r = (b->op == DNS_DIFFOP_DEL) - (a->op == DNS_DIFFOP_DEL);
if (r != 0)
return (r);
r = (b->rdata.type == dns_rdatatype_soa) -
(a->rdata.type == dns_rdatatype_soa);
if (r != 0)
return (r);
r = (a->rdata.type - b->rdata.type);
return (r);
}
/*
* Advance '*pos' to the next journal transaction.
*
* Requires:
* *pos refers to a valid journal transaction.
*
* Ensures:
* When ISC_R_SUCCESS is returned,
* *pos refers to the next journal transaction.
*
* Returns one of:
*
* ISC_R_SUCCESS
* ISC_R_NOMORE *pos pointed at the last transaction
* Other results due to file errors are possible.
*/
static isc_result_t
journal_next(dns_journal_t *j, journal_pos_t *pos) {
isc_result_t result;
journal_xhdr_t xhdr;
REQUIRE(DNS_JOURNAL_VALID(j));
result = journal_seek(j, pos->offset);
if (result != ISC_R_SUCCESS)
return (result);
if (pos->serial == j->header.end.serial)
return (ISC_R_NOMORE);
/*
* Read the header of the current transaction.
* This will return ISC_R_NOMORE if we are at EOF.
*/
result = journal_read_xhdr(j, &xhdr);
if (result != ISC_R_SUCCESS)
return (result);
/*
* Check serial number consistency.
*/
if (xhdr.serial0 != pos->serial) {
isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR,
"%s: journal file corrupt: "
"expected serial %u, got %u",
j->filename, pos->serial, xhdr.serial0);
return (ISC_R_UNEXPECTED);
}
/*
* Check for offset wraparound.
*/
if ((isc_offset_t)(pos->offset + sizeof(journal_rawxhdr_t) + xhdr.size)
< pos->offset) {
isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR,
"%s: offset too large", j->filename);
return (ISC_R_UNEXPECTED);
}
pos->offset += sizeof(journal_rawxhdr_t) + xhdr.size;
pos->serial = xhdr.serial1;
return (ISC_R_SUCCESS);
}
/*
* If the index of the journal 'j' contains an entry "better"
* than '*best_guess', replace '*best_guess' with it.
*
* "Better" means having a serial number closer to 'serial'
* but not greater than 'serial'.
*/
static void
index_find(dns_journal_t *j, isc_uint32_t serial, journal_pos_t *best_guess) {
unsigned int i;
if (j->index == NULL)
return;
for (i = 0; i < j->header.index_size; i++) {
if (POS_VALID(j->index[i]) &&
DNS_SERIAL_GE(serial, j->index[i].serial) &&
DNS_SERIAL_GT(j->index[i].serial, best_guess->serial))
*best_guess = j->index[i];
}
}
/*
* Add a new index entry. If there is no room, make room by removing
* the odd-numbered entries and compacting the others into the first
* half of the index. This decimates old index entries exponentially
* over time, so that the index always contains a much larger fraction
* of recent serial numbers than of old ones. This is deliberate -
* most index searches are for outgoing IXFR, and IXFR tends to request
* recent versions more often than old ones.
*/
static void
index_add(dns_journal_t *j, journal_pos_t *pos) {
unsigned int i;
if (j->index == NULL)
return;
/*
* Search for a vacant position.
*/
for (i = 0; i < j->header.index_size; i++) {
if (! POS_VALID(j->index[i]))
break;
}
if (i == j->header.index_size) {
unsigned int k = 0;
/*
* Found no vacant position. Make some room.
*/
for (i = 0; i < j->header.index_size; i += 2) {
j->index[k++] = j->index[i];
}
i = k; /* 'i' identifies the first vacant position. */
while (k < j->header.index_size) {
POS_INVALIDATE(j->index[k]);
k++;
}
}
INSIST(i < j->header.index_size);
INSIST(! POS_VALID(j->index[i]));
/*
* Store the new index entry.
*/
j->index[i] = *pos;
}
/*
* Invalidate any existing index entries that could become
* ambiguous when a new transaction with number 'serial' is added.
*/
static void
index_invalidate(dns_journal_t *j, isc_uint32_t serial) {
unsigned int i;
if (j->index == NULL)
return;
for (i = 0; i < j->header.index_size; i++) {
if (! DNS_SERIAL_GT(serial, j->index[i].serial))
POS_INVALIDATE(j->index[i]);
}
}
/*
* Try to find a transaction with initial serial number 'serial'
* in the journal 'j'.
*
* If found, store its position at '*pos' and return ISC_R_SUCCESS.
*
* If 'serial' is current (= the ending serial number of the
* last transaction in the journal), set '*pos' to
* the position immediately following the last transaction and
* return ISC_R_SUCCESS.
*
* If 'serial' is within the range of addressable serial numbers
* covered by the journal but that particular serial number is missing
* (from the journal, not just from the index), return ISC_R_NOTFOUND.
*
* If 'serial' is outside the range of addressable serial numbers
* covered by the journal, return ISC_R_RANGE.
