src/journal/sd-journal.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2011 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU General Public License as published by
  10   the Free Software Foundation; either version 2 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <errno.h>
  23 #include <fcntl.h>
  24 #include <stddef.h>
  25 #include <unistd.h>
  26 #include <sys/inotify.h>
  27
  28 #include "sd-journal.h"
  29 #include "journal-def.h"
  30 #include "journal-file.h"
  31 #include "hashmap.h"
  32 #include "list.h"
  33 #include "lookup3.h"
  34 #include "compress.h"
  35 #include "journal-internal.h"
  36
  37 #define JOURNAL_FILES_MAX 1024
  38
  39 static void detach_location(sd_journal *j) {
  40         Iterator i;
  41         JournalFile *f;
  42
  43         assert(j);
  44
  45         j->current_file = NULL;
  46         j->current_field = 0;
  47
  48         HASHMAP_FOREACH(f, j->files, i)
  49                 f->current_offset = 0;
  50 }
  51
  52 static void reset_location(sd_journal *j) {
  53         assert(j);
  54
  55         detach_location(j);
  56         zero(j->current_location);
  57 }
  58
  59 static void init_location(Location *l, JournalFile *f, Object *o) {
  60         assert(l);
  61         assert(f);
  62         assert(o->object.type == OBJECT_ENTRY);
  63
  64         l->type = LOCATION_DISCRETE;
  65         l->seqnum = le64toh(o->entry.seqnum);
  66         l->seqnum_id = f->header->seqnum_id;
  67         l->realtime = le64toh(o->entry.realtime);
  68         l->monotonic = le64toh(o->entry.monotonic);
  69         l->boot_id = le64toh(o->entry.boot_id);
  70         l->xor_hash = le64toh(o->entry.xor_hash);
  71
  72         l->seqnum_set = l->realtime_set = l->monotonic_set = l->xor_hash_set = true;
  73 }
  74
  75 static void set_location(sd_journal *j, JournalFile *f, Object *o, uint64_t offset) {
  76         assert(j);
  77         assert(f);
  78         assert(o);
  79
  80         init_location(&j->current_location, f, o);
  81
  82         j->current_file = f;
  83         j->current_field = 0;
  84
  85         f->current_offset = offset;
  86 }
  87
  88 static int same_field(const void *_a, size_t s, const void *_b, size_t t) {
  89         const uint8_t *a = _a, *b = _b;
  90         size_t j;
  91         bool a_good = false, b_good = false, different = false;
  92
  93         for (j = 0; j < s && j < t; j++) {
  94
  95                 if (a[j] == '=')
  96                         a_good = true;
  97                 if (b[j] == '=')
  98                         b_good = true;
  99                 if (a[j] != b[j])
 100                         different = true;
 101
 102                 if (a_good && b_good)
 103                         return different ? 0 : 1;
 104         }
 105
 106         return -EINVAL;
 107 }
 108
 109 _public_ int sd_journal_add_match(sd_journal *j, const void *data, size_t size) {
 110         Match *m, *after = NULL;
 111         uint64_t le_hash;
 112
 113         if (!j)
 114                 return -EINVAL;
 115         if (!data)
 116                 return -EINVAL;
 117         if (size <= 0)
 118                 return -EINVAL;
 119
 120         le_hash = htole64(hash64(data, size));
 121
 122         LIST_FOREACH(matches, m, j->matches) {
 123                 int r;
 124
 125                 if (m->le_hash == le_hash &&
 126                     m->size == size &&
 127                     memcmp(m->data, data, size) == 0)
 128                         return 0;
 129
 130                 r = same_field(data, size, m->data, m->size);
 131                 if (r < 0)
 132                         return r;
 133                 else if (r > 0)
 134                         after = m;
 135         }
 136
 137         m = new0(Match, 1);
 138         if (!m)
 139                 return -ENOMEM;
 140
 141         m->size = size;
 142
 143         m->data = malloc(m->size);
 144         if (!m->data) {
 145                 free(m);
 146                 return -ENOMEM;
 147         }
 148
 149         memcpy(m->data, data, size);
 150         m->le_hash = le_hash;
 151
 152         /* Matches for the same fields we order adjacent to each
 153          * other */
 154         LIST_INSERT_AFTER(Match, matches, j->matches, after, m);
 155         j->n_matches ++;
 156
 157         detach_location(j);
 158
 159         return 0;
 160 }
 161
 162 _public_ void sd_journal_flush_matches(sd_journal *j) {
 163         if (!j)
 164                 return;
 165
 166         while (j->matches) {
 167                 Match *m = j->matches;
 168
 169                 LIST_REMOVE(Match, matches, j->matches, m);
 170                 free(m->data);
 171                 free(m);
 172         }
 173
 174         j->n_matches = 0;
 175
 176         detach_location(j);
 177 }
 178
 179 static int compare_order(JournalFile *af, Object *ao,
 180                          JournalFile *bf, Object *bo) {
 181
 182         uint64_t a, b;
 183
 184         assert(af);
 185         assert(ao);
 186         assert(bf);
 187         assert(bo);
 188
 189         /* We operate on two different files here, hence we can access
 190          * two objects at the same time, which we normally can't.
