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
  26 #include "sd-journal.h"
  27 #include "journal-def.h"
  28 #include "journal-file.h"
  29 #include "hashmap.h"
  30 #include "list.h"
  31
  32 typedef struct Match Match;
  33
  34 struct Match {
  35         char *data;
  36         size_t size;
  37         uint64_t hash;
  38
  39         LIST_FIELDS(Match, matches);
  40 };
  41
  42 struct sd_journal {
  43         Hashmap *files;
  44
  45         JournalFile *current_file;
  46
  47         LIST_HEAD(Match, matches);
  48 };
  49
  50 int sd_journal_add_match(sd_journal *j, const char *field, const void *data, size_t size) {
  51         Match *m;
  52         char *e;
  53
  54         assert(j);
  55         assert(field);
  56         assert(data || size == 0);
  57
  58         m = new0(Match, 1);
  59         if (!m)
  60                 return -ENOMEM;
  61
  62         m->size = strlen(field) + 1 + size;
  63         m->data = malloc(m->size);
  64         if (!m->data) {
  65                 free(m);
  66                 return -ENOMEM;
  67         }
  68
  69         e = stpcpy(m->data, field);
  70         *(e++) = '=';
  71         memcpy(e, data, size);
  72
  73         LIST_PREPEND(Match, matches, j->matches, m);
  74         return 0;
  75 }
  76
  77 void sd_journal_flush_matches(sd_journal *j) {
  78         assert(j);
  79
  80         while (j->matches) {
  81                 Match *m = j->matches;
  82
  83                 LIST_REMOVE(Match, matches, j->matches, m);
  84                 free(m->data);
  85                 free(m);
  86         }
  87 }
  88
  89 static int compare_order(JournalFile *af, Object *ao, uint64_t ap,
  90                          JournalFile *bf, Object *bo, uint64_t bp) {
  91
  92         uint64_t a, b;
  93
  94         /* We operate on two different files here, hence we can access
  95          * two objects at the same time, which we normally can't */
  96
  97         if (sd_id128_equal(af->header->seqnum_id, bf->header->seqnum_id)) {
  98
  99                 /* If this is from the same seqnum source, compare
 100                  * seqnums */
 101                 a = le64toh(ao->entry.seqnum);
 102                 b = le64toh(bo->entry.seqnum);
 103
 104                 if (a < b)
 105                         return -1;
 106                 if (a > b)
 107                         return 1;
 108         }
 109
 110         if (sd_id128_equal(ao->entry.boot_id, bo->entry.boot_id)) {
 111
 112                 /* If the boot id matches compare monotonic time */
 113                 a = le64toh(ao->entry.monotonic);
 114                 b = le64toh(bo->entry.monotonic);
 115
 116                 if (a < b)
 117                         return -1;
 118                 if (a > b)
 119                         return 1;
 120         }
 121
 122         /* Otherwise compare UTC time */
 123         a = le64toh(ao->entry.realtime);
 124         b = le64toh(ao->entry.realtime);
 125
 126         if (a < b)
 127                 return -1;
 128         if (a > b)
 129                 return 1;
 130
 131         /* Finally, compare by contents */
 132         a = le64toh(ao->entry.xor_hash);
 133         b = le64toh(ao->entry.xor_hash);
 134
 135         if (a < b)
 136                 return -1;
 137         if (a > b)
 138                 return 1;
 139
 140         return 0;
 141 }
 142
 143 int sd_journal_next(sd_journal *j) {
 144         JournalFile *f, *new_current = NULL;
 145         Iterator i;
 146         int r;
 147         uint64_t new_offset = 0;
 148         Object *new_entry = NULL;
 149
 150         assert(j);
 151
 152         HASHMAP_FOREACH(f, j->files, i) {
 153                 Object *o;
 154                 uint64_t p;
 155
 156                 if (f->current_offset > 0) {
 157                         r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &o);
 158                         if (r < 0)
 159                                 return r;
 160                 } else
 161                         o = NULL;
 162
 163                 r = journal_file_next_entry(f, o, &o, &p);
 164                 if (r < 0)
 165                         return r;
 166                 else if (r == 0)
 167                         continue;
 168
 169                 if (!new_current ||
 170                     compare_order(new_current, new_entry, new_offset, f, o, p) > 0) {
 171                         new_current = f;
 172                         new_entry = o;
 173                         new_offset = p;
 174                 }
 175         }
 176
 177         if (new_current) {
 178                 j->current_file = new_current;
