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         if (sd_id128_equal(af->header->seqnum_id, bf->header->seqnum_id)) {
  95
  96                 /* If this is from the same seqnum source, compare
  97                  * seqnums */
  98                 a = le64toh(ao->entry.seqnum);
  99                 b = le64toh(bo->entry.seqnum);
 100
 101
 102         } else if (sd_id128_equal(ao->entry.boot_id, bo->entry.boot_id)) {
 103
 104                 /* If the boot id matches compare monotonic time */
 105                 a = le64toh(ao->entry.monotonic);
 106                 b = le64toh(bo->entry.monotonic);
 107
 108         } else {
 109
 110                 /* Otherwise compare UTC time */
 111                 a = le64toh(ao->entry.realtime);
 112                 b = le64toh(ao->entry.realtime);
 113         }
 114
 115         return
 116                 a < b ? -1 :
 117                 a > b ? +1 : 0;
 118 }
 119
 120 int sd_journal_next(sd_journal *j) {
 121         JournalFile *f, *new_current = NULL;
 122         Iterator i;
 123         int r;
 124         uint64_t new_offset = 0;
 125         Object *new_entry = NULL;
 126
 127         assert(j);
 128
 129         HASHMAP_FOREACH(f, j->files, i) {
 130                 Object *o;
 131                 uint64_t p;
 132
 133                 if (f->current_offset > 0) {
 134                         r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &o);
 135                         if (r < 0)
 136                                 return r;
 137                 } else
 138                         o = NULL;
 139
 140                 r = journal_file_next_entry(f, o, &o, &p);
 141                 if (r < 0)
 142                         return r;
 143                 else if (r == 0)
 144                         continue;
 145
 146                 if (!new_current || compare_order(new_current, new_entry, new_offset, f, o, p) > 0) {
 147                         new_current = f;
 148                         new_entry = o;
 149                         new_offset = p;
 150                 }
 151         }
 152
 153         if (new_current) {
 154                 j->current_file = new_current;
 155                 j->current_file->current_offset = new_offset;
 156                 j->current_file->current_field = 0;
 157                 return 1;
 158         }
 159
 160         return 0;
 161 }
 162
 163 int sd_journal_previous(sd_journal *j) {
 164         JournalFile *f, *new_current = NULL;
 165         Iterator i;
 166         int r;
 167         uint64_t new_offset = 0;
 168         Object *new_entry = NULL;
 169
 170         assert(j);
 171
 172         HASHMAP_FOREACH(f, j->files, i) {
 173                 Object *o;
 174                 uint64_t p;
 175
 176                 if (f->current_offset > 0) {
 177                         r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &o);
 178                         if (r < 0)
 179                                 return r;
 180                 } else
 181                         o = NULL;
 182
 183                 r = journal_file_prev_entry(f, o, &o, &p);
 184                 if (r < 0)
 185                         return r;
 186                 else if (r == 0)
 187                         continue;
 188
 189                 if (!new_current || compare_order(new_current, new_entry, new_offset, f, o, p) > 0) {
 190                         new_current = f;
 191                         new_entry = o;
 192                         new_offset = p;
 193                 }
 194         }
 195
 196         if (new_current) {
 197                 j->current_file = new_current;
 198                 j->current_file->current_offset = new_offset;
 199                 j->current_file->current_field = 0;
 200                 return 1;
 201         }
 202
 203         return 0;
 204 }
 205
 206 int sd_journal_get_cursor(sd_journal *j, char **cursor) {
 207         Object *o;
 208         int r;
 209         char bid[33], sid[33];
 210
 211         assert(j);
 212         assert(cursor);
 213
 214         if (!j->current_file || j->current_file->current_offset <= 0)
 215                 return -EADDRNOTAVAIL;
 216
 217         r = journal_file_move_to_object(j->current_file, j->current_file->current_offset, OBJECT_ENTRY, &o);
 218         if (r < 0)
 219                 return r;
 220
 221         sd_id128_to_string(j->current_file->header->seqnum_id, sid);
 222         sd_id128_to_string(o->entry.boot_id, bid);
 223
 224         if (asprintf(cursor,
 225                      "s=%s;i=%llx;b=%s;m=%llx;t=%llx;x=%llx;p=%s",
 226                      sid, (unsigned long long) le64toh(o->entry.seqnum),
 227                      bid, (unsigned long long) le64toh(o->entry.monotonic),
 228                      (unsigned long long) le64toh(o->entry.realtime),
 229                      (unsigned long long) le64toh(o->entry.xor_hash),