*
*/
static isc_result_t
journal_find(dns_journal_t *j, isc_uint32_t serial, journal_pos_t *pos) {
isc_result_t result;
journal_pos_t current_pos;
REQUIRE(DNS_JOURNAL_VALID(j));
if (DNS_SERIAL_GT(j->header.begin.serial, serial))
return (ISC_R_RANGE);
if (DNS_SERIAL_GT(serial, j->header.end.serial))
return (ISC_R_RANGE);
if (serial == j->header.end.serial) {
*pos = j->header.end;
return (ISC_R_SUCCESS);
}
current_pos = j->header.begin;
index_find(j, serial, &current_pos);
while (current_pos.serial != serial) {
if (DNS_SERIAL_GT(current_pos.serial, serial))
return (ISC_R_NOTFOUND);
result = journal_next(j, &current_pos);
if (result != ISC_R_SUCCESS)
return (result);
}
*pos = current_pos;
return (ISC_R_SUCCESS);
}
isc_result_t
dns_journal_begin_transaction(dns_journal_t *j) {
isc_uint32_t offset;
isc_result_t result;
journal_rawxhdr_t hdr;
REQUIRE(DNS_JOURNAL_VALID(j));
REQUIRE(j->state == JOURNAL_STATE_WRITE);
/*
* Find the file offset where the new transaction should
* be written, and seek there.
*/
if (JOURNAL_EMPTY(&j->header)) {
offset = sizeof(journal_rawheader_t) +
j->header.index_size * sizeof(journal_rawpos_t);
} else {
offset = j->header.end.offset;
}
j->x.pos[0].offset = offset;
j->x.pos[1].offset = offset; /* Initial value, will be incremented. */
j->x.n_soa = 0;
CHECK(journal_seek(j, offset));
/*
* Write a dummy transaction header of all zeroes to reserve
* space. It will be filled in when the transaction is
* finished.
*/
memset(&hdr, 0, sizeof(hdr));
CHECK(journal_write(j, &hdr, sizeof(hdr)));
j->x.pos[1].offset = j->offset;
j->state = JOURNAL_STATE_TRANSACTION;
result = ISC_R_SUCCESS;
failure:
return (result);
}
isc_result_t
dns_journal_writediff(dns_journal_t *j, dns_diff_t *diff) {
dns_difftuple_t *t;
isc_buffer_t buffer;
void *mem = NULL;
unsigned int size;
isc_result_t result;
isc_region_t used;
REQUIRE(DNS_DIFF_VALID(diff));
REQUIRE(j->state == JOURNAL_STATE_TRANSACTION);
isc_log_write(JOURNAL_DEBUG_LOGARGS(3), "writing to journal");
(void)dns_diff_print(diff, NULL);
/*
* Pass 1: determine the buffer size needed, and
* keep track of SOA serial numbers.
*/
size = 0;
for (t = ISC_LIST_HEAD(diff->tuples); t != NULL;
t = ISC_LIST_NEXT(t, link))
{
if (t->rdata.type == dns_rdatatype_soa) {
if (j->x.n_soa < 2)
j->x.pos[j->x.n_soa].serial =
dns_soa_getserial(&t->rdata);
j->x.n_soa++;
}
size += sizeof(journal_rawrrhdr_t);
size += t->name.length; /* XXX should have access macro? */
size += 10;
size += t->rdata.length;
}
mem = isc_mem_get(j->mctx, size);
if (mem == NULL)
return (ISC_R_NOMEMORY);
isc_buffer_init(&buffer, mem, size);
/*
* Pass 2. Write RRs to buffer.
*/
for (t = ISC_LIST_HEAD(diff->tuples); t != NULL;
t = ISC_LIST_NEXT(t, link))
{
/*
* Write the RR header.
*/
isc_buffer_putuint32(&buffer, t->name.length + 10 +
t->rdata.length);
/*
* Write the owner name, RR header, and RR data.
*/
isc_buffer_putmem(&buffer, t->name.ndata, t->name.length);
isc_buffer_putuint16(&buffer, t->rdata.type);
isc_buffer_putuint16(&buffer, t->rdata.rdclass);
isc_buffer_putuint32(&buffer, t->ttl);
INSIST(t->rdata.length < 65536);
isc_buffer_putuint16(&buffer, (isc_uint16_t)t->rdata.length);
INSIST(isc_buffer_availablelength(&buffer) >= t->rdata.length);
isc_buffer_putmem(&buffer, t->rdata.data, t->rdata.length);
}
isc_buffer_usedregion(&buffer, &used);
INSIST(used.length == size);
j->x.pos[1].offset += used.length;
/*
* Write the buffer contents to the journal file.
*/
CHECK(journal_write(j, used.base, used.length));
result = ISC_R_SUCCESS;
failure:
if (mem != NULL)
isc_mem_put(j->mctx, mem, size);
return (result);
}
isc_result_t
dns_journal_commit(dns_journal_t *j) {
isc_result_t result;
journal_rawheader_t rawheader;
REQUIRE(DNS_JOURNAL_VALID(j));
REQUIRE(j->state == JOURNAL_STATE_TRANSACTION);
/*
* Perform some basic consistency checks.
*/
if (j->x.n_soa != 2) {
isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR,
"%s: malformed transaction: %d SOAs",
j->filename, j->x.n_soa);
return (ISC_R_UNEXPECTED);
}
if (! (DNS_SERIAL_GT(j->x.pos[1].serial, j->x.pos[0].serial) ||
(bind8_compat &&
j->x.pos[1].serial == j->x.pos[0].serial)))
{
isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR,
"%s: malformed transaction: serial number "
"would decrease", j->filename);
return (ISC_R_UNEXPECTED);
}
if (! JOURNAL_EMPTY(&j->header)) {
if (j->x.pos[0].serial != j->header.end.serial) {
isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR,
"malformed transaction: "
"%s last serial %u != "
"transaction first serial %u",
j->filename,
j->header.end.serial,
j->x.pos[0].serial);
return (ISC_R_UNEXPECTED);
}
}
/*
* Some old journal entries may become non-addressable
* when we increment the current serial number. Purge them
* by stepping header.begin forward to the first addressable
* transaction. Also purge them from the index.
