1 /* 2 * Copyright (C) Internet Systems Consortium, Inc. ("ISC") 3 * 4 * SPDX-License-Identifier: MPL-2.0 5 * 6 * This Source Code Form is subject to the terms of the Mozilla Public 7 * License, v. 2.0. If a copy of the MPL was not distributed with this 8 * file, you can obtain one at https://mozilla.org/MPL/2.0/. 9 * 10 * See the COPYRIGHT file distributed with this work for additional 11 * information regarding copyright ownership. 12 */ 13 14 #ifndef DNS_JOURNAL_H 15 #define DNS_JOURNAL_H 1 16 17 /***** 18 ***** Module Info 19 *****/ 20 21 /*! \file dns/journal.h 22 * \brief 23 * Database journaling. 24 */ 25 26 /*** 27 *** Imports 28 ***/ 29 30 #include <inttypes.h> 31 #include <stdbool.h> 32 33 #include <isc/lang.h> 34 #include <isc/magic.h> 35 36 #include <dns/diff.h> 37 #include <dns/name.h> 38 #include <dns/rdata.h> 39 #include <dns/types.h> 40 41 /*** 42 *** Defines. 43 ***/ 44 #define DNS_JOURNALOPT_RESIGN 0x00000001 45 46 #define DNS_JOURNAL_READ 0x00000000 /* false */ 47 #define DNS_JOURNAL_CREATE 0x00000001 /* true */ 48 #define DNS_JOURNAL_WRITE 0x00000002 49 50 #define DNS_JOURNAL_SIZE_MAX INT32_MAX 51 #define DNS_JOURNAL_SIZE_MIN 4096 52 53 /*% Print transaction header data */ 54 #define DNS_JOURNAL_PRINTXHDR 0x0001 55 56 /*% Rewrite whole journal file instead of compacting */ 57 #define DNS_JOURNAL_COMPACTALL 0x0001 58 #define DNS_JOURNAL_VERSION1 0x0002 59 60 /*** 61 *** Types 62 ***/ 63 64 /*% 65 * A dns_journal_t represents an open journal file. This is an opaque type. 66 * 67 * A particular dns_journal_t object may be opened for writing, in which case 68 * it can be used for writing transactions to a journal file, or it can be 69 * opened for reading, in which case it can be used for reading transactions 70 * from (iterating over) a journal file. A single dns_journal_t object may 71 * not be used for both purposes. 72 */ 73 typedef struct dns_journal dns_journal_t; 74 75 /*** 76 *** Functions 77 ***/ 78 79 ISC_LANG_BEGINDECLS 80 81 /**************************************************************************/ 82 83 isc_result_t 84 dns_db_createsoatuple(dns_db_t *db, dns_dbversion_t *ver, isc_mem_t *mctx, 85 dns_diffop_t op, dns_difftuple_t **tp); 86 /*!< brief 87 * Create a diff tuple for the current database SOA. 88 * XXX this probably belongs somewhere else. 89 */ 90 91 /*@{*/ 92 #define DNS_SERIAL_GT(a, b) ((int)(((a) - (b)) & 0xFFFFFFFF) > 0) 93 #define DNS_SERIAL_GE(a, b) ((int)(((a) - (b)) & 0xFFFFFFFF) >= 0) 94 /*!< brief 95 * Compare SOA serial numbers. DNS_SERIAL_GT(a, b) returns true iff 96 * a is "greater than" b where "greater than" is as defined in RFC1982. 97 * DNS_SERIAL_GE(a, b) returns true iff a is "greater than or equal to" b. 98 */ 99 /*@}*/ 100 101 /**************************************************************************/ 102 /* 103 * Journal object creation and destruction. 104 */ 105 106 isc_result_t 107 dns_journal_open(isc_mem_t *mctx, const char *filename, unsigned int mode, 108 dns_journal_t **journalp); 109 /*%< 110 * Open the journal file 'filename' and create a dns_journal_t object for it. 111 * 112 * DNS_JOURNAL_CREATE open the journal for reading and writing and create 113 * the journal if it does not exist. 114 * DNS_JOURNAL_WRITE open the journal for reading and writing. 115 * DNS_JOURNAL_READ open the journal for reading only. 116 */ 117 118 void 119 dns_journal_destroy(dns_journal_t **journalp); 120 /*%< 121 * Destroy a dns_journal_t, closing any open files and freeing its memory. 