 230                      file_name_from_path(j->current_file->path)) < 0)
 231                 return -ENOMEM;
 232
 233         return 1;
 234 }
 235
 236 int sd_journal_set_cursor(sd_journal *j, const char *cursor) {
 237         return -EINVAL;
 238 }
 239
 240 static int add_file(sd_journal *j, const char *prefix, const char *dir, const char *filename) {
 241         char *fn;
 242         int r;
 243         JournalFile *f;
 244
 245         assert(j);
 246         assert(prefix);
 247         assert(filename);
 248
 249         if (dir)
 250                 fn = join(prefix, "/", dir, "/", filename, NULL);
 251         else
 252                 fn = join(prefix, "/", filename, NULL);
 253
 254         if (!fn)
 255                 return -ENOMEM;
 256
 257         r = journal_file_open(fn, O_RDONLY, 0, NULL, &f);
 258         free(fn);
 259
 260         if (r < 0) {
 261                 if (errno == ENOENT)
 262                         return 0;
 263
 264                 return r;
 265         }
 266
 267         r = hashmap_put(j->files, f->path, f);
 268         if (r < 0) {
 269                 journal_file_close(f);
 270                 return r;
 271         }
 272
 273         return 0;
 274 }
 275
 276 static int add_directory(sd_journal *j, const char *prefix, const char *dir) {
 277         char *fn;
 278         int r;
 279         DIR *d;
 280
 281         assert(j);
 282         assert(prefix);
 283         assert(dir);
 284
 285         fn = join(prefix, "/", dir, NULL);
 286         if (!fn)
 287                 return -ENOMEM;
 288
 289         d = opendir(fn);
 290         free(fn);
 291
 292         if (!d) {
 293                 if (errno == ENOENT)
 294                         return 0;
 295
 296                 return -errno;
 297         }
 298
 299         for (;;) {
 300                 struct dirent buf, *de;
 301
 302                 r = readdir_r(d, &buf, &de);
 303                 if (r != 0 || !de)
 304                         break;
 305
 306                 if (!dirent_is_file_with_suffix(de, ".journal"))
 307                         continue;
 308
 309                 r = add_file(j, prefix, dir, de->d_name);
 310                 if (r < 0)
 311                         log_debug("Failed to add file %s/%s/%s: %s", prefix, dir, de->d_name, strerror(-r));
 312         }
 313
 314         closedir(d);
 315
 316         return 0;
 317 }
 318
 319 int sd_journal_open(sd_journal **ret) {
 320         sd_journal *j;
 321         const char *p;
 322         const char search_paths[] =
 323                 "/run/log/journal\0"
 324                 "/var/log/journal\0";
 325         int r;
 326
 327         assert(ret);
 328
 329         j = new0(sd_journal, 1);
 330         if (!j)
 331                 return -ENOMEM;
 332
 333         j->files = hashmap_new(string_hash_func, string_compare_func);
 334         if (!j->files) {
 335                 r = -ENOMEM;
 336                 goto fail;
 337         }
 338
 339         /* We ignore most errors here, since the idea is to only open
 340          * what's actually accessible, and ignore the rest. */
 341
 342         NULSTR_FOREACH(p, search_paths) {
 343                 DIR *d;
 344
 345                 d = opendir(p);
 346                 if (!d) {
 347                         if (errno != ENOENT)
 348                                 log_debug("Failed to open %s: %m", p);
 349                         continue;
 350                 }
 351
 352                 for (;;) {
 353                         struct dirent buf, *de;
 354                         sd_id128_t id;
 355
 356                         r = readdir_r(d, &buf, &de);
 357                         if (r != 0 || !de)
 358                                 break;
 359
 360                         if (dirent_is_file_with_suffix(de, ".journal")) {
 361                                 r = add_file(j, p, NULL, de->d_name);
 362                                 if (r < 0)
 363                                         log_debug("Failed to add file %s/%s: %s", p, de->d_name, strerror(-r));
 364
 365                         } else if ((de->d_type == DT_DIR || de->d_type == DT_UNKNOWN) &&
 366                                    sd_id128_from_string(de->d_name, &id) >= 0) {
 367
 368                                 r = add_directory(j, p, de->d_name);
 369                                 if (r < 0)
 370                                         log_debug("Failed to add directory %s/%s: %s", p, de->d_name, strerror(-r));
 371                         }
 372                 }
 373
 374                 closedir(d);
 375         }
 376
 377         *ret = j;
 378         return 0;
 379
 380 fail:
 381         sd_journal_close(j);
 382
 383         return r;
 384 };
 385
 386 void sd_journal_close(sd_journal *j) {
 387         assert(j);
 388
 389         if (j->files) {
 390                 JournalFile *f;
 391