 191          *
 192          * If contents and timestamps match, these entries are
 193          * identical, even if the seqnum does not match */
 194
 195         if (sd_id128_equal(ao->entry.boot_id, bo->entry.boot_id) &&
 196             ao->entry.monotonic == bo->entry.monotonic &&
 197             ao->entry.realtime == bo->entry.realtime &&
 198             ao->entry.xor_hash == bo->entry.xor_hash)
 199                 return 0;
 200
 201         if (sd_id128_equal(af->header->seqnum_id, bf->header->seqnum_id)) {
 202
 203                 /* If this is from the same seqnum source, compare
 204                  * seqnums */
 205                 a = le64toh(ao->entry.seqnum);
 206                 b = le64toh(bo->entry.seqnum);
 207
 208                 if (a < b)
 209                         return -1;
 210                 if (a > b)
 211                         return 1;
 212
 213                 /* Wow! This is weird, different data but the same
 214                  * seqnums? Something is borked, but let's make the
 215                  * best of it and compare by time. */
 216         }
 217
 218         if (sd_id128_equal(ao->entry.boot_id, bo->entry.boot_id)) {
 219
 220                 /* If the boot id matches compare monotonic time */
 221                 a = le64toh(ao->entry.monotonic);
 222                 b = le64toh(bo->entry.monotonic);
 223
 224                 if (a < b)
 225                         return -1;
 226                 if (a > b)
 227                         return 1;
 228         }
 229
 230         /* Otherwise compare UTC time */
 231         a = le64toh(ao->entry.realtime);
 232         b = le64toh(ao->entry.realtime);
 233
 234         if (a < b)
 235                 return -1;
 236         if (a > b)
 237                 return 1;
 238
 239         /* Finally, compare by contents */
 240         a = le64toh(ao->entry.xor_hash);
 241         b = le64toh(ao->entry.xor_hash);
 242
 243         if (a < b)
 244                 return -1;
 245         if (a > b)
 246                 return 1;
 247
 248         return 0;
 249 }
 250
 251 static int compare_with_location(JournalFile *af, Object *ao, Location *l) {
 252         uint64_t a;
 253
 254         assert(af);
 255         assert(ao);
 256         assert(l);
 257         assert(l->type == LOCATION_DISCRETE);
 258
 259         if (l->monotonic_set &&
 260             sd_id128_equal(ao->entry.boot_id, l->boot_id) &&
 261             l->realtime_set &&
 262             le64toh(ao->entry.realtime) == l->realtime &&
 263             l->xor_hash_set &&
 264             le64toh(ao->entry.xor_hash) == l->xor_hash)
 265                 return 0;
 266
 267         if (l->seqnum_set &&
 268             sd_id128_equal(af->header->seqnum_id, l->seqnum_id)) {
 269
 270                 a = le64toh(ao->entry.seqnum);
 271
 272                 if (a < l->seqnum)
 273                         return -1;
 274                 if (a > l->seqnum)
 275                         return 1;
 276         }
 277
 278         if (l->monotonic_set &&
 279             sd_id128_equal(ao->entry.boot_id, l->boot_id)) {
 280
 281                 a = le64toh(ao->entry.monotonic);
 282
 283                 if (a < l->monotonic)
 284                         return -1;
 285                 if (a > l->monotonic)
 286                         return 1;
 287         }
 288
 289         if (l->realtime_set) {
 290
 291                 a = le64toh(ao->entry.realtime);
 292
 293                 if (a < l->realtime)
 294                         return -1;
 295                 if (a > l->realtime)
 296                         return 1;
 297         }
 298
 299         if (l->xor_hash_set) {
 300                 a = le64toh(ao->entry.xor_hash);
 301
 302                 if (a < l->xor_hash)
 303                         return -1;
 304                 if (a > l->xor_hash)
 305                         return 1;
 306         }
 307
 308         return 0;
 309 }
 310
 311 static int find_location(sd_journal *j, JournalFile *f, direction_t direction, Object **ret, uint64_t *offset) {
 312         Object *o = NULL;
 313         uint64_t p = 0;
 314         int r;
 315
 316         assert(j);
 317
 318         if (!j->matches) {
 319                 /* No matches is simple */
 320
 321                 if (j->current_location.type == LOCATION_HEAD)
 322                         r = journal_file_next_entry(f, NULL, 0, DIRECTION_DOWN, &o, &p);
 323                 else if (j->current_location.type == LOCATION_TAIL)
 324                         r = journal_file_next_entry(f, NULL, 0, DIRECTION_UP, &o, &p);
 325                 else if (j->current_location.seqnum_set &&
 326                          sd_id128_equal(j->current_location.seqnum_id, f->header->seqnum_id))
 327                         r = journal_file_move_to_entry_by_seqnum(f, j->current_location.seqnum, direction, &o, &p);
 328                 else if (j->current_location.monotonic_set)
 329                         r = journal_file_move_to_entry_by_monotonic(f, j->current_location.boot_id, j->current_location.monotonic, direction, &o, &p);
 330                 else if (j->current_location.realtime_set)
 331                         r = journal_file_move_to_entry_by_realtime(f, j->current_location.realtime, direction, &o, &p);
 332                 else
 333                         r = journal_file_next_entry(f, NULL, 0, direction, &o, &p);
 334
 335                 if (r <= 0)
 336                         return r;
 337
 338         } else  {
 339                 Match *m, *term_match = NULL;
 340                 Object *to = NULL;
 341                 uint64_t tp = 0;
 342
 343                 /* We have matches, first, let's jump to the monotonic
 344                  * position if we have any, since it implies a
 345                  * match. */
 346
 347                 if (j->current_location.type == LOCATION_DISCRETE &&
 348                     j->current_location.monotonic_set) {
 349
 350                         r = journal_file_move_to_entry_by_monotonic(f, j->current_location.boot_id, j->current_location.monotonic, direction, &o, &p);
 351                         if (r <= 0)
 352                                 return r;
 353                 }
 354
 355                 LIST_FOREACH(matches, m, j->matches) {
 356                         Object *c, *d;
 357                         uint64_t cp, dp;
 358
 359                         r = journal_file_find_data_object_with_hash(f, m->data, m->size, m->le_hash, &d, &dp);
 360                         if (r <= 0)
 361                                 return r;
 362
 363                         if (j->current_location.type == LOCATION_HEAD)
 364                                 r = journal_file_next_entry_for_data(f, NULL, 0, dp, DIRECTION_DOWN, &c, &cp);
 365                         else if (j->current_location.type == LOCATION_TAIL)
 366                                 r = journal_file_next_entry_for_data(f, NULL, 0, dp, DIRECTION_UP, &c, &cp);
 367                         else if (j->current_location.seqnum_set &&
