| 1 | #! @PYTHON@ |
| 2 | ### |
| 3 | ### Efficiently construct canonical digests of filesystems |
| 4 | ### |
| 5 | ### (c) 2012 Mark Wooding |
| 6 | ### |
| 7 | |
| 8 | ###----- Licensing notice --------------------------------------------------- |
| 9 | ### |
| 10 | ### This file is part of the `rsync-backup' program. |
| 11 | ### |
| 12 | ### rsync-backup is free software; you can redistribute it and/or modify |
| 13 | ### it under the terms of the GNU General Public License as published by |
| 14 | ### the Free Software Foundation; either version 2 of the License, or |
| 15 | ### (at your option) any later version. |
| 16 | ### |
| 17 | ### rsync-backup is distributed in the hope that it will be useful, |
| 18 | ### but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | ### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | ### GNU General Public License for more details. |
| 21 | ### |
| 22 | ### You should have received a copy of the GNU General Public License |
| 23 | ### along with rsync-backup; if not, write to the Free Software Foundation, |
| 24 | ### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 25 | |
| 26 | from sys import argv, exit, stdin, stdout, stderr |
| 27 | import os as OS |
| 28 | import re as RX |
| 29 | import time as T |
| 30 | import stat as ST |
| 31 | import optparse as OP |
| 32 | import hashlib as H |
| 33 | import sqlite3 as DB |
| 34 | import zlib as Z |
| 35 | |
| 36 | PACKAGE = '@PACKAGE@' |
| 37 | VERSION = '@VERSION@' |
| 38 | |
| 39 | ###-------------------------------------------------------------------------- |
| 40 | ### Utilities. |
| 41 | |
| 42 | QUIS = OS.path.basename(argv[0]) |
| 43 | |
| 44 | def moan(msg): |
| 45 | stderr.write('%s: %s\n' % (QUIS, msg)) |
| 46 | |
| 47 | def die(msg, rc = 1): |
| 48 | moan(msg) |
| 49 | exit(rc) |
| 50 | |
| 51 | SYSERR = 0 |
| 52 | def syserr(msg): |
| 53 | global SYSERR |
| 54 | moan(msg) |
| 55 | SYSERR += 1 |
| 56 | |
| 57 | ###-------------------------------------------------------------------------- |
| 58 | ### File system enumeration. |
| 59 | |
| 60 | class FileInfo (object): |
| 61 | def __init__(me, file, st = None): |
| 62 | me.name = file |
| 63 | if st: |
| 64 | me.st = st |
| 65 | me.err = None |
| 66 | else: |
| 67 | try: |
| 68 | me.st = OS.lstat(file) |
| 69 | me.err = None |
| 70 | except OSError, err: |
| 71 | me.st = None |
| 72 | me.err = err |
| 73 | |
| 74 | def enum_walk(file, func): |
| 75 | |
| 76 | def dirents(name): |
| 77 | try: |
| 78 | return OS.listdir(name) |
| 79 | except OSError, err: |
| 80 | syserr("failed to read directory `%s': %s" % (name, err.strerror)) |
| 81 | return [] |
| 82 | |
| 83 | def dir(ee, dev): |
| 84 | ff = [] |
| 85 | dd = [] |
| 86 | for e in ee: |
| 87 | fi = FileInfo(e) |
| 88 | if fi.st and fi.st.st_dev != dev: pass |
| 89 | if fi.st and ST.S_ISDIR(fi.st.st_mode): dd.append(fi) |
| 90 | else: ff.append(fi) |
| 91 | ff.sort(key = lambda fi: fi.name) |
| 92 | dd.sort(key = lambda fi: fi.name + '/') |
| 93 | for f in ff: |
| 94 | func(f) |
| 95 | for d in dd: |
| 96 | if d.st.st_dev == dev: |
| 97 | func(d) |
| 98 | dir([OS.path.join(d.name, e) for e in dirents(d.name)], dev) |
| 99 | |
| 100 | if file.endswith('/'): |
| 101 | cwd = OS.open('.', OS.O_RDONLY) |
| 102 | try: |
| 103 | OS.chdir(file) |
| 104 | fi = FileInfo('.') |