*/
if (! JOURNAL_EMPTY(&j->header)) {
while (! DNS_SERIAL_GT(j->x.pos[1].serial,
j->header.begin.serial)) {
CHECK(journal_next(j, &j->header.begin));
}
index_invalidate(j, j->x.pos[1].serial);
}
#ifdef notyet
if (DNS_SERIAL_GT(last_dumped_serial, j->x.pos[1].serial)) {
force_dump(...);
}
#endif
/*
* Commit the transaction data to stable storage.
*/
CHECK(journal_fsync(j));
/*
* Update the transaction header.
*/
CHECK(journal_seek(j, j->x.pos[0].offset));
CHECK(journal_write_xhdr(j, (j->x.pos[1].offset - j->x.pos[0].offset) -
sizeof(journal_rawxhdr_t),
j->x.pos[0].serial, j->x.pos[1].serial));
/*
* Update the journal header.
*/
if (JOURNAL_EMPTY(&j->header)) {
j->header.begin = j->x.pos[0];
}
j->header.end = j->x.pos[1];
journal_header_encode(&j->header, &rawheader);
CHECK(journal_seek(j, 0));
CHECK(journal_write(j, &rawheader, sizeof(rawheader)));
/*
* Update the index.
*/
index_add(j, &j->x.pos[0]);
/*
* Convert the index into on-disk format and write
* it to disk.
*/
CHECK(index_to_disk(j));
/*
* Commit the header to stable storage.
*/
CHECK(journal_fsync(j));
/*
* We no longer have a transaction open.
*/
j->state = JOURNAL_STATE_WRITE;
result = ISC_R_SUCCESS;
failure:
return (result);
}
isc_result_t
dns_journal_write_transaction(dns_journal_t *j, dns_diff_t *diff) {
isc_result_t result;
CHECK(dns_diff_sort(diff, ixfr_order));
CHECK(dns_journal_begin_transaction(j));
CHECK(dns_journal_writediff(j, diff));
CHECK(dns_journal_commit(j));
result = ISC_R_SUCCESS;
failure:
return (result);
}
void
dns_journal_destroy(dns_journal_t **journalp) {
dns_journal_t *j = *journalp;
REQUIRE(DNS_JOURNAL_VALID(j));
j->it.result = ISC_R_FAILURE;
dns_name_invalidate(&j->it.name);
dns_decompress_invalidate(&j->it.dctx);
if (j->rawindex != NULL)
isc_mem_put(j->mctx, j->rawindex, j->header.index_size *
sizeof(journal_rawpos_t));
if (j->index != NULL)
isc_mem_put(j->mctx, j->index, j->header.index_size *
sizeof(journal_pos_t));
if (j->it.target.base != NULL)
isc_mem_put(j->mctx, j->it.target.base, j->it.target.length);
if (j->it.source.base != NULL)
isc_mem_put(j->mctx, j->it.source.base, j->it.source.length);
if (j->fp != NULL)
(void)isc_stdio_close(j->fp);
j->magic = 0;
isc_mem_put(j->mctx, j, sizeof(*j));
*journalp = NULL;
}
/*
* Roll the open journal 'j' into the database 'db'.
* A new database version will be created.
*/
/* XXX Share code with incoming IXFR? */
static isc_result_t
roll_forward(dns_journal_t *j, dns_db_t *db) {
isc_buffer_t source; /* Transaction data from disk */
isc_buffer_t target; /* Ditto after _fromwire check */
isc_uint32_t db_serial; /* Database SOA serial */
isc_uint32_t end_serial; /* Last journal SOA serial */
isc_result_t result;
dns_dbversion_t *ver = NULL;
journal_pos_t pos;
dns_diff_t diff;
unsigned int n_soa = 0;
unsigned int n_put = 0;
REQUIRE(DNS_JOURNAL_VALID(j));
REQUIRE(DNS_DB_VALID(db));
dns_diff_init(j->mctx, &diff);
/*
* Set up empty initial buffers for uncheched and checked
* wire format transaction data. They will be reallocated
* later.
*/
isc_buffer_init(&source, NULL, 0);
isc_buffer_init(&target, NULL, 0);
/*
* Create the new database version.
*/
CHECK(dns_db_newversion(db, &ver));
/*
* Get the current database SOA serial number.
*/
CHECK(dns_db_getsoaserial(db, ver, &db_serial));
/*
* Locate a journal entry for the current database serial.
*/
CHECK(journal_find(j, db_serial, &pos));
/*
* XXX do more drastic things, like marking zone stale,
* if this fails?
*/
/*
* XXXRTH The zone code should probably mark the zone as bad and
* scream loudly into the log if this is a dynamic update
* log reply that failed.
*/
end_serial = dns_journal_last_serial(j);
if (db_serial == end_serial)
CHECK(DNS_R_UPTODATE);
CHECK(dns_journal_iter_init(j, db_serial, end_serial));
for (result = dns_journal_first_rr(j);
result == ISC_R_SUCCESS;
result = dns_journal_next_rr(j))
{
dns_name_t *name;
isc_uint32_t ttl;
dns_rdata_t *rdata;
dns_difftuple_t *tuple = NULL;
name = NULL;
rdata = NULL;
dns_journal_current_rr(j, &name, &ttl, &rdata);
if (rdata->type == dns_rdatatype_soa) {
n_soa++;
if (n_soa == 2)
db_serial = j->it.current_serial;
}
if (n_soa == 3)
n_soa = 1;
if (n_soa == 0) {
isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR,
"%s: journal file corrupt: missing "
"initial SOA", j->filename);
FAIL(ISC_R_UNEXPECTED);
}
CHECK(dns_difftuple_create(diff.mctx, n_soa == 1 ?