 368                                  sd_id128_equal(j->current_location.seqnum_id, f->header->seqnum_id))
 369                                 r = journal_file_move_to_entry_by_seqnum_for_data(f, dp, j->current_location.seqnum, direction, &c, &cp);
 370                         else if (j->current_location.realtime_set)
 371                                 r = journal_file_move_to_entry_by_realtime_for_data(f, dp, j->current_location.realtime, direction, &c, &cp);
 372                         else
 373                                 r = journal_file_next_entry_for_data(f, NULL, 0, dp, direction, &c, &cp);
 374
 375                         if (!term_match) {
 376                                 term_match = m;
 377
 378                                 if (r > 0) {
 379                                         to = c;
 380                                         tp = cp;
 381                                 }
 382                         } else if (same_field(term_match->data, term_match->size, m->data, m->size)) {
 383
 384                                 /* Same field as previous match... */
 385                                 if (r > 0) {
 386
 387                                         /* Find the earliest of the OR matches */
 388
 389                                         if (!to ||
 390                                             (direction == DIRECTION_DOWN && cp < tp) ||
 391                                             (direction == DIRECTION_UP && cp > tp)) {
 392                                                 to = c;
 393                                                 tp = cp;
 394                                         }
 395
 396                                 }
 397
 398                         } else {
 399
 400                                 /* Previous term is finished, did anything match? */
 401                                 if (!to)
 402                                         return 0;
 403
 404                                 /* Find the last of the AND matches */
 405                                 if (!o ||
 406                                     (direction == DIRECTION_DOWN && tp > p) ||
 407                                     (direction == DIRECTION_UP && tp < p)) {
 408                                         o = to;
 409                                         p = tp;
 410                                 }
 411
 412                                 term_match = m;
 413
 414                                 if (r > 0) {
 415                                         to = c;
 416                                         tp = cp;
 417                                 } else {
 418                                         to = NULL;
 419                                         tp = 0;
 420                                 }
 421                         }
 422                 }
 423
 424                 /* Last term is finished, did anything match? */
 425                 if (!to)
 426                         return 0;
 427
 428                 if (!o ||
 429                     (direction == DIRECTION_DOWN && tp > p) ||
 430                     (direction == DIRECTION_UP && tp < p)) {
 431                         o = to;
 432                         p = tp;
 433                 }
 434
 435                 if (!o)
 436                         return 0;
 437         }
 438
 439         if (ret)
 440                 *ret = o;
 441
 442         if (offset)
 443                 *offset = p;
 444
 445         return 1;
 446 }
 447
 448 static int next_with_matches(sd_journal *j, JournalFile *f, direction_t direction, Object **ret, uint64_t *offset) {
 449         int r;
 450         uint64_t cp;
 451         Object *c;
 452
 453         assert(j);
 454         assert(f);
 455         assert(ret);
 456         assert(offset);
 457
 458         c = *ret;
 459         cp = *offset;
 460
 461         if (!j->matches) {
 462                 /* No matches is easy */
 463
 464                 r = journal_file_next_entry(f, c, cp, direction, &c, &cp);
 465                 if (r <= 0)
 466                         return r;
 467
 468                 if (ret)
 469                         *ret = c;
 470                 if (offset)
 471                         *offset = cp;
 472                 return 1;
 473         }
 474
 475         /* So there are matches we have to adhere to, let's find the
 476          * first entry that matches all of them */
 477
 478         for (;;) {
 479                 uint64_t np, n;
 480                 bool found, term_result = false;
 481                 Match *m, *term_match = NULL;
 482                 Object *npo = NULL;
 483
 484                 n = journal_file_entry_n_items(c);
 485
 486                 /* Make sure we don't match the entry we are starting
 487                  * from. */
 488                 found = cp > *offset;
 489
 490                 np = 0;
 491                 LIST_FOREACH(matches, m, j->matches) {
 492                         uint64_t q, k;
 493                         Object *qo = NULL;
 494
 495                         /* Let's check if this is the beginning of a
 496                          * new term, i.e. has a different field prefix
 497                          * as the preceeding match. */
 498                         if (!term_match) {
 499                                 term_match = m;
 500                                 term_result = false;
 501                         } else if (!same_field(term_match->data, term_match->size, m->data, m->size)) {
 502                                 if (!term_result)
 503                                         found = false;
 504
 505                                 term_match = m;
 506                                 term_result = false;
 507                         }
 508
 509                         for (k = 0; k < n; k++)
 510                                 if (c->entry.items[k].hash == m->le_hash)
 511                                         break;
 512
 513                         if (k >= n) {
 514                                 /* Hmm, didn't find any field that
 515                                  * matched this rule, so ignore this
 516                                  * match. Go on with next match */
 517                                 continue;
 518                         }
 519
 520                         term_result = true;
 521
 522                         /* Hmm, so, this field matched, let's remember
 523                          * where we'd have to try next, in case the other
 524                          * matches are not OK */
 525
 526                         r = journal_file_next_entry_for_data(f, c, cp, le64toh(c->entry.items[k].object_offset), direction, &qo, &q);
 527                         if (r > 0) {
 528
 529                                 if (direction == DIRECTION_DOWN) {
 530                                         if (q > np) {
 531                                                 np = q;
 532                                                 npo = qo;
 533                                         }
 534                                 } else {
