src/journal/journald.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 <sys/epoll.h>
  23 #include <sys/socket.h>
  24 #include <errno.h>
  25 #include <sys/signalfd.h>
  26 #include <unistd.h>
  27 #include <fcntl.h>
  28 #include <sys/acl.h>
  29 #include <acl/libacl.h>
  30
  31 #include "hashmap.h"
  32 #include "journal-file.h"
  33 #include "sd-daemon.h"
  34 #include "socket-util.h"
  35 #include "acl-util.h"
  36 #include "cgroup-util.h"
  37
  38 typedef struct Server {
  39         int syslog_fd;
  40         int epoll_fd;
  41         int signal_fd;
  42
  43         JournalFile *runtime_journal;
  44         JournalFile *system_journal;
  45         Hashmap *user_journals;
  46
  47         uint64_t seqnum;
  48 } Server;
  49
  50 static void fix_perms(JournalFile *f, uid_t uid) {
  51         acl_t acl;
  52         acl_entry_t entry;
  53         acl_permset_t permset;
  54         int r;
  55
  56         assert(f);
  57
  58         r = fchmod_and_fchown(f->fd, 0640, 0, 0);
  59         if (r < 0)
  60                 log_warning("Failed to fix access mode/rights on %s, ignoring: %s", f->path, strerror(-r));
  61
  62         if (uid <= 0)
  63                 return;
  64
  65         acl = acl_get_fd(f->fd);
  66         if (!acl) {
  67                 log_warning("Failed to read ACL on %s, ignoring: %m", f->path);
  68                 return;
  69         }
  70
  71         r = acl_find_uid(acl, uid, &entry);
  72         if (r <= 0) {
  73
  74                 if (acl_create_entry(&acl, &entry) < 0 ||
  75                     acl_set_tag_type(entry, ACL_USER) < 0 ||
  76                     acl_set_qualifier(entry, &uid) < 0) {
  77                         log_warning("Failed to patch ACL on %s, ignoring: %m", f->path);
  78                         goto finish;
  79                 }
  80         }
  81
  82         if (acl_get_permset(entry, &permset) < 0 ||
  83             acl_add_perm(permset, ACL_READ) < 0 ||
  84             acl_calc_mask(&acl) < 0) {
  85                 log_warning("Failed to patch ACL on %s, ignoring: %m", f->path);
  86                 goto finish;
  87         }
  88
  89         if (acl_set_fd(f->fd, acl) < 0)
  90                 log_warning("Failed to set ACL on %s, ignoring: %m", f->path);
  91
  92 finish:
  93         acl_free(acl);
  94 }
  95
  96 static JournalFile* find_journal(Server *s, uid_t uid) {
  97         char *p;
  98         int r;
  99         JournalFile *f;
 100         char ids[33];
 101         sd_id128_t machine;
 102
 103         assert(s);
 104
 105         /* We split up user logs only on /var, not on /run */
 106         if (!s->system_journal)
 107                 return s->runtime_journal;
 108
 109         if (uid <= 0)
 110                 return s->system_journal;
 111
 112         r = sd_id128_get_machine(&machine);
 113         if (r < 0)
 114                 return s->system_journal;
 115
 116         f = hashmap_get(s->user_journals, UINT32_TO_PTR(uid));
 117         if (f)
 118                 return f;
 119
 120         if (asprintf(&p, "/var/log/journal/%s/user-%lu.journal", sd_id128_to_string(machine, ids), (unsigned long) uid) < 0)
 121                 return s->system_journal;
 122
 123         r = journal_file_open(p, O_RDWR|O_CREAT, 0640, s->system_journal, &f);
 124         free(p);
 125
 126         if (r < 0)
 127                 return s->system_journal;
 128
 129         fix_perms(f, uid);
 130
 131         r = hashmap_put(s->user_journals, UINT32_TO_PTR(uid), f);
 132         if (r < 0) {
 133                 journal_file_close(f);
 134                 return s->system_journal;
 135         }
 136
 137         return f;
 138 }
 139
 140 static void process_message(Server *s, const char *buf, struct ucred *ucred, struct timeval *tv) {
 141         char *message = NULL, *pid = NULL, *uid = NULL, *gid = NULL,
 142                 *source_time = NULL, *boot_id = NULL, *machine_id = NULL,
 143                 *comm = NULL, *cmdline = NULL, *hostname = NULL,
 144                 *audit_session = NULL, *audit_loginuid = NULL,
 145                 *syslog_priority = NULL, *syslog_facility = NULL,
 146                 *exe = NULL, *cgroup = NULL;
 147         struct iovec iovec[16];
 148         unsigned n = 0;
 149         char idbuf[33];
 150         sd_id128_t id;
 151         int r;
 152         char *t;