DNS_DIFFOP_DEL : DNS_DIFFOP_ADD,
name, ttl, rdata, &tuple));
dns_diff_append(&diff, &tuple);
if (++n_put > 100) {
isc_log_write(JOURNAL_DEBUG_LOGARGS(3),
"%s: applying diff to database (%u)",
j->filename, db_serial);
(void)dns_diff_print(&diff, NULL);
CHECK(dns_diff_apply(&diff, db, ver));
dns_diff_clear(&diff);
n_put = 0;
}
}
if (result == ISC_R_NOMORE)
result = ISC_R_SUCCESS;
CHECK(result);
if (n_put != 0) {
isc_log_write(JOURNAL_DEBUG_LOGARGS(3),
"%s: applying final diff to database (%u)",
j->filename, db_serial);
(void)dns_diff_print(&diff, NULL);
CHECK(dns_diff_apply(&diff, db, ver));
dns_diff_clear(&diff);
}
failure:
if (ver != NULL)
dns_db_closeversion(db, &ver, result == ISC_R_SUCCESS ?
ISC_TRUE : ISC_FALSE);
if (source.base != NULL)
isc_mem_put(j->mctx, source.base, source.length);
if (target.base != NULL)
isc_mem_put(j->mctx, target.base, target.length);
dns_diff_clear(&diff);
return (result);
}
isc_result_t
dns_journal_rollforward(isc_mem_t *mctx, dns_db_t *db, const char *filename) {
dns_journal_t *j;
isc_result_t result;
REQUIRE(DNS_DB_VALID(db));
REQUIRE(filename != NULL);
j = NULL;
result = dns_journal_open(mctx, filename, ISC_FALSE, &j);
if (result == ISC_R_NOTFOUND) {
isc_log_write(JOURNAL_DEBUG_LOGARGS(3),
"no journal file, but that's OK");
return (DNS_R_NOJOURNAL);
}
if (result != ISC_R_SUCCESS)
return (result);
if (JOURNAL_EMPTY(&j->header))
result = DNS_R_UPTODATE;
else
result = roll_forward(j, db);
dns_journal_destroy(&j);
return (result);
}
isc_result_t
dns_journal_print(isc_mem_t *mctx, const char *filename, FILE *file) {
dns_journal_t *j;
isc_buffer_t source; /* Transaction data from disk */
isc_buffer_t target; /* Ditto after _fromwire check */
isc_uint32_t start_serial; /* Database SOA serial */
isc_uint32_t end_serial; /* Last journal SOA serial */
isc_result_t result;
dns_diff_t diff;
unsigned int n_soa = 0;
unsigned int n_put = 0;
REQUIRE(filename != NULL);
j = NULL;
result = dns_journal_open(mctx, filename, ISC_FALSE, &j);
if (result == ISC_R_NOTFOUND) {
isc_log_write(JOURNAL_DEBUG_LOGARGS(3), "no journal file");
return (DNS_R_NOJOURNAL);
}
if (result != ISC_R_SUCCESS) {
isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR,
"journal open failure: %s: %s",
isc_result_totext(result), filename);
return (result);
}
dns_diff_init(j->mctx, &diff);
/*
* Set up empty initial buffers for uncheched and checked
* wire format transaction data. They will be reallocated
* later.
*/
isc_buffer_init(&source, NULL, 0);
isc_buffer_init(&target, NULL, 0);
start_serial = dns_journal_first_serial(j);
end_serial = dns_journal_last_serial(j);
CHECK(dns_journal_iter_init(j, start_serial, end_serial));
for (result = dns_journal_first_rr(j);
result == ISC_R_SUCCESS;
result = dns_journal_next_rr(j))
{
dns_name_t *name;
isc_uint32_t ttl;
dns_rdata_t *rdata;
dns_difftuple_t *tuple = NULL;
name = NULL;
rdata = NULL;
dns_journal_current_rr(j, &name, &ttl, &rdata);
if (rdata->type == dns_rdatatype_soa)
n_soa++;
if (n_soa == 3)
n_soa = 1;
if (n_soa == 0) {
isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR,
"%s: journal file corrupt: missing "
"initial SOA", j->filename);
FAIL(ISC_R_UNEXPECTED);
}
CHECK(dns_difftuple_create(diff.mctx, n_soa == 1 ?
DNS_DIFFOP_DEL : DNS_DIFFOP_ADD,
name, ttl, rdata, &tuple));
dns_diff_append(&diff, &tuple);
if (++n_put > 100) {
result = dns_diff_print(&diff, file);
dns_diff_clear(&diff);
n_put = 0;
if (result != ISC_R_SUCCESS)
break;
}
}
if (result == ISC_R_NOMORE)
result = ISC_R_SUCCESS;
CHECK(result);
if (n_put != 0) {
result = dns_diff_print(&diff, file);
dns_diff_clear(&diff);
}
goto cleanup;
failure:
isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR,
"%s: cannot print: journal file corrupt", j->filename);
cleanup:
if (source.base != NULL)
isc_mem_put(j->mctx, source.base, source.length);
if (target.base != NULL)
isc_mem_put(j->mctx, target.base, target.length);
dns_diff_clear(&diff);
dns_journal_destroy(&j);
return (result);
}
/**************************************************************************/
/*
* Miscellaneous accessors.
*/
isc_uint32_t dns_journal_first_serial(dns_journal_t *j) {
return (j->header.begin.serial);
}
isc_uint32_t dns_journal_last_serial(dns_journal_t *j) {
return (j->header.end.serial);
}
/**************************************************************************/
/*
* Iteration support.