| 105 | func(fi) |
| 106 | dir(dirents('.'), fi.st.st_dev) |
| 107 | finally: |
| 108 | OS.fchdir(cwd) |
| 109 | OS.close(cwd) |
| 110 | else: |
| 111 | fi = FileInfo(file) |
| 112 | func(fi) |
| 113 | if fi.st and ST.S_ISDIR(fi.st.st_mode): |
| 114 | dir([OS.path.join(fi.name, e) for e in dirents(fi.name)], |
| 115 | fi.st.st_dev) |
| 116 | |
| 117 | def enum_find0(f, func): |
| 118 | tail = "" |
| 119 | while True: |
| 120 | buf = f.read(8192) |
| 121 | last = len(buf) == 0 |
| 122 | names = (tail + buf).split('\0') |
| 123 | tail = names.pop() |
| 124 | for n in names: |
| 125 | func(FileInfo(n)) |
| 126 | if last: |
| 127 | break |
| 128 | if len(tail): |
| 129 | moan("ignored trailing junk after last filename") |
| 130 | |
| 131 | RX_RSYNCESC = RX.compile(r'\\ \# ([0-7]{3})', RX.VERBOSE) |
| 132 | def enum_rsync(f, func): |
| 133 | |
| 134 | ## The format is a little fiddly. Each line consists of PERMS SIZE DATE |
| 135 | ## TIME NAME, separated by runs of whitespace, but the NAME starts exactly |
| 136 | ## one space character after the TIME and may begin with a space. |
| 137 | ## Sequences of the form `\#OOO' where OOO are three octal digits, stand |
| 138 | ## for a byte with that value. Newlines and backslashes which would be |
| 139 | ## ambiguous are converted into this form; all other characters are |
| 140 | ## literal. |
| 141 | ## |
| 142 | ## We ignore the stat information and retrieve it ourselves, because it's |
| 143 | ## incomplete. Hopefully the dcache is still warm. |
| 144 | |
| 145 | for line in f: |
| 146 | if line.endswith('\n'): line = line[:-1] |
| 147 | |
| 148 | ## Extract the escaped name. |
| 149 | ff = line.split(None, 3) |
| 150 | if len(ff) != 4: |
| 151 | syserr("ignoring invalid line from rsync: `%s'" % line) |
| 152 | continue |
| 153 | tail = ff[3] |
| 154 | try: |
| 155 | spc = tail.index(' ') |
| 156 | except ValueError: |
| 157 | syserr("ignoring invalid line from rsync: `%s'" % line) |
| 158 | continue |
| 159 | name = tail[spc + 1:] |
| 160 | |
| 161 | ## Now translate escape sequences. |
| 162 | name = RX_RSYNCESC.sub(lambda m: chr(int(m.group(1), 8)), name) |
| 163 | |
| 164 | ## Call the client. |
| 165 | try: |
| 166 | fi = FileInfo(name) |
| 167 | except OSError, err: |
| 168 | syserr("failed to stat `%s': %s" % (name, err.strerror)) |
| 169 | continue |
| 170 | func(fi) |
| 171 | |
| 172 | ###-------------------------------------------------------------------------- |
| 173 | ### The hash cache. |
| 174 | |
| 175 | class HashCache (object): |
| 176 | |
| 177 | VERSION = 0 |
| 178 | BUFSZ = 128*1024 |
| 179 | |
| 180 | INIT = [ |
| 181 | """CREATE TABLE meta ( |
| 182 | version INTEGER NOT NULL, |
| 183 | hash TEXT NOT NULL |
| 184 | );""", |
| 185 | """CREATE TABLE hash ( |
| 186 | ino INTEGER PRIMARY KEY, |
| 187 | mtime INTEGER NOT NULL, |
| 188 | ctime INTEGER NOT NULL, |
| 189 | size INTEGER NOT NULL, |
| 190 | hash TEXT NOT NULL, |
| 191 | seen BOOLEAN NOT NULL DEFAULT TRUE |
| 192 | );""", |
| 193 | """PRAGMA journal_mode = WAL;""" |
| 194 | ] |
| 195 | |
| 196 | def __init__(me, file, hash = None): |
| 197 | |
| 198 | if file is None: |
| 199 | |
| 200 | ## We're going this alone, with no cache. |
| 201 | db = None |
| 202 | if hash is None: |
| 203 | die("no hash specified and no database cache to read from") |