 179                 j->current_file->current_offset = new_offset;
 180                 j->current_file->current_field = 0;
 181
 182                 /* Skip over any identical entries in the other files too */
 183
 184                 HASHMAP_FOREACH(f, j->files, i) {
 185                         Object *o;
 186                         uint64_t p;
 187
 188                         if (j->current_file == f)
 189                                 continue;
 190
 191                         if (f->current_offset > 0) {
 192                                 r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &o);
 193                                 if (r < 0)
 194                                         return r;
 195                         } else
 196                                 o = NULL;
 197
 198                         r = journal_file_next_entry(f, o, &o, &p);
 199                         if (r < 0)
 200                                 return r;
 201                         else if (r == 0)
 202                                 continue;
 203
 204                         if (compare_order(new_current, new_entry, new_offset, f, o, p) == 0) {
 205                                 f->current_offset = p;
 206                                 f->current_field = 0;
 207                         }
 208                 }
 209
 210                 return 1;
 211         }
 212
 213         return 0;
 214 }
 215
 216 int sd_journal_previous(sd_journal *j) {
 217         JournalFile *f, *new_current = NULL;
 218         Iterator i;
 219         int r;
 220         uint64_t new_offset = 0;
 221         Object *new_entry = NULL;
 222
 223         assert(j);
 224
 225         HASHMAP_FOREACH(f, j->files, i) {
 226                 Object *o;
 227                 uint64_t p;
 228
 229                 if (f->current_offset > 0) {
 230                         r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &o);
 231                         if (r < 0)
 232                                 return r;
 233                 } else
 234                         o = NULL;
 235
 236                 r = journal_file_prev_entry(f, o, &o, &p);
 237                 if (r < 0)
 238                         return r;
 239                 else if (r == 0)
 240                         continue;
 241
 242                 if (!new_current || compare_order(new_current, new_entry, new_offset, f, o, p) > 0) {
 243                         new_current = f;
 244                         new_entry = o;
 245                         new_offset = p;
 246                 }
 247         }
 248
 249         if (new_current) {
 250                 j->current_file = new_current;
 251                 j->current_file->current_offset = new_offset;
 252                 j->current_file->current_field = 0;
 253                 return 1;
 254         }
 255
 256         return 0;
 257 }
 258
 259 int sd_journal_get_cursor(sd_journal *j, char **cursor) {
 260         Object *o;
 261         int r;
 262         char bid[33], sid[33];
 263
 264         assert(j);
 265         assert(cursor);
 266
 267         if (!j->current_file || j->current_file->current_offset <= 0)
 268                 return -EADDRNOTAVAIL;
 269
 270         r = journal_file_move_to_object(j->current_file, j->current_file->current_offset, OBJECT_ENTRY, &o);
 271         if (r < 0)
 272                 return r;
 273
 274         sd_id128_to_string(j->current_file->header->seqnum_id, sid);
 275         sd_id128_to_string(o->entry.boot_id, bid);
 276
 277         if (asprintf(cursor,
 278                      "s=%s;i=%llx;b=%s;m=%llx;t=%llx;x=%llx;p=%s",
 279                      sid, (unsigned long long) le64toh(o->entry.seqnum),
 280                      bid, (unsigned long long) le64toh(o->entry.monotonic),
 281                      (unsigned long long) le64toh(o->entry.realtime),
 282                      (unsigned long long) le64toh(o->entry.xor_hash),
 283                      file_name_from_path(j->current_file->path)) < 0)
 284                 return -ENOMEM;
 285
 286         return 1;
 287 }
 288
 289 int sd_journal_set_cursor(sd_journal *j, const char *cursor) {
 290         return -EINVAL;
 291 }
 292
 293 static int add_file(sd_journal *j, const char *prefix, const char *dir, const char *filename) {
 294         char *fn;
 295         int r;
 296         JournalFile *f;
 297
 298         assert(j);
 299         assert(prefix);
 300         assert(filename);
 301
 302         if (dir)
 303                 fn = join(prefix, "/", dir, "/", filename, NULL);
 304         else
 305                 fn = join(prefix, "/", filename, NULL);
 306
 307         if (!fn)