*
* When serving an outgoing IXFR, we transmit a part the journal starting
* at the serial number in the IXFR request and ending at the serial
* number that is current when the IXFR request arrives. The ending
* serial number is not necessarily at the end of the journal:
* the journal may grow while the IXFR is in progress, but we stop
* when we reach the serial number that was current when the IXFR started.
*/
static isc_result_t read_one_rr(dns_journal_t *j);
/*
* Make sure the buffer 'b' is has at least 'size' bytes
* allocated, and clear it.
*
* Requires:
* Either b->base is NULL, or it points to b->length bytes of memory
* previously allocated by isc_mem_get().
*/
static isc_result_t
size_buffer(isc_mem_t *mctx, isc_buffer_t *b, unsigned size) {
if (b->length < size) {
void *mem = isc_mem_get(mctx, size);
if (mem == NULL)
return (ISC_R_NOMEMORY);
if (b->base != NULL)
isc_mem_put(mctx, b->base, b->length);
b->base = mem;
b->length = size;
}
isc_buffer_clear(b);
return (ISC_R_SUCCESS);
}
isc_result_t
dns_journal_iter_init(dns_journal_t *j,
isc_uint32_t begin_serial, isc_uint32_t end_serial)
{
isc_result_t result;
CHECK(journal_find(j, begin_serial, &j->it.bpos));
INSIST(j->it.bpos.serial == begin_serial);
CHECK(journal_find(j, end_serial, &j->it.epos));
INSIST(j->it.epos.serial == end_serial);
result = ISC_R_SUCCESS;
failure:
j->it.result = result;
return (j->it.result);
}
isc_result_t
dns_journal_first_rr(dns_journal_t *j) {
isc_result_t result;
/*
* Seek to the beginning of the first transaction we are
* interested in.
*/
CHECK(journal_seek(j, j->it.bpos.offset));
j->it.current_serial = j->it.bpos.serial;
j->it.xsize = 0; /* We have no transaction data yet... */
j->it.xpos = 0; /* ...and haven't used any of it. */
return (read_one_rr(j));
failure:
return (result);
}
static isc_result_t
read_one_rr(dns_journal_t *j) {
isc_result_t result;
dns_rdatatype_t rdtype;
dns_rdataclass_t rdclass;
unsigned int rdlen;
isc_uint32_t ttl;
journal_xhdr_t xhdr;
journal_rrhdr_t rrhdr;
INSIST(j->offset <= j->it.epos.offset);
if (j->offset == j->it.epos.offset)
return (ISC_R_NOMORE);
if (j->it.xpos == j->it.xsize) {
/*
* We are at a transaction boundary.
* Read another transaction header.
*/
CHECK(journal_read_xhdr(j, &xhdr));
if (xhdr.size == 0) {
isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR,
"%s: journal corrupt: empty transaction",
j->filename);
FAIL(ISC_R_UNEXPECTED);
}
if (xhdr.serial0 != j->it.current_serial) {
isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR,
"%s: journal file corrupt: "
"expected serial %u, got %u",
j->filename,
j->it.current_serial, xhdr.serial0);
FAIL(ISC_R_UNEXPECTED);
}
j->it.xsize = xhdr.size;
j->it.xpos = 0;
}
/*
* Read an RR.
*/
CHECK(journal_read_rrhdr(j, &rrhdr));
/*
* Perform a sanity check on the journal RR size.
* The smallest possible RR has a 1-byte owner name
* and a 10-byte header. The largest possible
* RR has 65535 bytes of data, a header, and a maximum-
* size owner name, well below 70 k total.
*/
if (rrhdr.size < 1+10 || rrhdr.size > 70000) {
isc_log_write(JOURNAL_COMMON_LOGARGS, ISC_LOG_ERROR,
"%s: journal corrupt: impossible RR size "
"(%d bytes)", j->filename, rrhdr.size);
FAIL(ISC_R_UNEXPECTED);
}
CHECK(size_buffer(j->mctx, &j->it.source, rrhdr.size));
CHECK(journal_read(j, j->it.source.base, rrhdr.size));
isc_buffer_add(&j->it.source, rrhdr.size);
/*
* The target buffer is made the same size
* as the source buffer, with the assumption that when
* no compression in present, the output of dns_*_fromwire()
* is no larger than the input.
*/
CHECK(size_buffer(j->mctx, &j->it.target, rrhdr.size));
/*
* Parse the owner name. We don't know where it
* ends yet, so we make the entire "remaining"
* part of the buffer "active".
*/
isc_buffer_setactive(&j->it.source,
j->it.source.used - j->it.source.current);
CHECK(dns_name_fromwire(&j->it.name, &j->it.source,
&j->it.dctx, 0, &j->it.target));
/*
* Check that the RR header is there, and parse it.
*/
if (isc_buffer_remaininglength(&j->it.source) < 10)
FAIL(DNS_R_FORMERR);
rdtype = isc_buffer_getuint16(&j->it.source);
rdclass = isc_buffer_getuint16(&j->it.source);
ttl = isc_buffer_getuint32(&j->it.source);
rdlen = isc_buffer_getuint16(&j->it.source);
/*
* Parse the rdata.