| 204 | else: |
| 205 | |
| 206 | ## Connect to the database. |
| 207 | db = DB.connect(file) |
| 208 | db.text_factory = str |
| 209 | |
| 210 | ## See whether we can understand the cache database. |
| 211 | c = db.cursor() |
| 212 | v = h = None |
| 213 | try: |
| 214 | c.execute('SELECT version, hash FROM meta') |
| 215 | v, h = c.fetchone() |
| 216 | if c.fetchone() is not None: |
| 217 | die("cache database corrupt: meta table has mutliple rows") |
| 218 | except (DB.Error, TypeError): |
| 219 | pass |
| 220 | |
| 221 | ## If that didn't work, we'd better clear the thing and start again. |
| 222 | ## But only if we know how to initialize it. |
| 223 | if v != me.VERSION: |
| 224 | |
| 225 | ## Explain the situation. |
| 226 | moan("cache version %s not understood" % v) |
| 227 | if hash is None: |
| 228 | if h is None: |
| 229 | die("can't initialize cache: no hash function set") |
| 230 | else: |
| 231 | hash = h |
| 232 | try: |
| 233 | H.new(hash) |
| 234 | except Exception: |
| 235 | die("unknown hash function `%s'" % hash) |
| 236 | |
| 237 | ## Drop old things. |
| 238 | c.execute('SELECT type, name FROM sqlite_master') |
| 239 | for type, name in c.fetchall(): |
| 240 | c.execute('DROP %s IF EXISTS %s' % (type, name)) |
| 241 | |
| 242 | ## Now we're ready to go. |
| 243 | for stmt in me.INIT: |
| 244 | c.execute(stmt) |
| 245 | c.execute('INSERT INTO meta VALUES (?, ?)', [me.VERSION, hash]) |
| 246 | db.commit() |
| 247 | |
| 248 | ## Check the hash function if necessary. |
| 249 | if hash is None: |
| 250 | hash = h |
| 251 | elif h is not None and h != hash: |
| 252 | die("hash mismatch: cache uses %s but %s requested" % (h, hash)) |
| 253 | |
| 254 | ## All done. |
| 255 | me.hash = hash |
| 256 | me._db = db |
| 257 | me._pend = 0 |
| 258 | |
| 259 | def hashfile(me, fi): |
| 260 | |
| 261 | ## If this isn't a proper file then don't try to hash it. |
| 262 | if fi.err or not ST.S_ISREG(fi.st.st_mode): |
| 263 | return None |
| 264 | |
| 265 | ## See whether there's a valid entry in the cache. |
| 266 | if me._db: |
| 267 | c = me._db.cursor() |
| 268 | c.execute( |
| 269 | 'SELECT mtime, size, hash, seen FROM hash WHERE ino = ?;', |
| 270 | [fi.st.st_ino]) |
| 271 | r = c.fetchone() |
| 272 | if r is not None: |
| 273 | mt, sz, h, s = r |
| 274 | if mt == fi.st.st_mtime and \ |
| 275 | sz == fi.st.st_size: |
| 276 | if not s: |
| 277 | c.execute('UPDATE hash SET seen = 1 WHERE ino = ?', |
| 278 | [fi.st.st_ino]) |
| 279 | me._update() |
| 280 | return h |
| 281 | |
| 282 | ## Hash the file. Beware raciness: update the file information from the |
| 283 | ## open descriptor, but set the size from what we actually read. |
| 284 | h = H.new(me.hash) |
| 285 | try: |
| 286 | with open(fi.name, 'rb') as f: |
| 287 | sz = 0 |
| 288 | while True: |
| 289 | buf = f.read(me.BUFSZ) |
| 290 | if len(buf) == 0: |
| 291 | break |
| 292 | sz += len(buf) |
| 293 | h.update(buf) |
| 294 | fi.st = OS.fstat(f.fileno()) |
| 295 | ##fi.st.st_size = sz |
| 296 | hash = h.digest() |
| 297 | except (OSError, IOError), err: |
| 298 | fi.st = None |
| 299 | fi.err = err |
| 300 | return None |
| 301 | hash = hash.encode('hex') |
| 302 | |
| 303 | ## Insert a record into the database. |
| 304 | if me._db: |
| 305 | c.execute(""" |
| 306 | INSERT OR REPLACE INTO hash |