 308                 return -ENOMEM;
 309
 310         r = journal_file_open(fn, O_RDONLY, 0, NULL, &f);
 311         free(fn);
 312
 313         if (r < 0) {
 314                 if (errno == ENOENT)
 315                         return 0;
 316
 317                 return r;
 318         }
 319
 320         r = hashmap_put(j->files, f->path, f);
 321         if (r < 0) {
 322                 journal_file_close(f);
 323                 return r;
 324         }
 325
 326         return 0;
 327 }
 328
 329 static int add_directory(sd_journal *j, const char *prefix, const char *dir) {
 330         char *fn;
 331         int r;
 332         DIR *d;
 333
 334         assert(j);
 335         assert(prefix);
 336         assert(dir);
 337
 338         fn = join(prefix, "/", dir, NULL);
 339         if (!fn)
 340                 return -ENOMEM;
 341
 342         d = opendir(fn);
 343         free(fn);
 344
 345         if (!d) {
 346                 if (errno == ENOENT)
 347                         return 0;
 348
 349                 return -errno;
 350         }
 351
 352         for (;;) {
 353                 struct dirent buf, *de;
 354
 355                 r = readdir_r(d, &buf, &de);
 356                 if (r != 0 || !de)
 357                         break;
 358
 359                 if (!dirent_is_file_with_suffix(de, ".journal"))
 360                         continue;
 361
 362                 r = add_file(j, prefix, dir, de->d_name);
 363                 if (r < 0)
 364                         log_debug("Failed to add file %s/%s/%s: %s", prefix, dir, de->d_name, strerror(-r));
 365         }
 366
 367         closedir(d);
 368
 369         return 0;
 370 }
 371
 372 int sd_journal_open(sd_journal **ret) {
 373         sd_journal *j;
 374         const char *p;
 375         const char search_paths[] =
 376                 "/run/log/journal\0"
 377                 "/var/log/journal\0";
 378         int r;
 379
 380         assert(ret);
 381
 382         j = new0(sd_journal, 1);
 383         if (!j)
 384                 return -ENOMEM;
 385
 386         j->files = hashmap_new(string_hash_func, string_compare_func);
 387         if (!j->files) {
 388                 r = -ENOMEM;
 389                 goto fail;
 390         }
 391
 392         /* We ignore most errors here, since the idea is to only open
 393          * what's actually accessible, and ignore the rest. */
 394
 395         NULSTR_FOREACH(p, search_paths) {
 396                 DIR *d;
 397
 398                 d = opendir(p);
 399                 if (!d) {
 400                         if (errno != ENOENT)
 401                                 log_debug("Failed to open %s: %m", p);
 402                         continue;
 403                 }
 404
 405                 for (;;) {
 406                         struct dirent buf, *de;
 407                         sd_id128_t id;
 408
 409                         r = readdir_r(d, &buf, &de);
 410                         if (r != 0 || !de)
 411                                 break;
 412
 413                         if (dirent_is_file_with_suffix(de, ".journal")) {
 414                                 r = add_file(j, p, NULL, de->d_name);
 415                                 if (r < 0)
 416                                         log_debug("Failed to add file %s/%s: %s", p, de->d_name, strerror(-r));
 417
 418                         } else if ((de->d_type == DT_DIR || de->d_type == DT_UNKNOWN) &&
 419                                    sd_id128_from_string(de->d_name, &id) >= 0) {
 420
 421                                 r = add_directory(j, p, de->d_name);
 422                                 if (r < 0)
 423                                         log_debug("Failed to add directory %s/%s: %s", p, de->d_name, strerror(-r));
 424                         }
 425                 }
 426
 427                 closedir(d);
 428         }
 429
 430         *ret = j;
 431         return 0;
 432
 433 fail:
 434         sd_journal_close(j);
 435
 436         return r;
 437 };
 438
 439 void sd_journal_close(sd_journal *j) {
 440         assert(j);
 441
 442         if (j->files) {
 443                 JournalFile *f;
 444
 445                 while ((f = hashmap_steal_first(j->files)))
 446                         journal_file_close(f);
 447
 448                 hashmap_free(j->files);
 449         }
 450
 451         free(j);
 452 }
 453
 454 int sd_journal_get_realtime_usec(sd_journal *j, uint64_t *ret) {
 455         Object *o;
 456         JournalFile *f;
 457         int r;
 458
 459         assert(j);
 460         assert(ret);
 461
 462         f = j->current_file;
 463         if (!f)