 392                 while ((f = hashmap_steal_first(j->files)))
 393                         journal_file_close(f);
 394
 395                 hashmap_free(j->files);
 396         }
 397
 398         free(j);
 399 }
 400
 401 int sd_journal_get_realtime_usec(sd_journal *j, uint64_t *ret) {
 402         Object *o;
 403         JournalFile *f;
 404         int r;
 405
 406         assert(j);
 407         assert(ret);
 408
 409         f = j->current_file;
 410         if (!f)
 411                 return 0;
 412
 413         if (f->current_offset <= 0)
 414                 return 0;
 415
 416         r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &o);
 417         if (r < 0)
 418                 return r;
 419
 420         *ret = le64toh(o->entry.realtime);
 421         return 1;
 422 }
 423
 424 int sd_journal_get_monotonic_usec(sd_journal *j, uint64_t *ret) {
 425         Object *o;
 426         JournalFile *f;
 427         int r;
 428         sd_id128_t id;
 429
 430         assert(j);
 431         assert(ret);
 432
 433         f = j->current_file;
 434         if (!f)
 435                 return 0;
 436
 437         if (f->current_offset <= 0)
 438                 return 0;
 439
 440         r = sd_id128_get_machine(&id);
 441         if (r < 0)
 442                 return r;
 443
 444         r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &o);
 445         if (r < 0)
 446                 return r;
 447
 448         if (!sd_id128_equal(id, o->entry.boot_id))
 449                 return 0;
 450
 451         *ret = le64toh(o->entry.monotonic);
 452         return 1;
 453
 454 }
 455
 456 int sd_journal_get_field(sd_journal *j, const char *field, const void **data, size_t *size) {
 457         JournalFile *f;
 458         uint64_t i, n;
 459         size_t field_length;
 460         int r;
 461         Object *o;
 462
 463         assert(j);
 464         assert(field);
 465         assert(data);
 466         assert(size);
 467
 468         if (isempty(field) || strchr(field, '='))
 469                 return -EINVAL;
 470
 471         f = j->current_file;
 472         if (!f)
 473                 return 0;
 474
 475         if (f->current_offset <= 0)
 476                 return 0;
 477
 478         r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &o);
 479         if (r < 0)
 480                 return r;
 481
 482         field_length = strlen(field);
 483
 484         n = journal_file_entry_n_items(o);
 485         for (i = 0; i < n; i++) {
 486                 uint64_t p, l;
 487                 size_t t;
 488
 489                 p = le64toh(o->entry.items[i].object_offset);
 490                 r = journal_file_move_to_object(f, p, OBJECT_DATA, &o);
 491                 if (r < 0)
 492                         return r;
 493
 494                 l = le64toh(o->object.size) - offsetof(Object, data.payload);
 495
 496                 if (l >= field_length+1 &&
 497                     memcmp(o->data.payload, field, field_length) == 0 &&
 498                     o->data.payload[field_length] == '=') {
 499
 500                         t = (size_t) l;
 501
 502                         if ((uint64_t) t != l)
 503                                 return -E2BIG;
 504
 505                         *data = o->data.payload;
 506                         *size = t;
 507
 508                         return 1;
 509                 }
 510
 511                 r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &o);
 512                 if (r < 0)
 513                         return r;
 514         }
 515
 516         return 0;
 517 }
 518
 519 int sd_journal_iterate_fields(sd_journal *j, const void **data, size_t *size) {
 520         JournalFile *f;
 521         uint64_t p, l, n;
 522         size_t t;
 523         int r;
 524         Object *o;
 525
 526         assert(j);
 527         assert(data);
 528         assert(size);
 529
 530         f = j->current_file;
 531         if (!f)
 532                 return 0;
 533
 534         if (f->current_offset <= 0)
 535                 return 0;
 536
 537         r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &o);
 538         if (r < 0)
 539                 return r;
 540
 541         n = journal_file_entry_n_items(o);
 542         if (f->current_field >= n)
 543                 return 0;
 544
 545         p = le64toh(o->entry.items[f->current_field].object_offset);
 546         r = journal_file_move_to_object(f, p, OBJECT_DATA, &o);
 547         if (r < 0)
 548                 return r;
 549
 550         l = le64toh(o->object.size) - offsetof(Object, data.payload);
 551         t = (size_t) l;
 552
 553         /* We can't read objects larger than 4G on a 32bit machine */
 554         if ((uint64_t) t != l)
 555                 return -E2BIG;
 556
 557         *data = o->data.payload;
 558         *size = t;
 559
 560         f->current_field ++;
 561
 562         return 1;
 563 }