 153         int priority = LOG_USER | LOG_INFO;
 154         uid_t loginuid = 0;
 155         JournalFile *f;
 156
 157         parse_syslog_priority((char**) &buf, &priority);
 158         skip_syslog_date((char**) &buf);
 159
 160         if (asprintf(&syslog_priority, "PRIORITY=%i", priority & LOG_PRIMASK) >= 0)
 161                 IOVEC_SET_STRING(iovec[n++], syslog_priority);
 162
 163         if (asprintf(&syslog_facility, "SYSLOG_FACILITY=%i", LOG_FAC(priority)) >= 0)
 164                 IOVEC_SET_STRING(iovec[n++], syslog_facility);
 165
 166         message = strappend("MESSAGE=", buf);
 167         if (message)
 168                 IOVEC_SET_STRING(iovec[n++], message);
 169
 170         if (ucred) {
 171                 uint32_t session;
 172                 char *path;
 173
 174                 if (asprintf(&pid, "PID=%lu", (unsigned long) ucred->pid) >= 0)
 175                         IOVEC_SET_STRING(iovec[n++], pid);
 176
 177                 if (asprintf(&uid, "UID=%lu", (unsigned long) ucred->uid) >= 0)
 178                         IOVEC_SET_STRING(iovec[n++], uid);
 179
 180                 if (asprintf(&gid, "GID=%lu", (unsigned long) ucred->gid) >= 0)
 181                         IOVEC_SET_STRING(iovec[n++], gid);
 182
 183                 r = get_process_comm(ucred->pid, &t);
 184                 if (r >= 0) {
 185                         comm = strappend("COMM=", t);
 186                         if (comm)
 187                                 IOVEC_SET_STRING(iovec[n++], comm);
 188                         free(t);
 189                 }
 190
 191                 r = get_process_exe(ucred->pid, &t);
 192                 if (r >= 0) {
 193                         exe = strappend("EXE=", t);
 194                         if (comm)
 195                                 IOVEC_SET_STRING(iovec[n++], exe);
 196                         free(t);
 197                 }
 198
 199                 r = get_process_cmdline(ucred->pid, LINE_MAX, false, &t);
 200                 if (r >= 0) {
 201                         cmdline = strappend("CMDLINE=", t);
 202                         if (cmdline)
 203                                 IOVEC_SET_STRING(iovec[n++], cmdline);
 204                         free(t);
 205                 }
 206
 207                 r = audit_session_from_pid(ucred->pid, &session);
 208                 if (r >= 0)
 209                         if (asprintf(&audit_session, "AUDIT_SESSION=%lu", (unsigned long) session) >= 0)
 210                                 IOVEC_SET_STRING(iovec[n++], audit_session);
 211
 212                 r = audit_loginuid_from_pid(ucred->pid, &loginuid);
 213                 if (r >= 0)
 214                         if (asprintf(&audit_loginuid, "AUDIT_LOGINUID=%lu", (unsigned long) loginuid) >= 0)
 215                                 IOVEC_SET_STRING(iovec[n++], audit_loginuid);
 216
 217                 r = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, ucred->pid, &path);
 218                 if (r >= 0) {
 219                         cgroup = strappend("SYSTEMD_CGROUP=", path);
 220                         if (cgroup)
 221                                 IOVEC_SET_STRING(iovec[n++], cgroup);
 222                         free(path);
 223                 }
 224         }
 225
 226         if (tv) {
 227                 if (asprintf(&source_time, "SOURCE_REALTIME_TIMESTAMP=%llu",
 228                              (unsigned long long) timeval_load(tv)) >= 0)
 229                         IOVEC_SET_STRING(iovec[n++], source_time);
 230         }
 231
 232         /* Note that strictly speaking storing the boot id here is
 233          * redundant since the entry includes this in-line
 234          * anyway. However, we need this indexed, too. */
 235         r = sd_id128_get_boot(&id);
 236         if (r >= 0)
 237                 if (asprintf(&boot_id, "BOOT_ID=%s", sd_id128_to_string(id, idbuf)) >= 0)
 238                         IOVEC_SET_STRING(iovec[n++], boot_id);
 239
 240         r = sd_id128_get_machine(&id);
 241         if (r >= 0)
 242                 if (asprintf(&machine_id, "MACHINE_ID=%s", sd_id128_to_string(id, idbuf)) >= 0)
 243                         IOVEC_SET_STRING(iovec[n++], machine_id);
 244
 245         t = gethostname_malloc();
 246         if (t) {
 247                 hostname = strappend("HOSTNAME=", t);