 535                                         if (np == 0 || q < np) {
 536                                                 np = q;
 537                                                 npo = qo;
 538                                         }
 539                                 }
 540                         }
 541                 }
 542
 543                 /* Check the last term */
 544                 if (term_match && !term_result)
 545                         found = false;
 546
 547                 /* Did this entry match against all matches? */
 548                 if (found) {
 549                         if (ret)
 550                                 *ret = c;
 551                         if (offset)
 552                                 *offset = cp;
 553                         return 1;
 554                 }
 555
 556                 /* Did we find a subsequent entry? */
 557                 if (np == 0)
 558                         return 0;
 559
 560                 /* Hmm, ok, this entry only matched partially, so
 561                  * let's try another one */
 562                 cp = np;
 563                 c = npo;
 564         }
 565 }
 566
 567 static int next_beyond_location(sd_journal *j, JournalFile *f, direction_t direction, Object **ret, uint64_t *offset) {
 568         Object *c;
 569         uint64_t cp;
 570         int compare_value, r;
 571
 572         assert(j);
 573         assert(f);
 574
 575         if (f->current_offset > 0) {
 576                 cp = f->current_offset;
 577
 578                 r = journal_file_move_to_object(f, OBJECT_ENTRY, cp, &c);
 579                 if (r < 0)
 580                         return r;
 581
 582                 r = next_with_matches(j, f, direction, &c, &cp);
 583                 if (r <= 0)
 584                         return r;
 585
 586                 compare_value = 1;
 587         } else {
 588                 r = find_location(j, f, direction, &c, &cp);
 589                 if (r <= 0)
 590                         return r;
 591
 592                 compare_value = 0;
 593         }
 594
 595         for (;;) {
 596                 bool found;
 597
 598                 if (j->current_location.type == LOCATION_DISCRETE) {
 599                         int k;
 600
 601                         k = compare_with_location(f, c, &j->current_location);
 602                         if (direction == DIRECTION_DOWN)
 603                                 found = k >= compare_value;
 604                         else
 605                                 found = k <= -compare_value;
 606                 } else
 607                         found = true;
 608
 609                 if (found) {
 610                         if (ret)
 611                                 *ret = c;
 612                         if (offset)
 613                                 *offset = cp;
 614                         return 1;
 615                 }
 616
 617                 r = next_with_matches(j, f, direction, &c, &cp);
 618                 if (r <= 0)
 619                         return r;
 620         }
 621 }
 622
 623 static int real_journal_next(sd_journal *j, direction_t direction) {
 624         JournalFile *f, *new_current = NULL;
 625         Iterator i;
 626         int r;
 627         uint64_t new_offset = 0;
 628         Object *new_entry = NULL;
 629
 630         if (!j)
 631                 return -EINVAL;
 632
 633         HASHMAP_FOREACH(f, j->files, i) {
 634                 Object *o;
 635                 uint64_t p;
 636                 bool found;
 637
 638                 r = next_beyond_location(j, f, direction, &o, &p);
 639                 if (r < 0)
 640                         return r;
 641                 else if (r == 0)
 642                         continue;
 643
 644                 if (!new_current)
 645                         found = true;
 646                 else {
 647                         int k;
 648
 649                         k = compare_order(f, o, new_current, new_entry);
 650
 651                         if (direction == DIRECTION_DOWN)
 652                                 found = k < 0;
 653                         else
 654                                 found = k > 0;
 655                 }
 656
 657                 if (found) {
 658                         new_current = f;
 659                         new_entry = o;
 660                         new_offset = p;
 661                 }
 662         }
 663
 664         if (!new_current)
 665                 return 0;
 666
 667         set_location(j, new_current, new_entry, new_offset);
 668
 669         return 1;
 670 }
 671
 672 _public_ int sd_journal_next(sd_journal *j) {
 673         return real_journal_next(j, DIRECTION_DOWN);
 674 }
 675
 676 _public_ int sd_journal_previous(sd_journal *j) {
 677         return real_journal_next(j, DIRECTION_UP);
 678 }
 679
 680 _public_ int sd_journal_next_skip(sd_journal *j, uint64_t skip) {
 681         int c = 0, r;
 682
 683         if (!j)
 684                 return -EINVAL;
 685
 686         while (skip > 0) {
 687                 r = sd_journal_next(j);
 688                 if (r < 0)
 689                         return r;
 690
 691                 if (r == 0)
 692                         return c;
 693
 694                 skip--;
 695                 c++;
 696         }
 697
 698         return c;
 699 }
 700
 701 _public_ int sd_journal_previous_skip(sd_journal *j, uint64_t skip) {
 702         int c = 0, r;
 703
 704         if (!j)
 705                 return -EINVAL;
 706
 707         while (skip > 0) {
 708                 r = sd_journal_previous(j);
 709                 if (r < 0)
 710                         return r;
 711
 712                 if (r == 0)
 713                         return c;
 714
 715                 skip--;
 716                 c++;
 717         }
 718
 719         return 1;
 720 }
 721
 722 _public_ int sd_journal_get_cursor(sd_journal *j, char **cursor) {
 723         Object *o;
 724         int r;
 725         char bid[33], sid[33];
 726
 727         if (!j)
 728                 return -EINVAL;
 729         if (!cursor)
 730                 return -EINVAL;
 731
 732         if (!j->current_file || j->current_file->current_offset <= 0)
 733                 return -EADDRNOTAVAIL;
 734
 735         r = journal_file_move_to_object(j->current_file, OBJECT_ENTRY, j->current_file->current_offset, &o);
 736         if (r < 0)
 737                 return r;
 738
 739         sd_id128_to_string(j->current_file->header->seqnum_id, sid);
 740         sd_id128_to_string(o->entry.boot_id, bid);
 741
 742         if (asprintf(cursor,
 743                      "s=%s;i=%llx;b=%s;m=%llx;t=%llx;x=%llx;p=%s",
 744                      sid, (unsigned long long) le64toh(o->entry.seqnum),
 745                      bid, (unsigned long long) le64toh(o->entry.monotonic),
 746                      (unsigned long long) le64toh(o->entry.realtime),
 747                      (unsigned long long) le64toh(o->entry.xor_hash),
 748                      file_name_from_path(j->current_file->path)) < 0)
 749                 return -ENOMEM;