122 */ 123 124 /**************************************************************************/ 125 /* 126 * Writing transactions to journals. 127 */ 128 129 isc_result_t 130 dns_journal_begin_transaction(dns_journal_t *j); 131 /*%< 132 * Prepare to write a new transaction to the open journal file 'j'. 133 * 134 * Requires: 135 * \li 'j' is open for writing. 136 */ 137 138 isc_result_t 139 dns_journal_writediff(dns_journal_t *j, dns_diff_t *diff); 140 /*%< 141 * Write 'diff' to the current transaction of journal file 'j'. 142 * 143 * Requires: 144 * \li 'j' is open for writing and dns_journal_begin_transaction() 145 * has been called. 146 * 147 *\li 'diff' is a full or partial, correctly ordered IXFR 148 * difference sequence. 149 */ 150 151 isc_result_t 152 dns_journal_commit(dns_journal_t *j); 153 /*%< 154 * Commit the current transaction of journal file 'j'. 155 * 156 * Requires: 157 * \li 'j' is open for writing and dns_journal_begin_transaction() 158 * has been called. 159 * 160 * \li dns_journal_writediff() has been called one or more times 161 * to form a complete, correctly ordered IXFR difference 162 * sequence. 163 */ 164 165 isc_result_t 166 dns_journal_write_transaction(dns_journal_t *j, dns_diff_t *diff); 167 /*% 168 * Write a complete transaction at once to a journal file, 169 * sorting it if necessary, and commit it. Equivalent to calling 170 * dns_diff_sort(), dns_journal_begin_transaction(), 171 * dns_journal_writediff(), and dns_journal_commit(). 172 * 173 * Requires: 174 *\li 'j' is open for writing. 175 * 176 * \li 'diff' contains exactly one SOA deletion, one SOA addition 177 * with a greater serial number, and possibly other changes, 178 * in arbitrary order. 179 */ 180 181 /**************************************************************************/ 182 /* 183 * Reading transactions from journals. 184 */ 185 186 bool 187 dns_journal_empty(dns_journal_t *j); 188 /*< 189 * Find out if a journal is empty. 190 */ 191 192 bool 193 dns_journal_recovered(dns_journal_t *j); 194 /*< 195 * Find out if the journal could be opened using old journal format 196 */ 197 198 uint32_t 199 dns_journal_first_serial(dns_journal_t *j); 200 uint32_t 201 dns_journal_last_serial(dns_journal_t *j); 202 /*%< 203 * Get the first and last addressable serial number in the journal. 204 */ 205 206 isc_result_t 207 dns_journal_iter_init(dns_journal_t *j, uint32_t begin_serial, 208 uint32_t end_serial, size_t *xfrsizep); 209 /*%< 210 * Prepare to iterate over the transactions that will bring the database 211 * from SOA serial number 'begin_serial' to 'end_serial'. 212 * 213 * If 'xfrsizep' is not NULL, then on success it will be set to the 214 * total size of all records in the iteration (excluding headers). This 215 * is meant to be a rough approximation of the size of an incremental 216 * zone transfer, though it does not account for DNS message overhead 217 * or name compression.) 218 * 219 * Returns: 220 *\li ISC_R_SUCCESS 221 *\li ISC_R_RANGE begin_serial is outside the addressable range. 222 *\li ISC_R_NOTFOUND begin_serial is within the range of addressable 223 * serial numbers covered by the journal, but 224 * this particular serial number does not exist. 225 */ 226 227 /*@{*/ 228 isc_result_t 229 dns_journal_first_rr(dns_journal_t *j); 230 isc_result_t 231 dns_journal_next_rr(dns_journal_t *j); 232 /*%< 233 * Position the iterator at the first/next RR in a journal 234 * transaction sequence established using dns_journal_iter_init(). 235 * 236 * Requires: 237 * \li dns_journal_iter_init() has been called. 