 248                 if (hostname)
 249                         IOVEC_SET_STRING(iovec[n++], hostname);
 250                 free(t);
 251         }
 252
 253         f = find_journal(s, loginuid);
 254         if (!f)
 255                 log_warning("Dropping message, as we can't find a place to store the data.");
 256         else {
 257                 r = journal_file_append_entry(f, NULL, iovec, n, &s->seqnum, NULL, NULL);
 258
 259                 if (r < 0)
 260                         log_error("Failed to write entry, ignoring: %s", strerror(-r));
 261         }
 262
 263         free(message);
 264         free(pid);
 265         free(uid);
 266         free(gid);
 267         free(comm);
 268         free(exe);
 269         free(cmdline);
 270         free(source_time);
 271         free(boot_id);
 272         free(machine_id);
 273         free(hostname);
 274         free(audit_session);
 275         free(audit_loginuid);
 276         free(syslog_facility);
 277         free(syslog_priority);
 278         free(cgroup);
 279 }
 280
 281 static int process_event(Server *s, struct epoll_event *ev) {
 282         assert(s);
 283
 284         if (ev->events != EPOLLIN) {
 285                 log_info("Got invalid event from epoll.");
 286                 return -EIO;
 287         }
 288
 289         if (ev->data.fd == s->signal_fd) {
 290                 struct signalfd_siginfo sfsi;
 291                 ssize_t n;
 292
 293                 n = read(s->signal_fd, &sfsi, sizeof(sfsi));
 294                 if (n != sizeof(sfsi)) {
 295
 296                         if (n >= 0)
 297                                 return -EIO;
 298
 299                         if (errno == EINTR || errno == EAGAIN)
 300                                 return 0;
 301
 302                         return -errno;
 303                 }
 304
 305                 log_debug("Received SIG%s", signal_to_string(sfsi.ssi_signo));
 306                 return 0;
 307
 308         }
 309
 310         if (ev->data.fd == s->syslog_fd) {
 311                 for (;;) {
 312                         char buf[LINE_MAX+1];
 313                         struct msghdr msghdr;
 314                         struct iovec iovec;
 315                         struct ucred *ucred = NULL;
 316                         struct timeval *tv = NULL;
 317                         struct cmsghdr *cmsg;
 318                         union {
 319                                 struct cmsghdr cmsghdr;
 320                                 uint8_t buf[CMSG_SPACE(sizeof(struct ucred)) +
 321                                             CMSG_SPACE(sizeof(struct timeval))];
 322                         } control;
 323                         ssize_t n;
 324                         char *e;
 325
 326                         zero(iovec);
 327                         iovec.iov_base = buf;
 328                         iovec.iov_len = sizeof(buf)-1;
 329
 330                         zero(control);
 331                         zero(msghdr);
 332                         msghdr.msg_iov = &iovec;
 333                         msghdr.msg_iovlen = 1;
 334                         msghdr.msg_control = &control;
 335                         msghdr.msg_controllen = sizeof(control);
 336
 337                         n = recvmsg(ev->data.fd, &msghdr, MSG_DONTWAIT);
 338                         if (n < 0) {
 339
 340                                 if (errno == EINTR || errno == EAGAIN)
 341                                         return 1;
 342
 343                                 log_error("recvmsg() failed: %m");
 344                                 return -errno;
 345                         }
 346
 347                         for (cmsg = CMSG_FIRSTHDR(&msghdr); cmsg; cmsg = CMSG_NXTHDR(&msghdr, cmsg)) {
 348
 349                                 if (cmsg->cmsg_level == SOL_SOCKET &&
 350                                     cmsg->cmsg_type == SCM_CREDENTIALS &&
 351                                     cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred)))
 352                                         ucred = (struct ucred*) CMSG_DATA(cmsg);
 353                                 else if (cmsg->cmsg_level == SOL_SOCKET &&
 354                                          cmsg->cmsg_type == SO_TIMESTAMP &&
 355                                          cmsg->cmsg_len == CMSG_LEN(sizeof(struct timeval)))