 464                 return 0;
 465
 466         if (f->current_offset <= 0)
 467                 return 0;
 468
 469         r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &o);
 470         if (r < 0)
 471                 return r;
 472
 473         *ret = le64toh(o->entry.realtime);
 474         return 1;
 475 }
 476
 477 int sd_journal_get_monotonic_usec(sd_journal *j, uint64_t *ret) {
 478         Object *o;
 479         JournalFile *f;
 480         int r;
 481         sd_id128_t id;
 482
 483         assert(j);
 484         assert(ret);
 485
 486         f = j->current_file;
 487         if (!f)
 488                 return 0;
 489
 490         if (f->current_offset <= 0)
 491                 return 0;
 492
 493         r = sd_id128_get_machine(&id);
 494         if (r < 0)
 495                 return r;
 496
 497         r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &o);
 498         if (r < 0)
 499                 return r;
 500
 501         if (!sd_id128_equal(id, o->entry.boot_id))
 502                 return 0;
 503
 504         *ret = le64toh(o->entry.monotonic);
 505         return 1;
 506
 507 }
 508
 509 int sd_journal_get_field(sd_journal *j, const char *field, const void **data, size_t *size) {
 510         JournalFile *f;
 511         uint64_t i, n;
 512         size_t field_length;
 513         int r;
 514         Object *o;
 515
 516         assert(j);
 517         assert(field);
 518         assert(data);
 519         assert(size);
 520
 521         if (isempty(field) || strchr(field, '='))
 522                 return -EINVAL;
 523
 524         f = j->current_file;
 525         if (!f)
 526                 return 0;
 527
 528         if (f->current_offset <= 0)
 529                 return 0;
 530
 531         r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &o);
 532         if (r < 0)
 533                 return r;
 534
 535         field_length = strlen(field);
 536
 537         n = journal_file_entry_n_items(o);
 538         for (i = 0; i < n; i++) {
 539                 uint64_t p, l;
 540                 size_t t;
 541
 542                 p = le64toh(o->entry.items[i].object_offset);
 543                 r = journal_file_move_to_object(f, p, OBJECT_DATA, &o);
 544                 if (r < 0)
 545                         return r;
 546
 547                 l = le64toh(o->object.size) - offsetof(Object, data.payload);
 548
 549                 if (l >= field_length+1 &&
 550                     memcmp(o->data.payload, field, field_length) == 0 &&
 551                     o->data.payload[field_length] == '=') {
 552
 553                         t = (size_t) l;
 554
 555                         if ((uint64_t) t != l)
 556                                 return -E2BIG;
 557
 558                         *data = o->data.payload;
 559                         *size = t;
 560
 561                         return 1;
 562                 }
 563
 564                 r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &o);
 565                 if (r < 0)
 566                         return r;
 567         }
 568
 569         return 0;
 570 }
 571
 572 int sd_journal_iterate_fields(sd_journal *j, const void **data, size_t *size) {
 573         JournalFile *f;
 574         uint64_t p, l, n;
 575         size_t t;
 576         int r;
 577         Object *o;
 578
 579         assert(j);
 580         assert(data);
 581         assert(size);
 582
 583         f = j->current_file;
 584         if (!f)
 585                 return 0;
 586
 587         if (f->current_offset <= 0)
 588                 return 0;
 589
 590         r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &o);
 591         if (r < 0)
 592                 return r;
 593
 594         n = journal_file_entry_n_items(o);
 595         if (f->current_field >= n)
 596                 return 0;
 597
 598         p = le64toh(o->entry.items[f->current_field].object_offset);
 599         r = journal_file_move_to_object(f, p, OBJECT_DATA, &o);
 600         if (r < 0)
 601                 return r;
 602
 603         l = le64toh(o->object.size) - offsetof(Object, data.payload);
 604         t = (size_t) l;
 605
 606         /* We can't read objects larger than 4G on a 32bit machine */
 607         if ((uint64_t) t != l)
 608                 return -E2BIG;
 609
 610         *data = o->data.payload;
 611         *size = t;
 612
 613         f->current_field ++;
 614
 615         return 1;
 616 }
 617
 618 int sd_journal_seek_head(sd_journal *j) {
 619         assert(j);
 620         return -EINVAL;
 621 }
 622
 623 int sd_journal_seek_tail(sd_journal *j) {
 624         assert(j);
 625         return -EINVAL;
 626 }