 750
 751         return 1;
 752 }
 753
 754 _public_ int sd_journal_seek_cursor(sd_journal *j, const char *cursor) {
 755         char *w;
 756         size_t l;
 757         char *state;
 758         unsigned long long seqnum, monotonic, realtime, xor_hash;
 759         bool
 760                 seqnum_id_set = false,
 761                 seqnum_set = false,
 762                 boot_id_set = false,
 763                 monotonic_set = false,
 764                 realtime_set = false,
 765                 xor_hash_set = false;
 766         sd_id128_t seqnum_id, boot_id;
 767
 768         if (!j)
 769                 return -EINVAL;
 770         if (!cursor)
 771                 return -EINVAL;
 772
 773         FOREACH_WORD_SEPARATOR(w, l, cursor, ";", state) {
 774                 char *item;
 775                 int k = 0;
 776
 777                 if (l < 2 || w[1] != '=')
 778                         return -EINVAL;
 779
 780                 item = strndup(w, l);
 781                 if (!item)
 782                         return -ENOMEM;
 783
 784                 switch (w[0]) {
 785
 786                 case 's':
 787                         seqnum_id_set = true;
 788                         k = sd_id128_from_string(w+2, &seqnum_id);
 789                         break;
 790
 791                 case 'i':
 792                         seqnum_set = true;
 793                         if (sscanf(w+2, "%llx", &seqnum) != 1)
 794                                 k = -EINVAL;
 795                         break;
 796
 797                 case 'b':
 798                         boot_id_set = true;
 799                         k = sd_id128_from_string(w+2, &boot_id);
 800                         break;
 801
 802                 case 'm':
 803                         monotonic_set = true;
 804                         if (sscanf(w+2, "%llx", &monotonic) != 1)
 805                                 k = -EINVAL;
 806                         break;
 807
 808                 case 't':
 809                         realtime_set = true;
 810                         if (sscanf(w+2, "%llx", &realtime) != 1)
 811                                 k = -EINVAL;
 812                         break;
 813
 814                 case 'x':
 815                         xor_hash_set = true;
 816                         if (sscanf(w+2, "%llx", &xor_hash) != 1)
 817                                 k = -EINVAL;
 818                         break;
 819                 }
 820
 821                 free(item);
 822
 823                 if (k < 0)
 824                         return k;
 825         }
 826
 827         if ((!seqnum_set || !seqnum_id_set) &&
 828             (!monotonic_set || !boot_id_set) &&
 829             !realtime_set)
 830                 return -EINVAL;
 831
 832         reset_location(j);
 833
 834         j->current_location.type = LOCATION_DISCRETE;
 835
 836         if (realtime_set) {
 837                 j->current_location.realtime = (uint64_t) realtime;
 838                 j->current_location.realtime_set = true;
 839         }
 840
 841         if (seqnum_set && seqnum_id_set) {
 842                 j->current_location.seqnum = (uint64_t) seqnum;
 843                 j->current_location.seqnum_id = seqnum_id;
 844                 j->current_location.seqnum_set = true;
 845         }
 846
 847         if (monotonic_set && boot_id_set) {
 848                 j->current_location.monotonic = (uint64_t) monotonic;
 849                 j->current_location.boot_id = boot_id;
 850                 j->current_location.monotonic_set = true;
 851         }
 852
 853         if (xor_hash_set) {
 854                 j->current_location.xor_hash = (uint64_t) xor_hash;
 855                 j->current_location.xor_hash_set = true;
 856         }
 857
 858         return 0;
 859 }
 860
 861 _public_ int sd_journal_seek_monotonic_usec(sd_journal *j, sd_id128_t boot_id, uint64_t usec) {
 862         if (!j)
 863                 return -EINVAL;
 864
 865         reset_location(j);
 866         j->current_location.type = LOCATION_DISCRETE;
 867         j->current_location.boot_id = boot_id;
 868         j->current_location.monotonic = usec;
 869         j->current_location.monotonic_set = true;
 870
 871         return 0;
 872 }
 873
 874 _public_ int sd_journal_seek_realtime_usec(sd_journal *j, uint64_t usec) {
 875         if (!j)
 876                 return -EINVAL;
 877
 878         reset_location(j);
 879         j->current_location.type = LOCATION_DISCRETE;
 880         j->current_location.realtime = usec;
 881         j->current_location.realtime_set = true;
 882
 883         return 0;
 884 }
 885
 886 _public_ int sd_journal_seek_head(sd_journal *j) {
 887         if (!j)
 888                 return -EINVAL;
 889
 890         reset_location(j);
 891         j->current_location.type = LOCATION_HEAD;
 892
 893         return 0;
 894 }
 895
 896 _public_ int sd_journal_seek_tail(sd_journal *j) {
 897         if (!j)
 898                 return -EINVAL;
 899
 900         reset_location(j);
 901         j->current_location.type = LOCATION_TAIL;
 902
 903         return 0;
 904 }
 905
 906 static int add_file(sd_journal *j, const char *prefix, const char *dir, const char *filename) {
 907         char *fn;
 908         int r;
 909         JournalFile *f;
 910
 911         assert(j);
 912         assert(prefix);
 913         assert(filename);
 914
 915         if ((j->flags & SD_JOURNAL_SYSTEM_ONLY) &&
 916             !startswith(filename, "system.journal"))
 917                 return 0;
 918
 919         if (dir)
 920                 fn = join(prefix, "/", dir, "/", filename, NULL);
 921         else
 922                 fn = join(prefix, "/", filename, NULL);
 923
 924         if (!fn)
 925                 return -ENOMEM;
 926
 927         if (hashmap_get(j->files, fn)) {
 928                 free(fn);
 929                 return 0;
 930         }
 931
 932         if (hashmap_size(j->files) >= JOURNAL_FILES_MAX) {
 933                 log_debug("Too many open journal files, not adding %s, ignoring.", fn);
 934                 free(fn);
 935                 return 0;
 936         }
 937
 938         r = journal_file_open(fn, O_RDONLY, 0, NULL, &f);
 939         free(fn);
 940
 941         if (r < 0) {
 942                 if (errno == ENOENT)
 943                         return 0;
 944
 945                 return r;
 946         }
 947
 948         /* journal_file_dump(f); */
 949
 950         r = hashmap_put(j->files, f->path, f);
 951         if (r < 0) {
 952                 journal_file_close(f);
 953                 return r;
 954         }
 955
 956         log_debug("File %s got added.", f->path);
 957
 958         return 0;
 959 }
 960
 961 static int remove_file(sd_journal *j, const char *prefix, const char *dir, const char *filename) {
 962         char *fn;
 963         JournalFile *f;
 964
 965         assert(j);
 966         assert(prefix);
 967         assert(filename);
 968
 969         if (dir)
 970                 fn = join(prefix, "/", dir, "/", filename, NULL);
 971         else