 356                                         tv = (struct timeval*) CMSG_DATA(cmsg);
 357                         }
 358
 359                         e = memchr(buf, '\n', n);
 360                         if (e)
 361                                 *e = 0;
 362                         else
 363                                 buf[n] = 0;
 364
 365                         process_message(s, strstrip(buf), ucred, tv);
 366                 }
 367
 368                 return 1;
 369         }
 370
 371         log_error("Unknown event.");
 372         return 0;
 373 }
 374
 375 static int system_journal_open(Server *s) {
 376         int r;
 377         char *fn;
 378         sd_id128_t machine;
 379         char ids[33];
 380
 381         r = sd_id128_get_machine(&machine);
 382         if (r < 0)
 383                 return r;
 384
 385         /* First try to create the machine path, but not the prefix */
 386         fn = strappend("/var/log/journal/", sd_id128_to_string(machine, ids));
 387         if (!fn)
 388                 return -ENOMEM;
 389         (void) mkdir(fn, 0755);
 390         free(fn);
 391
 392         /* The create the system journal file */
 393         fn = join("/var/log/journal/", ids, "/system.journal", NULL);
 394         if (!fn)
 395                 return -ENOMEM;
 396
 397         r = journal_file_open(fn, O_RDWR|O_CREAT, 0640, NULL, &s->system_journal);
 398         free(fn);
 399
 400         if (r >= 0) {
 401                 fix_perms(s->system_journal, 0);
 402                 return r;
 403         }
 404
 405         if (r < 0 && r != -ENOENT) {
 406                 log_error("Failed to open system journal: %s", strerror(-r));
 407                 return r;
 408         }
 409
 410         /* /var didn't work, so try /run, but this time we
 411          * create the prefix too */
 412         fn = join("/run/log/journal/", ids, "/system.journal", NULL);
 413         if (!fn)
 414                 return -ENOMEM;
 415
 416         (void) mkdir_parents(fn, 0755);
 417         r = journal_file_open(fn, O_RDWR|O_CREAT, 0640, NULL, &s->runtime_journal);
 418         free(fn);
 419
 420         if (r < 0) {
 421                 log_error("Failed to open runtime journal: %s", strerror(-r));
 422                 return r;
 423         }
 424
 425         fix_perms(s->runtime_journal, 0);
 426         return r;
 427 }
 428
 429 static int server_init(Server *s) {
 430         int n, one, r;
 431         struct epoll_event ev;
 432         sigset_t mask;
 433
 434         assert(s);
 435
 436         zero(*s);
 437         s->syslog_fd = s->signal_fd = -1;
 438
 439         s->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
 440         if (s->epoll_fd < 0) {
 441                 log_error("Failed to create epoll object: %m");
 442                 return -errno;
 443         }
 444
 445         n = sd_listen_fds(true);
 446         if (n < 0) {
 447                 log_error("Failed to read listening file descriptors from environment: %s", strerror(-n));
 448                 return n;
 449         }
 450
 451         if (n > 1) {
 452                 log_error("Too many file descriptors passed.");
 453                 return -EINVAL;
 454         }
 455
 456         if (n == 1)
 457                 s->syslog_fd = SD_LISTEN_FDS_START;
 458         else {
 459                 union sockaddr_union sa;
 460
 461                 s->syslog_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0);
 462                 if (s->syslog_fd < 0) {
 463                         log_error("socket() failed: %m");
 464                         return -errno;
 465                 }
 466
 467                 zero(sa);
 468                 sa.un.sun_family = AF_UNIX;
 469                 strncpy(sa.un.sun_path, "/run/systemd/syslog", sizeof(sa.un.sun_path));
 470
 471                 unlink(sa.un.sun_path);
 472
 473                 r = bind(s->syslog_fd, &sa.sa, sizeof(sa.un));
 474                 if (r < 0) {
 475                         log_error("bind() failed: %m");
 476                         return -errno;
 477                 }
 478
 479                 chmod(sa.un.sun_path, 0666);
 480         }
 481
 482         one = 1;
 483         r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one));
 484         if (r < 0) {
 485                 log_error("SO_PASSCRED failed: %m");