| 307 | (ino, mtime, ctime, size, hash, seen) |
| 308 | VALUES |
| 309 | (?, ?, ?, ?, ?, 1); |
| 310 | """, [fi.st.st_ino, |
| 311 | fi.st.st_mtime, |
| 312 | fi.st.st_ctime, |
| 313 | fi.st.st_size, |
| 314 | hash]) |
| 315 | me._update() |
| 316 | |
| 317 | ## Done. |
| 318 | return hash |
| 319 | |
| 320 | def _update(me): |
| 321 | me._pend += 1 |
| 322 | if me._pend >= 1024: |
| 323 | me.flush() |
| 324 | |
| 325 | def flush(me): |
| 326 | if me._db: |
| 327 | me._db.commit() |
| 328 | me._pend = 0 |
| 329 | |
| 330 | def need_db(me): |
| 331 | if not me._db: |
| 332 | die("no cache database") |
| 333 | |
| 334 | def reset(me): |
| 335 | me.need_db() |
| 336 | c = me._db.cursor() |
| 337 | c.execute('UPDATE hash SET seen = 0 WHERE seen') |
| 338 | me.flush() |
| 339 | |
| 340 | def prune(me): |
| 341 | me.need_db() |
| 342 | c = me._db.cursor() |
| 343 | c.execute('DELETE FROM hash WHERE NOT seen') |
| 344 | me.flush() |
| 345 | |
| 346 | ###-------------------------------------------------------------------------- |
| 347 | ### Printing output. |
| 348 | |
| 349 | class GenericFormatter (object): |
| 350 | def __init__(me, fi): |
| 351 | me.fi = fi |
| 352 | def _fmt_time(me, t): |
| 353 | tm = T.gmtime(t) |
| 354 | return T.strftime('%Y-%m-%dT%H:%M:%SZ', tm) |
| 355 | def _enc_name(me, n): |
| 356 | return ' \\-> '.join(n.encode('string_escape').split(' -> ')) |
| 357 | def name(me): |
| 358 | return me._enc_name(me.fi.name) |
| 359 | def info(me): |
| 360 | return me.TYPE |
| 361 | def mode(me): |
| 362 | return '%06o' % me.fi.st.st_mode |
| 363 | def size(me): |
| 364 | return me.fi.st.st_size |
| 365 | def mtime(me): |
| 366 | return me._fmt_time(me.fi.st.st_mtime) |
| 367 | def owner(me): |
| 368 | return '%5d:%d' % (me.fi.st.st_uid, me.fi.st.st_gid) |
| 369 | |
| 370 | class ErrorFormatter (GenericFormatter): |
| 371 | def info(me): |
| 372 | return 'E%d %s' % (me.fi.err.errno, me.fi.err.strerror) |
| 373 | def error(me): return 'error' |
| 374 | mode = size = mtime = owner = error |
| 375 | |
| 376 | class SocketFormatter (GenericFormatter): |
| 377 | TYPE = 'socket' |
| 378 | class PipeFormatter (GenericFormatter): |
| 379 | TYPE = 'fifo' |
| 380 | |
| 381 | class LinkFormatter (GenericFormatter): |
| 382 | TYPE = 'symbolic-link' |
| 383 | def name(me): |
| 384 | n = GenericFormatter.name(me) |
| 385 | try: |
| 386 | d = OS.readlink(me.fi.name) |
| 387 | return '%s -> %s' % (n, me._enc_name(d)) |
| 388 | except OSError, err: |
| 389 | return '%s -> <E%d %s>' % (n, err.errno, err.strerror) |
| 390 | |
| 391 | class DirectoryFormatter (GenericFormatter): |
| 392 | TYPE = 'directory' |
| 393 | def name(me): return GenericFormatter.name(me) + '/' |
| 394 | def size(me): return 'dir' |
| 395 | |
| 396 | class DeviceFormatter (GenericFormatter): |
| 397 | def info(me): |
| 398 | return '%s %d:%d' % (me.TYPE, |
| 399 | OS.major(me.fi.st.st_rdev), |
| 400 | OS.minor(me.fi.st.st_rdev)) |
| 401 | class BlockDeviceFormatter (DeviceFormatter): |
| 402 | TYPE = 'block-device' |
| 403 | class CharDeviceFormatter (DeviceFormatter): |
| 404 | TYPE = 'character-device' |
| 405 | |
| 406 | class FileFormatter (GenericFormatter): |
| 407 | TYPE = 'regular-file' |
| 408 | |
| 409 | class Reporter (object): |
| 410 | |
| 411 | TYMAP = { |
| 412 | ST.S_IFSOCK: SocketFormatter, |
| 413 | ST.S_IFDIR: DirectoryFormatter, |