 972                 fn = join(prefix, "/", filename, NULL);
 973
 974         if (!fn)
 975                 return -ENOMEM;
 976
 977         f = hashmap_get(j->files, fn);
 978         free(fn);
 979
 980         if (!f)
 981                 return 0;
 982
 983         hashmap_remove(j->files, f->path);
 984         journal_file_close(f);
 985
 986         log_debug("File %s got removed.", f->path);
 987         return 0;
 988 }
 989
 990 static int add_directory(sd_journal *j, const char *prefix, const char *dir) {
 991         char *fn;
 992         int r;
 993         DIR *d;
 994         int wd;
 995         sd_id128_t id, mid;
 996
 997         assert(j);
 998         assert(prefix);
 999         assert(dir);
1000
1001         if ((j->flags & SD_JOURNAL_LOCAL_ONLY) &&
1002             (sd_id128_from_string(dir, &id) < 0 ||
1003              sd_id128_get_machine(&mid) < 0 ||
1004              !sd_id128_equal(id, mid)))
1005             return 0;
1006
1007         fn = join(prefix, "/", dir, NULL);
1008         if (!fn)
1009                 return -ENOMEM;
1010
1011         d = opendir(fn);
1012
1013         if (!d) {
1014                 free(fn);
1015                 if (errno == ENOENT)
1016                         return 0;
1017
1018                 return -errno;
1019         }
1020
1021         wd = inotify_add_watch(j->inotify_fd, fn,
1022                                IN_CREATE|IN_MOVED_TO|IN_MODIFY|IN_ATTRIB|IN_DELETE|
1023                                IN_DELETE_SELF|IN_MOVE_SELF|IN_UNMOUNT|
1024                                IN_DONT_FOLLOW|IN_ONLYDIR);
1025         if (wd > 0) {
1026                 if (hashmap_put(j->inotify_wd_dirs, INT_TO_PTR(wd), fn) < 0)
1027                         inotify_rm_watch(j->inotify_fd, wd);
1028                 else
1029                         fn = NULL;
1030         }
1031
1032         free(fn);
1033
1034         for (;;) {
1035                 struct dirent buf, *de;
1036
1037                 r = readdir_r(d, &buf, &de);
1038                 if (r != 0 || !de)
1039                         break;
1040
1041                 if (!dirent_is_file_with_suffix(de, ".journal"))
1042                         continue;
1043
1044                 r = add_file(j, prefix, dir, de->d_name);
1045                 if (r < 0)
1046                         log_debug("Failed to add file %s/%s/%s: %s", prefix, dir, de->d_name, strerror(-r));
1047         }
1048
1049         closedir(d);
1050
1051         log_debug("Directory %s/%s got added.", prefix, dir);
1052
1053         return 0;
1054 }
1055
1056 static void remove_directory_wd(sd_journal *j, int wd) {
1057         char *p;
1058
1059         assert(j);
1060         assert(wd > 0);
1061
1062         if (j->inotify_fd >= 0)
1063                 inotify_rm_watch(j->inotify_fd, wd);
1064
1065         p = hashmap_remove(j->inotify_wd_dirs, INT_TO_PTR(wd));
1066
1067         if (p) {
1068                 log_debug("Directory %s got removed.", p);
1069                 free(p);
1070         }
1071 }
1072
1073 static void add_root_wd(sd_journal *j, const char *p) {
1074         int wd;
1075         char *k;
1076
1077         assert(j);
1078         assert(p);
1079
1080         wd = inotify_add_watch(j->inotify_fd, p,
1081                                IN_CREATE|IN_MOVED_TO|IN_MODIFY|IN_ATTRIB|IN_DELETE|
1082                                IN_DONT_FOLLOW|IN_ONLYDIR);
1083         if (wd <= 0)
1084                 return;
1085
1086         k = strdup(p);
1087         if (!k || hashmap_put(j->inotify_wd_roots, INT_TO_PTR(wd), k) < 0) {
1088                 inotify_rm_watch(j->inotify_fd, wd);
1089                 free(k);
1090         }
1091 }
1092
1093 static void remove_root_wd(sd_journal *j, int wd) {
1094         char *p;
1095
1096         assert(j);
1097         assert(wd > 0);
1098
1099         if (j->inotify_fd >= 0)
1100                 inotify_rm_watch(j->inotify_fd, wd);
1101
1102         p = hashmap_remove(j->inotify_wd_roots, INT_TO_PTR(wd));
1103
1104         if (p) {
1105                 log_debug("Root %s got removed.", p);
1106                 free(p);
1107         }
1108 }
1109
1110 _public_ int sd_journal_open(sd_journal **ret, int flags) {
1111         sd_journal *j;
1112         const char *p;
1113         const char search_paths[] =
1114                 "/run/log/journal\0"
1115                 "/var/log/journal\0";
1116         int r;
1117
1118         if (!ret)
1119                 return -EINVAL;
1120
1121         if (flags & ~(SD_JOURNAL_LOCAL_ONLY|
1122                       SD_JOURNAL_RUNTIME_ONLY|
1123                       SD_JOURNAL_SYSTEM_ONLY))
1124                 return -EINVAL;
1125
1126         j = new0(sd_journal, 1);
1127         if (!j)
1128                 return -ENOMEM;
1129
1130         j->flags = flags;
1131
1132         j->inotify_fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC);
1133         if (j->inotify_fd < 0) {
1134                 r = -errno;
1135                 goto fail;
1136         }
1137
1138         j->files = hashmap_new(string_hash_func, string_compare_func);
1139         if (!j->files) {
1140                 r = -ENOMEM;
1141                 goto fail;
1142         }
1143
1144         j->inotify_wd_dirs = hashmap_new(trivial_hash_func, trivial_compare_func);
1145         j->inotify_wd_roots = hashmap_new(trivial_hash_func, trivial_compare_func);
1146
1147         if (!j->inotify_wd_dirs || !j->inotify_wd_roots) {
1148                 r = -ENOMEM;
1149                 goto fail;
1150         }
1151
1152         /* We ignore most errors here, since the idea is to only open
1153          * what's actually accessible, and ignore the rest. */
1154
1155         NULSTR_FOREACH(p, search_paths) {
1156                 DIR *d;
1157
1158                 if ((flags & SD_JOURNAL_RUNTIME_ONLY) &&
1159                     !path_startswith(p, "/run"))
1160                         continue;
1161
1162                 d = opendir(p);
1163                 if (!d) {
1164                         if (errno != ENOENT)
1165                                 log_debug("Failed to open %s: %m", p);
1166                         continue;
1167                 }
1168
1169                 add_root_wd(j, p);
1170
1171                 for (;;) {
1172                         struct dirent buf, *de;
1173                         sd_id128_t id;
1174
1175                         r = readdir_r(d, &buf, &de);
1176                         if (r != 0 || !de)
1177                                 break;
1178
1179                         if (dirent_is_file_with_suffix(de, ".journal")) {
1180                                 r = add_file(j, p, NULL, de->d_name);
1181                                 if (r < 0)
1182                                         log_debug("Failed to add file %s/%s: %s", p, de->d_name, strerror(-r));
1183
1184                         } else if ((de->d_type == DT_DIR || de->d_type == DT_UNKNOWN) &&
1185                                    sd_id128_from_string(de->d_name, &id) >= 0) {
1186
1187                                 r = add_directory(j, p, de->d_name);
1188                                 if (r < 0)