*/
if (isc_buffer_remaininglength(&j->it.source) != rdlen)
FAIL(DNS_R_FORMERR);
isc_buffer_setactive(&j->it.source, rdlen);
dns_rdata_reset(&j->it.rdata);
CHECK(dns_rdata_fromwire(&j->it.rdata, rdclass,
rdtype, &j->it.source, &j->it.dctx,
0, &j->it.target));
j->it.ttl = ttl;
j->it.xpos += sizeof(journal_rawrrhdr_t) + rrhdr.size;
if (rdtype == dns_rdatatype_soa) {
/* XXX could do additional consistency checks here */
j->it.current_serial = dns_soa_getserial(&j->it.rdata);
}
result = ISC_R_SUCCESS;
failure:
j->it.result = result;
return (result);
}
isc_result_t
dns_journal_next_rr(dns_journal_t *j) {
j->it.result = read_one_rr(j);
return (j->it.result);
}
void
dns_journal_current_rr(dns_journal_t *j, dns_name_t **name, isc_uint32_t *ttl,
dns_rdata_t **rdata)
{
REQUIRE(j->it.result == ISC_R_SUCCESS);
*name = &j->it.name;
*ttl = j->it.ttl;
*rdata = &j->it.rdata;
}
/**************************************************************************/
/*
* Generating diffs from databases
*/
/*
* Construct a diff containing all the RRs at the current name of the
* database iterator 'dbit' in database 'db', version 'ver'.
* Set '*name' to the current name, and append the diff to 'diff'.
* All new tuples will have the operation 'op'.
*
* Requires: 'name' must have buffer large enough to hold the name.
* Typically, a dns_fixedname_t would be used.
*/
static isc_result_t
get_name_diff(dns_db_t *db, dns_dbversion_t *ver, isc_stdtime_t now,
dns_dbiterator_t *dbit, dns_name_t *name, dns_diffop_t op,
dns_diff_t *diff)
{
isc_result_t result;
dns_dbnode_t *node = NULL;
dns_rdatasetiter_t *rdsiter = NULL;
dns_difftuple_t *tuple = NULL;
result = dns_dbiterator_current(dbit, &node, name);
if (result != ISC_R_SUCCESS)
return (result);
result = dns_db_allrdatasets(db, node, ver, now, &rdsiter);
if (result != ISC_R_SUCCESS)
goto cleanup_node;
for (result = dns_rdatasetiter_first(rdsiter);
result == ISC_R_SUCCESS;
result = dns_rdatasetiter_next(rdsiter))
{
dns_rdataset_t rdataset;
dns_rdataset_init(&rdataset);
dns_rdatasetiter_current(rdsiter, &rdataset);
for (result = dns_rdataset_first(&rdataset);
result == ISC_R_SUCCESS;
result = dns_rdataset_next(&rdataset))
{
dns_rdata_t rdata = DNS_RDATA_INIT;
dns_rdataset_current(&rdataset, &rdata);
result = dns_difftuple_create(diff->mctx, op, name,
rdataset.ttl, &rdata,
&tuple);
if (result != ISC_R_SUCCESS) {
dns_rdataset_disassociate(&rdataset);
goto cleanup_iterator;
}
dns_diff_append(diff, &tuple);
}
dns_rdataset_disassociate(&rdataset);
if (result != ISC_R_NOMORE)
goto cleanup_iterator;
}
if (result != ISC_R_NOMORE)
goto cleanup_iterator;
result = ISC_R_SUCCESS;
cleanup_iterator:
dns_rdatasetiter_destroy(&rdsiter);
cleanup_node:
dns_db_detachnode(db, &node);
return (result);
}
/*
* Comparison function for use by dns_diff_subtract when sorting
* the diffs to be subtracted. The sort keys are the rdata type
* and the rdata itself. The owner name is ignored, because
* it is known to be the same for all tuples.
*/
static int
rdata_order(const void *av, const void *bv) {
dns_difftuple_t const * const *ap = av;
dns_difftuple_t const * const *bp = bv;
dns_difftuple_t const *a = *ap;
dns_difftuple_t const *b = *bp;
int r;
r = (b->rdata.type - a->rdata.type);
if (r != 0)
return (r);
r = dns_rdata_compare(&a->rdata, &b->rdata);
return (r);
}
static isc_result_t
dns_diff_subtract(dns_diff_t diff[2], dns_diff_t *r) {
isc_result_t result;
dns_difftuple_t *p[2];
int i, t;
isc_boolean_t append;
CHECK(dns_diff_sort(&diff[0], rdata_order));
CHECK(dns_diff_sort(&diff[1], rdata_order));
for (;;) {
p[0] = ISC_LIST_HEAD(diff[0].tuples);
p[1] = ISC_LIST_HEAD(diff[1].tuples);
if (p[0] == NULL && p[1] == NULL)
break;
for (i = 0; i < 2; i++)
if (p[!i] == NULL) {
ISC_LIST_UNLINK(diff[i].tuples, p[i], link);
ISC_LIST_APPEND(r->tuples, p[i], link);
goto next;
}
t = rdata_order(&p[0], &p[1]);
if (t < 0) {
ISC_LIST_UNLINK(diff[0].tuples, p[0], link);
ISC_LIST_APPEND(r->tuples, p[0], link);
goto next;
}
if (t > 0) {
ISC_LIST_UNLINK(diff[1].tuples, p[1], link);
ISC_LIST_APPEND(r->tuples, p[1], link);
goto next;
}
INSIST(t == 0);
/*
* Identical RRs in both databases; skip them both
* if the ttl differs.
*/
append = ISC_TF(p[0]->ttl != p[1]->ttl);
for (i = 0; i < 2; i++) {
ISC_LIST_UNLINK(diff[i].tuples, p[i], link);
if (append) {
ISC_LIST_APPEND(r->tuples, p[i], link);
} else {
dns_difftuple_free(&p[i]);
}
}
next: ;
}
result = ISC_R_SUCCESS;
failure:
return (result);
}
/*
* Compare the databases 'dba' and 'dbb' and generate a journal
* entry containing the changes to make 'dba' from 'dbb' (note
* the order). This journal entry will consist of a single,
* possibly very large transaction.