238 * 239 */ 240 /*@}*/ 241 242 void 243 dns_journal_current_rr(dns_journal_t *j, dns_name_t **name, uint32_t *ttl, 244 dns_rdata_t **rdata); 245 /*%< 246 * Get the name, ttl, and rdata of the current journal RR. 247 * 248 * Requires: 249 * \li The last call to dns_journal_first_rr() or dns_journal_next_rr() 250 * returned ISC_R_SUCCESS. 251 */ 252 253 /**************************************************************************/ 254 /* 255 * Database roll-forward. 256 */ 257 258 isc_result_t 259 dns_journal_rollforward(dns_journal_t *j, dns_db_t *db, unsigned int options); 260 /*%< 261 * Roll forward (play back) the journal file "filename" into the 262 * database "db". This should be called when the server starts 263 * after a shutdown or crash. 264 * 265 * Requires: 266 *\li 'journal' is a valid journal 267 *\li 'db' is a valid database which does not have a version 268 * open for writing. 269 * 270 * Returns: 271 *\li ISC_R_NOTFOUND when current serial in not in journal. 272 *\li ISC_R_RANGE when current serial in not in journals range. 273 *\li DNS_R_UPTODATE when the database was already up to date. 274 *\li ISC_R_SUCCESS journal has been applied successfully to the 275 * database without any issues. 276 * 277 * others 278 */ 279 280 isc_result_t 281 dns_journal_print(isc_mem_t *mctx, uint32_t flags, const char *filename, 282 FILE *file); 283 /* For debugging not general use */ 284 285 isc_result_t 286 dns_db_diff(isc_mem_t *mctx, dns_db_t *dba, dns_dbversion_t *dbvera, 287 dns_db_t *dbb, dns_dbversion_t *dbverb, 288 const char *journal_filename); 289 290 isc_result_t 291 dns_db_diffx(dns_diff_t *diff, dns_db_t *dba, dns_dbversion_t *dbvera, 292 dns_db_t *dbb, dns_dbversion_t *dbverb, 293 const char *journal_filename); 294 /*%< 295 * Compare the databases 'dba' and 'dbb' and generate a diff/journal 296 * entry containing the changes to make 'dba' from 'dbb' (note 297 * the order). This journal entry will consist of a single, 298 * possibly very large transaction. Append the journal 299 * entry to the journal file specified by 'journal_filename' if 300 * non-NULL. 301 */ 302 303 isc_result_t 304 dns_journal_compact(isc_mem_t *mctx, char *filename, uint32_t serial, 305 uint32_t flags, uint32_t target_size); 306 /*%< 307 * Attempt to compact the journal if it is greater that 'target_size'. 308 * Changes from 'serial' onwards will be preserved. Changes prior than 309 * that may be dropped in order to get the journal below `target_size`. 310 * 311 * If 'flags' includes DNS_JOURNAL_COMPACTALL, the entire journal is copied. 312 * In this case, `serial` is ignored. This flag is used when upgrading or 313 * downgrading the format version of the journal. If 'flags' also includes 314 * DNS_JOURNAL_VERSION1, then the journal is copied out in the original 315 * format used prior to BIND 9.16.12; otherwise it is copied in the 316 * current format. 317 * 318 * If _COMPACTALL is not in use, and the journal file exists and is 319 * non-empty, then 'serial' must exist in the journal. 320 * 321 * Returns: 322 *\li ISC_R_SUCCESS 323 *\li ISC_R_RANGE serial is outside the range existing in the journal 324 * 325 * Other errors may be returned from file operations. 326 */ 327 328 bool 329 dns_journal_get_sourceserial(dns_journal_t *j, uint32_t *sourceserial); 330 void 331 dns_journal_set_sourceserial(dns_journal_t *j, uint32_t sourceserial); 332 /*%< 333 * Get and set source serial. 334 * 335 * Returns: 336 * true if sourceserial has previously been set. 337 */ 338 339 ISC_LANG_ENDDECLS 340 341 #endif /* DNS_JOURNAL_H */ 342