1189                                         log_debug("Failed to add directory %s/%s: %s", p, de->d_name, strerror(-r));
1190                         }
1191                 }
1192
1193                 closedir(d);
1194         }
1195
1196         *ret = j;
1197         return 0;
1198
1199 fail:
1200         sd_journal_close(j);
1201
1202         return r;
1203 };
1204
1205 _public_ void sd_journal_close(sd_journal *j) {
1206         if (!j)
1207                 return;
1208
1209         if (j->inotify_wd_dirs) {
1210                 void *k;
1211
1212                 while ((k = hashmap_first_key(j->inotify_wd_dirs)))
1213                         remove_directory_wd(j, PTR_TO_INT(k));
1214
1215                 hashmap_free(j->inotify_wd_dirs);
1216         }
1217
1218         if (j->inotify_wd_roots) {
1219                 void *k;
1220
1221                 while ((k = hashmap_first_key(j->inotify_wd_roots)))
1222                         remove_root_wd(j, PTR_TO_INT(k));
1223
1224                 hashmap_free(j->inotify_wd_roots);
1225         }
1226
1227         if (j->files) {
1228                 JournalFile *f;
1229
1230                 while ((f = hashmap_steal_first(j->files)))
1231                         journal_file_close(f);
1232
1233                 hashmap_free(j->files);
1234         }
1235
1236         sd_journal_flush_matches(j);
1237
1238         if (j->inotify_fd >= 0)
1239                 close_nointr_nofail(j->inotify_fd);
1240
1241         free(j);
1242 }
1243
1244 _public_ int sd_journal_get_realtime_usec(sd_journal *j, uint64_t *ret) {
1245         Object *o;
1246         JournalFile *f;
1247         int r;
1248
1249         if (!j)
1250                 return -EINVAL;
1251         if (!ret)
1252                 return -EINVAL;
1253
1254         f = j->current_file;
1255         if (!f)
1256                 return -EADDRNOTAVAIL;
1257
1258         if (f->current_offset <= 0)
1259                 return -EADDRNOTAVAIL;
1260
1261         r = journal_file_move_to_object(f, OBJECT_ENTRY, f->current_offset, &o);
1262         if (r < 0)
1263                 return r;
1264
1265         *ret = le64toh(o->entry.realtime);
1266         return 0;
1267 }
1268
1269 _public_ int sd_journal_get_monotonic_usec(sd_journal *j, uint64_t *ret, sd_id128_t *ret_boot_id) {
1270         Object *o;
1271         JournalFile *f;
1272         int r;
1273         sd_id128_t id;
1274
1275         if (!j)
1276                 return -EINVAL;
1277         if (!ret)
1278                 return -EINVAL;
1279
1280         f = j->current_file;
1281         if (!f)
1282                 return -EADDRNOTAVAIL;
1283
1284         if (f->current_offset <= 0)
1285                 return -EADDRNOTAVAIL;
1286
1287         r = journal_file_move_to_object(f, OBJECT_ENTRY, f->current_offset, &o);
1288         if (r < 0)
1289                 return r;
1290
1291         if (ret_boot_id)
1292                 *ret_boot_id = o->entry.boot_id;
1293         else {
1294                 r = sd_id128_get_boot(&id);
1295                 if (r < 0)
1296                         return r;
1297
1298                 if (!sd_id128_equal(id, o->entry.boot_id))
1299                         return -ENOENT;
1300         }
1301
1302         *ret = le64toh(o->entry.monotonic);
1303         return 0;
1304 }
1305
1306 _public_ int sd_journal_get_data(sd_journal *j, const char *field, const void **data, size_t *size) {
1307         JournalFile *f;
1308         uint64_t i, n;
1309         size_t field_length;
1310         int r;
1311         Object *o;
1312
1313         if (!j)
1314                 return -EINVAL;
1315         if (!field)
1316                 return -EINVAL;
1317         if (!data)
1318                 return -EINVAL;
1319         if (!size)
1320                 return -EINVAL;
1321
1322         if (isempty(field) || strchr(field, '='))
1323                 return -EINVAL;
1324
1325         f = j->current_file;
1326         if (!f)
1327                 return -EADDRNOTAVAIL;
1328
1329         if (f->current_offset <= 0)
1330                 return -EADDRNOTAVAIL;
1331
1332         r = journal_file_move_to_object(f, OBJECT_ENTRY, f->current_offset, &o);
1333         if (r < 0)
1334                 return r;
1335
1336         field_length = strlen(field);
1337
1338         n = journal_file_entry_n_items(o);
1339         for (i = 0; i < n; i++) {
1340                 uint64_t p, l, le_hash;
1341                 size_t t;
1342
1343                 p = le64toh(o->entry.items[i].object_offset);
1344                 le_hash = o->entry.items[i].hash;
1345                 r = journal_file_move_to_object(f, OBJECT_DATA, p, &o);
1346                 if (r < 0)
1347                         return r;
1348
1349                 if (le_hash != o->data.hash)
1350                         return -EBADMSG;
1351
1352                 l = le64toh(o->object.size) - offsetof(Object, data.payload);
1353
1354                 if (o->object.flags & OBJECT_COMPRESSED) {
1355
1356 #ifdef HAVE_XZ
1357                         if (uncompress_startswith(o->data.payload, l,
1358                                                   &f->compress_buffer, &f->compress_buffer_size,
1359                                                   field, field_length, '=')) {
1360
1361                                 uint64_t rsize;
1362
1363                                 if (!uncompress_blob(o->data.payload, l,
1364                                                      &f->compress_buffer, &f->compress_buffer_size, &rsize))
1365                                         return -EBADMSG;
1366
1367                                 *data = f->compress_buffer;
1368                                 *size = (size_t) rsize;
1369
1370                                 return 0;
1371                         }
1372 #else
1373                         return -EPROTONOSUPPORT;
1374 #endif
1375
1376                 } else if (l >= field_length+1 &&
1377                            memcmp(o->data.payload, field, field_length) == 0 &&
1378                            o->data.payload[field_length] == '=') {
1379
1380                         t = (size_t) l;
1381
1382                         if ((uint64_t) t != l)
1383                                 return -E2BIG;
1384
1385                         *data = o->data.payload;
1386                         *size = t;
1387
1388                         return 0;
1389                 }
1390
1391                 r = journal_file_move_to_object(f, OBJECT_ENTRY, f->current_offset, &o);
1392                 if (r < 0)
1393                         return r;
1394         }
1395
1396         return -ENOENT;
1397 }
1398
1399 _public_ int sd_journal_enumerate_data(sd_journal *j, const void **data, size_t *size) {
1400         JournalFile *f;
1401         uint64_t p, l, n, le_hash;
1402         int r;
1403         Object *o;
1404         size_t t;
1405
1406         if (!j)
1407                 return -EINVAL;
1408         if (!data)
1409                 return -EINVAL;
1410         if (!size)
1411                 return -EINVAL;
1412
1413         f = j->current_file;