*/
isc_result_t
dns_db_diff(isc_mem_t *mctx,
dns_db_t *dba, dns_dbversion_t *dbvera,
dns_db_t *dbb, dns_dbversion_t *dbverb,
const char *journal_filename)
{
dns_db_t *db[2];
dns_dbversion_t *ver[2];
dns_dbiterator_t *dbit[2] = { NULL, NULL };
isc_boolean_t have[2] = { ISC_FALSE, ISC_FALSE };
dns_fixedname_t fixname[2];
isc_result_t result, itresult[2];
dns_diff_t diff[2], resultdiff;
int i, t;
dns_journal_t *journal = NULL;
db[0] = dba, db[1] = dbb;
ver[0] = dbvera, ver[1] = dbverb;
dns_diff_init(mctx, &diff[0]);
dns_diff_init(mctx, &diff[1]);
dns_diff_init(mctx, &resultdiff);
dns_fixedname_init(&fixname[0]);
dns_fixedname_init(&fixname[1]);
result = dns_journal_open(mctx, journal_filename, ISC_TRUE, &journal);
if (result != ISC_R_SUCCESS)
return (result);
result = dns_db_createiterator(db[0], ISC_FALSE, &dbit[0]);
if (result != ISC_R_SUCCESS)
goto cleanup_journal;
result = dns_db_createiterator(db[1], ISC_FALSE, &dbit[1]);
if (result != ISC_R_SUCCESS)
goto cleanup_interator0;
itresult[0] = dns_dbiterator_first(dbit[0]);
itresult[1] = dns_dbiterator_first(dbit[1]);
for (;;) {
for (i = 0; i < 2; i++) {
if (! have[i] && itresult[i] == ISC_R_SUCCESS) {
CHECK(get_name_diff(db[i], ver[i], 0, dbit[i],
dns_fixedname_name(&fixname[i]),
i == 0 ?
DNS_DIFFOP_ADD :
DNS_DIFFOP_DEL,
&diff[i]));
itresult[i] = dns_dbiterator_next(dbit[i]);
have[i] = ISC_TRUE;
}
}
if (! have[0] && ! have[1]) {
INSIST(ISC_LIST_EMPTY(diff[0].tuples));
INSIST(ISC_LIST_EMPTY(diff[1].tuples));
break;
}
for (i = 0; i < 2; i++) {
if (! have[!i]) {
ISC_LIST_APPENDLIST(resultdiff.tuples,
diff[i].tuples, link);
INSIST(ISC_LIST_EMPTY(diff[i].tuples));
have[i] = ISC_FALSE;
goto next;
}
}
t = dns_name_compare(dns_fixedname_name(&fixname[0]),
dns_fixedname_name(&fixname[1]));
if (t < 0) {
ISC_LIST_APPENDLIST(resultdiff.tuples,
diff[0].tuples, link);
INSIST(ISC_LIST_EMPTY(diff[0].tuples));
have[0] = ISC_FALSE;
continue;
}
if (t > 0) {
ISC_LIST_APPENDLIST(resultdiff.tuples,
diff[1].tuples, link);
INSIST(ISC_LIST_EMPTY(diff[1].tuples));
have[1] = ISC_FALSE;
continue;
}
INSIST(t == 0);
CHECK(dns_diff_subtract(diff, &resultdiff));
INSIST(ISC_LIST_EMPTY(diff[0].tuples));
INSIST(ISC_LIST_EMPTY(diff[1].tuples));
have[0] = have[1] = ISC_FALSE;
next: ;
}
if (itresult[0] != ISC_R_NOMORE)
FAIL(itresult[0]);
if (itresult[1] != ISC_R_NOMORE)
FAIL(itresult[1]);
if (ISC_LIST_EMPTY(resultdiff.tuples)) {
isc_log_write(JOURNAL_DEBUG_LOGARGS(3), "no changes");
} else {
CHECK(dns_journal_write_transaction(journal, &resultdiff));
}
INSIST(ISC_LIST_EMPTY(diff[0].tuples));
INSIST(ISC_LIST_EMPTY(diff[1].tuples));
failure:
dns_diff_clear(&resultdiff);
dns_dbiterator_destroy(&dbit[1]);
cleanup_interator0:
dns_dbiterator_destroy(&dbit[0]);
cleanup_journal:
dns_journal_destroy(&journal);
return (result);
}
isc_result_t
dns_journal_compact(isc_mem_t *mctx, char *filename, isc_uint32_t serial,
isc_uint32_t target_size)
{
unsigned int i;
journal_pos_t best_guess;
journal_pos_t current_pos;
dns_journal_t *j = NULL;
dns_journal_t *new = NULL;
journal_rawheader_t rawheader;
unsigned int copy_length;
int namelen;
char *buf = NULL;
unsigned int size = 0;
isc_result_t result;
unsigned int indexend;
char newname[1024];
char backup[1024];
isc_boolean_t is_backup = ISC_FALSE;
namelen = strlen(filename);
if (namelen > 4 && strcmp(filename + namelen - 4, ".jnl") == 0)
namelen -= 4;
result = isc_string_printf(newname, sizeof(newname), "%.*s.jnw",
namelen, filename);
if (result != ISC_R_SUCCESS)
return (result);
result = isc_string_printf(backup, sizeof(backup), "%.*s.jbk",
namelen, filename);
if (result != ISC_R_SUCCESS)
return (result);
result = journal_open(mctx, filename, ISC_FALSE, ISC_FALSE, &j);
if (result == ISC_R_NOTFOUND) {
is_backup = ISC_TRUE;
result = journal_open(mctx, backup, ISC_FALSE, ISC_FALSE, &j);
}
if (result != ISC_R_SUCCESS)
return (result);
if (JOURNAL_EMPTY(&j->header)) {
dns_journal_destroy(&j);
return (ISC_R_SUCCESS);
}
if (DNS_SERIAL_GT(j->header.begin.serial, serial) ||
DNS_SERIAL_GT(serial, j->header.end.serial)) {
dns_journal_destroy(&j);
return (ISC_R_RANGE);
}
/*
* Cope with very small target sizes.