 486                 return -errno;
 487         }
 488
 489         one = 1;
 490         r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_TIMESTAMP, &one, sizeof(one));
 491         if (r < 0) {
 492                 log_error("SO_TIMESTAMP failed: %m");
 493                 return -errno;
 494         }
 495
 496         zero(ev);
 497         ev.events = EPOLLIN;
 498         ev.data.fd = s->syslog_fd;
 499         if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->syslog_fd, &ev) < 0) {
 500                 log_error("Failed to add server fd to epoll object: %m");
 501                 return -errno;
 502         }
 503
 504         s->user_journals = hashmap_new(trivial_hash_func, trivial_compare_func);
 505         if (!s->user_journals) {
 506                 log_error("Out of memory.");
 507                 return -ENOMEM;
 508         }
 509
 510         r = system_journal_open(s);
 511         if (r < 0)
 512                 return r;
 513
 514         assert_se(sigemptyset(&mask) == 0);
 515         sigset_add_many(&mask, SIGINT, SIGTERM, -1);
 516         assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
 517
 518         s->signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
 519         if (s->signal_fd < 0) {
 520                 log_error("signalfd(): %m");
 521                 return -errno;
 522         }
 523
 524         zero(ev);
 525         ev.events = EPOLLIN;
 526         ev.data.fd = s->signal_fd;
 527
 528         if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->signal_fd, &ev) < 0) {
 529                 log_error("epoll_ctl(): %m");
 530                 return -errno;
 531         }
 532
 533         return 0;
 534 }
 535
 536 static void server_done(Server *s) {
 537         JournalFile *f;
 538         assert(s);
 539
 540         if (s->system_journal)
 541                 journal_file_close(s->system_journal);
 542
 543         if (s->runtime_journal)
 544                 journal_file_close(s->runtime_journal);
 545
 546         while ((f = hashmap_steal_first(s->user_journals)))
 547                 journal_file_close(f);
 548
 549         hashmap_free(s->user_journals);
 550
 551         if (s->epoll_fd >= 0)
 552                 close_nointr_nofail(s->epoll_fd);
 553
 554         if (s->signal_fd >= 0)
 555                 close_nointr_nofail(s->signal_fd);
 556
 557         if (s->syslog_fd >= 0)
 558                 close_nointr_nofail(s->syslog_fd);
 559 }
 560
 561 int main(int argc, char *argv[]) {
 562         Server server;
 563         int r;
 564
 565         /* if (getppid() != 1) { */
 566         /*         log_error("This program should be invoked by init only."); */
 567         /*         return EXIT_FAILURE; */
 568         /* } */
 569
 570         if (argc > 1) {
 571                 log_error("This program does not take arguments.");
 572                 return EXIT_FAILURE;
 573         }
 574
 575         log_set_target(LOG_TARGET_CONSOLE);
 576         log_parse_environment();
 577         log_open();
 578
 579         umask(0022);
 580
 581         r = server_init(&server);
 582         if (r < 0)
 583                 goto finish;
 584
 585         log_debug("systemd-journald running as pid %lu", (unsigned long) getpid());
 586
 587         sd_notify(false,
 588                   "READY=1\n"
 589                   "STATUS=Processing messages...");
 590 #
 591         for (;;) {
 592                 struct epoll_event event;
 593
 594                 r = epoll_wait(server.epoll_fd, &event, 1, -1);
 595                 if (r < 0) {
 596
 597                         if (errno == EINTR)
 598                                 continue;
 599
 600                         log_error("epoll_wait() failed: %m");
 601                         r = -errno;
 602                         goto finish;
 603                 } else if (r == 0)
 604                         break;
 605
 606                 r = process_event(&server, &event);
 607                 if (r < 0)
 608                         goto finish;
 609                 else if (r == 0)
 610                         break;
 611         }
 612
 613 finish:
 614         sd_notify(false,
 615                   "STATUS=Shutting down...");
 616
 617         server_done(&server);
 618
 619         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 620 }