1414         if (!f)
1415                 return -EADDRNOTAVAIL;
1416
1417         if (f->current_offset <= 0)
1418                 return -EADDRNOTAVAIL;
1419
1420         r = journal_file_move_to_object(f, OBJECT_ENTRY, f->current_offset, &o);
1421         if (r < 0)
1422                 return r;
1423
1424         n = journal_file_entry_n_items(o);
1425         if (j->current_field >= n)
1426                 return 0;
1427
1428         p = le64toh(o->entry.items[j->current_field].object_offset);
1429         le_hash = o->entry.items[j->current_field].hash;
1430         r = journal_file_move_to_object(f, OBJECT_DATA, p, &o);
1431         if (r < 0)
1432                 return r;
1433
1434         if (le_hash != o->data.hash)
1435                 return -EBADMSG;
1436
1437         l = le64toh(o->object.size) - offsetof(Object, data.payload);
1438         t = (size_t) l;
1439
1440         /* We can't read objects larger than 4G on a 32bit machine */
1441         if ((uint64_t) t != l)
1442                 return -E2BIG;
1443
1444         if (o->object.flags & OBJECT_COMPRESSED) {
1445 #ifdef HAVE_XZ
1446                 uint64_t rsize;
1447
1448                 if (!uncompress_blob(o->data.payload, l, &f->compress_buffer, &f->compress_buffer_size, &rsize))
1449                         return -EBADMSG;
1450
1451                 *data = f->compress_buffer;
1452                 *size = (size_t) rsize;
1453 #else
1454                 return -EPROTONOSUPPORT;
1455 #endif
1456         } else {
1457                 *data = o->data.payload;
1458                 *size = t;
1459         }
1460
1461         j->current_field ++;
1462
1463         return 1;
1464 }
1465
1466 _public_ void sd_journal_restart_data(sd_journal *j) {
1467         if (!j)
1468                 return;
1469
1470         j->current_field = 0;
1471 }
1472
1473 _public_ int sd_journal_get_fd(sd_journal *j) {
1474         if (!j)
1475                 return -EINVAL;
1476
1477         return j->inotify_fd;
1478 }
1479
1480 static void process_inotify_event(sd_journal *j, struct inotify_event *e) {
1481         char *p;
1482         int r;
1483
1484         assert(j);
1485         assert(e);
1486
1487         /* Is this a subdirectory we watch? */
1488         p = hashmap_get(j->inotify_wd_dirs, INT_TO_PTR(e->wd));
1489         if (p) {
1490
1491                 if (!(e->mask & IN_ISDIR) && e->len > 0 && endswith(e->name, ".journal")) {
1492
1493                         /* Event for a journal file */
1494
1495                         if (e->mask & (IN_CREATE|IN_MOVED_TO|IN_MODIFY|IN_ATTRIB)) {
1496                                 r = add_file(j, p, NULL, e->name);
1497                                 if (r < 0)
1498                                         log_debug("Failed to add file %s/%s: %s", p, e->name, strerror(-r));
1499                         } else if (e->mask & (IN_DELETE|IN_UNMOUNT)) {
1500
1501                                 r = remove_file(j, p, NULL, e->name);
1502                                 if (r < 0)
1503                                         log_debug("Failed to remove file %s/%s: %s", p, e->name, strerror(-r));
1504                         }
1505
1506                 } else if (e->len == 0) {
1507
1508                         /* Event for the directory itself */
1509
1510                         if (e->mask & (IN_DELETE_SELF|IN_MOVE_SELF|IN_UNMOUNT))
1511                                 remove_directory_wd(j, e->wd);
1512                 }
1513
1514                 return;
1515         }
1516
1517         /* Must be the root directory then? */
1518         p = hashmap_get(j->inotify_wd_roots, INT_TO_PTR(e->wd));
1519         if (p) {
1520                 sd_id128_t id;
1521
1522                 if (!(e->mask & IN_ISDIR) && e->len > 0 && endswith(e->name, ".journal")) {
1523
1524                         /* Event for a journal file */
1525
1526                         if (e->mask & (IN_CREATE|IN_MOVED_TO|IN_MODIFY|IN_ATTRIB)) {
1527                                 r = add_file(j, p, NULL, e->name);
1528                                 if (r < 0)
1529                                         log_debug("Failed to add file %s/%s: %s", p, e->name, strerror(-r));
1530                         } else if (e->mask & (IN_DELETE|IN_UNMOUNT)) {
1531
1532                                 r = remove_file(j, p, NULL, e->name);
1533                                 if (r < 0)
1534                                         log_debug("Failed to remove file %s/%s: %s", p, e->name, strerror(-r));
1535                         }
1536
1537                 } else if ((e->mask & IN_ISDIR) && e->len > 0 && sd_id128_from_string(e->name, &id) >= 0) {
1538
1539                         /* Event for subdirectory */
1540
1541                         if (e->mask & (IN_CREATE|IN_MOVED_TO|IN_MODIFY|IN_ATTRIB)) {
1542
1543                                 r = add_directory(j, p, e->name);
1544                                 if (r < 0)
1545                                         log_debug("Failed to add directory %s/%s: %s", p, e->name, strerror(-r));
1546                         }
1547                 }
1548
1549                 return;
1550         }
1551
1552         if (e->mask & IN_IGNORED)
1553                 return;
1554
1555         log_warning("Unknown inotify event.");
1556 }
1557
1558 _public_ int sd_journal_process(sd_journal *j) {
1559         uint8_t buffer[sizeof(struct inotify_event) + FILENAME_MAX];
1560
1561         if (!j)
1562                 return -EINVAL;
1563
1564         for (;;) {
1565                 struct inotify_event *e;
1566                 ssize_t l;
1567
1568                 l = read(j->inotify_fd, buffer, sizeof(buffer));
1569                 if (l < 0) {
1570                         if (errno == EINTR || errno == EAGAIN)
1571                                 return 0;
1572
1573                         return -errno;
1574                 }
1575
1576                 e = (struct inotify_event*) buffer;
1577                 while (l > 0) {
1578                         size_t step;
1579
1580                         process_inotify_event(j, e);
1581
1582                         step = sizeof(struct inotify_event) + e->len;
1583                         assert(step <= (size_t) l);
1584
1585                         e = (struct inotify_event*) ((uint8_t*) e + step);
1586                         l -= step;
1587                 }
1588         }
1589 }
1590
1591 _public_ int sd_journal_query_unique(sd_journal *j, const char *field) {
1592         if (!j)
1593                 return -EINVAL;
1594         if (!field)
1595                 return -EINVAL;
1596
1597         return -ENOTSUP;
1598 }
1599
1600 _public_ int sd_journal_enumerate_unique(sd_journal *j, const void **data, size_t *l) {
1601         if (!j)
1602                 return -EINVAL;
1603         if (!data)
1604                 return -EINVAL;
1605         if (!l)
1606                 return -EINVAL;
1607
1608         return -ENOTSUP;
1609 }
1610
1611 _public_ void sd_journal_restart_unique(sd_journal *j) {
1612         if (!j)
1613                 return;
1614 }