*/
indexend = sizeof(journal_rawheader_t) +
j->header.index_size * sizeof(journal_rawpos_t);
if (target_size < indexend * 2)
target_size = target_size/2 + indexend;
/*
* See if there is any work to do.
*/
if ((isc_uint32_t) j->header.end.offset < target_size) {
dns_journal_destroy(&j);
return (ISC_R_SUCCESS);
}
CHECK(journal_open(mctx, newname, ISC_TRUE, ISC_TRUE, &new));
/*
* Remove overhead so space test below can succeed.
*/
if (target_size >= indexend)
target_size -= indexend;
/*
* Find if we can create enough free space.
*/
best_guess = j->header.begin;
for (i = 0; i < j->header.index_size; i++) {
if (POS_VALID(j->index[i]) &&
DNS_SERIAL_GE(serial, j->index[i].serial) &&
((isc_uint32_t)(j->header.end.offset - j->index[i].offset)
>= target_size / 2) &&
j->index[i].offset > best_guess.offset)
best_guess = j->index[i];
}
current_pos = best_guess;
while (current_pos.serial != serial) {
CHECK(journal_next(j, &current_pos));
if (current_pos.serial == j->header.end.serial)
break;
if (DNS_SERIAL_GE(serial, current_pos.serial) &&
((isc_uint32_t)(j->header.end.offset - current_pos.offset)
>= (target_size / 2)) &&
current_pos.offset > best_guess.offset)
best_guess = current_pos;
else
break;
}
INSIST(best_guess.serial != j->header.end.serial);
if (best_guess.serial != serial)
CHECK(journal_next(j, &best_guess));
/*
* We should now be roughly half target_size provided
* we did not reach 'serial'. If not we will just copy
* all uncommitted deltas regardless of the size.
*/
copy_length = j->header.end.offset - best_guess.offset;
if (copy_length != 0) {
/*
* Copy best_guess to end into space just freed.
*/
size = 64*1024;
if (copy_length < size)
size = copy_length;
buf = isc_mem_get(mctx, size);
if (buf == NULL) {
result = ISC_R_NOMEMORY;
goto failure;
}
CHECK(journal_seek(j, best_guess.offset));
CHECK(journal_seek(new, indexend));
for (i = 0; i < copy_length; i += size) {
unsigned int len = (copy_length - i) > size ? size :
(copy_length - i);
CHECK(journal_read(j, buf, len));
CHECK(journal_write(new, buf, len));
}
CHECK(journal_fsync(new));
/*
* Compute new header.
*/
new->header.begin.serial = best_guess.serial;
new->header.begin.offset = indexend;
new->header.end.serial = j->header.end.serial;
new->header.end.offset = indexend + copy_length;
/*
* Update the journal header.
*/
journal_header_encode(&new->header, &rawheader);
CHECK(journal_seek(new, 0));
CHECK(journal_write(new, &rawheader, sizeof(rawheader)));
CHECK(journal_fsync(new));
/*
* Build new index.
*/
current_pos = new->header.begin;
while (current_pos.serial != new->header.end.serial) {
index_add(new, &current_pos);
CHECK(journal_next(new, &current_pos));
}
/*
* Write index.
*/
CHECK(index_to_disk(new));
CHECK(journal_fsync(new));
indexend = new->header.end.offset;
}
dns_journal_destroy(&new);
/*
* With a UFS file system this should just succeed and be atomic.
* Any IXFR outs will just continue and the old journal will be
* removed on final close.
*
* With MSDOS / NTFS we need to do a two stage rename triggered
* bu EEXISTS. Hopefully all IXFR's that were active at the last
* rename are now complete.
*/
if (rename(newname, filename) == -1) {
if (errno == EACCES && !is_backup) {
result = isc_file_remove(backup);
if (result != ISC_R_SUCCESS &&
result != ISC_R_FILENOTFOUND)
goto failure;
if (rename(filename, backup) == -1)
goto maperrno;
if (rename(newname, filename) == -1)
goto maperrno;
(void)isc_file_remove(backup);
} else {
maperrno:
result = ISC_R_FAILURE;
goto failure;
}
}
dns_journal_destroy(&j);
result = ISC_R_SUCCESS;
failure:
(void)isc_file_remove(newname);
if (buf != NULL)
isc_mem_put(mctx, buf, size);
if (j != NULL)
dns_journal_destroy(&j);
if (new != NULL)
dns_journal_destroy(&new);
return (result);
}
static isc_result_t
index_to_disk(dns_journal_t *j) {
isc_result_t result = ISC_R_SUCCESS;
if (j->header.index_size != 0) {
unsigned int i;
unsigned char *p;
unsigned int rawbytes;
rawbytes = j->header.index_size * sizeof(journal_rawpos_t);
p = j->rawindex;
for (i = 0; i < j->header.index_size; i++) {
encode_uint32(j->index[i].serial, p);
p += 4;
encode_uint32(j->index[i].offset, p);
p += 4;
}
INSIST(p == j->rawindex + rawbytes);
CHECK(journal_seek(j, sizeof(journal_rawheader_t)));
CHECK(journal_write(j, j->rawindex, rawbytes));
}
failure:
return (result);
}
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