| 414 | ST.S_IFLNK: LinkFormatter, |
| 415 | ST.S_IFREG: FileFormatter, |
| 416 | ST.S_IFBLK: BlockDeviceFormatter, |
| 417 | ST.S_IFCHR: CharDeviceFormatter, |
| 418 | ST.S_IFIFO: PipeFormatter, |
| 419 | } |
| 420 | |
| 421 | def __init__(me, db): |
| 422 | me._inomap = {} |
| 423 | me._vinomap = {} |
| 424 | me._db = db |
| 425 | me._hsz = int(H.new(db.hash).digest_size) |
| 426 | |
| 427 | def file(me, fi): |
| 428 | h = me._db.hashfile(fi) |
| 429 | if fi.err: |
| 430 | fmt = ErrorFormatter(fi) |
| 431 | vino = 'error' |
| 432 | else: |
| 433 | fmt = me.TYMAP[ST.S_IFMT(fi.st.st_mode)](fi) |
| 434 | inoidx = fi.st.st_dev, fi.st.st_ino |
| 435 | try: |
| 436 | vino = me._inomap[inoidx] |
| 437 | except KeyError: |
| 438 | suffix = '' |
| 439 | seq = 0 |
| 440 | while True: |
| 441 | vino = '%08x' % (Z.crc32(fi.name + suffix) & 0xffffffff) |
| 442 | if vino not in me._vinomap: break |
| 443 | suffix = '\0%d' % seq |
| 444 | seq += 1 |
| 445 | me._inomap[inoidx] = vino |
| 446 | if h: info = h |
| 447 | else: info = '[%-*s]' % (2*me._hsz - 2, fmt.info()) |
| 448 | print '%s %8s %6s %-12s %-20s %20s %s' % ( |
| 449 | info, vino, fmt.mode(), fmt.owner(), |
| 450 | fmt.mtime(), fmt.size(), fmt.name()) |
| 451 | |
| 452 | ###-------------------------------------------------------------------------- |
| 453 | ### Main program. |
| 454 | |
| 455 | FMTMAP = { |
| 456 | 'rsync': lambda f: enum_rsync(stdin, f), |
| 457 | 'find0': lambda f: enum_find0(stdin, f) |
| 458 | } |
| 459 | op = OP.OptionParser( |
| 460 | usage = '%prog [-a] [-c CACHE] [-f FORMAT] [-H HASH] [FILE ...]', |
| 461 | version = '%%prog, version %s' % VERSION, |
| 462 | description = '''\ |
| 463 | Print a digest of a filesystem (or a collection of specified files) to |
| 464 | standard output. The idea is that the digest should be mostly /complete/ |
| 465 | (i.e., any `interesting\' change to the filesystem results in a different |
| 466 | digest) and /canonical/ (i.e., identical filesystem contents result in |
| 467 | identical output). |
| 468 | ''') |
| 469 | |
| 470 | for short, long, props in [ |
| 471 | ('-a', '--all', { 'action': 'store_true', 'dest': 'all', |
| 472 | 'help': 'clear cache of all files not seen' }), |
| 473 | ('-c', '--cache', { 'dest': 'cache', 'metavar': 'FILE', |
| 474 | 'help': 'use FILE as a cache for file hashes' }), |
| 475 | ('-f', '--files', { 'dest': 'files', 'metavar': 'FORMAT', |
| 476 | 'type': 'choice', 'choices': FMTMAP.keys(), |
| 477 | 'help': 'read files to report in the given FORMAT' }), |
| 478 | ('-H', '--hash', { 'dest': 'hash', 'metavar': 'HASH', |
| 479 | ##'type': 'choice', 'choices': H.algorithms, |
| 480 | 'help': 'use HASH as the hash function' })]: |
| 481 | op.add_option(short, long, **props) |
| 482 | opts, args = op.parse_args(argv) |
| 483 | |
| 484 | if not opts.files and len(args) <= 1: |
| 485 | die("no filename sources: nothing to do") |
| 486 | db = HashCache(opts.cache, opts.hash) |
| 487 | if opts.all: |
| 488 | db.reset() |
| 489 | rep = Reporter(db) |
| 490 | if opts.files: |
| 491 | FMTMAP[opts.files](rep.file) |
| 492 | for dir in args[1:]: |
| 493 | enum_walk(dir, rep.file) |
| 494 | if opts.all: |
| 495 | db.prune() |
| 496 | db.flush() |
| 497 | |
| 498 | ###----- That's all, folks -------------------------------------------------- |